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252b5132 | 1 | \input texinfo @c -*-Texinfo-*- |
82704155 | 2 | @c Copyright (C) 1991-2019 Free Software Foundation, Inc. |
252b5132 RH |
3 | @c UPDATE!! On future updates-- |
4 | @c (1) check for new machine-dep cmdline options in | |
5 | @c md_parse_option definitions in config/tc-*.c | |
6 | @c (2) for platform-specific directives, examine md_pseudo_op | |
7 | @c in config/tc-*.c | |
8 | @c (3) for object-format specific directives, examine obj_pseudo_op | |
01642c12 | 9 | @c in config/obj-*.c |
252b5132 RH |
10 | @c (4) portable directives in potable[] in read.c |
11 | @c %**start of header | |
12 | @setfilename as.info | |
13 | @c ---config--- | |
a4fb0134 SC |
14 | @macro gcctabopt{body} |
15 | @code{\body\} | |
16 | @end macro | |
252b5132 RH |
17 | @c defaults, config file may override: |
18 | @set have-stabs | |
19 | @c --- | |
4a4c4a1d MR |
20 | @c man begin NAME |
21 | @c --- | |
252b5132 | 22 | @include asconfig.texi |
c428fa83 | 23 | @include bfdver.texi |
252b5132 | 24 | @c --- |
0285c67d | 25 | @c man end |
4a4c4a1d | 26 | @c --- |
252b5132 | 27 | @c common OR combinations of conditions |
c1253627 NC |
28 | @ifset COFF |
29 | @set COFF-ELF | |
30 | @end ifset | |
31 | @ifset ELF | |
32 | @set COFF-ELF | |
33 | @end ifset | |
252b5132 | 34 | @ifset AOUT |
a8eb42a8 | 35 | @set aout |
252b5132 RH |
36 | @end ifset |
37 | @ifset ARM/Thumb | |
38 | @set ARM | |
39 | @end ifset | |
9982501a JZ |
40 | @ifset Blackfin |
41 | @set Blackfin | |
42 | @end ifset | |
f8861f5d JM |
43 | @ifset BPF |
44 | @set BPF | |
45 | @end ifset | |
252b5132 RH |
46 | @ifset H8/300 |
47 | @set H8 | |
48 | @end ifset | |
252b5132 RH |
49 | @ifset SH |
50 | @set H8 | |
51 | @end ifset | |
52 | @ifset HPPA | |
53 | @set abnormal-separator | |
54 | @end ifset | |
55 | @c ------------ | |
56 | @ifset GENERIC | |
57 | @settitle Using @value{AS} | |
58 | @end ifset | |
59 | @ifclear GENERIC | |
60 | @settitle Using @value{AS} (@value{TARGET}) | |
61 | @end ifclear | |
62 | @setchapternewpage odd | |
63 | @c %**end of header | |
64 | ||
65 | @c @smallbook | |
66 | @c @set SMALL | |
67 | @c WARE! Some of the machine-dependent sections contain tables of machine | |
68 | @c instructions. Except in multi-column format, these tables look silly. | |
69 | @c Unfortunately, Texinfo doesn't have a general-purpose multi-col format, so | |
70 | @c the multi-col format is faked within @example sections. | |
01642c12 | 71 | @c |
252b5132 RH |
72 | @c Again unfortunately, the natural size that fits on a page, for these tables, |
73 | @c is different depending on whether or not smallbook is turned on. | |
74 | @c This matters, because of order: text flow switches columns at each page | |
75 | @c break. | |
01642c12 | 76 | @c |
252b5132 RH |
77 | @c The format faked in this source works reasonably well for smallbook, |
78 | @c not well for the default large-page format. This manual expects that if you | |
79 | @c turn on @smallbook, you will also uncomment the "@set SMALL" to enable the | |
80 | @c tables in question. You can turn on one without the other at your | |
01642c12 | 81 | @c discretion, of course. |
252b5132 RH |
82 | @ifinfo |
83 | @set SMALL | |
84 | @c the insn tables look just as silly in info files regardless of smallbook, | |
85 | @c might as well show 'em anyways. | |
86 | @end ifinfo | |
87 | ||
9160ea82 AM |
88 | @ifnottex |
89 | @dircategory Software development | |
90 | @direntry | |
252b5132 | 91 | * As: (as). The GNU assembler. |
59455fb1 | 92 | * Gas: (as). The GNU assembler. |
9160ea82 AM |
93 | @end direntry |
94 | @end ifnottex | |
252b5132 RH |
95 | |
96 | @finalout | |
97 | @syncodeindex ky cp | |
98 | ||
0e9517a9 | 99 | @copying |
252b5132 RH |
100 | This file documents the GNU Assembler "@value{AS}". |
101 | ||
0285c67d | 102 | @c man begin COPYRIGHT |
82704155 | 103 | Copyright @copyright{} 1991-2019 Free Software Foundation, Inc. |
252b5132 | 104 | |
0285c67d | 105 | Permission is granted to copy, distribute and/or modify this document |
793c5807 | 106 | under the terms of the GNU Free Documentation License, Version 1.3 |
0285c67d NC |
107 | or any later version published by the Free Software Foundation; |
108 | with no Invariant Sections, with no Front-Cover Texts, and with no | |
109 | Back-Cover Texts. A copy of the license is included in the | |
c1253627 | 110 | section entitled ``GNU Free Documentation License''. |
0285c67d NC |
111 | |
112 | @c man end | |
0e9517a9 | 113 | @end copying |
252b5132 RH |
114 | |
115 | @titlepage | |
116 | @title Using @value{AS} | |
117 | @subtitle The @sc{gnu} Assembler | |
118 | @ifclear GENERIC | |
119 | @subtitle for the @value{TARGET} family | |
120 | @end ifclear | |
e49e529d JM |
121 | @ifset VERSION_PACKAGE |
122 | @sp 1 | |
123 | @subtitle @value{VERSION_PACKAGE} | |
124 | @end ifset | |
252b5132 RH |
125 | @sp 1 |
126 | @subtitle Version @value{VERSION} | |
127 | @sp 1 | |
128 | @sp 13 | |
b45619c0 | 129 | The Free Software Foundation Inc.@: thanks The Nice Computer |
252b5132 | 130 | Company of Australia for loaning Dean Elsner to write the |
a4fb0134 | 131 | first (Vax) version of @command{as} for Project @sc{gnu}. |
252b5132 RH |
132 | The proprietors, management and staff of TNCCA thank FSF for |
133 | distracting the boss while they got some work | |
134 | done. | |
135 | @sp 3 | |
136 | @author Dean Elsner, Jay Fenlason & friends | |
137 | @page | |
138 | @tex | |
139 | {\parskip=0pt | |
140 | \hfill {\it Using {\tt @value{AS}}}\par | |
141 | \hfill Edited by Cygnus Support\par | |
142 | } | |
143 | %"boxit" macro for figures: | |
144 | %Modified from Knuth's ``boxit'' macro from TeXbook (answer to exercise 21.3) | |
145 | \gdef\boxit#1#2{\vbox{\hrule\hbox{\vrule\kern3pt | |
146 | \vbox{\parindent=0pt\parskip=0pt\hsize=#1\kern3pt\strut\hfil | |
147 | #2\hfil\strut\kern3pt}\kern3pt\vrule}\hrule}}%box with visible outline | |
148 | \gdef\ibox#1#2{\hbox to #1{#2\hfil}\kern8pt}% invisible box | |
149 | @end tex | |
150 | ||
151 | @vskip 0pt plus 1filll | |
82704155 | 152 | Copyright @copyright{} 1991-2019 Free Software Foundation, Inc. |
252b5132 | 153 | |
cf055d54 | 154 | Permission is granted to copy, distribute and/or modify this document |
793c5807 | 155 | under the terms of the GNU Free Documentation License, Version 1.3 |
cf055d54 NC |
156 | or any later version published by the Free Software Foundation; |
157 | with no Invariant Sections, with no Front-Cover Texts, and with no | |
158 | Back-Cover Texts. A copy of the license is included in the | |
c1253627 | 159 | section entitled ``GNU Free Documentation License''. |
252b5132 | 160 | |
252b5132 | 161 | @end titlepage |
4ecceb71 | 162 | @contents |
252b5132 | 163 | |
2e64b665 | 164 | @ifnottex |
252b5132 RH |
165 | @node Top |
166 | @top Using @value{AS} | |
167 | ||
e49e529d JM |
168 | This file is a user guide to the @sc{gnu} assembler @command{@value{AS}} |
169 | @ifset VERSION_PACKAGE | |
170 | @value{VERSION_PACKAGE} | |
171 | @end ifset | |
172 | version @value{VERSION}. | |
252b5132 | 173 | @ifclear GENERIC |
a4fb0134 | 174 | This version of the file describes @command{@value{AS}} configured to generate |
252b5132 RH |
175 | code for @value{TARGET} architectures. |
176 | @end ifclear | |
cf055d54 NC |
177 | |
178 | This document is distributed under the terms of the GNU Free | |
179 | Documentation License. A copy of the license is included in the | |
c1253627 | 180 | section entitled ``GNU Free Documentation License''. |
cf055d54 | 181 | |
252b5132 RH |
182 | @menu |
183 | * Overview:: Overview | |
184 | * Invoking:: Command-Line Options | |
185 | * Syntax:: Syntax | |
186 | * Sections:: Sections and Relocation | |
187 | * Symbols:: Symbols | |
188 | * Expressions:: Expressions | |
189 | * Pseudo Ops:: Assembler Directives | |
3a99f02f DJ |
190 | @ifset ELF |
191 | * Object Attributes:: Object Attributes | |
192 | @end ifset | |
252b5132 RH |
193 | * Machine Dependencies:: Machine Dependent Features |
194 | * Reporting Bugs:: Reporting Bugs | |
195 | * Acknowledgements:: Who Did What | |
cf055d54 | 196 | * GNU Free Documentation License:: GNU Free Documentation License |
28c9d252 | 197 | * AS Index:: AS Index |
252b5132 | 198 | @end menu |
2e64b665 | 199 | @end ifnottex |
252b5132 RH |
200 | |
201 | @node Overview | |
202 | @chapter Overview | |
203 | @iftex | |
a4fb0134 | 204 | This manual is a user guide to the @sc{gnu} assembler @command{@value{AS}}. |
252b5132 | 205 | @ifclear GENERIC |
a4fb0134 | 206 | This version of the manual describes @command{@value{AS}} configured to generate |
252b5132 RH |
207 | code for @value{TARGET} architectures. |
208 | @end ifclear | |
209 | @end iftex | |
210 | ||
211 | @cindex invocation summary | |
212 | @cindex option summary | |
213 | @cindex summary of options | |
a4fb0134 | 214 | Here is a brief summary of how to invoke @command{@value{AS}}. For details, |
96e9638b | 215 | see @ref{Invoking,,Command-Line Options}. |
252b5132 | 216 | |
0285c67d NC |
217 | @c man title AS the portable GNU assembler. |
218 | ||
a4fb0134 | 219 | @ignore |
0285c67d NC |
220 | @c man begin SEEALSO |
221 | gcc(1), ld(1), and the Info entries for @file{binutils} and @file{ld}. | |
222 | @c man end | |
a4fb0134 | 223 | @end ignore |
0285c67d | 224 | |
252b5132 RH |
225 | @c We don't use deffn and friends for the following because they seem |
226 | @c to be limited to one line for the header. | |
227 | @smallexample | |
0285c67d | 228 | @c man begin SYNOPSIS |
83f10cb2 | 229 | @value{AS} [@b{-a}[@b{cdghlns}][=@var{file}]] [@b{--alternate}] [@b{-D}] |
955974c6 | 230 | [@b{--compress-debug-sections}] [@b{--nocompress-debug-sections}] |
3d6b762c | 231 | [@b{--debug-prefix-map} @var{old}=@var{new}] |
4bdd3565 | 232 | [@b{--defsym} @var{sym}=@var{val}] [@b{-f}] [@b{-g}] [@b{--gstabs}] |
b40bf0a2 NC |
233 | [@b{--gstabs+}] [@b{--gdwarf-2}] [@b{--gdwarf-sections}] |
234 | [@b{--help}] [@b{-I} @var{dir}] [@b{-J}] | |
4bdd3565 NC |
235 | [@b{-K}] [@b{-L}] [@b{--listing-lhs-width}=@var{NUM}] |
236 | [@b{--listing-lhs-width2}=@var{NUM}] [@b{--listing-rhs-width}=@var{NUM}] | |
d60646b9 | 237 | [@b{--listing-cont-lines}=@var{NUM}] [@b{--keep-locals}] |
2edb36e7 | 238 | [@b{--no-pad-sections}] |
d60646b9 NC |
239 | [@b{-o} @var{objfile}] [@b{-R}] |
240 | [@b{--hash-size}=@var{NUM}] [@b{--reduce-memory-overheads}] | |
241 | [@b{--statistics}] | |
242 | [@b{-v}] [@b{-version}] [@b{--version}] | |
243 | [@b{-W}] [@b{--warn}] [@b{--fatal-warnings}] [@b{-w}] [@b{-x}] | |
244 | [@b{-Z}] [@b{@@@var{FILE}}] | |
451133ce | 245 | [@b{--sectname-subst}] [@b{--size-check=[error|warning]}] |
b8871f35 | 246 | [@b{--elf-stt-common=[no|yes]}] |
0df8ad28 | 247 | [@b{--generate-missing-build-notes=[no|yes]}] |
a0b7da79 MM |
248 | [@b{--target-help}] [@var{target-options}] |
249 | [@b{--}|@var{files} @dots{}] | |
a4fb0134 | 250 | @c |
6387924a | 251 | @c man end |
a4fb0134 | 252 | @c Target dependent options are listed below. Keep the list sorted. |
01642c12 | 253 | @c Add an empty line for separation. |
6387924a | 254 | @c man begin TARGET |
a06ea964 NC |
255 | @ifset AARCH64 |
256 | ||
257 | @emph{Target AArch64 options:} | |
258 | [@b{-EB}|@b{-EL}] | |
69091a2c | 259 | [@b{-mabi}=@var{ABI}] |
a06ea964 | 260 | @end ifset |
625e1353 RH |
261 | @ifset ALPHA |
262 | ||
263 | @emph{Target Alpha options:} | |
264 | [@b{-m@var{cpu}}] | |
265 | [@b{-mdebug} | @b{-no-mdebug}] | |
198f1251 | 266 | [@b{-replace} | @b{-noreplace}] |
625e1353 RH |
267 | [@b{-relax}] [@b{-g}] [@b{-G@var{size}}] |
268 | [@b{-F}] [@b{-32addr}] | |
269 | @end ifset | |
252b5132 | 270 | @ifset ARC |
a4fb0134 SC |
271 | |
272 | @emph{Target ARC options:} | |
886a2506 NC |
273 | [@b{-mcpu=@var{cpu}}] |
274 | [@b{-mA6}|@b{-mARC600}|@b{-mARC601}|@b{-mA7}|@b{-mARC700}|@b{-mEM}|@b{-mHS}] | |
275 | [@b{-mcode-density}] | |
4670103e | 276 | [@b{-mrelax}] |
a4fb0134 | 277 | [@b{-EB}|@b{-EL}] |
252b5132 RH |
278 | @end ifset |
279 | @ifset ARM | |
a4fb0134 SC |
280 | |
281 | @emph{Target ARM options:} | |
03b1477f | 282 | @c Don't document the deprecated options |
92081f48 HPN |
283 | [@b{-mcpu}=@var{processor}[+@var{extension}@dots{}]] |
284 | [@b{-march}=@var{architecture}[+@var{extension}@dots{}]] | |
33a392fb PB |
285 | [@b{-mfpu}=@var{floating-point-format}] |
286 | [@b{-mfloat-abi}=@var{abi}] | |
d507cf36 | 287 | [@b{-meabi}=@var{ver}] |
03b1477f | 288 | [@b{-mthumb}] |
a4fb0134 SC |
289 | [@b{-EB}|@b{-EL}] |
290 | [@b{-mapcs-32}|@b{-mapcs-26}|@b{-mapcs-float}| | |
291 | @b{-mapcs-reentrant}] | |
7f266840 | 292 | [@b{-mthumb-interwork}] [@b{-k}] |
252b5132 | 293 | @end ifset |
9982501a JZ |
294 | @ifset Blackfin |
295 | ||
296 | @emph{Target Blackfin options:} | |
297 | [@b{-mcpu}=@var{processor}[-@var{sirevision}]] | |
298 | [@b{-mfdpic}] | |
299 | [@b{-mno-fdpic}] | |
300 | [@b{-mnopic}] | |
301 | @end ifset | |
f8861f5d JM |
302 | @ifset BPF |
303 | ||
304 | @emph{Target BPF options:} | |
305 | [@b{-EL}] [@b{-EB}] | |
306 | @end ifset | |
328eb32e HPN |
307 | @ifset CRIS |
308 | ||
309 | @emph{Target CRIS options:} | |
310 | [@b{--underscore} | @b{--no-underscore}] | |
311 | [@b{--pic}] [@b{-N}] | |
312 | [@b{--emulation=criself} | @b{--emulation=crisaout}] | |
ae57792d | 313 | [@b{--march=v0_v10} | @b{--march=v10} | @b{--march=v32} | @b{--march=common_v10_v32}] |
328eb32e HPN |
314 | @c Deprecated -- deliberately not documented. |
315 | @c [@b{-h}] [@b{-H}] | |
316 | @end ifset | |
b8891f8d AJ |
317 | @ifset CSKY |
318 | ||
319 | @emph{Target C-SKY options:} | |
320 | [@b{-march=@var{arch}}] [@b{-mcpu=@var{cpu}}] | |
321 | [@b{-EL}] [@b{-mlittle-endian}] [@b{-EB}] [@b{-mbig-endian}] | |
322 | [@b{-fpic}] [@b{-pic}] | |
323 | [@b{-mljump}] [@b{-mno-ljump}] | |
324 | [@b{-force2bsr}] [@b{-mforce2bsr}] [@b{-no-force2bsr}] [@b{-mno-force2bsr}] | |
325 | [@b{-jsri2bsr}] [@b{-mjsri2bsr}] [@b{-no-jsri2bsr }] [@b{-mno-jsri2bsr}] | |
326 | [@b{-mnolrw }] [@b{-mno-lrw}] | |
327 | [@b{-melrw}] [@b{-mno-elrw}] | |
328 | [@b{-mlaf }] [@b{-mliterals-after-func}] | |
329 | [@b{-mno-laf}] [@b{-mno-literals-after-func}] | |
330 | [@b{-mlabr}] [@b{-mliterals-after-br}] | |
331 | [@b{-mno-labr}] [@b{-mnoliterals-after-br}] | |
332 | [@b{-mistack}] [@b{-mno-istack}] | |
333 | [@b{-mhard-float}] [@b{-mmp}] [@b{-mcp}] [@b{-mcache}] | |
334 | [@b{-msecurity}] [@b{-mtrust}] | |
335 | [@b{-mdsp}] [@b{-medsp}] [@b{-mvdsp}] | |
336 | @end ifset | |
252b5132 | 337 | @ifset D10V |
a4fb0134 SC |
338 | |
339 | @emph{Target D10V options:} | |
340 | [@b{-O}] | |
252b5132 RH |
341 | @end ifset |
342 | @ifset D30V | |
a4fb0134 SC |
343 | |
344 | @emph{Target D30V options:} | |
345 | [@b{-O}|@b{-n}|@b{-N}] | |
252b5132 | 346 | @end ifset |
cfb8c092 NC |
347 | @ifset EPIPHANY |
348 | ||
349 | @emph{Target EPIPHANY options:} | |
350 | [@b{-mepiphany}|@b{-mepiphany16}] | |
351 | @end ifset | |
252b5132 | 352 | @ifset H8 |
6fd4f6cc DD |
353 | |
354 | @emph{Target H8/300 options:} | |
355 | [-h-tick-hex] | |
252b5132 RH |
356 | @end ifset |
357 | @ifset HPPA | |
358 | @c HPPA has no machine-dependent assembler options (yet). | |
359 | @end ifset | |
a4fb0134 SC |
360 | @ifset I80386 |
361 | ||
362 | @emph{Target i386 options:} | |
542385d9 | 363 | [@b{--32}|@b{--x32}|@b{--64}] [@b{-n}] |
1ef52f49 | 364 | [@b{-march}=@var{CPU}[+@var{EXTENSION}@dots{}]] [@b{-mtune}=@var{CPU}] |
252b5132 | 365 | @end ifset |
587fe2b3 | 366 | @ifset IA64 |
a4fb0134 | 367 | |
9e32ca89 NC |
368 | @emph{Target IA-64 options:} |
369 | [@b{-mconstant-gp}|@b{-mauto-pic}] | |
370 | [@b{-milp32}|@b{-milp64}|@b{-mlp64}|@b{-mp64}] | |
371 | [@b{-mle}|@b{mbe}] | |
8c2fda1d | 372 | [@b{-mtune=itanium1}|@b{-mtune=itanium2}] |
970d6792 | 373 | [@b{-munwind-check=warning}|@b{-munwind-check=error}] |
91d777ee | 374 | [@b{-mhint.b=ok}|@b{-mhint.b=warning}|@b{-mhint.b=error}] |
9e32ca89 NC |
375 | [@b{-x}|@b{-xexplicit}] [@b{-xauto}] [@b{-xdebug}] |
376 | @end ifset | |
a40cbfa3 NC |
377 | @ifset IP2K |
378 | ||
379 | @emph{Target IP2K options:} | |
380 | [@b{-mip2022}|@b{-mip2022ext}] | |
381 | @end ifset | |
49f58d10 JB |
382 | @ifset M32C |
383 | ||
384 | @emph{Target M32C options:} | |
c54b5932 | 385 | [@b{-m32c}|@b{-m16c}] [-relax] [-h-tick-hex] |
49f58d10 | 386 | @end ifset |
587fe2b3 | 387 | @ifset M32R |
9e32ca89 | 388 | |
a4fb0134 SC |
389 | @emph{Target M32R options:} |
390 | [@b{--m32rx}|@b{--[no-]warn-explicit-parallel-conflicts}| | |
587fe2b3 | 391 | @b{--W[n]p}] |
ec694b89 | 392 | @end ifset |
252b5132 | 393 | @ifset M680X0 |
a4fb0134 SC |
394 | |
395 | @emph{Target M680X0 options:} | |
396 | [@b{-l}] [@b{-m68000}|@b{-m68010}|@b{-m68020}|@dots{}] | |
252b5132 | 397 | @end ifset |
60bcf0fa | 398 | @ifset M68HC11 |
a4fb0134 SC |
399 | |
400 | @emph{Target M68HC11 options:} | |
6927f982 | 401 | [@b{-m68hc11}|@b{-m68hc12}|@b{-m68hcs12}|@b{-mm9s12x}|@b{-mm9s12xg}] |
2f904664 SC |
402 | [@b{-mshort}|@b{-mlong}] |
403 | [@b{-mshort-double}|@b{-mlong-double}] | |
1370e33d | 404 | [@b{--force-long-branches}] [@b{--short-branches}] |
a4fb0134 SC |
405 | [@b{--strict-direct-mode}] [@b{--print-insn-syntax}] |
406 | [@b{--print-opcodes}] [@b{--generate-example}] | |
407 | @end ifset | |
408 | @ifset MCORE | |
409 | ||
410 | @emph{Target MCORE options:} | |
411 | [@b{-jsri2bsr}] [@b{-sifilter}] [@b{-relax}] | |
412 | [@b{-mcpu=[210|340]}] | |
60bcf0fa | 413 | @end ifset |
a3c62988 NC |
414 | @ifset METAG |
415 | ||
416 | @emph{Target Meta options:} | |
417 | [@b{-mcpu=@var{cpu}}] [@b{-mfpu=@var{cpu}}] [@b{-mdsp=@var{cpu}}] | |
418 | @end ifset | |
7ba29e2a NC |
419 | @ifset MICROBLAZE |
420 | @emph{Target MICROBLAZE options:} | |
421 | @c MicroBlaze has no machine-dependent assembler options. | |
422 | @end ifset | |
252b5132 | 423 | @ifset MIPS |
a4fb0134 SC |
424 | |
425 | @emph{Target MIPS options:} | |
78849248 | 426 | [@b{-nocpp}] [@b{-EL}] [@b{-EB}] [@b{-O}[@var{optimization level}]] |
437ee9d5 | 427 | [@b{-g}[@var{debug level}]] [@b{-G} @var{num}] [@b{-KPIC}] [@b{-call_shared}] |
0c000745 | 428 | [@b{-non_shared}] [@b{-xgot} [@b{-mvxworks-pic}] |
437ee9d5 | 429 | [@b{-mabi}=@var{ABI}] [@b{-32}] [@b{-n32}] [@b{-64}] [@b{-mfp32}] [@b{-mgp32}] |
351cdf24 MF |
430 | [@b{-mfp64}] [@b{-mgp64}] [@b{-mfpxx}] |
431 | [@b{-modd-spreg}] [@b{-mno-odd-spreg}] | |
437ee9d5 | 432 | [@b{-march}=@var{CPU}] [@b{-mtune}=@var{CPU}] [@b{-mips1}] [@b{-mips2}] |
af7ee8bf | 433 | [@b{-mips3}] [@b{-mips4}] [@b{-mips5}] [@b{-mips32}] [@b{-mips32r2}] |
7361da2c AB |
434 | [@b{-mips32r3}] [@b{-mips32r5}] [@b{-mips32r6}] [@b{-mips64}] [@b{-mips64r2}] |
435 | [@b{-mips64r3}] [@b{-mips64r5}] [@b{-mips64r6}] | |
437ee9d5 | 436 | [@b{-construct-floats}] [@b{-no-construct-floats}] |
8b10b0b3 | 437 | [@b{-mignore-branch-isa}] [@b{-mno-ignore-branch-isa}] |
ba92f887 | 438 | [@b{-mnan=@var{encoding}}] |
437ee9d5 | 439 | [@b{-trap}] [@b{-no-break}] [@b{-break}] [@b{-no-trap}] |
437ee9d5 | 440 | [@b{-mips16}] [@b{-no-mips16}] |
25499ac7 | 441 | [@b{-mmips16e2}] [@b{-mno-mips16e2}] |
df58fc94 | 442 | [@b{-mmicromips}] [@b{-mno-micromips}] |
e16bfa71 | 443 | [@b{-msmartmips}] [@b{-mno-smartmips}] |
1f25f5d3 | 444 | [@b{-mips3d}] [@b{-no-mips3d}] |
deec1734 | 445 | [@b{-mdmx}] [@b{-no-mdmx}] |
2ef2b9ae | 446 | [@b{-mdsp}] [@b{-mno-dsp}] |
8b082fb1 | 447 | [@b{-mdspr2}] [@b{-mno-dspr2}] |
8f4f9071 | 448 | [@b{-mdspr3}] [@b{-mno-dspr3}] |
56d438b1 | 449 | [@b{-mmsa}] [@b{-mno-msa}] |
7d64c587 | 450 | [@b{-mxpa}] [@b{-mno-xpa}] |
ef2e4d86 | 451 | [@b{-mmt}] [@b{-mno-mt}] |
dec0624d | 452 | [@b{-mmcu}] [@b{-mno-mcu}] |
730c3174 | 453 | [@b{-mcrc}] [@b{-mno-crc}] |
6f20c942 | 454 | [@b{-mginv}] [@b{-mno-ginv}] |
8095d2f7 | 455 | [@b{-mloongson-mmi}] [@b{-mno-loongson-mmi}] |
716c08de | 456 | [@b{-mloongson-cam}] [@b{-mno-loongson-cam}] |
bdc6c06e | 457 | [@b{-mloongson-ext}] [@b{-mno-loongson-ext}] |
a693765e | 458 | [@b{-mloongson-ext2}] [@b{-mno-loongson-ext2}] |
833794fc | 459 | [@b{-minsn32}] [@b{-mno-insn32}] |
2babba43 | 460 | [@b{-mfix7000}] [@b{-mno-fix7000}] |
a8d14a88 | 461 | [@b{-mfix-rm7000}] [@b{-mno-fix-rm7000}] |
2babba43 MR |
462 | [@b{-mfix-vr4120}] [@b{-mno-fix-vr4120}] |
463 | [@b{-mfix-vr4130}] [@b{-mno-fix-vr4130}] | |
27c634e0 | 464 | [@b{-mfix-r5900}] [@b{-mno-fix-r5900}] |
ecb4347a | 465 | [@b{-mdebug}] [@b{-no-mdebug}] |
dcd410fe | 466 | [@b{-mpdr}] [@b{-mno-pdr}] |
3c3bdf30 NC |
467 | @end ifset |
468 | @ifset MMIX | |
a4fb0134 SC |
469 | |
470 | @emph{Target MMIX options:} | |
471 | [@b{--fixed-special-register-names}] [@b{--globalize-symbols}] | |
472 | [@b{--gnu-syntax}] [@b{--relax}] [@b{--no-predefined-symbols}] | |
473 | [@b{--no-expand}] [@b{--no-merge-gregs}] [@b{-x}] | |
973eb340 | 474 | [@b{--linker-allocated-gregs}] |
a4fb0134 | 475 | @end ifset |
36591ba1 SL |
476 | @ifset NIOSII |
477 | ||
478 | @emph{Target Nios II options:} | |
479 | [@b{-relax-all}] [@b{-relax-section}] [@b{-no-relax}] | |
480 | [@b{-EB}] [@b{-EL}] | |
481 | @end ifset | |
35c08157 KLC |
482 | @ifset NDS32 |
483 | ||
484 | @emph{Target NDS32 options:} | |
485 | [@b{-EL}] [@b{-EB}] [@b{-O}] [@b{-Os}] [@b{-mcpu=@var{cpu}}] | |
486 | [@b{-misa=@var{isa}}] [@b{-mabi=@var{abi}}] [@b{-mall-ext}] | |
487 | [@b{-m[no-]16-bit}] [@b{-m[no-]perf-ext}] [@b{-m[no-]perf2-ext}] | |
488 | [@b{-m[no-]string-ext}] [@b{-m[no-]dsp-ext}] [@b{-m[no-]mac}] [@b{-m[no-]div}] | |
489 | [@b{-m[no-]audio-isa-ext}] [@b{-m[no-]fpu-sp-ext}] [@b{-m[no-]fpu-dp-ext}] | |
490 | [@b{-m[no-]fpu-fma}] [@b{-mfpu-freg=@var{FREG}}] [@b{-mreduced-regs}] | |
491 | [@b{-mfull-regs}] [@b{-m[no-]dx-regs}] [@b{-mpic}] [@b{-mno-relax}] | |
492 | [@b{-mb2bb}] | |
493 | @end ifset | |
1f041c6e SH |
494 | @ifset OPENRISC |
495 | @c OpenRISC has no machine-dependent assembler options. | |
496 | @end ifset | |
a4fb0134 SC |
497 | @ifset PDP11 |
498 | ||
499 | @emph{Target PDP11 options:} | |
500 | [@b{-mpic}|@b{-mno-pic}] [@b{-mall}] [@b{-mno-extensions}] | |
501 | [@b{-m}@var{extension}|@b{-mno-}@var{extension}] | |
01642c12 | 502 | [@b{-m}@var{cpu}] [@b{-m}@var{machine}] |
a4fb0134 SC |
503 | @end ifset |
504 | @ifset PJ | |
505 | ||
506 | @emph{Target picoJava options:} | |
507 | [@b{-mb}|@b{-me}] | |
508 | @end ifset | |
509 | @ifset PPC | |
510 | ||
511 | @emph{Target PowerPC options:} | |
b8b738ac AM |
512 | [@b{-a32}|@b{-a64}] |
513 | [@b{-mpwrx}|@b{-mpwr2}|@b{-mpwr}|@b{-m601}|@b{-mppc}|@b{-mppc32}|@b{-m603}|@b{-m604}|@b{-m403}|@b{-m405}| | |
fa758a70 AC |
514 | @b{-m440}|@b{-m464}|@b{-m476}|@b{-m7400}|@b{-m7410}|@b{-m7450}|@b{-m7455}|@b{-m750cl}|@b{-mgekko}| |
515 | @b{-mbroadway}|@b{-mppc64}|@b{-m620}|@b{-me500}|@b{-e500x2}|@b{-me500mc}|@b{-me500mc64}|@b{-me5500}| | |
516 | @b{-me6500}|@b{-mppc64bridge}|@b{-mbooke}|@b{-mpower4}|@b{-mpwr4}|@b{-mpower5}|@b{-mpwr5}|@b{-mpwr5x}| | |
517 | @b{-mpower6}|@b{-mpwr6}|@b{-mpower7}|@b{-mpwr7}|@b{-mpower8}|@b{-mpwr8}|@b{-mpower9}|@b{-mpwr9}@b{-ma2}| | |
74081948 | 518 | @b{-mcell}|@b{-mspe}|@b{-mspe2}|@b{-mtitan}|@b{-me300}|@b{-mcom}] |
5817ffd1 | 519 | [@b{-many}] [@b{-maltivec}|@b{-mvsx}|@b{-mhtm}|@b{-mvle}] |
a4fb0134 | 520 | [@b{-mregnames}|@b{-mno-regnames}] |
b8b738ac AM |
521 | [@b{-mrelocatable}|@b{-mrelocatable-lib}|@b{-K PIC}] [@b{-memb}] |
522 | [@b{-mlittle}|@b{-mlittle-endian}|@b{-le}|@b{-mbig}|@b{-mbig-endian}|@b{-be}] | |
a4fb0134 | 523 | [@b{-msolaris}|@b{-mno-solaris}] |
b8b738ac | 524 | [@b{-nops=@var{count}}] |
a4fb0134 | 525 | @end ifset |
93f11b16 DD |
526 | @ifset PRU |
527 | ||
528 | @emph{Target PRU options:} | |
529 | [@b{-link-relax}] | |
530 | [@b{-mnolink-relax}] | |
531 | [@b{-mno-warn-regname-label}] | |
532 | @end ifset | |
b57e49f7 JW |
533 | @ifset RISCV |
534 | ||
535 | @emph{Target RISC-V options:} | |
536 | [@b{-fpic}|@b{-fPIC}|@b{-fno-pic}] | |
537 | [@b{-march}=@var{ISA}] | |
538 | [@b{-mabi}=@var{ABI}] | |
539 | @end ifset | |
856ea05c KP |
540 | @ifset RL78 |
541 | ||
542 | @emph{Target RL78 options:} | |
543 | [@b{-mg10}] | |
544 | [@b{-m32bit-doubles}|@b{-m64bit-doubles}] | |
545 | @end ifset | |
c7927a3c NC |
546 | @ifset RX |
547 | ||
548 | @emph{Target RX options:} | |
549 | [@b{-mlittle-endian}|@b{-mbig-endian}] | |
c7927a3c | 550 | [@b{-m32bit-doubles}|@b{-m64bit-doubles}] |
708e2187 NC |
551 | [@b{-muse-conventional-section-names}] |
552 | [@b{-msmall-data-limit}] | |
553 | [@b{-mpid}] | |
554 | [@b{-mrelax}] | |
555 | [@b{-mint-register=@var{number}}] | |
556 | [@b{-mgcc-abi}|@b{-mrx-abi}] | |
c7927a3c | 557 | @end ifset |
11c19e16 MS |
558 | @ifset S390 |
559 | ||
560 | @emph{Target s390 options:} | |
561 | [@b{-m31}|@b{-m64}] [@b{-mesa}|@b{-mzarch}] [@b{-march}=@var{CPU}] | |
562 | [@b{-mregnames}|@b{-mno-regnames}] | |
563 | [@b{-mwarn-areg-zero}] | |
564 | @end ifset | |
c3b7224a NC |
565 | @ifset SCORE |
566 | ||
567 | @emph{Target SCORE options:} | |
568 | [@b{-EB}][@b{-EL}][@b{-FIXDD}][@b{-NWARN}] | |
569 | [@b{-SCORE5}][@b{-SCORE5U}][@b{-SCORE7}][@b{-SCORE3}] | |
570 | [@b{-march=score7}][@b{-march=score3}] | |
571 | [@b{-USE_R1}][@b{-KPIC}][@b{-O0}][@b{-G} @var{num}][@b{-V}] | |
572 | @end ifset | |
a4fb0134 SC |
573 | @ifset SPARC |
574 | ||
575 | @emph{Target SPARC options:} | |
576 | @c The order here is important. See c-sparc.texi. | |
46a2d504 JM |
577 | [@b{-Av6}|@b{-Av7}|@b{-Av8}|@b{-Aleon}|@b{-Asparclet}|@b{-Asparclite} |
578 | @b{-Av8plus}|@b{-Av8plusa}|@b{-Av8plusb}|@b{-Av8plusc}|@b{-Av8plusd} | |
579 | @b{-Av8plusv}|@b{-Av8plusm}|@b{-Av9}|@b{-Av9a}|@b{-Av9b}|@b{-Av9c} | |
580 | @b{-Av9d}|@b{-Av9e}|@b{-Av9v}|@b{-Av9m}|@b{-Asparc}|@b{-Asparcvis} | |
581 | @b{-Asparcvis2}|@b{-Asparcfmaf}|@b{-Asparcima}|@b{-Asparcvis3} | |
582 | @b{-Asparcvisr}|@b{-Asparc5}] | |
583 | [@b{-xarch=v8plus}|@b{-xarch=v8plusa}]|@b{-xarch=v8plusb}|@b{-xarch=v8plusc} | |
584 | @b{-xarch=v8plusd}|@b{-xarch=v8plusv}|@b{-xarch=v8plusm}|@b{-xarch=v9} | |
585 | @b{-xarch=v9a}|@b{-xarch=v9b}|@b{-xarch=v9c}|@b{-xarch=v9d}|@b{-xarch=v9e} | |
586 | @b{-xarch=v9v}|@b{-xarch=v9m}|@b{-xarch=sparc}|@b{-xarch=sparcvis} | |
587 | @b{-xarch=sparcvis2}|@b{-xarch=sparcfmaf}|@b{-xarch=sparcima} | |
588 | @b{-xarch=sparcvis3}|@b{-xarch=sparcvisr}|@b{-xarch=sparc5} | |
589 | @b{-bump}] | |
a4fb0134 | 590 | [@b{-32}|@b{-64}] |
46a2d504 | 591 | [@b{--enforce-aligned-data}][@b{--dcti-couples-detect}] |
a4fb0134 SC |
592 | @end ifset |
593 | @ifset TIC54X | |
594 | ||
595 | @emph{Target TIC54X options:} | |
01642c12 | 596 | [@b{-mcpu=54[123589]}|@b{-mcpu=54[56]lp}] [@b{-mfar-mode}|@b{-mf}] |
a4fb0134 SC |
597 | [@b{-merrors-to-file} @var{<filename>}|@b{-me} @var{<filename>}] |
598 | @end ifset | |
40b36596 JM |
599 | @ifset TIC6X |
600 | ||
601 | @emph{Target TIC6X options:} | |
98d23bef BS |
602 | [@b{-march=@var{arch}}] [@b{-mbig-endian}|@b{-mlittle-endian}] |
603 | [@b{-mdsbt}|@b{-mno-dsbt}] [@b{-mpid=no}|@b{-mpid=near}|@b{-mpid=far}] | |
604 | [@b{-mpic}|@b{-mno-pic}] | |
40b36596 | 605 | @end ifset |
aa137e4d NC |
606 | @ifset TILEGX |
607 | ||
608 | @emph{Target TILE-Gx options:} | |
fb6cedde | 609 | [@b{-m32}|@b{-m64}][@b{-EB}][@b{-EL}] |
aa137e4d NC |
610 | @end ifset |
611 | @ifset TILEPRO | |
612 | @c TILEPro has no machine-dependent assembler options | |
613 | @end ifset | |
b6605ddd | 614 | @ifset VISIUM |
40b36596 | 615 | |
b6605ddd EB |
616 | @emph{Target Visium options:} |
617 | [@b{-mtune=@var{arch}}] | |
618 | @end ifset | |
2d8b84ae SA |
619 | @ifset XTENSA |
620 | ||
621 | @emph{Target Xtensa options:} | |
b46824bd MF |
622 | [@b{--[no-]text-section-literals}] [@b{--[no-]auto-litpools}] |
623 | [@b{--[no-]absolute-literals}] | |
2d8b84ae SA |
624 | [@b{--[no-]target-align}] [@b{--[no-]longcalls}] |
625 | [@b{--[no-]transform}] | |
626 | [@b{--rename-section} @var{oldname}=@var{newname}] | |
a82c7d90 | 627 | [@b{--[no-]trampolines}] |
2d8b84ae | 628 | @end ifset |
3c9b82ba NC |
629 | @ifset Z80 |
630 | ||
631 | @emph{Target Z80 options:} | |
632 | [@b{-z80}] [@b{-r800}] | |
633 | [@b{ -ignore-undocumented-instructions}] [@b{-Wnud}] | |
634 | [@b{ -ignore-unportable-instructions}] [@b{-Wnup}] | |
635 | [@b{ -warn-undocumented-instructions}] [@b{-Wud}] | |
636 | [@b{ -warn-unportable-instructions}] [@b{-Wup}] | |
637 | [@b{ -forbid-undocumented-instructions}] [@b{-Fud}] | |
638 | [@b{ -forbid-unportable-instructions}] [@b{-Fup}] | |
639 | @end ifset | |
a4fb0134 | 640 | @ifset Z8000 |
b6605ddd | 641 | |
a4fb0134 | 642 | @c Z8000 has no machine-dependent assembler options |
252b5132 | 643 | @end ifset |
e0001a05 | 644 | |
0285c67d | 645 | @c man end |
252b5132 RH |
646 | @end smallexample |
647 | ||
0285c67d NC |
648 | @c man begin OPTIONS |
649 | ||
a4fb0134 | 650 | @table @gcctabopt |
38fc1cb1 | 651 | @include at-file.texi |
a0b7da79 | 652 | |
83f10cb2 | 653 | @item -a[cdghlmns] |
252b5132 RH |
654 | Turn on listings, in any of a variety of ways: |
655 | ||
a4fb0134 | 656 | @table @gcctabopt |
252b5132 RH |
657 | @item -ac |
658 | omit false conditionals | |
659 | ||
660 | @item -ad | |
661 | omit debugging directives | |
662 | ||
83f10cb2 NC |
663 | @item -ag |
664 | include general information, like @value{AS} version and options passed | |
665 | ||
252b5132 RH |
666 | @item -ah |
667 | include high-level source | |
668 | ||
669 | @item -al | |
670 | include assembly | |
671 | ||
672 | @item -am | |
673 | include macro expansions | |
674 | ||
675 | @item -an | |
676 | omit forms processing | |
677 | ||
678 | @item -as | |
679 | include symbols | |
680 | ||
681 | @item =file | |
682 | set the name of the listing file | |
683 | @end table | |
684 | ||
685 | You may combine these options; for example, use @samp{-aln} for assembly | |
686 | listing without forms processing. The @samp{=file} option, if used, must be | |
687 | the last one. By itself, @samp{-a} defaults to @samp{-ahls}. | |
688 | ||
caa32fe5 | 689 | @item --alternate |
96e9638b BW |
690 | Begin in alternate macro mode. |
691 | @ifclear man | |
692 | @xref{Altmacro,,@code{.altmacro}}. | |
693 | @end ifclear | |
caa32fe5 | 694 | |
955974c6 | 695 | @item --compress-debug-sections |
19a7fe52 L |
696 | Compress DWARF debug sections using zlib with SHF_COMPRESSED from the |
697 | ELF ABI. The resulting object file may not be compatible with older | |
698 | linkers and object file utilities. Note if compression would make a | |
699 | given section @emph{larger} then it is not compressed. | |
955974c6 | 700 | |
151411f8 L |
701 | @ifset ELF |
702 | @cindex @samp{--compress-debug-sections=} option | |
703 | @item --compress-debug-sections=none | |
704 | @itemx --compress-debug-sections=zlib | |
705 | @itemx --compress-debug-sections=zlib-gnu | |
706 | @itemx --compress-debug-sections=zlib-gabi | |
707 | These options control how DWARF debug sections are compressed. | |
708 | @option{--compress-debug-sections=none} is equivalent to | |
709 | @option{--nocompress-debug-sections}. | |
710 | @option{--compress-debug-sections=zlib} and | |
19a7fe52 | 711 | @option{--compress-debug-sections=zlib-gabi} are equivalent to |
151411f8 | 712 | @option{--compress-debug-sections}. |
19a7fe52 L |
713 | @option{--compress-debug-sections=zlib-gnu} compresses DWARF debug |
714 | sections using zlib. The debug sections are renamed to begin with | |
715 | @samp{.zdebug}. Note if compression would make a given section | |
716 | @emph{larger} then it is not compressed nor renamed. | |
717 | ||
151411f8 L |
718 | @end ifset |
719 | ||
955974c6 | 720 | @item --nocompress-debug-sections |
e12fe555 NC |
721 | Do not compress DWARF debug sections. This is usually the default for all |
722 | targets except the x86/x86_64, but a configure time option can be used to | |
723 | override this. | |
955974c6 | 724 | |
252b5132 RH |
725 | @item -D |
726 | Ignored. This option is accepted for script compatibility with calls to | |
727 | other assemblers. | |
728 | ||
3d6b762c JM |
729 | @item --debug-prefix-map @var{old}=@var{new} |
730 | When assembling files in directory @file{@var{old}}, record debugging | |
731 | information describing them as in @file{@var{new}} instead. | |
732 | ||
252b5132 RH |
733 | @item --defsym @var{sym}=@var{value} |
734 | Define the symbol @var{sym} to be @var{value} before assembling the input file. | |
735 | @var{value} must be an integer constant. As in C, a leading @samp{0x} | |
bf083c64 NC |
736 | indicates a hexadecimal value, and a leading @samp{0} indicates an octal |
737 | value. The value of the symbol can be overridden inside a source file via the | |
738 | use of a @code{.set} pseudo-op. | |
252b5132 RH |
739 | |
740 | @item -f | |
741 | ``fast''---skip whitespace and comment preprocessing (assume source is | |
742 | compiler output). | |
743 | ||
329e276d NC |
744 | @item -g |
745 | @itemx --gen-debug | |
746 | Generate debugging information for each assembler source line using whichever | |
747 | debug format is preferred by the target. This currently means either STABS, | |
748 | ECOFF or DWARF2. | |
749 | ||
252b5132 RH |
750 | @item --gstabs |
751 | Generate stabs debugging information for each assembler line. This | |
752 | may help debugging assembler code, if the debugger can handle it. | |
753 | ||
05da4302 NC |
754 | @item --gstabs+ |
755 | Generate stabs debugging information for each assembler line, with GNU | |
756 | extensions that probably only gdb can handle, and that could make other | |
757 | debuggers crash or refuse to read your program. This | |
758 | may help debugging assembler code. Currently the only GNU extension is | |
759 | the location of the current working directory at assembling time. | |
760 | ||
329e276d | 761 | @item --gdwarf-2 |
cdf82bcf | 762 | Generate DWARF2 debugging information for each assembler line. This |
c1253627 | 763 | may help debugging assembler code, if the debugger can handle it. Note---this |
85a39694 | 764 | option is only supported by some targets, not all of them. |
cdf82bcf | 765 | |
b40bf0a2 NC |
766 | @item --gdwarf-sections |
767 | Instead of creating a .debug_line section, create a series of | |
768 | .debug_line.@var{foo} sections where @var{foo} is the name of the | |
769 | corresponding code section. For example a code section called @var{.text.func} | |
770 | will have its dwarf line number information placed into a section called | |
771 | @var{.debug_line.text.func}. If the code section is just called @var{.text} | |
772 | then debug line section will still be called just @var{.debug_line} without any | |
773 | suffix. | |
774 | ||
b8871f35 | 775 | @ifset ELF |
21be61f5 L |
776 | @item --size-check=error |
777 | @itemx --size-check=warning | |
778 | Issue an error or warning for invalid ELF .size directive. | |
779 | ||
b8871f35 L |
780 | @item --elf-stt-common=no |
781 | @itemx --elf-stt-common=yes | |
782 | These options control whether the ELF assembler should generate common | |
783 | symbols with the @code{STT_COMMON} type. The default can be controlled | |
784 | by a configure option @option{--enable-elf-stt-common}. | |
0df8ad28 NC |
785 | |
786 | @item --generate-missing-build-notes=yes | |
787 | @itemx --generate-missing-build-notes=no | |
788 | These options control whether the ELF assembler should generate GNU Build | |
789 | attribute notes if none are present in the input sources. | |
790 | The default can be controlled by the @option{--enable-generate-build-notes} | |
791 | configure option. | |
792 | ||
b8871f35 L |
793 | @end ifset |
794 | ||
252b5132 | 795 | @item --help |
a05a5b64 | 796 | Print a summary of the command-line options and exit. |
252b5132 | 797 | |
ea20a7da CC |
798 | @item --target-help |
799 | Print a summary of all target specific options and exit. | |
800 | ||
252b5132 RH |
801 | @item -I @var{dir} |
802 | Add directory @var{dir} to the search list for @code{.include} directives. | |
803 | ||
804 | @item -J | |
805 | Don't warn about signed overflow. | |
806 | ||
807 | @item -K | |
808 | @ifclear DIFF-TBL-KLUGE | |
809 | This option is accepted but has no effect on the @value{TARGET} family. | |
810 | @end ifclear | |
811 | @ifset DIFF-TBL-KLUGE | |
812 | Issue warnings when difference tables altered for long displacements. | |
813 | @end ifset | |
814 | ||
815 | @item -L | |
816 | @itemx --keep-locals | |
ba83aca1 BW |
817 | Keep (in the symbol table) local symbols. These symbols start with |
818 | system-specific local label prefixes, typically @samp{.L} for ELF systems | |
819 | or @samp{L} for traditional a.out systems. | |
820 | @ifclear man | |
821 | @xref{Symbol Names}. | |
822 | @end ifclear | |
252b5132 | 823 | |
c3a27914 NC |
824 | @item --listing-lhs-width=@var{number} |
825 | Set the maximum width, in words, of the output data column for an assembler | |
826 | listing to @var{number}. | |
827 | ||
828 | @item --listing-lhs-width2=@var{number} | |
829 | Set the maximum width, in words, of the output data column for continuation | |
830 | lines in an assembler listing to @var{number}. | |
831 | ||
832 | @item --listing-rhs-width=@var{number} | |
833 | Set the maximum width of an input source line, as displayed in a listing, to | |
834 | @var{number} bytes. | |
835 | ||
836 | @item --listing-cont-lines=@var{number} | |
837 | Set the maximum number of lines printed in a listing for a single line of input | |
838 | to @var{number} + 1. | |
839 | ||
2edb36e7 NC |
840 | @item --no-pad-sections |
841 | Stop the assembler for padding the ends of output sections to the alignment | |
842 | of that section. The default is to pad the sections, but this can waste space | |
843 | which might be needed on targets which have tight memory constraints. | |
844 | ||
252b5132 | 845 | @item -o @var{objfile} |
a4fb0134 | 846 | Name the object-file output from @command{@value{AS}} @var{objfile}. |
252b5132 RH |
847 | |
848 | @item -R | |
849 | Fold the data section into the text section. | |
850 | ||
d60646b9 | 851 | @item --hash-size=@var{number} |
4bdd3565 NC |
852 | Set the default size of GAS's hash tables to a prime number close to |
853 | @var{number}. Increasing this value can reduce the length of time it takes the | |
854 | assembler to perform its tasks, at the expense of increasing the assembler's | |
855 | memory requirements. Similarly reducing this value can reduce the memory | |
856 | requirements at the expense of speed. | |
857 | ||
858 | @item --reduce-memory-overheads | |
859 | This option reduces GAS's memory requirements, at the expense of making the | |
860 | assembly processes slower. Currently this switch is a synonym for | |
861 | @samp{--hash-size=4051}, but in the future it may have other effects as well. | |
862 | ||
451133ce NP |
863 | @ifset ELF |
864 | @item --sectname-subst | |
865 | Honor substitution sequences in section names. | |
866 | @ifclear man | |
867 | @xref{Section Name Substitutions,,@code{.section @var{name}}}. | |
868 | @end ifclear | |
869 | @end ifset | |
870 | ||
252b5132 RH |
871 | @item --statistics |
872 | Print the maximum space (in bytes) and total time (in seconds) used by | |
873 | assembly. | |
874 | ||
875 | @item --strip-local-absolute | |
876 | Remove local absolute symbols from the outgoing symbol table. | |
877 | ||
878 | @item -v | |
879 | @itemx -version | |
a4fb0134 | 880 | Print the @command{as} version. |
252b5132 RH |
881 | |
882 | @item --version | |
a4fb0134 | 883 | Print the @command{as} version and exit. |
252b5132 RH |
884 | |
885 | @item -W | |
2bdd6cf5 | 886 | @itemx --no-warn |
252b5132 RH |
887 | Suppress warning messages. |
888 | ||
2bdd6cf5 GK |
889 | @item --fatal-warnings |
890 | Treat warnings as errors. | |
891 | ||
892 | @item --warn | |
893 | Don't suppress warning messages or treat them as errors. | |
894 | ||
252b5132 RH |
895 | @item -w |
896 | Ignored. | |
897 | ||
898 | @item -x | |
899 | Ignored. | |
900 | ||
901 | @item -Z | |
902 | Generate an object file even after errors. | |
903 | ||
904 | @item -- | @var{files} @dots{} | |
905 | Standard input, or source files to assemble. | |
906 | ||
907 | @end table | |
2a633939 JM |
908 | @c man end |
909 | ||
a06ea964 NC |
910 | @ifset AARCH64 |
911 | ||
912 | @ifclear man | |
913 | @xref{AArch64 Options}, for the options available when @value{AS} is configured | |
914 | for the 64-bit mode of the ARM Architecture (AArch64). | |
915 | @end ifclear | |
916 | ||
917 | @ifset man | |
918 | @c man begin OPTIONS | |
919 | The following options are available when @value{AS} is configured for the | |
920 | 64-bit mode of the ARM Architecture (AArch64). | |
921 | @c man end | |
922 | @c man begin INCLUDE | |
923 | @include c-aarch64.texi | |
924 | @c ended inside the included file | |
925 | @end ifset | |
926 | ||
927 | @end ifset | |
928 | ||
2a633939 JM |
929 | @ifset ALPHA |
930 | ||
931 | @ifclear man | |
932 | @xref{Alpha Options}, for the options available when @value{AS} is configured | |
933 | for an Alpha processor. | |
934 | @end ifclear | |
935 | ||
936 | @ifset man | |
937 | @c man begin OPTIONS | |
938 | The following options are available when @value{AS} is configured for an Alpha | |
939 | processor. | |
940 | @c man end | |
941 | @c man begin INCLUDE | |
942 | @include c-alpha.texi | |
943 | @c ended inside the included file | |
944 | @end ifset | |
945 | ||
946 | @end ifset | |
252b5132 | 947 | |
2a633939 | 948 | @c man begin OPTIONS |
252b5132 | 949 | @ifset ARC |
886a2506 NC |
950 | The following options are available when @value{AS} is configured for an ARC |
951 | processor. | |
252b5132 | 952 | |
a4fb0134 | 953 | @table @gcctabopt |
886a2506 | 954 | @item -mcpu=@var{cpu} |
0d2bcfaf NC |
955 | This option selects the core processor variant. |
956 | @item -EB | -EL | |
957 | Select either big-endian (-EB) or little-endian (-EL) output. | |
886a2506 NC |
958 | @item -mcode-density |
959 | Enable Code Density extenssion instructions. | |
252b5132 RH |
960 | @end table |
961 | @end ifset | |
962 | ||
963 | @ifset ARM | |
964 | The following options are available when @value{AS} is configured for the ARM | |
965 | processor family. | |
966 | ||
a4fb0134 | 967 | @table @gcctabopt |
92081f48 | 968 | @item -mcpu=@var{processor}[+@var{extension}@dots{}] |
cdf82bcf | 969 | Specify which ARM processor variant is the target. |
92081f48 | 970 | @item -march=@var{architecture}[+@var{extension}@dots{}] |
cdf82bcf | 971 | Specify which ARM architecture variant is used by the target. |
03b1477f | 972 | @item -mfpu=@var{floating-point-format} |
a349d9dd | 973 | Select which Floating Point architecture is the target. |
33a392fb PB |
974 | @item -mfloat-abi=@var{abi} |
975 | Select which floating point ABI is in use. | |
03b1477f RE |
976 | @item -mthumb |
977 | Enable Thumb only instruction decoding. | |
7f266840 | 978 | @item -mapcs-32 | -mapcs-26 | -mapcs-float | -mapcs-reentrant |
252b5132 RH |
979 | Select which procedure calling convention is in use. |
980 | @item -EB | -EL | |
981 | Select either big-endian (-EB) or little-endian (-EL) output. | |
cdf82bcf NC |
982 | @item -mthumb-interwork |
983 | Specify that the code has been generated with interworking between Thumb and | |
984 | ARM code in mind. | |
2e6976a8 DG |
985 | @item -mccs |
986 | Turns on CodeComposer Studio assembly syntax compatibility mode. | |
cdf82bcf NC |
987 | @item -k |
988 | Specify that PIC code has been generated. | |
252b5132 RH |
989 | @end table |
990 | @end ifset | |
635fb38d | 991 | @c man end |
252b5132 | 992 | |
9982501a | 993 | @ifset Blackfin |
8611b8fd MF |
994 | |
995 | @ifclear man | |
996 | @xref{Blackfin Options}, for the options available when @value{AS} is | |
997 | configured for the Blackfin processor family. | |
998 | @end ifclear | |
999 | ||
1000 | @ifset man | |
1001 | @c man begin OPTIONS | |
9982501a JZ |
1002 | The following options are available when @value{AS} is configured for |
1003 | the Blackfin processor family. | |
8611b8fd MF |
1004 | @c man end |
1005 | @c man begin INCLUDE | |
1006 | @include c-bfin.texi | |
1007 | @c ended inside the included file | |
1008 | @end ifset | |
9982501a | 1009 | |
9982501a JZ |
1010 | @end ifset |
1011 | ||
f8861f5d JM |
1012 | @ifset BPF |
1013 | ||
1014 | @ifclear man | |
1015 | @xref{BPF Options}, for the options available when @value{AS} is | |
1016 | configured for the Linux kernel BPF processor family. | |
1017 | @end ifclear | |
1018 | ||
1019 | @ifset man | |
1020 | @c man begin OPTIONS | |
1021 | The following options are available when @value{AS} is configured for | |
1022 | the Linux kernel BPF processor family. | |
1023 | @c man end | |
1024 | @c man begin INCLUDE | |
1025 | @include c-bpf.texi | |
1026 | @c ended inside the included file | |
1027 | @end ifset | |
1028 | ||
1029 | @end ifset | |
1030 | ||
635fb38d | 1031 | @c man begin OPTIONS |
328eb32e HPN |
1032 | @ifset CRIS |
1033 | See the info pages for documentation of the CRIS-specific options. | |
1034 | @end ifset | |
1035 | ||
b8891f8d AJ |
1036 | @ifset CSKY |
1037 | ||
1038 | @ifclear man | |
1039 | @xref{C-SKY Options}, for the options available when @value{AS} is | |
1040 | configured for the C-SKY processor family. | |
1041 | @end ifclear | |
1042 | ||
1043 | @ifset man | |
1044 | @c man begin OPTIONS | |
1045 | The following options are available when @value{AS} is configured for | |
1046 | the C-SKY processor family. | |
1047 | @c man end | |
1048 | @c man begin INCLUDE | |
1049 | @include c-csky.texi | |
1050 | @c ended inside the included file | |
1051 | @end ifset | |
1052 | ||
1053 | @end ifset | |
1054 | ||
252b5132 RH |
1055 | @ifset D10V |
1056 | The following options are available when @value{AS} is configured for | |
1057 | a D10V processor. | |
a4fb0134 | 1058 | @table @gcctabopt |
252b5132 RH |
1059 | @cindex D10V optimization |
1060 | @cindex optimization, D10V | |
1061 | @item -O | |
1062 | Optimize output by parallelizing instructions. | |
1063 | @end table | |
1064 | @end ifset | |
1065 | ||
1066 | @ifset D30V | |
1067 | The following options are available when @value{AS} is configured for a D30V | |
1068 | processor. | |
a4fb0134 | 1069 | @table @gcctabopt |
252b5132 RH |
1070 | @cindex D30V optimization |
1071 | @cindex optimization, D30V | |
1072 | @item -O | |
1073 | Optimize output by parallelizing instructions. | |
1074 | ||
1075 | @cindex D30V nops | |
1076 | @item -n | |
1077 | Warn when nops are generated. | |
1078 | ||
1079 | @cindex D30V nops after 32-bit multiply | |
1080 | @item -N | |
1081 | Warn when a nop after a 32-bit multiply instruction is generated. | |
1082 | @end table | |
1083 | @end ifset | |
731caf76 L |
1084 | @c man end |
1085 | ||
cfb8c092 NC |
1086 | @ifset EPIPHANY |
1087 | The following options are available when @value{AS} is configured for the | |
1088 | Adapteva EPIPHANY series. | |
1089 | ||
56b13185 JR |
1090 | @ifclear man |
1091 | @xref{Epiphany Options}, for the options available when @value{AS} is | |
1092 | configured for an Epiphany processor. | |
1093 | @end ifclear | |
cfb8c092 | 1094 | |
56b13185 JR |
1095 | @ifset man |
1096 | @c man begin OPTIONS | |
1097 | The following options are available when @value{AS} is configured for | |
1098 | an Epiphany processor. | |
1099 | @c man end | |
1100 | @c man begin INCLUDE | |
1101 | @include c-epiphany.texi | |
0c76cae8 AM |
1102 | @c ended inside the included file |
1103 | @end ifset | |
1104 | ||
1105 | @end ifset | |
1106 | ||
1107 | @ifset H8300 | |
1108 | ||
1109 | @ifclear man | |
1110 | @xref{H8/300 Options}, for the options available when @value{AS} is configured | |
1111 | for an H8/300 processor. | |
1112 | @end ifclear | |
1113 | ||
1114 | @ifset man | |
1115 | @c man begin OPTIONS | |
1116 | The following options are available when @value{AS} is configured for an H8/300 | |
1117 | processor. | |
1118 | @c man end | |
1119 | @c man begin INCLUDE | |
1120 | @include c-h8300.texi | |
56b13185 JR |
1121 | @c ended inside the included file |
1122 | @end ifset | |
cfb8c092 | 1123 | |
cfb8c092 NC |
1124 | @end ifset |
1125 | ||
731caf76 | 1126 | @ifset I80386 |
252b5132 | 1127 | |
731caf76 L |
1128 | @ifclear man |
1129 | @xref{i386-Options}, for the options available when @value{AS} is | |
1130 | configured for an i386 processor. | |
1131 | @end ifclear | |
1132 | ||
1133 | @ifset man | |
1134 | @c man begin OPTIONS | |
1135 | The following options are available when @value{AS} is configured for | |
1136 | an i386 processor. | |
1137 | @c man end | |
1138 | @c man begin INCLUDE | |
1139 | @include c-i386.texi | |
1140 | @c ended inside the included file | |
1141 | @end ifset | |
1142 | ||
1143 | @end ifset | |
1144 | ||
1145 | @c man begin OPTIONS | |
a40cbfa3 NC |
1146 | @ifset IP2K |
1147 | The following options are available when @value{AS} is configured for the | |
ec88d317 | 1148 | Ubicom IP2K series. |
a40cbfa3 NC |
1149 | |
1150 | @table @gcctabopt | |
1151 | ||
1152 | @item -mip2022ext | |
1153 | Specifies that the extended IP2022 instructions are allowed. | |
1154 | ||
1155 | @item -mip2022 | |
8dfa0188 | 1156 | Restores the default behaviour, which restricts the permitted instructions to |
a40cbfa3 NC |
1157 | just the basic IP2022 ones. |
1158 | ||
1159 | @end table | |
1160 | @end ifset | |
1161 | ||
49f58d10 JB |
1162 | @ifset M32C |
1163 | The following options are available when @value{AS} is configured for the | |
1164 | Renesas M32C and M16C processors. | |
1165 | ||
1166 | @table @gcctabopt | |
1167 | ||
1168 | @item -m32c | |
1169 | Assemble M32C instructions. | |
1170 | ||
1171 | @item -m16c | |
1172 | Assemble M16C instructions (the default). | |
1173 | ||
c54b5932 DD |
1174 | @item -relax |
1175 | Enable support for link-time relaxations. | |
1176 | ||
1177 | @item -h-tick-hex | |
1178 | Support H'00 style hex constants in addition to 0x00 style. | |
1179 | ||
49f58d10 JB |
1180 | @end table |
1181 | @end ifset | |
1182 | ||
ec694b89 NC |
1183 | @ifset M32R |
1184 | The following options are available when @value{AS} is configured for the | |
26597c86 | 1185 | Renesas M32R (formerly Mitsubishi M32R) series. |
ec694b89 | 1186 | |
a4fb0134 | 1187 | @table @gcctabopt |
ec694b89 NC |
1188 | |
1189 | @item --m32rx | |
1190 | Specify which processor in the M32R family is the target. The default | |
1191 | is normally the M32R, but this option changes it to the M32RX. | |
1192 | ||
1193 | @item --warn-explicit-parallel-conflicts or --Wp | |
1194 | Produce warning messages when questionable parallel constructs are | |
01642c12 | 1195 | encountered. |
ec694b89 NC |
1196 | |
1197 | @item --no-warn-explicit-parallel-conflicts or --Wnp | |
01642c12 RM |
1198 | Do not produce warning messages when questionable parallel constructs are |
1199 | encountered. | |
ec694b89 NC |
1200 | |
1201 | @end table | |
1202 | @end ifset | |
252b5132 RH |
1203 | |
1204 | @ifset M680X0 | |
1205 | The following options are available when @value{AS} is configured for the | |
1206 | Motorola 68000 series. | |
1207 | ||
a4fb0134 | 1208 | @table @gcctabopt |
252b5132 RH |
1209 | |
1210 | @item -l | |
1211 | Shorten references to undefined symbols, to one word instead of two. | |
1212 | ||
0285c67d NC |
1213 | @item -m68000 | -m68008 | -m68010 | -m68020 | -m68030 |
1214 | @itemx | -m68040 | -m68060 | -m68302 | -m68331 | -m68332 | |
1215 | @itemx | -m68333 | -m68340 | -mcpu32 | -m5200 | |
252b5132 RH |
1216 | Specify what processor in the 68000 family is the target. The default |
1217 | is normally the 68020, but this can be changed at configuration time. | |
1218 | ||
1219 | @item -m68881 | -m68882 | -mno-68881 | -mno-68882 | |
1220 | The target machine does (or does not) have a floating-point coprocessor. | |
1221 | The default is to assume a coprocessor for 68020, 68030, and cpu32. Although | |
1222 | the basic 68000 is not compatible with the 68881, a combination of the | |
1223 | two can be specified, since it's possible to do emulation of the | |
1224 | coprocessor instructions with the main processor. | |
1225 | ||
1226 | @item -m68851 | -mno-68851 | |
1227 | The target machine does (or does not) have a memory-management | |
1228 | unit coprocessor. The default is to assume an MMU for 68020 and up. | |
1229 | ||
1230 | @end table | |
1231 | @end ifset | |
1232 | ||
36591ba1 SL |
1233 | @ifset NIOSII |
1234 | ||
1235 | @ifclear man | |
1236 | @xref{Nios II Options}, for the options available when @value{AS} is configured | |
1237 | for an Altera Nios II processor. | |
1238 | @end ifclear | |
1239 | ||
1240 | @ifset man | |
1241 | @c man begin OPTIONS | |
1242 | The following options are available when @value{AS} is configured for an | |
1243 | Altera Nios II processor. | |
1244 | @c man end | |
1245 | @c man begin INCLUDE | |
1246 | @include c-nios2.texi | |
1247 | @c ended inside the included file | |
1248 | @end ifset | |
1249 | @end ifset | |
1250 | ||
e135f41b NC |
1251 | @ifset PDP11 |
1252 | ||
1253 | For details about the PDP-11 machine dependent features options, | |
1254 | see @ref{PDP-11-Options}. | |
1255 | ||
a4fb0134 | 1256 | @table @gcctabopt |
e135f41b NC |
1257 | @item -mpic | -mno-pic |
1258 | Generate position-independent (or position-dependent) code. The | |
a4fb0134 | 1259 | default is @option{-mpic}. |
e135f41b NC |
1260 | |
1261 | @item -mall | |
1262 | @itemx -mall-extensions | |
1263 | Enable all instruction set extensions. This is the default. | |
1264 | ||
1265 | @item -mno-extensions | |
1266 | Disable all instruction set extensions. | |
1267 | ||
1268 | @item -m@var{extension} | -mno-@var{extension} | |
1269 | Enable (or disable) a particular instruction set extension. | |
1270 | ||
1271 | @item -m@var{cpu} | |
1272 | Enable the instruction set extensions supported by a particular CPU, and | |
1273 | disable all other extensions. | |
1274 | ||
1275 | @item -m@var{machine} | |
1276 | Enable the instruction set extensions supported by a particular machine | |
1277 | model, and disable all other extensions. | |
1278 | @end table | |
1279 | ||
1280 | @end ifset | |
1281 | ||
041dd5a9 ILT |
1282 | @ifset PJ |
1283 | The following options are available when @value{AS} is configured for | |
1284 | a picoJava processor. | |
1285 | ||
a4fb0134 | 1286 | @table @gcctabopt |
041dd5a9 ILT |
1287 | |
1288 | @cindex PJ endianness | |
1289 | @cindex endianness, PJ | |
1290 | @cindex big endian output, PJ | |
1291 | @item -mb | |
1292 | Generate ``big endian'' format output. | |
1293 | ||
1294 | @cindex little endian output, PJ | |
1295 | @item -ml | |
1296 | Generate ``little endian'' format output. | |
1297 | ||
1298 | @end table | |
1299 | @end ifset | |
1300 | ||
93f11b16 DD |
1301 | @ifset PRU |
1302 | ||
1303 | @ifclear man | |
1304 | @xref{PRU Options}, for the options available when @value{AS} is configured | |
1305 | for a PRU processor. | |
1306 | @end ifclear | |
1307 | ||
1308 | @ifset man | |
1309 | @c man begin OPTIONS | |
1310 | The following options are available when @value{AS} is configured for a | |
1311 | PRU processor. | |
1312 | @c man end | |
1313 | @c man begin INCLUDE | |
1314 | @include c-pru.texi | |
1315 | @c ended inside the included file | |
1316 | @end ifset | |
1317 | @end ifset | |
1318 | ||
60bcf0fa NC |
1319 | @ifset M68HC11 |
1320 | The following options are available when @value{AS} is configured for the | |
1321 | Motorola 68HC11 or 68HC12 series. | |
1322 | ||
a4fb0134 | 1323 | @table @gcctabopt |
60bcf0fa | 1324 | |
6927f982 | 1325 | @item -m68hc11 | -m68hc12 | -m68hcs12 | -mm9s12x | -mm9s12xg |
60bcf0fa NC |
1326 | Specify what processor is the target. The default is |
1327 | defined by the configuration option when building the assembler. | |
1328 | ||
6927f982 NC |
1329 | @item --xgate-ramoffset |
1330 | Instruct the linker to offset RAM addresses from S12X address space into | |
1331 | XGATE address space. | |
1332 | ||
2f904664 SC |
1333 | @item -mshort |
1334 | Specify to use the 16-bit integer ABI. | |
1335 | ||
1336 | @item -mlong | |
01642c12 | 1337 | Specify to use the 32-bit integer ABI. |
2f904664 SC |
1338 | |
1339 | @item -mshort-double | |
01642c12 | 1340 | Specify to use the 32-bit double ABI. |
2f904664 SC |
1341 | |
1342 | @item -mlong-double | |
01642c12 | 1343 | Specify to use the 64-bit double ABI. |
2f904664 | 1344 | |
1370e33d | 1345 | @item --force-long-branches |
60bcf0fa NC |
1346 | Relative branches are turned into absolute ones. This concerns |
1347 | conditional branches, unconditional branches and branches to a | |
1348 | sub routine. | |
1349 | ||
1370e33d NC |
1350 | @item -S | --short-branches |
1351 | Do not turn relative branches into absolute ones | |
60bcf0fa NC |
1352 | when the offset is out of range. |
1353 | ||
1354 | @item --strict-direct-mode | |
1355 | Do not turn the direct addressing mode into extended addressing mode | |
1356 | when the instruction does not support direct addressing mode. | |
1357 | ||
1358 | @item --print-insn-syntax | |
1359 | Print the syntax of instruction in case of error. | |
1360 | ||
1361 | @item --print-opcodes | |
6927f982 | 1362 | Print the list of instructions with syntax and then exit. |
60bcf0fa NC |
1363 | |
1364 | @item --generate-example | |
6927f982 | 1365 | Print an example of instruction for each possible instruction and then exit. |
a4fb0134 | 1366 | This option is only useful for testing @command{@value{AS}}. |
60bcf0fa NC |
1367 | |
1368 | @end table | |
1369 | @end ifset | |
1370 | ||
252b5132 | 1371 | @ifset SPARC |
a4fb0134 | 1372 | The following options are available when @command{@value{AS}} is configured |
252b5132 RH |
1373 | for the SPARC architecture: |
1374 | ||
a4fb0134 | 1375 | @table @gcctabopt |
252b5132 RH |
1376 | @item -Av6 | -Av7 | -Av8 | -Asparclet | -Asparclite |
1377 | @itemx -Av8plus | -Av8plusa | -Av9 | -Av9a | |
1378 | Explicitly select a variant of the SPARC architecture. | |
1379 | ||
1380 | @samp{-Av8plus} and @samp{-Av8plusa} select a 32 bit environment. | |
1381 | @samp{-Av9} and @samp{-Av9a} select a 64 bit environment. | |
1382 | ||
1383 | @samp{-Av8plusa} and @samp{-Av9a} enable the SPARC V9 instruction set with | |
1384 | UltraSPARC extensions. | |
1385 | ||
1386 | @item -xarch=v8plus | -xarch=v8plusa | |
1387 | For compatibility with the Solaris v9 assembler. These options are | |
1388 | equivalent to -Av8plus and -Av8plusa, respectively. | |
1389 | ||
1390 | @item -bump | |
1391 | Warn when the assembler switches to another architecture. | |
1392 | @end table | |
1393 | @end ifset | |
1394 | ||
39bec121 TW |
1395 | @ifset TIC54X |
1396 | The following options are available when @value{AS} is configured for the 'c54x | |
01642c12 | 1397 | architecture. |
39bec121 | 1398 | |
a4fb0134 | 1399 | @table @gcctabopt |
39bec121 TW |
1400 | @item -mfar-mode |
1401 | Enable extended addressing mode. All addresses and relocations will assume | |
1402 | extended addressing (usually 23 bits). | |
1403 | @item -mcpu=@var{CPU_VERSION} | |
1404 | Sets the CPU version being compiled for. | |
1405 | @item -merrors-to-file @var{FILENAME} | |
1406 | Redirect error output to a file, for broken systems which don't support such | |
1407 | behaviour in the shell. | |
1408 | @end table | |
1409 | @end ifset | |
1410 | ||
252b5132 | 1411 | @ifset MIPS |
73201331 | 1412 | @c man begin OPTIONS |
252b5132 | 1413 | The following options are available when @value{AS} is configured for |
98508b2a | 1414 | a MIPS processor. |
252b5132 | 1415 | |
a4fb0134 | 1416 | @table @gcctabopt |
252b5132 RH |
1417 | @item -G @var{num} |
1418 | This option sets the largest size of an object that can be referenced | |
1419 | implicitly with the @code{gp} register. It is only accepted for targets that | |
1420 | use ECOFF format, such as a DECstation running Ultrix. The default value is 8. | |
1421 | ||
1422 | @cindex MIPS endianness | |
1423 | @cindex endianness, MIPS | |
1424 | @cindex big endian output, MIPS | |
1425 | @item -EB | |
1426 | Generate ``big endian'' format output. | |
1427 | ||
1428 | @cindex little endian output, MIPS | |
1429 | @item -EL | |
1430 | Generate ``little endian'' format output. | |
1431 | ||
1432 | @cindex MIPS ISA | |
1433 | @item -mips1 | |
1434 | @itemx -mips2 | |
1435 | @itemx -mips3 | |
e7af610e | 1436 | @itemx -mips4 |
437ee9d5 | 1437 | @itemx -mips5 |
e7af610e | 1438 | @itemx -mips32 |
af7ee8bf | 1439 | @itemx -mips32r2 |
ae52f483 AB |
1440 | @itemx -mips32r3 |
1441 | @itemx -mips32r5 | |
7361da2c | 1442 | @itemx -mips32r6 |
4058e45f | 1443 | @itemx -mips64 |
5f74bc13 | 1444 | @itemx -mips64r2 |
ae52f483 AB |
1445 | @itemx -mips64r3 |
1446 | @itemx -mips64r5 | |
7361da2c | 1447 | @itemx -mips64r6 |
98508b2a | 1448 | Generate code for a particular MIPS Instruction Set Architecture level. |
437ee9d5 TS |
1449 | @samp{-mips1} is an alias for @samp{-march=r3000}, @samp{-mips2} is an |
1450 | alias for @samp{-march=r6000}, @samp{-mips3} is an alias for | |
1451 | @samp{-march=r4000} and @samp{-mips4} is an alias for @samp{-march=r8000}. | |
ae52f483 | 1452 | @samp{-mips5}, @samp{-mips32}, @samp{-mips32r2}, @samp{-mips32r3}, |
7361da2c AB |
1453 | @samp{-mips32r5}, @samp{-mips32r6}, @samp{-mips64}, @samp{-mips64r2}, |
1454 | @samp{-mips64r3}, @samp{-mips64r5}, and @samp{-mips64r6} correspond to generic | |
1455 | MIPS V, MIPS32, MIPS32 Release 2, MIPS32 Release 3, MIPS32 Release 5, MIPS32 | |
1456 | Release 6, MIPS64, MIPS64 Release 2, MIPS64 Release 3, MIPS64 Release 5, and | |
1457 | MIPS64 Release 6 ISA processors, respectively. | |
437ee9d5 | 1458 | |
98508b2a RS |
1459 | @item -march=@var{cpu} |
1460 | Generate code for a particular MIPS CPU. | |
437ee9d5 TS |
1461 | |
1462 | @item -mtune=@var{cpu} | |
98508b2a | 1463 | Schedule and tune for a particular MIPS CPU. |
437ee9d5 TS |
1464 | |
1465 | @item -mfix7000 | |
1466 | @itemx -mno-fix7000 | |
1467 | Cause nops to be inserted if the read of the destination register | |
1468 | of an mfhi or mflo instruction occurs in the following two instructions. | |
1469 | ||
a8d14a88 CM |
1470 | @item -mfix-rm7000 |
1471 | @itemx -mno-fix-rm7000 | |
1472 | Cause nops to be inserted if a dmult or dmultu instruction is | |
1473 | followed by a load instruction. | |
1474 | ||
27c634e0 FN |
1475 | @item -mfix-r5900 |
1476 | @itemx -mno-fix-r5900 | |
1477 | Do not attempt to schedule the preceding instruction into the delay slot | |
1478 | of a branch instruction placed at the end of a short loop of six | |
1479 | instructions or fewer and always schedule a @code{nop} instruction there | |
1480 | instead. The short loop bug under certain conditions causes loops to | |
1481 | execute only once or twice, due to a hardware bug in the R5900 chip. | |
1482 | ||
ecb4347a DJ |
1483 | @item -mdebug |
1484 | @itemx -no-mdebug | |
1485 | Cause stabs-style debugging output to go into an ECOFF-style .mdebug | |
1486 | section instead of the standard ELF .stabs sections. | |
1487 | ||
dcd410fe RO |
1488 | @item -mpdr |
1489 | @itemx -mno-pdr | |
1490 | Control generation of @code{.pdr} sections. | |
1491 | ||
437ee9d5 TS |
1492 | @item -mgp32 |
1493 | @itemx -mfp32 | |
1494 | The register sizes are normally inferred from the ISA and ABI, but these | |
1495 | flags force a certain group of registers to be treated as 32 bits wide at | |
1496 | all times. @samp{-mgp32} controls the size of general-purpose registers | |
1497 | and @samp{-mfp32} controls the size of floating-point registers. | |
1498 | ||
351cdf24 MF |
1499 | @item -mgp64 |
1500 | @itemx -mfp64 | |
1501 | The register sizes are normally inferred from the ISA and ABI, but these | |
1502 | flags force a certain group of registers to be treated as 64 bits wide at | |
1503 | all times. @samp{-mgp64} controls the size of general-purpose registers | |
1504 | and @samp{-mfp64} controls the size of floating-point registers. | |
1505 | ||
1506 | @item -mfpxx | |
1507 | The register sizes are normally inferred from the ISA and ABI, but using | |
1508 | this flag in combination with @samp{-mabi=32} enables an ABI variant | |
1509 | which will operate correctly with floating-point registers which are | |
1510 | 32 or 64 bits wide. | |
1511 | ||
1512 | @item -modd-spreg | |
1513 | @itemx -mno-odd-spreg | |
1514 | Enable use of floating-point operations on odd-numbered single-precision | |
1515 | registers when supported by the ISA. @samp{-mfpxx} implies | |
1516 | @samp{-mno-odd-spreg}, otherwise the default is @samp{-modd-spreg}. | |
1517 | ||
437ee9d5 TS |
1518 | @item -mips16 |
1519 | @itemx -no-mips16 | |
1520 | Generate code for the MIPS 16 processor. This is equivalent to putting | |
32035f51 | 1521 | @code{.module mips16} at the start of the assembly file. @samp{-no-mips16} |
437ee9d5 | 1522 | turns off this option. |
252b5132 | 1523 | |
25499ac7 MR |
1524 | @item -mmips16e2 |
1525 | @itemx -mno-mips16e2 | |
1526 | Enable the use of MIPS16e2 instructions in MIPS16 mode. This is equivalent | |
1527 | to putting @code{.module mips16e2} at the start of the assembly file. | |
1528 | @samp{-mno-mips16e2} turns off this option. | |
1529 | ||
df58fc94 RS |
1530 | @item -mmicromips |
1531 | @itemx -mno-micromips | |
1532 | Generate code for the microMIPS processor. This is equivalent to putting | |
32035f51 MR |
1533 | @code{.module micromips} at the start of the assembly file. |
1534 | @samp{-mno-micromips} turns off this option. This is equivalent to putting | |
1535 | @code{.module nomicromips} at the start of the assembly file. | |
df58fc94 | 1536 | |
e16bfa71 TS |
1537 | @item -msmartmips |
1538 | @itemx -mno-smartmips | |
32035f51 MR |
1539 | Enables the SmartMIPS extension to the MIPS32 instruction set. This is |
1540 | equivalent to putting @code{.module smartmips} at the start of the assembly | |
1541 | file. @samp{-mno-smartmips} turns off this option. | |
e16bfa71 | 1542 | |
1f25f5d3 CD |
1543 | @item -mips3d |
1544 | @itemx -no-mips3d | |
1545 | Generate code for the MIPS-3D Application Specific Extension. | |
1546 | This tells the assembler to accept MIPS-3D instructions. | |
1547 | @samp{-no-mips3d} turns off this option. | |
1548 | ||
deec1734 CD |
1549 | @item -mdmx |
1550 | @itemx -no-mdmx | |
1551 | Generate code for the MDMX Application Specific Extension. | |
1552 | This tells the assembler to accept MDMX instructions. | |
1553 | @samp{-no-mdmx} turns off this option. | |
1554 | ||
2ef2b9ae CF |
1555 | @item -mdsp |
1556 | @itemx -mno-dsp | |
8b082fb1 TS |
1557 | Generate code for the DSP Release 1 Application Specific Extension. |
1558 | This tells the assembler to accept DSP Release 1 instructions. | |
2ef2b9ae CF |
1559 | @samp{-mno-dsp} turns off this option. |
1560 | ||
8b082fb1 TS |
1561 | @item -mdspr2 |
1562 | @itemx -mno-dspr2 | |
1563 | Generate code for the DSP Release 2 Application Specific Extension. | |
8f4f9071 | 1564 | This option implies @samp{-mdsp}. |
8b082fb1 TS |
1565 | This tells the assembler to accept DSP Release 2 instructions. |
1566 | @samp{-mno-dspr2} turns off this option. | |
1567 | ||
8f4f9071 MF |
1568 | @item -mdspr3 |
1569 | @itemx -mno-dspr3 | |
1570 | Generate code for the DSP Release 3 Application Specific Extension. | |
1571 | This option implies @samp{-mdsp} and @samp{-mdspr2}. | |
1572 | This tells the assembler to accept DSP Release 3 instructions. | |
1573 | @samp{-mno-dspr3} turns off this option. | |
1574 | ||
56d438b1 CF |
1575 | @item -mmsa |
1576 | @itemx -mno-msa | |
1577 | Generate code for the MIPS SIMD Architecture Extension. | |
1578 | This tells the assembler to accept MSA instructions. | |
1579 | @samp{-mno-msa} turns off this option. | |
1580 | ||
7d64c587 AB |
1581 | @item -mxpa |
1582 | @itemx -mno-xpa | |
1583 | Generate code for the MIPS eXtended Physical Address (XPA) Extension. | |
1584 | This tells the assembler to accept XPA instructions. | |
1585 | @samp{-mno-xpa} turns off this option. | |
1586 | ||
ef2e4d86 CF |
1587 | @item -mmt |
1588 | @itemx -mno-mt | |
1589 | Generate code for the MT Application Specific Extension. | |
1590 | This tells the assembler to accept MT instructions. | |
1591 | @samp{-mno-mt} turns off this option. | |
1592 | ||
dec0624d MR |
1593 | @item -mmcu |
1594 | @itemx -mno-mcu | |
1595 | Generate code for the MCU Application Specific Extension. | |
1596 | This tells the assembler to accept MCU instructions. | |
1597 | @samp{-mno-mcu} turns off this option. | |
1598 | ||
730c3174 SE |
1599 | @item -mcrc |
1600 | @itemx -mno-crc | |
1601 | Generate code for the MIPS cyclic redundancy check (CRC) Application | |
1602 | Specific Extension. This tells the assembler to accept CRC instructions. | |
1603 | @samp{-mno-crc} turns off this option. | |
1604 | ||
6f20c942 FS |
1605 | @item -mginv |
1606 | @itemx -mno-ginv | |
1607 | Generate code for the Global INValidate (GINV) Application Specific | |
1608 | Extension. This tells the assembler to accept GINV instructions. | |
1609 | @samp{-mno-ginv} turns off this option. | |
1610 | ||
8095d2f7 CX |
1611 | @item -mloongson-mmi |
1612 | @itemx -mno-loongson-mmi | |
1613 | Generate code for the Loongson MultiMedia extensions Instructions (MMI) | |
1614 | Application Specific Extension. This tells the assembler to accept MMI | |
1615 | instructions. | |
1616 | @samp{-mno-loongson-mmi} turns off this option. | |
1617 | ||
716c08de CX |
1618 | @item -mloongson-cam |
1619 | @itemx -mno-loongson-cam | |
1620 | Generate code for the Loongson Content Address Memory (CAM) instructions. | |
1621 | This tells the assembler to accept Loongson CAM instructions. | |
1622 | @samp{-mno-loongson-cam} turns off this option. | |
1623 | ||
bdc6c06e CX |
1624 | @item -mloongson-ext |
1625 | @itemx -mno-loongson-ext | |
1626 | Generate code for the Loongson EXTensions (EXT) instructions. | |
1627 | This tells the assembler to accept Loongson EXT instructions. | |
1628 | @samp{-mno-loongson-ext} turns off this option. | |
1629 | ||
a693765e CX |
1630 | @item -mloongson-ext2 |
1631 | @itemx -mno-loongson-ext2 | |
1632 | Generate code for the Loongson EXTensions R2 (EXT2) instructions. | |
1633 | This option implies @samp{-mloongson-ext}. | |
1634 | This tells the assembler to accept Loongson EXT2 instructions. | |
1635 | @samp{-mno-loongson-ext2} turns off this option. | |
1636 | ||
833794fc MR |
1637 | @item -minsn32 |
1638 | @itemx -mno-insn32 | |
1639 | Only use 32-bit instruction encodings when generating code for the | |
1640 | microMIPS processor. This option inhibits the use of any 16-bit | |
1641 | instructions. This is equivalent to putting @code{.set insn32} at | |
1642 | the start of the assembly file. @samp{-mno-insn32} turns off this | |
1643 | option. This is equivalent to putting @code{.set noinsn32} at the | |
1644 | start of the assembly file. By default @samp{-mno-insn32} is | |
1645 | selected, allowing all instructions to be used. | |
1646 | ||
437ee9d5 TS |
1647 | @item --construct-floats |
1648 | @itemx --no-construct-floats | |
1649 | The @samp{--no-construct-floats} option disables the construction of | |
1650 | double width floating point constants by loading the two halves of the | |
1651 | value into the two single width floating point registers that make up | |
1652 | the double width register. By default @samp{--construct-floats} is | |
1653 | selected, allowing construction of these floating point constants. | |
252b5132 | 1654 | |
3bf0dbfb MR |
1655 | @item --relax-branch |
1656 | @itemx --no-relax-branch | |
1657 | The @samp{--relax-branch} option enables the relaxation of out-of-range | |
1658 | branches. By default @samp{--no-relax-branch} is selected, causing any | |
1659 | out-of-range branches to produce an error. | |
1660 | ||
8b10b0b3 MR |
1661 | @item -mignore-branch-isa |
1662 | @itemx -mno-ignore-branch-isa | |
1663 | Ignore branch checks for invalid transitions between ISA modes. The | |
1664 | semantics of branches does not provide for an ISA mode switch, so in | |
1665 | most cases the ISA mode a branch has been encoded for has to be the | |
1666 | same as the ISA mode of the branch's target label. Therefore GAS has | |
1667 | checks implemented that verify in branch assembly that the two ISA | |
1668 | modes match. @samp{-mignore-branch-isa} disables these checks. By | |
1669 | default @samp{-mno-ignore-branch-isa} is selected, causing any invalid | |
1670 | branch requiring a transition between ISA modes to produce an error. | |
1671 | ||
ba92f887 MR |
1672 | @item -mnan=@var{encoding} |
1673 | Select between the IEEE 754-2008 (@option{-mnan=2008}) or the legacy | |
1674 | (@option{-mnan=legacy}) NaN encoding format. The latter is the default. | |
1675 | ||
252b5132 RH |
1676 | @cindex emulation |
1677 | @item --emulation=@var{name} | |
e8044f35 RS |
1678 | This option was formerly used to switch between ELF and ECOFF output |
1679 | on targets like IRIX 5 that supported both. MIPS ECOFF support was | |
1680 | removed in GAS 2.24, so the option now serves little purpose. | |
1681 | It is retained for backwards compatibility. | |
1682 | ||
1683 | The available configuration names are: @samp{mipself}, @samp{mipslelf} and | |
1684 | @samp{mipsbelf}. Choosing @samp{mipself} now has no effect, since the output | |
1685 | is always ELF. @samp{mipslelf} and @samp{mipsbelf} select little- and | |
1686 | big-endian output respectively, but @samp{-EL} and @samp{-EB} are now the | |
1687 | preferred options instead. | |
252b5132 RH |
1688 | |
1689 | @item -nocpp | |
a4fb0134 | 1690 | @command{@value{AS}} ignores this option. It is accepted for compatibility with |
252b5132 RH |
1691 | the native tools. |
1692 | ||
252b5132 RH |
1693 | @item --trap |
1694 | @itemx --no-trap | |
1695 | @itemx --break | |
1696 | @itemx --no-break | |
1697 | Control how to deal with multiplication overflow and division by zero. | |
1698 | @samp{--trap} or @samp{--no-break} (which are synonyms) take a trap exception | |
1699 | (and only work for Instruction Set Architecture level 2 and higher); | |
1700 | @samp{--break} or @samp{--no-trap} (also synonyms, and the default) take a | |
1701 | break exception. | |
63486801 L |
1702 | |
1703 | @item -n | |
a4fb0134 | 1704 | When this option is used, @command{@value{AS}} will issue a warning every |
63486801 | 1705 | time it generates a nop instruction from a macro. |
252b5132 | 1706 | @end table |
73201331 | 1707 | @c man end |
252b5132 RH |
1708 | @end ifset |
1709 | ||
1710 | @ifset MCORE | |
1711 | The following options are available when @value{AS} is configured for | |
1712 | an MCore processor. | |
1713 | ||
a4fb0134 | 1714 | @table @gcctabopt |
252b5132 RH |
1715 | @item -jsri2bsr |
1716 | @itemx -nojsri2bsr | |
1717 | Enable or disable the JSRI to BSR transformation. By default this is enabled. | |
a05a5b64 | 1718 | The command-line option @samp{-nojsri2bsr} can be used to disable it. |
252b5132 RH |
1719 | |
1720 | @item -sifilter | |
1721 | @itemx -nosifilter | |
1722 | Enable or disable the silicon filter behaviour. By default this is disabled. | |
a05a5b64 | 1723 | The default can be overridden by the @samp{-sifilter} command-line option. |
252b5132 RH |
1724 | |
1725 | @item -relax | |
1726 | Alter jump instructions for long displacements. | |
1727 | ||
ec694b89 NC |
1728 | @item -mcpu=[210|340] |
1729 | Select the cpu type on the target hardware. This controls which instructions | |
1730 | can be assembled. | |
1731 | ||
1732 | @item -EB | |
1733 | Assemble for a big endian target. | |
1734 | ||
1735 | @item -EL | |
1736 | Assemble for a little endian target. | |
252b5132 RH |
1737 | |
1738 | @end table | |
1739 | @end ifset | |
a3c62988 | 1740 | @c man end |
252b5132 | 1741 | |
a3c62988 NC |
1742 | @ifset METAG |
1743 | ||
1744 | @ifclear man | |
1745 | @xref{Meta Options}, for the options available when @value{AS} is configured | |
1746 | for a Meta processor. | |
1747 | @end ifclear | |
1748 | ||
1749 | @ifset man | |
1750 | @c man begin OPTIONS | |
1751 | The following options are available when @value{AS} is configured for a | |
1752 | Meta processor. | |
1753 | @c man end | |
1754 | @c man begin INCLUDE | |
1755 | @include c-metag.texi | |
1756 | @c ended inside the included file | |
1757 | @end ifset | |
1758 | ||
1759 | @end ifset | |
1760 | ||
1761 | @c man begin OPTIONS | |
3c3bdf30 NC |
1762 | @ifset MMIX |
1763 | See the info pages for documentation of the MMIX-specific options. | |
1764 | @end ifset | |
1765 | ||
35c08157 KLC |
1766 | @ifset NDS32 |
1767 | ||
1768 | @ifclear man | |
1769 | @xref{NDS32 Options}, for the options available when @value{AS} is configured | |
1770 | for a NDS32 processor. | |
1771 | @end ifclear | |
1772 | @c ended inside the included file | |
1773 | @end ifset | |
1774 | ||
1775 | @ifset man | |
1776 | @c man begin OPTIONS | |
1777 | The following options are available when @value{AS} is configured for a | |
1778 | NDS32 processor. | |
1779 | @c man end | |
1780 | @c man begin INCLUDE | |
1781 | @include c-nds32.texi | |
1782 | @c ended inside the included file | |
1783 | @end ifset | |
1784 | ||
635fb38d | 1785 | @c man end |
b8b738ac AM |
1786 | @ifset PPC |
1787 | ||
1788 | @ifclear man | |
1789 | @xref{PowerPC-Opts}, for the options available when @value{AS} is configured | |
1790 | for a PowerPC processor. | |
1791 | @end ifclear | |
1792 | ||
1793 | @ifset man | |
1794 | @c man begin OPTIONS | |
1795 | The following options are available when @value{AS} is configured for a | |
1796 | PowerPC processor. | |
1797 | @c man end | |
1798 | @c man begin INCLUDE | |
1799 | @include c-ppc.texi | |
1800 | @c ended inside the included file | |
1801 | @end ifset | |
1802 | ||
1803 | @end ifset | |
1804 | ||
e23eba97 NC |
1805 | @ifset RISCV |
1806 | ||
1807 | @ifclear man | |
b57e49f7 | 1808 | @xref{RISC-V-Options}, for the options available when @value{AS} is configured |
e23eba97 NC |
1809 | for a RISC-V processor. |
1810 | @end ifclear | |
1811 | ||
1812 | @ifset man | |
1813 | @c man begin OPTIONS | |
1814 | The following options are available when @value{AS} is configured for a | |
b57e49f7 | 1815 | RISC-V processor. |
e23eba97 NC |
1816 | @c man end |
1817 | @c man begin INCLUDE | |
1818 | @include c-riscv.texi | |
1819 | @c ended inside the included file | |
1820 | @end ifset | |
1821 | ||
1822 | @end ifset | |
1823 | ||
635fb38d | 1824 | @c man begin OPTIONS |
046d31c2 NC |
1825 | @ifset RX |
1826 | See the info pages for documentation of the RX-specific options. | |
1827 | @end ifset | |
1828 | ||
11c19e16 MS |
1829 | @ifset S390 |
1830 | The following options are available when @value{AS} is configured for the s390 | |
1831 | processor family. | |
1832 | ||
1833 | @table @gcctabopt | |
1834 | @item -m31 | |
1835 | @itemx -m64 | |
1836 | Select the word size, either 31/32 bits or 64 bits. | |
1837 | @item -mesa | |
1838 | @item -mzarch | |
1839 | Select the architecture mode, either the Enterprise System | |
1840 | Architecture (esa) or the z/Architecture mode (zarch). | |
1841 | @item -march=@var{processor} | |
952c3f51 AK |
1842 | Specify which s390 processor variant is the target, @samp{g5} (or |
1843 | @samp{arch3}), @samp{g6}, @samp{z900} (or @samp{arch5}), @samp{z990} (or | |
1844 | @samp{arch6}), @samp{z9-109}, @samp{z9-ec} (or @samp{arch7}), @samp{z10} (or | |
1845 | @samp{arch8}), @samp{z196} (or @samp{arch9}), @samp{zEC12} (or @samp{arch10}), | |
46e292ab AK |
1846 | @samp{z13} (or @samp{arch11}), @samp{z14} (or @samp{arch12}), or @samp{z15} |
1847 | (or @samp{arch13}). | |
11c19e16 MS |
1848 | @item -mregnames |
1849 | @itemx -mno-regnames | |
1850 | Allow or disallow symbolic names for registers. | |
1851 | @item -mwarn-areg-zero | |
1852 | Warn whenever the operand for a base or index register has been specified | |
1853 | but evaluates to zero. | |
1854 | @end table | |
1855 | @end ifset | |
2a633939 | 1856 | @c man end |
11c19e16 | 1857 | |
40b36596 | 1858 | @ifset TIC6X |
2a633939 JM |
1859 | |
1860 | @ifclear man | |
1861 | @xref{TIC6X Options}, for the options available when @value{AS} is configured | |
1862 | for a TMS320C6000 processor. | |
1863 | @end ifclear | |
1864 | ||
1865 | @ifset man | |
1866 | @c man begin OPTIONS | |
40b36596 JM |
1867 | The following options are available when @value{AS} is configured for a |
1868 | TMS320C6000 processor. | |
2a633939 JM |
1869 | @c man end |
1870 | @c man begin INCLUDE | |
1871 | @include c-tic6x.texi | |
1872 | @c ended inside the included file | |
1873 | @end ifset | |
40b36596 JM |
1874 | |
1875 | @end ifset | |
1876 | ||
aa137e4d NC |
1877 | @ifset TILEGX |
1878 | ||
1879 | @ifclear man | |
1880 | @xref{TILE-Gx Options}, for the options available when @value{AS} is configured | |
1881 | for a TILE-Gx processor. | |
1882 | @end ifclear | |
1883 | ||
1884 | @ifset man | |
1885 | @c man begin OPTIONS | |
1886 | The following options are available when @value{AS} is configured for a TILE-Gx | |
1887 | processor. | |
1888 | @c man end | |
1889 | @c man begin INCLUDE | |
1890 | @include c-tilegx.texi | |
1891 | @c ended inside the included file | |
1892 | @end ifset | |
1893 | ||
1894 | @end ifset | |
1895 | ||
b6605ddd EB |
1896 | @ifset VISIUM |
1897 | ||
1898 | @ifclear man | |
1899 | @xref{Visium Options}, for the options available when @value{AS} is configured | |
1900 | for a Visium processor. | |
1901 | @end ifclear | |
1902 | ||
1903 | @ifset man | |
1904 | @c man begin OPTIONS | |
1905 | The following option is available when @value{AS} is configured for a Visium | |
1906 | processor. | |
1907 | @c man end | |
1908 | @c man begin INCLUDE | |
1909 | @include c-visium.texi | |
1910 | @c ended inside the included file | |
1911 | @end ifset | |
1912 | ||
1913 | @end ifset | |
1914 | ||
e0001a05 | 1915 | @ifset XTENSA |
e0001a05 | 1916 | |
2d8b84ae SA |
1917 | @ifclear man |
1918 | @xref{Xtensa Options}, for the options available when @value{AS} is configured | |
1919 | for an Xtensa processor. | |
1920 | @end ifclear | |
1921 | ||
1922 | @ifset man | |
1923 | @c man begin OPTIONS | |
1924 | The following options are available when @value{AS} is configured for an | |
1925 | Xtensa processor. | |
1926 | @c man end | |
1927 | @c man begin INCLUDE | |
1928 | @include c-xtensa.texi | |
1929 | @c ended inside the included file | |
e0001a05 NC |
1930 | @end ifset |
1931 | ||
2d8b84ae SA |
1932 | @end ifset |
1933 | ||
1934 | @c man begin OPTIONS | |
1935 | ||
3c9b82ba NC |
1936 | @ifset Z80 |
1937 | The following options are available when @value{AS} is configured for | |
1938 | a Z80 family processor. | |
1939 | @table @gcctabopt | |
1940 | @item -z80 | |
1941 | Assemble for Z80 processor. | |
1942 | @item -r800 | |
1943 | Assemble for R800 processor. | |
01642c12 | 1944 | @item -ignore-undocumented-instructions |
3c9b82ba NC |
1945 | @itemx -Wnud |
1946 | Assemble undocumented Z80 instructions that also work on R800 without warning. | |
01642c12 | 1947 | @item -ignore-unportable-instructions |
3c9b82ba NC |
1948 | @itemx -Wnup |
1949 | Assemble all undocumented Z80 instructions without warning. | |
01642c12 | 1950 | @item -warn-undocumented-instructions |
3c9b82ba NC |
1951 | @itemx -Wud |
1952 | Issue a warning for undocumented Z80 instructions that also work on R800. | |
01642c12 | 1953 | @item -warn-unportable-instructions |
3c9b82ba | 1954 | @itemx -Wup |
01642c12 RM |
1955 | Issue a warning for undocumented Z80 instructions that do not work on R800. |
1956 | @item -forbid-undocumented-instructions | |
3c9b82ba NC |
1957 | @itemx -Fud |
1958 | Treat all undocumented instructions as errors. | |
01642c12 | 1959 | @item -forbid-unportable-instructions |
3c9b82ba | 1960 | @itemx -Fup |
b45619c0 | 1961 | Treat undocumented Z80 instructions that do not work on R800 as errors. |
3c9b82ba NC |
1962 | @end table |
1963 | @end ifset | |
1964 | ||
0285c67d NC |
1965 | @c man end |
1966 | ||
252b5132 RH |
1967 | @menu |
1968 | * Manual:: Structure of this Manual | |
1969 | * GNU Assembler:: The GNU Assembler | |
1970 | * Object Formats:: Object File Formats | |
1971 | * Command Line:: Command Line | |
1972 | * Input Files:: Input Files | |
1973 | * Object:: Output (Object) File | |
1974 | * Errors:: Error and Warning Messages | |
1975 | @end menu | |
1976 | ||
1977 | @node Manual | |
1978 | @section Structure of this Manual | |
1979 | ||
1980 | @cindex manual, structure and purpose | |
1981 | This manual is intended to describe what you need to know to use | |
a4fb0134 | 1982 | @sc{gnu} @command{@value{AS}}. We cover the syntax expected in source files, including |
252b5132 | 1983 | notation for symbols, constants, and expressions; the directives that |
a4fb0134 | 1984 | @command{@value{AS}} understands; and of course how to invoke @command{@value{AS}}. |
252b5132 RH |
1985 | |
1986 | @ifclear GENERIC | |
1987 | We also cover special features in the @value{TARGET} | |
a4fb0134 | 1988 | configuration of @command{@value{AS}}, including assembler directives. |
252b5132 RH |
1989 | @end ifclear |
1990 | @ifset GENERIC | |
1991 | This manual also describes some of the machine-dependent features of | |
1992 | various flavors of the assembler. | |
1993 | @end ifset | |
1994 | ||
1995 | @cindex machine instructions (not covered) | |
1996 | On the other hand, this manual is @emph{not} intended as an introduction | |
1997 | to programming in assembly language---let alone programming in general! | |
1998 | In a similar vein, we make no attempt to introduce the machine | |
1999 | architecture; we do @emph{not} describe the instruction set, standard | |
2000 | mnemonics, registers or addressing modes that are standard to a | |
2001 | particular architecture. | |
2002 | @ifset GENERIC | |
2003 | You may want to consult the manufacturer's | |
2004 | machine architecture manual for this information. | |
2005 | @end ifset | |
2006 | @ifclear GENERIC | |
2007 | @ifset H8/300 | |
2008 | For information on the H8/300 machine instruction set, see @cite{H8/300 | |
c2dcd04e NC |
2009 | Series Programming Manual}. For the H8/300H, see @cite{H8/300H Series |
2010 | Programming Manual} (Renesas). | |
252b5132 | 2011 | @end ifset |
252b5132 | 2012 | @ifset SH |
ef230218 JR |
2013 | For information on the Renesas (formerly Hitachi) / SuperH SH machine instruction set, |
2014 | see @cite{SH-Microcomputer User's Manual} (Renesas) or | |
2015 | @cite{SH-4 32-bit CPU Core Architecture} (SuperH) and | |
2016 | @cite{SuperH (SH) 64-Bit RISC Series} (SuperH). | |
252b5132 RH |
2017 | @end ifset |
2018 | @ifset Z8000 | |
2019 | For information on the Z8000 machine instruction set, see @cite{Z8000 CPU Technical Manual} | |
2020 | @end ifset | |
2021 | @end ifclear | |
2022 | ||
2023 | @c I think this is premature---doc@cygnus.com, 17jan1991 | |
2024 | @ignore | |
2025 | Throughout this manual, we assume that you are running @dfn{GNU}, | |
2026 | the portable operating system from the @dfn{Free Software | |
2027 | Foundation, Inc.}. This restricts our attention to certain kinds of | |
2028 | computer (in particular, the kinds of computers that @sc{gnu} can run on); | |
2029 | once this assumption is granted examples and definitions need less | |
2030 | qualification. | |
2031 | ||
a4fb0134 | 2032 | @command{@value{AS}} is part of a team of programs that turn a high-level |
252b5132 RH |
2033 | human-readable series of instructions into a low-level |
2034 | computer-readable series of instructions. Different versions of | |
a4fb0134 | 2035 | @command{@value{AS}} are used for different kinds of computer. |
252b5132 RH |
2036 | @end ignore |
2037 | ||
2038 | @c There used to be a section "Terminology" here, which defined | |
2039 | @c "contents", "byte", "word", and "long". Defining "word" to any | |
2040 | @c particular size is confusing when the .word directive may generate 16 | |
2041 | @c bits on one machine and 32 bits on another; in general, for the user | |
2042 | @c version of this manual, none of these terms seem essential to define. | |
2043 | @c They were used very little even in the former draft of the manual; | |
2044 | @c this draft makes an effort to avoid them (except in names of | |
2045 | @c directives). | |
2046 | ||
2047 | @node GNU Assembler | |
2048 | @section The GNU Assembler | |
2049 | ||
0285c67d NC |
2050 | @c man begin DESCRIPTION |
2051 | ||
a4fb0134 | 2052 | @sc{gnu} @command{as} is really a family of assemblers. |
252b5132 | 2053 | @ifclear GENERIC |
a4fb0134 | 2054 | This manual describes @command{@value{AS}}, a member of that family which is |
252b5132 RH |
2055 | configured for the @value{TARGET} architectures. |
2056 | @end ifclear | |
2057 | If you use (or have used) the @sc{gnu} assembler on one architecture, you | |
2058 | should find a fairly similar environment when you use it on another | |
2059 | architecture. Each version has much in common with the others, | |
2060 | including object file formats, most assembler directives (often called | |
2061 | @dfn{pseudo-ops}) and assembler syntax.@refill | |
2062 | ||
2063 | @cindex purpose of @sc{gnu} assembler | |
a4fb0134 | 2064 | @command{@value{AS}} is primarily intended to assemble the output of the |
252b5132 | 2065 | @sc{gnu} C compiler @code{@value{GCC}} for use by the linker |
a4fb0134 | 2066 | @code{@value{LD}}. Nevertheless, we've tried to make @command{@value{AS}} |
252b5132 RH |
2067 | assemble correctly everything that other assemblers for the same |
2068 | machine would assemble. | |
2069 | @ifset VAX | |
2070 | Any exceptions are documented explicitly (@pxref{Machine Dependencies}). | |
2071 | @end ifset | |
2072 | @ifset M680X0 | |
2073 | @c This remark should appear in generic version of manual; assumption | |
2074 | @c here is that generic version sets M680x0. | |
a4fb0134 | 2075 | This doesn't mean @command{@value{AS}} always uses the same syntax as another |
252b5132 RH |
2076 | assembler for the same architecture; for example, we know of several |
2077 | incompatible versions of 680x0 assembly language syntax. | |
2078 | @end ifset | |
2079 | ||
0285c67d NC |
2080 | @c man end |
2081 | ||
a4fb0134 | 2082 | Unlike older assemblers, @command{@value{AS}} is designed to assemble a source |
252b5132 RH |
2083 | program in one pass of the source file. This has a subtle impact on the |
2084 | @kbd{.org} directive (@pxref{Org,,@code{.org}}). | |
2085 | ||
2086 | @node Object Formats | |
2087 | @section Object File Formats | |
2088 | ||
2089 | @cindex object file format | |
2090 | The @sc{gnu} assembler can be configured to produce several alternative | |
2091 | object file formats. For the most part, this does not affect how you | |
2092 | write assembly language programs; but directives for debugging symbols | |
2093 | are typically different in different file formats. @xref{Symbol | |
2094 | Attributes,,Symbol Attributes}. | |
2095 | @ifclear GENERIC | |
2096 | @ifclear MULTI-OBJ | |
c1253627 | 2097 | For the @value{TARGET} target, @command{@value{AS}} is configured to produce |
252b5132 RH |
2098 | @value{OBJ-NAME} format object files. |
2099 | @end ifclear | |
2100 | @c The following should exhaust all configs that set MULTI-OBJ, ideally | |
252b5132 | 2101 | @ifset HPPA |
a4fb0134 | 2102 | On the @value{TARGET}, @command{@value{AS}} can be configured to produce either |
252b5132 RH |
2103 | SOM or ELF format object files. |
2104 | @end ifset | |
2105 | @end ifclear | |
2106 | ||
2107 | @node Command Line | |
2108 | @section Command Line | |
2109 | ||
2110 | @cindex command line conventions | |
0285c67d | 2111 | |
a4fb0134 | 2112 | After the program name @command{@value{AS}}, the command line may contain |
252b5132 RH |
2113 | options and file names. Options may appear in any order, and may be |
2114 | before, after, or between file names. The order of file names is | |
2115 | significant. | |
2116 | ||
2117 | @cindex standard input, as input file | |
2118 | @kindex -- | |
2119 | @file{--} (two hyphens) by itself names the standard input file | |
a4fb0134 | 2120 | explicitly, as one of the files for @command{@value{AS}} to assemble. |
252b5132 RH |
2121 | |
2122 | @cindex options, command line | |
a05a5b64 | 2123 | Except for @samp{--} any command-line argument that begins with a |
252b5132 | 2124 | hyphen (@samp{-}) is an option. Each option changes the behavior of |
a4fb0134 | 2125 | @command{@value{AS}}. No option changes the way another option works. An |
252b5132 RH |
2126 | option is a @samp{-} followed by one or more letters; the case of |
2127 | the letter is important. All options are optional. | |
2128 | ||
2129 | Some options expect exactly one file name to follow them. The file | |
2130 | name may either immediately follow the option's letter (compatible | |
2131 | with older assemblers) or it may be the next command argument (@sc{gnu} | |
2132 | standard). These two command lines are equivalent: | |
2133 | ||
2134 | @smallexample | |
2135 | @value{AS} -o my-object-file.o mumble.s | |
2136 | @value{AS} -omy-object-file.o mumble.s | |
2137 | @end smallexample | |
2138 | ||
2139 | @node Input Files | |
2140 | @section Input Files | |
2141 | ||
2142 | @cindex input | |
2143 | @cindex source program | |
2144 | @cindex files, input | |
2145 | We use the phrase @dfn{source program}, abbreviated @dfn{source}, to | |
a4fb0134 | 2146 | describe the program input to one run of @command{@value{AS}}. The program may |
252b5132 RH |
2147 | be in one or more files; how the source is partitioned into files |
2148 | doesn't change the meaning of the source. | |
2149 | ||
2150 | @c I added "con" prefix to "catenation" just to prove I can overcome my | |
2151 | @c APL training... doc@cygnus.com | |
2152 | The source program is a concatenation of the text in all the files, in the | |
2153 | order specified. | |
2154 | ||
0285c67d | 2155 | @c man begin DESCRIPTION |
a4fb0134 | 2156 | Each time you run @command{@value{AS}} it assembles exactly one source |
252b5132 RH |
2157 | program. The source program is made up of one or more files. |
2158 | (The standard input is also a file.) | |
2159 | ||
a4fb0134 | 2160 | You give @command{@value{AS}} a command line that has zero or more input file |
252b5132 | 2161 | names. The input files are read (from left file name to right). A |
a05a5b64 | 2162 | command-line argument (in any position) that has no special meaning |
252b5132 RH |
2163 | is taken to be an input file name. |
2164 | ||
a4fb0134 SC |
2165 | If you give @command{@value{AS}} no file names it attempts to read one input file |
2166 | from the @command{@value{AS}} standard input, which is normally your terminal. You | |
2167 | may have to type @key{ctl-D} to tell @command{@value{AS}} there is no more program | |
252b5132 RH |
2168 | to assemble. |
2169 | ||
2170 | Use @samp{--} if you need to explicitly name the standard input file | |
2171 | in your command line. | |
2172 | ||
a4fb0134 | 2173 | If the source is empty, @command{@value{AS}} produces a small, empty object |
252b5132 RH |
2174 | file. |
2175 | ||
0285c67d NC |
2176 | @c man end |
2177 | ||
252b5132 RH |
2178 | @subheading Filenames and Line-numbers |
2179 | ||
2180 | @cindex input file linenumbers | |
2181 | @cindex line numbers, in input files | |
2182 | There are two ways of locating a line in the input file (or files) and | |
2183 | either may be used in reporting error messages. One way refers to a line | |
2184 | number in a physical file; the other refers to a line number in a | |
2185 | ``logical'' file. @xref{Errors, ,Error and Warning Messages}. | |
2186 | ||
2187 | @dfn{Physical files} are those files named in the command line given | |
a4fb0134 | 2188 | to @command{@value{AS}}. |
252b5132 RH |
2189 | |
2190 | @dfn{Logical files} are simply names declared explicitly by assembler | |
2191 | directives; they bear no relation to physical files. Logical file names help | |
a4fb0134 SC |
2192 | error messages reflect the original source file, when @command{@value{AS}} source |
2193 | is itself synthesized from other files. @command{@value{AS}} understands the | |
252b5132 RH |
2194 | @samp{#} directives emitted by the @code{@value{GCC}} preprocessor. See also |
2195 | @ref{File,,@code{.file}}. | |
2196 | ||
2197 | @node Object | |
2198 | @section Output (Object) File | |
2199 | ||
2200 | @cindex object file | |
2201 | @cindex output file | |
2202 | @kindex a.out | |
2203 | @kindex .o | |
a4fb0134 | 2204 | Every time you run @command{@value{AS}} it produces an output file, which is |
252b5132 | 2205 | your assembly language program translated into numbers. This file |
a8eb42a8 | 2206 | is the object file. Its default name is @code{a.out}. |
a4fb0134 | 2207 | You can give it another name by using the @option{-o} option. Conventionally, |
252b5132 RH |
2208 | object file names end with @file{.o}. The default name is used for historical |
2209 | reasons: older assemblers were capable of assembling self-contained programs | |
2210 | directly into a runnable program. (For some formats, this isn't currently | |
2211 | possible, but it can be done for the @code{a.out} format.) | |
2212 | ||
2213 | @cindex linker | |
2214 | @kindex ld | |
2215 | The object file is meant for input to the linker @code{@value{LD}}. It contains | |
2216 | assembled program code, information to help @code{@value{LD}} integrate | |
2217 | the assembled program into a runnable file, and (optionally) symbolic | |
2218 | information for the debugger. | |
2219 | ||
2220 | @c link above to some info file(s) like the description of a.out. | |
2221 | @c don't forget to describe @sc{gnu} info as well as Unix lossage. | |
2222 | ||
2223 | @node Errors | |
2224 | @section Error and Warning Messages | |
2225 | ||
0285c67d NC |
2226 | @c man begin DESCRIPTION |
2227 | ||
a349d9dd | 2228 | @cindex error messages |
252b5132 RH |
2229 | @cindex warning messages |
2230 | @cindex messages from assembler | |
a4fb0134 | 2231 | @command{@value{AS}} may write warnings and error messages to the standard error |
252b5132 | 2232 | file (usually your terminal). This should not happen when a compiler |
a4fb0134 SC |
2233 | runs @command{@value{AS}} automatically. Warnings report an assumption made so |
2234 | that @command{@value{AS}} could keep assembling a flawed program; errors report a | |
252b5132 RH |
2235 | grave problem that stops the assembly. |
2236 | ||
0285c67d NC |
2237 | @c man end |
2238 | ||
252b5132 RH |
2239 | @cindex format of warning messages |
2240 | Warning messages have the format | |
2241 | ||
2242 | @smallexample | |
2243 | file_name:@b{NNN}:Warning Message Text | |
2244 | @end smallexample | |
2245 | ||
2246 | @noindent | |
72e0b254 NC |
2247 | @cindex file names and line numbers, in warnings/errors |
2248 | (where @b{NNN} is a line number). If both a logical file name | |
2249 | (@pxref{File,,@code{.file}}) and a logical line number | |
252b5132 RH |
2250 | @ifset GENERIC |
2251 | (@pxref{Line,,@code{.line}}) | |
2252 | @end ifset | |
72e0b254 NC |
2253 | have been given then they will be used, otherwise the file name and line number |
2254 | in the current assembler source file will be used. The message text is | |
2255 | intended to be self explanatory (in the grand Unix tradition). | |
2256 | ||
2257 | Note the file name must be set via the logical version of the @code{.file} | |
2258 | directive, not the DWARF2 version of the @code{.file} directive. For example: | |
2259 | ||
2260 | @smallexample | |
2261 | .file 2 "bar.c" | |
2262 | error_assembler_source | |
2263 | .file "foo.c" | |
2264 | .line 30 | |
2265 | error_c_source | |
2266 | @end smallexample | |
2267 | ||
2268 | produces this output: | |
2269 | ||
2270 | @smallexample | |
2271 | Assembler messages: | |
2272 | asm.s:2: Error: no such instruction: `error_assembler_source' | |
2273 | foo.c:31: Error: no such instruction: `error_c_source' | |
2274 | @end smallexample | |
252b5132 RH |
2275 | |
2276 | @cindex format of error messages | |
2277 | Error messages have the format | |
72e0b254 | 2278 | |
252b5132 RH |
2279 | @smallexample |
2280 | file_name:@b{NNN}:FATAL:Error Message Text | |
2281 | @end smallexample | |
72e0b254 | 2282 | |
252b5132 RH |
2283 | The file name and line number are derived as for warning |
2284 | messages. The actual message text may be rather less explanatory | |
2285 | because many of them aren't supposed to happen. | |
2286 | ||
2287 | @node Invoking | |
2288 | @chapter Command-Line Options | |
2289 | ||
2290 | @cindex options, all versions of assembler | |
2291 | This chapter describes command-line options available in @emph{all} | |
96e9638b BW |
2292 | versions of the @sc{gnu} assembler; see @ref{Machine Dependencies}, |
2293 | for options specific | |
252b5132 | 2294 | @ifclear GENERIC |
c1253627 | 2295 | to the @value{TARGET} target. |
252b5132 RH |
2296 | @end ifclear |
2297 | @ifset GENERIC | |
2298 | to particular machine architectures. | |
2299 | @end ifset | |
2300 | ||
0285c67d NC |
2301 | @c man begin DESCRIPTION |
2302 | ||
c1253627 | 2303 | If you are invoking @command{@value{AS}} via the @sc{gnu} C compiler, |
252b5132 RH |
2304 | you can use the @samp{-Wa} option to pass arguments through to the assembler. |
2305 | The assembler arguments must be separated from each other (and the @samp{-Wa}) | |
2306 | by commas. For example: | |
2307 | ||
2308 | @smallexample | |
2309 | gcc -c -g -O -Wa,-alh,-L file.c | |
2310 | @end smallexample | |
2311 | ||
2312 | @noindent | |
2313 | This passes two options to the assembler: @samp{-alh} (emit a listing to | |
5f5e16be | 2314 | standard output with high-level and assembly source) and @samp{-L} (retain |
252b5132 RH |
2315 | local symbols in the symbol table). |
2316 | ||
2317 | Usually you do not need to use this @samp{-Wa} mechanism, since many compiler | |
2318 | command-line options are automatically passed to the assembler by the compiler. | |
2319 | (You can call the @sc{gnu} compiler driver with the @samp{-v} option to see | |
2320 | precisely what options it passes to each compilation pass, including the | |
2321 | assembler.) | |
2322 | ||
0285c67d NC |
2323 | @c man end |
2324 | ||
252b5132 | 2325 | @menu |
83f10cb2 | 2326 | * a:: -a[cdghlns] enable listings |
caa32fe5 | 2327 | * alternate:: --alternate enable alternate macro syntax |
252b5132 RH |
2328 | * D:: -D for compatibility |
2329 | * f:: -f to work faster | |
2330 | * I:: -I for .include search path | |
2331 | @ifclear DIFF-TBL-KLUGE | |
2332 | * K:: -K for compatibility | |
2333 | @end ifclear | |
2334 | @ifset DIFF-TBL-KLUGE | |
2335 | * K:: -K for difference tables | |
2336 | @end ifset | |
2337 | ||
ba83aca1 | 2338 | * L:: -L to retain local symbols |
c3a27914 | 2339 | * listing:: --listing-XXX to configure listing output |
252b5132 RH |
2340 | * M:: -M or --mri to assemble in MRI compatibility mode |
2341 | * MD:: --MD for dependency tracking | |
2edb36e7 | 2342 | * no-pad-sections:: --no-pad-sections to stop section padding |
252b5132 RH |
2343 | * o:: -o to name the object file |
2344 | * R:: -R to join data and text sections | |
2345 | * statistics:: --statistics to see statistics about assembly | |
2346 | * traditional-format:: --traditional-format for compatible output | |
2347 | * v:: -v to announce version | |
2bdd6cf5 | 2348 | * W:: -W, --no-warn, --warn, --fatal-warnings to control warnings |
252b5132 RH |
2349 | * Z:: -Z to make object file even after errors |
2350 | @end menu | |
2351 | ||
2352 | @node a | |
83f10cb2 | 2353 | @section Enable Listings: @option{-a[cdghlns]} |
252b5132 RH |
2354 | |
2355 | @kindex -a | |
2356 | @kindex -ac | |
2357 | @kindex -ad | |
83f10cb2 | 2358 | @kindex -ag |
252b5132 RH |
2359 | @kindex -ah |
2360 | @kindex -al | |
2361 | @kindex -an | |
2362 | @kindex -as | |
2363 | @cindex listings, enabling | |
2364 | @cindex assembly listings, enabling | |
2365 | ||
2366 | These options enable listing output from the assembler. By itself, | |
2367 | @samp{-a} requests high-level, assembly, and symbols listing. | |
2368 | You can use other letters to select specific options for the list: | |
2369 | @samp{-ah} requests a high-level language listing, | |
2370 | @samp{-al} requests an output-program assembly listing, and | |
2371 | @samp{-as} requests a symbol table listing. | |
2372 | High-level listings require that a compiler debugging option like | |
2373 | @samp{-g} be used, and that assembly listings (@samp{-al}) be requested | |
2374 | also. | |
2375 | ||
83f10cb2 NC |
2376 | Use the @samp{-ag} option to print a first section with general assembly |
2377 | information, like @value{AS} version, switches passed, or time stamp. | |
2378 | ||
252b5132 RH |
2379 | Use the @samp{-ac} option to omit false conditionals from a listing. Any lines |
2380 | which are not assembled because of a false @code{.if} (or @code{.ifdef}, or any | |
2381 | other conditional), or a true @code{.if} followed by an @code{.else}, will be | |
2382 | omitted from the listing. | |
2383 | ||
2384 | Use the @samp{-ad} option to omit debugging directives from the | |
2385 | listing. | |
2386 | ||
2387 | Once you have specified one of these options, you can further control | |
2388 | listing output and its appearance using the directives @code{.list}, | |
2389 | @code{.nolist}, @code{.psize}, @code{.eject}, @code{.title}, and | |
2390 | @code{.sbttl}. | |
2391 | The @samp{-an} option turns off all forms processing. | |
2392 | If you do not request listing output with one of the @samp{-a} options, the | |
2393 | listing-control directives have no effect. | |
2394 | ||
2395 | The letters after @samp{-a} may be combined into one option, | |
2396 | @emph{e.g.}, @samp{-aln}. | |
2397 | ||
96e9638b BW |
2398 | Note if the assembler source is coming from the standard input (e.g., |
2399 | because it | |
a05a5b64 | 2400 | is being created by @code{@value{GCC}} and the @samp{-pipe} command-line switch |
c3a27914 NC |
2401 | is being used) then the listing will not contain any comments or preprocessor |
2402 | directives. This is because the listing code buffers input source lines from | |
2403 | stdin only after they have been preprocessed by the assembler. This reduces | |
2404 | memory usage and makes the code more efficient. | |
2405 | ||
caa32fe5 NC |
2406 | @node alternate |
2407 | @section @option{--alternate} | |
2408 | ||
2409 | @kindex --alternate | |
2410 | Begin in alternate macro mode, see @ref{Altmacro,,@code{.altmacro}}. | |
2411 | ||
252b5132 | 2412 | @node D |
a4fb0134 | 2413 | @section @option{-D} |
252b5132 RH |
2414 | |
2415 | @kindex -D | |
2416 | This option has no effect whatsoever, but it is accepted to make it more | |
2417 | likely that scripts written for other assemblers also work with | |
a4fb0134 | 2418 | @command{@value{AS}}. |
252b5132 RH |
2419 | |
2420 | @node f | |
a4fb0134 | 2421 | @section Work Faster: @option{-f} |
252b5132 RH |
2422 | |
2423 | @kindex -f | |
2424 | @cindex trusted compiler | |
a4fb0134 | 2425 | @cindex faster processing (@option{-f}) |
252b5132 RH |
2426 | @samp{-f} should only be used when assembling programs written by a |
2427 | (trusted) compiler. @samp{-f} stops the assembler from doing whitespace | |
2428 | and comment preprocessing on | |
2429 | the input file(s) before assembling them. @xref{Preprocessing, | |
2430 | ,Preprocessing}. | |
2431 | ||
2432 | @quotation | |
2433 | @emph{Warning:} if you use @samp{-f} when the files actually need to be | |
a4fb0134 | 2434 | preprocessed (if they contain comments, for example), @command{@value{AS}} does |
252b5132 RH |
2435 | not work correctly. |
2436 | @end quotation | |
2437 | ||
2438 | @node I | |
c1253627 | 2439 | @section @code{.include} Search Path: @option{-I} @var{path} |
252b5132 RH |
2440 | |
2441 | @kindex -I @var{path} | |
2442 | @cindex paths for @code{.include} | |
2443 | @cindex search path for @code{.include} | |
2444 | @cindex @code{include} directive search path | |
2445 | Use this option to add a @var{path} to the list of directories | |
a4fb0134 SC |
2446 | @command{@value{AS}} searches for files specified in @code{.include} |
2447 | directives (@pxref{Include,,@code{.include}}). You may use @option{-I} as | |
252b5132 | 2448 | many times as necessary to include a variety of paths. The current |
a4fb0134 | 2449 | working directory is always searched first; after that, @command{@value{AS}} |
252b5132 RH |
2450 | searches any @samp{-I} directories in the same order as they were |
2451 | specified (left to right) on the command line. | |
2452 | ||
2453 | @node K | |
a4fb0134 | 2454 | @section Difference Tables: @option{-K} |
252b5132 RH |
2455 | |
2456 | @kindex -K | |
2457 | @ifclear DIFF-TBL-KLUGE | |
2458 | On the @value{TARGET} family, this option is allowed, but has no effect. It is | |
2459 | permitted for compatibility with the @sc{gnu} assembler on other platforms, | |
2460 | where it can be used to warn when the assembler alters the machine code | |
2461 | generated for @samp{.word} directives in difference tables. The @value{TARGET} | |
2462 | family does not have the addressing limitations that sometimes lead to this | |
2463 | alteration on other platforms. | |
2464 | @end ifclear | |
2465 | ||
2466 | @ifset DIFF-TBL-KLUGE | |
2467 | @cindex difference tables, warning | |
2468 | @cindex warning for altered difference tables | |
96e9638b BW |
2469 | @command{@value{AS}} sometimes alters the code emitted for directives of the |
2470 | form @samp{.word @var{sym1}-@var{sym2}}. @xref{Word,,@code{.word}}. | |
252b5132 RH |
2471 | You can use the @samp{-K} option if you want a warning issued when this |
2472 | is done. | |
2473 | @end ifset | |
2474 | ||
2475 | @node L | |
ba83aca1 | 2476 | @section Include Local Symbols: @option{-L} |
252b5132 RH |
2477 | |
2478 | @kindex -L | |
ba83aca1 BW |
2479 | @cindex local symbols, retaining in output |
2480 | Symbols beginning with system-specific local label prefixes, typically | |
2481 | @samp{.L} for ELF systems or @samp{L} for traditional a.out systems, are | |
2482 | called @dfn{local symbols}. @xref{Symbol Names}. Normally you do not see | |
2483 | such symbols when debugging, because they are intended for the use of | |
2484 | programs (like compilers) that compose assembler programs, not for your | |
2485 | notice. Normally both @command{@value{AS}} and @code{@value{LD}} discard | |
2486 | such symbols, so you do not normally debug with them. | |
2487 | ||
2488 | This option tells @command{@value{AS}} to retain those local symbols | |
252b5132 | 2489 | in the object file. Usually if you do this you also tell the linker |
ba83aca1 | 2490 | @code{@value{LD}} to preserve those symbols. |
252b5132 | 2491 | |
c3a27914 | 2492 | @node listing |
a4fb0134 | 2493 | @section Configuring listing output: @option{--listing} |
c3a27914 | 2494 | |
a05a5b64 | 2495 | The listing feature of the assembler can be enabled via the command-line switch |
c3a27914 NC |
2496 | @samp{-a} (@pxref{a}). This feature combines the input source file(s) with a |
2497 | hex dump of the corresponding locations in the output object file, and displays | |
96e9638b BW |
2498 | them as a listing file. The format of this listing can be controlled by |
2499 | directives inside the assembler source (i.e., @code{.list} (@pxref{List}), | |
2500 | @code{.title} (@pxref{Title}), @code{.sbttl} (@pxref{Sbttl}), | |
2501 | @code{.psize} (@pxref{Psize}), and | |
2502 | @code{.eject} (@pxref{Eject}) and also by the following switches: | |
c3a27914 | 2503 | |
a4fb0134 | 2504 | @table @gcctabopt |
c3a27914 NC |
2505 | @item --listing-lhs-width=@samp{number} |
2506 | @kindex --listing-lhs-width | |
2507 | @cindex Width of first line disassembly output | |
2508 | Sets the maximum width, in words, of the first line of the hex byte dump. This | |
2509 | dump appears on the left hand side of the listing output. | |
2510 | ||
2511 | @item --listing-lhs-width2=@samp{number} | |
2512 | @kindex --listing-lhs-width2 | |
2513 | @cindex Width of continuation lines of disassembly output | |
2514 | Sets the maximum width, in words, of any further lines of the hex byte dump for | |
8dfa0188 | 2515 | a given input source line. If this value is not specified, it defaults to being |
c3a27914 NC |
2516 | the same as the value specified for @samp{--listing-lhs-width}. If neither |
2517 | switch is used the default is to one. | |
2518 | ||
2519 | @item --listing-rhs-width=@samp{number} | |
2520 | @kindex --listing-rhs-width | |
2521 | @cindex Width of source line output | |
2522 | Sets the maximum width, in characters, of the source line that is displayed | |
2523 | alongside the hex dump. The default value for this parameter is 100. The | |
2524 | source line is displayed on the right hand side of the listing output. | |
2525 | ||
2526 | @item --listing-cont-lines=@samp{number} | |
2527 | @kindex --listing-cont-lines | |
2528 | @cindex Maximum number of continuation lines | |
2529 | Sets the maximum number of continuation lines of hex dump that will be | |
2530 | displayed for a given single line of source input. The default value is 4. | |
2531 | @end table | |
2532 | ||
252b5132 | 2533 | @node M |
a4fb0134 | 2534 | @section Assemble in MRI Compatibility Mode: @option{-M} |
252b5132 RH |
2535 | |
2536 | @kindex -M | |
2537 | @cindex MRI compatibility mode | |
a4fb0134 SC |
2538 | The @option{-M} or @option{--mri} option selects MRI compatibility mode. This |
2539 | changes the syntax and pseudo-op handling of @command{@value{AS}} to make it | |
a8eb42a8 AM |
2540 | compatible with the @code{ASM68K} assembler from Microtec Research. |
2541 | The exact nature of the | |
252b5132 RH |
2542 | MRI syntax will not be documented here; see the MRI manuals for more |
2543 | information. Note in particular that the handling of macros and macro | |
2544 | arguments is somewhat different. The purpose of this option is to permit | |
a4fb0134 | 2545 | assembling existing MRI assembler code using @command{@value{AS}}. |
252b5132 RH |
2546 | |
2547 | The MRI compatibility is not complete. Certain operations of the MRI assembler | |
2548 | depend upon its object file format, and can not be supported using other object | |
2549 | file formats. Supporting these would require enhancing each object file format | |
2550 | individually. These are: | |
2551 | ||
2552 | @itemize @bullet | |
2553 | @item global symbols in common section | |
2554 | ||
2555 | The m68k MRI assembler supports common sections which are merged by the linker. | |
a4fb0134 | 2556 | Other object file formats do not support this. @command{@value{AS}} handles |
252b5132 RH |
2557 | common sections by treating them as a single common symbol. It permits local |
2558 | symbols to be defined within a common section, but it can not support global | |
2559 | symbols, since it has no way to describe them. | |
2560 | ||
2561 | @item complex relocations | |
2562 | ||
2563 | The MRI assemblers support relocations against a negated section address, and | |
2564 | relocations which combine the start addresses of two or more sections. These | |
2565 | are not support by other object file formats. | |
2566 | ||
2567 | @item @code{END} pseudo-op specifying start address | |
2568 | ||
2569 | The MRI @code{END} pseudo-op permits the specification of a start address. | |
2570 | This is not supported by other object file formats. The start address may | |
a4fb0134 | 2571 | instead be specified using the @option{-e} option to the linker, or in a linker |
252b5132 RH |
2572 | script. |
2573 | ||
2574 | @item @code{IDNT}, @code{.ident} and @code{NAME} pseudo-ops | |
2575 | ||
2576 | The MRI @code{IDNT}, @code{.ident} and @code{NAME} pseudo-ops assign a module | |
2577 | name to the output file. This is not supported by other object file formats. | |
2578 | ||
2579 | @item @code{ORG} pseudo-op | |
2580 | ||
2581 | The m68k MRI @code{ORG} pseudo-op begins an absolute section at a given | |
a4fb0134 | 2582 | address. This differs from the usual @command{@value{AS}} @code{.org} pseudo-op, |
252b5132 RH |
2583 | which changes the location within the current section. Absolute sections are |
2584 | not supported by other object file formats. The address of a section may be | |
2585 | assigned within a linker script. | |
2586 | @end itemize | |
2587 | ||
2588 | There are some other features of the MRI assembler which are not supported by | |
a4fb0134 | 2589 | @command{@value{AS}}, typically either because they are difficult or because they |
252b5132 RH |
2590 | seem of little consequence. Some of these may be supported in future releases. |
2591 | ||
2592 | @itemize @bullet | |
2593 | ||
2594 | @item EBCDIC strings | |
2595 | ||
2596 | EBCDIC strings are not supported. | |
2597 | ||
2598 | @item packed binary coded decimal | |
2599 | ||
2600 | Packed binary coded decimal is not supported. This means that the @code{DC.P} | |
2601 | and @code{DCB.P} pseudo-ops are not supported. | |
2602 | ||
2603 | @item @code{FEQU} pseudo-op | |
2604 | ||
2605 | The m68k @code{FEQU} pseudo-op is not supported. | |
2606 | ||
2607 | @item @code{NOOBJ} pseudo-op | |
2608 | ||
2609 | The m68k @code{NOOBJ} pseudo-op is not supported. | |
2610 | ||
2611 | @item @code{OPT} branch control options | |
2612 | ||
2613 | The m68k @code{OPT} branch control options---@code{B}, @code{BRS}, @code{BRB}, | |
a4fb0134 | 2614 | @code{BRL}, and @code{BRW}---are ignored. @command{@value{AS}} automatically |
252b5132 RH |
2615 | relaxes all branches, whether forward or backward, to an appropriate size, so |
2616 | these options serve no purpose. | |
2617 | ||
2618 | @item @code{OPT} list control options | |
2619 | ||
2620 | The following m68k @code{OPT} list control options are ignored: @code{C}, | |
2621 | @code{CEX}, @code{CL}, @code{CRE}, @code{E}, @code{G}, @code{I}, @code{M}, | |
2622 | @code{MEX}, @code{MC}, @code{MD}, @code{X}. | |
2623 | ||
2624 | @item other @code{OPT} options | |
2625 | ||
2626 | The following m68k @code{OPT} options are ignored: @code{NEST}, @code{O}, | |
2627 | @code{OLD}, @code{OP}, @code{P}, @code{PCO}, @code{PCR}, @code{PCS}, @code{R}. | |
2628 | ||
2629 | @item @code{OPT} @code{D} option is default | |
2630 | ||
2631 | The m68k @code{OPT} @code{D} option is the default, unlike the MRI assembler. | |
2632 | @code{OPT NOD} may be used to turn it off. | |
2633 | ||
2634 | @item @code{XREF} pseudo-op. | |
2635 | ||
2636 | The m68k @code{XREF} pseudo-op is ignored. | |
2637 | ||
252b5132 RH |
2638 | @end itemize |
2639 | ||
2640 | @node MD | |
c1253627 | 2641 | @section Dependency Tracking: @option{--MD} |
252b5132 RH |
2642 | |
2643 | @kindex --MD | |
2644 | @cindex dependency tracking | |
2645 | @cindex make rules | |
2646 | ||
a4fb0134 | 2647 | @command{@value{AS}} can generate a dependency file for the file it creates. This |
252b5132 RH |
2648 | file consists of a single rule suitable for @code{make} describing the |
2649 | dependencies of the main source file. | |
2650 | ||
2651 | The rule is written to the file named in its argument. | |
2652 | ||
2653 | This feature is used in the automatic updating of makefiles. | |
2654 | ||
2edb36e7 NC |
2655 | @node no-pad-sections |
2656 | @section Output Section Padding | |
2657 | @kindex --no-pad-sections | |
2658 | @cindex output section padding | |
2659 | Normally the assembler will pad the end of each output section up to its | |
2660 | alignment boundary. But this can waste space, which can be significant on | |
2661 | memory constrained targets. So the @option{--no-pad-sections} option will | |
2662 | disable this behaviour. | |
2663 | ||
252b5132 | 2664 | @node o |
a4fb0134 | 2665 | @section Name the Object File: @option{-o} |
252b5132 RH |
2666 | |
2667 | @kindex -o | |
2668 | @cindex naming object file | |
2669 | @cindex object file name | |
a4fb0134 | 2670 | There is always one object file output when you run @command{@value{AS}}. By |
a8eb42a8 | 2671 | default it has the name @file{a.out}. |
252b5132 RH |
2672 | You use this option (which takes exactly one filename) to give the |
2673 | object file a different name. | |
2674 | ||
a4fb0134 | 2675 | Whatever the object file is called, @command{@value{AS}} overwrites any |
252b5132 RH |
2676 | existing file of the same name. |
2677 | ||
2678 | @node R | |
a4fb0134 | 2679 | @section Join Data and Text Sections: @option{-R} |
252b5132 RH |
2680 | |
2681 | @kindex -R | |
2682 | @cindex data and text sections, joining | |
2683 | @cindex text and data sections, joining | |
2684 | @cindex joining text and data sections | |
2685 | @cindex merging text and data sections | |
a4fb0134 | 2686 | @option{-R} tells @command{@value{AS}} to write the object file as if all |
252b5132 RH |
2687 | data-section data lives in the text section. This is only done at |
2688 | the very last moment: your binary data are the same, but data | |
2689 | section parts are relocated differently. The data section part of | |
2690 | your object file is zero bytes long because all its bytes are | |
2691 | appended to the text section. (@xref{Sections,,Sections and Relocation}.) | |
2692 | ||
a4fb0134 | 2693 | When you specify @option{-R} it would be possible to generate shorter |
252b5132 RH |
2694 | address displacements (because we do not have to cross between text and |
2695 | data section). We refrain from doing this simply for compatibility with | |
a4fb0134 | 2696 | older versions of @command{@value{AS}}. In future, @option{-R} may work this way. |
252b5132 | 2697 | |
c1253627 NC |
2698 | @ifset COFF-ELF |
2699 | When @command{@value{AS}} is configured for COFF or ELF output, | |
252b5132 RH |
2700 | this option is only useful if you use sections named @samp{.text} and |
2701 | @samp{.data}. | |
2702 | @end ifset | |
2703 | ||
2704 | @ifset HPPA | |
a4fb0134 SC |
2705 | @option{-R} is not supported for any of the HPPA targets. Using |
2706 | @option{-R} generates a warning from @command{@value{AS}}. | |
252b5132 RH |
2707 | @end ifset |
2708 | ||
2709 | @node statistics | |
a4fb0134 | 2710 | @section Display Assembly Statistics: @option{--statistics} |
252b5132 RH |
2711 | |
2712 | @kindex --statistics | |
2713 | @cindex statistics, about assembly | |
2714 | @cindex time, total for assembly | |
2715 | @cindex space used, maximum for assembly | |
2716 | Use @samp{--statistics} to display two statistics about the resources used by | |
a4fb0134 | 2717 | @command{@value{AS}}: the maximum amount of space allocated during the assembly |
252b5132 RH |
2718 | (in bytes), and the total execution time taken for the assembly (in @sc{cpu} |
2719 | seconds). | |
2720 | ||
2721 | @node traditional-format | |
c1253627 | 2722 | @section Compatible Output: @option{--traditional-format} |
252b5132 RH |
2723 | |
2724 | @kindex --traditional-format | |
a4fb0134 | 2725 | For some targets, the output of @command{@value{AS}} is different in some ways |
252b5132 | 2726 | from the output of some existing assembler. This switch requests |
a4fb0134 | 2727 | @command{@value{AS}} to use the traditional format instead. |
252b5132 RH |
2728 | |
2729 | For example, it disables the exception frame optimizations which | |
a4fb0134 | 2730 | @command{@value{AS}} normally does by default on @code{@value{GCC}} output. |
252b5132 RH |
2731 | |
2732 | @node v | |
a4fb0134 | 2733 | @section Announce Version: @option{-v} |
252b5132 RH |
2734 | |
2735 | @kindex -v | |
2736 | @kindex -version | |
2737 | @cindex assembler version | |
2738 | @cindex version of assembler | |
2739 | You can find out what version of as is running by including the | |
2740 | option @samp{-v} (which you can also spell as @samp{-version}) on the | |
2741 | command line. | |
2742 | ||
2743 | @node W | |
a4fb0134 | 2744 | @section Control Warnings: @option{-W}, @option{--warn}, @option{--no-warn}, @option{--fatal-warnings} |
252b5132 | 2745 | |
a4fb0134 | 2746 | @command{@value{AS}} should never give a warning or error message when |
252b5132 | 2747 | assembling compiler output. But programs written by people often |
a4fb0134 | 2748 | cause @command{@value{AS}} to give a warning that a particular assumption was |
252b5132 | 2749 | made. All such warnings are directed to the standard error file. |
2bdd6cf5 | 2750 | |
c1253627 NC |
2751 | @kindex -W |
2752 | @kindex --no-warn | |
2bdd6cf5 GK |
2753 | @cindex suppressing warnings |
2754 | @cindex warnings, suppressing | |
a4fb0134 | 2755 | If you use the @option{-W} and @option{--no-warn} options, no warnings are issued. |
2bdd6cf5 | 2756 | This only affects the warning messages: it does not change any particular of |
a4fb0134 | 2757 | how @command{@value{AS}} assembles your file. Errors, which stop the assembly, |
2bdd6cf5 GK |
2758 | are still reported. |
2759 | ||
c1253627 | 2760 | @kindex --fatal-warnings |
2bdd6cf5 GK |
2761 | @cindex errors, caused by warnings |
2762 | @cindex warnings, causing error | |
a4fb0134 | 2763 | If you use the @option{--fatal-warnings} option, @command{@value{AS}} considers |
2bdd6cf5 GK |
2764 | files that generate warnings to be in error. |
2765 | ||
c1253627 | 2766 | @kindex --warn |
2bdd6cf5 | 2767 | @cindex warnings, switching on |
a4fb0134 | 2768 | You can switch these options off again by specifying @option{--warn}, which |
2bdd6cf5 | 2769 | causes warnings to be output as usual. |
252b5132 RH |
2770 | |
2771 | @node Z | |
a4fb0134 | 2772 | @section Generate Object File in Spite of Errors: @option{-Z} |
252b5132 RH |
2773 | @cindex object file, after errors |
2774 | @cindex errors, continuing after | |
a4fb0134 | 2775 | After an error message, @command{@value{AS}} normally produces no output. If for |
252b5132 | 2776 | some reason you are interested in object file output even after |
a4fb0134 SC |
2777 | @command{@value{AS}} gives an error message on your program, use the @samp{-Z} |
2778 | option. If there are any errors, @command{@value{AS}} continues anyways, and | |
252b5132 RH |
2779 | writes an object file after a final warning message of the form @samp{@var{n} |
2780 | errors, @var{m} warnings, generating bad object file.} | |
2781 | ||
2782 | @node Syntax | |
2783 | @chapter Syntax | |
2784 | ||
2785 | @cindex machine-independent syntax | |
2786 | @cindex syntax, machine-independent | |
2787 | This chapter describes the machine-independent syntax allowed in a | |
a4fb0134 | 2788 | source file. @command{@value{AS}} syntax is similar to what many other |
252b5132 RH |
2789 | assemblers use; it is inspired by the BSD 4.2 |
2790 | @ifclear VAX | |
2791 | assembler. | |
2792 | @end ifclear | |
2793 | @ifset VAX | |
a4fb0134 | 2794 | assembler, except that @command{@value{AS}} does not assemble Vax bit-fields. |
252b5132 RH |
2795 | @end ifset |
2796 | ||
2797 | @menu | |
7c31ae13 | 2798 | * Preprocessing:: Preprocessing |
252b5132 RH |
2799 | * Whitespace:: Whitespace |
2800 | * Comments:: Comments | |
2801 | * Symbol Intro:: Symbols | |
2802 | * Statements:: Statements | |
2803 | * Constants:: Constants | |
2804 | @end menu | |
2805 | ||
2806 | @node Preprocessing | |
2807 | @section Preprocessing | |
2808 | ||
2809 | @cindex preprocessing | |
a4fb0134 | 2810 | The @command{@value{AS}} internal preprocessor: |
252b5132 RH |
2811 | @itemize @bullet |
2812 | @cindex whitespace, removed by preprocessor | |
2813 | @item | |
2814 | adjusts and removes extra whitespace. It leaves one space or tab before | |
2815 | the keywords on a line, and turns any other whitespace on the line into | |
2816 | a single space. | |
2817 | ||
2818 | @cindex comments, removed by preprocessor | |
2819 | @item | |
2820 | removes all comments, replacing them with a single space, or an | |
2821 | appropriate number of newlines. | |
2822 | ||
2823 | @cindex constants, converted by preprocessor | |
2824 | @item | |
2825 | converts character constants into the appropriate numeric values. | |
2826 | @end itemize | |
2827 | ||
2828 | It does not do macro processing, include file handling, or | |
2829 | anything else you may get from your C compiler's preprocessor. You can | |
2830 | do include file processing with the @code{.include} directive | |
2831 | (@pxref{Include,,@code{.include}}). You can use the @sc{gnu} C compiler driver | |
c1253627 | 2832 | to get other ``CPP'' style preprocessing by giving the input file a |
96e9638b | 2833 | @samp{.S} suffix. @xref{Overall Options, ,Options Controlling the Kind of |
2edb36e7 | 2834 | Output, gcc info, Using GNU CC}. |
252b5132 RH |
2835 | |
2836 | Excess whitespace, comments, and character constants | |
2837 | cannot be used in the portions of the input text that are not | |
2838 | preprocessed. | |
2839 | ||
2840 | @cindex turning preprocessing on and off | |
2841 | @cindex preprocessing, turning on and off | |
2842 | @kindex #NO_APP | |
2843 | @kindex #APP | |
2844 | If the first line of an input file is @code{#NO_APP} or if you use the | |
2845 | @samp{-f} option, whitespace and comments are not removed from the input file. | |
2846 | Within an input file, you can ask for whitespace and comment removal in | |
2847 | specific portions of the by putting a line that says @code{#APP} before the | |
2848 | text that may contain whitespace or comments, and putting a line that says | |
2849 | @code{#NO_APP} after this text. This feature is mainly intend to support | |
2850 | @code{asm} statements in compilers whose output is otherwise free of comments | |
2851 | and whitespace. | |
2852 | ||
2853 | @node Whitespace | |
2854 | @section Whitespace | |
2855 | ||
2856 | @cindex whitespace | |
2857 | @dfn{Whitespace} is one or more blanks or tabs, in any order. | |
2858 | Whitespace is used to separate symbols, and to make programs neater for | |
2859 | people to read. Unless within character constants | |
2860 | (@pxref{Characters,,Character Constants}), any whitespace means the same | |
2861 | as exactly one space. | |
2862 | ||
2863 | @node Comments | |
2864 | @section Comments | |
2865 | ||
2866 | @cindex comments | |
a4fb0134 | 2867 | There are two ways of rendering comments to @command{@value{AS}}. In both |
252b5132 RH |
2868 | cases the comment is equivalent to one space. |
2869 | ||
2870 | Anything from @samp{/*} through the next @samp{*/} is a comment. | |
2871 | This means you may not nest these comments. | |
2872 | ||
2873 | @smallexample | |
2874 | /* | |
2875 | The only way to include a newline ('\n') in a comment | |
2876 | is to use this sort of comment. | |
2877 | */ | |
2878 | ||
2879 | /* This sort of comment does not nest. */ | |
2880 | @end smallexample | |
2881 | ||
2882 | @cindex line comment character | |
7c31ae13 NC |
2883 | Anything from a @dfn{line comment} character up to the next newline is |
2884 | considered a comment and is ignored. The line comment character is target | |
2885 | specific, and some targets multiple comment characters. Some targets also have | |
2886 | line comment characters that only work if they are the first character on a | |
2887 | line. Some targets use a sequence of two characters to introduce a line | |
2888 | comment. Some targets can also change their line comment characters depending | |
a05a5b64 | 2889 | upon command-line options that have been used. For more details see the |
7c31ae13 NC |
2890 | @emph{Syntax} section in the documentation for individual targets. |
2891 | ||
2892 | If the line comment character is the hash sign (@samp{#}) then it still has the | |
2893 | special ability to enable and disable preprocessing (@pxref{Preprocessing}) and | |
2894 | to specify logical line numbers: | |
252b5132 RH |
2895 | |
2896 | @kindex # | |
2897 | @cindex lines starting with @code{#} | |
2898 | @cindex logical line numbers | |
2899 | To be compatible with past assemblers, lines that begin with @samp{#} have a | |
2900 | special interpretation. Following the @samp{#} should be an absolute | |
2901 | expression (@pxref{Expressions}): the logical line number of the @emph{next} | |
96e9638b | 2902 | line. Then a string (@pxref{Strings, ,Strings}) is allowed: if present it is a |
252b5132 RH |
2903 | new logical file name. The rest of the line, if any, should be whitespace. |
2904 | ||
2905 | If the first non-whitespace characters on the line are not numeric, | |
2906 | the line is ignored. (Just like a comment.) | |
2907 | ||
2908 | @smallexample | |
2909 | # This is an ordinary comment. | |
2910 | # 42-6 "new_file_name" # New logical file name | |
2911 | # This is logical line # 36. | |
2912 | @end smallexample | |
2913 | This feature is deprecated, and may disappear from future versions | |
a4fb0134 | 2914 | of @command{@value{AS}}. |
252b5132 RH |
2915 | |
2916 | @node Symbol Intro | |
2917 | @section Symbols | |
2918 | ||
2919 | @cindex characters used in symbols | |
2920 | @ifclear SPECIAL-SYMS | |
2921 | A @dfn{symbol} is one or more characters chosen from the set of all | |
2922 | letters (both upper and lower case), digits and the three characters | |
2923 | @samp{_.$}. | |
2924 | @end ifclear | |
2925 | @ifset SPECIAL-SYMS | |
2926 | @ifclear GENERIC | |
2927 | @ifset H8 | |
2928 | A @dfn{symbol} is one or more characters chosen from the set of all | |
2929 | letters (both upper and lower case), digits and the three characters | |
2930 | @samp{._$}. (Save that, on the H8/300 only, you may not use @samp{$} in | |
2931 | symbol names.) | |
2932 | @end ifset | |
2933 | @end ifclear | |
2934 | @end ifset | |
2935 | @ifset GENERIC | |
2936 | On most machines, you can also use @code{$} in symbol names; exceptions | |
2937 | are noted in @ref{Machine Dependencies}. | |
2938 | @end ifset | |
2939 | No symbol may begin with a digit. Case is significant. | |
d02603dc | 2940 | There is no length limit; all characters are significant. Multibyte characters |
7bfd842d NC |
2941 | are supported. Symbols are delimited by characters not in that set, or by the |
2942 | beginning of a file (since the source program must end with a newline, the end | |
2943 | of a file is not a possible symbol delimiter). @xref{Symbols}. | |
d02603dc NC |
2944 | |
2945 | Symbol names may also be enclosed in double quote @code{"} characters. In such | |
2946 | cases any characters are allowed, except for the NUL character. If a double | |
2947 | quote character is to be included in the symbol name it must be preceeded by a | |
2948 | backslash @code{\} character. | |
252b5132 RH |
2949 | @cindex length of symbols |
2950 | ||
2951 | @node Statements | |
2952 | @section Statements | |
2953 | ||
2954 | @cindex statements, structure of | |
2955 | @cindex line separator character | |
2956 | @cindex statement separator character | |
7c31ae13 NC |
2957 | |
2958 | A @dfn{statement} ends at a newline character (@samp{\n}) or a | |
2959 | @dfn{line separator character}. The line separator character is target | |
2960 | specific and described in the @emph{Syntax} section of each | |
2961 | target's documentation. Not all targets support a line separator character. | |
2962 | The newline or line separator character is considered to be part of the | |
2963 | preceding statement. Newlines and separators within character constants are an | |
252b5132 | 2964 | exception: they do not end statements. |
252b5132 RH |
2965 | |
2966 | @cindex newline, required at file end | |
2967 | @cindex EOF, newline must precede | |
2968 | It is an error to end any statement with end-of-file: the last | |
2969 | character of any input file should be a newline.@refill | |
2970 | ||
2971 | An empty statement is allowed, and may include whitespace. It is ignored. | |
2972 | ||
2973 | @cindex instructions and directives | |
2974 | @cindex directives and instructions | |
2975 | @c "key symbol" is not used elsewhere in the document; seems pedantic to | |
2976 | @c @defn{} it in that case, as was done previously... doc@cygnus.com, | |
2977 | @c 13feb91. | |
2978 | A statement begins with zero or more labels, optionally followed by a | |
2979 | key symbol which determines what kind of statement it is. The key | |
2980 | symbol determines the syntax of the rest of the statement. If the | |
2981 | symbol begins with a dot @samp{.} then the statement is an assembler | |
2982 | directive: typically valid for any computer. If the symbol begins with | |
2983 | a letter the statement is an assembly language @dfn{instruction}: it | |
2984 | assembles into a machine language instruction. | |
2985 | @ifset GENERIC | |
a4fb0134 | 2986 | Different versions of @command{@value{AS}} for different computers |
252b5132 RH |
2987 | recognize different instructions. In fact, the same symbol may |
2988 | represent a different instruction in a different computer's assembly | |
2989 | language.@refill | |
2990 | @end ifset | |
2991 | ||
2992 | @cindex @code{:} (label) | |
2993 | @cindex label (@code{:}) | |
2994 | A label is a symbol immediately followed by a colon (@code{:}). | |
2995 | Whitespace before a label or after a colon is permitted, but you may not | |
2996 | have whitespace between a label's symbol and its colon. @xref{Labels}. | |
2997 | ||
2998 | @ifset HPPA | |
01642c12 | 2999 | For HPPA targets, labels need not be immediately followed by a colon, but |
252b5132 RH |
3000 | the definition of a label must begin in column zero. This also implies that |
3001 | only one label may be defined on each line. | |
3002 | @end ifset | |
3003 | ||
3004 | @smallexample | |
3005 | label: .directive followed by something | |
3006 | another_label: # This is an empty statement. | |
3007 | instruction operand_1, operand_2, @dots{} | |
3008 | @end smallexample | |
3009 | ||
3010 | @node Constants | |
3011 | @section Constants | |
3012 | ||
3013 | @cindex constants | |
3014 | A constant is a number, written so that its value is known by | |
3015 | inspection, without knowing any context. Like this: | |
3016 | @smallexample | |
3017 | @group | |
3018 | .byte 74, 0112, 092, 0x4A, 0X4a, 'J, '\J # All the same value. | |
3019 | .ascii "Ring the bell\7" # A string constant. | |
3020 | .octa 0x123456789abcdef0123456789ABCDEF0 # A bignum. | |
3021 | .float 0f-314159265358979323846264338327\ | |
3022 | 95028841971.693993751E-40 # - pi, a flonum. | |
3023 | @end group | |
3024 | @end smallexample | |
3025 | ||
3026 | @menu | |
3027 | * Characters:: Character Constants | |
3028 | * Numbers:: Number Constants | |
3029 | @end menu | |
3030 | ||
3031 | @node Characters | |
3032 | @subsection Character Constants | |
3033 | ||
3034 | @cindex character constants | |
3035 | @cindex constants, character | |
3036 | There are two kinds of character constants. A @dfn{character} stands | |
3037 | for one character in one byte and its value may be used in | |
3038 | numeric expressions. String constants (properly called string | |
3039 | @emph{literals}) are potentially many bytes and their values may not be | |
3040 | used in arithmetic expressions. | |
3041 | ||
3042 | @menu | |
3043 | * Strings:: Strings | |
3044 | * Chars:: Characters | |
3045 | @end menu | |
3046 | ||
3047 | @node Strings | |
3048 | @subsubsection Strings | |
3049 | ||
3050 | @cindex string constants | |
3051 | @cindex constants, string | |
3052 | A @dfn{string} is written between double-quotes. It may contain | |
3053 | double-quotes or null characters. The way to get special characters | |
3054 | into a string is to @dfn{escape} these characters: precede them with | |
3055 | a backslash @samp{\} character. For example @samp{\\} represents | |
3056 | one backslash: the first @code{\} is an escape which tells | |
a4fb0134 SC |
3057 | @command{@value{AS}} to interpret the second character literally as a backslash |
3058 | (which prevents @command{@value{AS}} from recognizing the second @code{\} as an | |
252b5132 RH |
3059 | escape character). The complete list of escapes follows. |
3060 | ||
3061 | @cindex escape codes, character | |
3062 | @cindex character escape codes | |
361fa3a4 NC |
3063 | @c NOTE: Cindex entries must not start with a backlash character. |
3064 | @c NOTE: This confuses the pdf2texi script when it is creating the | |
3065 | @c NOTE: index based upon the first character and so it generates: | |
3066 | @c NOTE: \initial {\\} | |
3067 | @c NOTE: which then results in the error message: | |
3068 | @c NOTE: Argument of \\ has an extra }. | |
3069 | @c NOTE: So in the index entries below a space character has been | |
3070 | @c NOTE: prepended to avoid this problem. | |
252b5132 RH |
3071 | @table @kbd |
3072 | @c @item \a | |
3073 | @c Mnemonic for ACKnowledge; for ASCII this is octal code 007. | |
3074 | @c | |
361fa3a4 | 3075 | @cindex @code{ \b} (backspace character) |
252b5132 RH |
3076 | @cindex backspace (@code{\b}) |
3077 | @item \b | |
3078 | Mnemonic for backspace; for ASCII this is octal code 010. | |
3079 | ||
3080 | @c @item \e | |
3081 | @c Mnemonic for EOText; for ASCII this is octal code 004. | |
3082 | @c | |
361fa3a4 | 3083 | @cindex @code{ \f} (formfeed character) |
252b5132 | 3084 | @cindex formfeed (@code{\f}) |
361fa3a4 | 3085 | @item backslash-f |
252b5132 RH |
3086 | Mnemonic for FormFeed; for ASCII this is octal code 014. |
3087 | ||
361fa3a4 | 3088 | @cindex @code{ \n} (newline character) |
252b5132 RH |
3089 | @cindex newline (@code{\n}) |
3090 | @item \n | |
3091 | Mnemonic for newline; for ASCII this is octal code 012. | |
3092 | ||
3093 | @c @item \p | |
3094 | @c Mnemonic for prefix; for ASCII this is octal code 033, usually known as @code{escape}. | |
3095 | @c | |
361fa3a4 NC |
3096 | @cindex @code{ \r} (carriage return character) |
3097 | @cindex carriage return (@code{backslash-r}) | |
252b5132 RH |
3098 | @item \r |
3099 | Mnemonic for carriage-Return; for ASCII this is octal code 015. | |
3100 | ||
3101 | @c @item \s | |
3102 | @c Mnemonic for space; for ASCII this is octal code 040. Included for compliance with | |
3103 | @c other assemblers. | |
3104 | @c | |
361fa3a4 | 3105 | @cindex @code{ \t} (tab) |
252b5132 RH |
3106 | @cindex tab (@code{\t}) |
3107 | @item \t | |
3108 | Mnemonic for horizontal Tab; for ASCII this is octal code 011. | |
3109 | ||
3110 | @c @item \v | |
3111 | @c Mnemonic for Vertical tab; for ASCII this is octal code 013. | |
3112 | @c @item \x @var{digit} @var{digit} @var{digit} | |
3113 | @c A hexadecimal character code. The numeric code is 3 hexadecimal digits. | |
3114 | @c | |
361fa3a4 | 3115 | @cindex @code{ \@var{ddd}} (octal character code) |
252b5132 RH |
3116 | @cindex octal character code (@code{\@var{ddd}}) |
3117 | @item \ @var{digit} @var{digit} @var{digit} | |
3118 | An octal character code. The numeric code is 3 octal digits. | |
3119 | For compatibility with other Unix systems, 8 and 9 are accepted as digits: | |
3120 | for example, @code{\008} has the value 010, and @code{\009} the value 011. | |
3121 | ||
361fa3a4 | 3122 | @cindex @code{ \@var{xd...}} (hex character code) |
252b5132 RH |
3123 | @cindex hex character code (@code{\@var{xd...}}) |
3124 | @item \@code{x} @var{hex-digits...} | |
3125 | A hex character code. All trailing hex digits are combined. Either upper or | |
3126 | lower case @code{x} works. | |
3127 | ||
361fa3a4 | 3128 | @cindex @code{ \\} (@samp{\} character) |
252b5132 RH |
3129 | @cindex backslash (@code{\\}) |
3130 | @item \\ | |
3131 | Represents one @samp{\} character. | |
3132 | ||
3133 | @c @item \' | |
3134 | @c Represents one @samp{'} (accent acute) character. | |
3135 | @c This is needed in single character literals | |
3136 | @c (@xref{Characters,,Character Constants}.) to represent | |
3137 | @c a @samp{'}. | |
3138 | @c | |
361fa3a4 | 3139 | @cindex @code{ \"} (doublequote character) |
252b5132 RH |
3140 | @cindex doublequote (@code{\"}) |
3141 | @item \" | |
3142 | Represents one @samp{"} character. Needed in strings to represent | |
3143 | this character, because an unescaped @samp{"} would end the string. | |
3144 | ||
3145 | @item \ @var{anything-else} | |
3146 | Any other character when escaped by @kbd{\} gives a warning, but | |
3147 | assembles as if the @samp{\} was not present. The idea is that if | |
3148 | you used an escape sequence you clearly didn't want the literal | |
a4fb0134 SC |
3149 | interpretation of the following character. However @command{@value{AS}} has no |
3150 | other interpretation, so @command{@value{AS}} knows it is giving you the wrong | |
252b5132 RH |
3151 | code and warns you of the fact. |
3152 | @end table | |
3153 | ||
3154 | Which characters are escapable, and what those escapes represent, | |
3155 | varies widely among assemblers. The current set is what we think | |
3156 | the BSD 4.2 assembler recognizes, and is a subset of what most C | |
3157 | compilers recognize. If you are in doubt, do not use an escape | |
3158 | sequence. | |
3159 | ||
3160 | @node Chars | |
3161 | @subsubsection Characters | |
3162 | ||
3163 | @cindex single character constant | |
3164 | @cindex character, single | |
3165 | @cindex constant, single character | |
9962fe29 AM |
3166 | A single character may be written as a single quote immediately followed by |
3167 | that character. Some backslash escapes apply to characters, @code{\b}, | |
3168 | @code{\f}, @code{\n}, @code{\r}, @code{\t}, and @code{\"} with the same meaning | |
3169 | as for strings, plus @code{\'} for a single quote. So if you want to write the | |
3170 | character backslash, you must write @kbd{'\\} where the first @code{\} escapes | |
3171 | the second @code{\}. As you can see, the quote is an acute accent, not a grave | |
3172 | accent. A newline | |
252b5132 RH |
3173 | @ifclear GENERIC |
3174 | @ifclear abnormal-separator | |
3175 | (or semicolon @samp{;}) | |
3176 | @end ifclear | |
3177 | @ifset abnormal-separator | |
252b5132 RH |
3178 | @ifset H8 |
3179 | (or dollar sign @samp{$}, for the H8/300; or semicolon @samp{;} for the | |
7be1c489 | 3180 | Renesas SH) |
252b5132 RH |
3181 | @end ifset |
3182 | @end ifset | |
3183 | @end ifclear | |
3184 | immediately following an acute accent is taken as a literal character | |
3185 | and does not count as the end of a statement. The value of a character | |
3186 | constant in a numeric expression is the machine's byte-wide code for | |
a4fb0134 | 3187 | that character. @command{@value{AS}} assumes your character code is ASCII: |
252b5132 RH |
3188 | @kbd{'A} means 65, @kbd{'B} means 66, and so on. @refill |
3189 | ||
3190 | @node Numbers | |
3191 | @subsection Number Constants | |
3192 | ||
3193 | @cindex constants, number | |
3194 | @cindex number constants | |
a4fb0134 | 3195 | @command{@value{AS}} distinguishes three kinds of numbers according to how they |
252b5132 RH |
3196 | are stored in the target machine. @emph{Integers} are numbers that |
3197 | would fit into an @code{int} in the C language. @emph{Bignums} are | |
3198 | integers, but they are stored in more than 32 bits. @emph{Flonums} | |
3199 | are floating point numbers, described below. | |
3200 | ||
3201 | @menu | |
3202 | * Integers:: Integers | |
3203 | * Bignums:: Bignums | |
3204 | * Flonums:: Flonums | |
3205 | @ifclear GENERIC | |
252b5132 RH |
3206 | @end ifclear |
3207 | @end menu | |
3208 | ||
3209 | @node Integers | |
3210 | @subsubsection Integers | |
3211 | @cindex integers | |
3212 | @cindex constants, integer | |
3213 | ||
3214 | @cindex binary integers | |
3215 | @cindex integers, binary | |
3216 | A binary integer is @samp{0b} or @samp{0B} followed by zero or more of | |
3217 | the binary digits @samp{01}. | |
3218 | ||
3219 | @cindex octal integers | |
3220 | @cindex integers, octal | |
3221 | An octal integer is @samp{0} followed by zero or more of the octal | |
3222 | digits (@samp{01234567}). | |
3223 | ||
3224 | @cindex decimal integers | |
3225 | @cindex integers, decimal | |
3226 | A decimal integer starts with a non-zero digit followed by zero or | |
3227 | more digits (@samp{0123456789}). | |
3228 | ||
3229 | @cindex hexadecimal integers | |
3230 | @cindex integers, hexadecimal | |
3231 | A hexadecimal integer is @samp{0x} or @samp{0X} followed by one or | |
3232 | more hexadecimal digits chosen from @samp{0123456789abcdefABCDEF}. | |
3233 | ||
3234 | Integers have the usual values. To denote a negative integer, use | |
3235 | the prefix operator @samp{-} discussed under expressions | |
3236 | (@pxref{Prefix Ops,,Prefix Operators}). | |
3237 | ||
3238 | @node Bignums | |
3239 | @subsubsection Bignums | |
3240 | ||
3241 | @cindex bignums | |
3242 | @cindex constants, bignum | |
3243 | A @dfn{bignum} has the same syntax and semantics as an integer | |
3244 | except that the number (or its negative) takes more than 32 bits to | |
3245 | represent in binary. The distinction is made because in some places | |
3246 | integers are permitted while bignums are not. | |
3247 | ||
3248 | @node Flonums | |
3249 | @subsubsection Flonums | |
3250 | @cindex flonums | |
3251 | @cindex floating point numbers | |
3252 | @cindex constants, floating point | |
3253 | ||
3254 | @cindex precision, floating point | |
3255 | A @dfn{flonum} represents a floating point number. The translation is | |
3256 | indirect: a decimal floating point number from the text is converted by | |
a4fb0134 | 3257 | @command{@value{AS}} to a generic binary floating point number of more than |
252b5132 RH |
3258 | sufficient precision. This generic floating point number is converted |
3259 | to a particular computer's floating point format (or formats) by a | |
a4fb0134 | 3260 | portion of @command{@value{AS}} specialized to that computer. |
252b5132 RH |
3261 | |
3262 | A flonum is written by writing (in order) | |
3263 | @itemize @bullet | |
3264 | @item | |
3265 | The digit @samp{0}. | |
3266 | @ifset HPPA | |
3267 | (@samp{0} is optional on the HPPA.) | |
3268 | @end ifset | |
3269 | ||
3270 | @item | |
a4fb0134 | 3271 | A letter, to tell @command{@value{AS}} the rest of the number is a flonum. |
252b5132 RH |
3272 | @ifset GENERIC |
3273 | @kbd{e} is recommended. Case is not important. | |
3274 | @ignore | |
3275 | @c FIXME: verify if flonum syntax really this vague for most cases | |
3276 | (Any otherwise illegal letter works here, but that might be changed. Vax BSD | |
3277 | 4.2 assembler seems to allow any of @samp{defghDEFGH}.) | |
3278 | @end ignore | |
3279 | ||
a8eb42a8 | 3280 | On the H8/300 and Renesas / SuperH SH architectures, the letter must be |
252b5132 RH |
3281 | one of the letters @samp{DFPRSX} (in upper or lower case). |
3282 | ||
3283 | On the ARC, the letter must be one of the letters @samp{DFRS} | |
3284 | (in upper or lower case). | |
3285 | ||
252b5132 RH |
3286 | On the HPPA architecture, the letter must be @samp{E} (upper case only). |
3287 | @end ifset | |
3288 | @ifclear GENERIC | |
252b5132 RH |
3289 | @ifset ARC |
3290 | One of the letters @samp{DFRS} (in upper or lower case). | |
3291 | @end ifset | |
3292 | @ifset H8 | |
3293 | One of the letters @samp{DFPRSX} (in upper or lower case). | |
3294 | @end ifset | |
3295 | @ifset HPPA | |
3296 | The letter @samp{E} (upper case only). | |
3297 | @end ifset | |
252b5132 RH |
3298 | @end ifclear |
3299 | ||
3300 | @item | |
3301 | An optional sign: either @samp{+} or @samp{-}. | |
3302 | ||
3303 | @item | |
3304 | An optional @dfn{integer part}: zero or more decimal digits. | |
3305 | ||
3306 | @item | |
3307 | An optional @dfn{fractional part}: @samp{.} followed by zero | |
3308 | or more decimal digits. | |
3309 | ||
3310 | @item | |
3311 | An optional exponent, consisting of: | |
3312 | ||
3313 | @itemize @bullet | |
3314 | @item | |
3315 | An @samp{E} or @samp{e}. | |
3316 | @c I can't find a config where "EXP_CHARS" is other than 'eE', but in | |
3317 | @c principle this can perfectly well be different on different targets. | |
3318 | @item | |
3319 | Optional sign: either @samp{+} or @samp{-}. | |
3320 | @item | |
3321 | One or more decimal digits. | |
3322 | @end itemize | |
3323 | ||
3324 | @end itemize | |
3325 | ||
3326 | At least one of the integer part or the fractional part must be | |
3327 | present. The floating point number has the usual base-10 value. | |
3328 | ||
a4fb0134 | 3329 | @command{@value{AS}} does all processing using integers. Flonums are computed |
252b5132 | 3330 | independently of any floating point hardware in the computer running |
a4fb0134 | 3331 | @command{@value{AS}}. |
252b5132 | 3332 | |
252b5132 RH |
3333 | @node Sections |
3334 | @chapter Sections and Relocation | |
3335 | @cindex sections | |
3336 | @cindex relocation | |
3337 | ||
3338 | @menu | |
3339 | * Secs Background:: Background | |
3340 | * Ld Sections:: Linker Sections | |
3341 | * As Sections:: Assembler Internal Sections | |
3342 | * Sub-Sections:: Sub-Sections | |
3343 | * bss:: bss Section | |
3344 | @end menu | |
3345 | ||
3346 | @node Secs Background | |
3347 | @section Background | |
3348 | ||
3349 | Roughly, a section is a range of addresses, with no gaps; all data | |
3350 | ``in'' those addresses is treated the same for some particular purpose. | |
3351 | For example there may be a ``read only'' section. | |
3352 | ||
3353 | @cindex linker, and assembler | |
3354 | @cindex assembler, and linker | |
3355 | The linker @code{@value{LD}} reads many object files (partial programs) and | |
a4fb0134 | 3356 | combines their contents to form a runnable program. When @command{@value{AS}} |
252b5132 RH |
3357 | emits an object file, the partial program is assumed to start at address 0. |
3358 | @code{@value{LD}} assigns the final addresses for the partial program, so that | |
3359 | different partial programs do not overlap. This is actually an | |
a4fb0134 | 3360 | oversimplification, but it suffices to explain how @command{@value{AS}} uses |
252b5132 RH |
3361 | sections. |
3362 | ||
3363 | @code{@value{LD}} moves blocks of bytes of your program to their run-time | |
3364 | addresses. These blocks slide to their run-time addresses as rigid | |
3365 | units; their length does not change and neither does the order of bytes | |
3366 | within them. Such a rigid unit is called a @emph{section}. Assigning | |
3367 | run-time addresses to sections is called @dfn{relocation}. It includes | |
3368 | the task of adjusting mentions of object-file addresses so they refer to | |
3369 | the proper run-time addresses. | |
3370 | @ifset H8 | |
7be1c489 | 3371 | For the H8/300, and for the Renesas / SuperH SH, |
a4fb0134 | 3372 | @command{@value{AS}} pads sections if needed to |
252b5132 RH |
3373 | ensure they end on a word (sixteen bit) boundary. |
3374 | @end ifset | |
3375 | ||
3376 | @cindex standard assembler sections | |
a4fb0134 | 3377 | An object file written by @command{@value{AS}} has at least three sections, any |
252b5132 RH |
3378 | of which may be empty. These are named @dfn{text}, @dfn{data} and |
3379 | @dfn{bss} sections. | |
3380 | ||
c1253627 | 3381 | @ifset COFF-ELF |
252b5132 | 3382 | @ifset GENERIC |
c1253627 | 3383 | When it generates COFF or ELF output, |
252b5132 | 3384 | @end ifset |
a4fb0134 | 3385 | @command{@value{AS}} can also generate whatever other named sections you specify |
252b5132 RH |
3386 | using the @samp{.section} directive (@pxref{Section,,@code{.section}}). |
3387 | If you do not use any directives that place output in the @samp{.text} | |
3388 | or @samp{.data} sections, these sections still exist, but are empty. | |
3389 | @end ifset | |
3390 | ||
3391 | @ifset HPPA | |
3392 | @ifset GENERIC | |
a4fb0134 | 3393 | When @command{@value{AS}} generates SOM or ELF output for the HPPA, |
252b5132 | 3394 | @end ifset |
a4fb0134 | 3395 | @command{@value{AS}} can also generate whatever other named sections you |
252b5132 RH |
3396 | specify using the @samp{.space} and @samp{.subspace} directives. See |
3397 | @cite{HP9000 Series 800 Assembly Language Reference Manual} | |
3398 | (HP 92432-90001) for details on the @samp{.space} and @samp{.subspace} | |
3399 | assembler directives. | |
3400 | ||
3401 | @ifset SOM | |
a4fb0134 | 3402 | Additionally, @command{@value{AS}} uses different names for the standard |
252b5132 RH |
3403 | text, data, and bss sections when generating SOM output. Program text |
3404 | is placed into the @samp{$CODE$} section, data into @samp{$DATA$}, and | |
3405 | BSS into @samp{$BSS$}. | |
3406 | @end ifset | |
3407 | @end ifset | |
3408 | ||
3409 | Within the object file, the text section starts at address @code{0}, the | |
3410 | data section follows, and the bss section follows the data section. | |
3411 | ||
3412 | @ifset HPPA | |
3413 | When generating either SOM or ELF output files on the HPPA, the text | |
3414 | section starts at address @code{0}, the data section at address | |
3415 | @code{0x4000000}, and the bss section follows the data section. | |
3416 | @end ifset | |
3417 | ||
3418 | To let @code{@value{LD}} know which data changes when the sections are | |
a4fb0134 | 3419 | relocated, and how to change that data, @command{@value{AS}} also writes to the |
252b5132 RH |
3420 | object file details of the relocation needed. To perform relocation |
3421 | @code{@value{LD}} must know, each time an address in the object | |
3422 | file is mentioned: | |
3423 | @itemize @bullet | |
3424 | @item | |
3425 | Where in the object file is the beginning of this reference to | |
3426 | an address? | |
3427 | @item | |
3428 | How long (in bytes) is this reference? | |
3429 | @item | |
3430 | Which section does the address refer to? What is the numeric value of | |
3431 | @display | |
3432 | (@var{address}) @minus{} (@var{start-address of section})? | |
3433 | @end display | |
3434 | @item | |
3435 | Is the reference to an address ``Program-Counter relative''? | |
3436 | @end itemize | |
3437 | ||
3438 | @cindex addresses, format of | |
3439 | @cindex section-relative addressing | |
a4fb0134 | 3440 | In fact, every address @command{@value{AS}} ever uses is expressed as |
252b5132 RH |
3441 | @display |
3442 | (@var{section}) + (@var{offset into section}) | |
3443 | @end display | |
3444 | @noindent | |
a4fb0134 | 3445 | Further, most expressions @command{@value{AS}} computes have this section-relative |
252b5132 RH |
3446 | nature. |
3447 | @ifset SOM | |
3448 | (For some object formats, such as SOM for the HPPA, some expressions are | |
3449 | symbol-relative instead.) | |
3450 | @end ifset | |
3451 | ||
3452 | In this manual we use the notation @{@var{secname} @var{N}@} to mean ``offset | |
3453 | @var{N} into section @var{secname}.'' | |
3454 | ||
3455 | Apart from text, data and bss sections you need to know about the | |
3456 | @dfn{absolute} section. When @code{@value{LD}} mixes partial programs, | |
3457 | addresses in the absolute section remain unchanged. For example, address | |
3458 | @code{@{absolute 0@}} is ``relocated'' to run-time address 0 by | |
3459 | @code{@value{LD}}. Although the linker never arranges two partial programs' | |
3460 | data sections with overlapping addresses after linking, @emph{by definition} | |
3461 | their absolute sections must overlap. Address @code{@{absolute@ 239@}} in one | |
3462 | part of a program is always the same address when the program is running as | |
3463 | address @code{@{absolute@ 239@}} in any other part of the program. | |
3464 | ||
3465 | The idea of sections is extended to the @dfn{undefined} section. Any | |
3466 | address whose section is unknown at assembly time is by definition | |
3467 | rendered @{undefined @var{U}@}---where @var{U} is filled in later. | |
3468 | Since numbers are always defined, the only way to generate an undefined | |
3469 | address is to mention an undefined symbol. A reference to a named | |
3470 | common block would be such a symbol: its value is unknown at assembly | |
3471 | time so it has section @emph{undefined}. | |
3472 | ||
3473 | By analogy the word @emph{section} is used to describe groups of sections in | |
3474 | the linked program. @code{@value{LD}} puts all partial programs' text | |
3475 | sections in contiguous addresses in the linked program. It is | |
3476 | customary to refer to the @emph{text section} of a program, meaning all | |
3477 | the addresses of all partial programs' text sections. Likewise for | |
3478 | data and bss sections. | |
3479 | ||
3480 | Some sections are manipulated by @code{@value{LD}}; others are invented for | |
a4fb0134 | 3481 | use of @command{@value{AS}} and have no meaning except during assembly. |
252b5132 RH |
3482 | |
3483 | @node Ld Sections | |
3484 | @section Linker Sections | |
3485 | @code{@value{LD}} deals with just four kinds of sections, summarized below. | |
3486 | ||
3487 | @table @strong | |
3488 | ||
c1253627 | 3489 | @ifset COFF-ELF |
252b5132 RH |
3490 | @cindex named sections |
3491 | @cindex sections, named | |
3492 | @item named sections | |
3493 | @end ifset | |
a8eb42a8 | 3494 | @ifset aout |
252b5132 RH |
3495 | @cindex text section |
3496 | @cindex data section | |
3497 | @itemx text section | |
3498 | @itemx data section | |
3499 | @end ifset | |
a4fb0134 | 3500 | These sections hold your program. @command{@value{AS}} and @code{@value{LD}} treat them as |
252b5132 | 3501 | separate but equal sections. Anything you can say of one section is |
c1253627 | 3502 | true of another. |
a8eb42a8 | 3503 | @c @ifset aout |
252b5132 RH |
3504 | When the program is running, however, it is |
3505 | customary for the text section to be unalterable. The | |
3506 | text section is often shared among processes: it contains | |
3507 | instructions, constants and the like. The data section of a running | |
3508 | program is usually alterable: for example, C variables would be stored | |
3509 | in the data section. | |
c1253627 | 3510 | @c @end ifset |
252b5132 RH |
3511 | |
3512 | @cindex bss section | |
3513 | @item bss section | |
3514 | This section contains zeroed bytes when your program begins running. It | |
a349d9dd | 3515 | is used to hold uninitialized variables or common storage. The length of |
252b5132 RH |
3516 | each partial program's bss section is important, but because it starts |
3517 | out containing zeroed bytes there is no need to store explicit zero | |
3518 | bytes in the object file. The bss section was invented to eliminate | |
3519 | those explicit zeros from object files. | |
3520 | ||
3521 | @cindex absolute section | |
3522 | @item absolute section | |
3523 | Address 0 of this section is always ``relocated'' to runtime address 0. | |
3524 | This is useful if you want to refer to an address that @code{@value{LD}} must | |
3525 | not change when relocating. In this sense we speak of absolute | |
3526 | addresses being ``unrelocatable'': they do not change during relocation. | |
3527 | ||
3528 | @cindex undefined section | |
3529 | @item undefined section | |
3530 | This ``section'' is a catch-all for address references to objects not in | |
3531 | the preceding sections. | |
3532 | @c FIXME: ref to some other doc on obj-file formats could go here. | |
3533 | @end table | |
3534 | ||
3535 | @cindex relocation example | |
3536 | An idealized example of three relocatable sections follows. | |
c1253627 | 3537 | @ifset COFF-ELF |
252b5132 RH |
3538 | The example uses the traditional section names @samp{.text} and @samp{.data}. |
3539 | @end ifset | |
3540 | Memory addresses are on the horizontal axis. | |
3541 | ||
3542 | @c TEXI2ROFF-KILL | |
c1253627 | 3543 | @ifnottex |
252b5132 RH |
3544 | @c END TEXI2ROFF-KILL |
3545 | @smallexample | |
3546 | +-----+----+--+ | |
3547 | partial program # 1: |ttttt|dddd|00| | |
3548 | +-----+----+--+ | |
3549 | ||
3550 | text data bss | |
3551 | seg. seg. seg. | |
3552 | ||
3553 | +---+---+---+ | |
3554 | partial program # 2: |TTT|DDD|000| | |
3555 | +---+---+---+ | |
3556 | ||
3557 | +--+---+-----+--+----+---+-----+~~ | |
3558 | linked program: | |TTT|ttttt| |dddd|DDD|00000| | |
3559 | +--+---+-----+--+----+---+-----+~~ | |
3560 | ||
3561 | addresses: 0 @dots{} | |
3562 | @end smallexample | |
3563 | @c TEXI2ROFF-KILL | |
c1253627 | 3564 | @end ifnottex |
252b5132 RH |
3565 | @need 5000 |
3566 | @tex | |
c1253627 | 3567 | \bigskip |
252b5132 RH |
3568 | \line{\it Partial program \#1: \hfil} |
3569 | \line{\ibox{2.5cm}{\tt text}\ibox{2cm}{\tt data}\ibox{1cm}{\tt bss}\hfil} | |
3570 | \line{\boxit{2.5cm}{\tt ttttt}\boxit{2cm}{\tt dddd}\boxit{1cm}{\tt 00}\hfil} | |
3571 | ||
3572 | \line{\it Partial program \#2: \hfil} | |
3573 | \line{\ibox{1cm}{\tt text}\ibox{1.5cm}{\tt data}\ibox{1cm}{\tt bss}\hfil} | |
3574 | \line{\boxit{1cm}{\tt TTT}\boxit{1.5cm}{\tt DDDD}\boxit{1cm}{\tt 000}\hfil} | |
3575 | ||
3576 | \line{\it linked program: \hfil} | |
3577 | \line{\ibox{.5cm}{}\ibox{1cm}{\tt text}\ibox{2.5cm}{}\ibox{.75cm}{}\ibox{2cm}{\tt data}\ibox{1.5cm}{}\ibox{2cm}{\tt bss}\hfil} | |
3578 | \line{\boxit{.5cm}{}\boxit{1cm}{\tt TTT}\boxit{2.5cm}{\tt | |
3579 | ttttt}\boxit{.75cm}{}\boxit{2cm}{\tt dddd}\boxit{1.5cm}{\tt | |
3580 | DDDD}\boxit{2cm}{\tt 00000}\ \dots\hfil} | |
3581 | ||
3582 | \line{\it addresses: \hfil} | |
3583 | \line{0\dots\hfil} | |
3584 | ||
3585 | @end tex | |
3586 | @c END TEXI2ROFF-KILL | |
3587 | ||
3588 | @node As Sections | |
3589 | @section Assembler Internal Sections | |
3590 | ||
3591 | @cindex internal assembler sections | |
3592 | @cindex sections in messages, internal | |
a4fb0134 | 3593 | These sections are meant only for the internal use of @command{@value{AS}}. They |
252b5132 | 3594 | have no meaning at run-time. You do not really need to know about these |
a4fb0134 | 3595 | sections for most purposes; but they can be mentioned in @command{@value{AS}} |
252b5132 | 3596 | warning messages, so it might be helpful to have an idea of their |
a4fb0134 | 3597 | meanings to @command{@value{AS}}. These sections are used to permit the |
252b5132 RH |
3598 | value of every expression in your assembly language program to be a |
3599 | section-relative address. | |
3600 | ||
3601 | @table @b | |
3602 | @cindex assembler internal logic error | |
3603 | @item ASSEMBLER-INTERNAL-LOGIC-ERROR! | |
3604 | An internal assembler logic error has been found. This means there is a | |
3605 | bug in the assembler. | |
3606 | ||
3607 | @cindex expr (internal section) | |
3608 | @item expr section | |
3609 | The assembler stores complex expression internally as combinations of | |
3610 | symbols. When it needs to represent an expression as a symbol, it puts | |
3611 | it in the expr section. | |
3612 | @c FIXME item debug | |
3613 | @c FIXME item transfer[t] vector preload | |
3614 | @c FIXME item transfer[t] vector postload | |
3615 | @c FIXME item register | |
3616 | @end table | |
3617 | ||
3618 | @node Sub-Sections | |
3619 | @section Sub-Sections | |
3620 | ||
3621 | @cindex numbered subsections | |
3622 | @cindex grouping data | |
a8eb42a8 | 3623 | @ifset aout |
252b5132 | 3624 | Assembled bytes |
c1253627 | 3625 | @ifset COFF-ELF |
252b5132 RH |
3626 | conventionally |
3627 | @end ifset | |
3628 | fall into two sections: text and data. | |
3629 | @end ifset | |
3630 | You may have separate groups of | |
3631 | @ifset GENERIC | |
3632 | data in named sections | |
3633 | @end ifset | |
3634 | @ifclear GENERIC | |
a8eb42a8 | 3635 | @ifclear aout |
252b5132 RH |
3636 | data in named sections |
3637 | @end ifclear | |
a8eb42a8 | 3638 | @ifset aout |
252b5132 RH |
3639 | text or data |
3640 | @end ifset | |
3641 | @end ifclear | |
3642 | that you want to end up near to each other in the object file, even though they | |
a4fb0134 | 3643 | are not contiguous in the assembler source. @command{@value{AS}} allows you to |
252b5132 RH |
3644 | use @dfn{subsections} for this purpose. Within each section, there can be |
3645 | numbered subsections with values from 0 to 8192. Objects assembled into the | |
3646 | same subsection go into the object file together with other objects in the same | |
3647 | subsection. For example, a compiler might want to store constants in the text | |
3648 | section, but might not want to have them interspersed with the program being | |
3649 | assembled. In this case, the compiler could issue a @samp{.text 0} before each | |
3650 | section of code being output, and a @samp{.text 1} before each group of | |
3651 | constants being output. | |
3652 | ||
3653 | Subsections are optional. If you do not use subsections, everything | |
3654 | goes in subsection number zero. | |
3655 | ||
3656 | @ifset GENERIC | |
3657 | Each subsection is zero-padded up to a multiple of four bytes. | |
3658 | (Subsections may be padded a different amount on different flavors | |
a4fb0134 | 3659 | of @command{@value{AS}}.) |
252b5132 RH |
3660 | @end ifset |
3661 | @ifclear GENERIC | |
3662 | @ifset H8 | |
7be1c489 | 3663 | On the H8/300 platform, each subsection is zero-padded to a word |
252b5132 | 3664 | boundary (two bytes). |
c2dcd04e | 3665 | The same is true on the Renesas SH. |
252b5132 | 3666 | @end ifset |
252b5132 RH |
3667 | @end ifclear |
3668 | ||
3669 | Subsections appear in your object file in numeric order, lowest numbered | |
3670 | to highest. (All this to be compatible with other people's assemblers.) | |
3671 | The object file contains no representation of subsections; @code{@value{LD}} and | |
3672 | other programs that manipulate object files see no trace of them. | |
3673 | They just see all your text subsections as a text section, and all your | |
3674 | data subsections as a data section. | |
3675 | ||
3676 | To specify which subsection you want subsequent statements assembled | |
3677 | into, use a numeric argument to specify it, in a @samp{.text | |
3678 | @var{expression}} or a @samp{.data @var{expression}} statement. | |
ed9589d4 | 3679 | @ifset COFF |
252b5132 | 3680 | @ifset GENERIC |
ed9589d4 | 3681 | When generating COFF output, you |
252b5132 RH |
3682 | @end ifset |
3683 | @ifclear GENERIC | |
3684 | You | |
3685 | @end ifclear | |
3686 | can also use an extra subsection | |
3687 | argument with arbitrary named sections: @samp{.section @var{name}, | |
3688 | @var{expression}}. | |
3689 | @end ifset | |
ed9589d4 BW |
3690 | @ifset ELF |
3691 | @ifset GENERIC | |
3692 | When generating ELF output, you | |
3693 | @end ifset | |
3694 | @ifclear GENERIC | |
3695 | You | |
3696 | @end ifclear | |
3697 | can also use the @code{.subsection} directive (@pxref{SubSection}) | |
3698 | to specify a subsection: @samp{.subsection @var{expression}}. | |
3699 | @end ifset | |
96e9638b BW |
3700 | @var{Expression} should be an absolute expression |
3701 | (@pxref{Expressions}). If you just say @samp{.text} then @samp{.text 0} | |
252b5132 RH |
3702 | is assumed. Likewise @samp{.data} means @samp{.data 0}. Assembly |
3703 | begins in @code{text 0}. For instance: | |
3704 | @smallexample | |
3705 | .text 0 # The default subsection is text 0 anyway. | |
3706 | .ascii "This lives in the first text subsection. *" | |
3707 | .text 1 | |
3708 | .ascii "But this lives in the second text subsection." | |
3709 | .data 0 | |
3710 | .ascii "This lives in the data section," | |
3711 | .ascii "in the first data subsection." | |
3712 | .text 0 | |
3713 | .ascii "This lives in the first text section," | |
3714 | .ascii "immediately following the asterisk (*)." | |
3715 | @end smallexample | |
3716 | ||
3717 | Each section has a @dfn{location counter} incremented by one for every byte | |
3718 | assembled into that section. Because subsections are merely a convenience | |
a4fb0134 | 3719 | restricted to @command{@value{AS}} there is no concept of a subsection location |
252b5132 RH |
3720 | counter. There is no way to directly manipulate a location counter---but the |
3721 | @code{.align} directive changes it, and any label definition captures its | |
3722 | current value. The location counter of the section where statements are being | |
3723 | assembled is said to be the @dfn{active} location counter. | |
3724 | ||
3725 | @node bss | |
3726 | @section bss Section | |
3727 | ||
3728 | @cindex bss section | |
3729 | @cindex common variable storage | |
3730 | The bss section is used for local common variable storage. | |
3731 | You may allocate address space in the bss section, but you may | |
3732 | not dictate data to load into it before your program executes. When | |
3733 | your program starts running, all the contents of the bss | |
3734 | section are zeroed bytes. | |
3735 | ||
3736 | The @code{.lcomm} pseudo-op defines a symbol in the bss section; see | |
3737 | @ref{Lcomm,,@code{.lcomm}}. | |
3738 | ||
3739 | The @code{.comm} pseudo-op may be used to declare a common symbol, which is | |
96e9638b | 3740 | another form of uninitialized symbol; see @ref{Comm,,@code{.comm}}. |
252b5132 RH |
3741 | |
3742 | @ifset GENERIC | |
3743 | When assembling for a target which supports multiple sections, such as ELF or | |
3744 | COFF, you may switch into the @code{.bss} section and define symbols as usual; | |
3745 | see @ref{Section,,@code{.section}}. You may only assemble zero values into the | |
3746 | section. Typically the section will only contain symbol definitions and | |
3747 | @code{.skip} directives (@pxref{Skip,,@code{.skip}}). | |
3748 | @end ifset | |
3749 | ||
3750 | @node Symbols | |
3751 | @chapter Symbols | |
3752 | ||
3753 | @cindex symbols | |
3754 | Symbols are a central concept: the programmer uses symbols to name | |
3755 | things, the linker uses symbols to link, and the debugger uses symbols | |
3756 | to debug. | |
3757 | ||
3758 | @quotation | |
3759 | @cindex debuggers, and symbol order | |
a4fb0134 | 3760 | @emph{Warning:} @command{@value{AS}} does not place symbols in the object file in |
252b5132 RH |
3761 | the same order they were declared. This may break some debuggers. |
3762 | @end quotation | |
3763 | ||
3764 | @menu | |
3765 | * Labels:: Labels | |
3766 | * Setting Symbols:: Giving Symbols Other Values | |
3767 | * Symbol Names:: Symbol Names | |
3768 | * Dot:: The Special Dot Symbol | |
3769 | * Symbol Attributes:: Symbol Attributes | |
3770 | @end menu | |
3771 | ||
3772 | @node Labels | |
3773 | @section Labels | |
3774 | ||
3775 | @cindex labels | |
3776 | A @dfn{label} is written as a symbol immediately followed by a colon | |
3777 | @samp{:}. The symbol then represents the current value of the | |
3778 | active location counter, and is, for example, a suitable instruction | |
3779 | operand. You are warned if you use the same symbol to represent two | |
3780 | different locations: the first definition overrides any other | |
3781 | definitions. | |
3782 | ||
3783 | @ifset HPPA | |
3784 | On the HPPA, the usual form for a label need not be immediately followed by a | |
3785 | colon, but instead must start in column zero. Only one label may be defined on | |
a4fb0134 | 3786 | a single line. To work around this, the HPPA version of @command{@value{AS}} also |
252b5132 RH |
3787 | provides a special directive @code{.label} for defining labels more flexibly. |
3788 | @end ifset | |
3789 | ||
3790 | @node Setting Symbols | |
3791 | @section Giving Symbols Other Values | |
3792 | ||
3793 | @cindex assigning values to symbols | |
3794 | @cindex symbol values, assigning | |
3795 | A symbol can be given an arbitrary value by writing a symbol, followed | |
3796 | by an equals sign @samp{=}, followed by an expression | |
3797 | (@pxref{Expressions}). This is equivalent to using the @code{.set} | |
9497f5ac NC |
3798 | directive. @xref{Set,,@code{.set}}. In the same way, using a double |
3799 | equals sign @samp{=}@samp{=} here represents an equivalent of the | |
3800 | @code{.eqv} directive. @xref{Eqv,,@code{.eqv}}. | |
252b5132 | 3801 | |
f8739b83 JZ |
3802 | @ifset Blackfin |
3803 | Blackfin does not support symbol assignment with @samp{=}. | |
3804 | @end ifset | |
3805 | ||
252b5132 RH |
3806 | @node Symbol Names |
3807 | @section Symbol Names | |
3808 | ||
3809 | @cindex symbol names | |
3810 | @cindex names, symbol | |
3811 | @ifclear SPECIAL-SYMS | |
3812 | Symbol names begin with a letter or with one of @samp{._}. On most | |
3813 | machines, you can also use @code{$} in symbol names; exceptions are | |
3814 | noted in @ref{Machine Dependencies}. That character may be followed by any | |
96e9638b BW |
3815 | string of digits, letters, dollar signs (unless otherwise noted for a |
3816 | particular target machine), and underscores. | |
252b5132 | 3817 | @end ifclear |
252b5132 RH |
3818 | @ifset SPECIAL-SYMS |
3819 | @ifset H8 | |
3820 | Symbol names begin with a letter or with one of @samp{._}. On the | |
7be1c489 | 3821 | Renesas SH you can also use @code{$} in symbol names. That |
c2dcd04e NC |
3822 | character may be followed by any string of digits, letters, dollar signs (save |
3823 | on the H8/300), and underscores. | |
252b5132 RH |
3824 | @end ifset |
3825 | @end ifset | |
3826 | ||
3827 | Case of letters is significant: @code{foo} is a different symbol name | |
3828 | than @code{Foo}. | |
3829 | ||
ed1fcdd1 NC |
3830 | Symbol names do not start with a digit. An exception to this rule is made for |
3831 | Local Labels. See below. | |
3832 | ||
7bfd842d NC |
3833 | Multibyte characters are supported. To generate a symbol name containing |
3834 | multibyte characters enclose it within double quotes and use escape codes. cf | |
3835 | @xref{Strings}. Generating a multibyte symbol name from a label is not | |
3836 | currently supported. | |
3837 | ||
252b5132 RH |
3838 | Each symbol has exactly one name. Each name in an assembly language program |
3839 | refers to exactly one symbol. You may use that symbol name any number of times | |
3840 | in a program. | |
3841 | ||
3842 | @subheading Local Symbol Names | |
3843 | ||
3844 | @cindex local symbol names | |
3845 | @cindex symbol names, local | |
ba83aca1 BW |
3846 | A local symbol is any symbol beginning with certain local label prefixes. |
3847 | By default, the local label prefix is @samp{.L} for ELF systems or | |
3848 | @samp{L} for traditional a.out systems, but each target may have its own | |
3849 | set of local label prefixes. | |
3850 | @ifset HPPA | |
3851 | On the HPPA local symbols begin with @samp{L$}. | |
3852 | @end ifset | |
3853 | ||
3854 | Local symbols are defined and used within the assembler, but they are | |
3855 | normally not saved in object files. Thus, they are not visible when debugging. | |
5c9352f3 AM |
3856 | You may use the @samp{-L} option (@pxref{L, ,Include Local Symbols}) |
3857 | to retain the local symbols in the object files. | |
ba83aca1 BW |
3858 | |
3859 | @subheading Local Labels | |
3860 | ||
3861 | @cindex local labels | |
252b5132 RH |
3862 | @cindex temporary symbol names |
3863 | @cindex symbol names, temporary | |
ed1fcdd1 NC |
3864 | Local labels are different from local symbols. Local labels help compilers and |
3865 | programmers use names temporarily. They create symbols which are guaranteed to | |
3866 | be unique over the entire scope of the input source code and which can be | |
3867 | referred to by a simple notation. To define a local label, write a label of | |
9791c250 AM |
3868 | the form @samp{@b{N}:} (where @b{N} represents any non-negative integer). |
3869 | To refer to the most recent previous definition of that label write | |
3870 | @samp{@b{N}b}, using the same number as when you defined the label. To refer | |
3871 | to the next definition of a local label, write @samp{@b{N}f}. The @samp{b} | |
3872 | stands for ``backwards'' and the @samp{f} stands for ``forwards''. | |
2d5aaba0 NC |
3873 | |
3874 | There is no restriction on how you can use these labels, and you can reuse them | |
3875 | too. So that it is possible to repeatedly define the same local label (using | |
3876 | the same number @samp{@b{N}}), although you can only refer to the most recently | |
3877 | defined local label of that number (for a backwards reference) or the next | |
3878 | definition of a specific local label for a forward reference. It is also worth | |
3879 | noting that the first 10 local labels (@samp{@b{0:}}@dots{}@samp{@b{9:}}) are | |
3880 | implemented in a slightly more efficient manner than the others. | |
3881 | ||
3882 | Here is an example: | |
3883 | ||
3884 | @smallexample | |
3885 | 1: branch 1f | |
3886 | 2: branch 1b | |
3887 | 1: branch 2f | |
3888 | 2: branch 1b | |
3889 | @end smallexample | |
3890 | ||
3891 | Which is the equivalent of: | |
3892 | ||
3893 | @smallexample | |
3894 | label_1: branch label_3 | |
3895 | label_2: branch label_1 | |
3896 | label_3: branch label_4 | |
3897 | label_4: branch label_3 | |
3898 | @end smallexample | |
3899 | ||
ba83aca1 | 3900 | Local label names are only a notational device. They are immediately |
2d5aaba0 | 3901 | transformed into more conventional symbol names before the assembler uses them. |
96e9638b BW |
3902 | The symbol names are stored in the symbol table, appear in error messages, and |
3903 | are optionally emitted to the object file. The names are constructed using | |
3904 | these parts: | |
252b5132 RH |
3905 | |
3906 | @table @code | |
ba83aca1 BW |
3907 | @item @emph{local label prefix} |
3908 | All local symbols begin with the system-specific local label prefix. | |
3909 | Normally both @command{@value{AS}} and @code{@value{LD}} forget symbols | |
3910 | that start with the local label prefix. These labels are | |
252b5132 | 3911 | used for symbols you are never intended to see. If you use the |
a4fb0134 | 3912 | @samp{-L} option then @command{@value{AS}} retains these symbols in the |
252b5132 RH |
3913 | object file. If you also instruct @code{@value{LD}} to retain these symbols, |
3914 | you may use them in debugging. | |
3915 | ||
2d5aaba0 NC |
3916 | @item @var{number} |
3917 | This is the number that was used in the local label definition. So if the | |
01642c12 | 3918 | label is written @samp{55:} then the number is @samp{55}. |
252b5132 | 3919 | |
2d5aaba0 NC |
3920 | @item @kbd{C-B} |
3921 | This unusual character is included so you do not accidentally invent a symbol | |
3922 | of the same name. The character has ASCII value of @samp{\002} (control-B). | |
252b5132 RH |
3923 | |
3924 | @item @emph{ordinal number} | |
2d5aaba0 | 3925 | This is a serial number to keep the labels distinct. The first definition of |
01642c12 | 3926 | @samp{0:} gets the number @samp{1}. The 15th definition of @samp{0:} gets the |
2d5aaba0 | 3927 | number @samp{15}, and so on. Likewise the first definition of @samp{1:} gets |
b45619c0 | 3928 | the number @samp{1} and its 15th definition gets @samp{15} as well. |
252b5132 RH |
3929 | @end table |
3930 | ||
ba83aca1 BW |
3931 | So for example, the first @code{1:} may be named @code{.L1@kbd{C-B}1}, and |
3932 | the 44th @code{3:} may be named @code{.L3@kbd{C-B}44}. | |
2d5aaba0 NC |
3933 | |
3934 | @subheading Dollar Local Labels | |
3935 | @cindex dollar local symbols | |
3936 | ||
ed1fcdd1 NC |
3937 | On some targets @code{@value{AS}} also supports an even more local form of |
3938 | local labels called dollar labels. These labels go out of scope (i.e., they | |
3939 | become undefined) as soon as a non-local label is defined. Thus they remain | |
3940 | valid for only a small region of the input source code. Normal local labels, | |
3941 | by contrast, remain in scope for the entire file, or until they are redefined | |
3942 | by another occurrence of the same local label. | |
2d5aaba0 NC |
3943 | |
3944 | Dollar labels are defined in exactly the same way as ordinary local labels, | |
77cca80f NC |
3945 | except that they have a dollar sign suffix to their numeric value, e.g., |
3946 | @samp{@b{55$:}}. | |
2d5aaba0 NC |
3947 | |
3948 | They can also be distinguished from ordinary local labels by their transformed | |
96e9638b BW |
3949 | names which use ASCII character @samp{\001} (control-A) as the magic character |
3950 | to distinguish them from ordinary labels. For example, the fifth definition of | |
ba83aca1 | 3951 | @samp{6$} may be named @samp{.L6@kbd{C-A}5}. |
252b5132 RH |
3952 | |
3953 | @node Dot | |
3954 | @section The Special Dot Symbol | |
3955 | ||
3956 | @cindex dot (symbol) | |
3957 | @cindex @code{.} (symbol) | |
3958 | @cindex current address | |
3959 | @cindex location counter | |
3960 | The special symbol @samp{.} refers to the current address that | |
a4fb0134 | 3961 | @command{@value{AS}} is assembling into. Thus, the expression @samp{melvin: |
252b5132 RH |
3962 | .long .} defines @code{melvin} to contain its own address. |
3963 | Assigning a value to @code{.} is treated the same as a @code{.org} | |
884f0d36 | 3964 | directive. |
252b5132 | 3965 | @ifclear no-space-dir |
884f0d36 | 3966 | Thus, the expression @samp{.=.+4} is the same as saying |
252b5132 RH |
3967 | @samp{.space 4}. |
3968 | @end ifclear | |
252b5132 RH |
3969 | |
3970 | @node Symbol Attributes | |
3971 | @section Symbol Attributes | |
3972 | ||
3973 | @cindex symbol attributes | |
3974 | @cindex attributes, symbol | |
3975 | Every symbol has, as well as its name, the attributes ``Value'' and | |
3976 | ``Type''. Depending on output format, symbols can also have auxiliary | |
3977 | attributes. | |
3978 | @ifset INTERNALS | |
3979 | The detailed definitions are in @file{a.out.h}. | |
3980 | @end ifset | |
3981 | ||
a4fb0134 | 3982 | If you use a symbol without defining it, @command{@value{AS}} assumes zero for |
252b5132 RH |
3983 | all these attributes, and probably won't warn you. This makes the |
3984 | symbol an externally defined symbol, which is generally what you | |
3985 | would want. | |
3986 | ||
3987 | @menu | |
3988 | * Symbol Value:: Value | |
3989 | * Symbol Type:: Type | |
a8eb42a8 | 3990 | @ifset aout |
252b5132 RH |
3991 | * a.out Symbols:: Symbol Attributes: @code{a.out} |
3992 | @end ifset | |
252b5132 RH |
3993 | @ifset COFF |
3994 | * COFF Symbols:: Symbol Attributes for COFF | |
3995 | @end ifset | |
3996 | @ifset SOM | |
3997 | * SOM Symbols:: Symbol Attributes for SOM | |
3998 | @end ifset | |
3999 | @end menu | |
4000 | ||
4001 | @node Symbol Value | |
4002 | @subsection Value | |
4003 | ||
4004 | @cindex value of a symbol | |
4005 | @cindex symbol value | |
4006 | The value of a symbol is (usually) 32 bits. For a symbol which labels a | |
4007 | location in the text, data, bss or absolute sections the value is the | |
4008 | number of addresses from the start of that section to the label. | |
4009 | Naturally for text, data and bss sections the value of a symbol changes | |
4010 | as @code{@value{LD}} changes section base addresses during linking. Absolute | |
4011 | symbols' values do not change during linking: that is why they are | |
4012 | called absolute. | |
4013 | ||
4014 | The value of an undefined symbol is treated in a special way. If it is | |
4015 | 0 then the symbol is not defined in this assembler source file, and | |
4016 | @code{@value{LD}} tries to determine its value from other files linked into the | |
4017 | same program. You make this kind of symbol simply by mentioning a symbol | |
4018 | name without defining it. A non-zero value represents a @code{.comm} | |
4019 | common declaration. The value is how much common storage to reserve, in | |
4020 | bytes (addresses). The symbol refers to the first address of the | |
4021 | allocated storage. | |
4022 | ||
4023 | @node Symbol Type | |
4024 | @subsection Type | |
4025 | ||
4026 | @cindex type of a symbol | |
4027 | @cindex symbol type | |
4028 | The type attribute of a symbol contains relocation (section) | |
4029 | information, any flag settings indicating that a symbol is external, and | |
4030 | (optionally), other information for linkers and debuggers. The exact | |
4031 | format depends on the object-code output format in use. | |
4032 | ||
a8eb42a8 | 4033 | @ifset aout |
252b5132 RH |
4034 | @node a.out Symbols |
4035 | @subsection Symbol Attributes: @code{a.out} | |
4036 | ||
4037 | @cindex @code{a.out} symbol attributes | |
4038 | @cindex symbol attributes, @code{a.out} | |
4039 | ||
252b5132 RH |
4040 | @menu |
4041 | * Symbol Desc:: Descriptor | |
4042 | * Symbol Other:: Other | |
4043 | @end menu | |
4044 | ||
4045 | @node Symbol Desc | |
4046 | @subsubsection Descriptor | |
4047 | ||
4048 | @cindex descriptor, of @code{a.out} symbol | |
4049 | This is an arbitrary 16-bit value. You may establish a symbol's | |
4050 | descriptor value by using a @code{.desc} statement | |
4051 | (@pxref{Desc,,@code{.desc}}). A descriptor value means nothing to | |
a4fb0134 | 4052 | @command{@value{AS}}. |
252b5132 RH |
4053 | |
4054 | @node Symbol Other | |
4055 | @subsubsection Other | |
4056 | ||
4057 | @cindex other attribute, of @code{a.out} symbol | |
a4fb0134 | 4058 | This is an arbitrary 8-bit value. It means nothing to @command{@value{AS}}. |
252b5132 RH |
4059 | @end ifset |
4060 | ||
4061 | @ifset COFF | |
4062 | @node COFF Symbols | |
4063 | @subsection Symbol Attributes for COFF | |
4064 | ||
4065 | @cindex COFF symbol attributes | |
4066 | @cindex symbol attributes, COFF | |
4067 | ||
4068 | The COFF format supports a multitude of auxiliary symbol attributes; | |
4069 | like the primary symbol attributes, they are set between @code{.def} and | |
4070 | @code{.endef} directives. | |
4071 | ||
4072 | @subsubsection Primary Attributes | |
4073 | ||
4074 | @cindex primary attributes, COFF symbols | |
4075 | The symbol name is set with @code{.def}; the value and type, | |
4076 | respectively, with @code{.val} and @code{.type}. | |
4077 | ||
4078 | @subsubsection Auxiliary Attributes | |
4079 | ||
4080 | @cindex auxiliary attributes, COFF symbols | |
a4fb0134 | 4081 | The @command{@value{AS}} directives @code{.dim}, @code{.line}, @code{.scl}, |
c87db184 CF |
4082 | @code{.size}, @code{.tag}, and @code{.weak} can generate auxiliary symbol |
4083 | table information for COFF. | |
252b5132 RH |
4084 | @end ifset |
4085 | ||
4086 | @ifset SOM | |
4087 | @node SOM Symbols | |
4088 | @subsection Symbol Attributes for SOM | |
4089 | ||
4090 | @cindex SOM symbol attributes | |
4091 | @cindex symbol attributes, SOM | |
4092 | ||
4093 | The SOM format for the HPPA supports a multitude of symbol attributes set with | |
4094 | the @code{.EXPORT} and @code{.IMPORT} directives. | |
4095 | ||
01642c12 | 4096 | The attributes are described in @cite{HP9000 Series 800 Assembly |
252b5132 RH |
4097 | Language Reference Manual} (HP 92432-90001) under the @code{IMPORT} and |
4098 | @code{EXPORT} assembler directive documentation. | |
4099 | @end ifset | |
4100 | ||
4101 | @node Expressions | |
4102 | @chapter Expressions | |
4103 | ||
4104 | @cindex expressions | |
4105 | @cindex addresses | |
4106 | @cindex numeric values | |
4107 | An @dfn{expression} specifies an address or numeric value. | |
4108 | Whitespace may precede and/or follow an expression. | |
4109 | ||
4110 | The result of an expression must be an absolute number, or else an offset into | |
4111 | a particular section. If an expression is not absolute, and there is not | |
a4fb0134 | 4112 | enough information when @command{@value{AS}} sees the expression to know its |
252b5132 RH |
4113 | section, a second pass over the source program might be necessary to interpret |
4114 | the expression---but the second pass is currently not implemented. | |
a4fb0134 | 4115 | @command{@value{AS}} aborts with an error message in this situation. |
252b5132 RH |
4116 | |
4117 | @menu | |
4118 | * Empty Exprs:: Empty Expressions | |
4119 | * Integer Exprs:: Integer Expressions | |
4120 | @end menu | |
4121 | ||
4122 | @node Empty Exprs | |
4123 | @section Empty Expressions | |
4124 | ||
4125 | @cindex empty expressions | |
4126 | @cindex expressions, empty | |
4127 | An empty expression has no value: it is just whitespace or null. | |
4128 | Wherever an absolute expression is required, you may omit the | |
a4fb0134 | 4129 | expression, and @command{@value{AS}} assumes a value of (absolute) 0. This |
252b5132 RH |
4130 | is compatible with other assemblers. |
4131 | ||
4132 | @node Integer Exprs | |
4133 | @section Integer Expressions | |
4134 | ||
4135 | @cindex integer expressions | |
4136 | @cindex expressions, integer | |
4137 | An @dfn{integer expression} is one or more @emph{arguments} delimited | |
4138 | by @emph{operators}. | |
4139 | ||
4140 | @menu | |
4141 | * Arguments:: Arguments | |
4142 | * Operators:: Operators | |
4143 | * Prefix Ops:: Prefix Operators | |
4144 | * Infix Ops:: Infix Operators | |
4145 | @end menu | |
4146 | ||
4147 | @node Arguments | |
4148 | @subsection Arguments | |
4149 | ||
4150 | @cindex expression arguments | |
4151 | @cindex arguments in expressions | |
4152 | @cindex operands in expressions | |
4153 | @cindex arithmetic operands | |
4154 | @dfn{Arguments} are symbols, numbers or subexpressions. In other | |
4155 | contexts arguments are sometimes called ``arithmetic operands''. In | |
4156 | this manual, to avoid confusing them with the ``instruction operands'' of | |
4157 | the machine language, we use the term ``argument'' to refer to parts of | |
4158 | expressions only, reserving the word ``operand'' to refer only to machine | |
4159 | instruction operands. | |
4160 | ||
4161 | Symbols are evaluated to yield @{@var{section} @var{NNN}@} where | |
4162 | @var{section} is one of text, data, bss, absolute, | |
4163 | or undefined. @var{NNN} is a signed, 2's complement 32 bit | |
4164 | integer. | |
4165 | ||
4166 | Numbers are usually integers. | |
4167 | ||
4168 | A number can be a flonum or bignum. In this case, you are warned | |
a4fb0134 | 4169 | that only the low order 32 bits are used, and @command{@value{AS}} pretends |
252b5132 RH |
4170 | these 32 bits are an integer. You may write integer-manipulating |
4171 | instructions that act on exotic constants, compatible with other | |
4172 | assemblers. | |
4173 | ||
4174 | @cindex subexpressions | |
4175 | Subexpressions are a left parenthesis @samp{(} followed by an integer | |
4176 | expression, followed by a right parenthesis @samp{)}; or a prefix | |
4177 | operator followed by an argument. | |
4178 | ||
4179 | @node Operators | |
4180 | @subsection Operators | |
4181 | ||
4182 | @cindex operators, in expressions | |
4183 | @cindex arithmetic functions | |
4184 | @cindex functions, in expressions | |
4185 | @dfn{Operators} are arithmetic functions, like @code{+} or @code{%}. Prefix | |
4186 | operators are followed by an argument. Infix operators appear | |
4187 | between their arguments. Operators may be preceded and/or followed by | |
4188 | whitespace. | |
4189 | ||
4190 | @node Prefix Ops | |
4191 | @subsection Prefix Operator | |
4192 | ||
4193 | @cindex prefix operators | |
a4fb0134 | 4194 | @command{@value{AS}} has the following @dfn{prefix operators}. They each take |
252b5132 RH |
4195 | one argument, which must be absolute. |
4196 | ||
4197 | @c the tex/end tex stuff surrounding this small table is meant to make | |
4198 | @c it align, on the printed page, with the similar table in the next | |
4199 | @c section (which is inside an enumerate). | |
4200 | @tex | |
4201 | \global\advance\leftskip by \itemindent | |
4202 | @end tex | |
4203 | ||
4204 | @table @code | |
4205 | @item - | |
4206 | @dfn{Negation}. Two's complement negation. | |
4207 | @item ~ | |
4208 | @dfn{Complementation}. Bitwise not. | |
4209 | @end table | |
4210 | ||
4211 | @tex | |
4212 | \global\advance\leftskip by -\itemindent | |
4213 | @end tex | |
4214 | ||
4215 | @node Infix Ops | |
4216 | @subsection Infix Operators | |
4217 | ||
4218 | @cindex infix operators | |
4219 | @cindex operators, permitted arguments | |
4220 | @dfn{Infix operators} take two arguments, one on either side. Operators | |
4221 | have precedence, but operations with equal precedence are performed left | |
a4fb0134 | 4222 | to right. Apart from @code{+} or @option{-}, both arguments must be |
252b5132 RH |
4223 | absolute, and the result is absolute. |
4224 | ||
4225 | @enumerate | |
4226 | @cindex operator precedence | |
4227 | @cindex precedence of operators | |
4228 | ||
4229 | @item | |
4230 | Highest Precedence | |
4231 | ||
4232 | @table @code | |
4233 | @item * | |
4234 | @dfn{Multiplication}. | |
4235 | ||
4236 | @item / | |
4237 | @dfn{Division}. Truncation is the same as the C operator @samp{/} | |
4238 | ||
4239 | @item % | |
4240 | @dfn{Remainder}. | |
4241 | ||
d1eac9d9 | 4242 | @item << |
252b5132 RH |
4243 | @dfn{Shift Left}. Same as the C operator @samp{<<}. |
4244 | ||
d1eac9d9 | 4245 | @item >> |
252b5132 RH |
4246 | @dfn{Shift Right}. Same as the C operator @samp{>>}. |
4247 | @end table | |
4248 | ||
4249 | @item | |
4250 | Intermediate precedence | |
4251 | ||
4252 | @table @code | |
4253 | @item | | |
4254 | ||
4255 | @dfn{Bitwise Inclusive Or}. | |
4256 | ||
4257 | @item & | |
4258 | @dfn{Bitwise And}. | |
4259 | ||
4260 | @item ^ | |
4261 | @dfn{Bitwise Exclusive Or}. | |
4262 | ||
4263 | @item ! | |
4264 | @dfn{Bitwise Or Not}. | |
4265 | @end table | |
4266 | ||
4267 | @item | |
b131d4dc | 4268 | Low Precedence |
252b5132 RH |
4269 | |
4270 | @table @code | |
4271 | @cindex addition, permitted arguments | |
4272 | @cindex plus, permitted arguments | |
4273 | @cindex arguments for addition | |
4274 | @item + | |
4275 | @dfn{Addition}. If either argument is absolute, the result has the section of | |
4276 | the other argument. You may not add together arguments from different | |
4277 | sections. | |
4278 | ||
4279 | @cindex subtraction, permitted arguments | |
4280 | @cindex minus, permitted arguments | |
4281 | @cindex arguments for subtraction | |
4282 | @item - | |
4283 | @dfn{Subtraction}. If the right argument is absolute, the | |
4284 | result has the section of the left argument. | |
4285 | If both arguments are in the same section, the result is absolute. | |
4286 | You may not subtract arguments from different sections. | |
4287 | @c FIXME is there still something useful to say about undefined - undefined ? | |
b131d4dc NC |
4288 | |
4289 | @cindex comparison expressions | |
4290 | @cindex expressions, comparison | |
4291 | @item == | |
4292 | @dfn{Is Equal To} | |
4293 | @item <> | |
723a8472 | 4294 | @itemx != |
b131d4dc NC |
4295 | @dfn{Is Not Equal To} |
4296 | @item < | |
4297 | @dfn{Is Less Than} | |
d1eac9d9 | 4298 | @item > |
b131d4dc | 4299 | @dfn{Is Greater Than} |
d1eac9d9 | 4300 | @item >= |
b131d4dc | 4301 | @dfn{Is Greater Than Or Equal To} |
d1eac9d9 | 4302 | @item <= |
b131d4dc NC |
4303 | @dfn{Is Less Than Or Equal To} |
4304 | ||
4305 | The comparison operators can be used as infix operators. A true results has a | |
4306 | value of -1 whereas a false result has a value of 0. Note, these operators | |
4307 | perform signed comparisons. | |
4308 | @end table | |
4309 | ||
4310 | @item Lowest Precedence | |
4311 | ||
4312 | @table @code | |
4313 | @item && | |
4314 | @dfn{Logical And}. | |
4315 | ||
4316 | @item || | |
4317 | @dfn{Logical Or}. | |
4318 | ||
4319 | These two logical operations can be used to combine the results of sub | |
4320 | expressions. Note, unlike the comparison operators a true result returns a | |
4321 | value of 1 but a false results does still return 0. Also note that the logical | |
4322 | or operator has a slightly lower precedence than logical and. | |
4323 | ||
252b5132 RH |
4324 | @end table |
4325 | @end enumerate | |
4326 | ||
4327 | In short, it's only meaningful to add or subtract the @emph{offsets} in an | |
4328 | address; you can only have a defined section in one of the two arguments. | |
4329 | ||
4330 | @node Pseudo Ops | |
4331 | @chapter Assembler Directives | |
4332 | ||
4333 | @cindex directives, machine independent | |
4334 | @cindex pseudo-ops, machine independent | |
4335 | @cindex machine independent directives | |
4336 | All assembler directives have names that begin with a period (@samp{.}). | |
7e302352 RS |
4337 | The names are case insensitive for most targets, and usually written |
4338 | in lower case. | |
252b5132 RH |
4339 | |
4340 | This chapter discusses directives that are available regardless of the | |
4341 | target machine configuration for the @sc{gnu} assembler. | |
4342 | @ifset GENERIC | |
4343 | Some machine configurations provide additional directives. | |
4344 | @xref{Machine Dependencies}. | |
4345 | @end ifset | |
4346 | @ifclear GENERIC | |
4347 | @ifset machine-directives | |
96e9638b | 4348 | @xref{Machine Dependencies}, for additional directives. |
252b5132 RH |
4349 | @end ifset |
4350 | @end ifclear | |
4351 | ||
4352 | @menu | |
4353 | * Abort:: @code{.abort} | |
4354 | @ifset COFF | |
38a57ae7 | 4355 | * ABORT (COFF):: @code{.ABORT} |
252b5132 | 4356 | @end ifset |
f0dc282c | 4357 | |
252b5132 | 4358 | * Align:: @code{.align @var{abs-expr} , @var{abs-expr}} |
caa32fe5 | 4359 | * Altmacro:: @code{.altmacro} |
252b5132 RH |
4360 | * Ascii:: @code{.ascii "@var{string}"}@dots{} |
4361 | * Asciz:: @code{.asciz "@var{string}"}@dots{} | |
4362 | * Balign:: @code{.balign @var{abs-expr} , @var{abs-expr}} | |
d3b47e2b | 4363 | * Bundle directives:: @code{.bundle_align_mode @var{abs-expr}}, etc |
252b5132 | 4364 | * Byte:: @code{.byte @var{expressions}} |
4b7d318b | 4365 | * CFI directives:: @code{.cfi_startproc [simple]}, @code{.cfi_endproc}, etc. |
ccf8a69b | 4366 | * Comm:: @code{.comm @var{symbol} , @var{length} } |
252b5132 | 4367 | * Data:: @code{.data @var{subsection}} |
340d33e5 NC |
4368 | * Dc:: @code{.dc[@var{size}] @var{expressions}} |
4369 | * Dcb:: @code{.dcb[@var{size}] @var{number} [,@var{fill}]} | |
4370 | * Ds:: @code{.ds[@var{size}] @var{number} [,@var{fill}]} | |
252b5132 RH |
4371 | @ifset COFF |
4372 | * Def:: @code{.def @var{name}} | |
4373 | @end ifset | |
a8eb42a8 | 4374 | @ifset aout |
252b5132 RH |
4375 | * Desc:: @code{.desc @var{symbol}, @var{abs-expression}} |
4376 | @end ifset | |
4377 | @ifset COFF | |
4378 | * Dim:: @code{.dim} | |
4379 | @end ifset | |
f0dc282c | 4380 | |
252b5132 RH |
4381 | * Double:: @code{.double @var{flonums}} |
4382 | * Eject:: @code{.eject} | |
4383 | * Else:: @code{.else} | |
3fd9f047 | 4384 | * Elseif:: @code{.elseif} |
252b5132 RH |
4385 | * End:: @code{.end} |
4386 | @ifset COFF | |
4387 | * Endef:: @code{.endef} | |
4388 | @end ifset | |
f0dc282c | 4389 | |
252b5132 RH |
4390 | * Endfunc:: @code{.endfunc} |
4391 | * Endif:: @code{.endif} | |
4392 | * Equ:: @code{.equ @var{symbol}, @var{expression}} | |
4393 | * Equiv:: @code{.equiv @var{symbol}, @var{expression}} | |
9497f5ac | 4394 | * Eqv:: @code{.eqv @var{symbol}, @var{expression}} |
252b5132 | 4395 | * Err:: @code{.err} |
d190d046 | 4396 | * Error:: @code{.error @var{string}} |
252b5132 RH |
4397 | * Exitm:: @code{.exitm} |
4398 | * Extern:: @code{.extern} | |
4399 | * Fail:: @code{.fail} | |
14082c76 | 4400 | * File:: @code{.file} |
252b5132 RH |
4401 | * Fill:: @code{.fill @var{repeat} , @var{size} , @var{value}} |
4402 | * Float:: @code{.float @var{flonums}} | |
01642c12 | 4403 | * Func:: @code{.func} |
252b5132 | 4404 | * Global:: @code{.global @var{symbol}}, @code{.globl @var{symbol}} |
c91d2e08 | 4405 | @ifset ELF |
3a99f02f | 4406 | * Gnu_attribute:: @code{.gnu_attribute @var{tag},@var{value}} |
c91d2e08 NC |
4407 | * Hidden:: @code{.hidden @var{names}} |
4408 | @end ifset | |
f0dc282c | 4409 | |
252b5132 RH |
4410 | * hword:: @code{.hword @var{expressions}} |
4411 | * Ident:: @code{.ident} | |
4412 | * If:: @code{.if @var{absolute expression}} | |
7e005732 | 4413 | * Incbin:: @code{.incbin "@var{file}"[,@var{skip}[,@var{count}]]} |
252b5132 RH |
4414 | * Include:: @code{.include "@var{file}"} |
4415 | * Int:: @code{.int @var{expressions}} | |
c91d2e08 NC |
4416 | @ifset ELF |
4417 | * Internal:: @code{.internal @var{names}} | |
4418 | @end ifset | |
f0dc282c | 4419 | |
252b5132 RH |
4420 | * Irp:: @code{.irp @var{symbol},@var{values}}@dots{} |
4421 | * Irpc:: @code{.irpc @var{symbol},@var{values}}@dots{} | |
4422 | * Lcomm:: @code{.lcomm @var{symbol} , @var{length}} | |
4423 | * Lflags:: @code{.lflags} | |
4424 | @ifclear no-line-dir | |
4425 | * Line:: @code{.line @var{line-number}} | |
4426 | @end ifclear | |
f0dc282c | 4427 | |
252b5132 RH |
4428 | * Linkonce:: @code{.linkonce [@var{type}]} |
4429 | * List:: @code{.list} | |
bd0eb99b | 4430 | * Ln:: @code{.ln @var{line-number}} |
14082c76 BW |
4431 | * Loc:: @code{.loc @var{fileno} @var{lineno}} |
4432 | * Loc_mark_labels:: @code{.loc_mark_labels @var{enable}} | |
4d4175af BW |
4433 | @ifset ELF |
4434 | * Local:: @code{.local @var{names}} | |
4435 | @end ifset | |
bd0eb99b | 4436 | |
252b5132 RH |
4437 | * Long:: @code{.long @var{expressions}} |
4438 | @ignore | |
4439 | * Lsym:: @code{.lsym @var{symbol}, @var{expression}} | |
4440 | @end ignore | |
f0dc282c | 4441 | |
252b5132 RH |
4442 | * Macro:: @code{.macro @var{name} @var{args}}@dots{} |
4443 | * MRI:: @code{.mri @var{val}} | |
caa32fe5 | 4444 | * Noaltmacro:: @code{.noaltmacro} |
252b5132 | 4445 | * Nolist:: @code{.nolist} |
8f065d3b | 4446 | * Nops:: @code{.nops @var{size}[, @var{control}]} |
252b5132 | 4447 | * Octa:: @code{.octa @var{bignums}} |
9aec2026 | 4448 | * Offset:: @code{.offset @var{loc}} |
85234291 L |
4449 | * Org:: @code{.org @var{new-lc}, @var{fill}} |
4450 | * P2align:: @code{.p2align @var{abs-expr}, @var{abs-expr}, @var{abs-expr}} | |
c91d2e08 NC |
4451 | @ifset ELF |
4452 | * PopSection:: @code{.popsection} | |
4453 | * Previous:: @code{.previous} | |
4454 | @end ifset | |
f0dc282c | 4455 | |
252b5132 | 4456 | * Print:: @code{.print @var{string}} |
c91d2e08 NC |
4457 | @ifset ELF |
4458 | * Protected:: @code{.protected @var{names}} | |
4459 | @end ifset | |
f0dc282c | 4460 | |
252b5132 RH |
4461 | * Psize:: @code{.psize @var{lines}, @var{columns}} |
4462 | * Purgem:: @code{.purgem @var{name}} | |
c91d2e08 NC |
4463 | @ifset ELF |
4464 | * PushSection:: @code{.pushsection @var{name}} | |
4465 | @end ifset | |
f0dc282c | 4466 | |
252b5132 | 4467 | * Quad:: @code{.quad @var{bignums}} |
05e9452c | 4468 | * Reloc:: @code{.reloc @var{offset}, @var{reloc_name}[, @var{expression}]} |
252b5132 RH |
4469 | * Rept:: @code{.rept @var{count}} |
4470 | * Sbttl:: @code{.sbttl "@var{subheading}"} | |
4471 | @ifset COFF | |
4472 | * Scl:: @code{.scl @var{class}} | |
c1253627 NC |
4473 | @end ifset |
4474 | @ifset COFF-ELF | |
7337fc21 | 4475 | * Section:: @code{.section @var{name}[, @var{flags}]} |
252b5132 | 4476 | @end ifset |
f0dc282c | 4477 | |
252b5132 RH |
4478 | * Set:: @code{.set @var{symbol}, @var{expression}} |
4479 | * Short:: @code{.short @var{expressions}} | |
4480 | * Single:: @code{.single @var{flonums}} | |
c1253627 | 4481 | @ifset COFF-ELF |
c91d2e08 | 4482 | * Size:: @code{.size [@var{name} , @var{expression}]} |
c1253627 | 4483 | @end ifset |
884f0d36 | 4484 | @ifclear no-space-dir |
340d33e5 | 4485 | * Skip:: @code{.skip @var{size} [,@var{fill}]} |
884f0d36 BW |
4486 | @end ifclear |
4487 | ||
252b5132 | 4488 | * Sleb128:: @code{.sleb128 @var{expressions}} |
884f0d36 | 4489 | @ifclear no-space-dir |
340d33e5 | 4490 | * Space:: @code{.space @var{size} [,@var{fill}]} |
884f0d36 | 4491 | @end ifclear |
252b5132 RH |
4492 | @ifset have-stabs |
4493 | * Stab:: @code{.stabd, .stabn, .stabs} | |
4494 | @end ifset | |
f0dc282c | 4495 | |
38a57ae7 | 4496 | * String:: @code{.string "@var{str}"}, @code{.string8 "@var{str}"}, @code{.string16 "@var{str}"}, @code{.string32 "@var{str}"}, @code{.string64 "@var{str}"} |
252b5132 RH |
4497 | * Struct:: @code{.struct @var{expression}} |
4498 | @ifset ELF | |
c91d2e08 | 4499 | * SubSection:: @code{.subsection} |
252b5132 RH |
4500 | * Symver:: @code{.symver @var{name},@var{name2@@nodename}} |
4501 | @end ifset | |
f0dc282c | 4502 | |
252b5132 RH |
4503 | @ifset COFF |
4504 | * Tag:: @code{.tag @var{structname}} | |
4505 | @end ifset | |
f0dc282c | 4506 | |
252b5132 RH |
4507 | * Text:: @code{.text @var{subsection}} |
4508 | * Title:: @code{.title "@var{heading}"} | |
c1253627 | 4509 | @ifset COFF-ELF |
c91d2e08 | 4510 | * Type:: @code{.type <@var{int} | @var{name} , @var{type description}>} |
c1253627 NC |
4511 | @end ifset |
4512 | ||
c91d2e08 | 4513 | * Uleb128:: @code{.uleb128 @var{expressions}} |
252b5132 | 4514 | @ifset COFF |
252b5132 RH |
4515 | * Val:: @code{.val @var{addr}} |
4516 | @end ifset | |
f0dc282c | 4517 | |
2e13b764 | 4518 | @ifset ELF |
c91d2e08 | 4519 | * Version:: @code{.version "@var{string}"} |
c91d2e08 NC |
4520 | * VTableEntry:: @code{.vtable_entry @var{table}, @var{offset}} |
4521 | * VTableInherit:: @code{.vtable_inherit @var{child}, @var{parent}} | |
2e13b764 | 4522 | @end ifset |
f0dc282c | 4523 | |
d190d046 | 4524 | * Warning:: @code{.warning @var{string}} |
c87db184 | 4525 | * Weak:: @code{.weak @var{names}} |
06e77878 | 4526 | * Weakref:: @code{.weakref @var{alias}, @var{symbol}} |
252b5132 | 4527 | * Word:: @code{.word @var{expressions}} |
7ce98c16 NC |
4528 | @ifclear no-space-dir |
4529 | * Zero:: @code{.zero @var{size}} | |
4530 | @end ifclear | |
2b841ec2 AM |
4531 | @ifset ELF |
4532 | * 2byte:: @code{.2byte @var{expressions}} | |
4533 | * 4byte:: @code{.4byte @var{expressions}} | |
4534 | * 8byte:: @code{.8byte @var{bignums}} | |
4535 | @end ifset | |
252b5132 RH |
4536 | * Deprecated:: Deprecated Directives |
4537 | @end menu | |
4538 | ||
4539 | @node Abort | |
4540 | @section @code{.abort} | |
4541 | ||
4542 | @cindex @code{abort} directive | |
4543 | @cindex stopping the assembly | |
4544 | This directive stops the assembly immediately. It is for | |
4545 | compatibility with other assemblers. The original idea was that the | |
4546 | assembly language source would be piped into the assembler. If the sender | |
a4fb0134 | 4547 | of the source quit, it could use this directive tells @command{@value{AS}} to |
252b5132 RH |
4548 | quit also. One day @code{.abort} will not be supported. |
4549 | ||
4550 | @ifset COFF | |
370b66a1 CD |
4551 | @node ABORT (COFF) |
4552 | @section @code{.ABORT} (COFF) | |
252b5132 RH |
4553 | |
4554 | @cindex @code{ABORT} directive | |
a4fb0134 | 4555 | When producing COFF output, @command{@value{AS}} accepts this directive as a |
252b5132 RH |
4556 | synonym for @samp{.abort}. |
4557 | ||
252b5132 RH |
4558 | @end ifset |
4559 | ||
4560 | @node Align | |
4561 | @section @code{.align @var{abs-expr}, @var{abs-expr}, @var{abs-expr}} | |
4562 | ||
4563 | @cindex padding the location counter | |
4564 | @cindex @code{align} directive | |
4565 | Pad the location counter (in the current subsection) to a particular storage | |
4566 | boundary. The first expression (which must be absolute) is the alignment | |
4567 | required, as described below. | |
4568 | ||
4569 | The second expression (also absolute) gives the fill value to be stored in the | |
4570 | padding bytes. It (and the comma) may be omitted. If it is omitted, the | |
2ca23e65 | 4571 | padding bytes are normally zero. However, on most systems, if the section is |
252b5132 RH |
4572 | marked as containing code and the fill value is omitted, the space is filled |
4573 | with no-op instructions. | |
4574 | ||
4575 | The third expression is also absolute, and is also optional. If it is present, | |
4576 | it is the maximum number of bytes that should be skipped by this alignment | |
4577 | directive. If doing the alignment would require skipping more bytes than the | |
4578 | specified maximum, then the alignment is not done at all. You can omit the | |
4579 | fill value (the second argument) entirely by simply using two commas after the | |
4580 | required alignment; this can be useful if you want the alignment to be filled | |
4581 | with no-op instructions when appropriate. | |
4582 | ||
4583 | The way the required alignment is specified varies from system to system. | |
a8eb42a8 | 4584 | For the arc, hppa, i386 using ELF, iq2000, m68k, or1k, |
60946ad0 | 4585 | s390, sparc, tic4x, tic80 and xtensa, the first expression is the |
252b5132 RH |
4586 | alignment request in bytes. For example @samp{.align 8} advances |
4587 | the location counter until it is a multiple of 8. If the location counter | |
60946ad0 AM |
4588 | is already a multiple of 8, no change is needed. For the tic54x, the |
4589 | first expression is the alignment request in words. | |
252b5132 | 4590 | |
9e9a9798 | 4591 | For other systems, including ppc, i386 using a.out format, arm and |
adcf07e6 | 4592 | strongarm, it is the |
252b5132 RH |
4593 | number of low-order zero bits the location counter must have after |
4594 | advancement. For example @samp{.align 3} advances the location | |
a6ce99e9 | 4595 | counter until it is a multiple of 8. If the location counter is already a |
252b5132 RH |
4596 | multiple of 8, no change is needed. |
4597 | ||
4598 | This inconsistency is due to the different behaviors of the various | |
4599 | native assemblers for these systems which GAS must emulate. | |
4600 | GAS also provides @code{.balign} and @code{.p2align} directives, | |
4601 | described later, which have a consistent behavior across all | |
4602 | architectures (but are specific to GAS). | |
4603 | ||
ccf8a69b BW |
4604 | @node Altmacro |
4605 | @section @code{.altmacro} | |
4606 | Enable alternate macro mode, enabling: | |
4607 | ||
4608 | @ftable @code | |
4609 | @item LOCAL @var{name} [ , @dots{} ] | |
4610 | One additional directive, @code{LOCAL}, is available. It is used to | |
4611 | generate a string replacement for each of the @var{name} arguments, and | |
4612 | replace any instances of @var{name} in each macro expansion. The | |
4613 | replacement string is unique in the assembly, and different for each | |
4614 | separate macro expansion. @code{LOCAL} allows you to write macros that | |
4615 | define symbols, without fear of conflict between separate macro expansions. | |
4616 | ||
4617 | @item String delimiters | |
4618 | You can write strings delimited in these other ways besides | |
4619 | @code{"@var{string}"}: | |
4620 | ||
4621 | @table @code | |
4622 | @item '@var{string}' | |
4623 | You can delimit strings with single-quote characters. | |
4624 | ||
4625 | @item <@var{string}> | |
4626 | You can delimit strings with matching angle brackets. | |
4627 | @end table | |
4628 | ||
4629 | @item single-character string escape | |
4630 | To include any single character literally in a string (even if the | |
4631 | character would otherwise have some special meaning), you can prefix the | |
4632 | character with @samp{!} (an exclamation mark). For example, you can | |
4633 | write @samp{<4.3 !> 5.4!!>} to get the literal text @samp{4.3 > 5.4!}. | |
4634 | ||
4635 | @item Expression results as strings | |
4636 | You can write @samp{%@var{expr}} to evaluate the expression @var{expr} | |
01642c12 | 4637 | and use the result as a string. |
ccf8a69b BW |
4638 | @end ftable |
4639 | ||
252b5132 RH |
4640 | @node Ascii |
4641 | @section @code{.ascii "@var{string}"}@dots{} | |
4642 | ||
4643 | @cindex @code{ascii} directive | |
4644 | @cindex string literals | |
4645 | @code{.ascii} expects zero or more string literals (@pxref{Strings}) | |
4646 | separated by commas. It assembles each string (with no automatic | |
4647 | trailing zero byte) into consecutive addresses. | |
4648 | ||
4649 | @node Asciz | |
4650 | @section @code{.asciz "@var{string}"}@dots{} | |
4651 | ||
4652 | @cindex @code{asciz} directive | |
4653 | @cindex zero-terminated strings | |
4654 | @cindex null-terminated strings | |
4655 | @code{.asciz} is just like @code{.ascii}, but each string is followed by | |
4656 | a zero byte. The ``z'' in @samp{.asciz} stands for ``zero''. | |
4657 | ||
4658 | @node Balign | |
4659 | @section @code{.balign[wl] @var{abs-expr}, @var{abs-expr}, @var{abs-expr}} | |
4660 | ||
4661 | @cindex padding the location counter given number of bytes | |
4662 | @cindex @code{balign} directive | |
4663 | Pad the location counter (in the current subsection) to a particular | |
4664 | storage boundary. The first expression (which must be absolute) is the | |
4665 | alignment request in bytes. For example @samp{.balign 8} advances | |
4666 | the location counter until it is a multiple of 8. If the location counter | |
4667 | is already a multiple of 8, no change is needed. | |
4668 | ||
4669 | The second expression (also absolute) gives the fill value to be stored in the | |
4670 | padding bytes. It (and the comma) may be omitted. If it is omitted, the | |
2ca23e65 | 4671 | padding bytes are normally zero. However, on most systems, if the section is |
252b5132 RH |
4672 | marked as containing code and the fill value is omitted, the space is filled |
4673 | with no-op instructions. | |
4674 | ||
4675 | The third expression is also absolute, and is also optional. If it is present, | |
4676 | it is the maximum number of bytes that should be skipped by this alignment | |
4677 | directive. If doing the alignment would require skipping more bytes than the | |
4678 | specified maximum, then the alignment is not done at all. You can omit the | |
4679 | fill value (the second argument) entirely by simply using two commas after the | |
4680 | required alignment; this can be useful if you want the alignment to be filled | |
4681 | with no-op instructions when appropriate. | |
4682 | ||
4683 | @cindex @code{balignw} directive | |
4684 | @cindex @code{balignl} directive | |
4685 | The @code{.balignw} and @code{.balignl} directives are variants of the | |
4686 | @code{.balign} directive. The @code{.balignw} directive treats the fill | |
4687 | pattern as a two byte word value. The @code{.balignl} directives treats the | |
4688 | fill pattern as a four byte longword value. For example, @code{.balignw | |
4689 | 4,0x368d} will align to a multiple of 4. If it skips two bytes, they will be | |
4690 | filled in with the value 0x368d (the exact placement of the bytes depends upon | |
4691 | the endianness of the processor). If it skips 1 or 3 bytes, the fill value is | |
4692 | undefined. | |
4693 | ||
fa94de6b | 4694 | @node Bundle directives |
d3b47e2b L |
4695 | @section Bundle directives |
4696 | @subsection @code{.bundle_align_mode @var{abs-expr}} | |
fa94de6b RM |
4697 | @cindex @code{bundle_align_mode} directive |
4698 | @cindex bundle | |
4699 | @cindex instruction bundle | |
4700 | @cindex aligned instruction bundle | |
ec82c18e | 4701 | @code{.bundle_align_mode} enables or disables @dfn{aligned instruction |
fa94de6b | 4702 | bundle} mode. In this mode, sequences of adjacent instructions are grouped |
ec82c18e | 4703 | into fixed-sized @dfn{bundles}. If the argument is zero, this mode is |
27dcf5c0 | 4704 | disabled (which is the default state). If the argument it not zero, it |
fa94de6b RM |
4705 | gives the size of an instruction bundle as a power of two (as for the |
4706 | @code{.p2align} directive, @pxref{P2align}). | |
4707 | ||
4708 | For some targets, it's an ABI requirement that no instruction may span a | |
ec82c18e | 4709 | certain aligned boundary. A @dfn{bundle} is simply a sequence of |
fa94de6b RM |
4710 | instructions that starts on an aligned boundary. For example, if |
4711 | @var{abs-expr} is @code{5} then the bundle size is 32, so each aligned | |
4712 | chunk of 32 bytes is a bundle. When aligned instruction bundle mode is in | |
4713 | effect, no single instruction may span a boundary between bundles. If an | |
4714 | instruction would start too close to the end of a bundle for the length of | |
4715 | that particular instruction to fit within the bundle, then the space at the | |
4716 | end of that bundle is filled with no-op instructions so the instruction | |
4717 | starts in the next bundle. As a corollary, it's an error if any single | |
4718 | instruction's encoding is longer than the bundle size. | |
4719 | ||
d3b47e2b | 4720 | @subsection @code{.bundle_lock} and @code{.bundle_unlock} |
fa94de6b RM |
4721 | @cindex @code{bundle_lock} directive |
4722 | @cindex @code{bundle_unlock} directive | |
4723 | The @code{.bundle_lock} and directive @code{.bundle_unlock} directives | |
4724 | allow explicit control over instruction bundle padding. These directives | |
4725 | are only valid when @code{.bundle_align_mode} has been used to enable | |
4726 | aligned instruction bundle mode. It's an error if they appear when | |
4727 | @code{.bundle_align_mode} has not been used at all, or when the last | |
4728 | directive was @w{@code{.bundle_align_mode 0}}. | |
4729 | ||
4730 | @cindex bundle-locked | |
4731 | For some targets, it's an ABI requirement that certain instructions may | |
4732 | appear only as part of specified permissible sequences of multiple | |
4733 | instructions, all within the same bundle. A pair of @code{.bundle_lock} | |
ec82c18e | 4734 | and @code{.bundle_unlock} directives define a @dfn{bundle-locked} |
fa94de6b RM |
4735 | instruction sequence. For purposes of aligned instruction bundle mode, a |
4736 | sequence starting with @code{.bundle_lock} and ending with | |
4737 | @code{.bundle_unlock} is treated as a single instruction. That is, the | |
4738 | entire sequence must fit into a single bundle and may not span a bundle | |
4739 | boundary. If necessary, no-op instructions will be inserted before the | |
4740 | first instruction of the sequence so that the whole sequence starts on an | |
4741 | aligned bundle boundary. It's an error if the sequence is longer than the | |
4742 | bundle size. | |
4743 | ||
d416e51d RM |
4744 | For convenience when using @code{.bundle_lock} and @code{.bundle_unlock} |
4745 | inside assembler macros (@pxref{Macro}), bundle-locked sequences may be | |
4746 | nested. That is, a second @code{.bundle_lock} directive before the next | |
4747 | @code{.bundle_unlock} directive has no effect except that it must be | |
4748 | matched by another closing @code{.bundle_unlock} so that there is the | |
4749 | same number of @code{.bundle_lock} and @code{.bundle_unlock} directives. | |
fa94de6b | 4750 | |
252b5132 RH |
4751 | @node Byte |
4752 | @section @code{.byte @var{expressions}} | |
4753 | ||
4754 | @cindex @code{byte} directive | |
4755 | @cindex integers, one byte | |
4756 | @code{.byte} expects zero or more expressions, separated by commas. | |
4757 | Each expression is assembled into the next byte. | |
4758 | ||
54cfded0 | 4759 | @node CFI directives |
d3b47e2b L |
4760 | @section CFI directives |
4761 | @subsection @code{.cfi_sections @var{section_list}} | |
38462edf JJ |
4762 | @cindex @code{cfi_sections} directive |
4763 | @code{.cfi_sections} may be used to specify whether CFI directives | |
4764 | should emit @code{.eh_frame} section and/or @code{.debug_frame} section. | |
4765 | If @var{section_list} is @code{.eh_frame}, @code{.eh_frame} is emitted, | |
4766 | if @var{section_list} is @code{.debug_frame}, @code{.debug_frame} is emitted. | |
4767 | To emit both use @code{.eh_frame, .debug_frame}. The default if this | |
4768 | directive is not used is @code{.cfi_sections .eh_frame}. | |
4769 | ||
2f0c68f2 CM |
4770 | On targets that support compact unwinding tables these can be generated |
4771 | by specifying @code{.eh_frame_entry} instead of @code{.eh_frame}. | |
4772 | ||
bd5608dc NC |
4773 | Some targets may support an additional name, such as @code{.c6xabi.exidx} |
4774 | which is used by the @value{TIC6X} target. | |
4775 | ||
4776 | The @code{.cfi_sections} directive can be repeated, with the same or different | |
4777 | arguments, provided that CFI generation has not yet started. Once CFI | |
4778 | generation has started however the section list is fixed and any attempts to | |
4779 | redefine it will result in an error. | |
4780 | ||
d3b47e2b | 4781 | @subsection @code{.cfi_startproc [simple]} |
54cfded0 AM |
4782 | @cindex @code{cfi_startproc} directive |
4783 | @code{.cfi_startproc} is used at the beginning of each function that | |
4784 | should have an entry in @code{.eh_frame}. It initializes some internal | |
4b7d318b | 4785 | data structures. Don't forget to close the function by |
54cfded0 AM |
4786 | @code{.cfi_endproc}. |
4787 | ||
01642c12 | 4788 | Unless @code{.cfi_startproc} is used along with parameter @code{simple} |
4b7d318b | 4789 | it also emits some architecture dependent initial CFI instructions. |
01642c12 | 4790 | |
d3b47e2b | 4791 | @subsection @code{.cfi_endproc} |
54cfded0 AM |
4792 | @cindex @code{cfi_endproc} directive |
4793 | @code{.cfi_endproc} is used at the end of a function where it closes its | |
4794 | unwind entry previously opened by | |
b45619c0 | 4795 | @code{.cfi_startproc}, and emits it to @code{.eh_frame}. |
54cfded0 | 4796 | |
d3b47e2b | 4797 | @subsection @code{.cfi_personality @var{encoding} [, @var{exp}]} |
2f0c68f2 | 4798 | @cindex @code{cfi_personality} directive |
9b8ae42e JJ |
4799 | @code{.cfi_personality} defines personality routine and its encoding. |
4800 | @var{encoding} must be a constant determining how the personality | |
4801 | should be encoded. If it is 255 (@code{DW_EH_PE_omit}), second | |
4802 | argument is not present, otherwise second argument should be | |
4803 | a constant or a symbol name. When using indirect encodings, | |
4804 | the symbol provided should be the location where personality | |
4805 | can be loaded from, not the personality routine itself. | |
4806 | The default after @code{.cfi_startproc} is @code{.cfi_personality 0xff}, | |
4807 | no personality routine. | |
4808 | ||
2f0c68f2 CM |
4809 | @subsection @code{.cfi_personality_id @var{id}} |
4810 | @cindex @code{cfi_personality_id} directive | |
4811 | @code{cfi_personality_id} defines a personality routine by its index as | |
4812 | defined in a compact unwinding format. | |
4813 | Only valid when generating compact EH frames (i.e. | |
4814 | with @code{.cfi_sections eh_frame_entry}. | |
4815 | ||
4816 | @subsection @code{.cfi_fde_data [@var{opcode1} [, @dots{}]]} | |
4817 | @cindex @code{cfi_fde_data} directive | |
4818 | @code{cfi_fde_data} is used to describe the compact unwind opcodes to be | |
4819 | used for the current function. These are emitted inline in the | |
4820 | @code{.eh_frame_entry} section if small enough and there is no LSDA, or | |
4821 | in the @code{.gnu.extab} section otherwise. | |
4822 | Only valid when generating compact EH frames (i.e. | |
4823 | with @code{.cfi_sections eh_frame_entry}. | |
4824 | ||
d3b47e2b | 4825 | @subsection @code{.cfi_lsda @var{encoding} [, @var{exp}]} |
9b8ae42e JJ |
4826 | @code{.cfi_lsda} defines LSDA and its encoding. |
4827 | @var{encoding} must be a constant determining how the LSDA | |
2f0c68f2 CM |
4828 | should be encoded. If it is 255 (@code{DW_EH_PE_omit}), the second |
4829 | argument is not present, otherwise the second argument should be a constant | |
9b8ae42e | 4830 | or a symbol name. The default after @code{.cfi_startproc} is @code{.cfi_lsda 0xff}, |
2f0c68f2 CM |
4831 | meaning that no LSDA is present. |
4832 | ||
4833 | @subsection @code{.cfi_inline_lsda} [@var{align}] | |
4834 | @code{.cfi_inline_lsda} marks the start of a LSDA data section and | |
4835 | switches to the corresponding @code{.gnu.extab} section. | |
4836 | Must be preceded by a CFI block containing a @code{.cfi_lsda} directive. | |
4837 | Only valid when generating compact EH frames (i.e. | |
4838 | with @code{.cfi_sections eh_frame_entry}. | |
4839 | ||
4840 | The table header and unwinding opcodes will be generated at this point, | |
4841 | so that they are immediately followed by the LSDA data. The symbol | |
4842 | referenced by the @code{.cfi_lsda} directive should still be defined | |
4843 | in case a fallback FDE based encoding is used. The LSDA data is terminated | |
4844 | by a section directive. | |
4845 | ||
4846 | The optional @var{align} argument specifies the alignment required. | |
4847 | The alignment is specified as a power of two, as with the | |
4848 | @code{.p2align} directive. | |
9b8ae42e | 4849 | |
d3b47e2b | 4850 | @subsection @code{.cfi_def_cfa @var{register}, @var{offset}} |
01642c12 | 4851 | @code{.cfi_def_cfa} defines a rule for computing CFA as: @i{take |
54cfded0 AM |
4852 | address from @var{register} and add @var{offset} to it}. |
4853 | ||
d3b47e2b | 4854 | @subsection @code{.cfi_def_cfa_register @var{register}} |
54cfded0 AM |
4855 | @code{.cfi_def_cfa_register} modifies a rule for computing CFA. From |
4856 | now on @var{register} will be used instead of the old one. Offset | |
4857 | remains the same. | |
4858 | ||
d3b47e2b | 4859 | @subsection @code{.cfi_def_cfa_offset @var{offset}} |
54cfded0 AM |
4860 | @code{.cfi_def_cfa_offset} modifies a rule for computing CFA. Register |
4861 | remains the same, but @var{offset} is new. Note that it is the | |
4862 | absolute offset that will be added to a defined register to compute | |
4863 | CFA address. | |
4864 | ||
d3b47e2b | 4865 | @subsection @code{.cfi_adjust_cfa_offset @var{offset}} |
54cfded0 | 4866 | Same as @code{.cfi_def_cfa_offset} but @var{offset} is a relative |
33eaf5de | 4867 | value that is added/subtracted from the previous offset. |
54cfded0 | 4868 | |
d3b47e2b | 4869 | @subsection @code{.cfi_offset @var{register}, @var{offset}} |
54cfded0 | 4870 | Previous value of @var{register} is saved at offset @var{offset} from |
01642c12 | 4871 | CFA. |
54cfded0 | 4872 | |
084303b8 AK |
4873 | @subsection @code{.cfi_val_offset @var{register}, @var{offset}} |
4874 | Previous value of @var{register} is CFA + @var{offset}. | |
4875 | ||
d3b47e2b | 4876 | @subsection @code{.cfi_rel_offset @var{register}, @var{offset}} |
17076204 RH |
4877 | Previous value of @var{register} is saved at offset @var{offset} from |
4878 | the current CFA register. This is transformed to @code{.cfi_offset} | |
4879 | using the known displacement of the CFA register from the CFA. | |
4880 | This is often easier to use, because the number will match the | |
4881 | code it's annotating. | |
54cfded0 | 4882 | |
d3b47e2b | 4883 | @subsection @code{.cfi_register @var{register1}, @var{register2}} |
4b7d318b L |
4884 | Previous value of @var{register1} is saved in register @var{register2}. |
4885 | ||
d3b47e2b | 4886 | @subsection @code{.cfi_restore @var{register}} |
01642c12 RM |
4887 | @code{.cfi_restore} says that the rule for @var{register} is now the |
4888 | same as it was at the beginning of the function, after all initial | |
4b7d318b L |
4889 | instruction added by @code{.cfi_startproc} were executed. |
4890 | ||
d3b47e2b | 4891 | @subsection @code{.cfi_undefined @var{register}} |
4b7d318b L |
4892 | From now on the previous value of @var{register} can't be restored anymore. |
4893 | ||
d3b47e2b | 4894 | @subsection @code{.cfi_same_value @var{register}} |
01642c12 | 4895 | Current value of @var{register} is the same like in the previous frame, |
4b7d318b L |
4896 | i.e. no restoration needed. |
4897 | ||
48eac74c MG |
4898 | @subsection @code{.cfi_remember_state} and @code{.cfi_restore_state} |
4899 | @code{.cfi_remember_state} pushes the set of rules for every register onto an | |
4900 | implicit stack, while @code{.cfi_restore_state} pops them off the stack and | |
4901 | places them in the current row. This is useful for situations where you have | |
4902 | multiple @code{.cfi_*} directives that need to be undone due to the control | |
4903 | flow of the program. For example, we could have something like this (assuming | |
4904 | the CFA is the value of @code{rbp}): | |
4905 | ||
4906 | @smallexample | |
4907 | je label | |
4908 | popq %rbx | |
4909 | .cfi_restore %rbx | |
4910 | popq %r12 | |
4911 | .cfi_restore %r12 | |
4912 | popq %rbp | |
4913 | .cfi_restore %rbp | |
4914 | .cfi_def_cfa %rsp, 8 | |
4915 | ret | |
4916 | label: | |
4917 | /* Do something else */ | |
4918 | @end smallexample | |
4919 | ||
4920 | Here, we want the @code{.cfi} directives to affect only the rows corresponding | |
4921 | to the instructions before @code{label}. This means we'd have to add multiple | |
4922 | @code{.cfi} directives after @code{label} to recreate the original save | |
4923 | locations of the registers, as well as setting the CFA back to the value of | |
4924 | @code{rbp}. This would be clumsy, and result in a larger binary size. Instead, | |
4925 | we can write: | |
4926 | ||
4927 | @smallexample | |
4928 | je label | |
4929 | popq %rbx | |
4930 | .cfi_remember_state | |
4931 | .cfi_restore %rbx | |
4932 | popq %r12 | |
4933 | .cfi_restore %r12 | |
4934 | popq %rbp | |
4935 | .cfi_restore %rbp | |
4936 | .cfi_def_cfa %rsp, 8 | |
4937 | ret | |
4938 | label: | |
4939 | .cfi_restore_state | |
4940 | /* Do something else */ | |
4941 | @end smallexample | |
4942 | ||
4943 | That way, the rules for the instructions after @code{label} will be the same | |
4944 | as before the first @code{.cfi_restore} without having to use multiple | |
4945 | @code{.cfi} directives. | |
4b7d318b | 4946 | |
d3b47e2b | 4947 | @subsection @code{.cfi_return_column @var{register}} |
01642c12 | 4948 | Change return column @var{register}, i.e. the return address is either |
4b7d318b L |
4949 | directly in @var{register} or can be accessed by rules for @var{register}. |
4950 | ||
d3b47e2b | 4951 | @subsection @code{.cfi_signal_frame} |
63752a75 JJ |
4952 | Mark current function as signal trampoline. |
4953 | ||
d3b47e2b | 4954 | @subsection @code{.cfi_window_save} |
364b6d8b JJ |
4955 | SPARC register window has been saved. |
4956 | ||
d3b47e2b | 4957 | @subsection @code{.cfi_escape} @var{expression}[, @dots{}] |
cdfbf930 RH |
4958 | Allows the user to add arbitrary bytes to the unwind info. One |
4959 | might use this to add OS-specific CFI opcodes, or generic CFI | |
4960 | opcodes that GAS does not yet support. | |
252b5132 | 4961 | |
d3b47e2b | 4962 | @subsection @code{.cfi_val_encoded_addr @var{register}, @var{encoding}, @var{label}} |
f1c4cc75 RH |
4963 | The current value of @var{register} is @var{label}. The value of @var{label} |
4964 | will be encoded in the output file according to @var{encoding}; see the | |
4965 | description of @code{.cfi_personality} for details on this encoding. | |
4966 | ||
4967 | The usefulness of equating a register to a fixed label is probably | |
4968 | limited to the return address register. Here, it can be useful to | |
4969 | mark a code segment that has only one return address which is reached | |
4970 | by a direct branch and no copy of the return address exists in memory | |
4971 | or another register. | |
4972 | ||
ccf8a69b BW |
4973 | @node Comm |
4974 | @section @code{.comm @var{symbol} , @var{length} } | |
bd0eb99b | 4975 | |
ccf8a69b BW |
4976 | @cindex @code{comm} directive |
4977 | @cindex symbol, common | |
4978 | @code{.comm} declares a common symbol named @var{symbol}. When linking, a | |
4979 | common symbol in one object file may be merged with a defined or common symbol | |
4980 | of the same name in another object file. If @code{@value{LD}} does not see a | |
4981 | definition for the symbol--just one or more common symbols--then it will | |
4982 | allocate @var{length} bytes of uninitialized memory. @var{length} must be an | |
4983 | absolute expression. If @code{@value{LD}} sees multiple common symbols with | |
4984 | the same name, and they do not all have the same size, it will allocate space | |
4985 | using the largest size. | |
07a53e5c | 4986 | |
c1711530 DK |
4987 | @ifset COFF-ELF |
4988 | When using ELF or (as a GNU extension) PE, the @code{.comm} directive takes | |
01642c12 | 4989 | an optional third argument. This is the desired alignment of the symbol, |
c1711530 DK |
4990 | specified for ELF as a byte boundary (for example, an alignment of 16 means |
4991 | that the least significant 4 bits of the address should be zero), and for PE | |
4992 | as a power of two (for example, an alignment of 5 means aligned to a 32-byte | |
01642c12 | 4993 | boundary). The alignment must be an absolute expression, and it must be a |
c1711530 | 4994 | power of two. If @code{@value{LD}} allocates uninitialized memory for the |
01642c12 | 4995 | common symbol, it will use the alignment when placing the symbol. If no |
c1711530 | 4996 | alignment is specified, @command{@value{AS}} will set the alignment to the |
ccf8a69b | 4997 | largest power of two less than or equal to the size of the symbol, up to a |
c1711530 DK |
4998 | maximum of 16 on ELF, or the default section alignment of 4 on PE@footnote{This |
4999 | is not the same as the executable image file alignment controlled by @code{@value{LD}}'s | |
5000 | @samp{--section-alignment} option; image file sections in PE are aligned to | |
5001 | multiples of 4096, which is far too large an alignment for ordinary variables. | |
5002 | It is rather the default alignment for (non-debug) sections within object | |
5003 | (@samp{*.o}) files, which are less strictly aligned.}. | |
ccf8a69b | 5004 | @end ifset |
cd1fcb49 | 5005 | |
ccf8a69b BW |
5006 | @ifset HPPA |
5007 | The syntax for @code{.comm} differs slightly on the HPPA. The syntax is | |
5008 | @samp{@var{symbol} .comm, @var{length}}; @var{symbol} is optional. | |
5009 | @end ifset | |
07a53e5c | 5010 | |
252b5132 RH |
5011 | @node Data |
5012 | @section @code{.data @var{subsection}} | |
252b5132 | 5013 | @cindex @code{data} directive |
340d33e5 | 5014 | |
a4fb0134 | 5015 | @code{.data} tells @command{@value{AS}} to assemble the following statements onto the |
252b5132 RH |
5016 | end of the data subsection numbered @var{subsection} (which is an |
5017 | absolute expression). If @var{subsection} is omitted, it defaults | |
5018 | to zero. | |
5019 | ||
340d33e5 NC |
5020 | @node Dc |
5021 | @section @code{.dc[@var{size}] @var{expressions}} | |
5022 | @cindex @code{dc} directive | |
5023 | ||
46c685ac | 5024 | The @code{.dc} directive expects zero or more @var{expressions} separated by |
340d33e5 NC |
5025 | commas. These expressions are evaluated and their values inserted into the |
5026 | current section. The size of the emitted value depends upon the suffix to the | |
5027 | @code{.dc} directive: | |
5028 | ||
5029 | @table @code | |
5030 | @item @samp{.a} | |
5031 | Emits N-bit values, where N is the size of an address on the target system. | |
5032 | @item @samp{.b} | |
5033 | Emits 8-bit values. | |
5034 | @item @samp{.d} | |
5035 | Emits double precision floating-point values. | |
5036 | @item @samp{.l} | |
5037 | Emits 32-bit values. | |
5038 | @item @samp{.s} | |
5039 | Emits single precision floating-point values. | |
5040 | @item @samp{.w} | |
5041 | Emits 16-bit values. | |
5042 | Note - this is true even on targets where the @code{.word} directive would emit | |
5043 | 32-bit values. | |
5044 | @item @samp{.x} | |
5045 | Emits long double precision floating-point values. | |
5046 | @end table | |
5047 | ||
5048 | If no suffix is used then @samp{.w} is assumed. | |
5049 | ||
d7c79856 MR |
5050 | The byte ordering is target dependent, as is the size and format of floating |
5051 | point values. | |
340d33e5 NC |
5052 | |
5053 | @node Dcb | |
5054 | @section @code{.dcb[@var{size}] @var{number} [,@var{fill}]} | |
5055 | @cindex @code{dcb} directive | |
5056 | This directive emits @var{number} copies of @var{fill}, each of @var{size} | |
5057 | bytes. Both @var{number} and @var{fill} are absolute expressions. If the | |
5058 | comma and @var{fill} are omitted, @var{fill} is assumed to be zero. The | |
5059 | @var{size} suffix, if present, must be one of: | |
5060 | ||
5061 | @table @code | |
5062 | @item @samp{.b} | |
5063 | Emits single byte values. | |
5064 | @item @samp{.d} | |
5065 | Emits double-precision floating point values. | |
5066 | @item @samp{.l} | |
5067 | Emits 4-byte values. | |
5068 | @item @samp{.s} | |
5069 | Emits single-precision floating point values. | |
5070 | @item @samp{.w} | |
5071 | Emits 2-byte values. | |
5072 | @item @samp{.x} | |
5073 | Emits long double-precision floating point values. | |
5074 | @end table | |
5075 | ||
5076 | If the @var{size} suffix is omitted then @samp{.w} is assumed. | |
5077 | ||
5078 | The byte ordering is target dependent, as is the size and format of floating | |
5079 | point values. | |
5080 | ||
5081 | @node Ds | |
5082 | @section @code{.ds[@var{size}] @var{number} [,@var{fill}]} | |
5083 | @cindex @code{ds} directive | |
5084 | This directive emits @var{number} copies of @var{fill}, each of @var{size} | |
5085 | bytes. Both @var{number} and @var{fill} are absolute expressions. If the | |
5086 | comma and @var{fill} are omitted, @var{fill} is assumed to be zero. The | |
5087 | @var{size} suffix, if present, must be one of: | |
5088 | ||
5089 | @table @code | |
5090 | @item @samp{.b} | |
5091 | Emits single byte values. | |
5092 | @item @samp{.d} | |
5093 | Emits 8-byte values. | |
5094 | @item @samp{.l} | |
5095 | Emits 4-byte values. | |
5096 | @item @samp{.p} | |
5097 | Emits 12-byte values. | |
5098 | @item @samp{.s} | |
5099 | Emits 4-byte values. | |
5100 | @item @samp{.w} | |
5101 | Emits 2-byte values. | |
5102 | @item @samp{.x} | |
5103 | Emits 12-byte values. | |
5104 | @end table | |
5105 | ||
5106 | Note - unlike the @code{.dcb} directive the @samp{.d}, @samp{.s} and @samp{.x} | |
d7c79856 | 5107 | suffixes do not indicate that floating-point values are to be inserted. |
340d33e5 NC |
5108 | |
5109 | If the @var{size} suffix is omitted then @samp{.w} is assumed. | |
5110 | ||
d7c79856 | 5111 | The byte ordering is target dependent. |
340d33e5 NC |
5112 | |
5113 | ||
252b5132 RH |
5114 | @ifset COFF |
5115 | @node Def | |
5116 | @section @code{.def @var{name}} | |
5117 | ||
5118 | @cindex @code{def} directive | |
5119 | @cindex COFF symbols, debugging | |
5120 | @cindex debugging COFF symbols | |
5121 | Begin defining debugging information for a symbol @var{name}; the | |
5122 | definition extends until the @code{.endef} directive is encountered. | |
252b5132 RH |
5123 | @end ifset |
5124 | ||
a8eb42a8 | 5125 | @ifset aout |
252b5132 RH |
5126 | @node Desc |
5127 | @section @code{.desc @var{symbol}, @var{abs-expression}} | |
5128 | ||
5129 | @cindex @code{desc} directive | |
5130 | @cindex COFF symbol descriptor | |
5131 | @cindex symbol descriptor, COFF | |
5132 | This directive sets the descriptor of the symbol (@pxref{Symbol Attributes}) | |
5133 | to the low 16 bits of an absolute expression. | |
5134 | ||
5135 | @ifset COFF | |
a4fb0134 | 5136 | The @samp{.desc} directive is not available when @command{@value{AS}} is |
252b5132 | 5137 | configured for COFF output; it is only for @code{a.out} or @code{b.out} |
a4fb0134 | 5138 | object format. For the sake of compatibility, @command{@value{AS}} accepts |
252b5132 RH |
5139 | it, but produces no output, when configured for COFF. |
5140 | @end ifset | |
5141 | @end ifset | |
5142 | ||
5143 | @ifset COFF | |
5144 | @node Dim | |
5145 | @section @code{.dim} | |
5146 | ||
5147 | @cindex @code{dim} directive | |
5148 | @cindex COFF auxiliary symbol information | |
5149 | @cindex auxiliary symbol information, COFF | |
5150 | This directive is generated by compilers to include auxiliary debugging | |
5151 | information in the symbol table. It is only permitted inside | |
5152 | @code{.def}/@code{.endef} pairs. | |
252b5132 RH |
5153 | @end ifset |
5154 | ||
5155 | @node Double | |
5156 | @section @code{.double @var{flonums}} | |
5157 | ||
5158 | @cindex @code{double} directive | |
5159 | @cindex floating point numbers (double) | |
5160 | @code{.double} expects zero or more flonums, separated by commas. It | |
5161 | assembles floating point numbers. | |
5162 | @ifset GENERIC | |
5163 | The exact kind of floating point numbers emitted depends on how | |
a4fb0134 | 5164 | @command{@value{AS}} is configured. @xref{Machine Dependencies}. |
252b5132 RH |
5165 | @end ifset |
5166 | @ifclear GENERIC | |
5167 | @ifset IEEEFLOAT | |
5168 | On the @value{TARGET} family @samp{.double} emits 64-bit floating-point numbers | |
5169 | in @sc{ieee} format. | |
5170 | @end ifset | |
5171 | @end ifclear | |
5172 | ||
5173 | @node Eject | |
5174 | @section @code{.eject} | |
5175 | ||
5176 | @cindex @code{eject} directive | |
5177 | @cindex new page, in listings | |
5178 | @cindex page, in listings | |
5179 | @cindex listing control: new page | |
5180 | Force a page break at this point, when generating assembly listings. | |
5181 | ||
5182 | @node Else | |
5183 | @section @code{.else} | |
5184 | ||
5185 | @cindex @code{else} directive | |
a4fb0134 | 5186 | @code{.else} is part of the @command{@value{AS}} support for conditional |
96e9638b | 5187 | assembly; see @ref{If,,@code{.if}}. It marks the beginning of a section |
252b5132 RH |
5188 | of code to be assembled if the condition for the preceding @code{.if} |
5189 | was false. | |
5190 | ||
3fd9f047 TW |
5191 | @node Elseif |
5192 | @section @code{.elseif} | |
5193 | ||
5194 | @cindex @code{elseif} directive | |
a4fb0134 | 5195 | @code{.elseif} is part of the @command{@value{AS}} support for conditional |
96e9638b | 5196 | assembly; see @ref{If,,@code{.if}}. It is shorthand for beginning a new |
3fd9f047 TW |
5197 | @code{.if} block that would otherwise fill the entire @code{.else} section. |
5198 | ||
252b5132 RH |
5199 | @node End |
5200 | @section @code{.end} | |
5201 | ||
5202 | @cindex @code{end} directive | |
a4fb0134 | 5203 | @code{.end} marks the end of the assembly file. @command{@value{AS}} does not |
252b5132 RH |
5204 | process anything in the file past the @code{.end} directive. |
5205 | ||
5206 | @ifset COFF | |
5207 | @node Endef | |
5208 | @section @code{.endef} | |
5209 | ||
5210 | @cindex @code{endef} directive | |
5211 | This directive flags the end of a symbol definition begun with | |
5212 | @code{.def}. | |
252b5132 RH |
5213 | @end ifset |
5214 | ||
5215 | @node Endfunc | |
5216 | @section @code{.endfunc} | |
5217 | @cindex @code{endfunc} directive | |
5218 | @code{.endfunc} marks the end of a function specified with @code{.func}. | |
5219 | ||
5220 | @node Endif | |
5221 | @section @code{.endif} | |
5222 | ||
5223 | @cindex @code{endif} directive | |
a4fb0134 | 5224 | @code{.endif} is part of the @command{@value{AS}} support for conditional assembly; |
252b5132 RH |
5225 | it marks the end of a block of code that is only assembled |
5226 | conditionally. @xref{If,,@code{.if}}. | |
5227 | ||
5228 | @node Equ | |
5229 | @section @code{.equ @var{symbol}, @var{expression}} | |
5230 | ||
5231 | @cindex @code{equ} directive | |
5232 | @cindex assigning values to symbols | |
5233 | @cindex symbols, assigning values to | |
5234 | This directive sets the value of @var{symbol} to @var{expression}. | |
96e9638b | 5235 | It is synonymous with @samp{.set}; see @ref{Set,,@code{.set}}. |
252b5132 RH |
5236 | |
5237 | @ifset HPPA | |
01642c12 | 5238 | The syntax for @code{equ} on the HPPA is |
252b5132 RH |
5239 | @samp{@var{symbol} .equ @var{expression}}. |
5240 | @end ifset | |
5241 | ||
3c9b82ba | 5242 | @ifset Z80 |
01642c12 RM |
5243 | The syntax for @code{equ} on the Z80 is |
5244 | @samp{@var{symbol} equ @var{expression}}. | |
33eaf5de | 5245 | On the Z80 it is an error if @var{symbol} is already defined, |
01642c12 | 5246 | but the symbol is not protected from later redefinition. |
96e9638b | 5247 | Compare @ref{Equiv}. |
3c9b82ba NC |
5248 | @end ifset |
5249 | ||
252b5132 RH |
5250 | @node Equiv |
5251 | @section @code{.equiv @var{symbol}, @var{expression}} | |
5252 | @cindex @code{equiv} directive | |
5253 | The @code{.equiv} directive is like @code{.equ} and @code{.set}, except that | |
8dfa0188 NC |
5254 | the assembler will signal an error if @var{symbol} is already defined. Note a |
5255 | symbol which has been referenced but not actually defined is considered to be | |
5256 | undefined. | |
252b5132 | 5257 | |
01642c12 | 5258 | Except for the contents of the error message, this is roughly equivalent to |
252b5132 RH |
5259 | @smallexample |
5260 | .ifdef SYM | |
5261 | .err | |
5262 | .endif | |
5263 | .equ SYM,VAL | |
5264 | @end smallexample | |
9497f5ac NC |
5265 | plus it protects the symbol from later redefinition. |
5266 | ||
5267 | @node Eqv | |
5268 | @section @code{.eqv @var{symbol}, @var{expression}} | |
5269 | @cindex @code{eqv} directive | |
5270 | The @code{.eqv} directive is like @code{.equiv}, but no attempt is made to | |
5271 | evaluate the expression or any part of it immediately. Instead each time | |
5272 | the resulting symbol is used in an expression, a snapshot of its current | |
5273 | value is taken. | |
252b5132 RH |
5274 | |
5275 | @node Err | |
5276 | @section @code{.err} | |
5277 | @cindex @code{err} directive | |
a4fb0134 SC |
5278 | If @command{@value{AS}} assembles a @code{.err} directive, it will print an error |
5279 | message and, unless the @option{-Z} option was used, it will not generate an | |
f9eb6721 | 5280 | object file. This can be used to signal an error in conditionally compiled code. |
252b5132 | 5281 | |
d190d046 HPN |
5282 | @node Error |
5283 | @section @code{.error "@var{string}"} | |
5284 | @cindex error directive | |
5285 | ||
5286 | Similarly to @code{.err}, this directive emits an error, but you can specify a | |
5287 | string that will be emitted as the error message. If you don't specify the | |
5288 | message, it defaults to @code{".error directive invoked in source file"}. | |
5289 | @xref{Errors, ,Error and Warning Messages}. | |
5290 | ||
5291 | @smallexample | |
5292 | .error "This code has not been assembled and tested." | |
5293 | @end smallexample | |
5294 | ||
252b5132 RH |
5295 | @node Exitm |
5296 | @section @code{.exitm} | |
5297 | Exit early from the current macro definition. @xref{Macro}. | |
5298 | ||
5299 | @node Extern | |
5300 | @section @code{.extern} | |
5301 | ||
5302 | @cindex @code{extern} directive | |
5303 | @code{.extern} is accepted in the source program---for compatibility | |
a4fb0134 | 5304 | with other assemblers---but it is ignored. @command{@value{AS}} treats |
252b5132 RH |
5305 | all undefined symbols as external. |
5306 | ||
5307 | @node Fail | |
5308 | @section @code{.fail @var{expression}} | |
5309 | ||
5310 | @cindex @code{fail} directive | |
5311 | Generates an error or a warning. If the value of the @var{expression} is 500 | |
a4fb0134 SC |
5312 | or more, @command{@value{AS}} will print a warning message. If the value is less |
5313 | than 500, @command{@value{AS}} will print an error message. The message will | |
252b5132 RH |
5314 | include the value of @var{expression}. This can occasionally be useful inside |
5315 | complex nested macros or conditional assembly. | |
5316 | ||
252b5132 | 5317 | @node File |
14082c76 | 5318 | @section @code{.file} |
252b5132 | 5319 | @cindex @code{file} directive |
14082c76 BW |
5320 | |
5321 | @ifclear no-file-dir | |
5322 | There are two different versions of the @code{.file} directive. Targets | |
5323 | that support DWARF2 line number information use the DWARF2 version of | |
5324 | @code{.file}. Other targets use the default version. | |
5325 | ||
5326 | @subheading Default Version | |
5327 | ||
252b5132 RH |
5328 | @cindex logical file name |
5329 | @cindex file name, logical | |
14082c76 BW |
5330 | This version of the @code{.file} directive tells @command{@value{AS}} that we |
5331 | are about to start a new logical file. The syntax is: | |
5332 | ||
5333 | @smallexample | |
5334 | .file @var{string} | |
5335 | @end smallexample | |
5336 | ||
5337 | @var{string} is the new file name. In general, the filename is | |
252b5132 RH |
5338 | recognized whether or not it is surrounded by quotes @samp{"}; but if you wish |
5339 | to specify an empty file name, you must give the quotes--@code{""}. This | |
5340 | statement may go away in future: it is only recognized to be compatible with | |
a4fb0134 | 5341 | old @command{@value{AS}} programs. |
14082c76 BW |
5342 | |
5343 | @subheading DWARF2 Version | |
252b5132 RH |
5344 | @end ifclear |
5345 | ||
14082c76 BW |
5346 | When emitting DWARF2 line number information, @code{.file} assigns filenames |
5347 | to the @code{.debug_line} file name table. The syntax is: | |
5348 | ||
5349 | @smallexample | |
5350 | .file @var{fileno} @var{filename} | |
5351 | @end smallexample | |
5352 | ||
5353 | The @var{fileno} operand should be a unique positive integer to use as the | |
5354 | index of the entry in the table. The @var{filename} operand is a C string | |
5355 | literal. | |
5356 | ||
5357 | The detail of filename indices is exposed to the user because the filename | |
5358 | table is shared with the @code{.debug_info} section of the DWARF2 debugging | |
5359 | information, and thus the user must know the exact indices that table | |
5360 | entries will have. | |
5361 | ||
252b5132 RH |
5362 | @node Fill |
5363 | @section @code{.fill @var{repeat} , @var{size} , @var{value}} | |
5364 | ||
5365 | @cindex @code{fill} directive | |
5366 | @cindex writing patterns in memory | |
5367 | @cindex patterns, writing in memory | |
bc64be0c | 5368 | @var{repeat}, @var{size} and @var{value} are absolute expressions. |
252b5132 RH |
5369 | This emits @var{repeat} copies of @var{size} bytes. @var{Repeat} |
5370 | may be zero or more. @var{Size} may be zero or more, but if it is | |
5371 | more than 8, then it is deemed to have the value 8, compatible with | |
5372 | other people's assemblers. The contents of each @var{repeat} bytes | |
5373 | is taken from an 8-byte number. The highest order 4 bytes are | |
5374 | zero. The lowest order 4 bytes are @var{value} rendered in the | |
a4fb0134 | 5375 | byte-order of an integer on the computer @command{@value{AS}} is assembling for. |
252b5132 RH |
5376 | Each @var{size} bytes in a repetition is taken from the lowest order |
5377 | @var{size} bytes of this number. Again, this bizarre behavior is | |
5378 | compatible with other people's assemblers. | |
5379 | ||
5380 | @var{size} and @var{value} are optional. | |
5381 | If the second comma and @var{value} are absent, @var{value} is | |
5382 | assumed zero. If the first comma and following tokens are absent, | |
5383 | @var{size} is assumed to be 1. | |
5384 | ||
5385 | @node Float | |
5386 | @section @code{.float @var{flonums}} | |
5387 | ||
5388 | @cindex floating point numbers (single) | |
5389 | @cindex @code{float} directive | |
5390 | This directive assembles zero or more flonums, separated by commas. It | |
5391 | has the same effect as @code{.single}. | |
5392 | @ifset GENERIC | |
5393 | The exact kind of floating point numbers emitted depends on how | |
a4fb0134 | 5394 | @command{@value{AS}} is configured. |
252b5132 RH |
5395 | @xref{Machine Dependencies}. |
5396 | @end ifset | |
5397 | @ifclear GENERIC | |
5398 | @ifset IEEEFLOAT | |
5399 | On the @value{TARGET} family, @code{.float} emits 32-bit floating point numbers | |
5400 | in @sc{ieee} format. | |
5401 | @end ifset | |
5402 | @end ifclear | |
5403 | ||
5404 | @node Func | |
5405 | @section @code{.func @var{name}[,@var{label}]} | |
5406 | @cindex @code{func} directive | |
5407 | @code{.func} emits debugging information to denote function @var{name}, and | |
5408 | is ignored unless the file is assembled with debugging enabled. | |
05da4302 | 5409 | Only @samp{--gstabs[+]} is currently supported. |
252b5132 RH |
5410 | @var{label} is the entry point of the function and if omitted @var{name} |
5411 | prepended with the @samp{leading char} is used. | |
5412 | @samp{leading char} is usually @code{_} or nothing, depending on the target. | |
5413 | All functions are currently defined to have @code{void} return type. | |
5414 | The function must be terminated with @code{.endfunc}. | |
5415 | ||
5416 | @node Global | |
5417 | @section @code{.global @var{symbol}}, @code{.globl @var{symbol}} | |
5418 | ||
5419 | @cindex @code{global} directive | |
5420 | @cindex symbol, making visible to linker | |
5421 | @code{.global} makes the symbol visible to @code{@value{LD}}. If you define | |
5422 | @var{symbol} in your partial program, its value is made available to | |
5423 | other partial programs that are linked with it. Otherwise, | |
5424 | @var{symbol} takes its attributes from a symbol of the same name | |
5425 | from another file linked into the same program. | |
5426 | ||
5427 | Both spellings (@samp{.globl} and @samp{.global}) are accepted, for | |
5428 | compatibility with other assemblers. | |
5429 | ||
5430 | @ifset HPPA | |
5431 | On the HPPA, @code{.global} is not always enough to make it accessible to other | |
5432 | partial programs. You may need the HPPA-only @code{.EXPORT} directive as well. | |
96e9638b | 5433 | @xref{HPPA Directives, ,HPPA Assembler Directives}. |
252b5132 RH |
5434 | @end ifset |
5435 | ||
c91d2e08 | 5436 | @ifset ELF |
3a99f02f DJ |
5437 | @node Gnu_attribute |
5438 | @section @code{.gnu_attribute @var{tag},@var{value}} | |
5439 | Record a @sc{gnu} object attribute for this file. @xref{Object Attributes}. | |
5440 | ||
c91d2e08 NC |
5441 | @node Hidden |
5442 | @section @code{.hidden @var{names}} | |
5443 | ||
c1253627 NC |
5444 | @cindex @code{hidden} directive |
5445 | @cindex visibility | |
ed9589d4 | 5446 | This is one of the ELF visibility directives. The other two are |
01642c12 | 5447 | @code{.internal} (@pxref{Internal,,@code{.internal}}) and |
a349d9dd | 5448 | @code{.protected} (@pxref{Protected,,@code{.protected}}). |
c91d2e08 NC |
5449 | |
5450 | This directive overrides the named symbols default visibility (which is set by | |
5451 | their binding: local, global or weak). The directive sets the visibility to | |
5452 | @code{hidden} which means that the symbols are not visible to other components. | |
01642c12 | 5453 | Such symbols are always considered to be @code{protected} as well. |
c91d2e08 NC |
5454 | @end ifset |
5455 | ||
252b5132 RH |
5456 | @node hword |
5457 | @section @code{.hword @var{expressions}} | |
5458 | ||
5459 | @cindex @code{hword} directive | |
5460 | @cindex integers, 16-bit | |
5461 | @cindex numbers, 16-bit | |
5462 | @cindex sixteen bit integers | |
5463 | This expects zero or more @var{expressions}, and emits | |
5464 | a 16 bit number for each. | |
5465 | ||
5466 | @ifset GENERIC | |
5467 | This directive is a synonym for @samp{.short}; depending on the target | |
5468 | architecture, it may also be a synonym for @samp{.word}. | |
5469 | @end ifset | |
5470 | @ifclear GENERIC | |
5471 | @ifset W32 | |
5472 | This directive is a synonym for @samp{.short}. | |
5473 | @end ifset | |
5474 | @ifset W16 | |
5475 | This directive is a synonym for both @samp{.short} and @samp{.word}. | |
5476 | @end ifset | |
5477 | @end ifclear | |
5478 | ||
5479 | @node Ident | |
5480 | @section @code{.ident} | |
5481 | ||
5482 | @cindex @code{ident} directive | |
cb4c78d6 BE |
5483 | |
5484 | This directive is used by some assemblers to place tags in object files. The | |
5485 | behavior of this directive varies depending on the target. When using the | |
5486 | a.out object file format, @command{@value{AS}} simply accepts the directive for | |
5487 | source-file compatibility with existing assemblers, but does not emit anything | |
5488 | for it. When using COFF, comments are emitted to the @code{.comment} or | |
5489 | @code{.rdata} section, depending on the target. When using ELF, comments are | |
5490 | emitted to the @code{.comment} section. | |
252b5132 RH |
5491 | |
5492 | @node If | |
5493 | @section @code{.if @var{absolute expression}} | |
5494 | ||
5495 | @cindex conditional assembly | |
5496 | @cindex @code{if} directive | |
5497 | @code{.if} marks the beginning of a section of code which is only | |
5498 | considered part of the source program being assembled if the argument | |
5499 | (which must be an @var{absolute expression}) is non-zero. The end of | |
5500 | the conditional section of code must be marked by @code{.endif} | |
5501 | (@pxref{Endif,,@code{.endif}}); optionally, you may include code for the | |
5502 | alternative condition, flagged by @code{.else} (@pxref{Else,,@code{.else}}). | |
3fd9f047 TW |
5503 | If you have several conditions to check, @code{.elseif} may be used to avoid |
5504 | nesting blocks if/else within each subsequent @code{.else} block. | |
252b5132 RH |
5505 | |
5506 | The following variants of @code{.if} are also supported: | |
5507 | @table @code | |
5508 | @cindex @code{ifdef} directive | |
5509 | @item .ifdef @var{symbol} | |
5510 | Assembles the following section of code if the specified @var{symbol} | |
8dfa0188 NC |
5511 | has been defined. Note a symbol which has been referenced but not yet defined |
5512 | is considered to be undefined. | |
252b5132 | 5513 | |
26aca5f6 JB |
5514 | @cindex @code{ifb} directive |
5515 | @item .ifb @var{text} | |
5516 | Assembles the following section of code if the operand is blank (empty). | |
5517 | ||
252b5132 RH |
5518 | @cindex @code{ifc} directive |
5519 | @item .ifc @var{string1},@var{string2} | |
5520 | Assembles the following section of code if the two strings are the same. The | |
5521 | strings may be optionally quoted with single quotes. If they are not quoted, | |
5522 | the first string stops at the first comma, and the second string stops at the | |
5523 | end of the line. Strings which contain whitespace should be quoted. The | |
5524 | string comparison is case sensitive. | |
5525 | ||
5526 | @cindex @code{ifeq} directive | |
5527 | @item .ifeq @var{absolute expression} | |
5528 | Assembles the following section of code if the argument is zero. | |
5529 | ||
5530 | @cindex @code{ifeqs} directive | |
5531 | @item .ifeqs @var{string1},@var{string2} | |
5532 | Another form of @code{.ifc}. The strings must be quoted using double quotes. | |
5533 | ||
5534 | @cindex @code{ifge} directive | |
5535 | @item .ifge @var{absolute expression} | |
5536 | Assembles the following section of code if the argument is greater than or | |
5537 | equal to zero. | |
5538 | ||
5539 | @cindex @code{ifgt} directive | |
5540 | @item .ifgt @var{absolute expression} | |
5541 | Assembles the following section of code if the argument is greater than zero. | |
5542 | ||
5543 | @cindex @code{ifle} directive | |
5544 | @item .ifle @var{absolute expression} | |
5545 | Assembles the following section of code if the argument is less than or equal | |
5546 | to zero. | |
5547 | ||
5548 | @cindex @code{iflt} directive | |
5549 | @item .iflt @var{absolute expression} | |
5550 | Assembles the following section of code if the argument is less than zero. | |
5551 | ||
26aca5f6 JB |
5552 | @cindex @code{ifnb} directive |
5553 | @item .ifnb @var{text} | |
5554 | Like @code{.ifb}, but the sense of the test is reversed: this assembles the | |
5555 | following section of code if the operand is non-blank (non-empty). | |
5556 | ||
252b5132 RH |
5557 | @cindex @code{ifnc} directive |
5558 | @item .ifnc @var{string1},@var{string2}. | |
5559 | Like @code{.ifc}, but the sense of the test is reversed: this assembles the | |
5560 | following section of code if the two strings are not the same. | |
5561 | ||
5562 | @cindex @code{ifndef} directive | |
5563 | @cindex @code{ifnotdef} directive | |
5564 | @item .ifndef @var{symbol} | |
5565 | @itemx .ifnotdef @var{symbol} | |
5566 | Assembles the following section of code if the specified @var{symbol} | |
8dfa0188 NC |
5567 | has not been defined. Both spelling variants are equivalent. Note a symbol |
5568 | which has been referenced but not yet defined is considered to be undefined. | |
252b5132 RH |
5569 | |
5570 | @cindex @code{ifne} directive | |
5571 | @item .ifne @var{absolute expression} | |
5572 | Assembles the following section of code if the argument is not equal to zero | |
5573 | (in other words, this is equivalent to @code{.if}). | |
5574 | ||
5575 | @cindex @code{ifnes} directive | |
5576 | @item .ifnes @var{string1},@var{string2} | |
5577 | Like @code{.ifeqs}, but the sense of the test is reversed: this assembles the | |
5578 | following section of code if the two strings are not the same. | |
5579 | @end table | |
5580 | ||
7e005732 NC |
5581 | @node Incbin |
5582 | @section @code{.incbin "@var{file}"[,@var{skip}[,@var{count}]]} | |
5583 | ||
5584 | @cindex @code{incbin} directive | |
5585 | @cindex binary files, including | |
5586 | The @code{incbin} directive includes @var{file} verbatim at the current | |
5587 | location. You can control the search paths used with the @samp{-I} command-line | |
5588 | option (@pxref{Invoking,,Command-Line Options}). Quotation marks are required | |
5589 | around @var{file}. | |
5590 | ||
5591 | The @var{skip} argument skips a number of bytes from the start of the | |
5592 | @var{file}. The @var{count} argument indicates the maximum number of bytes to | |
15dcfbc3 NC |
5593 | read. Note that the data is not aligned in any way, so it is the user's |
5594 | responsibility to make sure that proper alignment is provided both before and | |
5595 | after the @code{incbin} directive. | |
7e005732 | 5596 | |
252b5132 RH |
5597 | @node Include |
5598 | @section @code{.include "@var{file}"} | |
5599 | ||
5600 | @cindex @code{include} directive | |
5601 | @cindex supporting files, including | |
5602 | @cindex files, including | |
5603 | This directive provides a way to include supporting files at specified | |
5604 | points in your source program. The code from @var{file} is assembled as | |
5605 | if it followed the point of the @code{.include}; when the end of the | |
5606 | included file is reached, assembly of the original file continues. You | |
5607 | can control the search paths used with the @samp{-I} command-line option | |
5608 | (@pxref{Invoking,,Command-Line Options}). Quotation marks are required | |
5609 | around @var{file}. | |
5610 | ||
5611 | @node Int | |
5612 | @section @code{.int @var{expressions}} | |
5613 | ||
5614 | @cindex @code{int} directive | |
5615 | @cindex integers, 32-bit | |
5616 | Expect zero or more @var{expressions}, of any section, separated by commas. | |
5617 | For each expression, emit a number that, at run time, is the value of that | |
5618 | expression. The byte order and bit size of the number depends on what kind | |
5619 | of target the assembly is for. | |
5620 | ||
5621 | @ifclear GENERIC | |
5622 | @ifset H8 | |
7be1c489 | 5623 | On most forms of the H8/300, @code{.int} emits 16-bit |
c2dcd04e | 5624 | integers. On the H8/300H and the Renesas SH, however, @code{.int} emits |
252b5132 RH |
5625 | 32-bit integers. |
5626 | @end ifset | |
5627 | @end ifclear | |
5628 | ||
c91d2e08 NC |
5629 | @ifset ELF |
5630 | @node Internal | |
5631 | @section @code{.internal @var{names}} | |
5632 | ||
c1253627 NC |
5633 | @cindex @code{internal} directive |
5634 | @cindex visibility | |
ed9589d4 | 5635 | This is one of the ELF visibility directives. The other two are |
01642c12 | 5636 | @code{.hidden} (@pxref{Hidden,,@code{.hidden}}) and |
a349d9dd | 5637 | @code{.protected} (@pxref{Protected,,@code{.protected}}). |
c91d2e08 NC |
5638 | |
5639 | This directive overrides the named symbols default visibility (which is set by | |
5640 | their binding: local, global or weak). The directive sets the visibility to | |
5641 | @code{internal} which means that the symbols are considered to be @code{hidden} | |
c1253627 | 5642 | (i.e., not visible to other components), and that some extra, processor specific |
c91d2e08 NC |
5643 | processing must also be performed upon the symbols as well. |
5644 | @end ifset | |
5645 | ||
252b5132 RH |
5646 | @node Irp |
5647 | @section @code{.irp @var{symbol},@var{values}}@dots{} | |
5648 | ||
5649 | @cindex @code{irp} directive | |
5650 | Evaluate a sequence of statements assigning different values to @var{symbol}. | |
5651 | The sequence of statements starts at the @code{.irp} directive, and is | |
5652 | terminated by an @code{.endr} directive. For each @var{value}, @var{symbol} is | |
5653 | set to @var{value}, and the sequence of statements is assembled. If no | |
5654 | @var{value} is listed, the sequence of statements is assembled once, with | |
5655 | @var{symbol} set to the null string. To refer to @var{symbol} within the | |
5656 | sequence of statements, use @var{\symbol}. | |
5657 | ||
5658 | For example, assembling | |
5659 | ||
5660 | @example | |
5661 | .irp param,1,2,3 | |
5662 | move d\param,sp@@- | |
5663 | .endr | |
5664 | @end example | |
5665 | ||
5666 | is equivalent to assembling | |
5667 | ||
5668 | @example | |
5669 | move d1,sp@@- | |
5670 | move d2,sp@@- | |
5671 | move d3,sp@@- | |
5672 | @end example | |
5673 | ||
96e9638b | 5674 | For some caveats with the spelling of @var{symbol}, see also @ref{Macro}. |
5e75c3ab | 5675 | |
252b5132 RH |
5676 | @node Irpc |
5677 | @section @code{.irpc @var{symbol},@var{values}}@dots{} | |
5678 | ||
5679 | @cindex @code{irpc} directive | |
5680 | Evaluate a sequence of statements assigning different values to @var{symbol}. | |
5681 | The sequence of statements starts at the @code{.irpc} directive, and is | |
5682 | terminated by an @code{.endr} directive. For each character in @var{value}, | |
5683 | @var{symbol} is set to the character, and the sequence of statements is | |
5684 | assembled. If no @var{value} is listed, the sequence of statements is | |
5685 | assembled once, with @var{symbol} set to the null string. To refer to | |
5686 | @var{symbol} within the sequence of statements, use @var{\symbol}. | |
5687 | ||
5688 | For example, assembling | |
5689 | ||
5690 | @example | |
5691 | .irpc param,123 | |
5692 | move d\param,sp@@- | |
5693 | .endr | |
5694 | @end example | |
5695 | ||
5696 | is equivalent to assembling | |
5697 | ||
5698 | @example | |
5699 | move d1,sp@@- | |
5700 | move d2,sp@@- | |
5701 | move d3,sp@@- | |
5702 | @end example | |
5703 | ||
5e75c3ab JB |
5704 | For some caveats with the spelling of @var{symbol}, see also the discussion |
5705 | at @xref{Macro}. | |
5706 | ||
252b5132 RH |
5707 | @node Lcomm |
5708 | @section @code{.lcomm @var{symbol} , @var{length}} | |
5709 | ||
5710 | @cindex @code{lcomm} directive | |
5711 | @cindex local common symbols | |
5712 | @cindex symbols, local common | |
5713 | Reserve @var{length} (an absolute expression) bytes for a local common | |
5714 | denoted by @var{symbol}. The section and value of @var{symbol} are | |
5715 | those of the new local common. The addresses are allocated in the bss | |
5716 | section, so that at run-time the bytes start off zeroed. @var{Symbol} | |
5717 | is not declared global (@pxref{Global,,@code{.global}}), so is normally | |
5718 | not visible to @code{@value{LD}}. | |
5719 | ||
5720 | @ifset GENERIC | |
5721 | Some targets permit a third argument to be used with @code{.lcomm}. This | |
5722 | argument specifies the desired alignment of the symbol in the bss section. | |
5723 | @end ifset | |
5724 | ||
5725 | @ifset HPPA | |
5726 | The syntax for @code{.lcomm} differs slightly on the HPPA. The syntax is | |
5727 | @samp{@var{symbol} .lcomm, @var{length}}; @var{symbol} is optional. | |
5728 | @end ifset | |
5729 | ||
5730 | @node Lflags | |
5731 | @section @code{.lflags} | |
5732 | ||
5733 | @cindex @code{lflags} directive (ignored) | |
a4fb0134 | 5734 | @command{@value{AS}} accepts this directive, for compatibility with other |
252b5132 RH |
5735 | assemblers, but ignores it. |
5736 | ||
5737 | @ifclear no-line-dir | |
5738 | @node Line | |
5739 | @section @code{.line @var{line-number}} | |
5740 | ||
5741 | @cindex @code{line} directive | |
252b5132 | 5742 | @cindex logical line number |
a8eb42a8 | 5743 | @ifset aout |
252b5132 RH |
5744 | Change the logical line number. @var{line-number} must be an absolute |
5745 | expression. The next line has that logical line number. Therefore any other | |
5746 | statements on the current line (after a statement separator character) are | |
5747 | reported as on logical line number @var{line-number} @minus{} 1. One day | |
a4fb0134 | 5748 | @command{@value{AS}} will no longer support this directive: it is recognized only |
252b5132 | 5749 | for compatibility with existing assembler programs. |
252b5132 RH |
5750 | @end ifset |
5751 | ||
252b5132 | 5752 | Even though this is a directive associated with the @code{a.out} or |
a4fb0134 | 5753 | @code{b.out} object-code formats, @command{@value{AS}} still recognizes it |
252b5132 RH |
5754 | when producing COFF output, and treats @samp{.line} as though it |
5755 | were the COFF @samp{.ln} @emph{if} it is found outside a | |
5756 | @code{.def}/@code{.endef} pair. | |
5757 | ||
5758 | Inside a @code{.def}, @samp{.line} is, instead, one of the directives | |
5759 | used by compilers to generate auxiliary symbol information for | |
5760 | debugging. | |
5761 | @end ifclear | |
5762 | ||
5763 | @node Linkonce | |
5764 | @section @code{.linkonce [@var{type}]} | |
5765 | @cindex COMDAT | |
5766 | @cindex @code{linkonce} directive | |
5767 | @cindex common sections | |
5768 | Mark the current section so that the linker only includes a single copy of it. | |
5769 | This may be used to include the same section in several different object files, | |
5770 | but ensure that the linker will only include it once in the final output file. | |
5771 | The @code{.linkonce} pseudo-op must be used for each instance of the section. | |
5772 | Duplicate sections are detected based on the section name, so it should be | |
5773 | unique. | |
5774 | ||
5775 | This directive is only supported by a few object file formats; as of this | |
5776 | writing, the only object file format which supports it is the Portable | |
5777 | Executable format used on Windows NT. | |
5778 | ||
5779 | The @var{type} argument is optional. If specified, it must be one of the | |
5780 | following strings. For example: | |
5781 | @smallexample | |
5782 | .linkonce same_size | |
5783 | @end smallexample | |
5784 | Not all types may be supported on all object file formats. | |
5785 | ||
5786 | @table @code | |
5787 | @item discard | |
5788 | Silently discard duplicate sections. This is the default. | |
5789 | ||
5790 | @item one_only | |
5791 | Warn if there are duplicate sections, but still keep only one copy. | |
5792 | ||
5793 | @item same_size | |
5794 | Warn if any of the duplicates have different sizes. | |
5795 | ||
5796 | @item same_contents | |
5797 | Warn if any of the duplicates do not have exactly the same contents. | |
5798 | @end table | |
5799 | ||
ccf8a69b BW |
5800 | @node List |
5801 | @section @code{.list} | |
5802 | ||
5803 | @cindex @code{list} directive | |
5804 | @cindex listing control, turning on | |
5805 | Control (in conjunction with the @code{.nolist} directive) whether or | |
5806 | not assembly listings are generated. These two directives maintain an | |
5807 | internal counter (which is zero initially). @code{.list} increments the | |
5808 | counter, and @code{.nolist} decrements it. Assembly listings are | |
5809 | generated whenever the counter is greater than zero. | |
5810 | ||
5811 | By default, listings are disabled. When you enable them (with the | |
a05a5b64 | 5812 | @samp{-a} command-line option; @pxref{Invoking,,Command-Line Options}), |
ccf8a69b BW |
5813 | the initial value of the listing counter is one. |
5814 | ||
252b5132 RH |
5815 | @node Ln |
5816 | @section @code{.ln @var{line-number}} | |
5817 | ||
5818 | @cindex @code{ln} directive | |
5819 | @ifclear no-line-dir | |
5820 | @samp{.ln} is a synonym for @samp{.line}. | |
5821 | @end ifclear | |
5822 | @ifset no-line-dir | |
a4fb0134 | 5823 | Tell @command{@value{AS}} to change the logical line number. @var{line-number} |
252b5132 RH |
5824 | must be an absolute expression. The next line has that logical |
5825 | line number, so any other statements on the current line (after a | |
5826 | statement separator character @code{;}) are reported as on logical | |
5827 | line number @var{line-number} @minus{} 1. | |
252b5132 RH |
5828 | @end ifset |
5829 | ||
ccf8a69b BW |
5830 | @node Loc |
5831 | @section @code{.loc @var{fileno} @var{lineno} [@var{column}] [@var{options}]} | |
5832 | @cindex @code{loc} directive | |
5833 | When emitting DWARF2 line number information, | |
5834 | the @code{.loc} directive will add a row to the @code{.debug_line} line | |
5835 | number matrix corresponding to the immediately following assembly | |
5836 | instruction. The @var{fileno}, @var{lineno}, and optional @var{column} | |
5837 | arguments will be applied to the @code{.debug_line} state machine before | |
5838 | the row is added. | |
252b5132 | 5839 | |
ccf8a69b BW |
5840 | The @var{options} are a sequence of the following tokens in any order: |
5841 | ||
5842 | @table @code | |
5843 | @item basic_block | |
5844 | This option will set the @code{basic_block} register in the | |
5845 | @code{.debug_line} state machine to @code{true}. | |
5846 | ||
5847 | @item prologue_end | |
5848 | This option will set the @code{prologue_end} register in the | |
5849 | @code{.debug_line} state machine to @code{true}. | |
5850 | ||
5851 | @item epilogue_begin | |
5852 | This option will set the @code{epilogue_begin} register in the | |
5853 | @code{.debug_line} state machine to @code{true}. | |
5854 | ||
5855 | @item is_stmt @var{value} | |
5856 | This option will set the @code{is_stmt} register in the | |
01642c12 | 5857 | @code{.debug_line} state machine to @code{value}, which must be |
ccf8a69b BW |
5858 | either 0 or 1. |
5859 | ||
5860 | @item isa @var{value} | |
5861 | This directive will set the @code{isa} register in the @code{.debug_line} | |
5862 | state machine to @var{value}, which must be an unsigned integer. | |
5863 | ||
92846e72 CC |
5864 | @item discriminator @var{value} |
5865 | This directive will set the @code{discriminator} register in the @code{.debug_line} | |
5866 | state machine to @var{value}, which must be an unsigned integer. | |
5867 | ||
ba8826a8 AO |
5868 | @item view @var{value} |
5869 | This option causes a row to be added to @code{.debug_line} in reference to the | |
5870 | current address (which might not be the same as that of the following assembly | |
5871 | instruction), and to associate @var{value} with the @code{view} register in the | |
5872 | @code{.debug_line} state machine. If @var{value} is a label, both the | |
5873 | @code{view} register and the label are set to the number of prior @code{.loc} | |
5874 | directives at the same program location. If @var{value} is the literal | |
5875 | @code{0}, the @code{view} register is set to zero, and the assembler asserts | |
5876 | that there aren't any prior @code{.loc} directives at the same program | |
5877 | location. If @var{value} is the literal @code{-0}, the assembler arrange for | |
5878 | the @code{view} register to be reset in this row, even if there are prior | |
5879 | @code{.loc} directives at the same program location. | |
5880 | ||
ccf8a69b BW |
5881 | @end table |
5882 | ||
5883 | @node Loc_mark_labels | |
5884 | @section @code{.loc_mark_labels @var{enable}} | |
5885 | @cindex @code{loc_mark_labels} directive | |
5886 | When emitting DWARF2 line number information, | |
5887 | the @code{.loc_mark_labels} directive makes the assembler emit an entry | |
5888 | to the @code{.debug_line} line number matrix with the @code{basic_block} | |
5889 | register in the state machine set whenever a code label is seen. | |
5890 | The @var{enable} argument should be either 1 or 0, to enable or disable | |
5891 | this function respectively. | |
252b5132 | 5892 | |
4d4175af BW |
5893 | @ifset ELF |
5894 | @node Local | |
5895 | @section @code{.local @var{names}} | |
5896 | ||
5897 | @cindex @code{local} directive | |
5898 | This directive, which is available for ELF targets, marks each symbol in | |
5899 | the comma-separated list of @code{names} as a local symbol so that it | |
5900 | will not be externally visible. If the symbols do not already exist, | |
5901 | they will be created. | |
5902 | ||
5903 | For targets where the @code{.lcomm} directive (@pxref{Lcomm}) does not | |
5904 | accept an alignment argument, which is the case for most ELF targets, | |
5905 | the @code{.local} directive can be used in combination with @code{.comm} | |
5906 | (@pxref{Comm}) to define aligned local common data. | |
5907 | @end ifset | |
5908 | ||
252b5132 RH |
5909 | @node Long |
5910 | @section @code{.long @var{expressions}} | |
5911 | ||
5912 | @cindex @code{long} directive | |
96e9638b | 5913 | @code{.long} is the same as @samp{.int}. @xref{Int,,@code{.int}}. |
252b5132 RH |
5914 | |
5915 | @ignore | |
5916 | @c no one seems to know what this is for or whether this description is | |
5917 | @c what it really ought to do | |
5918 | @node Lsym | |
5919 | @section @code{.lsym @var{symbol}, @var{expression}} | |
5920 | ||
5921 | @cindex @code{lsym} directive | |
5922 | @cindex symbol, not referenced in assembly | |
5923 | @code{.lsym} creates a new symbol named @var{symbol}, but does not put it in | |
5924 | the hash table, ensuring it cannot be referenced by name during the | |
5925 | rest of the assembly. This sets the attributes of the symbol to be | |
5926 | the same as the expression value: | |
5927 | @smallexample | |
5928 | @var{other} = @var{descriptor} = 0 | |
5929 | @var{type} = @r{(section of @var{expression})} | |
5930 | @var{value} = @var{expression} | |
5931 | @end smallexample | |
5932 | @noindent | |
5933 | The new symbol is not flagged as external. | |
5934 | @end ignore | |
5935 | ||
5936 | @node Macro | |
5937 | @section @code{.macro} | |
5938 | ||
5939 | @cindex macros | |
5940 | The commands @code{.macro} and @code{.endm} allow you to define macros that | |
5941 | generate assembly output. For example, this definition specifies a macro | |
5942 | @code{sum} that puts a sequence of numbers into memory: | |
5943 | ||
5944 | @example | |
5945 | .macro sum from=0, to=5 | |
5946 | .long \from | |
5947 | .if \to-\from | |
5948 | sum "(\from+1)",\to | |
5949 | .endif | |
5950 | .endm | |
5951 | @end example | |
5952 | ||
5953 | @noindent | |
5954 | With that definition, @samp{SUM 0,5} is equivalent to this assembly input: | |
5955 | ||
5956 | @example | |
5957 | .long 0 | |
5958 | .long 1 | |
5959 | .long 2 | |
5960 | .long 3 | |
5961 | .long 4 | |
5962 | .long 5 | |
5963 | @end example | |
5964 | ||
5965 | @ftable @code | |
5966 | @item .macro @var{macname} | |
5967 | @itemx .macro @var{macname} @var{macargs} @dots{} | |
5968 | @cindex @code{macro} directive | |
5969 | Begin the definition of a macro called @var{macname}. If your macro | |
5970 | definition requires arguments, specify their names after the macro name, | |
6eaeac8a JB |
5971 | separated by commas or spaces. You can qualify the macro argument to |
5972 | indicate whether all invocations must specify a non-blank value (through | |
5973 | @samp{:@code{req}}), or whether it takes all of the remaining arguments | |
5974 | (through @samp{:@code{vararg}}). You can supply a default value for any | |
fffeaa5f JB |
5975 | macro argument by following the name with @samp{=@var{deflt}}. You |
5976 | cannot define two macros with the same @var{macname} unless it has been | |
96e9638b | 5977 | subject to the @code{.purgem} directive (@pxref{Purgem}) between the two |
fffeaa5f | 5978 | definitions. For example, these are all valid @code{.macro} statements: |
252b5132 RH |
5979 | |
5980 | @table @code | |
5981 | @item .macro comm | |
5982 | Begin the definition of a macro called @code{comm}, which takes no | |
5983 | arguments. | |
5984 | ||
6258339f | 5985 | @item .macro plus1 p, p1 |
252b5132 RH |
5986 | @itemx .macro plus1 p p1 |
5987 | Either statement begins the definition of a macro called @code{plus1}, | |
5988 | which takes two arguments; within the macro definition, write | |
5989 | @samp{\p} or @samp{\p1} to evaluate the arguments. | |
5990 | ||
5991 | @item .macro reserve_str p1=0 p2 | |
5992 | Begin the definition of a macro called @code{reserve_str}, with two | |
5993 | arguments. The first argument has a default value, but not the second. | |
5994 | After the definition is complete, you can call the macro either as | |
5995 | @samp{reserve_str @var{a},@var{b}} (with @samp{\p1} evaluating to | |
5996 | @var{a} and @samp{\p2} evaluating to @var{b}), or as @samp{reserve_str | |
5997 | ,@var{b}} (with @samp{\p1} evaluating as the default, in this case | |
5998 | @samp{0}, and @samp{\p2} evaluating to @var{b}). | |
252b5132 | 5999 | |
6eaeac8a JB |
6000 | @item .macro m p1:req, p2=0, p3:vararg |
6001 | Begin the definition of a macro called @code{m}, with at least three | |
6002 | arguments. The first argument must always have a value specified, but | |
6003 | not the second, which instead has a default value. The third formal | |
6004 | will get assigned all remaining arguments specified at invocation time. | |
6005 | ||
252b5132 RH |
6006 | When you call a macro, you can specify the argument values either by |
6007 | position, or by keyword. For example, @samp{sum 9,17} is equivalent to | |
6008 | @samp{sum to=17, from=9}. | |
6009 | ||
6258339f NC |
6010 | @end table |
6011 | ||
5e75c3ab JB |
6012 | Note that since each of the @var{macargs} can be an identifier exactly |
6013 | as any other one permitted by the target architecture, there may be | |
6014 | occasional problems if the target hand-crafts special meanings to certain | |
6258339f | 6015 | characters when they occur in a special position. For example, if the colon |
5e75c3ab | 6016 | (@code{:}) is generally permitted to be part of a symbol name, but the |
6258339f | 6017 | architecture specific code special-cases it when occurring as the final |
5e75c3ab JB |
6018 | character of a symbol (to denote a label), then the macro parameter |
6019 | replacement code will have no way of knowing that and consider the whole | |
6020 | construct (including the colon) an identifier, and check only this | |
6258339f NC |
6021 | identifier for being the subject to parameter substitution. So for example |
6022 | this macro definition: | |
6023 | ||
6024 | @example | |
6025 | .macro label l | |
6026 | \l: | |
6027 | .endm | |
6028 | @end example | |
6029 | ||
6030 | might not work as expected. Invoking @samp{label foo} might not create a label | |
6031 | called @samp{foo} but instead just insert the text @samp{\l:} into the | |
6032 | assembler source, probably generating an error about an unrecognised | |
6033 | identifier. | |
6034 | ||
6035 | Similarly problems might occur with the period character (@samp{.}) | |
6036 | which is often allowed inside opcode names (and hence identifier names). So | |
6037 | for example constructing a macro to build an opcode from a base name and a | |
6038 | length specifier like this: | |
6039 | ||
6040 | @example | |
6041 | .macro opcode base length | |
6042 | \base.\length | |
6043 | .endm | |
6044 | @end example | |
6045 | ||
6046 | and invoking it as @samp{opcode store l} will not create a @samp{store.l} | |
6047 | instruction but instead generate some kind of error as the assembler tries to | |
6048 | interpret the text @samp{\base.\length}. | |
6049 | ||
6050 | There are several possible ways around this problem: | |
6051 | ||
6052 | @table @code | |
6053 | @item Insert white space | |
6054 | If it is possible to use white space characters then this is the simplest | |
6055 | solution. eg: | |
6056 | ||
6057 | @example | |
6058 | .macro label l | |
6059 | \l : | |
6060 | .endm | |
6061 | @end example | |
6062 | ||
6063 | @item Use @samp{\()} | |
6064 | The string @samp{\()} can be used to separate the end of a macro argument from | |
6065 | the following text. eg: | |
6066 | ||
6067 | @example | |
6068 | .macro opcode base length | |
6069 | \base\().\length | |
6070 | .endm | |
6071 | @end example | |
6072 | ||
6073 | @item Use the alternate macro syntax mode | |
6074 | In the alternative macro syntax mode the ampersand character (@samp{&}) can be | |
6075 | used as a separator. eg: | |
5e75c3ab JB |
6076 | |
6077 | @example | |
6078 | .altmacro | |
6079 | .macro label l | |
6080 | l&: | |
6081 | .endm | |
6082 | @end example | |
6258339f | 6083 | @end table |
5e75c3ab | 6084 | |
96e9638b | 6085 | Note: this problem of correctly identifying string parameters to pseudo ops |
01642c12 | 6086 | also applies to the identifiers used in @code{.irp} (@pxref{Irp}) |
96e9638b | 6087 | and @code{.irpc} (@pxref{Irpc}) as well. |
5e75c3ab | 6088 | |
252b5132 RH |
6089 | @item .endm |
6090 | @cindex @code{endm} directive | |
6091 | Mark the end of a macro definition. | |
6092 | ||
6093 | @item .exitm | |
6094 | @cindex @code{exitm} directive | |
6095 | Exit early from the current macro definition. | |
6096 | ||
6097 | @cindex number of macros executed | |
6098 | @cindex macros, count executed | |
6099 | @item \@@ | |
a4fb0134 | 6100 | @command{@value{AS}} maintains a counter of how many macros it has |
252b5132 RH |
6101 | executed in this pseudo-variable; you can copy that number to your |
6102 | output with @samp{\@@}, but @emph{only within a macro definition}. | |
6103 | ||
252b5132 RH |
6104 | @item LOCAL @var{name} [ , @dots{} ] |
6105 | @emph{Warning: @code{LOCAL} is only available if you select ``alternate | |
caa32fe5 NC |
6106 | macro syntax'' with @samp{--alternate} or @code{.altmacro}.} |
6107 | @xref{Altmacro,,@code{.altmacro}}. | |
6108 | @end ftable | |
252b5132 | 6109 | |
ccf8a69b BW |
6110 | @node MRI |
6111 | @section @code{.mri @var{val}} | |
caa32fe5 | 6112 | |
ccf8a69b BW |
6113 | @cindex @code{mri} directive |
6114 | @cindex MRI mode, temporarily | |
6115 | If @var{val} is non-zero, this tells @command{@value{AS}} to enter MRI mode. If | |
6116 | @var{val} is zero, this tells @command{@value{AS}} to exit MRI mode. This change | |
6117 | affects code assembled until the next @code{.mri} directive, or until the end | |
6118 | of the file. @xref{M, MRI mode, MRI mode}. | |
252b5132 | 6119 | |
caa32fe5 NC |
6120 | @node Noaltmacro |
6121 | @section @code{.noaltmacro} | |
96e9638b | 6122 | Disable alternate macro mode. @xref{Altmacro}. |
caa32fe5 | 6123 | |
252b5132 RH |
6124 | @node Nolist |
6125 | @section @code{.nolist} | |
6126 | ||
6127 | @cindex @code{nolist} directive | |
6128 | @cindex listing control, turning off | |
6129 | Control (in conjunction with the @code{.list} directive) whether or | |
6130 | not assembly listings are generated. These two directives maintain an | |
6131 | internal counter (which is zero initially). @code{.list} increments the | |
6132 | counter, and @code{.nolist} decrements it. Assembly listings are | |
6133 | generated whenever the counter is greater than zero. | |
6134 | ||
8f065d3b L |
6135 | @node Nops |
6136 | @section @code{.nops @var{size}[, @var{control}]} | |
62a02d25 | 6137 | |
8f065d3b | 6138 | @cindex @code{nops} directive |
62a02d25 L |
6139 | @cindex filling memory with no-op instructions |
6140 | This directive emits @var{size} bytes filled with no-op instructions. | |
6141 | @var{size} is absolute expression, which must be a positve value. | |
6142 | @var{control} controls how no-op instructions should be generated. If | |
6143 | the comma and @var{control} are omitted, @var{control} is assumed to be | |
6144 | zero. | |
6145 | ||
6146 | Note: For Intel 80386 and AMD x86-64 targets, @var{control} specifies | |
6147 | the size limit of a no-op instruction. The valid values of @var{control} | |
3ae729d5 L |
6148 | are between 0 and 4 in 16-bit mode, between 0 and 7 when tuning for |
6149 | older processors in 32-bit mode, between 0 and 11 in 64-bit mode or when | |
6150 | tuning for newer processors in 32-bit mode. When 0 is used, the no-op | |
6151 | instruction size limit is set to the maximum supported size. | |
62a02d25 | 6152 | |
252b5132 RH |
6153 | @node Octa |
6154 | @section @code{.octa @var{bignums}} | |
6155 | ||
a8eb42a8 | 6156 | @c FIXME: double size emitted for "octa" on some? Or warn? |
252b5132 RH |
6157 | @cindex @code{octa} directive |
6158 | @cindex integer, 16-byte | |
6159 | @cindex sixteen byte integer | |
6160 | This directive expects zero or more bignums, separated by commas. For each | |
6161 | bignum, it emits a 16-byte integer. | |
6162 | ||
6163 | The term ``octa'' comes from contexts in which a ``word'' is two bytes; | |
6164 | hence @emph{octa}-word for 16 bytes. | |
6165 | ||
9aec2026 NC |
6166 | @node Offset |
6167 | @section @code{.offset @var{loc}} | |
6168 | ||
6169 | @cindex @code{offset} directive | |
6170 | Set the location counter to @var{loc} in the absolute section. @var{loc} must | |
6171 | be an absolute expression. This directive may be useful for defining | |
6172 | symbols with absolute values. Do not confuse it with the @code{.org} | |
fa94de6b | 6173 | directive. |
9aec2026 | 6174 | |
252b5132 RH |
6175 | @node Org |
6176 | @section @code{.org @var{new-lc} , @var{fill}} | |
6177 | ||
6178 | @cindex @code{org} directive | |
6179 | @cindex location counter, advancing | |
6180 | @cindex advancing location counter | |
6181 | @cindex current address, advancing | |
6182 | Advance the location counter of the current section to | |
6183 | @var{new-lc}. @var{new-lc} is either an absolute expression or an | |
6184 | expression with the same section as the current subsection. That is, | |
6185 | you can't use @code{.org} to cross sections: if @var{new-lc} has the | |
6186 | wrong section, the @code{.org} directive is ignored. To be compatible | |
6187 | with former assemblers, if the section of @var{new-lc} is absolute, | |
a4fb0134 | 6188 | @command{@value{AS}} issues a warning, then pretends the section of @var{new-lc} |
252b5132 RH |
6189 | is the same as the current subsection. |
6190 | ||
6191 | @code{.org} may only increase the location counter, or leave it | |
6192 | unchanged; you cannot use @code{.org} to move the location counter | |
6193 | backwards. | |
6194 | ||
6195 | @c double negative used below "not undefined" because this is a specific | |
6196 | @c reference to "undefined" (as SEG_UNKNOWN is called in this manual) | |
6197 | @c section. doc@cygnus.com 18feb91 | |
a4fb0134 | 6198 | Because @command{@value{AS}} tries to assemble programs in one pass, @var{new-lc} |
252b5132 RH |
6199 | may not be undefined. If you really detest this restriction we eagerly await |
6200 | a chance to share your improved assembler. | |
6201 | ||
6202 | Beware that the origin is relative to the start of the section, not | |
6203 | to the start of the subsection. This is compatible with other | |
6204 | people's assemblers. | |
6205 | ||
6206 | When the location counter (of the current subsection) is advanced, the | |
6207 | intervening bytes are filled with @var{fill} which should be an | |
6208 | absolute expression. If the comma and @var{fill} are omitted, | |
6209 | @var{fill} defaults to zero. | |
6210 | ||
6211 | @node P2align | |
6212 | @section @code{.p2align[wl] @var{abs-expr}, @var{abs-expr}, @var{abs-expr}} | |
6213 | ||
6214 | @cindex padding the location counter given a power of two | |
6215 | @cindex @code{p2align} directive | |
6216 | Pad the location counter (in the current subsection) to a particular | |
6217 | storage boundary. The first expression (which must be absolute) is the | |
6218 | number of low-order zero bits the location counter must have after | |
6219 | advancement. For example @samp{.p2align 3} advances the location | |
a6ce99e9 | 6220 | counter until it is a multiple of 8. If the location counter is already a |
252b5132 RH |
6221 | multiple of 8, no change is needed. |
6222 | ||
6223 | The second expression (also absolute) gives the fill value to be stored in the | |
6224 | padding bytes. It (and the comma) may be omitted. If it is omitted, the | |
2ca23e65 | 6225 | padding bytes are normally zero. However, on most systems, if the section is |
252b5132 RH |
6226 | marked as containing code and the fill value is omitted, the space is filled |
6227 | with no-op instructions. | |
6228 | ||
6229 | The third expression is also absolute, and is also optional. If it is present, | |
6230 | it is the maximum number of bytes that should be skipped by this alignment | |
6231 | directive. If doing the alignment would require skipping more bytes than the | |
6232 | specified maximum, then the alignment is not done at all. You can omit the | |
6233 | fill value (the second argument) entirely by simply using two commas after the | |
6234 | required alignment; this can be useful if you want the alignment to be filled | |
6235 | with no-op instructions when appropriate. | |
6236 | ||
6237 | @cindex @code{p2alignw} directive | |
6238 | @cindex @code{p2alignl} directive | |
6239 | The @code{.p2alignw} and @code{.p2alignl} directives are variants of the | |
6240 | @code{.p2align} directive. The @code{.p2alignw} directive treats the fill | |
6241 | pattern as a two byte word value. The @code{.p2alignl} directives treats the | |
6242 | fill pattern as a four byte longword value. For example, @code{.p2alignw | |
6243 | 2,0x368d} will align to a multiple of 4. If it skips two bytes, they will be | |
6244 | filled in with the value 0x368d (the exact placement of the bytes depends upon | |
6245 | the endianness of the processor). If it skips 1 or 3 bytes, the fill value is | |
6246 | undefined. | |
6247 | ||
ccf8a69b BW |
6248 | @ifset ELF |
6249 | @node PopSection | |
6250 | @section @code{.popsection} | |
6251 | ||
6252 | @cindex @code{popsection} directive | |
6253 | @cindex Section Stack | |
6254 | This is one of the ELF section stack manipulation directives. The others are | |
01642c12 RM |
6255 | @code{.section} (@pxref{Section}), @code{.subsection} (@pxref{SubSection}), |
6256 | @code{.pushsection} (@pxref{PushSection}), and @code{.previous} | |
ccf8a69b BW |
6257 | (@pxref{Previous}). |
6258 | ||
6259 | This directive replaces the current section (and subsection) with the top | |
6260 | section (and subsection) on the section stack. This section is popped off the | |
01642c12 | 6261 | stack. |
ccf8a69b BW |
6262 | @end ifset |
6263 | ||
c91d2e08 NC |
6264 | @ifset ELF |
6265 | @node Previous | |
6266 | @section @code{.previous} | |
6267 | ||
c1253627 | 6268 | @cindex @code{previous} directive |
c91d2e08 NC |
6269 | @cindex Section Stack |
6270 | This is one of the ELF section stack manipulation directives. The others are | |
a349d9dd PB |
6271 | @code{.section} (@pxref{Section}), @code{.subsection} (@pxref{SubSection}), |
6272 | @code{.pushsection} (@pxref{PushSection}), and @code{.popsection} | |
6273 | (@pxref{PopSection}). | |
c91d2e08 NC |
6274 | |
6275 | This directive swaps the current section (and subsection) with most recently | |
8b040e0a | 6276 | referenced section/subsection pair prior to this one. Multiple |
c91d2e08 | 6277 | @code{.previous} directives in a row will flip between two sections (and their |
8b040e0a NC |
6278 | subsections). For example: |
6279 | ||
6280 | @smallexample | |
6281 | .section A | |
6282 | .subsection 1 | |
6283 | .word 0x1234 | |
6284 | .subsection 2 | |
6285 | .word 0x5678 | |
6286 | .previous | |
6287 | .word 0x9abc | |
6288 | @end smallexample | |
6289 | ||
6290 | Will place 0x1234 and 0x9abc into subsection 1 and 0x5678 into subsection 2 of | |
6291 | section A. Whilst: | |
6292 | ||
6293 | @smallexample | |
6294 | .section A | |
6295 | .subsection 1 | |
6296 | # Now in section A subsection 1 | |
6297 | .word 0x1234 | |
6298 | .section B | |
6299 | .subsection 0 | |
6300 | # Now in section B subsection 0 | |
6301 | .word 0x5678 | |
6302 | .subsection 1 | |
6303 | # Now in section B subsection 1 | |
6304 | .word 0x9abc | |
6305 | .previous | |
6306 | # Now in section B subsection 0 | |
6307 | .word 0xdef0 | |
6308 | @end smallexample | |
6309 | ||
6310 | Will place 0x1234 into section A, 0x5678 and 0xdef0 into subsection 0 of | |
6311 | section B and 0x9abc into subsection 1 of section B. | |
c91d2e08 NC |
6312 | |
6313 | In terms of the section stack, this directive swaps the current section with | |
6314 | the top section on the section stack. | |
6315 | @end ifset | |
6316 | ||
252b5132 RH |
6317 | @node Print |
6318 | @section @code{.print @var{string}} | |
6319 | ||
6320 | @cindex @code{print} directive | |
a4fb0134 | 6321 | @command{@value{AS}} will print @var{string} on the standard output during |
252b5132 RH |
6322 | assembly. You must put @var{string} in double quotes. |
6323 | ||
c91d2e08 NC |
6324 | @ifset ELF |
6325 | @node Protected | |
6326 | @section @code{.protected @var{names}} | |
6327 | ||
c1253627 NC |
6328 | @cindex @code{protected} directive |
6329 | @cindex visibility | |
ed9589d4 | 6330 | This is one of the ELF visibility directives. The other two are |
a349d9dd | 6331 | @code{.hidden} (@pxref{Hidden}) and @code{.internal} (@pxref{Internal}). |
c91d2e08 NC |
6332 | |
6333 | This directive overrides the named symbols default visibility (which is set by | |
6334 | their binding: local, global or weak). The directive sets the visibility to | |
6335 | @code{protected} which means that any references to the symbols from within the | |
6336 | components that defines them must be resolved to the definition in that | |
6337 | component, even if a definition in another component would normally preempt | |
01642c12 | 6338 | this. |
c91d2e08 NC |
6339 | @end ifset |
6340 | ||
252b5132 RH |
6341 | @node Psize |
6342 | @section @code{.psize @var{lines} , @var{columns}} | |
6343 | ||
6344 | @cindex @code{psize} directive | |
6345 | @cindex listing control: paper size | |
6346 | @cindex paper size, for listings | |
6347 | Use this directive to declare the number of lines---and, optionally, the | |
6348 | number of columns---to use for each page, when generating listings. | |
6349 | ||
6350 | If you do not use @code{.psize}, listings use a default line-count | |
6351 | of 60. You may omit the comma and @var{columns} specification; the | |
6352 | default width is 200 columns. | |
6353 | ||
a4fb0134 | 6354 | @command{@value{AS}} generates formfeeds whenever the specified number of |
252b5132 RH |
6355 | lines is exceeded (or whenever you explicitly request one, using |
6356 | @code{.eject}). | |
6357 | ||
6358 | If you specify @var{lines} as @code{0}, no formfeeds are generated save | |
6359 | those explicitly specified with @code{.eject}. | |
6360 | ||
6361 | @node Purgem | |
6362 | @section @code{.purgem @var{name}} | |
6363 | ||
6364 | @cindex @code{purgem} directive | |
6365 | Undefine the macro @var{name}, so that later uses of the string will not be | |
6366 | expanded. @xref{Macro}. | |
6367 | ||
c91d2e08 NC |
6368 | @ifset ELF |
6369 | @node PushSection | |
9cfc3331 | 6370 | @section @code{.pushsection @var{name} [, @var{subsection}] [, "@var{flags}"[, @@@var{type}[,@var{arguments}]]]} |
c91d2e08 | 6371 | |
c1253627 | 6372 | @cindex @code{pushsection} directive |
c91d2e08 NC |
6373 | @cindex Section Stack |
6374 | This is one of the ELF section stack manipulation directives. The others are | |
01642c12 RM |
6375 | @code{.section} (@pxref{Section}), @code{.subsection} (@pxref{SubSection}), |
6376 | @code{.popsection} (@pxref{PopSection}), and @code{.previous} | |
a349d9dd | 6377 | (@pxref{Previous}). |
c91d2e08 | 6378 | |
e9863d7f DJ |
6379 | This directive pushes the current section (and subsection) onto the |
6380 | top of the section stack, and then replaces the current section and | |
9cfc3331 L |
6381 | subsection with @code{name} and @code{subsection}. The optional |
6382 | @code{flags}, @code{type} and @code{arguments} are treated the same | |
6383 | as in the @code{.section} (@pxref{Section}) directive. | |
c91d2e08 NC |
6384 | @end ifset |
6385 | ||
252b5132 RH |
6386 | @node Quad |
6387 | @section @code{.quad @var{bignums}} | |
6388 | ||
6389 | @cindex @code{quad} directive | |
6390 | @code{.quad} expects zero or more bignums, separated by commas. For | |
6391 | each bignum, it emits | |
6392 | @ifclear bignum-16 | |
6393 | an 8-byte integer. If the bignum won't fit in 8 bytes, it prints a | |
6394 | warning message; and just takes the lowest order 8 bytes of the bignum. | |
6395 | @cindex eight-byte integer | |
6396 | @cindex integer, 8-byte | |
6397 | ||
6398 | The term ``quad'' comes from contexts in which a ``word'' is two bytes; | |
6399 | hence @emph{quad}-word for 8 bytes. | |
6400 | @end ifclear | |
6401 | @ifset bignum-16 | |
6402 | a 16-byte integer. If the bignum won't fit in 16 bytes, it prints a | |
6403 | warning message; and just takes the lowest order 16 bytes of the bignum. | |
6404 | @cindex sixteen-byte integer | |
6405 | @cindex integer, 16-byte | |
6406 | @end ifset | |
6407 | ||
05e9452c AM |
6408 | @node Reloc |
6409 | @section @code{.reloc @var{offset}, @var{reloc_name}[, @var{expression}]} | |
6410 | ||
6411 | @cindex @code{reloc} directive | |
6412 | Generate a relocation at @var{offset} of type @var{reloc_name} with value | |
6413 | @var{expression}. If @var{offset} is a number, the relocation is generated in | |
6414 | the current section. If @var{offset} is an expression that resolves to a | |
6415 | symbol plus offset, the relocation is generated in the given symbol's section. | |
6416 | @var{expression}, if present, must resolve to a symbol plus addend or to an | |
6417 | absolute value, but note that not all targets support an addend. e.g. ELF REL | |
6418 | targets such as i386 store an addend in the section contents rather than in the | |
6419 | relocation. This low level interface does not support addends stored in the | |
6420 | section. | |
6421 | ||
252b5132 RH |
6422 | @node Rept |
6423 | @section @code{.rept @var{count}} | |
6424 | ||
6425 | @cindex @code{rept} directive | |
6426 | Repeat the sequence of lines between the @code{.rept} directive and the next | |
6427 | @code{.endr} directive @var{count} times. | |
6428 | ||
6429 | For example, assembling | |
6430 | ||
6431 | @example | |
6432 | .rept 3 | |
6433 | .long 0 | |
6434 | .endr | |
6435 | @end example | |
6436 | ||
6437 | is equivalent to assembling | |
6438 | ||
6439 | @example | |
6440 | .long 0 | |
6441 | .long 0 | |
6442 | .long 0 | |
6443 | @end example | |
6444 | ||
808811a3 NC |
6445 | A count of zero is allowed, but nothing is generated. Negative counts are not |
6446 | allowed and if encountered will be treated as if they were zero. | |
6447 | ||
252b5132 RH |
6448 | @node Sbttl |
6449 | @section @code{.sbttl "@var{subheading}"} | |
6450 | ||
6451 | @cindex @code{sbttl} directive | |
6452 | @cindex subtitles for listings | |
6453 | @cindex listing control: subtitle | |
6454 | Use @var{subheading} as the title (third line, immediately after the | |
6455 | title line) when generating assembly listings. | |
6456 | ||
6457 | This directive affects subsequent pages, as well as the current page if | |
6458 | it appears within ten lines of the top of a page. | |
6459 | ||
6460 | @ifset COFF | |
6461 | @node Scl | |
6462 | @section @code{.scl @var{class}} | |
6463 | ||
6464 | @cindex @code{scl} directive | |
6465 | @cindex symbol storage class (COFF) | |
6466 | @cindex COFF symbol storage class | |
6467 | Set the storage-class value for a symbol. This directive may only be | |
6468 | used inside a @code{.def}/@code{.endef} pair. Storage class may flag | |
6469 | whether a symbol is static or external, or it may record further | |
6470 | symbolic debugging information. | |
252b5132 RH |
6471 | @end ifset |
6472 | ||
c1253627 | 6473 | @ifset COFF-ELF |
252b5132 | 6474 | @node Section |
c1253627 | 6475 | @section @code{.section @var{name}} |
252b5132 | 6476 | |
252b5132 RH |
6477 | @cindex named section |
6478 | Use the @code{.section} directive to assemble the following code into a section | |
6479 | named @var{name}. | |
6480 | ||
6481 | This directive is only supported for targets that actually support arbitrarily | |
6482 | named sections; on @code{a.out} targets, for example, it is not accepted, even | |
6483 | with a standard @code{a.out} section name. | |
6484 | ||
c1253627 NC |
6485 | @ifset COFF |
6486 | @ifset ELF | |
6487 | @c only print the extra heading if both COFF and ELF are set | |
6488 | @subheading COFF Version | |
6489 | @end ifset | |
6490 | ||
6491 | @cindex @code{section} directive (COFF version) | |
252b5132 RH |
6492 | For COFF targets, the @code{.section} directive is used in one of the following |
6493 | ways: | |
c91d2e08 | 6494 | |
252b5132 RH |
6495 | @smallexample |
6496 | .section @var{name}[, "@var{flags}"] | |
4e188d17 | 6497 | .section @var{name}[, @var{subsection}] |
252b5132 RH |
6498 | @end smallexample |
6499 | ||
6500 | If the optional argument is quoted, it is taken as flags to use for the | |
6501 | section. Each flag is a single character. The following flags are recognized: | |
eda683bb | 6502 | |
252b5132 RH |
6503 | @table @code |
6504 | @item b | |
6505 | bss section (uninitialized data) | |
6506 | @item n | |
6507 | section is not loaded | |
6508 | @item w | |
6509 | writable section | |
6510 | @item d | |
6511 | data section | |
70e0ee1a KT |
6512 | @item e |
6513 | exclude section from linking | |
252b5132 RH |
6514 | @item r |
6515 | read-only section | |
6516 | @item x | |
6517 | executable section | |
2dcc60be ILT |
6518 | @item s |
6519 | shared section (meaningful for PE targets) | |
6ff96af6 NC |
6520 | @item a |
6521 | ignored. (For compatibility with the ELF version) | |
63ad59ae KT |
6522 | @item y |
6523 | section is not readable (meaningful for PE targets) | |
31907d5e DK |
6524 | @item 0-9 |
6525 | single-digit power-of-two section alignment (GNU extension) | |
252b5132 RH |
6526 | @end table |
6527 | ||
6528 | If no flags are specified, the default flags depend upon the section name. If | |
6529 | the section name is not recognized, the default will be for the section to be | |
7e84d676 NC |
6530 | loaded and writable. Note the @code{n} and @code{w} flags remove attributes |
6531 | from the section, rather than adding them, so if they are used on their own it | |
6532 | will be as if no flags had been specified at all. | |
252b5132 RH |
6533 | |
6534 | If the optional argument to the @code{.section} directive is not quoted, it is | |
4e188d17 | 6535 | taken as a subsection number (@pxref{Sub-Sections}). |
c1253627 | 6536 | @end ifset |
252b5132 RH |
6537 | |
6538 | @ifset ELF | |
c1253627 NC |
6539 | @ifset COFF |
6540 | @c only print the extra heading if both COFF and ELF are set | |
6541 | @subheading ELF Version | |
6542 | @end ifset | |
6543 | ||
c91d2e08 NC |
6544 | @cindex Section Stack |
6545 | This is one of the ELF section stack manipulation directives. The others are | |
01642c12 | 6546 | @code{.subsection} (@pxref{SubSection}), @code{.pushsection} |
a349d9dd PB |
6547 | (@pxref{PushSection}), @code{.popsection} (@pxref{PopSection}), and |
6548 | @code{.previous} (@pxref{Previous}). | |
c91d2e08 | 6549 | |
c1253627 | 6550 | @cindex @code{section} directive (ELF version) |
252b5132 | 6551 | For ELF targets, the @code{.section} directive is used like this: |
c91d2e08 | 6552 | |
252b5132 | 6553 | @smallexample |
7047dd1e | 6554 | .section @var{name} [, "@var{flags}"[, @@@var{type}[,@var{flag_specific_arguments}]]] |
252b5132 | 6555 | @end smallexample |
c91d2e08 | 6556 | |
451133ce NP |
6557 | @anchor{Section Name Substitutions} |
6558 | @kindex --sectname-subst | |
6559 | @cindex section name substitution | |
6560 | If the @samp{--sectname-subst} command-line option is provided, the @var{name} | |
6561 | argument may contain a substitution sequence. Only @code{%S} is supported | |
6562 | at the moment, and substitutes the current section name. For example: | |
6563 | ||
6564 | @smallexample | |
6565 | .macro exception_code | |
6566 | .section %S.exception | |
6567 | [exception code here] | |
6568 | .previous | |
6569 | .endm | |
6570 | ||
6571 | .text | |
6572 | [code] | |
6573 | exception_code | |
6574 | [...] | |
6575 | ||
6576 | .section .init | |
6577 | [init code] | |
6578 | exception_code | |
6579 | [...] | |
6580 | @end smallexample | |
6581 | ||
6582 | The two @code{exception_code} invocations above would create the | |
6583 | @code{.text.exception} and @code{.init.exception} sections respectively. | |
33eaf5de NC |
6584 | This is useful e.g. to discriminate between ancillary sections that are |
6585 | tied to setup code to be discarded after use from ancillary sections that | |
451133ce NP |
6586 | need to stay resident without having to define multiple @code{exception_code} |
6587 | macros just for that purpose. | |
6588 | ||
252b5132 | 6589 | The optional @var{flags} argument is a quoted string which may contain any |
a349d9dd | 6590 | combination of the following characters: |
eda683bb | 6591 | |
252b5132 RH |
6592 | @table @code |
6593 | @item a | |
6594 | section is allocatable | |
a91e1603 L |
6595 | @item d |
6596 | section is a GNU_MBIND section | |
18ae9cc1 L |
6597 | @item e |
6598 | section is excluded from executable and shared library. | |
252b5132 RH |
6599 | @item w |
6600 | section is writable | |
6601 | @item x | |
6602 | section is executable | |
ec38dd05 JJ |
6603 | @item M |
6604 | section is mergeable | |
6605 | @item S | |
6606 | section contains zero terminated strings | |
22fe14ad NC |
6607 | @item G |
6608 | section is a member of a section group | |
6609 | @item T | |
6610 | section is used for thread-local-storage | |
01642c12 RM |
6611 | @item ? |
6612 | section is a member of the previously-current section's group, if any | |
eda683bb | 6613 | @item @code{<number>} |
9fb71ee4 NC |
6614 | a numeric value indicating the bits to be set in the ELF section header's flags |
6615 | field. Note - if one or more of the alphabetic characters described above is | |
6616 | also included in the flags field, their bit values will be ORed into the | |
6617 | resulting value. | |
eda683bb NC |
6618 | @item @code{<target specific>} |
6619 | some targets extend this list with their own flag characters | |
252b5132 RH |
6620 | @end table |
6621 | ||
9fb71ee4 NC |
6622 | Note - once a section's flags have been set they cannot be changed. There are |
6623 | a few exceptions to this rule however. Processor and application specific | |
6624 | flags can be added to an already defined section. The @code{.interp}, | |
6625 | @code{.strtab} and @code{.symtab} sections can have the allocate flag | |
6626 | (@code{a}) set after they are initially defined, and the @code{.note-GNU-stack} | |
eda683bb | 6627 | section may have the executable (@code{x}) flag added. |
9fb71ee4 | 6628 | |
252b5132 | 6629 | The optional @var{type} argument may contain one of the following constants: |
eda683bb | 6630 | |
252b5132 RH |
6631 | @table @code |
6632 | @item @@progbits | |
6633 | section contains data | |
6634 | @item @@nobits | |
6635 | section does not contain data (i.e., section only occupies space) | |
22fe14ad NC |
6636 | @item @@note |
6637 | section contains data which is used by things other than the program | |
10b016c2 PB |
6638 | @item @@init_array |
6639 | section contains an array of pointers to init functions | |
6640 | @item @@fini_array | |
6641 | section contains an array of pointers to finish functions | |
6642 | @item @@preinit_array | |
6643 | section contains an array of pointers to pre-init functions | |
eda683bb | 6644 | @item @@@code{<number>} |
9fb71ee4 | 6645 | a numeric value to be set as the ELF section header's type field. |
eda683bb | 6646 | @item @@@code{<target specific>} |
9fb71ee4 | 6647 | some targets extend this list with their own types |
252b5132 RH |
6648 | @end table |
6649 | ||
9fb71ee4 NC |
6650 | Many targets only support the first three section types. The type may be |
6651 | enclosed in double quotes if necessary. | |
10b016c2 | 6652 | |
ececec60 NC |
6653 | Note on targets where the @code{@@} character is the start of a comment (eg |
6654 | ARM) then another character is used instead. For example the ARM port uses the | |
6655 | @code{%} character. | |
6656 | ||
9fb71ee4 NC |
6657 | Note - some sections, eg @code{.text} and @code{.data} are considered to be |
6658 | special and have fixed types. Any attempt to declare them with a different | |
6659 | type will generate an error from the assembler. | |
6660 | ||
22fe14ad | 6661 | If @var{flags} contains the @code{M} symbol then the @var{type} argument must |
96e9638b | 6662 | be specified as well as an extra argument---@var{entsize}---like this: |
22fe14ad NC |
6663 | |
6664 | @smallexample | |
6665 | .section @var{name} , "@var{flags}"M, @@@var{type}, @var{entsize} | |
6666 | @end smallexample | |
6667 | ||
6668 | Sections with the @code{M} flag but not @code{S} flag must contain fixed size | |
6669 | constants, each @var{entsize} octets long. Sections with both @code{M} and | |
6670 | @code{S} must contain zero terminated strings where each character is | |
6671 | @var{entsize} bytes long. The linker may remove duplicates within sections with | |
6672 | the same name, same entity size and same flags. @var{entsize} must be an | |
90dce00a AM |
6673 | absolute expression. For sections with both @code{M} and @code{S}, a string |
6674 | which is a suffix of a larger string is considered a duplicate. Thus | |
6675 | @code{"def"} will be merged with @code{"abcdef"}; A reference to the first | |
6676 | @code{"def"} will be changed to a reference to @code{"abcdef"+3}. | |
22fe14ad NC |
6677 | |
6678 | If @var{flags} contains the @code{G} symbol then the @var{type} argument must | |
6679 | be present along with an additional field like this: | |
6680 | ||
6681 | @smallexample | |
6682 | .section @var{name} , "@var{flags}"G, @@@var{type}, @var{GroupName}[, @var{linkage}] | |
6683 | @end smallexample | |
6684 | ||
6685 | The @var{GroupName} field specifies the name of the section group to which this | |
6686 | particular section belongs. The optional linkage field can contain: | |
eda683bb | 6687 | |
22fe14ad NC |
6688 | @table @code |
6689 | @item comdat | |
6690 | indicates that only one copy of this section should be retained | |
6691 | @item .gnu.linkonce | |
6692 | an alias for comdat | |
6693 | @end table | |
6694 | ||
96e9638b | 6695 | Note: if both the @var{M} and @var{G} flags are present then the fields for |
22fe14ad NC |
6696 | the Merge flag should come first, like this: |
6697 | ||
6698 | @smallexample | |
6699 | .section @var{name} , "@var{flags}"MG, @@@var{type}, @var{entsize}, @var{GroupName}[, @var{linkage}] | |
6700 | @end smallexample | |
ec38dd05 | 6701 | |
01642c12 RM |
6702 | If @var{flags} contains the @code{?} symbol then it may not also contain the |
6703 | @code{G} symbol and the @var{GroupName} or @var{linkage} fields should not be | |
6704 | present. Instead, @code{?} says to consider the section that's current before | |
6705 | this directive. If that section used @code{G}, then the new section will use | |
6706 | @code{G} with those same @var{GroupName} and @var{linkage} fields implicitly. | |
6707 | If not, then the @code{?} symbol has no effect. | |
6708 | ||
252b5132 RH |
6709 | If no flags are specified, the default flags depend upon the section name. If |
6710 | the section name is not recognized, the default will be for the section to have | |
6711 | none of the above flags: it will not be allocated in memory, nor writable, nor | |
6712 | executable. The section will contain data. | |
6713 | ||
6714 | For ELF targets, the assembler supports another type of @code{.section} | |
6715 | directive for compatibility with the Solaris assembler: | |
c91d2e08 | 6716 | |
252b5132 RH |
6717 | @smallexample |
6718 | .section "@var{name}"[, @var{flags}...] | |
6719 | @end smallexample | |
c91d2e08 | 6720 | |
252b5132 RH |
6721 | Note that the section name is quoted. There may be a sequence of comma |
6722 | separated flags: | |
eda683bb | 6723 | |
252b5132 RH |
6724 | @table @code |
6725 | @item #alloc | |
6726 | section is allocatable | |
6727 | @item #write | |
6728 | section is writable | |
6729 | @item #execinstr | |
6730 | section is executable | |
18ae9cc1 L |
6731 | @item #exclude |
6732 | section is excluded from executable and shared library. | |
22fe14ad NC |
6733 | @item #tls |
6734 | section is used for thread local storage | |
252b5132 | 6735 | @end table |
c91d2e08 | 6736 | |
e9863d7f DJ |
6737 | This directive replaces the current section and subsection. See the |
6738 | contents of the gas testsuite directory @code{gas/testsuite/gas/elf} for | |
6739 | some examples of how this directive and the other section stack directives | |
6740 | work. | |
c1253627 NC |
6741 | @end ifset |
6742 | @end ifset | |
252b5132 RH |
6743 | |
6744 | @node Set | |
6745 | @section @code{.set @var{symbol}, @var{expression}} | |
6746 | ||
6747 | @cindex @code{set} directive | |
6748 | @cindex symbol value, setting | |
6749 | Set the value of @var{symbol} to @var{expression}. This | |
6750 | changes @var{symbol}'s value and type to conform to | |
6751 | @var{expression}. If @var{symbol} was flagged as external, it remains | |
6752 | flagged (@pxref{Symbol Attributes}). | |
6753 | ||
5d239759 NC |
6754 | You may @code{.set} a symbol many times in the same assembly provided that the |
6755 | values given to the symbol are constants. Values that are based on expressions | |
6756 | involving other symbols are allowed, but some targets may restrict this to only | |
6757 | being done once per assembly. This is because those targets do not set the | |
6758 | addresses of symbols at assembly time, but rather delay the assignment until a | |
6759 | final link is performed. This allows the linker a chance to change the code in | |
6760 | the files, changing the location of, and the relative distance between, various | |
6761 | different symbols. | |
252b5132 RH |
6762 | |
6763 | If you @code{.set} a global symbol, the value stored in the object | |
6764 | file is the last value stored into it. | |
6765 | ||
3c9b82ba NC |
6766 | @ifset Z80 |
6767 | On Z80 @code{set} is a real instruction, use | |
6768 | @samp{@var{symbol} defl @var{expression}} instead. | |
6769 | @end ifset | |
6770 | ||
252b5132 RH |
6771 | @node Short |
6772 | @section @code{.short @var{expressions}} | |
6773 | ||
6774 | @cindex @code{short} directive | |
6775 | @ifset GENERIC | |
6776 | @code{.short} is normally the same as @samp{.word}. | |
6777 | @xref{Word,,@code{.word}}. | |
6778 | ||
6779 | In some configurations, however, @code{.short} and @code{.word} generate | |
96e9638b | 6780 | numbers of different lengths. @xref{Machine Dependencies}. |
252b5132 RH |
6781 | @end ifset |
6782 | @ifclear GENERIC | |
6783 | @ifset W16 | |
6784 | @code{.short} is the same as @samp{.word}. @xref{Word,,@code{.word}}. | |
6785 | @end ifset | |
6786 | @ifset W32 | |
6787 | This expects zero or more @var{expressions}, and emits | |
6788 | a 16 bit number for each. | |
6789 | @end ifset | |
6790 | @end ifclear | |
6791 | ||
6792 | @node Single | |
6793 | @section @code{.single @var{flonums}} | |
6794 | ||
6795 | @cindex @code{single} directive | |
6796 | @cindex floating point numbers (single) | |
6797 | This directive assembles zero or more flonums, separated by commas. It | |
6798 | has the same effect as @code{.float}. | |
6799 | @ifset GENERIC | |
6800 | The exact kind of floating point numbers emitted depends on how | |
a4fb0134 | 6801 | @command{@value{AS}} is configured. @xref{Machine Dependencies}. |
252b5132 RH |
6802 | @end ifset |
6803 | @ifclear GENERIC | |
6804 | @ifset IEEEFLOAT | |
6805 | On the @value{TARGET} family, @code{.single} emits 32-bit floating point | |
6806 | numbers in @sc{ieee} format. | |
6807 | @end ifset | |
6808 | @end ifclear | |
6809 | ||
c1253627 | 6810 | @ifset COFF-ELF |
252b5132 | 6811 | @node Size |
c1253627 | 6812 | @section @code{.size} |
c91d2e08 | 6813 | |
c1253627 NC |
6814 | This directive is used to set the size associated with a symbol. |
6815 | ||
6816 | @ifset COFF | |
6817 | @ifset ELF | |
6818 | @c only print the extra heading if both COFF and ELF are set | |
6819 | @subheading COFF Version | |
6820 | @end ifset | |
6821 | ||
6822 | @cindex @code{size} directive (COFF version) | |
6823 | For COFF targets, the @code{.size} directive is only permitted inside | |
6824 | @code{.def}/@code{.endef} pairs. It is used like this: | |
6825 | ||
6826 | @smallexample | |
6827 | .size @var{expression} | |
6828 | @end smallexample | |
252b5132 | 6829 | |
c1253627 | 6830 | @end ifset |
c91d2e08 | 6831 | |
c1253627 NC |
6832 | @ifset ELF |
6833 | @ifset COFF | |
6834 | @c only print the extra heading if both COFF and ELF are set | |
6835 | @subheading ELF Version | |
6836 | @end ifset | |
6837 | ||
6838 | @cindex @code{size} directive (ELF version) | |
6839 | For ELF targets, the @code{.size} directive is used like this: | |
c91d2e08 | 6840 | |
c1253627 NC |
6841 | @smallexample |
6842 | .size @var{name} , @var{expression} | |
6843 | @end smallexample | |
6844 | ||
6845 | This directive sets the size associated with a symbol @var{name}. | |
c91d2e08 NC |
6846 | The size in bytes is computed from @var{expression} which can make use of label |
6847 | arithmetic. This directive is typically used to set the size of function | |
6848 | symbols. | |
c1253627 NC |
6849 | @end ifset |
6850 | @end ifset | |
252b5132 | 6851 | |
252b5132 RH |
6852 | @ifclear no-space-dir |
6853 | @node Skip | |
340d33e5 | 6854 | @section @code{.skip @var{size} [,@var{fill}]} |
252b5132 RH |
6855 | |
6856 | @cindex @code{skip} directive | |
6857 | @cindex filling memory | |
6858 | This directive emits @var{size} bytes, each of value @var{fill}. Both | |
6859 | @var{size} and @var{fill} are absolute expressions. If the comma and | |
6860 | @var{fill} are omitted, @var{fill} is assumed to be zero. This is the same as | |
6861 | @samp{.space}. | |
884f0d36 | 6862 | @end ifclear |
252b5132 | 6863 | |
ccf8a69b BW |
6864 | @node Sleb128 |
6865 | @section @code{.sleb128 @var{expressions}} | |
6866 | ||
6867 | @cindex @code{sleb128} directive | |
01642c12 | 6868 | @var{sleb128} stands for ``signed little endian base 128.'' This is a |
ccf8a69b BW |
6869 | compact, variable length representation of numbers used by the DWARF |
6870 | symbolic debugging format. @xref{Uleb128, ,@code{.uleb128}}. | |
6871 | ||
884f0d36 | 6872 | @ifclear no-space-dir |
252b5132 | 6873 | @node Space |
340d33e5 | 6874 | @section @code{.space @var{size} [,@var{fill}]} |
252b5132 RH |
6875 | |
6876 | @cindex @code{space} directive | |
6877 | @cindex filling memory | |
6878 | This directive emits @var{size} bytes, each of value @var{fill}. Both | |
6879 | @var{size} and @var{fill} are absolute expressions. If the comma | |
6880 | and @var{fill} are omitted, @var{fill} is assumed to be zero. This is the same | |
6881 | as @samp{.skip}. | |
6882 | ||
6883 | @ifset HPPA | |
6884 | @quotation | |
6885 | @emph{Warning:} @code{.space} has a completely different meaning for HPPA | |
6886 | targets; use @code{.block} as a substitute. See @cite{HP9000 Series 800 | |
6887 | Assembly Language Reference Manual} (HP 92432-90001) for the meaning of the | |
6888 | @code{.space} directive. @xref{HPPA Directives,,HPPA Assembler Directives}, | |
6889 | for a summary. | |
6890 | @end quotation | |
6891 | @end ifset | |
6892 | @end ifclear | |
6893 | ||
252b5132 RH |
6894 | @ifset have-stabs |
6895 | @node Stab | |
6896 | @section @code{.stabd, .stabn, .stabs} | |
6897 | ||
6898 | @cindex symbolic debuggers, information for | |
6899 | @cindex @code{stab@var{x}} directives | |
6900 | There are three directives that begin @samp{.stab}. | |
6901 | All emit symbols (@pxref{Symbols}), for use by symbolic debuggers. | |
a4fb0134 | 6902 | The symbols are not entered in the @command{@value{AS}} hash table: they |
252b5132 RH |
6903 | cannot be referenced elsewhere in the source file. |
6904 | Up to five fields are required: | |
6905 | ||
6906 | @table @var | |
6907 | @item string | |
6908 | This is the symbol's name. It may contain any character except | |
6909 | @samp{\000}, so is more general than ordinary symbol names. Some | |
6910 | debuggers used to code arbitrarily complex structures into symbol names | |
6911 | using this field. | |
6912 | ||
6913 | @item type | |
6914 | An absolute expression. The symbol's type is set to the low 8 bits of | |
6915 | this expression. Any bit pattern is permitted, but @code{@value{LD}} | |
6916 | and debuggers choke on silly bit patterns. | |
6917 | ||
6918 | @item other | |
6919 | An absolute expression. The symbol's ``other'' attribute is set to the | |
6920 | low 8 bits of this expression. | |
6921 | ||
6922 | @item desc | |
6923 | An absolute expression. The symbol's descriptor is set to the low 16 | |
6924 | bits of this expression. | |
6925 | ||
6926 | @item value | |
6927 | An absolute expression which becomes the symbol's value. | |
6928 | @end table | |
6929 | ||
6930 | If a warning is detected while reading a @code{.stabd}, @code{.stabn}, | |
6931 | or @code{.stabs} statement, the symbol has probably already been created; | |
6932 | you get a half-formed symbol in your object file. This is | |
6933 | compatible with earlier assemblers! | |
6934 | ||
6935 | @table @code | |
6936 | @cindex @code{stabd} directive | |
6937 | @item .stabd @var{type} , @var{other} , @var{desc} | |
6938 | ||
6939 | The ``name'' of the symbol generated is not even an empty string. | |
6940 | It is a null pointer, for compatibility. Older assemblers used a | |
6941 | null pointer so they didn't waste space in object files with empty | |
6942 | strings. | |
6943 | ||
6944 | The symbol's value is set to the location counter, | |
6945 | relocatably. When your program is linked, the value of this symbol | |
6946 | is the address of the location counter when the @code{.stabd} was | |
6947 | assembled. | |
6948 | ||
6949 | @cindex @code{stabn} directive | |
6950 | @item .stabn @var{type} , @var{other} , @var{desc} , @var{value} | |
6951 | The name of the symbol is set to the empty string @code{""}. | |
6952 | ||
6953 | @cindex @code{stabs} directive | |
6954 | @item .stabs @var{string} , @var{type} , @var{other} , @var{desc} , @var{value} | |
6955 | All five fields are specified. | |
6956 | @end table | |
6957 | @end ifset | |
6958 | @c end have-stabs | |
6959 | ||
6960 | @node String | |
38a57ae7 | 6961 | @section @code{.string} "@var{str}", @code{.string8} "@var{str}", @code{.string16} |
01642c12 | 6962 | "@var{str}", @code{.string32} "@var{str}", @code{.string64} "@var{str}" |
252b5132 RH |
6963 | |
6964 | @cindex string, copying to object file | |
38a57ae7 NC |
6965 | @cindex string8, copying to object file |
6966 | @cindex string16, copying to object file | |
6967 | @cindex string32, copying to object file | |
6968 | @cindex string64, copying to object file | |
252b5132 | 6969 | @cindex @code{string} directive |
38a57ae7 NC |
6970 | @cindex @code{string8} directive |
6971 | @cindex @code{string16} directive | |
6972 | @cindex @code{string32} directive | |
6973 | @cindex @code{string64} directive | |
252b5132 RH |
6974 | |
6975 | Copy the characters in @var{str} to the object file. You may specify more than | |
6976 | one string to copy, separated by commas. Unless otherwise specified for a | |
6977 | particular machine, the assembler marks the end of each string with a 0 byte. | |
6978 | You can use any of the escape sequences described in @ref{Strings,,Strings}. | |
6979 | ||
01642c12 | 6980 | The variants @code{string16}, @code{string32} and @code{string64} differ from |
38a57ae7 NC |
6981 | the @code{string} pseudo opcode in that each 8-bit character from @var{str} is |
6982 | copied and expanded to 16, 32 or 64 bits respectively. The expanded characters | |
6983 | are stored in target endianness byte order. | |
6984 | ||
6985 | Example: | |
6986 | @smallexample | |
6987 | .string32 "BYE" | |
6988 | expands to: | |
6989 | .string "B\0\0\0Y\0\0\0E\0\0\0" /* On little endian targets. */ | |
6990 | .string "\0\0\0B\0\0\0Y\0\0\0E" /* On big endian targets. */ | |
6991 | @end smallexample | |
6992 | ||
6993 | ||
252b5132 RH |
6994 | @node Struct |
6995 | @section @code{.struct @var{expression}} | |
6996 | ||
6997 | @cindex @code{struct} directive | |
6998 | Switch to the absolute section, and set the section offset to @var{expression}, | |
6999 | which must be an absolute expression. You might use this as follows: | |
7000 | @smallexample | |
7001 | .struct 0 | |
7002 | field1: | |
7003 | .struct field1 + 4 | |
7004 | field2: | |
7005 | .struct field2 + 4 | |
7006 | field3: | |
7007 | @end smallexample | |
7008 | This would define the symbol @code{field1} to have the value 0, the symbol | |
7009 | @code{field2} to have the value 4, and the symbol @code{field3} to have the | |
7010 | value 8. Assembly would be left in the absolute section, and you would need to | |
7011 | use a @code{.section} directive of some sort to change to some other section | |
7012 | before further assembly. | |
7013 | ||
c91d2e08 NC |
7014 | @ifset ELF |
7015 | @node SubSection | |
7016 | @section @code{.subsection @var{name}} | |
7017 | ||
c1253627 | 7018 | @cindex @code{subsection} directive |
c91d2e08 NC |
7019 | @cindex Section Stack |
7020 | This is one of the ELF section stack manipulation directives. The others are | |
01642c12 RM |
7021 | @code{.section} (@pxref{Section}), @code{.pushsection} (@pxref{PushSection}), |
7022 | @code{.popsection} (@pxref{PopSection}), and @code{.previous} | |
a349d9dd | 7023 | (@pxref{Previous}). |
c91d2e08 NC |
7024 | |
7025 | This directive replaces the current subsection with @code{name}. The current | |
7026 | section is not changed. The replaced subsection is put onto the section stack | |
7027 | in place of the then current top of stack subsection. | |
c91d2e08 NC |
7028 | @end ifset |
7029 | ||
252b5132 RH |
7030 | @ifset ELF |
7031 | @node Symver | |
7032 | @section @code{.symver} | |
7033 | @cindex @code{symver} directive | |
7034 | @cindex symbol versioning | |
7035 | @cindex versions of symbols | |
7036 | Use the @code{.symver} directive to bind symbols to specific version nodes | |
7037 | within a source file. This is only supported on ELF platforms, and is | |
7038 | typically used when assembling files to be linked into a shared library. | |
7039 | There are cases where it may make sense to use this in objects to be bound | |
7040 | into an application itself so as to override a versioned symbol from a | |
7041 | shared library. | |
7042 | ||
79082ff0 | 7043 | For ELF targets, the @code{.symver} directive can be used like this: |
252b5132 RH |
7044 | @smallexample |
7045 | .symver @var{name}, @var{name2@@nodename} | |
7046 | @end smallexample | |
339681c0 | 7047 | If the symbol @var{name} is defined within the file |
79082ff0 | 7048 | being assembled, the @code{.symver} directive effectively creates a symbol |
252b5132 RH |
7049 | alias with the name @var{name2@@nodename}, and in fact the main reason that we |
7050 | just don't try and create a regular alias is that the @var{@@} character isn't | |
7051 | permitted in symbol names. The @var{name2} part of the name is the actual name | |
7052 | of the symbol by which it will be externally referenced. The name @var{name} | |
7053 | itself is merely a name of convenience that is used so that it is possible to | |
7054 | have definitions for multiple versions of a function within a single source | |
7055 | file, and so that the compiler can unambiguously know which version of a | |
7056 | function is being mentioned. The @var{nodename} portion of the alias should be | |
7057 | the name of a node specified in the version script supplied to the linker when | |
7058 | building a shared library. If you are attempting to override a versioned | |
7059 | symbol from a shared library, then @var{nodename} should correspond to the | |
7060 | nodename of the symbol you are trying to override. | |
339681c0 L |
7061 | |
7062 | If the symbol @var{name} is not defined within the file being assembled, all | |
7063 | references to @var{name} will be changed to @var{name2@@nodename}. If no | |
7064 | reference to @var{name} is made, @var{name2@@nodename} will be removed from the | |
7065 | symbol table. | |
79082ff0 L |
7066 | |
7067 | Another usage of the @code{.symver} directive is: | |
7068 | @smallexample | |
7069 | .symver @var{name}, @var{name2@@@@nodename} | |
7070 | @end smallexample | |
7071 | In this case, the symbol @var{name} must exist and be defined within | |
a349d9dd | 7072 | the file being assembled. It is similar to @var{name2@@nodename}. The |
79082ff0 L |
7073 | difference is @var{name2@@@@nodename} will also be used to resolve |
7074 | references to @var{name2} by the linker. | |
7075 | ||
7076 | The third usage of the @code{.symver} directive is: | |
7077 | @smallexample | |
7078 | .symver @var{name}, @var{name2@@@@@@nodename} | |
7079 | @end smallexample | |
7080 | When @var{name} is not defined within the | |
7081 | file being assembled, it is treated as @var{name2@@nodename}. When | |
7082 | @var{name} is defined within the file being assembled, the symbol | |
7083 | name, @var{name}, will be changed to @var{name2@@@@nodename}. | |
252b5132 RH |
7084 | @end ifset |
7085 | ||
7086 | @ifset COFF | |
7087 | @node Tag | |
7088 | @section @code{.tag @var{structname}} | |
7089 | ||
7090 | @cindex COFF structure debugging | |
7091 | @cindex structure debugging, COFF | |
7092 | @cindex @code{tag} directive | |
7093 | This directive is generated by compilers to include auxiliary debugging | |
7094 | information in the symbol table. It is only permitted inside | |
7095 | @code{.def}/@code{.endef} pairs. Tags are used to link structure | |
7096 | definitions in the symbol table with instances of those structures. | |
252b5132 RH |
7097 | @end ifset |
7098 | ||
7099 | @node Text | |
7100 | @section @code{.text @var{subsection}} | |
7101 | ||
7102 | @cindex @code{text} directive | |
a4fb0134 | 7103 | Tells @command{@value{AS}} to assemble the following statements onto the end of |
252b5132 RH |
7104 | the text subsection numbered @var{subsection}, which is an absolute |
7105 | expression. If @var{subsection} is omitted, subsection number zero | |
7106 | is used. | |
7107 | ||
7108 | @node Title | |
7109 | @section @code{.title "@var{heading}"} | |
7110 | ||
7111 | @cindex @code{title} directive | |
7112 | @cindex listing control: title line | |
7113 | Use @var{heading} as the title (second line, immediately after the | |
7114 | source file name and pagenumber) when generating assembly listings. | |
7115 | ||
7116 | This directive affects subsequent pages, as well as the current page if | |
7117 | it appears within ten lines of the top of a page. | |
7118 | ||
c1253627 | 7119 | @ifset COFF-ELF |
252b5132 | 7120 | @node Type |
c1253627 NC |
7121 | @section @code{.type} |
7122 | ||
7123 | This directive is used to set the type of a symbol. | |
7124 | ||
7125 | @ifset COFF | |
7126 | @ifset ELF | |
7127 | @c only print the extra heading if both COFF and ELF are set | |
7128 | @subheading COFF Version | |
7129 | @end ifset | |
252b5132 RH |
7130 | |
7131 | @cindex COFF symbol type | |
7132 | @cindex symbol type, COFF | |
c1253627 NC |
7133 | @cindex @code{type} directive (COFF version) |
7134 | For COFF targets, this directive is permitted only within | |
7135 | @code{.def}/@code{.endef} pairs. It is used like this: | |
7136 | ||
7137 | @smallexample | |
7138 | .type @var{int} | |
7139 | @end smallexample | |
7140 | ||
7141 | This records the integer @var{int} as the type attribute of a symbol table | |
7142 | entry. | |
252b5132 | 7143 | |
c1253627 | 7144 | @end ifset |
c91d2e08 | 7145 | |
c1253627 NC |
7146 | @ifset ELF |
7147 | @ifset COFF | |
7148 | @c only print the extra heading if both COFF and ELF are set | |
7149 | @subheading ELF Version | |
7150 | @end ifset | |
c91d2e08 NC |
7151 | |
7152 | @cindex ELF symbol type | |
7153 | @cindex symbol type, ELF | |
c1253627 NC |
7154 | @cindex @code{type} directive (ELF version) |
7155 | For ELF targets, the @code{.type} directive is used like this: | |
7156 | ||
7157 | @smallexample | |
7158 | .type @var{name} , @var{type description} | |
7159 | @end smallexample | |
7160 | ||
7161 | This sets the type of symbol @var{name} to be either a | |
a349d9dd | 7162 | function symbol or an object symbol. There are five different syntaxes |
c91d2e08 | 7163 | supported for the @var{type description} field, in order to provide |
28c9d252 | 7164 | compatibility with various other assemblers. |
58ab4f3d MM |
7165 | |
7166 | Because some of the characters used in these syntaxes (such as @samp{@@} and | |
7167 | @samp{#}) are comment characters for some architectures, some of the syntaxes | |
7168 | below do not work on all architectures. The first variant will be accepted by | |
7169 | the GNU assembler on all architectures so that variant should be used for | |
7170 | maximum portability, if you do not need to assemble your code with other | |
7171 | assemblers. | |
7172 | ||
7173 | The syntaxes supported are: | |
c91d2e08 NC |
7174 | |
7175 | @smallexample | |
5671778d NC |
7176 | .type <name> STT_<TYPE_IN_UPPER_CASE> |
7177 | .type <name>,#<type> | |
7178 | .type <name>,@@<type> | |
e7c33416 | 7179 | .type <name>,%<type> |
5671778d NC |
7180 | .type <name>,"<type>" |
7181 | @end smallexample | |
7182 | ||
7183 | The types supported are: | |
58ab4f3d | 7184 | |
5671778d NC |
7185 | @table @gcctabopt |
7186 | @item STT_FUNC | |
7187 | @itemx function | |
7188 | Mark the symbol as being a function name. | |
c91d2e08 | 7189 | |
d8045f23 NC |
7190 | @item STT_GNU_IFUNC |
7191 | @itemx gnu_indirect_function | |
7192 | Mark the symbol as an indirect function when evaluated during reloc | |
9c55345c | 7193 | processing. (This is only supported on assemblers targeting GNU systems). |
d8045f23 | 7194 | |
5671778d NC |
7195 | @item STT_OBJECT |
7196 | @itemx object | |
7197 | Mark the symbol as being a data object. | |
7198 | ||
7199 | @item STT_TLS | |
7200 | @itemx tls_object | |
33eaf5de | 7201 | Mark the symbol as being a thread-local data object. |
5671778d NC |
7202 | |
7203 | @item STT_COMMON | |
7204 | @itemx common | |
7205 | Mark the symbol as being a common data object. | |
e7c33416 NC |
7206 | |
7207 | @item STT_NOTYPE | |
7208 | @itemx notype | |
7209 | Does not mark the symbol in any way. It is supported just for completeness. | |
7210 | ||
3e7a7d11 NC |
7211 | @item gnu_unique_object |
7212 | Marks the symbol as being a globally unique data object. The dynamic linker | |
7213 | will make sure that in the entire process there is just one symbol with this | |
9c55345c TS |
7214 | name and type in use. (This is only supported on assemblers targeting GNU |
7215 | systems). | |
3e7a7d11 | 7216 | |
5671778d NC |
7217 | @end table |
7218 | ||
f2d4ba38 JB |
7219 | Changing between incompatible types other than from/to STT_NOTYPE will |
7220 | result in a diagnostic. An intermediate change to STT_NOTYPE will silence | |
7221 | this. | |
7222 | ||
5671778d | 7223 | Note: Some targets support extra types in addition to those listed above. |
c91d2e08 | 7224 | |
c1253627 NC |
7225 | @end ifset |
7226 | @end ifset | |
c91d2e08 NC |
7227 | |
7228 | @node Uleb128 | |
7229 | @section @code{.uleb128 @var{expressions}} | |
7230 | ||
7231 | @cindex @code{uleb128} directive | |
01642c12 | 7232 | @var{uleb128} stands for ``unsigned little endian base 128.'' This is a |
c91d2e08 | 7233 | compact, variable length representation of numbers used by the DWARF |
96e9638b | 7234 | symbolic debugging format. @xref{Sleb128, ,@code{.sleb128}}. |
252b5132 RH |
7235 | |
7236 | @ifset COFF | |
7237 | @node Val | |
7238 | @section @code{.val @var{addr}} | |
7239 | ||
7240 | @cindex @code{val} directive | |
7241 | @cindex COFF value attribute | |
7242 | @cindex value attribute, COFF | |
7243 | This directive, permitted only within @code{.def}/@code{.endef} pairs, | |
7244 | records the address @var{addr} as the value attribute of a symbol table | |
7245 | entry. | |
252b5132 RH |
7246 | @end ifset |
7247 | ||
2e13b764 | 7248 | @ifset ELF |
c91d2e08 NC |
7249 | @node Version |
7250 | @section @code{.version "@var{string}"} | |
2e13b764 | 7251 | |
c1253627 | 7252 | @cindex @code{version} directive |
c91d2e08 NC |
7253 | This directive creates a @code{.note} section and places into it an ELF |
7254 | formatted note of type NT_VERSION. The note's name is set to @code{string}. | |
9a297610 | 7255 | @end ifset |
2e13b764 | 7256 | |
c91d2e08 NC |
7257 | @ifset ELF |
7258 | @node VTableEntry | |
7259 | @section @code{.vtable_entry @var{table}, @var{offset}} | |
2e13b764 | 7260 | |
653cfe85 | 7261 | @cindex @code{vtable_entry} directive |
c91d2e08 NC |
7262 | This directive finds or creates a symbol @code{table} and creates a |
7263 | @code{VTABLE_ENTRY} relocation for it with an addend of @code{offset}. | |
2e13b764 | 7264 | |
c91d2e08 NC |
7265 | @node VTableInherit |
7266 | @section @code{.vtable_inherit @var{child}, @var{parent}} | |
2e13b764 | 7267 | |
653cfe85 | 7268 | @cindex @code{vtable_inherit} directive |
c91d2e08 NC |
7269 | This directive finds the symbol @code{child} and finds or creates the symbol |
7270 | @code{parent} and then creates a @code{VTABLE_INHERIT} relocation for the | |
a349d9dd | 7271 | parent whose addend is the value of the child symbol. As a special case the |
96e9638b | 7272 | parent name of @code{0} is treated as referring to the @code{*ABS*} section. |
c91d2e08 | 7273 | @end ifset |
2e13b764 | 7274 | |
d190d046 HPN |
7275 | @node Warning |
7276 | @section @code{.warning "@var{string}"} | |
7277 | @cindex warning directive | |
7278 | Similar to the directive @code{.error} | |
7279 | (@pxref{Error,,@code{.error "@var{string}"}}), but just emits a warning. | |
7280 | ||
c91d2e08 NC |
7281 | @node Weak |
7282 | @section @code{.weak @var{names}} | |
2e13b764 | 7283 | |
c1253627 | 7284 | @cindex @code{weak} directive |
a349d9dd | 7285 | This directive sets the weak attribute on the comma separated list of symbol |
c91d2e08 | 7286 | @code{names}. If the symbols do not already exist, they will be created. |
c87db184 | 7287 | |
01642c12 | 7288 | On COFF targets other than PE, weak symbols are a GNU extension. This |
977cdf5a | 7289 | directive sets the weak attribute on the comma separated list of symbol |
c87db184 CF |
7290 | @code{names}. If the symbols do not already exist, they will be created. |
7291 | ||
977cdf5a | 7292 | On the PE target, weak symbols are supported natively as weak aliases. |
01642c12 | 7293 | When a weak symbol is created that is not an alias, GAS creates an |
977cdf5a | 7294 | alternate symbol to hold the default value. |
2e13b764 | 7295 | |
06e77878 AO |
7296 | @node Weakref |
7297 | @section @code{.weakref @var{alias}, @var{target}} | |
7298 | ||
7299 | @cindex @code{weakref} directive | |
7300 | This directive creates an alias to the target symbol that enables the symbol to | |
7301 | be referenced with weak-symbol semantics, but without actually making it weak. | |
7302 | If direct references or definitions of the symbol are present, then the symbol | |
7303 | will not be weak, but if all references to it are through weak references, the | |
7304 | symbol will be marked as weak in the symbol table. | |
7305 | ||
7306 | The effect is equivalent to moving all references to the alias to a separate | |
7307 | assembly source file, renaming the alias to the symbol in it, declaring the | |
7308 | symbol as weak there, and running a reloadable link to merge the object files | |
7309 | resulting from the assembly of the new source file and the old source file that | |
7310 | had the references to the alias removed. | |
7311 | ||
7312 | The alias itself never makes to the symbol table, and is entirely handled | |
7313 | within the assembler. | |
7314 | ||
252b5132 RH |
7315 | @node Word |
7316 | @section @code{.word @var{expressions}} | |
7317 | ||
7318 | @cindex @code{word} directive | |
7319 | This directive expects zero or more @var{expressions}, of any section, | |
7320 | separated by commas. | |
7321 | @ifclear GENERIC | |
7322 | @ifset W32 | |
a4fb0134 | 7323 | For each expression, @command{@value{AS}} emits a 32-bit number. |
252b5132 RH |
7324 | @end ifset |
7325 | @ifset W16 | |
a4fb0134 | 7326 | For each expression, @command{@value{AS}} emits a 16-bit number. |
252b5132 RH |
7327 | @end ifset |
7328 | @end ifclear | |
7329 | @ifset GENERIC | |
7330 | ||
7331 | The size of the number emitted, and its byte order, | |
7332 | depend on what target computer the assembly is for. | |
7333 | @end ifset | |
7334 | ||
a8eb42a8 | 7335 | @c on sparc the "special treatment to support compilers" doesn't |
252b5132 RH |
7336 | @c happen---32-bit addressability, period; no long/short jumps. |
7337 | @ifset DIFF-TBL-KLUGE | |
7338 | @cindex difference tables altered | |
7339 | @cindex altered difference tables | |
7340 | @quotation | |
7341 | @emph{Warning: Special Treatment to support Compilers} | |
7342 | @end quotation | |
7343 | ||
7344 | @ifset GENERIC | |
7345 | Machines with a 32-bit address space, but that do less than 32-bit | |
7346 | addressing, require the following special treatment. If the machine of | |
7347 | interest to you does 32-bit addressing (or doesn't require it; | |
7348 | @pxref{Machine Dependencies}), you can ignore this issue. | |
7349 | ||
7350 | @end ifset | |
7351 | In order to assemble compiler output into something that works, | |
a4fb0134 | 7352 | @command{@value{AS}} occasionally does strange things to @samp{.word} directives. |
252b5132 | 7353 | Directives of the form @samp{.word sym1-sym2} are often emitted by |
a4fb0134 | 7354 | compilers as part of jump tables. Therefore, when @command{@value{AS}} assembles a |
252b5132 | 7355 | directive of the form @samp{.word sym1-sym2}, and the difference between |
a4fb0134 | 7356 | @code{sym1} and @code{sym2} does not fit in 16 bits, @command{@value{AS}} |
252b5132 RH |
7357 | creates a @dfn{secondary jump table}, immediately before the next label. |
7358 | This secondary jump table is preceded by a short-jump to the | |
7359 | first byte after the secondary table. This short-jump prevents the flow | |
7360 | of control from accidentally falling into the new table. Inside the | |
7361 | table is a long-jump to @code{sym2}. The original @samp{.word} | |
7362 | contains @code{sym1} minus the address of the long-jump to | |
7363 | @code{sym2}. | |
7364 | ||
7365 | If there were several occurrences of @samp{.word sym1-sym2} before the | |
7366 | secondary jump table, all of them are adjusted. If there was a | |
7367 | @samp{.word sym3-sym4}, that also did not fit in sixteen bits, a | |
7368 | long-jump to @code{sym4} is included in the secondary jump table, | |
7369 | and the @code{.word} directives are adjusted to contain @code{sym3} | |
7370 | minus the address of the long-jump to @code{sym4}; and so on, for as many | |
7371 | entries in the original jump table as necessary. | |
7372 | ||
7373 | @ifset INTERNALS | |
a4fb0134 | 7374 | @emph{This feature may be disabled by compiling @command{@value{AS}} with the |
252b5132 RH |
7375 | @samp{-DWORKING_DOT_WORD} option.} This feature is likely to confuse |
7376 | assembly language programmers. | |
7377 | @end ifset | |
7378 | @end ifset | |
7379 | @c end DIFF-TBL-KLUGE | |
7380 | ||
7ce98c16 NC |
7381 | @ifclear no-space-dir |
7382 | @node Zero | |
7383 | @section @code{.zero @var{size}} | |
7384 | ||
7385 | @cindex @code{zero} directive | |
7386 | @cindex filling memory with zero bytes | |
7387 | This directive emits @var{size} 0-valued bytes. @var{size} must be an absolute | |
7388 | expression. This directive is actually an alias for the @samp{.skip} directive | |
900e33b9 | 7389 | so it can take an optional second argument of the value to store in the bytes |
7ce98c16 NC |
7390 | instead of zero. Using @samp{.zero} in this way would be confusing however. |
7391 | @end ifclear | |
7392 | ||
2b841ec2 AM |
7393 | @ifset ELF |
7394 | @node 2byte | |
ea86f534 | 7395 | @section @code{.2byte @var{expression} [, @var{expression}]*} |
2b841ec2 AM |
7396 | @cindex @code{2byte} directive |
7397 | @cindex two-byte integer | |
7398 | @cindex integer, 2-byte | |
2b841ec2 | 7399 | |
e406e428 NC |
7400 | This directive expects zero or more expressions, separated by commas. If there |
7401 | are no expressions then the directive does nothing. Otherwise each expression | |
7402 | is evaluated in turn and placed in the next two bytes of the current output | |
7403 | section, using the endian model of the target. If an expression will not fit | |
7404 | in two bytes, a warning message is displayed and the least significant two | |
7405 | bytes of the expression's value are used. If an expression cannot be evaluated | |
7406 | at assembly time then relocations will be generated in order to compute the | |
7407 | value at link time. | |
7408 | ||
7409 | This directive does not apply any alignment before or after inserting the | |
7410 | values. As a result of this, if relocations are generated, they may be | |
7411 | different from those used for inserting values with a guaranteed alignment. | |
7412 | ||
8b1e5da1 | 7413 | This directive is only available for ELF targets, |
2b841ec2 AM |
7414 | |
7415 | @node 4byte | |
ea86f534 | 7416 | @section @code{.4byte @var{expression} [, @var{expression}]*} |
2b841ec2 AM |
7417 | @cindex @code{4byte} directive |
7418 | @cindex four-byte integer | |
7419 | @cindex integer, 4-byte | |
2b841ec2 | 7420 | |
e406e428 NC |
7421 | Like the @option{.2byte} directive, except that it inserts unaligned, four byte |
7422 | long values into the output. | |
2b841ec2 AM |
7423 | |
7424 | @node 8byte | |
ea86f534 | 7425 | @section @code{.8byte @var{expression} [, @var{expression}]*} |
2b841ec2 AM |
7426 | @cindex @code{8byte} directive |
7427 | @cindex eight-byte integer | |
7428 | @cindex integer, 8-byte | |
2b841ec2 | 7429 | |
e21126b7 | 7430 | Like the @option{.2byte} directive, except that it inserts unaligned, eight |
e406e428 NC |
7431 | byte long bignum values into the output. |
7432 | ||
2b841ec2 AM |
7433 | @end ifset |
7434 | ||
252b5132 RH |
7435 | @node Deprecated |
7436 | @section Deprecated Directives | |
7437 | ||
7438 | @cindex deprecated directives | |
7439 | @cindex obsolescent directives | |
7440 | One day these directives won't work. | |
7441 | They are included for compatibility with older assemblers. | |
7442 | @table @t | |
7443 | @item .abort | |
7444 | @item .line | |
7445 | @end table | |
7446 | ||
3a99f02f DJ |
7447 | @ifset ELF |
7448 | @node Object Attributes | |
7449 | @chapter Object Attributes | |
7450 | @cindex object attributes | |
7451 | ||
7452 | @command{@value{AS}} assembles source files written for a specific architecture | |
7453 | into object files for that architecture. But not all object files are alike. | |
7454 | Many architectures support incompatible variations. For instance, floating | |
7455 | point arguments might be passed in floating point registers if the object file | |
7456 | requires hardware floating point support---or floating point arguments might be | |
7457 | passed in integer registers if the object file supports processors with no | |
7458 | hardware floating point unit. Or, if two objects are built for different | |
7459 | generations of the same architecture, the combination may require the | |
7460 | newer generation at run-time. | |
7461 | ||
7462 | This information is useful during and after linking. At link time, | |
7463 | @command{@value{LD}} can warn about incompatible object files. After link | |
7464 | time, tools like @command{gdb} can use it to process the linked file | |
7465 | correctly. | |
7466 | ||
7467 | Compatibility information is recorded as a series of object attributes. Each | |
7468 | attribute has a @dfn{vendor}, @dfn{tag}, and @dfn{value}. The vendor is a | |
7469 | string, and indicates who sets the meaning of the tag. The tag is an integer, | |
7470 | and indicates what property the attribute describes. The value may be a string | |
7471 | or an integer, and indicates how the property affects this object. Missing | |
7472 | attributes are the same as attributes with a zero value or empty string value. | |
7473 | ||
7474 | Object attributes were developed as part of the ABI for the ARM Architecture. | |
7475 | The file format is documented in @cite{ELF for the ARM Architecture}. | |
7476 | ||
7477 | @menu | |
7478 | * GNU Object Attributes:: @sc{gnu} Object Attributes | |
7479 | * Defining New Object Attributes:: Defining New Object Attributes | |
7480 | @end menu | |
7481 | ||
7482 | @node GNU Object Attributes | |
7483 | @section @sc{gnu} Object Attributes | |
7484 | ||
7485 | The @code{.gnu_attribute} directive records an object attribute | |
7486 | with vendor @samp{gnu}. | |
7487 | ||
7488 | Except for @samp{Tag_compatibility}, which has both an integer and a string for | |
7489 | its value, @sc{gnu} attributes have a string value if the tag number is odd and | |
7490 | an integer value if the tag number is even. The second bit (@code{@var{tag} & | |
7491 | 2} is set for architecture-independent attributes and clear for | |
7492 | architecture-dependent ones. | |
7493 | ||
7494 | @subsection Common @sc{gnu} attributes | |
7495 | ||
7496 | These attributes are valid on all architectures. | |
7497 | ||
7498 | @table @r | |
7499 | @item Tag_compatibility (32) | |
7500 | The compatibility attribute takes an integer flag value and a vendor name. If | |
7501 | the flag value is 0, the file is compatible with other toolchains. If it is 1, | |
7502 | then the file is only compatible with the named toolchain. If it is greater | |
7503 | than 1, the file can only be processed by other toolchains under some private | |
7504 | arrangement indicated by the flag value and the vendor name. | |
7505 | @end table | |
7506 | ||
7507 | @subsection MIPS Attributes | |
7508 | ||
7509 | @table @r | |
7510 | @item Tag_GNU_MIPS_ABI_FP (4) | |
7511 | The floating-point ABI used by this object file. The value will be: | |
7512 | ||
7513 | @itemize @bullet | |
7514 | @item | |
7515 | 0 for files not affected by the floating-point ABI. | |
7516 | @item | |
f179c512 MF |
7517 | 1 for files using the hardware floating-point ABI with a standard |
7518 | double-precision FPU. | |
3a99f02f DJ |
7519 | @item |
7520 | 2 for files using the hardware floating-point ABI with a single-precision FPU. | |
7521 | @item | |
7522 | 3 for files using the software floating-point ABI. | |
42554f6a | 7523 | @item |
f179c512 MF |
7524 | 4 for files using the deprecated hardware floating-point ABI which used 64-bit |
7525 | floating-point registers, 32-bit general-purpose registers and increased the | |
7526 | number of callee-saved floating-point registers. | |
7527 | @item | |
7528 | 5 for files using the hardware floating-point ABI with a double-precision FPU | |
7529 | with either 32-bit or 64-bit floating-point registers and 32-bit | |
7530 | general-purpose registers. | |
7531 | @item | |
7532 | 6 for files using the hardware floating-point ABI with 64-bit floating-point | |
7533 | registers and 32-bit general-purpose registers. | |
7534 | @item | |
7535 | 7 for files using the hardware floating-point ABI with 64-bit floating-point | |
7536 | registers, 32-bit general-purpose registers and a rule that forbids the | |
7537 | direct use of odd-numbered single-precision floating-point registers. | |
3a99f02f DJ |
7538 | @end itemize |
7539 | @end table | |
7540 | ||
7541 | @subsection PowerPC Attributes | |
7542 | ||
7543 | @table @r | |
7544 | @item Tag_GNU_Power_ABI_FP (4) | |
7545 | The floating-point ABI used by this object file. The value will be: | |
7546 | ||
7547 | @itemize @bullet | |
7548 | @item | |
7549 | 0 for files not affected by the floating-point ABI. | |
7550 | @item | |
3c7b9897 | 7551 | 1 for files using double-precision hardware floating-point ABI. |
3a99f02f DJ |
7552 | @item |
7553 | 2 for files using the software floating-point ABI. | |
3c7b9897 AM |
7554 | @item |
7555 | 3 for files using single-precision hardware floating-point ABI. | |
3a99f02f DJ |
7556 | @end itemize |
7557 | ||
7558 | @item Tag_GNU_Power_ABI_Vector (8) | |
7559 | The vector ABI used by this object file. The value will be: | |
7560 | ||
7561 | @itemize @bullet | |
7562 | @item | |
7563 | 0 for files not affected by the vector ABI. | |
7564 | @item | |
7565 | 1 for files using general purpose registers to pass vectors. | |
7566 | @item | |
7567 | 2 for files using AltiVec registers to pass vectors. | |
7568 | @item | |
7569 | 3 for files using SPE registers to pass vectors. | |
7570 | @end itemize | |
7571 | @end table | |
7572 | ||
643f7afb AK |
7573 | @subsection IBM z Systems Attributes |
7574 | ||
7575 | @table @r | |
7576 | @item Tag_GNU_S390_ABI_Vector (8) | |
7577 | The vector ABI used by this object file. The value will be: | |
7578 | ||
7579 | @itemize @bullet | |
7580 | @item | |
7581 | 0 for files not affected by the vector ABI. | |
7582 | @item | |
7583 | 1 for files using software vector ABI. | |
7584 | @item | |
7585 | 2 for files using hardware vector ABI. | |
7586 | @end itemize | |
7587 | @end table | |
7588 | ||
c0ea7c52 JL |
7589 | @subsection MSP430 Attributes |
7590 | ||
7591 | @table @r | |
7592 | @item Tag_GNU_MSP430_Data_Region (4) | |
7593 | The data region used by this object file. The value will be: | |
7594 | ||
7595 | @itemize @bullet | |
7596 | @item | |
7597 | 0 for files not using the large memory model. | |
7598 | @item | |
7599 | 1 for files which have been compiled with the condition that all | |
7600 | data is in the lower memory region, i.e. below address 0x10000. | |
7601 | @item | |
7602 | 2 for files which allow data to be placed in the full 20-bit memory range. | |
7603 | @end itemize | |
7604 | @end table | |
7605 | ||
3a99f02f DJ |
7606 | @node Defining New Object Attributes |
7607 | @section Defining New Object Attributes | |
7608 | ||
7609 | If you want to define a new @sc{gnu} object attribute, here are the places you | |
7610 | will need to modify. New attributes should be discussed on the @samp{binutils} | |
7611 | mailing list. | |
7612 | ||
7613 | @itemize @bullet | |
7614 | @item | |
7615 | This manual, which is the official register of attributes. | |
7616 | @item | |
7617 | The header for your architecture @file{include/elf}, to define the tag. | |
7618 | @item | |
7619 | The @file{bfd} support file for your architecture, to merge the attribute | |
7620 | and issue any appropriate link warnings. | |
7621 | @item | |
7622 | Test cases in @file{ld/testsuite} for merging and link warnings. | |
7623 | @item | |
7624 | @file{binutils/readelf.c} to display your attribute. | |
7625 | @item | |
7626 | GCC, if you want the compiler to mark the attribute automatically. | |
7627 | @end itemize | |
7628 | ||
7629 | @end ifset | |
7630 | ||
252b5132 RH |
7631 | @ifset GENERIC |
7632 | @node Machine Dependencies | |
7633 | @chapter Machine Dependent Features | |
7634 | ||
7635 | @cindex machine dependencies | |
7636 | The machine instruction sets are (almost by definition) different on | |
a4fb0134 SC |
7637 | each machine where @command{@value{AS}} runs. Floating point representations |
7638 | vary as well, and @command{@value{AS}} often supports a few additional | |
252b5132 RH |
7639 | directives or command-line options for compatibility with other |
7640 | assemblers on a particular platform. Finally, some versions of | |
a4fb0134 | 7641 | @command{@value{AS}} support special pseudo-instructions for branch |
252b5132 RH |
7642 | optimization. |
7643 | ||
7644 | This chapter discusses most of these differences, though it does not | |
7645 | include details on any machine's instruction set. For details on that | |
7646 | subject, see the hardware manufacturer's manual. | |
7647 | ||
7648 | @menu | |
a06ea964 NC |
7649 | @ifset AARCH64 |
7650 | * AArch64-Dependent:: AArch64 Dependent Features | |
7651 | @end ifset | |
625e1353 RH |
7652 | @ifset ALPHA |
7653 | * Alpha-Dependent:: Alpha Dependent Features | |
7654 | @end ifset | |
252b5132 RH |
7655 | @ifset ARC |
7656 | * ARC-Dependent:: ARC Dependent Features | |
7657 | @end ifset | |
7658 | @ifset ARM | |
7659 | * ARM-Dependent:: ARM Dependent Features | |
7660 | @end ifset | |
8473f7a4 DC |
7661 | @ifset AVR |
7662 | * AVR-Dependent:: AVR Dependent Features | |
7663 | @end ifset | |
3b4e1885 JZ |
7664 | @ifset Blackfin |
7665 | * Blackfin-Dependent:: Blackfin Dependent Features | |
07c1b327 | 7666 | @end ifset |
f8861f5d JM |
7667 | @ifset BPF |
7668 | * BPF-Dependent:: BPF Dependent Features | |
7669 | @end ifset | |
3d3d428f NC |
7670 | @ifset CR16 |
7671 | * CR16-Dependent:: CR16 Dependent Features | |
7672 | @end ifset | |
8bf549a8 | 7673 | @ifset CRIS |
328eb32e HPN |
7674 | * CRIS-Dependent:: CRIS Dependent Features |
7675 | @end ifset | |
b8891f8d AJ |
7676 | @ifset CSKY |
7677 | * C-SKY-Dependent:: C-SKY Dependent Features | |
7678 | @end ifset | |
252b5132 RH |
7679 | @ifset D10V |
7680 | * D10V-Dependent:: D10V Dependent Features | |
7681 | @end ifset | |
7682 | @ifset D30V | |
7683 | * D30V-Dependent:: D30V Dependent Features | |
7684 | @end ifset | |
cfb8c092 NC |
7685 | @ifset EPIPHANY |
7686 | * Epiphany-Dependent:: EPIPHANY Dependent Features | |
7687 | @end ifset | |
252b5132 | 7688 | @ifset H8/300 |
c2dcd04e | 7689 | * H8/300-Dependent:: Renesas H8/300 Dependent Features |
252b5132 | 7690 | @end ifset |
252b5132 RH |
7691 | @ifset HPPA |
7692 | * HPPA-Dependent:: HPPA Dependent Features | |
7693 | @end ifset | |
7694 | @ifset I80386 | |
55b62671 | 7695 | * i386-Dependent:: Intel 80386 and AMD x86-64 Dependent Features |
252b5132 | 7696 | @end ifset |
5cb53c21 L |
7697 | @ifset IA64 |
7698 | * IA-64-Dependent:: Intel IA-64 Dependent Features | |
7699 | @end ifset | |
a40cbfa3 NC |
7700 | @ifset IP2K |
7701 | * IP2K-Dependent:: IP2K Dependent Features | |
7702 | @end ifset | |
84e94c90 NC |
7703 | @ifset LM32 |
7704 | * LM32-Dependent:: LM32 Dependent Features | |
7705 | @end ifset | |
49f58d10 JB |
7706 | @ifset M32C |
7707 | * M32C-Dependent:: M32C Dependent Features | |
7708 | @end ifset | |
ec694b89 NC |
7709 | @ifset M32R |
7710 | * M32R-Dependent:: M32R Dependent Features | |
7711 | @end ifset | |
252b5132 RH |
7712 | @ifset M680X0 |
7713 | * M68K-Dependent:: M680x0 Dependent Features | |
7714 | @end ifset | |
60bcf0fa NC |
7715 | @ifset M68HC11 |
7716 | * M68HC11-Dependent:: M68HC11 and 68HC12 Dependent Features | |
7717 | @end ifset | |
7b4ae824 | 7718 | @ifset S12Z |
905f5b3f | 7719 | * S12Z-Dependent:: S12Z Dependent Features |
7b4ae824 | 7720 | @end ifset |
a3c62988 NC |
7721 | @ifset METAG |
7722 | * Meta-Dependent :: Meta Dependent Features | |
7723 | @end ifset | |
7ba29e2a NC |
7724 | @ifset MICROBLAZE |
7725 | * MicroBlaze-Dependent:: MICROBLAZE Dependent Features | |
7726 | @end ifset | |
252b5132 RH |
7727 | @ifset MIPS |
7728 | * MIPS-Dependent:: MIPS Dependent Features | |
7729 | @end ifset | |
3c3bdf30 NC |
7730 | @ifset MMIX |
7731 | * MMIX-Dependent:: MMIX Dependent Features | |
7732 | @end ifset | |
2469cfa2 NC |
7733 | @ifset MSP430 |
7734 | * MSP430-Dependent:: MSP430 Dependent Features | |
7735 | @end ifset | |
35c08157 KLC |
7736 | @ifset NDS32 |
7737 | * NDS32-Dependent:: Andes NDS32 Dependent Features | |
7738 | @end ifset | |
36591ba1 SL |
7739 | @ifset NIOSII |
7740 | * NiosII-Dependent:: Altera Nios II Dependent Features | |
7741 | @end ifset | |
7c31ae13 NC |
7742 | @ifset NS32K |
7743 | * NS32K-Dependent:: NS32K Dependent Features | |
7744 | @end ifset | |
1f041c6e SH |
7745 | @ifset OPENRISC |
7746 | * OpenRISC-Dependent:: OpenRISC 1000 Features | |
7747 | @end ifset | |
e135f41b NC |
7748 | @ifset PDP11 |
7749 | * PDP-11-Dependent:: PDP-11 Dependent Features | |
7750 | @end ifset | |
041dd5a9 ILT |
7751 | @ifset PJ |
7752 | * PJ-Dependent:: picoJava Dependent Features | |
7753 | @end ifset | |
418c1742 MG |
7754 | @ifset PPC |
7755 | * PPC-Dependent:: PowerPC Dependent Features | |
7756 | @end ifset | |
93f11b16 DD |
7757 | @ifset PRU |
7758 | * PRU-Dependent:: PRU Dependent Features | |
7759 | @end ifset | |
4f7eddc4 PD |
7760 | @ifset RISCV |
7761 | * RISC-V-Dependent:: RISC-V Dependent Features | |
7762 | @end ifset | |
b57e49f7 JW |
7763 | @ifset RL78 |
7764 | * RL78-Dependent:: RL78 Dependent Features | |
7765 | @end ifset | |
046d31c2 NC |
7766 | @ifset RX |
7767 | * RX-Dependent:: RX Dependent Features | |
7768 | @end ifset | |
11c19e16 MS |
7769 | @ifset S390 |
7770 | * S/390-Dependent:: IBM S/390 Dependent Features | |
7771 | @end ifset | |
c0157db4 NC |
7772 | @ifset SCORE |
7773 | * SCORE-Dependent:: SCORE Dependent Features | |
7774 | @end ifset | |
d3b47e2b L |
7775 | @ifset SH |
7776 | * SH-Dependent:: Renesas / SuperH SH Dependent Features | |
d3b47e2b | 7777 | @end ifset |
252b5132 RH |
7778 | @ifset SPARC |
7779 | * Sparc-Dependent:: SPARC Dependent Features | |
7780 | @end ifset | |
39bec121 TW |
7781 | @ifset TIC54X |
7782 | * TIC54X-Dependent:: TI TMS320C54x Dependent Features | |
7783 | @end ifset | |
40b36596 JM |
7784 | @ifset TIC6X |
7785 | * TIC6X-Dependent :: TI TMS320C6x Dependent Features | |
7786 | @end ifset | |
aa137e4d NC |
7787 | @ifset TILEGX |
7788 | * TILE-Gx-Dependent :: Tilera TILE-Gx Dependent Features | |
7789 | @end ifset | |
7790 | @ifset TILEPRO | |
7791 | * TILEPro-Dependent :: Tilera TILEPro Dependent Features | |
7792 | @end ifset | |
252b5132 RH |
7793 | @ifset V850 |
7794 | * V850-Dependent:: V850 Dependent Features | |
7795 | @end ifset | |
b6605ddd EB |
7796 | @ifset VAX |
7797 | * Vax-Dependent:: VAX Dependent Features | |
7798 | @end ifset | |
7799 | @ifset VISIUM | |
7800 | * Visium-Dependent:: Visium Dependent Features | |
7801 | @end ifset | |
f96bd6c2 PC |
7802 | @ifset WASM32 |
7803 | * WebAssembly-Dependent:: WebAssembly Dependent Features | |
7804 | @end ifset | |
f6c1a2d5 | 7805 | @ifset XGATE |
f96bd6c2 | 7806 | * XGATE-Dependent:: XGATE Dependent Features |
f6c1a2d5 | 7807 | @end ifset |
6753e72f NC |
7808 | @ifset XSTORMY16 |
7809 | * XSTORMY16-Dependent:: XStormy16 Dependent Features | |
7810 | @end ifset | |
e0001a05 NC |
7811 | @ifset XTENSA |
7812 | * Xtensa-Dependent:: Xtensa Dependent Features | |
7813 | @end ifset | |
3c9b82ba NC |
7814 | @ifset Z80 |
7815 | * Z80-Dependent:: Z80 Dependent Features | |
7816 | @end ifset | |
252b5132 RH |
7817 | @ifset Z8000 |
7818 | * Z8000-Dependent:: Z8000 Dependent Features | |
7819 | @end ifset | |
252b5132 RH |
7820 | @end menu |
7821 | ||
7822 | @lowersections | |
7823 | @end ifset | |
7824 | ||
7825 | @c The following major nodes are *sections* in the GENERIC version, *chapters* | |
7826 | @c in single-cpu versions. This is mainly achieved by @lowersections. There is a | |
7827 | @c peculiarity: to preserve cross-references, there must be a node called | |
7828 | @c "Machine Dependencies". Hence the conditional nodenames in each | |
7829 | @c major node below. Node defaulting in makeinfo requires adjacency of | |
7830 | @c node and sectioning commands; hence the repetition of @chapter BLAH | |
7831 | @c in both conditional blocks. | |
7832 | ||
a06ea964 NC |
7833 | @ifset AARCH64 |
7834 | @include c-aarch64.texi | |
7835 | @end ifset | |
7836 | ||
625e1353 RH |
7837 | @ifset ALPHA |
7838 | @include c-alpha.texi | |
7839 | @end ifset | |
7840 | ||
7841 | @ifset ARC | |
7842 | @include c-arc.texi | |
7843 | @end ifset | |
7844 | ||
252b5132 RH |
7845 | @ifset ARM |
7846 | @include c-arm.texi | |
7847 | @end ifset | |
7848 | ||
8473f7a4 DC |
7849 | @ifset AVR |
7850 | @include c-avr.texi | |
7851 | @end ifset | |
7852 | ||
3b4e1885 | 7853 | @ifset Blackfin |
07c1b327 CM |
7854 | @include c-bfin.texi |
7855 | @end ifset | |
7856 | ||
f8861f5d JM |
7857 | @ifset BPF |
7858 | @include c-bpf.texi | |
7859 | @end ifset | |
7860 | ||
3d3d428f NC |
7861 | @ifset CR16 |
7862 | @include c-cr16.texi | |
7863 | @end ifset | |
7864 | ||
328eb32e HPN |
7865 | @ifset CRIS |
7866 | @include c-cris.texi | |
7867 | @end ifset | |
7868 | ||
b8891f8d AJ |
7869 | @ifset CSKY |
7870 | @include c-csky.texi | |
7871 | @end ifset | |
7872 | ||
c2dcd04e | 7873 | @ifset Renesas-all |
252b5132 RH |
7874 | @ifclear GENERIC |
7875 | @node Machine Dependencies | |
7876 | @chapter Machine Dependent Features | |
7877 | ||
c2dcd04e | 7878 | The machine instruction sets are different on each Renesas chip family, |
252b5132 | 7879 | and there are also some syntax differences among the families. This |
a4fb0134 | 7880 | chapter describes the specific @command{@value{AS}} features for each |
252b5132 RH |
7881 | family. |
7882 | ||
7883 | @menu | |
c2dcd04e | 7884 | * H8/300-Dependent:: Renesas H8/300 Dependent Features |
c2dcd04e | 7885 | * SH-Dependent:: Renesas SH Dependent Features |
252b5132 RH |
7886 | @end menu |
7887 | @lowersections | |
7888 | @end ifclear | |
7889 | @end ifset | |
7890 | ||
7891 | @ifset D10V | |
7892 | @include c-d10v.texi | |
7893 | @end ifset | |
7894 | ||
7895 | @ifset D30V | |
7896 | @include c-d30v.texi | |
7897 | @end ifset | |
7898 | ||
cfb8c092 NC |
7899 | @ifset EPIPHANY |
7900 | @include c-epiphany.texi | |
7901 | @end ifset | |
7902 | ||
252b5132 RH |
7903 | @ifset H8/300 |
7904 | @include c-h8300.texi | |
7905 | @end ifset | |
7906 | ||
252b5132 RH |
7907 | @ifset HPPA |
7908 | @include c-hppa.texi | |
7909 | @end ifset | |
7910 | ||
7911 | @ifset I80386 | |
7912 | @include c-i386.texi | |
7913 | @end ifset | |
7914 | ||
9e32ca89 NC |
7915 | @ifset IA64 |
7916 | @include c-ia64.texi | |
7917 | @end ifset | |
7918 | ||
a40cbfa3 NC |
7919 | @ifset IP2K |
7920 | @include c-ip2k.texi | |
7921 | @end ifset | |
7922 | ||
84e94c90 NC |
7923 | @ifset LM32 |
7924 | @include c-lm32.texi | |
7925 | @end ifset | |
7926 | ||
49f58d10 JB |
7927 | @ifset M32C |
7928 | @include c-m32c.texi | |
7929 | @end ifset | |
7930 | ||
ec694b89 NC |
7931 | @ifset M32R |
7932 | @include c-m32r.texi | |
7933 | @end ifset | |
252b5132 RH |
7934 | |
7935 | @ifset M680X0 | |
7936 | @include c-m68k.texi | |
7937 | @end ifset | |
7938 | ||
60bcf0fa NC |
7939 | @ifset M68HC11 |
7940 | @include c-m68hc11.texi | |
7941 | @end ifset | |
7942 | ||
7b4ae824 JD |
7943 | @ifset S12Z |
7944 | @include c-s12z.texi | |
7945 | @end ifset | |
7946 | ||
a3c62988 NC |
7947 | @ifset METAG |
7948 | @include c-metag.texi | |
7949 | @end ifset | |
7950 | ||
01642c12 | 7951 | @ifset MICROBLAZE |
7ba29e2a NC |
7952 | @include c-microblaze.texi |
7953 | @end ifset | |
7954 | ||
252b5132 RH |
7955 | @ifset MIPS |
7956 | @include c-mips.texi | |
7957 | @end ifset | |
7958 | ||
3c3bdf30 NC |
7959 | @ifset MMIX |
7960 | @include c-mmix.texi | |
7961 | @end ifset | |
7962 | ||
2469cfa2 NC |
7963 | @ifset MSP430 |
7964 | @include c-msp430.texi | |
7965 | @end ifset | |
7966 | ||
35c08157 KLC |
7967 | @ifset NDS32 |
7968 | @include c-nds32.texi | |
7969 | @end ifset | |
7970 | ||
36591ba1 SL |
7971 | @ifset NIOSII |
7972 | @include c-nios2.texi | |
7973 | @end ifset | |
7974 | ||
252b5132 RH |
7975 | @ifset NS32K |
7976 | @include c-ns32k.texi | |
7977 | @end ifset | |
7978 | ||
1f041c6e SH |
7979 | @ifset OPENRISC |
7980 | @include c-or1k.texi | |
7981 | @end ifset | |
7982 | ||
e135f41b NC |
7983 | @ifset PDP11 |
7984 | @include c-pdp11.texi | |
7985 | @end ifset | |
7986 | ||
041dd5a9 ILT |
7987 | @ifset PJ |
7988 | @include c-pj.texi | |
7989 | @end ifset | |
7990 | ||
418c1742 MG |
7991 | @ifset PPC |
7992 | @include c-ppc.texi | |
7993 | @end ifset | |
7994 | ||
93f11b16 DD |
7995 | @ifset PRU |
7996 | @include c-pru.texi | |
7997 | @end ifset | |
7998 | ||
4f7eddc4 PD |
7999 | @ifset RISCV |
8000 | @include c-riscv.texi | |
8001 | @end ifset | |
8002 | ||
b57e49f7 JW |
8003 | @ifset RL78 |
8004 | @include c-rl78.texi | |
8005 | @end ifset | |
8006 | ||
046d31c2 NC |
8007 | @ifset RX |
8008 | @include c-rx.texi | |
8009 | @end ifset | |
8010 | ||
11c19e16 MS |
8011 | @ifset S390 |
8012 | @include c-s390.texi | |
8013 | @end ifset | |
8014 | ||
c0157db4 NC |
8015 | @ifset SCORE |
8016 | @include c-score.texi | |
8017 | @end ifset | |
8018 | ||
252b5132 RH |
8019 | @ifset SH |
8020 | @include c-sh.texi | |
8021 | @end ifset | |
8022 | ||
8023 | @ifset SPARC | |
8024 | @include c-sparc.texi | |
8025 | @end ifset | |
8026 | ||
39bec121 TW |
8027 | @ifset TIC54X |
8028 | @include c-tic54x.texi | |
8029 | @end ifset | |
8030 | ||
40b36596 JM |
8031 | @ifset TIC6X |
8032 | @include c-tic6x.texi | |
8033 | @end ifset | |
8034 | ||
aa137e4d NC |
8035 | @ifset TILEGX |
8036 | @include c-tilegx.texi | |
8037 | @end ifset | |
8038 | ||
8039 | @ifset TILEPRO | |
8040 | @include c-tilepro.texi | |
8041 | @end ifset | |
8042 | ||
b6605ddd EB |
8043 | @ifset V850 |
8044 | @include c-v850.texi | |
252b5132 RH |
8045 | @end ifset |
8046 | ||
8047 | @ifset VAX | |
8048 | @include c-vax.texi | |
8049 | @end ifset | |
8050 | ||
b6605ddd EB |
8051 | @ifset VISIUM |
8052 | @include c-visium.texi | |
252b5132 RH |
8053 | @end ifset |
8054 | ||
f96bd6c2 PC |
8055 | @ifset WASM32 |
8056 | @include c-wasm32.texi | |
8057 | @end ifset | |
8058 | ||
f6c1a2d5 NC |
8059 | @ifset XGATE |
8060 | @include c-xgate.texi | |
8061 | @end ifset | |
8062 | ||
6753e72f NC |
8063 | @ifset XSTORMY16 |
8064 | @include c-xstormy16.texi | |
8065 | @end ifset | |
8066 | ||
e0001a05 NC |
8067 | @ifset XTENSA |
8068 | @include c-xtensa.texi | |
8069 | @end ifset | |
8070 | ||
b6605ddd EB |
8071 | @ifset Z80 |
8072 | @include c-z80.texi | |
8073 | @end ifset | |
8074 | ||
8075 | @ifset Z8000 | |
8076 | @include c-z8k.texi | |
8077 | @end ifset | |
8078 | ||
252b5132 RH |
8079 | @ifset GENERIC |
8080 | @c reverse effect of @down at top of generic Machine-Dep chapter | |
8081 | @raisesections | |
8082 | @end ifset | |
8083 | ||
8084 | @node Reporting Bugs | |
8085 | @chapter Reporting Bugs | |
8086 | @cindex bugs in assembler | |
8087 | @cindex reporting bugs in assembler | |
8088 | ||
a4fb0134 | 8089 | Your bug reports play an essential role in making @command{@value{AS}} reliable. |
252b5132 RH |
8090 | |
8091 | Reporting a bug may help you by bringing a solution to your problem, or it may | |
8092 | not. But in any case the principal function of a bug report is to help the | |
a4fb0134 SC |
8093 | entire community by making the next version of @command{@value{AS}} work better. |
8094 | Bug reports are your contribution to the maintenance of @command{@value{AS}}. | |
252b5132 RH |
8095 | |
8096 | In order for a bug report to serve its purpose, you must include the | |
8097 | information that enables us to fix the bug. | |
8098 | ||
8099 | @menu | |
8100 | * Bug Criteria:: Have you found a bug? | |
8101 | * Bug Reporting:: How to report bugs | |
8102 | @end menu | |
8103 | ||
8104 | @node Bug Criteria | |
c1253627 | 8105 | @section Have You Found a Bug? |
252b5132 RH |
8106 | @cindex bug criteria |
8107 | ||
8108 | If you are not sure whether you have found a bug, here are some guidelines: | |
8109 | ||
8110 | @itemize @bullet | |
8111 | @cindex fatal signal | |
8112 | @cindex assembler crash | |
8113 | @cindex crash of assembler | |
8114 | @item | |
8115 | If the assembler gets a fatal signal, for any input whatever, that is a | |
a4fb0134 | 8116 | @command{@value{AS}} bug. Reliable assemblers never crash. |
252b5132 RH |
8117 | |
8118 | @cindex error on valid input | |
8119 | @item | |
a4fb0134 | 8120 | If @command{@value{AS}} produces an error message for valid input, that is a bug. |
252b5132 RH |
8121 | |
8122 | @cindex invalid input | |
8123 | @item | |
a4fb0134 | 8124 | If @command{@value{AS}} does not produce an error message for invalid input, that |
252b5132 RH |
8125 | is a bug. However, you should note that your idea of ``invalid input'' might |
8126 | be our idea of ``an extension'' or ``support for traditional practice''. | |
8127 | ||
8128 | @item | |
8129 | If you are an experienced user of assemblers, your suggestions for improvement | |
a4fb0134 | 8130 | of @command{@value{AS}} are welcome in any case. |
252b5132 RH |
8131 | @end itemize |
8132 | ||
8133 | @node Bug Reporting | |
c1253627 | 8134 | @section How to Report Bugs |
252b5132 RH |
8135 | @cindex bug reports |
8136 | @cindex assembler bugs, reporting | |
8137 | ||
8138 | A number of companies and individuals offer support for @sc{gnu} products. If | |
a4fb0134 | 8139 | you obtained @command{@value{AS}} from a support organization, we recommend you |
252b5132 RH |
8140 | contact that organization first. |
8141 | ||
8142 | You can find contact information for many support companies and | |
8143 | individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs | |
8144 | distribution. | |
8145 | ||
ad22bfe8 | 8146 | @ifset BUGURL |
a4fb0134 | 8147 | In any event, we also recommend that you send bug reports for @command{@value{AS}} |
ad22bfe8 JM |
8148 | to @value{BUGURL}. |
8149 | @end ifset | |
252b5132 RH |
8150 | |
8151 | The fundamental principle of reporting bugs usefully is this: | |
8152 | @strong{report all the facts}. If you are not sure whether to state a | |
8153 | fact or leave it out, state it! | |
8154 | ||
8155 | Often people omit facts because they think they know what causes the problem | |
8156 | and assume that some details do not matter. Thus, you might assume that the | |
8157 | name of a symbol you use in an example does not matter. Well, probably it does | |
8158 | not, but one cannot be sure. Perhaps the bug is a stray memory reference which | |
8159 | happens to fetch from the location where that name is stored in memory; | |
8160 | perhaps, if the name were different, the contents of that location would fool | |
8161 | the assembler into doing the right thing despite the bug. Play it safe and | |
8162 | give a specific, complete example. That is the easiest thing for you to do, | |
8163 | and the most helpful. | |
8164 | ||
8165 | Keep in mind that the purpose of a bug report is to enable us to fix the bug if | |
8166 | it is new to us. Therefore, always write your bug reports on the assumption | |
8167 | that the bug has not been reported previously. | |
8168 | ||
8169 | Sometimes people give a few sketchy facts and ask, ``Does this ring a | |
c1253627 NC |
8170 | bell?'' This cannot help us fix a bug, so it is basically useless. We |
8171 | respond by asking for enough details to enable us to investigate. | |
8172 | You might as well expedite matters by sending them to begin with. | |
252b5132 RH |
8173 | |
8174 | To enable us to fix the bug, you should include all these things: | |
8175 | ||
8176 | @itemize @bullet | |
8177 | @item | |
a4fb0134 | 8178 | The version of @command{@value{AS}}. @command{@value{AS}} announces it if you start |
252b5132 RH |
8179 | it with the @samp{--version} argument. |
8180 | ||
8181 | Without this, we will not know whether there is any point in looking for | |
a4fb0134 | 8182 | the bug in the current version of @command{@value{AS}}. |
252b5132 RH |
8183 | |
8184 | @item | |
a4fb0134 | 8185 | Any patches you may have applied to the @command{@value{AS}} source. |
252b5132 RH |
8186 | |
8187 | @item | |
8188 | The type of machine you are using, and the operating system name and | |
8189 | version number. | |
8190 | ||
8191 | @item | |
a4fb0134 | 8192 | What compiler (and its version) was used to compile @command{@value{AS}}---e.g. |
252b5132 RH |
8193 | ``@code{gcc-2.7}''. |
8194 | ||
8195 | @item | |
8196 | The command arguments you gave the assembler to assemble your example and | |
8197 | observe the bug. To guarantee you will not omit something important, list them | |
8198 | all. A copy of the Makefile (or the output from make) is sufficient. | |
8199 | ||
8200 | If we were to try to guess the arguments, we would probably guess wrong | |
8201 | and then we might not encounter the bug. | |
8202 | ||
8203 | @item | |
8204 | A complete input file that will reproduce the bug. If the bug is observed when | |
8205 | the assembler is invoked via a compiler, send the assembler source, not the | |
8206 | high level language source. Most compilers will produce the assembler source | |
8207 | when run with the @samp{-S} option. If you are using @code{@value{GCC}}, use | |
8208 | the options @samp{-v --save-temps}; this will save the assembler source in a | |
8209 | file with an extension of @file{.s}, and also show you exactly how | |
a4fb0134 | 8210 | @command{@value{AS}} is being run. |
252b5132 RH |
8211 | |
8212 | @item | |
8213 | A description of what behavior you observe that you believe is | |
8214 | incorrect. For example, ``It gets a fatal signal.'' | |
8215 | ||
a4fb0134 | 8216 | Of course, if the bug is that @command{@value{AS}} gets a fatal signal, then we |
252b5132 RH |
8217 | will certainly notice it. But if the bug is incorrect output, we might not |
8218 | notice unless it is glaringly wrong. You might as well not give us a chance to | |
8219 | make a mistake. | |
8220 | ||
8221 | Even if the problem you experience is a fatal signal, you should still say so | |
8222 | explicitly. Suppose something strange is going on, such as, your copy of | |
b45619c0 | 8223 | @command{@value{AS}} is out of sync, or you have encountered a bug in the C |
252b5132 RH |
8224 | library on your system. (This has happened!) Your copy might crash and ours |
8225 | would not. If you told us to expect a crash, then when ours fails to crash, we | |
8226 | would know that the bug was not happening for us. If you had not told us to | |
8227 | expect a crash, then we would not be able to draw any conclusion from our | |
8228 | observations. | |
8229 | ||
8230 | @item | |
a4fb0134 | 8231 | If you wish to suggest changes to the @command{@value{AS}} source, send us context |
252b5132 RH |
8232 | diffs, as generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p} |
8233 | option. Always send diffs from the old file to the new file. If you even | |
a4fb0134 | 8234 | discuss something in the @command{@value{AS}} source, refer to it by context, not |
252b5132 RH |
8235 | by line number. |
8236 | ||
8237 | The line numbers in our development sources will not match those in your | |
8238 | sources. Your line numbers would convey no useful information to us. | |
8239 | @end itemize | |
8240 | ||
8241 | Here are some things that are not necessary: | |
8242 | ||
8243 | @itemize @bullet | |
8244 | @item | |
8245 | A description of the envelope of the bug. | |
8246 | ||
8247 | Often people who encounter a bug spend a lot of time investigating | |
8248 | which changes to the input file will make the bug go away and which | |
8249 | changes will not affect it. | |
8250 | ||
8251 | This is often time consuming and not very useful, because the way we | |
8252 | will find the bug is by running a single example under the debugger | |
8253 | with breakpoints, not by pure deduction from a series of examples. | |
8254 | We recommend that you save your time for something else. | |
8255 | ||
8256 | Of course, if you can find a simpler example to report @emph{instead} | |
8257 | of the original one, that is a convenience for us. Errors in the | |
8258 | output will be easier to spot, running under the debugger will take | |
8259 | less time, and so on. | |
8260 | ||
8261 | However, simplification is not vital; if you do not want to do this, | |
8262 | report the bug anyway and send us the entire test case you used. | |
8263 | ||
8264 | @item | |
8265 | A patch for the bug. | |
8266 | ||
8267 | A patch for the bug does help us if it is a good one. But do not omit | |
8268 | the necessary information, such as the test case, on the assumption that | |
8269 | a patch is all we need. We might see problems with your patch and decide | |
8270 | to fix the problem another way, or we might not understand it at all. | |
8271 | ||
a4fb0134 | 8272 | Sometimes with a program as complicated as @command{@value{AS}} it is very hard to |
252b5132 RH |
8273 | construct an example that will make the program follow a certain path through |
8274 | the code. If you do not send us the example, we will not be able to construct | |
8275 | one, so we will not be able to verify that the bug is fixed. | |
8276 | ||
8277 | And if we cannot understand what bug you are trying to fix, or why your | |
8278 | patch should be an improvement, we will not install it. A test case will | |
8279 | help us to understand. | |
8280 | ||
8281 | @item | |
8282 | A guess about what the bug is or what it depends on. | |
8283 | ||
8284 | Such guesses are usually wrong. Even we cannot guess right about such | |
8285 | things without first using the debugger to find the facts. | |
8286 | @end itemize | |
8287 | ||
8288 | @node Acknowledgements | |
8289 | @chapter Acknowledgements | |
8290 | ||
653cfe85 | 8291 | If you have contributed to GAS and your name isn't listed here, |
252b5132 | 8292 | it is not meant as a slight. We just don't know about it. Send mail to the |
01642c12 | 8293 | maintainer, and we'll correct the situation. Currently |
3bfcb652 NC |
8294 | @c (October 2012), |
8295 | the maintainer is Nick Clifton (email address @code{nickc@@redhat.com}). | |
252b5132 RH |
8296 | |
8297 | Dean Elsner wrote the original @sc{gnu} assembler for the VAX.@footnote{Any | |
8298 | more details?} | |
8299 | ||
8300 | Jay Fenlason maintained GAS for a while, adding support for GDB-specific debug | |
8301 | information and the 68k series machines, most of the preprocessing pass, and | |
8302 | extensive changes in @file{messages.c}, @file{input-file.c}, @file{write.c}. | |
8303 | ||
8304 | K. Richard Pixley maintained GAS for a while, adding various enhancements and | |
8305 | many bug fixes, including merging support for several processors, breaking GAS | |
8306 | up to handle multiple object file format back ends (including heavy rewrite, | |
8307 | testing, an integration of the coff and b.out back ends), adding configuration | |
8308 | including heavy testing and verification of cross assemblers and file splits | |
8309 | and renaming, converted GAS to strictly ANSI C including full prototypes, added | |
8310 | support for m680[34]0 and cpu32, did considerable work on i960 including a COFF | |
8311 | port (including considerable amounts of reverse engineering), a SPARC opcode | |
8312 | file rewrite, DECstation, rs6000, and hp300hpux host ports, updated ``know'' | |
8313 | assertions and made them work, much other reorganization, cleanup, and lint. | |
8314 | ||
8315 | Ken Raeburn wrote the high-level BFD interface code to replace most of the code | |
8316 | in format-specific I/O modules. | |
8317 | ||
8318 | The original VMS support was contributed by David L. Kashtan. Eric Youngdale | |
8319 | has done much work with it since. | |
8320 | ||
8321 | The Intel 80386 machine description was written by Eliot Dresselhaus. | |
8322 | ||
8323 | Minh Tran-Le at IntelliCorp contributed some AIX 386 support. | |
8324 | ||
8325 | The Motorola 88k machine description was contributed by Devon Bowen of Buffalo | |
8326 | University and Torbjorn Granlund of the Swedish Institute of Computer Science. | |
8327 | ||
8328 | Keith Knowles at the Open Software Foundation wrote the original MIPS back end | |
8329 | (@file{tc-mips.c}, @file{tc-mips.h}), and contributed Rose format support | |
8330 | (which hasn't been merged in yet). Ralph Campbell worked with the MIPS code to | |
8331 | support a.out format. | |
8332 | ||
7be1c489 AM |
8333 | Support for the Zilog Z8k and Renesas H8/300 processors (tc-z8k, |
8334 | tc-h8300), and IEEE 695 object file format (obj-ieee), was written by | |
252b5132 RH |
8335 | Steve Chamberlain of Cygnus Support. Steve also modified the COFF back end to |
8336 | use BFD for some low-level operations, for use with the H8/300 and AMD 29k | |
8337 | targets. | |
8338 | ||
8339 | John Gilmore built the AMD 29000 support, added @code{.include} support, and | |
8340 | simplified the configuration of which versions accept which directives. He | |
8341 | updated the 68k machine description so that Motorola's opcodes always produced | |
c1253627 | 8342 | fixed-size instructions (e.g., @code{jsr}), while synthetic instructions |
252b5132 RH |
8343 | remained shrinkable (@code{jbsr}). John fixed many bugs, including true tested |
8344 | cross-compilation support, and one bug in relaxation that took a week and | |
8345 | required the proverbial one-bit fix. | |
8346 | ||
8347 | Ian Lance Taylor of Cygnus Support merged the Motorola and MIT syntax for the | |
8348 | 68k, completed support for some COFF targets (68k, i386 SVR3, and SCO Unix), | |
8349 | added support for MIPS ECOFF and ELF targets, wrote the initial RS/6000 and | |
8350 | PowerPC assembler, and made a few other minor patches. | |
8351 | ||
653cfe85 | 8352 | Steve Chamberlain made GAS able to generate listings. |
252b5132 RH |
8353 | |
8354 | Hewlett-Packard contributed support for the HP9000/300. | |
8355 | ||
8356 | Jeff Law wrote GAS and BFD support for the native HPPA object format (SOM) | |
8357 | along with a fairly extensive HPPA testsuite (for both SOM and ELF object | |
8358 | formats). This work was supported by both the Center for Software Science at | |
8359 | the University of Utah and Cygnus Support. | |
8360 | ||
8361 | Support for ELF format files has been worked on by Mark Eichin of Cygnus | |
8362 | Support (original, incomplete implementation for SPARC), Pete Hoogenboom and | |
8363 | Jeff Law at the University of Utah (HPPA mainly), Michael Meissner of the Open | |
8364 | Software Foundation (i386 mainly), and Ken Raeburn of Cygnus Support (sparc, | |
8365 | and some initial 64-bit support). | |
8366 | ||
c1253627 | 8367 | Linas Vepstas added GAS support for the ESA/390 ``IBM 370'' architecture. |
5b93d8bb | 8368 | |
252b5132 RH |
8369 | Richard Henderson rewrote the Alpha assembler. Klaus Kaempf wrote GAS and BFD |
8370 | support for openVMS/Alpha. | |
8371 | ||
39bec121 TW |
8372 | Timothy Wall, Michael Hayes, and Greg Smart contributed to the various tic* |
8373 | flavors. | |
8374 | ||
e0001a05 | 8375 | David Heine, Sterling Augustine, Bob Wilson and John Ruttenberg from Tensilica, |
b45619c0 | 8376 | Inc.@: added support for Xtensa processors. |
e0001a05 | 8377 | |
252b5132 RH |
8378 | Several engineers at Cygnus Support have also provided many small bug fixes and |
8379 | configuration enhancements. | |
8380 | ||
84e94c90 NC |
8381 | Jon Beniston added support for the Lattice Mico32 architecture. |
8382 | ||
252b5132 RH |
8383 | Many others have contributed large or small bugfixes and enhancements. If |
8384 | you have contributed significant work and are not mentioned on this list, and | |
8385 | want to be, let us know. Some of the history has been lost; we are not | |
8386 | intentionally leaving anyone out. | |
8387 | ||
793c5807 NC |
8388 | @node GNU Free Documentation License |
8389 | @appendix GNU Free Documentation License | |
c1253627 | 8390 | @include fdl.texi |
cf055d54 | 8391 | |
370b66a1 CD |
8392 | @node AS Index |
8393 | @unnumbered AS Index | |
252b5132 RH |
8394 | |
8395 | @printindex cp | |
8396 | ||
252b5132 RH |
8397 | @bye |
8398 | @c Local Variables: | |
8399 | @c fill-column: 79 | |
8400 | @c End: |