* binutils.texi (ar cmdline): Document that q now works like r.
[deliverable/binutils-gdb.git] / binutils / binutils.texi
1 \input texinfo @c -*- Texinfo -*-
2 @setfilename binutils.info
3 @include config.texi
4
5 @ifinfo
6 @format
7 START-INFO-DIR-ENTRY
8 * Binutils: (binutils). The GNU binary utilities "ar", "objcopy",
9 "objdump", "nm", "nlmconv", "size",
10 "strings", "strip", and "ranlib".
11 END-INFO-DIR-ENTRY
12 @end format
13 @end ifinfo
14
15 @ifinfo
16 Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.
17
18 Permission is granted to make and distribute verbatim copies of
19 this manual provided the copyright notice and this permission notice
20 are preserved on all copies.
21
22 @ignore
23 Permission is granted to process this file through TeX and print the
24 results, provided the printed document carries a copying permission
25 notice identical to this one except for the removal of this paragraph
26 (this paragraph not being relevant to the printed manual).
27
28 @end ignore
29
30 Permission is granted to copy and distribute modified versions of this
31 manual under the conditions for verbatim copying, provided also that
32 the entire resulting derived work is distributed under the terms of a
33 permission notice identical to this one.
34
35 Permission is granted to copy and distribute translations of this manual
36 into another language, under the above conditions for modified versions.
37 @end ifinfo
38
39 @synindex ky cp
40 @c
41 @c This file documents the GNU binary utilities "ar", "ld", "objcopy",
42 @c "objdump", "nm", "size", "strings", "strip", and "ranlib".
43 @c
44 @c Copyright (C) 1991, 92, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.
45 @c
46 @c This text may be freely distributed under the terms of the GNU
47 @c General Public License.
48 @c
49
50 @setchapternewpage odd
51 @settitle @sc{gnu} Binary Utilities
52 @titlepage
53 @finalout
54 @title The @sc{gnu} Binary Utilities
55 @subtitle Version @value{VERSION}
56 @sp 1
57 @subtitle May 1993
58 @author Roland H. Pesch
59 @author Jeffrey M. Osier
60 @author Cygnus Support
61 @page
62
63 @tex
64 {\parskip=0pt \hfill Cygnus Support\par \hfill
65 \TeX{}info \texinfoversion\par }
66 @end tex
67
68 @vskip 0pt plus 1filll
69 Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.
70
71 Permission is granted to make and distribute verbatim copies of
72 this manual provided the copyright notice and this permission notice
73 are preserved on all copies.
74
75 Permission is granted to copy and distribute modified versions of this
76 manual under the conditions for verbatim copying, provided also that
77 the entire resulting derived work is distributed under the terms of a
78 permission notice identical to this one.
79
80 Permission is granted to copy and distribute translations of this manual
81 into another language, under the above conditions for modified versions.
82 @end titlepage
83
84 @node Top
85 @top Introduction
86
87 @cindex version
88 This brief manual contains preliminary documentation for the @sc{gnu} binary
89 utilities (collectively version @value{VERSION}):
90
91 @iftex
92 @table @code
93 @item ar
94 Create, modify, and extract from archives
95
96 @item nm
97 List symbols from object files
98
99 @item objcopy
100 Copy and translate object files
101
102 @item objdump
103 Display information from object files
104
105 @item ranlib
106 Generate index to archive contents
107
108 @item size
109 List file section sizes and total size
110
111 @item strings
112 List printable strings from files
113
114 @item strip
115 Discard symbols
116
117 @item c++filt
118 Demangle encoded C++ symbols
119
120 @item addr2line
121 Convert addresses into file names and line numbers
122
123 @item nlmconv
124 Convert object code into a Netware Loadable Module
125
126 @item windres
127 Manipulate Windows resources
128 @end table
129 @end iftex
130
131 @menu
132 * ar:: Create, modify, and extract from archives
133 * nm:: List symbols from object files
134 * objcopy:: Copy and translate object files
135 * objdump:: Display information from object files
136 * ranlib:: Generate index to archive contents
137 * size:: List section sizes and total size
138 * strings:: List printable strings from files
139 * strip:: Discard symbols
140 * c++filt:: Filter to demangle encoded C++ symbols
141 * addr2line:: Convert addresses to file and line
142 * nlmconv:: Converts object code into an NLM
143 * windres:: Manipulate Windows resources
144 * Selecting The Target System:: How these utilities determine the target.
145 * Reporting Bugs:: Reporting Bugs
146 * Index:: Index
147 @end menu
148
149 @node ar
150 @chapter ar
151
152 @kindex ar
153 @cindex archives
154 @cindex collections of files
155 @smallexample
156 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
157 ar -M [ <mri-script ]
158 @end smallexample
159
160 The @sc{gnu} @code{ar} program creates, modifies, and extracts from
161 archives. An @dfn{archive} is a single file holding a collection of
162 other files in a structure that makes it possible to retrieve
163 the original individual files (called @dfn{members} of the archive).
164
165 The original files' contents, mode (permissions), timestamp, owner, and
166 group are preserved in the archive, and can be restored on
167 extraction.
168
169 @cindex name length
170 @sc{gnu} @code{ar} can maintain archives whose members have names of any
171 length; however, depending on how @code{ar} is configured on your
172 system, a limit on member-name length may be imposed for compatibility
173 with archive formats maintained with other tools. If it exists, the
174 limit is often 15 characters (typical of formats related to a.out) or 16
175 characters (typical of formats related to coff).
176
177 @cindex libraries
178 @code{ar} is considered a binary utility because archives of this sort
179 are most often used as @dfn{libraries} holding commonly needed
180 subroutines.
181
182 @cindex symbol index
183 @code{ar} creates an index to the symbols defined in relocatable
184 object modules in the archive when you specify the modifier @samp{s}.
185 Once created, this index is updated in the archive whenever @code{ar}
186 makes a change to its contents (save for the @samp{q} update operation).
187 An archive with such an index speeds up linking to the library, and
188 allows routines in the library to call each other without regard to
189 their placement in the archive.
190
191 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
192 table. If an archive lacks the table, another form of @code{ar} called
193 @code{ranlib} can be used to add just the table.
194
195 @cindex compatibility, @code{ar}
196 @cindex @code{ar} compatibility
197 @sc{gnu} @code{ar} is designed to be compatible with two different
198 facilities. You can control its activity using command-line options,
199 like the different varieties of @code{ar} on Unix systems; or, if you
200 specify the single command-line option @samp{-M}, you can control it
201 with a script supplied via standard input, like the MRI ``librarian''
202 program.
203
204 @menu
205 * ar cmdline:: Controlling @code{ar} on the command line
206 * ar scripts:: Controlling @code{ar} with a script
207 @end menu
208
209 @page
210 @node ar cmdline
211 @section Controlling @code{ar} on the command line
212
213 @smallexample
214 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
215 @end smallexample
216
217 @cindex Unix compatibility, @code{ar}
218 When you use @code{ar} in the Unix style, @code{ar} insists on at least two
219 arguments to execute: one keyletter specifying the @emph{operation}
220 (optionally accompanied by other keyletters specifying
221 @emph{modifiers}), and the archive name to act on.
222
223 Most operations can also accept further @var{member} arguments,
224 specifying particular files to operate on.
225
226 @sc{gnu} @code{ar} allows you to mix the operation code @var{p} and modifier
227 flags @var{mod} in any order, within the first command-line argument.
228
229 If you wish, you may begin the first command-line argument with a
230 dash.
231
232 @cindex operations on archive
233 The @var{p} keyletter specifies what operation to execute; it may be
234 any of the following, but you must specify only one of them:
235
236 @table @code
237 @item d
238 @cindex deleting from archive
239 @emph{Delete} modules from the archive. Specify the names of modules to
240 be deleted as @var{member}@dots{}; the archive is untouched if you
241 specify no files to delete.
242
243 If you specify the @samp{v} modifier, @code{ar} lists each module
244 as it is deleted.
245
246 @item m
247 @cindex moving in archive
248 Use this operation to @emph{move} members in an archive.
249
250 The ordering of members in an archive can make a difference in how
251 programs are linked using the library, if a symbol is defined in more
252 than one member.
253
254 If no modifiers are used with @code{m}, any members you name in the
255 @var{member} arguments are moved to the @emph{end} of the archive;
256 you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
257 specified place instead.
258
259 @item p
260 @cindex printing from archive
261 @emph{Print} the specified members of the archive, to the standard
262 output file. If the @samp{v} modifier is specified, show the member
263 name before copying its contents to standard output.
264
265 If you specify no @var{member} arguments, all the files in the archive are
266 printed.
267
268 @item q
269 @cindex quick append to archive
270 @emph{Quick append}; Historically, add the files @var{member}@dots{} to the end of
271 @var{archive}, without checking for replacement.
272
273 The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
274 operation; new members are always placed at the end of the archive.
275
276 The modifier @samp{v} makes @code{ar} list each file as it is appended.
277
278 Since the point of this operation is speed, the archive's symbol table
279 index is not updated, even if it already existed; you can use @samp{ar s} or
280 @code{ranlib} explicitly to update the symbol table index.
281
282 However, too many different system assume quick append rebuilds the
283 index, so GNU ar treats @code{q} to same way its treats @code{r}.
284
285 @item r
286 @cindex replacement in archive
287 Insert the files @var{member}@dots{} into @var{archive} (with
288 @emph{replacement}). This operation differs from @samp{q} in that any
289 previously existing members are deleted if their names match those being
290 added.
291
292 If one of the files named in @var{member}@dots{} does not exist, @code{ar}
293 displays an error message, and leaves undisturbed any existing members
294 of the archive matching that name.
295
296 By default, new members are added at the end of the file; but you may
297 use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
298 placement relative to some existing member.
299
300 The modifier @samp{v} used with this operation elicits a line of
301 output for each file inserted, along with one of the letters @samp{a} or
302 @samp{r} to indicate whether the file was appended (no old member
303 deleted) or replaced.
304
305 @item t
306 @cindex contents of archive
307 Display a @emph{table} listing the contents of @var{archive}, or those
308 of the files listed in @var{member}@dots{} that are present in the
309 archive. Normally only the member name is shown; if you also want to
310 see the modes (permissions), timestamp, owner, group, and size, you can
311 request that by also specifying the @samp{v} modifier.
312
313 If you do not specify a @var{member}, all files in the archive
314 are listed.
315
316 @cindex repeated names in archive
317 @cindex name duplication in archive
318 If there is more than one file with the same name (say, @samp{fie}) in
319 an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
320 first instance; to see them all, you must ask for a complete
321 listing---in our example, @samp{ar t b.a}.
322 @c WRS only; per Gumby, this is implementation-dependent, and in a more
323 @c recent case in fact works the other way.
324
325 @item x
326 @cindex extract from archive
327 @emph{Extract} members (named @var{member}) from the archive. You can
328 use the @samp{v} modifier with this operation, to request that
329 @code{ar} list each name as it extracts it.
330
331 If you do not specify a @var{member}, all files in the archive
332 are extracted.
333
334 @end table
335
336 A number of modifiers (@var{mod}) may immediately follow the @var{p}
337 keyletter, to specify variations on an operation's behavior:
338
339 @table @code
340 @item a
341 @cindex relative placement in archive
342 Add new files @emph{after} an existing member of the
343 archive. If you use the modifier @samp{a}, the name of an existing archive
344 member must be present as the @var{relpos} argument, before the
345 @var{archive} specification.
346
347 @item b
348 Add new files @emph{before} an existing member of the
349 archive. If you use the modifier @samp{b}, the name of an existing archive
350 member must be present as the @var{relpos} argument, before the
351 @var{archive} specification. (same as @samp{i}).
352
353 @item c
354 @cindex creating archives
355 @emph{Create} the archive. The specified @var{archive} is always
356 created if it did not exist, when you request an update. But a warning is
357 issued unless you specify in advance that you expect to create it, by
358 using this modifier.
359
360 @item f
361 Truncate names in the archive. @sc{gnu} @code{ar} will normally permit file
362 names of any length. This will cause it to create archives which are
363 not compatible with the native @code{ar} program on some systems. If
364 this is a concern, the @samp{f} modifier may be used to truncate file
365 names when putting them in the archive.
366
367 @item i
368 Insert new files @emph{before} an existing member of the
369 archive. If you use the modifier @samp{i}, the name of an existing archive
370 member must be present as the @var{relpos} argument, before the
371 @var{archive} specification. (same as @samp{b}).
372
373 @item l
374 This modifier is accepted but not used.
375 @c whaffor ar l modifier??? presumably compat; with
376 @c what???---doc@@cygnus.com, 25jan91
377
378 @item o
379 @cindex dates in archive
380 Preserve the @emph{original} dates of members when extracting them. If
381 you do not specify this modifier, files extracted from the archive
382 are stamped with the time of extraction.
383
384 @item s
385 @cindex writing archive index
386 Write an object-file index into the archive, or update an existing one,
387 even if no other change is made to the archive. You may use this modifier
388 flag either with any operation, or alone. Running @samp{ar s} on an
389 archive is equivalent to running @samp{ranlib} on it.
390
391 @item u
392 @cindex updating an archive
393 Normally, @samp{ar r}@dots{} inserts all files
394 listed into the archive. If you would like to insert @emph{only} those
395 of the files you list that are newer than existing members of the same
396 names, use this modifier. The @samp{u} modifier is allowed only for the
397 operation @samp{r} (replace). In particular, the combination @samp{qu} is
398 not allowed, since checking the timestamps would lose any speed
399 advantage from the operation @samp{q}.
400
401 @item v
402 This modifier requests the @emph{verbose} version of an operation. Many
403 operations display additional information, such as filenames processed,
404 when the modifier @samp{v} is appended.
405
406 @item V
407 This modifier shows the version number of @code{ar}.
408 @end table
409
410 @node ar scripts
411 @section Controlling @code{ar} with a script
412
413 @smallexample
414 ar -M [ <@var{script} ]
415 @end smallexample
416
417 @cindex MRI compatibility, @code{ar}
418 @cindex scripts, @code{ar}
419 If you use the single command-line option @samp{-M} with @code{ar}, you
420 can control its operation with a rudimentary command language. This
421 form of @code{ar} operates interactively if standard input is coming
422 directly from a terminal. During interactive use, @code{ar} prompts for
423 input (the prompt is @samp{AR >}), and continues executing even after
424 errors. If you redirect standard input to a script file, no prompts are
425 issued, and @code{ar} abandons execution (with a nonzero exit code)
426 on any error.
427
428 The @code{ar} command language is @emph{not} designed to be equivalent
429 to the command-line options; in fact, it provides somewhat less control
430 over archives. The only purpose of the command language is to ease the
431 transition to @sc{gnu} @code{ar} for developers who already have scripts
432 written for the MRI ``librarian'' program.
433
434 The syntax for the @code{ar} command language is straightforward:
435 @itemize @bullet
436 @item
437 commands are recognized in upper or lower case; for example, @code{LIST}
438 is the same as @code{list}. In the following descriptions, commands are
439 shown in upper case for clarity.
440
441 @item
442 a single command may appear on each line; it is the first word on the
443 line.
444
445 @item
446 empty lines are allowed, and have no effect.
447
448 @item
449 comments are allowed; text after either of the characters @samp{*}
450 or @samp{;} is ignored.
451
452 @item
453 Whenever you use a list of names as part of the argument to an @code{ar}
454 command, you can separate the individual names with either commas or
455 blanks. Commas are shown in the explanations below, for clarity.
456
457 @item
458 @samp{+} is used as a line continuation character; if @samp{+} appears
459 at the end of a line, the text on the following line is considered part
460 of the current command.
461 @end itemize
462
463 Here are the commands you can use in @code{ar} scripts, or when using
464 @code{ar} interactively. Three of them have special significance:
465
466 @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
467 a temporary file required for most of the other commands.
468
469 @code{SAVE} commits the changes so far specified by the script. Prior
470 to @code{SAVE}, commands affect only the temporary copy of the current
471 archive.
472
473 @table @code
474 @item ADDLIB @var{archive}
475 @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
476 Add all the contents of @var{archive} (or, if specified, each named
477 @var{module} from @var{archive}) to the current archive.
478
479 Requires prior use of @code{OPEN} or @code{CREATE}.
480
481 @item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
482 @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
483 @c else like "ar q..."
484 Add each named @var{member} as a module in the current archive.
485
486 Requires prior use of @code{OPEN} or @code{CREATE}.
487
488 @item CLEAR
489 Discard the contents of the current archive, cancelling the effect of
490 any operations since the last @code{SAVE}. May be executed (with no
491 effect) even if no current archive is specified.
492
493 @item CREATE @var{archive}
494 Creates an archive, and makes it the current archive (required for many
495 other commands). The new archive is created with a temporary name; it
496 is not actually saved as @var{archive} until you use @code{SAVE}.
497 You can overwrite existing archives; similarly, the contents of any
498 existing file named @var{archive} will not be destroyed until @code{SAVE}.
499
500 @item DELETE @var{module}, @var{module}, @dots{} @var{module}
501 Delete each listed @var{module} from the current archive; equivalent to
502 @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
503
504 Requires prior use of @code{OPEN} or @code{CREATE}.
505
506 @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
507 @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
508 List each named @var{module} present in @var{archive}. The separate
509 command @code{VERBOSE} specifies the form of the output: when verbose
510 output is off, output is like that of @samp{ar -t @var{archive}
511 @var{module}@dots{}}. When verbose output is on, the listing is like
512 @samp{ar -tv @var{archive} @var{module}@dots{}}.
513
514 Output normally goes to the standard output stream; however, if you
515 specify @var{outputfile} as a final argument, @code{ar} directs the
516 output to that file.
517
518 @item END
519 Exit from @code{ar}, with a @code{0} exit code to indicate successful
520 completion. This command does not save the output file; if you have
521 changed the current archive since the last @code{SAVE} command, those
522 changes are lost.
523
524 @item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
525 Extract each named @var{module} from the current archive, writing them
526 into the current directory as separate files. Equivalent to @samp{ar -x
527 @var{archive} @var{module}@dots{}}.
528
529 Requires prior use of @code{OPEN} or @code{CREATE}.
530
531 @ignore
532 @c FIXME Tokens but no commands???
533 @item FULLDIR
534
535 @item HELP
536 @end ignore
537
538 @item LIST
539 Display full contents of the current archive, in ``verbose'' style
540 regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
541 tv @var{archive}}). (This single command is a @sc{gnu} @code{ld}
542 enhancement, rather than present for MRI compatibility.)
543
544 Requires prior use of @code{OPEN} or @code{CREATE}.
545
546 @item OPEN @var{archive}
547 Opens an existing archive for use as the current archive (required for
548 many other commands). Any changes as the result of subsequent commands
549 will not actually affect @var{archive} until you next use @code{SAVE}.
550
551 @item REPLACE @var{module}, @var{module}, @dots{} @var{module}
552 In the current archive, replace each existing @var{module} (named in
553 the @code{REPLACE} arguments) from files in the current working directory.
554 To execute this command without errors, both the file, and the module in
555 the current archive, must exist.
556
557 Requires prior use of @code{OPEN} or @code{CREATE}.
558
559 @item VERBOSE
560 Toggle an internal flag governing the output from @code{DIRECTORY}.
561 When the flag is on, @code{DIRECTORY} output matches output from
562 @samp{ar -tv }@dots{}.
563
564 @item SAVE
565 Commit your changes to the current archive, and actually save it as a
566 file with the name specified in the last @code{CREATE} or @code{OPEN}
567 command.
568
569 Requires prior use of @code{OPEN} or @code{CREATE}.
570
571 @end table
572
573 @iftex
574 @node ld
575 @chapter ld
576 @cindex linker
577 @kindex ld
578 The @sc{gnu} linker @code{ld} is now described in a separate manual.
579 @xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
580 @end iftex
581
582 @node nm
583 @chapter nm
584 @cindex symbols
585 @kindex nm
586
587 @smallexample
588 nm [ -a | --debug-syms ] [ -g | --extern-only ]
589 [ -B ] [ -C | --demangle ] [ -D | --dynamic ]
590 [ -s | --print-armap ] [ -A | -o | --print-file-name ]
591 [ -n | -v | --numeric-sort ] [ -p | --no-sort ]
592 [ -r | --reverse-sort ] [ --size-sort ] [ -u | --undefined-only ]
593 [ -t @var{radix} | --radix=@var{radix} ] [ -P | --portability ]
594 [ --target=@var{bfdname} ] [ -f @var{format} | --format=@var{format} ]
595 [ --defined-only ] [-l | --line-numbers ]
596 [ --no-demangle ] [ -V | --version ] [ --help ] [ @var{objfile}@dots{} ]
597 @end smallexample
598
599 @sc{gnu} @code{nm} lists the symbols from object files @var{objfile}@dots{}.
600 If no object files are listed as arguments, @code{nm} assumes
601 @file{a.out}.
602
603 For each symbol, @code{nm} shows:
604
605 @itemize @bullet
606 @item
607 The symbol value, in the radix selected by options (see below), or
608 hexadecimal by default.
609
610 @item
611 The symbol type. At least the following types are used; others are, as
612 well, depending on the object file format. If lowercase, the symbol is
613 local; if uppercase, the symbol is global (external).
614
615 @c Some more detail on exactly what these symbol types are used for
616 @c would be nice.
617 @table @code
618 @item A
619 The symbol's value is absolute, and will not be changed by further
620 linking.
621
622 @item B
623 The symbol is in the uninitialized data section (known as BSS).
624
625 @item C
626 The symbol is common. Common symbols are uninitialized data. When
627 linking, multiple common symbols may appear with the same name. If the
628 symbol is defined anywhere, the common symbols are treated as undefined
629 references. For more details on common symbols, see the discussion of
630 --warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
631
632 @item D
633 The symbol is in the initialized data section.
634
635 @item G
636 The symbol is in an initialized data section for small objects. Some
637 object file formats permit more efficient access to small data objects,
638 such as a global int variable as opposed to a large global array.
639
640 @item I
641 The symbol is an indirect reference to another symbol. This is a GNU
642 extension to the a.out object file format which is rarely used.
643
644 @item N
645 The symbol is a debugging symbol.
646
647 @item R
648 The symbol is in a read only data section.
649
650 @item S
651 The symbol is in an uninitialized data section for small objects.
652
653 @item T
654 The symbol is in the text (code) section.
655
656 @item U
657 The symbol is undefined.
658
659 @item W
660 The symbol is weak. When a weak defined symbol is linked with a normal
661 defined symbol, the normal defined symbol is used with no error. When a
662 weak undefined symbol is linked and the symbol is not defined, the value
663 of the weak symbol becomes zero with no error.
664
665 @item -
666 The symbol is a stabs symbol in an a.out object file. In this case, the
667 next values printed are the stabs other field, the stabs desc field, and
668 the stab type. Stabs symbols are used to hold debugging information;
669 for more information, see @ref{Top,Stabs,Stabs Overview,stabs.info, The
670 ``stabs'' debug format}.
671
672 @item ?
673 The symbol type is unknown, or object file format specific.
674 @end table
675
676 @item
677 The symbol name.
678 @end itemize
679
680 The long and short forms of options, shown here as alternatives, are
681 equivalent.
682
683 @table @code
684 @item -A
685 @itemx -o
686 @itemx --print-file-name
687 @cindex input file name
688 @cindex file name
689 @cindex source file name
690 Precede each symbol by the name of the input file (or archive element)
691 in which it was found, rather than identifying the input file once only,
692 before all of its symbols.
693
694 @item -a
695 @itemx --debug-syms
696 @cindex debugging symbols
697 Display all symbols, even debugger-only symbols; normally these are not
698 listed.
699
700 @item -B
701 @cindex @code{nm} format
702 @cindex @code{nm} compatibility
703 The same as @samp{--format=bsd} (for compatibility with the MIPS @code{nm}).
704
705 @item -C
706 @itemx --demangle
707 @cindex demangling in nm
708 Decode (@dfn{demangle}) low-level symbol names into user-level names.
709 Besides removing any initial underscore prepended by the system, this
710 makes C++ function names readable. @xref{c++filt}, for more information
711 on demangling.
712
713 @item --no-demangle
714 Do not demangle low-level symbol names. This is the default.
715
716 @item -D
717 @itemx --dynamic
718 @cindex dynamic symbols
719 Display the dynamic symbols rather than the normal symbols. This is
720 only meaningful for dynamic objects, such as certain types of shared
721 libraries.
722
723 @item -f @var{format}
724 @itemx --format=@var{format}
725 @cindex @code{nm} format
726 @cindex @code{nm} compatibility
727 Use the output format @var{format}, which can be @code{bsd},
728 @code{sysv}, or @code{posix}. The default is @code{bsd}.
729 Only the first character of @var{format} is significant; it can be
730 either upper or lower case.
731
732 @item -g
733 @itemx --extern-only
734 @cindex external symbols
735 Display only external symbols.
736
737 @item -l
738 @itemx --line-numbers
739 @cindex symbol line numbers
740 For each symbol, use debugging information to try to find a filename and
741 line number. For a defined symbol, look for the line number of the
742 address of the symbol. For an undefined symbol, look for the line
743 number of a relocation entry which refers to the symbol. If line number
744 information can be found, print it after the other symbol information.
745
746 @item -n
747 @itemx -v
748 @itemx --numeric-sort
749 Sort symbols numerically by their addresses, rather than alphabetically
750 by their names.
751
752 @item -p
753 @itemx --no-sort
754 @cindex sorting symbols
755 Do not bother to sort the symbols in any order; print them in the order
756 encountered.
757
758 @item -P
759 @itemx --portability
760 Use the POSIX.2 standard output format instead of the default format.
761 Equivalent to @samp{-f posix}.
762
763 @item -s
764 @itemx --print-armap
765 @cindex symbol index, listing
766 When listing symbols from archive members, include the index: a mapping
767 (stored in the archive by @code{ar} or @code{ranlib}) of which modules
768 contain definitions for which names.
769
770 @item -r
771 @itemx --reverse-sort
772 Reverse the order of the sort (whether numeric or alphabetic); let the
773 last come first.
774
775 @item --size-sort
776 Sort symbols by size. The size is computed as the difference between
777 the value of the symbol and the value of the symbol with the next higher
778 value. The size of the symbol is printed, rather than the value.
779
780 @item -t @var{radix}
781 @itemx --radix=@var{radix}
782 Use @var{radix} as the radix for printing the symbol values. It must be
783 @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
784
785 @item --target=@var{bfdname}
786 @cindex object code format
787 Specify an object code format other than your system's default format.
788 @xref{Target Selection}, for more information.
789
790 @item -u
791 @itemx --undefined-only
792 @cindex external symbols
793 @cindex undefined symbols
794 Display only undefined symbols (those external to each object file).
795
796 @item --defined-only
797 @cindex external symbols
798 @cindex undefined symbols
799 Display only defined symbols for each object file.
800
801 @item -V
802 @itemx --version
803 Show the version number of @code{nm} and exit.
804
805 @item --help
806 Show a summary of the options to @code{nm} and exit.
807 @end table
808
809 @node objcopy
810 @chapter objcopy
811
812 @smallexample
813 objcopy [ -F @var{bfdname} | --target=@var{bfdname} ]
814 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
815 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
816 [ -S | --strip-all ] [ -g | --strip-debug ]
817 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
818 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
819 [ -x | --discard-all ] [ -X | --discard-locals ]
820 [ -b @var{byte} | --byte=@var{byte} ]
821 [ -i @var{interleave} | --interleave=@var{interleave} ]
822 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
823 [ -p | --preserve-dates ] [ --debugging ]
824 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
825 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
826 [ --adjust-vma=@var{incr} ]
827 [ --adjust-section-vma=@var{section}@{=,+,-@}@var{val} ]
828 [ --adjust-warnings ] [ --no-adjust-warnings ]
829 [ --set-section-flags=@var{section}=@var{flags} ]
830 [ --add-section=@var{sectionname}=@var{filename} ]
831 [ --change-leading-char ] [ --remove-leading-char ]
832 [ --weaken ]
833 [ -v | --verbose ] [ -V | --version ] [ --help ]
834 @var{infile} [@var{outfile}]
835 @end smallexample
836
837 The @sc{gnu} @code{objcopy} utility copies the contents of an object
838 file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
839 read and write the object files. It can write the destination object
840 file in a format different from that of the source object file. The
841 exact behavior of @code{objcopy} is controlled by command-line options.
842
843 @code{objcopy} creates temporary files to do its translations and
844 deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
845 translation work; it has access to all the formats described in @sc{bfd}
846 and thus is able to recognize most formats without being told
847 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
848
849 @code{objcopy} can be used to generate S-records by using an output
850 target of @samp{srec} (e.g., use @samp{-O srec}).
851
852 @code{objcopy} can be used to generate a raw binary file by using an
853 output target of @samp{binary} (e.g., use @samp{-O binary}). When
854 @code{objcopy} generates a raw binary file, it will essentially produce
855 a memory dump of the contents of the input object file. All symbols and
856 relocation information will be discarded. The memory dump will start at
857 the load address of the lowest section copied into the output file.
858
859 When generating an S-record or a raw binary file, it may be helpful to
860 use @samp{-S} to remove sections containing debugging information. In
861 some cases @samp{-R} will be useful to remove sections which contain
862 information which is not needed by the binary file.
863
864 @table @code
865 @item @var{infile}
866 @itemx @var{outfile}
867 The source and output files, respectively.
868 If you do not specify @var{outfile}, @code{objcopy} creates a
869 temporary file and destructively renames the result with
870 the name of @var{infile}.
871
872 @item -I @var{bfdname}
873 @itemx --input-target=@var{bfdname}
874 Consider the source file's object format to be @var{bfdname}, rather than
875 attempting to deduce it. @xref{Target Selection}, for more information.
876
877 @item -O @var{bfdname}
878 @itemx --output-target=@var{bfdname}
879 Write the output file using the object format @var{bfdname}.
880 @xref{Target Selection}, for more information.
881
882 @item -F @var{bfdname}
883 @itemx --target=@var{bfdname}
884 Use @var{bfdname} as the object format for both the input and the output
885 file; i.e., simply transfer data from source to destination with no
886 translation. @xref{Target Selection}, for more information.
887
888 @item -R @var{sectionname}
889 @itemx --remove-section=@var{sectionname}
890 Remove any section named @var{sectionname} from the output file. This
891 option may be given more than once. Note that using this option
892 inappropriately may make the output file unusable.
893
894 @item -S
895 @itemx --strip-all
896 Do not copy relocation and symbol information from the source file.
897
898 @item -g
899 @itemx --strip-debug
900 Do not copy debugging symbols from the source file.
901
902 @item --strip-unneeded
903 Strip all symbols that are not needed for relocation processing.
904
905 @item -K @var{symbolname}
906 @itemx --keep-symbol=@var{symbolname}
907 Copy only symbol @var{symbolname} from the source file. This option may
908 be given more than once.
909
910 @item -N @var{symbolname}
911 @itemx --strip-symbol=@var{symbolname}
912 Do not copy symbol @var{symbolname} from the source file. This option
913 may be given more than once, and may be combined with strip options
914 other than @code{-K}.
915
916 @item -x
917 @itemx --discard-all
918 Do not copy non-global symbols from the source file.
919 @c FIXME any reason to prefer "non-global" to "local" here?
920
921 @item -X
922 @itemx --discard-locals
923 Do not copy compiler-generated local symbols.
924 (These usually start with @samp{L} or @samp{.}.)
925
926 @item -b @var{byte}
927 @itemx --byte=@var{byte}
928 Keep only every @var{byte}th byte of the input file (header data is not
929 affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
930 where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
931 option, or the default of 4. This option is useful for creating files
932 to program @sc{rom}. It is typically used with an @code{srec} output
933 target.
934
935 @item -i @var{interleave}
936 @itemx --interleave=@var{interleave}
937 Only copy one out of every @var{interleave} bytes. Select which byte to
938 copy with the @var{-b} or @samp{--byte} option. The default is 4.
939 @code{objcopy} ignores this option if you do not specify either @samp{-b} or
940 @samp{--byte}.
941
942 @item -p
943 @itemx --preserve-dates
944 Set the access and modification dates of the output file to be the same
945 as those of the input file.
946
947 @item --debugging
948 Convert debugging information, if possible. This is not the default
949 because only certain debugging formats are supported, and the
950 conversion process can be time consuming.
951
952 @item --gap-fill @var{val}
953 Fill gaps between sections with @var{val}. This is done by increasing
954 the size of the section with the lower address, and filling in the extra
955 space created with @var{val}.
956
957 @item --pad-to @var{address}
958 Pad the output file up to the virtual address @var{address}. This is
959 done by increasing the size of the last section. The extra space is
960 filled in with the value specified by @samp{--gap-fill} (default zero).
961
962 @item --set-start @var{val}
963 Set the address of the new file to @var{val}. Not all object file
964 formats support setting the start address.
965
966 @item --adjust-start @var{incr}
967 Adjust the start address by adding @var{incr}. Not all object file
968 formats support setting the start address.
969
970 @item --adjust-vma @var{incr}
971 Adjust the address of all sections, as well as the start address, by
972 adding @var{incr}. Some object file formats do not permit section
973 addresses to be changed arbitrarily. Note that this does not relocate
974 the sections; if the program expects sections to be loaded at a certain
975 address, and this option is used to change the sections such that they
976 are loaded at a different address, the program may fail.
977
978 @item --adjust-section-vma @var{section}@{=,+,-@}@var{val}
979 Set or adjust the address of the named @var{section}. If @samp{=} is
980 used, the section address is set to @var{val}. Otherwise, @var{val} is
981 added to or subtracted from the section address. See the comments under
982 @samp{--adjust-vma}, above. If @var{section} does not exist in the
983 input file, a warning will be issued, unless @samp{--no-adjust-warnings}
984 is used.
985
986 @item --adjust-warnings
987 If @samp{--adjust-section-vma} is used, and the named section does not
988 exist, issue a warning. This is the default.
989
990 @item --no-adjust-warnings
991 Do not issue a warning if @samp{--adjust-section-vma} is used, even if
992 the named section does not exist.
993
994 @item --set-section-flags @var{section}=@var{flags}
995 Set the flags for the named section. The @var{flags} argument is a
996 comma separated string of flag names. The recognized names are
997 @samp{alloc}, @samp{load}, @samp{readonly}, @samp{code}, @samp{data},
998 and @samp{rom}. Not all flags are meaningful for all object file
999 formats.
1000
1001 @item --add-section @var{sectionname}=@var{filename}
1002 Add a new section named @var{sectionname} while copying the file. The
1003 contents of the new section are taken from the file @var{filename}. The
1004 size of the section will be the size of the file. This option only
1005 works on file formats which can support sections with arbitrary names.
1006
1007 @item --change-leading-char
1008 Some object file formats use special characters at the start of
1009 symbols. The most common such character is underscore, which compilers
1010 often add before every symbol. This option tells @code{objcopy} to
1011 change the leading character of every symbol when it converts between
1012 object file formats. If the object file formats use the same leading
1013 character, this option has no effect. Otherwise, it will add a
1014 character, or remove a character, or change a character, as
1015 appropriate.
1016
1017 @item --remove-leading-char
1018 If the first character of a global symbol is a special symbol leading
1019 character used by the object file format, remove the character. The
1020 most common symbol leading character is underscore. This option will
1021 remove a leading underscore from all global symbols. This can be useful
1022 if you want to link together objects of different file formats with
1023 different conventions for symbol names. This is different from
1024 @code{--change-leading-char} because it always changes the symbol name
1025 when appropriate, regardless of the object file format of the output
1026 file.
1027
1028 @item --weaken
1029 Change all global symbols in the file to be weak. This can be useful
1030 when building an object which will be linked against other objects using
1031 the @code{-R} option to the linker. This option is only effective when
1032 using an object file format which supports weak symbols.
1033
1034 @item -V
1035 @itemx --version
1036 Show the version number of @code{objcopy}.
1037
1038 @item -v
1039 @itemx --verbose
1040 Verbose output: list all object files modified. In the case of
1041 archives, @samp{objcopy -V} lists all members of the archive.
1042
1043 @item --help
1044 Show a summary of the options to @code{objcopy}.
1045 @end table
1046
1047 @node objdump
1048 @chapter objdump
1049
1050 @cindex object file information
1051 @kindex objdump
1052
1053 @smallexample
1054 objdump [ -a | --archive-headers ]
1055 [ -b @var{bfdname} | --target=@var{bfdname} ] [ --debugging ]
1056 [ -C | --demangle ] [ -d | --disassemble ]
1057 [ -D | --disassemble-all ] [ --disassemble-zeroes ]
1058 [ -EB | -EL | --endian=@{big | little @} ]
1059 [ -f | --file-headers ]
1060 [ -h | --section-headers | --headers ] [ -i | --info ]
1061 [ -j @var{section} | --section=@var{section} ]
1062 [ -l | --line-numbers ] [ -S | --source ]
1063 [ -m @var{machine} | --architecture=@var{machine} ]
1064 [ -r | --reloc ] [ -R | --dynamic-reloc ]
1065 [ -s | --full-contents ] [ --stabs ]
1066 [ -t | --syms ] [ -T | --dynamic-syms ] [ -x | --all-headers ]
1067 [ -w | --wide ] [ --start-address=@var{address} ]
1068 [ --stop-address=@var{address} ]
1069 [ --prefix-addresses] [ --[no-]show-raw-insn ]
1070 [ --adjust-vma=@var{offset} ]
1071 [ --version ] [ --help ]
1072 @var{objfile}@dots{}
1073 @end smallexample
1074
1075 @code{objdump} displays information about one or more object files.
1076 The options control what particular information to display. This
1077 information is mostly useful to programmers who are working on the
1078 compilation tools, as opposed to programmers who just want their
1079 program to compile and work.
1080
1081 @var{objfile}@dots{} are the object files to be examined. When you
1082 specify archives, @code{objdump} shows information on each of the member
1083 object files.
1084
1085 The long and short forms of options, shown here as alternatives, are
1086 equivalent. At least one option besides @samp{-l} must be given.
1087
1088 @table @code
1089 @item -a
1090 @itemx --archive-header
1091 @cindex archive headers
1092 If any of the @var{objfile} files are archives, display the archive
1093 header information (in a format similar to @samp{ls -l}). Besides the
1094 information you could list with @samp{ar tv}, @samp{objdump -a} shows
1095 the object file format of each archive member.
1096
1097 @item --adjust-vma=@var{offset}
1098 @cindex section addresses in objdump
1099 @cindex VMA in objdump
1100 When dumping information, first add @var{offset} to all the section
1101 addresses. This is useful if the section addresses do not correspond to
1102 the symbol table, which can happen when putting sections at particular
1103 addresses when using a format which can not represent section addresses,
1104 such as a.out.
1105
1106 @item -b @var{bfdname}
1107 @itemx --target=@var{bfdname}
1108 @cindex object code format
1109 Specify that the object-code format for the object files is
1110 @var{bfdname}. This option may not be necessary; @var{objdump} can
1111 automatically recognize many formats.
1112
1113 For example,
1114 @example
1115 objdump -b oasys -m vax -h fu.o
1116 @end example
1117 @noindent
1118 displays summary information from the section headers (@samp{-h}) of
1119 @file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1120 file in the format produced by Oasys compilers. You can list the
1121 formats available with the @samp{-i} option.
1122 @xref{Target Selection}, for more information.
1123
1124 @item -C
1125 @itemx --demangle
1126 @cindex demangling in objdump
1127 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1128 Besides removing any initial underscore prepended by the system, this
1129 makes C++ function names readable. @xref{c++filt}, for more information
1130 on demangling.
1131
1132 @item --debugging
1133 Display debugging information. This attempts to parse debugging
1134 information stored in the file and print it out using a C like syntax.
1135 Only certain types of debugging information have been implemented.
1136
1137 @item -d
1138 @itemx --disassemble
1139 @cindex disassembling object code
1140 @cindex machine instructions
1141 Display the assembler mnemonics for the machine instructions from
1142 @var{objfile}. This option only disassembles those sections which are
1143 expected to contain instructions.
1144
1145 @item -D
1146 @itemx --disassemble-all
1147 Like @samp{-d}, but disassemble the contents of all sections, not just
1148 those expected to contain instructions.
1149
1150 @item --prefix-addresses
1151 When disassembling, print the complete address on each line. This is
1152 the older disassembly format.
1153
1154 @item --disassemble-zeroes
1155 Normally the disassembly output will skip blocks of zeroes. This
1156 option directs the disassembler to disassemble those blocks, just like
1157 any other data.
1158
1159 @item -EB
1160 @itemx -EL
1161 @itemx --endian=@{big|little@}
1162 @cindex endianness
1163 @cindex disassembly endianness
1164 Specify the endianness of the object files. This only affects
1165 disassembly. This can be useful when disassembling a file format which
1166 does not describe endianness information, such as S-records.
1167
1168 @item -f
1169 @itemx --file-header
1170 @cindex object file header
1171 Display summary information from the overall header of
1172 each of the @var{objfile} files.
1173
1174 @item -h
1175 @itemx --section-header
1176 @itemx --header
1177 @cindex section headers
1178 Display summary information from the section headers of the
1179 object file.
1180
1181 File segments may be relocated to nonstandard addresses, for example by
1182 using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1183 @code{ld}. However, some object file formats, such as a.out, do not
1184 store the starting address of the file segments. In those situations,
1185 although @code{ld} relocates the sections correctly, using @samp{objdump
1186 -h} to list the file section headers cannot show the correct addresses.
1187 Instead, it shows the usual addresses, which are implicit for the
1188 target.
1189
1190 @item --help
1191 Print a summary of the options to @code{objdump} and exit.
1192
1193 @item -i
1194 @itemx --info
1195 @cindex architectures available
1196 @cindex object formats available
1197 Display a list showing all architectures and object formats available
1198 for specification with @samp{-b} or @samp{-m}.
1199
1200 @item -j @var{name}
1201 @itemx --section=@var{name}
1202 @cindex section information
1203 Display information only for section @var{name}.
1204
1205 @item -l
1206 @itemx --line-numbers
1207 @cindex source filenames for object files
1208 Label the display (using debugging information) with the filename and
1209 source line numbers corresponding to the object code or relocs shown.
1210 Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1211
1212 @item -m @var{machine}
1213 @itemx --architecture=@var{machine}
1214 @cindex architecture
1215 @cindex disassembly architecture
1216 Specify the architecture to use when disassembling object files. This
1217 can be useful when disasembling object files which do not describe
1218 architecture information, such as S-records. You can list the available
1219 architectures with the @samp{-i} option.
1220
1221 @item -r
1222 @itemx --reloc
1223 @cindex relocation entries, in object file
1224 Print the relocation entries of the file. If used with @samp{-d} or
1225 @samp{-D}, the relocations are printed interspersed with the
1226 disassembly.
1227
1228 @item -R
1229 @itemx --dynamic-reloc
1230 @cindex dynamic relocation entries, in object file
1231 Print the dynamic relocation entries of the file. This is only
1232 meaningful for dynamic objects, such as certain types of shared
1233 libraries.
1234
1235 @item -s
1236 @itemx --full-contents
1237 @cindex sections, full contents
1238 @cindex object file sections
1239 Display the full contents of any sections requested.
1240
1241 @item -S
1242 @itemx --source
1243 @cindex source disassembly
1244 @cindex disassembly, with source
1245 Display source code intermixed with disassembly, if possible. Implies
1246 @samp{-d}.
1247
1248 @item --show-raw-insn
1249 When disassembling instructions, print the instruction in hex as well as
1250 in symbolic form. This is the default except when
1251 @code{--prefix-addresses} is used.
1252
1253 @item --no-show-raw-insn
1254 When disassembling instructions, do not print the instruction bytes.
1255 This is the default when @code{--prefix-addresses} is used.
1256
1257 @item --stabs
1258 @cindex stab
1259 @cindex .stab
1260 @cindex debug symbols
1261 @cindex ELF object file format
1262 Display the full contents of any sections requested. Display the
1263 contents of the .stab and .stab.index and .stab.excl sections from an
1264 ELF file. This is only useful on systems (such as Solaris 2.0) in which
1265 @code{.stab} debugging symbol-table entries are carried in an ELF
1266 section. In most other file formats, debugging symbol-table entries are
1267 interleaved with linkage symbols, and are visible in the @samp{--syms}
1268 output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1269 Overview,stabs.info, The ``stabs'' debug format}.
1270
1271 @item --start-address=@var{address}
1272 @cindex start-address
1273 Start displaying data at the specified address. This affects the output
1274 of the @code{-d}, @code{-r} and @code{-s} options.
1275
1276 @item --stop-address=@var{address}
1277 @cindex stop-address
1278 Stop displaying data at the specified address. This affects the output
1279 of the @code{-d}, @code{-r} and @code{-s} options.
1280
1281 @item -t
1282 @itemx --syms
1283 @cindex symbol table entries, printing
1284 Print the symbol table entries of the file.
1285 This is similar to the information provided by the @samp{nm} program.
1286
1287 @item -T
1288 @itemx --dynamic-syms
1289 @cindex dynamic symbol table entries, printing
1290 Print the dynamic symbol table entries of the file. This is only
1291 meaningful for dynamic objects, such as certain types of shared
1292 libraries. This is similar to the information provided by the @samp{nm}
1293 program when given the @samp{-D} (@samp{--dynamic}) option.
1294
1295 @item --version
1296 Print the version number of @code{objdump} and exit.
1297
1298 @item -x
1299 @itemx --all-header
1300 @cindex all header information, object file
1301 @cindex header information, all
1302 Display all available header information, including the symbol table and
1303 relocation entries. Using @samp{-x} is equivalent to specifying all of
1304 @samp{-a -f -h -r -t}.
1305
1306 @item -w
1307 @item --wide
1308 @cindex wide output, printing
1309 Format some lines for output devices that have more than 80 columns.
1310 @end table
1311
1312 @node ranlib
1313 @chapter ranlib
1314
1315 @kindex ranlib
1316 @cindex archive contents
1317 @cindex symbol index
1318
1319 @smallexample
1320 ranlib [-vV] @var{archive}
1321 @end smallexample
1322
1323 @code{ranlib} generates an index to the contents of an archive and
1324 stores it in the archive. The index lists each symbol defined by a
1325 member of an archive that is a relocatable object file.
1326
1327 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1328
1329 An archive with such an index speeds up linking to the library and
1330 allows routines in the library to call each other without regard to
1331 their placement in the archive.
1332
1333 The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1334 @code{ranlib} is completely equivalent to executing @samp{ar -s}.
1335 @xref{ar}.
1336
1337 @table @code
1338 @item -v
1339 @itemx -V
1340 Show the version number of @code{ranlib}.
1341 @end table
1342
1343 @node size
1344 @chapter size
1345
1346 @kindex size
1347 @cindex section sizes
1348
1349 @smallexample
1350 size [ -A | -B | --format=@var{compatibility} ]
1351 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1352 [ --target=@var{bfdname} ] [ -V | --version ]
1353 [ @var{objfile}@dots{} ]
1354 @end smallexample
1355
1356 The @sc{gnu} @code{size} utility lists the section sizes---and the total
1357 size---for each of the object or archive files @var{objfile} in its
1358 argument list. By default, one line of output is generated for each
1359 object file or each module in an archive.
1360
1361 @var{objfile}@dots{} are the object files to be examined.
1362 If none are specified, the file @code{a.out} will be used.
1363
1364 The command line options have the following meanings:
1365
1366 @table @code
1367 @item -A
1368 @itemx -B
1369 @itemx --format=@var{compatibility}
1370 @cindex @code{size} display format
1371 Using one of these options, you can choose whether the output from @sc{gnu}
1372 @code{size} resembles output from System V @code{size} (using @samp{-A},
1373 or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1374 @samp{--format=berkeley}). The default is the one-line format similar to
1375 Berkeley's.
1376 @c Bonus for doc-source readers: you can also say --format=strange (or
1377 @c anything else that starts with 's') for sysv, and --format=boring (or
1378 @c anything else that starts with 'b') for Berkeley.
1379
1380 Here is an example of the Berkeley (default) format of output from
1381 @code{size}:
1382 @smallexample
1383 size --format=Berkeley ranlib size
1384 text data bss dec hex filename
1385 294880 81920 11592 388392 5ed28 ranlib
1386 294880 81920 11888 388688 5ee50 size
1387 @end smallexample
1388
1389 @noindent
1390 This is the same data, but displayed closer to System V conventions:
1391
1392 @smallexample
1393 size --format=SysV ranlib size
1394 ranlib :
1395 section size addr
1396 .text 294880 8192
1397 .data 81920 303104
1398 .bss 11592 385024
1399 Total 388392
1400
1401
1402 size :
1403 section size addr
1404 .text 294880 8192
1405 .data 81920 303104
1406 .bss 11888 385024
1407 Total 388688
1408 @end smallexample
1409
1410 @item --help
1411 Show a summary of acceptable arguments and options.
1412
1413 @item -d
1414 @itemx -o
1415 @itemx -x
1416 @itemx --radix=@var{number}
1417 @cindex @code{size} number format
1418 @cindex radix for section sizes
1419 Using one of these options, you can control whether the size of each
1420 section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1421 (@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1422 @samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1423 values (8, 10, 16) are supported. The total size is always given in two
1424 radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1425 octal and hexadecimal if you're using @samp{-o}.
1426
1427 @item --target=@var{bfdname}
1428 @cindex object code format
1429 Specify that the object-code format for @var{objfile} is
1430 @var{bfdname}. This option may not be necessary; @code{size} can
1431 automatically recognize many formats.
1432 @xref{Target Selection}, for more information.
1433
1434 @item -V
1435 @itemx --version
1436 Display the version number of @code{size}.
1437 @end table
1438
1439 @node strings
1440 @chapter strings
1441 @kindex strings
1442 @cindex listings strings
1443 @cindex printing strings
1444 @cindex strings, printing
1445
1446 @smallexample
1447 strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1448 [--all] [--print-file-name] [--bytes=@var{min-len}]
1449 [--radix=@var{radix}] [--target=@var{bfdname}]
1450 [--help] [--version] @var{file}@dots{}
1451 @end smallexample
1452
1453 For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1454 character sequences that are at least 4 characters long (or the number
1455 given with the options below) and are followed by an unprintable
1456 character. By default, it only prints the strings from the initialized
1457 and loaded sections of object files; for other types of files, it prints
1458 the strings from the whole file.
1459
1460 @code{strings} is mainly useful for determining the contents of non-text
1461 files.
1462
1463 @table @code
1464 @item -a
1465 @itemx --all
1466 @itemx -
1467 Do not scan only the initialized and loaded sections of object files;
1468 scan the whole files.
1469
1470 @item -f
1471 @itemx --print-file-name
1472 Print the name of the file before each string.
1473
1474 @item --help
1475 Print a summary of the program usage on the standard output and exit.
1476
1477 @itemx -@var{min-len}
1478 @item -n @var{min-len}
1479 @itemx --bytes=@var{min-len}
1480 Print sequences of characters that are at least @var{min-len} characters
1481 long, instead of the default 4.
1482
1483 @item -o
1484 Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1485 act like @samp{-t d} instead. Since we can not be compatible with both
1486 ways, we simply chose one.
1487
1488 @item -t @var{radix}
1489 @itemx --radix=@var{radix}
1490 Print the offset within the file before each string. The single
1491 character argument specifies the radix of the offset---@samp{o} for
1492 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1493
1494 @item --target=@var{bfdname}
1495 @cindex object code format
1496 Specify an object code format other than your system's default format.
1497 @xref{Target Selection}, for more information.
1498
1499 @item -v
1500 @itemx --version
1501 Print the program version number on the standard output and exit.
1502 @end table
1503
1504 @node strip
1505 @chapter strip
1506
1507 @kindex strip
1508 @cindex removing symbols
1509 @cindex discarding symbols
1510 @cindex symbols, discarding
1511
1512 @smallexample
1513 strip [ -F @var{bfdname} | --target=@var{bfdname} | --target=@var{bfdname} ]
1514 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1515 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1516 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1517 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1518 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1519 [ -x | --discard-all ] [ -X | --discard-locals ]
1520 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1521 [ -o @var{file} ] [ -p | --preserve-dates ]
1522 [ -v | --verbose ] [ -V | --version ] [ --help ]
1523 @var{objfile}@dots{}
1524 @end smallexample
1525
1526 @sc{gnu} @code{strip} discards all symbols from object files
1527 @var{objfile}. The list of object files may include archives.
1528 At least one object file must be given.
1529
1530 @code{strip} modifies the files named in its argument,
1531 rather than writing modified copies under different names.
1532
1533 @table @code
1534 @item -F @var{bfdname}
1535 @itemx --target=@var{bfdname}
1536 Treat the original @var{objfile} as a file with the object
1537 code format @var{bfdname}, and rewrite it in the same format.
1538 @xref{Target Selection}, for more information.
1539
1540 @item --help
1541 Show a summary of the options to @code{strip} and exit.
1542
1543 @item -I @var{bfdname}
1544 @itemx --input-target=@var{bfdname}
1545 Treat the original @var{objfile} as a file with the object
1546 code format @var{bfdname}.
1547 @xref{Target Selection}, for more information.
1548
1549 @item -O @var{bfdname}
1550 @itemx --output-target=@var{bfdname}
1551 Replace @var{objfile} with a file in the output format @var{bfdname}.
1552 @xref{Target Selection}, for more information.
1553
1554 @item -R @var{sectionname}
1555 @itemx --remove-section=@var{sectionname}
1556 Remove any section named @var{sectionname} from the output file. This
1557 option may be given more than once. Note that using this option
1558 inappropriately may make the output file unusable.
1559
1560 @item -s
1561 @itemx --strip-all
1562 Remove all symbols.
1563
1564 @item -g
1565 @itemx -S
1566 @itemx --strip-debug
1567 Remove debugging symbols only.
1568
1569 @item --strip-unneeded
1570 Remove all symbols that are not needed for relocation processing.
1571
1572 @item -K @var{symbolname}
1573 @itemx --keep-symbol=@var{symbolname}
1574 Keep only symbol @var{symbolname} from the source file. This option may
1575 be given more than once.
1576
1577 @item -N @var{symbolname}
1578 @itemx --strip-symbol=@var{symbolname}
1579 Remove symbol @var{symbolname} from the source file. This option may be
1580 given more than once, and may be combined with strip options other than
1581 @code{-K}.
1582
1583 @item -o @var{file}
1584 Put the stripped output in @var{file}, rather than replacing the
1585 existing file. When this argument is used, only one @var{objfile}
1586 argument may be specified.
1587
1588 @item -p
1589 @itemx --preserve-dates
1590 Preserve the access and modification dates of the file.
1591
1592 @item -x
1593 @itemx --discard-all
1594 Remove non-global symbols.
1595
1596 @item -X
1597 @itemx --discard-locals
1598 Remove compiler-generated local symbols.
1599 (These usually start with @samp{L} or @samp{.}.)
1600
1601 @item -V
1602 @itemx --version
1603 Show the version number for @code{strip}.
1604
1605 @item -v
1606 @itemx --verbose
1607 Verbose output: list all object files modified. In the case of
1608 archives, @samp{strip -v} lists all members of the archive.
1609 @end table
1610
1611 @node c++filt
1612 @chapter c++filt
1613
1614 @kindex c++filt
1615 @cindex demangling C++ symbols
1616
1617 @smallexample
1618 c++filt [ -_ | --strip-underscores ]
1619 [ -n | --no-strip-underscores ]
1620 [ -s @var{format} | --format=@var{format} ]
1621 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1622 @end smallexample
1623
1624 The C++ language provides function overloading, which means that you can
1625 write many functions with the same name (providing each takes parameters
1626 of different types). All C++ function names are encoded into a
1627 low-level assembly label (this process is known as
1628 @dfn{mangling}). The @code{c++filt} program does the inverse mapping: it
1629 decodes (@dfn{demangles}) low-level names into user-level names so that
1630 the linker can keep these overloaded functions from clashing.
1631
1632 Every alphanumeric word (consisting of letters, digits, underscores,
1633 dollars, or periods) seen in the input is a potential label. If the
1634 label decodes into a C++ name, the C++ name replaces the low-level
1635 name in the output.
1636
1637 You can use @code{c++filt} to decipher individual symbols:
1638
1639 @example
1640 c++filt @var{symbol}
1641 @end example
1642
1643 If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1644 names from the standard input and writes the demangled names to the
1645 standard output. All results are printed on the standard output.
1646
1647 @table @code
1648 @item -_
1649 @itemx --strip-underscores
1650 On some systems, both the C and C++ compilers put an underscore in front
1651 of every name. For example, the C name @code{foo} gets the low-level
1652 name @code{_foo}. This option removes the initial underscore. Whether
1653 @code{c++filt} removes the underscore by default is target dependent.
1654
1655 @item -n
1656 @itemx --no-strip-underscores
1657 Do not remove the initial underscore.
1658
1659 @item -s @var{format}
1660 @itemx --format=@var{format}
1661 @sc{gnu} @code{nm} can decode three different methods of mangling, used by
1662 different C++ compilers. The argument to this option selects which
1663 method it uses:
1664
1665 @table @code
1666 @item gnu
1667 the one used by the @sc{gnu} compiler (the default method)
1668 @item lucid
1669 the one used by the Lucid compiler
1670 @item arm
1671 the one specified by the C++ Annotated Reference Manual
1672 @end table
1673
1674 @item --help
1675 Print a summary of the options to @code{c++filt} and exit.
1676
1677 @item --version
1678 Print the version number of @code{c++filt} and exit.
1679 @end table
1680
1681 @quotation
1682 @emph{Warning:} @code{c++filt} is a new utility, and the details of its
1683 user interface are subject to change in future releases. In particular,
1684 a command-line option may be required in the the future to decode a name
1685 passed as an argument on the command line; in other words,
1686
1687 @example
1688 c++filt @var{symbol}
1689 @end example
1690
1691 @noindent
1692 may in a future release become
1693
1694 @example
1695 c++filt @var{option} @var{symbol}
1696 @end example
1697 @end quotation
1698
1699 @node addr2line
1700 @chapter addr2line
1701
1702 @kindex addr2line
1703 @cindex address to file name and line number
1704
1705 @smallexample
1706 addr2line [ -b @var{bfdname} | --target=@var{bfdname} ]
1707 [ -C | --demangle ]
1708 [ -e @var{filename} | --exe=@var{filename} ]
1709 [ -f | --functions ] [ -s | --basename ]
1710 [ -H | --help ] [ -V | --version ]
1711 [ addr addr ... ]
1712 @end smallexample
1713
1714 @code{addr2line} translates program addresses into file names and line
1715 numbers. Given an address and an executable, it uses the debugging
1716 information in the executable to figure out which file name and line
1717 number are associated with a given address.
1718
1719 The executable to use is specified with the @code{-e} option. The
1720 default is @file{a.out}.
1721
1722 @code{addr2line} has two modes of operation.
1723
1724 In the first, hexadecimal addresses are specified on the command line,
1725 and @code{addr2line} displays the file name and line number for each
1726 address.
1727
1728 In the second, @code{addr2line} reads hexadecimal addresses from
1729 standard input, and prints the file name and line number for each
1730 address on standard output. In this mode, @code{addr2line} may be used
1731 in a pipe to convert dynamically chosen addresses.
1732
1733 The format of the output is @samp{FILENAME:LINENO}. The file name and
1734 line number for each address is printed on a separate line. If the
1735 @code{-f} option is used, then each @samp{FILENAME:LINENO} line is
1736 preceded by a @samp{FUNCTIONNAME} line which is the name of the function
1737 containing the address.
1738
1739 If the file name or function name can not be determined,
1740 @code{addr2line} will print two question marks in their place. If the
1741 line number can not be determined, @code{addr2line} will print 0.
1742
1743 The long and short forms of options, shown here as alternatives, are
1744 equivalent.
1745
1746 @table @code
1747 @item -b @var{bfdname}
1748 @itemx --target=@var{bfdname}
1749 @cindex object code format
1750 Specify that the object-code format for the object files is
1751 @var{bfdname}.
1752
1753 @item -C
1754 @itemx --demangle
1755 @cindex demangling in objdump
1756 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1757 Besides removing any initial underscore prepended by the system, this
1758 makes C++ function names readable. @xref{c++filt}, for more information
1759 on demangling.
1760
1761 @item -e @var{filename}
1762 @itemx --exe=@var{filename}
1763 Specify the name of the executable for which addresses should be
1764 translated. The default file is @file{a.out}.
1765
1766 @item -f
1767 @itemx --functions
1768 Display function names as well as file and line number information.
1769
1770 @item -s
1771 @itemx --basenames
1772 Display only the base of each file name.
1773 @end table
1774
1775 @node nlmconv
1776 @chapter nlmconv
1777
1778 @code{nlmconv} converts a relocatable object file into a NetWare
1779 Loadable Module.
1780
1781 @ignore
1782 @code{nlmconv} currently works with @samp{i386} object
1783 files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1784 object files in @sc{elf}, or @code{a.out} format@footnote{
1785 @code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1786 format in the Binary File Descriptor library. It has only been tested
1787 with the above formats.}.
1788 @end ignore
1789
1790 @quotation
1791 @emph{Warning:} @code{nlmconv} is not always built as part of the binary
1792 utilities, since it is only useful for NLM targets.
1793 @end quotation
1794
1795 @smallexample
1796 nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1797 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1798 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1799 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1800 [ -h | --help ] [ -V | --version ]
1801 @var{infile} @var{outfile}
1802 @end smallexample
1803
1804 @code{nlmconv} converts the relocatable @samp{i386} object file
1805 @var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1806 reading @var{headerfile} for NLM header information. For instructions
1807 on writing the NLM command file language used in header files, see the
1808 @samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1809 Development and Tools Overview}, which is part of the NLM Software
1810 Developer's Kit (``NLM SDK''), available from Novell, Inc.
1811 @code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1812 @var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1813 more information.
1814
1815 @code{nlmconv} can perform a link step. In other words, you can list
1816 more than one object file for input if you list them in the definitions
1817 file (rather than simply specifying one input file on the command line).
1818 In this case, @code{nlmconv} calls the linker for you.
1819
1820 @table @code
1821 @item -I @var{bfdname}
1822 @itemx --input-target=@var{bfdname}
1823 Object format of the input file. @code{nlmconv} can usually determine
1824 the format of a given file (so no default is necessary).
1825 @xref{Target Selection}, for more information.
1826
1827 @item -O @var{bfdname}
1828 @itemx --output-target=@var{bfdname}
1829 Object format of the output file. @code{nlmconv} infers the output
1830 format based on the input format, e.g. for a @samp{i386} input file the
1831 output format is @samp{nlm32-i386}.
1832 @xref{Target Selection}, for more information.
1833
1834 @item -T @var{headerfile}
1835 @itemx --header-file=@var{headerfile}
1836 Reads @var{headerfile} for NLM header information. For instructions on
1837 writing the NLM command file language used in header files, see@ see the
1838 @samp{linkers} section, of the @cite{NLM Development and Tools
1839 Overview}, which is part of the NLM Software Developer's Kit, available
1840 from Novell, Inc.
1841
1842 @item -d
1843 @itemx --debug
1844 Displays (on standard error) the linker command line used by @code{nlmconv}.
1845
1846 @item -l @var{linker}
1847 @itemx --linker=@var{linker}
1848 Use @var{linker} for any linking. @var{linker} can be an abosolute or a
1849 relative pathname.
1850
1851 @item -h
1852 @itemx --help
1853 Prints a usage summary.
1854
1855 @item -V
1856 @itemx --version
1857 Prints the version number for @code{nlmconv}.
1858 @end table
1859
1860 @node windres
1861 @chapter windres
1862
1863 @code{windres} may be used to manipulate Windows resources.
1864
1865 @quotation
1866 @emph{Warning:} @code{windres} is not always built as part of the binary
1867 utilities, since it is only useful for Windows targets.
1868 @end quotation
1869
1870 @smallexample
1871 windres [options] [input-file] [output-file]
1872 @end smallexample
1873
1874 @code{windres} reads resources from an input file and copies them into
1875 an output file. Either file may be in one of three formats:
1876
1877 @table @code
1878 @item rc
1879 A text format read by the Resource Compiler.
1880
1881 @item res
1882 A binary format generated by the Resource Compiler.
1883
1884 @item coff
1885 A COFF object or executable.
1886 @end table
1887
1888 The exact description of these different formats is available in
1889 documentation from Microsoft.
1890
1891 When @code{windres} converts from the @code{rc} format to the @code{res}
1892 format, it is acting like the Windows Resource Compiler. When
1893 @code{windres} converts from the @code{res} format to the @code{coff}
1894 format, it is acting like the Windows @code{CVTRES} program.
1895
1896 When @code{windres} generates an @code{rc} file, the output is similar
1897 but not identical to the format expected for the input. When an input
1898 @code{rc} file refers to an external filename, an output @code{rc} file
1899 will instead include the file contents.
1900
1901 If the input or output format is not specified, @code{windres} will
1902 guess based on the file name, or, for the input file, the file contents.
1903 A file with an extension of @file{.rc} will be treated as an @code{rc}
1904 file, a file with an extension of @file{.res} will be treated as a
1905 @code{res} file, and a file with an extension of @file{.o} or
1906 @file{.exe} will be treated as a @code{coff} file.
1907
1908 If no output file is specified, @code{windres} will print the resources
1909 in @code{rc} format to standard output.
1910
1911 The normal use is for you to write an @code{rc} file, use @code{windres}
1912 to convert it to a COFF object file, and then link the COFF file into
1913 your application. This will make the resources described in the
1914 @code{rc} file available to Windows.
1915
1916 @table @code
1917 @item -i @var{filename}
1918 @itemx --input @var{filename}
1919 The name of the input file. If this option is not used, then
1920 @code{windres} will use the first non-option argument as the input file
1921 name. If there are no non-option arguments, then @code{windres} will
1922 read from standard input. @code{windres} can not read a COFF file from
1923 standard input.
1924
1925 @item -o @var{filename}
1926 @itemx --output @var{filename}
1927 The name of the output file. If this option is not used, then
1928 @code{windres} will use the first non-option argument, after any used
1929 for the input file name, as the output file name. If there is no
1930 non-option argument, then @code{windres} will write to standard output.
1931 @code{windres} can not write a COFF file to standard output.
1932
1933 @item -I @var{format}
1934 @itemx --input-format @var{format}
1935 The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
1936 @samp{coff}. If no input format is specified, @code{windres} will
1937 guess, as described above.
1938
1939 @item -O @var{format}
1940 @itemx --output-format @var{format}
1941 The output format to generate. @var{format} may be @samp{res},
1942 @samp{rc}, or @samp{coff}. If no output format is specified,
1943 @code{windres} will guess, as described above.
1944
1945 @item -F @var{target}
1946 @itemx --target @var{target}
1947 Specify the BFD format to use for a COFF file as input or output. This
1948 is a BFD target name; you can use the @code{--help} option to see a list
1949 of supported targets. Normally @code{windres} will use the default
1950 format, which is the first one listed by the @code{--help} option.
1951 @ref{Target Selection}.
1952
1953 @item --preprocessor @var{program}
1954 When @code{windres} reads an @code{rc} file, it runs it through the C
1955 preprocessor first. This option may be used to specify the preprocessor
1956 to use, including any leading arguments. The default preprocessor
1957 argument is @code{gcc -E -xc-header -DRC_INVOKED}.
1958
1959 @item --include-dir @var{directory}
1960 Specify an include directory to use when reading an @code{rc} file.
1961 @code{windres} will pass this to the preprocessor as an @code{-I}
1962 option. @code{windres} will also search this directory when looking for
1963 files named in the @code{rc} file.
1964
1965 @item --define @var{sym[=val]}
1966 Specify a @code{-D} option to pass to the preprocessor when reading an
1967 @code{rc} file.
1968
1969 @item --language @var{val}
1970 Specify the default language to use when reading an @code{rc} file.
1971 @var{val} should be a hexadecimal language code. The low eight bits are
1972 the language, and the high eight bits are the sublanguage.
1973
1974 @item --help
1975 Prints a usage summary.
1976
1977 @item --version
1978 Prints the version number for @code{windres}.
1979
1980 @item --yydebug
1981 If @code{windres} is compiled with @code{YYDEBUG} defined as @code{1},
1982 this will turn on parser debugging.
1983 @end table
1984
1985 @node Selecting The Target System
1986 @chapter Selecting the target system
1987
1988 You can specify three aspects of the target system to the @sc{gnu}
1989 binary file utilities, each in several ways:
1990
1991 @itemize @bullet
1992 @item
1993 the target
1994
1995 @item
1996 the architecture
1997
1998 @item
1999 the linker emulation (which applies to the linker only)
2000 @end itemize
2001
2002 In the following summaries, the lists of ways to specify values are in
2003 order of decreasing precedence. The ways listed first override those
2004 listed later.
2005
2006 The commands to list valid values only list the values for which the
2007 programs you are running were configured. If they were configured with
2008 @samp{--enable-targets=all}, the commands list most of the available
2009 values, but a few are left out; not all targets can be configured in at
2010 once because some of them can only be configured @dfn{native} (on hosts
2011 with the same type as the target system).
2012
2013 @menu
2014 * Target Selection::
2015 * Architecture Selection::
2016 * Linker Emulation Selection::
2017 @end menu
2018
2019 @node Target Selection
2020 @section Target Selection
2021
2022 A @dfn{target} is an object file format. A given target may be
2023 supported for multiple architectures (@pxref{Architecture Selection}).
2024 A target selection may also have variations for different operating
2025 systems or architectures.
2026
2027 The command to list valid target values is @samp{objdump -i}
2028 (the first column of output contains the relevant information).
2029
2030 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
2031 @samp{a.out-sunos-big}.
2032
2033 You can also specify a target using a configuration triplet. This is
2034 the same sort of name that is passed to configure to specify a target.
2035 When you use a configuration triplet as an argument, it must be fully
2036 canonicalized. You can see the canonical version of a triplet by
2037 running the shell script @file{config.sub} which is included with the
2038 sources.
2039
2040 Some sample configuration triplets are: @samp{m68k-hp-bsd},
2041 @samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
2042
2043 @subheading @code{objdump} Target
2044
2045 Ways to specify:
2046
2047 @enumerate
2048 @item
2049 command line option: @samp{-b} or @samp{--target}
2050
2051 @item
2052 environment variable @code{GNUTARGET}
2053
2054 @item
2055 deduced from the input file
2056 @end enumerate
2057
2058 @subheading @code{objcopy} and @code{strip} Input Target
2059
2060 Ways to specify:
2061
2062 @enumerate
2063 @item
2064 command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
2065
2066 @item
2067 environment variable @code{GNUTARGET}
2068
2069 @item
2070 deduced from the input file
2071 @end enumerate
2072
2073 @subheading @code{objcopy} and @code{strip} Output Target
2074
2075 Ways to specify:
2076
2077 @enumerate
2078 @item
2079 command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
2080
2081 @item
2082 the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
2083
2084 @item
2085 environment variable @code{GNUTARGET}
2086
2087 @item
2088 deduced from the input file
2089 @end enumerate
2090
2091 @subheading @code{nm}, @code{size}, and @code{strings} Target
2092
2093 Ways to specify:
2094
2095 @enumerate
2096 @item
2097 command line option: @samp{--target}
2098
2099 @item
2100 environment variable @code{GNUTARGET}
2101
2102 @item
2103 deduced from the input file
2104 @end enumerate
2105
2106 @subheading Linker Input Target
2107
2108 Ways to specify:
2109
2110 @enumerate
2111 @item
2112 command line option: @samp{-b} or @samp{--format}
2113 (@pxref{Options,,Options,ld.info,Using LD})
2114
2115 @item
2116 script command @code{TARGET}
2117 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2118
2119 @item
2120 environment variable @code{GNUTARGET}
2121 (@pxref{Environment,,Environment,ld.info,Using LD})
2122
2123 @item
2124 the default target of the selected linker emulation
2125 (@pxref{Linker Emulation Selection})
2126 @end enumerate
2127
2128 @subheading Linker Output Target
2129
2130 Ways to specify:
2131
2132 @enumerate
2133 @item
2134 command line option: @samp{-oformat}
2135 (@pxref{Options,,Options,ld.info,Using LD})
2136
2137 @item
2138 script command @code{OUTPUT_FORMAT}
2139 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2140
2141 @item
2142 the linker input target (see ``Linker Input Target'' above)
2143 @end enumerate
2144
2145 @node Architecture Selection
2146 @section Architecture selection
2147
2148 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
2149 to run. Its name may contain a colon, separating the name of the
2150 processor family from the name of the particular @sc{cpu}.
2151
2152 The command to list valid architecture values is @samp{objdump -i} (the
2153 second column contains the relevant information).
2154
2155 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
2156
2157 @subheading @code{objdump} Architecture
2158
2159 Ways to specify:
2160
2161 @enumerate
2162 @item
2163 command line option: @samp{-m} or @samp{--architecture}
2164
2165 @item
2166 deduced from the input file
2167 @end enumerate
2168
2169 @subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
2170
2171 Ways to specify:
2172
2173 @enumerate
2174 @item
2175 deduced from the input file
2176 @end enumerate
2177
2178 @subheading Linker Input Architecture
2179
2180 Ways to specify:
2181
2182 @enumerate
2183 @item
2184 deduced from the input file
2185 @end enumerate
2186
2187 @subheading Linker Output Architecture
2188
2189 Ways to specify:
2190
2191 @enumerate
2192 @item
2193 script command @code{OUTPUT_ARCH}
2194 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2195
2196 @item
2197 the default architecture from the linker output target
2198 (@pxref{Target Selection})
2199 @end enumerate
2200
2201 @node Linker Emulation Selection
2202 @section Linker emulation selection
2203
2204 A linker @dfn{emulation} is a ``personality'' of the linker, which gives
2205 the linker default values for the other aspects of the target system.
2206 In particular, it consists of
2207
2208 @itemize @bullet
2209 @item
2210 the linker script
2211
2212 @item
2213 the target
2214
2215 @item
2216 several ``hook'' functions that are run at certain stages of the linking
2217 process to do special things that some targets require
2218 @end itemize
2219
2220 The command to list valid linker emulation values is @samp{ld -V}.
2221
2222 Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
2223
2224 Ways to specify:
2225
2226 @enumerate
2227 @item
2228 command line option: @samp{-m}
2229 (@pxref{Options,,Options,ld.info,Using LD})
2230
2231 @item
2232 environment variable @code{LDEMULATION}
2233
2234 @item
2235 compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2236 which comes from @code{EMUL} in @file{config/@var{target}.mt}
2237 @end enumerate
2238
2239 @node Reporting Bugs
2240 @chapter Reporting Bugs
2241 @cindex bugs
2242 @cindex reporting bugs
2243
2244 Your bug reports play an essential role in making the binary utilities
2245 reliable.
2246
2247 Reporting a bug may help you by bringing a solution to your problem, or
2248 it may not. But in any case the principal function of a bug report is
2249 to help the entire community by making the next version of the binary
2250 utilities work better. Bug reports are your contribution to their
2251 maintenance.
2252
2253 In order for a bug report to serve its purpose, you must include the
2254 information that enables us to fix the bug.
2255
2256 @menu
2257 * Bug Criteria:: Have you found a bug?
2258 * Bug Reporting:: How to report bugs
2259 @end menu
2260
2261 @node Bug Criteria
2262 @section Have you found a bug?
2263 @cindex bug criteria
2264
2265 If you are not sure whether you have found a bug, here are some guidelines:
2266
2267 @itemize @bullet
2268 @cindex fatal signal
2269 @cindex crash
2270 @item
2271 If a binary utility gets a fatal signal, for any input whatever, that is
2272 a bug. Reliable utilities never crash.
2273
2274 @cindex error on valid input
2275 @item
2276 If a binary utility produces an error message for valid input, that is a
2277 bug.
2278
2279 @item
2280 If you are an experienced user of binary utilities, your suggestions for
2281 improvement are welcome in any case.
2282 @end itemize
2283
2284 @node Bug Reporting
2285 @section How to report bugs
2286 @cindex bug reports
2287 @cindex bugs, reporting
2288
2289 A number of companies and individuals offer support for @sc{gnu}
2290 products. If you obtained the binary utilities from a support
2291 organization, we recommend you contact that organization first.
2292
2293 You can find contact information for many support companies and
2294 individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2295 distribution.
2296
2297 In any event, we also recommend that you send bug reports for the binary
2298 utilities to @samp{bug-gnu-utils@@prep.ai.mit.edu}.
2299
2300 The fundamental principle of reporting bugs usefully is this:
2301 @strong{report all the facts}. If you are not sure whether to state a
2302 fact or leave it out, state it!
2303
2304 Often people omit facts because they think they know what causes the
2305 problem and assume that some details do not matter. Thus, you might
2306 assume that the name of a file you use in an example does not matter.
2307 Well, probably it does not, but one cannot be sure. Perhaps the bug is
2308 a stray memory reference which happens to fetch from the location where
2309 that pathname is stored in memory; perhaps, if the pathname were
2310 different, the contents of that location would fool the utility into
2311 doing the right thing despite the bug. Play it safe and give a
2312 specific, complete example. That is the easiest thing for you to do,
2313 and the most helpful.
2314
2315 Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2316 it is new to us. Therefore, always write your bug reports on the assumption
2317 that the bug has not been reported previously.
2318
2319 Sometimes people give a few sketchy facts and ask, ``Does this ring a
2320 bell?'' Those bug reports are useless, and we urge everyone to
2321 @emph{refuse to respond to them} except to chide the sender to report
2322 bugs properly.
2323
2324 To enable us to fix the bug, you should include all these things:
2325
2326 @itemize @bullet
2327 @item
2328 The version of the utility. Each utility announces it if you start it
2329 with the @samp{--version} argument.
2330
2331 Without this, we will not know whether there is any point in looking for
2332 the bug in the current version of the binary utilities.
2333
2334 @item
2335 Any patches you may have applied to the source, including any patches
2336 made to the @code{BFD} library.
2337
2338 @item
2339 The type of machine you are using, and the operating system name and
2340 version number.
2341
2342 @item
2343 What compiler (and its version) was used to compile the utilities---e.g.
2344 ``@code{gcc-2.7}''.
2345
2346 @item
2347 The command arguments you gave the utility to observe the bug. To
2348 guarantee you will not omit something important, list them all. A copy
2349 of the Makefile (or the output from make) is sufficient.
2350
2351 If we were to try to guess the arguments, we would probably guess wrong
2352 and then we might not encounter the bug.
2353
2354 @item
2355 A complete input file, or set of input files, that will reproduce the
2356 bug. If the utility is reading an object file or files, then it is
2357 generally most helpful to send the actual object files, uuencoded if
2358 necessary to get them through the mail system. Making them available
2359 for anonymous FTP is not as good, but may be the only reasonable choice
2360 for large object files.
2361
2362 If the source files were produced exclusively using @sc{gnu} programs
2363 (e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2364 may be OK to send the source files rather than the object files. In
2365 this case, be sure to say exactly what version of @code{gcc}, or
2366 whatever, was used to produce the object files. Also say how
2367 @code{gcc}, or whatever, was configured.
2368
2369 @item
2370 A description of what behavior you observe that you believe is
2371 incorrect. For example, ``It gets a fatal signal.''
2372
2373 Of course, if the bug is that the utility gets a fatal signal, then we
2374 will certainly notice it. But if the bug is incorrect output, we might
2375 not notice unless it is glaringly wrong. You might as well not give us
2376 a chance to make a mistake.
2377
2378 Even if the problem you experience is a fatal signal, you should still
2379 say so explicitly. Suppose something strange is going on, such as, your
2380 copy of the utility is out of synch, or you have encountered a bug in
2381 the C library on your system. (This has happened!) Your copy might
2382 crash and ours would not. If you told us to expect a crash, then when
2383 ours fails to crash, we would know that the bug was not happening for
2384 us. If you had not told us to expect a crash, then we would not be able
2385 to draw any conclusion from our observations.
2386
2387 @item
2388 If you wish to suggest changes to the source, send us context diffs, as
2389 generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2390 option. Always send diffs from the old file to the new file. If you
2391 even discuss something in the @code{ld} source, refer to it by context,
2392 not by line number.
2393
2394 The line numbers in our development sources will not match those in your
2395 sources. Your line numbers would convey no useful information to us.
2396 @end itemize
2397
2398 Here are some things that are not necessary:
2399
2400 @itemize @bullet
2401 @item
2402 A description of the envelope of the bug.
2403
2404 Often people who encounter a bug spend a lot of time investigating
2405 which changes to the input file will make the bug go away and which
2406 changes will not affect it.
2407
2408 This is often time consuming and not very useful, because the way we
2409 will find the bug is by running a single example under the debugger
2410 with breakpoints, not by pure deduction from a series of examples.
2411 We recommend that you save your time for something else.
2412
2413 Of course, if you can find a simpler example to report @emph{instead}
2414 of the original one, that is a convenience for us. Errors in the
2415 output will be easier to spot, running under the debugger will take
2416 less time, and so on.
2417
2418 However, simplification is not vital; if you do not want to do this,
2419 report the bug anyway and send us the entire test case you used.
2420
2421 @item
2422 A patch for the bug.
2423
2424 A patch for the bug does help us if it is a good one. But do not omit
2425 the necessary information, such as the test case, on the assumption that
2426 a patch is all we need. We might see problems with your patch and decide
2427 to fix the problem another way, or we might not understand it at all.
2428
2429 Sometimes with programs as complicated as the binary utilities it is
2430 very hard to construct an example that will make the program follow a
2431 certain path through the code. If you do not send us the example, we
2432 will not be able to construct one, so we will not be able to verify that
2433 the bug is fixed.
2434
2435 And if we cannot understand what bug you are trying to fix, or why your
2436 patch should be an improvement, we will not install it. A test case will
2437 help us to understand.
2438
2439 @item
2440 A guess about what the bug is or what it depends on.
2441
2442 Such guesses are usually wrong. Even we cannot guess right about such
2443 things without first using the debugger to find the facts.
2444 @end itemize
2445
2446 @node Index
2447 @unnumbered Index
2448
2449 @printindex cp
2450
2451 @contents
2452 @bye
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