Fix GDB_GREGSET_T, GDB_FPREGSET_T typos.
[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.
9 * ar: (binutils)ar. Create, modify, and extract from archives
10 * nm: (binutils)nm. List symbols from object files
11 * objcopy: (binutils)objcopy. Copy and translate object files
12 * objdump: (binutils)objdump. Display information from object files
13 * ranlib: (binutils)ranlib. Generate index to archive contents
14 * readelf: (binutils)readelf. Display the contents of ELF format files.
15 * size: (binutils)size. List section sizes and total size
16 * strings: (binutils)strings. List printable strings from files
17 * strip: (binutils)strip. Discard symbols
18 * c++filt: (binutils)c++filt. Filter to demangle encoded C++ symbols
19 * cxxfilt: (binutils)c++filt. MS-DOS name for c++filt
20 * addr2line: (binutils)addr2line. Convert addresses to file and line
21 * nlmconv: (binutils)nlmconv. Converts object code into an NLM
22 * windres: (binutils)windres. Manipulate Windows resources
23 * dlltool: (binutils)dlltool. Create files needed to build and use DLLs
24 END-INFO-DIR-ENTRY
25 @end format
26 @end ifinfo
27
28 @ifinfo
29 Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
30
31 Permission is granted to make and distribute verbatim copies of
32 this manual provided the copyright notice and this permission notice
33 are preserved on all copies.
34
35 @ignore
36 Permission is granted to process this file through TeX and print the
37 results, provided the printed document carries a copying permission
38 notice identical to this one except for the removal of this paragraph
39 (this paragraph not being relevant to the printed manual).
40
41 @end ignore
42
43 Permission is granted to copy and distribute modified versions of this
44 manual under the conditions for verbatim copying, provided also that
45 the entire resulting derived work is distributed under the terms of a
46 permission notice identical to this one.
47
48 Permission is granted to copy and distribute translations of this manual
49 into another language, under the above conditions for modified versions.
50 @end ifinfo
51
52 @synindex ky cp
53 @c
54 @c This file documents the GNU binary utilities "ar", "ld", "objcopy",
55 @c "objdump", "nm", "size", "strings", "strip", "readelf" and "ranlib".
56 @c
57 @c Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
58 @c
59 @c This text may be freely distributed under the terms of the GNU
60 @c General Public License.
61 @c
62
63 @setchapternewpage odd
64 @settitle @sc{gnu} Binary Utilities
65 @titlepage
66 @finalout
67 @title The @sc{gnu} Binary Utilities
68 @subtitle Version @value{VERSION}
69 @sp 1
70 @subtitle May 1993
71 @author Roland H. Pesch
72 @author Jeffrey M. Osier
73 @author Cygnus Support
74 @page
75
76 @tex
77 {\parskip=0pt \hfill Cygnus Support\par \hfill
78 \TeX{}info \texinfoversion\par }
79 @end tex
80
81 @vskip 0pt plus 1filll
82 Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 1998 Free Software Foundation, Inc.
83
84 Permission is granted to make and distribute verbatim copies of
85 this manual provided the copyright notice and this permission notice
86 are preserved on all copies.
87
88 Permission is granted to copy and distribute modified versions of this
89 manual under the conditions for verbatim copying, provided also that
90 the entire resulting derived work is distributed under the terms of a
91 permission notice identical to this one.
92
93 Permission is granted to copy and distribute translations of this manual
94 into another language, under the above conditions for modified versions.
95 @end titlepage
96
97 @node Top
98 @top Introduction
99
100 @cindex version
101 This brief manual contains preliminary documentation for the @sc{gnu} binary
102 utilities (collectively version @value{VERSION}):
103
104 @iftex
105 @table @code
106 @item ar
107 Create, modify, and extract from archives
108
109 @item nm
110 List symbols from object files
111
112 @item objcopy
113 Copy and translate object files
114
115 @item objdump
116 Display information from object files
117
118 @item ranlib
119 Generate index to archive contents
120
121 @item readelf
122 Display the contents of ELF format files.
123
124 @item size
125 List file section sizes and total size
126
127 @item strings
128 List printable strings from files
129
130 @item strip
131 Discard symbols
132
133 @item c++filt
134 Demangle encoded C++ symbols (on MS-DOS, this program is named
135 @code{cxxfilt})
136
137 @item addr2line
138 Convert addresses into file names and line numbers
139
140 @item nlmconv
141 Convert object code into a Netware Loadable Module
142
143 @item windres
144 Manipulate Windows resources
145
146 @item dlltool
147 Create the files needed to build and use Dynamic Link Libraries
148 @end table
149 @end iftex
150
151 @menu
152 * ar:: Create, modify, and extract from archives
153 * nm:: List symbols from object files
154 * objcopy:: Copy and translate object files
155 * objdump:: Display information from object files
156 * ranlib:: Generate index to archive contents
157 * readelf:: Display the contents of ELF format files.
158 * size:: List section sizes and total size
159 * strings:: List printable strings from files
160 * strip:: Discard symbols
161 * c++filt:: Filter to demangle encoded C++ symbols
162 * cxxfilt: c++filt. MS-DOS name for c++filt
163 * addr2line:: Convert addresses to file and line
164 * nlmconv:: Converts object code into an NLM
165 * windres:: Manipulate Windows resources
166 * dlltool:: Create files needed to build and use DLLs
167 * Selecting The Target System:: How these utilities determine the target.
168 * Reporting Bugs:: Reporting Bugs
169 * Index:: Index
170 @end menu
171
172 @node ar
173 @chapter ar
174
175 @kindex ar
176 @cindex archives
177 @cindex collections of files
178 @smallexample
179 ar [-]@var{p}[@var{mod} [@var{relpos}] [@var{count}]] @var{archive} [@var{member}@dots{}]
180 ar -M [ <mri-script ]
181 @end smallexample
182
183 The @sc{gnu} @code{ar} program creates, modifies, and extracts from
184 archives. An @dfn{archive} is a single file holding a collection of
185 other files in a structure that makes it possible to retrieve
186 the original individual files (called @dfn{members} of the archive).
187
188 The original files' contents, mode (permissions), timestamp, owner, and
189 group are preserved in the archive, and can be restored on
190 extraction.
191
192 @cindex name length
193 @sc{gnu} @code{ar} can maintain archives whose members have names of any
194 length; however, depending on how @code{ar} is configured on your
195 system, a limit on member-name length may be imposed for compatibility
196 with archive formats maintained with other tools. If it exists, the
197 limit is often 15 characters (typical of formats related to a.out) or 16
198 characters (typical of formats related to coff).
199
200 @cindex libraries
201 @code{ar} is considered a binary utility because archives of this sort
202 are most often used as @dfn{libraries} holding commonly needed
203 subroutines.
204
205 @cindex symbol index
206 @code{ar} creates an index to the symbols defined in relocatable
207 object modules in the archive when you specify the modifier @samp{s}.
208 Once created, this index is updated in the archive whenever @code{ar}
209 makes a change to its contents (save for the @samp{q} update operation).
210 An archive with such an index speeds up linking to the library, and
211 allows routines in the library to call each other without regard to
212 their placement in the archive.
213
214 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
215 table. If an archive lacks the table, another form of @code{ar} called
216 @code{ranlib} can be used to add just the table.
217
218 @cindex compatibility, @code{ar}
219 @cindex @code{ar} compatibility
220 @sc{gnu} @code{ar} is designed to be compatible with two different
221 facilities. You can control its activity using command-line options,
222 like the different varieties of @code{ar} on Unix systems; or, if you
223 specify the single command-line option @samp{-M}, you can control it
224 with a script supplied via standard input, like the MRI ``librarian''
225 program.
226
227 @menu
228 * ar cmdline:: Controlling @code{ar} on the command line
229 * ar scripts:: Controlling @code{ar} with a script
230 @end menu
231
232 @page
233 @node ar cmdline
234 @section Controlling @code{ar} on the command line
235
236 @smallexample
237 ar [-]@var{p}[@var{mod} [@var{relpos}] [@var{count}]] @var{archive} [@var{member}@dots{}]
238 @end smallexample
239
240 @cindex Unix compatibility, @code{ar}
241 When you use @code{ar} in the Unix style, @code{ar} insists on at least two
242 arguments to execute: one keyletter specifying the @emph{operation}
243 (optionally accompanied by other keyletters specifying
244 @emph{modifiers}), and the archive name to act on.
245
246 Most operations can also accept further @var{member} arguments,
247 specifying particular files to operate on.
248
249 @sc{gnu} @code{ar} allows you to mix the operation code @var{p} and modifier
250 flags @var{mod} in any order, within the first command-line argument.
251
252 If you wish, you may begin the first command-line argument with a
253 dash.
254
255 @cindex operations on archive
256 The @var{p} keyletter specifies what operation to execute; it may be
257 any of the following, but you must specify only one of them:
258
259 @table @code
260 @item d
261 @cindex deleting from archive
262 @emph{Delete} modules from the archive. Specify the names of modules to
263 be deleted as @var{member}@dots{}; the archive is untouched if you
264 specify no files to delete.
265
266 If you specify the @samp{v} modifier, @code{ar} lists each module
267 as it is deleted.
268
269 @item m
270 @cindex moving in archive
271 Use this operation to @emph{move} members in an archive.
272
273 The ordering of members in an archive can make a difference in how
274 programs are linked using the library, if a symbol is defined in more
275 than one member.
276
277 If no modifiers are used with @code{m}, any members you name in the
278 @var{member} arguments are moved to the @emph{end} of the archive;
279 you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
280 specified place instead.
281
282 @item p
283 @cindex printing from archive
284 @emph{Print} the specified members of the archive, to the standard
285 output file. If the @samp{v} modifier is specified, show the member
286 name before copying its contents to standard output.
287
288 If you specify no @var{member} arguments, all the files in the archive are
289 printed.
290
291 @item q
292 @cindex quick append to archive
293 @emph{Quick append}; Historically, add the files @var{member}@dots{} to the end of
294 @var{archive}, without checking for replacement.
295
296 The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
297 operation; new members are always placed at the end of the archive.
298
299 The modifier @samp{v} makes @code{ar} list each file as it is appended.
300
301 Since the point of this operation is speed, the archive's symbol table
302 index is not updated, even if it already existed; you can use @samp{ar s} or
303 @code{ranlib} explicitly to update the symbol table index.
304
305 However, too many different systems assume quick append rebuilds the
306 index, so GNU ar implements @code{q} as a synonym for @code{r}.
307
308 @item r
309 @cindex replacement in archive
310 Insert the files @var{member}@dots{} into @var{archive} (with
311 @emph{replacement}). This operation differs from @samp{q} in that any
312 previously existing members are deleted if their names match those being
313 added.
314
315 If one of the files named in @var{member}@dots{} does not exist, @code{ar}
316 displays an error message, and leaves undisturbed any existing members
317 of the archive matching that name.
318
319 By default, new members are added at the end of the file; but you may
320 use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
321 placement relative to some existing member.
322
323 The modifier @samp{v} used with this operation elicits a line of
324 output for each file inserted, along with one of the letters @samp{a} or
325 @samp{r} to indicate whether the file was appended (no old member
326 deleted) or replaced.
327
328 @item t
329 @cindex contents of archive
330 Display a @emph{table} listing the contents of @var{archive}, or those
331 of the files listed in @var{member}@dots{} that are present in the
332 archive. Normally only the member name is shown; if you also want to
333 see the modes (permissions), timestamp, owner, group, and size, you can
334 request that by also specifying the @samp{v} modifier.
335
336 If you do not specify a @var{member}, all files in the archive
337 are listed.
338
339 @cindex repeated names in archive
340 @cindex name duplication in archive
341 If there is more than one file with the same name (say, @samp{fie}) in
342 an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
343 first instance; to see them all, you must ask for a complete
344 listing---in our example, @samp{ar t b.a}.
345 @c WRS only; per Gumby, this is implementation-dependent, and in a more
346 @c recent case in fact works the other way.
347
348 @item x
349 @cindex extract from archive
350 @emph{Extract} members (named @var{member}) from the archive. You can
351 use the @samp{v} modifier with this operation, to request that
352 @code{ar} list each name as it extracts it.
353
354 If you do not specify a @var{member}, all files in the archive
355 are extracted.
356
357 @end table
358
359 A number of modifiers (@var{mod}) may immediately follow the @var{p}
360 keyletter, to specify variations on an operation's behavior:
361
362 @table @code
363 @item a
364 @cindex relative placement in archive
365 Add new files @emph{after} an existing member of the
366 archive. If you use the modifier @samp{a}, the name of an existing archive
367 member must be present as the @var{relpos} argument, before the
368 @var{archive} specification.
369
370 @item b
371 Add new files @emph{before} an existing member of the
372 archive. If you use the modifier @samp{b}, the name of an existing archive
373 member must be present as the @var{relpos} argument, before the
374 @var{archive} specification. (same as @samp{i}).
375
376 @item c
377 @cindex creating archives
378 @emph{Create} the archive. The specified @var{archive} is always
379 created if it did not exist, when you request an update. But a warning is
380 issued unless you specify in advance that you expect to create it, by
381 using this modifier.
382
383 @item f
384 Truncate names in the archive. @sc{gnu} @code{ar} will normally permit file
385 names of any length. This will cause it to create archives which are
386 not compatible with the native @code{ar} program on some systems. If
387 this is a concern, the @samp{f} modifier may be used to truncate file
388 names when putting them in the archive.
389
390 @item i
391 Insert new files @emph{before} an existing member of the
392 archive. If you use the modifier @samp{i}, the name of an existing archive
393 member must be present as the @var{relpos} argument, before the
394 @var{archive} specification. (same as @samp{b}).
395
396 @item l
397 This modifier is accepted but not used.
398 @c whaffor ar l modifier??? presumably compat; with
399 @c what???---doc@@cygnus.com, 25jan91
400
401 @item N
402 Uses the @var{count} parameter. This is used if there are multiple
403 entries in the archive with the same name. Extract or delete instance
404 @var{count} of the given name from the archive.
405
406 @item o
407 @cindex dates in archive
408 Preserve the @emph{original} dates of members when extracting them. If
409 you do not specify this modifier, files extracted from the archive
410 are stamped with the time of extraction.
411
412 @item P
413 Use the full path name when matching names in the archive. @sc{gnu}
414 @code{ar} can not create an archive with a full path name (such archives
415 are not POSIX complaint), but other archive creators can. This option
416 will cause @sc{gnu} @code{ar} to match file names using a complete path
417 name, which can be convenient when extracting a single file from an
418 archive created by another tool.
419
420 @item s
421 @cindex writing archive index
422 Write an object-file index into the archive, or update an existing one,
423 even if no other change is made to the archive. You may use this modifier
424 flag either with any operation, or alone. Running @samp{ar s} on an
425 archive is equivalent to running @samp{ranlib} on it.
426
427 @item S
428 @cindex not writing archive index
429 Do not generate an archive symbol table. This can speed up building a
430 large library in several steps. The resulting archive can not be used
431 with the linker. In order to build a symbol table, you must omit the
432 @samp{S} modifier on the last execution of @samp{ar}, or you must run
433 @samp{ranlib} on the archive.
434
435 @item u
436 @cindex updating an archive
437 Normally, @samp{ar r}@dots{} inserts all files
438 listed into the archive. If you would like to insert @emph{only} those
439 of the files you list that are newer than existing members of the same
440 names, use this modifier. The @samp{u} modifier is allowed only for the
441 operation @samp{r} (replace). In particular, the combination @samp{qu} is
442 not allowed, since checking the timestamps would lose any speed
443 advantage from the operation @samp{q}.
444
445 @item v
446 This modifier requests the @emph{verbose} version of an operation. Many
447 operations display additional information, such as filenames processed,
448 when the modifier @samp{v} is appended.
449
450 @item V
451 This modifier shows the version number of @code{ar}.
452 @end table
453
454 @node ar scripts
455 @section Controlling @code{ar} with a script
456
457 @smallexample
458 ar -M [ <@var{script} ]
459 @end smallexample
460
461 @cindex MRI compatibility, @code{ar}
462 @cindex scripts, @code{ar}
463 If you use the single command-line option @samp{-M} with @code{ar}, you
464 can control its operation with a rudimentary command language. This
465 form of @code{ar} operates interactively if standard input is coming
466 directly from a terminal. During interactive use, @code{ar} prompts for
467 input (the prompt is @samp{AR >}), and continues executing even after
468 errors. If you redirect standard input to a script file, no prompts are
469 issued, and @code{ar} abandons execution (with a nonzero exit code)
470 on any error.
471
472 The @code{ar} command language is @emph{not} designed to be equivalent
473 to the command-line options; in fact, it provides somewhat less control
474 over archives. The only purpose of the command language is to ease the
475 transition to @sc{gnu} @code{ar} for developers who already have scripts
476 written for the MRI ``librarian'' program.
477
478 The syntax for the @code{ar} command language is straightforward:
479 @itemize @bullet
480 @item
481 commands are recognized in upper or lower case; for example, @code{LIST}
482 is the same as @code{list}. In the following descriptions, commands are
483 shown in upper case for clarity.
484
485 @item
486 a single command may appear on each line; it is the first word on the
487 line.
488
489 @item
490 empty lines are allowed, and have no effect.
491
492 @item
493 comments are allowed; text after either of the characters @samp{*}
494 or @samp{;} is ignored.
495
496 @item
497 Whenever you use a list of names as part of the argument to an @code{ar}
498 command, you can separate the individual names with either commas or
499 blanks. Commas are shown in the explanations below, for clarity.
500
501 @item
502 @samp{+} is used as a line continuation character; if @samp{+} appears
503 at the end of a line, the text on the following line is considered part
504 of the current command.
505 @end itemize
506
507 Here are the commands you can use in @code{ar} scripts, or when using
508 @code{ar} interactively. Three of them have special significance:
509
510 @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
511 a temporary file required for most of the other commands.
512
513 @code{SAVE} commits the changes so far specified by the script. Prior
514 to @code{SAVE}, commands affect only the temporary copy of the current
515 archive.
516
517 @table @code
518 @item ADDLIB @var{archive}
519 @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
520 Add all the contents of @var{archive} (or, if specified, each named
521 @var{module} from @var{archive}) to the current archive.
522
523 Requires prior use of @code{OPEN} or @code{CREATE}.
524
525 @item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
526 @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
527 @c else like "ar q..."
528 Add each named @var{member} as a module in the current archive.
529
530 Requires prior use of @code{OPEN} or @code{CREATE}.
531
532 @item CLEAR
533 Discard the contents of the current archive, canceling the effect of
534 any operations since the last @code{SAVE}. May be executed (with no
535 effect) even if no current archive is specified.
536
537 @item CREATE @var{archive}
538 Creates an archive, and makes it the current archive (required for many
539 other commands). The new archive is created with a temporary name; it
540 is not actually saved as @var{archive} until you use @code{SAVE}.
541 You can overwrite existing archives; similarly, the contents of any
542 existing file named @var{archive} will not be destroyed until @code{SAVE}.
543
544 @item DELETE @var{module}, @var{module}, @dots{} @var{module}
545 Delete each listed @var{module} from the current archive; equivalent to
546 @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
547
548 Requires prior use of @code{OPEN} or @code{CREATE}.
549
550 @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
551 @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
552 List each named @var{module} present in @var{archive}. The separate
553 command @code{VERBOSE} specifies the form of the output: when verbose
554 output is off, output is like that of @samp{ar -t @var{archive}
555 @var{module}@dots{}}. When verbose output is on, the listing is like
556 @samp{ar -tv @var{archive} @var{module}@dots{}}.
557
558 Output normally goes to the standard output stream; however, if you
559 specify @var{outputfile} as a final argument, @code{ar} directs the
560 output to that file.
561
562 @item END
563 Exit from @code{ar}, with a @code{0} exit code to indicate successful
564 completion. This command does not save the output file; if you have
565 changed the current archive since the last @code{SAVE} command, those
566 changes are lost.
567
568 @item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
569 Extract each named @var{module} from the current archive, writing them
570 into the current directory as separate files. Equivalent to @samp{ar -x
571 @var{archive} @var{module}@dots{}}.
572
573 Requires prior use of @code{OPEN} or @code{CREATE}.
574
575 @ignore
576 @c FIXME Tokens but no commands???
577 @item FULLDIR
578
579 @item HELP
580 @end ignore
581
582 @item LIST
583 Display full contents of the current archive, in ``verbose'' style
584 regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
585 tv @var{archive}}. (This single command is a @sc{gnu} @code{ar}
586 enhancement, rather than present for MRI compatibility.)
587
588 Requires prior use of @code{OPEN} or @code{CREATE}.
589
590 @item OPEN @var{archive}
591 Opens an existing archive for use as the current archive (required for
592 many other commands). Any changes as the result of subsequent commands
593 will not actually affect @var{archive} until you next use @code{SAVE}.
594
595 @item REPLACE @var{module}, @var{module}, @dots{} @var{module}
596 In the current archive, replace each existing @var{module} (named in
597 the @code{REPLACE} arguments) from files in the current working directory.
598 To execute this command without errors, both the file, and the module in
599 the current archive, must exist.
600
601 Requires prior use of @code{OPEN} or @code{CREATE}.
602
603 @item VERBOSE
604 Toggle an internal flag governing the output from @code{DIRECTORY}.
605 When the flag is on, @code{DIRECTORY} output matches output from
606 @samp{ar -tv }@dots{}.
607
608 @item SAVE
609 Commit your changes to the current archive, and actually save it as a
610 file with the name specified in the last @code{CREATE} or @code{OPEN}
611 command.
612
613 Requires prior use of @code{OPEN} or @code{CREATE}.
614
615 @end table
616
617 @iftex
618 @node ld
619 @chapter ld
620 @cindex linker
621 @kindex ld
622 The @sc{gnu} linker @code{ld} is now described in a separate manual.
623 @xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
624 @end iftex
625
626 @node nm
627 @chapter nm
628 @cindex symbols
629 @kindex nm
630
631 @smallexample
632 nm [ -a | --debug-syms ] [ -g | --extern-only ]
633 [ -B ] [ -C | --demangle ] [ -D | --dynamic ]
634 [ -s | --print-armap ] [ -A | -o | --print-file-name ]
635 [ -n | -v | --numeric-sort ] [ -p | --no-sort ]
636 [ -r | --reverse-sort ] [ --size-sort ] [ -u | --undefined-only ]
637 [ -t @var{radix} | --radix=@var{radix} ] [ -P | --portability ]
638 [ --target=@var{bfdname} ] [ -f @var{format} | --format=@var{format} ]
639 [ --defined-only ] [-l | --line-numbers ]
640 [ --no-demangle ] [ -V | --version ] [ --help ] [ @var{objfile}@dots{} ]
641 @end smallexample
642
643 @sc{gnu} @code{nm} lists the symbols from object files @var{objfile}@dots{}.
644 If no object files are listed as arguments, @code{nm} assumes the file
645 @file{a.out}.
646
647 For each symbol, @code{nm} shows:
648
649 @itemize @bullet
650 @item
651 The symbol value, in the radix selected by options (see below), or
652 hexadecimal by default.
653
654 @item
655 The symbol type. At least the following types are used; others are, as
656 well, depending on the object file format. If lowercase, the symbol is
657 local; if uppercase, the symbol is global (external).
658
659 @c Some more detail on exactly what these symbol types are used for
660 @c would be nice.
661 @table @code
662 @item A
663 The symbol's value is absolute, and will not be changed by further
664 linking.
665
666 @item B
667 The symbol is in the uninitialized data section (known as BSS).
668
669 @item C
670 The symbol is common. Common symbols are uninitialized data. When
671 linking, multiple common symbols may appear with the same name. If the
672 symbol is defined anywhere, the common symbols are treated as undefined
673 references. For more details on common symbols, see the discussion of
674 --warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
675
676 @item D
677 The symbol is in the initialized data section.
678
679 @item G
680 The symbol is in an initialized data section for small objects. Some
681 object file formats permit more efficient access to small data objects,
682 such as a global int variable as opposed to a large global array.
683
684 @item I
685 The symbol is an indirect reference to another symbol. This is a GNU
686 extension to the a.out object file format which is rarely used.
687
688 @item N
689 The symbol is a debugging symbol.
690
691 @item R
692 The symbol is in a read only data section.
693
694 @item S
695 The symbol is in an uninitialized data section for small objects.
696
697 @item T
698 The symbol is in the text (code) section.
699
700 @item U
701 The symbol is undefined.
702
703 @item V
704 The symbol is a weak object. When a weak defined symbol is linked with
705 a normal defined symbol, the normal defined symbol is used with no error.
706 When a weak undefined symbol is linked and the symbol is not defined,
707 the value of the weak symbol becomes zero with no error.
708
709 @item W
710 The symbol is a weak symbol that has not been specifically tagged as a
711 weak object symbol. When a weak defined symbol is linked with a normal
712 defined symbol, the normal defined symbol is used with no error.
713 When a weak undefined symbol is linked and the symbol is not defined,
714 the value of the weak symbol becomes zero with no error.
715
716 @item -
717 The symbol is a stabs symbol in an a.out object file. In this case, the
718 next values printed are the stabs other field, the stabs desc field, and
719 the stab type. Stabs symbols are used to hold debugging information;
720 for more information, see @ref{Top,Stabs,Stabs Overview,stabs.info, The
721 ``stabs'' debug format}.
722
723 @item ?
724 The symbol type is unknown, or object file format specific.
725 @end table
726
727 @item
728 The symbol name.
729 @end itemize
730
731 The long and short forms of options, shown here as alternatives, are
732 equivalent.
733
734 @table @code
735 @item -A
736 @itemx -o
737 @itemx --print-file-name
738 @cindex input file name
739 @cindex file name
740 @cindex source file name
741 Precede each symbol by the name of the input file (or archive member)
742 in which it was found, rather than identifying the input file once only,
743 before all of its symbols.
744
745 @item -a
746 @itemx --debug-syms
747 @cindex debugging symbols
748 Display all symbols, even debugger-only symbols; normally these are not
749 listed.
750
751 @item -B
752 @cindex @code{nm} format
753 @cindex @code{nm} compatibility
754 The same as @samp{--format=bsd} (for compatibility with the MIPS @code{nm}).
755
756 @item -C
757 @itemx --demangle
758 @cindex demangling in nm
759 Decode (@dfn{demangle}) low-level symbol names into user-level names.
760 Besides removing any initial underscore prepended by the system, this
761 makes C++ function names readable. @xref{c++filt}, for more information
762 on demangling.
763
764 @item --no-demangle
765 Do not demangle low-level symbol names. This is the default.
766
767 @item -D
768 @itemx --dynamic
769 @cindex dynamic symbols
770 Display the dynamic symbols rather than the normal symbols. This is
771 only meaningful for dynamic objects, such as certain types of shared
772 libraries.
773
774 @item -f @var{format}
775 @itemx --format=@var{format}
776 @cindex @code{nm} format
777 @cindex @code{nm} compatibility
778 Use the output format @var{format}, which can be @code{bsd},
779 @code{sysv}, or @code{posix}. The default is @code{bsd}.
780 Only the first character of @var{format} is significant; it can be
781 either upper or lower case.
782
783 @item -g
784 @itemx --extern-only
785 @cindex external symbols
786 Display only external symbols.
787
788 @item -l
789 @itemx --line-numbers
790 @cindex symbol line numbers
791 For each symbol, use debugging information to try to find a filename and
792 line number. For a defined symbol, look for the line number of the
793 address of the symbol. For an undefined symbol, look for the line
794 number of a relocation entry which refers to the symbol. If line number
795 information can be found, print it after the other symbol information.
796
797 @item -n
798 @itemx -v
799 @itemx --numeric-sort
800 Sort symbols numerically by their addresses, rather than alphabetically
801 by their names.
802
803 @item -p
804 @itemx --no-sort
805 @cindex sorting symbols
806 Do not bother to sort the symbols in any order; print them in the order
807 encountered.
808
809 @item -P
810 @itemx --portability
811 Use the POSIX.2 standard output format instead of the default format.
812 Equivalent to @samp{-f posix}.
813
814 @item -s
815 @itemx --print-armap
816 @cindex symbol index, listing
817 When listing symbols from archive members, include the index: a mapping
818 (stored in the archive by @code{ar} or @code{ranlib}) of which modules
819 contain definitions for which names.
820
821 @item -r
822 @itemx --reverse-sort
823 Reverse the order of the sort (whether numeric or alphabetic); let the
824 last come first.
825
826 @item --size-sort
827 Sort symbols by size. The size is computed as the difference between
828 the value of the symbol and the value of the symbol with the next higher
829 value. The size of the symbol is printed, rather than the value.
830
831 @item -t @var{radix}
832 @itemx --radix=@var{radix}
833 Use @var{radix} as the radix for printing the symbol values. It must be
834 @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
835
836 @item --target=@var{bfdname}
837 @cindex object code format
838 Specify an object code format other than your system's default format.
839 @xref{Target Selection}, for more information.
840
841 @item -u
842 @itemx --undefined-only
843 @cindex external symbols
844 @cindex undefined symbols
845 Display only undefined symbols (those external to each object file).
846
847 @item --defined-only
848 @cindex external symbols
849 @cindex undefined symbols
850 Display only defined symbols for each object file.
851
852 @item -V
853 @itemx --version
854 Show the version number of @code{nm} and exit.
855
856 @item --help
857 Show a summary of the options to @code{nm} and exit.
858 @end table
859
860 @node objcopy
861 @chapter objcopy
862
863 @smallexample
864 objcopy [ -F @var{bfdname} | --target=@var{bfdname} ]
865 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
866 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
867 [ -S | --strip-all ] [ -g | --strip-debug ]
868 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
869 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
870 [ -L @var{symbolname} | --localize-symbol=@var{symbolname} ]
871 [ -W @var{symbolname} | --weaken-symbol=@var{symbolname} ]
872 [ -x | --discard-all ] [ -X | --discard-locals ]
873 [ -b @var{byte} | --byte=@var{byte} ]
874 [ -i @var{interleave} | --interleave=@var{interleave} ]
875 [ -j @var{sectionname} | --only-section=@var{sectionname} ]
876 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
877 [ -p | --preserve-dates ] [ --debugging ]
878 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
879 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
880 [ --change-addresses=@var{incr} ]
881 [ --change-section-address @var{section}@{=,+,-@}@var{val} ]
882 [ --change-section-lma @var{section}@{=,+,-@}@var{val} ]
883 [ --change-section-vma @var{section}@{=,+,-@}@var{val} ]
884 [ --change-warnings ] [ --no-change-warnings ]
885 [ --set-section-flags @var{section}=@var{flags} ]
886 [ --add-section @var{sectionname}=@var{filename} ]
887 [ --change-leading-char ] [ --remove-leading-char ]
888 [ --redefine-sym @var{old}=@var{new} ] [ --weaken ]
889 [ -v | --verbose ] [ -V | --version ] [ --help ]
890 @var{infile} [@var{outfile}]
891 @end smallexample
892
893 The @sc{gnu} @code{objcopy} utility copies the contents of an object
894 file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
895 read and write the object files. It can write the destination object
896 file in a format different from that of the source object file. The
897 exact behavior of @code{objcopy} is controlled by command-line options.
898
899 @code{objcopy} creates temporary files to do its translations and
900 deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
901 translation work; it has access to all the formats described in @sc{bfd}
902 and thus is able to recognize most formats without being told
903 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
904
905 @code{objcopy} can be used to generate S-records by using an output
906 target of @samp{srec} (e.g., use @samp{-O srec}).
907
908 @code{objcopy} can be used to generate a raw binary file by using an
909 output target of @samp{binary} (e.g., use @samp{-O binary}). When
910 @code{objcopy} generates a raw binary file, it will essentially produce
911 a memory dump of the contents of the input object file. All symbols and
912 relocation information will be discarded. The memory dump will start at
913 the load address of the lowest section copied into the output file.
914
915 When generating an S-record or a raw binary file, it may be helpful to
916 use @samp{-S} to remove sections containing debugging information. In
917 some cases @samp{-R} will be useful to remove sections which contain
918 information that is not needed by the binary file.
919
920 @table @code
921 @item @var{infile}
922 @itemx @var{outfile}
923 The input and output files, respectively.
924 If you do not specify @var{outfile}, @code{objcopy} creates a
925 temporary file and destructively renames the result with
926 the name of @var{infile}.
927
928 @item -I @var{bfdname}
929 @itemx --input-target=@var{bfdname}
930 Consider the source file's object format to be @var{bfdname}, rather than
931 attempting to deduce it. @xref{Target Selection}, for more information.
932
933 @item -O @var{bfdname}
934 @itemx --output-target=@var{bfdname}
935 Write the output file using the object format @var{bfdname}.
936 @xref{Target Selection}, for more information.
937
938 @item -F @var{bfdname}
939 @itemx --target=@var{bfdname}
940 Use @var{bfdname} as the object format for both the input and the output
941 file; i.e., simply transfer data from source to destination with no
942 translation. @xref{Target Selection}, for more information.
943
944 @item -j @var{sectionname}
945 @itemx --only-section=@var{sectionname}
946 Copy only the named section from the input file to the output file.
947 This option may be given more than once. Note that using this option
948 inappropriately may make the output file unusable.
949
950 @item -R @var{sectionname}
951 @itemx --remove-section=@var{sectionname}
952 Remove any section named @var{sectionname} from the output file. This
953 option may be given more than once. Note that using this option
954 inappropriately may make the output file unusable.
955
956 @item -S
957 @itemx --strip-all
958 Do not copy relocation and symbol information from the source file.
959
960 @item -g
961 @itemx --strip-debug
962 Do not copy debugging symbols from the source file.
963
964 @item --strip-unneeded
965 Strip all symbols that are not needed for relocation processing.
966
967 @item -K @var{symbolname}
968 @itemx --keep-symbol=@var{symbolname}
969 Copy only symbol @var{symbolname} from the source file. This option may
970 be given more than once.
971
972 @item -N @var{symbolname}
973 @itemx --strip-symbol=@var{symbolname}
974 Do not copy symbol @var{symbolname} from the source file. This option
975 may be given more than once.
976
977 @item -L @var{symbolname}
978 @itemx --localize-symbol=@var{symbolname}
979 Make symbol @var{symbolname} local to the file, so that it is not
980 visible externally. This option may be given more than once.
981
982 @item -W @var{symbolname}
983 @itemx --weaken-symbol=@var{symbolname}
984 Make symbol @var{symbolname} weak. This option may be given more than once.
985
986 @item -x
987 @itemx --discard-all
988 Do not copy non-global symbols from the source file.
989 @c FIXME any reason to prefer "non-global" to "local" here?
990
991 @item -X
992 @itemx --discard-locals
993 Do not copy compiler-generated local symbols.
994 (These usually start with @samp{L} or @samp{.}.)
995
996 @item -b @var{byte}
997 @itemx --byte=@var{byte}
998 Keep only every @var{byte}th byte of the input file (header data is not
999 affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
1000 where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
1001 option, or the default of 4. This option is useful for creating files
1002 to program @sc{rom}. It is typically used with an @code{srec} output
1003 target.
1004
1005 @item -i @var{interleave}
1006 @itemx --interleave=@var{interleave}
1007 Only copy one out of every @var{interleave} bytes. Select which byte to
1008 copy with the @var{-b} or @samp{--byte} option. The default is 4.
1009 @code{objcopy} ignores this option if you do not specify either @samp{-b} or
1010 @samp{--byte}.
1011
1012 @item -p
1013 @itemx --preserve-dates
1014 Set the access and modification dates of the output file to be the same
1015 as those of the input file.
1016
1017 @item --debugging
1018 Convert debugging information, if possible. This is not the default
1019 because only certain debugging formats are supported, and the
1020 conversion process can be time consuming.
1021
1022 @item --gap-fill @var{val}
1023 Fill gaps between sections with @var{val}. This operation applies to
1024 the @emph{load address} (LMA) of the sections. It is done by increasing
1025 the size of the section with the lower address, and filling in the extra
1026 space created with @var{val}.
1027
1028 @item --pad-to @var{address}
1029 Pad the output file up to the load address @var{address}. This is
1030 done by increasing the size of the last section. The extra space is
1031 filled in with the value specified by @samp{--gap-fill} (default zero).
1032
1033 @item --set-start @var{val}
1034 Set the start address of the new file to @var{val}. Not all object file
1035 formats support setting the start address.
1036
1037 @item --change-start @var{incr}
1038 @itemx --adjust-start @var{incr}
1039 @cindex changing start address
1040 Change the start address by adding @var{incr}. Not all object file
1041 formats support setting the start address.
1042
1043 @item --change-addresses @var{incr}
1044 @itemx --adjust-vma @var{incr}
1045 @cindex changing object addresses
1046 Change the VMA and LMA addresses of all sections, as well as the start
1047 address, by adding @var{incr}. Some object file formats do not permit
1048 section addresses to be changed arbitrarily. Note that this does not
1049 relocate the sections; if the program expects sections to be loaded at a
1050 certain address, and this option is used to change the sections such
1051 that they are loaded at a different address, the program may fail.
1052
1053 @item --change-section-address @var{section}@{=,+,-@}@var{val}
1054 @itemx --adjust-section-vma @var{section}@{=,+,-@}@var{val}
1055 @cindex changing section address
1056 Set or change both the VMA address and the LMA address of the named
1057 @var{section}. If @samp{=} is used, the section address is set to
1058 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1059 section address. See the comments under @samp{--change-addresses},
1060 above. If @var{section} does not exist in the input file, a warning will
1061 be issued, unless @samp{--no-change-warnings} is used.
1062
1063 @item --change-section-lma @var{section}@{=,+,-@}@var{val}
1064 @cindex changing section LMA
1065 Set or change the LMA address of the named @var{section}. The LMA
1066 address is the address where the section will be loaded into memory at
1067 program load time. Normally this is the same as the VMA address, which
1068 is the address of the section at program run time, but on some systems,
1069 especially those where a program is held in ROM, the two can be
1070 different. If @samp{=} is used, the section address is set to
1071 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1072 section address. See the comments under @samp{--change-addresses},
1073 above. If @var{section} does not exist in the input file, a warning
1074 will be issued, unless @samp{--no-change-warnings} is used.
1075
1076 @item --change-section-vma @var{section}@{=,+,-@}@var{val}
1077 @cindex changing section VMA
1078 Set or change the VMA address of the named @var{section}. The VMA
1079 address is the address where the section will be located once the
1080 program has started executing. Normally this is the same as the LMA
1081 address, which is the address where the section will be loaded into
1082 memory, but on some systems, especially those where a program is held in
1083 ROM, the two can be different. If @samp{=} is used, the section address
1084 is set to @var{val}. Otherwise, @var{val} is added to or subtracted
1085 from the section address. See the comments under
1086 @samp{--change-addresses}, above. If @var{section} does not exist in
1087 the input file, a warning will be issued, unless
1088 @samp{--no-change-warnings} is used.
1089
1090 @item --change-warnings
1091 @itemx --adjust-warnings
1092 If @samp{--change-section-address} or @samp{--change-section-lma} or
1093 @samp{--change-section-vma} is used, and the named section does not
1094 exist, issue a warning. This is the default.
1095
1096 @item --no-change-warnings
1097 @itemx --no-adjust-warnings
1098 Do not issue a warning if @samp{--change-section-address} or
1099 @samp{--adjust-section-lma} or @samp{--adjust-section-vma} is used, even
1100 if the named section does not exist.
1101
1102 @item --set-section-flags @var{section}=@var{flags}
1103 Set the flags for the named section. The @var{flags} argument is a
1104 comma separated string of flag names. The recognized names are
1105 @samp{alloc}, @samp{contents}, @samp{load}, @samp{noload},
1106 @samp{readonly}, @samp{code}, @samp{data}, @samp{rom}, @samp{share}, and
1107 @samp{debug}. You can set the @samp{contents} flag for a section which
1108 does not have contents, but it is not meaningful to clear the
1109 @samp{contents} flag of a section which does have contents--just remove
1110 the section instead. Not all flags are meaningful for all object file
1111 formats.
1112
1113 @item --add-section @var{sectionname}=@var{filename}
1114 Add a new section named @var{sectionname} while copying the file. The
1115 contents of the new section are taken from the file @var{filename}. The
1116 size of the section will be the size of the file. This option only
1117 works on file formats which can support sections with arbitrary names.
1118
1119 @item --change-leading-char
1120 Some object file formats use special characters at the start of
1121 symbols. The most common such character is underscore, which compilers
1122 often add before every symbol. This option tells @code{objcopy} to
1123 change the leading character of every symbol when it converts between
1124 object file formats. If the object file formats use the same leading
1125 character, this option has no effect. Otherwise, it will add a
1126 character, or remove a character, or change a character, as
1127 appropriate.
1128
1129 @item --remove-leading-char
1130 If the first character of a global symbol is a special symbol leading
1131 character used by the object file format, remove the character. The
1132 most common symbol leading character is underscore. This option will
1133 remove a leading underscore from all global symbols. This can be useful
1134 if you want to link together objects of different file formats with
1135 different conventions for symbol names. This is different from
1136 @code{--change-leading-char} because it always changes the symbol name
1137 when appropriate, regardless of the object file format of the output
1138 file.
1139
1140 @item --redefine-sym @var{old}=@var{new}
1141 Change the name of a symbol @var{old}, to @var{new}. This can be useful
1142 when one is trying link two things together for which you have no
1143 source, and there are name collisions.
1144
1145 @item --weaken
1146 Change all global symbols in the file to be weak. This can be useful
1147 when building an object which will be linked against other objects using
1148 the @code{-R} option to the linker. This option is only effective when
1149 using an object file format which supports weak symbols.
1150
1151 @item -V
1152 @itemx --version
1153 Show the version number of @code{objcopy}.
1154
1155 @item -v
1156 @itemx --verbose
1157 Verbose output: list all object files modified. In the case of
1158 archives, @samp{objcopy -V} lists all members of the archive.
1159
1160 @item --help
1161 Show a summary of the options to @code{objcopy}.
1162 @end table
1163
1164 @node objdump
1165 @chapter objdump
1166
1167 @cindex object file information
1168 @kindex objdump
1169
1170 @smallexample
1171 objdump [ -a | --archive-headers ]
1172 [ -b @var{bfdname} | --target=@var{bfdname} ]
1173 [ -C | --demangle ]
1174 [ -d | --disassemble ]
1175 [ -D | --disassemble-all ]
1176 [ -z | --disassemble-zeroes ]
1177 [ -EB | -EL | --endian=@{big | little @} ]
1178 [ -f | --file-headers ]
1179 [ --file-start-context ]
1180 [ -g | --debugging ]
1181 [ -h | --section-headers | --headers ]
1182 [ -i | --info ]
1183 [ -j @var{section} | --section=@var{section} ]
1184 [ -l | --line-numbers ]
1185 [ -S | --source ]
1186 [ -m @var{machine} | --architecture=@var{machine} ]
1187 [ -M @var{options} | --disassembler-options=@var{options}]
1188 [ -p | --private-headers ]
1189 [ -r | --reloc ]
1190 [ -R | --dynamic-reloc ]
1191 [ -s | --full-contents ]
1192 [ -G | --stabs ]
1193 [ -t | --syms ]
1194 [ -T | --dynamic-syms ]
1195 [ -x | --all-headers ]
1196 [ -w | --wide ]
1197 [ --start-address=@var{address} ]
1198 [ --stop-address=@var{address} ]
1199 [ --prefix-addresses]
1200 [ --[no-]show-raw-insn ]
1201 [ --adjust-vma=@var{offset} ]
1202 [ -V | --version ]
1203 [ -H | --help ]
1204 @var{objfile}@dots{}
1205 @end smallexample
1206
1207 @code{objdump} displays information about one or more object files.
1208 The options control what particular information to display. This
1209 information is mostly useful to programmers who are working on the
1210 compilation tools, as opposed to programmers who just want their
1211 program to compile and work.
1212
1213 @var{objfile}@dots{} are the object files to be examined. When you
1214 specify archives, @code{objdump} shows information on each of the member
1215 object files.
1216
1217 The long and short forms of options, shown here as alternatives, are
1218 equivalent. At least one option from the list
1219 @samp{-a,-d,-D,-f,-g,-G,-h,-H,-p,-r,-R,-S,-t,-T,-V,-x} must be given.
1220
1221 @table @code
1222 @item -a
1223 @itemx --archive-header
1224 @cindex archive headers
1225 If any of the @var{objfile} files are archives, display the archive
1226 header information (in a format similar to @samp{ls -l}). Besides the
1227 information you could list with @samp{ar tv}, @samp{objdump -a} shows
1228 the object file format of each archive member.
1229
1230 @item --adjust-vma=@var{offset}
1231 @cindex section addresses in objdump
1232 @cindex VMA in objdump
1233 When dumping information, first add @var{offset} to all the section
1234 addresses. This is useful if the section addresses do not correspond to
1235 the symbol table, which can happen when putting sections at particular
1236 addresses when using a format which can not represent section addresses,
1237 such as a.out.
1238
1239 @item -b @var{bfdname}
1240 @itemx --target=@var{bfdname}
1241 @cindex object code format
1242 Specify that the object-code format for the object files is
1243 @var{bfdname}. This option may not be necessary; @var{objdump} can
1244 automatically recognize many formats.
1245
1246 For example,
1247 @example
1248 objdump -b oasys -m vax -h fu.o
1249 @end example
1250 @noindent
1251 displays summary information from the section headers (@samp{-h}) of
1252 @file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1253 file in the format produced by Oasys compilers. You can list the
1254 formats available with the @samp{-i} option.
1255 @xref{Target Selection}, for more information.
1256
1257 @item -C
1258 @itemx --demangle
1259 @cindex demangling in objdump
1260 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1261 Besides removing any initial underscore prepended by the system, this
1262 makes C++ function names readable. @xref{c++filt}, for more information
1263 on demangling.
1264
1265 @item -G
1266 @item --debugging
1267 Display debugging information. This attempts to parse debugging
1268 information stored in the file and print it out using a C like syntax.
1269 Only certain types of debugging information have been implemented.
1270
1271 @item -d
1272 @itemx --disassemble
1273 @cindex disassembling object code
1274 @cindex machine instructions
1275 Display the assembler mnemonics for the machine instructions from
1276 @var{objfile}. This option only disassembles those sections which are
1277 expected to contain instructions.
1278
1279 @item -D
1280 @itemx --disassemble-all
1281 Like @samp{-d}, but disassemble the contents of all sections, not just
1282 those expected to contain instructions.
1283
1284 @item --prefix-addresses
1285 When disassembling, print the complete address on each line. This is
1286 the older disassembly format.
1287
1288 @item --disassemble-zeroes
1289 Normally the disassembly output will skip blocks of zeroes. This
1290 option directs the disassembler to disassemble those blocks, just like
1291 any other data.
1292
1293 @item -EB
1294 @itemx -EL
1295 @itemx --endian=@{big|little@}
1296 @cindex endianness
1297 @cindex disassembly endianness
1298 Specify the endianness of the object files. This only affects
1299 disassembly. This can be useful when disassembling a file format which
1300 does not describe endianness information, such as S-records.
1301
1302 @item -f
1303 @itemx --file-header
1304 @cindex object file header
1305 Display summary information from the overall header of
1306 each of the @var{objfile} files.
1307
1308 @item --file-start-context
1309 @cindex source code context
1310 Specify that when displaying interlisted source code/disassembly
1311 (assumes '-S') from a file that has not yet been displayed, extend the
1312 context to the start of the file.
1313
1314 @item -h
1315 @itemx --section-header
1316 @itemx --header
1317 @cindex section headers
1318 Display summary information from the section headers of the
1319 object file.
1320
1321 File segments may be relocated to nonstandard addresses, for example by
1322 using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1323 @code{ld}. However, some object file formats, such as a.out, do not
1324 store the starting address of the file segments. In those situations,
1325 although @code{ld} relocates the sections correctly, using @samp{objdump
1326 -h} to list the file section headers cannot show the correct addresses.
1327 Instead, it shows the usual addresses, which are implicit for the
1328 target.
1329
1330 @item --help
1331 Print a summary of the options to @code{objdump} and exit.
1332
1333 @item -i
1334 @itemx --info
1335 @cindex architectures available
1336 @cindex object formats available
1337 Display a list showing all architectures and object formats available
1338 for specification with @samp{-b} or @samp{-m}.
1339
1340 @item -j @var{name}
1341 @itemx --section=@var{name}
1342 @cindex section information
1343 Display information only for section @var{name}.
1344
1345 @item -l
1346 @itemx --line-numbers
1347 @cindex source filenames for object files
1348 Label the display (using debugging information) with the filename and
1349 source line numbers corresponding to the object code or relocs shown.
1350 Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1351
1352 @item -m @var{machine}
1353 @itemx --architecture=@var{machine}
1354 @cindex architecture
1355 @cindex disassembly architecture
1356 Specify the architecture to use when disassembling object files. This
1357 can be useful when disassembling object files which do not describe
1358 architecture information, such as S-records. You can list the available
1359 architectures with the @samp{-i} option.
1360
1361 @item -M @var{options}
1362 @itemx --disassembler-options=@var{options}
1363 Pass target specific information to the disassembler. Only supported on
1364 some targets.
1365
1366 If the target is an ARM architecture then this switch can be used to
1367 select which register name set is used during disassembler. Specifying
1368 @samp{-M reg-name-std} (the default) will select the register names as
1369 used in ARM's instruction set documentation, but with register 13 called
1370 'sp', register 14 called 'lr' and register 15 called 'pc'. Specifying
1371 @samp{-M reg-names-apcs} will select the name set used by the ARM
1372 Procedure Call Standard, whilst specifying @samp{-M reg-names-raw} will
1373 just use @samp{r} followed by the register number.
1374
1375 There are also two variants on the APCS register naming scheme enabled
1376 by @samp{-M reg-names-atpcs} and @samp{-M reg-names-special-atpcs} which
1377 use the ARM/Thumb Procedure Call Standard naming conventions. (Eiuther
1378 with the normal register name sor the special register names).
1379
1380 This option can also be used for ARM architectures to force the
1381 disassembler to interpret all instructions as THUMB instructions by
1382 using the switch @samp{--disassembler-options=force-thumb}. This can be
1383 useful when attempting to disassemble thumb code produced by other
1384 compilers.
1385
1386 @item -p
1387 @itemx --private-headers
1388 Print information that is specific to the object file format. The exact
1389 information printed depends upon the object file format. For some
1390 object file formats, no additional information is printed.
1391
1392 @item -r
1393 @itemx --reloc
1394 @cindex relocation entries, in object file
1395 Print the relocation entries of the file. If used with @samp{-d} or
1396 @samp{-D}, the relocations are printed interspersed with the
1397 disassembly.
1398
1399 @item -R
1400 @itemx --dynamic-reloc
1401 @cindex dynamic relocation entries, in object file
1402 Print the dynamic relocation entries of the file. This is only
1403 meaningful for dynamic objects, such as certain types of shared
1404 libraries.
1405
1406 @item -s
1407 @itemx --full-contents
1408 @cindex sections, full contents
1409 @cindex object file sections
1410 Display the full contents of any sections requested.
1411
1412 @item -S
1413 @itemx --source
1414 @cindex source disassembly
1415 @cindex disassembly, with source
1416 Display source code intermixed with disassembly, if possible. Implies
1417 @samp{-d}.
1418
1419 @item --show-raw-insn
1420 When disassembling instructions, print the instruction in hex as well as
1421 in symbolic form. This is the default except when
1422 @code{--prefix-addresses} is used.
1423
1424 @item --no-show-raw-insn
1425 When disassembling instructions, do not print the instruction bytes.
1426 This is the default when @code{--prefix-addresses} is used.
1427
1428 @item -G
1429 @item --stabs
1430 @cindex stab
1431 @cindex .stab
1432 @cindex debug symbols
1433 @cindex ELF object file format
1434 Display the full contents of any sections requested. Display the
1435 contents of the .stab and .stab.index and .stab.excl sections from an
1436 ELF file. This is only useful on systems (such as Solaris 2.0) in which
1437 @code{.stab} debugging symbol-table entries are carried in an ELF
1438 section. In most other file formats, debugging symbol-table entries are
1439 interleaved with linkage symbols, and are visible in the @samp{--syms}
1440 output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1441 Overview,stabs.info, The ``stabs'' debug format}.
1442
1443 @item --start-address=@var{address}
1444 @cindex start-address
1445 Start displaying data at the specified address. This affects the output
1446 of the @code{-d}, @code{-r} and @code{-s} options.
1447
1448 @item --stop-address=@var{address}
1449 @cindex stop-address
1450 Stop displaying data at the specified address. This affects the output
1451 of the @code{-d}, @code{-r} and @code{-s} options.
1452
1453 @item -t
1454 @itemx --syms
1455 @cindex symbol table entries, printing
1456 Print the symbol table entries of the file.
1457 This is similar to the information provided by the @samp{nm} program.
1458
1459 @item -T
1460 @itemx --dynamic-syms
1461 @cindex dynamic symbol table entries, printing
1462 Print the dynamic symbol table entries of the file. This is only
1463 meaningful for dynamic objects, such as certain types of shared
1464 libraries. This is similar to the information provided by the @samp{nm}
1465 program when given the @samp{-D} (@samp{--dynamic}) option.
1466
1467 @item --version
1468 Print the version number of @code{objdump} and exit.
1469
1470 @item -x
1471 @itemx --all-header
1472 @cindex all header information, object file
1473 @cindex header information, all
1474 Display all available header information, including the symbol table and
1475 relocation entries. Using @samp{-x} is equivalent to specifying all of
1476 @samp{-a -f -h -r -t}.
1477
1478 @item -w
1479 @itemx --wide
1480 @cindex wide output, printing
1481 Format some lines for output devices that have more than 80 columns.
1482 @end table
1483
1484 @node ranlib
1485 @chapter ranlib
1486
1487 @kindex ranlib
1488 @cindex archive contents
1489 @cindex symbol index
1490
1491 @smallexample
1492 ranlib [-vV] @var{archive}
1493 @end smallexample
1494
1495 @code{ranlib} generates an index to the contents of an archive and
1496 stores it in the archive. The index lists each symbol defined by a
1497 member of an archive that is a relocatable object file.
1498
1499 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1500
1501 An archive with such an index speeds up linking to the library and
1502 allows routines in the library to call each other without regard to
1503 their placement in the archive.
1504
1505 The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1506 @code{ranlib} is completely equivalent to executing @samp{ar -s}.
1507 @xref{ar}.
1508
1509 @table @code
1510 @item -v
1511 @itemx -V
1512 @itemx --version
1513 Show the version number of @code{ranlib}.
1514 @end table
1515
1516 @node size
1517 @chapter size
1518
1519 @kindex size
1520 @cindex section sizes
1521
1522 @smallexample
1523 size [ -A | -B | --format=@var{compatibility} ]
1524 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1525 [ --target=@var{bfdname} ] [ -V | --version ]
1526 [ @var{objfile}@dots{} ]
1527 @end smallexample
1528
1529 The @sc{gnu} @code{size} utility lists the section sizes---and the total
1530 size---for each of the object or archive files @var{objfile} in its
1531 argument list. By default, one line of output is generated for each
1532 object file or each module in an archive.
1533
1534 @var{objfile}@dots{} are the object files to be examined.
1535 If none are specified, the file @code{a.out} will be used.
1536
1537 The command line options have the following meanings:
1538
1539 @table @code
1540 @item -A
1541 @itemx -B
1542 @itemx --format=@var{compatibility}
1543 @cindex @code{size} display format
1544 Using one of these options, you can choose whether the output from @sc{gnu}
1545 @code{size} resembles output from System V @code{size} (using @samp{-A},
1546 or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1547 @samp{--format=berkeley}). The default is the one-line format similar to
1548 Berkeley's.
1549 @c Bonus for doc-source readers: you can also say --format=strange (or
1550 @c anything else that starts with 's') for sysv, and --format=boring (or
1551 @c anything else that starts with 'b') for Berkeley.
1552
1553 Here is an example of the Berkeley (default) format of output from
1554 @code{size}:
1555 @smallexample
1556 $ size --format=Berkeley ranlib size
1557 text data bss dec hex filename
1558 294880 81920 11592 388392 5ed28 ranlib
1559 294880 81920 11888 388688 5ee50 size
1560 @end smallexample
1561
1562 @noindent
1563 This is the same data, but displayed closer to System V conventions:
1564
1565 @smallexample
1566 $ size --format=SysV ranlib size
1567 ranlib :
1568 section size addr
1569 .text 294880 8192
1570 .data 81920 303104
1571 .bss 11592 385024
1572 Total 388392
1573
1574
1575 size :
1576 section size addr
1577 .text 294880 8192
1578 .data 81920 303104
1579 .bss 11888 385024
1580 Total 388688
1581 @end smallexample
1582
1583 @item --help
1584 Show a summary of acceptable arguments and options.
1585
1586 @item -d
1587 @itemx -o
1588 @itemx -x
1589 @itemx --radix=@var{number}
1590 @cindex @code{size} number format
1591 @cindex radix for section sizes
1592 Using one of these options, you can control whether the size of each
1593 section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1594 (@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1595 @samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1596 values (8, 10, 16) are supported. The total size is always given in two
1597 radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1598 octal and hexadecimal if you're using @samp{-o}.
1599
1600 @item --target=@var{bfdname}
1601 @cindex object code format
1602 Specify that the object-code format for @var{objfile} is
1603 @var{bfdname}. This option may not be necessary; @code{size} can
1604 automatically recognize many formats.
1605 @xref{Target Selection}, for more information.
1606
1607 @item -V
1608 @itemx --version
1609 Display the version number of @code{size}.
1610 @end table
1611
1612 @node strings
1613 @chapter strings
1614 @kindex strings
1615 @cindex listings strings
1616 @cindex printing strings
1617 @cindex strings, printing
1618
1619 @smallexample
1620 strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1621 [--all] [--print-file-name] [--bytes=@var{min-len}]
1622 [--radix=@var{radix}] [--target=@var{bfdname}]
1623 [--help] [--version] @var{file}@dots{}
1624 @end smallexample
1625
1626 For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1627 character sequences that are at least 4 characters long (or the number
1628 given with the options below) and are followed by an unprintable
1629 character. By default, it only prints the strings from the initialized
1630 and loaded sections of object files; for other types of files, it prints
1631 the strings from the whole file.
1632
1633 @code{strings} is mainly useful for determining the contents of non-text
1634 files.
1635
1636 @table @code
1637 @item -a
1638 @itemx --all
1639 @itemx -
1640 Do not scan only the initialized and loaded sections of object files;
1641 scan the whole files.
1642
1643 @item -f
1644 @itemx --print-file-name
1645 Print the name of the file before each string.
1646
1647 @item --help
1648 Print a summary of the program usage on the standard output and exit.
1649
1650 @item -@var{min-len}
1651 @itemx -n @var{min-len}
1652 @itemx --bytes=@var{min-len}
1653 Print sequences of characters that are at least @var{min-len} characters
1654 long, instead of the default 4.
1655
1656 @item -o
1657 Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1658 act like @samp{-t d} instead. Since we can not be compatible with both
1659 ways, we simply chose one.
1660
1661 @item -t @var{radix}
1662 @itemx --radix=@var{radix}
1663 Print the offset within the file before each string. The single
1664 character argument specifies the radix of the offset---@samp{o} for
1665 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1666
1667 @item --target=@var{bfdname}
1668 @cindex object code format
1669 Specify an object code format other than your system's default format.
1670 @xref{Target Selection}, for more information.
1671
1672 @item -v
1673 @itemx --version
1674 Print the program version number on the standard output and exit.
1675 @end table
1676
1677 @node strip
1678 @chapter strip
1679
1680 @kindex strip
1681 @cindex removing symbols
1682 @cindex discarding symbols
1683 @cindex symbols, discarding
1684
1685 @smallexample
1686 strip [ -F @var{bfdname} | --target=@var{bfdname} ]
1687 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1688 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1689 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1690 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1691 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1692 [ -x | --discard-all ] [ -X | --discard-locals ]
1693 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1694 [ -o @var{file} ] [ -p | --preserve-dates ]
1695 [ -v | --verbose ] [ -V | --version ] [ --help ]
1696 @var{objfile}@dots{}
1697 @end smallexample
1698
1699 @sc{gnu} @code{strip} discards all symbols from object files
1700 @var{objfile}. The list of object files may include archives.
1701 At least one object file must be given.
1702
1703 @code{strip} modifies the files named in its argument,
1704 rather than writing modified copies under different names.
1705
1706 @table @code
1707 @item -F @var{bfdname}
1708 @itemx --target=@var{bfdname}
1709 Treat the original @var{objfile} as a file with the object
1710 code format @var{bfdname}, and rewrite it in the same format.
1711 @xref{Target Selection}, for more information.
1712
1713 @item --help
1714 Show a summary of the options to @code{strip} and exit.
1715
1716 @item -I @var{bfdname}
1717 @itemx --input-target=@var{bfdname}
1718 Treat the original @var{objfile} as a file with the object
1719 code format @var{bfdname}.
1720 @xref{Target Selection}, for more information.
1721
1722 @item -O @var{bfdname}
1723 @itemx --output-target=@var{bfdname}
1724 Replace @var{objfile} with a file in the output format @var{bfdname}.
1725 @xref{Target Selection}, for more information.
1726
1727 @item -R @var{sectionname}
1728 @itemx --remove-section=@var{sectionname}
1729 Remove any section named @var{sectionname} from the output file. This
1730 option may be given more than once. Note that using this option
1731 inappropriately may make the output file unusable.
1732
1733 @item -s
1734 @itemx --strip-all
1735 Remove all symbols.
1736
1737 @item -g
1738 @itemx -S
1739 @itemx --strip-debug
1740 Remove debugging symbols only.
1741
1742 @item --strip-unneeded
1743 Remove all symbols that are not needed for relocation processing.
1744
1745 @item -K @var{symbolname}
1746 @itemx --keep-symbol=@var{symbolname}
1747 Keep only symbol @var{symbolname} from the source file. This option may
1748 be given more than once.
1749
1750 @item -N @var{symbolname}
1751 @itemx --strip-symbol=@var{symbolname}
1752 Remove symbol @var{symbolname} from the source file. This option may be
1753 given more than once, and may be combined with strip options other than
1754 @code{-K}.
1755
1756 @item -o @var{file}
1757 Put the stripped output in @var{file}, rather than replacing the
1758 existing file. When this argument is used, only one @var{objfile}
1759 argument may be specified.
1760
1761 @item -p
1762 @itemx --preserve-dates
1763 Preserve the access and modification dates of the file.
1764
1765 @item -x
1766 @itemx --discard-all
1767 Remove non-global symbols.
1768
1769 @item -X
1770 @itemx --discard-locals
1771 Remove compiler-generated local symbols.
1772 (These usually start with @samp{L} or @samp{.}.)
1773
1774 @item -V
1775 @itemx --version
1776 Show the version number for @code{strip}.
1777
1778 @item -v
1779 @itemx --verbose
1780 Verbose output: list all object files modified. In the case of
1781 archives, @samp{strip -v} lists all members of the archive.
1782 @end table
1783
1784 @node c++filt, addr2line, strip, Top
1785 @chapter c++filt
1786
1787 @kindex c++filt
1788 @cindex demangling C++ symbols
1789
1790 @smallexample
1791 c++filt [ -_ | --strip-underscores ]
1792 [ -j | --java ]
1793 [ -n | --no-strip-underscores ]
1794 [ -s @var{format} | --format=@var{format} ]
1795 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1796 @end smallexample
1797
1798 @kindex cxxfilt
1799 The C++ and Java languages provides function overloading, which means
1800 that you can write many functions with the same name (providing each
1801 takes parameters of different types). All C++ and Java function names
1802 are encoded into a low-level assembly label (this process is known as
1803 @dfn{mangling}). The @code{c++filt}
1804 @footnote{MS-DOS does not allow @kbd{+} characters in file names, so on
1805 MS-DOS this program is named @code{cxxfilt}.}
1806 program does the inverse mapping: it decodes (@dfn{demangles}) low-level
1807 names into user-level names so that the linker can keep these overloaded
1808 functions from clashing.
1809
1810 Every alphanumeric word (consisting of letters, digits, underscores,
1811 dollars, or periods) seen in the input is a potential label. If the
1812 label decodes into a C++ name, the C++ name replaces the low-level
1813 name in the output.
1814
1815 You can use @code{c++filt} to decipher individual symbols:
1816
1817 @example
1818 c++filt @var{symbol}
1819 @end example
1820
1821 If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1822 names from the standard input and writes the demangled names to the
1823 standard output. All results are printed on the standard output.
1824
1825 @table @code
1826 @item -_
1827 @itemx --strip-underscores
1828 On some systems, both the C and C++ compilers put an underscore in front
1829 of every name. For example, the C name @code{foo} gets the low-level
1830 name @code{_foo}. This option removes the initial underscore. Whether
1831 @code{c++filt} removes the underscore by default is target dependent.
1832
1833 @item -j
1834 @itemx --java
1835 Prints demangled names using Java syntax. The default is to use C++
1836 syntax.
1837
1838 @item -n
1839 @itemx --no-strip-underscores
1840 Do not remove the initial underscore.
1841
1842 @item -s @var{format}
1843 @itemx --format=@var{format}
1844 @sc{gnu} @code{nm} can decode three different methods of mangling, used by
1845 different C++ compilers. The argument to this option selects which
1846 method it uses:
1847
1848 @table @code
1849 @item gnu
1850 the one used by the @sc{gnu} compiler (the default method)
1851 @item lucid
1852 the one used by the Lucid compiler
1853 @item arm
1854 the one specified by the C++ Annotated Reference Manual
1855 @item hp
1856 the one used by the HP compiler
1857 @item edg
1858 the one used by the EDG compiler
1859 @end table
1860
1861 @item --help
1862 Print a summary of the options to @code{c++filt} and exit.
1863
1864 @item --version
1865 Print the version number of @code{c++filt} and exit.
1866 @end table
1867
1868 @quotation
1869 @emph{Warning:} @code{c++filt} is a new utility, and the details of its
1870 user interface are subject to change in future releases. In particular,
1871 a command-line option may be required in the the future to decode a name
1872 passed as an argument on the command line; in other words,
1873
1874 @example
1875 c++filt @var{symbol}
1876 @end example
1877
1878 @noindent
1879 may in a future release become
1880
1881 @example
1882 c++filt @var{option} @var{symbol}
1883 @end example
1884 @end quotation
1885
1886 @node addr2line
1887 @chapter addr2line
1888
1889 @kindex addr2line
1890 @cindex address to file name and line number
1891
1892 @smallexample
1893 addr2line [ -b @var{bfdname} | --target=@var{bfdname} ]
1894 [ -C | --demangle ]
1895 [ -e @var{filename} | --exe=@var{filename} ]
1896 [ -f | --functions ] [ -s | --basename ]
1897 [ -H | --help ] [ -V | --version ]
1898 [ addr addr ... ]
1899 @end smallexample
1900
1901 @code{addr2line} translates program addresses into file names and line
1902 numbers. Given an address and an executable, it uses the debugging
1903 information in the executable to figure out which file name and line
1904 number are associated with a given address.
1905
1906 The executable to use is specified with the @code{-e} option. The
1907 default is the file @file{a.out}.
1908
1909 @code{addr2line} has two modes of operation.
1910
1911 In the first, hexadecimal addresses are specified on the command line,
1912 and @code{addr2line} displays the file name and line number for each
1913 address.
1914
1915 In the second, @code{addr2line} reads hexadecimal addresses from
1916 standard input, and prints the file name and line number for each
1917 address on standard output. In this mode, @code{addr2line} may be used
1918 in a pipe to convert dynamically chosen addresses.
1919
1920 The format of the output is @samp{FILENAME:LINENO}. The file name and
1921 line number for each address is printed on a separate line. If the
1922 @code{-f} option is used, then each @samp{FILENAME:LINENO} line is
1923 preceded by a @samp{FUNCTIONNAME} line which is the name of the function
1924 containing the address.
1925
1926 If the file name or function name can not be determined,
1927 @code{addr2line} will print two question marks in their place. If the
1928 line number can not be determined, @code{addr2line} will print 0.
1929
1930 The long and short forms of options, shown here as alternatives, are
1931 equivalent.
1932
1933 @table @code
1934 @item -b @var{bfdname}
1935 @itemx --target=@var{bfdname}
1936 @cindex object code format
1937 Specify that the object-code format for the object files is
1938 @var{bfdname}.
1939
1940 @item -C
1941 @itemx --demangle
1942 @cindex demangling in objdump
1943 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1944 Besides removing any initial underscore prepended by the system, this
1945 makes C++ function names readable. @xref{c++filt}, for more information
1946 on demangling.
1947
1948 @item -e @var{filename}
1949 @itemx --exe=@var{filename}
1950 Specify the name of the executable for which addresses should be
1951 translated. The default file is @file{a.out}.
1952
1953 @item -f
1954 @itemx --functions
1955 Display function names as well as file and line number information.
1956
1957 @item -s
1958 @itemx --basenames
1959 Display only the base of each file name.
1960 @end table
1961
1962 @node nlmconv
1963 @chapter nlmconv
1964
1965 @code{nlmconv} converts a relocatable object file into a NetWare
1966 Loadable Module.
1967
1968 @ignore
1969 @code{nlmconv} currently works with @samp{i386} object
1970 files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1971 object files in @sc{elf}, or @code{a.out} format@footnote{
1972 @code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1973 format in the Binary File Descriptor library. It has only been tested
1974 with the above formats.}.
1975 @end ignore
1976
1977 @quotation
1978 @emph{Warning:} @code{nlmconv} is not always built as part of the binary
1979 utilities, since it is only useful for NLM targets.
1980 @end quotation
1981
1982 @smallexample
1983 nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1984 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1985 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1986 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1987 [ -h | --help ] [ -V | --version ]
1988 @var{infile} @var{outfile}
1989 @end smallexample
1990
1991 @code{nlmconv} converts the relocatable @samp{i386} object file
1992 @var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1993 reading @var{headerfile} for NLM header information. For instructions
1994 on writing the NLM command file language used in header files, see the
1995 @samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1996 Development and Tools Overview}, which is part of the NLM Software
1997 Developer's Kit (``NLM SDK''), available from Novell, Inc.
1998 @code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1999 @var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
2000 more information.
2001
2002 @code{nlmconv} can perform a link step. In other words, you can list
2003 more than one object file for input if you list them in the definitions
2004 file (rather than simply specifying one input file on the command line).
2005 In this case, @code{nlmconv} calls the linker for you.
2006
2007 @table @code
2008 @item -I @var{bfdname}
2009 @itemx --input-target=@var{bfdname}
2010 Object format of the input file. @code{nlmconv} can usually determine
2011 the format of a given file (so no default is necessary).
2012 @xref{Target Selection}, for more information.
2013
2014 @item -O @var{bfdname}
2015 @itemx --output-target=@var{bfdname}
2016 Object format of the output file. @code{nlmconv} infers the output
2017 format based on the input format, e.g. for a @samp{i386} input file the
2018 output format is @samp{nlm32-i386}.
2019 @xref{Target Selection}, for more information.
2020
2021 @item -T @var{headerfile}
2022 @itemx --header-file=@var{headerfile}
2023 Reads @var{headerfile} for NLM header information. For instructions on
2024 writing the NLM command file language used in header files, see@ see the
2025 @samp{linkers} section, of the @cite{NLM Development and Tools
2026 Overview}, which is part of the NLM Software Developer's Kit, available
2027 from Novell, Inc.
2028
2029 @item -d
2030 @itemx --debug
2031 Displays (on standard error) the linker command line used by @code{nlmconv}.
2032
2033 @item -l @var{linker}
2034 @itemx --linker=@var{linker}
2035 Use @var{linker} for any linking. @var{linker} can be an absolute or a
2036 relative pathname.
2037
2038 @item -h
2039 @itemx --help
2040 Prints a usage summary.
2041
2042 @item -V
2043 @itemx --version
2044 Prints the version number for @code{nlmconv}.
2045 @end table
2046
2047 @node windres
2048 @chapter windres
2049
2050 @code{windres} may be used to manipulate Windows resources.
2051
2052 @quotation
2053 @emph{Warning:} @code{windres} is not always built as part of the binary
2054 utilities, since it is only useful for Windows targets.
2055 @end quotation
2056
2057 @smallexample
2058 windres [options] [input-file] [output-file]
2059 @end smallexample
2060
2061 @code{windres} reads resources from an input file and copies them into
2062 an output file. Either file may be in one of three formats:
2063
2064 @table @code
2065 @item rc
2066 A text format read by the Resource Compiler.
2067
2068 @item res
2069 A binary format generated by the Resource Compiler.
2070
2071 @item coff
2072 A COFF object or executable.
2073 @end table
2074
2075 The exact description of these different formats is available in
2076 documentation from Microsoft.
2077
2078 When @code{windres} converts from the @code{rc} format to the @code{res}
2079 format, it is acting like the Windows Resource Compiler. When
2080 @code{windres} converts from the @code{res} format to the @code{coff}
2081 format, it is acting like the Windows @code{CVTRES} program.
2082
2083 When @code{windres} generates an @code{rc} file, the output is similar
2084 but not identical to the format expected for the input. When an input
2085 @code{rc} file refers to an external filename, an output @code{rc} file
2086 will instead include the file contents.
2087
2088 If the input or output format is not specified, @code{windres} will
2089 guess based on the file name, or, for the input file, the file contents.
2090 A file with an extension of @file{.rc} will be treated as an @code{rc}
2091 file, a file with an extension of @file{.res} will be treated as a
2092 @code{res} file, and a file with an extension of @file{.o} or
2093 @file{.exe} will be treated as a @code{coff} file.
2094
2095 If no output file is specified, @code{windres} will print the resources
2096 in @code{rc} format to standard output.
2097
2098 The normal use is for you to write an @code{rc} file, use @code{windres}
2099 to convert it to a COFF object file, and then link the COFF file into
2100 your application. This will make the resources described in the
2101 @code{rc} file available to Windows.
2102
2103 @table @code
2104 @item -i @var{filename}
2105 @itemx --input @var{filename}
2106 The name of the input file. If this option is not used, then
2107 @code{windres} will use the first non-option argument as the input file
2108 name. If there are no non-option arguments, then @code{windres} will
2109 read from standard input. @code{windres} can not read a COFF file from
2110 standard input.
2111
2112 @item -o @var{filename}
2113 @itemx --output @var{filename}
2114 The name of the output file. If this option is not used, then
2115 @code{windres} will use the first non-option argument, after any used
2116 for the input file name, as the output file name. If there is no
2117 non-option argument, then @code{windres} will write to standard output.
2118 @code{windres} can not write a COFF file to standard output.
2119
2120 @item -I @var{format}
2121 @itemx --input-format @var{format}
2122 The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
2123 @samp{coff}. If no input format is specified, @code{windres} will
2124 guess, as described above.
2125
2126 @item -O @var{format}
2127 @itemx --output-format @var{format}
2128 The output format to generate. @var{format} may be @samp{res},
2129 @samp{rc}, or @samp{coff}. If no output format is specified,
2130 @code{windres} will guess, as described above.
2131
2132 @item -F @var{target}
2133 @itemx --target @var{target}
2134 Specify the BFD format to use for a COFF file as input or output. This
2135 is a BFD target name; you can use the @code{--help} option to see a list
2136 of supported targets. Normally @code{windres} will use the default
2137 format, which is the first one listed by the @code{--help} option.
2138 @ref{Target Selection}.
2139
2140 @item --preprocessor @var{program}
2141 When @code{windres} reads an @code{rc} file, it runs it through the C
2142 preprocessor first. This option may be used to specify the preprocessor
2143 to use, including any leading arguments. The default preprocessor
2144 argument is @code{gcc -E -xc-header -DRC_INVOKED}.
2145
2146 @item --include-dir @var{directory}
2147 Specify an include directory to use when reading an @code{rc} file.
2148 @code{windres} will pass this to the preprocessor as an @code{-I}
2149 option. @code{windres} will also search this directory when looking for
2150 files named in the @code{rc} file.
2151
2152 @item -D @var{target}
2153 @itemx --define @var{sym}[=@var{val}]
2154 Specify a @code{-D} option to pass to the preprocessor when reading an
2155 @code{rc} file.
2156
2157 @item -v
2158 Enable verbose mode. This tells you what the preprocessor is if you
2159 didn't specify one.
2160
2161 @item --language @var{val}
2162 Specify the default language to use when reading an @code{rc} file.
2163 @var{val} should be a hexadecimal language code. The low eight bits are
2164 the language, and the high eight bits are the sublanguage.
2165
2166 @item --use-temp-file
2167 Use a temporary file to instead of using popen to read the output of
2168 the preprocessor. Use this option if the popen implementation is buggy
2169 on the host (eg., certain non-English language versions of Windows 95 and
2170 Windows 98 are known to have buggy popen where the output will instead
2171 go the console).
2172
2173 @item --no-use-temp-file
2174 Use popen, not a temporary file, to read the output of the preprocessor.
2175 This is the default behaviour.
2176
2177 @item --help
2178 Prints a usage summary.
2179
2180 @item --version
2181 Prints the version number for @code{windres}.
2182
2183 @item --yydebug
2184 If @code{windres} is compiled with @code{YYDEBUG} defined as @code{1},
2185 this will turn on parser debugging.
2186 @end table
2187
2188
2189 @node dlltool
2190 @chapter Create files needed to build and use DLLs
2191 @cindex DLL
2192 @kindex dlltool
2193
2194 @code{dlltool} may be used to create the files needed to build and use
2195 dynamic link libraries (DLLs).
2196
2197 @quotation
2198 @emph{Warning:} @code{dlltool} is not always built as part of the binary
2199 utilities, since it is only useful for those targets which support DLLs.
2200 @end quotation
2201
2202 @smallexample
2203 dlltool [-d|--input-def @var{def-file-name}]
2204 [-b|--base-file @var{base-file-name}]
2205 [-e|--output-exp @var{exports-file-name}]
2206 [-z|--output-def @var{def-file-name}]
2207 [-l|--output-lib @var{library-file-name}]
2208 [--export-all-symbols] [--no-export-all-symbols]
2209 [--exclude-symbols @var{list}]
2210 [--no-default-excludes]
2211 [-S|--as @var{path-to-assembler}] [-f|--as-flags @var{options}]
2212 [-D|--dllname @var{name}] [-m|--machine @var{machine}]
2213 [-a|--add-indirect] [-U|--add-underscore] [-k|--kill-at]
2214 [-A|--add-stdcall-alias]
2215 [-x|--no-idata4] [-c|--no-idata5] [-i|--interwork]
2216 [-n|--nodelete] [-v|--verbose] [-h|--help] [-V|--version]
2217 [object-file @dots{}]
2218 @end smallexample
2219
2220 @code{dlltool} reads its inputs, which can come from the @samp{-d} and
2221 @samp{-b} options as well as object files specified on the command
2222 line. It then processes these inputs and if the @samp{-e} option has
2223 been specified it creates a exports file. If the @samp{-l} option
2224 has been specified it creates a library file and if the @samp{-z} option
2225 has been specified it creates a def file. Any or all of the -e, -l
2226 and -z options can be present in one invocation of dlltool.
2227
2228 When creating a DLL, along with the source for the DLL, it is necessary
2229 to have three other files. @code{dlltool} can help with the creation of
2230 these files.
2231
2232 The first file is a @samp{.def} file which specifies which functions are
2233 exported from the DLL, which functions the DLL imports, and so on. This
2234 is a text file and can be created by hand, or @code{dlltool} can be used
2235 to create it using the @samp{-z} option. In this case @code{dlltool}
2236 will scan the object files specified on its command line looking for
2237 those functions which have been specially marked as being exported and
2238 put entries for them in the .def file it creates.
2239
2240 In order to mark a function as being exported from a DLL, it needs to
2241 have an @samp{-export:<name_of_function>} entry in the @samp{.drectve}
2242 section of the object file. This can be done in C by using the
2243 asm() operator:
2244
2245 @smallexample
2246 asm (".section .drectve");
2247 asm (".ascii \"-export:my_func\"");
2248
2249 int my_func (void) @{ @dots{} @}
2250 @end smallexample
2251
2252 The second file needed for DLL creation is an exports file. This file
2253 is linked with the object files that make up the body of the DLL and it
2254 handles the interface between the DLL and the outside world. This is a
2255 binary file and it can be created by giving the @samp{-e} option to
2256 @code{dlltool} when it is creating or reading in a .def file.
2257
2258 The third file needed for DLL creation is the library file that programs
2259 will link with in order to access the functions in the DLL. This file
2260 can be created by giving the @samp{-l} option to dlltool when it
2261 is creating or reading in a .def file.
2262
2263 @code{dlltool} builds the library file by hand, but it builds the
2264 exports file by creating temporary files containing assembler statements
2265 and then assembling these. The @samp{-S} command line option can be
2266 used to specify the path to the assembler that dlltool will use,
2267 and the @samp{-f} option can be used to pass specific flags to that
2268 assembler. The @samp{-n} can be used to prevent dlltool from deleting
2269 these temporary assembler files when it is done, and if @samp{-n} is
2270 specified twice then this will prevent dlltool from deleting the
2271 temporary object files it used to build the library.
2272
2273 Here is an example of creating a DLL from a source file @samp{dll.c} and
2274 also creating a program (from an object file called @samp{program.o})
2275 that uses that DLL:
2276
2277 @smallexample
2278 gcc -c dll.c
2279 dlltool -e exports.o -l dll.lib dll.o
2280 gcc dll.o exports.o -o dll.dll
2281 gcc program.o dll.lib -o program
2282 @end smallexample
2283
2284 The command line options have the following meanings:
2285
2286 @table @code
2287
2288 @item -d @var{filename}
2289 @itemx --input-def @var{filename}
2290 @cindex input .def file
2291 Specifies the name of a .def file to be read in and processed.
2292
2293 @item -b @var{filename}
2294 @itemx --base-file @var{filename}
2295 @cindex base files
2296 Specifies the name of a base file to be read in and processed. The
2297 contents of this file will be added to the relocation section in the
2298 exports file generated by dlltool.
2299
2300 @item -e @var{filename}
2301 @itemx --output-exp @var{filename}
2302 Specifies the name of the export file to be created by dlltool.
2303
2304 @item -z @var{filename}
2305 @itemx --output-def @var{filename}
2306 Specifies the name of the .def file to be created by dlltool.
2307
2308 @item -l @var{filename}
2309 @itemx --output-lib @var{filename}
2310 Specifies the name of the library file to be created by dlltool.
2311
2312 @item --export-all-symbols
2313 Treat all global and weak defined symbols found in the input object
2314 files as symbols to be exported. There is a small list of symbols which
2315 are not exported by default; see the @code{--no-default-excludes}
2316 option. You may add to the list of symbols to not export by using the
2317 @code{--exclude-symbols} option.
2318
2319 @item --no-export-all-symbols
2320 Only export symbols explicitly listed in an input .def file or in
2321 @samp{.drectve} sections in the input object files. This is the default
2322 behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
2323 attributes in the source code.
2324
2325 @item --exclude-symbols @var{list}
2326 Do not export the symbols in @var{list}. This is a list of symbol names
2327 separated by comma or colon characters. The symbol names should not
2328 contain a leading underscore. This is only meaningful when
2329 @code{--export-all-symbols} is used.
2330
2331 @item --no-default-excludes
2332 When @code{--export-all-symbols} is used, it will by default avoid
2333 exporting certain special symbols. The current list of symbols to avoid
2334 exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
2335 @samp{impure_ptr}. You may use the @code{--no-default-excludes} option
2336 to go ahead and export these special symbols. This is only meaningful
2337 when @code{--export-all-symbols} is used.
2338
2339 @item -S @var{path}
2340 @itemx --as @var{path}
2341 Specifies the path, including the filename, of the assembler to be used
2342 to create the exports file.
2343
2344 @item -f @var{switches}
2345 @itemx --as-flags @var{switches}
2346 Specifies any specific command line switches to be passed to the
2347 assembler when building the exports file. This option will work even if
2348 the @samp{-S} option is not used. This option only takes one argument,
2349 and if it occurs more than once on the command line, then later
2350 occurrences will override earlier occurrences. So if it is necessary to
2351 pass multiple switches to the assembler they should be enclosed in
2352 double quotes.
2353
2354 @item -D @var{name}
2355 @itemx --dll-name @var{name}
2356 Specifies the name to be stored in the .def file as the name of the DLL
2357 when the @samp{-e} option is used. If this option is not present, then
2358 the filename given to the @samp{-e} option will be used as the name of
2359 the DLL.
2360
2361 @item -m @var{machine}
2362 @itemx -machine @var{machine}
2363 Specifies the type of machine for which the library file should be
2364 built. @code{dlltool} has a built in default type, depending upon how
2365 it was created, but this option can be used to override that. This is
2366 normally only useful when creating DLLs for an ARM processor, when the
2367 contents of the DLL are actually encode using THUMB instructions.
2368
2369 @item -a
2370 @itemx --add-indirect
2371 Specifies that when @code{dlltool} is creating the exports file it
2372 should add a section which allows the exported functions to be
2373 referenced without using the import library. Whatever the hell that
2374 means!
2375
2376 @item -U
2377 @itemx --add-underscore
2378 Specifies that when @code{dlltool} is creating the exports file it
2379 should prepend an underscore to the names of the exported functions.
2380
2381 @item -k
2382 @itemx --kill-at
2383 Specifies that when @code{dlltool} is creating the exports file it
2384 should not append the string @samp{@@ <number>}. These numbers are
2385 called ordinal numbers and they represent another way of accessing the
2386 function in a DLL, other than by name.
2387
2388 @item -A
2389 @itemx --add-stdcall-alias
2390 Specifies that when @code{dlltool} is creating the exports file it
2391 should add aliases for stdcall symbols without @samp{@@ <number>}
2392 in addition to the symbols with @samp{@@ <number>}.
2393
2394 @item -x
2395 @itemx --no-idata4
2396 Specifies that when @code{dlltool} is creating the exports and library
2397 files it should omit the .idata4 section. This is for compatibility
2398 with certain operating systems.
2399
2400 @item -c
2401 @itemx --no-idata5
2402 Specifies that when @code{dlltool} is creating the exports and library
2403 files it should omit the .idata5 section. This is for compatibility
2404 with certain operating systems.
2405
2406 @item -i
2407 @itemx --interwork
2408 Specifies that @code{dlltool} should mark the objects in the library
2409 file and exports file that it produces as supporting interworking
2410 between ARM and THUMB code.
2411
2412 @item -n
2413 @itemx --nodelete
2414 Makes @code{dlltool} preserve the temporary assembler files it used to
2415 create the exports file. If this option is repeated then dlltool will
2416 also preserve the temporary object files it uses to create the library
2417 file.
2418
2419 @item -v
2420 @itemx --verbose
2421 Make dlltool describe what it is doing.
2422
2423 @item -h
2424 @itemx --help
2425 Displays a list of command line options and then exits.
2426
2427 @item -V
2428 @itemx --version
2429 Displays dlltool's version number and then exits.
2430
2431 @end table
2432
2433 @node readelf
2434 @chapter readelf
2435
2436 @cindex ELF file information
2437 @kindex readelf
2438
2439 @smallexample
2440 readelf [ -a | --all ]
2441 [ -h | --file-header]
2442 [ -l | --program-headers | --segments]
2443 [ -S | --section-headers | --sections]
2444 [ -e | --headers]
2445 [ -s | --syms | --symbols]
2446 [ -n | --notes]
2447 [ -r | --relocs]
2448 [ -d | --dynamic]
2449 [ -V | --version-info]
2450 [ -D | --use-dynamic]
2451 [ -x <number> | --hex-dump=<number>]
2452 [ -w[liapr] | --debug-dump[=info,=line,=abbrev,=pubnames,=ranges]]
2453 [ --histogram]
2454 [ -v | --version]
2455 [ -H | --help]
2456 @var{elffile}@dots{}
2457 @end smallexample
2458
2459 @code{readelf} displays information about one or more ELF format object
2460 files. The options control what particular information to display.
2461
2462 @var{elffile}@dots{} are the object files to be examined. At the
2463 moment, @code{readelf} does not support examining archives, nor does it
2464 support examing 64 bit ELF files.
2465
2466 The long and short forms of options, shown here as alternatives, are
2467 equivalent. At least one option besides @samp{-v} or @samp{-H} must be
2468 given.
2469
2470 @table @code
2471 @item -a
2472 @itemx --all
2473 Equivalent to specifiying @samp{--file-header},
2474 @samp{--program-headers}, @samp{--sections}, @samp{--symbols},
2475 @samp{--relocs}, @samp{--dynamic}, @samp{--notes} and
2476 @samp{--version-info}.
2477
2478 @item -h
2479 @itemx --file-header
2480 @cindex ELF file header information
2481 Displays the information contained in the ELF header at the start of the
2482 file.
2483
2484 @item -l
2485 @itemx --program-headers
2486 @itemx --segments
2487 @cindex ELF program header information
2488 @cindex ELF segment information
2489 Displays the information contained in the file's segment headers, if it
2490 has any.
2491
2492 @item -S
2493 @itemx --sections
2494 @itemx --section-headers
2495 @cindex ELF section information
2496 Displays the information contained in the file's section headers, if it
2497 has any.
2498
2499 @item -s
2500 @itemx --symbols
2501 @itemx --syms
2502 @cindex ELF symbol table information
2503 Displays the entries in symbol table section of the file, if it has one.
2504
2505 @item -e
2506 @itemx --headers
2507 Display all the headers in the file. Equivalent to @samp{-h -l -S}.
2508
2509 @item -n
2510 @itemx --notes
2511 @cindex ELF core notes
2512 Displays the contents of the NOTE segment, if it exists.
2513
2514 @item -r
2515 @itemx --relocs
2516 @cindex ELF reloc information
2517 Displays the contents of the file's relocation section, if it ha one.
2518
2519 @item -d
2520 @itemx --dynamic
2521 @cindex ELF dynamic section information
2522 Displays the contents of the file's dynamic section, if it has one.
2523
2524 @item -V
2525 @itemx --version-info
2526 @cindex ELF version sections informations
2527 Displays the contents of the version sections in the file, it they
2528 exist.
2529
2530 @item -D
2531 @itemx --use-dynamic
2532 When displaying symbols, this option makes @code{readelf} use the
2533 symblol table in the file's dynamic section, rather than the one in the
2534 symbols section.
2535
2536 @item -x <number>
2537 @itemx --hex-dump=<number>
2538 Displays the contents of the indicated section as a hexadecimal dump.
2539
2540 @item -w[liapr]
2541 @itemx --debug-dump[=line,=info,=abbrev,=pubnames,=ranges]
2542 Displays the contents of the debug sections in the file, if any are
2543 present. If one of the optional letters or words follows the switch
2544 then only data found in those specific sections will be dumped.
2545
2546 @item --histogram
2547 Display a histogram of bucket list lengths when displaying the contents
2548 of the symbol tables.
2549
2550 @item -v
2551 @itemx --version
2552 Display the version number of readelf.
2553
2554 @item -H
2555 @itemx --help
2556 Display the command line options understood by @code{readelf}.
2557
2558 @end table
2559
2560
2561 @node Selecting The Target System
2562 @chapter Selecting the target system
2563
2564 You can specify three aspects of the target system to the @sc{gnu}
2565 binary file utilities, each in several ways:
2566
2567 @itemize @bullet
2568 @item
2569 the target
2570
2571 @item
2572 the architecture
2573
2574 @item
2575 the linker emulation (which applies to the linker only)
2576 @end itemize
2577
2578 In the following summaries, the lists of ways to specify values are in
2579 order of decreasing precedence. The ways listed first override those
2580 listed later.
2581
2582 The commands to list valid values only list the values for which the
2583 programs you are running were configured. If they were configured with
2584 @samp{--enable-targets=all}, the commands list most of the available
2585 values, but a few are left out; not all targets can be configured in at
2586 once because some of them can only be configured @dfn{native} (on hosts
2587 with the same type as the target system).
2588
2589 @menu
2590 * Target Selection::
2591 * Architecture Selection::
2592 * Linker Emulation Selection::
2593 @end menu
2594
2595 @node Target Selection
2596 @section Target Selection
2597
2598 A @dfn{target} is an object file format. A given target may be
2599 supported for multiple architectures (@pxref{Architecture Selection}).
2600 A target selection may also have variations for different operating
2601 systems or architectures.
2602
2603 The command to list valid target values is @samp{objdump -i}
2604 (the first column of output contains the relevant information).
2605
2606 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
2607 @samp{a.out-sunos-big}.
2608
2609 You can also specify a target using a configuration triplet. This is
2610 the same sort of name that is passed to @file{configure} to specify a
2611 target. When you use a configuration triplet as an argument, it must be
2612 fully canonicalized. You can see the canonical version of a triplet by
2613 running the shell script @file{config.sub} which is included with the
2614 sources.
2615
2616 Some sample configuration triplets are: @samp{m68k-hp-bsd},
2617 @samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
2618
2619 @subheading @code{objdump} Target
2620
2621 Ways to specify:
2622
2623 @enumerate
2624 @item
2625 command line option: @samp{-b} or @samp{--target}
2626
2627 @item
2628 environment variable @code{GNUTARGET}
2629
2630 @item
2631 deduced from the input file
2632 @end enumerate
2633
2634 @subheading @code{objcopy} and @code{strip} Input Target
2635
2636 Ways to specify:
2637
2638 @enumerate
2639 @item
2640 command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
2641
2642 @item
2643 environment variable @code{GNUTARGET}
2644
2645 @item
2646 deduced from the input file
2647 @end enumerate
2648
2649 @subheading @code{objcopy} and @code{strip} Output Target
2650
2651 Ways to specify:
2652
2653 @enumerate
2654 @item
2655 command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
2656
2657 @item
2658 the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
2659
2660 @item
2661 environment variable @code{GNUTARGET}
2662
2663 @item
2664 deduced from the input file
2665 @end enumerate
2666
2667 @subheading @code{nm}, @code{size}, and @code{strings} Target
2668
2669 Ways to specify:
2670
2671 @enumerate
2672 @item
2673 command line option: @samp{--target}
2674
2675 @item
2676 environment variable @code{GNUTARGET}
2677
2678 @item
2679 deduced from the input file
2680 @end enumerate
2681
2682 @subheading Linker Input Target
2683
2684 Ways to specify:
2685
2686 @enumerate
2687 @item
2688 command line option: @samp{-b} or @samp{--format}
2689 (@pxref{Options,,Options,ld.info,Using LD})
2690
2691 @item
2692 script command @code{TARGET}
2693 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2694
2695 @item
2696 environment variable @code{GNUTARGET}
2697 (@pxref{Environment,,Environment,ld.info,Using LD})
2698
2699 @item
2700 the default target of the selected linker emulation
2701 (@pxref{Linker Emulation Selection})
2702 @end enumerate
2703
2704 @subheading Linker Output Target
2705
2706 Ways to specify:
2707
2708 @enumerate
2709 @item
2710 command line option: @samp{-oformat}
2711 (@pxref{Options,,Options,ld.info,Using LD})
2712
2713 @item
2714 script command @code{OUTPUT_FORMAT}
2715 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2716
2717 @item
2718 the linker input target (see ``Linker Input Target'' above)
2719 @end enumerate
2720
2721 @node Architecture Selection
2722 @section Architecture selection
2723
2724 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
2725 to run. Its name may contain a colon, separating the name of the
2726 processor family from the name of the particular @sc{cpu}.
2727
2728 The command to list valid architecture values is @samp{objdump -i} (the
2729 second column contains the relevant information).
2730
2731 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
2732
2733 @subheading @code{objdump} Architecture
2734
2735 Ways to specify:
2736
2737 @enumerate
2738 @item
2739 command line option: @samp{-m} or @samp{--architecture}
2740
2741 @item
2742 deduced from the input file
2743 @end enumerate
2744
2745 @subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
2746
2747 Ways to specify:
2748
2749 @enumerate
2750 @item
2751 deduced from the input file
2752 @end enumerate
2753
2754 @subheading Linker Input Architecture
2755
2756 Ways to specify:
2757
2758 @enumerate
2759 @item
2760 deduced from the input file
2761 @end enumerate
2762
2763 @subheading Linker Output Architecture
2764
2765 Ways to specify:
2766
2767 @enumerate
2768 @item
2769 script command @code{OUTPUT_ARCH}
2770 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2771
2772 @item
2773 the default architecture from the linker output target
2774 (@pxref{Target Selection})
2775 @end enumerate
2776
2777 @node Linker Emulation Selection
2778 @section Linker emulation selection
2779
2780 A linker @dfn{emulation} is a ``personality'' of the linker, which gives
2781 the linker default values for the other aspects of the target system.
2782 In particular, it consists of
2783
2784 @itemize @bullet
2785 @item
2786 the linker script
2787
2788 @item
2789 the target
2790
2791 @item
2792 several ``hook'' functions that are run at certain stages of the linking
2793 process to do special things that some targets require
2794 @end itemize
2795
2796 The command to list valid linker emulation values is @samp{ld -V}.
2797
2798 Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
2799
2800 Ways to specify:
2801
2802 @enumerate
2803 @item
2804 command line option: @samp{-m}
2805 (@pxref{Options,,Options,ld.info,Using LD})
2806
2807 @item
2808 environment variable @code{LDEMULATION}
2809
2810 @item
2811 compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2812 which comes from @code{EMUL} in @file{config/@var{target}.mt}
2813 @end enumerate
2814
2815 @node Reporting Bugs
2816 @chapter Reporting Bugs
2817 @cindex bugs
2818 @cindex reporting bugs
2819
2820 Your bug reports play an essential role in making the binary utilities
2821 reliable.
2822
2823 Reporting a bug may help you by bringing a solution to your problem, or
2824 it may not. But in any case the principal function of a bug report is
2825 to help the entire community by making the next version of the binary
2826 utilities work better. Bug reports are your contribution to their
2827 maintenance.
2828
2829 In order for a bug report to serve its purpose, you must include the
2830 information that enables us to fix the bug.
2831
2832 @menu
2833 * Bug Criteria:: Have you found a bug?
2834 * Bug Reporting:: How to report bugs
2835 @end menu
2836
2837 @node Bug Criteria
2838 @section Have you found a bug?
2839 @cindex bug criteria
2840
2841 If you are not sure whether you have found a bug, here are some guidelines:
2842
2843 @itemize @bullet
2844 @cindex fatal signal
2845 @cindex crash
2846 @item
2847 If a binary utility gets a fatal signal, for any input whatever, that is
2848 a bug. Reliable utilities never crash.
2849
2850 @cindex error on valid input
2851 @item
2852 If a binary utility produces an error message for valid input, that is a
2853 bug.
2854
2855 @item
2856 If you are an experienced user of binary utilities, your suggestions for
2857 improvement are welcome in any case.
2858 @end itemize
2859
2860 @node Bug Reporting
2861 @section How to report bugs
2862 @cindex bug reports
2863 @cindex bugs, reporting
2864
2865 A number of companies and individuals offer support for @sc{gnu}
2866 products. If you obtained the binary utilities from a support
2867 organization, we recommend you contact that organization first.
2868
2869 You can find contact information for many support companies and
2870 individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2871 distribution.
2872
2873 In any event, we also recommend that you send bug reports for the binary
2874 utilities to @samp{bug-gnu-utils@@gnu.org}.
2875
2876 The fundamental principle of reporting bugs usefully is this:
2877 @strong{report all the facts}. If you are not sure whether to state a
2878 fact or leave it out, state it!
2879
2880 Often people omit facts because they think they know what causes the
2881 problem and assume that some details do not matter. Thus, you might
2882 assume that the name of a file you use in an example does not matter.
2883 Well, probably it does not, but one cannot be sure. Perhaps the bug is
2884 a stray memory reference which happens to fetch from the location where
2885 that pathname is stored in memory; perhaps, if the pathname were
2886 different, the contents of that location would fool the utility into
2887 doing the right thing despite the bug. Play it safe and give a
2888 specific, complete example. That is the easiest thing for you to do,
2889 and the most helpful.
2890
2891 Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2892 it is new to us. Therefore, always write your bug reports on the assumption
2893 that the bug has not been reported previously.
2894
2895 Sometimes people give a few sketchy facts and ask, ``Does this ring a
2896 bell?'' Those bug reports are useless, and we urge everyone to
2897 @emph{refuse to respond to them} except to chide the sender to report
2898 bugs properly.
2899
2900 To enable us to fix the bug, you should include all these things:
2901
2902 @itemize @bullet
2903 @item
2904 The version of the utility. Each utility announces it if you start it
2905 with the @samp{--version} argument.
2906
2907 Without this, we will not know whether there is any point in looking for
2908 the bug in the current version of the binary utilities.
2909
2910 @item
2911 Any patches you may have applied to the source, including any patches
2912 made to the @code{BFD} library.
2913
2914 @item
2915 The type of machine you are using, and the operating system name and
2916 version number.
2917
2918 @item
2919 What compiler (and its version) was used to compile the utilities---e.g.
2920 ``@code{gcc-2.7}''.
2921
2922 @item
2923 The command arguments you gave the utility to observe the bug. To
2924 guarantee you will not omit something important, list them all. A copy
2925 of the Makefile (or the output from make) is sufficient.
2926
2927 If we were to try to guess the arguments, we would probably guess wrong
2928 and then we might not encounter the bug.
2929
2930 @item
2931 A complete input file, or set of input files, that will reproduce the
2932 bug. If the utility is reading an object file or files, then it is
2933 generally most helpful to send the actual object files, uuencoded if
2934 necessary to get them through the mail system. Note that
2935 @samp{bug-gnu-utils@@gnu.org} is a mailing list, so you should avoid
2936 sending very large files to it. Making the files available for
2937 anonymous FTP is OK.
2938
2939 If the source files were produced exclusively using @sc{gnu} programs
2940 (e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2941 may be OK to send the source files rather than the object files. In
2942 this case, be sure to say exactly what version of @code{gcc}, or
2943 whatever, was used to produce the object files. Also say how
2944 @code{gcc}, or whatever, was configured.
2945
2946 @item
2947 A description of what behavior you observe that you believe is
2948 incorrect. For example, ``It gets a fatal signal.''
2949
2950 Of course, if the bug is that the utility gets a fatal signal, then we
2951 will certainly notice it. But if the bug is incorrect output, we might
2952 not notice unless it is glaringly wrong. You might as well not give us
2953 a chance to make a mistake.
2954
2955 Even if the problem you experience is a fatal signal, you should still
2956 say so explicitly. Suppose something strange is going on, such as your
2957 copy of the utility is out of synch, or you have encountered a bug in
2958 the C library on your system. (This has happened!) Your copy might
2959 crash and ours would not. If you told us to expect a crash, then when
2960 ours fails to crash, we would know that the bug was not happening for
2961 us. If you had not told us to expect a crash, then we would not be able
2962 to draw any conclusion from our observations.
2963
2964 @item
2965 If you wish to suggest changes to the source, send us context diffs, as
2966 generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2967 option. Always send diffs from the old file to the new file. If you
2968 wish to discuss something in the @code{ld} source, refer to it by
2969 context, not by line number.
2970
2971 The line numbers in our development sources will not match those in your
2972 sources. Your line numbers would convey no useful information to us.
2973 @end itemize
2974
2975 Here are some things that are not necessary:
2976
2977 @itemize @bullet
2978 @item
2979 A description of the envelope of the bug.
2980
2981 Often people who encounter a bug spend a lot of time investigating
2982 which changes to the input file will make the bug go away and which
2983 changes will not affect it.
2984
2985 This is often time consuming and not very useful, because the way we
2986 will find the bug is by running a single example under the debugger
2987 with breakpoints, not by pure deduction from a series of examples.
2988 We recommend that you save your time for something else.
2989
2990 Of course, if you can find a simpler example to report @emph{instead}
2991 of the original one, that is a convenience for us. Errors in the
2992 output will be easier to spot, running under the debugger will take
2993 less time, and so on.
2994
2995 However, simplification is not vital; if you do not want to do this,
2996 report the bug anyway and send us the entire test case you used.
2997
2998 @item
2999 A patch for the bug.
3000
3001 A patch for the bug does help us if it is a good one. But do not omit
3002 the necessary information, such as the test case, on the assumption that
3003 a patch is all we need. We might see problems with your patch and decide
3004 to fix the problem another way, or we might not understand it at all.
3005
3006 Sometimes with programs as complicated as the binary utilities it is
3007 very hard to construct an example that will make the program follow a
3008 certain path through the code. If you do not send us the example, we
3009 will not be able to construct one, so we will not be able to verify that
3010 the bug is fixed.
3011
3012 And if we cannot understand what bug you are trying to fix, or why your
3013 patch should be an improvement, we will not install it. A test case will
3014 help us to understand.
3015
3016 @item
3017 A guess about what the bug is or what it depends on.
3018
3019 Such guesses are usually wrong. Even we cannot guess right about such
3020 things without first using the debugger to find the facts.
3021 @end itemize
3022
3023 @node Index
3024 @unnumbered Index
3025
3026 @printindex cp
3027
3028 @contents
3029 @bye
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