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