* libhppa.h: Fix various formatting errors.
[deliverable/binutils-gdb.git] / binutils / binutils.texi
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1\input texinfo @c -*- Texinfo -*-
2@setfilename binutils.info
3@include config.texi
4
5@ifinfo
6@format
7START-INFO-DIR-ENTRY
8* Binutils: (binutils). The GNU binary utilities "ar", "objcopy",
9 "objdump", "nm", "nlmconv", "size", "readelf"
10 "strings", "strip", "ranlib" and "dlltool".
11END-INFO-DIR-ENTRY
12@end format
13@end ifinfo
14
15@ifinfo
16Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 98, 1999 Free Software Foundation, Inc.
17
18Permission is granted to make and distribute verbatim copies of
19this manual provided the copyright notice and this permission notice
20are preserved on all copies.
21
22@ignore
23Permission is granted to process this file through TeX and print the
24results, provided the printed document carries a copying permission
25notice 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
30Permission is granted to copy and distribute modified versions of this
31manual under the conditions for verbatim copying, provided also that
32the entire resulting derived work is distributed under the terms of a
33permission notice identical to this one.
34
35Permission is granted to copy and distribute translations of this manual
36into 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", "readelf" and "ranlib".
43@c
44@c Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 1999 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
69Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 1998 Free Software Foundation, Inc.
70
71Permission is granted to make and distribute verbatim copies of
72this manual provided the copyright notice and this permission notice
73are preserved on all copies.
74
75Permission is granted to copy and distribute modified versions of this
76manual under the conditions for verbatim copying, provided also that
77the entire resulting derived work is distributed under the terms of a
78permission notice identical to this one.
79
80Permission is granted to copy and distribute translations of this manual
81into another language, under the above conditions for modified versions.
82@end titlepage
83
84@node Top
85@top Introduction
86
87@cindex version
88This brief manual contains preliminary documentation for the @sc{gnu} binary
89utilities (collectively version @value{VERSION}):
90
91@iftex
92@table @code
93@item ar
94Create, modify, and extract from archives
95
96@item nm
97List symbols from object files
98
99@item objcopy
100Copy and translate object files
101
102@item objdump
103Display information from object files
104
105@item ranlib
106Generate index to archive contents
107
108@item readelf
109Display the contents of ELF format files.
110
111@item size
112List file section sizes and total size
113
114@item strings
115List printable strings from files
116
117@item strip
118Discard symbols
119
120@item c++filt
121Demangle encoded C++ symbols
122
123@item addr2line
124Convert addresses into file names and line numbers
125
126@item nlmconv
127Convert object code into a Netware Loadable Module
128
129@item windres
130Manipulate Windows resources
131
132@item dlltool
133Create the files needed to build and use Dynamic Link Libraries
134@end table
135@end iftex
136
137@menu
138* ar:: Create, modify, and extract from archives
139* nm:: List symbols from object files
140* objcopy:: Copy and translate object files
141* objdump:: Display information from object files
142* ranlib:: Generate index to archive contents
143* readelf:: Display the contents of ELF format files.
144* size:: List section sizes and total size
145* strings:: List printable strings from files
146* strip:: Discard symbols
147* c++filt:: Filter to demangle encoded C++ symbols
148* addr2line:: Convert addresses to file and line
149* nlmconv:: Converts object code into an NLM
150* windres:: Manipulate Windows resources
151* dlltool:: Create files needed to build and use DLLs
152* Selecting The Target System:: How these utilities determine the target.
153* Reporting Bugs:: Reporting Bugs
154* Index:: Index
155@end menu
156
157@node ar
158@chapter ar
159
160@kindex ar
161@cindex archives
162@cindex collections of files
163@smallexample
164ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
165ar -M [ <mri-script ]
166@end smallexample
167
168The @sc{gnu} @code{ar} program creates, modifies, and extracts from
169archives. An @dfn{archive} is a single file holding a collection of
170other files in a structure that makes it possible to retrieve
171the original individual files (called @dfn{members} of the archive).
172
173The original files' contents, mode (permissions), timestamp, owner, and
174group are preserved in the archive, and can be restored on
175extraction.
176
177@cindex name length
178@sc{gnu} @code{ar} can maintain archives whose members have names of any
179length; however, depending on how @code{ar} is configured on your
180system, a limit on member-name length may be imposed for compatibility
181with archive formats maintained with other tools. If it exists, the
182limit is often 15 characters (typical of formats related to a.out) or 16
183characters (typical of formats related to coff).
184
185@cindex libraries
186@code{ar} is considered a binary utility because archives of this sort
187are most often used as @dfn{libraries} holding commonly needed
188subroutines.
189
190@cindex symbol index
191@code{ar} creates an index to the symbols defined in relocatable
192object modules in the archive when you specify the modifier @samp{s}.
193Once created, this index is updated in the archive whenever @code{ar}
194makes a change to its contents (save for the @samp{q} update operation).
195An archive with such an index speeds up linking to the library, and
196allows routines in the library to call each other without regard to
197their placement in the archive.
198
199You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
200table. If an archive lacks the table, another form of @code{ar} called
201@code{ranlib} can be used to add just the table.
202
203@cindex compatibility, @code{ar}
204@cindex @code{ar} compatibility
205@sc{gnu} @code{ar} is designed to be compatible with two different
206facilities. You can control its activity using command-line options,
207like the different varieties of @code{ar} on Unix systems; or, if you
208specify the single command-line option @samp{-M}, you can control it
209with a script supplied via standard input, like the MRI ``librarian''
210program.
211
212@menu
213* ar cmdline:: Controlling @code{ar} on the command line
214* ar scripts:: Controlling @code{ar} with a script
215@end menu
216
217@page
218@node ar cmdline
219@section Controlling @code{ar} on the command line
220
221@smallexample
222ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
223@end smallexample
224
225@cindex Unix compatibility, @code{ar}
226When you use @code{ar} in the Unix style, @code{ar} insists on at least two
227arguments to execute: one keyletter specifying the @emph{operation}
228(optionally accompanied by other keyletters specifying
229@emph{modifiers}), and the archive name to act on.
230
231Most operations can also accept further @var{member} arguments,
232specifying particular files to operate on.
233
234@sc{gnu} @code{ar} allows you to mix the operation code @var{p} and modifier
235flags @var{mod} in any order, within the first command-line argument.
236
237If you wish, you may begin the first command-line argument with a
238dash.
239
240@cindex operations on archive
241The @var{p} keyletter specifies what operation to execute; it may be
242any of the following, but you must specify only one of them:
243
244@table @code
245@item d
246@cindex deleting from archive
247@emph{Delete} modules from the archive. Specify the names of modules to
248be deleted as @var{member}@dots{}; the archive is untouched if you
249specify no files to delete.
250
251If you specify the @samp{v} modifier, @code{ar} lists each module
252as it is deleted.
253
254@item m
255@cindex moving in archive
256Use this operation to @emph{move} members in an archive.
257
258The ordering of members in an archive can make a difference in how
259programs are linked using the library, if a symbol is defined in more
260than one member.
261
262If no modifiers are used with @code{m}, any members you name in the
263@var{member} arguments are moved to the @emph{end} of the archive;
264you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
265specified place instead.
266
267@item p
268@cindex printing from archive
269@emph{Print} the specified members of the archive, to the standard
270output file. If the @samp{v} modifier is specified, show the member
271name before copying its contents to standard output.
272
273If you specify no @var{member} arguments, all the files in the archive are
274printed.
275
276@item q
277@cindex quick append to archive
278@emph{Quick append}; Historically, add the files @var{member}@dots{} to the end of
279@var{archive}, without checking for replacement.
280
281The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
282operation; new members are always placed at the end of the archive.
283
284The modifier @samp{v} makes @code{ar} list each file as it is appended.
285
286Since the point of this operation is speed, the archive's symbol table
287index is not updated, even if it already existed; you can use @samp{ar s} or
288@code{ranlib} explicitly to update the symbol table index.
289
290However, too many different systems assume quick append rebuilds the
291index, so GNU ar implements @code{q} as a synonym for @code{r}.
292
293@item r
294@cindex replacement in archive
295Insert the files @var{member}@dots{} into @var{archive} (with
296@emph{replacement}). This operation differs from @samp{q} in that any
297previously existing members are deleted if their names match those being
298added.
299
300If one of the files named in @var{member}@dots{} does not exist, @code{ar}
301displays an error message, and leaves undisturbed any existing members
302of the archive matching that name.
303
304By default, new members are added at the end of the file; but you may
305use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
306placement relative to some existing member.
307
308The modifier @samp{v} used with this operation elicits a line of
309output for each file inserted, along with one of the letters @samp{a} or
310@samp{r} to indicate whether the file was appended (no old member
311deleted) or replaced.
312
313@item t
314@cindex contents of archive
315Display a @emph{table} listing the contents of @var{archive}, or those
316of the files listed in @var{member}@dots{} that are present in the
317archive. Normally only the member name is shown; if you also want to
318see the modes (permissions), timestamp, owner, group, and size, you can
319request that by also specifying the @samp{v} modifier.
320
321If you do not specify a @var{member}, all files in the archive
322are listed.
323
324@cindex repeated names in archive
325@cindex name duplication in archive
326If there is more than one file with the same name (say, @samp{fie}) in
327an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
328first instance; to see them all, you must ask for a complete
329listing---in our example, @samp{ar t b.a}.
330@c WRS only; per Gumby, this is implementation-dependent, and in a more
331@c recent case in fact works the other way.
332
333@item x
334@cindex extract from archive
335@emph{Extract} members (named @var{member}) from the archive. You can
336use the @samp{v} modifier with this operation, to request that
337@code{ar} list each name as it extracts it.
338
339If you do not specify a @var{member}, all files in the archive
340are extracted.
341
342@end table
343
344A number of modifiers (@var{mod}) may immediately follow the @var{p}
345keyletter, to specify variations on an operation's behavior:
346
347@table @code
348@item a
349@cindex relative placement in archive
350Add new files @emph{after} an existing member of the
351archive. If you use the modifier @samp{a}, the name of an existing archive
352member must be present as the @var{relpos} argument, before the
353@var{archive} specification.
354
355@item b
356Add new files @emph{before} an existing member of the
357archive. If you use the modifier @samp{b}, the name of an existing archive
358member must be present as the @var{relpos} argument, before the
359@var{archive} specification. (same as @samp{i}).
360
361@item c
362@cindex creating archives
363@emph{Create} the archive. The specified @var{archive} is always
364created if it did not exist, when you request an update. But a warning is
365issued unless you specify in advance that you expect to create it, by
366using this modifier.
367
368@item f
369Truncate names in the archive. @sc{gnu} @code{ar} will normally permit file
370names of any length. This will cause it to create archives which are
371not compatible with the native @code{ar} program on some systems. If
372this is a concern, the @samp{f} modifier may be used to truncate file
373names when putting them in the archive.
374
375@item i
376Insert new files @emph{before} an existing member of the
377archive. If you use the modifier @samp{i}, the name of an existing archive
378member must be present as the @var{relpos} argument, before the
379@var{archive} specification. (same as @samp{b}).
380
381@item l
382This modifier is accepted but not used.
383@c whaffor ar l modifier??? presumably compat; with
384@c what???---doc@@cygnus.com, 25jan91
385
386@item o
387@cindex dates in archive
388Preserve the @emph{original} dates of members when extracting them. If
389you do not specify this modifier, files extracted from the archive
390are stamped with the time of extraction.
391
392@item s
393@cindex writing archive index
394Write an object-file index into the archive, or update an existing one,
395even if no other change is made to the archive. You may use this modifier
396flag either with any operation, or alone. Running @samp{ar s} on an
397archive is equivalent to running @samp{ranlib} on it.
398
399@item S
400@cindex not writing archive index
401Do not generate an archive symbol table. This can speed up building a
402large library in several steps. The resulting archive can not be used
403with the linker. In order to build a symbol table, you must omit the
404@samp{S} modifier on the last execution of @samp{ar}, or you must run
405@samp{ranlib} on the archive.
406
407@item u
408@cindex updating an archive
409Normally, @samp{ar r}@dots{} inserts all files
410listed into the archive. If you would like to insert @emph{only} those
411of the files you list that are newer than existing members of the same
412names, use this modifier. The @samp{u} modifier is allowed only for the
413operation @samp{r} (replace). In particular, the combination @samp{qu} is
414not allowed, since checking the timestamps would lose any speed
415advantage from the operation @samp{q}.
416
417@item v
418This modifier requests the @emph{verbose} version of an operation. Many
419operations display additional information, such as filenames processed,
420when the modifier @samp{v} is appended.
421
422@item V
423This modifier shows the version number of @code{ar}.
424@end table
425
426@node ar scripts
427@section Controlling @code{ar} with a script
428
429@smallexample
430ar -M [ <@var{script} ]
431@end smallexample
432
433@cindex MRI compatibility, @code{ar}
434@cindex scripts, @code{ar}
435If you use the single command-line option @samp{-M} with @code{ar}, you
436can control its operation with a rudimentary command language. This
437form of @code{ar} operates interactively if standard input is coming
438directly from a terminal. During interactive use, @code{ar} prompts for
439input (the prompt is @samp{AR >}), and continues executing even after
440errors. If you redirect standard input to a script file, no prompts are
441issued, and @code{ar} abandons execution (with a nonzero exit code)
442on any error.
443
444The @code{ar} command language is @emph{not} designed to be equivalent
445to the command-line options; in fact, it provides somewhat less control
446over archives. The only purpose of the command language is to ease the
447transition to @sc{gnu} @code{ar} for developers who already have scripts
448written for the MRI ``librarian'' program.
449
450The syntax for the @code{ar} command language is straightforward:
451@itemize @bullet
452@item
453commands are recognized in upper or lower case; for example, @code{LIST}
454is the same as @code{list}. In the following descriptions, commands are
455shown in upper case for clarity.
456
457@item
458a single command may appear on each line; it is the first word on the
459line.
460
461@item
462empty lines are allowed, and have no effect.
463
464@item
465comments are allowed; text after either of the characters @samp{*}
466or @samp{;} is ignored.
467
468@item
469Whenever you use a list of names as part of the argument to an @code{ar}
470command, you can separate the individual names with either commas or
471blanks. Commas are shown in the explanations below, for clarity.
472
473@item
474@samp{+} is used as a line continuation character; if @samp{+} appears
475at the end of a line, the text on the following line is considered part
476of the current command.
477@end itemize
478
479Here are the commands you can use in @code{ar} scripts, or when using
480@code{ar} interactively. Three of them have special significance:
481
482@code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
483a temporary file required for most of the other commands.
484
485@code{SAVE} commits the changes so far specified by the script. Prior
486to @code{SAVE}, commands affect only the temporary copy of the current
487archive.
488
489@table @code
490@item ADDLIB @var{archive}
491@itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
492Add all the contents of @var{archive} (or, if specified, each named
493@var{module} from @var{archive}) to the current archive.
494
495Requires prior use of @code{OPEN} or @code{CREATE}.
496
497@item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
498@c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
499@c else like "ar q..."
500Add each named @var{member} as a module in the current archive.
501
502Requires prior use of @code{OPEN} or @code{CREATE}.
503
504@item CLEAR
505Discard the contents of the current archive, canceling the effect of
506any operations since the last @code{SAVE}. May be executed (with no
507effect) even if no current archive is specified.
508
509@item CREATE @var{archive}
510Creates an archive, and makes it the current archive (required for many
511other commands). The new archive is created with a temporary name; it
512is not actually saved as @var{archive} until you use @code{SAVE}.
513You can overwrite existing archives; similarly, the contents of any
514existing file named @var{archive} will not be destroyed until @code{SAVE}.
515
516@item DELETE @var{module}, @var{module}, @dots{} @var{module}
517Delete each listed @var{module} from the current archive; equivalent to
518@samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
519
520Requires prior use of @code{OPEN} or @code{CREATE}.
521
522@item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
523@itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
524List each named @var{module} present in @var{archive}. The separate
525command @code{VERBOSE} specifies the form of the output: when verbose
526output is off, output is like that of @samp{ar -t @var{archive}
527@var{module}@dots{}}. When verbose output is on, the listing is like
528@samp{ar -tv @var{archive} @var{module}@dots{}}.
529
530Output normally goes to the standard output stream; however, if you
531specify @var{outputfile} as a final argument, @code{ar} directs the
532output to that file.
533
534@item END
535Exit from @code{ar}, with a @code{0} exit code to indicate successful
536completion. This command does not save the output file; if you have
537changed the current archive since the last @code{SAVE} command, those
538changes are lost.
539
540@item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
541Extract each named @var{module} from the current archive, writing them
542into the current directory as separate files. Equivalent to @samp{ar -x
543@var{archive} @var{module}@dots{}}.
544
545Requires prior use of @code{OPEN} or @code{CREATE}.
546
547@ignore
548@c FIXME Tokens but no commands???
549@item FULLDIR
550
551@item HELP
552@end ignore
553
554@item LIST
555Display full contents of the current archive, in ``verbose'' style
556regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
c89746f6 557tv @var{archive}}. (This single command is a @sc{gnu} @code{ar}
252b5132
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558enhancement, rather than present for MRI compatibility.)
559
560Requires prior use of @code{OPEN} or @code{CREATE}.
561
562@item OPEN @var{archive}
563Opens an existing archive for use as the current archive (required for
564many other commands). Any changes as the result of subsequent commands
565will not actually affect @var{archive} until you next use @code{SAVE}.
566
567@item REPLACE @var{module}, @var{module}, @dots{} @var{module}
568In the current archive, replace each existing @var{module} (named in
569the @code{REPLACE} arguments) from files in the current working directory.
570To execute this command without errors, both the file, and the module in
571the current archive, must exist.
572
573Requires prior use of @code{OPEN} or @code{CREATE}.
574
575@item VERBOSE
576Toggle an internal flag governing the output from @code{DIRECTORY}.
577When the flag is on, @code{DIRECTORY} output matches output from
578@samp{ar -tv }@dots{}.
579
580@item SAVE
581Commit your changes to the current archive, and actually save it as a
582file with the name specified in the last @code{CREATE} or @code{OPEN}
583command.
584
585Requires prior use of @code{OPEN} or @code{CREATE}.
586
587@end table
588
589@iftex
590@node ld
591@chapter ld
592@cindex linker
593@kindex ld
594The @sc{gnu} linker @code{ld} is now described in a separate manual.
595@xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
596@end iftex
597
598@node nm
599@chapter nm
600@cindex symbols
601@kindex nm
602
603@smallexample
604nm [ -a | --debug-syms ] [ -g | --extern-only ]
605 [ -B ] [ -C | --demangle ] [ -D | --dynamic ]
606 [ -s | --print-armap ] [ -A | -o | --print-file-name ]
607 [ -n | -v | --numeric-sort ] [ -p | --no-sort ]
608 [ -r | --reverse-sort ] [ --size-sort ] [ -u | --undefined-only ]
609 [ -t @var{radix} | --radix=@var{radix} ] [ -P | --portability ]
610 [ --target=@var{bfdname} ] [ -f @var{format} | --format=@var{format} ]
611 [ --defined-only ] [-l | --line-numbers ]
612 [ --no-demangle ] [ -V | --version ] [ --help ] [ @var{objfile}@dots{} ]
613@end smallexample
614
615@sc{gnu} @code{nm} lists the symbols from object files @var{objfile}@dots{}.
616If no object files are listed as arguments, @code{nm} assumes
617@file{a.out}.
618
619For each symbol, @code{nm} shows:
620
621@itemize @bullet
622@item
623The symbol value, in the radix selected by options (see below), or
624hexadecimal by default.
625
626@item
627The symbol type. At least the following types are used; others are, as
628well, depending on the object file format. If lowercase, the symbol is
629local; if uppercase, the symbol is global (external).
630
631@c Some more detail on exactly what these symbol types are used for
632@c would be nice.
633@table @code
634@item A
635The symbol's value is absolute, and will not be changed by further
636linking.
637
638@item B
639The symbol is in the uninitialized data section (known as BSS).
640
641@item C
642The symbol is common. Common symbols are uninitialized data. When
643linking, multiple common symbols may appear with the same name. If the
644symbol is defined anywhere, the common symbols are treated as undefined
645references. For more details on common symbols, see the discussion of
646--warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
647
648@item D
649The symbol is in the initialized data section.
650
651@item G
652The symbol is in an initialized data section for small objects. Some
653object file formats permit more efficient access to small data objects,
654such as a global int variable as opposed to a large global array.
655
656@item I
657The symbol is an indirect reference to another symbol. This is a GNU
658extension to the a.out object file format which is rarely used.
659
660@item N
661The symbol is a debugging symbol.
662
663@item R
664The symbol is in a read only data section.
665
666@item S
667The symbol is in an uninitialized data section for small objects.
668
669@item T
670The symbol is in the text (code) section.
671
672@item U
673The symbol is undefined.
674
675@item W
676The symbol is weak. When a weak defined symbol is linked with a normal
677defined symbol, the normal defined symbol is used with no error. When a
678weak undefined symbol is linked and the symbol is not defined, the value
679of the weak symbol becomes zero with no error.
680
681@item -
682The symbol is a stabs symbol in an a.out object file. In this case, the
683next values printed are the stabs other field, the stabs desc field, and
684the stab type. Stabs symbols are used to hold debugging information;
685for more information, see @ref{Top,Stabs,Stabs Overview,stabs.info, The
686``stabs'' debug format}.
687
688@item ?
689The symbol type is unknown, or object file format specific.
690@end table
691
692@item
693The symbol name.
694@end itemize
695
696The long and short forms of options, shown here as alternatives, are
697equivalent.
698
699@table @code
700@item -A
701@itemx -o
702@itemx --print-file-name
703@cindex input file name
704@cindex file name
705@cindex source file name
706Precede each symbol by the name of the input file (or archive element)
707in which it was found, rather than identifying the input file once only,
708before all of its symbols.
709
710@item -a
711@itemx --debug-syms
712@cindex debugging symbols
713Display all symbols, even debugger-only symbols; normally these are not
714listed.
715
716@item -B
717@cindex @code{nm} format
718@cindex @code{nm} compatibility
719The same as @samp{--format=bsd} (for compatibility with the MIPS @code{nm}).
720
721@item -C
722@itemx --demangle
723@cindex demangling in nm
724Decode (@dfn{demangle}) low-level symbol names into user-level names.
725Besides removing any initial underscore prepended by the system, this
726makes C++ function names readable. @xref{c++filt}, for more information
727on demangling.
728
729@item --no-demangle
730Do not demangle low-level symbol names. This is the default.
731
732@item -D
733@itemx --dynamic
734@cindex dynamic symbols
735Display the dynamic symbols rather than the normal symbols. This is
736only meaningful for dynamic objects, such as certain types of shared
737libraries.
738
739@item -f @var{format}
740@itemx --format=@var{format}
741@cindex @code{nm} format
742@cindex @code{nm} compatibility
743Use the output format @var{format}, which can be @code{bsd},
744@code{sysv}, or @code{posix}. The default is @code{bsd}.
745Only the first character of @var{format} is significant; it can be
746either upper or lower case.
747
748@item -g
749@itemx --extern-only
750@cindex external symbols
751Display only external symbols.
752
753@item -l
754@itemx --line-numbers
755@cindex symbol line numbers
756For each symbol, use debugging information to try to find a filename and
757line number. For a defined symbol, look for the line number of the
758address of the symbol. For an undefined symbol, look for the line
759number of a relocation entry which refers to the symbol. If line number
760information can be found, print it after the other symbol information.
761
762@item -n
763@itemx -v
764@itemx --numeric-sort
765Sort symbols numerically by their addresses, rather than alphabetically
766by their names.
767
768@item -p
769@itemx --no-sort
770@cindex sorting symbols
771Do not bother to sort the symbols in any order; print them in the order
772encountered.
773
774@item -P
775@itemx --portability
776Use the POSIX.2 standard output format instead of the default format.
777Equivalent to @samp{-f posix}.
778
779@item -s
780@itemx --print-armap
781@cindex symbol index, listing
782When listing symbols from archive members, include the index: a mapping
783(stored in the archive by @code{ar} or @code{ranlib}) of which modules
784contain definitions for which names.
785
786@item -r
787@itemx --reverse-sort
788Reverse the order of the sort (whether numeric or alphabetic); let the
789last come first.
790
791@item --size-sort
792Sort symbols by size. The size is computed as the difference between
793the value of the symbol and the value of the symbol with the next higher
794value. The size of the symbol is printed, rather than the value.
795
796@item -t @var{radix}
797@itemx --radix=@var{radix}
798Use @var{radix} as the radix for printing the symbol values. It must be
799@samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
800
801@item --target=@var{bfdname}
802@cindex object code format
803Specify an object code format other than your system's default format.
804@xref{Target Selection}, for more information.
805
806@item -u
807@itemx --undefined-only
808@cindex external symbols
809@cindex undefined symbols
810Display only undefined symbols (those external to each object file).
811
812@item --defined-only
813@cindex external symbols
814@cindex undefined symbols
815Display only defined symbols for each object file.
816
817@item -V
818@itemx --version
819Show the version number of @code{nm} and exit.
820
821@item --help
822Show a summary of the options to @code{nm} and exit.
823@end table
824
825@node objcopy
826@chapter objcopy
827
828@smallexample
829objcopy [ -F @var{bfdname} | --target=@var{bfdname} ]
830 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
831 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
832 [ -S | --strip-all ] [ -g | --strip-debug ]
833 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
834 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
835 [ -L @var{symbolname} | --localize-symbol=@var{symbolname} ]
836 [ -W @var{symbolname} | --weaken-symbol=@var{symbolname} ]
837 [ -x | --discard-all ] [ -X | --discard-locals ]
838 [ -b @var{byte} | --byte=@var{byte} ]
839 [ -i @var{interleave} | --interleave=@var{interleave} ]
f91ea849 840 [ -j @var{sectionname} | --only-section=@var{sectionname} ]
252b5132
RH
841 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
842 [ -p | --preserve-dates ] [ --debugging ]
843 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
844 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
845 [ --change-addresses=@var{incr} ]
846 [ --change-section-address=@var{section}@{=,+,-@}@var{val} ]
847 [ --change-section-lma=@var{section}@{=,+,-@}@var{val} ]
848 [ --change-section-vma=@var{section}@{=,+,-@}@var{val} ]
849 [ --change-warnings ] [ --no-change-warnings ]
850 [ --set-section-flags=@var{section}=@var{flags} ]
851 [ --add-section=@var{sectionname}=@var{filename} ]
852 [ --change-leading-char ] [ --remove-leading-char ]
853 [ --weaken ]
854 [ -v | --verbose ] [ -V | --version ] [ --help ]
855 @var{infile} [@var{outfile}]
856@end smallexample
857
858The @sc{gnu} @code{objcopy} utility copies the contents of an object
859file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
860read and write the object files. It can write the destination object
861file in a format different from that of the source object file. The
862exact behavior of @code{objcopy} is controlled by command-line options.
863
864@code{objcopy} creates temporary files to do its translations and
865deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
866translation work; it has access to all the formats described in @sc{bfd}
867and thus is able to recognize most formats without being told
868explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
869
870@code{objcopy} can be used to generate S-records by using an output
871target of @samp{srec} (e.g., use @samp{-O srec}).
872
873@code{objcopy} can be used to generate a raw binary file by using an
874output target of @samp{binary} (e.g., use @samp{-O binary}). When
875@code{objcopy} generates a raw binary file, it will essentially produce
876a memory dump of the contents of the input object file. All symbols and
877relocation information will be discarded. The memory dump will start at
878the load address of the lowest section copied into the output file.
879
880When generating an S-record or a raw binary file, it may be helpful to
881use @samp{-S} to remove sections containing debugging information. In
882some cases @samp{-R} will be useful to remove sections which contain
883information which is not needed by the binary file.
884
885@table @code
886@item @var{infile}
887@itemx @var{outfile}
888The source and output files, respectively.
889If you do not specify @var{outfile}, @code{objcopy} creates a
890temporary file and destructively renames the result with
891the name of @var{infile}.
892
893@item -I @var{bfdname}
894@itemx --input-target=@var{bfdname}
895Consider the source file's object format to be @var{bfdname}, rather than
896attempting to deduce it. @xref{Target Selection}, for more information.
897
898@item -O @var{bfdname}
899@itemx --output-target=@var{bfdname}
900Write the output file using the object format @var{bfdname}.
901@xref{Target Selection}, for more information.
902
903@item -F @var{bfdname}
904@itemx --target=@var{bfdname}
905Use @var{bfdname} as the object format for both the input and the output
906file; i.e., simply transfer data from source to destination with no
907translation. @xref{Target Selection}, for more information.
908
f91ea849
ILT
909@item -j @var{sectionname}
910@itemx --only-section=@var{sectionname}
911Copy only the named section from the input file to the output file.
912This option may be given more than once. Note that using this option
913inappropriately may make the output file unusable.
914
252b5132
RH
915@item -R @var{sectionname}
916@itemx --remove-section=@var{sectionname}
917Remove any section named @var{sectionname} from the output file. This
918option may be given more than once. Note that using this option
919inappropriately may make the output file unusable.
920
921@item -S
922@itemx --strip-all
923Do not copy relocation and symbol information from the source file.
924
925@item -g
926@itemx --strip-debug
927Do not copy debugging symbols from the source file.
928
929@item --strip-unneeded
930Strip all symbols that are not needed for relocation processing.
931
932@item -K @var{symbolname}
933@itemx --keep-symbol=@var{symbolname}
934Copy only symbol @var{symbolname} from the source file. This option may
935be given more than once.
936
937@item -N @var{symbolname}
938@itemx --strip-symbol=@var{symbolname}
939Do not copy symbol @var{symbolname} from the source file. This option
940may be given more than once.
941
942@item -L @var{symbolname}
943@itemx --localize-symbol=@var{symbolname}
944Make symbol @var{symbolname} local to the file, so that it is not
945visible externally. This option may be given more than once.
946
947@item -W @var{symbolname}
948@itemx --weaken-symbol=@var{symbolname}
949Make symbol @var{symbolname} weak. This option may be given more than once.
950
951@item -x
952@itemx --discard-all
953Do not copy non-global symbols from the source file.
954@c FIXME any reason to prefer "non-global" to "local" here?
955
956@item -X
957@itemx --discard-locals
958Do not copy compiler-generated local symbols.
959(These usually start with @samp{L} or @samp{.}.)
960
961@item -b @var{byte}
962@itemx --byte=@var{byte}
963Keep only every @var{byte}th byte of the input file (header data is not
964affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
965where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
966option, or the default of 4. This option is useful for creating files
967to program @sc{rom}. It is typically used with an @code{srec} output
968target.
969
970@item -i @var{interleave}
971@itemx --interleave=@var{interleave}
972Only copy one out of every @var{interleave} bytes. Select which byte to
973copy with the @var{-b} or @samp{--byte} option. The default is 4.
974@code{objcopy} ignores this option if you do not specify either @samp{-b} or
975@samp{--byte}.
976
977@item -p
978@itemx --preserve-dates
979Set the access and modification dates of the output file to be the same
980as those of the input file.
981
982@item --debugging
983Convert debugging information, if possible. This is not the default
984because only certain debugging formats are supported, and the
985conversion process can be time consuming.
986
987@item --gap-fill @var{val}
988Fill gaps between sections with @var{val}. This operation applies to
989the @emph{load address} (LMA) of the sections. It is done by increasing
990the size of the section with the lower address, and filling in the extra
991space created with @var{val}.
992
993@item --pad-to @var{address}
994Pad the output file up to the load address @var{address}. This is
995done by increasing the size of the last section. The extra space is
996filled in with the value specified by @samp{--gap-fill} (default zero).
997
998@item --set-start @var{val}
999Set the address of the new file to @var{val}. Not all object file
1000formats support setting the start address.
1001
1002@item --change-start @var{incr}
1003@itemx --adjust-start @var{incr}
1004@cindex changing start address
1005Change the start address by adding @var{incr}. Not all object file
1006formats support setting the start address.
1007
1008@item --change-addresses @var{incr}
1009@itemx --adjust-vma @var{incr}
1010@cindex changing object addresses
1011Change the VMA and LMA addresses of all sections, as well as the start
1012address, by adding @var{incr}. Some object file formats do not permit
1013section addresses to be changed arbitrarily. Note that this does not
1014relocate the sections; if the program expects sections to be loaded at a
1015certain address, and this option is used to change the sections such
1016that they are loaded at a different address, the program may fail.
1017
1018@item --change-section-address @var{section}@{=,+,-@}@var{val}
1019@itemx --adjust-section-vma @var{section}@{=,+,-@}@var{val}
1020@cindex changing section address
1021Set or change both the VMA address and the LMA address of the named
1022@var{section}. If @samp{=} is used, the section address is set to
1023@var{val}. Otherwise, @var{val} is added to or subtracted from the
1024section address. See the comments under @samp{--change-addresses},
1025above. If @var{section} does not exist in the input file, a warning will
1026be issued, unless @samp{--no-change-warnings} is used.
1027
1028@item --change-section-lma @var{section}@{=,+,-@}@var{val}
1029@cindex changing section LMA
1030Set or change the LMA address of the named @var{section}. The LMA
1031address is the address where the section will be loaded into memory at
1032program load time. Normally this is the same as the VMA address, which
1033is the address of the section at program run time, but on some systems,
1034especially those where a program is held in ROM, the two can be
1035different. If @samp{=} is used, the section address is set to
1036@var{val}. Otherwise, @var{val} is added to or subtracted from the
1037section address. See the comments under @samp{--change-addresses},
1038above. If @var{section} does not exist in the input file, a warning
1039will be issued, unless @samp{--no-change-warnings} is used.
1040
1041@item --change-section-vma @var{section}@{=,+,-@}@var{val}
1042@cindex changing section VMA
1043Set or change the VMA address of the named @var{section}. The VMA
1044address is the address where the section will be located once the
1045program has started executing. Normally this is the same as the LMA
1046address, which is the address where the section will be loaded into
1047memory, but on some systems, especially those where a program is held in
1048ROM, the two can be different. If @samp{=} is used, the section address
1049is set to @var{val}. Otherwise, @var{val} is added to or subtracted
1050from the section address. See the comments under
1051@samp{--change-addresses}, above. If @var{section} does not exist in
1052the input file, a warning will be issued, unless
1053@samp{--no-change-warnings} is used.
1054
1055@item --change-warnings
1056@itemx --adjust-warnings
1057If @samp{--change-section-address} or @samp{--change-section-lma} or
1058@samp{--change-section-vma} is used, and the named section does not
1059exist, issue a warning. This is the default.
1060
1061@item --no-change-warnings
1062@itemx --no-adjust-warnings
1063Do not issue a warning if @samp{--change-section-address} or
1064@samp{--adjust-section-lma} or @samp{--adjust-section-vma} is used, even
1065if the named section does not exist.
1066
1067@item --set-section-flags @var{section}=@var{flags}
1068Set the flags for the named section. The @var{flags} argument is a
1069comma separated string of flag names. The recognized names are
1070@samp{alloc}, @samp{contents}, @samp{load}, @samp{readonly},
1071@samp{code}, @samp{data}, and @samp{rom}. You can set the
1072@samp{contents} flag for a section which does not have contents, but it
1073is not meaningful to clear the @samp{contents} flag of a section which
1074does have contents--just remove the section instead. Not all flags are
1075meaningful for all object file formats.
1076
1077@item --add-section @var{sectionname}=@var{filename}
1078Add a new section named @var{sectionname} while copying the file. The
1079contents of the new section are taken from the file @var{filename}. The
1080size of the section will be the size of the file. This option only
1081works on file formats which can support sections with arbitrary names.
1082
1083@item --change-leading-char
1084Some object file formats use special characters at the start of
1085symbols. The most common such character is underscore, which compilers
1086often add before every symbol. This option tells @code{objcopy} to
1087change the leading character of every symbol when it converts between
1088object file formats. If the object file formats use the same leading
1089character, this option has no effect. Otherwise, it will add a
1090character, or remove a character, or change a character, as
1091appropriate.
1092
1093@item --remove-leading-char
1094If the first character of a global symbol is a special symbol leading
1095character used by the object file format, remove the character. The
1096most common symbol leading character is underscore. This option will
1097remove a leading underscore from all global symbols. This can be useful
1098if you want to link together objects of different file formats with
1099different conventions for symbol names. This is different from
1100@code{--change-leading-char} because it always changes the symbol name
1101when appropriate, regardless of the object file format of the output
1102file.
1103
1104@item --weaken
1105Change all global symbols in the file to be weak. This can be useful
1106when building an object which will be linked against other objects using
1107the @code{-R} option to the linker. This option is only effective when
1108using an object file format which supports weak symbols.
1109
1110@item -V
1111@itemx --version
1112Show the version number of @code{objcopy}.
1113
1114@item -v
1115@itemx --verbose
1116Verbose output: list all object files modified. In the case of
1117archives, @samp{objcopy -V} lists all members of the archive.
1118
1119@item --help
1120Show a summary of the options to @code{objcopy}.
1121@end table
1122
1123@node objdump
1124@chapter objdump
1125
1126@cindex object file information
1127@kindex objdump
1128
1129@smallexample
1130objdump [ -a | --archive-headers ]
1131 [ -b @var{bfdname} | --target=@var{bfdname} ] [ --debugging ]
1132 [ -C | --demangle ] [ -d | --disassemble ]
1133 [ -D | --disassemble-all ] [ --disassemble-zeroes ]
1134 [ -EB | -EL | --endian=@{big | little @} ]
1135 [ -f | --file-headers ]
1136 [ -h | --section-headers | --headers ] [ -i | --info ]
1137 [ -j @var{section} | --section=@var{section} ]
1138 [ -l | --line-numbers ] [ -S | --source ]
1139 [ -m @var{machine} | --architecture=@var{machine} ]
1140 [ -p | --private-headers ]
1141 [ -r | --reloc ] [ -R | --dynamic-reloc ]
1142 [ -s | --full-contents ] [ --stabs ]
1143 [ -t | --syms ] [ -T | --dynamic-syms ] [ -x | --all-headers ]
1144 [ -w | --wide ] [ --start-address=@var{address} ]
1145 [ --stop-address=@var{address} ]
1146 [ --prefix-addresses] [ --[no-]show-raw-insn ]
1147 [ --adjust-vma=@var{offset} ]
1148 [ --version ] [ --help ]
1149 @var{objfile}@dots{}
1150@end smallexample
1151
1152@code{objdump} displays information about one or more object files.
1153The options control what particular information to display. This
1154information is mostly useful to programmers who are working on the
1155compilation tools, as opposed to programmers who just want their
1156program to compile and work.
1157
1158@var{objfile}@dots{} are the object files to be examined. When you
1159specify archives, @code{objdump} shows information on each of the member
1160object files.
1161
1162The long and short forms of options, shown here as alternatives, are
1163equivalent. At least one option besides @samp{-l} must be given.
1164
1165@table @code
1166@item -a
1167@itemx --archive-header
1168@cindex archive headers
1169If any of the @var{objfile} files are archives, display the archive
1170header information (in a format similar to @samp{ls -l}). Besides the
1171information you could list with @samp{ar tv}, @samp{objdump -a} shows
1172the object file format of each archive member.
1173
1174@item --adjust-vma=@var{offset}
1175@cindex section addresses in objdump
1176@cindex VMA in objdump
1177When dumping information, first add @var{offset} to all the section
1178addresses. This is useful if the section addresses do not correspond to
1179the symbol table, which can happen when putting sections at particular
1180addresses when using a format which can not represent section addresses,
1181such as a.out.
1182
1183@item -b @var{bfdname}
1184@itemx --target=@var{bfdname}
1185@cindex object code format
1186Specify that the object-code format for the object files is
1187@var{bfdname}. This option may not be necessary; @var{objdump} can
1188automatically recognize many formats.
1189
1190For example,
1191@example
1192objdump -b oasys -m vax -h fu.o
1193@end example
1194@noindent
1195displays summary information from the section headers (@samp{-h}) of
1196@file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1197file in the format produced by Oasys compilers. You can list the
1198formats available with the @samp{-i} option.
1199@xref{Target Selection}, for more information.
1200
1201@item -C
1202@itemx --demangle
1203@cindex demangling in objdump
1204Decode (@dfn{demangle}) low-level symbol names into user-level names.
1205Besides removing any initial underscore prepended by the system, this
1206makes C++ function names readable. @xref{c++filt}, for more information
1207on demangling.
1208
1209@item --debugging
1210Display debugging information. This attempts to parse debugging
1211information stored in the file and print it out using a C like syntax.
1212Only certain types of debugging information have been implemented.
1213
1214@item -d
1215@itemx --disassemble
1216@cindex disassembling object code
1217@cindex machine instructions
1218Display the assembler mnemonics for the machine instructions from
1219@var{objfile}. This option only disassembles those sections which are
1220expected to contain instructions.
1221
1222@item -D
1223@itemx --disassemble-all
1224Like @samp{-d}, but disassemble the contents of all sections, not just
1225those expected to contain instructions.
1226
1227@item --prefix-addresses
1228When disassembling, print the complete address on each line. This is
1229the older disassembly format.
1230
1231@item --disassemble-zeroes
1232Normally the disassembly output will skip blocks of zeroes. This
1233option directs the disassembler to disassemble those blocks, just like
1234any other data.
1235
1236@item -EB
1237@itemx -EL
1238@itemx --endian=@{big|little@}
1239@cindex endianness
1240@cindex disassembly endianness
1241Specify the endianness of the object files. This only affects
1242disassembly. This can be useful when disassembling a file format which
1243does not describe endianness information, such as S-records.
1244
1245@item -f
1246@itemx --file-header
1247@cindex object file header
1248Display summary information from the overall header of
1249each of the @var{objfile} files.
1250
1251@item -h
1252@itemx --section-header
1253@itemx --header
1254@cindex section headers
1255Display summary information from the section headers of the
1256object file.
1257
1258File segments may be relocated to nonstandard addresses, for example by
1259using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1260@code{ld}. However, some object file formats, such as a.out, do not
1261store the starting address of the file segments. In those situations,
1262although @code{ld} relocates the sections correctly, using @samp{objdump
1263-h} to list the file section headers cannot show the correct addresses.
1264Instead, it shows the usual addresses, which are implicit for the
1265target.
1266
1267@item --help
1268Print a summary of the options to @code{objdump} and exit.
1269
1270@item -i
1271@itemx --info
1272@cindex architectures available
1273@cindex object formats available
1274Display a list showing all architectures and object formats available
1275for specification with @samp{-b} or @samp{-m}.
1276
1277@item -j @var{name}
1278@itemx --section=@var{name}
1279@cindex section information
1280Display information only for section @var{name}.
1281
1282@item -l
1283@itemx --line-numbers
1284@cindex source filenames for object files
1285Label the display (using debugging information) with the filename and
1286source line numbers corresponding to the object code or relocs shown.
1287Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1288
1289@item -m @var{machine}
1290@itemx --architecture=@var{machine}
1291@cindex architecture
1292@cindex disassembly architecture
1293Specify the architecture to use when disassembling object files. This
1294can be useful when disassembling object files which do not describe
1295architecture information, such as S-records. You can list the available
1296architectures with the @samp{-i} option.
1297
1298@item -p
1299@itemx --private-headers
1300Print information that is specific to the object file format. The exact
1301information printed depends upon the object file format. For some
1302object file formats, no additional information is printed.
1303
1304@item -r
1305@itemx --reloc
1306@cindex relocation entries, in object file
1307Print the relocation entries of the file. If used with @samp{-d} or
1308@samp{-D}, the relocations are printed interspersed with the
1309disassembly.
1310
1311@item -R
1312@itemx --dynamic-reloc
1313@cindex dynamic relocation entries, in object file
1314Print the dynamic relocation entries of the file. This is only
1315meaningful for dynamic objects, such as certain types of shared
1316libraries.
1317
1318@item -s
1319@itemx --full-contents
1320@cindex sections, full contents
1321@cindex object file sections
1322Display the full contents of any sections requested.
1323
1324@item -S
1325@itemx --source
1326@cindex source disassembly
1327@cindex disassembly, with source
1328Display source code intermixed with disassembly, if possible. Implies
1329@samp{-d}.
1330
1331@item --show-raw-insn
1332When disassembling instructions, print the instruction in hex as well as
1333in symbolic form. This is the default except when
1334@code{--prefix-addresses} is used.
1335
1336@item --no-show-raw-insn
1337When disassembling instructions, do not print the instruction bytes.
1338This is the default when @code{--prefix-addresses} is used.
1339
1340@item --stabs
1341@cindex stab
1342@cindex .stab
1343@cindex debug symbols
1344@cindex ELF object file format
1345Display the full contents of any sections requested. Display the
1346contents of the .stab and .stab.index and .stab.excl sections from an
1347ELF file. This is only useful on systems (such as Solaris 2.0) in which
1348@code{.stab} debugging symbol-table entries are carried in an ELF
1349section. In most other file formats, debugging symbol-table entries are
1350interleaved with linkage symbols, and are visible in the @samp{--syms}
1351output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1352Overview,stabs.info, The ``stabs'' debug format}.
1353
1354@item --start-address=@var{address}
1355@cindex start-address
1356Start displaying data at the specified address. This affects the output
1357of the @code{-d}, @code{-r} and @code{-s} options.
1358
1359@item --stop-address=@var{address}
1360@cindex stop-address
1361Stop displaying data at the specified address. This affects the output
1362of the @code{-d}, @code{-r} and @code{-s} options.
1363
1364@item -t
1365@itemx --syms
1366@cindex symbol table entries, printing
1367Print the symbol table entries of the file.
1368This is similar to the information provided by the @samp{nm} program.
1369
1370@item -T
1371@itemx --dynamic-syms
1372@cindex dynamic symbol table entries, printing
1373Print the dynamic symbol table entries of the file. This is only
1374meaningful for dynamic objects, such as certain types of shared
1375libraries. This is similar to the information provided by the @samp{nm}
1376program when given the @samp{-D} (@samp{--dynamic}) option.
1377
1378@item --version
1379Print the version number of @code{objdump} and exit.
1380
1381@item -x
1382@itemx --all-header
1383@cindex all header information, object file
1384@cindex header information, all
1385Display all available header information, including the symbol table and
1386relocation entries. Using @samp{-x} is equivalent to specifying all of
1387@samp{-a -f -h -r -t}.
1388
1389@item -w
1390@itemx --wide
1391@cindex wide output, printing
1392Format some lines for output devices that have more than 80 columns.
1393@end table
1394
1395@node ranlib
1396@chapter ranlib
1397
1398@kindex ranlib
1399@cindex archive contents
1400@cindex symbol index
1401
1402@smallexample
1403ranlib [-vV] @var{archive}
1404@end smallexample
1405
1406@code{ranlib} generates an index to the contents of an archive and
1407stores it in the archive. The index lists each symbol defined by a
1408member of an archive that is a relocatable object file.
1409
1410You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1411
1412An archive with such an index speeds up linking to the library and
1413allows routines in the library to call each other without regard to
1414their placement in the archive.
1415
1416The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1417@code{ranlib} is completely equivalent to executing @samp{ar -s}.
1418@xref{ar}.
1419
1420@table @code
1421@item -v
1422@itemx -V
1423Show the version number of @code{ranlib}.
1424@end table
1425
1426@node size
1427@chapter size
1428
1429@kindex size
1430@cindex section sizes
1431
1432@smallexample
1433size [ -A | -B | --format=@var{compatibility} ]
1434 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1435 [ --target=@var{bfdname} ] [ -V | --version ]
1436 [ @var{objfile}@dots{} ]
1437@end smallexample
1438
1439The @sc{gnu} @code{size} utility lists the section sizes---and the total
1440size---for each of the object or archive files @var{objfile} in its
1441argument list. By default, one line of output is generated for each
1442object file or each module in an archive.
1443
1444@var{objfile}@dots{} are the object files to be examined.
1445If none are specified, the file @code{a.out} will be used.
1446
1447The command line options have the following meanings:
1448
1449@table @code
1450@item -A
1451@itemx -B
1452@itemx --format=@var{compatibility}
1453@cindex @code{size} display format
1454Using one of these options, you can choose whether the output from @sc{gnu}
1455@code{size} resembles output from System V @code{size} (using @samp{-A},
1456or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1457@samp{--format=berkeley}). The default is the one-line format similar to
1458Berkeley's.
1459@c Bonus for doc-source readers: you can also say --format=strange (or
1460@c anything else that starts with 's') for sysv, and --format=boring (or
1461@c anything else that starts with 'b') for Berkeley.
1462
1463Here is an example of the Berkeley (default) format of output from
1464@code{size}:
1465@smallexample
1466size --format=Berkeley ranlib size
1467text data bss dec hex filename
1468294880 81920 11592 388392 5ed28 ranlib
1469294880 81920 11888 388688 5ee50 size
1470@end smallexample
1471
1472@noindent
1473This is the same data, but displayed closer to System V conventions:
1474
1475@smallexample
1476size --format=SysV ranlib size
1477ranlib :
1478section size addr
1479.text 294880 8192
1480.data 81920 303104
1481.bss 11592 385024
1482Total 388392
1483
1484
1485size :
1486section size addr
1487.text 294880 8192
1488.data 81920 303104
1489.bss 11888 385024
1490Total 388688
1491@end smallexample
1492
1493@item --help
1494Show a summary of acceptable arguments and options.
1495
1496@item -d
1497@itemx -o
1498@itemx -x
1499@itemx --radix=@var{number}
1500@cindex @code{size} number format
1501@cindex radix for section sizes
1502Using one of these options, you can control whether the size of each
1503section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1504(@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1505@samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1506values (8, 10, 16) are supported. The total size is always given in two
1507radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1508octal and hexadecimal if you're using @samp{-o}.
1509
1510@item --target=@var{bfdname}
1511@cindex object code format
1512Specify that the object-code format for @var{objfile} is
1513@var{bfdname}. This option may not be necessary; @code{size} can
1514automatically recognize many formats.
1515@xref{Target Selection}, for more information.
1516
1517@item -V
1518@itemx --version
1519Display the version number of @code{size}.
1520@end table
1521
1522@node strings
1523@chapter strings
1524@kindex strings
1525@cindex listings strings
1526@cindex printing strings
1527@cindex strings, printing
1528
1529@smallexample
1530strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1531 [--all] [--print-file-name] [--bytes=@var{min-len}]
1532 [--radix=@var{radix}] [--target=@var{bfdname}]
1533 [--help] [--version] @var{file}@dots{}
1534@end smallexample
1535
1536For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1537character sequences that are at least 4 characters long (or the number
1538given with the options below) and are followed by an unprintable
1539character. By default, it only prints the strings from the initialized
1540and loaded sections of object files; for other types of files, it prints
1541the strings from the whole file.
1542
1543@code{strings} is mainly useful for determining the contents of non-text
1544files.
1545
1546@table @code
1547@item -a
1548@itemx --all
1549@itemx -
1550Do not scan only the initialized and loaded sections of object files;
1551scan the whole files.
1552
1553@item -f
1554@itemx --print-file-name
1555Print the name of the file before each string.
1556
1557@item --help
1558Print a summary of the program usage on the standard output and exit.
1559
1560@item -@var{min-len}
1561@itemx -n @var{min-len}
1562@itemx --bytes=@var{min-len}
1563Print sequences of characters that are at least @var{min-len} characters
1564long, instead of the default 4.
1565
1566@item -o
1567Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1568act like @samp{-t d} instead. Since we can not be compatible with both
1569ways, we simply chose one.
1570
1571@item -t @var{radix}
1572@itemx --radix=@var{radix}
1573Print the offset within the file before each string. The single
1574character argument specifies the radix of the offset---@samp{o} for
1575octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1576
1577@item --target=@var{bfdname}
1578@cindex object code format
1579Specify an object code format other than your system's default format.
1580@xref{Target Selection}, for more information.
1581
1582@item -v
1583@itemx --version
1584Print the program version number on the standard output and exit.
1585@end table
1586
1587@node strip
1588@chapter strip
1589
1590@kindex strip
1591@cindex removing symbols
1592@cindex discarding symbols
1593@cindex symbols, discarding
1594
1595@smallexample
1596strip [ -F @var{bfdname} | --target=@var{bfdname} ]
1597 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1598 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1599 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1600 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1601 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1602 [ -x | --discard-all ] [ -X | --discard-locals ]
1603 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1604 [ -o @var{file} ] [ -p | --preserve-dates ]
1605 [ -v | --verbose ] [ -V | --version ] [ --help ]
1606 @var{objfile}@dots{}
1607@end smallexample
1608
1609@sc{gnu} @code{strip} discards all symbols from object files
1610@var{objfile}. The list of object files may include archives.
1611At least one object file must be given.
1612
1613@code{strip} modifies the files named in its argument,
1614rather than writing modified copies under different names.
1615
1616@table @code
1617@item -F @var{bfdname}
1618@itemx --target=@var{bfdname}
1619Treat the original @var{objfile} as a file with the object
1620code format @var{bfdname}, and rewrite it in the same format.
1621@xref{Target Selection}, for more information.
1622
1623@item --help
1624Show a summary of the options to @code{strip} and exit.
1625
1626@item -I @var{bfdname}
1627@itemx --input-target=@var{bfdname}
1628Treat the original @var{objfile} as a file with the object
1629code format @var{bfdname}.
1630@xref{Target Selection}, for more information.
1631
1632@item -O @var{bfdname}
1633@itemx --output-target=@var{bfdname}
1634Replace @var{objfile} with a file in the output format @var{bfdname}.
1635@xref{Target Selection}, for more information.
1636
1637@item -R @var{sectionname}
1638@itemx --remove-section=@var{sectionname}
1639Remove any section named @var{sectionname} from the output file. This
1640option may be given more than once. Note that using this option
1641inappropriately may make the output file unusable.
1642
1643@item -s
1644@itemx --strip-all
1645Remove all symbols.
1646
1647@item -g
1648@itemx -S
1649@itemx --strip-debug
1650Remove debugging symbols only.
1651
1652@item --strip-unneeded
1653Remove all symbols that are not needed for relocation processing.
1654
1655@item -K @var{symbolname}
1656@itemx --keep-symbol=@var{symbolname}
1657Keep only symbol @var{symbolname} from the source file. This option may
1658be given more than once.
1659
1660@item -N @var{symbolname}
1661@itemx --strip-symbol=@var{symbolname}
1662Remove symbol @var{symbolname} from the source file. This option may be
1663given more than once, and may be combined with strip options other than
1664@code{-K}.
1665
1666@item -o @var{file}
1667Put the stripped output in @var{file}, rather than replacing the
1668existing file. When this argument is used, only one @var{objfile}
1669argument may be specified.
1670
1671@item -p
1672@itemx --preserve-dates
1673Preserve the access and modification dates of the file.
1674
1675@item -x
1676@itemx --discard-all
1677Remove non-global symbols.
1678
1679@item -X
1680@itemx --discard-locals
1681Remove compiler-generated local symbols.
1682(These usually start with @samp{L} or @samp{.}.)
1683
1684@item -V
1685@itemx --version
1686Show the version number for @code{strip}.
1687
1688@item -v
1689@itemx --verbose
1690Verbose output: list all object files modified. In the case of
1691archives, @samp{strip -v} lists all members of the archive.
1692@end table
1693
1694@node c++filt
1695@chapter c++filt
1696
1697@kindex c++filt
1698@cindex demangling C++ symbols
1699
1700@smallexample
1701c++filt [ -_ | --strip-underscores ]
1702 [ -j | --java ]
1703 [ -n | --no-strip-underscores ]
1704 [ -s @var{format} | --format=@var{format} ]
1705 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1706@end smallexample
1707
1708The C++ and Java languages provides function overloading, which means
1709that you can write many functions with the same name (providing each
1710takes parameters of different types). All C++ and Java function names
1711are encoded into a low-level assembly label (this process is known as
1712@dfn{mangling}). The @code{c++filt} program does the inverse mapping: it
1713decodes (@dfn{demangles}) low-level names into user-level names so that
1714the linker can keep these overloaded functions from clashing.
1715
1716Every alphanumeric word (consisting of letters, digits, underscores,
1717dollars, or periods) seen in the input is a potential label. If the
1718label decodes into a C++ name, the C++ name replaces the low-level
1719name in the output.
1720
1721You can use @code{c++filt} to decipher individual symbols:
1722
1723@example
1724c++filt @var{symbol}
1725@end example
1726
1727If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1728names from the standard input and writes the demangled names to the
1729standard output. All results are printed on the standard output.
1730
1731@table @code
1732@item -_
1733@itemx --strip-underscores
1734On some systems, both the C and C++ compilers put an underscore in front
1735of every name. For example, the C name @code{foo} gets the low-level
1736name @code{_foo}. This option removes the initial underscore. Whether
1737@code{c++filt} removes the underscore by default is target dependent.
1738
1739@item -j
1740@itemx --java
1741Prints demangled names using Java syntax. The default is to use C++
1742syntax.
1743
1744@item -n
1745@itemx --no-strip-underscores
1746Do not remove the initial underscore.
1747
1748@item -s @var{format}
1749@itemx --format=@var{format}
1750@sc{gnu} @code{nm} can decode three different methods of mangling, used by
1751different C++ compilers. The argument to this option selects which
1752method it uses:
1753
1754@table @code
1755@item gnu
1756the one used by the @sc{gnu} compiler (the default method)
1757@item lucid
1758the one used by the Lucid compiler
1759@item arm
1760the one specified by the C++ Annotated Reference Manual
1761@item hp
1762the one used by the HP compiler
1763@item edg
1764the one used by the EDG compiler
1765@end table
1766
1767@item --help
1768Print a summary of the options to @code{c++filt} and exit.
1769
1770@item --version
1771Print the version number of @code{c++filt} and exit.
1772@end table
1773
1774@quotation
1775@emph{Warning:} @code{c++filt} is a new utility, and the details of its
1776user interface are subject to change in future releases. In particular,
1777a command-line option may be required in the the future to decode a name
1778passed as an argument on the command line; in other words,
1779
1780@example
1781c++filt @var{symbol}
1782@end example
1783
1784@noindent
1785may in a future release become
1786
1787@example
1788c++filt @var{option} @var{symbol}
1789@end example
1790@end quotation
1791
1792@node addr2line
1793@chapter addr2line
1794
1795@kindex addr2line
1796@cindex address to file name and line number
1797
1798@smallexample
1799addr2line [ -b @var{bfdname} | --target=@var{bfdname} ]
1800 [ -C | --demangle ]
1801 [ -e @var{filename} | --exe=@var{filename} ]
1802 [ -f | --functions ] [ -s | --basename ]
1803 [ -H | --help ] [ -V | --version ]
1804 [ addr addr ... ]
1805@end smallexample
1806
1807@code{addr2line} translates program addresses into file names and line
1808numbers. Given an address and an executable, it uses the debugging
1809information in the executable to figure out which file name and line
1810number are associated with a given address.
1811
1812The executable to use is specified with the @code{-e} option. The
1813default is @file{a.out}.
1814
1815@code{addr2line} has two modes of operation.
1816
1817In the first, hexadecimal addresses are specified on the command line,
1818and @code{addr2line} displays the file name and line number for each
1819address.
1820
1821In the second, @code{addr2line} reads hexadecimal addresses from
1822standard input, and prints the file name and line number for each
1823address on standard output. In this mode, @code{addr2line} may be used
1824in a pipe to convert dynamically chosen addresses.
1825
1826The format of the output is @samp{FILENAME:LINENO}. The file name and
1827line number for each address is printed on a separate line. If the
1828@code{-f} option is used, then each @samp{FILENAME:LINENO} line is
1829preceded by a @samp{FUNCTIONNAME} line which is the name of the function
1830containing the address.
1831
1832If the file name or function name can not be determined,
1833@code{addr2line} will print two question marks in their place. If the
1834line number can not be determined, @code{addr2line} will print 0.
1835
1836The long and short forms of options, shown here as alternatives, are
1837equivalent.
1838
1839@table @code
1840@item -b @var{bfdname}
1841@itemx --target=@var{bfdname}
1842@cindex object code format
1843Specify that the object-code format for the object files is
1844@var{bfdname}.
1845
1846@item -C
1847@itemx --demangle
1848@cindex demangling in objdump
1849Decode (@dfn{demangle}) low-level symbol names into user-level names.
1850Besides removing any initial underscore prepended by the system, this
1851makes C++ function names readable. @xref{c++filt}, for more information
1852on demangling.
1853
1854@item -e @var{filename}
1855@itemx --exe=@var{filename}
1856Specify the name of the executable for which addresses should be
1857translated. The default file is @file{a.out}.
1858
1859@item -f
1860@itemx --functions
1861Display function names as well as file and line number information.
1862
1863@item -s
1864@itemx --basenames
1865Display only the base of each file name.
1866@end table
1867
1868@node nlmconv
1869@chapter nlmconv
1870
1871@code{nlmconv} converts a relocatable object file into a NetWare
1872Loadable Module.
1873
1874@ignore
1875@code{nlmconv} currently works with @samp{i386} object
1876files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1877object files in @sc{elf}, or @code{a.out} format@footnote{
1878@code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1879format in the Binary File Descriptor library. It has only been tested
1880with the above formats.}.
1881@end ignore
1882
1883@quotation
1884@emph{Warning:} @code{nlmconv} is not always built as part of the binary
1885utilities, since it is only useful for NLM targets.
1886@end quotation
1887
1888@smallexample
1889nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1890 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1891 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1892 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1893 [ -h | --help ] [ -V | --version ]
1894 @var{infile} @var{outfile}
1895@end smallexample
1896
1897@code{nlmconv} converts the relocatable @samp{i386} object file
1898@var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1899reading @var{headerfile} for NLM header information. For instructions
1900on writing the NLM command file language used in header files, see the
1901@samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1902Development and Tools Overview}, which is part of the NLM Software
1903Developer's Kit (``NLM SDK''), available from Novell, Inc.
1904@code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1905@var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1906more information.
1907
1908@code{nlmconv} can perform a link step. In other words, you can list
1909more than one object file for input if you list them in the definitions
1910file (rather than simply specifying one input file on the command line).
1911In this case, @code{nlmconv} calls the linker for you.
1912
1913@table @code
1914@item -I @var{bfdname}
1915@itemx --input-target=@var{bfdname}
1916Object format of the input file. @code{nlmconv} can usually determine
1917the format of a given file (so no default is necessary).
1918@xref{Target Selection}, for more information.
1919
1920@item -O @var{bfdname}
1921@itemx --output-target=@var{bfdname}
1922Object format of the output file. @code{nlmconv} infers the output
1923format based on the input format, e.g. for a @samp{i386} input file the
1924output format is @samp{nlm32-i386}.
1925@xref{Target Selection}, for more information.
1926
1927@item -T @var{headerfile}
1928@itemx --header-file=@var{headerfile}
1929Reads @var{headerfile} for NLM header information. For instructions on
1930writing the NLM command file language used in header files, see@ see the
1931@samp{linkers} section, of the @cite{NLM Development and Tools
1932Overview}, which is part of the NLM Software Developer's Kit, available
1933from Novell, Inc.
1934
1935@item -d
1936@itemx --debug
1937Displays (on standard error) the linker command line used by @code{nlmconv}.
1938
1939@item -l @var{linker}
1940@itemx --linker=@var{linker}
1941Use @var{linker} for any linking. @var{linker} can be an absolute or a
1942relative pathname.
1943
1944@item -h
1945@itemx --help
1946Prints a usage summary.
1947
1948@item -V
1949@itemx --version
1950Prints the version number for @code{nlmconv}.
1951@end table
1952
1953@node windres
1954@chapter windres
1955
1956@code{windres} may be used to manipulate Windows resources.
1957
1958@quotation
1959@emph{Warning:} @code{windres} is not always built as part of the binary
1960utilities, since it is only useful for Windows targets.
1961@end quotation
1962
1963@smallexample
1964windres [options] [input-file] [output-file]
1965@end smallexample
1966
1967@code{windres} reads resources from an input file and copies them into
1968an output file. Either file may be in one of three formats:
1969
1970@table @code
1971@item rc
1972A text format read by the Resource Compiler.
1973
1974@item res
1975A binary format generated by the Resource Compiler.
1976
1977@item coff
1978A COFF object or executable.
1979@end table
1980
1981The exact description of these different formats is available in
1982documentation from Microsoft.
1983
1984When @code{windres} converts from the @code{rc} format to the @code{res}
1985format, it is acting like the Windows Resource Compiler. When
1986@code{windres} converts from the @code{res} format to the @code{coff}
1987format, it is acting like the Windows @code{CVTRES} program.
1988
1989When @code{windres} generates an @code{rc} file, the output is similar
1990but not identical to the format expected for the input. When an input
1991@code{rc} file refers to an external filename, an output @code{rc} file
1992will instead include the file contents.
1993
1994If the input or output format is not specified, @code{windres} will
1995guess based on the file name, or, for the input file, the file contents.
1996A file with an extension of @file{.rc} will be treated as an @code{rc}
1997file, a file with an extension of @file{.res} will be treated as a
1998@code{res} file, and a file with an extension of @file{.o} or
1999@file{.exe} will be treated as a @code{coff} file.
2000
2001If no output file is specified, @code{windres} will print the resources
2002in @code{rc} format to standard output.
2003
2004The normal use is for you to write an @code{rc} file, use @code{windres}
2005to convert it to a COFF object file, and then link the COFF file into
2006your application. This will make the resources described in the
2007@code{rc} file available to Windows.
2008
2009@table @code
2010@item -i @var{filename}
2011@itemx --input @var{filename}
2012The name of the input file. If this option is not used, then
2013@code{windres} will use the first non-option argument as the input file
2014name. If there are no non-option arguments, then @code{windres} will
2015read from standard input. @code{windres} can not read a COFF file from
2016standard input.
2017
2018@item -o @var{filename}
2019@itemx --output @var{filename}
2020The name of the output file. If this option is not used, then
2021@code{windres} will use the first non-option argument, after any used
2022for the input file name, as the output file name. If there is no
2023non-option argument, then @code{windres} will write to standard output.
2024@code{windres} can not write a COFF file to standard output.
2025
2026@item -I @var{format}
2027@itemx --input-format @var{format}
2028The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
2029@samp{coff}. If no input format is specified, @code{windres} will
2030guess, as described above.
2031
2032@item -O @var{format}
2033@itemx --output-format @var{format}
2034The output format to generate. @var{format} may be @samp{res},
2035@samp{rc}, or @samp{coff}. If no output format is specified,
2036@code{windres} will guess, as described above.
2037
2038@item -F @var{target}
2039@itemx --target @var{target}
2040Specify the BFD format to use for a COFF file as input or output. This
2041is a BFD target name; you can use the @code{--help} option to see a list
2042of supported targets. Normally @code{windres} will use the default
2043format, which is the first one listed by the @code{--help} option.
2044@ref{Target Selection}.
2045
2046@item --preprocessor @var{program}
2047When @code{windres} reads an @code{rc} file, it runs it through the C
2048preprocessor first. This option may be used to specify the preprocessor
2049to use, including any leading arguments. The default preprocessor
2050argument is @code{gcc -E -xc-header -DRC_INVOKED}.
2051
2052@item --include-dir @var{directory}
2053Specify an include directory to use when reading an @code{rc} file.
2054@code{windres} will pass this to the preprocessor as an @code{-I}
2055option. @code{windres} will also search this directory when looking for
2056files named in the @code{rc} file.
2057
751d21b5 2058@item -D @var{target}
c89746f6 2059@itemx --define @var{sym[=val]}
252b5132
RH
2060Specify a @code{-D} option to pass to the preprocessor when reading an
2061@code{rc} file.
2062
751d21b5
DD
2063@item -v
2064Enable verbose mode. This tells you what the preprocessor is if you
2065didn't specify one.
2066
252b5132
RH
2067@item --language @var{val}
2068Specify the default language to use when reading an @code{rc} file.
2069@var{val} should be a hexadecimal language code. The low eight bits are
2070the language, and the high eight bits are the sublanguage.
2071
2072@item --help
2073Prints a usage summary.
2074
2075@item --version
2076Prints the version number for @code{windres}.
2077
2078@item --yydebug
2079If @code{windres} is compiled with @code{YYDEBUG} defined as @code{1},
2080this will turn on parser debugging.
2081@end table
2082
2083
2084@node dlltool
2085@chapter Create files needed to build and use DLLs
2086@cindex DLL
2087@kindex dlltool
2088
2089@code{dlltool} may be used to create the files needed to build and use
2090dynamic link libraries (DLLs).
2091
2092@quotation
2093@emph{Warning:} @code{dlltool} is not always built as part of the binary
2094utilities, since it is only useful for those targets which support DLLs.
2095@end quotation
2096
2097@smallexample
2098dlltool [-d|--input-def @var{def-file-name}]
2099 [-b|--base-file @var{base-file-name}]
2100 [-e|--output-exp @var{exports-file-name}]
2101 [-z|--output-def @var{def-file-name}]
2102 [-l|--output-lib @var{library-file-name}]
2103 [--export-all-symbols] [--no-export-all-symbols]
2104 [--exclude-symbols @var{list}]
2105 [--no-default-excludes]
2106 [-S|--as @var{path-to-assembler}] [-f|--as-flags @var{options}]
2107 [-D|--dllname @var{name}] [-m|--machine @var{machine}]
2108 [-a|--add-indirect] [-U|--add-underscore] [-k|--kill-at]
2109 [-A|--add-stdcall-alias]
2110 [-x|--no-idata4] [-c|--no-idata5] [-i|--interwork]
2111 [-n|--nodelete] [-v|--verbose] [-h|--help] [-V|--version]
2112 [object-file @dots{}]
2113@end smallexample
2114
2115@code{dlltool} reads its inputs, which can come from the @samp{-d} and
2116@samp{-b} options as well as object files specified on the command
2117line. It then processes these inputs and if the @samp{-e} option has
2118been specified it creates a exports file. If the @samp{-l} option
2119has been specified it creates a library file and if the @samp{-z} option
2120has been specified it creates a def file. Any or all of the -e, -l
2121and -z options can be present in one invocation of dlltool.
2122
2123When creating a DLL, along with the source for the DLL, it is necessary
2124to have three other files. @code{dlltool} can help with the creation of
2125these files.
2126
2127The first file is a @samp{.def} file which specifies which functions are
2128exported from the DLL, which functions the DLL imports, and so on. This
2129is a text file and can be created by hand, or @code{dlltool} can be used
2130to create it using the @samp{-z} option. In this case @code{dlltool}
2131will scan the object files specified on its command line looking for
2132those functions which have been specially marked as being exported and
2133put entries for them in the .def file it creates.
2134
2135In order to mark a function as being exported from a DLL, it needs to
2136have an @samp{-export:<name_of_function>} entry in the @samp{.drectve}
2137section of the object file. This can be done in C by using the
2138asm() operator:
2139
2140@smallexample
2141 asm (".section .drectve");
2142 asm (".ascii \"-export:my_func\"");
2143
2144 int my_func (void) @{ @dots{} @}
2145@end smallexample
2146
2147The second file needed for DLL creation is an exports file. This file
2148is linked with the object files that make up the body of the DLL and it
2149handles the interface between the DLL and the outside world. This is a
2150binary file and it can be created by giving the @samp{-e} option to
2151@code{dlltool} when it is creating or reading in a .def file.
2152
2153The third file needed for DLL creation is the library file that programs
2154will link with in order to access the functions in the DLL. This file
2155can be created by giving the @samp{-l} option to dlltool when it
2156is creating or reading in a .def file.
2157
2158@code{dlltool} builds the library file by hand, but it builds the
2159exports file by creating temporary files containing assembler statements
2160and then assembling these. The @samp{-S} command line option can be
2161used to specify the path to the assembler that dlltool will use,
2162and the @samp{-f} option can be used to pass specific flags to that
2163assembler. The @samp{-n} can be used to prevent dlltool from deleting
2164these temporary assembler files when it is done, and if @samp{-n} is
2165specified twice then this will prevent dlltool from deleting the
2166temporary object files it used to build the library.
2167
2168Here is an example of creating a DLL from a source file @samp{dll.c} and
2169also creating a program (from an object file called @samp{program.o})
2170that uses that DLL:
2171
2172@smallexample
2173 gcc -c dll.c
2174 dlltool -e exports.o -l dll.lib dll.o
2175 gcc dll.o exports.o -o dll.dll
2176 gcc program.o dll.lib -o program
2177@end smallexample
2178
2179The command line options have the following meanings:
2180
2181@table @code
2182
2183@item -d @var{filename}
2184@itemx --input-def @var{filename}
2185@cindex input .def file
2186Specifies the name of a .def file to be read in and processed.
2187
2188@item -b @var{filename}
2189@itemx --base-file @var{filename}
2190@cindex base files
2191Specifies the name of a base file to be read in and processed. The
2192contents of this file will be added to the relocation section in the
2193exports file generated by dlltool.
2194
2195@item -e @var{filename}
2196@itemx --output-exp @var{filename}
2197Specifies the name of the export file to be created by dlltool.
2198
2199@item -z @var{filename}
2200@itemx --output-def @var{filename}
2201Specifies the name of the .def file to be created by dlltool.
2202
2203@item -l @var{filename}
2204@itemx --output-lib @var{filename}
2205Specifies the name of the library file to be created by dlltool.
2206
2207@item --export-all-symbols
2208Treat all global and weak defined symbols found in the input object
2209files as symbols to be exported. There is a small list of symbols which
2210are not exported by default; see the @code{--no-default-excludes}
2211option. You may add to the list of symbols to not export by using the
2212@code{--exclude-symbols} option.
2213
2214@item --no-export-all-symbols
2215Only export symbols explicitly listed in an input .def file or in
2216@samp{.drectve} sections in the input object files. This is the default
2217behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
2218attributes in the source code.
2219
2220@item --exclude-symbols @var{list}
2221Do not export the symbols in @var{list}. This is a list of symbol names
2222separated by comma or colon characters. The symbol names should not
2223contain a leading underscore. This is only meaningful when
2224@code{--export-all-symbols} is used.
2225
2226@item --no-default-excludes
2227When @code{--export-all-symbols} is used, it will by default avoid
2228exporting certain special symbols. The current list of symbols to avoid
2229exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
2230@samp{impure_ptr}. You may use the @code{--no-default-excludes} option
2231to go ahead and export these special symbols. This is only meaningful
2232when @code{--export-all-symbols} is used.
2233
2234@item -S @var{path}
2235@itemx --as @var{path}
2236Specifies the path, including the filename, of the assembler to be used
2237to create the exports file.
2238
2239@item -f @var{switches}
2240@itemx --as-flags @var{switches}
2241Specifies any specific command line switches to be passed to the
2242assembler when building the exports file. This option will work even if
2243the @samp{-S} option is not used. This option only takes one argument,
2244and if it occurs more than once on the command line, then later
2245occurrences will override earlier occurrences. So if it is necessary to
2246pass multiple switches to the assembler they should be enclosed in
2247double quotes.
2248
2249@item -D @var{name}
2250@itemx --dll-name @var{name}
2251Specifies the name to be stored in the .def file as the name of the DLL
2252when the @samp{-e} option is used. If this option is not present, then
2253the filename given to the @samp{-e} option will be used as the name of
2254the DLL.
2255
2256@item -m @var{machine}
2257@itemx -machine @var{machine}
2258Specifies the type of machine for which the library file should be
2259built. @code{dlltool} has a built in default type, depending upon how
2260it was created, but this option can be used to override that. This is
2261normally only useful when creating DLLs for an ARM processor, when the
2262contents of the DLL are actually encode using THUMB instructions.
2263
2264@item -a
2265@itemx --add-indirect
2266Specifies that when @code{dlltool} is creating the exports file it
2267should add a section which allows the exported functions to be
2268referenced without using the import library. Whatever the hell that
2269means!
2270
2271@item -U
2272@itemx --add-underscore
2273Specifies that when @code{dlltool} is creating the exports file it
2274should prepend an underscore to the names of the exported functions.
2275
2276@item -k
2277@itemx --kill-at
2278Specifies that when @code{dlltool} is creating the exports file it
2279should not append the string @samp{@@ <number>}. These numbers are
2280called ordinal numbers and they represent another way of accessing the
2281function in a DLL, other than by name.
2282
2283@item -A
2284@itemx --add-stdcall-alias
2285Specifies that when @code{dlltool} is creating the exports file it
2286should add aliases for stdcall symbols without @samp{@@ <number>}
2287in addition to the symbols with @samp{@@ <number>}.
2288
2289@item -x
2290@itemx --no-idata4
2291Specifies that when @code{dlltool} is creating the exports and library
2292files it should omit the .idata4 section. This is for compatibility
2293with certain operating systems.
2294
2295@item -c
2296@itemx --no-idata5
2297Specifies that when @code{dlltool} is creating the exports and library
2298files it should omit the .idata5 section. This is for compatibility
2299with certain operating systems.
2300
2301@item -i
2302@itemx --interwork
2303Specifies that @code{dlltool} should mark the objects in the library
2304file and exports file that it produces as supporting interworking
2305between ARM and THUMB code.
2306
2307@item -n
2308@itemx --nodelete
2309Makes @code{dlltool} preserve the temporary assembler files it used to
2310create the exports file. If this option is repeated then dlltool will
2311also preserve the temporary object files it uses to create the library
2312file.
2313
2314@item -v
2315@itemx --verbose
2316Make dlltool describe what it is doing.
2317
2318@item -h
2319@itemx --help
2320Displays a list of command line options and then exits.
2321
2322@item -V
2323@itemx --version
2324Displays dlltool's version number and then exits.
2325
2326@end table
2327
2328@node readelf
2329@chapter readelf
2330
2331@cindex ELF file information
2332@kindex readelf
2333
2334@smallexample
2335readelf [ -a | --all ]
2336 [ -h | --file-header]
2337 [ -l | --program-headers | --segments]
2338 [ -S | --section-headers | --sections]
2339 [ -e | --headers]
2340 [ -s | --syms | --symbols]
2341 [ -r | --relocs]
2342 [ -d | --dynamic]
2343 [ -V | --version-info]
2344 [ -D | --use-dynamic]
2345 [ -x <number> | --hex-dump=<number>]
2346 [ -w[liapr] | --debug-dump[=info,=line,=abbrev,=pubnames,=ranges]]
2347 [ --histogram]
2348 [ -v | --version]
2349 [ -H | --help]
2350 @var{elffile}@dots{}
2351@end smallexample
2352
2353@code{readelf} displays information about one or more ELF format object
2354files. The options control what particular information to display.
2355
2356@var{elffile}@dots{} are the object files to be examined. At the
2357moment, @code{readelf} does not support examining archives, nor does it
2358support examing 64 bit ELF files.
2359
2360The long and short forms of options, shown here as alternatives, are
2361equivalent. At least one option besides @samp{-v} or @samp{-H} must be
2362given.
2363
2364@table @code
2365@item -a
2366@itemx --all
2367Equivalent to specifiying @samp{--file-header},
2368@samp{--program-headers}, @samp{--sections}, @samp{--symbols},
2369@samp{--relocs}, @samp{--dynamic} and @samp{--version-info}.
2370
2371@item -h
2372@itemx --file-header
2373@cindex ELF file header information
2374Displays the information contained in the ELF header at the start of the
2375file.
2376
2377@item -l
2378@itemx --program-headers
2379@itemx --segments
2380@cindex ELF program header information
2381@cindex ELF segment information
2382Displays the information contained in the file's segment headers, if it
2383has any.
2384
2385@item -S
2386@itemx --sections
2387@itemx --section-headers
2388@cindex ELF section information
2389Displays the information contained in the file's section headers, if it
2390has any.
2391
2392@item -s
2393@itemx --symbols
2394@itemx --syms
2395@cindex ELF symbol table information
2396Displays the entries in symbol table section of the file, if it has one.
2397
2398@item -e
2399@itemx --headers
2400Display all the headers in the file. Equivalent to @samp{-h -l -S}.
2401
2402@item -r
2403@itemx --relocs
2404@cindex ELF reloc information
2405Displays the contents of the file's relocation section, if it ha one.
2406
2407@item -d
2408@itemx --dynamic
2409@cindex ELF dynamic section information
2410Displays the contents of the file's dynamic section, if it has one.
2411
2412@item -V
2413@itemx --version-info
2414@cindex ELF version sections informations
2415Displays the contents of the version sections in the file, it they
2416exist.
2417
2418@item -D
2419@itemx --use-dynamic
2420When displaying symbols, this option makes @code{readelf} use the
2421symblol table in the file's dynamic section, rather than the one in the
2422symbols section.
2423
2424@item -x <number>
2425@itemx --hex-dump=<number>
2426Displays the contents of the indicated section as a hexadecimal dump.
2427
2428@item -w[liapr]
2429@itemx --debug-dump[=line,=info,=abbrev,=pubnames,=ranges]
2430Displays the contents of the debug sections in the file, if any are
2431present. If one of the optional letters or words follows the switch
2432then only data found in those specific sections will be dumped.
2433
2434@item --histogram
2435Display a histogram of bucket list lengths when displaying the contents
2436of the symbol tables.
2437
2438@item -v
2439@itemx --version
2440Display the version number of readelf.
2441
2442@item -H
2443@itemx --help
2444Display the command line options understood by @code{readelf}.
2445
2446@end table
2447
2448
2449@node Selecting The Target System
2450@chapter Selecting the target system
2451
2452You can specify three aspects of the target system to the @sc{gnu}
2453binary file utilities, each in several ways:
2454
2455@itemize @bullet
2456@item
2457the target
2458
2459@item
2460the architecture
2461
2462@item
2463the linker emulation (which applies to the linker only)
2464@end itemize
2465
2466In the following summaries, the lists of ways to specify values are in
2467order of decreasing precedence. The ways listed first override those
2468listed later.
2469
2470The commands to list valid values only list the values for which the
2471programs you are running were configured. If they were configured with
2472@samp{--enable-targets=all}, the commands list most of the available
2473values, but a few are left out; not all targets can be configured in at
2474once because some of them can only be configured @dfn{native} (on hosts
2475with the same type as the target system).
2476
2477@menu
2478* Target Selection::
2479* Architecture Selection::
2480* Linker Emulation Selection::
2481@end menu
2482
2483@node Target Selection
2484@section Target Selection
2485
2486A @dfn{target} is an object file format. A given target may be
2487supported for multiple architectures (@pxref{Architecture Selection}).
2488A target selection may also have variations for different operating
2489systems or architectures.
2490
2491The command to list valid target values is @samp{objdump -i}
2492(the first column of output contains the relevant information).
2493
2494Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
2495@samp{a.out-sunos-big}.
2496
2497You can also specify a target using a configuration triplet. This is
2498the same sort of name that is passed to configure to specify a target.
2499When you use a configuration triplet as an argument, it must be fully
2500canonicalized. You can see the canonical version of a triplet by
2501running the shell script @file{config.sub} which is included with the
2502sources.
2503
2504Some sample configuration triplets are: @samp{m68k-hp-bsd},
2505@samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
2506
2507@subheading @code{objdump} Target
2508
2509Ways to specify:
2510
2511@enumerate
2512@item
2513command line option: @samp{-b} or @samp{--target}
2514
2515@item
2516environment variable @code{GNUTARGET}
2517
2518@item
2519deduced from the input file
2520@end enumerate
2521
2522@subheading @code{objcopy} and @code{strip} Input Target
2523
2524Ways to specify:
2525
2526@enumerate
2527@item
2528command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
2529
2530@item
2531environment variable @code{GNUTARGET}
2532
2533@item
2534deduced from the input file
2535@end enumerate
2536
2537@subheading @code{objcopy} and @code{strip} Output Target
2538
2539Ways to specify:
2540
2541@enumerate
2542@item
2543command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
2544
2545@item
2546the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
2547
2548@item
2549environment variable @code{GNUTARGET}
2550
2551@item
2552deduced from the input file
2553@end enumerate
2554
2555@subheading @code{nm}, @code{size}, and @code{strings} Target
2556
2557Ways to specify:
2558
2559@enumerate
2560@item
2561command line option: @samp{--target}
2562
2563@item
2564environment variable @code{GNUTARGET}
2565
2566@item
2567deduced from the input file
2568@end enumerate
2569
2570@subheading Linker Input Target
2571
2572Ways to specify:
2573
2574@enumerate
2575@item
2576command line option: @samp{-b} or @samp{--format}
2577(@pxref{Options,,Options,ld.info,Using LD})
2578
2579@item
2580script command @code{TARGET}
2581(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2582
2583@item
2584environment variable @code{GNUTARGET}
2585(@pxref{Environment,,Environment,ld.info,Using LD})
2586
2587@item
2588the default target of the selected linker emulation
2589(@pxref{Linker Emulation Selection})
2590@end enumerate
2591
2592@subheading Linker Output Target
2593
2594Ways to specify:
2595
2596@enumerate
2597@item
2598command line option: @samp{-oformat}
2599(@pxref{Options,,Options,ld.info,Using LD})
2600
2601@item
2602script command @code{OUTPUT_FORMAT}
2603(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2604
2605@item
2606the linker input target (see ``Linker Input Target'' above)
2607@end enumerate
2608
2609@node Architecture Selection
2610@section Architecture selection
2611
2612An @dfn{architecture} is a type of @sc{cpu} on which an object file is
2613to run. Its name may contain a colon, separating the name of the
2614processor family from the name of the particular @sc{cpu}.
2615
2616The command to list valid architecture values is @samp{objdump -i} (the
2617second column contains the relevant information).
2618
2619Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
2620
2621@subheading @code{objdump} Architecture
2622
2623Ways to specify:
2624
2625@enumerate
2626@item
2627command line option: @samp{-m} or @samp{--architecture}
2628
2629@item
2630deduced from the input file
2631@end enumerate
2632
2633@subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
2634
2635Ways to specify:
2636
2637@enumerate
2638@item
2639deduced from the input file
2640@end enumerate
2641
2642@subheading Linker Input Architecture
2643
2644Ways to specify:
2645
2646@enumerate
2647@item
2648deduced from the input file
2649@end enumerate
2650
2651@subheading Linker Output Architecture
2652
2653Ways to specify:
2654
2655@enumerate
2656@item
2657script command @code{OUTPUT_ARCH}
2658(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2659
2660@item
2661the default architecture from the linker output target
2662(@pxref{Target Selection})
2663@end enumerate
2664
2665@node Linker Emulation Selection
2666@section Linker emulation selection
2667
2668A linker @dfn{emulation} is a ``personality'' of the linker, which gives
2669the linker default values for the other aspects of the target system.
2670In particular, it consists of
2671
2672@itemize @bullet
2673@item
2674the linker script
2675
2676@item
2677the target
2678
2679@item
2680several ``hook'' functions that are run at certain stages of the linking
2681process to do special things that some targets require
2682@end itemize
2683
2684The command to list valid linker emulation values is @samp{ld -V}.
2685
2686Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
2687
2688Ways to specify:
2689
2690@enumerate
2691@item
2692command line option: @samp{-m}
2693(@pxref{Options,,Options,ld.info,Using LD})
2694
2695@item
2696environment variable @code{LDEMULATION}
2697
2698@item
2699compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2700which comes from @code{EMUL} in @file{config/@var{target}.mt}
2701@end enumerate
2702
2703@node Reporting Bugs
2704@chapter Reporting Bugs
2705@cindex bugs
2706@cindex reporting bugs
2707
2708Your bug reports play an essential role in making the binary utilities
2709reliable.
2710
2711Reporting a bug may help you by bringing a solution to your problem, or
2712it may not. But in any case the principal function of a bug report is
2713to help the entire community by making the next version of the binary
2714utilities work better. Bug reports are your contribution to their
2715maintenance.
2716
2717In order for a bug report to serve its purpose, you must include the
2718information that enables us to fix the bug.
2719
2720@menu
2721* Bug Criteria:: Have you found a bug?
2722* Bug Reporting:: How to report bugs
2723@end menu
2724
2725@node Bug Criteria
2726@section Have you found a bug?
2727@cindex bug criteria
2728
2729If you are not sure whether you have found a bug, here are some guidelines:
2730
2731@itemize @bullet
2732@cindex fatal signal
2733@cindex crash
2734@item
2735If a binary utility gets a fatal signal, for any input whatever, that is
2736a bug. Reliable utilities never crash.
2737
2738@cindex error on valid input
2739@item
2740If a binary utility produces an error message for valid input, that is a
2741bug.
2742
2743@item
2744If you are an experienced user of binary utilities, your suggestions for
2745improvement are welcome in any case.
2746@end itemize
2747
2748@node Bug Reporting
2749@section How to report bugs
2750@cindex bug reports
2751@cindex bugs, reporting
2752
2753A number of companies and individuals offer support for @sc{gnu}
2754products. If you obtained the binary utilities from a support
2755organization, we recommend you contact that organization first.
2756
2757You can find contact information for many support companies and
2758individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2759distribution.
2760
2761In any event, we also recommend that you send bug reports for the binary
2762utilities to @samp{bug-gnu-utils@@gnu.org}.
2763
2764The fundamental principle of reporting bugs usefully is this:
2765@strong{report all the facts}. If you are not sure whether to state a
2766fact or leave it out, state it!
2767
2768Often people omit facts because they think they know what causes the
2769problem and assume that some details do not matter. Thus, you might
2770assume that the name of a file you use in an example does not matter.
2771Well, probably it does not, but one cannot be sure. Perhaps the bug is
2772a stray memory reference which happens to fetch from the location where
2773that pathname is stored in memory; perhaps, if the pathname were
2774different, the contents of that location would fool the utility into
2775doing the right thing despite the bug. Play it safe and give a
2776specific, complete example. That is the easiest thing for you to do,
2777and the most helpful.
2778
2779Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2780it is new to us. Therefore, always write your bug reports on the assumption
2781that the bug has not been reported previously.
2782
2783Sometimes people give a few sketchy facts and ask, ``Does this ring a
2784bell?'' Those bug reports are useless, and we urge everyone to
2785@emph{refuse to respond to them} except to chide the sender to report
2786bugs properly.
2787
2788To enable us to fix the bug, you should include all these things:
2789
2790@itemize @bullet
2791@item
2792The version of the utility. Each utility announces it if you start it
2793with the @samp{--version} argument.
2794
2795Without this, we will not know whether there is any point in looking for
2796the bug in the current version of the binary utilities.
2797
2798@item
2799Any patches you may have applied to the source, including any patches
2800made to the @code{BFD} library.
2801
2802@item
2803The type of machine you are using, and the operating system name and
2804version number.
2805
2806@item
2807What compiler (and its version) was used to compile the utilities---e.g.
2808``@code{gcc-2.7}''.
2809
2810@item
2811The command arguments you gave the utility to observe the bug. To
2812guarantee you will not omit something important, list them all. A copy
2813of the Makefile (or the output from make) is sufficient.
2814
2815If we were to try to guess the arguments, we would probably guess wrong
2816and then we might not encounter the bug.
2817
2818@item
2819A complete input file, or set of input files, that will reproduce the
2820bug. If the utility is reading an object file or files, then it is
2821generally most helpful to send the actual object files, uuencoded if
2822necessary to get them through the mail system. Making them available
2823for anonymous FTP is not as good, but may be the only reasonable choice
2824for large object files.
2825
2826If the source files were produced exclusively using @sc{gnu} programs
2827(e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2828may be OK to send the source files rather than the object files. In
2829this case, be sure to say exactly what version of @code{gcc}, or
2830whatever, was used to produce the object files. Also say how
2831@code{gcc}, or whatever, was configured.
2832
2833@item
2834A description of what behavior you observe that you believe is
2835incorrect. For example, ``It gets a fatal signal.''
2836
2837Of course, if the bug is that the utility gets a fatal signal, then we
2838will certainly notice it. But if the bug is incorrect output, we might
2839not notice unless it is glaringly wrong. You might as well not give us
2840a chance to make a mistake.
2841
2842Even if the problem you experience is a fatal signal, you should still
2843say so explicitly. Suppose something strange is going on, such as, your
2844copy of the utility is out of synch, or you have encountered a bug in
2845the C library on your system. (This has happened!) Your copy might
2846crash and ours would not. If you told us to expect a crash, then when
2847ours fails to crash, we would know that the bug was not happening for
2848us. If you had not told us to expect a crash, then we would not be able
2849to draw any conclusion from our observations.
2850
2851@item
2852If you wish to suggest changes to the source, send us context diffs, as
2853generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2854option. Always send diffs from the old file to the new file. If you
2855even discuss something in the @code{ld} source, refer to it by context,
2856not by line number.
2857
2858The line numbers in our development sources will not match those in your
2859sources. Your line numbers would convey no useful information to us.
2860@end itemize
2861
2862Here are some things that are not necessary:
2863
2864@itemize @bullet
2865@item
2866A description of the envelope of the bug.
2867
2868Often people who encounter a bug spend a lot of time investigating
2869which changes to the input file will make the bug go away and which
2870changes will not affect it.
2871
2872This is often time consuming and not very useful, because the way we
2873will find the bug is by running a single example under the debugger
2874with breakpoints, not by pure deduction from a series of examples.
2875We recommend that you save your time for something else.
2876
2877Of course, if you can find a simpler example to report @emph{instead}
2878of the original one, that is a convenience for us. Errors in the
2879output will be easier to spot, running under the debugger will take
2880less time, and so on.
2881
2882However, simplification is not vital; if you do not want to do this,
2883report the bug anyway and send us the entire test case you used.
2884
2885@item
2886A patch for the bug.
2887
2888A patch for the bug does help us if it is a good one. But do not omit
2889the necessary information, such as the test case, on the assumption that
2890a patch is all we need. We might see problems with your patch and decide
2891to fix the problem another way, or we might not understand it at all.
2892
2893Sometimes with programs as complicated as the binary utilities it is
2894very hard to construct an example that will make the program follow a
2895certain path through the code. If you do not send us the example, we
2896will not be able to construct one, so we will not be able to verify that
2897the bug is fixed.
2898
2899And if we cannot understand what bug you are trying to fix, or why your
2900patch should be an improvement, we will not install it. A test case will
2901help us to understand.
2902
2903@item
2904A guess about what the bug is or what it depends on.
2905
2906Such guesses are usually wrong. Even we cannot guess right about such
2907things without first using the debugger to find the facts.
2908@end itemize
2909
2910@node Index
2911@unnumbered Index
2912
2913@printindex cp
2914
2915@contents
2916@bye
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