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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
557tv @var{archive}}). (This single command is a @sc{gnu} @code{ld}
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} ]
840 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
841 [ -p | --preserve-dates ] [ --debugging ]
842 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
843 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
844 [ --change-addresses=@var{incr} ]
845 [ --change-section-address=@var{section}@{=,+,-@}@var{val} ]
846 [ --change-section-lma=@var{section}@{=,+,-@}@var{val} ]
847 [ --change-section-vma=@var{section}@{=,+,-@}@var{val} ]
848 [ --change-warnings ] [ --no-change-warnings ]
849 [ --set-section-flags=@var{section}=@var{flags} ]
850 [ --add-section=@var{sectionname}=@var{filename} ]
851 [ --change-leading-char ] [ --remove-leading-char ]
852 [ --weaken ]
853 [ -v | --verbose ] [ -V | --version ] [ --help ]
854 @var{infile} [@var{outfile}]
855@end smallexample
856
857The @sc{gnu} @code{objcopy} utility copies the contents of an object
858file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
859read and write the object files. It can write the destination object
860file in a format different from that of the source object file. The
861exact behavior of @code{objcopy} is controlled by command-line options.
862
863@code{objcopy} creates temporary files to do its translations and
864deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
865translation work; it has access to all the formats described in @sc{bfd}
866and thus is able to recognize most formats without being told
867explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
868
869@code{objcopy} can be used to generate S-records by using an output
870target of @samp{srec} (e.g., use @samp{-O srec}).
871
872@code{objcopy} can be used to generate a raw binary file by using an
873output target of @samp{binary} (e.g., use @samp{-O binary}). When
874@code{objcopy} generates a raw binary file, it will essentially produce
875a memory dump of the contents of the input object file. All symbols and
876relocation information will be discarded. The memory dump will start at
877the load address of the lowest section copied into the output file.
878
879When generating an S-record or a raw binary file, it may be helpful to
880use @samp{-S} to remove sections containing debugging information. In
881some cases @samp{-R} will be useful to remove sections which contain
882information which is not needed by the binary file.
883
884@table @code
885@item @var{infile}
886@itemx @var{outfile}
887The source and output files, respectively.
888If you do not specify @var{outfile}, @code{objcopy} creates a
889temporary file and destructively renames the result with
890the name of @var{infile}.
891
892@item -I @var{bfdname}
893@itemx --input-target=@var{bfdname}
894Consider the source file's object format to be @var{bfdname}, rather than
895attempting to deduce it. @xref{Target Selection}, for more information.
896
897@item -O @var{bfdname}
898@itemx --output-target=@var{bfdname}
899Write the output file using the object format @var{bfdname}.
900@xref{Target Selection}, for more information.
901
902@item -F @var{bfdname}
903@itemx --target=@var{bfdname}
904Use @var{bfdname} as the object format for both the input and the output
905file; i.e., simply transfer data from source to destination with no
906translation. @xref{Target Selection}, for more information.
907
908@item -R @var{sectionname}
909@itemx --remove-section=@var{sectionname}
910Remove any section named @var{sectionname} from the output file. This
911option may be given more than once. Note that using this option
912inappropriately may make the output file unusable.
913
914@item -S
915@itemx --strip-all
916Do not copy relocation and symbol information from the source file.
917
918@item -g
919@itemx --strip-debug
920Do not copy debugging symbols from the source file.
921
922@item --strip-unneeded
923Strip all symbols that are not needed for relocation processing.
924
925@item -K @var{symbolname}
926@itemx --keep-symbol=@var{symbolname}
927Copy only symbol @var{symbolname} from the source file. This option may
928be given more than once.
929
930@item -N @var{symbolname}
931@itemx --strip-symbol=@var{symbolname}
932Do not copy symbol @var{symbolname} from the source file. This option
933may be given more than once.
934
935@item -L @var{symbolname}
936@itemx --localize-symbol=@var{symbolname}
937Make symbol @var{symbolname} local to the file, so that it is not
938visible externally. This option may be given more than once.
939
940@item -W @var{symbolname}
941@itemx --weaken-symbol=@var{symbolname}
942Make symbol @var{symbolname} weak. This option may be given more than once.
943
944@item -x
945@itemx --discard-all
946Do not copy non-global symbols from the source file.
947@c FIXME any reason to prefer "non-global" to "local" here?
948
949@item -X
950@itemx --discard-locals
951Do not copy compiler-generated local symbols.
952(These usually start with @samp{L} or @samp{.}.)
953
954@item -b @var{byte}
955@itemx --byte=@var{byte}
956Keep only every @var{byte}th byte of the input file (header data is not
957affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
958where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
959option, or the default of 4. This option is useful for creating files
960to program @sc{rom}. It is typically used with an @code{srec} output
961target.
962
963@item -i @var{interleave}
964@itemx --interleave=@var{interleave}
965Only copy one out of every @var{interleave} bytes. Select which byte to
966copy with the @var{-b} or @samp{--byte} option. The default is 4.
967@code{objcopy} ignores this option if you do not specify either @samp{-b} or
968@samp{--byte}.
969
970@item -p
971@itemx --preserve-dates
972Set the access and modification dates of the output file to be the same
973as those of the input file.
974
975@item --debugging
976Convert debugging information, if possible. This is not the default
977because only certain debugging formats are supported, and the
978conversion process can be time consuming.
979
980@item --gap-fill @var{val}
981Fill gaps between sections with @var{val}. This operation applies to
982the @emph{load address} (LMA) of the sections. It is done by increasing
983the size of the section with the lower address, and filling in the extra
984space created with @var{val}.
985
986@item --pad-to @var{address}
987Pad the output file up to the load address @var{address}. This is
988done by increasing the size of the last section. The extra space is
989filled in with the value specified by @samp{--gap-fill} (default zero).
990
991@item --set-start @var{val}
992Set the address of the new file to @var{val}. Not all object file
993formats support setting the start address.
994
995@item --change-start @var{incr}
996@itemx --adjust-start @var{incr}
997@cindex changing start address
998Change the start address by adding @var{incr}. Not all object file
999formats support setting the start address.
1000
1001@item --change-addresses @var{incr}
1002@itemx --adjust-vma @var{incr}
1003@cindex changing object addresses
1004Change the VMA and LMA addresses of all sections, as well as the start
1005address, by adding @var{incr}. Some object file formats do not permit
1006section addresses to be changed arbitrarily. Note that this does not
1007relocate the sections; if the program expects sections to be loaded at a
1008certain address, and this option is used to change the sections such
1009that they are loaded at a different address, the program may fail.
1010
1011@item --change-section-address @var{section}@{=,+,-@}@var{val}
1012@itemx --adjust-section-vma @var{section}@{=,+,-@}@var{val}
1013@cindex changing section address
1014Set or change both the VMA address and the LMA address of the named
1015@var{section}. If @samp{=} is used, the section address is set to
1016@var{val}. Otherwise, @var{val} is added to or subtracted from the
1017section address. See the comments under @samp{--change-addresses},
1018above. If @var{section} does not exist in the input file, a warning will
1019be issued, unless @samp{--no-change-warnings} is used.
1020
1021@item --change-section-lma @var{section}@{=,+,-@}@var{val}
1022@cindex changing section LMA
1023Set or change the LMA address of the named @var{section}. The LMA
1024address is the address where the section will be loaded into memory at
1025program load time. Normally this is the same as the VMA address, which
1026is the address of the section at program run time, but on some systems,
1027especially those where a program is held in ROM, the two can be
1028different. If @samp{=} is used, the section address is set to
1029@var{val}. Otherwise, @var{val} is added to or subtracted from the
1030section address. See the comments under @samp{--change-addresses},
1031above. If @var{section} does not exist in the input file, a warning
1032will be issued, unless @samp{--no-change-warnings} is used.
1033
1034@item --change-section-vma @var{section}@{=,+,-@}@var{val}
1035@cindex changing section VMA
1036Set or change the VMA address of the named @var{section}. The VMA
1037address is the address where the section will be located once the
1038program has started executing. Normally this is the same as the LMA
1039address, which is the address where the section will be loaded into
1040memory, but on some systems, especially those where a program is held in
1041ROM, the two can be different. If @samp{=} is used, the section address
1042is set to @var{val}. Otherwise, @var{val} is added to or subtracted
1043from the section address. See the comments under
1044@samp{--change-addresses}, above. If @var{section} does not exist in
1045the input file, a warning will be issued, unless
1046@samp{--no-change-warnings} is used.
1047
1048@item --change-warnings
1049@itemx --adjust-warnings
1050If @samp{--change-section-address} or @samp{--change-section-lma} or
1051@samp{--change-section-vma} is used, and the named section does not
1052exist, issue a warning. This is the default.
1053
1054@item --no-change-warnings
1055@itemx --no-adjust-warnings
1056Do not issue a warning if @samp{--change-section-address} or
1057@samp{--adjust-section-lma} or @samp{--adjust-section-vma} is used, even
1058if the named section does not exist.
1059
1060@item --set-section-flags @var{section}=@var{flags}
1061Set the flags for the named section. The @var{flags} argument is a
1062comma separated string of flag names. The recognized names are
1063@samp{alloc}, @samp{contents}, @samp{load}, @samp{readonly},
1064@samp{code}, @samp{data}, and @samp{rom}. You can set the
1065@samp{contents} flag for a section which does not have contents, but it
1066is not meaningful to clear the @samp{contents} flag of a section which
1067does have contents--just remove the section instead. Not all flags are
1068meaningful for all object file formats.
1069
1070@item --add-section @var{sectionname}=@var{filename}
1071Add a new section named @var{sectionname} while copying the file. The
1072contents of the new section are taken from the file @var{filename}. The
1073size of the section will be the size of the file. This option only
1074works on file formats which can support sections with arbitrary names.
1075
1076@item --change-leading-char
1077Some object file formats use special characters at the start of
1078symbols. The most common such character is underscore, which compilers
1079often add before every symbol. This option tells @code{objcopy} to
1080change the leading character of every symbol when it converts between
1081object file formats. If the object file formats use the same leading
1082character, this option has no effect. Otherwise, it will add a
1083character, or remove a character, or change a character, as
1084appropriate.
1085
1086@item --remove-leading-char
1087If the first character of a global symbol is a special symbol leading
1088character used by the object file format, remove the character. The
1089most common symbol leading character is underscore. This option will
1090remove a leading underscore from all global symbols. This can be useful
1091if you want to link together objects of different file formats with
1092different conventions for symbol names. This is different from
1093@code{--change-leading-char} because it always changes the symbol name
1094when appropriate, regardless of the object file format of the output
1095file.
1096
1097@item --weaken
1098Change all global symbols in the file to be weak. This can be useful
1099when building an object which will be linked against other objects using
1100the @code{-R} option to the linker. This option is only effective when
1101using an object file format which supports weak symbols.
1102
1103@item -V
1104@itemx --version
1105Show the version number of @code{objcopy}.
1106
1107@item -v
1108@itemx --verbose
1109Verbose output: list all object files modified. In the case of
1110archives, @samp{objcopy -V} lists all members of the archive.
1111
1112@item --help
1113Show a summary of the options to @code{objcopy}.
1114@end table
1115
1116@node objdump
1117@chapter objdump
1118
1119@cindex object file information
1120@kindex objdump
1121
1122@smallexample
1123objdump [ -a | --archive-headers ]
1124 [ -b @var{bfdname} | --target=@var{bfdname} ] [ --debugging ]
1125 [ -C | --demangle ] [ -d | --disassemble ]
1126 [ -D | --disassemble-all ] [ --disassemble-zeroes ]
1127 [ -EB | -EL | --endian=@{big | little @} ]
1128 [ -f | --file-headers ]
1129 [ -h | --section-headers | --headers ] [ -i | --info ]
1130 [ -j @var{section} | --section=@var{section} ]
1131 [ -l | --line-numbers ] [ -S | --source ]
1132 [ -m @var{machine} | --architecture=@var{machine} ]
1133 [ -p | --private-headers ]
1134 [ -r | --reloc ] [ -R | --dynamic-reloc ]
1135 [ -s | --full-contents ] [ --stabs ]
1136 [ -t | --syms ] [ -T | --dynamic-syms ] [ -x | --all-headers ]
1137 [ -w | --wide ] [ --start-address=@var{address} ]
1138 [ --stop-address=@var{address} ]
1139 [ --prefix-addresses] [ --[no-]show-raw-insn ]
1140 [ --adjust-vma=@var{offset} ]
1141 [ --version ] [ --help ]
1142 @var{objfile}@dots{}
1143@end smallexample
1144
1145@code{objdump} displays information about one or more object files.
1146The options control what particular information to display. This
1147information is mostly useful to programmers who are working on the
1148compilation tools, as opposed to programmers who just want their
1149program to compile and work.
1150
1151@var{objfile}@dots{} are the object files to be examined. When you
1152specify archives, @code{objdump} shows information on each of the member
1153object files.
1154
1155The long and short forms of options, shown here as alternatives, are
1156equivalent. At least one option besides @samp{-l} must be given.
1157
1158@table @code
1159@item -a
1160@itemx --archive-header
1161@cindex archive headers
1162If any of the @var{objfile} files are archives, display the archive
1163header information (in a format similar to @samp{ls -l}). Besides the
1164information you could list with @samp{ar tv}, @samp{objdump -a} shows
1165the object file format of each archive member.
1166
1167@item --adjust-vma=@var{offset}
1168@cindex section addresses in objdump
1169@cindex VMA in objdump
1170When dumping information, first add @var{offset} to all the section
1171addresses. This is useful if the section addresses do not correspond to
1172the symbol table, which can happen when putting sections at particular
1173addresses when using a format which can not represent section addresses,
1174such as a.out.
1175
1176@item -b @var{bfdname}
1177@itemx --target=@var{bfdname}
1178@cindex object code format
1179Specify that the object-code format for the object files is
1180@var{bfdname}. This option may not be necessary; @var{objdump} can
1181automatically recognize many formats.
1182
1183For example,
1184@example
1185objdump -b oasys -m vax -h fu.o
1186@end example
1187@noindent
1188displays summary information from the section headers (@samp{-h}) of
1189@file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1190file in the format produced by Oasys compilers. You can list the
1191formats available with the @samp{-i} option.
1192@xref{Target Selection}, for more information.
1193
1194@item -C
1195@itemx --demangle
1196@cindex demangling in objdump
1197Decode (@dfn{demangle}) low-level symbol names into user-level names.
1198Besides removing any initial underscore prepended by the system, this
1199makes C++ function names readable. @xref{c++filt}, for more information
1200on demangling.
1201
1202@item --debugging
1203Display debugging information. This attempts to parse debugging
1204information stored in the file and print it out using a C like syntax.
1205Only certain types of debugging information have been implemented.
1206
1207@item -d
1208@itemx --disassemble
1209@cindex disassembling object code
1210@cindex machine instructions
1211Display the assembler mnemonics for the machine instructions from
1212@var{objfile}. This option only disassembles those sections which are
1213expected to contain instructions.
1214
1215@item -D
1216@itemx --disassemble-all
1217Like @samp{-d}, but disassemble the contents of all sections, not just
1218those expected to contain instructions.
1219
1220@item --prefix-addresses
1221When disassembling, print the complete address on each line. This is
1222the older disassembly format.
1223
1224@item --disassemble-zeroes
1225Normally the disassembly output will skip blocks of zeroes. This
1226option directs the disassembler to disassemble those blocks, just like
1227any other data.
1228
1229@item -EB
1230@itemx -EL
1231@itemx --endian=@{big|little@}
1232@cindex endianness
1233@cindex disassembly endianness
1234Specify the endianness of the object files. This only affects
1235disassembly. This can be useful when disassembling a file format which
1236does not describe endianness information, such as S-records.
1237
1238@item -f
1239@itemx --file-header
1240@cindex object file header
1241Display summary information from the overall header of
1242each of the @var{objfile} files.
1243
1244@item -h
1245@itemx --section-header
1246@itemx --header
1247@cindex section headers
1248Display summary information from the section headers of the
1249object file.
1250
1251File segments may be relocated to nonstandard addresses, for example by
1252using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1253@code{ld}. However, some object file formats, such as a.out, do not
1254store the starting address of the file segments. In those situations,
1255although @code{ld} relocates the sections correctly, using @samp{objdump
1256-h} to list the file section headers cannot show the correct addresses.
1257Instead, it shows the usual addresses, which are implicit for the
1258target.
1259
1260@item --help
1261Print a summary of the options to @code{objdump} and exit.
1262
1263@item -i
1264@itemx --info
1265@cindex architectures available
1266@cindex object formats available
1267Display a list showing all architectures and object formats available
1268for specification with @samp{-b} or @samp{-m}.
1269
1270@item -j @var{name}
1271@itemx --section=@var{name}
1272@cindex section information
1273Display information only for section @var{name}.
1274
1275@item -l
1276@itemx --line-numbers
1277@cindex source filenames for object files
1278Label the display (using debugging information) with the filename and
1279source line numbers corresponding to the object code or relocs shown.
1280Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1281
1282@item -m @var{machine}
1283@itemx --architecture=@var{machine}
1284@cindex architecture
1285@cindex disassembly architecture
1286Specify the architecture to use when disassembling object files. This
1287can be useful when disassembling object files which do not describe
1288architecture information, such as S-records. You can list the available
1289architectures with the @samp{-i} option.
1290
1291@item -p
1292@itemx --private-headers
1293Print information that is specific to the object file format. The exact
1294information printed depends upon the object file format. For some
1295object file formats, no additional information is printed.
1296
1297@item -r
1298@itemx --reloc
1299@cindex relocation entries, in object file
1300Print the relocation entries of the file. If used with @samp{-d} or
1301@samp{-D}, the relocations are printed interspersed with the
1302disassembly.
1303
1304@item -R
1305@itemx --dynamic-reloc
1306@cindex dynamic relocation entries, in object file
1307Print the dynamic relocation entries of the file. This is only
1308meaningful for dynamic objects, such as certain types of shared
1309libraries.
1310
1311@item -s
1312@itemx --full-contents
1313@cindex sections, full contents
1314@cindex object file sections
1315Display the full contents of any sections requested.
1316
1317@item -S
1318@itemx --source
1319@cindex source disassembly
1320@cindex disassembly, with source
1321Display source code intermixed with disassembly, if possible. Implies
1322@samp{-d}.
1323
1324@item --show-raw-insn
1325When disassembling instructions, print the instruction in hex as well as
1326in symbolic form. This is the default except when
1327@code{--prefix-addresses} is used.
1328
1329@item --no-show-raw-insn
1330When disassembling instructions, do not print the instruction bytes.
1331This is the default when @code{--prefix-addresses} is used.
1332
1333@item --stabs
1334@cindex stab
1335@cindex .stab
1336@cindex debug symbols
1337@cindex ELF object file format
1338Display the full contents of any sections requested. Display the
1339contents of the .stab and .stab.index and .stab.excl sections from an
1340ELF file. This is only useful on systems (such as Solaris 2.0) in which
1341@code{.stab} debugging symbol-table entries are carried in an ELF
1342section. In most other file formats, debugging symbol-table entries are
1343interleaved with linkage symbols, and are visible in the @samp{--syms}
1344output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1345Overview,stabs.info, The ``stabs'' debug format}.
1346
1347@item --start-address=@var{address}
1348@cindex start-address
1349Start displaying data at the specified address. This affects the output
1350of the @code{-d}, @code{-r} and @code{-s} options.
1351
1352@item --stop-address=@var{address}
1353@cindex stop-address
1354Stop displaying data at the specified address. This affects the output
1355of the @code{-d}, @code{-r} and @code{-s} options.
1356
1357@item -t
1358@itemx --syms
1359@cindex symbol table entries, printing
1360Print the symbol table entries of the file.
1361This is similar to the information provided by the @samp{nm} program.
1362
1363@item -T
1364@itemx --dynamic-syms
1365@cindex dynamic symbol table entries, printing
1366Print the dynamic symbol table entries of the file. This is only
1367meaningful for dynamic objects, such as certain types of shared
1368libraries. This is similar to the information provided by the @samp{nm}
1369program when given the @samp{-D} (@samp{--dynamic}) option.
1370
1371@item --version
1372Print the version number of @code{objdump} and exit.
1373
1374@item -x
1375@itemx --all-header
1376@cindex all header information, object file
1377@cindex header information, all
1378Display all available header information, including the symbol table and
1379relocation entries. Using @samp{-x} is equivalent to specifying all of
1380@samp{-a -f -h -r -t}.
1381
1382@item -w
1383@itemx --wide
1384@cindex wide output, printing
1385Format some lines for output devices that have more than 80 columns.
1386@end table
1387
1388@node ranlib
1389@chapter ranlib
1390
1391@kindex ranlib
1392@cindex archive contents
1393@cindex symbol index
1394
1395@smallexample
1396ranlib [-vV] @var{archive}
1397@end smallexample
1398
1399@code{ranlib} generates an index to the contents of an archive and
1400stores it in the archive. The index lists each symbol defined by a
1401member of an archive that is a relocatable object file.
1402
1403You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1404
1405An archive with such an index speeds up linking to the library and
1406allows routines in the library to call each other without regard to
1407their placement in the archive.
1408
1409The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1410@code{ranlib} is completely equivalent to executing @samp{ar -s}.
1411@xref{ar}.
1412
1413@table @code
1414@item -v
1415@itemx -V
1416Show the version number of @code{ranlib}.
1417@end table
1418
1419@node size
1420@chapter size
1421
1422@kindex size
1423@cindex section sizes
1424
1425@smallexample
1426size [ -A | -B | --format=@var{compatibility} ]
1427 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1428 [ --target=@var{bfdname} ] [ -V | --version ]
1429 [ @var{objfile}@dots{} ]
1430@end smallexample
1431
1432The @sc{gnu} @code{size} utility lists the section sizes---and the total
1433size---for each of the object or archive files @var{objfile} in its
1434argument list. By default, one line of output is generated for each
1435object file or each module in an archive.
1436
1437@var{objfile}@dots{} are the object files to be examined.
1438If none are specified, the file @code{a.out} will be used.
1439
1440The command line options have the following meanings:
1441
1442@table @code
1443@item -A
1444@itemx -B
1445@itemx --format=@var{compatibility}
1446@cindex @code{size} display format
1447Using one of these options, you can choose whether the output from @sc{gnu}
1448@code{size} resembles output from System V @code{size} (using @samp{-A},
1449or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1450@samp{--format=berkeley}). The default is the one-line format similar to
1451Berkeley's.
1452@c Bonus for doc-source readers: you can also say --format=strange (or
1453@c anything else that starts with 's') for sysv, and --format=boring (or
1454@c anything else that starts with 'b') for Berkeley.
1455
1456Here is an example of the Berkeley (default) format of output from
1457@code{size}:
1458@smallexample
1459size --format=Berkeley ranlib size
1460text data bss dec hex filename
1461294880 81920 11592 388392 5ed28 ranlib
1462294880 81920 11888 388688 5ee50 size
1463@end smallexample
1464
1465@noindent
1466This is the same data, but displayed closer to System V conventions:
1467
1468@smallexample
1469size --format=SysV ranlib size
1470ranlib :
1471section size addr
1472.text 294880 8192
1473.data 81920 303104
1474.bss 11592 385024
1475Total 388392
1476
1477
1478size :
1479section size addr
1480.text 294880 8192
1481.data 81920 303104
1482.bss 11888 385024
1483Total 388688
1484@end smallexample
1485
1486@item --help
1487Show a summary of acceptable arguments and options.
1488
1489@item -d
1490@itemx -o
1491@itemx -x
1492@itemx --radix=@var{number}
1493@cindex @code{size} number format
1494@cindex radix for section sizes
1495Using one of these options, you can control whether the size of each
1496section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1497(@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1498@samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1499values (8, 10, 16) are supported. The total size is always given in two
1500radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1501octal and hexadecimal if you're using @samp{-o}.
1502
1503@item --target=@var{bfdname}
1504@cindex object code format
1505Specify that the object-code format for @var{objfile} is
1506@var{bfdname}. This option may not be necessary; @code{size} can
1507automatically recognize many formats.
1508@xref{Target Selection}, for more information.
1509
1510@item -V
1511@itemx --version
1512Display the version number of @code{size}.
1513@end table
1514
1515@node strings
1516@chapter strings
1517@kindex strings
1518@cindex listings strings
1519@cindex printing strings
1520@cindex strings, printing
1521
1522@smallexample
1523strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1524 [--all] [--print-file-name] [--bytes=@var{min-len}]
1525 [--radix=@var{radix}] [--target=@var{bfdname}]
1526 [--help] [--version] @var{file}@dots{}
1527@end smallexample
1528
1529For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1530character sequences that are at least 4 characters long (or the number
1531given with the options below) and are followed by an unprintable
1532character. By default, it only prints the strings from the initialized
1533and loaded sections of object files; for other types of files, it prints
1534the strings from the whole file.
1535
1536@code{strings} is mainly useful for determining the contents of non-text
1537files.
1538
1539@table @code
1540@item -a
1541@itemx --all
1542@itemx -
1543Do not scan only the initialized and loaded sections of object files;
1544scan the whole files.
1545
1546@item -f
1547@itemx --print-file-name
1548Print the name of the file before each string.
1549
1550@item --help
1551Print a summary of the program usage on the standard output and exit.
1552
1553@item -@var{min-len}
1554@itemx -n @var{min-len}
1555@itemx --bytes=@var{min-len}
1556Print sequences of characters that are at least @var{min-len} characters
1557long, instead of the default 4.
1558
1559@item -o
1560Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1561act like @samp{-t d} instead. Since we can not be compatible with both
1562ways, we simply chose one.
1563
1564@item -t @var{radix}
1565@itemx --radix=@var{radix}
1566Print the offset within the file before each string. The single
1567character argument specifies the radix of the offset---@samp{o} for
1568octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1569
1570@item --target=@var{bfdname}
1571@cindex object code format
1572Specify an object code format other than your system's default format.
1573@xref{Target Selection}, for more information.
1574
1575@item -v
1576@itemx --version
1577Print the program version number on the standard output and exit.
1578@end table
1579
1580@node strip
1581@chapter strip
1582
1583@kindex strip
1584@cindex removing symbols
1585@cindex discarding symbols
1586@cindex symbols, discarding
1587
1588@smallexample
1589strip [ -F @var{bfdname} | --target=@var{bfdname} ]
1590 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1591 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1592 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1593 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1594 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1595 [ -x | --discard-all ] [ -X | --discard-locals ]
1596 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1597 [ -o @var{file} ] [ -p | --preserve-dates ]
1598 [ -v | --verbose ] [ -V | --version ] [ --help ]
1599 @var{objfile}@dots{}
1600@end smallexample
1601
1602@sc{gnu} @code{strip} discards all symbols from object files
1603@var{objfile}. The list of object files may include archives.
1604At least one object file must be given.
1605
1606@code{strip} modifies the files named in its argument,
1607rather than writing modified copies under different names.
1608
1609@table @code
1610@item -F @var{bfdname}
1611@itemx --target=@var{bfdname}
1612Treat the original @var{objfile} as a file with the object
1613code format @var{bfdname}, and rewrite it in the same format.
1614@xref{Target Selection}, for more information.
1615
1616@item --help
1617Show a summary of the options to @code{strip} and exit.
1618
1619@item -I @var{bfdname}
1620@itemx --input-target=@var{bfdname}
1621Treat the original @var{objfile} as a file with the object
1622code format @var{bfdname}.
1623@xref{Target Selection}, for more information.
1624
1625@item -O @var{bfdname}
1626@itemx --output-target=@var{bfdname}
1627Replace @var{objfile} with a file in the output format @var{bfdname}.
1628@xref{Target Selection}, for more information.
1629
1630@item -R @var{sectionname}
1631@itemx --remove-section=@var{sectionname}
1632Remove any section named @var{sectionname} from the output file. This
1633option may be given more than once. Note that using this option
1634inappropriately may make the output file unusable.
1635
1636@item -s
1637@itemx --strip-all
1638Remove all symbols.
1639
1640@item -g
1641@itemx -S
1642@itemx --strip-debug
1643Remove debugging symbols only.
1644
1645@item --strip-unneeded
1646Remove all symbols that are not needed for relocation processing.
1647
1648@item -K @var{symbolname}
1649@itemx --keep-symbol=@var{symbolname}
1650Keep only symbol @var{symbolname} from the source file. This option may
1651be given more than once.
1652
1653@item -N @var{symbolname}
1654@itemx --strip-symbol=@var{symbolname}
1655Remove symbol @var{symbolname} from the source file. This option may be
1656given more than once, and may be combined with strip options other than
1657@code{-K}.
1658
1659@item -o @var{file}
1660Put the stripped output in @var{file}, rather than replacing the
1661existing file. When this argument is used, only one @var{objfile}
1662argument may be specified.
1663
1664@item -p
1665@itemx --preserve-dates
1666Preserve the access and modification dates of the file.
1667
1668@item -x
1669@itemx --discard-all
1670Remove non-global symbols.
1671
1672@item -X
1673@itemx --discard-locals
1674Remove compiler-generated local symbols.
1675(These usually start with @samp{L} or @samp{.}.)
1676
1677@item -V
1678@itemx --version
1679Show the version number for @code{strip}.
1680
1681@item -v
1682@itemx --verbose
1683Verbose output: list all object files modified. In the case of
1684archives, @samp{strip -v} lists all members of the archive.
1685@end table
1686
1687@node c++filt
1688@chapter c++filt
1689
1690@kindex c++filt
1691@cindex demangling C++ symbols
1692
1693@smallexample
1694c++filt [ -_ | --strip-underscores ]
1695 [ -j | --java ]
1696 [ -n | --no-strip-underscores ]
1697 [ -s @var{format} | --format=@var{format} ]
1698 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1699@end smallexample
1700
1701The C++ and Java languages provides function overloading, which means
1702that you can write many functions with the same name (providing each
1703takes parameters of different types). All C++ and Java function names
1704are encoded into a low-level assembly label (this process is known as
1705@dfn{mangling}). The @code{c++filt} program does the inverse mapping: it
1706decodes (@dfn{demangles}) low-level names into user-level names so that
1707the linker can keep these overloaded functions from clashing.
1708
1709Every alphanumeric word (consisting of letters, digits, underscores,
1710dollars, or periods) seen in the input is a potential label. If the
1711label decodes into a C++ name, the C++ name replaces the low-level
1712name in the output.
1713
1714You can use @code{c++filt} to decipher individual symbols:
1715
1716@example
1717c++filt @var{symbol}
1718@end example
1719
1720If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1721names from the standard input and writes the demangled names to the
1722standard output. All results are printed on the standard output.
1723
1724@table @code
1725@item -_
1726@itemx --strip-underscores
1727On some systems, both the C and C++ compilers put an underscore in front
1728of every name. For example, the C name @code{foo} gets the low-level
1729name @code{_foo}. This option removes the initial underscore. Whether
1730@code{c++filt} removes the underscore by default is target dependent.
1731
1732@item -j
1733@itemx --java
1734Prints demangled names using Java syntax. The default is to use C++
1735syntax.
1736
1737@item -n
1738@itemx --no-strip-underscores
1739Do not remove the initial underscore.
1740
1741@item -s @var{format}
1742@itemx --format=@var{format}
1743@sc{gnu} @code{nm} can decode three different methods of mangling, used by
1744different C++ compilers. The argument to this option selects which
1745method it uses:
1746
1747@table @code
1748@item gnu
1749the one used by the @sc{gnu} compiler (the default method)
1750@item lucid
1751the one used by the Lucid compiler
1752@item arm
1753the one specified by the C++ Annotated Reference Manual
1754@item hp
1755the one used by the HP compiler
1756@item edg
1757the one used by the EDG compiler
1758@end table
1759
1760@item --help
1761Print a summary of the options to @code{c++filt} and exit.
1762
1763@item --version
1764Print the version number of @code{c++filt} and exit.
1765@end table
1766
1767@quotation
1768@emph{Warning:} @code{c++filt} is a new utility, and the details of its
1769user interface are subject to change in future releases. In particular,
1770a command-line option may be required in the the future to decode a name
1771passed as an argument on the command line; in other words,
1772
1773@example
1774c++filt @var{symbol}
1775@end example
1776
1777@noindent
1778may in a future release become
1779
1780@example
1781c++filt @var{option} @var{symbol}
1782@end example
1783@end quotation
1784
1785@node addr2line
1786@chapter addr2line
1787
1788@kindex addr2line
1789@cindex address to file name and line number
1790
1791@smallexample
1792addr2line [ -b @var{bfdname} | --target=@var{bfdname} ]
1793 [ -C | --demangle ]
1794 [ -e @var{filename} | --exe=@var{filename} ]
1795 [ -f | --functions ] [ -s | --basename ]
1796 [ -H | --help ] [ -V | --version ]
1797 [ addr addr ... ]
1798@end smallexample
1799
1800@code{addr2line} translates program addresses into file names and line
1801numbers. Given an address and an executable, it uses the debugging
1802information in the executable to figure out which file name and line
1803number are associated with a given address.
1804
1805The executable to use is specified with the @code{-e} option. The
1806default is @file{a.out}.
1807
1808@code{addr2line} has two modes of operation.
1809
1810In the first, hexadecimal addresses are specified on the command line,
1811and @code{addr2line} displays the file name and line number for each
1812address.
1813
1814In the second, @code{addr2line} reads hexadecimal addresses from
1815standard input, and prints the file name and line number for each
1816address on standard output. In this mode, @code{addr2line} may be used
1817in a pipe to convert dynamically chosen addresses.
1818
1819The format of the output is @samp{FILENAME:LINENO}. The file name and
1820line number for each address is printed on a separate line. If the
1821@code{-f} option is used, then each @samp{FILENAME:LINENO} line is
1822preceded by a @samp{FUNCTIONNAME} line which is the name of the function
1823containing the address.
1824
1825If the file name or function name can not be determined,
1826@code{addr2line} will print two question marks in their place. If the
1827line number can not be determined, @code{addr2line} will print 0.
1828
1829The long and short forms of options, shown here as alternatives, are
1830equivalent.
1831
1832@table @code
1833@item -b @var{bfdname}
1834@itemx --target=@var{bfdname}
1835@cindex object code format
1836Specify that the object-code format for the object files is
1837@var{bfdname}.
1838
1839@item -C
1840@itemx --demangle
1841@cindex demangling in objdump
1842Decode (@dfn{demangle}) low-level symbol names into user-level names.
1843Besides removing any initial underscore prepended by the system, this
1844makes C++ function names readable. @xref{c++filt}, for more information
1845on demangling.
1846
1847@item -e @var{filename}
1848@itemx --exe=@var{filename}
1849Specify the name of the executable for which addresses should be
1850translated. The default file is @file{a.out}.
1851
1852@item -f
1853@itemx --functions
1854Display function names as well as file and line number information.
1855
1856@item -s
1857@itemx --basenames
1858Display only the base of each file name.
1859@end table
1860
1861@node nlmconv
1862@chapter nlmconv
1863
1864@code{nlmconv} converts a relocatable object file into a NetWare
1865Loadable Module.
1866
1867@ignore
1868@code{nlmconv} currently works with @samp{i386} object
1869files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1870object files in @sc{elf}, or @code{a.out} format@footnote{
1871@code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1872format in the Binary File Descriptor library. It has only been tested
1873with the above formats.}.
1874@end ignore
1875
1876@quotation
1877@emph{Warning:} @code{nlmconv} is not always built as part of the binary
1878utilities, since it is only useful for NLM targets.
1879@end quotation
1880
1881@smallexample
1882nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1883 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1884 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1885 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1886 [ -h | --help ] [ -V | --version ]
1887 @var{infile} @var{outfile}
1888@end smallexample
1889
1890@code{nlmconv} converts the relocatable @samp{i386} object file
1891@var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1892reading @var{headerfile} for NLM header information. For instructions
1893on writing the NLM command file language used in header files, see the
1894@samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1895Development and Tools Overview}, which is part of the NLM Software
1896Developer's Kit (``NLM SDK''), available from Novell, Inc.
1897@code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1898@var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1899more information.
1900
1901@code{nlmconv} can perform a link step. In other words, you can list
1902more than one object file for input if you list them in the definitions
1903file (rather than simply specifying one input file on the command line).
1904In this case, @code{nlmconv} calls the linker for you.
1905
1906@table @code
1907@item -I @var{bfdname}
1908@itemx --input-target=@var{bfdname}
1909Object format of the input file. @code{nlmconv} can usually determine
1910the format of a given file (so no default is necessary).
1911@xref{Target Selection}, for more information.
1912
1913@item -O @var{bfdname}
1914@itemx --output-target=@var{bfdname}
1915Object format of the output file. @code{nlmconv} infers the output
1916format based on the input format, e.g. for a @samp{i386} input file the
1917output format is @samp{nlm32-i386}.
1918@xref{Target Selection}, for more information.
1919
1920@item -T @var{headerfile}
1921@itemx --header-file=@var{headerfile}
1922Reads @var{headerfile} for NLM header information. For instructions on
1923writing the NLM command file language used in header files, see@ see the
1924@samp{linkers} section, of the @cite{NLM Development and Tools
1925Overview}, which is part of the NLM Software Developer's Kit, available
1926from Novell, Inc.
1927
1928@item -d
1929@itemx --debug
1930Displays (on standard error) the linker command line used by @code{nlmconv}.
1931
1932@item -l @var{linker}
1933@itemx --linker=@var{linker}
1934Use @var{linker} for any linking. @var{linker} can be an absolute or a
1935relative pathname.
1936
1937@item -h
1938@itemx --help
1939Prints a usage summary.
1940
1941@item -V
1942@itemx --version
1943Prints the version number for @code{nlmconv}.
1944@end table
1945
1946@node windres
1947@chapter windres
1948
1949@code{windres} may be used to manipulate Windows resources.
1950
1951@quotation
1952@emph{Warning:} @code{windres} is not always built as part of the binary
1953utilities, since it is only useful for Windows targets.
1954@end quotation
1955
1956@smallexample
1957windres [options] [input-file] [output-file]
1958@end smallexample
1959
1960@code{windres} reads resources from an input file and copies them into
1961an output file. Either file may be in one of three formats:
1962
1963@table @code
1964@item rc
1965A text format read by the Resource Compiler.
1966
1967@item res
1968A binary format generated by the Resource Compiler.
1969
1970@item coff
1971A COFF object or executable.
1972@end table
1973
1974The exact description of these different formats is available in
1975documentation from Microsoft.
1976
1977When @code{windres} converts from the @code{rc} format to the @code{res}
1978format, it is acting like the Windows Resource Compiler. When
1979@code{windres} converts from the @code{res} format to the @code{coff}
1980format, it is acting like the Windows @code{CVTRES} program.
1981
1982When @code{windres} generates an @code{rc} file, the output is similar
1983but not identical to the format expected for the input. When an input
1984@code{rc} file refers to an external filename, an output @code{rc} file
1985will instead include the file contents.
1986
1987If the input or output format is not specified, @code{windres} will
1988guess based on the file name, or, for the input file, the file contents.
1989A file with an extension of @file{.rc} will be treated as an @code{rc}
1990file, a file with an extension of @file{.res} will be treated as a
1991@code{res} file, and a file with an extension of @file{.o} or
1992@file{.exe} will be treated as a @code{coff} file.
1993
1994If no output file is specified, @code{windres} will print the resources
1995in @code{rc} format to standard output.
1996
1997The normal use is for you to write an @code{rc} file, use @code{windres}
1998to convert it to a COFF object file, and then link the COFF file into
1999your application. This will make the resources described in the
2000@code{rc} file available to Windows.
2001
2002@table @code
2003@item -i @var{filename}
2004@itemx --input @var{filename}
2005The name of the input file. If this option is not used, then
2006@code{windres} will use the first non-option argument as the input file
2007name. If there are no non-option arguments, then @code{windres} will
2008read from standard input. @code{windres} can not read a COFF file from
2009standard input.
2010
2011@item -o @var{filename}
2012@itemx --output @var{filename}
2013The name of the output file. If this option is not used, then
2014@code{windres} will use the first non-option argument, after any used
2015for the input file name, as the output file name. If there is no
2016non-option argument, then @code{windres} will write to standard output.
2017@code{windres} can not write a COFF file to standard output.
2018
2019@item -I @var{format}
2020@itemx --input-format @var{format}
2021The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
2022@samp{coff}. If no input format is specified, @code{windres} will
2023guess, as described above.
2024
2025@item -O @var{format}
2026@itemx --output-format @var{format}
2027The output format to generate. @var{format} may be @samp{res},
2028@samp{rc}, or @samp{coff}. If no output format is specified,
2029@code{windres} will guess, as described above.
2030
2031@item -F @var{target}
2032@itemx --target @var{target}
2033Specify the BFD format to use for a COFF file as input or output. This
2034is a BFD target name; you can use the @code{--help} option to see a list
2035of supported targets. Normally @code{windres} will use the default
2036format, which is the first one listed by the @code{--help} option.
2037@ref{Target Selection}.
2038
2039@item --preprocessor @var{program}
2040When @code{windres} reads an @code{rc} file, it runs it through the C
2041preprocessor first. This option may be used to specify the preprocessor
2042to use, including any leading arguments. The default preprocessor
2043argument is @code{gcc -E -xc-header -DRC_INVOKED}.
2044
2045@item --include-dir @var{directory}
2046Specify an include directory to use when reading an @code{rc} file.
2047@code{windres} will pass this to the preprocessor as an @code{-I}
2048option. @code{windres} will also search this directory when looking for
2049files named in the @code{rc} file.
2050
2051@item --define @var{sym[=val]}
2052Specify a @code{-D} option to pass to the preprocessor when reading an
2053@code{rc} file.
2054
2055@item --language @var{val}
2056Specify the default language to use when reading an @code{rc} file.
2057@var{val} should be a hexadecimal language code. The low eight bits are
2058the language, and the high eight bits are the sublanguage.
2059
2060@item --help
2061Prints a usage summary.
2062
2063@item --version
2064Prints the version number for @code{windres}.
2065
2066@item --yydebug
2067If @code{windres} is compiled with @code{YYDEBUG} defined as @code{1},
2068this will turn on parser debugging.
2069@end table
2070
2071
2072@node dlltool
2073@chapter Create files needed to build and use DLLs
2074@cindex DLL
2075@kindex dlltool
2076
2077@code{dlltool} may be used to create the files needed to build and use
2078dynamic link libraries (DLLs).
2079
2080@quotation
2081@emph{Warning:} @code{dlltool} is not always built as part of the binary
2082utilities, since it is only useful for those targets which support DLLs.
2083@end quotation
2084
2085@smallexample
2086dlltool [-d|--input-def @var{def-file-name}]
2087 [-b|--base-file @var{base-file-name}]
2088 [-e|--output-exp @var{exports-file-name}]
2089 [-z|--output-def @var{def-file-name}]
2090 [-l|--output-lib @var{library-file-name}]
2091 [--export-all-symbols] [--no-export-all-symbols]
2092 [--exclude-symbols @var{list}]
2093 [--no-default-excludes]
2094 [-S|--as @var{path-to-assembler}] [-f|--as-flags @var{options}]
2095 [-D|--dllname @var{name}] [-m|--machine @var{machine}]
2096 [-a|--add-indirect] [-U|--add-underscore] [-k|--kill-at]
2097 [-A|--add-stdcall-alias]
2098 [-x|--no-idata4] [-c|--no-idata5] [-i|--interwork]
2099 [-n|--nodelete] [-v|--verbose] [-h|--help] [-V|--version]
2100 [object-file @dots{}]
2101@end smallexample
2102
2103@code{dlltool} reads its inputs, which can come from the @samp{-d} and
2104@samp{-b} options as well as object files specified on the command
2105line. It then processes these inputs and if the @samp{-e} option has
2106been specified it creates a exports file. If the @samp{-l} option
2107has been specified it creates a library file and if the @samp{-z} option
2108has been specified it creates a def file. Any or all of the -e, -l
2109and -z options can be present in one invocation of dlltool.
2110
2111When creating a DLL, along with the source for the DLL, it is necessary
2112to have three other files. @code{dlltool} can help with the creation of
2113these files.
2114
2115The first file is a @samp{.def} file which specifies which functions are
2116exported from the DLL, which functions the DLL imports, and so on. This
2117is a text file and can be created by hand, or @code{dlltool} can be used
2118to create it using the @samp{-z} option. In this case @code{dlltool}
2119will scan the object files specified on its command line looking for
2120those functions which have been specially marked as being exported and
2121put entries for them in the .def file it creates.
2122
2123In order to mark a function as being exported from a DLL, it needs to
2124have an @samp{-export:<name_of_function>} entry in the @samp{.drectve}
2125section of the object file. This can be done in C by using the
2126asm() operator:
2127
2128@smallexample
2129 asm (".section .drectve");
2130 asm (".ascii \"-export:my_func\"");
2131
2132 int my_func (void) @{ @dots{} @}
2133@end smallexample
2134
2135The second file needed for DLL creation is an exports file. This file
2136is linked with the object files that make up the body of the DLL and it
2137handles the interface between the DLL and the outside world. This is a
2138binary file and it can be created by giving the @samp{-e} option to
2139@code{dlltool} when it is creating or reading in a .def file.
2140
2141The third file needed for DLL creation is the library file that programs
2142will link with in order to access the functions in the DLL. This file
2143can be created by giving the @samp{-l} option to dlltool when it
2144is creating or reading in a .def file.
2145
2146@code{dlltool} builds the library file by hand, but it builds the
2147exports file by creating temporary files containing assembler statements
2148and then assembling these. The @samp{-S} command line option can be
2149used to specify the path to the assembler that dlltool will use,
2150and the @samp{-f} option can be used to pass specific flags to that
2151assembler. The @samp{-n} can be used to prevent dlltool from deleting
2152these temporary assembler files when it is done, and if @samp{-n} is
2153specified twice then this will prevent dlltool from deleting the
2154temporary object files it used to build the library.
2155
2156Here is an example of creating a DLL from a source file @samp{dll.c} and
2157also creating a program (from an object file called @samp{program.o})
2158that uses that DLL:
2159
2160@smallexample
2161 gcc -c dll.c
2162 dlltool -e exports.o -l dll.lib dll.o
2163 gcc dll.o exports.o -o dll.dll
2164 gcc program.o dll.lib -o program
2165@end smallexample
2166
2167The command line options have the following meanings:
2168
2169@table @code
2170
2171@item -d @var{filename}
2172@itemx --input-def @var{filename}
2173@cindex input .def file
2174Specifies the name of a .def file to be read in and processed.
2175
2176@item -b @var{filename}
2177@itemx --base-file @var{filename}
2178@cindex base files
2179Specifies the name of a base file to be read in and processed. The
2180contents of this file will be added to the relocation section in the
2181exports file generated by dlltool.
2182
2183@item -e @var{filename}
2184@itemx --output-exp @var{filename}
2185Specifies the name of the export file to be created by dlltool.
2186
2187@item -z @var{filename}
2188@itemx --output-def @var{filename}
2189Specifies the name of the .def file to be created by dlltool.
2190
2191@item -l @var{filename}
2192@itemx --output-lib @var{filename}
2193Specifies the name of the library file to be created by dlltool.
2194
2195@item --export-all-symbols
2196Treat all global and weak defined symbols found in the input object
2197files as symbols to be exported. There is a small list of symbols which
2198are not exported by default; see the @code{--no-default-excludes}
2199option. You may add to the list of symbols to not export by using the
2200@code{--exclude-symbols} option.
2201
2202@item --no-export-all-symbols
2203Only export symbols explicitly listed in an input .def file or in
2204@samp{.drectve} sections in the input object files. This is the default
2205behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
2206attributes in the source code.
2207
2208@item --exclude-symbols @var{list}
2209Do not export the symbols in @var{list}. This is a list of symbol names
2210separated by comma or colon characters. The symbol names should not
2211contain a leading underscore. This is only meaningful when
2212@code{--export-all-symbols} is used.
2213
2214@item --no-default-excludes
2215When @code{--export-all-symbols} is used, it will by default avoid
2216exporting certain special symbols. The current list of symbols to avoid
2217exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
2218@samp{impure_ptr}. You may use the @code{--no-default-excludes} option
2219to go ahead and export these special symbols. This is only meaningful
2220when @code{--export-all-symbols} is used.
2221
2222@item -S @var{path}
2223@itemx --as @var{path}
2224Specifies the path, including the filename, of the assembler to be used
2225to create the exports file.
2226
2227@item -f @var{switches}
2228@itemx --as-flags @var{switches}
2229Specifies any specific command line switches to be passed to the
2230assembler when building the exports file. This option will work even if
2231the @samp{-S} option is not used. This option only takes one argument,
2232and if it occurs more than once on the command line, then later
2233occurrences will override earlier occurrences. So if it is necessary to
2234pass multiple switches to the assembler they should be enclosed in
2235double quotes.
2236
2237@item -D @var{name}
2238@itemx --dll-name @var{name}
2239Specifies the name to be stored in the .def file as the name of the DLL
2240when the @samp{-e} option is used. If this option is not present, then
2241the filename given to the @samp{-e} option will be used as the name of
2242the DLL.
2243
2244@item -m @var{machine}
2245@itemx -machine @var{machine}
2246Specifies the type of machine for which the library file should be
2247built. @code{dlltool} has a built in default type, depending upon how
2248it was created, but this option can be used to override that. This is
2249normally only useful when creating DLLs for an ARM processor, when the
2250contents of the DLL are actually encode using THUMB instructions.
2251
2252@item -a
2253@itemx --add-indirect
2254Specifies that when @code{dlltool} is creating the exports file it
2255should add a section which allows the exported functions to be
2256referenced without using the import library. Whatever the hell that
2257means!
2258
2259@item -U
2260@itemx --add-underscore
2261Specifies that when @code{dlltool} is creating the exports file it
2262should prepend an underscore to the names of the exported functions.
2263
2264@item -k
2265@itemx --kill-at
2266Specifies that when @code{dlltool} is creating the exports file it
2267should not append the string @samp{@@ <number>}. These numbers are
2268called ordinal numbers and they represent another way of accessing the
2269function in a DLL, other than by name.
2270
2271@item -A
2272@itemx --add-stdcall-alias
2273Specifies that when @code{dlltool} is creating the exports file it
2274should add aliases for stdcall symbols without @samp{@@ <number>}
2275in addition to the symbols with @samp{@@ <number>}.
2276
2277@item -x
2278@itemx --no-idata4
2279Specifies that when @code{dlltool} is creating the exports and library
2280files it should omit the .idata4 section. This is for compatibility
2281with certain operating systems.
2282
2283@item -c
2284@itemx --no-idata5
2285Specifies that when @code{dlltool} is creating the exports and library
2286files it should omit the .idata5 section. This is for compatibility
2287with certain operating systems.
2288
2289@item -i
2290@itemx --interwork
2291Specifies that @code{dlltool} should mark the objects in the library
2292file and exports file that it produces as supporting interworking
2293between ARM and THUMB code.
2294
2295@item -n
2296@itemx --nodelete
2297Makes @code{dlltool} preserve the temporary assembler files it used to
2298create the exports file. If this option is repeated then dlltool will
2299also preserve the temporary object files it uses to create the library
2300file.
2301
2302@item -v
2303@itemx --verbose
2304Make dlltool describe what it is doing.
2305
2306@item -h
2307@itemx --help
2308Displays a list of command line options and then exits.
2309
2310@item -V
2311@itemx --version
2312Displays dlltool's version number and then exits.
2313
2314@end table
2315
2316@node readelf
2317@chapter readelf
2318
2319@cindex ELF file information
2320@kindex readelf
2321
2322@smallexample
2323readelf [ -a | --all ]
2324 [ -h | --file-header]
2325 [ -l | --program-headers | --segments]
2326 [ -S | --section-headers | --sections]
2327 [ -e | --headers]
2328 [ -s | --syms | --symbols]
2329 [ -r | --relocs]
2330 [ -d | --dynamic]
2331 [ -V | --version-info]
2332 [ -D | --use-dynamic]
2333 [ -x <number> | --hex-dump=<number>]
2334 [ -w[liapr] | --debug-dump[=info,=line,=abbrev,=pubnames,=ranges]]
2335 [ --histogram]
2336 [ -v | --version]
2337 [ -H | --help]
2338 @var{elffile}@dots{}
2339@end smallexample
2340
2341@code{readelf} displays information about one or more ELF format object
2342files. The options control what particular information to display.
2343
2344@var{elffile}@dots{} are the object files to be examined. At the
2345moment, @code{readelf} does not support examining archives, nor does it
2346support examing 64 bit ELF files.
2347
2348The long and short forms of options, shown here as alternatives, are
2349equivalent. At least one option besides @samp{-v} or @samp{-H} must be
2350given.
2351
2352@table @code
2353@item -a
2354@itemx --all
2355Equivalent to specifiying @samp{--file-header},
2356@samp{--program-headers}, @samp{--sections}, @samp{--symbols},
2357@samp{--relocs}, @samp{--dynamic} and @samp{--version-info}.
2358
2359@item -h
2360@itemx --file-header
2361@cindex ELF file header information
2362Displays the information contained in the ELF header at the start of the
2363file.
2364
2365@item -l
2366@itemx --program-headers
2367@itemx --segments
2368@cindex ELF program header information
2369@cindex ELF segment information
2370Displays the information contained in the file's segment headers, if it
2371has any.
2372
2373@item -S
2374@itemx --sections
2375@itemx --section-headers
2376@cindex ELF section information
2377Displays the information contained in the file's section headers, if it
2378has any.
2379
2380@item -s
2381@itemx --symbols
2382@itemx --syms
2383@cindex ELF symbol table information
2384Displays the entries in symbol table section of the file, if it has one.
2385
2386@item -e
2387@itemx --headers
2388Display all the headers in the file. Equivalent to @samp{-h -l -S}.
2389
2390@item -r
2391@itemx --relocs
2392@cindex ELF reloc information
2393Displays the contents of the file's relocation section, if it ha one.
2394
2395@item -d
2396@itemx --dynamic
2397@cindex ELF dynamic section information
2398Displays the contents of the file's dynamic section, if it has one.
2399
2400@item -V
2401@itemx --version-info
2402@cindex ELF version sections informations
2403Displays the contents of the version sections in the file, it they
2404exist.
2405
2406@item -D
2407@itemx --use-dynamic
2408When displaying symbols, this option makes @code{readelf} use the
2409symblol table in the file's dynamic section, rather than the one in the
2410symbols section.
2411
2412@item -x <number>
2413@itemx --hex-dump=<number>
2414Displays the contents of the indicated section as a hexadecimal dump.
2415
2416@item -w[liapr]
2417@itemx --debug-dump[=line,=info,=abbrev,=pubnames,=ranges]
2418Displays the contents of the debug sections in the file, if any are
2419present. If one of the optional letters or words follows the switch
2420then only data found in those specific sections will be dumped.
2421
2422@item --histogram
2423Display a histogram of bucket list lengths when displaying the contents
2424of the symbol tables.
2425
2426@item -v
2427@itemx --version
2428Display the version number of readelf.
2429
2430@item -H
2431@itemx --help
2432Display the command line options understood by @code{readelf}.
2433
2434@end table
2435
2436
2437@node Selecting The Target System
2438@chapter Selecting the target system
2439
2440You can specify three aspects of the target system to the @sc{gnu}
2441binary file utilities, each in several ways:
2442
2443@itemize @bullet
2444@item
2445the target
2446
2447@item
2448the architecture
2449
2450@item
2451the linker emulation (which applies to the linker only)
2452@end itemize
2453
2454In the following summaries, the lists of ways to specify values are in
2455order of decreasing precedence. The ways listed first override those
2456listed later.
2457
2458The commands to list valid values only list the values for which the
2459programs you are running were configured. If they were configured with
2460@samp{--enable-targets=all}, the commands list most of the available
2461values, but a few are left out; not all targets can be configured in at
2462once because some of them can only be configured @dfn{native} (on hosts
2463with the same type as the target system).
2464
2465@menu
2466* Target Selection::
2467* Architecture Selection::
2468* Linker Emulation Selection::
2469@end menu
2470
2471@node Target Selection
2472@section Target Selection
2473
2474A @dfn{target} is an object file format. A given target may be
2475supported for multiple architectures (@pxref{Architecture Selection}).
2476A target selection may also have variations for different operating
2477systems or architectures.
2478
2479The command to list valid target values is @samp{objdump -i}
2480(the first column of output contains the relevant information).
2481
2482Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
2483@samp{a.out-sunos-big}.
2484
2485You can also specify a target using a configuration triplet. This is
2486the same sort of name that is passed to configure to specify a target.
2487When you use a configuration triplet as an argument, it must be fully
2488canonicalized. You can see the canonical version of a triplet by
2489running the shell script @file{config.sub} which is included with the
2490sources.
2491
2492Some sample configuration triplets are: @samp{m68k-hp-bsd},
2493@samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
2494
2495@subheading @code{objdump} Target
2496
2497Ways to specify:
2498
2499@enumerate
2500@item
2501command line option: @samp{-b} or @samp{--target}
2502
2503@item
2504environment variable @code{GNUTARGET}
2505
2506@item
2507deduced from the input file
2508@end enumerate
2509
2510@subheading @code{objcopy} and @code{strip} Input Target
2511
2512Ways to specify:
2513
2514@enumerate
2515@item
2516command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
2517
2518@item
2519environment variable @code{GNUTARGET}
2520
2521@item
2522deduced from the input file
2523@end enumerate
2524
2525@subheading @code{objcopy} and @code{strip} Output Target
2526
2527Ways to specify:
2528
2529@enumerate
2530@item
2531command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
2532
2533@item
2534the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
2535
2536@item
2537environment variable @code{GNUTARGET}
2538
2539@item
2540deduced from the input file
2541@end enumerate
2542
2543@subheading @code{nm}, @code{size}, and @code{strings} Target
2544
2545Ways to specify:
2546
2547@enumerate
2548@item
2549command line option: @samp{--target}
2550
2551@item
2552environment variable @code{GNUTARGET}
2553
2554@item
2555deduced from the input file
2556@end enumerate
2557
2558@subheading Linker Input Target
2559
2560Ways to specify:
2561
2562@enumerate
2563@item
2564command line option: @samp{-b} or @samp{--format}
2565(@pxref{Options,,Options,ld.info,Using LD})
2566
2567@item
2568script command @code{TARGET}
2569(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2570
2571@item
2572environment variable @code{GNUTARGET}
2573(@pxref{Environment,,Environment,ld.info,Using LD})
2574
2575@item
2576the default target of the selected linker emulation
2577(@pxref{Linker Emulation Selection})
2578@end enumerate
2579
2580@subheading Linker Output Target
2581
2582Ways to specify:
2583
2584@enumerate
2585@item
2586command line option: @samp{-oformat}
2587(@pxref{Options,,Options,ld.info,Using LD})
2588
2589@item
2590script command @code{OUTPUT_FORMAT}
2591(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2592
2593@item
2594the linker input target (see ``Linker Input Target'' above)
2595@end enumerate
2596
2597@node Architecture Selection
2598@section Architecture selection
2599
2600An @dfn{architecture} is a type of @sc{cpu} on which an object file is
2601to run. Its name may contain a colon, separating the name of the
2602processor family from the name of the particular @sc{cpu}.
2603
2604The command to list valid architecture values is @samp{objdump -i} (the
2605second column contains the relevant information).
2606
2607Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
2608
2609@subheading @code{objdump} Architecture
2610
2611Ways to specify:
2612
2613@enumerate
2614@item
2615command line option: @samp{-m} or @samp{--architecture}
2616
2617@item
2618deduced from the input file
2619@end enumerate
2620
2621@subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
2622
2623Ways to specify:
2624
2625@enumerate
2626@item
2627deduced from the input file
2628@end enumerate
2629
2630@subheading Linker Input Architecture
2631
2632Ways to specify:
2633
2634@enumerate
2635@item
2636deduced from the input file
2637@end enumerate
2638
2639@subheading Linker Output Architecture
2640
2641Ways to specify:
2642
2643@enumerate
2644@item
2645script command @code{OUTPUT_ARCH}
2646(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2647
2648@item
2649the default architecture from the linker output target
2650(@pxref{Target Selection})
2651@end enumerate
2652
2653@node Linker Emulation Selection
2654@section Linker emulation selection
2655
2656A linker @dfn{emulation} is a ``personality'' of the linker, which gives
2657the linker default values for the other aspects of the target system.
2658In particular, it consists of
2659
2660@itemize @bullet
2661@item
2662the linker script
2663
2664@item
2665the target
2666
2667@item
2668several ``hook'' functions that are run at certain stages of the linking
2669process to do special things that some targets require
2670@end itemize
2671
2672The command to list valid linker emulation values is @samp{ld -V}.
2673
2674Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
2675
2676Ways to specify:
2677
2678@enumerate
2679@item
2680command line option: @samp{-m}
2681(@pxref{Options,,Options,ld.info,Using LD})
2682
2683@item
2684environment variable @code{LDEMULATION}
2685
2686@item
2687compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2688which comes from @code{EMUL} in @file{config/@var{target}.mt}
2689@end enumerate
2690
2691@node Reporting Bugs
2692@chapter Reporting Bugs
2693@cindex bugs
2694@cindex reporting bugs
2695
2696Your bug reports play an essential role in making the binary utilities
2697reliable.
2698
2699Reporting a bug may help you by bringing a solution to your problem, or
2700it may not. But in any case the principal function of a bug report is
2701to help the entire community by making the next version of the binary
2702utilities work better. Bug reports are your contribution to their
2703maintenance.
2704
2705In order for a bug report to serve its purpose, you must include the
2706information that enables us to fix the bug.
2707
2708@menu
2709* Bug Criteria:: Have you found a bug?
2710* Bug Reporting:: How to report bugs
2711@end menu
2712
2713@node Bug Criteria
2714@section Have you found a bug?
2715@cindex bug criteria
2716
2717If you are not sure whether you have found a bug, here are some guidelines:
2718
2719@itemize @bullet
2720@cindex fatal signal
2721@cindex crash
2722@item
2723If a binary utility gets a fatal signal, for any input whatever, that is
2724a bug. Reliable utilities never crash.
2725
2726@cindex error on valid input
2727@item
2728If a binary utility produces an error message for valid input, that is a
2729bug.
2730
2731@item
2732If you are an experienced user of binary utilities, your suggestions for
2733improvement are welcome in any case.
2734@end itemize
2735
2736@node Bug Reporting
2737@section How to report bugs
2738@cindex bug reports
2739@cindex bugs, reporting
2740
2741A number of companies and individuals offer support for @sc{gnu}
2742products. If you obtained the binary utilities from a support
2743organization, we recommend you contact that organization first.
2744
2745You can find contact information for many support companies and
2746individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2747distribution.
2748
2749In any event, we also recommend that you send bug reports for the binary
2750utilities to @samp{bug-gnu-utils@@gnu.org}.
2751
2752The fundamental principle of reporting bugs usefully is this:
2753@strong{report all the facts}. If you are not sure whether to state a
2754fact or leave it out, state it!
2755
2756Often people omit facts because they think they know what causes the
2757problem and assume that some details do not matter. Thus, you might
2758assume that the name of a file you use in an example does not matter.
2759Well, probably it does not, but one cannot be sure. Perhaps the bug is
2760a stray memory reference which happens to fetch from the location where
2761that pathname is stored in memory; perhaps, if the pathname were
2762different, the contents of that location would fool the utility into
2763doing the right thing despite the bug. Play it safe and give a
2764specific, complete example. That is the easiest thing for you to do,
2765and the most helpful.
2766
2767Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2768it is new to us. Therefore, always write your bug reports on the assumption
2769that the bug has not been reported previously.
2770
2771Sometimes people give a few sketchy facts and ask, ``Does this ring a
2772bell?'' Those bug reports are useless, and we urge everyone to
2773@emph{refuse to respond to them} except to chide the sender to report
2774bugs properly.
2775
2776To enable us to fix the bug, you should include all these things:
2777
2778@itemize @bullet
2779@item
2780The version of the utility. Each utility announces it if you start it
2781with the @samp{--version} argument.
2782
2783Without this, we will not know whether there is any point in looking for
2784the bug in the current version of the binary utilities.
2785
2786@item
2787Any patches you may have applied to the source, including any patches
2788made to the @code{BFD} library.
2789
2790@item
2791The type of machine you are using, and the operating system name and
2792version number.
2793
2794@item
2795What compiler (and its version) was used to compile the utilities---e.g.
2796``@code{gcc-2.7}''.
2797
2798@item
2799The command arguments you gave the utility to observe the bug. To
2800guarantee you will not omit something important, list them all. A copy
2801of the Makefile (or the output from make) is sufficient.
2802
2803If we were to try to guess the arguments, we would probably guess wrong
2804and then we might not encounter the bug.
2805
2806@item
2807A complete input file, or set of input files, that will reproduce the
2808bug. If the utility is reading an object file or files, then it is
2809generally most helpful to send the actual object files, uuencoded if
2810necessary to get them through the mail system. Making them available
2811for anonymous FTP is not as good, but may be the only reasonable choice
2812for large object files.
2813
2814If the source files were produced exclusively using @sc{gnu} programs
2815(e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2816may be OK to send the source files rather than the object files. In
2817this case, be sure to say exactly what version of @code{gcc}, or
2818whatever, was used to produce the object files. Also say how
2819@code{gcc}, or whatever, was configured.
2820
2821@item
2822A description of what behavior you observe that you believe is
2823incorrect. For example, ``It gets a fatal signal.''
2824
2825Of course, if the bug is that the utility gets a fatal signal, then we
2826will certainly notice it. But if the bug is incorrect output, we might
2827not notice unless it is glaringly wrong. You might as well not give us
2828a chance to make a mistake.
2829
2830Even if the problem you experience is a fatal signal, you should still
2831say so explicitly. Suppose something strange is going on, such as, your
2832copy of the utility is out of synch, or you have encountered a bug in
2833the C library on your system. (This has happened!) Your copy might
2834crash and ours would not. If you told us to expect a crash, then when
2835ours fails to crash, we would know that the bug was not happening for
2836us. If you had not told us to expect a crash, then we would not be able
2837to draw any conclusion from our observations.
2838
2839@item
2840If you wish to suggest changes to the source, send us context diffs, as
2841generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2842option. Always send diffs from the old file to the new file. If you
2843even discuss something in the @code{ld} source, refer to it by context,
2844not by line number.
2845
2846The line numbers in our development sources will not match those in your
2847sources. Your line numbers would convey no useful information to us.
2848@end itemize
2849
2850Here are some things that are not necessary:
2851
2852@itemize @bullet
2853@item
2854A description of the envelope of the bug.
2855
2856Often people who encounter a bug spend a lot of time investigating
2857which changes to the input file will make the bug go away and which
2858changes will not affect it.
2859
2860This is often time consuming and not very useful, because the way we
2861will find the bug is by running a single example under the debugger
2862with breakpoints, not by pure deduction from a series of examples.
2863We recommend that you save your time for something else.
2864
2865Of course, if you can find a simpler example to report @emph{instead}
2866of the original one, that is a convenience for us. Errors in the
2867output will be easier to spot, running under the debugger will take
2868less time, and so on.
2869
2870However, simplification is not vital; if you do not want to do this,
2871report the bug anyway and send us the entire test case you used.
2872
2873@item
2874A patch for the bug.
2875
2876A patch for the bug does help us if it is a good one. But do not omit
2877the necessary information, such as the test case, on the assumption that
2878a patch is all we need. We might see problems with your patch and decide
2879to fix the problem another way, or we might not understand it at all.
2880
2881Sometimes with programs as complicated as the binary utilities it is
2882very hard to construct an example that will make the program follow a
2883certain path through the code. If you do not send us the example, we
2884will not be able to construct one, so we will not be able to verify that
2885the bug is fixed.
2886
2887And if we cannot understand what bug you are trying to fix, or why your
2888patch should be an improvement, we will not install it. A test case will
2889help us to understand.
2890
2891@item
2892A guess about what the bug is or what it depends on.
2893
2894Such guesses are usually wrong. Even we cannot guess right about such
2895things without first using the debugger to find the facts.
2896@end itemize
2897
2898@node Index
2899@unnumbered Index
2900
2901@printindex cp
2902
2903@contents
2904@bye