2000-02-08 Elena Zannoni <ezannoni@kwikemart.cygnus.com>
[deliverable/binutils-gdb.git] / binutils / binutils.texi
CommitLineData
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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
ad0481cd
AS
8* Binutils: (binutils). The GNU binary utilities.
9* ar: (binutils)ar. Create, modify, and extract from archives
10* nm: (binutils)nm. List symbols from object files
11* objcopy: (binutils)objcopy. Copy and translate object files
12* objdump: (binutils)objdump. Display information from object files
13* ranlib: (binutils)ranlib. Generate index to archive contents
14* readelf: (binutils)readelf. Display the contents of ELF format files.
15* size: (binutils)size. List section sizes and total size
16* strings: (binutils)strings. List printable strings from files
17* strip: (binutils)strip. Discard symbols
18* c++filt: (binutils)c++filt. Filter to demangle encoded C++ symbols
19* cxxfilt: (binutils)c++filt. MS-DOS name for c++filt
20* addr2line: (binutils)addr2line. Convert addresses to file and line
21* nlmconv: (binutils)nlmconv. Converts object code into an NLM
22* windres: (binutils)windres. Manipulate Windows resources
23* dlltool: (binutils)dlltool. Create files needed to build and use DLLs
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24END-INFO-DIR-ENTRY
25@end format
26@end ifinfo
27
28@ifinfo
8f915f68 29Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
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30
31Permission is granted to make and distribute verbatim copies of
32this manual provided the copyright notice and this permission notice
33are preserved on all copies.
34
35@ignore
36Permission is granted to process this file through TeX and print the
37results, provided the printed document carries a copying permission
38notice identical to this one except for the removal of this paragraph
39(this paragraph not being relevant to the printed manual).
40
41@end ignore
42
43Permission is granted to copy and distribute modified versions of this
44manual under the conditions for verbatim copying, provided also that
45the entire resulting derived work is distributed under the terms of a
46permission notice identical to this one.
47
48Permission is granted to copy and distribute translations of this manual
49into another language, under the above conditions for modified versions.
50@end ifinfo
51
52@synindex ky cp
53@c
54@c This file documents the GNU binary utilities "ar", "ld", "objcopy",
55@c "objdump", "nm", "size", "strings", "strip", "readelf" and "ranlib".
56@c
8f915f68 57@c Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
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58@c
59@c This text may be freely distributed under the terms of the GNU
60@c General Public License.
61@c
62
63@setchapternewpage odd
64@settitle @sc{gnu} Binary Utilities
65@titlepage
66@finalout
67@title The @sc{gnu} Binary Utilities
68@subtitle Version @value{VERSION}
69@sp 1
70@subtitle May 1993
71@author Roland H. Pesch
72@author Jeffrey M. Osier
73@author Cygnus Support
74@page
75
76@tex
77{\parskip=0pt \hfill Cygnus Support\par \hfill
78\TeX{}info \texinfoversion\par }
79@end tex
80
81@vskip 0pt plus 1filll
82Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 1998 Free Software Foundation, Inc.
83
84Permission is granted to make and distribute verbatim copies of
85this manual provided the copyright notice and this permission notice
86are preserved on all copies.
87
88Permission is granted to copy and distribute modified versions of this
89manual under the conditions for verbatim copying, provided also that
90the entire resulting derived work is distributed under the terms of a
91permission notice identical to this one.
92
93Permission is granted to copy and distribute translations of this manual
94into another language, under the above conditions for modified versions.
95@end titlepage
96
97@node Top
98@top Introduction
99
100@cindex version
101This brief manual contains preliminary documentation for the @sc{gnu} binary
102utilities (collectively version @value{VERSION}):
103
104@iftex
105@table @code
106@item ar
107Create, modify, and extract from archives
108
109@item nm
110List symbols from object files
111
112@item objcopy
113Copy and translate object files
114
115@item objdump
116Display information from object files
117
118@item ranlib
119Generate index to archive contents
120
121@item readelf
122Display the contents of ELF format files.
123
124@item size
125List file section sizes and total size
126
127@item strings
128List printable strings from files
129
130@item strip
131Discard symbols
132
133@item c++filt
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134Demangle encoded C++ symbols (on MS-DOS, this program is named
135@code{cxxfilt})
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136
137@item addr2line
138Convert addresses into file names and line numbers
139
140@item nlmconv
141Convert object code into a Netware Loadable Module
142
143@item windres
144Manipulate Windows resources
145
146@item dlltool
147Create the files needed to build and use Dynamic Link Libraries
148@end table
149@end iftex
150
151@menu
152* ar:: Create, modify, and extract from archives
153* nm:: List symbols from object files
154* objcopy:: Copy and translate object files
155* objdump:: Display information from object files
156* ranlib:: Generate index to archive contents
157* readelf:: Display the contents of ELF format files.
158* size:: List section sizes and total size
159* strings:: List printable strings from files
160* strip:: Discard symbols
161* c++filt:: Filter to demangle encoded C++ symbols
9d51cc66 162* cxxfilt: c++filt. MS-DOS name for c++filt
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163* addr2line:: Convert addresses to file and line
164* nlmconv:: Converts object code into an NLM
165* windres:: Manipulate Windows resources
166* dlltool:: Create files needed to build and use DLLs
167* Selecting The Target System:: How these utilities determine the target.
168* Reporting Bugs:: Reporting Bugs
169* Index:: Index
170@end menu
171
172@node ar
173@chapter ar
174
175@kindex ar
176@cindex archives
177@cindex collections of files
178@smallexample
3de39064 179ar [-]@var{p}[@var{mod} [@var{relpos}] [@var{count}]] @var{archive} [@var{member}@dots{}]
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180ar -M [ <mri-script ]
181@end smallexample
182
183The @sc{gnu} @code{ar} program creates, modifies, and extracts from
184archives. An @dfn{archive} is a single file holding a collection of
185other files in a structure that makes it possible to retrieve
186the original individual files (called @dfn{members} of the archive).
187
188The original files' contents, mode (permissions), timestamp, owner, and
189group are preserved in the archive, and can be restored on
190extraction.
191
192@cindex name length
193@sc{gnu} @code{ar} can maintain archives whose members have names of any
194length; however, depending on how @code{ar} is configured on your
195system, a limit on member-name length may be imposed for compatibility
196with archive formats maintained with other tools. If it exists, the
197limit is often 15 characters (typical of formats related to a.out) or 16
198characters (typical of formats related to coff).
199
200@cindex libraries
201@code{ar} is considered a binary utility because archives of this sort
202are most often used as @dfn{libraries} holding commonly needed
203subroutines.
204
205@cindex symbol index
206@code{ar} creates an index to the symbols defined in relocatable
207object modules in the archive when you specify the modifier @samp{s}.
208Once created, this index is updated in the archive whenever @code{ar}
209makes a change to its contents (save for the @samp{q} update operation).
210An archive with such an index speeds up linking to the library, and
211allows routines in the library to call each other without regard to
212their placement in the archive.
213
214You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
215table. If an archive lacks the table, another form of @code{ar} called
216@code{ranlib} can be used to add just the table.
217
218@cindex compatibility, @code{ar}
219@cindex @code{ar} compatibility
220@sc{gnu} @code{ar} is designed to be compatible with two different
221facilities. You can control its activity using command-line options,
222like the different varieties of @code{ar} on Unix systems; or, if you
223specify the single command-line option @samp{-M}, you can control it
224with a script supplied via standard input, like the MRI ``librarian''
225program.
226
227@menu
228* ar cmdline:: Controlling @code{ar} on the command line
229* ar scripts:: Controlling @code{ar} with a script
230@end menu
231
232@page
233@node ar cmdline
234@section Controlling @code{ar} on the command line
235
236@smallexample
3de39064 237ar [-]@var{p}[@var{mod} [@var{relpos}] [@var{count}]] @var{archive} [@var{member}@dots{}]
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238@end smallexample
239
240@cindex Unix compatibility, @code{ar}
241When you use @code{ar} in the Unix style, @code{ar} insists on at least two
242arguments to execute: one keyletter specifying the @emph{operation}
243(optionally accompanied by other keyletters specifying
244@emph{modifiers}), and the archive name to act on.
245
246Most operations can also accept further @var{member} arguments,
247specifying particular files to operate on.
248
249@sc{gnu} @code{ar} allows you to mix the operation code @var{p} and modifier
250flags @var{mod} in any order, within the first command-line argument.
251
252If you wish, you may begin the first command-line argument with a
253dash.
254
255@cindex operations on archive
256The @var{p} keyletter specifies what operation to execute; it may be
257any of the following, but you must specify only one of them:
258
259@table @code
260@item d
261@cindex deleting from archive
262@emph{Delete} modules from the archive. Specify the names of modules to
263be deleted as @var{member}@dots{}; the archive is untouched if you
264specify no files to delete.
265
266If you specify the @samp{v} modifier, @code{ar} lists each module
267as it is deleted.
268
269@item m
270@cindex moving in archive
271Use this operation to @emph{move} members in an archive.
272
273The ordering of members in an archive can make a difference in how
274programs are linked using the library, if a symbol is defined in more
275than one member.
276
277If no modifiers are used with @code{m}, any members you name in the
278@var{member} arguments are moved to the @emph{end} of the archive;
279you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
280specified place instead.
281
282@item p
283@cindex printing from archive
284@emph{Print} the specified members of the archive, to the standard
285output file. If the @samp{v} modifier is specified, show the member
286name before copying its contents to standard output.
287
288If you specify no @var{member} arguments, all the files in the archive are
289printed.
290
291@item q
292@cindex quick append to archive
293@emph{Quick append}; Historically, add the files @var{member}@dots{} to the end of
294@var{archive}, without checking for replacement.
295
296The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
297operation; new members are always placed at the end of the archive.
298
299The modifier @samp{v} makes @code{ar} list each file as it is appended.
300
301Since the point of this operation is speed, the archive's symbol table
302index is not updated, even if it already existed; you can use @samp{ar s} or
303@code{ranlib} explicitly to update the symbol table index.
304
305However, too many different systems assume quick append rebuilds the
306index, so GNU ar implements @code{q} as a synonym for @code{r}.
307
308@item r
309@cindex replacement in archive
310Insert the files @var{member}@dots{} into @var{archive} (with
311@emph{replacement}). This operation differs from @samp{q} in that any
312previously existing members are deleted if their names match those being
313added.
314
315If one of the files named in @var{member}@dots{} does not exist, @code{ar}
316displays an error message, and leaves undisturbed any existing members
317of the archive matching that name.
318
319By default, new members are added at the end of the file; but you may
320use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
321placement relative to some existing member.
322
323The modifier @samp{v} used with this operation elicits a line of
324output for each file inserted, along with one of the letters @samp{a} or
325@samp{r} to indicate whether the file was appended (no old member
326deleted) or replaced.
327
328@item t
329@cindex contents of archive
330Display a @emph{table} listing the contents of @var{archive}, or those
331of the files listed in @var{member}@dots{} that are present in the
332archive. Normally only the member name is shown; if you also want to
333see the modes (permissions), timestamp, owner, group, and size, you can
334request that by also specifying the @samp{v} modifier.
335
336If you do not specify a @var{member}, all files in the archive
337are listed.
338
339@cindex repeated names in archive
340@cindex name duplication in archive
341If there is more than one file with the same name (say, @samp{fie}) in
342an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
343first instance; to see them all, you must ask for a complete
344listing---in our example, @samp{ar t b.a}.
345@c WRS only; per Gumby, this is implementation-dependent, and in a more
346@c recent case in fact works the other way.
347
348@item x
349@cindex extract from archive
350@emph{Extract} members (named @var{member}) from the archive. You can
351use the @samp{v} modifier with this operation, to request that
352@code{ar} list each name as it extracts it.
353
354If you do not specify a @var{member}, all files in the archive
355are extracted.
356
357@end table
358
359A number of modifiers (@var{mod}) may immediately follow the @var{p}
360keyletter, to specify variations on an operation's behavior:
361
362@table @code
363@item a
364@cindex relative placement in archive
365Add new files @emph{after} an existing member of the
366archive. If you use the modifier @samp{a}, the name of an existing archive
367member must be present as the @var{relpos} argument, before the
368@var{archive} specification.
369
370@item b
371Add new files @emph{before} an existing member of the
372archive. If you use the modifier @samp{b}, the name of an existing archive
373member must be present as the @var{relpos} argument, before the
374@var{archive} specification. (same as @samp{i}).
375
376@item c
377@cindex creating archives
378@emph{Create} the archive. The specified @var{archive} is always
379created if it did not exist, when you request an update. But a warning is
380issued unless you specify in advance that you expect to create it, by
381using this modifier.
382
383@item f
384Truncate names in the archive. @sc{gnu} @code{ar} will normally permit file
385names of any length. This will cause it to create archives which are
386not compatible with the native @code{ar} program on some systems. If
387this is a concern, the @samp{f} modifier may be used to truncate file
388names when putting them in the archive.
389
390@item i
391Insert new files @emph{before} an existing member of the
392archive. If you use the modifier @samp{i}, the name of an existing archive
393member must be present as the @var{relpos} argument, before the
394@var{archive} specification. (same as @samp{b}).
395
396@item l
397This modifier is accepted but not used.
398@c whaffor ar l modifier??? presumably compat; with
399@c what???---doc@@cygnus.com, 25jan91
400
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401@item N
402Uses the @var{count} parameter. This is used if there are multiple
403entries in the archive with the same name. Extract or delete instance
404@var{count} of the given name from the archive.
405
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406@item o
407@cindex dates in archive
408Preserve the @emph{original} dates of members when extracting them. If
409you do not specify this modifier, files extracted from the archive
410are stamped with the time of extraction.
411
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412@item P
413Use the full path name when matching names in the archive. @sc{gnu}
414@code{ar} can not create an archive with a full path name (such archives
415are not POSIX complaint), but other archive creators can. This option
416will cause @sc{gnu} @code{ar} to match file names using a complete path
417name, which can be convenient when extracting a single file from an
418archive created by another tool.
419
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420@item s
421@cindex writing archive index
422Write an object-file index into the archive, or update an existing one,
423even if no other change is made to the archive. You may use this modifier
424flag either with any operation, or alone. Running @samp{ar s} on an
425archive is equivalent to running @samp{ranlib} on it.
426
427@item S
428@cindex not writing archive index
429Do not generate an archive symbol table. This can speed up building a
430large library in several steps. The resulting archive can not be used
431with the linker. In order to build a symbol table, you must omit the
432@samp{S} modifier on the last execution of @samp{ar}, or you must run
433@samp{ranlib} on the archive.
434
435@item u
436@cindex updating an archive
437Normally, @samp{ar r}@dots{} inserts all files
438listed into the archive. If you would like to insert @emph{only} those
439of the files you list that are newer than existing members of the same
440names, use this modifier. The @samp{u} modifier is allowed only for the
441operation @samp{r} (replace). In particular, the combination @samp{qu} is
442not allowed, since checking the timestamps would lose any speed
443advantage from the operation @samp{q}.
444
445@item v
446This modifier requests the @emph{verbose} version of an operation. Many
447operations display additional information, such as filenames processed,
448when the modifier @samp{v} is appended.
449
450@item V
451This modifier shows the version number of @code{ar}.
452@end table
453
454@node ar scripts
455@section Controlling @code{ar} with a script
456
457@smallexample
458ar -M [ <@var{script} ]
459@end smallexample
460
461@cindex MRI compatibility, @code{ar}
462@cindex scripts, @code{ar}
463If you use the single command-line option @samp{-M} with @code{ar}, you
464can control its operation with a rudimentary command language. This
465form of @code{ar} operates interactively if standard input is coming
466directly from a terminal. During interactive use, @code{ar} prompts for
467input (the prompt is @samp{AR >}), and continues executing even after
468errors. If you redirect standard input to a script file, no prompts are
469issued, and @code{ar} abandons execution (with a nonzero exit code)
470on any error.
471
472The @code{ar} command language is @emph{not} designed to be equivalent
473to the command-line options; in fact, it provides somewhat less control
474over archives. The only purpose of the command language is to ease the
475transition to @sc{gnu} @code{ar} for developers who already have scripts
476written for the MRI ``librarian'' program.
477
478The syntax for the @code{ar} command language is straightforward:
479@itemize @bullet
480@item
481commands are recognized in upper or lower case; for example, @code{LIST}
482is the same as @code{list}. In the following descriptions, commands are
483shown in upper case for clarity.
484
485@item
486a single command may appear on each line; it is the first word on the
487line.
488
489@item
490empty lines are allowed, and have no effect.
491
492@item
493comments are allowed; text after either of the characters @samp{*}
494or @samp{;} is ignored.
495
496@item
497Whenever you use a list of names as part of the argument to an @code{ar}
498command, you can separate the individual names with either commas or
499blanks. Commas are shown in the explanations below, for clarity.
500
501@item
502@samp{+} is used as a line continuation character; if @samp{+} appears
503at the end of a line, the text on the following line is considered part
504of the current command.
505@end itemize
506
507Here are the commands you can use in @code{ar} scripts, or when using
508@code{ar} interactively. Three of them have special significance:
509
510@code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
511a temporary file required for most of the other commands.
512
513@code{SAVE} commits the changes so far specified by the script. Prior
514to @code{SAVE}, commands affect only the temporary copy of the current
515archive.
516
517@table @code
518@item ADDLIB @var{archive}
519@itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
520Add all the contents of @var{archive} (or, if specified, each named
521@var{module} from @var{archive}) to the current archive.
522
523Requires prior use of @code{OPEN} or @code{CREATE}.
524
525@item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
526@c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
527@c else like "ar q..."
528Add each named @var{member} as a module in the current archive.
529
530Requires prior use of @code{OPEN} or @code{CREATE}.
531
532@item CLEAR
533Discard the contents of the current archive, canceling the effect of
534any operations since the last @code{SAVE}. May be executed (with no
535effect) even if no current archive is specified.
536
537@item CREATE @var{archive}
538Creates an archive, and makes it the current archive (required for many
539other commands). The new archive is created with a temporary name; it
540is not actually saved as @var{archive} until you use @code{SAVE}.
541You can overwrite existing archives; similarly, the contents of any
542existing file named @var{archive} will not be destroyed until @code{SAVE}.
543
544@item DELETE @var{module}, @var{module}, @dots{} @var{module}
545Delete each listed @var{module} from the current archive; equivalent to
546@samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
547
548Requires prior use of @code{OPEN} or @code{CREATE}.
549
550@item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
551@itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
552List each named @var{module} present in @var{archive}. The separate
553command @code{VERBOSE} specifies the form of the output: when verbose
554output is off, output is like that of @samp{ar -t @var{archive}
555@var{module}@dots{}}. When verbose output is on, the listing is like
556@samp{ar -tv @var{archive} @var{module}@dots{}}.
557
558Output normally goes to the standard output stream; however, if you
559specify @var{outputfile} as a final argument, @code{ar} directs the
560output to that file.
561
562@item END
563Exit from @code{ar}, with a @code{0} exit code to indicate successful
564completion. This command does not save the output file; if you have
565changed the current archive since the last @code{SAVE} command, those
566changes are lost.
567
568@item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
569Extract each named @var{module} from the current archive, writing them
570into the current directory as separate files. Equivalent to @samp{ar -x
571@var{archive} @var{module}@dots{}}.
572
573Requires prior use of @code{OPEN} or @code{CREATE}.
574
575@ignore
576@c FIXME Tokens but no commands???
577@item FULLDIR
578
579@item HELP
580@end ignore
581
582@item LIST
583Display full contents of the current archive, in ``verbose'' style
584regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
c89746f6 585tv @var{archive}}. (This single command is a @sc{gnu} @code{ar}
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586enhancement, rather than present for MRI compatibility.)
587
588Requires prior use of @code{OPEN} or @code{CREATE}.
589
590@item OPEN @var{archive}
591Opens an existing archive for use as the current archive (required for
592many other commands). Any changes as the result of subsequent commands
593will not actually affect @var{archive} until you next use @code{SAVE}.
594
595@item REPLACE @var{module}, @var{module}, @dots{} @var{module}
596In the current archive, replace each existing @var{module} (named in
597the @code{REPLACE} arguments) from files in the current working directory.
598To execute this command without errors, both the file, and the module in
599the current archive, must exist.
600
601Requires prior use of @code{OPEN} or @code{CREATE}.
602
603@item VERBOSE
604Toggle an internal flag governing the output from @code{DIRECTORY}.
605When the flag is on, @code{DIRECTORY} output matches output from
606@samp{ar -tv }@dots{}.
607
608@item SAVE
609Commit your changes to the current archive, and actually save it as a
610file with the name specified in the last @code{CREATE} or @code{OPEN}
611command.
612
613Requires prior use of @code{OPEN} or @code{CREATE}.
614
615@end table
616
617@iftex
618@node ld
619@chapter ld
620@cindex linker
621@kindex ld
622The @sc{gnu} linker @code{ld} is now described in a separate manual.
623@xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
624@end iftex
625
626@node nm
627@chapter nm
628@cindex symbols
629@kindex nm
630
631@smallexample
632nm [ -a | --debug-syms ] [ -g | --extern-only ]
633 [ -B ] [ -C | --demangle ] [ -D | --dynamic ]
634 [ -s | --print-armap ] [ -A | -o | --print-file-name ]
635 [ -n | -v | --numeric-sort ] [ -p | --no-sort ]
636 [ -r | --reverse-sort ] [ --size-sort ] [ -u | --undefined-only ]
637 [ -t @var{radix} | --radix=@var{radix} ] [ -P | --portability ]
638 [ --target=@var{bfdname} ] [ -f @var{format} | --format=@var{format} ]
639 [ --defined-only ] [-l | --line-numbers ]
640 [ --no-demangle ] [ -V | --version ] [ --help ] [ @var{objfile}@dots{} ]
641@end smallexample
642
643@sc{gnu} @code{nm} lists the symbols from object files @var{objfile}@dots{}.
f20a759a 644If no object files are listed as arguments, @code{nm} assumes the file
252b5132
RH
645@file{a.out}.
646
647For each symbol, @code{nm} shows:
648
649@itemize @bullet
650@item
651The symbol value, in the radix selected by options (see below), or
652hexadecimal by default.
653
654@item
655The symbol type. At least the following types are used; others are, as
656well, depending on the object file format. If lowercase, the symbol is
657local; if uppercase, the symbol is global (external).
658
659@c Some more detail on exactly what these symbol types are used for
660@c would be nice.
661@table @code
662@item A
663The symbol's value is absolute, and will not be changed by further
664linking.
665
666@item B
667The symbol is in the uninitialized data section (known as BSS).
668
669@item C
670The symbol is common. Common symbols are uninitialized data. When
671linking, multiple common symbols may appear with the same name. If the
672symbol is defined anywhere, the common symbols are treated as undefined
673references. For more details on common symbols, see the discussion of
674--warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
675
676@item D
677The symbol is in the initialized data section.
678
679@item G
680The symbol is in an initialized data section for small objects. Some
681object file formats permit more efficient access to small data objects,
682such as a global int variable as opposed to a large global array.
683
684@item I
685The symbol is an indirect reference to another symbol. This is a GNU
686extension to the a.out object file format which is rarely used.
687
688@item N
689The symbol is a debugging symbol.
690
691@item R
692The symbol is in a read only data section.
693
694@item S
695The symbol is in an uninitialized data section for small objects.
696
697@item T
698The symbol is in the text (code) section.
699
700@item U
701The symbol is undefined.
702
fad6fcbb
NC
703@item V
704The symbol is a weak object. When a weak defined symbol is linked with
705a normal defined symbol, the normal defined symbol is used with no error.
706When a weak undefined symbol is linked and the symbol is not defined,
707the value of the weak symbol becomes zero with no error.
708
252b5132 709@item W
fad6fcbb
NC
710The symbol is a weak symbol that has not been specifically tagged as a
711weak object symbol. When a weak defined symbol is linked with a normal
712defined symbol, the normal defined symbol is used with no error.
713When a weak undefined symbol is linked and the symbol is not defined,
714the value of the weak symbol becomes zero with no error.
252b5132
RH
715
716@item -
717The symbol is a stabs symbol in an a.out object file. In this case, the
718next values printed are the stabs other field, the stabs desc field, and
719the stab type. Stabs symbols are used to hold debugging information;
720for more information, see @ref{Top,Stabs,Stabs Overview,stabs.info, The
721``stabs'' debug format}.
722
723@item ?
724The symbol type is unknown, or object file format specific.
725@end table
726
727@item
728The symbol name.
729@end itemize
730
731The long and short forms of options, shown here as alternatives, are
732equivalent.
733
734@table @code
735@item -A
736@itemx -o
737@itemx --print-file-name
738@cindex input file name
739@cindex file name
740@cindex source file name
f20a759a 741Precede each symbol by the name of the input file (or archive member)
252b5132
RH
742in which it was found, rather than identifying the input file once only,
743before all of its symbols.
744
745@item -a
746@itemx --debug-syms
747@cindex debugging symbols
748Display all symbols, even debugger-only symbols; normally these are not
749listed.
750
751@item -B
752@cindex @code{nm} format
753@cindex @code{nm} compatibility
754The same as @samp{--format=bsd} (for compatibility with the MIPS @code{nm}).
755
756@item -C
757@itemx --demangle
758@cindex demangling in nm
759Decode (@dfn{demangle}) low-level symbol names into user-level names.
760Besides removing any initial underscore prepended by the system, this
761makes C++ function names readable. @xref{c++filt}, for more information
762on demangling.
763
764@item --no-demangle
765Do not demangle low-level symbol names. This is the default.
766
767@item -D
768@itemx --dynamic
769@cindex dynamic symbols
770Display the dynamic symbols rather than the normal symbols. This is
771only meaningful for dynamic objects, such as certain types of shared
772libraries.
773
774@item -f @var{format}
775@itemx --format=@var{format}
776@cindex @code{nm} format
777@cindex @code{nm} compatibility
778Use the output format @var{format}, which can be @code{bsd},
779@code{sysv}, or @code{posix}. The default is @code{bsd}.
780Only the first character of @var{format} is significant; it can be
781either upper or lower case.
782
783@item -g
784@itemx --extern-only
785@cindex external symbols
786Display only external symbols.
787
788@item -l
789@itemx --line-numbers
790@cindex symbol line numbers
791For each symbol, use debugging information to try to find a filename and
792line number. For a defined symbol, look for the line number of the
793address of the symbol. For an undefined symbol, look for the line
794number of a relocation entry which refers to the symbol. If line number
795information can be found, print it after the other symbol information.
796
797@item -n
798@itemx -v
799@itemx --numeric-sort
800Sort symbols numerically by their addresses, rather than alphabetically
801by their names.
802
803@item -p
804@itemx --no-sort
805@cindex sorting symbols
806Do not bother to sort the symbols in any order; print them in the order
807encountered.
808
809@item -P
810@itemx --portability
811Use the POSIX.2 standard output format instead of the default format.
812Equivalent to @samp{-f posix}.
813
814@item -s
815@itemx --print-armap
816@cindex symbol index, listing
817When listing symbols from archive members, include the index: a mapping
818(stored in the archive by @code{ar} or @code{ranlib}) of which modules
819contain definitions for which names.
820
821@item -r
822@itemx --reverse-sort
823Reverse the order of the sort (whether numeric or alphabetic); let the
824last come first.
825
826@item --size-sort
827Sort symbols by size. The size is computed as the difference between
828the value of the symbol and the value of the symbol with the next higher
829value. The size of the symbol is printed, rather than the value.
830
831@item -t @var{radix}
832@itemx --radix=@var{radix}
833Use @var{radix} as the radix for printing the symbol values. It must be
834@samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
835
836@item --target=@var{bfdname}
837@cindex object code format
838Specify an object code format other than your system's default format.
839@xref{Target Selection}, for more information.
840
841@item -u
842@itemx --undefined-only
843@cindex external symbols
844@cindex undefined symbols
845Display only undefined symbols (those external to each object file).
846
847@item --defined-only
848@cindex external symbols
849@cindex undefined symbols
850Display only defined symbols for each object file.
851
852@item -V
853@itemx --version
854Show the version number of @code{nm} and exit.
855
856@item --help
857Show a summary of the options to @code{nm} and exit.
858@end table
859
860@node objcopy
861@chapter objcopy
862
863@smallexample
864objcopy [ -F @var{bfdname} | --target=@var{bfdname} ]
865 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
866 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
867 [ -S | --strip-all ] [ -g | --strip-debug ]
868 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
869 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
870 [ -L @var{symbolname} | --localize-symbol=@var{symbolname} ]
871 [ -W @var{symbolname} | --weaken-symbol=@var{symbolname} ]
872 [ -x | --discard-all ] [ -X | --discard-locals ]
873 [ -b @var{byte} | --byte=@var{byte} ]
874 [ -i @var{interleave} | --interleave=@var{interleave} ]
f91ea849 875 [ -j @var{sectionname} | --only-section=@var{sectionname} ]
252b5132
RH
876 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
877 [ -p | --preserve-dates ] [ --debugging ]
878 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
879 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
880 [ --change-addresses=@var{incr} ]
881 [ --change-section-address=@var{section}@{=,+,-@}@var{val} ]
882 [ --change-section-lma=@var{section}@{=,+,-@}@var{val} ]
883 [ --change-section-vma=@var{section}@{=,+,-@}@var{val} ]
884 [ --change-warnings ] [ --no-change-warnings ]
885 [ --set-section-flags=@var{section}=@var{flags} ]
886 [ --add-section=@var{sectionname}=@var{filename} ]
887 [ --change-leading-char ] [ --remove-leading-char ]
888 [ --weaken ]
889 [ -v | --verbose ] [ -V | --version ] [ --help ]
890 @var{infile} [@var{outfile}]
891@end smallexample
892
893The @sc{gnu} @code{objcopy} utility copies the contents of an object
894file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
895read and write the object files. It can write the destination object
896file in a format different from that of the source object file. The
897exact behavior of @code{objcopy} is controlled by command-line options.
898
899@code{objcopy} creates temporary files to do its translations and
900deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
901translation work; it has access to all the formats described in @sc{bfd}
902and thus is able to recognize most formats without being told
903explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
904
905@code{objcopy} can be used to generate S-records by using an output
906target of @samp{srec} (e.g., use @samp{-O srec}).
907
908@code{objcopy} can be used to generate a raw binary file by using an
909output target of @samp{binary} (e.g., use @samp{-O binary}). When
910@code{objcopy} generates a raw binary file, it will essentially produce
911a memory dump of the contents of the input object file. All symbols and
912relocation information will be discarded. The memory dump will start at
913the load address of the lowest section copied into the output file.
914
915When generating an S-record or a raw binary file, it may be helpful to
916use @samp{-S} to remove sections containing debugging information. In
917some cases @samp{-R} will be useful to remove sections which contain
f20a759a 918information that is not needed by the binary file.
252b5132
RH
919
920@table @code
921@item @var{infile}
922@itemx @var{outfile}
f20a759a 923The input and output files, respectively.
252b5132
RH
924If you do not specify @var{outfile}, @code{objcopy} creates a
925temporary file and destructively renames the result with
926the name of @var{infile}.
927
928@item -I @var{bfdname}
929@itemx --input-target=@var{bfdname}
930Consider the source file's object format to be @var{bfdname}, rather than
931attempting to deduce it. @xref{Target Selection}, for more information.
932
933@item -O @var{bfdname}
934@itemx --output-target=@var{bfdname}
935Write the output file using the object format @var{bfdname}.
936@xref{Target Selection}, for more information.
937
938@item -F @var{bfdname}
939@itemx --target=@var{bfdname}
940Use @var{bfdname} as the object format for both the input and the output
941file; i.e., simply transfer data from source to destination with no
942translation. @xref{Target Selection}, for more information.
943
f91ea849
ILT
944@item -j @var{sectionname}
945@itemx --only-section=@var{sectionname}
946Copy only the named section from the input file to the output file.
947This option may be given more than once. Note that using this option
948inappropriately may make the output file unusable.
949
252b5132
RH
950@item -R @var{sectionname}
951@itemx --remove-section=@var{sectionname}
952Remove any section named @var{sectionname} from the output file. This
953option may be given more than once. Note that using this option
954inappropriately may make the output file unusable.
955
956@item -S
957@itemx --strip-all
958Do not copy relocation and symbol information from the source file.
959
960@item -g
961@itemx --strip-debug
962Do not copy debugging symbols from the source file.
963
964@item --strip-unneeded
965Strip all symbols that are not needed for relocation processing.
966
967@item -K @var{symbolname}
968@itemx --keep-symbol=@var{symbolname}
969Copy only symbol @var{symbolname} from the source file. This option may
970be given more than once.
971
972@item -N @var{symbolname}
973@itemx --strip-symbol=@var{symbolname}
974Do not copy symbol @var{symbolname} from the source file. This option
975may be given more than once.
976
977@item -L @var{symbolname}
978@itemx --localize-symbol=@var{symbolname}
979Make symbol @var{symbolname} local to the file, so that it is not
980visible externally. This option may be given more than once.
981
982@item -W @var{symbolname}
983@itemx --weaken-symbol=@var{symbolname}
984Make symbol @var{symbolname} weak. This option may be given more than once.
985
986@item -x
987@itemx --discard-all
988Do not copy non-global symbols from the source file.
989@c FIXME any reason to prefer "non-global" to "local" here?
990
991@item -X
992@itemx --discard-locals
993Do not copy compiler-generated local symbols.
994(These usually start with @samp{L} or @samp{.}.)
995
996@item -b @var{byte}
997@itemx --byte=@var{byte}
998Keep only every @var{byte}th byte of the input file (header data is not
999affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
1000where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
1001option, or the default of 4. This option is useful for creating files
1002to program @sc{rom}. It is typically used with an @code{srec} output
1003target.
1004
1005@item -i @var{interleave}
1006@itemx --interleave=@var{interleave}
1007Only copy one out of every @var{interleave} bytes. Select which byte to
1008copy with the @var{-b} or @samp{--byte} option. The default is 4.
1009@code{objcopy} ignores this option if you do not specify either @samp{-b} or
1010@samp{--byte}.
1011
1012@item -p
1013@itemx --preserve-dates
1014Set the access and modification dates of the output file to be the same
1015as those of the input file.
1016
1017@item --debugging
1018Convert debugging information, if possible. This is not the default
1019because only certain debugging formats are supported, and the
1020conversion process can be time consuming.
1021
1022@item --gap-fill @var{val}
1023Fill gaps between sections with @var{val}. This operation applies to
1024the @emph{load address} (LMA) of the sections. It is done by increasing
1025the size of the section with the lower address, and filling in the extra
1026space created with @var{val}.
1027
1028@item --pad-to @var{address}
1029Pad the output file up to the load address @var{address}. This is
1030done by increasing the size of the last section. The extra space is
1031filled in with the value specified by @samp{--gap-fill} (default zero).
1032
1033@item --set-start @var{val}
f20a759a 1034Set the start address of the new file to @var{val}. Not all object file
252b5132
RH
1035formats support setting the start address.
1036
1037@item --change-start @var{incr}
1038@itemx --adjust-start @var{incr}
1039@cindex changing start address
1040Change the start address by adding @var{incr}. Not all object file
1041formats support setting the start address.
1042
1043@item --change-addresses @var{incr}
1044@itemx --adjust-vma @var{incr}
1045@cindex changing object addresses
1046Change the VMA and LMA addresses of all sections, as well as the start
1047address, by adding @var{incr}. Some object file formats do not permit
1048section addresses to be changed arbitrarily. Note that this does not
1049relocate the sections; if the program expects sections to be loaded at a
1050certain address, and this option is used to change the sections such
1051that they are loaded at a different address, the program may fail.
1052
1053@item --change-section-address @var{section}@{=,+,-@}@var{val}
1054@itemx --adjust-section-vma @var{section}@{=,+,-@}@var{val}
1055@cindex changing section address
1056Set or change both the VMA address and the LMA address of the named
1057@var{section}. If @samp{=} is used, the section address is set to
1058@var{val}. Otherwise, @var{val} is added to or subtracted from the
1059section address. See the comments under @samp{--change-addresses},
1060above. If @var{section} does not exist in the input file, a warning will
1061be issued, unless @samp{--no-change-warnings} is used.
1062
1063@item --change-section-lma @var{section}@{=,+,-@}@var{val}
1064@cindex changing section LMA
1065Set or change the LMA address of the named @var{section}. The LMA
1066address is the address where the section will be loaded into memory at
1067program load time. Normally this is the same as the VMA address, which
1068is the address of the section at program run time, but on some systems,
1069especially those where a program is held in ROM, the two can be
1070different. If @samp{=} is used, the section address is set to
1071@var{val}. Otherwise, @var{val} is added to or subtracted from the
1072section address. See the comments under @samp{--change-addresses},
1073above. If @var{section} does not exist in the input file, a warning
1074will be issued, unless @samp{--no-change-warnings} is used.
1075
1076@item --change-section-vma @var{section}@{=,+,-@}@var{val}
1077@cindex changing section VMA
1078Set or change the VMA address of the named @var{section}. The VMA
1079address is the address where the section will be located once the
1080program has started executing. Normally this is the same as the LMA
1081address, which is the address where the section will be loaded into
1082memory, but on some systems, especially those where a program is held in
1083ROM, the two can be different. If @samp{=} is used, the section address
1084is set to @var{val}. Otherwise, @var{val} is added to or subtracted
1085from the section address. See the comments under
1086@samp{--change-addresses}, above. If @var{section} does not exist in
1087the input file, a warning will be issued, unless
1088@samp{--no-change-warnings} is used.
1089
1090@item --change-warnings
1091@itemx --adjust-warnings
1092If @samp{--change-section-address} or @samp{--change-section-lma} or
1093@samp{--change-section-vma} is used, and the named section does not
1094exist, issue a warning. This is the default.
1095
1096@item --no-change-warnings
1097@itemx --no-adjust-warnings
1098Do not issue a warning if @samp{--change-section-address} or
1099@samp{--adjust-section-lma} or @samp{--adjust-section-vma} is used, even
1100if the named section does not exist.
1101
1102@item --set-section-flags @var{section}=@var{flags}
1103Set the flags for the named section. The @var{flags} argument is a
1104comma separated string of flag names. The recognized names are
3994e2c6
ILT
1105@samp{alloc}, @samp{contents}, @samp{load}, @samp{noload},
1106@samp{readonly}, @samp{code}, @samp{data}, @samp{rom}, @samp{share}, and
1107@samp{debug}. You can set the @samp{contents} flag for a section which
1108does not have contents, but it is not meaningful to clear the
1109@samp{contents} flag of a section which does have contents--just remove
1110the section instead. Not all flags are meaningful for all object file
1111formats.
252b5132
RH
1112
1113@item --add-section @var{sectionname}=@var{filename}
1114Add a new section named @var{sectionname} while copying the file. The
1115contents of the new section are taken from the file @var{filename}. The
1116size of the section will be the size of the file. This option only
1117works on file formats which can support sections with arbitrary names.
1118
1119@item --change-leading-char
1120Some object file formats use special characters at the start of
1121symbols. The most common such character is underscore, which compilers
1122often add before every symbol. This option tells @code{objcopy} to
1123change the leading character of every symbol when it converts between
1124object file formats. If the object file formats use the same leading
1125character, this option has no effect. Otherwise, it will add a
1126character, or remove a character, or change a character, as
1127appropriate.
1128
1129@item --remove-leading-char
1130If the first character of a global symbol is a special symbol leading
1131character used by the object file format, remove the character. The
1132most common symbol leading character is underscore. This option will
1133remove a leading underscore from all global symbols. This can be useful
1134if you want to link together objects of different file formats with
1135different conventions for symbol names. This is different from
1136@code{--change-leading-char} because it always changes the symbol name
1137when appropriate, regardless of the object file format of the output
1138file.
1139
1140@item --weaken
1141Change all global symbols in the file to be weak. This can be useful
1142when building an object which will be linked against other objects using
1143the @code{-R} option to the linker. This option is only effective when
1144using an object file format which supports weak symbols.
1145
1146@item -V
1147@itemx --version
1148Show the version number of @code{objcopy}.
1149
1150@item -v
1151@itemx --verbose
1152Verbose output: list all object files modified. In the case of
1153archives, @samp{objcopy -V} lists all members of the archive.
1154
1155@item --help
1156Show a summary of the options to @code{objcopy}.
1157@end table
1158
1159@node objdump
1160@chapter objdump
1161
1162@cindex object file information
1163@kindex objdump
1164
1165@smallexample
1166objdump [ -a | --archive-headers ]
1dada9c5
NC
1167 [ -b @var{bfdname} | --target=@var{bfdname} ]
1168 [ -C | --demangle ]
1169 [ -d | --disassemble ]
1170 [ -D | --disassemble-all ]
1171 [ -z | --disassemble-zeroes ]
252b5132
RH
1172 [ -EB | -EL | --endian=@{big | little @} ]
1173 [ -f | --file-headers ]
1dada9c5
NC
1174 [ -g | --debugging ]
1175 [ -h | --section-headers | --headers ]
1176 [ -i | --info ]
252b5132 1177 [ -j @var{section} | --section=@var{section} ]
1dada9c5
NC
1178 [ -l | --line-numbers ]
1179 [ -S | --source ]
252b5132 1180 [ -m @var{machine} | --architecture=@var{machine} ]
dd92f639 1181 [ -M @var{options} | --disassembler-options=@var{options}]
252b5132 1182 [ -p | --private-headers ]
1dada9c5
NC
1183 [ -r | --reloc ]
1184 [ -R | --dynamic-reloc ]
1185 [ -s | --full-contents ]
1186 [ -G | --stabs ]
1187 [ -t | --syms ]
1188 [ -T | --dynamic-syms ]
1189 [ -x | --all-headers ]
1190 [ -w | --wide ]
1191 [ --start-address=@var{address} ]
252b5132 1192 [ --stop-address=@var{address} ]
1dada9c5
NC
1193 [ --prefix-addresses]
1194 [ --[no-]show-raw-insn ]
252b5132 1195 [ --adjust-vma=@var{offset} ]
1dada9c5
NC
1196 [ -V | --version ]
1197 [ -H | --help ]
252b5132
RH
1198 @var{objfile}@dots{}
1199@end smallexample
1200
1201@code{objdump} displays information about one or more object files.
1202The options control what particular information to display. This
1203information is mostly useful to programmers who are working on the
1204compilation tools, as opposed to programmers who just want their
1205program to compile and work.
1206
1207@var{objfile}@dots{} are the object files to be examined. When you
1208specify archives, @code{objdump} shows information on each of the member
1209object files.
1210
1211The long and short forms of options, shown here as alternatives, are
1dada9c5
NC
1212equivalent. At least one option from the list
1213@samp{-a,-d,-D,-f,-g,-G,-h,-H,-p,-r,-R,-S,-t,-T,-V,-x} must be given.
252b5132
RH
1214
1215@table @code
1216@item -a
1217@itemx --archive-header
1218@cindex archive headers
1219If any of the @var{objfile} files are archives, display the archive
1220header information (in a format similar to @samp{ls -l}). Besides the
1221information you could list with @samp{ar tv}, @samp{objdump -a} shows
1222the object file format of each archive member.
1223
1224@item --adjust-vma=@var{offset}
1225@cindex section addresses in objdump
1226@cindex VMA in objdump
1227When dumping information, first add @var{offset} to all the section
1228addresses. This is useful if the section addresses do not correspond to
1229the symbol table, which can happen when putting sections at particular
1230addresses when using a format which can not represent section addresses,
1231such as a.out.
1232
1233@item -b @var{bfdname}
1234@itemx --target=@var{bfdname}
1235@cindex object code format
1236Specify that the object-code format for the object files is
1237@var{bfdname}. This option may not be necessary; @var{objdump} can
1238automatically recognize many formats.
1239
1240For example,
1241@example
1242objdump -b oasys -m vax -h fu.o
1243@end example
1244@noindent
1245displays summary information from the section headers (@samp{-h}) of
1246@file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1247file in the format produced by Oasys compilers. You can list the
1248formats available with the @samp{-i} option.
1249@xref{Target Selection}, for more information.
1250
1251@item -C
1252@itemx --demangle
1253@cindex demangling in objdump
1254Decode (@dfn{demangle}) low-level symbol names into user-level names.
1255Besides removing any initial underscore prepended by the system, this
1256makes C++ function names readable. @xref{c++filt}, for more information
1257on demangling.
1258
1dada9c5 1259@item -G
252b5132
RH
1260@item --debugging
1261Display debugging information. This attempts to parse debugging
1262information stored in the file and print it out using a C like syntax.
1263Only certain types of debugging information have been implemented.
1264
1265@item -d
1266@itemx --disassemble
1267@cindex disassembling object code
1268@cindex machine instructions
1269Display the assembler mnemonics for the machine instructions from
1270@var{objfile}. This option only disassembles those sections which are
1271expected to contain instructions.
1272
1273@item -D
1274@itemx --disassemble-all
1275Like @samp{-d}, but disassemble the contents of all sections, not just
1276those expected to contain instructions.
1277
1278@item --prefix-addresses
1279When disassembling, print the complete address on each line. This is
1280the older disassembly format.
1281
1282@item --disassemble-zeroes
1283Normally the disassembly output will skip blocks of zeroes. This
1284option directs the disassembler to disassemble those blocks, just like
1285any other data.
1286
1287@item -EB
1288@itemx -EL
1289@itemx --endian=@{big|little@}
1290@cindex endianness
1291@cindex disassembly endianness
1292Specify the endianness of the object files. This only affects
1293disassembly. This can be useful when disassembling a file format which
1294does not describe endianness information, such as S-records.
1295
1296@item -f
1297@itemx --file-header
1298@cindex object file header
1299Display summary information from the overall header of
1300each of the @var{objfile} files.
1301
1302@item -h
1303@itemx --section-header
1304@itemx --header
1305@cindex section headers
1306Display summary information from the section headers of the
1307object file.
1308
1309File segments may be relocated to nonstandard addresses, for example by
1310using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1311@code{ld}. However, some object file formats, such as a.out, do not
1312store the starting address of the file segments. In those situations,
1313although @code{ld} relocates the sections correctly, using @samp{objdump
1314-h} to list the file section headers cannot show the correct addresses.
1315Instead, it shows the usual addresses, which are implicit for the
1316target.
1317
1318@item --help
1319Print a summary of the options to @code{objdump} and exit.
1320
1321@item -i
1322@itemx --info
1323@cindex architectures available
1324@cindex object formats available
1325Display a list showing all architectures and object formats available
1326for specification with @samp{-b} or @samp{-m}.
1327
1328@item -j @var{name}
1329@itemx --section=@var{name}
1330@cindex section information
1331Display information only for section @var{name}.
1332
1333@item -l
1334@itemx --line-numbers
1335@cindex source filenames for object files
1336Label the display (using debugging information) with the filename and
1337source line numbers corresponding to the object code or relocs shown.
1338Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1339
1340@item -m @var{machine}
1341@itemx --architecture=@var{machine}
1342@cindex architecture
1343@cindex disassembly architecture
1344Specify the architecture to use when disassembling object files. This
1345can be useful when disassembling object files which do not describe
1346architecture information, such as S-records. You can list the available
1347architectures with the @samp{-i} option.
1348
dd92f639
NC
1349@item -M @var{options}
1350@itemx --disassembler-options=@var{options}
1351Pass target specific information to the disassembler. Only supported on
1352some targets.
1353
1354If the target is an ARM architecture then this switch can be used to
1355select which register name set is used during disassembler. Specifying
58efb6c0
NC
1356@samp{-M reg-name-std} (the default) will select the register names as
1357used in ARM's instruction set documentation, but with register 13 called
1358'sp', register 14 called 'lr' and register 15 called 'pc'. Specifying
1359@samp{-M reg-names-apcs} will select the name set used by the ARM
1360Procedure Call Standard, whilst specifying @samp{-M reg-names-raw} will
1361just use @samp{r} followed by the register number.
1362
1363There are also two variants on the APCS register naming scheme enabled
1364by @samp{-M reg-names-atpcs} and @samp{-M reg-names-atpcs-special} which
1365use the ARM/Thumb Procedure Call Standard naming conventions. (Eiuther
1366with the normal register name sor the special register names).
dd92f639 1367
8f915f68
NC
1368This option can also be used for ARM architectures to force the
1369disassembler to interpret all instructions as THUMB instructions by
1370using the switch @samp{--disassembler-options=force-thumb}. This can be
1371useful when attempting to disassemble thumb code produced by other
1372compilers.
1373
252b5132
RH
1374@item -p
1375@itemx --private-headers
1376Print information that is specific to the object file format. The exact
1377information printed depends upon the object file format. For some
1378object file formats, no additional information is printed.
1379
1380@item -r
1381@itemx --reloc
1382@cindex relocation entries, in object file
1383Print the relocation entries of the file. If used with @samp{-d} or
1384@samp{-D}, the relocations are printed interspersed with the
1385disassembly.
1386
1387@item -R
1388@itemx --dynamic-reloc
1389@cindex dynamic relocation entries, in object file
1390Print the dynamic relocation entries of the file. This is only
1391meaningful for dynamic objects, such as certain types of shared
1392libraries.
1393
1394@item -s
1395@itemx --full-contents
1396@cindex sections, full contents
1397@cindex object file sections
1398Display the full contents of any sections requested.
1399
1400@item -S
1401@itemx --source
1402@cindex source disassembly
1403@cindex disassembly, with source
1404Display source code intermixed with disassembly, if possible. Implies
1405@samp{-d}.
1406
1407@item --show-raw-insn
1408When disassembling instructions, print the instruction in hex as well as
1409in symbolic form. This is the default except when
1410@code{--prefix-addresses} is used.
1411
1412@item --no-show-raw-insn
1413When disassembling instructions, do not print the instruction bytes.
1414This is the default when @code{--prefix-addresses} is used.
1415
1dada9c5 1416@item -G
252b5132
RH
1417@item --stabs
1418@cindex stab
1419@cindex .stab
1420@cindex debug symbols
1421@cindex ELF object file format
1422Display the full contents of any sections requested. Display the
1423contents of the .stab and .stab.index and .stab.excl sections from an
1424ELF file. This is only useful on systems (such as Solaris 2.0) in which
1425@code{.stab} debugging symbol-table entries are carried in an ELF
1426section. In most other file formats, debugging symbol-table entries are
1427interleaved with linkage symbols, and are visible in the @samp{--syms}
1428output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1429Overview,stabs.info, The ``stabs'' debug format}.
1430
1431@item --start-address=@var{address}
1432@cindex start-address
1433Start displaying data at the specified address. This affects the output
1434of the @code{-d}, @code{-r} and @code{-s} options.
1435
1436@item --stop-address=@var{address}
1437@cindex stop-address
1438Stop displaying data at the specified address. This affects the output
1439of the @code{-d}, @code{-r} and @code{-s} options.
1440
1441@item -t
1442@itemx --syms
1443@cindex symbol table entries, printing
1444Print the symbol table entries of the file.
1445This is similar to the information provided by the @samp{nm} program.
1446
1447@item -T
1448@itemx --dynamic-syms
1449@cindex dynamic symbol table entries, printing
1450Print the dynamic symbol table entries of the file. This is only
1451meaningful for dynamic objects, such as certain types of shared
1452libraries. This is similar to the information provided by the @samp{nm}
1453program when given the @samp{-D} (@samp{--dynamic}) option.
1454
1455@item --version
1456Print the version number of @code{objdump} and exit.
1457
1458@item -x
1459@itemx --all-header
1460@cindex all header information, object file
1461@cindex header information, all
1462Display all available header information, including the symbol table and
1463relocation entries. Using @samp{-x} is equivalent to specifying all of
1464@samp{-a -f -h -r -t}.
1465
1466@item -w
1467@itemx --wide
1468@cindex wide output, printing
1469Format some lines for output devices that have more than 80 columns.
1470@end table
1471
1472@node ranlib
1473@chapter ranlib
1474
1475@kindex ranlib
1476@cindex archive contents
1477@cindex symbol index
1478
1479@smallexample
1480ranlib [-vV] @var{archive}
1481@end smallexample
1482
1483@code{ranlib} generates an index to the contents of an archive and
1484stores it in the archive. The index lists each symbol defined by a
1485member of an archive that is a relocatable object file.
1486
1487You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1488
1489An archive with such an index speeds up linking to the library and
1490allows routines in the library to call each other without regard to
1491their placement in the archive.
1492
1493The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1494@code{ranlib} is completely equivalent to executing @samp{ar -s}.
1495@xref{ar}.
1496
1497@table @code
1498@item -v
1499@itemx -V
f20a759a 1500@itemx --version
252b5132
RH
1501Show the version number of @code{ranlib}.
1502@end table
1503
1504@node size
1505@chapter size
1506
1507@kindex size
1508@cindex section sizes
1509
1510@smallexample
1511size [ -A | -B | --format=@var{compatibility} ]
1512 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1513 [ --target=@var{bfdname} ] [ -V | --version ]
1514 [ @var{objfile}@dots{} ]
1515@end smallexample
1516
1517The @sc{gnu} @code{size} utility lists the section sizes---and the total
1518size---for each of the object or archive files @var{objfile} in its
1519argument list. By default, one line of output is generated for each
1520object file or each module in an archive.
1521
1522@var{objfile}@dots{} are the object files to be examined.
1523If none are specified, the file @code{a.out} will be used.
1524
1525The command line options have the following meanings:
1526
1527@table @code
1528@item -A
1529@itemx -B
1530@itemx --format=@var{compatibility}
1531@cindex @code{size} display format
1532Using one of these options, you can choose whether the output from @sc{gnu}
1533@code{size} resembles output from System V @code{size} (using @samp{-A},
1534or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1535@samp{--format=berkeley}). The default is the one-line format similar to
1536Berkeley's.
1537@c Bonus for doc-source readers: you can also say --format=strange (or
1538@c anything else that starts with 's') for sysv, and --format=boring (or
1539@c anything else that starts with 'b') for Berkeley.
1540
1541Here is an example of the Berkeley (default) format of output from
1542@code{size}:
1543@smallexample
f20a759a 1544$ size --format=Berkeley ranlib size
252b5132
RH
1545text data bss dec hex filename
1546294880 81920 11592 388392 5ed28 ranlib
1547294880 81920 11888 388688 5ee50 size
1548@end smallexample
1549
1550@noindent
1551This is the same data, but displayed closer to System V conventions:
1552
1553@smallexample
f20a759a 1554$ size --format=SysV ranlib size
252b5132
RH
1555ranlib :
1556section size addr
1557.text 294880 8192
1558.data 81920 303104
1559.bss 11592 385024
1560Total 388392
1561
1562
1563size :
1564section size addr
1565.text 294880 8192
1566.data 81920 303104
1567.bss 11888 385024
1568Total 388688
1569@end smallexample
1570
1571@item --help
1572Show a summary of acceptable arguments and options.
1573
1574@item -d
1575@itemx -o
1576@itemx -x
1577@itemx --radix=@var{number}
1578@cindex @code{size} number format
1579@cindex radix for section sizes
1580Using one of these options, you can control whether the size of each
1581section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1582(@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1583@samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1584values (8, 10, 16) are supported. The total size is always given in two
1585radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1586octal and hexadecimal if you're using @samp{-o}.
1587
1588@item --target=@var{bfdname}
1589@cindex object code format
1590Specify that the object-code format for @var{objfile} is
1591@var{bfdname}. This option may not be necessary; @code{size} can
1592automatically recognize many formats.
1593@xref{Target Selection}, for more information.
1594
1595@item -V
1596@itemx --version
1597Display the version number of @code{size}.
1598@end table
1599
1600@node strings
1601@chapter strings
1602@kindex strings
1603@cindex listings strings
1604@cindex printing strings
1605@cindex strings, printing
1606
1607@smallexample
1608strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1609 [--all] [--print-file-name] [--bytes=@var{min-len}]
1610 [--radix=@var{radix}] [--target=@var{bfdname}]
1611 [--help] [--version] @var{file}@dots{}
1612@end smallexample
1613
1614For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1615character sequences that are at least 4 characters long (or the number
1616given with the options below) and are followed by an unprintable
1617character. By default, it only prints the strings from the initialized
1618and loaded sections of object files; for other types of files, it prints
1619the strings from the whole file.
1620
1621@code{strings} is mainly useful for determining the contents of non-text
1622files.
1623
1624@table @code
1625@item -a
1626@itemx --all
1627@itemx -
1628Do not scan only the initialized and loaded sections of object files;
1629scan the whole files.
1630
1631@item -f
1632@itemx --print-file-name
1633Print the name of the file before each string.
1634
1635@item --help
1636Print a summary of the program usage on the standard output and exit.
1637
1638@item -@var{min-len}
1639@itemx -n @var{min-len}
1640@itemx --bytes=@var{min-len}
1641Print sequences of characters that are at least @var{min-len} characters
1642long, instead of the default 4.
1643
1644@item -o
1645Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1646act like @samp{-t d} instead. Since we can not be compatible with both
1647ways, we simply chose one.
1648
1649@item -t @var{radix}
1650@itemx --radix=@var{radix}
1651Print the offset within the file before each string. The single
1652character argument specifies the radix of the offset---@samp{o} for
1653octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1654
1655@item --target=@var{bfdname}
1656@cindex object code format
1657Specify an object code format other than your system's default format.
1658@xref{Target Selection}, for more information.
1659
1660@item -v
1661@itemx --version
1662Print the program version number on the standard output and exit.
1663@end table
1664
1665@node strip
1666@chapter strip
1667
1668@kindex strip
1669@cindex removing symbols
1670@cindex discarding symbols
1671@cindex symbols, discarding
1672
1673@smallexample
1674strip [ -F @var{bfdname} | --target=@var{bfdname} ]
1675 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1676 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1677 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1678 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1679 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1680 [ -x | --discard-all ] [ -X | --discard-locals ]
1681 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1682 [ -o @var{file} ] [ -p | --preserve-dates ]
1683 [ -v | --verbose ] [ -V | --version ] [ --help ]
1684 @var{objfile}@dots{}
1685@end smallexample
1686
1687@sc{gnu} @code{strip} discards all symbols from object files
1688@var{objfile}. The list of object files may include archives.
1689At least one object file must be given.
1690
1691@code{strip} modifies the files named in its argument,
1692rather than writing modified copies under different names.
1693
1694@table @code
1695@item -F @var{bfdname}
1696@itemx --target=@var{bfdname}
1697Treat the original @var{objfile} as a file with the object
1698code format @var{bfdname}, and rewrite it in the same format.
1699@xref{Target Selection}, for more information.
1700
1701@item --help
1702Show a summary of the options to @code{strip} and exit.
1703
1704@item -I @var{bfdname}
1705@itemx --input-target=@var{bfdname}
1706Treat the original @var{objfile} as a file with the object
1707code format @var{bfdname}.
1708@xref{Target Selection}, for more information.
1709
1710@item -O @var{bfdname}
1711@itemx --output-target=@var{bfdname}
1712Replace @var{objfile} with a file in the output format @var{bfdname}.
1713@xref{Target Selection}, for more information.
1714
1715@item -R @var{sectionname}
1716@itemx --remove-section=@var{sectionname}
1717Remove any section named @var{sectionname} from the output file. This
1718option may be given more than once. Note that using this option
1719inappropriately may make the output file unusable.
1720
1721@item -s
1722@itemx --strip-all
1723Remove all symbols.
1724
1725@item -g
1726@itemx -S
1727@itemx --strip-debug
1728Remove debugging symbols only.
1729
1730@item --strip-unneeded
1731Remove all symbols that are not needed for relocation processing.
1732
1733@item -K @var{symbolname}
1734@itemx --keep-symbol=@var{symbolname}
1735Keep only symbol @var{symbolname} from the source file. This option may
1736be given more than once.
1737
1738@item -N @var{symbolname}
1739@itemx --strip-symbol=@var{symbolname}
1740Remove symbol @var{symbolname} from the source file. This option may be
1741given more than once, and may be combined with strip options other than
1742@code{-K}.
1743
1744@item -o @var{file}
1745Put the stripped output in @var{file}, rather than replacing the
1746existing file. When this argument is used, only one @var{objfile}
1747argument may be specified.
1748
1749@item -p
1750@itemx --preserve-dates
1751Preserve the access and modification dates of the file.
1752
1753@item -x
1754@itemx --discard-all
1755Remove non-global symbols.
1756
1757@item -X
1758@itemx --discard-locals
1759Remove compiler-generated local symbols.
1760(These usually start with @samp{L} or @samp{.}.)
1761
1762@item -V
1763@itemx --version
1764Show the version number for @code{strip}.
1765
1766@item -v
1767@itemx --verbose
1768Verbose output: list all object files modified. In the case of
1769archives, @samp{strip -v} lists all members of the archive.
1770@end table
1771
9d51cc66 1772@node c++filt, addr2line, strip, Top
252b5132
RH
1773@chapter c++filt
1774
1775@kindex c++filt
1776@cindex demangling C++ symbols
1777
1778@smallexample
1779c++filt [ -_ | --strip-underscores ]
1780 [ -j | --java ]
1781 [ -n | --no-strip-underscores ]
1782 [ -s @var{format} | --format=@var{format} ]
1783 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1784@end smallexample
1785
9d51cc66 1786@kindex cxxfilt
252b5132
RH
1787The C++ and Java languages provides function overloading, which means
1788that you can write many functions with the same name (providing each
1789takes parameters of different types). All C++ and Java function names
1790are encoded into a low-level assembly label (this process is known as
9d51cc66
ILT
1791@dfn{mangling}). The @code{c++filt}
1792@footnote{MS-DOS does not allow @kbd{+} characters in file names, so on
1793MS-DOS this program is named @code{cxxfilt}.}
1794program does the inverse mapping: it decodes (@dfn{demangles}) low-level
1795names into user-level names so that the linker can keep these overloaded
1796functions from clashing.
252b5132
RH
1797
1798Every alphanumeric word (consisting of letters, digits, underscores,
1799dollars, or periods) seen in the input is a potential label. If the
1800label decodes into a C++ name, the C++ name replaces the low-level
1801name in the output.
1802
1803You can use @code{c++filt} to decipher individual symbols:
1804
1805@example
1806c++filt @var{symbol}
1807@end example
1808
1809If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1810names from the standard input and writes the demangled names to the
1811standard output. All results are printed on the standard output.
1812
1813@table @code
1814@item -_
1815@itemx --strip-underscores
1816On some systems, both the C and C++ compilers put an underscore in front
1817of every name. For example, the C name @code{foo} gets the low-level
1818name @code{_foo}. This option removes the initial underscore. Whether
1819@code{c++filt} removes the underscore by default is target dependent.
1820
1821@item -j
1822@itemx --java
1823Prints demangled names using Java syntax. The default is to use C++
1824syntax.
1825
1826@item -n
1827@itemx --no-strip-underscores
1828Do not remove the initial underscore.
1829
1830@item -s @var{format}
1831@itemx --format=@var{format}
1832@sc{gnu} @code{nm} can decode three different methods of mangling, used by
1833different C++ compilers. The argument to this option selects which
1834method it uses:
1835
1836@table @code
1837@item gnu
1838the one used by the @sc{gnu} compiler (the default method)
1839@item lucid
1840the one used by the Lucid compiler
1841@item arm
1842the one specified by the C++ Annotated Reference Manual
1843@item hp
1844the one used by the HP compiler
1845@item edg
1846the one used by the EDG compiler
1847@end table
1848
1849@item --help
1850Print a summary of the options to @code{c++filt} and exit.
1851
1852@item --version
1853Print the version number of @code{c++filt} and exit.
1854@end table
1855
1856@quotation
1857@emph{Warning:} @code{c++filt} is a new utility, and the details of its
1858user interface are subject to change in future releases. In particular,
1859a command-line option may be required in the the future to decode a name
1860passed as an argument on the command line; in other words,
1861
1862@example
1863c++filt @var{symbol}
1864@end example
1865
1866@noindent
1867may in a future release become
1868
1869@example
1870c++filt @var{option} @var{symbol}
1871@end example
1872@end quotation
1873
1874@node addr2line
1875@chapter addr2line
1876
1877@kindex addr2line
1878@cindex address to file name and line number
1879
1880@smallexample
1881addr2line [ -b @var{bfdname} | --target=@var{bfdname} ]
1882 [ -C | --demangle ]
1883 [ -e @var{filename} | --exe=@var{filename} ]
1884 [ -f | --functions ] [ -s | --basename ]
1885 [ -H | --help ] [ -V | --version ]
1886 [ addr addr ... ]
1887@end smallexample
1888
1889@code{addr2line} translates program addresses into file names and line
1890numbers. Given an address and an executable, it uses the debugging
1891information in the executable to figure out which file name and line
1892number are associated with a given address.
1893
1894The executable to use is specified with the @code{-e} option. The
f20a759a 1895default is the file @file{a.out}.
252b5132
RH
1896
1897@code{addr2line} has two modes of operation.
1898
1899In the first, hexadecimal addresses are specified on the command line,
1900and @code{addr2line} displays the file name and line number for each
1901address.
1902
1903In the second, @code{addr2line} reads hexadecimal addresses from
1904standard input, and prints the file name and line number for each
1905address on standard output. In this mode, @code{addr2line} may be used
1906in a pipe to convert dynamically chosen addresses.
1907
1908The format of the output is @samp{FILENAME:LINENO}. The file name and
1909line number for each address is printed on a separate line. If the
1910@code{-f} option is used, then each @samp{FILENAME:LINENO} line is
1911preceded by a @samp{FUNCTIONNAME} line which is the name of the function
1912containing the address.
1913
1914If the file name or function name can not be determined,
1915@code{addr2line} will print two question marks in their place. If the
1916line number can not be determined, @code{addr2line} will print 0.
1917
1918The long and short forms of options, shown here as alternatives, are
1919equivalent.
1920
1921@table @code
1922@item -b @var{bfdname}
1923@itemx --target=@var{bfdname}
1924@cindex object code format
1925Specify that the object-code format for the object files is
1926@var{bfdname}.
1927
1928@item -C
1929@itemx --demangle
1930@cindex demangling in objdump
1931Decode (@dfn{demangle}) low-level symbol names into user-level names.
1932Besides removing any initial underscore prepended by the system, this
1933makes C++ function names readable. @xref{c++filt}, for more information
1934on demangling.
1935
1936@item -e @var{filename}
1937@itemx --exe=@var{filename}
1938Specify the name of the executable for which addresses should be
1939translated. The default file is @file{a.out}.
1940
1941@item -f
1942@itemx --functions
1943Display function names as well as file and line number information.
1944
1945@item -s
1946@itemx --basenames
1947Display only the base of each file name.
1948@end table
1949
1950@node nlmconv
1951@chapter nlmconv
1952
1953@code{nlmconv} converts a relocatable object file into a NetWare
1954Loadable Module.
1955
1956@ignore
1957@code{nlmconv} currently works with @samp{i386} object
1958files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1959object files in @sc{elf}, or @code{a.out} format@footnote{
1960@code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1961format in the Binary File Descriptor library. It has only been tested
1962with the above formats.}.
1963@end ignore
1964
1965@quotation
1966@emph{Warning:} @code{nlmconv} is not always built as part of the binary
1967utilities, since it is only useful for NLM targets.
1968@end quotation
1969
1970@smallexample
1971nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1972 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1973 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1974 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1975 [ -h | --help ] [ -V | --version ]
1976 @var{infile} @var{outfile}
1977@end smallexample
1978
1979@code{nlmconv} converts the relocatable @samp{i386} object file
1980@var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1981reading @var{headerfile} for NLM header information. For instructions
1982on writing the NLM command file language used in header files, see the
1983@samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1984Development and Tools Overview}, which is part of the NLM Software
1985Developer's Kit (``NLM SDK''), available from Novell, Inc.
1986@code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1987@var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1988more information.
1989
1990@code{nlmconv} can perform a link step. In other words, you can list
1991more than one object file for input if you list them in the definitions
1992file (rather than simply specifying one input file on the command line).
1993In this case, @code{nlmconv} calls the linker for you.
1994
1995@table @code
1996@item -I @var{bfdname}
1997@itemx --input-target=@var{bfdname}
1998Object format of the input file. @code{nlmconv} can usually determine
1999the format of a given file (so no default is necessary).
2000@xref{Target Selection}, for more information.
2001
2002@item -O @var{bfdname}
2003@itemx --output-target=@var{bfdname}
2004Object format of the output file. @code{nlmconv} infers the output
2005format based on the input format, e.g. for a @samp{i386} input file the
2006output format is @samp{nlm32-i386}.
2007@xref{Target Selection}, for more information.
2008
2009@item -T @var{headerfile}
2010@itemx --header-file=@var{headerfile}
2011Reads @var{headerfile} for NLM header information. For instructions on
2012writing the NLM command file language used in header files, see@ see the
2013@samp{linkers} section, of the @cite{NLM Development and Tools
2014Overview}, which is part of the NLM Software Developer's Kit, available
2015from Novell, Inc.
2016
2017@item -d
2018@itemx --debug
2019Displays (on standard error) the linker command line used by @code{nlmconv}.
2020
2021@item -l @var{linker}
2022@itemx --linker=@var{linker}
2023Use @var{linker} for any linking. @var{linker} can be an absolute or a
2024relative pathname.
2025
2026@item -h
2027@itemx --help
2028Prints a usage summary.
2029
2030@item -V
2031@itemx --version
2032Prints the version number for @code{nlmconv}.
2033@end table
2034
2035@node windres
2036@chapter windres
2037
2038@code{windres} may be used to manipulate Windows resources.
2039
2040@quotation
2041@emph{Warning:} @code{windres} is not always built as part of the binary
2042utilities, since it is only useful for Windows targets.
2043@end quotation
2044
2045@smallexample
2046windres [options] [input-file] [output-file]
2047@end smallexample
2048
2049@code{windres} reads resources from an input file and copies them into
2050an output file. Either file may be in one of three formats:
2051
2052@table @code
2053@item rc
2054A text format read by the Resource Compiler.
2055
2056@item res
2057A binary format generated by the Resource Compiler.
2058
2059@item coff
2060A COFF object or executable.
2061@end table
2062
2063The exact description of these different formats is available in
2064documentation from Microsoft.
2065
2066When @code{windres} converts from the @code{rc} format to the @code{res}
2067format, it is acting like the Windows Resource Compiler. When
2068@code{windres} converts from the @code{res} format to the @code{coff}
2069format, it is acting like the Windows @code{CVTRES} program.
2070
2071When @code{windres} generates an @code{rc} file, the output is similar
2072but not identical to the format expected for the input. When an input
2073@code{rc} file refers to an external filename, an output @code{rc} file
2074will instead include the file contents.
2075
2076If the input or output format is not specified, @code{windres} will
2077guess based on the file name, or, for the input file, the file contents.
2078A file with an extension of @file{.rc} will be treated as an @code{rc}
2079file, a file with an extension of @file{.res} will be treated as a
2080@code{res} file, and a file with an extension of @file{.o} or
2081@file{.exe} will be treated as a @code{coff} file.
2082
2083If no output file is specified, @code{windres} will print the resources
2084in @code{rc} format to standard output.
2085
2086The normal use is for you to write an @code{rc} file, use @code{windres}
2087to convert it to a COFF object file, and then link the COFF file into
2088your application. This will make the resources described in the
2089@code{rc} file available to Windows.
2090
2091@table @code
2092@item -i @var{filename}
2093@itemx --input @var{filename}
2094The name of the input file. If this option is not used, then
2095@code{windres} will use the first non-option argument as the input file
2096name. If there are no non-option arguments, then @code{windres} will
2097read from standard input. @code{windres} can not read a COFF file from
2098standard input.
2099
2100@item -o @var{filename}
2101@itemx --output @var{filename}
2102The name of the output file. If this option is not used, then
2103@code{windres} will use the first non-option argument, after any used
2104for the input file name, as the output file name. If there is no
2105non-option argument, then @code{windres} will write to standard output.
2106@code{windres} can not write a COFF file to standard output.
2107
2108@item -I @var{format}
2109@itemx --input-format @var{format}
2110The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
2111@samp{coff}. If no input format is specified, @code{windres} will
2112guess, as described above.
2113
2114@item -O @var{format}
2115@itemx --output-format @var{format}
2116The output format to generate. @var{format} may be @samp{res},
2117@samp{rc}, or @samp{coff}. If no output format is specified,
2118@code{windres} will guess, as described above.
2119
2120@item -F @var{target}
2121@itemx --target @var{target}
2122Specify the BFD format to use for a COFF file as input or output. This
2123is a BFD target name; you can use the @code{--help} option to see a list
2124of supported targets. Normally @code{windres} will use the default
2125format, which is the first one listed by the @code{--help} option.
2126@ref{Target Selection}.
2127
2128@item --preprocessor @var{program}
2129When @code{windres} reads an @code{rc} file, it runs it through the C
2130preprocessor first. This option may be used to specify the preprocessor
2131to use, including any leading arguments. The default preprocessor
2132argument is @code{gcc -E -xc-header -DRC_INVOKED}.
2133
2134@item --include-dir @var{directory}
2135Specify an include directory to use when reading an @code{rc} file.
2136@code{windres} will pass this to the preprocessor as an @code{-I}
2137option. @code{windres} will also search this directory when looking for
2138files named in the @code{rc} file.
2139
751d21b5 2140@item -D @var{target}
ad0481cd 2141@itemx --define @var{sym}[=@var{val}]
252b5132
RH
2142Specify a @code{-D} option to pass to the preprocessor when reading an
2143@code{rc} file.
2144
751d21b5
DD
2145@item -v
2146Enable verbose mode. This tells you what the preprocessor is if you
2147didn't specify one.
2148
252b5132
RH
2149@item --language @var{val}
2150Specify the default language to use when reading an @code{rc} file.
2151@var{val} should be a hexadecimal language code. The low eight bits are
2152the language, and the high eight bits are the sublanguage.
2153
5a298d2d
NC
2154@item --use-temp-file
2155Use a temporary file to instead of using popen to read the output of
2156the preprocessor. Use this option if the popen implementation is buggy
2157on the host (eg., certain non-English language versions of Windows 95 and
2158Windows 98 are known to have buggy popen where the output will instead
2159go the console).
2160
2161@item --no-use-temp-file
2162Use popen, not a temporary file, to read the output of the preprocessor.
2163This is the default behaviour.
2164
252b5132
RH
2165@item --help
2166Prints a usage summary.
2167
2168@item --version
2169Prints the version number for @code{windres}.
2170
2171@item --yydebug
2172If @code{windres} is compiled with @code{YYDEBUG} defined as @code{1},
2173this will turn on parser debugging.
2174@end table
2175
2176
2177@node dlltool
2178@chapter Create files needed to build and use DLLs
2179@cindex DLL
2180@kindex dlltool
2181
2182@code{dlltool} may be used to create the files needed to build and use
2183dynamic link libraries (DLLs).
2184
2185@quotation
2186@emph{Warning:} @code{dlltool} is not always built as part of the binary
2187utilities, since it is only useful for those targets which support DLLs.
2188@end quotation
2189
2190@smallexample
2191dlltool [-d|--input-def @var{def-file-name}]
2192 [-b|--base-file @var{base-file-name}]
2193 [-e|--output-exp @var{exports-file-name}]
2194 [-z|--output-def @var{def-file-name}]
2195 [-l|--output-lib @var{library-file-name}]
2196 [--export-all-symbols] [--no-export-all-symbols]
2197 [--exclude-symbols @var{list}]
2198 [--no-default-excludes]
2199 [-S|--as @var{path-to-assembler}] [-f|--as-flags @var{options}]
2200 [-D|--dllname @var{name}] [-m|--machine @var{machine}]
2201 [-a|--add-indirect] [-U|--add-underscore] [-k|--kill-at]
2202 [-A|--add-stdcall-alias]
2203 [-x|--no-idata4] [-c|--no-idata5] [-i|--interwork]
2204 [-n|--nodelete] [-v|--verbose] [-h|--help] [-V|--version]
2205 [object-file @dots{}]
2206@end smallexample
2207
2208@code{dlltool} reads its inputs, which can come from the @samp{-d} and
2209@samp{-b} options as well as object files specified on the command
2210line. It then processes these inputs and if the @samp{-e} option has
2211been specified it creates a exports file. If the @samp{-l} option
2212has been specified it creates a library file and if the @samp{-z} option
2213has been specified it creates a def file. Any or all of the -e, -l
2214and -z options can be present in one invocation of dlltool.
2215
2216When creating a DLL, along with the source for the DLL, it is necessary
2217to have three other files. @code{dlltool} can help with the creation of
2218these files.
2219
2220The first file is a @samp{.def} file which specifies which functions are
2221exported from the DLL, which functions the DLL imports, and so on. This
2222is a text file and can be created by hand, or @code{dlltool} can be used
2223to create it using the @samp{-z} option. In this case @code{dlltool}
2224will scan the object files specified on its command line looking for
2225those functions which have been specially marked as being exported and
2226put entries for them in the .def file it creates.
2227
2228In order to mark a function as being exported from a DLL, it needs to
2229have an @samp{-export:<name_of_function>} entry in the @samp{.drectve}
2230section of the object file. This can be done in C by using the
2231asm() operator:
2232
2233@smallexample
2234 asm (".section .drectve");
2235 asm (".ascii \"-export:my_func\"");
2236
2237 int my_func (void) @{ @dots{} @}
2238@end smallexample
2239
2240The second file needed for DLL creation is an exports file. This file
2241is linked with the object files that make up the body of the DLL and it
2242handles the interface between the DLL and the outside world. This is a
2243binary file and it can be created by giving the @samp{-e} option to
2244@code{dlltool} when it is creating or reading in a .def file.
2245
2246The third file needed for DLL creation is the library file that programs
2247will link with in order to access the functions in the DLL. This file
2248can be created by giving the @samp{-l} option to dlltool when it
2249is creating or reading in a .def file.
2250
2251@code{dlltool} builds the library file by hand, but it builds the
2252exports file by creating temporary files containing assembler statements
2253and then assembling these. The @samp{-S} command line option can be
2254used to specify the path to the assembler that dlltool will use,
2255and the @samp{-f} option can be used to pass specific flags to that
2256assembler. The @samp{-n} can be used to prevent dlltool from deleting
2257these temporary assembler files when it is done, and if @samp{-n} is
2258specified twice then this will prevent dlltool from deleting the
2259temporary object files it used to build the library.
2260
2261Here is an example of creating a DLL from a source file @samp{dll.c} and
2262also creating a program (from an object file called @samp{program.o})
2263that uses that DLL:
2264
2265@smallexample
2266 gcc -c dll.c
2267 dlltool -e exports.o -l dll.lib dll.o
2268 gcc dll.o exports.o -o dll.dll
2269 gcc program.o dll.lib -o program
2270@end smallexample
2271
2272The command line options have the following meanings:
2273
2274@table @code
2275
2276@item -d @var{filename}
2277@itemx --input-def @var{filename}
2278@cindex input .def file
2279Specifies the name of a .def file to be read in and processed.
2280
2281@item -b @var{filename}
2282@itemx --base-file @var{filename}
2283@cindex base files
2284Specifies the name of a base file to be read in and processed. The
2285contents of this file will be added to the relocation section in the
2286exports file generated by dlltool.
2287
2288@item -e @var{filename}
2289@itemx --output-exp @var{filename}
2290Specifies the name of the export file to be created by dlltool.
2291
2292@item -z @var{filename}
2293@itemx --output-def @var{filename}
2294Specifies the name of the .def file to be created by dlltool.
2295
2296@item -l @var{filename}
2297@itemx --output-lib @var{filename}
2298Specifies the name of the library file to be created by dlltool.
2299
2300@item --export-all-symbols
2301Treat all global and weak defined symbols found in the input object
2302files as symbols to be exported. There is a small list of symbols which
2303are not exported by default; see the @code{--no-default-excludes}
2304option. You may add to the list of symbols to not export by using the
2305@code{--exclude-symbols} option.
2306
2307@item --no-export-all-symbols
2308Only export symbols explicitly listed in an input .def file or in
2309@samp{.drectve} sections in the input object files. This is the default
2310behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
2311attributes in the source code.
2312
2313@item --exclude-symbols @var{list}
2314Do not export the symbols in @var{list}. This is a list of symbol names
2315separated by comma or colon characters. The symbol names should not
2316contain a leading underscore. This is only meaningful when
2317@code{--export-all-symbols} is used.
2318
2319@item --no-default-excludes
2320When @code{--export-all-symbols} is used, it will by default avoid
2321exporting certain special symbols. The current list of symbols to avoid
2322exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
2323@samp{impure_ptr}. You may use the @code{--no-default-excludes} option
2324to go ahead and export these special symbols. This is only meaningful
2325when @code{--export-all-symbols} is used.
2326
2327@item -S @var{path}
2328@itemx --as @var{path}
2329Specifies the path, including the filename, of the assembler to be used
2330to create the exports file.
2331
2332@item -f @var{switches}
2333@itemx --as-flags @var{switches}
2334Specifies any specific command line switches to be passed to the
2335assembler when building the exports file. This option will work even if
2336the @samp{-S} option is not used. This option only takes one argument,
2337and if it occurs more than once on the command line, then later
2338occurrences will override earlier occurrences. So if it is necessary to
2339pass multiple switches to the assembler they should be enclosed in
2340double quotes.
2341
2342@item -D @var{name}
2343@itemx --dll-name @var{name}
2344Specifies the name to be stored in the .def file as the name of the DLL
2345when the @samp{-e} option is used. If this option is not present, then
2346the filename given to the @samp{-e} option will be used as the name of
2347the DLL.
2348
2349@item -m @var{machine}
2350@itemx -machine @var{machine}
2351Specifies the type of machine for which the library file should be
2352built. @code{dlltool} has a built in default type, depending upon how
2353it was created, but this option can be used to override that. This is
2354normally only useful when creating DLLs for an ARM processor, when the
2355contents of the DLL are actually encode using THUMB instructions.
2356
2357@item -a
2358@itemx --add-indirect
2359Specifies that when @code{dlltool} is creating the exports file it
2360should add a section which allows the exported functions to be
2361referenced without using the import library. Whatever the hell that
2362means!
2363
2364@item -U
2365@itemx --add-underscore
2366Specifies that when @code{dlltool} is creating the exports file it
2367should prepend an underscore to the names of the exported functions.
2368
2369@item -k
2370@itemx --kill-at
2371Specifies that when @code{dlltool} is creating the exports file it
2372should not append the string @samp{@@ <number>}. These numbers are
2373called ordinal numbers and they represent another way of accessing the
2374function in a DLL, other than by name.
2375
2376@item -A
2377@itemx --add-stdcall-alias
2378Specifies that when @code{dlltool} is creating the exports file it
2379should add aliases for stdcall symbols without @samp{@@ <number>}
2380in addition to the symbols with @samp{@@ <number>}.
2381
2382@item -x
2383@itemx --no-idata4
2384Specifies that when @code{dlltool} is creating the exports and library
2385files it should omit the .idata4 section. This is for compatibility
2386with certain operating systems.
2387
2388@item -c
2389@itemx --no-idata5
2390Specifies that when @code{dlltool} is creating the exports and library
2391files it should omit the .idata5 section. This is for compatibility
2392with certain operating systems.
2393
2394@item -i
2395@itemx --interwork
2396Specifies that @code{dlltool} should mark the objects in the library
2397file and exports file that it produces as supporting interworking
2398between ARM and THUMB code.
2399
2400@item -n
2401@itemx --nodelete
2402Makes @code{dlltool} preserve the temporary assembler files it used to
2403create the exports file. If this option is repeated then dlltool will
2404also preserve the temporary object files it uses to create the library
2405file.
2406
2407@item -v
2408@itemx --verbose
2409Make dlltool describe what it is doing.
2410
2411@item -h
2412@itemx --help
2413Displays a list of command line options and then exits.
2414
2415@item -V
2416@itemx --version
2417Displays dlltool's version number and then exits.
2418
2419@end table
2420
2421@node readelf
2422@chapter readelf
2423
2424@cindex ELF file information
2425@kindex readelf
2426
2427@smallexample
2428readelf [ -a | --all ]
2429 [ -h | --file-header]
2430 [ -l | --program-headers | --segments]
2431 [ -S | --section-headers | --sections]
2432 [ -e | --headers]
2433 [ -s | --syms | --symbols]
779fe533 2434 [ -n | --notes]
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2435 [ -r | --relocs]
2436 [ -d | --dynamic]
2437 [ -V | --version-info]
2438 [ -D | --use-dynamic]
2439 [ -x <number> | --hex-dump=<number>]
2440 [ -w[liapr] | --debug-dump[=info,=line,=abbrev,=pubnames,=ranges]]
2441 [ --histogram]
2442 [ -v | --version]
2443 [ -H | --help]
2444 @var{elffile}@dots{}
2445@end smallexample
2446
2447@code{readelf} displays information about one or more ELF format object
2448files. The options control what particular information to display.
2449
2450@var{elffile}@dots{} are the object files to be examined. At the
2451moment, @code{readelf} does not support examining archives, nor does it
2452support examing 64 bit ELF files.
2453
2454The long and short forms of options, shown here as alternatives, are
2455equivalent. At least one option besides @samp{-v} or @samp{-H} must be
2456given.
2457
2458@table @code
2459@item -a
2460@itemx --all
2461Equivalent to specifiying @samp{--file-header},
2462@samp{--program-headers}, @samp{--sections}, @samp{--symbols},
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2463@samp{--relocs}, @samp{--dynamic}, @samp{--notes} and
2464@samp{--version-info}.
252b5132
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2465
2466@item -h
2467@itemx --file-header
2468@cindex ELF file header information
2469Displays the information contained in the ELF header at the start of the
2470file.
2471
2472@item -l
2473@itemx --program-headers
2474@itemx --segments
2475@cindex ELF program header information
2476@cindex ELF segment information
2477Displays the information contained in the file's segment headers, if it
2478has any.
2479
2480@item -S
2481@itemx --sections
2482@itemx --section-headers
2483@cindex ELF section information
2484Displays the information contained in the file's section headers, if it
2485has any.
2486
2487@item -s
2488@itemx --symbols
2489@itemx --syms
2490@cindex ELF symbol table information
2491Displays the entries in symbol table section of the file, if it has one.
2492
2493@item -e
2494@itemx --headers
2495Display all the headers in the file. Equivalent to @samp{-h -l -S}.
2496
779fe533
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2497@item -n
2498@itemx --notes
2499@cindex ELF core notes
2500Displays the contents of the NOTE segment, if it exists.
2501
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2502@item -r
2503@itemx --relocs
2504@cindex ELF reloc information
2505Displays the contents of the file's relocation section, if it ha one.
2506
2507@item -d
2508@itemx --dynamic
2509@cindex ELF dynamic section information
2510Displays the contents of the file's dynamic section, if it has one.
2511
2512@item -V
2513@itemx --version-info
2514@cindex ELF version sections informations
2515Displays the contents of the version sections in the file, it they
2516exist.
2517
2518@item -D
2519@itemx --use-dynamic
2520When displaying symbols, this option makes @code{readelf} use the
2521symblol table in the file's dynamic section, rather than the one in the
2522symbols section.
2523
2524@item -x <number>
2525@itemx --hex-dump=<number>
2526Displays the contents of the indicated section as a hexadecimal dump.
2527
2528@item -w[liapr]
2529@itemx --debug-dump[=line,=info,=abbrev,=pubnames,=ranges]
2530Displays the contents of the debug sections in the file, if any are
2531present. If one of the optional letters or words follows the switch
2532then only data found in those specific sections will be dumped.
2533
2534@item --histogram
2535Display a histogram of bucket list lengths when displaying the contents
2536of the symbol tables.
2537
2538@item -v
2539@itemx --version
2540Display the version number of readelf.
2541
2542@item -H
2543@itemx --help
2544Display the command line options understood by @code{readelf}.
2545
2546@end table
2547
2548
2549@node Selecting The Target System
2550@chapter Selecting the target system
2551
2552You can specify three aspects of the target system to the @sc{gnu}
2553binary file utilities, each in several ways:
2554
2555@itemize @bullet
2556@item
2557the target
2558
2559@item
2560the architecture
2561
2562@item
2563the linker emulation (which applies to the linker only)
2564@end itemize
2565
2566In the following summaries, the lists of ways to specify values are in
2567order of decreasing precedence. The ways listed first override those
2568listed later.
2569
2570The commands to list valid values only list the values for which the
2571programs you are running were configured. If they were configured with
2572@samp{--enable-targets=all}, the commands list most of the available
2573values, but a few are left out; not all targets can be configured in at
2574once because some of them can only be configured @dfn{native} (on hosts
2575with the same type as the target system).
2576
2577@menu
2578* Target Selection::
2579* Architecture Selection::
2580* Linker Emulation Selection::
2581@end menu
2582
2583@node Target Selection
2584@section Target Selection
2585
2586A @dfn{target} is an object file format. A given target may be
2587supported for multiple architectures (@pxref{Architecture Selection}).
2588A target selection may also have variations for different operating
2589systems or architectures.
2590
2591The command to list valid target values is @samp{objdump -i}
2592(the first column of output contains the relevant information).
2593
2594Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
2595@samp{a.out-sunos-big}.
2596
2597You can also specify a target using a configuration triplet. This is
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2598the same sort of name that is passed to @file{configure} to specify a
2599target. When you use a configuration triplet as an argument, it must be
2600fully canonicalized. You can see the canonical version of a triplet by
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2601running the shell script @file{config.sub} which is included with the
2602sources.
2603
2604Some sample configuration triplets are: @samp{m68k-hp-bsd},
2605@samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
2606
2607@subheading @code{objdump} Target
2608
2609Ways to specify:
2610
2611@enumerate
2612@item
2613command line option: @samp{-b} or @samp{--target}
2614
2615@item
2616environment variable @code{GNUTARGET}
2617
2618@item
2619deduced from the input file
2620@end enumerate
2621
2622@subheading @code{objcopy} and @code{strip} Input Target
2623
2624Ways to specify:
2625
2626@enumerate
2627@item
2628command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
2629
2630@item
2631environment variable @code{GNUTARGET}
2632
2633@item
2634deduced from the input file
2635@end enumerate
2636
2637@subheading @code{objcopy} and @code{strip} Output Target
2638
2639Ways to specify:
2640
2641@enumerate
2642@item
2643command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
2644
2645@item
2646the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
2647
2648@item
2649environment variable @code{GNUTARGET}
2650
2651@item
2652deduced from the input file
2653@end enumerate
2654
2655@subheading @code{nm}, @code{size}, and @code{strings} Target
2656
2657Ways to specify:
2658
2659@enumerate
2660@item
2661command line option: @samp{--target}
2662
2663@item
2664environment variable @code{GNUTARGET}
2665
2666@item
2667deduced from the input file
2668@end enumerate
2669
2670@subheading Linker Input Target
2671
2672Ways to specify:
2673
2674@enumerate
2675@item
2676command line option: @samp{-b} or @samp{--format}
2677(@pxref{Options,,Options,ld.info,Using LD})
2678
2679@item
2680script command @code{TARGET}
2681(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2682
2683@item
2684environment variable @code{GNUTARGET}
2685(@pxref{Environment,,Environment,ld.info,Using LD})
2686
2687@item
2688the default target of the selected linker emulation
2689(@pxref{Linker Emulation Selection})
2690@end enumerate
2691
2692@subheading Linker Output Target
2693
2694Ways to specify:
2695
2696@enumerate
2697@item
2698command line option: @samp{-oformat}
2699(@pxref{Options,,Options,ld.info,Using LD})
2700
2701@item
2702script command @code{OUTPUT_FORMAT}
2703(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2704
2705@item
2706the linker input target (see ``Linker Input Target'' above)
2707@end enumerate
2708
2709@node Architecture Selection
2710@section Architecture selection
2711
2712An @dfn{architecture} is a type of @sc{cpu} on which an object file is
2713to run. Its name may contain a colon, separating the name of the
2714processor family from the name of the particular @sc{cpu}.
2715
2716The command to list valid architecture values is @samp{objdump -i} (the
2717second column contains the relevant information).
2718
2719Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
2720
2721@subheading @code{objdump} Architecture
2722
2723Ways to specify:
2724
2725@enumerate
2726@item
2727command line option: @samp{-m} or @samp{--architecture}
2728
2729@item
2730deduced from the input file
2731@end enumerate
2732
2733@subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
2734
2735Ways to specify:
2736
2737@enumerate
2738@item
2739deduced from the input file
2740@end enumerate
2741
2742@subheading Linker Input Architecture
2743
2744Ways to specify:
2745
2746@enumerate
2747@item
2748deduced from the input file
2749@end enumerate
2750
2751@subheading Linker Output Architecture
2752
2753Ways to specify:
2754
2755@enumerate
2756@item
2757script command @code{OUTPUT_ARCH}
2758(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2759
2760@item
2761the default architecture from the linker output target
2762(@pxref{Target Selection})
2763@end enumerate
2764
2765@node Linker Emulation Selection
2766@section Linker emulation selection
2767
2768A linker @dfn{emulation} is a ``personality'' of the linker, which gives
2769the linker default values for the other aspects of the target system.
2770In particular, it consists of
2771
2772@itemize @bullet
2773@item
2774the linker script
2775
2776@item
2777the target
2778
2779@item
2780several ``hook'' functions that are run at certain stages of the linking
2781process to do special things that some targets require
2782@end itemize
2783
2784The command to list valid linker emulation values is @samp{ld -V}.
2785
2786Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
2787
2788Ways to specify:
2789
2790@enumerate
2791@item
2792command line option: @samp{-m}
2793(@pxref{Options,,Options,ld.info,Using LD})
2794
2795@item
2796environment variable @code{LDEMULATION}
2797
2798@item
2799compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2800which comes from @code{EMUL} in @file{config/@var{target}.mt}
2801@end enumerate
2802
2803@node Reporting Bugs
2804@chapter Reporting Bugs
2805@cindex bugs
2806@cindex reporting bugs
2807
2808Your bug reports play an essential role in making the binary utilities
2809reliable.
2810
2811Reporting a bug may help you by bringing a solution to your problem, or
2812it may not. But in any case the principal function of a bug report is
2813to help the entire community by making the next version of the binary
2814utilities work better. Bug reports are your contribution to their
2815maintenance.
2816
2817In order for a bug report to serve its purpose, you must include the
2818information that enables us to fix the bug.
2819
2820@menu
2821* Bug Criteria:: Have you found a bug?
2822* Bug Reporting:: How to report bugs
2823@end menu
2824
2825@node Bug Criteria
2826@section Have you found a bug?
2827@cindex bug criteria
2828
2829If you are not sure whether you have found a bug, here are some guidelines:
2830
2831@itemize @bullet
2832@cindex fatal signal
2833@cindex crash
2834@item
2835If a binary utility gets a fatal signal, for any input whatever, that is
2836a bug. Reliable utilities never crash.
2837
2838@cindex error on valid input
2839@item
2840If a binary utility produces an error message for valid input, that is a
2841bug.
2842
2843@item
2844If you are an experienced user of binary utilities, your suggestions for
2845improvement are welcome in any case.
2846@end itemize
2847
2848@node Bug Reporting
2849@section How to report bugs
2850@cindex bug reports
2851@cindex bugs, reporting
2852
2853A number of companies and individuals offer support for @sc{gnu}
2854products. If you obtained the binary utilities from a support
2855organization, we recommend you contact that organization first.
2856
2857You can find contact information for many support companies and
2858individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2859distribution.
2860
2861In any event, we also recommend that you send bug reports for the binary
2862utilities to @samp{bug-gnu-utils@@gnu.org}.
2863
2864The fundamental principle of reporting bugs usefully is this:
2865@strong{report all the facts}. If you are not sure whether to state a
2866fact or leave it out, state it!
2867
2868Often people omit facts because they think they know what causes the
2869problem and assume that some details do not matter. Thus, you might
2870assume that the name of a file you use in an example does not matter.
2871Well, probably it does not, but one cannot be sure. Perhaps the bug is
2872a stray memory reference which happens to fetch from the location where
2873that pathname is stored in memory; perhaps, if the pathname were
2874different, the contents of that location would fool the utility into
2875doing the right thing despite the bug. Play it safe and give a
2876specific, complete example. That is the easiest thing for you to do,
2877and the most helpful.
2878
2879Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2880it is new to us. Therefore, always write your bug reports on the assumption
2881that the bug has not been reported previously.
2882
2883Sometimes people give a few sketchy facts and ask, ``Does this ring a
2884bell?'' Those bug reports are useless, and we urge everyone to
2885@emph{refuse to respond to them} except to chide the sender to report
2886bugs properly.
2887
2888To enable us to fix the bug, you should include all these things:
2889
2890@itemize @bullet
2891@item
2892The version of the utility. Each utility announces it if you start it
2893with the @samp{--version} argument.
2894
2895Without this, we will not know whether there is any point in looking for
2896the bug in the current version of the binary utilities.
2897
2898@item
2899Any patches you may have applied to the source, including any patches
2900made to the @code{BFD} library.
2901
2902@item
2903The type of machine you are using, and the operating system name and
2904version number.
2905
2906@item
2907What compiler (and its version) was used to compile the utilities---e.g.
2908``@code{gcc-2.7}''.
2909
2910@item
2911The command arguments you gave the utility to observe the bug. To
2912guarantee you will not omit something important, list them all. A copy
2913of the Makefile (or the output from make) is sufficient.
2914
2915If we were to try to guess the arguments, we would probably guess wrong
2916and then we might not encounter the bug.
2917
2918@item
2919A complete input file, or set of input files, that will reproduce the
2920bug. If the utility is reading an object file or files, then it is
2921generally most helpful to send the actual object files, uuencoded if
757acbc5
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2922necessary to get them through the mail system. Note that
2923@samp{bug-gnu-utils@@gnu.org} is a mailing list, so you should avoid
2924sending very large files to it. Making the files available for
2925anonymous FTP is OK.
252b5132
RH
2926
2927If the source files were produced exclusively using @sc{gnu} programs
2928(e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2929may be OK to send the source files rather than the object files. In
2930this case, be sure to say exactly what version of @code{gcc}, or
2931whatever, was used to produce the object files. Also say how
2932@code{gcc}, or whatever, was configured.
2933
2934@item
2935A description of what behavior you observe that you believe is
2936incorrect. For example, ``It gets a fatal signal.''
2937
2938Of course, if the bug is that the utility gets a fatal signal, then we
2939will certainly notice it. But if the bug is incorrect output, we might
2940not notice unless it is glaringly wrong. You might as well not give us
2941a chance to make a mistake.
2942
2943Even if the problem you experience is a fatal signal, you should still
f20a759a 2944say so explicitly. Suppose something strange is going on, such as your
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RH
2945copy of the utility is out of synch, or you have encountered a bug in
2946the C library on your system. (This has happened!) Your copy might
2947crash and ours would not. If you told us to expect a crash, then when
2948ours fails to crash, we would know that the bug was not happening for
2949us. If you had not told us to expect a crash, then we would not be able
2950to draw any conclusion from our observations.
2951
2952@item
2953If you wish to suggest changes to the source, send us context diffs, as
2954generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2955option. Always send diffs from the old file to the new file. If you
f20a759a
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2956wish to discuss something in the @code{ld} source, refer to it by
2957context, not by line number.
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2958
2959The line numbers in our development sources will not match those in your
2960sources. Your line numbers would convey no useful information to us.
2961@end itemize
2962
2963Here are some things that are not necessary:
2964
2965@itemize @bullet
2966@item
2967A description of the envelope of the bug.
2968
2969Often people who encounter a bug spend a lot of time investigating
2970which changes to the input file will make the bug go away and which
2971changes will not affect it.
2972
2973This is often time consuming and not very useful, because the way we
2974will find the bug is by running a single example under the debugger
2975with breakpoints, not by pure deduction from a series of examples.
2976We recommend that you save your time for something else.
2977
2978Of course, if you can find a simpler example to report @emph{instead}
2979of the original one, that is a convenience for us. Errors in the
2980output will be easier to spot, running under the debugger will take
2981less time, and so on.
2982
2983However, simplification is not vital; if you do not want to do this,
2984report the bug anyway and send us the entire test case you used.
2985
2986@item
2987A patch for the bug.
2988
2989A patch for the bug does help us if it is a good one. But do not omit
2990the necessary information, such as the test case, on the assumption that
2991a patch is all we need. We might see problems with your patch and decide
2992to fix the problem another way, or we might not understand it at all.
2993
2994Sometimes with programs as complicated as the binary utilities it is
2995very hard to construct an example that will make the program follow a
2996certain path through the code. If you do not send us the example, we
2997will not be able to construct one, so we will not be able to verify that
2998the bug is fixed.
2999
3000And if we cannot understand what bug you are trying to fix, or why your
3001patch should be an improvement, we will not install it. A test case will
3002help us to understand.
3003
3004@item
3005A guess about what the bug is or what it depends on.
3006
3007Such guesses are usually wrong. Even we cannot guess right about such
3008things without first using the debugger to find the facts.
3009@end itemize
3010
3011@node Index
3012@unnumbered Index
3013
3014@printindex cp
3015
3016@contents
3017@bye
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