* infrun.c (handle_inferior_event): Call target_mourn_inferior
[deliverable/binutils-gdb.git] / binutils / binutils.texi
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1\input texinfo @c -*- Texinfo -*-
2@setfilename binutils.info
3@include config.texi
4
5@ifinfo
6@format
7START-INFO-DIR-ENTRY
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 ]
f1563258 1174 [ --file-start-context ]
1dada9c5
NC
1175 [ -g | --debugging ]
1176 [ -h | --section-headers | --headers ]
1177 [ -i | --info ]
252b5132 1178 [ -j @var{section} | --section=@var{section} ]
1dada9c5
NC
1179 [ -l | --line-numbers ]
1180 [ -S | --source ]
252b5132 1181 [ -m @var{machine} | --architecture=@var{machine} ]
dd92f639 1182 [ -M @var{options} | --disassembler-options=@var{options}]
252b5132 1183 [ -p | --private-headers ]
1dada9c5
NC
1184 [ -r | --reloc ]
1185 [ -R | --dynamic-reloc ]
1186 [ -s | --full-contents ]
1187 [ -G | --stabs ]
1188 [ -t | --syms ]
1189 [ -T | --dynamic-syms ]
1190 [ -x | --all-headers ]
1191 [ -w | --wide ]
1192 [ --start-address=@var{address} ]
252b5132 1193 [ --stop-address=@var{address} ]
1dada9c5
NC
1194 [ --prefix-addresses]
1195 [ --[no-]show-raw-insn ]
252b5132 1196 [ --adjust-vma=@var{offset} ]
1dada9c5
NC
1197 [ -V | --version ]
1198 [ -H | --help ]
252b5132
RH
1199 @var{objfile}@dots{}
1200@end smallexample
1201
1202@code{objdump} displays information about one or more object files.
1203The options control what particular information to display. This
1204information is mostly useful to programmers who are working on the
1205compilation tools, as opposed to programmers who just want their
1206program to compile and work.
1207
1208@var{objfile}@dots{} are the object files to be examined. When you
1209specify archives, @code{objdump} shows information on each of the member
1210object files.
1211
1212The long and short forms of options, shown here as alternatives, are
1dada9c5
NC
1213equivalent. At least one option from the list
1214@samp{-a,-d,-D,-f,-g,-G,-h,-H,-p,-r,-R,-S,-t,-T,-V,-x} must be given.
252b5132
RH
1215
1216@table @code
1217@item -a
1218@itemx --archive-header
1219@cindex archive headers
1220If any of the @var{objfile} files are archives, display the archive
1221header information (in a format similar to @samp{ls -l}). Besides the
1222information you could list with @samp{ar tv}, @samp{objdump -a} shows
1223the object file format of each archive member.
1224
1225@item --adjust-vma=@var{offset}
1226@cindex section addresses in objdump
1227@cindex VMA in objdump
1228When dumping information, first add @var{offset} to all the section
1229addresses. This is useful if the section addresses do not correspond to
1230the symbol table, which can happen when putting sections at particular
1231addresses when using a format which can not represent section addresses,
1232such as a.out.
1233
1234@item -b @var{bfdname}
1235@itemx --target=@var{bfdname}
1236@cindex object code format
1237Specify that the object-code format for the object files is
1238@var{bfdname}. This option may not be necessary; @var{objdump} can
1239automatically recognize many formats.
1240
1241For example,
1242@example
1243objdump -b oasys -m vax -h fu.o
1244@end example
1245@noindent
1246displays summary information from the section headers (@samp{-h}) of
1247@file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1248file in the format produced by Oasys compilers. You can list the
1249formats available with the @samp{-i} option.
1250@xref{Target Selection}, for more information.
1251
1252@item -C
1253@itemx --demangle
1254@cindex demangling in objdump
1255Decode (@dfn{demangle}) low-level symbol names into user-level names.
1256Besides removing any initial underscore prepended by the system, this
1257makes C++ function names readable. @xref{c++filt}, for more information
1258on demangling.
1259
1dada9c5 1260@item -G
252b5132
RH
1261@item --debugging
1262Display debugging information. This attempts to parse debugging
1263information stored in the file and print it out using a C like syntax.
1264Only certain types of debugging information have been implemented.
1265
1266@item -d
1267@itemx --disassemble
1268@cindex disassembling object code
1269@cindex machine instructions
1270Display the assembler mnemonics for the machine instructions from
1271@var{objfile}. This option only disassembles those sections which are
1272expected to contain instructions.
1273
1274@item -D
1275@itemx --disassemble-all
1276Like @samp{-d}, but disassemble the contents of all sections, not just
1277those expected to contain instructions.
1278
1279@item --prefix-addresses
1280When disassembling, print the complete address on each line. This is
1281the older disassembly format.
1282
1283@item --disassemble-zeroes
1284Normally the disassembly output will skip blocks of zeroes. This
1285option directs the disassembler to disassemble those blocks, just like
1286any other data.
1287
1288@item -EB
1289@itemx -EL
1290@itemx --endian=@{big|little@}
1291@cindex endianness
1292@cindex disassembly endianness
1293Specify the endianness of the object files. This only affects
1294disassembly. This can be useful when disassembling a file format which
1295does not describe endianness information, such as S-records.
1296
1297@item -f
1298@itemx --file-header
1299@cindex object file header
1300Display summary information from the overall header of
1301each of the @var{objfile} files.
1302
f1563258
TW
1303@item --file-start-context
1304@cindex source code context
1305Specify that when displaying interlisted source code/disassembly
1306(assumes '-S') from a file that has not yet been displayed, extend the
1307context to the start of the file.
1308
252b5132
RH
1309@item -h
1310@itemx --section-header
1311@itemx --header
1312@cindex section headers
1313Display summary information from the section headers of the
1314object file.
1315
1316File segments may be relocated to nonstandard addresses, for example by
1317using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1318@code{ld}. However, some object file formats, such as a.out, do not
1319store the starting address of the file segments. In those situations,
1320although @code{ld} relocates the sections correctly, using @samp{objdump
1321-h} to list the file section headers cannot show the correct addresses.
1322Instead, it shows the usual addresses, which are implicit for the
1323target.
1324
1325@item --help
1326Print a summary of the options to @code{objdump} and exit.
1327
1328@item -i
1329@itemx --info
1330@cindex architectures available
1331@cindex object formats available
1332Display a list showing all architectures and object formats available
1333for specification with @samp{-b} or @samp{-m}.
1334
1335@item -j @var{name}
1336@itemx --section=@var{name}
1337@cindex section information
1338Display information only for section @var{name}.
1339
1340@item -l
1341@itemx --line-numbers
1342@cindex source filenames for object files
1343Label the display (using debugging information) with the filename and
1344source line numbers corresponding to the object code or relocs shown.
1345Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1346
1347@item -m @var{machine}
1348@itemx --architecture=@var{machine}
1349@cindex architecture
1350@cindex disassembly architecture
1351Specify the architecture to use when disassembling object files. This
1352can be useful when disassembling object files which do not describe
1353architecture information, such as S-records. You can list the available
1354architectures with the @samp{-i} option.
1355
dd92f639
NC
1356@item -M @var{options}
1357@itemx --disassembler-options=@var{options}
1358Pass target specific information to the disassembler. Only supported on
1359some targets.
1360
1361If the target is an ARM architecture then this switch can be used to
1362select which register name set is used during disassembler. Specifying
58efb6c0
NC
1363@samp{-M reg-name-std} (the default) will select the register names as
1364used in ARM's instruction set documentation, but with register 13 called
1365'sp', register 14 called 'lr' and register 15 called 'pc'. Specifying
1366@samp{-M reg-names-apcs} will select the name set used by the ARM
1367Procedure Call Standard, whilst specifying @samp{-M reg-names-raw} will
1368just use @samp{r} followed by the register number.
1369
1370There are also two variants on the APCS register naming scheme enabled
0fff8110 1371by @samp{-M reg-names-atpcs} and @samp{-M reg-names-special-atpcs} which
58efb6c0
NC
1372use the ARM/Thumb Procedure Call Standard naming conventions. (Eiuther
1373with the normal register name sor the special register names).
dd92f639 1374
8f915f68
NC
1375This option can also be used for ARM architectures to force the
1376disassembler to interpret all instructions as THUMB instructions by
1377using the switch @samp{--disassembler-options=force-thumb}. This can be
1378useful when attempting to disassemble thumb code produced by other
1379compilers.
1380
252b5132
RH
1381@item -p
1382@itemx --private-headers
1383Print information that is specific to the object file format. The exact
1384information printed depends upon the object file format. For some
1385object file formats, no additional information is printed.
1386
1387@item -r
1388@itemx --reloc
1389@cindex relocation entries, in object file
1390Print the relocation entries of the file. If used with @samp{-d} or
1391@samp{-D}, the relocations are printed interspersed with the
1392disassembly.
1393
1394@item -R
1395@itemx --dynamic-reloc
1396@cindex dynamic relocation entries, in object file
1397Print the dynamic relocation entries of the file. This is only
1398meaningful for dynamic objects, such as certain types of shared
1399libraries.
1400
1401@item -s
1402@itemx --full-contents
1403@cindex sections, full contents
1404@cindex object file sections
1405Display the full contents of any sections requested.
1406
1407@item -S
1408@itemx --source
1409@cindex source disassembly
1410@cindex disassembly, with source
1411Display source code intermixed with disassembly, if possible. Implies
1412@samp{-d}.
1413
1414@item --show-raw-insn
1415When disassembling instructions, print the instruction in hex as well as
1416in symbolic form. This is the default except when
1417@code{--prefix-addresses} is used.
1418
1419@item --no-show-raw-insn
1420When disassembling instructions, do not print the instruction bytes.
1421This is the default when @code{--prefix-addresses} is used.
1422
1dada9c5 1423@item -G
252b5132
RH
1424@item --stabs
1425@cindex stab
1426@cindex .stab
1427@cindex debug symbols
1428@cindex ELF object file format
1429Display the full contents of any sections requested. Display the
1430contents of the .stab and .stab.index and .stab.excl sections from an
1431ELF file. This is only useful on systems (such as Solaris 2.0) in which
1432@code{.stab} debugging symbol-table entries are carried in an ELF
1433section. In most other file formats, debugging symbol-table entries are
1434interleaved with linkage symbols, and are visible in the @samp{--syms}
1435output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1436Overview,stabs.info, The ``stabs'' debug format}.
1437
1438@item --start-address=@var{address}
1439@cindex start-address
1440Start displaying data at the specified address. This affects the output
1441of the @code{-d}, @code{-r} and @code{-s} options.
1442
1443@item --stop-address=@var{address}
1444@cindex stop-address
1445Stop displaying data at the specified address. This affects the output
1446of the @code{-d}, @code{-r} and @code{-s} options.
1447
1448@item -t
1449@itemx --syms
1450@cindex symbol table entries, printing
1451Print the symbol table entries of the file.
1452This is similar to the information provided by the @samp{nm} program.
1453
1454@item -T
1455@itemx --dynamic-syms
1456@cindex dynamic symbol table entries, printing
1457Print the dynamic symbol table entries of the file. This is only
1458meaningful for dynamic objects, such as certain types of shared
1459libraries. This is similar to the information provided by the @samp{nm}
1460program when given the @samp{-D} (@samp{--dynamic}) option.
1461
1462@item --version
1463Print the version number of @code{objdump} and exit.
1464
1465@item -x
1466@itemx --all-header
1467@cindex all header information, object file
1468@cindex header information, all
1469Display all available header information, including the symbol table and
1470relocation entries. Using @samp{-x} is equivalent to specifying all of
1471@samp{-a -f -h -r -t}.
1472
1473@item -w
1474@itemx --wide
1475@cindex wide output, printing
1476Format some lines for output devices that have more than 80 columns.
1477@end table
1478
1479@node ranlib
1480@chapter ranlib
1481
1482@kindex ranlib
1483@cindex archive contents
1484@cindex symbol index
1485
1486@smallexample
1487ranlib [-vV] @var{archive}
1488@end smallexample
1489
1490@code{ranlib} generates an index to the contents of an archive and
1491stores it in the archive. The index lists each symbol defined by a
1492member of an archive that is a relocatable object file.
1493
1494You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1495
1496An archive with such an index speeds up linking to the library and
1497allows routines in the library to call each other without regard to
1498their placement in the archive.
1499
1500The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1501@code{ranlib} is completely equivalent to executing @samp{ar -s}.
1502@xref{ar}.
1503
1504@table @code
1505@item -v
1506@itemx -V
f20a759a 1507@itemx --version
252b5132
RH
1508Show the version number of @code{ranlib}.
1509@end table
1510
1511@node size
1512@chapter size
1513
1514@kindex size
1515@cindex section sizes
1516
1517@smallexample
1518size [ -A | -B | --format=@var{compatibility} ]
1519 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1520 [ --target=@var{bfdname} ] [ -V | --version ]
1521 [ @var{objfile}@dots{} ]
1522@end smallexample
1523
1524The @sc{gnu} @code{size} utility lists the section sizes---and the total
1525size---for each of the object or archive files @var{objfile} in its
1526argument list. By default, one line of output is generated for each
1527object file or each module in an archive.
1528
1529@var{objfile}@dots{} are the object files to be examined.
1530If none are specified, the file @code{a.out} will be used.
1531
1532The command line options have the following meanings:
1533
1534@table @code
1535@item -A
1536@itemx -B
1537@itemx --format=@var{compatibility}
1538@cindex @code{size} display format
1539Using one of these options, you can choose whether the output from @sc{gnu}
1540@code{size} resembles output from System V @code{size} (using @samp{-A},
1541or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1542@samp{--format=berkeley}). The default is the one-line format similar to
1543Berkeley's.
1544@c Bonus for doc-source readers: you can also say --format=strange (or
1545@c anything else that starts with 's') for sysv, and --format=boring (or
1546@c anything else that starts with 'b') for Berkeley.
1547
1548Here is an example of the Berkeley (default) format of output from
1549@code{size}:
1550@smallexample
f20a759a 1551$ size --format=Berkeley ranlib size
252b5132
RH
1552text data bss dec hex filename
1553294880 81920 11592 388392 5ed28 ranlib
1554294880 81920 11888 388688 5ee50 size
1555@end smallexample
1556
1557@noindent
1558This is the same data, but displayed closer to System V conventions:
1559
1560@smallexample
f20a759a 1561$ size --format=SysV ranlib size
252b5132
RH
1562ranlib :
1563section size addr
1564.text 294880 8192
1565.data 81920 303104
1566.bss 11592 385024
1567Total 388392
1568
1569
1570size :
1571section size addr
1572.text 294880 8192
1573.data 81920 303104
1574.bss 11888 385024
1575Total 388688
1576@end smallexample
1577
1578@item --help
1579Show a summary of acceptable arguments and options.
1580
1581@item -d
1582@itemx -o
1583@itemx -x
1584@itemx --radix=@var{number}
1585@cindex @code{size} number format
1586@cindex radix for section sizes
1587Using one of these options, you can control whether the size of each
1588section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1589(@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1590@samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1591values (8, 10, 16) are supported. The total size is always given in two
1592radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1593octal and hexadecimal if you're using @samp{-o}.
1594
1595@item --target=@var{bfdname}
1596@cindex object code format
1597Specify that the object-code format for @var{objfile} is
1598@var{bfdname}. This option may not be necessary; @code{size} can
1599automatically recognize many formats.
1600@xref{Target Selection}, for more information.
1601
1602@item -V
1603@itemx --version
1604Display the version number of @code{size}.
1605@end table
1606
1607@node strings
1608@chapter strings
1609@kindex strings
1610@cindex listings strings
1611@cindex printing strings
1612@cindex strings, printing
1613
1614@smallexample
1615strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1616 [--all] [--print-file-name] [--bytes=@var{min-len}]
1617 [--radix=@var{radix}] [--target=@var{bfdname}]
1618 [--help] [--version] @var{file}@dots{}
1619@end smallexample
1620
1621For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1622character sequences that are at least 4 characters long (or the number
1623given with the options below) and are followed by an unprintable
1624character. By default, it only prints the strings from the initialized
1625and loaded sections of object files; for other types of files, it prints
1626the strings from the whole file.
1627
1628@code{strings} is mainly useful for determining the contents of non-text
1629files.
1630
1631@table @code
1632@item -a
1633@itemx --all
1634@itemx -
1635Do not scan only the initialized and loaded sections of object files;
1636scan the whole files.
1637
1638@item -f
1639@itemx --print-file-name
1640Print the name of the file before each string.
1641
1642@item --help
1643Print a summary of the program usage on the standard output and exit.
1644
1645@item -@var{min-len}
1646@itemx -n @var{min-len}
1647@itemx --bytes=@var{min-len}
1648Print sequences of characters that are at least @var{min-len} characters
1649long, instead of the default 4.
1650
1651@item -o
1652Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1653act like @samp{-t d} instead. Since we can not be compatible with both
1654ways, we simply chose one.
1655
1656@item -t @var{radix}
1657@itemx --radix=@var{radix}
1658Print the offset within the file before each string. The single
1659character argument specifies the radix of the offset---@samp{o} for
1660octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1661
1662@item --target=@var{bfdname}
1663@cindex object code format
1664Specify an object code format other than your system's default format.
1665@xref{Target Selection}, for more information.
1666
1667@item -v
1668@itemx --version
1669Print the program version number on the standard output and exit.
1670@end table
1671
1672@node strip
1673@chapter strip
1674
1675@kindex strip
1676@cindex removing symbols
1677@cindex discarding symbols
1678@cindex symbols, discarding
1679
1680@smallexample
1681strip [ -F @var{bfdname} | --target=@var{bfdname} ]
1682 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1683 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1684 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1685 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1686 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1687 [ -x | --discard-all ] [ -X | --discard-locals ]
1688 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1689 [ -o @var{file} ] [ -p | --preserve-dates ]
1690 [ -v | --verbose ] [ -V | --version ] [ --help ]
1691 @var{objfile}@dots{}
1692@end smallexample
1693
1694@sc{gnu} @code{strip} discards all symbols from object files
1695@var{objfile}. The list of object files may include archives.
1696At least one object file must be given.
1697
1698@code{strip} modifies the files named in its argument,
1699rather than writing modified copies under different names.
1700
1701@table @code
1702@item -F @var{bfdname}
1703@itemx --target=@var{bfdname}
1704Treat the original @var{objfile} as a file with the object
1705code format @var{bfdname}, and rewrite it in the same format.
1706@xref{Target Selection}, for more information.
1707
1708@item --help
1709Show a summary of the options to @code{strip} and exit.
1710
1711@item -I @var{bfdname}
1712@itemx --input-target=@var{bfdname}
1713Treat the original @var{objfile} as a file with the object
1714code format @var{bfdname}.
1715@xref{Target Selection}, for more information.
1716
1717@item -O @var{bfdname}
1718@itemx --output-target=@var{bfdname}
1719Replace @var{objfile} with a file in the output format @var{bfdname}.
1720@xref{Target Selection}, for more information.
1721
1722@item -R @var{sectionname}
1723@itemx --remove-section=@var{sectionname}
1724Remove any section named @var{sectionname} from the output file. This
1725option may be given more than once. Note that using this option
1726inappropriately may make the output file unusable.
1727
1728@item -s
1729@itemx --strip-all
1730Remove all symbols.
1731
1732@item -g
1733@itemx -S
1734@itemx --strip-debug
1735Remove debugging symbols only.
1736
1737@item --strip-unneeded
1738Remove all symbols that are not needed for relocation processing.
1739
1740@item -K @var{symbolname}
1741@itemx --keep-symbol=@var{symbolname}
1742Keep only symbol @var{symbolname} from the source file. This option may
1743be given more than once.
1744
1745@item -N @var{symbolname}
1746@itemx --strip-symbol=@var{symbolname}
1747Remove symbol @var{symbolname} from the source file. This option may be
1748given more than once, and may be combined with strip options other than
1749@code{-K}.
1750
1751@item -o @var{file}
1752Put the stripped output in @var{file}, rather than replacing the
1753existing file. When this argument is used, only one @var{objfile}
1754argument may be specified.
1755
1756@item -p
1757@itemx --preserve-dates
1758Preserve the access and modification dates of the file.
1759
1760@item -x
1761@itemx --discard-all
1762Remove non-global symbols.
1763
1764@item -X
1765@itemx --discard-locals
1766Remove compiler-generated local symbols.
1767(These usually start with @samp{L} or @samp{.}.)
1768
1769@item -V
1770@itemx --version
1771Show the version number for @code{strip}.
1772
1773@item -v
1774@itemx --verbose
1775Verbose output: list all object files modified. In the case of
1776archives, @samp{strip -v} lists all members of the archive.
1777@end table
1778
9d51cc66 1779@node c++filt, addr2line, strip, Top
252b5132
RH
1780@chapter c++filt
1781
1782@kindex c++filt
1783@cindex demangling C++ symbols
1784
1785@smallexample
1786c++filt [ -_ | --strip-underscores ]
1787 [ -j | --java ]
1788 [ -n | --no-strip-underscores ]
1789 [ -s @var{format} | --format=@var{format} ]
1790 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1791@end smallexample
1792
9d51cc66 1793@kindex cxxfilt
252b5132
RH
1794The C++ and Java languages provides function overloading, which means
1795that you can write many functions with the same name (providing each
1796takes parameters of different types). All C++ and Java function names
1797are encoded into a low-level assembly label (this process is known as
9d51cc66
ILT
1798@dfn{mangling}). The @code{c++filt}
1799@footnote{MS-DOS does not allow @kbd{+} characters in file names, so on
1800MS-DOS this program is named @code{cxxfilt}.}
1801program does the inverse mapping: it decodes (@dfn{demangles}) low-level
1802names into user-level names so that the linker can keep these overloaded
1803functions from clashing.
252b5132
RH
1804
1805Every alphanumeric word (consisting of letters, digits, underscores,
1806dollars, or periods) seen in the input is a potential label. If the
1807label decodes into a C++ name, the C++ name replaces the low-level
1808name in the output.
1809
1810You can use @code{c++filt} to decipher individual symbols:
1811
1812@example
1813c++filt @var{symbol}
1814@end example
1815
1816If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1817names from the standard input and writes the demangled names to the
1818standard output. All results are printed on the standard output.
1819
1820@table @code
1821@item -_
1822@itemx --strip-underscores
1823On some systems, both the C and C++ compilers put an underscore in front
1824of every name. For example, the C name @code{foo} gets the low-level
1825name @code{_foo}. This option removes the initial underscore. Whether
1826@code{c++filt} removes the underscore by default is target dependent.
1827
1828@item -j
1829@itemx --java
1830Prints demangled names using Java syntax. The default is to use C++
1831syntax.
1832
1833@item -n
1834@itemx --no-strip-underscores
1835Do not remove the initial underscore.
1836
1837@item -s @var{format}
1838@itemx --format=@var{format}
1839@sc{gnu} @code{nm} can decode three different methods of mangling, used by
1840different C++ compilers. The argument to this option selects which
1841method it uses:
1842
1843@table @code
1844@item gnu
1845the one used by the @sc{gnu} compiler (the default method)
1846@item lucid
1847the one used by the Lucid compiler
1848@item arm
1849the one specified by the C++ Annotated Reference Manual
1850@item hp
1851the one used by the HP compiler
1852@item edg
1853the one used by the EDG compiler
1854@end table
1855
1856@item --help
1857Print a summary of the options to @code{c++filt} and exit.
1858
1859@item --version
1860Print the version number of @code{c++filt} and exit.
1861@end table
1862
1863@quotation
1864@emph{Warning:} @code{c++filt} is a new utility, and the details of its
1865user interface are subject to change in future releases. In particular,
1866a command-line option may be required in the the future to decode a name
1867passed as an argument on the command line; in other words,
1868
1869@example
1870c++filt @var{symbol}
1871@end example
1872
1873@noindent
1874may in a future release become
1875
1876@example
1877c++filt @var{option} @var{symbol}
1878@end example
1879@end quotation
1880
1881@node addr2line
1882@chapter addr2line
1883
1884@kindex addr2line
1885@cindex address to file name and line number
1886
1887@smallexample
1888addr2line [ -b @var{bfdname} | --target=@var{bfdname} ]
1889 [ -C | --demangle ]
1890 [ -e @var{filename} | --exe=@var{filename} ]
1891 [ -f | --functions ] [ -s | --basename ]
1892 [ -H | --help ] [ -V | --version ]
1893 [ addr addr ... ]
1894@end smallexample
1895
1896@code{addr2line} translates program addresses into file names and line
1897numbers. Given an address and an executable, it uses the debugging
1898information in the executable to figure out which file name and line
1899number are associated with a given address.
1900
1901The executable to use is specified with the @code{-e} option. The
f20a759a 1902default is the file @file{a.out}.
252b5132
RH
1903
1904@code{addr2line} has two modes of operation.
1905
1906In the first, hexadecimal addresses are specified on the command line,
1907and @code{addr2line} displays the file name and line number for each
1908address.
1909
1910In the second, @code{addr2line} reads hexadecimal addresses from
1911standard input, and prints the file name and line number for each
1912address on standard output. In this mode, @code{addr2line} may be used
1913in a pipe to convert dynamically chosen addresses.
1914
1915The format of the output is @samp{FILENAME:LINENO}. The file name and
1916line number for each address is printed on a separate line. If the
1917@code{-f} option is used, then each @samp{FILENAME:LINENO} line is
1918preceded by a @samp{FUNCTIONNAME} line which is the name of the function
1919containing the address.
1920
1921If the file name or function name can not be determined,
1922@code{addr2line} will print two question marks in their place. If the
1923line number can not be determined, @code{addr2line} will print 0.
1924
1925The long and short forms of options, shown here as alternatives, are
1926equivalent.
1927
1928@table @code
1929@item -b @var{bfdname}
1930@itemx --target=@var{bfdname}
1931@cindex object code format
1932Specify that the object-code format for the object files is
1933@var{bfdname}.
1934
1935@item -C
1936@itemx --demangle
1937@cindex demangling in objdump
1938Decode (@dfn{demangle}) low-level symbol names into user-level names.
1939Besides removing any initial underscore prepended by the system, this
1940makes C++ function names readable. @xref{c++filt}, for more information
1941on demangling.
1942
1943@item -e @var{filename}
1944@itemx --exe=@var{filename}
1945Specify the name of the executable for which addresses should be
1946translated. The default file is @file{a.out}.
1947
1948@item -f
1949@itemx --functions
1950Display function names as well as file and line number information.
1951
1952@item -s
1953@itemx --basenames
1954Display only the base of each file name.
1955@end table
1956
1957@node nlmconv
1958@chapter nlmconv
1959
1960@code{nlmconv} converts a relocatable object file into a NetWare
1961Loadable Module.
1962
1963@ignore
1964@code{nlmconv} currently works with @samp{i386} object
1965files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1966object files in @sc{elf}, or @code{a.out} format@footnote{
1967@code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1968format in the Binary File Descriptor library. It has only been tested
1969with the above formats.}.
1970@end ignore
1971
1972@quotation
1973@emph{Warning:} @code{nlmconv} is not always built as part of the binary
1974utilities, since it is only useful for NLM targets.
1975@end quotation
1976
1977@smallexample
1978nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1979 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1980 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1981 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1982 [ -h | --help ] [ -V | --version ]
1983 @var{infile} @var{outfile}
1984@end smallexample
1985
1986@code{nlmconv} converts the relocatable @samp{i386} object file
1987@var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1988reading @var{headerfile} for NLM header information. For instructions
1989on writing the NLM command file language used in header files, see the
1990@samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1991Development and Tools Overview}, which is part of the NLM Software
1992Developer's Kit (``NLM SDK''), available from Novell, Inc.
1993@code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1994@var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1995more information.
1996
1997@code{nlmconv} can perform a link step. In other words, you can list
1998more than one object file for input if you list them in the definitions
1999file (rather than simply specifying one input file on the command line).
2000In this case, @code{nlmconv} calls the linker for you.
2001
2002@table @code
2003@item -I @var{bfdname}
2004@itemx --input-target=@var{bfdname}
2005Object format of the input file. @code{nlmconv} can usually determine
2006the format of a given file (so no default is necessary).
2007@xref{Target Selection}, for more information.
2008
2009@item -O @var{bfdname}
2010@itemx --output-target=@var{bfdname}
2011Object format of the output file. @code{nlmconv} infers the output
2012format based on the input format, e.g. for a @samp{i386} input file the
2013output format is @samp{nlm32-i386}.
2014@xref{Target Selection}, for more information.
2015
2016@item -T @var{headerfile}
2017@itemx --header-file=@var{headerfile}
2018Reads @var{headerfile} for NLM header information. For instructions on
2019writing the NLM command file language used in header files, see@ see the
2020@samp{linkers} section, of the @cite{NLM Development and Tools
2021Overview}, which is part of the NLM Software Developer's Kit, available
2022from Novell, Inc.
2023
2024@item -d
2025@itemx --debug
2026Displays (on standard error) the linker command line used by @code{nlmconv}.
2027
2028@item -l @var{linker}
2029@itemx --linker=@var{linker}
2030Use @var{linker} for any linking. @var{linker} can be an absolute or a
2031relative pathname.
2032
2033@item -h
2034@itemx --help
2035Prints a usage summary.
2036
2037@item -V
2038@itemx --version
2039Prints the version number for @code{nlmconv}.
2040@end table
2041
2042@node windres
2043@chapter windres
2044
2045@code{windres} may be used to manipulate Windows resources.
2046
2047@quotation
2048@emph{Warning:} @code{windres} is not always built as part of the binary
2049utilities, since it is only useful for Windows targets.
2050@end quotation
2051
2052@smallexample
2053windres [options] [input-file] [output-file]
2054@end smallexample
2055
2056@code{windres} reads resources from an input file and copies them into
2057an output file. Either file may be in one of three formats:
2058
2059@table @code
2060@item rc
2061A text format read by the Resource Compiler.
2062
2063@item res
2064A binary format generated by the Resource Compiler.
2065
2066@item coff
2067A COFF object or executable.
2068@end table
2069
2070The exact description of these different formats is available in
2071documentation from Microsoft.
2072
2073When @code{windres} converts from the @code{rc} format to the @code{res}
2074format, it is acting like the Windows Resource Compiler. When
2075@code{windres} converts from the @code{res} format to the @code{coff}
2076format, it is acting like the Windows @code{CVTRES} program.
2077
2078When @code{windres} generates an @code{rc} file, the output is similar
2079but not identical to the format expected for the input. When an input
2080@code{rc} file refers to an external filename, an output @code{rc} file
2081will instead include the file contents.
2082
2083If the input or output format is not specified, @code{windres} will
2084guess based on the file name, or, for the input file, the file contents.
2085A file with an extension of @file{.rc} will be treated as an @code{rc}
2086file, a file with an extension of @file{.res} will be treated as a
2087@code{res} file, and a file with an extension of @file{.o} or
2088@file{.exe} will be treated as a @code{coff} file.
2089
2090If no output file is specified, @code{windres} will print the resources
2091in @code{rc} format to standard output.
2092
2093The normal use is for you to write an @code{rc} file, use @code{windres}
2094to convert it to a COFF object file, and then link the COFF file into
2095your application. This will make the resources described in the
2096@code{rc} file available to Windows.
2097
2098@table @code
2099@item -i @var{filename}
2100@itemx --input @var{filename}
2101The name of the input file. If this option is not used, then
2102@code{windres} will use the first non-option argument as the input file
2103name. If there are no non-option arguments, then @code{windres} will
2104read from standard input. @code{windres} can not read a COFF file from
2105standard input.
2106
2107@item -o @var{filename}
2108@itemx --output @var{filename}
2109The name of the output file. If this option is not used, then
2110@code{windres} will use the first non-option argument, after any used
2111for the input file name, as the output file name. If there is no
2112non-option argument, then @code{windres} will write to standard output.
2113@code{windres} can not write a COFF file to standard output.
2114
2115@item -I @var{format}
2116@itemx --input-format @var{format}
2117The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
2118@samp{coff}. If no input format is specified, @code{windres} will
2119guess, as described above.
2120
2121@item -O @var{format}
2122@itemx --output-format @var{format}
2123The output format to generate. @var{format} may be @samp{res},
2124@samp{rc}, or @samp{coff}. If no output format is specified,
2125@code{windres} will guess, as described above.
2126
2127@item -F @var{target}
2128@itemx --target @var{target}
2129Specify the BFD format to use for a COFF file as input or output. This
2130is a BFD target name; you can use the @code{--help} option to see a list
2131of supported targets. Normally @code{windres} will use the default
2132format, which is the first one listed by the @code{--help} option.
2133@ref{Target Selection}.
2134
2135@item --preprocessor @var{program}
2136When @code{windres} reads an @code{rc} file, it runs it through the C
2137preprocessor first. This option may be used to specify the preprocessor
2138to use, including any leading arguments. The default preprocessor
2139argument is @code{gcc -E -xc-header -DRC_INVOKED}.
2140
2141@item --include-dir @var{directory}
2142Specify an include directory to use when reading an @code{rc} file.
2143@code{windres} will pass this to the preprocessor as an @code{-I}
2144option. @code{windres} will also search this directory when looking for
2145files named in the @code{rc} file.
2146
751d21b5 2147@item -D @var{target}
ad0481cd 2148@itemx --define @var{sym}[=@var{val}]
252b5132
RH
2149Specify a @code{-D} option to pass to the preprocessor when reading an
2150@code{rc} file.
2151
751d21b5
DD
2152@item -v
2153Enable verbose mode. This tells you what the preprocessor is if you
2154didn't specify one.
2155
252b5132
RH
2156@item --language @var{val}
2157Specify the default language to use when reading an @code{rc} file.
2158@var{val} should be a hexadecimal language code. The low eight bits are
2159the language, and the high eight bits are the sublanguage.
2160
5a298d2d
NC
2161@item --use-temp-file
2162Use a temporary file to instead of using popen to read the output of
2163the preprocessor. Use this option if the popen implementation is buggy
2164on the host (eg., certain non-English language versions of Windows 95 and
2165Windows 98 are known to have buggy popen where the output will instead
2166go the console).
2167
2168@item --no-use-temp-file
2169Use popen, not a temporary file, to read the output of the preprocessor.
2170This is the default behaviour.
2171
252b5132
RH
2172@item --help
2173Prints a usage summary.
2174
2175@item --version
2176Prints the version number for @code{windres}.
2177
2178@item --yydebug
2179If @code{windres} is compiled with @code{YYDEBUG} defined as @code{1},
2180this will turn on parser debugging.
2181@end table
2182
2183
2184@node dlltool
2185@chapter Create files needed to build and use DLLs
2186@cindex DLL
2187@kindex dlltool
2188
2189@code{dlltool} may be used to create the files needed to build and use
2190dynamic link libraries (DLLs).
2191
2192@quotation
2193@emph{Warning:} @code{dlltool} is not always built as part of the binary
2194utilities, since it is only useful for those targets which support DLLs.
2195@end quotation
2196
2197@smallexample
2198dlltool [-d|--input-def @var{def-file-name}]
2199 [-b|--base-file @var{base-file-name}]
2200 [-e|--output-exp @var{exports-file-name}]
2201 [-z|--output-def @var{def-file-name}]
2202 [-l|--output-lib @var{library-file-name}]
2203 [--export-all-symbols] [--no-export-all-symbols]
2204 [--exclude-symbols @var{list}]
2205 [--no-default-excludes]
2206 [-S|--as @var{path-to-assembler}] [-f|--as-flags @var{options}]
2207 [-D|--dllname @var{name}] [-m|--machine @var{machine}]
2208 [-a|--add-indirect] [-U|--add-underscore] [-k|--kill-at]
2209 [-A|--add-stdcall-alias]
2210 [-x|--no-idata4] [-c|--no-idata5] [-i|--interwork]
2211 [-n|--nodelete] [-v|--verbose] [-h|--help] [-V|--version]
2212 [object-file @dots{}]
2213@end smallexample
2214
2215@code{dlltool} reads its inputs, which can come from the @samp{-d} and
2216@samp{-b} options as well as object files specified on the command
2217line. It then processes these inputs and if the @samp{-e} option has
2218been specified it creates a exports file. If the @samp{-l} option
2219has been specified it creates a library file and if the @samp{-z} option
2220has been specified it creates a def file. Any or all of the -e, -l
2221and -z options can be present in one invocation of dlltool.
2222
2223When creating a DLL, along with the source for the DLL, it is necessary
2224to have three other files. @code{dlltool} can help with the creation of
2225these files.
2226
2227The first file is a @samp{.def} file which specifies which functions are
2228exported from the DLL, which functions the DLL imports, and so on. This
2229is a text file and can be created by hand, or @code{dlltool} can be used
2230to create it using the @samp{-z} option. In this case @code{dlltool}
2231will scan the object files specified on its command line looking for
2232those functions which have been specially marked as being exported and
2233put entries for them in the .def file it creates.
2234
2235In order to mark a function as being exported from a DLL, it needs to
2236have an @samp{-export:<name_of_function>} entry in the @samp{.drectve}
2237section of the object file. This can be done in C by using the
2238asm() operator:
2239
2240@smallexample
2241 asm (".section .drectve");
2242 asm (".ascii \"-export:my_func\"");
2243
2244 int my_func (void) @{ @dots{} @}
2245@end smallexample
2246
2247The second file needed for DLL creation is an exports file. This file
2248is linked with the object files that make up the body of the DLL and it
2249handles the interface between the DLL and the outside world. This is a
2250binary file and it can be created by giving the @samp{-e} option to
2251@code{dlltool} when it is creating or reading in a .def file.
2252
2253The third file needed for DLL creation is the library file that programs
2254will link with in order to access the functions in the DLL. This file
2255can be created by giving the @samp{-l} option to dlltool when it
2256is creating or reading in a .def file.
2257
2258@code{dlltool} builds the library file by hand, but it builds the
2259exports file by creating temporary files containing assembler statements
2260and then assembling these. The @samp{-S} command line option can be
2261used to specify the path to the assembler that dlltool will use,
2262and the @samp{-f} option can be used to pass specific flags to that
2263assembler. The @samp{-n} can be used to prevent dlltool from deleting
2264these temporary assembler files when it is done, and if @samp{-n} is
2265specified twice then this will prevent dlltool from deleting the
2266temporary object files it used to build the library.
2267
2268Here is an example of creating a DLL from a source file @samp{dll.c} and
2269also creating a program (from an object file called @samp{program.o})
2270that uses that DLL:
2271
2272@smallexample
2273 gcc -c dll.c
2274 dlltool -e exports.o -l dll.lib dll.o
2275 gcc dll.o exports.o -o dll.dll
2276 gcc program.o dll.lib -o program
2277@end smallexample
2278
2279The command line options have the following meanings:
2280
2281@table @code
2282
2283@item -d @var{filename}
2284@itemx --input-def @var{filename}
2285@cindex input .def file
2286Specifies the name of a .def file to be read in and processed.
2287
2288@item -b @var{filename}
2289@itemx --base-file @var{filename}
2290@cindex base files
2291Specifies the name of a base file to be read in and processed. The
2292contents of this file will be added to the relocation section in the
2293exports file generated by dlltool.
2294
2295@item -e @var{filename}
2296@itemx --output-exp @var{filename}
2297Specifies the name of the export file to be created by dlltool.
2298
2299@item -z @var{filename}
2300@itemx --output-def @var{filename}
2301Specifies the name of the .def file to be created by dlltool.
2302
2303@item -l @var{filename}
2304@itemx --output-lib @var{filename}
2305Specifies the name of the library file to be created by dlltool.
2306
2307@item --export-all-symbols
2308Treat all global and weak defined symbols found in the input object
2309files as symbols to be exported. There is a small list of symbols which
2310are not exported by default; see the @code{--no-default-excludes}
2311option. You may add to the list of symbols to not export by using the
2312@code{--exclude-symbols} option.
2313
2314@item --no-export-all-symbols
2315Only export symbols explicitly listed in an input .def file or in
2316@samp{.drectve} sections in the input object files. This is the default
2317behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
2318attributes in the source code.
2319
2320@item --exclude-symbols @var{list}
2321Do not export the symbols in @var{list}. This is a list of symbol names
2322separated by comma or colon characters. The symbol names should not
2323contain a leading underscore. This is only meaningful when
2324@code{--export-all-symbols} is used.
2325
2326@item --no-default-excludes
2327When @code{--export-all-symbols} is used, it will by default avoid
2328exporting certain special symbols. The current list of symbols to avoid
2329exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
2330@samp{impure_ptr}. You may use the @code{--no-default-excludes} option
2331to go ahead and export these special symbols. This is only meaningful
2332when @code{--export-all-symbols} is used.
2333
2334@item -S @var{path}
2335@itemx --as @var{path}
2336Specifies the path, including the filename, of the assembler to be used
2337to create the exports file.
2338
2339@item -f @var{switches}
2340@itemx --as-flags @var{switches}
2341Specifies any specific command line switches to be passed to the
2342assembler when building the exports file. This option will work even if
2343the @samp{-S} option is not used. This option only takes one argument,
2344and if it occurs more than once on the command line, then later
2345occurrences will override earlier occurrences. So if it is necessary to
2346pass multiple switches to the assembler they should be enclosed in
2347double quotes.
2348
2349@item -D @var{name}
2350@itemx --dll-name @var{name}
2351Specifies the name to be stored in the .def file as the name of the DLL
2352when the @samp{-e} option is used. If this option is not present, then
2353the filename given to the @samp{-e} option will be used as the name of
2354the DLL.
2355
2356@item -m @var{machine}
2357@itemx -machine @var{machine}
2358Specifies the type of machine for which the library file should be
2359built. @code{dlltool} has a built in default type, depending upon how
2360it was created, but this option can be used to override that. This is
2361normally only useful when creating DLLs for an ARM processor, when the
2362contents of the DLL are actually encode using THUMB instructions.
2363
2364@item -a
2365@itemx --add-indirect
2366Specifies that when @code{dlltool} is creating the exports file it
2367should add a section which allows the exported functions to be
2368referenced without using the import library. Whatever the hell that
2369means!
2370
2371@item -U
2372@itemx --add-underscore
2373Specifies that when @code{dlltool} is creating the exports file it
2374should prepend an underscore to the names of the exported functions.
2375
2376@item -k
2377@itemx --kill-at
2378Specifies that when @code{dlltool} is creating the exports file it
2379should not append the string @samp{@@ <number>}. These numbers are
2380called ordinal numbers and they represent another way of accessing the
2381function in a DLL, other than by name.
2382
2383@item -A
2384@itemx --add-stdcall-alias
2385Specifies that when @code{dlltool} is creating the exports file it
2386should add aliases for stdcall symbols without @samp{@@ <number>}
2387in addition to the symbols with @samp{@@ <number>}.
2388
2389@item -x
2390@itemx --no-idata4
2391Specifies that when @code{dlltool} is creating the exports and library
2392files it should omit the .idata4 section. This is for compatibility
2393with certain operating systems.
2394
2395@item -c
2396@itemx --no-idata5
2397Specifies that when @code{dlltool} is creating the exports and library
2398files it should omit the .idata5 section. This is for compatibility
2399with certain operating systems.
2400
2401@item -i
2402@itemx --interwork
2403Specifies that @code{dlltool} should mark the objects in the library
2404file and exports file that it produces as supporting interworking
2405between ARM and THUMB code.
2406
2407@item -n
2408@itemx --nodelete
2409Makes @code{dlltool} preserve the temporary assembler files it used to
2410create the exports file. If this option is repeated then dlltool will
2411also preserve the temporary object files it uses to create the library
2412file.
2413
2414@item -v
2415@itemx --verbose
2416Make dlltool describe what it is doing.
2417
2418@item -h
2419@itemx --help
2420Displays a list of command line options and then exits.
2421
2422@item -V
2423@itemx --version
2424Displays dlltool's version number and then exits.
2425
2426@end table
2427
2428@node readelf
2429@chapter readelf
2430
2431@cindex ELF file information
2432@kindex readelf
2433
2434@smallexample
2435readelf [ -a | --all ]
2436 [ -h | --file-header]
2437 [ -l | --program-headers | --segments]
2438 [ -S | --section-headers | --sections]
2439 [ -e | --headers]
2440 [ -s | --syms | --symbols]
779fe533 2441 [ -n | --notes]
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2442 [ -r | --relocs]
2443 [ -d | --dynamic]
2444 [ -V | --version-info]
2445 [ -D | --use-dynamic]
2446 [ -x <number> | --hex-dump=<number>]
2447 [ -w[liapr] | --debug-dump[=info,=line,=abbrev,=pubnames,=ranges]]
2448 [ --histogram]
2449 [ -v | --version]
2450 [ -H | --help]
2451 @var{elffile}@dots{}
2452@end smallexample
2453
2454@code{readelf} displays information about one or more ELF format object
2455files. The options control what particular information to display.
2456
2457@var{elffile}@dots{} are the object files to be examined. At the
2458moment, @code{readelf} does not support examining archives, nor does it
2459support examing 64 bit ELF files.
2460
2461The long and short forms of options, shown here as alternatives, are
2462equivalent. At least one option besides @samp{-v} or @samp{-H} must be
2463given.
2464
2465@table @code
2466@item -a
2467@itemx --all
2468Equivalent to specifiying @samp{--file-header},
2469@samp{--program-headers}, @samp{--sections}, @samp{--symbols},
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2470@samp{--relocs}, @samp{--dynamic}, @samp{--notes} and
2471@samp{--version-info}.
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2472
2473@item -h
2474@itemx --file-header
2475@cindex ELF file header information
2476Displays the information contained in the ELF header at the start of the
2477file.
2478
2479@item -l
2480@itemx --program-headers
2481@itemx --segments
2482@cindex ELF program header information
2483@cindex ELF segment information
2484Displays the information contained in the file's segment headers, if it
2485has any.
2486
2487@item -S
2488@itemx --sections
2489@itemx --section-headers
2490@cindex ELF section information
2491Displays the information contained in the file's section headers, if it
2492has any.
2493
2494@item -s
2495@itemx --symbols
2496@itemx --syms
2497@cindex ELF symbol table information
2498Displays the entries in symbol table section of the file, if it has one.
2499
2500@item -e
2501@itemx --headers
2502Display all the headers in the file. Equivalent to @samp{-h -l -S}.
2503
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2504@item -n
2505@itemx --notes
2506@cindex ELF core notes
2507Displays the contents of the NOTE segment, if it exists.
2508
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2509@item -r
2510@itemx --relocs
2511@cindex ELF reloc information
2512Displays the contents of the file's relocation section, if it ha one.
2513
2514@item -d
2515@itemx --dynamic
2516@cindex ELF dynamic section information
2517Displays the contents of the file's dynamic section, if it has one.
2518
2519@item -V
2520@itemx --version-info
2521@cindex ELF version sections informations
2522Displays the contents of the version sections in the file, it they
2523exist.
2524
2525@item -D
2526@itemx --use-dynamic
2527When displaying symbols, this option makes @code{readelf} use the
2528symblol table in the file's dynamic section, rather than the one in the
2529symbols section.
2530
2531@item -x <number>
2532@itemx --hex-dump=<number>
2533Displays the contents of the indicated section as a hexadecimal dump.
2534
2535@item -w[liapr]
2536@itemx --debug-dump[=line,=info,=abbrev,=pubnames,=ranges]
2537Displays the contents of the debug sections in the file, if any are
2538present. If one of the optional letters or words follows the switch
2539then only data found in those specific sections will be dumped.
2540
2541@item --histogram
2542Display a histogram of bucket list lengths when displaying the contents
2543of the symbol tables.
2544
2545@item -v
2546@itemx --version
2547Display the version number of readelf.
2548
2549@item -H
2550@itemx --help
2551Display the command line options understood by @code{readelf}.
2552
2553@end table
2554
2555
2556@node Selecting The Target System
2557@chapter Selecting the target system
2558
2559You can specify three aspects of the target system to the @sc{gnu}
2560binary file utilities, each in several ways:
2561
2562@itemize @bullet
2563@item
2564the target
2565
2566@item
2567the architecture
2568
2569@item
2570the linker emulation (which applies to the linker only)
2571@end itemize
2572
2573In the following summaries, the lists of ways to specify values are in
2574order of decreasing precedence. The ways listed first override those
2575listed later.
2576
2577The commands to list valid values only list the values for which the
2578programs you are running were configured. If they were configured with
2579@samp{--enable-targets=all}, the commands list most of the available
2580values, but a few are left out; not all targets can be configured in at
2581once because some of them can only be configured @dfn{native} (on hosts
2582with the same type as the target system).
2583
2584@menu
2585* Target Selection::
2586* Architecture Selection::
2587* Linker Emulation Selection::
2588@end menu
2589
2590@node Target Selection
2591@section Target Selection
2592
2593A @dfn{target} is an object file format. A given target may be
2594supported for multiple architectures (@pxref{Architecture Selection}).
2595A target selection may also have variations for different operating
2596systems or architectures.
2597
2598The command to list valid target values is @samp{objdump -i}
2599(the first column of output contains the relevant information).
2600
2601Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
2602@samp{a.out-sunos-big}.
2603
2604You can also specify a target using a configuration triplet. This is
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2605the same sort of name that is passed to @file{configure} to specify a
2606target. When you use a configuration triplet as an argument, it must be
2607fully canonicalized. You can see the canonical version of a triplet by
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2608running the shell script @file{config.sub} which is included with the
2609sources.
2610
2611Some sample configuration triplets are: @samp{m68k-hp-bsd},
2612@samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
2613
2614@subheading @code{objdump} Target
2615
2616Ways to specify:
2617
2618@enumerate
2619@item
2620command line option: @samp{-b} or @samp{--target}
2621
2622@item
2623environment variable @code{GNUTARGET}
2624
2625@item
2626deduced from the input file
2627@end enumerate
2628
2629@subheading @code{objcopy} and @code{strip} Input Target
2630
2631Ways to specify:
2632
2633@enumerate
2634@item
2635command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
2636
2637@item
2638environment variable @code{GNUTARGET}
2639
2640@item
2641deduced from the input file
2642@end enumerate
2643
2644@subheading @code{objcopy} and @code{strip} Output Target
2645
2646Ways to specify:
2647
2648@enumerate
2649@item
2650command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
2651
2652@item
2653the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
2654
2655@item
2656environment variable @code{GNUTARGET}
2657
2658@item
2659deduced from the input file
2660@end enumerate
2661
2662@subheading @code{nm}, @code{size}, and @code{strings} Target
2663
2664Ways to specify:
2665
2666@enumerate
2667@item
2668command line option: @samp{--target}
2669
2670@item
2671environment variable @code{GNUTARGET}
2672
2673@item
2674deduced from the input file
2675@end enumerate
2676
2677@subheading Linker Input Target
2678
2679Ways to specify:
2680
2681@enumerate
2682@item
2683command line option: @samp{-b} or @samp{--format}
2684(@pxref{Options,,Options,ld.info,Using LD})
2685
2686@item
2687script command @code{TARGET}
2688(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2689
2690@item
2691environment variable @code{GNUTARGET}
2692(@pxref{Environment,,Environment,ld.info,Using LD})
2693
2694@item
2695the default target of the selected linker emulation
2696(@pxref{Linker Emulation Selection})
2697@end enumerate
2698
2699@subheading Linker Output Target
2700
2701Ways to specify:
2702
2703@enumerate
2704@item
2705command line option: @samp{-oformat}
2706(@pxref{Options,,Options,ld.info,Using LD})
2707
2708@item
2709script command @code{OUTPUT_FORMAT}
2710(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2711
2712@item
2713the linker input target (see ``Linker Input Target'' above)
2714@end enumerate
2715
2716@node Architecture Selection
2717@section Architecture selection
2718
2719An @dfn{architecture} is a type of @sc{cpu} on which an object file is
2720to run. Its name may contain a colon, separating the name of the
2721processor family from the name of the particular @sc{cpu}.
2722
2723The command to list valid architecture values is @samp{objdump -i} (the
2724second column contains the relevant information).
2725
2726Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
2727
2728@subheading @code{objdump} Architecture
2729
2730Ways to specify:
2731
2732@enumerate
2733@item
2734command line option: @samp{-m} or @samp{--architecture}
2735
2736@item
2737deduced from the input file
2738@end enumerate
2739
2740@subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
2741
2742Ways to specify:
2743
2744@enumerate
2745@item
2746deduced from the input file
2747@end enumerate
2748
2749@subheading Linker Input Architecture
2750
2751Ways to specify:
2752
2753@enumerate
2754@item
2755deduced from the input file
2756@end enumerate
2757
2758@subheading Linker Output Architecture
2759
2760Ways to specify:
2761
2762@enumerate
2763@item
2764script command @code{OUTPUT_ARCH}
2765(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2766
2767@item
2768the default architecture from the linker output target
2769(@pxref{Target Selection})
2770@end enumerate
2771
2772@node Linker Emulation Selection
2773@section Linker emulation selection
2774
2775A linker @dfn{emulation} is a ``personality'' of the linker, which gives
2776the linker default values for the other aspects of the target system.
2777In particular, it consists of
2778
2779@itemize @bullet
2780@item
2781the linker script
2782
2783@item
2784the target
2785
2786@item
2787several ``hook'' functions that are run at certain stages of the linking
2788process to do special things that some targets require
2789@end itemize
2790
2791The command to list valid linker emulation values is @samp{ld -V}.
2792
2793Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
2794
2795Ways to specify:
2796
2797@enumerate
2798@item
2799command line option: @samp{-m}
2800(@pxref{Options,,Options,ld.info,Using LD})
2801
2802@item
2803environment variable @code{LDEMULATION}
2804
2805@item
2806compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2807which comes from @code{EMUL} in @file{config/@var{target}.mt}
2808@end enumerate
2809
2810@node Reporting Bugs
2811@chapter Reporting Bugs
2812@cindex bugs
2813@cindex reporting bugs
2814
2815Your bug reports play an essential role in making the binary utilities
2816reliable.
2817
2818Reporting a bug may help you by bringing a solution to your problem, or
2819it may not. But in any case the principal function of a bug report is
2820to help the entire community by making the next version of the binary
2821utilities work better. Bug reports are your contribution to their
2822maintenance.
2823
2824In order for a bug report to serve its purpose, you must include the
2825information that enables us to fix the bug.
2826
2827@menu
2828* Bug Criteria:: Have you found a bug?
2829* Bug Reporting:: How to report bugs
2830@end menu
2831
2832@node Bug Criteria
2833@section Have you found a bug?
2834@cindex bug criteria
2835
2836If you are not sure whether you have found a bug, here are some guidelines:
2837
2838@itemize @bullet
2839@cindex fatal signal
2840@cindex crash
2841@item
2842If a binary utility gets a fatal signal, for any input whatever, that is
2843a bug. Reliable utilities never crash.
2844
2845@cindex error on valid input
2846@item
2847If a binary utility produces an error message for valid input, that is a
2848bug.
2849
2850@item
2851If you are an experienced user of binary utilities, your suggestions for
2852improvement are welcome in any case.
2853@end itemize
2854
2855@node Bug Reporting
2856@section How to report bugs
2857@cindex bug reports
2858@cindex bugs, reporting
2859
2860A number of companies and individuals offer support for @sc{gnu}
2861products. If you obtained the binary utilities from a support
2862organization, we recommend you contact that organization first.
2863
2864You can find contact information for many support companies and
2865individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2866distribution.
2867
2868In any event, we also recommend that you send bug reports for the binary
2869utilities to @samp{bug-gnu-utils@@gnu.org}.
2870
2871The fundamental principle of reporting bugs usefully is this:
2872@strong{report all the facts}. If you are not sure whether to state a
2873fact or leave it out, state it!
2874
2875Often people omit facts because they think they know what causes the
2876problem and assume that some details do not matter. Thus, you might
2877assume that the name of a file you use in an example does not matter.
2878Well, probably it does not, but one cannot be sure. Perhaps the bug is
2879a stray memory reference which happens to fetch from the location where
2880that pathname is stored in memory; perhaps, if the pathname were
2881different, the contents of that location would fool the utility into
2882doing the right thing despite the bug. Play it safe and give a
2883specific, complete example. That is the easiest thing for you to do,
2884and the most helpful.
2885
2886Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2887it is new to us. Therefore, always write your bug reports on the assumption
2888that the bug has not been reported previously.
2889
2890Sometimes people give a few sketchy facts and ask, ``Does this ring a
2891bell?'' Those bug reports are useless, and we urge everyone to
2892@emph{refuse to respond to them} except to chide the sender to report
2893bugs properly.
2894
2895To enable us to fix the bug, you should include all these things:
2896
2897@itemize @bullet
2898@item
2899The version of the utility. Each utility announces it if you start it
2900with the @samp{--version} argument.
2901
2902Without this, we will not know whether there is any point in looking for
2903the bug in the current version of the binary utilities.
2904
2905@item
2906Any patches you may have applied to the source, including any patches
2907made to the @code{BFD} library.
2908
2909@item
2910The type of machine you are using, and the operating system name and
2911version number.
2912
2913@item
2914What compiler (and its version) was used to compile the utilities---e.g.
2915``@code{gcc-2.7}''.
2916
2917@item
2918The command arguments you gave the utility to observe the bug. To
2919guarantee you will not omit something important, list them all. A copy
2920of the Makefile (or the output from make) is sufficient.
2921
2922If we were to try to guess the arguments, we would probably guess wrong
2923and then we might not encounter the bug.
2924
2925@item
2926A complete input file, or set of input files, that will reproduce the
2927bug. If the utility is reading an object file or files, then it is
2928generally most helpful to send the actual object files, uuencoded if
757acbc5
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2929necessary to get them through the mail system. Note that
2930@samp{bug-gnu-utils@@gnu.org} is a mailing list, so you should avoid
2931sending very large files to it. Making the files available for
2932anonymous FTP is OK.
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2933
2934If the source files were produced exclusively using @sc{gnu} programs
2935(e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2936may be OK to send the source files rather than the object files. In
2937this case, be sure to say exactly what version of @code{gcc}, or
2938whatever, was used to produce the object files. Also say how
2939@code{gcc}, or whatever, was configured.
2940
2941@item
2942A description of what behavior you observe that you believe is
2943incorrect. For example, ``It gets a fatal signal.''
2944
2945Of course, if the bug is that the utility gets a fatal signal, then we
2946will certainly notice it. But if the bug is incorrect output, we might
2947not notice unless it is glaringly wrong. You might as well not give us
2948a chance to make a mistake.
2949
2950Even if the problem you experience is a fatal signal, you should still
f20a759a 2951say so explicitly. Suppose something strange is going on, such as your
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2952copy of the utility is out of synch, or you have encountered a bug in
2953the C library on your system. (This has happened!) Your copy might
2954crash and ours would not. If you told us to expect a crash, then when
2955ours fails to crash, we would know that the bug was not happening for
2956us. If you had not told us to expect a crash, then we would not be able
2957to draw any conclusion from our observations.
2958
2959@item
2960If you wish to suggest changes to the source, send us context diffs, as
2961generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2962option. Always send diffs from the old file to the new file. If you
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2963wish to discuss something in the @code{ld} source, refer to it by
2964context, not by line number.
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2965
2966The line numbers in our development sources will not match those in your
2967sources. Your line numbers would convey no useful information to us.
2968@end itemize
2969
2970Here are some things that are not necessary:
2971
2972@itemize @bullet
2973@item
2974A description of the envelope of the bug.
2975
2976Often people who encounter a bug spend a lot of time investigating
2977which changes to the input file will make the bug go away and which
2978changes will not affect it.
2979
2980This is often time consuming and not very useful, because the way we
2981will find the bug is by running a single example under the debugger
2982with breakpoints, not by pure deduction from a series of examples.
2983We recommend that you save your time for something else.
2984
2985Of course, if you can find a simpler example to report @emph{instead}
2986of the original one, that is a convenience for us. Errors in the
2987output will be easier to spot, running under the debugger will take
2988less time, and so on.
2989
2990However, simplification is not vital; if you do not want to do this,
2991report the bug anyway and send us the entire test case you used.
2992
2993@item
2994A patch for the bug.
2995
2996A patch for the bug does help us if it is a good one. But do not omit
2997the necessary information, such as the test case, on the assumption that
2998a patch is all we need. We might see problems with your patch and decide
2999to fix the problem another way, or we might not understand it at all.
3000
3001Sometimes with programs as complicated as the binary utilities it is
3002very hard to construct an example that will make the program follow a
3003certain path through the code. If you do not send us the example, we
3004will not be able to construct one, so we will not be able to verify that
3005the bug is fixed.
3006
3007And if we cannot understand what bug you are trying to fix, or why your
3008patch should be an improvement, we will not install it. A test case will
3009help us to understand.
3010
3011@item
3012A guess about what the bug is or what it depends on.
3013
3014Such guesses are usually wrong. Even we cannot guess right about such
3015things without first using the debugger to find the facts.
3016@end itemize
3017
3018@node Index
3019@unnumbered Index
3020
3021@printindex cp
3022
3023@contents
3024@bye
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