]> git.ipfire.org Git - thirdparty/binutils-gdb.git/blame - binutils/binutils.texi
* gas/all/gas.exp: Don't run floating-point tests on CRIS.
[thirdparty/binutils-gdb.git] / binutils / binutils.texi
CommitLineData
252b5132
RH
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
252b5132
RH
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.
252b5132
RH
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.
252b5132
RH
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
9d51cc66
ILT
134Demangle encoded C++ symbols (on MS-DOS, this program is named
135@code{cxxfilt})
252b5132
RH
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
252b5132
RH
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{}]
252b5132
RH
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{}]
252b5132
RH
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
3de39064
ILT
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
252b5132
RH
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
3de39064
ILT
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
252b5132
RH
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}
252b5132
RH
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} ]
57938635
AM
881 [ --change-section-address @var{section}@{=,+,-@}@var{val} ]
882 [ --change-section-lma @var{section}@{=,+,-@}@var{val} ]
883 [ --change-section-vma @var{section}@{=,+,-@}@var{val} ]
252b5132 884 [ --change-warnings ] [ --no-change-warnings ]
57938635
AM
885 [ --set-section-flags @var{section}=@var{flags} ]
886 [ --add-section @var{sectionname}=@var{filename} ]
252b5132 887 [ --change-leading-char ] [ --remove-leading-char ]
57938635 888 [ --redefine-sym @var{old}=@var{new} ] [ --weaken ]
252b5132
RH
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.
ccd13d18
L
898Note that @code{objcopy} should be able to copy a fully linked file
899between any two formats. However, copying a relocatable object file
900between any two formats may not work as expected.
252b5132
RH
901
902@code{objcopy} creates temporary files to do its translations and
903deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
904translation work; it has access to all the formats described in @sc{bfd}
905and thus is able to recognize most formats without being told
906explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
907
908@code{objcopy} can be used to generate S-records by using an output
909target of @samp{srec} (e.g., use @samp{-O srec}).
910
911@code{objcopy} can be used to generate a raw binary file by using an
912output target of @samp{binary} (e.g., use @samp{-O binary}). When
913@code{objcopy} generates a raw binary file, it will essentially produce
914a memory dump of the contents of the input object file. All symbols and
915relocation information will be discarded. The memory dump will start at
916the load address of the lowest section copied into the output file.
917
918When generating an S-record or a raw binary file, it may be helpful to
919use @samp{-S} to remove sections containing debugging information. In
920some cases @samp{-R} will be useful to remove sections which contain
f20a759a 921information that is not needed by the binary file.
252b5132
RH
922
923@table @code
924@item @var{infile}
925@itemx @var{outfile}
f20a759a 926The input and output files, respectively.
252b5132
RH
927If you do not specify @var{outfile}, @code{objcopy} creates a
928temporary file and destructively renames the result with
929the name of @var{infile}.
930
931@item -I @var{bfdname}
932@itemx --input-target=@var{bfdname}
933Consider the source file's object format to be @var{bfdname}, rather than
934attempting to deduce it. @xref{Target Selection}, for more information.
935
936@item -O @var{bfdname}
937@itemx --output-target=@var{bfdname}
938Write the output file using the object format @var{bfdname}.
939@xref{Target Selection}, for more information.
940
941@item -F @var{bfdname}
942@itemx --target=@var{bfdname}
943Use @var{bfdname} as the object format for both the input and the output
944file; i.e., simply transfer data from source to destination with no
945translation. @xref{Target Selection}, for more information.
946
f91ea849
ILT
947@item -j @var{sectionname}
948@itemx --only-section=@var{sectionname}
949Copy only the named section from the input file to the output file.
950This option may be given more than once. Note that using this option
951inappropriately may make the output file unusable.
952
252b5132
RH
953@item -R @var{sectionname}
954@itemx --remove-section=@var{sectionname}
955Remove any section named @var{sectionname} from the output file. This
956option may be given more than once. Note that using this option
957inappropriately may make the output file unusable.
958
959@item -S
960@itemx --strip-all
961Do not copy relocation and symbol information from the source file.
962
963@item -g
964@itemx --strip-debug
965Do not copy debugging symbols from the source file.
966
967@item --strip-unneeded
968Strip all symbols that are not needed for relocation processing.
969
970@item -K @var{symbolname}
971@itemx --keep-symbol=@var{symbolname}
972Copy only symbol @var{symbolname} from the source file. This option may
973be given more than once.
974
975@item -N @var{symbolname}
976@itemx --strip-symbol=@var{symbolname}
977Do not copy symbol @var{symbolname} from the source file. This option
978may be given more than once.
979
980@item -L @var{symbolname}
981@itemx --localize-symbol=@var{symbolname}
982Make symbol @var{symbolname} local to the file, so that it is not
983visible externally. This option may be given more than once.
984
985@item -W @var{symbolname}
986@itemx --weaken-symbol=@var{symbolname}
987Make symbol @var{symbolname} weak. This option may be given more than once.
988
989@item -x
990@itemx --discard-all
991Do not copy non-global symbols from the source file.
992@c FIXME any reason to prefer "non-global" to "local" here?
993
994@item -X
995@itemx --discard-locals
996Do not copy compiler-generated local symbols.
997(These usually start with @samp{L} or @samp{.}.)
998
999@item -b @var{byte}
1000@itemx --byte=@var{byte}
1001Keep only every @var{byte}th byte of the input file (header data is not
1002affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
1003where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
1004option, or the default of 4. This option is useful for creating files
1005to program @sc{rom}. It is typically used with an @code{srec} output
1006target.
1007
1008@item -i @var{interleave}
1009@itemx --interleave=@var{interleave}
1010Only copy one out of every @var{interleave} bytes. Select which byte to
1011copy with the @var{-b} or @samp{--byte} option. The default is 4.
1012@code{objcopy} ignores this option if you do not specify either @samp{-b} or
1013@samp{--byte}.
1014
1015@item -p
1016@itemx --preserve-dates
1017Set the access and modification dates of the output file to be the same
1018as those of the input file.
1019
1020@item --debugging
1021Convert debugging information, if possible. This is not the default
1022because only certain debugging formats are supported, and the
1023conversion process can be time consuming.
1024
1025@item --gap-fill @var{val}
1026Fill gaps between sections with @var{val}. This operation applies to
1027the @emph{load address} (LMA) of the sections. It is done by increasing
1028the size of the section with the lower address, and filling in the extra
1029space created with @var{val}.
1030
1031@item --pad-to @var{address}
1032Pad the output file up to the load address @var{address}. This is
1033done by increasing the size of the last section. The extra space is
1034filled in with the value specified by @samp{--gap-fill} (default zero).
1035
1036@item --set-start @var{val}
f20a759a 1037Set the start address of the new file to @var{val}. Not all object file
252b5132
RH
1038formats support setting the start address.
1039
1040@item --change-start @var{incr}
1041@itemx --adjust-start @var{incr}
1042@cindex changing start address
1043Change the start address by adding @var{incr}. Not all object file
1044formats support setting the start address.
1045
1046@item --change-addresses @var{incr}
1047@itemx --adjust-vma @var{incr}
1048@cindex changing object addresses
1049Change the VMA and LMA addresses of all sections, as well as the start
1050address, by adding @var{incr}. Some object file formats do not permit
1051section addresses to be changed arbitrarily. Note that this does not
1052relocate the sections; if the program expects sections to be loaded at a
1053certain address, and this option is used to change the sections such
1054that they are loaded at a different address, the program may fail.
1055
1056@item --change-section-address @var{section}@{=,+,-@}@var{val}
1057@itemx --adjust-section-vma @var{section}@{=,+,-@}@var{val}
1058@cindex changing section address
1059Set or change both the VMA address and the LMA address of the named
1060@var{section}. If @samp{=} is used, the section address is set to
1061@var{val}. Otherwise, @var{val} is added to or subtracted from the
1062section address. See the comments under @samp{--change-addresses},
1063above. If @var{section} does not exist in the input file, a warning will
1064be issued, unless @samp{--no-change-warnings} is used.
1065
1066@item --change-section-lma @var{section}@{=,+,-@}@var{val}
1067@cindex changing section LMA
1068Set or change the LMA address of the named @var{section}. The LMA
1069address is the address where the section will be loaded into memory at
1070program load time. Normally this is the same as the VMA address, which
1071is the address of the section at program run time, but on some systems,
1072especially those where a program is held in ROM, the two can be
1073different. If @samp{=} is used, the section address is set to
1074@var{val}. Otherwise, @var{val} is added to or subtracted from the
1075section address. See the comments under @samp{--change-addresses},
1076above. If @var{section} does not exist in the input file, a warning
1077will be issued, unless @samp{--no-change-warnings} is used.
1078
1079@item --change-section-vma @var{section}@{=,+,-@}@var{val}
1080@cindex changing section VMA
1081Set or change the VMA address of the named @var{section}. The VMA
1082address is the address where the section will be located once the
1083program has started executing. Normally this is the same as the LMA
1084address, which is the address where the section will be loaded into
1085memory, but on some systems, especially those where a program is held in
1086ROM, the two can be different. If @samp{=} is used, the section address
1087is set to @var{val}. Otherwise, @var{val} is added to or subtracted
1088from the section address. See the comments under
1089@samp{--change-addresses}, above. If @var{section} does not exist in
1090the input file, a warning will be issued, unless
1091@samp{--no-change-warnings} is used.
1092
1093@item --change-warnings
1094@itemx --adjust-warnings
1095If @samp{--change-section-address} or @samp{--change-section-lma} or
1096@samp{--change-section-vma} is used, and the named section does not
1097exist, issue a warning. This is the default.
1098
1099@item --no-change-warnings
1100@itemx --no-adjust-warnings
1101Do not issue a warning if @samp{--change-section-address} or
1102@samp{--adjust-section-lma} or @samp{--adjust-section-vma} is used, even
1103if the named section does not exist.
1104
1105@item --set-section-flags @var{section}=@var{flags}
1106Set the flags for the named section. The @var{flags} argument is a
1107comma separated string of flag names. The recognized names are
3994e2c6
ILT
1108@samp{alloc}, @samp{contents}, @samp{load}, @samp{noload},
1109@samp{readonly}, @samp{code}, @samp{data}, @samp{rom}, @samp{share}, and
1110@samp{debug}. You can set the @samp{contents} flag for a section which
1111does not have contents, but it is not meaningful to clear the
1112@samp{contents} flag of a section which does have contents--just remove
1113the section instead. Not all flags are meaningful for all object file
1114formats.
252b5132
RH
1115
1116@item --add-section @var{sectionname}=@var{filename}
1117Add a new section named @var{sectionname} while copying the file. The
1118contents of the new section are taken from the file @var{filename}. The
1119size of the section will be the size of the file. This option only
1120works on file formats which can support sections with arbitrary names.
1121
1122@item --change-leading-char
1123Some object file formats use special characters at the start of
1124symbols. The most common such character is underscore, which compilers
1125often add before every symbol. This option tells @code{objcopy} to
1126change the leading character of every symbol when it converts between
1127object file formats. If the object file formats use the same leading
1128character, this option has no effect. Otherwise, it will add a
1129character, or remove a character, or change a character, as
1130appropriate.
1131
1132@item --remove-leading-char
1133If the first character of a global symbol is a special symbol leading
1134character used by the object file format, remove the character. The
1135most common symbol leading character is underscore. This option will
1136remove a leading underscore from all global symbols. This can be useful
1137if you want to link together objects of different file formats with
1138different conventions for symbol names. This is different from
1139@code{--change-leading-char} because it always changes the symbol name
1140when appropriate, regardless of the object file format of the output
1141file.
1142
57938635
AM
1143@item --redefine-sym @var{old}=@var{new}
1144Change the name of a symbol @var{old}, to @var{new}. This can be useful
1145when one is trying link two things together for which you have no
1146source, and there are name collisions.
1147
252b5132
RH
1148@item --weaken
1149Change all global symbols in the file to be weak. This can be useful
1150when building an object which will be linked against other objects using
1151the @code{-R} option to the linker. This option is only effective when
1152using an object file format which supports weak symbols.
1153
1154@item -V
1155@itemx --version
1156Show the version number of @code{objcopy}.
1157
1158@item -v
1159@itemx --verbose
1160Verbose output: list all object files modified. In the case of
1161archives, @samp{objcopy -V} lists all members of the archive.
1162
1163@item --help
1164Show a summary of the options to @code{objcopy}.
1165@end table
1166
1167@node objdump
1168@chapter objdump
1169
1170@cindex object file information
1171@kindex objdump
1172
1173@smallexample
1174objdump [ -a | --archive-headers ]
1dada9c5
NC
1175 [ -b @var{bfdname} | --target=@var{bfdname} ]
1176 [ -C | --demangle ]
1177 [ -d | --disassemble ]
1178 [ -D | --disassemble-all ]
1179 [ -z | --disassemble-zeroes ]
252b5132
RH
1180 [ -EB | -EL | --endian=@{big | little @} ]
1181 [ -f | --file-headers ]
f1563258 1182 [ --file-start-context ]
1dada9c5
NC
1183 [ -g | --debugging ]
1184 [ -h | --section-headers | --headers ]
1185 [ -i | --info ]
252b5132 1186 [ -j @var{section} | --section=@var{section} ]
1dada9c5
NC
1187 [ -l | --line-numbers ]
1188 [ -S | --source ]
252b5132 1189 [ -m @var{machine} | --architecture=@var{machine} ]
dd92f639 1190 [ -M @var{options} | --disassembler-options=@var{options}]
252b5132 1191 [ -p | --private-headers ]
1dada9c5
NC
1192 [ -r | --reloc ]
1193 [ -R | --dynamic-reloc ]
1194 [ -s | --full-contents ]
1195 [ -G | --stabs ]
1196 [ -t | --syms ]
1197 [ -T | --dynamic-syms ]
1198 [ -x | --all-headers ]
1199 [ -w | --wide ]
1200 [ --start-address=@var{address} ]
252b5132 1201 [ --stop-address=@var{address} ]
1dada9c5
NC
1202 [ --prefix-addresses]
1203 [ --[no-]show-raw-insn ]
252b5132 1204 [ --adjust-vma=@var{offset} ]
1dada9c5
NC
1205 [ -V | --version ]
1206 [ -H | --help ]
252b5132
RH
1207 @var{objfile}@dots{}
1208@end smallexample
1209
1210@code{objdump} displays information about one or more object files.
1211The options control what particular information to display. This
1212information is mostly useful to programmers who are working on the
1213compilation tools, as opposed to programmers who just want their
1214program to compile and work.
1215
1216@var{objfile}@dots{} are the object files to be examined. When you
1217specify archives, @code{objdump} shows information on each of the member
1218object files.
1219
1220The long and short forms of options, shown here as alternatives, are
1dada9c5
NC
1221equivalent. At least one option from the list
1222@samp{-a,-d,-D,-f,-g,-G,-h,-H,-p,-r,-R,-S,-t,-T,-V,-x} must be given.
252b5132
RH
1223
1224@table @code
1225@item -a
1226@itemx --archive-header
1227@cindex archive headers
1228If any of the @var{objfile} files are archives, display the archive
1229header information (in a format similar to @samp{ls -l}). Besides the
1230information you could list with @samp{ar tv}, @samp{objdump -a} shows
1231the object file format of each archive member.
1232
1233@item --adjust-vma=@var{offset}
1234@cindex section addresses in objdump
1235@cindex VMA in objdump
1236When dumping information, first add @var{offset} to all the section
1237addresses. This is useful if the section addresses do not correspond to
1238the symbol table, which can happen when putting sections at particular
1239addresses when using a format which can not represent section addresses,
1240such as a.out.
1241
1242@item -b @var{bfdname}
1243@itemx --target=@var{bfdname}
1244@cindex object code format
1245Specify that the object-code format for the object files is
1246@var{bfdname}. This option may not be necessary; @var{objdump} can
1247automatically recognize many formats.
1248
1249For example,
1250@example
1251objdump -b oasys -m vax -h fu.o
1252@end example
1253@noindent
1254displays summary information from the section headers (@samp{-h}) of
1255@file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1256file in the format produced by Oasys compilers. You can list the
1257formats available with the @samp{-i} option.
1258@xref{Target Selection}, for more information.
1259
1260@item -C
1261@itemx --demangle
1262@cindex demangling in objdump
1263Decode (@dfn{demangle}) low-level symbol names into user-level names.
1264Besides removing any initial underscore prepended by the system, this
1265makes C++ function names readable. @xref{c++filt}, for more information
1266on demangling.
1267
1dada9c5 1268@item -G
252b5132
RH
1269@item --debugging
1270Display debugging information. This attempts to parse debugging
1271information stored in the file and print it out using a C like syntax.
1272Only certain types of debugging information have been implemented.
1273
1274@item -d
1275@itemx --disassemble
1276@cindex disassembling object code
1277@cindex machine instructions
1278Display the assembler mnemonics for the machine instructions from
1279@var{objfile}. This option only disassembles those sections which are
1280expected to contain instructions.
1281
1282@item -D
1283@itemx --disassemble-all
1284Like @samp{-d}, but disassemble the contents of all sections, not just
1285those expected to contain instructions.
1286
1287@item --prefix-addresses
1288When disassembling, print the complete address on each line. This is
1289the older disassembly format.
1290
1291@item --disassemble-zeroes
1292Normally the disassembly output will skip blocks of zeroes. This
1293option directs the disassembler to disassemble those blocks, just like
1294any other data.
1295
1296@item -EB
1297@itemx -EL
1298@itemx --endian=@{big|little@}
1299@cindex endianness
1300@cindex disassembly endianness
1301Specify the endianness of the object files. This only affects
1302disassembly. This can be useful when disassembling a file format which
1303does not describe endianness information, such as S-records.
1304
1305@item -f
1306@itemx --file-header
1307@cindex object file header
1308Display summary information from the overall header of
1309each of the @var{objfile} files.
1310
f1563258
TW
1311@item --file-start-context
1312@cindex source code context
1313Specify that when displaying interlisted source code/disassembly
1314(assumes '-S') from a file that has not yet been displayed, extend the
1315context to the start of the file.
1316
252b5132
RH
1317@item -h
1318@itemx --section-header
1319@itemx --header
1320@cindex section headers
1321Display summary information from the section headers of the
1322object file.
1323
1324File segments may be relocated to nonstandard addresses, for example by
1325using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1326@code{ld}. However, some object file formats, such as a.out, do not
1327store the starting address of the file segments. In those situations,
1328although @code{ld} relocates the sections correctly, using @samp{objdump
1329-h} to list the file section headers cannot show the correct addresses.
1330Instead, it shows the usual addresses, which are implicit for the
1331target.
1332
1333@item --help
1334Print a summary of the options to @code{objdump} and exit.
1335
1336@item -i
1337@itemx --info
1338@cindex architectures available
1339@cindex object formats available
1340Display a list showing all architectures and object formats available
1341for specification with @samp{-b} or @samp{-m}.
1342
1343@item -j @var{name}
1344@itemx --section=@var{name}
1345@cindex section information
1346Display information only for section @var{name}.
1347
1348@item -l
1349@itemx --line-numbers
1350@cindex source filenames for object files
1351Label the display (using debugging information) with the filename and
1352source line numbers corresponding to the object code or relocs shown.
1353Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1354
1355@item -m @var{machine}
1356@itemx --architecture=@var{machine}
1357@cindex architecture
1358@cindex disassembly architecture
1359Specify the architecture to use when disassembling object files. This
1360can be useful when disassembling object files which do not describe
1361architecture information, such as S-records. You can list the available
1362architectures with the @samp{-i} option.
1363
dd92f639
NC
1364@item -M @var{options}
1365@itemx --disassembler-options=@var{options}
1366Pass target specific information to the disassembler. Only supported on
1367some targets.
1368
1369If the target is an ARM architecture then this switch can be used to
1370select which register name set is used during disassembler. Specifying
58efb6c0
NC
1371@samp{-M reg-name-std} (the default) will select the register names as
1372used in ARM's instruction set documentation, but with register 13 called
1373'sp', register 14 called 'lr' and register 15 called 'pc'. Specifying
1374@samp{-M reg-names-apcs} will select the name set used by the ARM
1375Procedure Call Standard, whilst specifying @samp{-M reg-names-raw} will
1376just use @samp{r} followed by the register number.
1377
1378There are also two variants on the APCS register naming scheme enabled
0fff8110 1379by @samp{-M reg-names-atpcs} and @samp{-M reg-names-special-atpcs} which
58efb6c0
NC
1380use the ARM/Thumb Procedure Call Standard naming conventions. (Eiuther
1381with the normal register name sor the special register names).
dd92f639 1382
8f915f68
NC
1383This option can also be used for ARM architectures to force the
1384disassembler to interpret all instructions as THUMB instructions by
1385using the switch @samp{--disassembler-options=force-thumb}. This can be
1386useful when attempting to disassemble thumb code produced by other
1387compilers.
1388
252b5132
RH
1389@item -p
1390@itemx --private-headers
1391Print information that is specific to the object file format. The exact
1392information printed depends upon the object file format. For some
1393object file formats, no additional information is printed.
1394
1395@item -r
1396@itemx --reloc
1397@cindex relocation entries, in object file
1398Print the relocation entries of the file. If used with @samp{-d} or
1399@samp{-D}, the relocations are printed interspersed with the
1400disassembly.
1401
1402@item -R
1403@itemx --dynamic-reloc
1404@cindex dynamic relocation entries, in object file
1405Print the dynamic relocation entries of the file. This is only
1406meaningful for dynamic objects, such as certain types of shared
1407libraries.
1408
1409@item -s
1410@itemx --full-contents
1411@cindex sections, full contents
1412@cindex object file sections
1413Display the full contents of any sections requested.
1414
1415@item -S
1416@itemx --source
1417@cindex source disassembly
1418@cindex disassembly, with source
1419Display source code intermixed with disassembly, if possible. Implies
1420@samp{-d}.
1421
1422@item --show-raw-insn
1423When disassembling instructions, print the instruction in hex as well as
1424in symbolic form. This is the default except when
1425@code{--prefix-addresses} is used.
1426
1427@item --no-show-raw-insn
1428When disassembling instructions, do not print the instruction bytes.
1429This is the default when @code{--prefix-addresses} is used.
1430
1dada9c5 1431@item -G
252b5132
RH
1432@item --stabs
1433@cindex stab
1434@cindex .stab
1435@cindex debug symbols
1436@cindex ELF object file format
1437Display the full contents of any sections requested. Display the
1438contents of the .stab and .stab.index and .stab.excl sections from an
1439ELF file. This is only useful on systems (such as Solaris 2.0) in which
1440@code{.stab} debugging symbol-table entries are carried in an ELF
1441section. In most other file formats, debugging symbol-table entries are
1442interleaved with linkage symbols, and are visible in the @samp{--syms}
1443output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1444Overview,stabs.info, The ``stabs'' debug format}.
1445
1446@item --start-address=@var{address}
1447@cindex start-address
1448Start displaying data at the specified address. This affects the output
1449of the @code{-d}, @code{-r} and @code{-s} options.
1450
1451@item --stop-address=@var{address}
1452@cindex stop-address
1453Stop displaying data at the specified address. This affects the output
1454of the @code{-d}, @code{-r} and @code{-s} options.
1455
1456@item -t
1457@itemx --syms
1458@cindex symbol table entries, printing
1459Print the symbol table entries of the file.
1460This is similar to the information provided by the @samp{nm} program.
1461
1462@item -T
1463@itemx --dynamic-syms
1464@cindex dynamic symbol table entries, printing
1465Print the dynamic symbol table entries of the file. This is only
1466meaningful for dynamic objects, such as certain types of shared
1467libraries. This is similar to the information provided by the @samp{nm}
1468program when given the @samp{-D} (@samp{--dynamic}) option.
1469
1470@item --version
1471Print the version number of @code{objdump} and exit.
1472
1473@item -x
1474@itemx --all-header
1475@cindex all header information, object file
1476@cindex header information, all
1477Display all available header information, including the symbol table and
1478relocation entries. Using @samp{-x} is equivalent to specifying all of
1479@samp{-a -f -h -r -t}.
1480
1481@item -w
1482@itemx --wide
1483@cindex wide output, printing
1484Format some lines for output devices that have more than 80 columns.
1485@end table
1486
1487@node ranlib
1488@chapter ranlib
1489
1490@kindex ranlib
1491@cindex archive contents
1492@cindex symbol index
1493
1494@smallexample
1495ranlib [-vV] @var{archive}
1496@end smallexample
1497
1498@code{ranlib} generates an index to the contents of an archive and
1499stores it in the archive. The index lists each symbol defined by a
1500member of an archive that is a relocatable object file.
1501
1502You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1503
1504An archive with such an index speeds up linking to the library and
1505allows routines in the library to call each other without regard to
1506their placement in the archive.
1507
1508The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1509@code{ranlib} is completely equivalent to executing @samp{ar -s}.
1510@xref{ar}.
1511
1512@table @code
1513@item -v
1514@itemx -V
f20a759a 1515@itemx --version
252b5132
RH
1516Show the version number of @code{ranlib}.
1517@end table
1518
1519@node size
1520@chapter size
1521
1522@kindex size
1523@cindex section sizes
1524
1525@smallexample
1526size [ -A | -B | --format=@var{compatibility} ]
1527 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1528 [ --target=@var{bfdname} ] [ -V | --version ]
1529 [ @var{objfile}@dots{} ]
1530@end smallexample
1531
1532The @sc{gnu} @code{size} utility lists the section sizes---and the total
1533size---for each of the object or archive files @var{objfile} in its
1534argument list. By default, one line of output is generated for each
1535object file or each module in an archive.
1536
1537@var{objfile}@dots{} are the object files to be examined.
1538If none are specified, the file @code{a.out} will be used.
1539
1540The command line options have the following meanings:
1541
1542@table @code
1543@item -A
1544@itemx -B
1545@itemx --format=@var{compatibility}
1546@cindex @code{size} display format
1547Using one of these options, you can choose whether the output from @sc{gnu}
1548@code{size} resembles output from System V @code{size} (using @samp{-A},
1549or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1550@samp{--format=berkeley}). The default is the one-line format similar to
1551Berkeley's.
1552@c Bonus for doc-source readers: you can also say --format=strange (or
1553@c anything else that starts with 's') for sysv, and --format=boring (or
1554@c anything else that starts with 'b') for Berkeley.
1555
1556Here is an example of the Berkeley (default) format of output from
1557@code{size}:
1558@smallexample
f20a759a 1559$ size --format=Berkeley ranlib size
252b5132
RH
1560text data bss dec hex filename
1561294880 81920 11592 388392 5ed28 ranlib
1562294880 81920 11888 388688 5ee50 size
1563@end smallexample
1564
1565@noindent
1566This is the same data, but displayed closer to System V conventions:
1567
1568@smallexample
f20a759a 1569$ size --format=SysV ranlib size
252b5132
RH
1570ranlib :
1571section size addr
1572.text 294880 8192
1573.data 81920 303104
1574.bss 11592 385024
1575Total 388392
1576
1577
1578size :
1579section size addr
1580.text 294880 8192
1581.data 81920 303104
1582.bss 11888 385024
1583Total 388688
1584@end smallexample
1585
1586@item --help
1587Show a summary of acceptable arguments and options.
1588
1589@item -d
1590@itemx -o
1591@itemx -x
1592@itemx --radix=@var{number}
1593@cindex @code{size} number format
1594@cindex radix for section sizes
1595Using one of these options, you can control whether the size of each
1596section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1597(@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1598@samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1599values (8, 10, 16) are supported. The total size is always given in two
1600radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1601octal and hexadecimal if you're using @samp{-o}.
1602
1603@item --target=@var{bfdname}
1604@cindex object code format
1605Specify that the object-code format for @var{objfile} is
1606@var{bfdname}. This option may not be necessary; @code{size} can
1607automatically recognize many formats.
1608@xref{Target Selection}, for more information.
1609
1610@item -V
1611@itemx --version
1612Display the version number of @code{size}.
1613@end table
1614
1615@node strings
1616@chapter strings
1617@kindex strings
1618@cindex listings strings
1619@cindex printing strings
1620@cindex strings, printing
1621
1622@smallexample
1623strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1624 [--all] [--print-file-name] [--bytes=@var{min-len}]
1625 [--radix=@var{radix}] [--target=@var{bfdname}]
1626 [--help] [--version] @var{file}@dots{}
1627@end smallexample
1628
1629For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1630character sequences that are at least 4 characters long (or the number
1631given with the options below) and are followed by an unprintable
1632character. By default, it only prints the strings from the initialized
1633and loaded sections of object files; for other types of files, it prints
1634the strings from the whole file.
1635
1636@code{strings} is mainly useful for determining the contents of non-text
1637files.
1638
1639@table @code
1640@item -a
1641@itemx --all
1642@itemx -
1643Do not scan only the initialized and loaded sections of object files;
1644scan the whole files.
1645
1646@item -f
1647@itemx --print-file-name
1648Print the name of the file before each string.
1649
1650@item --help
1651Print a summary of the program usage on the standard output and exit.
1652
1653@item -@var{min-len}
1654@itemx -n @var{min-len}
1655@itemx --bytes=@var{min-len}
1656Print sequences of characters that are at least @var{min-len} characters
1657long, instead of the default 4.
1658
1659@item -o
1660Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1661act like @samp{-t d} instead. Since we can not be compatible with both
1662ways, we simply chose one.
1663
1664@item -t @var{radix}
1665@itemx --radix=@var{radix}
1666Print the offset within the file before each string. The single
1667character argument specifies the radix of the offset---@samp{o} for
1668octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1669
1670@item --target=@var{bfdname}
1671@cindex object code format
1672Specify an object code format other than your system's default format.
1673@xref{Target Selection}, for more information.
1674
1675@item -v
1676@itemx --version
1677Print the program version number on the standard output and exit.
1678@end table
1679
1680@node strip
1681@chapter strip
1682
1683@kindex strip
1684@cindex removing symbols
1685@cindex discarding symbols
1686@cindex symbols, discarding
1687
1688@smallexample
1689strip [ -F @var{bfdname} | --target=@var{bfdname} ]
1690 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1691 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1692 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1693 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1694 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1695 [ -x | --discard-all ] [ -X | --discard-locals ]
1696 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1697 [ -o @var{file} ] [ -p | --preserve-dates ]
1698 [ -v | --verbose ] [ -V | --version ] [ --help ]
1699 @var{objfile}@dots{}
1700@end smallexample
1701
1702@sc{gnu} @code{strip} discards all symbols from object files
1703@var{objfile}. The list of object files may include archives.
1704At least one object file must be given.
1705
1706@code{strip} modifies the files named in its argument,
1707rather than writing modified copies under different names.
1708
1709@table @code
1710@item -F @var{bfdname}
1711@itemx --target=@var{bfdname}
1712Treat the original @var{objfile} as a file with the object
1713code format @var{bfdname}, and rewrite it in the same format.
1714@xref{Target Selection}, for more information.
1715
1716@item --help
1717Show a summary of the options to @code{strip} and exit.
1718
1719@item -I @var{bfdname}
1720@itemx --input-target=@var{bfdname}
1721Treat the original @var{objfile} as a file with the object
1722code format @var{bfdname}.
1723@xref{Target Selection}, for more information.
1724
1725@item -O @var{bfdname}
1726@itemx --output-target=@var{bfdname}
1727Replace @var{objfile} with a file in the output format @var{bfdname}.
1728@xref{Target Selection}, for more information.
1729
1730@item -R @var{sectionname}
1731@itemx --remove-section=@var{sectionname}
1732Remove any section named @var{sectionname} from the output file. This
1733option may be given more than once. Note that using this option
1734inappropriately may make the output file unusable.
1735
1736@item -s
1737@itemx --strip-all
1738Remove all symbols.
1739
1740@item -g
1741@itemx -S
1742@itemx --strip-debug
1743Remove debugging symbols only.
1744
1745@item --strip-unneeded
1746Remove all symbols that are not needed for relocation processing.
1747
1748@item -K @var{symbolname}
1749@itemx --keep-symbol=@var{symbolname}
1750Keep only symbol @var{symbolname} from the source file. This option may
1751be given more than once.
1752
1753@item -N @var{symbolname}
1754@itemx --strip-symbol=@var{symbolname}
1755Remove symbol @var{symbolname} from the source file. This option may be
1756given more than once, and may be combined with strip options other than
1757@code{-K}.
1758
1759@item -o @var{file}
1760Put the stripped output in @var{file}, rather than replacing the
1761existing file. When this argument is used, only one @var{objfile}
1762argument may be specified.
1763
1764@item -p
1765@itemx --preserve-dates
1766Preserve the access and modification dates of the file.
1767
1768@item -x
1769@itemx --discard-all
1770Remove non-global symbols.
1771
1772@item -X
1773@itemx --discard-locals
1774Remove compiler-generated local symbols.
1775(These usually start with @samp{L} or @samp{.}.)
1776
1777@item -V
1778@itemx --version
1779Show the version number for @code{strip}.
1780
1781@item -v
1782@itemx --verbose
1783Verbose output: list all object files modified. In the case of
1784archives, @samp{strip -v} lists all members of the archive.
1785@end table
1786
9d51cc66 1787@node c++filt, addr2line, strip, Top
252b5132
RH
1788@chapter c++filt
1789
1790@kindex c++filt
1791@cindex demangling C++ symbols
1792
1793@smallexample
1794c++filt [ -_ | --strip-underscores ]
1795 [ -j | --java ]
1796 [ -n | --no-strip-underscores ]
1797 [ -s @var{format} | --format=@var{format} ]
1798 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1799@end smallexample
1800
9d51cc66 1801@kindex cxxfilt
252b5132
RH
1802The C++ and Java languages provides function overloading, which means
1803that you can write many functions with the same name (providing each
1804takes parameters of different types). All C++ and Java function names
1805are encoded into a low-level assembly label (this process is known as
9d51cc66
ILT
1806@dfn{mangling}). The @code{c++filt}
1807@footnote{MS-DOS does not allow @kbd{+} characters in file names, so on
1808MS-DOS this program is named @code{cxxfilt}.}
1809program does the inverse mapping: it decodes (@dfn{demangles}) low-level
1810names into user-level names so that the linker can keep these overloaded
1811functions from clashing.
252b5132
RH
1812
1813Every alphanumeric word (consisting of letters, digits, underscores,
1814dollars, or periods) seen in the input is a potential label. If the
1815label decodes into a C++ name, the C++ name replaces the low-level
1816name in the output.
1817
1818You can use @code{c++filt} to decipher individual symbols:
1819
1820@example
1821c++filt @var{symbol}
1822@end example
1823
1824If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1825names from the standard input and writes the demangled names to the
1826standard output. All results are printed on the standard output.
1827
1828@table @code
1829@item -_
1830@itemx --strip-underscores
1831On some systems, both the C and C++ compilers put an underscore in front
1832of every name. For example, the C name @code{foo} gets the low-level
1833name @code{_foo}. This option removes the initial underscore. Whether
1834@code{c++filt} removes the underscore by default is target dependent.
1835
1836@item -j
1837@itemx --java
1838Prints demangled names using Java syntax. The default is to use C++
1839syntax.
1840
1841@item -n
1842@itemx --no-strip-underscores
1843Do not remove the initial underscore.
1844
1845@item -s @var{format}
1846@itemx --format=@var{format}
1847@sc{gnu} @code{nm} can decode three different methods of mangling, used by
1848different C++ compilers. The argument to this option selects which
1849method it uses:
1850
1851@table @code
1852@item gnu
1853the one used by the @sc{gnu} compiler (the default method)
1854@item lucid
1855the one used by the Lucid compiler
1856@item arm
1857the one specified by the C++ Annotated Reference Manual
1858@item hp
1859the one used by the HP compiler
1860@item edg
1861the one used by the EDG compiler
1862@end table
1863
1864@item --help
1865Print a summary of the options to @code{c++filt} and exit.
1866
1867@item --version
1868Print the version number of @code{c++filt} and exit.
1869@end table
1870
1871@quotation
1872@emph{Warning:} @code{c++filt} is a new utility, and the details of its
1873user interface are subject to change in future releases. In particular,
1874a command-line option may be required in the the future to decode a name
1875passed as an argument on the command line; in other words,
1876
1877@example
1878c++filt @var{symbol}
1879@end example
1880
1881@noindent
1882may in a future release become
1883
1884@example
1885c++filt @var{option} @var{symbol}
1886@end example
1887@end quotation
1888
1889@node addr2line
1890@chapter addr2line
1891
1892@kindex addr2line
1893@cindex address to file name and line number
1894
1895@smallexample
1896addr2line [ -b @var{bfdname} | --target=@var{bfdname} ]
1897 [ -C | --demangle ]
1898 [ -e @var{filename} | --exe=@var{filename} ]
1899 [ -f | --functions ] [ -s | --basename ]
1900 [ -H | --help ] [ -V | --version ]
1901 [ addr addr ... ]
1902@end smallexample
1903
1904@code{addr2line} translates program addresses into file names and line
1905numbers. Given an address and an executable, it uses the debugging
1906information in the executable to figure out which file name and line
1907number are associated with a given address.
1908
1909The executable to use is specified with the @code{-e} option. The
f20a759a 1910default is the file @file{a.out}.
252b5132
RH
1911
1912@code{addr2line} has two modes of operation.
1913
1914In the first, hexadecimal addresses are specified on the command line,
1915and @code{addr2line} displays the file name and line number for each
1916address.
1917
1918In the second, @code{addr2line} reads hexadecimal addresses from
1919standard input, and prints the file name and line number for each
1920address on standard output. In this mode, @code{addr2line} may be used
1921in a pipe to convert dynamically chosen addresses.
1922
1923The format of the output is @samp{FILENAME:LINENO}. The file name and
1924line number for each address is printed on a separate line. If the
1925@code{-f} option is used, then each @samp{FILENAME:LINENO} line is
1926preceded by a @samp{FUNCTIONNAME} line which is the name of the function
1927containing the address.
1928
1929If the file name or function name can not be determined,
1930@code{addr2line} will print two question marks in their place. If the
1931line number can not be determined, @code{addr2line} will print 0.
1932
1933The long and short forms of options, shown here as alternatives, are
1934equivalent.
1935
1936@table @code
1937@item -b @var{bfdname}
1938@itemx --target=@var{bfdname}
1939@cindex object code format
1940Specify that the object-code format for the object files is
1941@var{bfdname}.
1942
1943@item -C
1944@itemx --demangle
1945@cindex demangling in objdump
1946Decode (@dfn{demangle}) low-level symbol names into user-level names.
1947Besides removing any initial underscore prepended by the system, this
1948makes C++ function names readable. @xref{c++filt}, for more information
1949on demangling.
1950
1951@item -e @var{filename}
1952@itemx --exe=@var{filename}
1953Specify the name of the executable for which addresses should be
1954translated. The default file is @file{a.out}.
1955
1956@item -f
1957@itemx --functions
1958Display function names as well as file and line number information.
1959
1960@item -s
1961@itemx --basenames
1962Display only the base of each file name.
1963@end table
1964
1965@node nlmconv
1966@chapter nlmconv
1967
1968@code{nlmconv} converts a relocatable object file into a NetWare
1969Loadable Module.
1970
1971@ignore
1972@code{nlmconv} currently works with @samp{i386} object
1973files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1974object files in @sc{elf}, or @code{a.out} format@footnote{
1975@code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1976format in the Binary File Descriptor library. It has only been tested
1977with the above formats.}.
1978@end ignore
1979
1980@quotation
1981@emph{Warning:} @code{nlmconv} is not always built as part of the binary
1982utilities, since it is only useful for NLM targets.
1983@end quotation
1984
1985@smallexample
1986nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1987 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1988 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1989 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1990 [ -h | --help ] [ -V | --version ]
1991 @var{infile} @var{outfile}
1992@end smallexample
1993
1994@code{nlmconv} converts the relocatable @samp{i386} object file
1995@var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1996reading @var{headerfile} for NLM header information. For instructions
1997on writing the NLM command file language used in header files, see the
1998@samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1999Development and Tools Overview}, which is part of the NLM Software
2000Developer's Kit (``NLM SDK''), available from Novell, Inc.
2001@code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
2002@var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
2003more information.
2004
2005@code{nlmconv} can perform a link step. In other words, you can list
2006more than one object file for input if you list them in the definitions
2007file (rather than simply specifying one input file on the command line).
2008In this case, @code{nlmconv} calls the linker for you.
2009
2010@table @code
2011@item -I @var{bfdname}
2012@itemx --input-target=@var{bfdname}
2013Object format of the input file. @code{nlmconv} can usually determine
2014the format of a given file (so no default is necessary).
2015@xref{Target Selection}, for more information.
2016
2017@item -O @var{bfdname}
2018@itemx --output-target=@var{bfdname}
2019Object format of the output file. @code{nlmconv} infers the output
2020format based on the input format, e.g. for a @samp{i386} input file the
2021output format is @samp{nlm32-i386}.
2022@xref{Target Selection}, for more information.
2023
2024@item -T @var{headerfile}
2025@itemx --header-file=@var{headerfile}
2026Reads @var{headerfile} for NLM header information. For instructions on
2027writing the NLM command file language used in header files, see@ see the
2028@samp{linkers} section, of the @cite{NLM Development and Tools
2029Overview}, which is part of the NLM Software Developer's Kit, available
2030from Novell, Inc.
2031
2032@item -d
2033@itemx --debug
2034Displays (on standard error) the linker command line used by @code{nlmconv}.
2035
2036@item -l @var{linker}
2037@itemx --linker=@var{linker}
2038Use @var{linker} for any linking. @var{linker} can be an absolute or a
2039relative pathname.
2040
2041@item -h
2042@itemx --help
2043Prints a usage summary.
2044
2045@item -V
2046@itemx --version
2047Prints the version number for @code{nlmconv}.
2048@end table
2049
2050@node windres
2051@chapter windres
2052
2053@code{windres} may be used to manipulate Windows resources.
2054
2055@quotation
2056@emph{Warning:} @code{windres} is not always built as part of the binary
2057utilities, since it is only useful for Windows targets.
2058@end quotation
2059
2060@smallexample
2061windres [options] [input-file] [output-file]
2062@end smallexample
2063
2064@code{windres} reads resources from an input file and copies them into
2065an output file. Either file may be in one of three formats:
2066
2067@table @code
2068@item rc
2069A text format read by the Resource Compiler.
2070
2071@item res
2072A binary format generated by the Resource Compiler.
2073
2074@item coff
2075A COFF object or executable.
2076@end table
2077
2078The exact description of these different formats is available in
2079documentation from Microsoft.
2080
2081When @code{windres} converts from the @code{rc} format to the @code{res}
2082format, it is acting like the Windows Resource Compiler. When
2083@code{windres} converts from the @code{res} format to the @code{coff}
2084format, it is acting like the Windows @code{CVTRES} program.
2085
2086When @code{windres} generates an @code{rc} file, the output is similar
2087but not identical to the format expected for the input. When an input
2088@code{rc} file refers to an external filename, an output @code{rc} file
2089will instead include the file contents.
2090
2091If the input or output format is not specified, @code{windres} will
2092guess based on the file name, or, for the input file, the file contents.
2093A file with an extension of @file{.rc} will be treated as an @code{rc}
2094file, a file with an extension of @file{.res} will be treated as a
2095@code{res} file, and a file with an extension of @file{.o} or
2096@file{.exe} will be treated as a @code{coff} file.
2097
2098If no output file is specified, @code{windres} will print the resources
2099in @code{rc} format to standard output.
2100
2101The normal use is for you to write an @code{rc} file, use @code{windres}
2102to convert it to a COFF object file, and then link the COFF file into
2103your application. This will make the resources described in the
2104@code{rc} file available to Windows.
2105
2106@table @code
2107@item -i @var{filename}
2108@itemx --input @var{filename}
2109The name of the input file. If this option is not used, then
2110@code{windres} will use the first non-option argument as the input file
2111name. If there are no non-option arguments, then @code{windres} will
2112read from standard input. @code{windres} can not read a COFF file from
2113standard input.
2114
2115@item -o @var{filename}
2116@itemx --output @var{filename}
2117The name of the output file. If this option is not used, then
2118@code{windres} will use the first non-option argument, after any used
2119for the input file name, as the output file name. If there is no
2120non-option argument, then @code{windres} will write to standard output.
2121@code{windres} can not write a COFF file to standard output.
2122
2123@item -I @var{format}
2124@itemx --input-format @var{format}
2125The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
2126@samp{coff}. If no input format is specified, @code{windres} will
2127guess, as described above.
2128
2129@item -O @var{format}
2130@itemx --output-format @var{format}
2131The output format to generate. @var{format} may be @samp{res},
2132@samp{rc}, or @samp{coff}. If no output format is specified,
2133@code{windres} will guess, as described above.
2134
2135@item -F @var{target}
2136@itemx --target @var{target}
2137Specify the BFD format to use for a COFF file as input or output. This
2138is a BFD target name; you can use the @code{--help} option to see a list
2139of supported targets. Normally @code{windres} will use the default
2140format, which is the first one listed by the @code{--help} option.
2141@ref{Target Selection}.
2142
2143@item --preprocessor @var{program}
2144When @code{windres} reads an @code{rc} file, it runs it through the C
2145preprocessor first. This option may be used to specify the preprocessor
2146to use, including any leading arguments. The default preprocessor
2147argument is @code{gcc -E -xc-header -DRC_INVOKED}.
2148
2149@item --include-dir @var{directory}
2150Specify an include directory to use when reading an @code{rc} file.
2151@code{windres} will pass this to the preprocessor as an @code{-I}
2152option. @code{windres} will also search this directory when looking for
2153files named in the @code{rc} file.
2154
751d21b5 2155@item -D @var{target}
ad0481cd 2156@itemx --define @var{sym}[=@var{val}]
252b5132
RH
2157Specify a @code{-D} option to pass to the preprocessor when reading an
2158@code{rc} file.
2159
751d21b5
DD
2160@item -v
2161Enable verbose mode. This tells you what the preprocessor is if you
2162didn't specify one.
2163
252b5132
RH
2164@item --language @var{val}
2165Specify the default language to use when reading an @code{rc} file.
2166@var{val} should be a hexadecimal language code. The low eight bits are
2167the language, and the high eight bits are the sublanguage.
2168
5a298d2d
NC
2169@item --use-temp-file
2170Use a temporary file to instead of using popen to read the output of
2171the preprocessor. Use this option if the popen implementation is buggy
2172on the host (eg., certain non-English language versions of Windows 95 and
2173Windows 98 are known to have buggy popen where the output will instead
2174go the console).
2175
2176@item --no-use-temp-file
2177Use popen, not a temporary file, to read the output of the preprocessor.
2178This is the default behaviour.
2179
252b5132
RH
2180@item --help
2181Prints a usage summary.
2182
2183@item --version
2184Prints the version number for @code{windres}.
2185
2186@item --yydebug
2187If @code{windres} is compiled with @code{YYDEBUG} defined as @code{1},
2188this will turn on parser debugging.
2189@end table
2190
2191
2192@node dlltool
2193@chapter Create files needed to build and use DLLs
2194@cindex DLL
2195@kindex dlltool
2196
2197@code{dlltool} may be used to create the files needed to build and use
2198dynamic link libraries (DLLs).
2199
2200@quotation
2201@emph{Warning:} @code{dlltool} is not always built as part of the binary
2202utilities, since it is only useful for those targets which support DLLs.
2203@end quotation
2204
2205@smallexample
2206dlltool [-d|--input-def @var{def-file-name}]
2207 [-b|--base-file @var{base-file-name}]
2208 [-e|--output-exp @var{exports-file-name}]
2209 [-z|--output-def @var{def-file-name}]
2210 [-l|--output-lib @var{library-file-name}]
2211 [--export-all-symbols] [--no-export-all-symbols]
2212 [--exclude-symbols @var{list}]
2213 [--no-default-excludes]
2214 [-S|--as @var{path-to-assembler}] [-f|--as-flags @var{options}]
2215 [-D|--dllname @var{name}] [-m|--machine @var{machine}]
2216 [-a|--add-indirect] [-U|--add-underscore] [-k|--kill-at]
2217 [-A|--add-stdcall-alias]
2218 [-x|--no-idata4] [-c|--no-idata5] [-i|--interwork]
2219 [-n|--nodelete] [-v|--verbose] [-h|--help] [-V|--version]
2220 [object-file @dots{}]
2221@end smallexample
2222
2223@code{dlltool} reads its inputs, which can come from the @samp{-d} and
2224@samp{-b} options as well as object files specified on the command
2225line. It then processes these inputs and if the @samp{-e} option has
2226been specified it creates a exports file. If the @samp{-l} option
2227has been specified it creates a library file and if the @samp{-z} option
2228has been specified it creates a def file. Any or all of the -e, -l
2229and -z options can be present in one invocation of dlltool.
2230
2231When creating a DLL, along with the source for the DLL, it is necessary
2232to have three other files. @code{dlltool} can help with the creation of
2233these files.
2234
2235The first file is a @samp{.def} file which specifies which functions are
2236exported from the DLL, which functions the DLL imports, and so on. This
2237is a text file and can be created by hand, or @code{dlltool} can be used
2238to create it using the @samp{-z} option. In this case @code{dlltool}
2239will scan the object files specified on its command line looking for
2240those functions which have been specially marked as being exported and
2241put entries for them in the .def file it creates.
2242
2243In order to mark a function as being exported from a DLL, it needs to
2244have an @samp{-export:<name_of_function>} entry in the @samp{.drectve}
2245section of the object file. This can be done in C by using the
2246asm() operator:
2247
2248@smallexample
2249 asm (".section .drectve");
2250 asm (".ascii \"-export:my_func\"");
2251
2252 int my_func (void) @{ @dots{} @}
2253@end smallexample
2254
2255The second file needed for DLL creation is an exports file. This file
2256is linked with the object files that make up the body of the DLL and it
2257handles the interface between the DLL and the outside world. This is a
2258binary file and it can be created by giving the @samp{-e} option to
2259@code{dlltool} when it is creating or reading in a .def file.
2260
2261The third file needed for DLL creation is the library file that programs
2262will link with in order to access the functions in the DLL. This file
2263can be created by giving the @samp{-l} option to dlltool when it
2264is creating or reading in a .def file.
2265
2266@code{dlltool} builds the library file by hand, but it builds the
2267exports file by creating temporary files containing assembler statements
2268and then assembling these. The @samp{-S} command line option can be
2269used to specify the path to the assembler that dlltool will use,
2270and the @samp{-f} option can be used to pass specific flags to that
2271assembler. The @samp{-n} can be used to prevent dlltool from deleting
2272these temporary assembler files when it is done, and if @samp{-n} is
2273specified twice then this will prevent dlltool from deleting the
2274temporary object files it used to build the library.
2275
2276Here is an example of creating a DLL from a source file @samp{dll.c} and
2277also creating a program (from an object file called @samp{program.o})
2278that uses that DLL:
2279
2280@smallexample
2281 gcc -c dll.c
2282 dlltool -e exports.o -l dll.lib dll.o
2283 gcc dll.o exports.o -o dll.dll
2284 gcc program.o dll.lib -o program
2285@end smallexample
2286
2287The command line options have the following meanings:
2288
2289@table @code
2290
2291@item -d @var{filename}
2292@itemx --input-def @var{filename}
2293@cindex input .def file
2294Specifies the name of a .def file to be read in and processed.
2295
2296@item -b @var{filename}
2297@itemx --base-file @var{filename}
2298@cindex base files
2299Specifies the name of a base file to be read in and processed. The
2300contents of this file will be added to the relocation section in the
2301exports file generated by dlltool.
2302
2303@item -e @var{filename}
2304@itemx --output-exp @var{filename}
2305Specifies the name of the export file to be created by dlltool.
2306
2307@item -z @var{filename}
2308@itemx --output-def @var{filename}
2309Specifies the name of the .def file to be created by dlltool.
2310
2311@item -l @var{filename}
2312@itemx --output-lib @var{filename}
2313Specifies the name of the library file to be created by dlltool.
2314
2315@item --export-all-symbols
2316Treat all global and weak defined symbols found in the input object
2317files as symbols to be exported. There is a small list of symbols which
2318are not exported by default; see the @code{--no-default-excludes}
2319option. You may add to the list of symbols to not export by using the
2320@code{--exclude-symbols} option.
2321
2322@item --no-export-all-symbols
2323Only export symbols explicitly listed in an input .def file or in
2324@samp{.drectve} sections in the input object files. This is the default
2325behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
2326attributes in the source code.
2327
2328@item --exclude-symbols @var{list}
2329Do not export the symbols in @var{list}. This is a list of symbol names
2330separated by comma or colon characters. The symbol names should not
2331contain a leading underscore. This is only meaningful when
2332@code{--export-all-symbols} is used.
2333
2334@item --no-default-excludes
2335When @code{--export-all-symbols} is used, it will by default avoid
2336exporting certain special symbols. The current list of symbols to avoid
2337exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
2338@samp{impure_ptr}. You may use the @code{--no-default-excludes} option
2339to go ahead and export these special symbols. This is only meaningful
2340when @code{--export-all-symbols} is used.
2341
2342@item -S @var{path}
2343@itemx --as @var{path}
2344Specifies the path, including the filename, of the assembler to be used
2345to create the exports file.
2346
2347@item -f @var{switches}
2348@itemx --as-flags @var{switches}
2349Specifies any specific command line switches to be passed to the
2350assembler when building the exports file. This option will work even if
2351the @samp{-S} option is not used. This option only takes one argument,
2352and if it occurs more than once on the command line, then later
2353occurrences will override earlier occurrences. So if it is necessary to
2354pass multiple switches to the assembler they should be enclosed in
2355double quotes.
2356
2357@item -D @var{name}
2358@itemx --dll-name @var{name}
2359Specifies the name to be stored in the .def file as the name of the DLL
2360when the @samp{-e} option is used. If this option is not present, then
2361the filename given to the @samp{-e} option will be used as the name of
2362the DLL.
2363
2364@item -m @var{machine}
2365@itemx -machine @var{machine}
2366Specifies the type of machine for which the library file should be
2367built. @code{dlltool} has a built in default type, depending upon how
2368it was created, but this option can be used to override that. This is
2369normally only useful when creating DLLs for an ARM processor, when the
2370contents of the DLL are actually encode using THUMB instructions.
2371
2372@item -a
2373@itemx --add-indirect
2374Specifies that when @code{dlltool} is creating the exports file it
2375should add a section which allows the exported functions to be
2376referenced without using the import library. Whatever the hell that
2377means!
2378
2379@item -U
2380@itemx --add-underscore
2381Specifies that when @code{dlltool} is creating the exports file it
2382should prepend an underscore to the names of the exported functions.
2383
2384@item -k
2385@itemx --kill-at
2386Specifies that when @code{dlltool} is creating the exports file it
2387should not append the string @samp{@@ <number>}. These numbers are
2388called ordinal numbers and they represent another way of accessing the
2389function in a DLL, other than by name.
2390
2391@item -A
2392@itemx --add-stdcall-alias
2393Specifies that when @code{dlltool} is creating the exports file it
2394should add aliases for stdcall symbols without @samp{@@ <number>}
2395in addition to the symbols with @samp{@@ <number>}.
2396
2397@item -x
2398@itemx --no-idata4
2399Specifies that when @code{dlltool} is creating the exports and library
2400files it should omit the .idata4 section. This is for compatibility
2401with certain operating systems.
2402
2403@item -c
2404@itemx --no-idata5
2405Specifies that when @code{dlltool} is creating the exports and library
2406files it should omit the .idata5 section. This is for compatibility
2407with certain operating systems.
2408
2409@item -i
2410@itemx --interwork
2411Specifies that @code{dlltool} should mark the objects in the library
2412file and exports file that it produces as supporting interworking
2413between ARM and THUMB code.
2414
2415@item -n
2416@itemx --nodelete
2417Makes @code{dlltool} preserve the temporary assembler files it used to
2418create the exports file. If this option is repeated then dlltool will
2419also preserve the temporary object files it uses to create the library
2420file.
2421
2422@item -v
2423@itemx --verbose
2424Make dlltool describe what it is doing.
2425
2426@item -h
2427@itemx --help
2428Displays a list of command line options and then exits.
2429
2430@item -V
2431@itemx --version
2432Displays dlltool's version number and then exits.
2433
2434@end table
2435
2436@node readelf
2437@chapter readelf
2438
2439@cindex ELF file information
2440@kindex readelf
2441
2442@smallexample
2443readelf [ -a | --all ]
2444 [ -h | --file-header]
2445 [ -l | --program-headers | --segments]
2446 [ -S | --section-headers | --sections]
2447 [ -e | --headers]
2448 [ -s | --syms | --symbols]
779fe533 2449 [ -n | --notes]
252b5132
RH
2450 [ -r | --relocs]
2451 [ -d | --dynamic]
2452 [ -V | --version-info]
2453 [ -D | --use-dynamic]
2454 [ -x <number> | --hex-dump=<number>]
2455 [ -w[liapr] | --debug-dump[=info,=line,=abbrev,=pubnames,=ranges]]
2456 [ --histogram]
2457 [ -v | --version]
2458 [ -H | --help]
2459 @var{elffile}@dots{}
2460@end smallexample
2461
2462@code{readelf} displays information about one or more ELF format object
2463files. The options control what particular information to display.
2464
2465@var{elffile}@dots{} are the object files to be examined. At the
2466moment, @code{readelf} does not support examining archives, nor does it
2467support examing 64 bit ELF files.
2468
2469The long and short forms of options, shown here as alternatives, are
2470equivalent. At least one option besides @samp{-v} or @samp{-H} must be
2471given.
2472
2473@table @code
2474@item -a
2475@itemx --all
2476Equivalent to specifiying @samp{--file-header},
2477@samp{--program-headers}, @samp{--sections}, @samp{--symbols},
779fe533
NC
2478@samp{--relocs}, @samp{--dynamic}, @samp{--notes} and
2479@samp{--version-info}.
252b5132
RH
2480
2481@item -h
2482@itemx --file-header
2483@cindex ELF file header information
2484Displays the information contained in the ELF header at the start of the
2485file.
2486
2487@item -l
2488@itemx --program-headers
2489@itemx --segments
2490@cindex ELF program header information
2491@cindex ELF segment information
2492Displays the information contained in the file's segment headers, if it
2493has any.
2494
2495@item -S
2496@itemx --sections
2497@itemx --section-headers
2498@cindex ELF section information
2499Displays the information contained in the file's section headers, if it
2500has any.
2501
2502@item -s
2503@itemx --symbols
2504@itemx --syms
2505@cindex ELF symbol table information
2506Displays the entries in symbol table section of the file, if it has one.
2507
2508@item -e
2509@itemx --headers
2510Display all the headers in the file. Equivalent to @samp{-h -l -S}.
2511
779fe533
NC
2512@item -n
2513@itemx --notes
2514@cindex ELF core notes
2515Displays the contents of the NOTE segment, if it exists.
2516
252b5132
RH
2517@item -r
2518@itemx --relocs
2519@cindex ELF reloc information
2520Displays the contents of the file's relocation section, if it ha one.
2521
2522@item -d
2523@itemx --dynamic
2524@cindex ELF dynamic section information
2525Displays the contents of the file's dynamic section, if it has one.
2526
2527@item -V
2528@itemx --version-info
2529@cindex ELF version sections informations
2530Displays the contents of the version sections in the file, it they
2531exist.
2532
2533@item -D
2534@itemx --use-dynamic
2535When displaying symbols, this option makes @code{readelf} use the
6dbb55b6 2536symbol table in the file's dynamic section, rather than the one in the
252b5132
RH
2537symbols section.
2538
2539@item -x <number>
2540@itemx --hex-dump=<number>
2541Displays the contents of the indicated section as a hexadecimal dump.
2542
2543@item -w[liapr]
2544@itemx --debug-dump[=line,=info,=abbrev,=pubnames,=ranges]
2545Displays the contents of the debug sections in the file, if any are
2546present. If one of the optional letters or words follows the switch
2547then only data found in those specific sections will be dumped.
2548
2549@item --histogram
2550Display a histogram of bucket list lengths when displaying the contents
2551of the symbol tables.
2552
2553@item -v
2554@itemx --version
2555Display the version number of readelf.
2556
2557@item -H
2558@itemx --help
2559Display the command line options understood by @code{readelf}.
2560
2561@end table
2562
2563
2564@node Selecting The Target System
2565@chapter Selecting the target system
2566
2567You can specify three aspects of the target system to the @sc{gnu}
2568binary file utilities, each in several ways:
2569
2570@itemize @bullet
2571@item
2572the target
2573
2574@item
2575the architecture
2576
2577@item
2578the linker emulation (which applies to the linker only)
2579@end itemize
2580
2581In the following summaries, the lists of ways to specify values are in
2582order of decreasing precedence. The ways listed first override those
2583listed later.
2584
2585The commands to list valid values only list the values for which the
2586programs you are running were configured. If they were configured with
2587@samp{--enable-targets=all}, the commands list most of the available
2588values, but a few are left out; not all targets can be configured in at
2589once because some of them can only be configured @dfn{native} (on hosts
2590with the same type as the target system).
2591
2592@menu
2593* Target Selection::
2594* Architecture Selection::
2595* Linker Emulation Selection::
2596@end menu
2597
2598@node Target Selection
2599@section Target Selection
2600
2601A @dfn{target} is an object file format. A given target may be
2602supported for multiple architectures (@pxref{Architecture Selection}).
2603A target selection may also have variations for different operating
2604systems or architectures.
2605
2606The command to list valid target values is @samp{objdump -i}
2607(the first column of output contains the relevant information).
2608
2609Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
2610@samp{a.out-sunos-big}.
2611
2612You can also specify a target using a configuration triplet. This is
f20a759a
ILT
2613the same sort of name that is passed to @file{configure} to specify a
2614target. When you use a configuration triplet as an argument, it must be
2615fully canonicalized. You can see the canonical version of a triplet by
252b5132
RH
2616running the shell script @file{config.sub} which is included with the
2617sources.
2618
2619Some sample configuration triplets are: @samp{m68k-hp-bsd},
2620@samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
2621
2622@subheading @code{objdump} Target
2623
2624Ways to specify:
2625
2626@enumerate
2627@item
2628command line option: @samp{-b} or @samp{--target}
2629
2630@item
2631environment variable @code{GNUTARGET}
2632
2633@item
2634deduced from the input file
2635@end enumerate
2636
2637@subheading @code{objcopy} and @code{strip} Input Target
2638
2639Ways to specify:
2640
2641@enumerate
2642@item
2643command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
2644
2645@item
2646environment variable @code{GNUTARGET}
2647
2648@item
2649deduced from the input file
2650@end enumerate
2651
2652@subheading @code{objcopy} and @code{strip} Output Target
2653
2654Ways to specify:
2655
2656@enumerate
2657@item
2658command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
2659
2660@item
2661the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
2662
2663@item
2664environment variable @code{GNUTARGET}
2665
2666@item
2667deduced from the input file
2668@end enumerate
2669
2670@subheading @code{nm}, @code{size}, and @code{strings} Target
2671
2672Ways to specify:
2673
2674@enumerate
2675@item
2676command line option: @samp{--target}
2677
2678@item
2679environment variable @code{GNUTARGET}
2680
2681@item
2682deduced from the input file
2683@end enumerate
2684
2685@subheading Linker Input Target
2686
2687Ways to specify:
2688
2689@enumerate
2690@item
2691command line option: @samp{-b} or @samp{--format}
2692(@pxref{Options,,Options,ld.info,Using LD})
2693
2694@item
2695script command @code{TARGET}
2696(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2697
2698@item
2699environment variable @code{GNUTARGET}
2700(@pxref{Environment,,Environment,ld.info,Using LD})
2701
2702@item
2703the default target of the selected linker emulation
2704(@pxref{Linker Emulation Selection})
2705@end enumerate
2706
2707@subheading Linker Output Target
2708
2709Ways to specify:
2710
2711@enumerate
2712@item
2713command line option: @samp{-oformat}
2714(@pxref{Options,,Options,ld.info,Using LD})
2715
2716@item
2717script command @code{OUTPUT_FORMAT}
2718(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2719
2720@item
2721the linker input target (see ``Linker Input Target'' above)
2722@end enumerate
2723
2724@node Architecture Selection
2725@section Architecture selection
2726
2727An @dfn{architecture} is a type of @sc{cpu} on which an object file is
2728to run. Its name may contain a colon, separating the name of the
2729processor family from the name of the particular @sc{cpu}.
2730
2731The command to list valid architecture values is @samp{objdump -i} (the
2732second column contains the relevant information).
2733
2734Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
2735
2736@subheading @code{objdump} Architecture
2737
2738Ways to specify:
2739
2740@enumerate
2741@item
2742command line option: @samp{-m} or @samp{--architecture}
2743
2744@item
2745deduced from the input file
2746@end enumerate
2747
2748@subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
2749
2750Ways to specify:
2751
2752@enumerate
2753@item
2754deduced from the input file
2755@end enumerate
2756
2757@subheading Linker Input Architecture
2758
2759Ways to specify:
2760
2761@enumerate
2762@item
2763deduced from the input file
2764@end enumerate
2765
2766@subheading Linker Output Architecture
2767
2768Ways to specify:
2769
2770@enumerate
2771@item
2772script command @code{OUTPUT_ARCH}
2773(@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2774
2775@item
2776the default architecture from the linker output target
2777(@pxref{Target Selection})
2778@end enumerate
2779
2780@node Linker Emulation Selection
2781@section Linker emulation selection
2782
2783A linker @dfn{emulation} is a ``personality'' of the linker, which gives
2784the linker default values for the other aspects of the target system.
2785In particular, it consists of
2786
2787@itemize @bullet
2788@item
2789the linker script
2790
2791@item
2792the target
2793
2794@item
2795several ``hook'' functions that are run at certain stages of the linking
2796process to do special things that some targets require
2797@end itemize
2798
2799The command to list valid linker emulation values is @samp{ld -V}.
2800
2801Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
2802
2803Ways to specify:
2804
2805@enumerate
2806@item
2807command line option: @samp{-m}
2808(@pxref{Options,,Options,ld.info,Using LD})
2809
2810@item
2811environment variable @code{LDEMULATION}
2812
2813@item
2814compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2815which comes from @code{EMUL} in @file{config/@var{target}.mt}
2816@end enumerate
2817
2818@node Reporting Bugs
2819@chapter Reporting Bugs
2820@cindex bugs
2821@cindex reporting bugs
2822
2823Your bug reports play an essential role in making the binary utilities
2824reliable.
2825
2826Reporting a bug may help you by bringing a solution to your problem, or
2827it may not. But in any case the principal function of a bug report is
2828to help the entire community by making the next version of the binary
2829utilities work better. Bug reports are your contribution to their
2830maintenance.
2831
2832In order for a bug report to serve its purpose, you must include the
2833information that enables us to fix the bug.
2834
2835@menu
2836* Bug Criteria:: Have you found a bug?
2837* Bug Reporting:: How to report bugs
2838@end menu
2839
2840@node Bug Criteria
2841@section Have you found a bug?
2842@cindex bug criteria
2843
2844If you are not sure whether you have found a bug, here are some guidelines:
2845
2846@itemize @bullet
2847@cindex fatal signal
2848@cindex crash
2849@item
2850If a binary utility gets a fatal signal, for any input whatever, that is
2851a bug. Reliable utilities never crash.
2852
2853@cindex error on valid input
2854@item
2855If a binary utility produces an error message for valid input, that is a
2856bug.
2857
2858@item
2859If you are an experienced user of binary utilities, your suggestions for
2860improvement are welcome in any case.
2861@end itemize
2862
2863@node Bug Reporting
2864@section How to report bugs
2865@cindex bug reports
2866@cindex bugs, reporting
2867
2868A number of companies and individuals offer support for @sc{gnu}
2869products. If you obtained the binary utilities from a support
2870organization, we recommend you contact that organization first.
2871
2872You can find contact information for many support companies and
2873individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2874distribution.
2875
2876In any event, we also recommend that you send bug reports for the binary
2877utilities to @samp{bug-gnu-utils@@gnu.org}.
2878
2879The fundamental principle of reporting bugs usefully is this:
2880@strong{report all the facts}. If you are not sure whether to state a
2881fact or leave it out, state it!
2882
2883Often people omit facts because they think they know what causes the
2884problem and assume that some details do not matter. Thus, you might
2885assume that the name of a file you use in an example does not matter.
2886Well, probably it does not, but one cannot be sure. Perhaps the bug is
2887a stray memory reference which happens to fetch from the location where
2888that pathname is stored in memory; perhaps, if the pathname were
2889different, the contents of that location would fool the utility into
2890doing the right thing despite the bug. Play it safe and give a
2891specific, complete example. That is the easiest thing for you to do,
2892and the most helpful.
2893
2894Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2895it is new to us. Therefore, always write your bug reports on the assumption
2896that the bug has not been reported previously.
2897
2898Sometimes people give a few sketchy facts and ask, ``Does this ring a
2899bell?'' Those bug reports are useless, and we urge everyone to
2900@emph{refuse to respond to them} except to chide the sender to report
2901bugs properly.
2902
2903To enable us to fix the bug, you should include all these things:
2904
2905@itemize @bullet
2906@item
2907The version of the utility. Each utility announces it if you start it
2908with the @samp{--version} argument.
2909
2910Without this, we will not know whether there is any point in looking for
2911the bug in the current version of the binary utilities.
2912
2913@item
2914Any patches you may have applied to the source, including any patches
2915made to the @code{BFD} library.
2916
2917@item
2918The type of machine you are using, and the operating system name and
2919version number.
2920
2921@item
2922What compiler (and its version) was used to compile the utilities---e.g.
2923``@code{gcc-2.7}''.
2924
2925@item
2926The command arguments you gave the utility to observe the bug. To
2927guarantee you will not omit something important, list them all. A copy
2928of the Makefile (or the output from make) is sufficient.
2929
2930If we were to try to guess the arguments, we would probably guess wrong
2931and then we might not encounter the bug.
2932
2933@item
2934A complete input file, or set of input files, that will reproduce the
2935bug. If the utility is reading an object file or files, then it is
2936generally most helpful to send the actual object files, uuencoded if
757acbc5
ILT
2937necessary to get them through the mail system. Note that
2938@samp{bug-gnu-utils@@gnu.org} is a mailing list, so you should avoid
2939sending very large files to it. Making the files available for
2940anonymous FTP is OK.
252b5132
RH
2941
2942If the source files were produced exclusively using @sc{gnu} programs
2943(e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2944may be OK to send the source files rather than the object files. In
2945this case, be sure to say exactly what version of @code{gcc}, or
2946whatever, was used to produce the object files. Also say how
2947@code{gcc}, or whatever, was configured.
2948
2949@item
2950A description of what behavior you observe that you believe is
2951incorrect. For example, ``It gets a fatal signal.''
2952
2953Of course, if the bug is that the utility gets a fatal signal, then we
2954will certainly notice it. But if the bug is incorrect output, we might
2955not notice unless it is glaringly wrong. You might as well not give us
2956a chance to make a mistake.
2957
2958Even if the problem you experience is a fatal signal, you should still
f20a759a 2959say so explicitly. Suppose something strange is going on, such as your
252b5132
RH
2960copy of the utility is out of synch, or you have encountered a bug in
2961the C library on your system. (This has happened!) Your copy might
2962crash and ours would not. If you told us to expect a crash, then when
2963ours fails to crash, we would know that the bug was not happening for
2964us. If you had not told us to expect a crash, then we would not be able
2965to draw any conclusion from our observations.
2966
2967@item
2968If you wish to suggest changes to the source, send us context diffs, as
2969generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2970option. Always send diffs from the old file to the new file. If you
f20a759a
ILT
2971wish to discuss something in the @code{ld} source, refer to it by
2972context, not by line number.
252b5132
RH
2973
2974The line numbers in our development sources will not match those in your
2975sources. Your line numbers would convey no useful information to us.
2976@end itemize
2977
2978Here are some things that are not necessary:
2979
2980@itemize @bullet
2981@item
2982A description of the envelope of the bug.
2983
2984Often people who encounter a bug spend a lot of time investigating
2985which changes to the input file will make the bug go away and which
2986changes will not affect it.
2987
2988This is often time consuming and not very useful, because the way we
2989will find the bug is by running a single example under the debugger
2990with breakpoints, not by pure deduction from a series of examples.
2991We recommend that you save your time for something else.
2992
2993Of course, if you can find a simpler example to report @emph{instead}
2994of the original one, that is a convenience for us. Errors in the
2995output will be easier to spot, running under the debugger will take
2996less time, and so on.
2997
2998However, simplification is not vital; if you do not want to do this,
2999report the bug anyway and send us the entire test case you used.
3000
3001@item
3002A patch for the bug.
3003
3004A patch for the bug does help us if it is a good one. But do not omit
3005the necessary information, such as the test case, on the assumption that
3006a patch is all we need. We might see problems with your patch and decide
3007to fix the problem another way, or we might not understand it at all.
3008
3009Sometimes with programs as complicated as the binary utilities it is
3010very hard to construct an example that will make the program follow a
3011certain path through the code. If you do not send us the example, we
3012will not be able to construct one, so we will not be able to verify that
3013the bug is fixed.
3014
3015And if we cannot understand what bug you are trying to fix, or why your
3016patch should be an improvement, we will not install it. A test case will
3017help us to understand.
3018
3019@item
3020A guess about what the bug is or what it depends on.
3021
3022Such guesses are usually wrong. Even we cannot guess right about such
3023things without first using the debugger to find the facts.
3024@end itemize
3025
3026@node Index
3027@unnumbered Index
3028
3029@printindex cp
3030
3031@contents
3032@bye