binutils/
[deliverable/binutils-gdb.git] / binutils / doc / binutils.texi
1 \input texinfo @c -*- Texinfo -*-
2 @setfilename binutils.info
3 @c Copyright 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
4
5 @c man begin INCLUDE
6 @include config.texi
7 @c man end
8
9 @ifinfo
10 @format
11 START-INFO-DIR-ENTRY
12 * Binutils: (binutils). The GNU binary utilities.
13 * ar: (binutils)ar. Create, modify, and extract from archives
14 * nm: (binutils)nm. List symbols from object files
15 * objcopy: (binutils)objcopy. Copy and translate object files
16 * objdump: (binutils)objdump. Display information from object files
17 * ranlib: (binutils)ranlib. Generate index to archive contents
18 * readelf: (binutils)readelf. Display the contents of ELF format files.
19 * size: (binutils)size. List section sizes and total size
20 * strings: (binutils)strings. List printable strings from files
21 * strip: (binutils)strip. Discard symbols
22 * c++filt: (binutils)c++filt. Filter to demangle encoded C++ symbols
23 * cxxfilt: (binutils)c++filt. MS-DOS name for c++filt
24 * addr2line: (binutils)addr2line. Convert addresses to file and line
25 * nlmconv: (binutils)nlmconv. Converts object code into an NLM
26 * windres: (binutils)windres. Manipulate Windows resources
27 * dlltool: (binutils)dlltool. Create files needed to build and use DLLs
28 END-INFO-DIR-ENTRY
29 @end format
30 @end ifinfo
31
32 @ifinfo
33 @c man begin COPYRIGHT
34 Copyright @copyright{} 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
35 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
36
37 Permission is granted to copy, distribute and/or modify this document
38 under the terms of the GNU Free Documentation License, Version 1.1
39 or any later version published by the Free Software Foundation;
40 with no Invariant Sections, with no Front-Cover Texts, and with no
41 Back-Cover Texts. A copy of the license is included in the
42 section entitled ``GNU Free Documentation License''.
43
44 @c man end
45 @ignore
46 Permission is granted to process this file through TeX and print the
47 results, provided the printed document carries a copying permission
48 notice identical to this one except for the removal of this paragraph
49 (this paragraph not being relevant to the printed manual).
50
51 @end ignore
52 @end ifinfo
53
54 @synindex ky cp
55 @c
56 @c This file documents the GNU binary utilities "ar", "ld", "objcopy",
57 @c "objdump", "nm", "size", "strings", "strip", "readelf" and "ranlib".
58 @c
59 @c Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
60 @c 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
61 @c
62 @c This text may be freely distributed under the terms of the GNU
63 @c Free Documentation License.
64 @c
65
66 @setchapternewpage odd
67 @settitle @sc{gnu} Binary Utilities
68 @titlepage
69 @finalout
70 @title The @sc{gnu} Binary Utilities
71 @subtitle Version @value{VERSION}
72 @sp 1
73 @subtitle @value{UPDATED}
74 @author Roland H. Pesch
75 @author Jeffrey M. Osier
76 @author Cygnus Support
77 @page
78
79 @tex
80 {\parskip=0pt \hfill Cygnus Support\par \hfill
81 \TeX{}info \texinfoversion\par }
82 @end tex
83
84 @vskip 0pt plus 1filll
85 Copyright @copyright{} 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
86 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
87
88 Permission is granted to copy, distribute and/or modify this document
89 under the terms of the GNU Free Documentation License, Version 1.1
90 or any later version published by the Free Software Foundation;
91 with no Invariant Sections, with no Front-Cover Texts, and with no
92 Back-Cover Texts. A copy of the license is included in the
93 section entitled ``GNU Free Documentation License''.
94
95 @end titlepage
96
97 @node Top
98 @top Introduction
99
100 @cindex version
101 This brief manual contains documentation for the @sc{gnu} binary
102 utilities (collectively version @value{VERSION}):
103
104 @iftex
105 @table @code
106 @item ar
107 Create, modify, and extract from archives
108
109 @item nm
110 List symbols from object files
111
112 @item objcopy
113 Copy and translate object files
114
115 @item objdump
116 Display information from object files
117
118 @item ranlib
119 Generate index to archive contents
120
121 @item readelf
122 Display the contents of ELF format files.
123
124 @item size
125 List file section sizes and total size
126
127 @item strings
128 List printable strings from files
129
130 @item strip
131 Discard symbols
132
133 @item c++filt
134 Demangle encoded C++ symbols (on MS-DOS, this program is named
135 @code{cxxfilt})
136
137 @item addr2line
138 Convert addresses into file names and line numbers
139
140 @item nlmconv
141 Convert object code into a Netware Loadable Module
142
143 @item windres
144 Manipulate Windows resources
145
146 @item dlltool
147 Create the files needed to build and use Dynamic Link Libraries
148 @end table
149 @end iftex
150
151 This document is distributed under the terms of the GNU Free
152 Documentation License. A copy of the license is included in the
153 section entitled "GNU Free Documentation License".
154
155 @menu
156 * ar:: Create, modify, and extract from archives
157 * nm:: List symbols from object files
158 * objcopy:: Copy and translate object files
159 * objdump:: Display information from object files
160 * ranlib:: Generate index to archive contents
161 * readelf:: Display the contents of ELF format files.
162 * size:: List section sizes and total size
163 * strings:: List printable strings from files
164 * strip:: Discard symbols
165 * c++filt:: Filter to demangle encoded C++ symbols
166 * cxxfilt: c++filt. MS-DOS name for c++filt
167 * addr2line:: Convert addresses to file and line
168 * nlmconv:: Converts object code into an NLM
169 * windres:: Manipulate Windows resources
170 * dlltool:: Create files needed to build and use DLLs
171 * Common Options:: Command-line options for all utilities
172 * Selecting The Target System:: How these utilities determine the target.
173 * Reporting Bugs:: Reporting Bugs
174 * GNU Free Documentation License:: GNU Free Documentation License
175 * Binutils Index:: Binutils Index
176 @end menu
177
178 @node ar
179 @chapter ar
180
181 @kindex ar
182 @cindex archives
183 @cindex collections of files
184
185 @c man title ar create, modify, and extract from archives
186
187 @smallexample
188 ar [-]@var{p}[@var{mod} [@var{relpos}] [@var{count}]] @var{archive} [@var{member}@dots{}]
189 ar -M [ <mri-script ]
190 @end smallexample
191
192 @c man begin DESCRIPTION ar
193
194 The @sc{gnu} @command{ar} program creates, modifies, and extracts from
195 archives. An @dfn{archive} is a single file holding a collection of
196 other files in a structure that makes it possible to retrieve
197 the original individual files (called @dfn{members} of the archive).
198
199 The original files' contents, mode (permissions), timestamp, owner, and
200 group are preserved in the archive, and can be restored on
201 extraction.
202
203 @cindex name length
204 @sc{gnu} @command{ar} can maintain archives whose members have names of any
205 length; however, depending on how @command{ar} is configured on your
206 system, a limit on member-name length may be imposed for compatibility
207 with archive formats maintained with other tools. If it exists, the
208 limit is often 15 characters (typical of formats related to a.out) or 16
209 characters (typical of formats related to coff).
210
211 @cindex libraries
212 @command{ar} is considered a binary utility because archives of this sort
213 are most often used as @dfn{libraries} holding commonly needed
214 subroutines.
215
216 @cindex symbol index
217 @command{ar} creates an index to the symbols defined in relocatable
218 object modules in the archive when you specify the modifier @samp{s}.
219 Once created, this index is updated in the archive whenever @command{ar}
220 makes a change to its contents (save for the @samp{q} update operation).
221 An archive with such an index speeds up linking to the library, and
222 allows routines in the library to call each other without regard to
223 their placement in the archive.
224
225 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
226 table. If an archive lacks the table, another form of @command{ar} called
227 @command{ranlib} can be used to add just the table.
228
229 @cindex compatibility, @command{ar}
230 @cindex @command{ar} compatibility
231 @sc{gnu} @command{ar} is designed to be compatible with two different
232 facilities. You can control its activity using command-line options,
233 like the different varieties of @command{ar} on Unix systems; or, if you
234 specify the single command-line option @option{-M}, you can control it
235 with a script supplied via standard input, like the MRI ``librarian''
236 program.
237
238 @c man end
239
240 @menu
241 * ar cmdline:: Controlling @command{ar} on the command line
242 * ar scripts:: Controlling @command{ar} with a script
243 @end menu
244
245 @page
246 @node ar cmdline
247 @section Controlling @command{ar} on the Command Line
248
249 @smallexample
250 @c man begin SYNOPSIS ar
251 ar [@option{-X32_64}] [@option{-}]@var{p}[@var{mod} [@var{relpos}] [@var{count}]] @var{archive} [@var{member}@dots{}]
252 @c man end
253 @end smallexample
254
255 @cindex Unix compatibility, @command{ar}
256 When you use @command{ar} in the Unix style, @command{ar} insists on at least two
257 arguments to execute: one keyletter specifying the @emph{operation}
258 (optionally accompanied by other keyletters specifying
259 @emph{modifiers}), and the archive name to act on.
260
261 Most operations can also accept further @var{member} arguments,
262 specifying particular files to operate on.
263
264 @c man begin OPTIONS ar
265
266 @sc{gnu} @command{ar} allows you to mix the operation code @var{p} and modifier
267 flags @var{mod} in any order, within the first command-line argument.
268
269 If you wish, you may begin the first command-line argument with a
270 dash.
271
272 @cindex operations on archive
273 The @var{p} keyletter specifies what operation to execute; it may be
274 any of the following, but you must specify only one of them:
275
276 @table @samp
277 @item d
278 @cindex deleting from archive
279 @emph{Delete} modules from the archive. Specify the names of modules to
280 be deleted as @var{member}@dots{}; the archive is untouched if you
281 specify no files to delete.
282
283 If you specify the @samp{v} modifier, @command{ar} lists each module
284 as it is deleted.
285
286 @item m
287 @cindex moving in archive
288 Use this operation to @emph{move} members in an archive.
289
290 The ordering of members in an archive can make a difference in how
291 programs are linked using the library, if a symbol is defined in more
292 than one member.
293
294 If no modifiers are used with @code{m}, any members you name in the
295 @var{member} arguments are moved to the @emph{end} of the archive;
296 you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
297 specified place instead.
298
299 @item p
300 @cindex printing from archive
301 @emph{Print} the specified members of the archive, to the standard
302 output file. If the @samp{v} modifier is specified, show the member
303 name before copying its contents to standard output.
304
305 If you specify no @var{member} arguments, all the files in the archive are
306 printed.
307
308 @item q
309 @cindex quick append to archive
310 @emph{Quick append}; Historically, add the files @var{member}@dots{} to the end of
311 @var{archive}, without checking for replacement.
312
313 The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
314 operation; new members are always placed at the end of the archive.
315
316 The modifier @samp{v} makes @command{ar} list each file as it is appended.
317
318 Since the point of this operation is speed, the archive's symbol table
319 index is not updated, even if it already existed; you can use @samp{ar s} or
320 @command{ranlib} explicitly to update the symbol table index.
321
322 However, too many different systems assume quick append rebuilds the
323 index, so @sc{gnu} @command{ar} implements @samp{q} as a synonym for @samp{r}.
324
325 @item r
326 @cindex replacement in archive
327 Insert the files @var{member}@dots{} into @var{archive} (with
328 @emph{replacement}). This operation differs from @samp{q} in that any
329 previously existing members are deleted if their names match those being
330 added.
331
332 If one of the files named in @var{member}@dots{} does not exist, @command{ar}
333 displays an error message, and leaves undisturbed any existing members
334 of the archive matching that name.
335
336 By default, new members are added at the end of the file; but you may
337 use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
338 placement relative to some existing member.
339
340 The modifier @samp{v} used with this operation elicits a line of
341 output for each file inserted, along with one of the letters @samp{a} or
342 @samp{r} to indicate whether the file was appended (no old member
343 deleted) or replaced.
344
345 @item t
346 @cindex contents of archive
347 Display a @emph{table} listing the contents of @var{archive}, or those
348 of the files listed in @var{member}@dots{} that are present in the
349 archive. Normally only the member name is shown; if you also want to
350 see the modes (permissions), timestamp, owner, group, and size, you can
351 request that by also specifying the @samp{v} modifier.
352
353 If you do not specify a @var{member}, all files in the archive
354 are listed.
355
356 @cindex repeated names in archive
357 @cindex name duplication in archive
358 If there is more than one file with the same name (say, @samp{fie}) in
359 an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
360 first instance; to see them all, you must ask for a complete
361 listing---in our example, @samp{ar t b.a}.
362 @c WRS only; per Gumby, this is implementation-dependent, and in a more
363 @c recent case in fact works the other way.
364
365 @item x
366 @cindex extract from archive
367 @emph{Extract} members (named @var{member}) from the archive. You can
368 use the @samp{v} modifier with this operation, to request that
369 @command{ar} list each name as it extracts it.
370
371 If you do not specify a @var{member}, all files in the archive
372 are extracted.
373
374 @end table
375
376 A number of modifiers (@var{mod}) may immediately follow the @var{p}
377 keyletter, to specify variations on an operation's behavior:
378
379 @table @samp
380 @item a
381 @cindex relative placement in archive
382 Add new files @emph{after} an existing member of the
383 archive. If you use the modifier @samp{a}, the name of an existing archive
384 member must be present as the @var{relpos} argument, before the
385 @var{archive} specification.
386
387 @item b
388 Add new files @emph{before} an existing member of the
389 archive. If you use the modifier @samp{b}, the name of an existing archive
390 member must be present as the @var{relpos} argument, before the
391 @var{archive} specification. (same as @samp{i}).
392
393 @item c
394 @cindex creating archives
395 @emph{Create} the archive. The specified @var{archive} is always
396 created if it did not exist, when you request an update. But a warning is
397 issued unless you specify in advance that you expect to create it, by
398 using this modifier.
399
400 @item f
401 Truncate names in the archive. @sc{gnu} @command{ar} will normally permit file
402 names of any length. This will cause it to create archives which are
403 not compatible with the native @command{ar} program on some systems. If
404 this is a concern, the @samp{f} modifier may be used to truncate file
405 names when putting them in the archive.
406
407 @item i
408 Insert new files @emph{before} an existing member of the
409 archive. If you use the modifier @samp{i}, the name of an existing archive
410 member must be present as the @var{relpos} argument, before the
411 @var{archive} specification. (same as @samp{b}).
412
413 @item l
414 This modifier is accepted but not used.
415 @c whaffor ar l modifier??? presumably compat; with
416 @c what???---doc@@cygnus.com, 25jan91
417
418 @item N
419 Uses the @var{count} parameter. This is used if there are multiple
420 entries in the archive with the same name. Extract or delete instance
421 @var{count} of the given name from the archive.
422
423 @item o
424 @cindex dates in archive
425 Preserve the @emph{original} dates of members when extracting them. If
426 you do not specify this modifier, files extracted from the archive
427 are stamped with the time of extraction.
428
429 @item P
430 Use the full path name when matching names in the archive. @sc{gnu}
431 @command{ar} can not create an archive with a full path name (such archives
432 are not POSIX complaint), but other archive creators can. This option
433 will cause @sc{gnu} @command{ar} to match file names using a complete path
434 name, which can be convenient when extracting a single file from an
435 archive created by another tool.
436
437 @item s
438 @cindex writing archive index
439 Write an object-file index into the archive, or update an existing one,
440 even if no other change is made to the archive. You may use this modifier
441 flag either with any operation, or alone. Running @samp{ar s} on an
442 archive is equivalent to running @samp{ranlib} on it.
443
444 @item S
445 @cindex not writing archive index
446 Do not generate an archive symbol table. This can speed up building a
447 large library in several steps. The resulting archive can not be used
448 with the linker. In order to build a symbol table, you must omit the
449 @samp{S} modifier on the last execution of @samp{ar}, or you must run
450 @samp{ranlib} on the archive.
451
452 @item u
453 @cindex updating an archive
454 Normally, @samp{ar r}@dots{} inserts all files
455 listed into the archive. If you would like to insert @emph{only} those
456 of the files you list that are newer than existing members of the same
457 names, use this modifier. The @samp{u} modifier is allowed only for the
458 operation @samp{r} (replace). In particular, the combination @samp{qu} is
459 not allowed, since checking the timestamps would lose any speed
460 advantage from the operation @samp{q}.
461
462 @item v
463 This modifier requests the @emph{verbose} version of an operation. Many
464 operations display additional information, such as filenames processed,
465 when the modifier @samp{v} is appended.
466
467 @item V
468 This modifier shows the version number of @command{ar}.
469 @end table
470
471 @command{ar} ignores an initial option spelt @samp{-X32_64}, for
472 compatibility with AIX. The behaviour produced by this option is the
473 default for @sc{gnu} @command{ar}. @command{ar} does not support any of the other
474 @samp{-X} options; in particular, it does not support @option{-X32}
475 which is the default for AIX @command{ar}.
476
477 @c man end
478
479 @ignore
480 @c man begin SEEALSO ar
481 nm(1), ranlib(1), and the Info entries for @file{binutils}.
482 @c man end
483 @end ignore
484
485 @node ar scripts
486 @section Controlling @command{ar} with a Script
487
488 @smallexample
489 ar -M [ <@var{script} ]
490 @end smallexample
491
492 @cindex MRI compatibility, @command{ar}
493 @cindex scripts, @command{ar}
494 If you use the single command-line option @samp{-M} with @command{ar}, you
495 can control its operation with a rudimentary command language. This
496 form of @command{ar} operates interactively if standard input is coming
497 directly from a terminal. During interactive use, @command{ar} prompts for
498 input (the prompt is @samp{AR >}), and continues executing even after
499 errors. If you redirect standard input to a script file, no prompts are
500 issued, and @command{ar} abandons execution (with a nonzero exit code)
501 on any error.
502
503 The @command{ar} command language is @emph{not} designed to be equivalent
504 to the command-line options; in fact, it provides somewhat less control
505 over archives. The only purpose of the command language is to ease the
506 transition to @sc{gnu} @command{ar} for developers who already have scripts
507 written for the MRI ``librarian'' program.
508
509 The syntax for the @command{ar} command language is straightforward:
510 @itemize @bullet
511 @item
512 commands are recognized in upper or lower case; for example, @code{LIST}
513 is the same as @code{list}. In the following descriptions, commands are
514 shown in upper case for clarity.
515
516 @item
517 a single command may appear on each line; it is the first word on the
518 line.
519
520 @item
521 empty lines are allowed, and have no effect.
522
523 @item
524 comments are allowed; text after either of the characters @samp{*}
525 or @samp{;} is ignored.
526
527 @item
528 Whenever you use a list of names as part of the argument to an @command{ar}
529 command, you can separate the individual names with either commas or
530 blanks. Commas are shown in the explanations below, for clarity.
531
532 @item
533 @samp{+} is used as a line continuation character; if @samp{+} appears
534 at the end of a line, the text on the following line is considered part
535 of the current command.
536 @end itemize
537
538 Here are the commands you can use in @command{ar} scripts, or when using
539 @command{ar} interactively. Three of them have special significance:
540
541 @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
542 a temporary file required for most of the other commands.
543
544 @code{SAVE} commits the changes so far specified by the script. Prior
545 to @code{SAVE}, commands affect only the temporary copy of the current
546 archive.
547
548 @table @code
549 @item ADDLIB @var{archive}
550 @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
551 Add all the contents of @var{archive} (or, if specified, each named
552 @var{module} from @var{archive}) to the current archive.
553
554 Requires prior use of @code{OPEN} or @code{CREATE}.
555
556 @item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
557 @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
558 @c else like "ar q..."
559 Add each named @var{member} as a module in the current archive.
560
561 Requires prior use of @code{OPEN} or @code{CREATE}.
562
563 @item CLEAR
564 Discard the contents of the current archive, canceling the effect of
565 any operations since the last @code{SAVE}. May be executed (with no
566 effect) even if no current archive is specified.
567
568 @item CREATE @var{archive}
569 Creates an archive, and makes it the current archive (required for many
570 other commands). The new archive is created with a temporary name; it
571 is not actually saved as @var{archive} until you use @code{SAVE}.
572 You can overwrite existing archives; similarly, the contents of any
573 existing file named @var{archive} will not be destroyed until @code{SAVE}.
574
575 @item DELETE @var{module}, @var{module}, @dots{} @var{module}
576 Delete each listed @var{module} from the current archive; equivalent to
577 @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
578
579 Requires prior use of @code{OPEN} or @code{CREATE}.
580
581 @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
582 @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
583 List each named @var{module} present in @var{archive}. The separate
584 command @code{VERBOSE} specifies the form of the output: when verbose
585 output is off, output is like that of @samp{ar -t @var{archive}
586 @var{module}@dots{}}. When verbose output is on, the listing is like
587 @samp{ar -tv @var{archive} @var{module}@dots{}}.
588
589 Output normally goes to the standard output stream; however, if you
590 specify @var{outputfile} as a final argument, @command{ar} directs the
591 output to that file.
592
593 @item END
594 Exit from @command{ar}, with a @code{0} exit code to indicate successful
595 completion. This command does not save the output file; if you have
596 changed the current archive since the last @code{SAVE} command, those
597 changes are lost.
598
599 @item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
600 Extract each named @var{module} from the current archive, writing them
601 into the current directory as separate files. Equivalent to @samp{ar -x
602 @var{archive} @var{module}@dots{}}.
603
604 Requires prior use of @code{OPEN} or @code{CREATE}.
605
606 @ignore
607 @c FIXME Tokens but no commands???
608 @item FULLDIR
609
610 @item HELP
611 @end ignore
612
613 @item LIST
614 Display full contents of the current archive, in ``verbose'' style
615 regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
616 tv @var{archive}}. (This single command is a @sc{gnu} @command{ar}
617 enhancement, rather than present for MRI compatibility.)
618
619 Requires prior use of @code{OPEN} or @code{CREATE}.
620
621 @item OPEN @var{archive}
622 Opens an existing archive for use as the current archive (required for
623 many other commands). Any changes as the result of subsequent commands
624 will not actually affect @var{archive} until you next use @code{SAVE}.
625
626 @item REPLACE @var{module}, @var{module}, @dots{} @var{module}
627 In the current archive, replace each existing @var{module} (named in
628 the @code{REPLACE} arguments) from files in the current working directory.
629 To execute this command without errors, both the file, and the module in
630 the current archive, must exist.
631
632 Requires prior use of @code{OPEN} or @code{CREATE}.
633
634 @item VERBOSE
635 Toggle an internal flag governing the output from @code{DIRECTORY}.
636 When the flag is on, @code{DIRECTORY} output matches output from
637 @samp{ar -tv }@dots{}.
638
639 @item SAVE
640 Commit your changes to the current archive, and actually save it as a
641 file with the name specified in the last @code{CREATE} or @code{OPEN}
642 command.
643
644 Requires prior use of @code{OPEN} or @code{CREATE}.
645
646 @end table
647
648 @iftex
649 @node ld
650 @chapter ld
651 @cindex linker
652 @kindex ld
653 The @sc{gnu} linker @command{ld} is now described in a separate manual.
654 @xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
655 @end iftex
656
657 @node nm
658 @chapter nm
659 @cindex symbols
660 @kindex nm
661
662 @c man title nm list symbols from object files
663
664 @smallexample
665 @c man begin SYNOPSIS nm
666 nm [@option{-a}|@option{--debug-syms}] [@option{-g}|@option{--extern-only}]
667 [@option{-B}] [@option{-C}|@option{--demangle}[=@var{style}]] [@option{-D}|@option{--dynamic}]
668 [@option{-S}|@option{--print-size}] [@option{-s}|@option{--print-armap}]
669 [@option{-A}|@option{-o}|@option{--print-file-name}][@option{--special-syms}]
670 [@option{-n}|@option{-v}|@option{--numeric-sort}] [@option{-p}|@option{--no-sort}]
671 [@option{-r}|@option{--reverse-sort}] [@option{--size-sort}] [@option{-u}|@option{--undefined-only}]
672 [@option{-t} @var{radix}|@option{--radix=}@var{radix}] [@option{-P}|@option{--portability}]
673 [@option{--target=}@var{bfdname}] [@option{-f}@var{format}|@option{--format=}@var{format}]
674 [@option{--defined-only}] [@option{-l}|@option{--line-numbers}] [@option{--no-demangle}]
675 [@option{-V}|@option{--version}] [@option{-X 32_64}] [@option{--help}] [@var{objfile}@dots{}]
676 @c man end
677 @end smallexample
678
679 @c man begin DESCRIPTION nm
680 @sc{gnu} @command{nm} lists the symbols from object files @var{objfile}@dots{}.
681 If no object files are listed as arguments, @command{nm} assumes the file
682 @file{a.out}.
683
684 For each symbol, @command{nm} shows:
685
686 @itemize @bullet
687 @item
688 The symbol value, in the radix selected by options (see below), or
689 hexadecimal by default.
690
691 @item
692 The symbol type. At least the following types are used; others are, as
693 well, depending on the object file format. If lowercase, the symbol is
694 local; if uppercase, the symbol is global (external).
695
696 @c Some more detail on exactly what these symbol types are used for
697 @c would be nice.
698 @table @code
699 @item A
700 The symbol's value is absolute, and will not be changed by further
701 linking.
702
703 @item B
704 The symbol is in the uninitialized data section (known as BSS).
705
706 @item C
707 The symbol is common. Common symbols are uninitialized data. When
708 linking, multiple common symbols may appear with the same name. If the
709 symbol is defined anywhere, the common symbols are treated as undefined
710 references.
711 @ifclear man
712 For more details on common symbols, see the discussion of
713 --warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
714 @end ifclear
715
716 @item D
717 The symbol is in the initialized data section.
718
719 @item G
720 The symbol is in an initialized data section for small objects. Some
721 object file formats permit more efficient access to small data objects,
722 such as a global int variable as opposed to a large global array.
723
724 @item I
725 The symbol is an indirect reference to another symbol. This is a @sc{gnu}
726 extension to the a.out object file format which is rarely used.
727
728 @item N
729 The symbol is a debugging symbol.
730
731 @item R
732 The symbol is in a read only data section.
733
734 @item S
735 The symbol is in an uninitialized data section for small objects.
736
737 @item T
738 The symbol is in the text (code) section.
739
740 @item U
741 The symbol is undefined.
742
743 @item V
744 The symbol is a weak object. When a weak defined symbol is linked with
745 a normal defined symbol, the normal defined symbol is used with no error.
746 When a weak undefined symbol is linked and the symbol is not defined,
747 the value of the weak symbol becomes zero with no error.
748
749 @item W
750 The symbol is a weak symbol that has not been specifically tagged as a
751 weak object symbol. When a weak defined symbol is linked with a normal
752 defined symbol, the normal defined symbol is used with no error.
753 When a weak undefined symbol is linked and the symbol is not defined,
754 the value of the symbol is determined in a system-specific manner without
755 error. On some systems, uppercase indicates that a default value has been
756 specified.
757
758
759 @item -
760 The symbol is a stabs symbol in an a.out object file. In this case, the
761 next values printed are the stabs other field, the stabs desc field, and
762 the stab type. Stabs symbols are used to hold debugging information.
763 @ifclear man
764 For more information, see @ref{Top,Stabs,Stabs Overview,stabs.info, The
765 ``stabs'' debug format}.
766 @end ifclear
767
768 @item ?
769 The symbol type is unknown, or object file format specific.
770 @end table
771
772 @item
773 The symbol name.
774 @end itemize
775
776 @c man end
777
778 @c man begin OPTIONS nm
779 The long and short forms of options, shown here as alternatives, are
780 equivalent.
781
782 @table @env
783 @item -A
784 @itemx -o
785 @itemx --print-file-name
786 @cindex input file name
787 @cindex file name
788 @cindex source file name
789 Precede each symbol by the name of the input file (or archive member)
790 in which it was found, rather than identifying the input file once only,
791 before all of its symbols.
792
793 @item -a
794 @itemx --debug-syms
795 @cindex debugging symbols
796 Display all symbols, even debugger-only symbols; normally these are not
797 listed.
798
799 @item -B
800 @cindex @command{nm} format
801 @cindex @command{nm} compatibility
802 The same as @option{--format=bsd} (for compatibility with the MIPS @command{nm}).
803
804 @item -C
805 @itemx --demangle[=@var{style}]
806 @cindex demangling in nm
807 Decode (@dfn{demangle}) low-level symbol names into user-level names.
808 Besides removing any initial underscore prepended by the system, this
809 makes C++ function names readable. Different compilers have different
810 mangling styles. The optional demangling style argument can be used to
811 choose an appropriate demangling style for your compiler. @xref{c++filt},
812 for more information on demangling.
813
814 @item --no-demangle
815 Do not demangle low-level symbol names. This is the default.
816
817 @item -D
818 @itemx --dynamic
819 @cindex dynamic symbols
820 Display the dynamic symbols rather than the normal symbols. This is
821 only meaningful for dynamic objects, such as certain types of shared
822 libraries.
823
824 @item -f @var{format}
825 @itemx --format=@var{format}
826 @cindex @command{nm} format
827 @cindex @command{nm} compatibility
828 Use the output format @var{format}, which can be @code{bsd},
829 @code{sysv}, or @code{posix}. The default is @code{bsd}.
830 Only the first character of @var{format} is significant; it can be
831 either upper or lower case.
832
833 @item -g
834 @itemx --extern-only
835 @cindex external symbols
836 Display only external symbols.
837
838 @item -l
839 @itemx --line-numbers
840 @cindex symbol line numbers
841 For each symbol, use debugging information to try to find a filename and
842 line number. For a defined symbol, look for the line number of the
843 address of the symbol. For an undefined symbol, look for the line
844 number of a relocation entry which refers to the symbol. If line number
845 information can be found, print it after the other symbol information.
846
847 @item -n
848 @itemx -v
849 @itemx --numeric-sort
850 Sort symbols numerically by their addresses, rather than alphabetically
851 by their names.
852
853 @item -p
854 @itemx --no-sort
855 @cindex sorting symbols
856 Do not bother to sort the symbols in any order; print them in the order
857 encountered.
858
859 @item -P
860 @itemx --portability
861 Use the POSIX.2 standard output format instead of the default format.
862 Equivalent to @samp{-f posix}.
863
864 @item -S
865 @itemx --print-size
866 Print size, not the value, of defined symbols for the @code{bsd} output format.
867
868 @item -s
869 @itemx --print-armap
870 @cindex symbol index, listing
871 When listing symbols from archive members, include the index: a mapping
872 (stored in the archive by @command{ar} or @command{ranlib}) of which modules
873 contain definitions for which names.
874
875 @item -r
876 @itemx --reverse-sort
877 Reverse the order of the sort (whether numeric or alphabetic); let the
878 last come first.
879
880 @item --size-sort
881 Sort symbols by size. The size is computed as the difference between
882 the value of the symbol and the value of the symbol with the next higher
883 value. If the @code{bsd} output format is used the size of the symbol
884 is printed, rather than the value, and @samp{-S} must be used in order
885 both size and value to be printed.
886
887 @item --special-syms
888 Display symbols which have a target-specific special meaning. These
889 symbols are usually used by the target for some special processing and
890 are not normally helpful when included included in the normal symbol
891 lists. For example for ARM targets this option would skip the mapping
892 symbols used to mark transitions between ARM code, THUMB code and
893 data.
894
895 @item -t @var{radix}
896 @itemx --radix=@var{radix}
897 Use @var{radix} as the radix for printing the symbol values. It must be
898 @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
899
900 @item --target=@var{bfdname}
901 @cindex object code format
902 Specify an object code format other than your system's default format.
903 @xref{Target Selection}, for more information.
904
905 @item -u
906 @itemx --undefined-only
907 @cindex external symbols
908 @cindex undefined symbols
909 Display only undefined symbols (those external to each object file).
910
911 @item --defined-only
912 @cindex external symbols
913 @cindex undefined symbols
914 Display only defined symbols for each object file.
915
916 @item -V
917 @itemx --version
918 Show the version number of @command{nm} and exit.
919
920 @item -X
921 This option is ignored for compatibility with the AIX version of
922 @command{nm}. It takes one parameter which must be the string
923 @option{32_64}. The default mode of AIX @command{nm} corresponds
924 to @option{-X 32}, which is not supported by @sc{gnu} @command{nm}.
925
926 @item --help
927 Show a summary of the options to @command{nm} and exit.
928 @end table
929
930 @c man end
931
932 @ignore
933 @c man begin SEEALSO nm
934 ar(1), objdump(1), ranlib(1), and the Info entries for @file{binutils}.
935 @c man end
936 @end ignore
937
938 @node objcopy
939 @chapter objcopy
940
941 @c man title objcopy copy and translate object files
942
943 @smallexample
944 @c man begin SYNOPSIS objcopy
945 objcopy [@option{-F} @var{bfdname}|@option{--target=}@var{bfdname}]
946 [@option{-I} @var{bfdname}|@option{--input-target=}@var{bfdname}]
947 [@option{-O} @var{bfdname}|@option{--output-target=}@var{bfdname}]
948 [@option{-B} @var{bfdarch}|@option{--binary-architecture=}@var{bfdarch}]
949 [@option{-S}|@option{--strip-all}]
950 [@option{-g}|@option{--strip-debug}]
951 [@option{-K} @var{symbolname}|@option{--keep-symbol=}@var{symbolname}]
952 [@option{-N} @var{symbolname}|@option{--strip-symbol=}@var{symbolname}]
953 [@option{--strip-unneeded-symbol=}@var{symbolname}]
954 [@option{-G} @var{symbolname}|@option{--keep-global-symbol=}@var{symbolname}]
955 [@option{--localize-hidden}]
956 [@option{-L} @var{symbolname}|@option{--localize-symbol=}@var{symbolname}]
957 [@option{--globalize-symbol=}@var{symbolname}]
958 [@option{-W} @var{symbolname}|@option{--weaken-symbol=}@var{symbolname}]
959 [@option{-w}|@option{--wildcard}]
960 [@option{-x}|@option{--discard-all}]
961 [@option{-X}|@option{--discard-locals}]
962 [@option{-b} @var{byte}|@option{--byte=}@var{byte}]
963 [@option{-i} @var{interleave}|@option{--interleave=}@var{interleave}]
964 [@option{-j} @var{sectionname}|@option{--only-section=}@var{sectionname}]
965 [@option{-R} @var{sectionname}|@option{--remove-section=}@var{sectionname}]
966 [@option{-p}|@option{--preserve-dates}]
967 [@option{--debugging}]
968 [@option{--gap-fill=}@var{val}]
969 [@option{--pad-to=}@var{address}]
970 [@option{--set-start=}@var{val}]
971 [@option{--adjust-start=}@var{incr}]
972 [@option{--change-addresses=}@var{incr}]
973 [@option{--change-section-address} @var{section}@{=,+,-@}@var{val}]
974 [@option{--change-section-lma} @var{section}@{=,+,-@}@var{val}]
975 [@option{--change-section-vma} @var{section}@{=,+,-@}@var{val}]
976 [@option{--change-warnings}] [@option{--no-change-warnings}]
977 [@option{--set-section-flags} @var{section}=@var{flags}]
978 [@option{--add-section} @var{sectionname}=@var{filename}]
979 [@option{--rename-section} @var{oldname}=@var{newname}[,@var{flags}]]
980 [@option{--change-leading-char}] [@option{--remove-leading-char}]
981 [@option{--srec-len=}@var{ival}] [@option{--srec-forceS3}]
982 [@option{--redefine-sym} @var{old}=@var{new}]
983 [@option{--redefine-syms=}@var{filename}]
984 [@option{--weaken}]
985 [@option{--keep-symbols=}@var{filename}]
986 [@option{--strip-symbols=}@var{filename}]
987 [@option{--strip-unneeded-symbols=}@var{filename}]
988 [@option{--keep-global-symbols=}@var{filename}]
989 [@option{--localize-symbols=}@var{filename}]
990 [@option{--globalize-symbols=}@var{filename}]
991 [@option{--weaken-symbols=}@var{filename}]
992 [@option{--alt-machine-code=}@var{index}]
993 [@option{--prefix-symbols=}@var{string}]
994 [@option{--prefix-sections=}@var{string}]
995 [@option{--prefix-alloc-sections=}@var{string}]
996 [@option{--add-gnu-debuglink=}@var{path-to-file}]
997 [@option{--keep-file-symbols}]
998 [@option{--only-keep-debug}]
999 [@option{--extract-symbol}]
1000 [@option{--writable-text}]
1001 [@option{--readonly-text}]
1002 [@option{--pure}]
1003 [@option{--impure}]
1004 [@option{-v}|@option{--verbose}]
1005 [@option{-V}|@option{--version}]
1006 [@option{--help}] [@option{--info}]
1007 @var{infile} [@var{outfile}]
1008 @c man end
1009 @end smallexample
1010
1011 @c man begin DESCRIPTION objcopy
1012 The @sc{gnu} @command{objcopy} utility copies the contents of an object
1013 file to another. @command{objcopy} uses the @sc{gnu} @sc{bfd} Library to
1014 read and write the object files. It can write the destination object
1015 file in a format different from that of the source object file. The
1016 exact behavior of @command{objcopy} is controlled by command-line options.
1017 Note that @command{objcopy} should be able to copy a fully linked file
1018 between any two formats. However, copying a relocatable object file
1019 between any two formats may not work as expected.
1020
1021 @command{objcopy} creates temporary files to do its translations and
1022 deletes them afterward. @command{objcopy} uses @sc{bfd} to do all its
1023 translation work; it has access to all the formats described in @sc{bfd}
1024 and thus is able to recognize most formats without being told
1025 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
1026
1027 @command{objcopy} can be used to generate S-records by using an output
1028 target of @samp{srec} (e.g., use @samp{-O srec}).
1029
1030 @command{objcopy} can be used to generate a raw binary file by using an
1031 output target of @samp{binary} (e.g., use @option{-O binary}). When
1032 @command{objcopy} generates a raw binary file, it will essentially produce
1033 a memory dump of the contents of the input object file. All symbols and
1034 relocation information will be discarded. The memory dump will start at
1035 the load address of the lowest section copied into the output file.
1036
1037 When generating an S-record or a raw binary file, it may be helpful to
1038 use @option{-S} to remove sections containing debugging information. In
1039 some cases @option{-R} will be useful to remove sections which contain
1040 information that is not needed by the binary file.
1041
1042 Note---@command{objcopy} is not able to change the endianness of its input
1043 files. If the input format has an endianness (some formats do not),
1044 @command{objcopy} can only copy the inputs into file formats that have the
1045 same endianness or which have no endianness (e.g., @samp{srec}).
1046
1047 @c man end
1048
1049 @c man begin OPTIONS objcopy
1050
1051 @table @env
1052 @item @var{infile}
1053 @itemx @var{outfile}
1054 The input and output files, respectively.
1055 If you do not specify @var{outfile}, @command{objcopy} creates a
1056 temporary file and destructively renames the result with
1057 the name of @var{infile}.
1058
1059 @item -I @var{bfdname}
1060 @itemx --input-target=@var{bfdname}
1061 Consider the source file's object format to be @var{bfdname}, rather than
1062 attempting to deduce it. @xref{Target Selection}, for more information.
1063
1064 @item -O @var{bfdname}
1065 @itemx --output-target=@var{bfdname}
1066 Write the output file using the object format @var{bfdname}.
1067 @xref{Target Selection}, for more information.
1068
1069 @item -F @var{bfdname}
1070 @itemx --target=@var{bfdname}
1071 Use @var{bfdname} as the object format for both the input and the output
1072 file; i.e., simply transfer data from source to destination with no
1073 translation. @xref{Target Selection}, for more information.
1074
1075 @item -B @var{bfdarch}
1076 @itemx --binary-architecture=@var{bfdarch}
1077 Useful when transforming a raw binary input file into an object file.
1078 In this case the output architecture can be set to @var{bfdarch}. This
1079 option will be ignored if the input file has a known @var{bfdarch}. You
1080 can access this binary data inside a program by referencing the special
1081 symbols that are created by the conversion process. These symbols are
1082 called _binary_@var{objfile}_start, _binary_@var{objfile}_end and
1083 _binary_@var{objfile}_size. e.g. you can transform a picture file into
1084 an object file and then access it in your code using these symbols.
1085
1086 @item -j @var{sectionname}
1087 @itemx --only-section=@var{sectionname}
1088 Copy only the named section from the input file to the output file.
1089 This option may be given more than once. Note that using this option
1090 inappropriately may make the output file unusable.
1091
1092 @item -R @var{sectionname}
1093 @itemx --remove-section=@var{sectionname}
1094 Remove any section named @var{sectionname} from the output file. This
1095 option may be given more than once. Note that using this option
1096 inappropriately may make the output file unusable.
1097
1098 @item -S
1099 @itemx --strip-all
1100 Do not copy relocation and symbol information from the source file.
1101
1102 @item -g
1103 @itemx --strip-debug
1104 Do not copy debugging symbols or sections from the source file.
1105
1106 @item --strip-unneeded
1107 Strip all symbols that are not needed for relocation processing.
1108
1109 @item -K @var{symbolname}
1110 @itemx --keep-symbol=@var{symbolname}
1111 When stripping symbols, keep symbol @var{symbolname} even if it would
1112 normally be stripped. This option may be given more than once.
1113
1114 @item -N @var{symbolname}
1115 @itemx --strip-symbol=@var{symbolname}
1116 Do not copy symbol @var{symbolname} from the source file. This option
1117 may be given more than once.
1118
1119 @item --strip-unneeded-symbol=@var{symbolname}
1120 Do not copy symbol @var{symbolname} from the source file unless it is needed
1121 by a relocation. This option may be given more than once.
1122
1123 @item -G @var{symbolname}
1124 @itemx --keep-global-symbol=@var{symbolname}
1125 Keep only symbol @var{symbolname} global. Make all other symbols local
1126 to the file, so that they are not visible externally. This option may
1127 be given more than once.
1128
1129 @item --localize-hidden
1130 In an ELF object, mark all symbols that have hidden or internal visibility
1131 as local. This option applies on top of symbol-specific localization options
1132 such as @option{-L}.
1133
1134 @item -L @var{symbolname}
1135 @itemx --localize-symbol=@var{symbolname}
1136 Make symbol @var{symbolname} local to the file, so that it is not
1137 visible externally. This option may be given more than once.
1138
1139 @item -W @var{symbolname}
1140 @itemx --weaken-symbol=@var{symbolname}
1141 Make symbol @var{symbolname} weak. This option may be given more than once.
1142
1143 @item --globalize-symbol=@var{symbolname}
1144 Give symbol @var{symbolname} global scoping so that it is visible
1145 outside of the file in which it is defined. This option may be given
1146 more than once.
1147
1148 @item -w
1149 @itemx --wildcard
1150 Permit regular expressions in @var{symbolname}s used in other command
1151 line options. The question mark (?), asterisk (*), backslash (\) and
1152 square brackets ([]) operators can be used anywhere in the symbol
1153 name. If the first character of the symbol name is the exclamation
1154 point (!) then the sense of the switch is reversed for that symbol.
1155 For example:
1156
1157 @smallexample
1158 -w -W !foo -W fo*
1159 @end smallexample
1160
1161 would cause objcopy to weaken all symbols that start with ``fo''
1162 except for the symbol ``foo''.
1163
1164 @item -x
1165 @itemx --discard-all
1166 Do not copy non-global symbols from the source file.
1167 @c FIXME any reason to prefer "non-global" to "local" here?
1168
1169 @item -X
1170 @itemx --discard-locals
1171 Do not copy compiler-generated local symbols.
1172 (These usually start with @samp{L} or @samp{.}.)
1173
1174 @item -b @var{byte}
1175 @itemx --byte=@var{byte}
1176 Keep only every @var{byte}th byte of the input file (header data is not
1177 affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
1178 where @var{interleave} is given by the @option{-i} or @option{--interleave}
1179 option, or the default of 4. This option is useful for creating files
1180 to program @sc{rom}. It is typically used with an @code{srec} output
1181 target.
1182
1183 @item -i @var{interleave}
1184 @itemx --interleave=@var{interleave}
1185 Only copy one out of every @var{interleave} bytes. Select which byte to
1186 copy with the @option{-b} or @option{--byte} option. The default is 4.
1187 @command{objcopy} ignores this option if you do not specify either @option{-b} or
1188 @option{--byte}.
1189
1190 @item -p
1191 @itemx --preserve-dates
1192 Set the access and modification dates of the output file to be the same
1193 as those of the input file.
1194
1195 @item --debugging
1196 Convert debugging information, if possible. This is not the default
1197 because only certain debugging formats are supported, and the
1198 conversion process can be time consuming.
1199
1200 @item --gap-fill @var{val}
1201 Fill gaps between sections with @var{val}. This operation applies to
1202 the @emph{load address} (LMA) of the sections. It is done by increasing
1203 the size of the section with the lower address, and filling in the extra
1204 space created with @var{val}.
1205
1206 @item --pad-to @var{address}
1207 Pad the output file up to the load address @var{address}. This is
1208 done by increasing the size of the last section. The extra space is
1209 filled in with the value specified by @option{--gap-fill} (default zero).
1210
1211 @item --set-start @var{val}
1212 Set the start address of the new file to @var{val}. Not all object file
1213 formats support setting the start address.
1214
1215 @item --change-start @var{incr}
1216 @itemx --adjust-start @var{incr}
1217 @cindex changing start address
1218 Change the start address by adding @var{incr}. Not all object file
1219 formats support setting the start address.
1220
1221 @item --change-addresses @var{incr}
1222 @itemx --adjust-vma @var{incr}
1223 @cindex changing object addresses
1224 Change the VMA and LMA addresses of all sections, as well as the start
1225 address, by adding @var{incr}. Some object file formats do not permit
1226 section addresses to be changed arbitrarily. Note that this does not
1227 relocate the sections; if the program expects sections to be loaded at a
1228 certain address, and this option is used to change the sections such
1229 that they are loaded at a different address, the program may fail.
1230
1231 @item --change-section-address @var{section}@{=,+,-@}@var{val}
1232 @itemx --adjust-section-vma @var{section}@{=,+,-@}@var{val}
1233 @cindex changing section address
1234 Set or change both the VMA address and the LMA address of the named
1235 @var{section}. If @samp{=} is used, the section address is set to
1236 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1237 section address. See the comments under @option{--change-addresses},
1238 above. If @var{section} does not exist in the input file, a warning will
1239 be issued, unless @option{--no-change-warnings} is used.
1240
1241 @item --change-section-lma @var{section}@{=,+,-@}@var{val}
1242 @cindex changing section LMA
1243 Set or change the LMA address of the named @var{section}. The LMA
1244 address is the address where the section will be loaded into memory at
1245 program load time. Normally this is the same as the VMA address, which
1246 is the address of the section at program run time, but on some systems,
1247 especially those where a program is held in ROM, the two can be
1248 different. If @samp{=} is used, the section address is set to
1249 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1250 section address. See the comments under @option{--change-addresses},
1251 above. If @var{section} does not exist in the input file, a warning
1252 will be issued, unless @option{--no-change-warnings} is used.
1253
1254 @item --change-section-vma @var{section}@{=,+,-@}@var{val}
1255 @cindex changing section VMA
1256 Set or change the VMA address of the named @var{section}. The VMA
1257 address is the address where the section will be located once the
1258 program has started executing. Normally this is the same as the LMA
1259 address, which is the address where the section will be loaded into
1260 memory, but on some systems, especially those where a program is held in
1261 ROM, the two can be different. If @samp{=} is used, the section address
1262 is set to @var{val}. Otherwise, @var{val} is added to or subtracted
1263 from the section address. See the comments under
1264 @option{--change-addresses}, above. If @var{section} does not exist in
1265 the input file, a warning will be issued, unless
1266 @option{--no-change-warnings} is used.
1267
1268 @item --change-warnings
1269 @itemx --adjust-warnings
1270 If @option{--change-section-address} or @option{--change-section-lma} or
1271 @option{--change-section-vma} is used, and the named section does not
1272 exist, issue a warning. This is the default.
1273
1274 @item --no-change-warnings
1275 @itemx --no-adjust-warnings
1276 Do not issue a warning if @option{--change-section-address} or
1277 @option{--adjust-section-lma} or @option{--adjust-section-vma} is used, even
1278 if the named section does not exist.
1279
1280 @item --set-section-flags @var{section}=@var{flags}
1281 Set the flags for the named section. The @var{flags} argument is a
1282 comma separated string of flag names. The recognized names are
1283 @samp{alloc}, @samp{contents}, @samp{load}, @samp{noload},
1284 @samp{readonly}, @samp{code}, @samp{data}, @samp{rom}, @samp{share}, and
1285 @samp{debug}. You can set the @samp{contents} flag for a section which
1286 does not have contents, but it is not meaningful to clear the
1287 @samp{contents} flag of a section which does have contents--just remove
1288 the section instead. Not all flags are meaningful for all object file
1289 formats.
1290
1291 @item --add-section @var{sectionname}=@var{filename}
1292 Add a new section named @var{sectionname} while copying the file. The
1293 contents of the new section are taken from the file @var{filename}. The
1294 size of the section will be the size of the file. This option only
1295 works on file formats which can support sections with arbitrary names.
1296
1297 @item --rename-section @var{oldname}=@var{newname}[,@var{flags}]
1298 Rename a section from @var{oldname} to @var{newname}, optionally
1299 changing the section's flags to @var{flags} in the process. This has
1300 the advantage over usng a linker script to perform the rename in that
1301 the output stays as an object file and does not become a linked
1302 executable.
1303
1304 This option is particularly helpful when the input format is binary,
1305 since this will always create a section called .data. If for example,
1306 you wanted instead to create a section called .rodata containing binary
1307 data you could use the following command line to achieve it:
1308
1309 @smallexample
1310 objcopy -I binary -O <output_format> -B <architecture> \
1311 --rename-section .data=.rodata,alloc,load,readonly,data,contents \
1312 <input_binary_file> <output_object_file>
1313 @end smallexample
1314
1315 @item --change-leading-char
1316 Some object file formats use special characters at the start of
1317 symbols. The most common such character is underscore, which compilers
1318 often add before every symbol. This option tells @command{objcopy} to
1319 change the leading character of every symbol when it converts between
1320 object file formats. If the object file formats use the same leading
1321 character, this option has no effect. Otherwise, it will add a
1322 character, or remove a character, or change a character, as
1323 appropriate.
1324
1325 @item --remove-leading-char
1326 If the first character of a global symbol is a special symbol leading
1327 character used by the object file format, remove the character. The
1328 most common symbol leading character is underscore. This option will
1329 remove a leading underscore from all global symbols. This can be useful
1330 if you want to link together objects of different file formats with
1331 different conventions for symbol names. This is different from
1332 @option{--change-leading-char} because it always changes the symbol name
1333 when appropriate, regardless of the object file format of the output
1334 file.
1335
1336 @item --srec-len=@var{ival}
1337 Meaningful only for srec output. Set the maximum length of the Srecords
1338 being produced to @var{ival}. This length covers both address, data and
1339 crc fields.
1340
1341 @item --srec-forceS3
1342 Meaningful only for srec output. Avoid generation of S1/S2 records,
1343 creating S3-only record format.
1344
1345 @item --redefine-sym @var{old}=@var{new}
1346 Change the name of a symbol @var{old}, to @var{new}. This can be useful
1347 when one is trying link two things together for which you have no
1348 source, and there are name collisions.
1349
1350 @item --redefine-syms=@var{filename}
1351 Apply @option{--redefine-sym} to each symbol pair "@var{old} @var{new}"
1352 listed in the file @var{filename}. @var{filename} is simply a flat file,
1353 with one symbol pair per line. Line comments may be introduced by the hash
1354 character. This option may be given more than once.
1355
1356 @item --weaken
1357 Change all global symbols in the file to be weak. This can be useful
1358 when building an object which will be linked against other objects using
1359 the @option{-R} option to the linker. This option is only effective when
1360 using an object file format which supports weak symbols.
1361
1362 @item --keep-symbols=@var{filename}
1363 Apply @option{--keep-symbol} option to each symbol listed in the file
1364 @var{filename}. @var{filename} is simply a flat file, with one symbol
1365 name per line. Line comments may be introduced by the hash character.
1366 This option may be given more than once.
1367
1368 @item --strip-symbols=@var{filename}
1369 Apply @option{--strip-symbol} option to each symbol listed in the file
1370 @var{filename}. @var{filename} is simply a flat file, with one symbol
1371 name per line. Line comments may be introduced by the hash character.
1372 This option may be given more than once.
1373
1374 @item --strip-unneeded-symbols=@var{filename}
1375 Apply @option{--strip-unneeded-symbol} option to each symbol listed in
1376 the file @var{filename}. @var{filename} is simply a flat file, with one
1377 symbol name per line. Line comments may be introduced by the hash
1378 character. This option may be given more than once.
1379
1380 @item --keep-global-symbols=@var{filename}
1381 Apply @option{--keep-global-symbol} option to each symbol listed in the
1382 file @var{filename}. @var{filename} is simply a flat file, with one
1383 symbol name per line. Line comments may be introduced by the hash
1384 character. This option may be given more than once.
1385
1386 @item --localize-symbols=@var{filename}
1387 Apply @option{--localize-symbol} option to each symbol listed in the file
1388 @var{filename}. @var{filename} is simply a flat file, with one symbol
1389 name per line. Line comments may be introduced by the hash character.
1390 This option may be given more than once.
1391
1392 @item --globalize-symbols=@var{filename}
1393 Apply @option{--globalize-symbol} option to each symbol listed in the file
1394 @var{filename}. @var{filename} is simply a flat file, with one symbol
1395 name per line. Line comments may be introduced by the hash character.
1396 This option may be given more than once.
1397
1398 @item --weaken-symbols=@var{filename}
1399 Apply @option{--weaken-symbol} option to each symbol listed in the file
1400 @var{filename}. @var{filename} is simply a flat file, with one symbol
1401 name per line. Line comments may be introduced by the hash character.
1402 This option may be given more than once.
1403
1404 @item --alt-machine-code=@var{index}
1405 If the output architecture has alternate machine codes, use the
1406 @var{index}th code instead of the default one. This is useful in case
1407 a machine is assigned an official code and the tool-chain adopts the
1408 new code, but other applications still depend on the original code
1409 being used. For ELF based architectures if the @var{index}
1410 alternative does not exist then the value is treated as an absolute
1411 number to be stored in the e_machine field of the ELF header.
1412
1413 @item --writable-text
1414 Mark the output text as writable. This option isn't meaningful for all
1415 object file formats.
1416
1417 @item --readonly-text
1418 Make the output text write protected. This option isn't meaningful for all
1419 object file formats.
1420
1421 @item --pure
1422 Mark the output file as demand paged. This option isn't meaningful for all
1423 object file formats.
1424
1425 @item --impure
1426 Mark the output file as impure. This option isn't meaningful for all
1427 object file formats.
1428
1429 @item --prefix-symbols=@var{string}
1430 Prefix all symbols in the output file with @var{string}.
1431
1432 @item --prefix-sections=@var{string}
1433 Prefix all section names in the output file with @var{string}.
1434
1435 @item --prefix-alloc-sections=@var{string}
1436 Prefix all the names of all allocated sections in the output file with
1437 @var{string}.
1438
1439 @item --add-gnu-debuglink=@var{path-to-file}
1440 Creates a .gnu_debuglink section which contains a reference to @var{path-to-file}
1441 and adds it to the output file.
1442
1443 @item --keep-file-symbols
1444 When stripping a file, perhaps with @option{--strip-debug} or
1445 @option{--strip-unneeded}, retain any symbols specifying source file names,
1446 which would otherwise get stripped.
1447
1448 @item --only-keep-debug
1449 Strip a file, removing contents of any sections that would not be
1450 stripped by @option{--strip-debug} and leaving the debugging sections
1451 intact.
1452
1453 The intention is that this option will be used in conjunction with
1454 @option{--add-gnu-debuglink} to create a two part executable. One a
1455 stripped binary which will occupy less space in RAM and in a
1456 distribution and the second a debugging information file which is only
1457 needed if debugging abilities are required. The suggested procedure
1458 to create these files is as follows:
1459
1460 @enumerate
1461 @item Link the executable as normal. Assuming that is is called
1462 @code{foo} then...
1463 @item Run @code{objcopy --only-keep-debug foo foo.dbg} to
1464 create a file containing the debugging info.
1465 @item Run @code{objcopy --strip-debug foo} to create a
1466 stripped executable.
1467 @item Run @code{objcopy --add-gnu-debuglink=foo.dbg foo}
1468 to add a link to the debugging info into the stripped executable.
1469 @end enumerate
1470
1471 Note - the choice of @code{.dbg} as an extension for the debug info
1472 file is arbitrary. Also the @code{--only-keep-debug} step is
1473 optional. You could instead do this:
1474
1475 @enumerate
1476 @item Link the executable as normal.
1477 @item Copy @code{foo} to @code{foo.full}
1478 @item Run @code{objcopy --strip-debug foo}
1479 @item Run @code{objcopy --add-gnu-debuglink=foo.full foo}
1480 @end enumerate
1481
1482 i.e., the file pointed to by the @option{--add-gnu-debuglink} can be the
1483 full executable. It does not have to be a file created by the
1484 @option{--only-keep-debug} switch.
1485
1486 Note - this switch is only intended for use on fully linked files. It
1487 does not make sense to use it on object files where the debugging
1488 information may be incomplete. Besides the gnu_debuglink feature
1489 currently only supports the presence of one filename containing
1490 debugging information, not multiple filenames on a one-per-object-file
1491 basis.
1492
1493 @item --extract-symbol
1494 Keep the file's section flags and symbols but remove all section data.
1495 Specifically, the option:
1496
1497 @itemize
1498 @item sets the virtual and load addresses of every section to zero;
1499 @item removes the contents of all sections;
1500 @item sets the size of every section to zero; and
1501 @item sets the file's start address to zero.
1502 @end itemize
1503
1504 This option is used to build a @file{.sym} file for a VxWorks kernel.
1505 It can also be a useful way of reducing the size of a @option{--just-symbols}
1506 linker input file.
1507
1508 @item -V
1509 @itemx --version
1510 Show the version number of @command{objcopy}.
1511
1512 @item -v
1513 @itemx --verbose
1514 Verbose output: list all object files modified. In the case of
1515 archives, @samp{objcopy -V} lists all members of the archive.
1516
1517 @item --help
1518 Show a summary of the options to @command{objcopy}.
1519
1520 @item --info
1521 Display a list showing all architectures and object formats available.
1522 @end table
1523
1524 @c man end
1525
1526 @ignore
1527 @c man begin SEEALSO objcopy
1528 ld(1), objdump(1), and the Info entries for @file{binutils}.
1529 @c man end
1530 @end ignore
1531
1532 @node objdump
1533 @chapter objdump
1534
1535 @cindex object file information
1536 @kindex objdump
1537
1538 @c man title objdump display information from object files.
1539
1540 @smallexample
1541 @c man begin SYNOPSIS objdump
1542 objdump [@option{-a}|@option{--archive-headers}]
1543 [@option{-b} @var{bfdname}|@option{--target=@var{bfdname}}]
1544 [@option{-C}|@option{--demangle}[=@var{style}] ]
1545 [@option{-d}|@option{--disassemble}]
1546 [@option{-D}|@option{--disassemble-all}]
1547 [@option{-z}|@option{--disassemble-zeroes}]
1548 [@option{-EB}|@option{-EL}|@option{--endian=}@{big | little @}]
1549 [@option{-f}|@option{--file-headers}]
1550 [@option{--file-start-context}]
1551 [@option{-g}|@option{--debugging}]
1552 [@option{-e}|@option{--debugging-tags}]
1553 [@option{-h}|@option{--section-headers}|@option{--headers}]
1554 [@option{-i}|@option{--info}]
1555 [@option{-j} @var{section}|@option{--section=}@var{section}]
1556 [@option{-l}|@option{--line-numbers}]
1557 [@option{-S}|@option{--source}]
1558 [@option{-m} @var{machine}|@option{--architecture=}@var{machine}]
1559 [@option{-M} @var{options}|@option{--disassembler-options=}@var{options}]
1560 [@option{-p}|@option{--private-headers}]
1561 [@option{-r}|@option{--reloc}]
1562 [@option{-R}|@option{--dynamic-reloc}]
1563 [@option{-s}|@option{--full-contents}]
1564 [@option{-W}|@option{--dwarf}]
1565 [@option{-G}|@option{--stabs}]
1566 [@option{-t}|@option{--syms}]
1567 [@option{-T}|@option{--dynamic-syms}]
1568 [@option{-x}|@option{--all-headers}]
1569 [@option{-w}|@option{--wide}]
1570 [@option{--start-address=}@var{address}]
1571 [@option{--stop-address=}@var{address}]
1572 [@option{--prefix-addresses}]
1573 [@option{--[no-]show-raw-insn}]
1574 [@option{--adjust-vma=}@var{offset}]
1575 [@option{--special-syms}]
1576 [@option{-V}|@option{--version}]
1577 [@option{-H}|@option{--help}]
1578 @var{objfile}@dots{}
1579 @c man end
1580 @end smallexample
1581
1582 @c man begin DESCRIPTION objdump
1583
1584 @command{objdump} displays information about one or more object files.
1585 The options control what particular information to display. This
1586 information is mostly useful to programmers who are working on the
1587 compilation tools, as opposed to programmers who just want their
1588 program to compile and work.
1589
1590 @var{objfile}@dots{} are the object files to be examined. When you
1591 specify archives, @command{objdump} shows information on each of the member
1592 object files.
1593
1594 @c man end
1595
1596 @c man begin OPTIONS objdump
1597
1598 The long and short forms of options, shown here as alternatives, are
1599 equivalent. At least one option from the list
1600 @option{-a,-d,-D,-e,-f,-g,-G,-h,-H,-p,-r,-R,-s,-S,-t,-T,-V,-x} must be given.
1601
1602 @table @env
1603 @item -a
1604 @itemx --archive-header
1605 @cindex archive headers
1606 If any of the @var{objfile} files are archives, display the archive
1607 header information (in a format similar to @samp{ls -l}). Besides the
1608 information you could list with @samp{ar tv}, @samp{objdump -a} shows
1609 the object file format of each archive member.
1610
1611 @item --adjust-vma=@var{offset}
1612 @cindex section addresses in objdump
1613 @cindex VMA in objdump
1614 When dumping information, first add @var{offset} to all the section
1615 addresses. This is useful if the section addresses do not correspond to
1616 the symbol table, which can happen when putting sections at particular
1617 addresses when using a format which can not represent section addresses,
1618 such as a.out.
1619
1620 @item -b @var{bfdname}
1621 @itemx --target=@var{bfdname}
1622 @cindex object code format
1623 Specify that the object-code format for the object files is
1624 @var{bfdname}. This option may not be necessary; @var{objdump} can
1625 automatically recognize many formats.
1626
1627 For example,
1628 @example
1629 objdump -b oasys -m vax -h fu.o
1630 @end example
1631 @noindent
1632 displays summary information from the section headers (@option{-h}) of
1633 @file{fu.o}, which is explicitly identified (@option{-m}) as a VAX object
1634 file in the format produced by Oasys compilers. You can list the
1635 formats available with the @option{-i} option.
1636 @xref{Target Selection}, for more information.
1637
1638 @item -C
1639 @itemx --demangle[=@var{style}]
1640 @cindex demangling in objdump
1641 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1642 Besides removing any initial underscore prepended by the system, this
1643 makes C++ function names readable. Different compilers have different
1644 mangling styles. The optional demangling style argument can be used to
1645 choose an appropriate demangling style for your compiler. @xref{c++filt},
1646 for more information on demangling.
1647
1648 @item -g
1649 @itemx --debugging
1650 Display debugging information. This attempts to parse debugging
1651 information stored in the file and print it out using a C like syntax.
1652 Only certain types of debugging information have been implemented.
1653 Some other types are supported by @command{readelf -w}.
1654 @xref{readelf}.
1655
1656 @item -e
1657 @itemx --debugging-tags
1658 Like @option{-g}, but the information is generated in a format compatible
1659 with ctags tool.
1660
1661 @item -d
1662 @itemx --disassemble
1663 @cindex disassembling object code
1664 @cindex machine instructions
1665 Display the assembler mnemonics for the machine instructions from
1666 @var{objfile}. This option only disassembles those sections which are
1667 expected to contain instructions.
1668
1669 @item -D
1670 @itemx --disassemble-all
1671 Like @option{-d}, but disassemble the contents of all sections, not just
1672 those expected to contain instructions.
1673
1674 @item --prefix-addresses
1675 When disassembling, print the complete address on each line. This is
1676 the older disassembly format.
1677
1678 @item -EB
1679 @itemx -EL
1680 @itemx --endian=@{big|little@}
1681 @cindex endianness
1682 @cindex disassembly endianness
1683 Specify the endianness of the object files. This only affects
1684 disassembly. This can be useful when disassembling a file format which
1685 does not describe endianness information, such as S-records.
1686
1687 @item -f
1688 @itemx --file-headers
1689 @cindex object file header
1690 Display summary information from the overall header of
1691 each of the @var{objfile} files.
1692
1693 @item --file-start-context
1694 @cindex source code context
1695 Specify that when displaying interlisted source code/disassembly
1696 (assumes @option{-S}) from a file that has not yet been displayed, extend the
1697 context to the start of the file.
1698
1699 @item -h
1700 @itemx --section-headers
1701 @itemx --headers
1702 @cindex section headers
1703 Display summary information from the section headers of the
1704 object file.
1705
1706 File segments may be relocated to nonstandard addresses, for example by
1707 using the @option{-Ttext}, @option{-Tdata}, or @option{-Tbss} options to
1708 @command{ld}. However, some object file formats, such as a.out, do not
1709 store the starting address of the file segments. In those situations,
1710 although @command{ld} relocates the sections correctly, using @samp{objdump
1711 -h} to list the file section headers cannot show the correct addresses.
1712 Instead, it shows the usual addresses, which are implicit for the
1713 target.
1714
1715 @item -H
1716 @itemx --help
1717 Print a summary of the options to @command{objdump} and exit.
1718
1719 @item -i
1720 @itemx --info
1721 @cindex architectures available
1722 @cindex object formats available
1723 Display a list showing all architectures and object formats available
1724 for specification with @option{-b} or @option{-m}.
1725
1726 @item -j @var{name}
1727 @itemx --section=@var{name}
1728 @cindex section information
1729 Display information only for section @var{name}.
1730
1731 @item -l
1732 @itemx --line-numbers
1733 @cindex source filenames for object files
1734 Label the display (using debugging information) with the filename and
1735 source line numbers corresponding to the object code or relocs shown.
1736 Only useful with @option{-d}, @option{-D}, or @option{-r}.
1737
1738 @item -m @var{machine}
1739 @itemx --architecture=@var{machine}
1740 @cindex architecture
1741 @cindex disassembly architecture
1742 Specify the architecture to use when disassembling object files. This
1743 can be useful when disassembling object files which do not describe
1744 architecture information, such as S-records. You can list the available
1745 architectures with the @option{-i} option.
1746
1747 @item -M @var{options}
1748 @itemx --disassembler-options=@var{options}
1749 Pass target specific information to the disassembler. Only supported on
1750 some targets. If it is necessary to specify more than one
1751 disassembler option then multiple @option{-M} options can be used or
1752 can be placed together into a comma separated list.
1753
1754 If the target is an ARM architecture then this switch can be used to
1755 select which register name set is used during disassembler. Specifying
1756 @option{-M reg-names-std} (the default) will select the register names as
1757 used in ARM's instruction set documentation, but with register 13 called
1758 'sp', register 14 called 'lr' and register 15 called 'pc'. Specifying
1759 @option{-M reg-names-apcs} will select the name set used by the ARM
1760 Procedure Call Standard, whilst specifying @option{-M reg-names-raw} will
1761 just use @samp{r} followed by the register number.
1762
1763 There are also two variants on the APCS register naming scheme enabled
1764 by @option{-M reg-names-atpcs} and @option{-M reg-names-special-atpcs} which
1765 use the ARM/Thumb Procedure Call Standard naming conventions. (Either
1766 with the normal register names or the special register names).
1767
1768 This option can also be used for ARM architectures to force the
1769 disassembler to interpret all instructions as Thumb instructions by
1770 using the switch @option{--disassembler-options=force-thumb}. This can be
1771 useful when attempting to disassemble thumb code produced by other
1772 compilers.
1773
1774 For the x86, some of the options duplicate functions of the @option{-m}
1775 switch, but allow finer grained control. Multiple selections from the
1776 following may be specified as a comma separated string.
1777 @option{x86-64}, @option{i386} and @option{i8086} select disassembly for
1778 the given architecture. @option{intel} and @option{att} select between
1779 intel syntax mode and AT&T syntax mode. @option{addr64}, @option{addr32},
1780 @option{addr16}, @option{data32} and @option{data16} specify the default
1781 address size and operand size. These four options will be overridden if
1782 @option{x86-64}, @option{i386} or @option{i8086} appear later in the
1783 option string. Lastly, @option{suffix}, when in AT&T mode,
1784 instructs the disassembler to print a mnemonic suffix even when the
1785 suffix could be inferred by the operands.
1786
1787 For PPC, @option{booke}, @option{booke32} and @option{booke64} select
1788 disassembly of BookE instructions. @option{32} and @option{64} select
1789 PowerPC and PowerPC64 disassembly, respectively. @option{e300} selects
1790 disassembly for the e300 family. @option{440} selects disassembly for
1791 the powerPC 440.
1792
1793 For MIPS, this option controls the printing of instruction mnemonic
1794 names and register names in disassembled instructions. Multiple
1795 selections from the following may be specified as a comma separated
1796 string, and invalid options are ignored:
1797
1798 @table @code
1799 @item no-aliases
1800 Print the 'raw' instruction mnemonic instead of some pseudo
1801 instruction mnemonic. I.e., print 'daddu' or 'or' instead of 'move',
1802 'sll' instead of 'nop', etc.
1803
1804 @item gpr-names=@var{ABI}
1805 Print GPR (general-purpose register) names as appropriate
1806 for the specified ABI. By default, GPR names are selected according to
1807 the ABI of the binary being disassembled.
1808
1809 @item fpr-names=@var{ABI}
1810 Print FPR (floating-point register) names as
1811 appropriate for the specified ABI. By default, FPR numbers are printed
1812 rather than names.
1813
1814 @item cp0-names=@var{ARCH}
1815 Print CP0 (system control coprocessor; coprocessor 0) register names
1816 as appropriate for the CPU or architecture specified by
1817 @var{ARCH}. By default, CP0 register names are selected according to
1818 the architecture and CPU of the binary being disassembled.
1819
1820 @item hwr-names=@var{ARCH}
1821 Print HWR (hardware register, used by the @code{rdhwr} instruction) names
1822 as appropriate for the CPU or architecture specified by
1823 @var{ARCH}. By default, HWR names are selected according to
1824 the architecture and CPU of the binary being disassembled.
1825
1826 @item reg-names=@var{ABI}
1827 Print GPR and FPR names as appropriate for the selected ABI.
1828
1829 @item reg-names=@var{ARCH}
1830 Print CPU-specific register names (CP0 register and HWR names)
1831 as appropriate for the selected CPU or architecture.
1832 @end table
1833
1834 For any of the options listed above, @var{ABI} or
1835 @var{ARCH} may be specified as @samp{numeric} to have numbers printed
1836 rather than names, for the selected types of registers.
1837 You can list the available values of @var{ABI} and @var{ARCH} using
1838 the @option{--help} option.
1839
1840 For VAX, you can specify function entry addresses with @option{-M
1841 entry:0xf00ba}. You can use this multiple times to properly
1842 disassemble VAX binary files that don't contain symbol tables (like
1843 ROM dumps). In these cases, the function entry mask would otherwise
1844 be decoded as VAX instructions, which would probably lead the rest
1845 of the function being wrongly disassembled.
1846
1847 @item -p
1848 @itemx --private-headers
1849 Print information that is specific to the object file format. The exact
1850 information printed depends upon the object file format. For some
1851 object file formats, no additional information is printed.
1852
1853 @item -r
1854 @itemx --reloc
1855 @cindex relocation entries, in object file
1856 Print the relocation entries of the file. If used with @option{-d} or
1857 @option{-D}, the relocations are printed interspersed with the
1858 disassembly.
1859
1860 @item -R
1861 @itemx --dynamic-reloc
1862 @cindex dynamic relocation entries, in object file
1863 Print the dynamic relocation entries of the file. This is only
1864 meaningful for dynamic objects, such as certain types of shared
1865 libraries.
1866
1867 @item -s
1868 @itemx --full-contents
1869 @cindex sections, full contents
1870 @cindex object file sections
1871 Display the full contents of any sections requested. By default all
1872 non-empty sections are displayed.
1873
1874 @item -S
1875 @itemx --source
1876 @cindex source disassembly
1877 @cindex disassembly, with source
1878 Display source code intermixed with disassembly, if possible. Implies
1879 @option{-d}.
1880
1881 @item --show-raw-insn
1882 When disassembling instructions, print the instruction in hex as well as
1883 in symbolic form. This is the default except when
1884 @option{--prefix-addresses} is used.
1885
1886 @item --no-show-raw-insn
1887 When disassembling instructions, do not print the instruction bytes.
1888 This is the default when @option{--prefix-addresses} is used.
1889
1890 @item -W
1891 @itemx --dwarf
1892 @cindex DWARF
1893 @cindex debug symbols
1894 Displays the contents of the DWARF debug sections in the file, if any
1895 are present.
1896
1897 @item -G
1898 @itemx --stabs
1899 @cindex stab
1900 @cindex .stab
1901 @cindex debug symbols
1902 @cindex ELF object file format
1903 Display the full contents of any sections requested. Display the
1904 contents of the .stab and .stab.index and .stab.excl sections from an
1905 ELF file. This is only useful on systems (such as Solaris 2.0) in which
1906 @code{.stab} debugging symbol-table entries are carried in an ELF
1907 section. In most other file formats, debugging symbol-table entries are
1908 interleaved with linkage symbols, and are visible in the @option{--syms}
1909 output.
1910 @ifclear man
1911 For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1912 Overview,stabs.info, The ``stabs'' debug format}.
1913 @end ifclear
1914
1915 @item --start-address=@var{address}
1916 @cindex start-address
1917 Start displaying data at the specified address. This affects the output
1918 of the @option{-d}, @option{-r} and @option{-s} options.
1919
1920 @item --stop-address=@var{address}
1921 @cindex stop-address
1922 Stop displaying data at the specified address. This affects the output
1923 of the @option{-d}, @option{-r} and @option{-s} options.
1924
1925 @item -t
1926 @itemx --syms
1927 @cindex symbol table entries, printing
1928 Print the symbol table entries of the file.
1929 This is similar to the information provided by the @samp{nm} program.
1930
1931 @item -T
1932 @itemx --dynamic-syms
1933 @cindex dynamic symbol table entries, printing
1934 Print the dynamic symbol table entries of the file. This is only
1935 meaningful for dynamic objects, such as certain types of shared
1936 libraries. This is similar to the information provided by the @samp{nm}
1937 program when given the @option{-D} (@option{--dynamic}) option.
1938
1939 @item --special-syms
1940 When displaying symbols include those which the target considers to be
1941 special in some way and which would not normally be of interest to the
1942 user.
1943
1944 @item -V
1945 @itemx --version
1946 Print the version number of @command{objdump} and exit.
1947
1948 @item -x
1949 @itemx --all-headers
1950 @cindex all header information, object file
1951 @cindex header information, all
1952 Display all available header information, including the symbol table and
1953 relocation entries. Using @option{-x} is equivalent to specifying all of
1954 @option{-a -f -h -p -r -t}.
1955
1956 @item -w
1957 @itemx --wide
1958 @cindex wide output, printing
1959 Format some lines for output devices that have more than 80 columns.
1960 Also do not truncate symbol names when they are displayed.
1961
1962 @item -z
1963 @itemx --disassemble-zeroes
1964 Normally the disassembly output will skip blocks of zeroes. This
1965 option directs the disassembler to disassemble those blocks, just like
1966 any other data.
1967 @end table
1968
1969 @c man end
1970
1971 @ignore
1972 @c man begin SEEALSO objdump
1973 nm(1), readelf(1), and the Info entries for @file{binutils}.
1974 @c man end
1975 @end ignore
1976
1977 @node ranlib
1978 @chapter ranlib
1979
1980 @kindex ranlib
1981 @cindex archive contents
1982 @cindex symbol index
1983
1984 @c man title ranlib generate index to archive.
1985
1986 @smallexample
1987 @c man begin SYNOPSIS ranlib
1988 ranlib [@option{-vV}] @var{archive}
1989 @c man end
1990 @end smallexample
1991
1992 @c man begin DESCRIPTION ranlib
1993
1994 @command{ranlib} generates an index to the contents of an archive and
1995 stores it in the archive. The index lists each symbol defined by a
1996 member of an archive that is a relocatable object file.
1997
1998 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1999
2000 An archive with such an index speeds up linking to the library and
2001 allows routines in the library to call each other without regard to
2002 their placement in the archive.
2003
2004 The @sc{gnu} @command{ranlib} program is another form of @sc{gnu} @command{ar}; running
2005 @command{ranlib} is completely equivalent to executing @samp{ar -s}.
2006 @xref{ar}.
2007
2008 @c man end
2009
2010 @c man begin OPTIONS ranlib
2011
2012 @table @env
2013 @item -v
2014 @itemx -V
2015 @itemx --version
2016 Show the version number of @command{ranlib}.
2017 @end table
2018
2019 @c man end
2020
2021 @ignore
2022 @c man begin SEEALSO ranlib
2023 ar(1), nm(1), and the Info entries for @file{binutils}.
2024 @c man end
2025 @end ignore
2026
2027 @node size
2028 @chapter size
2029
2030 @kindex size
2031 @cindex section sizes
2032
2033 @c man title size list section sizes and total size.
2034
2035 @smallexample
2036 @c man begin SYNOPSIS size
2037 size [@option{-A}|@option{-B}|@option{--format=}@var{compatibility}]
2038 [@option{--help}]
2039 [@option{-d}|@option{-o}|@option{-x}|@option{--radix=}@var{number}]
2040 [@option{-t}|@option{--totals}]
2041 [@option{--target=}@var{bfdname}] [@option{-V}|@option{--version}]
2042 [@var{objfile}@dots{}]
2043 @c man end
2044 @end smallexample
2045
2046 @c man begin DESCRIPTION size
2047
2048 The @sc{gnu} @command{size} utility lists the section sizes---and the total
2049 size---for each of the object or archive files @var{objfile} in its
2050 argument list. By default, one line of output is generated for each
2051 object file or each module in an archive.
2052
2053 @var{objfile}@dots{} are the object files to be examined.
2054 If none are specified, the file @code{a.out} will be used.
2055
2056 @c man end
2057
2058 @c man begin OPTIONS size
2059
2060 The command line options have the following meanings:
2061
2062 @table @env
2063 @item -A
2064 @itemx -B
2065 @itemx --format=@var{compatibility}
2066 @cindex @command{size} display format
2067 Using one of these options, you can choose whether the output from @sc{gnu}
2068 @command{size} resembles output from System V @command{size} (using @option{-A},
2069 or @option{--format=sysv}), or Berkeley @command{size} (using @option{-B}, or
2070 @option{--format=berkeley}). The default is the one-line format similar to
2071 Berkeley's.
2072 @c Bonus for doc-source readers: you can also say --format=strange (or
2073 @c anything else that starts with 's') for sysv, and --format=boring (or
2074 @c anything else that starts with 'b') for Berkeley.
2075
2076 Here is an example of the Berkeley (default) format of output from
2077 @command{size}:
2078 @smallexample
2079 $ size --format=Berkeley ranlib size
2080 text data bss dec hex filename
2081 294880 81920 11592 388392 5ed28 ranlib
2082 294880 81920 11888 388688 5ee50 size
2083 @end smallexample
2084
2085 @noindent
2086 This is the same data, but displayed closer to System V conventions:
2087
2088 @smallexample
2089 $ size --format=SysV ranlib size
2090 ranlib :
2091 section size addr
2092 .text 294880 8192
2093 .data 81920 303104
2094 .bss 11592 385024
2095 Total 388392
2096
2097
2098 size :
2099 section size addr
2100 .text 294880 8192
2101 .data 81920 303104
2102 .bss 11888 385024
2103 Total 388688
2104 @end smallexample
2105
2106 @item --help
2107 Show a summary of acceptable arguments and options.
2108
2109 @item -d
2110 @itemx -o
2111 @itemx -x
2112 @itemx --radix=@var{number}
2113 @cindex @command{size} number format
2114 @cindex radix for section sizes
2115 Using one of these options, you can control whether the size of each
2116 section is given in decimal (@option{-d}, or @option{--radix=10}); octal
2117 (@option{-o}, or @option{--radix=8}); or hexadecimal (@option{-x}, or
2118 @option{--radix=16}). In @option{--radix=@var{number}}, only the three
2119 values (8, 10, 16) are supported. The total size is always given in two
2120 radices; decimal and hexadecimal for @option{-d} or @option{-x} output, or
2121 octal and hexadecimal if you're using @option{-o}.
2122
2123 @item -t
2124 @itemx --totals
2125 Show totals of all objects listed (Berkeley format listing mode only).
2126
2127 @item --target=@var{bfdname}
2128 @cindex object code format
2129 Specify that the object-code format for @var{objfile} is
2130 @var{bfdname}. This option may not be necessary; @command{size} can
2131 automatically recognize many formats.
2132 @xref{Target Selection}, for more information.
2133
2134 @item -V
2135 @itemx --version
2136 Display the version number of @command{size}.
2137 @end table
2138
2139 @c man end
2140
2141 @ignore
2142 @c man begin SEEALSO size
2143 ar(1), objdump(1), readelf(1), and the Info entries for @file{binutils}.
2144 @c man end
2145 @end ignore
2146
2147 @node strings
2148 @chapter strings
2149 @kindex strings
2150 @cindex listings strings
2151 @cindex printing strings
2152 @cindex strings, printing
2153
2154 @c man title strings print the strings of printable characters in files.
2155
2156 @smallexample
2157 @c man begin SYNOPSIS strings
2158 strings [@option{-afov}] [@option{-}@var{min-len}]
2159 [@option{-n} @var{min-len}] [@option{--bytes=}@var{min-len}]
2160 [@option{-t} @var{radix}] [@option{--radix=}@var{radix}]
2161 [@option{-e} @var{encoding}] [@option{--encoding=}@var{encoding}]
2162 [@option{-}] [@option{--all}] [@option{--print-file-name}]
2163 [@option{-T} @var{bfdname}] [@option{--target=}@var{bfdname}]
2164 [@option{--help}] [@option{--version}] @var{file}@dots{}
2165 @c man end
2166 @end smallexample
2167
2168 @c man begin DESCRIPTION strings
2169
2170 For each @var{file} given, @sc{gnu} @command{strings} prints the printable
2171 character sequences that are at least 4 characters long (or the number
2172 given with the options below) and are followed by an unprintable
2173 character. By default, it only prints the strings from the initialized
2174 and loaded sections of object files; for other types of files, it prints
2175 the strings from the whole file.
2176
2177 @command{strings} is mainly useful for determining the contents of non-text
2178 files.
2179
2180 @c man end
2181
2182 @c man begin OPTIONS strings
2183
2184 @table @env
2185 @item -a
2186 @itemx --all
2187 @itemx -
2188 Do not scan only the initialized and loaded sections of object files;
2189 scan the whole files.
2190
2191 @item -f
2192 @itemx --print-file-name
2193 Print the name of the file before each string.
2194
2195 @item --help
2196 Print a summary of the program usage on the standard output and exit.
2197
2198 @item -@var{min-len}
2199 @itemx -n @var{min-len}
2200 @itemx --bytes=@var{min-len}
2201 Print sequences of characters that are at least @var{min-len} characters
2202 long, instead of the default 4.
2203
2204 @item -o
2205 Like @samp{-t o}. Some other versions of @command{strings} have @option{-o}
2206 act like @samp{-t d} instead. Since we can not be compatible with both
2207 ways, we simply chose one.
2208
2209 @item -t @var{radix}
2210 @itemx --radix=@var{radix}
2211 Print the offset within the file before each string. The single
2212 character argument specifies the radix of the offset---@samp{o} for
2213 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
2214
2215 @item -e @var{encoding}
2216 @itemx --encoding=@var{encoding}
2217 Select the character encoding of the strings that are to be found.
2218 Possible values for @var{encoding} are: @samp{s} = single-7-bit-byte
2219 characters (ASCII, ISO 8859, etc., default), @samp{S} =
2220 single-8-bit-byte characters, @samp{b} = 16-bit bigendian, @samp{l} =
2221 16-bit littleendian, @samp{B} = 32-bit bigendian, @samp{L} = 32-bit
2222 littleendian. Useful for finding wide character strings.
2223
2224 @item -T @var{bfdname}
2225 @itemx --target=@var{bfdname}
2226 @cindex object code format
2227 Specify an object code format other than your system's default format.
2228 @xref{Target Selection}, for more information.
2229
2230 @item -v
2231 @itemx --version
2232 Print the program version number on the standard output and exit.
2233 @end table
2234
2235 @c man end
2236
2237 @ignore
2238 @c man begin SEEALSO strings
2239 ar(1), nm(1), objdump(1), ranlib(1), readelf(1)
2240 and the Info entries for @file{binutils}.
2241 @c man end
2242 @end ignore
2243
2244 @node strip
2245 @chapter strip
2246
2247 @kindex strip
2248 @cindex removing symbols
2249 @cindex discarding symbols
2250 @cindex symbols, discarding
2251
2252 @c man title strip Discard symbols from object files.
2253
2254 @smallexample
2255 @c man begin SYNOPSIS strip
2256 strip [@option{-F} @var{bfdname} |@option{--target=}@var{bfdname}]
2257 [@option{-I} @var{bfdname} |@option{--input-target=}@var{bfdname}]
2258 [@option{-O} @var{bfdname} |@option{--output-target=}@var{bfdname}]
2259 [@option{-s}|@option{--strip-all}]
2260 [@option{-S}|@option{-g}|@option{-d}|@option{--strip-debug}]
2261 [@option{-K} @var{symbolname} |@option{--keep-symbol=}@var{symbolname}]
2262 [@option{-N} @var{symbolname} |@option{--strip-symbol=}@var{symbolname}]
2263 [@option{-w}|@option{--wildcard}]
2264 [@option{-x}|@option{--discard-all}] [@option{-X} |@option{--discard-locals}]
2265 [@option{-R} @var{sectionname} |@option{--remove-section=}@var{sectionname}]
2266 [@option{-o} @var{file}] [@option{-p}|@option{--preserve-dates}]
2267 [@option{--keep-file-symbols}]
2268 [@option{--only-keep-debug}]
2269 [@option{-v} |@option{--verbose}] [@option{-V}|@option{--version}]
2270 [@option{--help}] [@option{--info}]
2271 @var{objfile}@dots{}
2272 @c man end
2273 @end smallexample
2274
2275 @c man begin DESCRIPTION strip
2276
2277 @sc{gnu} @command{strip} discards all symbols from object files
2278 @var{objfile}. The list of object files may include archives.
2279 At least one object file must be given.
2280
2281 @command{strip} modifies the files named in its argument,
2282 rather than writing modified copies under different names.
2283
2284 @c man end
2285
2286 @c man begin OPTIONS strip
2287
2288 @table @env
2289 @item -F @var{bfdname}
2290 @itemx --target=@var{bfdname}
2291 Treat the original @var{objfile} as a file with the object
2292 code format @var{bfdname}, and rewrite it in the same format.
2293 @xref{Target Selection}, for more information.
2294
2295 @item --help
2296 Show a summary of the options to @command{strip} and exit.
2297
2298 @item --info
2299 Display a list showing all architectures and object formats available.
2300
2301 @item -I @var{bfdname}
2302 @itemx --input-target=@var{bfdname}
2303 Treat the original @var{objfile} as a file with the object
2304 code format @var{bfdname}.
2305 @xref{Target Selection}, for more information.
2306
2307 @item -O @var{bfdname}
2308 @itemx --output-target=@var{bfdname}
2309 Replace @var{objfile} with a file in the output format @var{bfdname}.
2310 @xref{Target Selection}, for more information.
2311
2312 @item -R @var{sectionname}
2313 @itemx --remove-section=@var{sectionname}
2314 Remove any section named @var{sectionname} from the output file. This
2315 option may be given more than once. Note that using this option
2316 inappropriately may make the output file unusable.
2317
2318 @item -s
2319 @itemx --strip-all
2320 Remove all symbols.
2321
2322 @item -g
2323 @itemx -S
2324 @itemx -d
2325 @itemx --strip-debug
2326 Remove debugging symbols only.
2327
2328 @item --strip-unneeded
2329 Remove all symbols that are not needed for relocation processing.
2330
2331 @item -K @var{symbolname}
2332 @itemx --keep-symbol=@var{symbolname}
2333 When stripping symbols, keep symbol @var{symbolname} even if it would
2334 normally be stripped. This option may be given more than once.
2335
2336 @item -N @var{symbolname}
2337 @itemx --strip-symbol=@var{symbolname}
2338 Remove symbol @var{symbolname} from the source file. This option may be
2339 given more than once, and may be combined with strip options other than
2340 @option{-K}.
2341
2342 @item -o @var{file}
2343 Put the stripped output in @var{file}, rather than replacing the
2344 existing file. When this argument is used, only one @var{objfile}
2345 argument may be specified.
2346
2347 @item -p
2348 @itemx --preserve-dates
2349 Preserve the access and modification dates of the file.
2350
2351 @item -w
2352 @itemx --wildcard
2353 Permit regular expressions in @var{symbolname}s used in other command
2354 line options. The question mark (?), asterisk (*), backslash (\) and
2355 square brackets ([]) operators can be used anywhere in the symbol
2356 name. If the first character of the symbol name is the exclamation
2357 point (!) then the sense of the switch is reversed for that symbol.
2358 For example:
2359
2360 @smallexample
2361 -w -K !foo -K fo*
2362 @end smallexample
2363
2364 would cause strip to only keep symbols that start with the letters
2365 ``fo'', but to discard the symbol ``foo''.
2366
2367 @item -x
2368 @itemx --discard-all
2369 Remove non-global symbols.
2370
2371 @item -X
2372 @itemx --discard-locals
2373 Remove compiler-generated local symbols.
2374 (These usually start with @samp{L} or @samp{.}.)
2375
2376 @item --keep-file-symbols
2377 When stripping a file, perhaps with @option{--strip-debug} or
2378 @option{--strip-unneeded}, retain any symbols specifying source file names,
2379 which would otherwise get stripped.
2380
2381 @item --only-keep-debug
2382 Strip a file, removing any sections that would be stripped by
2383 @option{--strip-debug} and leaving the debugging sections.
2384
2385 The intention is that this option will be used in conjunction with
2386 @option{--add-gnu-debuglink} to create a two part executable. One a
2387 stripped binary which will occupy less space in RAM and in a
2388 distribution and the second a debugging information file which is only
2389 needed if debugging abilities are required. The suggested procedure
2390 to create these files is as follows:
2391
2392 @enumerate
2393 @item Link the executable as normal. Assuming that is is called
2394 @code{foo} then...
2395 @item Run @code{objcopy --only-keep-debug foo foo.dbg} to
2396 create a file containing the debugging info.
2397 @item Run @code{objcopy --strip-debug foo} to create a
2398 stripped executable.
2399 @item Run @code{objcopy --add-gnu-debuglink=foo.dbg foo}
2400 to add a link to the debugging info into the stripped executable.
2401 @end enumerate
2402
2403 Note - the choice of @code{.dbg} as an extension for the debug info
2404 file is arbitrary. Also the @code{--only-keep-debug} step is
2405 optional. You could instead do this:
2406
2407 @enumerate
2408 @item Link the executable as normal.
2409 @item Copy @code{foo} to @code{foo.full}
2410 @item Run @code{strip --strip-debug foo}
2411 @item Run @code{objcopy --add-gnu-debuglink=foo.full foo}
2412 @end enumerate
2413
2414 ie the file pointed to by the @option{--add-gnu-debuglink} can be the
2415 full executable. It does not have to be a file created by the
2416 @option{--only-keep-debug} switch.
2417
2418 Note - this switch is only intended for use on fully linked files. It
2419 does not make sense to use it on object files where the debugging
2420 information may be incomplete. Besides the gnu_debuglink feature
2421 currently only supports the presence of one filename containing
2422 debugging information, not multiple filenames on a one-per-object-file
2423 basis.
2424
2425 @item -V
2426 @itemx --version
2427 Show the version number for @command{strip}.
2428
2429 @item -v
2430 @itemx --verbose
2431 Verbose output: list all object files modified. In the case of
2432 archives, @samp{strip -v} lists all members of the archive.
2433 @end table
2434
2435 @c man end
2436
2437 @ignore
2438 @c man begin SEEALSO strip
2439 the Info entries for @file{binutils}.
2440 @c man end
2441 @end ignore
2442
2443 @node c++filt, addr2line, strip, Top
2444 @chapter c++filt
2445
2446 @kindex c++filt
2447 @cindex demangling C++ symbols
2448
2449 @c man title cxxfilt Demangle C++ and Java symbols.
2450
2451 @smallexample
2452 @c man begin SYNOPSIS cxxfilt
2453 c++filt [@option{-_}|@option{--strip-underscores}]
2454 [@option{-n}|@option{--no-strip-underscores}]
2455 [@option{-p}|@option{--no-params}]
2456 [@option{-t}|@option{--types}]
2457 [@option{-i}|@option{--no-verbose}]
2458 [@option{-s} @var{format}|@option{--format=}@var{format}]
2459 [@option{--help}] [@option{--version}] [@var{symbol}@dots{}]
2460 @c man end
2461 @end smallexample
2462
2463 @c man begin DESCRIPTION cxxfilt
2464
2465 @kindex cxxfilt
2466 The C++ and Java languages provide function overloading, which means
2467 that you can write many functions with the same name, providing that
2468 each function takes parameters of different types. In order to be
2469 able to distinguish these similarly named functions C++ and Java
2470 encode them into a low-level assembler name which uniquely identifies
2471 each different version. This process is known as @dfn{mangling}. The
2472 @command{c++filt}
2473 @footnote{MS-DOS does not allow @kbd{+} characters in file names, so on
2474 MS-DOS this program is named @command{CXXFILT}.}
2475 program does the inverse mapping: it decodes (@dfn{demangles}) low-level
2476 names into user-level names so that they can be read.
2477
2478 Every alphanumeric word (consisting of letters, digits, underscores,
2479 dollars, or periods) seen in the input is a potential mangled name.
2480 If the name decodes into a C++ name, the C++ name replaces the
2481 low-level name in the output, otherwise the original word is output.
2482 In this way you can pass an entire assembler source file, containing
2483 mangled names, through @command{c++filt} and see the same source file
2484 containing demangled names.
2485
2486 You can also use @command{c++filt} to decipher individual symbols by
2487 passing them on the command line:
2488
2489 @example
2490 c++filt @var{symbol}
2491 @end example
2492
2493 If no @var{symbol} arguments are given, @command{c++filt} reads symbol
2494 names from the standard input instead. All the results are printed on
2495 the standard output. The difference between reading names from the
2496 command line versus reading names from the standard input is that
2497 command line arguments are expected to be just mangled names and no
2498 checking is performed to separate them from surrounding text. Thus
2499 for example:
2500
2501 @smallexample
2502 c++filt -n _Z1fv
2503 @end smallexample
2504
2505 will work and demangle the name to ``f()'' whereas:
2506
2507 @smallexample
2508 c++filt -n _Z1fv,
2509 @end smallexample
2510
2511 will not work. (Note the extra comma at the end of the mangled
2512 name which makes it invalid). This command however will work:
2513
2514 @smallexample
2515 echo _Z1fv, | c++filt -n
2516 @end smallexample
2517
2518 and will display ``f(),'' ie the demangled name followed by a
2519 trailing comma. This behaviour is because when the names are read
2520 from the standard input it is expected that they might be part of an
2521 assembler source file where there might be extra, extraneous
2522 characters trailing after a mangled name. eg:
2523
2524 @smallexample
2525 .type _Z1fv, @@function
2526 @end smallexample
2527
2528 @c man end
2529
2530 @c man begin OPTIONS cxxfilt
2531
2532 @table @env
2533 @item -_
2534 @itemx --strip-underscores
2535 On some systems, both the C and C++ compilers put an underscore in front
2536 of every name. For example, the C name @code{foo} gets the low-level
2537 name @code{_foo}. This option removes the initial underscore. Whether
2538 @command{c++filt} removes the underscore by default is target dependent.
2539
2540 @item -j
2541 @itemx --java
2542 Prints demangled names using Java syntax. The default is to use C++
2543 syntax.
2544
2545 @item -n
2546 @itemx --no-strip-underscores
2547 Do not remove the initial underscore.
2548
2549 @item -p
2550 @itemx --no-params
2551 When demangling the name of a function, do not display the types of
2552 the function's parameters.
2553
2554 @item -t
2555 @itemx --types
2556 Attempt to demangle types as well as function names. This is disabled
2557 by default since mangled types are normally only used internally in
2558 the compiler, and they can be confused with non-mangled names. eg
2559 a function called ``a'' treated as a mangled type name would be
2560 demangled to ``signed char''.
2561
2562 @item -i
2563 @itemx --no-verbose
2564 Do not include implementation details (if any) in the demangled
2565 output.
2566
2567 @item -s @var{format}
2568 @itemx --format=@var{format}
2569 @command{c++filt} can decode various methods of mangling, used by
2570 different compilers. The argument to this option selects which
2571 method it uses:
2572
2573 @table @code
2574 @item auto
2575 Automatic selection based on executable (the default method)
2576 @item gnu
2577 the one used by the @sc{gnu} C++ compiler (g++)
2578 @item lucid
2579 the one used by the Lucid compiler (lcc)
2580 @item arm
2581 the one specified by the C++ Annotated Reference Manual
2582 @item hp
2583 the one used by the HP compiler (aCC)
2584 @item edg
2585 the one used by the EDG compiler
2586 @item gnu-v3
2587 the one used by the @sc{gnu} C++ compiler (g++) with the V3 ABI.
2588 @item java
2589 the one used by the @sc{gnu} Java compiler (gcj)
2590 @item gnat
2591 the one used by the @sc{gnu} Ada compiler (GNAT).
2592 @end table
2593
2594 @item --help
2595 Print a summary of the options to @command{c++filt} and exit.
2596
2597 @item --version
2598 Print the version number of @command{c++filt} and exit.
2599 @end table
2600
2601 @c man end
2602
2603 @ignore
2604 @c man begin SEEALSO cxxfilt
2605 the Info entries for @file{binutils}.
2606 @c man end
2607 @end ignore
2608
2609 @quotation
2610 @emph{Warning:} @command{c++filt} is a new utility, and the details of its
2611 user interface are subject to change in future releases. In particular,
2612 a command-line option may be required in the future to decode a name
2613 passed as an argument on the command line; in other words,
2614
2615 @example
2616 c++filt @var{symbol}
2617 @end example
2618
2619 @noindent
2620 may in a future release become
2621
2622 @example
2623 c++filt @var{option} @var{symbol}
2624 @end example
2625 @end quotation
2626
2627 @node addr2line
2628 @chapter addr2line
2629
2630 @kindex addr2line
2631 @cindex address to file name and line number
2632
2633 @c man title addr2line convert addresses into file names and line numbers.
2634
2635 @smallexample
2636 @c man begin SYNOPSIS addr2line
2637 addr2line [@option{-b} @var{bfdname}|@option{--target=}@var{bfdname}]
2638 [@option{-C}|@option{--demangle}[=@var{style}]]
2639 [@option{-e} @var{filename}|@option{--exe=}@var{filename}]
2640 [@option{-f}|@option{--functions}] [@option{-s}|@option{--basename}]
2641 [@option{-i}|@option{--inlines}]
2642 [@option{-j}|@option{--section=}@var{name}]
2643 [@option{-H}|@option{--help}] [@option{-V}|@option{--version}]
2644 [addr addr @dots{}]
2645 @c man end
2646 @end smallexample
2647
2648 @c man begin DESCRIPTION addr2line
2649
2650 @command{addr2line} translates addresses into file names and line numbers.
2651 Given an address in an executable or an offset in a section of a relocatable
2652 object, it uses the debugging information to figure out which file name and
2653 line number are associated with it.
2654
2655 The executable or relocatable object to use is specified with the @option{-e}
2656 option. The default is the file @file{a.out}. The section in the relocatable
2657 object to use is specified with the @option{-j} option.
2658
2659 @command{addr2line} has two modes of operation.
2660
2661 In the first, hexadecimal addresses are specified on the command line,
2662 and @command{addr2line} displays the file name and line number for each
2663 address.
2664
2665 In the second, @command{addr2line} reads hexadecimal addresses from
2666 standard input, and prints the file name and line number for each
2667 address on standard output. In this mode, @command{addr2line} may be used
2668 in a pipe to convert dynamically chosen addresses.
2669
2670 The format of the output is @samp{FILENAME:LINENO}. The file name and
2671 line number for each address is printed on a separate line. If the
2672 @command{-f} option is used, then each @samp{FILENAME:LINENO} line is
2673 preceded by a @samp{FUNCTIONNAME} line which is the name of the function
2674 containing the address.
2675
2676 If the file name or function name can not be determined,
2677 @command{addr2line} will print two question marks in their place. If the
2678 line number can not be determined, @command{addr2line} will print 0.
2679
2680 @c man end
2681
2682 @c man begin OPTIONS addr2line
2683
2684 The long and short forms of options, shown here as alternatives, are
2685 equivalent.
2686
2687 @table @env
2688 @item -b @var{bfdname}
2689 @itemx --target=@var{bfdname}
2690 @cindex object code format
2691 Specify that the object-code format for the object files is
2692 @var{bfdname}.
2693
2694 @item -C
2695 @itemx --demangle[=@var{style}]
2696 @cindex demangling in objdump
2697 Decode (@dfn{demangle}) low-level symbol names into user-level names.
2698 Besides removing any initial underscore prepended by the system, this
2699 makes C++ function names readable. Different compilers have different
2700 mangling styles. The optional demangling style argument can be used to
2701 choose an appropriate demangling style for your compiler. @xref{c++filt},
2702 for more information on demangling.
2703
2704 @item -e @var{filename}
2705 @itemx --exe=@var{filename}
2706 Specify the name of the executable for which addresses should be
2707 translated. The default file is @file{a.out}.
2708
2709 @item -f
2710 @itemx --functions
2711 Display function names as well as file and line number information.
2712
2713 @item -s
2714 @itemx --basenames
2715 Display only the base of each file name.
2716
2717 @item -i
2718 @itemx --inlines
2719 If the address belongs to a function that was inlined, the source
2720 information for all enclosing scopes back to the first non-inlined
2721 function will also be printed. For example, if @code{main} inlines
2722 @code{callee1} which inlines @code{callee2}, and address is from
2723 @code{callee2}, the source information for @code{callee1} and @code{main}
2724 will also be printed.
2725
2726 @item -j
2727 @itemx --section
2728 Read offsets relative to the specified section instead of absolute addresses.
2729 @end table
2730
2731 @c man end
2732
2733 @ignore
2734 @c man begin SEEALSO addr2line
2735 Info entries for @file{binutils}.
2736 @c man end
2737 @end ignore
2738
2739 @node nlmconv
2740 @chapter nlmconv
2741
2742 @command{nlmconv} converts a relocatable object file into a NetWare
2743 Loadable Module.
2744
2745 @ignore
2746 @command{nlmconv} currently works with @samp{i386} object
2747 files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
2748 object files in @sc{elf}, or @code{a.out} format@footnote{
2749 @command{nlmconv} should work with any @samp{i386} or @sc{sparc} object
2750 format in the Binary File Descriptor library. It has only been tested
2751 with the above formats.}.
2752 @end ignore
2753
2754 @quotation
2755 @emph{Warning:} @command{nlmconv} is not always built as part of the binary
2756 utilities, since it is only useful for NLM targets.
2757 @end quotation
2758
2759 @c man title nlmconv converts object code into an NLM.
2760
2761 @smallexample
2762 @c man begin SYNOPSIS nlmconv
2763 nlmconv [@option{-I} @var{bfdname}|@option{--input-target=}@var{bfdname}]
2764 [@option{-O} @var{bfdname}|@option{--output-target=}@var{bfdname}]
2765 [@option{-T} @var{headerfile}|@option{--header-file=}@var{headerfile}]
2766 [@option{-d}|@option{--debug}] [@option{-l} @var{linker}|@option{--linker=}@var{linker}]
2767 [@option{-h}|@option{--help}] [@option{-V}|@option{--version}]
2768 @var{infile} @var{outfile}
2769 @c man end
2770 @end smallexample
2771
2772 @c man begin DESCRIPTION nlmconv
2773
2774 @command{nlmconv} converts the relocatable @samp{i386} object file
2775 @var{infile} into the NetWare Loadable Module @var{outfile}, optionally
2776 reading @var{headerfile} for NLM header information. For instructions
2777 on writing the NLM command file language used in header files, see the
2778 @samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
2779 Development and Tools Overview}, which is part of the NLM Software
2780 Developer's Kit (``NLM SDK''), available from Novell, Inc.
2781 @command{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
2782 @var{infile};
2783 @ifclear man
2784 see @ref{BFD,,BFD,ld.info,Using LD}, for more information.
2785 @end ifclear
2786
2787 @command{nlmconv} can perform a link step. In other words, you can list
2788 more than one object file for input if you list them in the definitions
2789 file (rather than simply specifying one input file on the command line).
2790 In this case, @command{nlmconv} calls the linker for you.
2791
2792 @c man end
2793
2794 @c man begin OPTIONS nlmconv
2795
2796 @table @env
2797 @item -I @var{bfdname}
2798 @itemx --input-target=@var{bfdname}
2799 Object format of the input file. @command{nlmconv} can usually determine
2800 the format of a given file (so no default is necessary).
2801 @xref{Target Selection}, for more information.
2802
2803 @item -O @var{bfdname}
2804 @itemx --output-target=@var{bfdname}
2805 Object format of the output file. @command{nlmconv} infers the output
2806 format based on the input format, e.g. for a @samp{i386} input file the
2807 output format is @samp{nlm32-i386}.
2808 @xref{Target Selection}, for more information.
2809
2810 @item -T @var{headerfile}
2811 @itemx --header-file=@var{headerfile}
2812 Reads @var{headerfile} for NLM header information. For instructions on
2813 writing the NLM command file language used in header files, see@ see the
2814 @samp{linkers} section, of the @cite{NLM Development and Tools
2815 Overview}, which is part of the NLM Software Developer's Kit, available
2816 from Novell, Inc.
2817
2818 @item -d
2819 @itemx --debug
2820 Displays (on standard error) the linker command line used by @command{nlmconv}.
2821
2822 @item -l @var{linker}
2823 @itemx --linker=@var{linker}
2824 Use @var{linker} for any linking. @var{linker} can be an absolute or a
2825 relative pathname.
2826
2827 @item -h
2828 @itemx --help
2829 Prints a usage summary.
2830
2831 @item -V
2832 @itemx --version
2833 Prints the version number for @command{nlmconv}.
2834 @end table
2835
2836 @c man end
2837
2838 @ignore
2839 @c man begin SEEALSO nlmconv
2840 the Info entries for @file{binutils}.
2841 @c man end
2842 @end ignore
2843
2844 @node windres
2845 @chapter windres
2846
2847 @command{windres} may be used to manipulate Windows resources.
2848
2849 @quotation
2850 @emph{Warning:} @command{windres} is not always built as part of the binary
2851 utilities, since it is only useful for Windows targets.
2852 @end quotation
2853
2854 @c man title windres manipulate Windows resources.
2855
2856 @smallexample
2857 @c man begin SYNOPSIS windres
2858 windres [options] [input-file] [output-file]
2859 @c man end
2860 @end smallexample
2861
2862 @c man begin DESCRIPTION windres
2863
2864 @command{windres} reads resources from an input file and copies them into
2865 an output file. Either file may be in one of three formats:
2866
2867 @table @code
2868 @item rc
2869 A text format read by the Resource Compiler.
2870
2871 @item res
2872 A binary format generated by the Resource Compiler.
2873
2874 @item coff
2875 A COFF object or executable.
2876 @end table
2877
2878 The exact description of these different formats is available in
2879 documentation from Microsoft.
2880
2881 When @command{windres} converts from the @code{rc} format to the @code{res}
2882 format, it is acting like the Windows Resource Compiler. When
2883 @command{windres} converts from the @code{res} format to the @code{coff}
2884 format, it is acting like the Windows @code{CVTRES} program.
2885
2886 When @command{windres} generates an @code{rc} file, the output is similar
2887 but not identical to the format expected for the input. When an input
2888 @code{rc} file refers to an external filename, an output @code{rc} file
2889 will instead include the file contents.
2890
2891 If the input or output format is not specified, @command{windres} will
2892 guess based on the file name, or, for the input file, the file contents.
2893 A file with an extension of @file{.rc} will be treated as an @code{rc}
2894 file, a file with an extension of @file{.res} will be treated as a
2895 @code{res} file, and a file with an extension of @file{.o} or
2896 @file{.exe} will be treated as a @code{coff} file.
2897
2898 If no output file is specified, @command{windres} will print the resources
2899 in @code{rc} format to standard output.
2900
2901 The normal use is for you to write an @code{rc} file, use @command{windres}
2902 to convert it to a COFF object file, and then link the COFF file into
2903 your application. This will make the resources described in the
2904 @code{rc} file available to Windows.
2905
2906 @c man end
2907
2908 @c man begin OPTIONS windres
2909
2910 @table @env
2911 @item -i @var{filename}
2912 @itemx --input @var{filename}
2913 The name of the input file. If this option is not used, then
2914 @command{windres} will use the first non-option argument as the input file
2915 name. If there are no non-option arguments, then @command{windres} will
2916 read from standard input. @command{windres} can not read a COFF file from
2917 standard input.
2918
2919 @item -o @var{filename}
2920 @itemx --output @var{filename}
2921 The name of the output file. If this option is not used, then
2922 @command{windres} will use the first non-option argument, after any used
2923 for the input file name, as the output file name. If there is no
2924 non-option argument, then @command{windres} will write to standard output.
2925 @command{windres} can not write a COFF file to standard output. Note,
2926 for compatibility with @command{rc} the option @option{-fo} is also
2927 accepted, but its use is not recommended.
2928
2929 @item -J @var{format}
2930 @itemx --input-format @var{format}
2931 The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
2932 @samp{coff}. If no input format is specified, @command{windres} will
2933 guess, as described above.
2934
2935 @item -O @var{format}
2936 @itemx --output-format @var{format}
2937 The output format to generate. @var{format} may be @samp{res},
2938 @samp{rc}, or @samp{coff}. If no output format is specified,
2939 @command{windres} will guess, as described above.
2940
2941 @item -F @var{target}
2942 @itemx --target @var{target}
2943 Specify the BFD format to use for a COFF file as input or output. This
2944 is a BFD target name; you can use the @option{--help} option to see a list
2945 of supported targets. Normally @command{windres} will use the default
2946 format, which is the first one listed by the @option{--help} option.
2947 @ifclear man
2948 @ref{Target Selection}.
2949 @end ifclear
2950
2951 @item --preprocessor @var{program}
2952 When @command{windres} reads an @code{rc} file, it runs it through the C
2953 preprocessor first. This option may be used to specify the preprocessor
2954 to use, including any leading arguments. The default preprocessor
2955 argument is @code{gcc -E -xc-header -DRC_INVOKED}.
2956
2957 @item -I @var{directory}
2958 @itemx --include-dir @var{directory}
2959 Specify an include directory to use when reading an @code{rc} file.
2960 @command{windres} will pass this to the preprocessor as an @option{-I}
2961 option. @command{windres} will also search this directory when looking for
2962 files named in the @code{rc} file. If the argument passed to this command
2963 matches any of the supported @var{formats} (as described in the @option{-J}
2964 option), it will issue a deprecation warning, and behave just like the
2965 @option{-J} option. New programs should not use this behaviour. If a
2966 directory happens to match a @var{format}, simple prefix it with @samp{./}
2967 to disable the backward compatibility.
2968
2969 @item -D @var{target}
2970 @itemx --define @var{sym}[=@var{val}]
2971 Specify a @option{-D} option to pass to the preprocessor when reading an
2972 @code{rc} file.
2973
2974 @item -U @var{target}
2975 @itemx --undefine @var{sym}
2976 Specify a @option{-U} option to pass to the preprocessor when reading an
2977 @code{rc} file.
2978
2979 @item -r
2980 Ignored for compatibility with rc.
2981
2982 @item -v
2983 Enable verbose mode. This tells you what the preprocessor is if you
2984 didn't specify one.
2985
2986 @item -l @var{val}
2987 @item --language @var{val}
2988 Specify the default language to use when reading an @code{rc} file.
2989 @var{val} should be a hexadecimal language code. The low eight bits are
2990 the language, and the high eight bits are the sublanguage.
2991
2992 @item --use-temp-file
2993 Use a temporary file to instead of using popen to read the output of
2994 the preprocessor. Use this option if the popen implementation is buggy
2995 on the host (eg., certain non-English language versions of Windows 95 and
2996 Windows 98 are known to have buggy popen where the output will instead
2997 go the console).
2998
2999 @item --no-use-temp-file
3000 Use popen, not a temporary file, to read the output of the preprocessor.
3001 This is the default behaviour.
3002
3003 @item -h
3004 @item --help
3005 Prints a usage summary.
3006
3007 @item -V
3008 @item --version
3009 Prints the version number for @command{windres}.
3010
3011 @item --yydebug
3012 If @command{windres} is compiled with @code{YYDEBUG} defined as @code{1},
3013 this will turn on parser debugging.
3014 @end table
3015
3016 @c man end
3017
3018 @ignore
3019 @c man begin SEEALSO windres
3020 the Info entries for @file{binutils}.
3021 @c man end
3022 @end ignore
3023
3024 @node dlltool
3025 @chapter dlltool
3026 @cindex DLL
3027 @kindex dlltool
3028
3029 @command{dlltool} is used to create the files needed to create dynamic
3030 link libraries (DLLs) on systems which understand PE format image
3031 files such as Windows. A DLL contains an export table which contains
3032 information that the runtime loader needs to resolve references from a
3033 referencing program.
3034
3035 The export table is generated by this program by reading in a
3036 @file{.def} file or scanning the @file{.a} and @file{.o} files which
3037 will be in the DLL. A @file{.o} file can contain information in
3038 special @samp{.drectve} sections with export information.
3039
3040 @quotation
3041 @emph{Note:} @command{dlltool} is not always built as part of the
3042 binary utilities, since it is only useful for those targets which
3043 support DLLs.
3044 @end quotation
3045
3046 @c man title dlltool Create files needed to build and use DLLs.
3047
3048 @smallexample
3049 @c man begin SYNOPSIS dlltool
3050 dlltool [@option{-d}|@option{--input-def} @var{def-file-name}]
3051 [@option{-b}|@option{--base-file} @var{base-file-name}]
3052 [@option{-e}|@option{--output-exp} @var{exports-file-name}]
3053 [@option{-z}|@option{--output-def} @var{def-file-name}]
3054 [@option{-l}|@option{--output-lib} @var{library-file-name}]
3055 [@option{--export-all-symbols}] [@option{--no-export-all-symbols}]
3056 [@option{--exclude-symbols} @var{list}]
3057 [@option{--no-default-excludes}]
3058 [@option{-S}|@option{--as} @var{path-to-assembler}] [@option{-f}|@option{--as-flags} @var{options}]
3059 [@option{-D}|@option{--dllname} @var{name}] [@option{-m}|@option{--machine} @var{machine}]
3060 [@option{-a}|@option{--add-indirect}]
3061 [@option{-U}|@option{--add-underscore}] [@option{--add-stdcall-underscore}]
3062 [@option{-k}|@option{--kill-at}] [@option{-A}|@option{--add-stdcall-alias}]
3063 [@option{-p}|@option{--ext-prefix-alias} @var{prefix}]
3064 [@option{-x}|@option{--no-idata4}] [@option{-c}|@option{--no-idata5}] [@option{-i}|@option{--interwork}]
3065 [@option{-n}|@option{--nodelete}] [@option{-t}|@option{--temp-prefix} @var{prefix}]
3066 [@option{-v}|@option{--verbose}]
3067 [@option{-h}|@option{--help}] [@option{-V}|@option{--version}]
3068 [object-file @dots{}]
3069 @c man end
3070 @end smallexample
3071
3072 @c man begin DESCRIPTION dlltool
3073
3074 @command{dlltool} reads its inputs, which can come from the @option{-d} and
3075 @option{-b} options as well as object files specified on the command
3076 line. It then processes these inputs and if the @option{-e} option has
3077 been specified it creates a exports file. If the @option{-l} option
3078 has been specified it creates a library file and if the @option{-z} option
3079 has been specified it creates a def file. Any or all of the @option{-e},
3080 @option{-l} and @option{-z} options can be present in one invocation of
3081 dlltool.
3082
3083 When creating a DLL, along with the source for the DLL, it is necessary
3084 to have three other files. @command{dlltool} can help with the creation of
3085 these files.
3086
3087 The first file is a @file{.def} file which specifies which functions are
3088 exported from the DLL, which functions the DLL imports, and so on. This
3089 is a text file and can be created by hand, or @command{dlltool} can be used
3090 to create it using the @option{-z} option. In this case @command{dlltool}
3091 will scan the object files specified on its command line looking for
3092 those functions which have been specially marked as being exported and
3093 put entries for them in the @file{.def} file it creates.
3094
3095 In order to mark a function as being exported from a DLL, it needs to
3096 have an @option{-export:<name_of_function>} entry in the @samp{.drectve}
3097 section of the object file. This can be done in C by using the
3098 asm() operator:
3099
3100 @smallexample
3101 asm (".section .drectve");
3102 asm (".ascii \"-export:my_func\"");
3103
3104 int my_func (void) @{ @dots{} @}
3105 @end smallexample
3106
3107 The second file needed for DLL creation is an exports file. This file
3108 is linked with the object files that make up the body of the DLL and it
3109 handles the interface between the DLL and the outside world. This is a
3110 binary file and it can be created by giving the @option{-e} option to
3111 @command{dlltool} when it is creating or reading in a @file{.def} file.
3112
3113 The third file needed for DLL creation is the library file that programs
3114 will link with in order to access the functions in the DLL. This file
3115 can be created by giving the @option{-l} option to dlltool when it
3116 is creating or reading in a @file{.def} file.
3117
3118 @command{dlltool} builds the library file by hand, but it builds the
3119 exports file by creating temporary files containing assembler statements
3120 and then assembling these. The @option{-S} command line option can be
3121 used to specify the path to the assembler that dlltool will use,
3122 and the @option{-f} option can be used to pass specific flags to that
3123 assembler. The @option{-n} can be used to prevent dlltool from deleting
3124 these temporary assembler files when it is done, and if @option{-n} is
3125 specified twice then this will prevent dlltool from deleting the
3126 temporary object files it used to build the library.
3127
3128 Here is an example of creating a DLL from a source file @samp{dll.c} and
3129 also creating a program (from an object file called @samp{program.o})
3130 that uses that DLL:
3131
3132 @smallexample
3133 gcc -c dll.c
3134 dlltool -e exports.o -l dll.lib dll.o
3135 gcc dll.o exports.o -o dll.dll
3136 gcc program.o dll.lib -o program
3137 @end smallexample
3138
3139 @c man end
3140
3141 @c man begin OPTIONS dlltool
3142
3143 The command line options have the following meanings:
3144
3145 @table @env
3146
3147 @item -d @var{filename}
3148 @itemx --input-def @var{filename}
3149 @cindex input .def file
3150 Specifies the name of a @file{.def} file to be read in and processed.
3151
3152 @item -b @var{filename}
3153 @itemx --base-file @var{filename}
3154 @cindex base files
3155 Specifies the name of a base file to be read in and processed. The
3156 contents of this file will be added to the relocation section in the
3157 exports file generated by dlltool.
3158
3159 @item -e @var{filename}
3160 @itemx --output-exp @var{filename}
3161 Specifies the name of the export file to be created by dlltool.
3162
3163 @item -z @var{filename}
3164 @itemx --output-def @var{filename}
3165 Specifies the name of the @file{.def} file to be created by dlltool.
3166
3167 @item -l @var{filename}
3168 @itemx --output-lib @var{filename}
3169 Specifies the name of the library file to be created by dlltool.
3170
3171 @item --export-all-symbols
3172 Treat all global and weak defined symbols found in the input object
3173 files as symbols to be exported. There is a small list of symbols which
3174 are not exported by default; see the @option{--no-default-excludes}
3175 option. You may add to the list of symbols to not export by using the
3176 @option{--exclude-symbols} option.
3177
3178 @item --no-export-all-symbols
3179 Only export symbols explicitly listed in an input @file{.def} file or in
3180 @samp{.drectve} sections in the input object files. This is the default
3181 behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
3182 attributes in the source code.
3183
3184 @item --exclude-symbols @var{list}
3185 Do not export the symbols in @var{list}. This is a list of symbol names
3186 separated by comma or colon characters. The symbol names should not
3187 contain a leading underscore. This is only meaningful when
3188 @option{--export-all-symbols} is used.
3189
3190 @item --no-default-excludes
3191 When @option{--export-all-symbols} is used, it will by default avoid
3192 exporting certain special symbols. The current list of symbols to avoid
3193 exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
3194 @samp{impure_ptr}. You may use the @option{--no-default-excludes} option
3195 to go ahead and export these special symbols. This is only meaningful
3196 when @option{--export-all-symbols} is used.
3197
3198 @item -S @var{path}
3199 @itemx --as @var{path}
3200 Specifies the path, including the filename, of the assembler to be used
3201 to create the exports file.
3202
3203 @item -f @var{options}
3204 @itemx --as-flags @var{options}
3205 Specifies any specific command line options to be passed to the
3206 assembler when building the exports file. This option will work even if
3207 the @option{-S} option is not used. This option only takes one argument,
3208 and if it occurs more than once on the command line, then later
3209 occurrences will override earlier occurrences. So if it is necessary to
3210 pass multiple options to the assembler they should be enclosed in
3211 double quotes.
3212
3213 @item -D @var{name}
3214 @itemx --dll-name @var{name}
3215 Specifies the name to be stored in the @file{.def} file as the name of
3216 the DLL when the @option{-e} option is used. If this option is not
3217 present, then the filename given to the @option{-e} option will be
3218 used as the name of the DLL.
3219
3220 @item -m @var{machine}
3221 @itemx -machine @var{machine}
3222 Specifies the type of machine for which the library file should be
3223 built. @command{dlltool} has a built in default type, depending upon how
3224 it was created, but this option can be used to override that. This is
3225 normally only useful when creating DLLs for an ARM processor, when the
3226 contents of the DLL are actually encode using Thumb instructions.
3227
3228 @item -a
3229 @itemx --add-indirect
3230 Specifies that when @command{dlltool} is creating the exports file it
3231 should add a section which allows the exported functions to be
3232 referenced without using the import library. Whatever the hell that
3233 means!
3234
3235 @item -U
3236 @itemx --add-underscore
3237 Specifies that when @command{dlltool} is creating the exports file it
3238 should prepend an underscore to the names of @emph{all} exported symbols.
3239
3240 @item --add-stdcall-underscore
3241 Specifies that when @command{dlltool} is creating the exports file it
3242 should prepend an underscore to the names of exported @emph{stdcall}
3243 functions. Variable names and non-stdcall function names are not modified.
3244 This option is useful when creating GNU-compatible import libs for third
3245 party DLLs that were built with MS-Windows tools.
3246
3247 @item -k
3248 @itemx --kill-at
3249 Specifies that when @command{dlltool} is creating the exports file it
3250 should not append the string @samp{@@ <number>}. These numbers are
3251 called ordinal numbers and they represent another way of accessing the
3252 function in a DLL, other than by name.
3253
3254 @item -A
3255 @itemx --add-stdcall-alias
3256 Specifies that when @command{dlltool} is creating the exports file it
3257 should add aliases for stdcall symbols without @samp{@@ <number>}
3258 in addition to the symbols with @samp{@@ <number>}.
3259
3260 @item -p
3261 @itemx --ext-prefix-alias @var{prefix}
3262 Causes @command{dlltool} to create external aliases for all DLL
3263 imports with the specified prefix. The aliases are created for both
3264 external and import symbols with no leading underscore.
3265
3266 @item -x
3267 @itemx --no-idata4
3268 Specifies that when @command{dlltool} is creating the exports and library
3269 files it should omit the @code{.idata4} section. This is for compatibility
3270 with certain operating systems.
3271
3272 @item -c
3273 @itemx --no-idata5
3274 Specifies that when @command{dlltool} is creating the exports and library
3275 files it should omit the @code{.idata5} section. This is for compatibility
3276 with certain operating systems.
3277
3278 @item -i
3279 @itemx --interwork
3280 Specifies that @command{dlltool} should mark the objects in the library
3281 file and exports file that it produces as supporting interworking
3282 between ARM and Thumb code.
3283
3284 @item -n
3285 @itemx --nodelete
3286 Makes @command{dlltool} preserve the temporary assembler files it used to
3287 create the exports file. If this option is repeated then dlltool will
3288 also preserve the temporary object files it uses to create the library
3289 file.
3290
3291 @item -t @var{prefix}
3292 @itemx --temp-prefix @var{prefix}
3293 Makes @command{dlltool} use @var{prefix} when constructing the names of
3294 temporary assembler and object files. By default, the temp file prefix
3295 is generated from the pid.
3296
3297 @item -v
3298 @itemx --verbose
3299 Make dlltool describe what it is doing.
3300
3301 @item -h
3302 @itemx --help
3303 Displays a list of command line options and then exits.
3304
3305 @item -V
3306 @itemx --version
3307 Displays dlltool's version number and then exits.
3308
3309 @end table
3310
3311 @c man end
3312
3313 @menu
3314 * def file format:: The format of the dlltool @file{.def} file
3315 @end menu
3316
3317 @node def file format
3318 @section The format of the @command{dlltool} @file{.def} file
3319
3320 A @file{.def} file contains any number of the following commands:
3321
3322 @table @asis
3323
3324 @item @code{NAME} @var{name} @code{[ ,} @var{base} @code{]}
3325 The result is going to be named @var{name}@code{.exe}.
3326
3327 @item @code{LIBRARY} @var{name} @code{[ ,} @var{base} @code{]}
3328 The result is going to be named @var{name}@code{.dll}.
3329
3330 @item @code{EXPORTS ( ( (} @var{name1} @code{[ = } @var{name2} @code{] ) | ( } @var{name1} @code{=} @var{module-name} @code{.} @var{external-name} @code{) )}
3331 @item @code{[} @var{integer} @code{] [ NONAME ] [ CONSTANT ] [ DATA ] [ PRIVATE ] ) *}
3332 Declares @var{name1} as an exported symbol from the DLL, with optional
3333 ordinal number @var{integer}, or declares @var{name1} as an alias
3334 (forward) of the function @var{external-name} in the DLL
3335 @var{module-name}.
3336
3337 @item @code{IMPORTS ( (} @var{internal-name} @code{=} @var{module-name} @code{.} @var{integer} @code{) | [} @var{internal-name} @code{= ]} @var{module-name} @code{.} @var{external-name} @code{) ) *}
3338 Declares that @var{external-name} or the exported function whose
3339 ordinal number is @var{integer} is to be imported from the file
3340 @var{module-name}. If @var{internal-name} is specified then this is
3341 the name that the imported function will be referred to in the body of
3342 the DLL.
3343
3344 @item @code{DESCRIPTION} @var{string}
3345 Puts @var{string} into the output @file{.exp} file in the
3346 @code{.rdata} section.
3347
3348 @item @code{STACKSIZE} @var{number-reserve} @code{[, } @var{number-commit} @code{]}
3349 @item @code{HEAPSIZE} @var{number-reserve} @code{[, } @var{number-commit} @code{]}
3350 Generates @code{--stack} or @code{--heap}
3351 @var{number-reserve},@var{number-commit} in the output @code{.drectve}
3352 section. The linker will see this and act upon it.
3353
3354 @item @code{CODE} @var{attr} @code{+}
3355 @item @code{DATA} @var{attr} @code{+}
3356 @item @code{SECTIONS (} @var{section-name} @var{attr}@code{ + ) *}
3357 Generates @code{--attr} @var{section-name} @var{attr} in the output
3358 @code{.drectve} section, where @var{attr} is one of @code{READ},
3359 @code{WRITE}, @code{EXECUTE} or @code{SHARED}. The linker will see
3360 this and act upon it.
3361
3362 @end table
3363
3364 @ignore
3365 @c man begin SEEALSO dlltool
3366 The Info pages for @file{binutils}.
3367 @c man end
3368 @end ignore
3369
3370 @node readelf
3371 @chapter readelf
3372
3373 @cindex ELF file information
3374 @kindex readelf
3375
3376 @c man title readelf Displays information about ELF files.
3377
3378 @smallexample
3379 @c man begin SYNOPSIS readelf
3380 readelf [@option{-a}|@option{--all}]
3381 [@option{-h}|@option{--file-header}]
3382 [@option{-l}|@option{--program-headers}|@option{--segments}]
3383 [@option{-S}|@option{--section-headers}|@option{--sections}]
3384 [@option{-g}|@option{--section-groups}]
3385 [@option{-t}|@option{--section-details}]
3386 [@option{-e}|@option{--headers}]
3387 [@option{-s}|@option{--syms}|@option{--symbols}]
3388 [@option{-n}|@option{--notes}]
3389 [@option{-r}|@option{--relocs}]
3390 [@option{-u}|@option{--unwind}]
3391 [@option{-d}|@option{--dynamic}]
3392 [@option{-V}|@option{--version-info}]
3393 [@option{-A}|@option{--arch-specific}]
3394 [@option{-D}|@option{--use-dynamic}]
3395 [@option{-x} <number or name>|@option{--hex-dump=}<number or name>]
3396 [@option{-w[liaprmfFsoR]}|
3397 @option{--debug-dump}[=line,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges]]
3398 [@option{-I}|@option{-histogram}]
3399 [@option{-v}|@option{--version}]
3400 [@option{-W}|@option{--wide}]
3401 [@option{-H}|@option{--help}]
3402 @var{elffile}@dots{}
3403 @c man end
3404 @end smallexample
3405
3406 @c man begin DESCRIPTION readelf
3407
3408 @command{readelf} displays information about one or more ELF format object
3409 files. The options control what particular information to display.
3410
3411 @var{elffile}@dots{} are the object files to be examined. 32-bit and
3412 64-bit ELF files are supported, as are archives containing ELF files.
3413
3414 This program performs a similar function to @command{objdump} but it
3415 goes into more detail and it exists independently of the @sc{bfd}
3416 library, so if there is a bug in @sc{bfd} then readelf will not be
3417 affected.
3418
3419 @c man end
3420
3421 @c man begin OPTIONS readelf
3422
3423 The long and short forms of options, shown here as alternatives, are
3424 equivalent. At least one option besides @samp{-v} or @samp{-H} must be
3425 given.
3426
3427 @table @env
3428 @item -a
3429 @itemx --all
3430 Equivalent to specifying @option{--file-header},
3431 @option{--program-headers}, @option{--sections}, @option{--symbols},
3432 @option{--relocs}, @option{--dynamic}, @option{--notes} and
3433 @option{--version-info}.
3434
3435 @item -h
3436 @itemx --file-header
3437 @cindex ELF file header information
3438 Displays the information contained in the ELF header at the start of the
3439 file.
3440
3441 @item -l
3442 @itemx --program-headers
3443 @itemx --segments
3444 @cindex ELF program header information
3445 @cindex ELF segment information
3446 Displays the information contained in the file's segment headers, if it
3447 has any.
3448
3449 @item -S
3450 @itemx --sections
3451 @itemx --section-headers
3452 @cindex ELF section information
3453 Displays the information contained in the file's section headers, if it
3454 has any.
3455
3456 @item -g
3457 @itemx --section-groups
3458 @cindex ELF section group information
3459 Displays the information contained in the file's section groups, if it
3460 has any.
3461
3462 @item -t
3463 @itemx --section-details
3464 @cindex ELF section information
3465 Displays the detailed section information. Implies @option{-S}.
3466
3467 @item -s
3468 @itemx --symbols
3469 @itemx --syms
3470 @cindex ELF symbol table information
3471 Displays the entries in symbol table section of the file, if it has one.
3472
3473 @item -e
3474 @itemx --headers
3475 Display all the headers in the file. Equivalent to @option{-h -l -S}.
3476
3477 @item -n
3478 @itemx --notes
3479 @cindex ELF notes
3480 Displays the contents of the NOTE segments and/or sections, if any.
3481
3482 @item -r
3483 @itemx --relocs
3484 @cindex ELF reloc information
3485 Displays the contents of the file's relocation section, if it has one.
3486
3487 @item -u
3488 @itemx --unwind
3489 @cindex unwind information
3490 Displays the contents of the file's unwind section, if it has one. Only
3491 the unwind sections for IA64 ELF files are currently supported.
3492
3493 @item -d
3494 @itemx --dynamic
3495 @cindex ELF dynamic section information
3496 Displays the contents of the file's dynamic section, if it has one.
3497
3498 @item -V
3499 @itemx --version-info
3500 @cindex ELF version sections informations
3501 Displays the contents of the version sections in the file, it they
3502 exist.
3503
3504 @item -A
3505 @itemx --arch-specific
3506 Displays architecture-specific information in the file, if there
3507 is any.
3508
3509 @item -D
3510 @itemx --use-dynamic
3511 When displaying symbols, this option makes @command{readelf} use the
3512 symbol table in the file's dynamic section, rather than the one in the
3513 symbols section.
3514
3515 @item -x <number or name>
3516 @itemx --hex-dump=<number or name>
3517 Displays the contents of the indicated section as a hexadecimal dump.
3518 A number identifies a particular section by index in the section table;
3519 any other string identifies all sections with that name in the object file.
3520
3521 @item -w[liaprmfFsoR]
3522 @itemx --debug-dump[=line,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges]
3523 Displays the contents of the debug sections in the file, if any are
3524 present. If one of the optional letters or words follows the switch
3525 then only data found in those specific sections will be dumped.
3526
3527 @item -I
3528 @itemx --histogram
3529 Display a histogram of bucket list lengths when displaying the contents
3530 of the symbol tables.
3531
3532 @item -v
3533 @itemx --version
3534 Display the version number of readelf.
3535
3536 @item -W
3537 @itemx --wide
3538 Don't break output lines to fit into 80 columns. By default
3539 @command{readelf} breaks section header and segment listing lines for
3540 64-bit ELF files, so that they fit into 80 columns. This option causes
3541 @command{readelf} to print each section header resp. each segment one a
3542 single line, which is far more readable on terminals wider than 80 columns.
3543
3544 @item -H
3545 @itemx --help
3546 Display the command line options understood by @command{readelf}.
3547
3548 @end table
3549
3550 @c man end
3551
3552 @ignore
3553 @c man begin SEEALSO readelf
3554 objdump(1), and the Info entries for @file{binutils}.
3555 @c man end
3556 @end ignore
3557
3558 @node Common Options
3559 @chapter Common Options
3560
3561 The following command-line options are supported by all of the
3562 programs described in this manual.
3563
3564 @c man begin OPTIONS
3565 @table @env
3566 @include at-file.texi
3567 @c man end
3568
3569 @item --help
3570 Display the command-line options supported by the program.
3571
3572 @item --version
3573 Display the version number of the program.
3574
3575 @c man begin OPTIONS
3576 @end table
3577 @c man end
3578
3579 @node Selecting The Target System
3580 @chapter Selecting the Target System
3581
3582 You can specify two aspects of the target system to the @sc{gnu}
3583 binary file utilities, each in several ways:
3584
3585 @itemize @bullet
3586 @item
3587 the target
3588
3589 @item
3590 the architecture
3591 @end itemize
3592
3593 In the following summaries, the lists of ways to specify values are in
3594 order of decreasing precedence. The ways listed first override those
3595 listed later.
3596
3597 The commands to list valid values only list the values for which the
3598 programs you are running were configured. If they were configured with
3599 @option{--enable-targets=all}, the commands list most of the available
3600 values, but a few are left out; not all targets can be configured in at
3601 once because some of them can only be configured @dfn{native} (on hosts
3602 with the same type as the target system).
3603
3604 @menu
3605 * Target Selection::
3606 * Architecture Selection::
3607 @end menu
3608
3609 @node Target Selection
3610 @section Target Selection
3611
3612 A @dfn{target} is an object file format. A given target may be
3613 supported for multiple architectures (@pxref{Architecture Selection}).
3614 A target selection may also have variations for different operating
3615 systems or architectures.
3616
3617 The command to list valid target values is @samp{objdump -i}
3618 (the first column of output contains the relevant information).
3619
3620 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
3621 @samp{a.out-sunos-big}.
3622
3623 You can also specify a target using a configuration triplet. This is
3624 the same sort of name that is passed to @file{configure} to specify a
3625 target. When you use a configuration triplet as an argument, it must be
3626 fully canonicalized. You can see the canonical version of a triplet by
3627 running the shell script @file{config.sub} which is included with the
3628 sources.
3629
3630 Some sample configuration triplets are: @samp{m68k-hp-bsd},
3631 @samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
3632
3633 @subheading @command{objdump} Target
3634
3635 Ways to specify:
3636
3637 @enumerate
3638 @item
3639 command line option: @option{-b} or @option{--target}
3640
3641 @item
3642 environment variable @code{GNUTARGET}
3643
3644 @item
3645 deduced from the input file
3646 @end enumerate
3647
3648 @subheading @command{objcopy} and @command{strip} Input Target
3649
3650 Ways to specify:
3651
3652 @enumerate
3653 @item
3654 command line options: @option{-I} or @option{--input-target}, or @option{-F} or @option{--target}
3655
3656 @item
3657 environment variable @code{GNUTARGET}
3658
3659 @item
3660 deduced from the input file
3661 @end enumerate
3662
3663 @subheading @command{objcopy} and @command{strip} Output Target
3664
3665 Ways to specify:
3666
3667 @enumerate
3668 @item
3669 command line options: @option{-O} or @option{--output-target}, or @option{-F} or @option{--target}
3670
3671 @item
3672 the input target (see ``@command{objcopy} and @command{strip} Input Target'' above)
3673
3674 @item
3675 environment variable @code{GNUTARGET}
3676
3677 @item
3678 deduced from the input file
3679 @end enumerate
3680
3681 @subheading @command{nm}, @command{size}, and @command{strings} Target
3682
3683 Ways to specify:
3684
3685 @enumerate
3686 @item
3687 command line option: @option{--target}
3688
3689 @item
3690 environment variable @code{GNUTARGET}
3691
3692 @item
3693 deduced from the input file
3694 @end enumerate
3695
3696 @node Architecture Selection
3697 @section Architecture Selection
3698
3699 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
3700 to run. Its name may contain a colon, separating the name of the
3701 processor family from the name of the particular @sc{cpu}.
3702
3703 The command to list valid architecture values is @samp{objdump -i} (the
3704 second column contains the relevant information).
3705
3706 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
3707
3708 @subheading @command{objdump} Architecture
3709
3710 Ways to specify:
3711
3712 @enumerate
3713 @item
3714 command line option: @option{-m} or @option{--architecture}
3715
3716 @item
3717 deduced from the input file
3718 @end enumerate
3719
3720 @subheading @command{objcopy}, @command{nm}, @command{size}, @command{strings} Architecture
3721
3722 Ways to specify:
3723
3724 @enumerate
3725 @item
3726 deduced from the input file
3727 @end enumerate
3728
3729 @node Reporting Bugs
3730 @chapter Reporting Bugs
3731 @cindex bugs
3732 @cindex reporting bugs
3733
3734 Your bug reports play an essential role in making the binary utilities
3735 reliable.
3736
3737 Reporting a bug may help you by bringing a solution to your problem, or
3738 it may not. But in any case the principal function of a bug report is
3739 to help the entire community by making the next version of the binary
3740 utilities work better. Bug reports are your contribution to their
3741 maintenance.
3742
3743 In order for a bug report to serve its purpose, you must include the
3744 information that enables us to fix the bug.
3745
3746 @menu
3747 * Bug Criteria:: Have you found a bug?
3748 * Bug Reporting:: How to report bugs
3749 @end menu
3750
3751 @node Bug Criteria
3752 @section Have You Found a Bug?
3753 @cindex bug criteria
3754
3755 If you are not sure whether you have found a bug, here are some guidelines:
3756
3757 @itemize @bullet
3758 @cindex fatal signal
3759 @cindex crash
3760 @item
3761 If a binary utility gets a fatal signal, for any input whatever, that is
3762 a bug. Reliable utilities never crash.
3763
3764 @cindex error on valid input
3765 @item
3766 If a binary utility produces an error message for valid input, that is a
3767 bug.
3768
3769 @item
3770 If you are an experienced user of binary utilities, your suggestions for
3771 improvement are welcome in any case.
3772 @end itemize
3773
3774 @node Bug Reporting
3775 @section How to Report Bugs
3776 @cindex bug reports
3777 @cindex bugs, reporting
3778
3779 A number of companies and individuals offer support for @sc{gnu}
3780 products. If you obtained the binary utilities from a support
3781 organization, we recommend you contact that organization first.
3782
3783 You can find contact information for many support companies and
3784 individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
3785 distribution.
3786
3787 In any event, we also recommend that you send bug reports for the binary
3788 utilities to @samp{bug-binutils@@gnu.org}.
3789
3790 The fundamental principle of reporting bugs usefully is this:
3791 @strong{report all the facts}. If you are not sure whether to state a
3792 fact or leave it out, state it!
3793
3794 Often people omit facts because they think they know what causes the
3795 problem and assume that some details do not matter. Thus, you might
3796 assume that the name of a file you use in an example does not matter.
3797 Well, probably it does not, but one cannot be sure. Perhaps the bug is
3798 a stray memory reference which happens to fetch from the location where
3799 that pathname is stored in memory; perhaps, if the pathname were
3800 different, the contents of that location would fool the utility into
3801 doing the right thing despite the bug. Play it safe and give a
3802 specific, complete example. That is the easiest thing for you to do,
3803 and the most helpful.
3804
3805 Keep in mind that the purpose of a bug report is to enable us to fix the bug if
3806 it is new to us. Therefore, always write your bug reports on the assumption
3807 that the bug has not been reported previously.
3808
3809 Sometimes people give a few sketchy facts and ask, ``Does this ring a
3810 bell?'' This cannot help us fix a bug, so it is basically useless. We
3811 respond by asking for enough details to enable us to investigate.
3812 You might as well expedite matters by sending them to begin with.
3813
3814 To enable us to fix the bug, you should include all these things:
3815
3816 @itemize @bullet
3817 @item
3818 The version of the utility. Each utility announces it if you start it
3819 with the @option{--version} argument.
3820
3821 Without this, we will not know whether there is any point in looking for
3822 the bug in the current version of the binary utilities.
3823
3824 @item
3825 Any patches you may have applied to the source, including any patches
3826 made to the @code{BFD} library.
3827
3828 @item
3829 The type of machine you are using, and the operating system name and
3830 version number.
3831
3832 @item
3833 What compiler (and its version) was used to compile the utilities---e.g.
3834 ``@code{gcc-2.7}''.
3835
3836 @item
3837 The command arguments you gave the utility to observe the bug. To
3838 guarantee you will not omit something important, list them all. A copy
3839 of the Makefile (or the output from make) is sufficient.
3840
3841 If we were to try to guess the arguments, we would probably guess wrong
3842 and then we might not encounter the bug.
3843
3844 @item
3845 A complete input file, or set of input files, that will reproduce the
3846 bug. If the utility is reading an object file or files, then it is
3847 generally most helpful to send the actual object files, uuencoded if
3848 necessary to get them through the mail system. Note that
3849 @samp{bug-binutils@@gnu.org} is a mailing list, so you should avoid
3850 sending very large files to it. Making the files available for
3851 anonymous FTP is OK.
3852
3853 If the source files were produced exclusively using @sc{gnu} programs
3854 (e.g., @command{gcc}, @command{gas}, and/or the @sc{gnu} @command{ld}), then it
3855 may be OK to send the source files rather than the object files. In
3856 this case, be sure to say exactly what version of @command{gcc}, or
3857 whatever, was used to produce the object files. Also say how
3858 @command{gcc}, or whatever, was configured.
3859
3860 @item
3861 A description of what behavior you observe that you believe is
3862 incorrect. For example, ``It gets a fatal signal.''
3863
3864 Of course, if the bug is that the utility gets a fatal signal, then we
3865 will certainly notice it. But if the bug is incorrect output, we might
3866 not notice unless it is glaringly wrong. You might as well not give us
3867 a chance to make a mistake.
3868
3869 Even if the problem you experience is a fatal signal, you should still
3870 say so explicitly. Suppose something strange is going on, such as your
3871 copy of the utility is out of sync, or you have encountered a bug in
3872 the C library on your system. (This has happened!) Your copy might
3873 crash and ours would not. If you told us to expect a crash, then when
3874 ours fails to crash, we would know that the bug was not happening for
3875 us. If you had not told us to expect a crash, then we would not be able
3876 to draw any conclusion from our observations.
3877
3878 @item
3879 If you wish to suggest changes to the source, send us context diffs, as
3880 generated by @command{diff} with the @option{-u}, @option{-c}, or @option{-p}
3881 option. Always send diffs from the old file to the new file. If you
3882 wish to discuss something in the @command{ld} source, refer to it by
3883 context, not by line number.
3884
3885 The line numbers in our development sources will not match those in your
3886 sources. Your line numbers would convey no useful information to us.
3887 @end itemize
3888
3889 Here are some things that are not necessary:
3890
3891 @itemize @bullet
3892 @item
3893 A description of the envelope of the bug.
3894
3895 Often people who encounter a bug spend a lot of time investigating
3896 which changes to the input file will make the bug go away and which
3897 changes will not affect it.
3898
3899 This is often time consuming and not very useful, because the way we
3900 will find the bug is by running a single example under the debugger
3901 with breakpoints, not by pure deduction from a series of examples.
3902 We recommend that you save your time for something else.
3903
3904 Of course, if you can find a simpler example to report @emph{instead}
3905 of the original one, that is a convenience for us. Errors in the
3906 output will be easier to spot, running under the debugger will take
3907 less time, and so on.
3908
3909 However, simplification is not vital; if you do not want to do this,
3910 report the bug anyway and send us the entire test case you used.
3911
3912 @item
3913 A patch for the bug.
3914
3915 A patch for the bug does help us if it is a good one. But do not omit
3916 the necessary information, such as the test case, on the assumption that
3917 a patch is all we need. We might see problems with your patch and decide
3918 to fix the problem another way, or we might not understand it at all.
3919
3920 Sometimes with programs as complicated as the binary utilities it is
3921 very hard to construct an example that will make the program follow a
3922 certain path through the code. If you do not send us the example, we
3923 will not be able to construct one, so we will not be able to verify that
3924 the bug is fixed.
3925
3926 And if we cannot understand what bug you are trying to fix, or why your
3927 patch should be an improvement, we will not install it. A test case will
3928 help us to understand.
3929
3930 @item
3931 A guess about what the bug is or what it depends on.
3932
3933 Such guesses are usually wrong. Even we cannot guess right about such
3934 things without first using the debugger to find the facts.
3935 @end itemize
3936
3937 @include fdl.texi
3938
3939 @node Binutils Index
3940 @unnumbered Binutils Index
3941
3942 @printindex cp
3943
3944 @contents
3945 @bye
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