* binutils.texi: Add info dir entries for all programs described
[binutils-gdb.git] / binutils / binutils.texi
1 \input texinfo @c -*- Texinfo -*-
2 @setfilename binutils.info
3 @include config.texi
4
5 @ifinfo
6 @format
7 START-INFO-DIR-ENTRY
8 * Binutils: (binutils). The GNU binary utilities.
9 * ar: (binutils)ar. Create, modify, and extract from archives
10 * nm: (binutils)nm. List symbols from object files
11 * objcopy: (binutils)objcopy. Copy and translate object files
12 * objdump: (binutils)objdump. Display information from object files
13 * ranlib: (binutils)ranlib. Generate index to archive contents
14 * readelf: (binutils)readelf. Display the contents of ELF format files.
15 * size: (binutils)size. List section sizes and total size
16 * strings: (binutils)strings. List printable strings from files
17 * strip: (binutils)strip. Discard symbols
18 * c++filt: (binutils)c++filt. Filter to demangle encoded C++ symbols
19 * cxxfilt: (binutils)c++filt. MS-DOS name for c++filt
20 * addr2line: (binutils)addr2line. Convert addresses to file and line
21 * nlmconv: (binutils)nlmconv. Converts object code into an NLM
22 * windres: (binutils)windres. Manipulate Windows resources
23 * dlltool: (binutils)dlltool. Create files needed to build and use DLLs
24 END-INFO-DIR-ENTRY
25 @end format
26 @end ifinfo
27
28 @ifinfo
29 Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 98, 1999 Free Software Foundation, Inc.
30
31 Permission is granted to make and distribute verbatim copies of
32 this manual provided the copyright notice and this permission notice
33 are preserved on all copies.
34
35 @ignore
36 Permission is granted to process this file through TeX and print the
37 results, provided the printed document carries a copying permission
38 notice identical to this one except for the removal of this paragraph
39 (this paragraph not being relevant to the printed manual).
40
41 @end ignore
42
43 Permission is granted to copy and distribute modified versions of this
44 manual under the conditions for verbatim copying, provided also that
45 the entire resulting derived work is distributed under the terms of a
46 permission notice identical to this one.
47
48 Permission is granted to copy and distribute translations of this manual
49 into another language, under the above conditions for modified versions.
50 @end ifinfo
51
52 @synindex ky cp
53 @c
54 @c This file documents the GNU binary utilities "ar", "ld", "objcopy",
55 @c "objdump", "nm", "size", "strings", "strip", "readelf" and "ranlib".
56 @c
57 @c Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 1999 Free Software Foundation, Inc.
58 @c
59 @c This text may be freely distributed under the terms of the GNU
60 @c General Public License.
61 @c
62
63 @setchapternewpage odd
64 @settitle @sc{gnu} Binary Utilities
65 @titlepage
66 @finalout
67 @title The @sc{gnu} Binary Utilities
68 @subtitle Version @value{VERSION}
69 @sp 1
70 @subtitle May 1993
71 @author Roland H. Pesch
72 @author Jeffrey M. Osier
73 @author Cygnus Support
74 @page
75
76 @tex
77 {\parskip=0pt \hfill Cygnus Support\par \hfill
78 \TeX{}info \texinfoversion\par }
79 @end tex
80
81 @vskip 0pt plus 1filll
82 Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 1998 Free Software Foundation, Inc.
83
84 Permission is granted to make and distribute verbatim copies of
85 this manual provided the copyright notice and this permission notice
86 are preserved on all copies.
87
88 Permission is granted to copy and distribute modified versions of this
89 manual under the conditions for verbatim copying, provided also that
90 the entire resulting derived work is distributed under the terms of a
91 permission notice identical to this one.
92
93 Permission is granted to copy and distribute translations of this manual
94 into another language, under the above conditions for modified versions.
95 @end titlepage
96
97 @node Top
98 @top Introduction
99
100 @cindex version
101 This brief manual contains preliminary 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 @menu
152 * ar:: Create, modify, and extract from archives
153 * nm:: List symbols from object files
154 * objcopy:: Copy and translate object files
155 * objdump:: Display information from object files
156 * ranlib:: Generate index to archive contents
157 * readelf:: Display the contents of ELF format files.
158 * size:: List section sizes and total size
159 * strings:: List printable strings from files
160 * strip:: Discard symbols
161 * c++filt:: Filter to demangle encoded C++ symbols
162 * cxxfilt: c++filt. MS-DOS name for c++filt
163 * addr2line:: Convert addresses to file and line
164 * nlmconv:: Converts object code into an NLM
165 * windres:: Manipulate Windows resources
166 * dlltool:: Create files needed to build and use DLLs
167 * Selecting The Target System:: How these utilities determine the target.
168 * Reporting Bugs:: Reporting Bugs
169 * Index:: Index
170 @end menu
171
172 @node ar
173 @chapter ar
174
175 @kindex ar
176 @cindex archives
177 @cindex collections of files
178 @smallexample
179 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
180 ar -M [ <mri-script ]
181 @end smallexample
182
183 The @sc{gnu} @code{ar} program creates, modifies, and extracts from
184 archives. An @dfn{archive} is a single file holding a collection of
185 other files in a structure that makes it possible to retrieve
186 the original individual files (called @dfn{members} of the archive).
187
188 The original files' contents, mode (permissions), timestamp, owner, and
189 group are preserved in the archive, and can be restored on
190 extraction.
191
192 @cindex name length
193 @sc{gnu} @code{ar} can maintain archives whose members have names of any
194 length; however, depending on how @code{ar} is configured on your
195 system, a limit on member-name length may be imposed for compatibility
196 with archive formats maintained with other tools. If it exists, the
197 limit is often 15 characters (typical of formats related to a.out) or 16
198 characters (typical of formats related to coff).
199
200 @cindex libraries
201 @code{ar} is considered a binary utility because archives of this sort
202 are most often used as @dfn{libraries} holding commonly needed
203 subroutines.
204
205 @cindex symbol index
206 @code{ar} creates an index to the symbols defined in relocatable
207 object modules in the archive when you specify the modifier @samp{s}.
208 Once created, this index is updated in the archive whenever @code{ar}
209 makes a change to its contents (save for the @samp{q} update operation).
210 An archive with such an index speeds up linking to the library, and
211 allows routines in the library to call each other without regard to
212 their placement in the archive.
213
214 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
215 table. If an archive lacks the table, another form of @code{ar} called
216 @code{ranlib} can be used to add just the table.
217
218 @cindex compatibility, @code{ar}
219 @cindex @code{ar} compatibility
220 @sc{gnu} @code{ar} is designed to be compatible with two different
221 facilities. You can control its activity using command-line options,
222 like the different varieties of @code{ar} on Unix systems; or, if you
223 specify the single command-line option @samp{-M}, you can control it
224 with a script supplied via standard input, like the MRI ``librarian''
225 program.
226
227 @menu
228 * ar cmdline:: Controlling @code{ar} on the command line
229 * ar scripts:: Controlling @code{ar} with a script
230 @end menu
231
232 @page
233 @node ar cmdline
234 @section Controlling @code{ar} on the command line
235
236 @smallexample
237 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
238 @end smallexample
239
240 @cindex Unix compatibility, @code{ar}
241 When you use @code{ar} in the Unix style, @code{ar} insists on at least two
242 arguments to execute: one keyletter specifying the @emph{operation}
243 (optionally accompanied by other keyletters specifying
244 @emph{modifiers}), and the archive name to act on.
245
246 Most operations can also accept further @var{member} arguments,
247 specifying particular files to operate on.
248
249 @sc{gnu} @code{ar} allows you to mix the operation code @var{p} and modifier
250 flags @var{mod} in any order, within the first command-line argument.
251
252 If you wish, you may begin the first command-line argument with a
253 dash.
254
255 @cindex operations on archive
256 The @var{p} keyletter specifies what operation to execute; it may be
257 any of the following, but you must specify only one of them:
258
259 @table @code
260 @item d
261 @cindex deleting from archive
262 @emph{Delete} modules from the archive. Specify the names of modules to
263 be deleted as @var{member}@dots{}; the archive is untouched if you
264 specify no files to delete.
265
266 If you specify the @samp{v} modifier, @code{ar} lists each module
267 as it is deleted.
268
269 @item m
270 @cindex moving in archive
271 Use this operation to @emph{move} members in an archive.
272
273 The ordering of members in an archive can make a difference in how
274 programs are linked using the library, if a symbol is defined in more
275 than one member.
276
277 If no modifiers are used with @code{m}, any members you name in the
278 @var{member} arguments are moved to the @emph{end} of the archive;
279 you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
280 specified place instead.
281
282 @item p
283 @cindex printing from archive
284 @emph{Print} the specified members of the archive, to the standard
285 output file. If the @samp{v} modifier is specified, show the member
286 name before copying its contents to standard output.
287
288 If you specify no @var{member} arguments, all the files in the archive are
289 printed.
290
291 @item q
292 @cindex quick append to archive
293 @emph{Quick append}; Historically, add the files @var{member}@dots{} to the end of
294 @var{archive}, without checking for replacement.
295
296 The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
297 operation; new members are always placed at the end of the archive.
298
299 The modifier @samp{v} makes @code{ar} list each file as it is appended.
300
301 Since the point of this operation is speed, the archive's symbol table
302 index is not updated, even if it already existed; you can use @samp{ar s} or
303 @code{ranlib} explicitly to update the symbol table index.
304
305 However, too many different systems assume quick append rebuilds the
306 index, so GNU ar implements @code{q} as a synonym for @code{r}.
307
308 @item r
309 @cindex replacement in archive
310 Insert the files @var{member}@dots{} into @var{archive} (with
311 @emph{replacement}). This operation differs from @samp{q} in that any
312 previously existing members are deleted if their names match those being
313 added.
314
315 If one of the files named in @var{member}@dots{} does not exist, @code{ar}
316 displays an error message, and leaves undisturbed any existing members
317 of the archive matching that name.
318
319 By default, new members are added at the end of the file; but you may
320 use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
321 placement relative to some existing member.
322
323 The modifier @samp{v} used with this operation elicits a line of
324 output for each file inserted, along with one of the letters @samp{a} or
325 @samp{r} to indicate whether the file was appended (no old member
326 deleted) or replaced.
327
328 @item t
329 @cindex contents of archive
330 Display a @emph{table} listing the contents of @var{archive}, or those
331 of the files listed in @var{member}@dots{} that are present in the
332 archive. Normally only the member name is shown; if you also want to
333 see the modes (permissions), timestamp, owner, group, and size, you can
334 request that by also specifying the @samp{v} modifier.
335
336 If you do not specify a @var{member}, all files in the archive
337 are listed.
338
339 @cindex repeated names in archive
340 @cindex name duplication in archive
341 If there is more than one file with the same name (say, @samp{fie}) in
342 an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
343 first instance; to see them all, you must ask for a complete
344 listing---in our example, @samp{ar t b.a}.
345 @c WRS only; per Gumby, this is implementation-dependent, and in a more
346 @c recent case in fact works the other way.
347
348 @item x
349 @cindex extract from archive
350 @emph{Extract} members (named @var{member}) from the archive. You can
351 use the @samp{v} modifier with this operation, to request that
352 @code{ar} list each name as it extracts it.
353
354 If you do not specify a @var{member}, all files in the archive
355 are extracted.
356
357 @end table
358
359 A number of modifiers (@var{mod}) may immediately follow the @var{p}
360 keyletter, to specify variations on an operation's behavior:
361
362 @table @code
363 @item a
364 @cindex relative placement in archive
365 Add new files @emph{after} an existing member of the
366 archive. If you use the modifier @samp{a}, the name of an existing archive
367 member must be present as the @var{relpos} argument, before the
368 @var{archive} specification.
369
370 @item b
371 Add new files @emph{before} an existing member of the
372 archive. If you use the modifier @samp{b}, the name of an existing archive
373 member must be present as the @var{relpos} argument, before the
374 @var{archive} specification. (same as @samp{i}).
375
376 @item c
377 @cindex creating archives
378 @emph{Create} the archive. The specified @var{archive} is always
379 created if it did not exist, when you request an update. But a warning is
380 issued unless you specify in advance that you expect to create it, by
381 using this modifier.
382
383 @item f
384 Truncate names in the archive. @sc{gnu} @code{ar} will normally permit file
385 names of any length. This will cause it to create archives which are
386 not compatible with the native @code{ar} program on some systems. If
387 this is a concern, the @samp{f} modifier may be used to truncate file
388 names when putting them in the archive.
389
390 @item i
391 Insert new files @emph{before} an existing member of the
392 archive. If you use the modifier @samp{i}, the name of an existing archive
393 member must be present as the @var{relpos} argument, before the
394 @var{archive} specification. (same as @samp{b}).
395
396 @item l
397 This modifier is accepted but not used.
398 @c whaffor ar l modifier??? presumably compat; with
399 @c what???---doc@@cygnus.com, 25jan91
400
401 @item o
402 @cindex dates in archive
403 Preserve the @emph{original} dates of members when extracting them. If
404 you do not specify this modifier, files extracted from the archive
405 are stamped with the time of extraction.
406
407 @item s
408 @cindex writing archive index
409 Write an object-file index into the archive, or update an existing one,
410 even if no other change is made to the archive. You may use this modifier
411 flag either with any operation, or alone. Running @samp{ar s} on an
412 archive is equivalent to running @samp{ranlib} on it.
413
414 @item S
415 @cindex not writing archive index
416 Do not generate an archive symbol table. This can speed up building a
417 large library in several steps. The resulting archive can not be used
418 with the linker. In order to build a symbol table, you must omit the
419 @samp{S} modifier on the last execution of @samp{ar}, or you must run
420 @samp{ranlib} on the archive.
421
422 @item u
423 @cindex updating an archive
424 Normally, @samp{ar r}@dots{} inserts all files
425 listed into the archive. If you would like to insert @emph{only} those
426 of the files you list that are newer than existing members of the same
427 names, use this modifier. The @samp{u} modifier is allowed only for the
428 operation @samp{r} (replace). In particular, the combination @samp{qu} is
429 not allowed, since checking the timestamps would lose any speed
430 advantage from the operation @samp{q}.
431
432 @item v
433 This modifier requests the @emph{verbose} version of an operation. Many
434 operations display additional information, such as filenames processed,
435 when the modifier @samp{v} is appended.
436
437 @item V
438 This modifier shows the version number of @code{ar}.
439 @end table
440
441 @node ar scripts
442 @section Controlling @code{ar} with a script
443
444 @smallexample
445 ar -M [ <@var{script} ]
446 @end smallexample
447
448 @cindex MRI compatibility, @code{ar}
449 @cindex scripts, @code{ar}
450 If you use the single command-line option @samp{-M} with @code{ar}, you
451 can control its operation with a rudimentary command language. This
452 form of @code{ar} operates interactively if standard input is coming
453 directly from a terminal. During interactive use, @code{ar} prompts for
454 input (the prompt is @samp{AR >}), and continues executing even after
455 errors. If you redirect standard input to a script file, no prompts are
456 issued, and @code{ar} abandons execution (with a nonzero exit code)
457 on any error.
458
459 The @code{ar} command language is @emph{not} designed to be equivalent
460 to the command-line options; in fact, it provides somewhat less control
461 over archives. The only purpose of the command language is to ease the
462 transition to @sc{gnu} @code{ar} for developers who already have scripts
463 written for the MRI ``librarian'' program.
464
465 The syntax for the @code{ar} command language is straightforward:
466 @itemize @bullet
467 @item
468 commands are recognized in upper or lower case; for example, @code{LIST}
469 is the same as @code{list}. In the following descriptions, commands are
470 shown in upper case for clarity.
471
472 @item
473 a single command may appear on each line; it is the first word on the
474 line.
475
476 @item
477 empty lines are allowed, and have no effect.
478
479 @item
480 comments are allowed; text after either of the characters @samp{*}
481 or @samp{;} is ignored.
482
483 @item
484 Whenever you use a list of names as part of the argument to an @code{ar}
485 command, you can separate the individual names with either commas or
486 blanks. Commas are shown in the explanations below, for clarity.
487
488 @item
489 @samp{+} is used as a line continuation character; if @samp{+} appears
490 at the end of a line, the text on the following line is considered part
491 of the current command.
492 @end itemize
493
494 Here are the commands you can use in @code{ar} scripts, or when using
495 @code{ar} interactively. Three of them have special significance:
496
497 @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
498 a temporary file required for most of the other commands.
499
500 @code{SAVE} commits the changes so far specified by the script. Prior
501 to @code{SAVE}, commands affect only the temporary copy of the current
502 archive.
503
504 @table @code
505 @item ADDLIB @var{archive}
506 @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
507 Add all the contents of @var{archive} (or, if specified, each named
508 @var{module} from @var{archive}) to the current archive.
509
510 Requires prior use of @code{OPEN} or @code{CREATE}.
511
512 @item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
513 @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
514 @c else like "ar q..."
515 Add each named @var{member} as a module in the current archive.
516
517 Requires prior use of @code{OPEN} or @code{CREATE}.
518
519 @item CLEAR
520 Discard the contents of the current archive, canceling the effect of
521 any operations since the last @code{SAVE}. May be executed (with no
522 effect) even if no current archive is specified.
523
524 @item CREATE @var{archive}
525 Creates an archive, and makes it the current archive (required for many
526 other commands). The new archive is created with a temporary name; it
527 is not actually saved as @var{archive} until you use @code{SAVE}.
528 You can overwrite existing archives; similarly, the contents of any
529 existing file named @var{archive} will not be destroyed until @code{SAVE}.
530
531 @item DELETE @var{module}, @var{module}, @dots{} @var{module}
532 Delete each listed @var{module} from the current archive; equivalent to
533 @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
534
535 Requires prior use of @code{OPEN} or @code{CREATE}.
536
537 @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
538 @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
539 List each named @var{module} present in @var{archive}. The separate
540 command @code{VERBOSE} specifies the form of the output: when verbose
541 output is off, output is like that of @samp{ar -t @var{archive}
542 @var{module}@dots{}}. When verbose output is on, the listing is like
543 @samp{ar -tv @var{archive} @var{module}@dots{}}.
544
545 Output normally goes to the standard output stream; however, if you
546 specify @var{outputfile} as a final argument, @code{ar} directs the
547 output to that file.
548
549 @item END
550 Exit from @code{ar}, with a @code{0} exit code to indicate successful
551 completion. This command does not save the output file; if you have
552 changed the current archive since the last @code{SAVE} command, those
553 changes are lost.
554
555 @item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
556 Extract each named @var{module} from the current archive, writing them
557 into the current directory as separate files. Equivalent to @samp{ar -x
558 @var{archive} @var{module}@dots{}}.
559
560 Requires prior use of @code{OPEN} or @code{CREATE}.
561
562 @ignore
563 @c FIXME Tokens but no commands???
564 @item FULLDIR
565
566 @item HELP
567 @end ignore
568
569 @item LIST
570 Display full contents of the current archive, in ``verbose'' style
571 regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
572 tv @var{archive}}. (This single command is a @sc{gnu} @code{ar}
573 enhancement, rather than present for MRI compatibility.)
574
575 Requires prior use of @code{OPEN} or @code{CREATE}.
576
577 @item OPEN @var{archive}
578 Opens an existing archive for use as the current archive (required for
579 many other commands). Any changes as the result of subsequent commands
580 will not actually affect @var{archive} until you next use @code{SAVE}.
581
582 @item REPLACE @var{module}, @var{module}, @dots{} @var{module}
583 In the current archive, replace each existing @var{module} (named in
584 the @code{REPLACE} arguments) from files in the current working directory.
585 To execute this command without errors, both the file, and the module in
586 the current archive, must exist.
587
588 Requires prior use of @code{OPEN} or @code{CREATE}.
589
590 @item VERBOSE
591 Toggle an internal flag governing the output from @code{DIRECTORY}.
592 When the flag is on, @code{DIRECTORY} output matches output from
593 @samp{ar -tv }@dots{}.
594
595 @item SAVE
596 Commit your changes to the current archive, and actually save it as a
597 file with the name specified in the last @code{CREATE} or @code{OPEN}
598 command.
599
600 Requires prior use of @code{OPEN} or @code{CREATE}.
601
602 @end table
603
604 @iftex
605 @node ld
606 @chapter ld
607 @cindex linker
608 @kindex ld
609 The @sc{gnu} linker @code{ld} is now described in a separate manual.
610 @xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
611 @end iftex
612
613 @node nm
614 @chapter nm
615 @cindex symbols
616 @kindex nm
617
618 @smallexample
619 nm [ -a | --debug-syms ] [ -g | --extern-only ]
620 [ -B ] [ -C | --demangle ] [ -D | --dynamic ]
621 [ -s | --print-armap ] [ -A | -o | --print-file-name ]
622 [ -n | -v | --numeric-sort ] [ -p | --no-sort ]
623 [ -r | --reverse-sort ] [ --size-sort ] [ -u | --undefined-only ]
624 [ -t @var{radix} | --radix=@var{radix} ] [ -P | --portability ]
625 [ --target=@var{bfdname} ] [ -f @var{format} | --format=@var{format} ]
626 [ --defined-only ] [-l | --line-numbers ]
627 [ --no-demangle ] [ -V | --version ] [ --help ] [ @var{objfile}@dots{} ]
628 @end smallexample
629
630 @sc{gnu} @code{nm} lists the symbols from object files @var{objfile}@dots{}.
631 If no object files are listed as arguments, @code{nm} assumes
632 @file{a.out}.
633
634 For each symbol, @code{nm} shows:
635
636 @itemize @bullet
637 @item
638 The symbol value, in the radix selected by options (see below), or
639 hexadecimal by default.
640
641 @item
642 The symbol type. At least the following types are used; others are, as
643 well, depending on the object file format. If lowercase, the symbol is
644 local; if uppercase, the symbol is global (external).
645
646 @c Some more detail on exactly what these symbol types are used for
647 @c would be nice.
648 @table @code
649 @item A
650 The symbol's value is absolute, and will not be changed by further
651 linking.
652
653 @item B
654 The symbol is in the uninitialized data section (known as BSS).
655
656 @item C
657 The symbol is common. Common symbols are uninitialized data. When
658 linking, multiple common symbols may appear with the same name. If the
659 symbol is defined anywhere, the common symbols are treated as undefined
660 references. For more details on common symbols, see the discussion of
661 --warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
662
663 @item D
664 The symbol is in the initialized data section.
665
666 @item G
667 The symbol is in an initialized data section for small objects. Some
668 object file formats permit more efficient access to small data objects,
669 such as a global int variable as opposed to a large global array.
670
671 @item I
672 The symbol is an indirect reference to another symbol. This is a GNU
673 extension to the a.out object file format which is rarely used.
674
675 @item N
676 The symbol is a debugging symbol.
677
678 @item R
679 The symbol is in a read only data section.
680
681 @item S
682 The symbol is in an uninitialized data section for small objects.
683
684 @item T
685 The symbol is in the text (code) section.
686
687 @item U
688 The symbol is undefined.
689
690 @item W
691 The symbol is weak. When a weak defined symbol is linked with a normal
692 defined symbol, the normal defined symbol is used with no error. When a
693 weak undefined symbol is linked and the symbol is not defined, the value
694 of the weak symbol becomes zero with no error.
695
696 @item -
697 The symbol is a stabs symbol in an a.out object file. In this case, the
698 next values printed are the stabs other field, the stabs desc field, and
699 the stab type. Stabs symbols are used to hold debugging information;
700 for more information, see @ref{Top,Stabs,Stabs Overview,stabs.info, The
701 ``stabs'' debug format}.
702
703 @item ?
704 The symbol type is unknown, or object file format specific.
705 @end table
706
707 @item
708 The symbol name.
709 @end itemize
710
711 The long and short forms of options, shown here as alternatives, are
712 equivalent.
713
714 @table @code
715 @item -A
716 @itemx -o
717 @itemx --print-file-name
718 @cindex input file name
719 @cindex file name
720 @cindex source file name
721 Precede each symbol by the name of the input file (or archive element)
722 in which it was found, rather than identifying the input file once only,
723 before all of its symbols.
724
725 @item -a
726 @itemx --debug-syms
727 @cindex debugging symbols
728 Display all symbols, even debugger-only symbols; normally these are not
729 listed.
730
731 @item -B
732 @cindex @code{nm} format
733 @cindex @code{nm} compatibility
734 The same as @samp{--format=bsd} (for compatibility with the MIPS @code{nm}).
735
736 @item -C
737 @itemx --demangle
738 @cindex demangling in nm
739 Decode (@dfn{demangle}) low-level symbol names into user-level names.
740 Besides removing any initial underscore prepended by the system, this
741 makes C++ function names readable. @xref{c++filt}, for more information
742 on demangling.
743
744 @item --no-demangle
745 Do not demangle low-level symbol names. This is the default.
746
747 @item -D
748 @itemx --dynamic
749 @cindex dynamic symbols
750 Display the dynamic symbols rather than the normal symbols. This is
751 only meaningful for dynamic objects, such as certain types of shared
752 libraries.
753
754 @item -f @var{format}
755 @itemx --format=@var{format}
756 @cindex @code{nm} format
757 @cindex @code{nm} compatibility
758 Use the output format @var{format}, which can be @code{bsd},
759 @code{sysv}, or @code{posix}. The default is @code{bsd}.
760 Only the first character of @var{format} is significant; it can be
761 either upper or lower case.
762
763 @item -g
764 @itemx --extern-only
765 @cindex external symbols
766 Display only external symbols.
767
768 @item -l
769 @itemx --line-numbers
770 @cindex symbol line numbers
771 For each symbol, use debugging information to try to find a filename and
772 line number. For a defined symbol, look for the line number of the
773 address of the symbol. For an undefined symbol, look for the line
774 number of a relocation entry which refers to the symbol. If line number
775 information can be found, print it after the other symbol information.
776
777 @item -n
778 @itemx -v
779 @itemx --numeric-sort
780 Sort symbols numerically by their addresses, rather than alphabetically
781 by their names.
782
783 @item -p
784 @itemx --no-sort
785 @cindex sorting symbols
786 Do not bother to sort the symbols in any order; print them in the order
787 encountered.
788
789 @item -P
790 @itemx --portability
791 Use the POSIX.2 standard output format instead of the default format.
792 Equivalent to @samp{-f posix}.
793
794 @item -s
795 @itemx --print-armap
796 @cindex symbol index, listing
797 When listing symbols from archive members, include the index: a mapping
798 (stored in the archive by @code{ar} or @code{ranlib}) of which modules
799 contain definitions for which names.
800
801 @item -r
802 @itemx --reverse-sort
803 Reverse the order of the sort (whether numeric or alphabetic); let the
804 last come first.
805
806 @item --size-sort
807 Sort symbols by size. The size is computed as the difference between
808 the value of the symbol and the value of the symbol with the next higher
809 value. The size of the symbol is printed, rather than the value.
810
811 @item -t @var{radix}
812 @itemx --radix=@var{radix}
813 Use @var{radix} as the radix for printing the symbol values. It must be
814 @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
815
816 @item --target=@var{bfdname}
817 @cindex object code format
818 Specify an object code format other than your system's default format.
819 @xref{Target Selection}, for more information.
820
821 @item -u
822 @itemx --undefined-only
823 @cindex external symbols
824 @cindex undefined symbols
825 Display only undefined symbols (those external to each object file).
826
827 @item --defined-only
828 @cindex external symbols
829 @cindex undefined symbols
830 Display only defined symbols for each object file.
831
832 @item -V
833 @itemx --version
834 Show the version number of @code{nm} and exit.
835
836 @item --help
837 Show a summary of the options to @code{nm} and exit.
838 @end table
839
840 @node objcopy
841 @chapter objcopy
842
843 @smallexample
844 objcopy [ -F @var{bfdname} | --target=@var{bfdname} ]
845 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
846 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
847 [ -S | --strip-all ] [ -g | --strip-debug ]
848 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
849 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
850 [ -L @var{symbolname} | --localize-symbol=@var{symbolname} ]
851 [ -W @var{symbolname} | --weaken-symbol=@var{symbolname} ]
852 [ -x | --discard-all ] [ -X | --discard-locals ]
853 [ -b @var{byte} | --byte=@var{byte} ]
854 [ -i @var{interleave} | --interleave=@var{interleave} ]
855 [ -j @var{sectionname} | --only-section=@var{sectionname} ]
856 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
857 [ -p | --preserve-dates ] [ --debugging ]
858 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
859 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
860 [ --change-addresses=@var{incr} ]
861 [ --change-section-address=@var{section}@{=,+,-@}@var{val} ]
862 [ --change-section-lma=@var{section}@{=,+,-@}@var{val} ]
863 [ --change-section-vma=@var{section}@{=,+,-@}@var{val} ]
864 [ --change-warnings ] [ --no-change-warnings ]
865 [ --set-section-flags=@var{section}=@var{flags} ]
866 [ --add-section=@var{sectionname}=@var{filename} ]
867 [ --change-leading-char ] [ --remove-leading-char ]
868 [ --weaken ]
869 [ -v | --verbose ] [ -V | --version ] [ --help ]
870 @var{infile} [@var{outfile}]
871 @end smallexample
872
873 The @sc{gnu} @code{objcopy} utility copies the contents of an object
874 file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
875 read and write the object files. It can write the destination object
876 file in a format different from that of the source object file. The
877 exact behavior of @code{objcopy} is controlled by command-line options.
878
879 @code{objcopy} creates temporary files to do its translations and
880 deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
881 translation work; it has access to all the formats described in @sc{bfd}
882 and thus is able to recognize most formats without being told
883 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
884
885 @code{objcopy} can be used to generate S-records by using an output
886 target of @samp{srec} (e.g., use @samp{-O srec}).
887
888 @code{objcopy} can be used to generate a raw binary file by using an
889 output target of @samp{binary} (e.g., use @samp{-O binary}). When
890 @code{objcopy} generates a raw binary file, it will essentially produce
891 a memory dump of the contents of the input object file. All symbols and
892 relocation information will be discarded. The memory dump will start at
893 the load address of the lowest section copied into the output file.
894
895 When generating an S-record or a raw binary file, it may be helpful to
896 use @samp{-S} to remove sections containing debugging information. In
897 some cases @samp{-R} will be useful to remove sections which contain
898 information which is not needed by the binary file.
899
900 @table @code
901 @item @var{infile}
902 @itemx @var{outfile}
903 The source and output files, respectively.
904 If you do not specify @var{outfile}, @code{objcopy} creates a
905 temporary file and destructively renames the result with
906 the name of @var{infile}.
907
908 @item -I @var{bfdname}
909 @itemx --input-target=@var{bfdname}
910 Consider the source file's object format to be @var{bfdname}, rather than
911 attempting to deduce it. @xref{Target Selection}, for more information.
912
913 @item -O @var{bfdname}
914 @itemx --output-target=@var{bfdname}
915 Write the output file using the object format @var{bfdname}.
916 @xref{Target Selection}, for more information.
917
918 @item -F @var{bfdname}
919 @itemx --target=@var{bfdname}
920 Use @var{bfdname} as the object format for both the input and the output
921 file; i.e., simply transfer data from source to destination with no
922 translation. @xref{Target Selection}, for more information.
923
924 @item -j @var{sectionname}
925 @itemx --only-section=@var{sectionname}
926 Copy only the named section from the input file to the output file.
927 This option may be given more than once. Note that using this option
928 inappropriately may make the output file unusable.
929
930 @item -R @var{sectionname}
931 @itemx --remove-section=@var{sectionname}
932 Remove any section named @var{sectionname} from the output file. This
933 option may be given more than once. Note that using this option
934 inappropriately may make the output file unusable.
935
936 @item -S
937 @itemx --strip-all
938 Do not copy relocation and symbol information from the source file.
939
940 @item -g
941 @itemx --strip-debug
942 Do not copy debugging symbols from the source file.
943
944 @item --strip-unneeded
945 Strip all symbols that are not needed for relocation processing.
946
947 @item -K @var{symbolname}
948 @itemx --keep-symbol=@var{symbolname}
949 Copy only symbol @var{symbolname} from the source file. This option may
950 be given more than once.
951
952 @item -N @var{symbolname}
953 @itemx --strip-symbol=@var{symbolname}
954 Do not copy symbol @var{symbolname} from the source file. This option
955 may be given more than once.
956
957 @item -L @var{symbolname}
958 @itemx --localize-symbol=@var{symbolname}
959 Make symbol @var{symbolname} local to the file, so that it is not
960 visible externally. This option may be given more than once.
961
962 @item -W @var{symbolname}
963 @itemx --weaken-symbol=@var{symbolname}
964 Make symbol @var{symbolname} weak. This option may be given more than once.
965
966 @item -x
967 @itemx --discard-all
968 Do not copy non-global symbols from the source file.
969 @c FIXME any reason to prefer "non-global" to "local" here?
970
971 @item -X
972 @itemx --discard-locals
973 Do not copy compiler-generated local symbols.
974 (These usually start with @samp{L} or @samp{.}.)
975
976 @item -b @var{byte}
977 @itemx --byte=@var{byte}
978 Keep only every @var{byte}th byte of the input file (header data is not
979 affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
980 where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
981 option, or the default of 4. This option is useful for creating files
982 to program @sc{rom}. It is typically used with an @code{srec} output
983 target.
984
985 @item -i @var{interleave}
986 @itemx --interleave=@var{interleave}
987 Only copy one out of every @var{interleave} bytes. Select which byte to
988 copy with the @var{-b} or @samp{--byte} option. The default is 4.
989 @code{objcopy} ignores this option if you do not specify either @samp{-b} or
990 @samp{--byte}.
991
992 @item -p
993 @itemx --preserve-dates
994 Set the access and modification dates of the output file to be the same
995 as those of the input file.
996
997 @item --debugging
998 Convert debugging information, if possible. This is not the default
999 because only certain debugging formats are supported, and the
1000 conversion process can be time consuming.
1001
1002 @item --gap-fill @var{val}
1003 Fill gaps between sections with @var{val}. This operation applies to
1004 the @emph{load address} (LMA) of the sections. It is done by increasing
1005 the size of the section with the lower address, and filling in the extra
1006 space created with @var{val}.
1007
1008 @item --pad-to @var{address}
1009 Pad the output file up to the load address @var{address}. This is
1010 done by increasing the size of the last section. The extra space is
1011 filled in with the value specified by @samp{--gap-fill} (default zero).
1012
1013 @item --set-start @var{val}
1014 Set the address of the new file to @var{val}. Not all object file
1015 formats support setting the start address.
1016
1017 @item --change-start @var{incr}
1018 @itemx --adjust-start @var{incr}
1019 @cindex changing start address
1020 Change the start address by adding @var{incr}. Not all object file
1021 formats support setting the start address.
1022
1023 @item --change-addresses @var{incr}
1024 @itemx --adjust-vma @var{incr}
1025 @cindex changing object addresses
1026 Change the VMA and LMA addresses of all sections, as well as the start
1027 address, by adding @var{incr}. Some object file formats do not permit
1028 section addresses to be changed arbitrarily. Note that this does not
1029 relocate the sections; if the program expects sections to be loaded at a
1030 certain address, and this option is used to change the sections such
1031 that they are loaded at a different address, the program may fail.
1032
1033 @item --change-section-address @var{section}@{=,+,-@}@var{val}
1034 @itemx --adjust-section-vma @var{section}@{=,+,-@}@var{val}
1035 @cindex changing section address
1036 Set or change both the VMA address and the LMA address of the named
1037 @var{section}. If @samp{=} is used, the section address is set to
1038 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1039 section address. See the comments under @samp{--change-addresses},
1040 above. If @var{section} does not exist in the input file, a warning will
1041 be issued, unless @samp{--no-change-warnings} is used.
1042
1043 @item --change-section-lma @var{section}@{=,+,-@}@var{val}
1044 @cindex changing section LMA
1045 Set or change the LMA address of the named @var{section}. The LMA
1046 address is the address where the section will be loaded into memory at
1047 program load time. Normally this is the same as the VMA address, which
1048 is the address of the section at program run time, but on some systems,
1049 especially those where a program is held in ROM, the two can be
1050 different. If @samp{=} is used, the section address is set to
1051 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1052 section address. See the comments under @samp{--change-addresses},
1053 above. If @var{section} does not exist in the input file, a warning
1054 will be issued, unless @samp{--no-change-warnings} is used.
1055
1056 @item --change-section-vma @var{section}@{=,+,-@}@var{val}
1057 @cindex changing section VMA
1058 Set or change the VMA address of the named @var{section}. The VMA
1059 address is the address where the section will be located once the
1060 program has started executing. Normally this is the same as the LMA
1061 address, which is the address where the section will be loaded into
1062 memory, but on some systems, especially those where a program is held in
1063 ROM, the two can be different. If @samp{=} is used, the section address
1064 is set to @var{val}. Otherwise, @var{val} is added to or subtracted
1065 from the section address. See the comments under
1066 @samp{--change-addresses}, above. If @var{section} does not exist in
1067 the input file, a warning will be issued, unless
1068 @samp{--no-change-warnings} is used.
1069
1070 @item --change-warnings
1071 @itemx --adjust-warnings
1072 If @samp{--change-section-address} or @samp{--change-section-lma} or
1073 @samp{--change-section-vma} is used, and the named section does not
1074 exist, issue a warning. This is the default.
1075
1076 @item --no-change-warnings
1077 @itemx --no-adjust-warnings
1078 Do not issue a warning if @samp{--change-section-address} or
1079 @samp{--adjust-section-lma} or @samp{--adjust-section-vma} is used, even
1080 if the named section does not exist.
1081
1082 @item --set-section-flags @var{section}=@var{flags}
1083 Set the flags for the named section. The @var{flags} argument is a
1084 comma separated string of flag names. The recognized names are
1085 @samp{alloc}, @samp{contents}, @samp{load}, @samp{readonly},
1086 @samp{code}, @samp{data}, and @samp{rom}. You can set the
1087 @samp{contents} flag for a section which does not have contents, but it
1088 is not meaningful to clear the @samp{contents} flag of a section which
1089 does have contents--just remove the section instead. Not all flags are
1090 meaningful for all object file formats.
1091
1092 @item --add-section @var{sectionname}=@var{filename}
1093 Add a new section named @var{sectionname} while copying the file. The
1094 contents of the new section are taken from the file @var{filename}. The
1095 size of the section will be the size of the file. This option only
1096 works on file formats which can support sections with arbitrary names.
1097
1098 @item --change-leading-char
1099 Some object file formats use special characters at the start of
1100 symbols. The most common such character is underscore, which compilers
1101 often add before every symbol. This option tells @code{objcopy} to
1102 change the leading character of every symbol when it converts between
1103 object file formats. If the object file formats use the same leading
1104 character, this option has no effect. Otherwise, it will add a
1105 character, or remove a character, or change a character, as
1106 appropriate.
1107
1108 @item --remove-leading-char
1109 If the first character of a global symbol is a special symbol leading
1110 character used by the object file format, remove the character. The
1111 most common symbol leading character is underscore. This option will
1112 remove a leading underscore from all global symbols. This can be useful
1113 if you want to link together objects of different file formats with
1114 different conventions for symbol names. This is different from
1115 @code{--change-leading-char} because it always changes the symbol name
1116 when appropriate, regardless of the object file format of the output
1117 file.
1118
1119 @item --weaken
1120 Change all global symbols in the file to be weak. This can be useful
1121 when building an object which will be linked against other objects using
1122 the @code{-R} option to the linker. This option is only effective when
1123 using an object file format which supports weak symbols.
1124
1125 @item -V
1126 @itemx --version
1127 Show the version number of @code{objcopy}.
1128
1129 @item -v
1130 @itemx --verbose
1131 Verbose output: list all object files modified. In the case of
1132 archives, @samp{objcopy -V} lists all members of the archive.
1133
1134 @item --help
1135 Show a summary of the options to @code{objcopy}.
1136 @end table
1137
1138 @node objdump
1139 @chapter objdump
1140
1141 @cindex object file information
1142 @kindex objdump
1143
1144 @smallexample
1145 objdump [ -a | --archive-headers ]
1146 [ -b @var{bfdname} | --target=@var{bfdname} ] [ --debugging ]
1147 [ -C | --demangle ] [ -d | --disassemble ]
1148 [ -D | --disassemble-all ] [ --disassemble-zeroes ]
1149 [ -EB | -EL | --endian=@{big | little @} ]
1150 [ -f | --file-headers ]
1151 [ -h | --section-headers | --headers ] [ -i | --info ]
1152 [ -j @var{section} | --section=@var{section} ]
1153 [ -l | --line-numbers ] [ -S | --source ]
1154 [ -m @var{machine} | --architecture=@var{machine} ]
1155 [ -M @var{options} | --disassembler-options=@var{options}]
1156 [ -p | --private-headers ]
1157 [ -r | --reloc ] [ -R | --dynamic-reloc ]
1158 [ -s | --full-contents ] [ --stabs ]
1159 [ -t | --syms ] [ -T | --dynamic-syms ] [ -x | --all-headers ]
1160 [ -w | --wide ] [ --start-address=@var{address} ]
1161 [ --stop-address=@var{address} ]
1162 [ --prefix-addresses] [ --[no-]show-raw-insn ]
1163 [ --adjust-vma=@var{offset} ]
1164 [ --version ] [ --help ]
1165 @var{objfile}@dots{}
1166 @end smallexample
1167
1168 @code{objdump} displays information about one or more object files.
1169 The options control what particular information to display. This
1170 information is mostly useful to programmers who are working on the
1171 compilation tools, as opposed to programmers who just want their
1172 program to compile and work.
1173
1174 @var{objfile}@dots{} are the object files to be examined. When you
1175 specify archives, @code{objdump} shows information on each of the member
1176 object files.
1177
1178 The long and short forms of options, shown here as alternatives, are
1179 equivalent. At least one option besides @samp{-l} must be given.
1180
1181 @table @code
1182 @item -a
1183 @itemx --archive-header
1184 @cindex archive headers
1185 If any of the @var{objfile} files are archives, display the archive
1186 header information (in a format similar to @samp{ls -l}). Besides the
1187 information you could list with @samp{ar tv}, @samp{objdump -a} shows
1188 the object file format of each archive member.
1189
1190 @item --adjust-vma=@var{offset}
1191 @cindex section addresses in objdump
1192 @cindex VMA in objdump
1193 When dumping information, first add @var{offset} to all the section
1194 addresses. This is useful if the section addresses do not correspond to
1195 the symbol table, which can happen when putting sections at particular
1196 addresses when using a format which can not represent section addresses,
1197 such as a.out.
1198
1199 @item -b @var{bfdname}
1200 @itemx --target=@var{bfdname}
1201 @cindex object code format
1202 Specify that the object-code format for the object files is
1203 @var{bfdname}. This option may not be necessary; @var{objdump} can
1204 automatically recognize many formats.
1205
1206 For example,
1207 @example
1208 objdump -b oasys -m vax -h fu.o
1209 @end example
1210 @noindent
1211 displays summary information from the section headers (@samp{-h}) of
1212 @file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1213 file in the format produced by Oasys compilers. You can list the
1214 formats available with the @samp{-i} option.
1215 @xref{Target Selection}, for more information.
1216
1217 @item -C
1218 @itemx --demangle
1219 @cindex demangling in objdump
1220 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1221 Besides removing any initial underscore prepended by the system, this
1222 makes C++ function names readable. @xref{c++filt}, for more information
1223 on demangling.
1224
1225 @item --debugging
1226 Display debugging information. This attempts to parse debugging
1227 information stored in the file and print it out using a C like syntax.
1228 Only certain types of debugging information have been implemented.
1229
1230 @item -d
1231 @itemx --disassemble
1232 @cindex disassembling object code
1233 @cindex machine instructions
1234 Display the assembler mnemonics for the machine instructions from
1235 @var{objfile}. This option only disassembles those sections which are
1236 expected to contain instructions.
1237
1238 @item -D
1239 @itemx --disassemble-all
1240 Like @samp{-d}, but disassemble the contents of all sections, not just
1241 those expected to contain instructions.
1242
1243 @item --prefix-addresses
1244 When disassembling, print the complete address on each line. This is
1245 the older disassembly format.
1246
1247 @item --disassemble-zeroes
1248 Normally the disassembly output will skip blocks of zeroes. This
1249 option directs the disassembler to disassemble those blocks, just like
1250 any other data.
1251
1252 @item -EB
1253 @itemx -EL
1254 @itemx --endian=@{big|little@}
1255 @cindex endianness
1256 @cindex disassembly endianness
1257 Specify the endianness of the object files. This only affects
1258 disassembly. This can be useful when disassembling a file format which
1259 does not describe endianness information, such as S-records.
1260
1261 @item -f
1262 @itemx --file-header
1263 @cindex object file header
1264 Display summary information from the overall header of
1265 each of the @var{objfile} files.
1266
1267 @item -h
1268 @itemx --section-header
1269 @itemx --header
1270 @cindex section headers
1271 Display summary information from the section headers of the
1272 object file.
1273
1274 File segments may be relocated to nonstandard addresses, for example by
1275 using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1276 @code{ld}. However, some object file formats, such as a.out, do not
1277 store the starting address of the file segments. In those situations,
1278 although @code{ld} relocates the sections correctly, using @samp{objdump
1279 -h} to list the file section headers cannot show the correct addresses.
1280 Instead, it shows the usual addresses, which are implicit for the
1281 target.
1282
1283 @item --help
1284 Print a summary of the options to @code{objdump} and exit.
1285
1286 @item -i
1287 @itemx --info
1288 @cindex architectures available
1289 @cindex object formats available
1290 Display a list showing all architectures and object formats available
1291 for specification with @samp{-b} or @samp{-m}.
1292
1293 @item -j @var{name}
1294 @itemx --section=@var{name}
1295 @cindex section information
1296 Display information only for section @var{name}.
1297
1298 @item -l
1299 @itemx --line-numbers
1300 @cindex source filenames for object files
1301 Label the display (using debugging information) with the filename and
1302 source line numbers corresponding to the object code or relocs shown.
1303 Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1304
1305 @item -m @var{machine}
1306 @itemx --architecture=@var{machine}
1307 @cindex architecture
1308 @cindex disassembly architecture
1309 Specify the architecture to use when disassembling object files. This
1310 can be useful when disassembling object files which do not describe
1311 architecture information, such as S-records. You can list the available
1312 architectures with the @samp{-i} option.
1313
1314 @item -M @var{options}
1315 @itemx --disassembler-options=@var{options}
1316 Pass target specific information to the disassembler. Only supported on
1317 some targets.
1318
1319 If the target is an ARM architecture then this switch can be used to
1320 select which register name set is used during disassembler. Specifying
1321 @samp{--disassembler-options=reg-name-std} (the default) will select the
1322 register names as used in ARM's instruction set documentation, but with
1323 register 13 called 'sp', register 14 called 'lr' and register 15 called
1324 'pc'. Specifying @samp{--disassembler-options=reg-names-apcs} will
1325 select the name set used by the ARM Procedure Call Standard, whilst
1326 specifying @samp{--disassembler-options=reg-names-raw} will just use
1327 @samp{r} followed by the register number.
1328
1329 @item -p
1330 @itemx --private-headers
1331 Print information that is specific to the object file format. The exact
1332 information printed depends upon the object file format. For some
1333 object file formats, no additional information is printed.
1334
1335 @item -r
1336 @itemx --reloc
1337 @cindex relocation entries, in object file
1338 Print the relocation entries of the file. If used with @samp{-d} or
1339 @samp{-D}, the relocations are printed interspersed with the
1340 disassembly.
1341
1342 @item -R
1343 @itemx --dynamic-reloc
1344 @cindex dynamic relocation entries, in object file
1345 Print the dynamic relocation entries of the file. This is only
1346 meaningful for dynamic objects, such as certain types of shared
1347 libraries.
1348
1349 @item -s
1350 @itemx --full-contents
1351 @cindex sections, full contents
1352 @cindex object file sections
1353 Display the full contents of any sections requested.
1354
1355 @item -S
1356 @itemx --source
1357 @cindex source disassembly
1358 @cindex disassembly, with source
1359 Display source code intermixed with disassembly, if possible. Implies
1360 @samp{-d}.
1361
1362 @item --show-raw-insn
1363 When disassembling instructions, print the instruction in hex as well as
1364 in symbolic form. This is the default except when
1365 @code{--prefix-addresses} is used.
1366
1367 @item --no-show-raw-insn
1368 When disassembling instructions, do not print the instruction bytes.
1369 This is the default when @code{--prefix-addresses} is used.
1370
1371 @item --stabs
1372 @cindex stab
1373 @cindex .stab
1374 @cindex debug symbols
1375 @cindex ELF object file format
1376 Display the full contents of any sections requested. Display the
1377 contents of the .stab and .stab.index and .stab.excl sections from an
1378 ELF file. This is only useful on systems (such as Solaris 2.0) in which
1379 @code{.stab} debugging symbol-table entries are carried in an ELF
1380 section. In most other file formats, debugging symbol-table entries are
1381 interleaved with linkage symbols, and are visible in the @samp{--syms}
1382 output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1383 Overview,stabs.info, The ``stabs'' debug format}.
1384
1385 @item --start-address=@var{address}
1386 @cindex start-address
1387 Start displaying data at the specified address. This affects the output
1388 of the @code{-d}, @code{-r} and @code{-s} options.
1389
1390 @item --stop-address=@var{address}
1391 @cindex stop-address
1392 Stop displaying data at the specified address. This affects the output
1393 of the @code{-d}, @code{-r} and @code{-s} options.
1394
1395 @item -t
1396 @itemx --syms
1397 @cindex symbol table entries, printing
1398 Print the symbol table entries of the file.
1399 This is similar to the information provided by the @samp{nm} program.
1400
1401 @item -T
1402 @itemx --dynamic-syms
1403 @cindex dynamic symbol table entries, printing
1404 Print the dynamic symbol table entries of the file. This is only
1405 meaningful for dynamic objects, such as certain types of shared
1406 libraries. This is similar to the information provided by the @samp{nm}
1407 program when given the @samp{-D} (@samp{--dynamic}) option.
1408
1409 @item --version
1410 Print the version number of @code{objdump} and exit.
1411
1412 @item -x
1413 @itemx --all-header
1414 @cindex all header information, object file
1415 @cindex header information, all
1416 Display all available header information, including the symbol table and
1417 relocation entries. Using @samp{-x} is equivalent to specifying all of
1418 @samp{-a -f -h -r -t}.
1419
1420 @item -w
1421 @itemx --wide
1422 @cindex wide output, printing
1423 Format some lines for output devices that have more than 80 columns.
1424 @end table
1425
1426 @node ranlib
1427 @chapter ranlib
1428
1429 @kindex ranlib
1430 @cindex archive contents
1431 @cindex symbol index
1432
1433 @smallexample
1434 ranlib [-vV] @var{archive}
1435 @end smallexample
1436
1437 @code{ranlib} generates an index to the contents of an archive and
1438 stores it in the archive. The index lists each symbol defined by a
1439 member of an archive that is a relocatable object file.
1440
1441 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1442
1443 An archive with such an index speeds up linking to the library and
1444 allows routines in the library to call each other without regard to
1445 their placement in the archive.
1446
1447 The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1448 @code{ranlib} is completely equivalent to executing @samp{ar -s}.
1449 @xref{ar}.
1450
1451 @table @code
1452 @item -v
1453 @itemx -V
1454 Show the version number of @code{ranlib}.
1455 @end table
1456
1457 @node size
1458 @chapter size
1459
1460 @kindex size
1461 @cindex section sizes
1462
1463 @smallexample
1464 size [ -A | -B | --format=@var{compatibility} ]
1465 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1466 [ --target=@var{bfdname} ] [ -V | --version ]
1467 [ @var{objfile}@dots{} ]
1468 @end smallexample
1469
1470 The @sc{gnu} @code{size} utility lists the section sizes---and the total
1471 size---for each of the object or archive files @var{objfile} in its
1472 argument list. By default, one line of output is generated for each
1473 object file or each module in an archive.
1474
1475 @var{objfile}@dots{} are the object files to be examined.
1476 If none are specified, the file @code{a.out} will be used.
1477
1478 The command line options have the following meanings:
1479
1480 @table @code
1481 @item -A
1482 @itemx -B
1483 @itemx --format=@var{compatibility}
1484 @cindex @code{size} display format
1485 Using one of these options, you can choose whether the output from @sc{gnu}
1486 @code{size} resembles output from System V @code{size} (using @samp{-A},
1487 or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1488 @samp{--format=berkeley}). The default is the one-line format similar to
1489 Berkeley's.
1490 @c Bonus for doc-source readers: you can also say --format=strange (or
1491 @c anything else that starts with 's') for sysv, and --format=boring (or
1492 @c anything else that starts with 'b') for Berkeley.
1493
1494 Here is an example of the Berkeley (default) format of output from
1495 @code{size}:
1496 @smallexample
1497 size --format=Berkeley ranlib size
1498 text data bss dec hex filename
1499 294880 81920 11592 388392 5ed28 ranlib
1500 294880 81920 11888 388688 5ee50 size
1501 @end smallexample
1502
1503 @noindent
1504 This is the same data, but displayed closer to System V conventions:
1505
1506 @smallexample
1507 size --format=SysV ranlib size
1508 ranlib :
1509 section size addr
1510 .text 294880 8192
1511 .data 81920 303104
1512 .bss 11592 385024
1513 Total 388392
1514
1515
1516 size :
1517 section size addr
1518 .text 294880 8192
1519 .data 81920 303104
1520 .bss 11888 385024
1521 Total 388688
1522 @end smallexample
1523
1524 @item --help
1525 Show a summary of acceptable arguments and options.
1526
1527 @item -d
1528 @itemx -o
1529 @itemx -x
1530 @itemx --radix=@var{number}
1531 @cindex @code{size} number format
1532 @cindex radix for section sizes
1533 Using one of these options, you can control whether the size of each
1534 section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1535 (@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1536 @samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1537 values (8, 10, 16) are supported. The total size is always given in two
1538 radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1539 octal and hexadecimal if you're using @samp{-o}.
1540
1541 @item --target=@var{bfdname}
1542 @cindex object code format
1543 Specify that the object-code format for @var{objfile} is
1544 @var{bfdname}. This option may not be necessary; @code{size} can
1545 automatically recognize many formats.
1546 @xref{Target Selection}, for more information.
1547
1548 @item -V
1549 @itemx --version
1550 Display the version number of @code{size}.
1551 @end table
1552
1553 @node strings
1554 @chapter strings
1555 @kindex strings
1556 @cindex listings strings
1557 @cindex printing strings
1558 @cindex strings, printing
1559
1560 @smallexample
1561 strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1562 [--all] [--print-file-name] [--bytes=@var{min-len}]
1563 [--radix=@var{radix}] [--target=@var{bfdname}]
1564 [--help] [--version] @var{file}@dots{}
1565 @end smallexample
1566
1567 For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1568 character sequences that are at least 4 characters long (or the number
1569 given with the options below) and are followed by an unprintable
1570 character. By default, it only prints the strings from the initialized
1571 and loaded sections of object files; for other types of files, it prints
1572 the strings from the whole file.
1573
1574 @code{strings} is mainly useful for determining the contents of non-text
1575 files.
1576
1577 @table @code
1578 @item -a
1579 @itemx --all
1580 @itemx -
1581 Do not scan only the initialized and loaded sections of object files;
1582 scan the whole files.
1583
1584 @item -f
1585 @itemx --print-file-name
1586 Print the name of the file before each string.
1587
1588 @item --help
1589 Print a summary of the program usage on the standard output and exit.
1590
1591 @item -@var{min-len}
1592 @itemx -n @var{min-len}
1593 @itemx --bytes=@var{min-len}
1594 Print sequences of characters that are at least @var{min-len} characters
1595 long, instead of the default 4.
1596
1597 @item -o
1598 Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1599 act like @samp{-t d} instead. Since we can not be compatible with both
1600 ways, we simply chose one.
1601
1602 @item -t @var{radix}
1603 @itemx --radix=@var{radix}
1604 Print the offset within the file before each string. The single
1605 character argument specifies the radix of the offset---@samp{o} for
1606 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1607
1608 @item --target=@var{bfdname}
1609 @cindex object code format
1610 Specify an object code format other than your system's default format.
1611 @xref{Target Selection}, for more information.
1612
1613 @item -v
1614 @itemx --version
1615 Print the program version number on the standard output and exit.
1616 @end table
1617
1618 @node strip
1619 @chapter strip
1620
1621 @kindex strip
1622 @cindex removing symbols
1623 @cindex discarding symbols
1624 @cindex symbols, discarding
1625
1626 @smallexample
1627 strip [ -F @var{bfdname} | --target=@var{bfdname} ]
1628 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1629 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1630 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1631 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1632 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1633 [ -x | --discard-all ] [ -X | --discard-locals ]
1634 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1635 [ -o @var{file} ] [ -p | --preserve-dates ]
1636 [ -v | --verbose ] [ -V | --version ] [ --help ]
1637 @var{objfile}@dots{}
1638 @end smallexample
1639
1640 @sc{gnu} @code{strip} discards all symbols from object files
1641 @var{objfile}. The list of object files may include archives.
1642 At least one object file must be given.
1643
1644 @code{strip} modifies the files named in its argument,
1645 rather than writing modified copies under different names.
1646
1647 @table @code
1648 @item -F @var{bfdname}
1649 @itemx --target=@var{bfdname}
1650 Treat the original @var{objfile} as a file with the object
1651 code format @var{bfdname}, and rewrite it in the same format.
1652 @xref{Target Selection}, for more information.
1653
1654 @item --help
1655 Show a summary of the options to @code{strip} and exit.
1656
1657 @item -I @var{bfdname}
1658 @itemx --input-target=@var{bfdname}
1659 Treat the original @var{objfile} as a file with the object
1660 code format @var{bfdname}.
1661 @xref{Target Selection}, for more information.
1662
1663 @item -O @var{bfdname}
1664 @itemx --output-target=@var{bfdname}
1665 Replace @var{objfile} with a file in the output format @var{bfdname}.
1666 @xref{Target Selection}, for more information.
1667
1668 @item -R @var{sectionname}
1669 @itemx --remove-section=@var{sectionname}
1670 Remove any section named @var{sectionname} from the output file. This
1671 option may be given more than once. Note that using this option
1672 inappropriately may make the output file unusable.
1673
1674 @item -s
1675 @itemx --strip-all
1676 Remove all symbols.
1677
1678 @item -g
1679 @itemx -S
1680 @itemx --strip-debug
1681 Remove debugging symbols only.
1682
1683 @item --strip-unneeded
1684 Remove all symbols that are not needed for relocation processing.
1685
1686 @item -K @var{symbolname}
1687 @itemx --keep-symbol=@var{symbolname}
1688 Keep only symbol @var{symbolname} from the source file. This option may
1689 be given more than once.
1690
1691 @item -N @var{symbolname}
1692 @itemx --strip-symbol=@var{symbolname}
1693 Remove symbol @var{symbolname} from the source file. This option may be
1694 given more than once, and may be combined with strip options other than
1695 @code{-K}.
1696
1697 @item -o @var{file}
1698 Put the stripped output in @var{file}, rather than replacing the
1699 existing file. When this argument is used, only one @var{objfile}
1700 argument may be specified.
1701
1702 @item -p
1703 @itemx --preserve-dates
1704 Preserve the access and modification dates of the file.
1705
1706 @item -x
1707 @itemx --discard-all
1708 Remove non-global symbols.
1709
1710 @item -X
1711 @itemx --discard-locals
1712 Remove compiler-generated local symbols.
1713 (These usually start with @samp{L} or @samp{.}.)
1714
1715 @item -V
1716 @itemx --version
1717 Show the version number for @code{strip}.
1718
1719 @item -v
1720 @itemx --verbose
1721 Verbose output: list all object files modified. In the case of
1722 archives, @samp{strip -v} lists all members of the archive.
1723 @end table
1724
1725 @node c++filt, addr2line, strip, Top
1726 @chapter c++filt
1727
1728 @kindex c++filt
1729 @cindex demangling C++ symbols
1730
1731 @smallexample
1732 c++filt [ -_ | --strip-underscores ]
1733 [ -j | --java ]
1734 [ -n | --no-strip-underscores ]
1735 [ -s @var{format} | --format=@var{format} ]
1736 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1737 @end smallexample
1738
1739 @kindex cxxfilt
1740 The C++ and Java languages provides function overloading, which means
1741 that you can write many functions with the same name (providing each
1742 takes parameters of different types). All C++ and Java function names
1743 are encoded into a low-level assembly label (this process is known as
1744 @dfn{mangling}). The @code{c++filt}
1745 @footnote{MS-DOS does not allow @kbd{+} characters in file names, so on
1746 MS-DOS this program is named @code{cxxfilt}.}
1747 program does the inverse mapping: it decodes (@dfn{demangles}) low-level
1748 names into user-level names so that the linker can keep these overloaded
1749 functions from clashing.
1750
1751 Every alphanumeric word (consisting of letters, digits, underscores,
1752 dollars, or periods) seen in the input is a potential label. If the
1753 label decodes into a C++ name, the C++ name replaces the low-level
1754 name in the output.
1755
1756 You can use @code{c++filt} to decipher individual symbols:
1757
1758 @example
1759 c++filt @var{symbol}
1760 @end example
1761
1762 If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1763 names from the standard input and writes the demangled names to the
1764 standard output. All results are printed on the standard output.
1765
1766 @table @code
1767 @item -_
1768 @itemx --strip-underscores
1769 On some systems, both the C and C++ compilers put an underscore in front
1770 of every name. For example, the C name @code{foo} gets the low-level
1771 name @code{_foo}. This option removes the initial underscore. Whether
1772 @code{c++filt} removes the underscore by default is target dependent.
1773
1774 @item -j
1775 @itemx --java
1776 Prints demangled names using Java syntax. The default is to use C++
1777 syntax.
1778
1779 @item -n
1780 @itemx --no-strip-underscores
1781 Do not remove the initial underscore.
1782
1783 @item -s @var{format}
1784 @itemx --format=@var{format}
1785 @sc{gnu} @code{nm} can decode three different methods of mangling, used by
1786 different C++ compilers. The argument to this option selects which
1787 method it uses:
1788
1789 @table @code
1790 @item gnu
1791 the one used by the @sc{gnu} compiler (the default method)
1792 @item lucid
1793 the one used by the Lucid compiler
1794 @item arm
1795 the one specified by the C++ Annotated Reference Manual
1796 @item hp
1797 the one used by the HP compiler
1798 @item edg
1799 the one used by the EDG compiler
1800 @end table
1801
1802 @item --help
1803 Print a summary of the options to @code{c++filt} and exit.
1804
1805 @item --version
1806 Print the version number of @code{c++filt} and exit.
1807 @end table
1808
1809 @quotation
1810 @emph{Warning:} @code{c++filt} is a new utility, and the details of its
1811 user interface are subject to change in future releases. In particular,
1812 a command-line option may be required in the the future to decode a name
1813 passed as an argument on the command line; in other words,
1814
1815 @example
1816 c++filt @var{symbol}
1817 @end example
1818
1819 @noindent
1820 may in a future release become
1821
1822 @example
1823 c++filt @var{option} @var{symbol}
1824 @end example
1825 @end quotation
1826
1827 @node addr2line
1828 @chapter addr2line
1829
1830 @kindex addr2line
1831 @cindex address to file name and line number
1832
1833 @smallexample
1834 addr2line [ -b @var{bfdname} | --target=@var{bfdname} ]
1835 [ -C | --demangle ]
1836 [ -e @var{filename} | --exe=@var{filename} ]
1837 [ -f | --functions ] [ -s | --basename ]
1838 [ -H | --help ] [ -V | --version ]
1839 [ addr addr ... ]
1840 @end smallexample
1841
1842 @code{addr2line} translates program addresses into file names and line
1843 numbers. Given an address and an executable, it uses the debugging
1844 information in the executable to figure out which file name and line
1845 number are associated with a given address.
1846
1847 The executable to use is specified with the @code{-e} option. The
1848 default is @file{a.out}.
1849
1850 @code{addr2line} has two modes of operation.
1851
1852 In the first, hexadecimal addresses are specified on the command line,
1853 and @code{addr2line} displays the file name and line number for each
1854 address.
1855
1856 In the second, @code{addr2line} reads hexadecimal addresses from
1857 standard input, and prints the file name and line number for each
1858 address on standard output. In this mode, @code{addr2line} may be used
1859 in a pipe to convert dynamically chosen addresses.
1860
1861 The format of the output is @samp{FILENAME:LINENO}. The file name and
1862 line number for each address is printed on a separate line. If the
1863 @code{-f} option is used, then each @samp{FILENAME:LINENO} line is
1864 preceded by a @samp{FUNCTIONNAME} line which is the name of the function
1865 containing the address.
1866
1867 If the file name or function name can not be determined,
1868 @code{addr2line} will print two question marks in their place. If the
1869 line number can not be determined, @code{addr2line} will print 0.
1870
1871 The long and short forms of options, shown here as alternatives, are
1872 equivalent.
1873
1874 @table @code
1875 @item -b @var{bfdname}
1876 @itemx --target=@var{bfdname}
1877 @cindex object code format
1878 Specify that the object-code format for the object files is
1879 @var{bfdname}.
1880
1881 @item -C
1882 @itemx --demangle
1883 @cindex demangling in objdump
1884 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1885 Besides removing any initial underscore prepended by the system, this
1886 makes C++ function names readable. @xref{c++filt}, for more information
1887 on demangling.
1888
1889 @item -e @var{filename}
1890 @itemx --exe=@var{filename}
1891 Specify the name of the executable for which addresses should be
1892 translated. The default file is @file{a.out}.
1893
1894 @item -f
1895 @itemx --functions
1896 Display function names as well as file and line number information.
1897
1898 @item -s
1899 @itemx --basenames
1900 Display only the base of each file name.
1901 @end table
1902
1903 @node nlmconv
1904 @chapter nlmconv
1905
1906 @code{nlmconv} converts a relocatable object file into a NetWare
1907 Loadable Module.
1908
1909 @ignore
1910 @code{nlmconv} currently works with @samp{i386} object
1911 files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1912 object files in @sc{elf}, or @code{a.out} format@footnote{
1913 @code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1914 format in the Binary File Descriptor library. It has only been tested
1915 with the above formats.}.
1916 @end ignore
1917
1918 @quotation
1919 @emph{Warning:} @code{nlmconv} is not always built as part of the binary
1920 utilities, since it is only useful for NLM targets.
1921 @end quotation
1922
1923 @smallexample
1924 nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1925 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1926 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1927 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1928 [ -h | --help ] [ -V | --version ]
1929 @var{infile} @var{outfile}
1930 @end smallexample
1931
1932 @code{nlmconv} converts the relocatable @samp{i386} object file
1933 @var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1934 reading @var{headerfile} for NLM header information. For instructions
1935 on writing the NLM command file language used in header files, see the
1936 @samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1937 Development and Tools Overview}, which is part of the NLM Software
1938 Developer's Kit (``NLM SDK''), available from Novell, Inc.
1939 @code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1940 @var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1941 more information.
1942
1943 @code{nlmconv} can perform a link step. In other words, you can list
1944 more than one object file for input if you list them in the definitions
1945 file (rather than simply specifying one input file on the command line).
1946 In this case, @code{nlmconv} calls the linker for you.
1947
1948 @table @code
1949 @item -I @var{bfdname}
1950 @itemx --input-target=@var{bfdname}
1951 Object format of the input file. @code{nlmconv} can usually determine
1952 the format of a given file (so no default is necessary).
1953 @xref{Target Selection}, for more information.
1954
1955 @item -O @var{bfdname}
1956 @itemx --output-target=@var{bfdname}
1957 Object format of the output file. @code{nlmconv} infers the output
1958 format based on the input format, e.g. for a @samp{i386} input file the
1959 output format is @samp{nlm32-i386}.
1960 @xref{Target Selection}, for more information.
1961
1962 @item -T @var{headerfile}
1963 @itemx --header-file=@var{headerfile}
1964 Reads @var{headerfile} for NLM header information. For instructions on
1965 writing the NLM command file language used in header files, see@ see the
1966 @samp{linkers} section, of the @cite{NLM Development and Tools
1967 Overview}, which is part of the NLM Software Developer's Kit, available
1968 from Novell, Inc.
1969
1970 @item -d
1971 @itemx --debug
1972 Displays (on standard error) the linker command line used by @code{nlmconv}.
1973
1974 @item -l @var{linker}
1975 @itemx --linker=@var{linker}
1976 Use @var{linker} for any linking. @var{linker} can be an absolute or a
1977 relative pathname.
1978
1979 @item -h
1980 @itemx --help
1981 Prints a usage summary.
1982
1983 @item -V
1984 @itemx --version
1985 Prints the version number for @code{nlmconv}.
1986 @end table
1987
1988 @node windres
1989 @chapter windres
1990
1991 @code{windres} may be used to manipulate Windows resources.
1992
1993 @quotation
1994 @emph{Warning:} @code{windres} is not always built as part of the binary
1995 utilities, since it is only useful for Windows targets.
1996 @end quotation
1997
1998 @smallexample
1999 windres [options] [input-file] [output-file]
2000 @end smallexample
2001
2002 @code{windres} reads resources from an input file and copies them into
2003 an output file. Either file may be in one of three formats:
2004
2005 @table @code
2006 @item rc
2007 A text format read by the Resource Compiler.
2008
2009 @item res
2010 A binary format generated by the Resource Compiler.
2011
2012 @item coff
2013 A COFF object or executable.
2014 @end table
2015
2016 The exact description of these different formats is available in
2017 documentation from Microsoft.
2018
2019 When @code{windres} converts from the @code{rc} format to the @code{res}
2020 format, it is acting like the Windows Resource Compiler. When
2021 @code{windres} converts from the @code{res} format to the @code{coff}
2022 format, it is acting like the Windows @code{CVTRES} program.
2023
2024 When @code{windres} generates an @code{rc} file, the output is similar
2025 but not identical to the format expected for the input. When an input
2026 @code{rc} file refers to an external filename, an output @code{rc} file
2027 will instead include the file contents.
2028
2029 If the input or output format is not specified, @code{windres} will
2030 guess based on the file name, or, for the input file, the file contents.
2031 A file with an extension of @file{.rc} will be treated as an @code{rc}
2032 file, a file with an extension of @file{.res} will be treated as a
2033 @code{res} file, and a file with an extension of @file{.o} or
2034 @file{.exe} will be treated as a @code{coff} file.
2035
2036 If no output file is specified, @code{windres} will print the resources
2037 in @code{rc} format to standard output.
2038
2039 The normal use is for you to write an @code{rc} file, use @code{windres}
2040 to convert it to a COFF object file, and then link the COFF file into
2041 your application. This will make the resources described in the
2042 @code{rc} file available to Windows.
2043
2044 @table @code
2045 @item -i @var{filename}
2046 @itemx --input @var{filename}
2047 The name of the input file. If this option is not used, then
2048 @code{windres} will use the first non-option argument as the input file
2049 name. If there are no non-option arguments, then @code{windres} will
2050 read from standard input. @code{windres} can not read a COFF file from
2051 standard input.
2052
2053 @item -o @var{filename}
2054 @itemx --output @var{filename}
2055 The name of the output file. If this option is not used, then
2056 @code{windres} will use the first non-option argument, after any used
2057 for the input file name, as the output file name. If there is no
2058 non-option argument, then @code{windres} will write to standard output.
2059 @code{windres} can not write a COFF file to standard output.
2060
2061 @item -I @var{format}
2062 @itemx --input-format @var{format}
2063 The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
2064 @samp{coff}. If no input format is specified, @code{windres} will
2065 guess, as described above.
2066
2067 @item -O @var{format}
2068 @itemx --output-format @var{format}
2069 The output format to generate. @var{format} may be @samp{res},
2070 @samp{rc}, or @samp{coff}. If no output format is specified,
2071 @code{windres} will guess, as described above.
2072
2073 @item -F @var{target}
2074 @itemx --target @var{target}
2075 Specify the BFD format to use for a COFF file as input or output. This
2076 is a BFD target name; you can use the @code{--help} option to see a list
2077 of supported targets. Normally @code{windres} will use the default
2078 format, which is the first one listed by the @code{--help} option.
2079 @ref{Target Selection}.
2080
2081 @item --preprocessor @var{program}
2082 When @code{windres} reads an @code{rc} file, it runs it through the C
2083 preprocessor first. This option may be used to specify the preprocessor
2084 to use, including any leading arguments. The default preprocessor
2085 argument is @code{gcc -E -xc-header -DRC_INVOKED}.
2086
2087 @item --include-dir @var{directory}
2088 Specify an include directory to use when reading an @code{rc} file.
2089 @code{windres} will pass this to the preprocessor as an @code{-I}
2090 option. @code{windres} will also search this directory when looking for
2091 files named in the @code{rc} file.
2092
2093 @item -D @var{target}
2094 @itemx --define @var{sym}[=@var{val}]
2095 Specify a @code{-D} option to pass to the preprocessor when reading an
2096 @code{rc} file.
2097
2098 @item -v
2099 Enable verbose mode. This tells you what the preprocessor is if you
2100 didn't specify one.
2101
2102 @item --language @var{val}
2103 Specify the default language to use when reading an @code{rc} file.
2104 @var{val} should be a hexadecimal language code. The low eight bits are
2105 the language, and the high eight bits are the sublanguage.
2106
2107 @item --help
2108 Prints a usage summary.
2109
2110 @item --version
2111 Prints the version number for @code{windres}.
2112
2113 @item --yydebug
2114 If @code{windres} is compiled with @code{YYDEBUG} defined as @code{1},
2115 this will turn on parser debugging.
2116 @end table
2117
2118
2119 @node dlltool
2120 @chapter Create files needed to build and use DLLs
2121 @cindex DLL
2122 @kindex dlltool
2123
2124 @code{dlltool} may be used to create the files needed to build and use
2125 dynamic link libraries (DLLs).
2126
2127 @quotation
2128 @emph{Warning:} @code{dlltool} is not always built as part of the binary
2129 utilities, since it is only useful for those targets which support DLLs.
2130 @end quotation
2131
2132 @smallexample
2133 dlltool [-d|--input-def @var{def-file-name}]
2134 [-b|--base-file @var{base-file-name}]
2135 [-e|--output-exp @var{exports-file-name}]
2136 [-z|--output-def @var{def-file-name}]
2137 [-l|--output-lib @var{library-file-name}]
2138 [--export-all-symbols] [--no-export-all-symbols]
2139 [--exclude-symbols @var{list}]
2140 [--no-default-excludes]
2141 [-S|--as @var{path-to-assembler}] [-f|--as-flags @var{options}]
2142 [-D|--dllname @var{name}] [-m|--machine @var{machine}]
2143 [-a|--add-indirect] [-U|--add-underscore] [-k|--kill-at]
2144 [-A|--add-stdcall-alias]
2145 [-x|--no-idata4] [-c|--no-idata5] [-i|--interwork]
2146 [-n|--nodelete] [-v|--verbose] [-h|--help] [-V|--version]
2147 [object-file @dots{}]
2148 @end smallexample
2149
2150 @code{dlltool} reads its inputs, which can come from the @samp{-d} and
2151 @samp{-b} options as well as object files specified on the command
2152 line. It then processes these inputs and if the @samp{-e} option has
2153 been specified it creates a exports file. If the @samp{-l} option
2154 has been specified it creates a library file and if the @samp{-z} option
2155 has been specified it creates a def file. Any or all of the -e, -l
2156 and -z options can be present in one invocation of dlltool.
2157
2158 When creating a DLL, along with the source for the DLL, it is necessary
2159 to have three other files. @code{dlltool} can help with the creation of
2160 these files.
2161
2162 The first file is a @samp{.def} file which specifies which functions are
2163 exported from the DLL, which functions the DLL imports, and so on. This
2164 is a text file and can be created by hand, or @code{dlltool} can be used
2165 to create it using the @samp{-z} option. In this case @code{dlltool}
2166 will scan the object files specified on its command line looking for
2167 those functions which have been specially marked as being exported and
2168 put entries for them in the .def file it creates.
2169
2170 In order to mark a function as being exported from a DLL, it needs to
2171 have an @samp{-export:<name_of_function>} entry in the @samp{.drectve}
2172 section of the object file. This can be done in C by using the
2173 asm() operator:
2174
2175 @smallexample
2176 asm (".section .drectve");
2177 asm (".ascii \"-export:my_func\"");
2178
2179 int my_func (void) @{ @dots{} @}
2180 @end smallexample
2181
2182 The second file needed for DLL creation is an exports file. This file
2183 is linked with the object files that make up the body of the DLL and it
2184 handles the interface between the DLL and the outside world. This is a
2185 binary file and it can be created by giving the @samp{-e} option to
2186 @code{dlltool} when it is creating or reading in a .def file.
2187
2188 The third file needed for DLL creation is the library file that programs
2189 will link with in order to access the functions in the DLL. This file
2190 can be created by giving the @samp{-l} option to dlltool when it
2191 is creating or reading in a .def file.
2192
2193 @code{dlltool} builds the library file by hand, but it builds the
2194 exports file by creating temporary files containing assembler statements
2195 and then assembling these. The @samp{-S} command line option can be
2196 used to specify the path to the assembler that dlltool will use,
2197 and the @samp{-f} option can be used to pass specific flags to that
2198 assembler. The @samp{-n} can be used to prevent dlltool from deleting
2199 these temporary assembler files when it is done, and if @samp{-n} is
2200 specified twice then this will prevent dlltool from deleting the
2201 temporary object files it used to build the library.
2202
2203 Here is an example of creating a DLL from a source file @samp{dll.c} and
2204 also creating a program (from an object file called @samp{program.o})
2205 that uses that DLL:
2206
2207 @smallexample
2208 gcc -c dll.c
2209 dlltool -e exports.o -l dll.lib dll.o
2210 gcc dll.o exports.o -o dll.dll
2211 gcc program.o dll.lib -o program
2212 @end smallexample
2213
2214 The command line options have the following meanings:
2215
2216 @table @code
2217
2218 @item -d @var{filename}
2219 @itemx --input-def @var{filename}
2220 @cindex input .def file
2221 Specifies the name of a .def file to be read in and processed.
2222
2223 @item -b @var{filename}
2224 @itemx --base-file @var{filename}
2225 @cindex base files
2226 Specifies the name of a base file to be read in and processed. The
2227 contents of this file will be added to the relocation section in the
2228 exports file generated by dlltool.
2229
2230 @item -e @var{filename}
2231 @itemx --output-exp @var{filename}
2232 Specifies the name of the export file to be created by dlltool.
2233
2234 @item -z @var{filename}
2235 @itemx --output-def @var{filename}
2236 Specifies the name of the .def file to be created by dlltool.
2237
2238 @item -l @var{filename}
2239 @itemx --output-lib @var{filename}
2240 Specifies the name of the library file to be created by dlltool.
2241
2242 @item --export-all-symbols
2243 Treat all global and weak defined symbols found in the input object
2244 files as symbols to be exported. There is a small list of symbols which
2245 are not exported by default; see the @code{--no-default-excludes}
2246 option. You may add to the list of symbols to not export by using the
2247 @code{--exclude-symbols} option.
2248
2249 @item --no-export-all-symbols
2250 Only export symbols explicitly listed in an input .def file or in
2251 @samp{.drectve} sections in the input object files. This is the default
2252 behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
2253 attributes in the source code.
2254
2255 @item --exclude-symbols @var{list}
2256 Do not export the symbols in @var{list}. This is a list of symbol names
2257 separated by comma or colon characters. The symbol names should not
2258 contain a leading underscore. This is only meaningful when
2259 @code{--export-all-symbols} is used.
2260
2261 @item --no-default-excludes
2262 When @code{--export-all-symbols} is used, it will by default avoid
2263 exporting certain special symbols. The current list of symbols to avoid
2264 exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
2265 @samp{impure_ptr}. You may use the @code{--no-default-excludes} option
2266 to go ahead and export these special symbols. This is only meaningful
2267 when @code{--export-all-symbols} is used.
2268
2269 @item -S @var{path}
2270 @itemx --as @var{path}
2271 Specifies the path, including the filename, of the assembler to be used
2272 to create the exports file.
2273
2274 @item -f @var{switches}
2275 @itemx --as-flags @var{switches}
2276 Specifies any specific command line switches to be passed to the
2277 assembler when building the exports file. This option will work even if
2278 the @samp{-S} option is not used. This option only takes one argument,
2279 and if it occurs more than once on the command line, then later
2280 occurrences will override earlier occurrences. So if it is necessary to
2281 pass multiple switches to the assembler they should be enclosed in
2282 double quotes.
2283
2284 @item -D @var{name}
2285 @itemx --dll-name @var{name}
2286 Specifies the name to be stored in the .def file as the name of the DLL
2287 when the @samp{-e} option is used. If this option is not present, then
2288 the filename given to the @samp{-e} option will be used as the name of
2289 the DLL.
2290
2291 @item -m @var{machine}
2292 @itemx -machine @var{machine}
2293 Specifies the type of machine for which the library file should be
2294 built. @code{dlltool} has a built in default type, depending upon how
2295 it was created, but this option can be used to override that. This is
2296 normally only useful when creating DLLs for an ARM processor, when the
2297 contents of the DLL are actually encode using THUMB instructions.
2298
2299 @item -a
2300 @itemx --add-indirect
2301 Specifies that when @code{dlltool} is creating the exports file it
2302 should add a section which allows the exported functions to be
2303 referenced without using the import library. Whatever the hell that
2304 means!
2305
2306 @item -U
2307 @itemx --add-underscore
2308 Specifies that when @code{dlltool} is creating the exports file it
2309 should prepend an underscore to the names of the exported functions.
2310
2311 @item -k
2312 @itemx --kill-at
2313 Specifies that when @code{dlltool} is creating the exports file it
2314 should not append the string @samp{@@ <number>}. These numbers are
2315 called ordinal numbers and they represent another way of accessing the
2316 function in a DLL, other than by name.
2317
2318 @item -A
2319 @itemx --add-stdcall-alias
2320 Specifies that when @code{dlltool} is creating the exports file it
2321 should add aliases for stdcall symbols without @samp{@@ <number>}
2322 in addition to the symbols with @samp{@@ <number>}.
2323
2324 @item -x
2325 @itemx --no-idata4
2326 Specifies that when @code{dlltool} is creating the exports and library
2327 files it should omit the .idata4 section. This is for compatibility
2328 with certain operating systems.
2329
2330 @item -c
2331 @itemx --no-idata5
2332 Specifies that when @code{dlltool} is creating the exports and library
2333 files it should omit the .idata5 section. This is for compatibility
2334 with certain operating systems.
2335
2336 @item -i
2337 @itemx --interwork
2338 Specifies that @code{dlltool} should mark the objects in the library
2339 file and exports file that it produces as supporting interworking
2340 between ARM and THUMB code.
2341
2342 @item -n
2343 @itemx --nodelete
2344 Makes @code{dlltool} preserve the temporary assembler files it used to
2345 create the exports file. If this option is repeated then dlltool will
2346 also preserve the temporary object files it uses to create the library
2347 file.
2348
2349 @item -v
2350 @itemx --verbose
2351 Make dlltool describe what it is doing.
2352
2353 @item -h
2354 @itemx --help
2355 Displays a list of command line options and then exits.
2356
2357 @item -V
2358 @itemx --version
2359 Displays dlltool's version number and then exits.
2360
2361 @end table
2362
2363 @node readelf
2364 @chapter readelf
2365
2366 @cindex ELF file information
2367 @kindex readelf
2368
2369 @smallexample
2370 readelf [ -a | --all ]
2371 [ -h | --file-header]
2372 [ -l | --program-headers | --segments]
2373 [ -S | --section-headers | --sections]
2374 [ -e | --headers]
2375 [ -s | --syms | --symbols]
2376 [ -n | --notes]
2377 [ -r | --relocs]
2378 [ -d | --dynamic]
2379 [ -V | --version-info]
2380 [ -D | --use-dynamic]
2381 [ -x <number> | --hex-dump=<number>]
2382 [ -w[liapr] | --debug-dump[=info,=line,=abbrev,=pubnames,=ranges]]
2383 [ --histogram]
2384 [ -v | --version]
2385 [ -H | --help]
2386 @var{elffile}@dots{}
2387 @end smallexample
2388
2389 @code{readelf} displays information about one or more ELF format object
2390 files. The options control what particular information to display.
2391
2392 @var{elffile}@dots{} are the object files to be examined. At the
2393 moment, @code{readelf} does not support examining archives, nor does it
2394 support examing 64 bit ELF files.
2395
2396 The long and short forms of options, shown here as alternatives, are
2397 equivalent. At least one option besides @samp{-v} or @samp{-H} must be
2398 given.
2399
2400 @table @code
2401 @item -a
2402 @itemx --all
2403 Equivalent to specifiying @samp{--file-header},
2404 @samp{--program-headers}, @samp{--sections}, @samp{--symbols},
2405 @samp{--relocs}, @samp{--dynamic}, @samp{--notes} and
2406 @samp{--version-info}.
2407
2408 @item -h
2409 @itemx --file-header
2410 @cindex ELF file header information
2411 Displays the information contained in the ELF header at the start of the
2412 file.
2413
2414 @item -l
2415 @itemx --program-headers
2416 @itemx --segments
2417 @cindex ELF program header information
2418 @cindex ELF segment information
2419 Displays the information contained in the file's segment headers, if it
2420 has any.
2421
2422 @item -S
2423 @itemx --sections
2424 @itemx --section-headers
2425 @cindex ELF section information
2426 Displays the information contained in the file's section headers, if it
2427 has any.
2428
2429 @item -s
2430 @itemx --symbols
2431 @itemx --syms
2432 @cindex ELF symbol table information
2433 Displays the entries in symbol table section of the file, if it has one.
2434
2435 @item -e
2436 @itemx --headers
2437 Display all the headers in the file. Equivalent to @samp{-h -l -S}.
2438
2439 @item -n
2440 @itemx --notes
2441 @cindex ELF core notes
2442 Displays the contents of the NOTE segment, if it exists.
2443
2444 @item -r
2445 @itemx --relocs
2446 @cindex ELF reloc information
2447 Displays the contents of the file's relocation section, if it ha one.
2448
2449 @item -d
2450 @itemx --dynamic
2451 @cindex ELF dynamic section information
2452 Displays the contents of the file's dynamic section, if it has one.
2453
2454 @item -V
2455 @itemx --version-info
2456 @cindex ELF version sections informations
2457 Displays the contents of the version sections in the file, it they
2458 exist.
2459
2460 @item -D
2461 @itemx --use-dynamic
2462 When displaying symbols, this option makes @code{readelf} use the
2463 symblol table in the file's dynamic section, rather than the one in the
2464 symbols section.
2465
2466 @item -x <number>
2467 @itemx --hex-dump=<number>
2468 Displays the contents of the indicated section as a hexadecimal dump.
2469
2470 @item -w[liapr]
2471 @itemx --debug-dump[=line,=info,=abbrev,=pubnames,=ranges]
2472 Displays the contents of the debug sections in the file, if any are
2473 present. If one of the optional letters or words follows the switch
2474 then only data found in those specific sections will be dumped.
2475
2476 @item --histogram
2477 Display a histogram of bucket list lengths when displaying the contents
2478 of the symbol tables.
2479
2480 @item -v
2481 @itemx --version
2482 Display the version number of readelf.
2483
2484 @item -H
2485 @itemx --help
2486 Display the command line options understood by @code{readelf}.
2487
2488 @end table
2489
2490
2491 @node Selecting The Target System
2492 @chapter Selecting the target system
2493
2494 You can specify three aspects of the target system to the @sc{gnu}
2495 binary file utilities, each in several ways:
2496
2497 @itemize @bullet
2498 @item
2499 the target
2500
2501 @item
2502 the architecture
2503
2504 @item
2505 the linker emulation (which applies to the linker only)
2506 @end itemize
2507
2508 In the following summaries, the lists of ways to specify values are in
2509 order of decreasing precedence. The ways listed first override those
2510 listed later.
2511
2512 The commands to list valid values only list the values for which the
2513 programs you are running were configured. If they were configured with
2514 @samp{--enable-targets=all}, the commands list most of the available
2515 values, but a few are left out; not all targets can be configured in at
2516 once because some of them can only be configured @dfn{native} (on hosts
2517 with the same type as the target system).
2518
2519 @menu
2520 * Target Selection::
2521 * Architecture Selection::
2522 * Linker Emulation Selection::
2523 @end menu
2524
2525 @node Target Selection
2526 @section Target Selection
2527
2528 A @dfn{target} is an object file format. A given target may be
2529 supported for multiple architectures (@pxref{Architecture Selection}).
2530 A target selection may also have variations for different operating
2531 systems or architectures.
2532
2533 The command to list valid target values is @samp{objdump -i}
2534 (the first column of output contains the relevant information).
2535
2536 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
2537 @samp{a.out-sunos-big}.
2538
2539 You can also specify a target using a configuration triplet. This is
2540 the same sort of name that is passed to configure to specify a target.
2541 When you use a configuration triplet as an argument, it must be fully
2542 canonicalized. You can see the canonical version of a triplet by
2543 running the shell script @file{config.sub} which is included with the
2544 sources.
2545
2546 Some sample configuration triplets are: @samp{m68k-hp-bsd},
2547 @samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
2548
2549 @subheading @code{objdump} Target
2550
2551 Ways to specify:
2552
2553 @enumerate
2554 @item
2555 command line option: @samp{-b} or @samp{--target}
2556
2557 @item
2558 environment variable @code{GNUTARGET}
2559
2560 @item
2561 deduced from the input file
2562 @end enumerate
2563
2564 @subheading @code{objcopy} and @code{strip} Input Target
2565
2566 Ways to specify:
2567
2568 @enumerate
2569 @item
2570 command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
2571
2572 @item
2573 environment variable @code{GNUTARGET}
2574
2575 @item
2576 deduced from the input file
2577 @end enumerate
2578
2579 @subheading @code{objcopy} and @code{strip} Output Target
2580
2581 Ways to specify:
2582
2583 @enumerate
2584 @item
2585 command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
2586
2587 @item
2588 the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
2589
2590 @item
2591 environment variable @code{GNUTARGET}
2592
2593 @item
2594 deduced from the input file
2595 @end enumerate
2596
2597 @subheading @code{nm}, @code{size}, and @code{strings} Target
2598
2599 Ways to specify:
2600
2601 @enumerate
2602 @item
2603 command line option: @samp{--target}
2604
2605 @item
2606 environment variable @code{GNUTARGET}
2607
2608 @item
2609 deduced from the input file
2610 @end enumerate
2611
2612 @subheading Linker Input Target
2613
2614 Ways to specify:
2615
2616 @enumerate
2617 @item
2618 command line option: @samp{-b} or @samp{--format}
2619 (@pxref{Options,,Options,ld.info,Using LD})
2620
2621 @item
2622 script command @code{TARGET}
2623 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2624
2625 @item
2626 environment variable @code{GNUTARGET}
2627 (@pxref{Environment,,Environment,ld.info,Using LD})
2628
2629 @item
2630 the default target of the selected linker emulation
2631 (@pxref{Linker Emulation Selection})
2632 @end enumerate
2633
2634 @subheading Linker Output Target
2635
2636 Ways to specify:
2637
2638 @enumerate
2639 @item
2640 command line option: @samp{-oformat}
2641 (@pxref{Options,,Options,ld.info,Using LD})
2642
2643 @item
2644 script command @code{OUTPUT_FORMAT}
2645 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2646
2647 @item
2648 the linker input target (see ``Linker Input Target'' above)
2649 @end enumerate
2650
2651 @node Architecture Selection
2652 @section Architecture selection
2653
2654 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
2655 to run. Its name may contain a colon, separating the name of the
2656 processor family from the name of the particular @sc{cpu}.
2657
2658 The command to list valid architecture values is @samp{objdump -i} (the
2659 second column contains the relevant information).
2660
2661 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
2662
2663 @subheading @code{objdump} Architecture
2664
2665 Ways to specify:
2666
2667 @enumerate
2668 @item
2669 command line option: @samp{-m} or @samp{--architecture}
2670
2671 @item
2672 deduced from the input file
2673 @end enumerate
2674
2675 @subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
2676
2677 Ways to specify:
2678
2679 @enumerate
2680 @item
2681 deduced from the input file
2682 @end enumerate
2683
2684 @subheading Linker Input Architecture
2685
2686 Ways to specify:
2687
2688 @enumerate
2689 @item
2690 deduced from the input file
2691 @end enumerate
2692
2693 @subheading Linker Output Architecture
2694
2695 Ways to specify:
2696
2697 @enumerate
2698 @item
2699 script command @code{OUTPUT_ARCH}
2700 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2701
2702 @item
2703 the default architecture from the linker output target
2704 (@pxref{Target Selection})
2705 @end enumerate
2706
2707 @node Linker Emulation Selection
2708 @section Linker emulation selection
2709
2710 A linker @dfn{emulation} is a ``personality'' of the linker, which gives
2711 the linker default values for the other aspects of the target system.
2712 In particular, it consists of
2713
2714 @itemize @bullet
2715 @item
2716 the linker script
2717
2718 @item
2719 the target
2720
2721 @item
2722 several ``hook'' functions that are run at certain stages of the linking
2723 process to do special things that some targets require
2724 @end itemize
2725
2726 The command to list valid linker emulation values is @samp{ld -V}.
2727
2728 Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
2729
2730 Ways to specify:
2731
2732 @enumerate
2733 @item
2734 command line option: @samp{-m}
2735 (@pxref{Options,,Options,ld.info,Using LD})
2736
2737 @item
2738 environment variable @code{LDEMULATION}
2739
2740 @item
2741 compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2742 which comes from @code{EMUL} in @file{config/@var{target}.mt}
2743 @end enumerate
2744
2745 @node Reporting Bugs
2746 @chapter Reporting Bugs
2747 @cindex bugs
2748 @cindex reporting bugs
2749
2750 Your bug reports play an essential role in making the binary utilities
2751 reliable.
2752
2753 Reporting a bug may help you by bringing a solution to your problem, or
2754 it may not. But in any case the principal function of a bug report is
2755 to help the entire community by making the next version of the binary
2756 utilities work better. Bug reports are your contribution to their
2757 maintenance.
2758
2759 In order for a bug report to serve its purpose, you must include the
2760 information that enables us to fix the bug.
2761
2762 @menu
2763 * Bug Criteria:: Have you found a bug?
2764 * Bug Reporting:: How to report bugs
2765 @end menu
2766
2767 @node Bug Criteria
2768 @section Have you found a bug?
2769 @cindex bug criteria
2770
2771 If you are not sure whether you have found a bug, here are some guidelines:
2772
2773 @itemize @bullet
2774 @cindex fatal signal
2775 @cindex crash
2776 @item
2777 If a binary utility gets a fatal signal, for any input whatever, that is
2778 a bug. Reliable utilities never crash.
2779
2780 @cindex error on valid input
2781 @item
2782 If a binary utility produces an error message for valid input, that is a
2783 bug.
2784
2785 @item
2786 If you are an experienced user of binary utilities, your suggestions for
2787 improvement are welcome in any case.
2788 @end itemize
2789
2790 @node Bug Reporting
2791 @section How to report bugs
2792 @cindex bug reports
2793 @cindex bugs, reporting
2794
2795 A number of companies and individuals offer support for @sc{gnu}
2796 products. If you obtained the binary utilities from a support
2797 organization, we recommend you contact that organization first.
2798
2799 You can find contact information for many support companies and
2800 individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2801 distribution.
2802
2803 In any event, we also recommend that you send bug reports for the binary
2804 utilities to @samp{bug-gnu-utils@@gnu.org}.
2805
2806 The fundamental principle of reporting bugs usefully is this:
2807 @strong{report all the facts}. If you are not sure whether to state a
2808 fact or leave it out, state it!
2809
2810 Often people omit facts because they think they know what causes the
2811 problem and assume that some details do not matter. Thus, you might
2812 assume that the name of a file you use in an example does not matter.
2813 Well, probably it does not, but one cannot be sure. Perhaps the bug is
2814 a stray memory reference which happens to fetch from the location where
2815 that pathname is stored in memory; perhaps, if the pathname were
2816 different, the contents of that location would fool the utility into
2817 doing the right thing despite the bug. Play it safe and give a
2818 specific, complete example. That is the easiest thing for you to do,
2819 and the most helpful.
2820
2821 Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2822 it is new to us. Therefore, always write your bug reports on the assumption
2823 that the bug has not been reported previously.
2824
2825 Sometimes people give a few sketchy facts and ask, ``Does this ring a
2826 bell?'' Those bug reports are useless, and we urge everyone to
2827 @emph{refuse to respond to them} except to chide the sender to report
2828 bugs properly.
2829
2830 To enable us to fix the bug, you should include all these things:
2831
2832 @itemize @bullet
2833 @item
2834 The version of the utility. Each utility announces it if you start it
2835 with the @samp{--version} argument.
2836
2837 Without this, we will not know whether there is any point in looking for
2838 the bug in the current version of the binary utilities.
2839
2840 @item
2841 Any patches you may have applied to the source, including any patches
2842 made to the @code{BFD} library.
2843
2844 @item
2845 The type of machine you are using, and the operating system name and
2846 version number.
2847
2848 @item
2849 What compiler (and its version) was used to compile the utilities---e.g.
2850 ``@code{gcc-2.7}''.
2851
2852 @item
2853 The command arguments you gave the utility to observe the bug. To
2854 guarantee you will not omit something important, list them all. A copy
2855 of the Makefile (or the output from make) is sufficient.
2856
2857 If we were to try to guess the arguments, we would probably guess wrong
2858 and then we might not encounter the bug.
2859
2860 @item
2861 A complete input file, or set of input files, that will reproduce the
2862 bug. If the utility is reading an object file or files, then it is
2863 generally most helpful to send the actual object files, uuencoded if
2864 necessary to get them through the mail system. Note that
2865 @samp{bug-gnu-utils@@gnu.org} is a mailing list, so you should avoid
2866 sending very large files to it. Making the files available for
2867 anonymous FTP is OK.
2868
2869 If the source files were produced exclusively using @sc{gnu} programs
2870 (e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2871 may be OK to send the source files rather than the object files. In
2872 this case, be sure to say exactly what version of @code{gcc}, or
2873 whatever, was used to produce the object files. Also say how
2874 @code{gcc}, or whatever, was configured.
2875
2876 @item
2877 A description of what behavior you observe that you believe is
2878 incorrect. For example, ``It gets a fatal signal.''
2879
2880 Of course, if the bug is that the utility gets a fatal signal, then we
2881 will certainly notice it. But if the bug is incorrect output, we might
2882 not notice unless it is glaringly wrong. You might as well not give us
2883 a chance to make a mistake.
2884
2885 Even if the problem you experience is a fatal signal, you should still
2886 say so explicitly. Suppose something strange is going on, such as, your
2887 copy of the utility is out of synch, or you have encountered a bug in
2888 the C library on your system. (This has happened!) Your copy might
2889 crash and ours would not. If you told us to expect a crash, then when
2890 ours fails to crash, we would know that the bug was not happening for
2891 us. If you had not told us to expect a crash, then we would not be able
2892 to draw any conclusion from our observations.
2893
2894 @item
2895 If you wish to suggest changes to the source, send us context diffs, as
2896 generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2897 option. Always send diffs from the old file to the new file. If you
2898 even discuss something in the @code{ld} source, refer to it by context,
2899 not by line number.
2900
2901 The line numbers in our development sources will not match those in your
2902 sources. Your line numbers would convey no useful information to us.
2903 @end itemize
2904
2905 Here are some things that are not necessary:
2906
2907 @itemize @bullet
2908 @item
2909 A description of the envelope of the bug.
2910
2911 Often people who encounter a bug spend a lot of time investigating
2912 which changes to the input file will make the bug go away and which
2913 changes will not affect it.
2914
2915 This is often time consuming and not very useful, because the way we
2916 will find the bug is by running a single example under the debugger
2917 with breakpoints, not by pure deduction from a series of examples.
2918 We recommend that you save your time for something else.
2919
2920 Of course, if you can find a simpler example to report @emph{instead}
2921 of the original one, that is a convenience for us. Errors in the
2922 output will be easier to spot, running under the debugger will take
2923 less time, and so on.
2924
2925 However, simplification is not vital; if you do not want to do this,
2926 report the bug anyway and send us the entire test case you used.
2927
2928 @item
2929 A patch for the bug.
2930
2931 A patch for the bug does help us if it is a good one. But do not omit
2932 the necessary information, such as the test case, on the assumption that
2933 a patch is all we need. We might see problems with your patch and decide
2934 to fix the problem another way, or we might not understand it at all.
2935
2936 Sometimes with programs as complicated as the binary utilities it is
2937 very hard to construct an example that will make the program follow a
2938 certain path through the code. If you do not send us the example, we
2939 will not be able to construct one, so we will not be able to verify that
2940 the bug is fixed.
2941
2942 And if we cannot understand what bug you are trying to fix, or why your
2943 patch should be an improvement, we will not install it. A test case will
2944 help us to understand.
2945
2946 @item
2947 A guess about what the bug is or what it depends on.
2948
2949 Such guesses are usually wrong. Even we cannot guess right about such
2950 things without first using the debugger to find the facts.
2951 @end itemize
2952
2953 @node Index
2954 @unnumbered Index
2955
2956 @printindex cp
2957
2958 @contents
2959 @bye