* binutils.texi (nm): Improve documentation on symbol types.
[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 "ar", "objcopy",
9 "objdump", "nm", "nlmconv", "size",
10 "strings", "strip", and "ranlib".
11 END-INFO-DIR-ENTRY
12 @end format
13 @end ifinfo
14
15 @ifinfo
16 Copyright @copyright{} 1991, 92, 93, 94, 95, 1996 Free Software Foundation, Inc.
17
18 Permission is granted to make and distribute verbatim copies of
19 this manual provided the copyright notice and this permission notice
20 are preserved on all copies.
21
22 @ignore
23 Permission is granted to process this file through TeX and print the
24 results, provided the printed document carries a copying permission
25 notice identical to this one except for the removal of this paragraph
26 (this paragraph not being relevant to the printed manual).
27
28 @end ignore
29
30 Permission is granted to copy and distribute modified versions of this
31 manual under the conditions for verbatim copying, provided also that
32 the entire resulting derived work is distributed under the terms of a
33 permission notice identical to this one.
34
35 Permission is granted to copy and distribute translations of this manual
36 into another language, under the above conditions for modified versions.
37 @end ifinfo
38
39 @synindex ky cp
40 @c
41 @c This file documents the GNU binary utilities "ar", "ld", "objcopy",
42 @c "objdump", "nm", "size", "strings", "strip", and "ranlib".
43 @c
44 @c Copyright (C) 1991, 92, 93, 94, 95, 1996 Free Software Foundation, Inc.
45 @c
46 @c This text may be freely distributed under the terms of the GNU
47 @c General Public License.
48 @c
49
50 @setchapternewpage odd
51 @settitle @sc{gnu} Binary Utilities
52 @titlepage
53 @finalout
54 @title The @sc{gnu} Binary Utilities
55 @subtitle Version @value{VERSION}
56 @sp 1
57 @subtitle May 1993
58 @author Roland H. Pesch
59 @author Jeffrey M. Osier
60 @author Cygnus Support
61 @page
62
63 @tex
64 {\parskip=0pt \hfill Cygnus Support\par \hfill
65 \TeX{}info \texinfoversion\par }
66 @end tex
67
68 @vskip 0pt plus 1filll
69 Copyright @copyright{} 1991, 92, 93, 94, 95, 1996 Free Software Foundation, Inc.
70
71 Permission is granted to make and distribute verbatim copies of
72 this manual provided the copyright notice and this permission notice
73 are preserved on all copies.
74
75 Permission is granted to copy and distribute modified versions of this
76 manual under the conditions for verbatim copying, provided also that
77 the entire resulting derived work is distributed under the terms of a
78 permission notice identical to this one.
79
80 Permission is granted to copy and distribute translations of this manual
81 into another language, under the above conditions for modified versions.
82 @end titlepage
83
84 @node Top
85 @top Introduction
86
87 @cindex version
88 This brief manual contains preliminary documentation for the @sc{gnu} binary
89 utilities (collectively version @value{VERSION}):
90
91 @iftex
92 @table @code
93 @item ar
94 Create, modify, and extract from archives
95
96 @item nm
97 List symbols from object files
98
99 @item objcopy
100 Copy and translate object files
101
102 @item objdump
103 Display information from object files
104
105 @item ranlib
106 Generate index to archive contents
107
108 @item size
109 List file section sizes and total size
110
111 @item strings
112 List printable strings from files
113
114 @item strip
115 Discard symbols
116
117 @item c++filt
118 Demangle encoded C++ symbols
119
120 @item nlmconv
121 Convert object code into a Netware Loadable Module
122 @end table
123 @end iftex
124
125 @menu
126 * ar:: Create, modify, and extract from archives
127 * nm:: List symbols from object files
128 * objcopy:: Copy and translate object files
129 * objdump:: Display information from object files
130 * ranlib:: Generate index to archive contents
131 * size:: List section sizes and total size
132 * strings:: List printable strings from files
133 * strip:: Discard symbols
134 * c++filt:: Filter to demangle encoded C++ symbols
135 * nlmconv:: Converts object code into an NLM
136 * Selecting The Target System:: How these utilities determine the target.
137 * Index::
138 @end menu
139
140 @node ar
141 @chapter ar
142
143 @kindex ar
144 @cindex archives
145 @cindex collections of files
146 @smallexample
147 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
148 ar -M [ <mri-script ]
149 @end smallexample
150
151 The @sc{gnu} @code{ar} program creates, modifies, and extracts from
152 archives. An @dfn{archive} is a single file holding a collection of
153 other files in a structure that makes it possible to retrieve
154 the original individual files (called @dfn{members} of the archive).
155
156 The original files' contents, mode (permissions), timestamp, owner, and
157 group are preserved in the archive, and can be restored on
158 extraction.
159
160 @cindex name length
161 @sc{gnu} @code{ar} can maintain archives whose members have names of any
162 length; however, depending on how @code{ar} is configured on your
163 system, a limit on member-name length may be imposed for compatibility
164 with archive formats maintained with other tools. If it exists, the
165 limit is often 15 characters (typical of formats related to a.out) or 16
166 characters (typical of formats related to coff).
167
168 @cindex libraries
169 @code{ar} is considered a binary utility because archives of this sort
170 are most often used as @dfn{libraries} holding commonly needed
171 subroutines.
172
173 @cindex symbol index
174 @code{ar} creates an index to the symbols defined in relocatable
175 object modules in the archive when you specify the modifier @samp{s}.
176 Once created, this index is updated in the archive whenever @code{ar}
177 makes a change to its contents (save for the @samp{q} update operation).
178 An archive with such an index speeds up linking to the library, and
179 allows routines in the library to call each other without regard to
180 their placement in the archive.
181
182 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
183 table. If an archive lacks the table, another form of @code{ar} called
184 @code{ranlib} can be used to add just the table.
185
186 @cindex compatibility, @code{ar}
187 @cindex @code{ar} compatibility
188 @sc{gnu} @code{ar} is designed to be compatible with two different
189 facilities. You can control its activity using command-line options,
190 like the different varieties of @code{ar} on Unix systems; or, if you
191 specify the single command-line option @samp{-M}, you can control it
192 with a script supplied via standard input, like the MRI ``librarian''
193 program.
194
195 @menu
196 * ar cmdline:: Controlling @code{ar} on the command line
197 * ar scripts:: Controlling @code{ar} with a script
198 @end menu
199
200 @page
201 @node ar cmdline
202 @section Controlling @code{ar} on the command line
203
204 @smallexample
205 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
206 @end smallexample
207
208 @cindex Unix compatibility, @code{ar}
209 When you use @code{ar} in the Unix style, @code{ar} insists on at least two
210 arguments to execute: one keyletter specifying the @emph{operation}
211 (optionally accompanied by other keyletters specifying
212 @emph{modifiers}), and the archive name to act on.
213
214 Most operations can also accept further @var{member} arguments,
215 specifying particular files to operate on.
216
217 @sc{gnu} @code{ar} allows you to mix the operation code @var{p} and modifier
218 flags @var{mod} in any order, within the first command-line argument.
219
220 If you wish, you may begin the first command-line argument with a
221 dash.
222
223 @cindex operations on archive
224 The @var{p} keyletter specifies what operation to execute; it may be
225 any of the following, but you must specify only one of them:
226
227 @table @code
228 @item d
229 @cindex deleting from archive
230 @emph{Delete} modules from the archive. Specify the names of modules to
231 be deleted as @var{member}@dots{}; the archive is untouched if you
232 specify no files to delete.
233
234 If you specify the @samp{v} modifier, @code{ar} lists each module
235 as it is deleted.
236
237 @item m
238 @cindex moving in archive
239 Use this operation to @emph{move} members in an archive.
240
241 The ordering of members in an archive can make a difference in how
242 programs are linked using the library, if a symbol is defined in more
243 than one member.
244
245 If no modifiers are used with @code{m}, any members you name in the
246 @var{member} arguments are moved to the @emph{end} of the archive;
247 you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
248 specified place instead.
249
250 @item p
251 @cindex printing from archive
252 @emph{Print} the specified members of the archive, to the standard
253 output file. If the @samp{v} modifier is specified, show the member
254 name before copying its contents to standard output.
255
256 If you specify no @var{member} arguments, all the files in the archive are
257 printed.
258
259 @item q
260 @cindex quick append to archive
261 @emph{Quick append}; add the files @var{member}@dots{} to the end of
262 @var{archive}, without checking for replacement.
263
264 The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
265 operation; new members are always placed at the end of the archive.
266
267 The modifier @samp{v} makes @code{ar} list each file as it is appended.
268
269 Since the point of this operation is speed, the archive's symbol table
270 index is not updated, even if it already existed; you can use @samp{ar s} or
271 @code{ranlib} explicitly to update the symbol table index.
272
273 @item r
274 @cindex replacement in archive
275 Insert the files @var{member}@dots{} into @var{archive} (with
276 @emph{replacement}). This operation differs from @samp{q} in that any
277 previously existing members are deleted if their names match those being
278 added.
279
280 If one of the files named in @var{member}@dots{} does not exist, @code{ar}
281 displays an error message, and leaves undisturbed any existing members
282 of the archive matching that name.
283
284 By default, new members are added at the end of the file; but you may
285 use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
286 placement relative to some existing member.
287
288 The modifier @samp{v} used with this operation elicits a line of
289 output for each file inserted, along with one of the letters @samp{a} or
290 @samp{r} to indicate whether the file was appended (no old member
291 deleted) or replaced.
292
293 @item t
294 @cindex contents of archive
295 Display a @emph{table} listing the contents of @var{archive}, or those
296 of the files listed in @var{member}@dots{} that are present in the
297 archive. Normally only the member name is shown; if you also want to
298 see the modes (permissions), timestamp, owner, group, and size, you can
299 request that by also specifying the @samp{v} modifier.
300
301 If you do not specify a @var{member}, all files in the archive
302 are listed.
303
304 @cindex repeated names in archive
305 @cindex name duplication in archive
306 If there is more than one file with the same name (say, @samp{fie}) in
307 an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
308 first instance; to see them all, you must ask for a complete
309 listing---in our example, @samp{ar t b.a}.
310 @c WRS only; per Gumby, this is implementation-dependent, and in a more
311 @c recent case in fact works the other way.
312
313 @item x
314 @cindex extract from archive
315 @emph{Extract} members (named @var{member}) from the archive. You can
316 use the @samp{v} modifier with this operation, to request that
317 @code{ar} list each name as it extracts it.
318
319 If you do not specify a @var{member}, all files in the archive
320 are extracted.
321
322 @end table
323
324 A number of modifiers (@var{mod}) may immediately follow the @var{p}
325 keyletter, to specify variations on an operation's behavior:
326
327 @table @code
328 @item a
329 @cindex relative placement in archive
330 Add new files @emph{after} an existing member of the
331 archive. If you use the modifier @samp{a}, the name of an existing archive
332 member must be present as the @var{relpos} argument, before the
333 @var{archive} specification.
334
335 @item b
336 Add new files @emph{before} an existing member of the
337 archive. If you use the modifier @samp{b}, the name of an existing archive
338 member must be present as the @var{relpos} argument, before the
339 @var{archive} specification. (same as @samp{i}).
340
341 @item c
342 @cindex creating archives
343 @emph{Create} the archive. The specified @var{archive} is always
344 created if it did not exist, when you request an update. But a warning is
345 issued unless you specify in advance that you expect to create it, by
346 using this modifier.
347
348 @item f
349 Truncate names in the archive. @sc{gnu} @code{ar} will normally permit file
350 names of any length. This will cause it to create archives which are
351 not compatible with the native @code{ar} program on some systems. If
352 this is a concern, the @samp{f} modifier may be used to truncate file
353 names when putting them in the archive.
354
355 @item i
356 Insert new files @emph{before} an existing member of the
357 archive. If you use the modifier @samp{i}, the name of an existing archive
358 member must be present as the @var{relpos} argument, before the
359 @var{archive} specification. (same as @samp{b}).
360
361 @item l
362 This modifier is accepted but not used.
363 @c whaffor ar l modifier??? presumably compat; with
364 @c what???---doc@@cygnus.com, 25jan91
365
366 @item o
367 @cindex dates in archive
368 Preserve the @emph{original} dates of members when extracting them. If
369 you do not specify this modifier, files extracted from the archive
370 are stamped with the time of extraction.
371
372 @item s
373 @cindex writing archive index
374 Write an object-file index into the archive, or update an existing one,
375 even if no other change is made to the archive. You may use this modifier
376 flag either with any operation, or alone. Running @samp{ar s} on an
377 archive is equivalent to running @samp{ranlib} on it.
378
379 @item u
380 @cindex updating an archive
381 Normally, @samp{ar r}@dots{} inserts all files
382 listed into the archive. If you would like to insert @emph{only} those
383 of the files you list that are newer than existing members of the same
384 names, use this modifier. The @samp{u} modifier is allowed only for the
385 operation @samp{r} (replace). In particular, the combination @samp{qu} is
386 not allowed, since checking the timestamps would lose any speed
387 advantage from the operation @samp{q}.
388
389 @item v
390 This modifier requests the @emph{verbose} version of an operation. Many
391 operations display additional information, such as filenames processed,
392 when the modifier @samp{v} is appended.
393
394 @item V
395 This modifier shows the version number of @code{ar}.
396 @end table
397
398 @node ar scripts
399 @section Controlling @code{ar} with a script
400
401 @smallexample
402 ar -M [ <@var{script} ]
403 @end smallexample
404
405 @cindex MRI compatibility, @code{ar}
406 @cindex scripts, @code{ar}
407 If you use the single command-line option @samp{-M} with @code{ar}, you
408 can control its operation with a rudimentary command language. This
409 form of @code{ar} operates interactively if standard input is coming
410 directly from a terminal. During interactive use, @code{ar} prompts for
411 input (the prompt is @samp{AR >}), and continues executing even after
412 errors. If you redirect standard input to a script file, no prompts are
413 issued, and @code{ar} abandons execution (with a nonzero exit code)
414 on any error.
415
416 The @code{ar} command language is @emph{not} designed to be equivalent
417 to the command-line options; in fact, it provides somewhat less control
418 over archives. The only purpose of the command language is to ease the
419 transition to @sc{gnu} @code{ar} for developers who already have scripts
420 written for the MRI ``librarian'' program.
421
422 The syntax for the @code{ar} command language is straightforward:
423 @itemize @bullet
424 @item
425 commands are recognized in upper or lower case; for example, @code{LIST}
426 is the same as @code{list}. In the following descriptions, commands are
427 shown in upper case for clarity.
428
429 @item
430 a single command may appear on each line; it is the first word on the
431 line.
432
433 @item
434 empty lines are allowed, and have no effect.
435
436 @item
437 comments are allowed; text after either of the characters @samp{*}
438 or @samp{;} is ignored.
439
440 @item
441 Whenever you use a list of names as part of the argument to an @code{ar}
442 command, you can separate the individual names with either commas or
443 blanks. Commas are shown in the explanations below, for clarity.
444
445 @item
446 @samp{+} is used as a line continuation character; if @samp{+} appears
447 at the end of a line, the text on the following line is considered part
448 of the current command.
449 @end itemize
450
451 Here are the commands you can use in @code{ar} scripts, or when using
452 @code{ar} interactively. Three of them have special significance:
453
454 @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
455 a temporary file required for most of the other commands.
456
457 @code{SAVE} commits the changes so far specified by the script. Prior
458 to @code{SAVE}, commands affect only the temporary copy of the current
459 archive.
460
461 @table @code
462 @item ADDLIB @var{archive}
463 @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
464 Add all the contents of @var{archive} (or, if specified, each named
465 @var{module} from @var{archive}) to the current archive.
466
467 Requires prior use of @code{OPEN} or @code{CREATE}.
468
469 @item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
470 @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
471 @c else like "ar q..."
472 Add each named @var{member} as a module in the current archive.
473
474 Requires prior use of @code{OPEN} or @code{CREATE}.
475
476 @item CLEAR
477 Discard the contents of the current archive, cancelling the effect of
478 any operations since the last @code{SAVE}. May be executed (with no
479 effect) even if no current archive is specified.
480
481 @item CREATE @var{archive}
482 Creates an archive, and makes it the current archive (required for many
483 other commands). The new archive is created with a temporary name; it
484 is not actually saved as @var{archive} until you use @code{SAVE}.
485 You can overwrite existing archives; similarly, the contents of any
486 existing file named @var{archive} will not be destroyed until @code{SAVE}.
487
488 @item DELETE @var{module}, @var{module}, @dots{} @var{module}
489 Delete each listed @var{module} from the current archive; equivalent to
490 @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
491
492 Requires prior use of @code{OPEN} or @code{CREATE}.
493
494 @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
495 @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
496 List each named @var{module} present in @var{archive}. The separate
497 command @code{VERBOSE} specifies the form of the output: when verbose
498 output is off, output is like that of @samp{ar -t @var{archive}
499 @var{module}@dots{}}. When verbose output is on, the listing is like
500 @samp{ar -tv @var{archive} @var{module}@dots{}}.
501
502 Output normally goes to the standard output stream; however, if you
503 specify @var{outputfile} as a final argument, @code{ar} directs the
504 output to that file.
505
506 @item END
507 Exit from @code{ar}, with a @code{0} exit code to indicate successful
508 completion. This command does not save the output file; if you have
509 changed the current archive since the last @code{SAVE} command, those
510 changes are lost.
511
512 @item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
513 Extract each named @var{module} from the current archive, writing them
514 into the current directory as separate files. Equivalent to @samp{ar -x
515 @var{archive} @var{module}@dots{}}.
516
517 Requires prior use of @code{OPEN} or @code{CREATE}.
518
519 @ignore
520 @c FIXME Tokens but no commands???
521 @item FULLDIR
522
523 @item HELP
524 @end ignore
525
526 @item LIST
527 Display full contents of the current archive, in ``verbose'' style
528 regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
529 tv @var{archive}}). (This single command is a @sc{gnu} @code{ld}
530 enhancement, rather than present for MRI compatibility.)
531
532 Requires prior use of @code{OPEN} or @code{CREATE}.
533
534 @item OPEN @var{archive}
535 Opens an existing archive for use as the current archive (required for
536 many other commands). Any changes as the result of subsequent commands
537 will not actually affect @var{archive} until you next use @code{SAVE}.
538
539 @item REPLACE @var{module}, @var{module}, @dots{} @var{module}
540 In the current archive, replace each existing @var{module} (named in
541 the @code{REPLACE} arguments) from files in the current working directory.
542 To execute this command without errors, both the file, and the module in
543 the current archive, must exist.
544
545 Requires prior use of @code{OPEN} or @code{CREATE}.
546
547 @item VERBOSE
548 Toggle an internal flag governing the output from @code{DIRECTORY}.
549 When the flag is on, @code{DIRECTORY} output matches output from
550 @samp{ar -tv }@dots{}.
551
552 @item SAVE
553 Commit your changes to the current archive, and actually save it as a
554 file with the name specified in the last @code{CREATE} or @code{OPEN}
555 command.
556
557 Requires prior use of @code{OPEN} or @code{CREATE}.
558
559 @end table
560
561 @iftex
562 @node ld
563 @chapter ld
564 @cindex linker
565 @kindex ld
566 The @sc{gnu} linker @code{ld} is now described in a separate manual.
567 @xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
568 @end iftex
569
570 @node nm
571 @chapter nm
572 @cindex symbols
573 @kindex nm
574
575 @smallexample
576 nm [ -a | --debug-syms ] [ -g | --extern-only ]
577 [ -B ] [ -C | --demangle ] [ -D | --dynamic ]
578 [ -s | --print-armap ] [ -A | -o | --print-file-name ]
579 [ -n | -v | --numeric-sort ] [ -p | --no-sort ]
580 [ -r | --reverse-sort ] [ --size-sort ] [ -u | --undefined-only ]
581 [ -t @var{radix} | --radix=@var{radix} ] [ -P | --portability ]
582 [ --target=@var{bfdname} ] [ -f @var{format} | --format=@var{format} ]
583 [ --defined-only ]
584 [ --no-demangle ] [ -V | --version ] [ --help ] [ @var{objfile}@dots{} ]
585 @end smallexample
586
587 @sc{gnu} @code{nm} lists the symbols from object files @var{objfile}@dots{}.
588 If no object files are listed as arguments, @code{nm} assumes
589 @file{a.out}.
590
591 For each symbol, @code{nm} shows:
592
593 @itemize @bullet
594 @item
595 The symbol value, in the radix selected by options (see below), or
596 hexadecimal by default.
597
598 @item
599 The symbol type. At least the following types are used; others are, as
600 well, depending on the object file format. If lowercase, the symbol is
601 local; if uppercase, the symbol is global (external).
602
603 @c Some more detail on exactly what these symbol types are used for
604 @c would be nice.
605 @table @code
606 @item A
607 The symbol's value is absolute, and will not be changed by further
608 linking.
609
610 @item B
611 The symbol is in the uninitialized data section (known as BSS).
612
613 @item C
614 The symbol is common. Common symbols are uninitialized data. When
615 linking, multiple common symbols may appear with the same name. If the
616 symbol is defined anywhere, the common symbols are treated as undefined
617 references. For more details on common symbols, see the discussion of
618 --warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
619
620 @item D
621 The symbol is in the initialized data section.
622
623 @item G
624 The symbol is in a initialized data section for small objects. Some
625 object file formats permit more efficient access to small data objects,
626 such as a global int variable as opposed to a large global array.
627
628 @item I
629 The symbol is an indirect reference to another symbol. This is a GNU
630 extension to the a.out object file format which is rarely used.
631
632 @item N
633 The symbol is a debugging symbol.
634
635 @item R
636 The symbol is in a read only data section.
637
638 @item S
639 The symbol is in a uninitialized data section for small objects.
640
641 @item T
642 The symbol is in the text (code) section.
643
644 @item U
645 The symbol is undefined.
646
647 @item W
648 The symbol is weak. When a weak defined symbol is linked with a normal
649 defined symbol, the normal defined symbol is used with no error. When a
650 weak undefined symbol is linked and the symbol is not defined, the value
651 of the weak symbol becomes zero with no error.
652
653 @item -
654 The symbol is a stabs symbol in an a.out object file. In this case, the
655 next values printed are the stabs other field, the stabs desc field, and
656 the stab type. Stabs symbols are used to hold debugging information;
657 for more information, see @ref{Top,Stabs,Stabs Overview,stabs.info, The
658 ``stabs'' debug format}.
659
660 @item ?
661 The symbol type is unknown, or object file format specific.
662 @end table
663
664 @item
665 The symbol name.
666 @end itemize
667
668 The long and short forms of options, shown here as alternatives, are
669 equivalent.
670
671 @table @code
672 @item -A
673 @itemx -o
674 @itemx --print-file-name
675 @cindex input file name
676 @cindex file name
677 @cindex source file name
678 Precede each symbol by the name of the input file (or archive element)
679 in which it was found, rather than identifying the input file once only,
680 before all of its symbols.
681
682 @item -a
683 @itemx --debug-syms
684 @cindex debugging symbols
685 Display all symbols, even debugger-only symbols; normally these are not
686 listed.
687
688 @item -B
689 @cindex @code{nm} format
690 @cindex @code{nm} compatibility
691 The same as @samp{--format=bsd} (for compatibility with the MIPS @code{nm}).
692
693 @item -C
694 @itemx --demangle
695 @cindex demangling C++ symbols
696 Decode (@dfn{demangle}) low-level symbol names into user-level names.
697 Besides removing any initial underscore prepended by the system, this
698 makes C++ function names readable. @xref{c++filt}, for more information
699 on demangling.
700
701 @item --no-demangle
702 Do not demangle low-level symbol names. This is the default.
703
704 @item -D
705 @itemx --dynamic
706 @cindex dynamic symbols
707 Display the dynamic symbols rather than the normal symbols. This is
708 only meaningful for dynamic objects, such as certain types of shared
709 libraries.
710
711 @item -f @var{format}
712 @itemx --format=@var{format}
713 @cindex @code{nm} format
714 @cindex @code{nm} compatibility
715 Use the output format @var{format}, which can be @code{bsd},
716 @code{sysv}, or @code{posix}. The default is @code{bsd}.
717 Only the first character of @var{format} is significant; it can be
718 either upper or lower case.
719
720 @item -g
721 @itemx --extern-only
722 @cindex external symbols
723 Display only external symbols.
724
725 @item -n
726 @itemx -v
727 @itemx --numeric-sort
728 Sort symbols numerically by their addresses, rather than alphabetically
729 by their names.
730
731 @item -p
732 @itemx --no-sort
733 @cindex sorting symbols
734 Do not bother to sort the symbols in any order; print them in the order
735 encountered.
736
737 @item -P
738 @itemx --portability
739 Use the POSIX.2 standard output format instead of the default format.
740 Equivalent to @samp{-f posix}.
741
742 @item -s
743 @itemx --print-armap
744 @cindex symbol index, listing
745 When listing symbols from archive members, include the index: a mapping
746 (stored in the archive by @code{ar} or @code{ranlib}) of which modules
747 contain definitions for which names.
748
749 @item -r
750 @itemx --reverse-sort
751 Reverse the order of the sort (whether numeric or alphabetic); let the
752 last come first.
753
754 @item --size-sort
755 Sort symbols by size. The size is computed as the difference between
756 the value of the symbol and the value of the symbol with the next higher
757 value. The size of the symbol is printed, rather than the value.
758
759 @item -t @var{radix}
760 @itemx --radix=@var{radix}
761 Use @var{radix} as the radix for printing the symbol values. It must be
762 @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
763
764 @item --target=@var{bfdname}
765 @cindex object code format
766 Specify an object code format other than your system's default format.
767 @xref{Target Selection}, for more information.
768
769 @item -u
770 @itemx --undefined-only
771 @cindex external symbols
772 @cindex undefined symbols
773 Display only undefined symbols (those external to each object file).
774
775 @item --defined-only
776 @cindex external symbols
777 @cindex undefined symbols
778 Display only defined symbols for each object file.
779
780 @item -V
781 @itemx --version
782 Show the version number of @code{nm} and exit.
783
784 @item --help
785 Show a summary of the options to @code{nm} and exit.
786 @end table
787
788 @node objcopy
789 @chapter objcopy
790
791 @smallexample
792 objcopy [ -F @var{bfdname} | --target=@var{bfdname} ]
793 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
794 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
795 [ -S | --strip-all ] [ -g | --strip-debug ]
796 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
797 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
798 [ -x | --discard-all ] [ -X | --discard-locals ]
799 [ -b @var{byte} | --byte=@var{byte} ]
800 [ -i @var{interleave} | --interleave=@var{interleave} ]
801 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
802 [ --debugging ]
803 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
804 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
805 [ --adjust-vma=@var{incr} ]
806 [ --adjust-section-vma=@var{section}@{=,+,-@}@var{val} ]
807 [ --adjust-warnings ] [ --no-adjust-warnings ]
808 [ --set-section-flags=@var{section}=@var{flags} ]
809 [ --add-section=@var{sectionname}=@var{filename} ]
810 [ -v | --verbose ] [ -V | --version ] [ --help ]
811 @var{infile} [@var{outfile}]
812 @end smallexample
813
814 The @sc{gnu} @code{objcopy} utility copies the contents of an object
815 file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
816 read and write the object files. It can write the destination object
817 file in a format different from that of the source object file. The
818 exact behavior of @code{objcopy} is controlled by command-line options.
819
820 @code{objcopy} creates temporary files to do its translations and
821 deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
822 translation work; it has access to all the formats described in @sc{bfd}
823 and thus is able to recognize most formats without being told
824 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
825
826 @code{objcopy} can be used to generate S-records by using an output
827 target of @samp{srec} (e.g., use @samp{-O srec}).
828
829 @code{objcopy} can be used to generate a raw binary file by using an
830 output target of @samp{binary} (e.g., use @samp{-O binary}). When
831 @code{objcopy} generates a raw binary file, it will essentially produce
832 a memory dump of the contents of the input object file. All symbols and
833 relocation information will be discarded. The memory dump will start at
834 the virtual address of the lowest section copied into the output file.
835
836 When generating an S-record or a raw binary file, it may be helpful to
837 use @samp{-S} to remove sections containing debugging information. In
838 some cases @samp{-R} will be useful to remove sections which contain
839 information which is not needed by the binary file.
840
841 @table @code
842 @item @var{infile}
843 @itemx @var{outfile}
844 The source and output files, respectively.
845 If you do not specify @var{outfile}, @code{objcopy} creates a
846 temporary file and destructively renames the result with
847 the name of @var{infile}.
848
849 @item -I @var{bfdname}
850 @itemx --input-target=@var{bfdname}
851 Consider the source file's object format to be @var{bfdname}, rather than
852 attempting to deduce it. @xref{Target Selection}, for more information.
853
854 @item -O @var{bfdname}
855 @itemx --output-target=@var{bfdname}
856 Write the output file using the object format @var{bfdname}.
857 @xref{Target Selection}, for more information.
858
859 @item -F @var{bfdname}
860 @itemx --target=@var{bfdname}
861 Use @var{bfdname} as the object format for both the input and the output
862 file; i.e., simply transfer data from source to destination with no
863 translation. @xref{Target Selection}, for more information.
864
865 @item -R @var{sectionname}
866 @itemx --remove-section=@var{sectionname}
867 Remove any section named @var{sectionname} from the output file. This
868 option may be given more than once. Note that using this option
869 inappropriately may make the output file unusable.
870
871 @item -S
872 @itemx --strip-all
873 Do not copy relocation and symbol information from the source file.
874
875 @item -g
876 @itemx --strip-debug
877 Do not copy debugging symbols from the source file.
878
879 @item --strip-unneeded
880 Strip all symbols that are not needed for relocation processing.
881
882 @item -K @var{symbolname}
883 @itemx --keep-symbol=@var{symbolname}
884 Copy only symbol @var{symbolname} from the source file. This option may
885 be given more than once.
886
887 @item -N @var{symbolname}
888 @itemx --strip-symbol=@var{symbolname}
889 Do not copy symbol @var{symbolname} from the source file. This option
890 may be given more than once, and may be combined with strip options
891 other than @code{-K}.
892
893 @item -x
894 @itemx --discard-all
895 Do not copy non-global symbols from the source file.
896 @c FIXME any reason to prefer "non-global" to "local" here?
897
898 @item -X
899 @itemx --discard-locals
900 Do not copy compiler-generated local symbols.
901 (These usually start with @samp{L} or @samp{.}.)
902
903 @item -b @var{byte}
904 @itemx --byte=@var{byte}
905 Keep only every @var{byte}th byte of the input file (header data is not
906 affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
907 where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
908 option, or the default of 4. This option is useful for creating files
909 to program @sc{rom}. It is typically used with an @code{srec} output
910 target.
911
912 @item -i @var{interleave}
913 @itemx --interleave=@var{interleave}
914 Only copy one out of every @var{interleave} bytes. Select which byte to
915 copy with the @var{-b} or @samp{--byte} option. The default is 4.
916 @code{objcopy} ignores this option if you do not specify either @samp{-b} or
917 @samp{--byte}.
918
919 @item --debugging
920 Convert debugging information, if possible. This is not the default
921 because only certain debugging formats are supported, and the
922 conversion process can be time consuming.
923
924 @item --gap-fill @var{val}
925 Fill gaps between sections with @var{val}. This is done by increasing
926 the size of the section with the lower address, and filling in the extra
927 space created with @var{val}.
928
929 @item --pad-to @var{address}
930 Pad the output file up to the virtual address @var{address}. This is
931 done by increasing the size of the last section. The extra space is
932 filled in with the value specified by @samp{--gap-fill} (default zero).
933
934 @item --set-start @var{val}
935 Set the address of the new file to @var{val}. Not all object file
936 formats support setting the start address.
937
938 @item --adjust-start @var{incr}
939 Adjust the start address by adding @var{incr}. Not all object file
940 formats support setting the start address.
941
942 @item --adjust-vma @var{incr}
943 Adjust the address of all sections, as well as the start address, by
944 adding @var{incr}. Some object file formats do not permit section
945 addresses to be changed arbitrarily. Note that this does not relocate
946 the sections; if the program expects sections to be loaded at a certain
947 address, and this option is used to change the sections such that they
948 are loaded at a different address, the program may fail.
949
950 @item --adjust-section-vma @var{section}@{=,+,-@}@var{val}
951 Set or adjust the address of the named @var{section}. If @samp{=} is
952 used, the section address is set to @var{val}. Otherwise, @var{val} is
953 added to or subtracted from the section address. See the comments under
954 @samp{--adjust-vma}, above. If @var{section} does not exist in the
955 input file, a warning will be issued, unless @samp{--no-adjust-warnings}
956 is used.
957
958 @item --adjust-warnings
959 If @samp{--adjust-section-vma} is used, and the named section does not
960 exist, issue a warning. This is the default.
961
962 @item --no-adjust-warnings
963 Do not issue a warning if @samp{--adjust-section-vma} is used, even if
964 the named section does not exist.
965
966 @item --set-section-flags @var{section}=@var{flags}
967 Set the flags for the named section. The @var{flags} argument is a
968 comma separated string of flag names. The recognized names are
969 @samp{alloc}, @samp{load}, @samp{readonly}, @samp{code}, @samp{data},
970 and @samp{rom}. Not all flags are meaningful for all object file
971 formats.
972
973 @item --add-section @var{sectionname}=@var{filename}
974 Add a new section named @var{sectionname} while copying the file. The
975 contents of the new section are taken from the file @var{filename}. The
976 size of the section will be the size of the file. This option only
977 works on file formats which can support sections with arbitrary names.
978
979 @item -V
980 @itemx --version
981 Show the version number of @code{objcopy}.
982
983 @item -v
984 @itemx --verbose
985 Verbose output: list all object files modified. In the case of
986 archives, @samp{objcopy -V} lists all members of the archive.
987
988 @item --help
989 Show a summary of the options to @code{objcopy}.
990 @end table
991
992 @node objdump
993 @chapter objdump
994
995 @cindex object file information
996 @kindex objdump
997
998 @smallexample
999 objdump [ -a | --archive-headers ]
1000 [ -b @var{bfdname} | --target=@var{bfdname} ] [ --debugging ]
1001 [ -d | --disassemble ] [ -D | --disassemble-all ]
1002 [ -f | --file-headers ]
1003 [ -h | --section-headers | --headers ] [ -i | --info ]
1004 [ -j @var{section} | --section=@var{section} ]
1005 [ -l | --line-numbers ] [ -S | --source ]
1006 [ -m @var{machine} | --architecture=@var{machine} ]
1007 [ -r | --reloc ] [ -R | --dynamic-reloc ]
1008 [ -s | --full-contents ] [ --stabs ]
1009 [ -t | --syms ] [ -T | --dynamic-syms ] [ -x | --all-headers ]
1010 [ -w | --wide ] [ --start-address=@var{address} ]
1011 [ --stop-address=@var{address} ] [ --show-raw-insn ]
1012 [ --version ] [ --help ]
1013 @var{objfile}@dots{}
1014 @end smallexample
1015
1016 @code{objdump} displays information about one or more object files.
1017 The options control what particular information to display. This
1018 information is mostly useful to programmers who are working on the
1019 compilation tools, as opposed to programmers who just want their
1020 program to compile and work.
1021
1022 @var{objfile}@dots{} are the object files to be examined. When you
1023 specify archives, @code{objdump} shows information on each of the member
1024 object files.
1025
1026 The long and short forms of options, shown here as alternatives, are
1027 equivalent. At least one option besides @samp{-l} must be given.
1028
1029 @table @code
1030 @item -a
1031 @itemx --archive-header
1032 @cindex archive headers
1033 If any of the @var{objfile} files are archives, display the archive
1034 header information (in a format similar to @samp{ls -l}). Besides the
1035 information you could list with @samp{ar tv}, @samp{objdump -a} shows
1036 the object file format of each archive member.
1037
1038 @item -b @var{bfdname}
1039 @itemx --target=@var{bfdname}
1040 @cindex object code format
1041 Specify that the object-code format for the object files is
1042 @var{bfdname}. This option may not be necessary; @var{objdump} can
1043 automatically recognize many formats.
1044
1045 For example,
1046 @example
1047 objdump -b oasys -m vax -h fu.o
1048 @end example
1049 @noindent
1050 displays summary information from the section headers (@samp{-h}) of
1051 @file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1052 file in the format produced by Oasys compilers. You can list the
1053 formats available with the @samp{-i} option.
1054 @xref{Target Selection}, for more information.
1055
1056 @item --debugging
1057 Display debugging information. This attempts to parse debugging
1058 information stored in the file and print it out using a C like syntax.
1059 Only certain types of debugging information have been implemented.
1060
1061 @item -d
1062 @itemx --disassemble
1063 @cindex disassembling object code
1064 @cindex machine instructions
1065 Display the assembler mnemonics for the machine instructions from
1066 @var{objfile}. This option only disassembles those sections which are
1067 expected to contain instructions.
1068
1069 @item -D
1070 @itemx --disassemble-all
1071 Like @samp{-d}, but disassemble the contents of all sections, not just
1072 those expected to contain instructions.
1073
1074 @item -f
1075 @itemx --file-header
1076 @cindex object file header
1077 Display summary information from the overall header of
1078 each of the @var{objfile} files.
1079
1080 @item -h
1081 @itemx --section-header
1082 @itemx --header
1083 @cindex section headers
1084 Display summary information from the section headers of the
1085 object file.
1086
1087 File segments may be relocated to nonstandard addresses, for example by
1088 using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1089 @code{ld}. However, some object file formats, such as a.out, do not
1090 store the starting address of the file segments. In those situations,
1091 although @code{ld} relocates the sections correctly, using @samp{objdump
1092 -h} to list the file section headers cannot show the correct addresses.
1093 Instead, it shows the usual addresses, which are implicit for the
1094 target.
1095
1096 @item --help
1097 Print a summary of the options to @code{objdump} and exit.
1098
1099 @item -i
1100 @itemx --info
1101 @cindex architectures available
1102 @cindex object formats available
1103 Display a list showing all architectures and object formats available
1104 for specification with @samp{-b} or @samp{-m}.
1105
1106 @item -j @var{name}
1107 @itemx --section=@var{name}
1108 @cindex section information
1109 Display information only for section @var{name}.
1110
1111 @item -l
1112 @itemx --line-numbers
1113 @cindex source filenames for object files
1114 Label the display (using debugging information) with the filename
1115 and source line numbers corresponding to the object code shown.
1116 Only useful with @samp{-d} or @samp{-D}.
1117
1118 @item -m @var{machine}
1119 @itemx --architecture=@var{machine}
1120 @cindex architecture
1121 Specify that the object files @var{objfile} are for architecture
1122 @var{machine}. You can list available architectures using the @samp{-i}
1123 option.
1124
1125 @item -r
1126 @itemx --reloc
1127 @cindex relocation entries, in object file
1128 Print the relocation entries of the file. If used with @samp{-d} or
1129 @samp{-D}, the relocations are printed interspersed with the
1130 disassembly.
1131
1132 @item -R
1133 @itemx --dynamic-reloc
1134 @cindex dynamic relocation entries, in object file
1135 Print the dynamic relocation entries of the file. This is only
1136 meaningful for dynamic objects, such as certain types of shared
1137 libraries.
1138
1139 @item -s
1140 @itemx --full-contents
1141 @cindex sections, full contents
1142 @cindex object file sections
1143 Display the full contents of any sections requested.
1144
1145 @item -S
1146 @itemx --source
1147 @cindex source disassembly
1148 @cindex disassembly, with source
1149 Display source code intermixed with disassembly, if possible. Implies
1150 @samp{-d}.
1151
1152 @item --show-raw-insn
1153 When disassembling instructions, print the instruction in hex as well as
1154 in symbolic form. Not all targets handle this correctly yet.
1155
1156 @item --stabs
1157 @cindex stab
1158 @cindex .stab
1159 @cindex debug symbols
1160 @cindex ELF object file format
1161 Display the full contents of any sections requested. Display the
1162 contents of the .stab and .stab.index and .stab.excl sections from an
1163 ELF file. This is only useful on systems (such as Solaris 2.0) in which
1164 @code{.stab} debugging symbol-table entries are carried in an ELF
1165 section. In most other file formats, debugging symbol-table entries are
1166 interleaved with linkage symbols, and are visible in the @samp{--syms}
1167 output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1168 Overview,stabs.info, The ``stabs'' debug format}.
1169
1170 @item --start-address=@var{address}
1171 @cindex start-address
1172 Start displaying data at the specified address. This affects the output
1173 of the @code{-d}, @code{-r} and @code{-s} options.
1174
1175 @item --stop-address=@var{address}
1176 @cindex stop-address
1177 Stop displaying data at the specified address. This affects the output
1178 of the @code{-d}, @code{-r} and @code{-s} options.
1179
1180 @item -t
1181 @itemx --syms
1182 @cindex symbol table entries, printing
1183 Print the symbol table entries of the file.
1184 This is similar to the information provided by the @samp{nm} program.
1185
1186 @item -T
1187 @itemx --dynamic-syms
1188 @cindex dynamic symbol table entries, printing
1189 Print the dynamic symbol table entries of the file. This is only
1190 meaningful for dynamic objects, such as certain types of shared
1191 libraries. This is similar to the information provided by the @samp{nm}
1192 program when given the @samp{-D} (@samp{--dynamic}) option.
1193
1194 @item --version
1195 Print the version number of @code{objdump} and exit.
1196
1197 @item -x
1198 @itemx --all-header
1199 @cindex all header information, object file
1200 @cindex header information, all
1201 Display all available header information, including the symbol table and
1202 relocation entries. Using @samp{-x} is equivalent to specifying all of
1203 @samp{-a -f -h -r -t}.
1204
1205 @item -w
1206 @item --wide
1207 @cindex wide output, printing
1208 Format some lines for output devices that have more than 80 columns.
1209 @end table
1210
1211 @node ranlib
1212 @chapter ranlib
1213
1214 @kindex ranlib
1215 @cindex archive contents
1216 @cindex symbol index
1217
1218 @smallexample
1219 ranlib [-vV] @var{archive}
1220 @end smallexample
1221
1222 @code{ranlib} generates an index to the contents of an archive and
1223 stores it in the archive. The index lists each symbol defined by a
1224 member of an archive that is a relocatable object file.
1225
1226 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1227
1228 An archive with such an index speeds up linking to the library and
1229 allows routines in the library to call each other without regard to
1230 their placement in the archive.
1231
1232 The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1233 @code{ranlib} is completely equivalent to executing @samp{ar -s}.
1234 @xref{ar}.
1235
1236 @table @code
1237 @item -v
1238 @itemx -V
1239 Show the version number of @code{ranlib}.
1240 @end table
1241
1242 @node size
1243 @chapter size
1244
1245 @kindex size
1246 @cindex section sizes
1247
1248 @smallexample
1249 size [ -A | -B | --format=@var{compatibility} ]
1250 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1251 [ --target=@var{bfdname} ] [ -V | --version ]
1252 @var{objfile}@dots{}
1253 @end smallexample
1254
1255 The @sc{gnu} @code{size} utility lists the section sizes---and the total
1256 size---for each of the object or archive files @var{objfile} in its
1257 argument list. By default, one line of output is generated for each
1258 object file or each module in an archive.
1259
1260 @var{objfile}@dots{} are the object files to be examined.
1261
1262 The command line options have the following meanings:
1263
1264 @table @code
1265 @item -A
1266 @itemx -B
1267 @itemx --format=@var{compatibility}
1268 @cindex @code{size} display format
1269 Using one of these options, you can choose whether the output from @sc{gnu}
1270 @code{size} resembles output from System V @code{size} (using @samp{-A},
1271 or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1272 @samp{--format=berkeley}). The default is the one-line format similar to
1273 Berkeley's.
1274 @c Bonus for doc-source readers: you can also say --format=strange (or
1275 @c anything else that starts with 's') for sysv, and --format=boring (or
1276 @c anything else that starts with 'b') for Berkeley.
1277
1278 Here is an example of the Berkeley (default) format of output from
1279 @code{size}:
1280 @smallexample
1281 size --format=Berkeley ranlib size
1282 text data bss dec hex filename
1283 294880 81920 11592 388392 5ed28 ranlib
1284 294880 81920 11888 388688 5ee50 size
1285 @end smallexample
1286
1287 @noindent
1288 This is the same data, but displayed closer to System V conventions:
1289
1290 @smallexample
1291 size --format=SysV ranlib size
1292 ranlib :
1293 section size addr
1294 .text 294880 8192
1295 .data 81920 303104
1296 .bss 11592 385024
1297 Total 388392
1298
1299
1300 size :
1301 section size addr
1302 .text 294880 8192
1303 .data 81920 303104
1304 .bss 11888 385024
1305 Total 388688
1306 @end smallexample
1307
1308 @item --help
1309 Show a summary of acceptable arguments and options.
1310
1311 @item -d
1312 @itemx -o
1313 @itemx -x
1314 @itemx --radix=@var{number}
1315 @cindex @code{size} number format
1316 @cindex radix for section sizes
1317 Using one of these options, you can control whether the size of each
1318 section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1319 (@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1320 @samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1321 values (8, 10, 16) are supported. The total size is always given in two
1322 radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1323 octal and hexadecimal if you're using @samp{-o}.
1324
1325 @item --target=@var{bfdname}
1326 @cindex object code format
1327 Specify that the object-code format for @var{objfile} is
1328 @var{bfdname}. This option may not be necessary; @code{size} can
1329 automatically recognize many formats.
1330 @xref{Target Selection}, for more information.
1331
1332 @item -V
1333 @itemx --version
1334 Display the version number of @code{size}.
1335 @end table
1336
1337 @node strings
1338 @chapter strings
1339 @kindex strings
1340 @cindex listings strings
1341 @cindex printing strings
1342 @cindex strings, printing
1343
1344 @smallexample
1345 strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1346 [--all] [--print-file-name] [--bytes=@var{min-len}]
1347 [--radix=@var{radix}] [--target=@var{bfdname}]
1348 [--help] [--version] @var{file}@dots{}
1349 @end smallexample
1350
1351 For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1352 character sequences that are at least 4 characters long (or the number
1353 given with the options below) and are followed by an unprintable
1354 character. By default, it only prints the strings from the initialized
1355 and loaded sections of object files; for other types of files, it prints
1356 the strings from the whole file.
1357
1358 @code{strings} is mainly useful for determining the contents of non-text
1359 files.
1360
1361 @table @code
1362 @item -a
1363 @itemx --all
1364 @itemx -
1365 Do not scan only the initialized and loaded sections of object files;
1366 scan the whole files.
1367
1368 @item -f
1369 @itemx --print-file-name
1370 Print the name of the file before each string.
1371
1372 @item --help
1373 Print a summary of the program usage on the standard output and exit.
1374
1375 @itemx -@var{min-len}
1376 @item -n @var{min-len}
1377 @itemx --bytes=@var{min-len}
1378 Print sequences of characters that are at least @var{min-len} characters
1379 long, instead of the default 4.
1380
1381 @item -o
1382 Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1383 act like @samp{-t d} instead. Since we can not be compatible with both
1384 ways, we simply chose one.
1385
1386 @item -t @var{radix}
1387 @itemx --radix=@var{radix}
1388 Print the offset within the file before each string. The single
1389 character argument specifies the radix of the offset---@samp{o} for
1390 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1391
1392 @item --target=@var{bfdname}
1393 @cindex object code format
1394 Specify an object code format other than your system's default format.
1395 @xref{Target Selection}, for more information.
1396
1397 @item -v
1398 @itemx --version
1399 Print the program version number on the standard output and exit.
1400 @end table
1401
1402 @node strip
1403 @chapter strip
1404
1405 @kindex strip
1406 @cindex removing symbols
1407 @cindex discarding symbols
1408 @cindex symbols, discarding
1409
1410 @smallexample
1411 strip [ -F @var{bfdname} | --target=@var{bfdname} | --target=@var{bfdname} ]
1412 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1413 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1414 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1415 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1416 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1417 [ -x | --discard-all ] [ -X | --discard-locals ]
1418 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1419 [ -v | --verbose ] [ -V | --version ] [ --help ]
1420 @var{objfile}@dots{}
1421 @end smallexample
1422
1423 @sc{gnu} @code{strip} discards all symbols from object files
1424 @var{objfile}. The list of object files may include archives.
1425 At least one object file must be given.
1426
1427 @code{strip} modifies the files named in its argument,
1428 rather than writing modified copies under different names.
1429
1430 @table @code
1431 @item -F @var{bfdname}
1432 @itemx --target=@var{bfdname}
1433 Treat the original @var{objfile} as a file with the object
1434 code format @var{bfdname}, and rewrite it in the same format.
1435 @xref{Target Selection}, for more information.
1436
1437 @item --help
1438 Show a summary of the options to @code{strip} and exit.
1439
1440 @item -I @var{bfdname}
1441 @itemx --input-target=@var{bfdname}
1442 Treat the original @var{objfile} as a file with the object
1443 code format @var{bfdname}.
1444 @xref{Target Selection}, for more information.
1445
1446 @item -O @var{bfdname}
1447 @itemx --output-target=@var{bfdname}
1448 Replace @var{objfile} with a file in the output format @var{bfdname}.
1449 @xref{Target Selection}, for more information.
1450
1451 @item -R @var{sectionname}
1452 @itemx --remove-section=@var{sectionname}
1453 Remove any section named @var{sectionname} from the output file. This
1454 option may be given more than once. Note that using this option
1455 inappropriately may make the output file unusable.
1456
1457 @item -s
1458 @itemx --strip-all
1459 Remove all symbols.
1460
1461 @item -g
1462 @itemx -S
1463 @itemx --strip-debug
1464 Remove debugging symbols only.
1465
1466 @item --strip-unneeded
1467 Remove all symbols that are not needed for relocation processing.
1468
1469 @item -K @var{symbolname}
1470 @itemx --keep-symbol=@var{symbolname}
1471 Keep only symbol @var{symbolname} from the source file. This option may
1472 be given more than once.
1473
1474 @item -N @var{symbolname}
1475 @itemx --strip-symbol=@var{symbolname}
1476 Remove symbol @var{symbolname} from the source file. This option may be
1477 given more than once, and may be combined with strip options other than
1478 @code{-K}.
1479
1480 @item -x
1481 @itemx --discard-all
1482 Remove non-global symbols.
1483
1484 @item -X
1485 @itemx --discard-locals
1486 Remove compiler-generated local symbols.
1487 (These usually start with @samp{L} or @samp{.}.)
1488
1489 @item -V
1490 @itemx --version
1491 Show the version number for @code{strip}.
1492
1493 @item -v
1494 @itemx --verbose
1495 Verbose output: list all object files modified. In the case of
1496 archives, @samp{strip -v} lists all members of the archive.
1497 @end table
1498
1499 @node c++filt
1500 @chapter c++filt
1501
1502 @kindex c++filt
1503 @cindex demangling C++ symbols
1504
1505 @smallexample
1506 c++filt [ -_ | --strip-underscores ]
1507 [ -n | --no-strip-underscores ]
1508 [ -s @var{format} | --format=@var{format} ]
1509 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1510 @end smallexample
1511
1512 The C++ language provides function overloading, which means that you can
1513 write many functions with the same name (providing each takes parameters
1514 of different types). All C++ function names are encoded into a
1515 low-level assembly label (this process is known as
1516 @dfn{mangling}). The @code{c++filt} program does the inverse mapping: it
1517 decodes (@dfn{demangles}) low-level names into user-level names so that
1518 the linker can keep these overloaded functions from clashing.
1519
1520 Every alphanumeric word (consisting of letters, digits, underscores,
1521 dollars, or periods) seen in the input is a potential label. If the
1522 label decodes into a C++ name, the C++ name replaces the low-level
1523 name in the output.
1524
1525 You can use @code{c++filt} to decipher individual symbols:
1526
1527 @example
1528 c++filt @var{symbol}
1529 @end example
1530
1531 If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1532 names from the standard input and writes the demangled names to the
1533 standard output. All results are printed on the standard output.
1534
1535 @table @code
1536 @item -_
1537 @itemx --strip-underscores
1538 On some systems, both the C and C++ compilers put an underscore in front
1539 of every name. For example, the C name @code{foo} gets the low-level
1540 name @code{_foo}. This option removes the initial underscore. Whether
1541 @code{c++filt} removes the underscore by default is target dependent.
1542
1543 @item -n
1544 @itemx --no-strip-underscores
1545 Do not remove the initial underscore.
1546
1547 @item -s @var{format}
1548 @itemx --format=@var{format}
1549 @sc{gnu} @code{nm} can decode three different methods of mangling, used by
1550 different C++ compilers. The argument to this option selects which
1551 method it uses:
1552
1553 @table @code
1554 @item gnu
1555 the one used by the @sc{gnu} compiler (the default method)
1556 @item lucid
1557 the one used by the Lucid compiler
1558 @item arm
1559 the one specified by the C++ Annotated Reference Manual
1560 @end table
1561
1562 @item --help
1563 Print a summary of the options to @code{c++filt} and exit.
1564
1565 @item --version
1566 Print the version number of @code{c++filt} and exit.
1567 @end table
1568
1569 @quotation
1570 @emph{Warning:} @code{c++filt} is a new utility, and the details of its
1571 user interface are subject to change in future releases. In particular,
1572 a command-line option may be required in the the future to decode a name
1573 passed as an argument on the command line; in other words,
1574
1575 @example
1576 c++filt @var{symbol}
1577 @end example
1578
1579 @noindent
1580 may in a future release become
1581
1582 @example
1583 c++filt @var{option} @var{symbol}
1584 @end example
1585 @end quotation
1586
1587 @node nlmconv
1588 @chapter nlmconv
1589
1590 @code{nlmconv} converts a relocatable object file into a NetWare
1591 Loadable Module.
1592
1593 @ignore
1594 @code{nlmconv} currently works with @samp{i386} object
1595 files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1596 object files in @sc{elf}, or @code{a.out} format@footnote{
1597 @code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1598 format in the Binary File Descriptor library. It has only been tested
1599 with the above formats.}.
1600 @end ignore
1601
1602 @quotation
1603 @emph{Warning:} @code{nlmconv} is not always built as part of the binary
1604 utilities, since it is only useful for NLM targets.
1605 @end quotation
1606
1607 @smallexample
1608 nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1609 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1610 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1611 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1612 [ -h | --help ] [ -V | --version ]
1613 @var{infile} @var{outfile}
1614 @end smallexample
1615
1616 @code{nlmconv} converts the relocatable @samp{i386} object file
1617 @var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1618 reading @var{headerfile} for NLM header information. For instructions
1619 on writing the NLM command file language used in header files, see the
1620 @samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1621 Development and Tools Overview}, which is part of the NLM Software
1622 Developer's Kit (``NLM SDK''), available from Novell, Inc.
1623 @code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1624 @var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1625 more information.
1626
1627 @code{nlmconv} can perform a link step. In other words, you can list
1628 more than one object file for input if you list them in the definitions
1629 file (rather than simply specifying one input file on the command line).
1630 In this case, @code{nlmconv} calls the linker for you.
1631
1632 @table @code
1633 @item -I @var{bfdname}
1634 @itemx --input-target=@var{bfdname}
1635 Object format of the input file. @code{nlmconv} can usually determine
1636 the format of a given file (so no default is necessary).
1637 @xref{Target Selection}, for more information.
1638
1639 @item -O @var{bfdname}
1640 @itemx --output-target=@var{bfdname}
1641 Object format of the output file. @code{nlmconv} infers the output
1642 format based on the input format, e.g. for a @samp{i386} input file the
1643 output format is @samp{nlm32-i386}.
1644 @xref{Target Selection}, for more information.
1645
1646 @item -T @var{headerfile}
1647 @itemx --header-file=@var{headerfile}
1648 Reads @var{headerfile} for NLM header information. For instructions on
1649 writing the NLM command file language used in header files, see@ see the
1650 @samp{linkers} section, of the @cite{NLM Development and Tools
1651 Overview}, which is part of the NLM Software Developer's Kit, available
1652 from Novell, Inc.
1653
1654 @item -d
1655 @itemx --debug
1656 Displays (on standard error) the linker command line used by @code{nlmconv}.
1657
1658 @item -l @var{linker}
1659 @itemx --linker=@var{linker}
1660 Use @var{linker} for any linking. @var{linker} can be an abosolute or a
1661 relative pathname.
1662
1663 @item -h
1664 @itemx --help
1665 Prints a usage summary.
1666
1667 @item -V
1668 @itemx --version
1669 Prints the version number for @code{nlmconv}.
1670 @end table
1671
1672 @node Selecting The Target System
1673 @chapter Selecting the target system
1674
1675 You can specify three aspects of the target system to the @sc{gnu}
1676 binary file utilities, each in several ways:
1677
1678 @itemize @bullet
1679 @item
1680 the target
1681
1682 @item
1683 the architecture
1684
1685 @item
1686 the linker emulation (which applies to the linker only)
1687 @end itemize
1688
1689 In the following summaries, the lists of ways to specify values are in
1690 order of decreasing precedence. The ways listed first override those
1691 listed later.
1692
1693 The commands to list valid values only list the values for which the
1694 programs you are running were configured. If they were configured with
1695 @samp{--enable-targets=all}, the commands list most of the available
1696 values, but a few are left out; not all targets can be configured in at
1697 once because some of them can only be configured @dfn{native} (on hosts
1698 with the same type as the target system).
1699
1700 @menu
1701 * Target Selection::
1702 * Architecture Selection::
1703 * Linker Emulation Selection::
1704 @end menu
1705
1706 @node Target Selection
1707 @section Target Selection
1708
1709 A @dfn{target} is an object file format. A given target may be
1710 supported for multiple architectures (@pxref{Architecture Selection}).
1711 A target selection may also have variations for different operating
1712 systems or architectures.
1713
1714 The command to list valid target values is @samp{objdump -i}
1715 (the first column of output contains the relevant information).
1716
1717 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
1718 @samp{a.out-sunos-big}.
1719
1720 @subheading @code{objdump} Target
1721
1722 Ways to specify:
1723
1724 @enumerate
1725 @item
1726 command line option: @samp{-b} or @samp{--target}
1727
1728 @item
1729 environment variable @code{GNUTARGET}
1730
1731 @item
1732 deduced from the input file
1733 @end enumerate
1734
1735 @subheading @code{objcopy} and @code{strip} Input Target
1736
1737 Ways to specify:
1738
1739 @enumerate
1740 @item
1741 command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
1742
1743 @item
1744 environment variable @code{GNUTARGET}
1745
1746 @item
1747 deduced from the input file
1748 @end enumerate
1749
1750 @subheading @code{objcopy} and @code{strip} Output Target
1751
1752 Ways to specify:
1753
1754 @enumerate
1755 @item
1756 command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
1757
1758 @item
1759 the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
1760
1761 @item
1762 environment variable @code{GNUTARGET}
1763
1764 @item
1765 deduced from the input file
1766 @end enumerate
1767
1768 @subheading @code{nm}, @code{size}, and @code{strings} Target
1769
1770 Ways to specify:
1771
1772 @enumerate
1773 @item
1774 command line option: @samp{--target}
1775
1776 @item
1777 environment variable @code{GNUTARGET}
1778
1779 @item
1780 deduced from the input file
1781 @end enumerate
1782
1783 @subheading Linker Input Target
1784
1785 Ways to specify:
1786
1787 @enumerate
1788 @item
1789 command line option: @samp{-b} or @samp{--format}
1790 (@pxref{Options,,Options,ld.info,Using LD})
1791
1792 @item
1793 script command @code{TARGET}
1794 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
1795
1796 @item
1797 environment variable @code{GNUTARGET}
1798 (@pxref{Environment,,Environment,ld.info,Using LD})
1799
1800 @item
1801 the default target of the selected linker emulation
1802 (@pxref{Linker Emulation Selection})
1803 @end enumerate
1804
1805 @subheading Linker Output Target
1806
1807 Ways to specify:
1808
1809 @enumerate
1810 @item
1811 command line option: @samp{-oformat}
1812 (@pxref{Options,,Options,ld.info,Using LD})
1813
1814 @item
1815 script command @code{OUTPUT_FORMAT}
1816 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
1817
1818 @item
1819 the linker input target (see ``Linker Input Target'' above)
1820 @end enumerate
1821
1822 @node Architecture Selection
1823 @section Architecture selection
1824
1825 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
1826 to run. Its name may contain a colon, separating the name of the
1827 processor family from the name of the particular @sc{cpu}.
1828
1829 The command to list valid architecture values is @samp{objdump -i} (the
1830 second column contains the relevant information).
1831
1832 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
1833
1834 @subheading @code{objdump} Architecture
1835
1836 Ways to specify:
1837
1838 @enumerate
1839 @item
1840 command line option: @samp{-m} or @samp{--architecture}
1841
1842 @item
1843 deduced from the input file
1844 @end enumerate
1845
1846 @subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
1847
1848 Ways to specify:
1849
1850 @enumerate
1851 @item
1852 deduced from the input file
1853 @end enumerate
1854
1855 @subheading Linker Input Architecture
1856
1857 Ways to specify:
1858
1859 @enumerate
1860 @item
1861 deduced from the input file
1862 @end enumerate
1863
1864 @subheading Linker Output Architecture
1865
1866 Ways to specify:
1867
1868 @enumerate
1869 @item
1870 script command @code{OUTPUT_ARCH}
1871 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
1872
1873 @item
1874 the default architecture from the linker output target
1875 (@pxref{Target Selection})
1876 @end enumerate
1877
1878 @node Linker Emulation Selection
1879 @section Linker emulation selection
1880
1881 A linker @dfn{emulation} is a ``personality'' of the linker, which gives
1882 the linker default values for the other aspects of the target system.
1883 In particular, it consists of
1884
1885 @itemize @bullet
1886 @item
1887 the linker script
1888
1889 @item
1890 the target
1891
1892 @item
1893 several ``hook'' functions that are run at certain stages of the linking
1894 process to do special things that some targets require
1895 @end itemize
1896
1897 The command to list valid linker emulation values is @samp{ld -V}.
1898
1899 Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
1900
1901 Ways to specify:
1902
1903 @enumerate
1904 @item
1905 command line option: @samp{-m}
1906 (@pxref{Options,,Options,ld.info,Using LD})
1907
1908 @item
1909 environment variable @code{LDEMULATION}
1910
1911 @item
1912 compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
1913 which comes from @code{EMUL} in @file{config/@var{target}.mt}
1914 @end enumerate
1915
1916 @node Index
1917 @unnumbered Index
1918
1919 @printindex cp
1920
1921 @contents
1922 @bye