1 \input texinfo @c -*- Texinfo -*-
2 @setfilename binutils.info
3 @settitle @sc{gnu} Binary Utilities
12 @c man begin COPYRIGHT
13 Copyright @copyright{} 1991-2019 Free Software Foundation, Inc.
15 Permission is granted to copy, distribute and/or modify this document
16 under the terms of the GNU Free Documentation License, Version 1.3
17 or any later version published by the Free Software Foundation;
18 with no Invariant Sections, with no Front-Cover Texts, and with no
19 Back-Cover Texts. A copy of the license is included in the
20 section entitled ``GNU Free Documentation License''.
25 @dircategory Software development
27 * Binutils: (binutils). The GNU binary utilities.
30 @dircategory Individual utilities
32 * addr2line: (binutils)addr2line. Convert addresses to file and line.
33 * ar: (binutils)ar. Create, modify, and extract from archives.
34 * c++filt: (binutils)c++filt. Filter to demangle encoded C++ symbols.
35 * cxxfilt: (binutils)c++filt. MS-DOS name for c++filt.
36 * dlltool: (binutils)dlltool. Create files needed to build and use DLLs.
37 * nm: (binutils)nm. List symbols from object files.
38 * objcopy: (binutils)objcopy. Copy and translate object files.
39 * objdump: (binutils)objdump. Display information from object files.
40 * ranlib: (binutils)ranlib. Generate index to archive contents.
41 * readelf: (binutils)readelf. Display the contents of ELF format files.
42 * size: (binutils)size. List section sizes and total size.
43 * strings: (binutils)strings. List printable strings from files.
44 * strip: (binutils)strip. Discard symbols.
45 * elfedit: (binutils)elfedit. Update ELF header and property of ELF files.
46 * windmc: (binutils)windmc. Generator for Windows message resources.
47 * windres: (binutils)windres. Manipulate Windows resources.
51 @title The @sc{gnu} Binary Utilities
52 @ifset VERSION_PACKAGE
53 @subtitle @value{VERSION_PACKAGE}
55 @subtitle Version @value{VERSION}
57 @subtitle @value{UPDATED}
58 @author Roland H. Pesch
59 @author Jeffrey M. Osier
60 @author Cygnus Support
64 {\parskip=0pt \hfill Cygnus Support\par \hfill
65 Texinfo \texinfoversion\par }
68 @vskip 0pt plus 1filll
77 This brief manual contains documentation for the @sc{gnu} binary
79 @ifset VERSION_PACKAGE
80 @value{VERSION_PACKAGE}
82 version @value{VERSION}:
87 Create, modify, and extract from archives
90 List symbols from object files
93 Copy and translate object files
96 Display information from object files
99 Generate index to archive contents
102 Display the contents of ELF format files.
105 List file section sizes and total size
108 List printable strings from files
114 Update the ELF header and program property of ELF files.
117 Demangle encoded C++ symbols (on MS-DOS, this program is named
121 Convert addresses into file names and line numbers
124 Manipulate Windows resources
127 Generator for Windows message resources
130 Create the files needed to build and use Dynamic Link Libraries
134 This document is distributed under the terms of the GNU Free
135 Documentation License version 1.3. A copy of the license is included
136 in the section entitled ``GNU Free Documentation License''.
139 * ar:: Create, modify, and extract from archives
140 * nm:: List symbols from object files
141 * objcopy:: Copy and translate object files
142 * objdump:: Display information from object files
143 * ranlib:: Generate index to archive contents
144 * size:: List section sizes and total size
145 * strings:: List printable strings from files
146 * strip:: Discard symbols
147 * c++filt:: Filter to demangle encoded C++ symbols
148 * cxxfilt: c++filt. MS-DOS name for c++filt
149 * addr2line:: Convert addresses to file and line
150 * windmc:: Generator for Windows message resources
151 * windres:: Manipulate Windows resources
152 * dlltool:: Create files needed to build and use DLLs
153 * readelf:: Display the contents of ELF format files
154 * elfedit:: Update ELF header and property of ELF files
155 * Common Options:: Command-line options for all utilities
156 * Selecting the Target System:: How these utilities determine the target
157 * Reporting Bugs:: Reporting Bugs
158 * GNU Free Documentation License:: GNU Free Documentation License
159 * Binutils Index:: Binutils Index
167 @cindex collections of files
169 @c man title ar create, modify, and extract from archives
172 ar [-]@var{p}[@var{mod}] [@option{--plugin} @var{name}] [@option{--target} @var{bfdname}] [@var{relpos}] [@var{count}] @var{archive} [@var{member}@dots{}]
173 ar -M [ <mri-script ]
176 @c man begin DESCRIPTION ar
178 The @sc{gnu} @command{ar} program creates, modifies, and extracts from
179 archives. An @dfn{archive} is a single file holding a collection of
180 other files in a structure that makes it possible to retrieve
181 the original individual files (called @dfn{members} of the archive).
183 The original files' contents, mode (permissions), timestamp, owner, and
184 group are preserved in the archive, and can be restored on
188 @sc{gnu} @command{ar} can maintain archives whose members have names of any
189 length; however, depending on how @command{ar} is configured on your
190 system, a limit on member-name length may be imposed for compatibility
191 with archive formats maintained with other tools. If it exists, the
192 limit is often 15 characters (typical of formats related to a.out) or 16
193 characters (typical of formats related to coff).
196 @command{ar} is considered a binary utility because archives of this sort
197 are most often used as @dfn{libraries} holding commonly needed
201 @command{ar} creates an index to the symbols defined in relocatable
202 object modules in the archive when you specify the modifier @samp{s}.
203 Once created, this index is updated in the archive whenever @command{ar}
204 makes a change to its contents (save for the @samp{q} update operation).
205 An archive with such an index speeds up linking to the library, and
206 allows routines in the library to call each other without regard to
207 their placement in the archive.
209 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
210 table. If an archive lacks the table, another form of @command{ar} called
211 @command{ranlib} can be used to add just the table.
213 @cindex thin archives
214 @sc{gnu} @command{ar} can optionally create a @emph{thin} archive,
215 which contains a symbol index and references to the original copies
216 of the member files of the archive. This is useful for building
217 libraries for use within a local build tree, where the relocatable
218 objects are expected to remain available, and copying the contents of
219 each object would only waste time and space.
221 An archive can either be @emph{thin} or it can be normal. It cannot
222 be both at the same time. Once an archive is created its format
223 cannot be changed without first deleting it and then creating a new
224 archive in its place.
226 Thin archives are also @emph{flattened}, so that adding one thin
227 archive to another thin archive does not nest it, as would happen with
228 a normal archive. Instead the elements of the first archive are added
229 individually to the second archive.
231 The paths to the elements of the archive are stored relative to the
234 @cindex compatibility, @command{ar}
235 @cindex @command{ar} compatibility
236 @sc{gnu} @command{ar} is designed to be compatible with two different
237 facilities. You can control its activity using command-line options,
238 like the different varieties of @command{ar} on Unix systems; or, if you
239 specify the single command-line option @option{-M}, you can control it
240 with a script supplied via standard input, like the MRI ``librarian''
246 * ar cmdline:: Controlling @command{ar} on the command line
247 * ar scripts:: Controlling @command{ar} with a script
252 @section Controlling @command{ar} on the Command Line
255 @c man begin SYNOPSIS ar
256 ar [@option{-X32_64}] [@option{-}]@var{p}[@var{mod}] [@option{--plugin} @var{name}] [@option{--target} @var{bfdname}] [@var{relpos}] [@var{count}] @var{archive} [@var{member}@dots{}]
260 @cindex Unix compatibility, @command{ar}
261 When you use @command{ar} in the Unix style, @command{ar} insists on at least two
262 arguments to execute: one keyletter specifying the @emph{operation}
263 (optionally accompanied by other keyletters specifying
264 @emph{modifiers}), and the archive name to act on.
266 Most operations can also accept further @var{member} arguments,
267 specifying particular files to operate on.
269 @c man begin OPTIONS ar
271 @sc{gnu} @command{ar} allows you to mix the operation code @var{p} and modifier
272 flags @var{mod} in any order, within the first command-line argument.
274 If you wish, you may begin the first command-line argument with a
277 @cindex operations on archive
278 The @var{p} keyletter specifies what operation to execute; it may be
279 any of the following, but you must specify only one of them:
283 @cindex deleting from archive
284 @emph{Delete} modules from the archive. Specify the names of modules to
285 be deleted as @var{member}@dots{}; the archive is untouched if you
286 specify no files to delete.
288 If you specify the @samp{v} modifier, @command{ar} lists each module
292 @cindex moving in archive
293 Use this operation to @emph{move} members in an archive.
295 The ordering of members in an archive can make a difference in how
296 programs are linked using the library, if a symbol is defined in more
299 If no modifiers are used with @code{m}, any members you name in the
300 @var{member} arguments are moved to the @emph{end} of the archive;
301 you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
302 specified place instead.
305 @cindex printing from archive
306 @emph{Print} the specified members of the archive, to the standard
307 output file. If the @samp{v} modifier is specified, show the member
308 name before copying its contents to standard output.
310 If you specify no @var{member} arguments, all the files in the archive are
314 @cindex quick append to archive
315 @emph{Quick append}; Historically, add the files @var{member}@dots{} to the end of
316 @var{archive}, without checking for replacement.
318 The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
319 operation; new members are always placed at the end of the archive.
321 The modifier @samp{v} makes @command{ar} list each file as it is appended.
323 Since the point of this operation is speed, implementations of
324 @command{ar} have the option of not updating the archive's symbol
325 table if one exists. Too many different systems however assume that
326 symbol tables are always up-to-date, so @sc{gnu} @command{ar} will
327 rebuild the table even with a quick append.
329 Note - @sc{gnu} @command{ar} treats the command @samp{qs} as a
330 synonym for @samp{r} - replacing already existing files in the
331 archive and appending new ones at the end.
334 @cindex replacement in archive
335 Insert the files @var{member}@dots{} into @var{archive} (with
336 @emph{replacement}). This operation differs from @samp{q} in that any
337 previously existing members are deleted if their names match those being
340 If one of the files named in @var{member}@dots{} does not exist, @command{ar}
341 displays an error message, and leaves undisturbed any existing members
342 of the archive matching that name.
344 By default, new members are added at the end of the file; but you may
345 use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
346 placement relative to some existing member.
348 The modifier @samp{v} used with this operation elicits a line of
349 output for each file inserted, along with one of the letters @samp{a} or
350 @samp{r} to indicate whether the file was appended (no old member
351 deleted) or replaced.
355 Add an index to the archive, or update it if it already exists. Note
356 this command is an exception to the rule that there can only be one
357 command letter, as it is possible to use it as either a command or a
358 modifier. In either case it does the same thing.
361 @cindex contents of archive
362 Display a @emph{table} listing the contents of @var{archive}, or those
363 of the files listed in @var{member}@dots{} that are present in the
364 archive. Normally only the member name is shown, but if the modifier
365 @samp{O} is specified, then the corresponding offset of the member is also
366 displayed. Finally, in order to see the modes (permissions), timestamp,
367 owner, group, and size the @samp{v} modifier should be included.
369 If you do not specify a @var{member}, all files in the archive
372 @cindex repeated names in archive
373 @cindex name duplication in archive
374 If there is more than one file with the same name (say, @samp{fie}) in
375 an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
376 first instance; to see them all, you must ask for a complete
377 listing---in our example, @samp{ar t b.a}.
378 @c WRS only; per Gumby, this is implementation-dependent, and in a more
379 @c recent case in fact works the other way.
382 @cindex extract from archive
383 @emph{Extract} members (named @var{member}) from the archive. You can
384 use the @samp{v} modifier with this operation, to request that
385 @command{ar} list each name as it extracts it.
387 If you do not specify a @var{member}, all files in the archive
390 Files cannot be extracted from a thin archive.
393 A number of modifiers (@var{mod}) may immediately follow the @var{p}
394 keyletter, to specify variations on an operation's behavior:
398 @cindex relative placement in archive
399 Add new files @emph{after} an existing member of the
400 archive. If you use the modifier @samp{a}, the name of an existing archive
401 member must be present as the @var{relpos} argument, before the
402 @var{archive} specification.
405 Add new files @emph{before} an existing member of the
406 archive. If you use the modifier @samp{b}, the name of an existing archive
407 member must be present as the @var{relpos} argument, before the
408 @var{archive} specification. (same as @samp{i}).
411 @cindex creating archives
412 @emph{Create} the archive. The specified @var{archive} is always
413 created if it did not exist, when you request an update. But a warning is
414 issued unless you specify in advance that you expect to create it, by
418 @cindex deterministic archives
419 @kindex --enable-deterministic-archives
420 Operate in @emph{deterministic} mode. When adding files and the archive
421 index use zero for UIDs, GIDs, timestamps, and use consistent file modes
422 for all files. When this option is used, if @command{ar} is used with
423 identical options and identical input files, multiple runs will create
424 identical output files regardless of the input files' owners, groups,
425 file modes, or modification times.
427 If @file{binutils} was configured with
428 @option{--enable-deterministic-archives}, then this mode is on by default.
429 It can be disabled with the @samp{U} modifier, below.
432 Truncate names in the archive. @sc{gnu} @command{ar} will normally permit file
433 names of any length. This will cause it to create archives which are
434 not compatible with the native @command{ar} program on some systems. If
435 this is a concern, the @samp{f} modifier may be used to truncate file
436 names when putting them in the archive.
439 Insert new files @emph{before} an existing member of the
440 archive. If you use the modifier @samp{i}, the name of an existing archive
441 member must be present as the @var{relpos} argument, before the
442 @var{archive} specification. (same as @samp{b}).
445 This modifier is accepted but not used.
446 @c whaffor ar l modifier??? presumably compat; with
447 @c what???---doc@@cygnus.com, 25jan91
450 Uses the @var{count} parameter. This is used if there are multiple
451 entries in the archive with the same name. Extract or delete instance
452 @var{count} of the given name from the archive.
455 @cindex dates in archive
456 Preserve the @emph{original} dates of members when extracting them. If
457 you do not specify this modifier, files extracted from the archive
458 are stamped with the time of extraction.
461 @cindex offsets of files
462 Display member offsets inside the archive. Use together with the @samp{t}
466 Use the full path name when matching names in the archive. @sc{gnu}
467 @command{ar} can not create an archive with a full path name (such archives
468 are not POSIX compliant), but other archive creators can. This option
469 will cause @sc{gnu} @command{ar} to match file names using a complete path
470 name, which can be convenient when extracting a single file from an
471 archive created by another tool.
474 @cindex writing archive index
475 Write an object-file index into the archive, or update an existing one,
476 even if no other change is made to the archive. You may use this modifier
477 flag either with any operation, or alone. Running @samp{ar s} on an
478 archive is equivalent to running @samp{ranlib} on it.
481 @cindex not writing archive index
482 Do not generate an archive symbol table. This can speed up building a
483 large library in several steps. The resulting archive can not be used
484 with the linker. In order to build a symbol table, you must omit the
485 @samp{S} modifier on the last execution of @samp{ar}, or you must run
486 @samp{ranlib} on the archive.
489 @cindex creating thin archive
490 Make the specified @var{archive} a @emph{thin} archive. If it already
491 exists and is a regular archive, the existing members must be present
492 in the same directory as @var{archive}.
495 @cindex updating an archive
496 Normally, @samp{ar r}@dots{} inserts all files
497 listed into the archive. If you would like to insert @emph{only} those
498 of the files you list that are newer than existing members of the same
499 names, use this modifier. The @samp{u} modifier is allowed only for the
500 operation @samp{r} (replace). In particular, the combination @samp{qu} is
501 not allowed, since checking the timestamps would lose any speed
502 advantage from the operation @samp{q}.
505 @cindex deterministic archives
506 @kindex --enable-deterministic-archives
507 Do @emph{not} operate in @emph{deterministic} mode. This is the inverse
508 of the @samp{D} modifier, above: added files and the archive index will
509 get their actual UID, GID, timestamp, and file mode values.
511 This is the default unless @file{binutils} was configured with
512 @option{--enable-deterministic-archives}.
515 This modifier requests the @emph{verbose} version of an operation. Many
516 operations display additional information, such as filenames processed,
517 when the modifier @samp{v} is appended.
520 This modifier shows the version number of @command{ar}.
523 The @command{ar} program also supports some command-line options which
524 are neither modifiers nor actions, but which do change its behaviour
529 Displays the list of command-line options supported by @command{ar}
533 Displays the version information of @command{ar} and then exits.
536 @command{ar} ignores an initial option spelt @samp{-X32_64}, for
537 compatibility with AIX. The behaviour produced by this option is the
538 default for @sc{gnu} @command{ar}. @command{ar} does not support any
539 of the other @samp{-X} options; in particular, it does not support
540 @option{-X32} which is the default for AIX @command{ar}.
542 @item --plugin @var{name}
544 The optional command-line switch @option{--plugin @var{name}} causes
545 @command{ar} to load the plugin called @var{name} which adds support
546 for more file formats, including object files with link-time
547 optimization information.
549 This option is only available if the toolchain has been built with
550 plugin support enabled.
552 If @option{--plugin} is not provided, but plugin support has been
553 enabled then @command{ar} iterates over the files in
554 @file{$@{libdir@}/bfd-plugins} in alphabetic order and the first
555 plugin that claims the object in question is used.
557 Please note that this plugin search directory is @emph{not} the one
558 used by @command{ld}'s @option{-plugin} option. In order to make
559 @command{ar} use the linker plugin it must be copied into the
560 @file{$@{libdir@}/bfd-plugins} directory. For GCC based compilations
561 the linker plugin is called @file{liblto_plugin.so.0.0.0}. For Clang
562 based compilations it is called @file{LLVMgold.so}. The GCC plugin
563 is always backwards compatible with earlier versions, so it is
564 sufficient to just copy the newest one.
566 @item --target @var{target}
567 The optional command-line switch @option{--target @var{bfdname}}
568 specifies that the archive members are in an object code format
569 different from your system's default format. See
570 @xref{Target Selection}, for more information.
575 @c man begin SEEALSO ar
576 nm(1), ranlib(1), and the Info entries for @file{binutils}.
581 @section Controlling @command{ar} with a Script
584 ar -M [ <@var{script} ]
587 @cindex MRI compatibility, @command{ar}
588 @cindex scripts, @command{ar}
589 If you use the single command-line option @samp{-M} with @command{ar}, you
590 can control its operation with a rudimentary command language. This
591 form of @command{ar} operates interactively if standard input is coming
592 directly from a terminal. During interactive use, @command{ar} prompts for
593 input (the prompt is @samp{AR >}), and continues executing even after
594 errors. If you redirect standard input to a script file, no prompts are
595 issued, and @command{ar} abandons execution (with a nonzero exit code)
598 The @command{ar} command language is @emph{not} designed to be equivalent
599 to the command-line options; in fact, it provides somewhat less control
600 over archives. The only purpose of the command language is to ease the
601 transition to @sc{gnu} @command{ar} for developers who already have scripts
602 written for the MRI ``librarian'' program.
604 The syntax for the @command{ar} command language is straightforward:
607 commands are recognized in upper or lower case; for example, @code{LIST}
608 is the same as @code{list}. In the following descriptions, commands are
609 shown in upper case for clarity.
612 a single command may appear on each line; it is the first word on the
616 empty lines are allowed, and have no effect.
619 comments are allowed; text after either of the characters @samp{*}
620 or @samp{;} is ignored.
623 Whenever you use a list of names as part of the argument to an @command{ar}
624 command, you can separate the individual names with either commas or
625 blanks. Commas are shown in the explanations below, for clarity.
628 @samp{+} is used as a line continuation character; if @samp{+} appears
629 at the end of a line, the text on the following line is considered part
630 of the current command.
633 Here are the commands you can use in @command{ar} scripts, or when using
634 @command{ar} interactively. Three of them have special significance:
636 @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
637 a temporary file required for most of the other commands.
639 @code{SAVE} commits the changes so far specified by the script. Prior
640 to @code{SAVE}, commands affect only the temporary copy of the current
644 @item ADDLIB @var{archive}
645 @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
646 Add all the contents of @var{archive} (or, if specified, each named
647 @var{module} from @var{archive}) to the current archive.
649 Requires prior use of @code{OPEN} or @code{CREATE}.
651 @item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
652 @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
653 @c else like "ar q..."
654 Add each named @var{member} as a module in the current archive.
656 Requires prior use of @code{OPEN} or @code{CREATE}.
659 Discard the contents of the current archive, canceling the effect of
660 any operations since the last @code{SAVE}. May be executed (with no
661 effect) even if no current archive is specified.
663 @item CREATE @var{archive}
664 Creates an archive, and makes it the current archive (required for many
665 other commands). The new archive is created with a temporary name; it
666 is not actually saved as @var{archive} until you use @code{SAVE}.
667 You can overwrite existing archives; similarly, the contents of any
668 existing file named @var{archive} will not be destroyed until @code{SAVE}.
670 @item DELETE @var{module}, @var{module}, @dots{} @var{module}
671 Delete each listed @var{module} from the current archive; equivalent to
672 @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
674 Requires prior use of @code{OPEN} or @code{CREATE}.
676 @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
677 @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
678 List each named @var{module} present in @var{archive}. The separate
679 command @code{VERBOSE} specifies the form of the output: when verbose
680 output is off, output is like that of @samp{ar -t @var{archive}
681 @var{module}@dots{}}. When verbose output is on, the listing is like
682 @samp{ar -tv @var{archive} @var{module}@dots{}}.
684 Output normally goes to the standard output stream; however, if you
685 specify @var{outputfile} as a final argument, @command{ar} directs the
689 Exit from @command{ar}, with a @code{0} exit code to indicate successful
690 completion. This command does not save the output file; if you have
691 changed the current archive since the last @code{SAVE} command, those
694 @item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
695 Extract each named @var{module} from the current archive, writing them
696 into the current directory as separate files. Equivalent to @samp{ar -x
697 @var{archive} @var{module}@dots{}}.
699 Requires prior use of @code{OPEN} or @code{CREATE}.
702 @c FIXME Tokens but no commands???
709 Display full contents of the current archive, in ``verbose'' style
710 regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
711 tv @var{archive}}. (This single command is a @sc{gnu} @command{ar}
712 enhancement, rather than present for MRI compatibility.)
714 Requires prior use of @code{OPEN} or @code{CREATE}.
716 @item OPEN @var{archive}
717 Opens an existing archive for use as the current archive (required for
718 many other commands). Any changes as the result of subsequent commands
719 will not actually affect @var{archive} until you next use @code{SAVE}.
721 @item REPLACE @var{module}, @var{module}, @dots{} @var{module}
722 In the current archive, replace each existing @var{module} (named in
723 the @code{REPLACE} arguments) from files in the current working directory.
724 To execute this command without errors, both the file, and the module in
725 the current archive, must exist.
727 Requires prior use of @code{OPEN} or @code{CREATE}.
730 Toggle an internal flag governing the output from @code{DIRECTORY}.
731 When the flag is on, @code{DIRECTORY} output matches output from
732 @samp{ar -tv }@dots{}.
735 Commit your changes to the current archive, and actually save it as a
736 file with the name specified in the last @code{CREATE} or @code{OPEN}
739 Requires prior use of @code{OPEN} or @code{CREATE}.
748 The @sc{gnu} linker @command{ld} is now described in a separate manual.
749 @xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
757 @c man title nm list symbols from object files
760 @c man begin SYNOPSIS nm
761 nm [@option{-A}|@option{-o}|@option{--print-file-name}] [@option{-a}|@option{--debug-syms}]
762 [@option{-B}|@option{--format=bsd}] [@option{-C}|@option{--demangle}[=@var{style}]]
763 [@option{-D}|@option{--dynamic}] [@option{-f}@var{format}|@option{--format=}@var{format}]
764 [@option{-g}|@option{--extern-only}] [@option{-h}|@option{--help}]
765 [@option{-l}|@option{--line-numbers}] [@option{--inlines}]
766 [@option{-n}|@option{-v}|@option{--numeric-sort}]
767 [@option{-P}|@option{--portability}] [@option{-p}|@option{--no-sort}]
768 [@option{-r}|@option{--reverse-sort}] [@option{-S}|@option{--print-size}]
769 [@option{-s}|@option{--print-armap}] [@option{-t} @var{radix}|@option{--radix=}@var{radix}]
770 [@option{-u}|@option{--undefined-only}] [@option{-V}|@option{--version}]
771 [@option{-X 32_64}] [@option{--defined-only}] [@option{--no-demangle}]
772 [@option{--plugin} @var{name}]
773 [@option{--no-recurse-limit}|@option{--recurse-limit}]]
774 [@option{--size-sort}] [@option{--special-syms}]
775 [@option{--synthetic}] [@option{--with-symbol-versions}] [@option{--target=}@var{bfdname}]
776 [@var{objfile}@dots{}]
780 @c man begin DESCRIPTION nm
781 @sc{gnu} @command{nm} lists the symbols from object files @var{objfile}@dots{}.
782 If no object files are listed as arguments, @command{nm} assumes the file
785 For each symbol, @command{nm} shows:
789 The symbol value, in the radix selected by options (see below), or
790 hexadecimal by default.
793 The symbol type. At least the following types are used; others are, as
794 well, depending on the object file format. If lowercase, the symbol is
795 usually local; if uppercase, the symbol is global (external). There
796 are however a few lowercase symbols that are shown for special global
797 symbols (@code{u}, @code{v} and @code{w}).
799 @c Some more detail on exactly what these symbol types are used for
803 The symbol's value is absolute, and will not be changed by further
808 The symbol is in the BSS data section. This section typically
809 contains zero-initialized or uninitialized data, although the exact
810 behavior is system dependent.
813 The symbol is common. Common symbols are uninitialized data. When
814 linking, multiple common symbols may appear with the same name. If the
815 symbol is defined anywhere, the common symbols are treated as undefined
818 For more details on common symbols, see the discussion of
819 --warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
824 The symbol is in the initialized data section.
828 The symbol is in an initialized data section for small objects. Some
829 object file formats permit more efficient access to small data objects,
830 such as a global int variable as opposed to a large global array.
833 For PE format files this indicates that the symbol is in a section
834 specific to the implementation of DLLs. For ELF format files this
835 indicates that the symbol is an indirect function. This is a GNU
836 extension to the standard set of ELF symbol types. It indicates a
837 symbol which if referenced by a relocation does not evaluate to its
838 address, but instead must be invoked at runtime. The runtime
839 execution will then return the value to be used in the relocation.
842 The symbol is an indirect reference to another symbol.
845 The symbol is a debugging symbol.
848 The symbols is in a stack unwind section.
852 The symbol is in a read only data section.
856 The symbol is in an uninitialized or zero-initialized data section
861 The symbol is in the text (code) section.
864 The symbol is undefined.
867 The symbol is a unique global symbol. This is a GNU extension to the
868 standard set of ELF symbol bindings. For such a symbol the dynamic linker
869 will make sure that in the entire process there is just one symbol with
870 this name and type in use.
874 The symbol is a weak object. When a weak defined symbol is linked with
875 a normal defined symbol, the normal defined symbol is used with no error.
876 When a weak undefined symbol is linked and the symbol is not defined,
877 the value of the weak symbol becomes zero with no error. On some
878 systems, uppercase indicates that a default value has been specified.
882 The symbol is a weak symbol that has not been specifically tagged as a
883 weak object symbol. When a weak defined symbol is linked with a normal
884 defined symbol, the normal defined symbol is used with no error.
885 When a weak undefined symbol is linked and the symbol is not defined,
886 the value of the symbol is determined in a system-specific manner without
887 error. On some systems, uppercase indicates that a default value has been
891 The symbol is a stabs symbol in an a.out object file. In this case, the
892 next values printed are the stabs other field, the stabs desc field, and
893 the stab type. Stabs symbols are used to hold debugging information.
896 The symbol type is unknown, or object file format specific.
905 @c man begin OPTIONS nm
906 The long and short forms of options, shown here as alternatives, are
912 @itemx --print-file-name
913 @cindex input file name
915 @cindex source file name
916 Precede each symbol by the name of the input file (or archive member)
917 in which it was found, rather than identifying the input file once only,
918 before all of its symbols.
922 @cindex debugging symbols
923 Display all symbols, even debugger-only symbols; normally these are not
927 @cindex @command{nm} format
928 @cindex @command{nm} compatibility
929 The same as @option{--format=bsd} (for compatibility with the MIPS @command{nm}).
932 @itemx --demangle[=@var{style}]
933 @cindex demangling in nm
934 Decode (@dfn{demangle}) low-level symbol names into user-level names.
935 Besides removing any initial underscore prepended by the system, this
936 makes C++ function names readable. Different compilers have different
937 mangling styles. The optional demangling style argument can be used to
938 choose an appropriate demangling style for your compiler. @xref{c++filt},
939 for more information on demangling.
942 Do not demangle low-level symbol names. This is the default.
944 @item --recurse-limit
945 @itemx --no-recurse-limit
946 @itemx --recursion-limit
947 @itemx --no-recursion-limit
948 Enables or disables a limit on the amount of recursion performed
949 whilst demangling strings. Since the name mangling formats allow for
950 an inifinite level of recursion it is possible to create strings whose
951 decoding will exhaust the amount of stack space available on the host
952 machine, triggering a memory fault. The limit tries to prevent this
953 from happening by restricting recursion to 2048 levels of nesting.
955 The default is for this limit to be enabled, but disabling it may be
956 necessary in order to demangle truly complicated names. Note however
957 that if the recursion limit is disabled then stack exhaustion is
958 possible and any bug reports about such an event will be rejected.
962 @cindex dynamic symbols
963 Display the dynamic symbols rather than the normal symbols. This is
964 only meaningful for dynamic objects, such as certain types of shared
967 @item -f @var{format}
968 @itemx --format=@var{format}
969 @cindex @command{nm} format
970 @cindex @command{nm} compatibility
971 Use the output format @var{format}, which can be @code{bsd},
972 @code{sysv}, or @code{posix}. The default is @code{bsd}.
973 Only the first character of @var{format} is significant; it can be
974 either upper or lower case.
978 @cindex external symbols
979 Display only external symbols.
983 Show a summary of the options to @command{nm} and exit.
986 @itemx --line-numbers
987 @cindex symbol line numbers
988 For each symbol, use debugging information to try to find a filename and
989 line number. For a defined symbol, look for the line number of the
990 address of the symbol. For an undefined symbol, look for the line
991 number of a relocation entry which refers to the symbol. If line number
992 information can be found, print it after the other symbol information.
995 @cindex objdump inlines
996 When option @option{-l} is active, if the address belongs to a
997 function that was inlined, then this option causes the source
998 information for all enclosing scopes back to the first non-inlined
999 function to be printed as well. For example, if @code{main} inlines
1000 @code{callee1} which inlines @code{callee2}, and address is from
1001 @code{callee2}, the source information for @code{callee1} and @code{main}
1002 will also be printed.
1006 @itemx --numeric-sort
1007 Sort symbols numerically by their addresses, rather than alphabetically
1012 @cindex sorting symbols
1013 Do not bother to sort the symbols in any order; print them in the order
1017 @itemx --portability
1018 Use the POSIX.2 standard output format instead of the default format.
1019 Equivalent to @samp{-f posix}.
1022 @itemx --reverse-sort
1023 Reverse the order of the sort (whether numeric or alphabetic); let the
1028 Print both value and size of defined symbols for the @code{bsd} output style.
1029 This option has no effect for object formats that do not record symbol
1030 sizes, unless @samp{--size-sort} is also used in which case a
1031 calculated size is displayed.
1034 @itemx --print-armap
1035 @cindex symbol index, listing
1036 When listing symbols from archive members, include the index: a mapping
1037 (stored in the archive by @command{ar} or @command{ranlib}) of which modules
1038 contain definitions for which names.
1040 @item -t @var{radix}
1041 @itemx --radix=@var{radix}
1042 Use @var{radix} as the radix for printing the symbol values. It must be
1043 @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
1046 @itemx --undefined-only
1047 @cindex external symbols
1048 @cindex undefined symbols
1049 Display only undefined symbols (those external to each object file).
1053 Show the version number of @command{nm} and exit.
1056 This option is ignored for compatibility with the AIX version of
1057 @command{nm}. It takes one parameter which must be the string
1058 @option{32_64}. The default mode of AIX @command{nm} corresponds
1059 to @option{-X 32}, which is not supported by @sc{gnu} @command{nm}.
1061 @item --defined-only
1062 @cindex external symbols
1063 @cindex undefined symbols
1064 Display only defined symbols for each object file.
1066 @item --plugin @var{name}
1068 Load the plugin called @var{name} to add support for extra target
1069 types. This option is only available if the toolchain has been built
1070 with plugin support enabled.
1072 If @option{--plugin} is not provided, but plugin support has been
1073 enabled then @command{nm} iterates over the files in
1074 @file{$@{libdir@}/bfd-plugins} in alphabetic order and the first
1075 plugin that claims the object in question is used.
1077 Please note that this plugin search directory is @emph{not} the one
1078 used by @command{ld}'s @option{-plugin} option. In order to make
1079 @command{nm} use the linker plugin it must be copied into the
1080 @file{$@{libdir@}/bfd-plugins} directory. For GCC based compilations
1081 the linker plugin is called @file{liblto_plugin.so.0.0.0}. For Clang
1082 based compilations it is called @file{LLVMgold.so}. The GCC plugin
1083 is always backwards compatible with earlier versions, so it is
1084 sufficient to just copy the newest one.
1087 Sort symbols by size. For ELF objects symbol sizes are read from the
1088 ELF, for other object types the symbol sizes are computed as the
1089 difference between the value of the symbol and the value of the symbol
1090 with the next higher value. If the @code{bsd} output format is used
1091 the size of the symbol is printed, rather than the value, and
1092 @samp{-S} must be used in order both size and value to be printed.
1094 @item --special-syms
1095 Display symbols which have a target-specific special meaning. These
1096 symbols are usually used by the target for some special processing and
1097 are not normally helpful when included in the normal symbol lists.
1098 For example for ARM targets this option would skip the mapping symbols
1099 used to mark transitions between ARM code, THUMB code and data.
1102 Include synthetic symbols in the output. These are special symbols
1103 created by the linker for various purposes. They are not shown by
1104 default since they are not part of the binary's original source code.
1106 @item --with-symbol-versions
1107 Enables the display of symbol version information if any exists. The
1108 version string is displayed as a suffix to the symbol name, preceeded by
1109 an @@ character. For example @samp{foo@@VER_1}. If the version is
1110 the default version to be used when resolving unversioned references
1111 to the symbol then it is displayed as a suffix preceeded by two @@
1112 characters. For example @samp{foo@@@@VER_2}.
1114 @item --target=@var{bfdname}
1115 @cindex object code format
1116 Specify an object code format other than your system's default format.
1117 @xref{Target Selection}, for more information.
1124 @c man begin SEEALSO nm
1125 ar(1), objdump(1), ranlib(1), and the Info entries for @file{binutils}.
1132 @c man title objcopy copy and translate object files
1135 @c man begin SYNOPSIS objcopy
1136 objcopy [@option{-F} @var{bfdname}|@option{--target=}@var{bfdname}]
1137 [@option{-I} @var{bfdname}|@option{--input-target=}@var{bfdname}]
1138 [@option{-O} @var{bfdname}|@option{--output-target=}@var{bfdname}]
1139 [@option{-B} @var{bfdarch}|@option{--binary-architecture=}@var{bfdarch}]
1140 [@option{-S}|@option{--strip-all}]
1141 [@option{-g}|@option{--strip-debug}]
1142 [@option{--strip-unneeded}]
1143 [@option{-K} @var{symbolname}|@option{--keep-symbol=}@var{symbolname}]
1144 [@option{-N} @var{symbolname}|@option{--strip-symbol=}@var{symbolname}]
1145 [@option{--strip-unneeded-symbol=}@var{symbolname}]
1146 [@option{-G} @var{symbolname}|@option{--keep-global-symbol=}@var{symbolname}]
1147 [@option{--localize-hidden}]
1148 [@option{-L} @var{symbolname}|@option{--localize-symbol=}@var{symbolname}]
1149 [@option{--globalize-symbol=}@var{symbolname}]
1150 [@option{--globalize-symbols=}@var{filename}]
1151 [@option{-W} @var{symbolname}|@option{--weaken-symbol=}@var{symbolname}]
1152 [@option{-w}|@option{--wildcard}]
1153 [@option{-x}|@option{--discard-all}]
1154 [@option{-X}|@option{--discard-locals}]
1155 [@option{-b} @var{byte}|@option{--byte=}@var{byte}]
1156 [@option{-i} [@var{breadth}]|@option{--interleave}[=@var{breadth}]]
1157 [@option{--interleave-width=}@var{width}]
1158 [@option{-j} @var{sectionpattern}|@option{--only-section=}@var{sectionpattern}]
1159 [@option{-R} @var{sectionpattern}|@option{--remove-section=}@var{sectionpattern}]
1160 [@option{--remove-relocations=}@var{sectionpattern}]
1161 [@option{-p}|@option{--preserve-dates}]
1162 [@option{-D}|@option{--enable-deterministic-archives}]
1163 [@option{-U}|@option{--disable-deterministic-archives}]
1164 [@option{--debugging}]
1165 [@option{--gap-fill=}@var{val}]
1166 [@option{--pad-to=}@var{address}]
1167 [@option{--set-start=}@var{val}]
1168 [@option{--adjust-start=}@var{incr}]
1169 [@option{--change-addresses=}@var{incr}]
1170 [@option{--change-section-address} @var{sectionpattern}@{=,+,-@}@var{val}]
1171 [@option{--change-section-lma} @var{sectionpattern}@{=,+,-@}@var{val}]
1172 [@option{--change-section-vma} @var{sectionpattern}@{=,+,-@}@var{val}]
1173 [@option{--change-warnings}] [@option{--no-change-warnings}]
1174 [@option{--set-section-flags} @var{sectionpattern}=@var{flags}]
1175 [@option{--add-section} @var{sectionname}=@var{filename}]
1176 [@option{--dump-section} @var{sectionname}=@var{filename}]
1177 [@option{--update-section} @var{sectionname}=@var{filename}]
1178 [@option{--rename-section} @var{oldname}=@var{newname}[,@var{flags}]]
1179 [@option{--long-section-names} @{enable,disable,keep@}]
1180 [@option{--change-leading-char}] [@option{--remove-leading-char}]
1181 [@option{--reverse-bytes=}@var{num}]
1182 [@option{--srec-len=}@var{ival}] [@option{--srec-forceS3}]
1183 [@option{--redefine-sym} @var{old}=@var{new}]
1184 [@option{--redefine-syms=}@var{filename}]
1186 [@option{--keep-symbols=}@var{filename}]
1187 [@option{--strip-symbols=}@var{filename}]
1188 [@option{--strip-unneeded-symbols=}@var{filename}]
1189 [@option{--keep-global-symbols=}@var{filename}]
1190 [@option{--localize-symbols=}@var{filename}]
1191 [@option{--weaken-symbols=}@var{filename}]
1192 [@option{--add-symbol} @var{name}=[@var{section}:]@var{value}[,@var{flags}]]
1193 [@option{--alt-machine-code=}@var{index}]
1194 [@option{--prefix-symbols=}@var{string}]
1195 [@option{--prefix-sections=}@var{string}]
1196 [@option{--prefix-alloc-sections=}@var{string}]
1197 [@option{--add-gnu-debuglink=}@var{path-to-file}]
1198 [@option{--keep-file-symbols}]
1199 [@option{--only-keep-debug}]
1200 [@option{--strip-dwo}]
1201 [@option{--extract-dwo}]
1202 [@option{--extract-symbol}]
1203 [@option{--writable-text}]
1204 [@option{--readonly-text}]
1207 [@option{--file-alignment=}@var{num}]
1208 [@option{--heap=}@var{size}]
1209 [@option{--image-base=}@var{address}]
1210 [@option{--section-alignment=}@var{num}]
1211 [@option{--stack=}@var{size}]
1212 [@option{--subsystem=}@var{which}:@var{major}.@var{minor}]
1213 [@option{--compress-debug-sections}]
1214 [@option{--decompress-debug-sections}]
1215 [@option{--elf-stt-common=@var{val}}]
1216 [@option{--merge-notes}]
1217 [@option{--no-merge-notes}]
1218 [@option{-v}|@option{--verbose}]
1219 [@option{-V}|@option{--version}]
1220 [@option{--help}] [@option{--info}]
1221 @var{infile} [@var{outfile}]
1225 @c man begin DESCRIPTION objcopy
1226 The @sc{gnu} @command{objcopy} utility copies the contents of an object
1227 file to another. @command{objcopy} uses the @sc{gnu} @sc{bfd} Library to
1228 read and write the object files. It can write the destination object
1229 file in a format different from that of the source object file. The
1230 exact behavior of @command{objcopy} is controlled by command-line options.
1231 Note that @command{objcopy} should be able to copy a fully linked file
1232 between any two formats. However, copying a relocatable object file
1233 between any two formats may not work as expected.
1235 @command{objcopy} creates temporary files to do its translations and
1236 deletes them afterward. @command{objcopy} uses @sc{bfd} to do all its
1237 translation work; it has access to all the formats described in @sc{bfd}
1238 and thus is able to recognize most formats without being told
1239 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
1241 @command{objcopy} can be used to generate S-records by using an output
1242 target of @samp{srec} (e.g., use @samp{-O srec}).
1244 @command{objcopy} can be used to generate a raw binary file by using an
1245 output target of @samp{binary} (e.g., use @option{-O binary}). When
1246 @command{objcopy} generates a raw binary file, it will essentially produce
1247 a memory dump of the contents of the input object file. All symbols and
1248 relocation information will be discarded. The memory dump will start at
1249 the load address of the lowest section copied into the output file.
1251 When generating an S-record or a raw binary file, it may be helpful to
1252 use @option{-S} to remove sections containing debugging information. In
1253 some cases @option{-R} will be useful to remove sections which contain
1254 information that is not needed by the binary file.
1256 Note---@command{objcopy} is not able to change the endianness of its input
1257 files. If the input format has an endianness (some formats do not),
1258 @command{objcopy} can only copy the inputs into file formats that have the
1259 same endianness or which have no endianness (e.g., @samp{srec}).
1260 (However, see the @option{--reverse-bytes} option.)
1264 @c man begin OPTIONS objcopy
1268 @itemx @var{outfile}
1269 The input and output files, respectively.
1270 If you do not specify @var{outfile}, @command{objcopy} creates a
1271 temporary file and destructively renames the result with
1272 the name of @var{infile}.
1274 @item -I @var{bfdname}
1275 @itemx --input-target=@var{bfdname}
1276 Consider the source file's object format to be @var{bfdname}, rather than
1277 attempting to deduce it. @xref{Target Selection}, for more information.
1279 @item -O @var{bfdname}
1280 @itemx --output-target=@var{bfdname}
1281 Write the output file using the object format @var{bfdname}.
1282 @xref{Target Selection}, for more information.
1284 @item -F @var{bfdname}
1285 @itemx --target=@var{bfdname}
1286 Use @var{bfdname} as the object format for both the input and the output
1287 file; i.e., simply transfer data from source to destination with no
1288 translation. @xref{Target Selection}, for more information.
1290 @item -B @var{bfdarch}
1291 @itemx --binary-architecture=@var{bfdarch}
1292 Useful when transforming a architecture-less input file into an object file.
1293 In this case the output architecture can be set to @var{bfdarch}. This
1294 option will be ignored if the input file has a known @var{bfdarch}. You
1295 can access this binary data inside a program by referencing the special
1296 symbols that are created by the conversion process. These symbols are
1297 called _binary_@var{objfile}_start, _binary_@var{objfile}_end and
1298 _binary_@var{objfile}_size. e.g. you can transform a picture file into
1299 an object file and then access it in your code using these symbols.
1301 @item -j @var{sectionpattern}
1302 @itemx --only-section=@var{sectionpattern}
1303 Copy only the indicated sections from the input file to the output file.
1304 This option may be given more than once. Note that using this option
1305 inappropriately may make the output file unusable. Wildcard
1306 characters are accepted in @var{sectionpattern}.
1308 If the first character of @var{sectionpattern} is the exclamation
1309 point (!) then matching sections will not be copied, even if earlier
1310 use of @option{--only-section} on the same command line would
1311 otherwise copy it. For example:
1314 --only-section=.text.* --only-section=!.text.foo
1317 will copy all sectinos maching '.text.*' but not the section
1320 @item -R @var{sectionpattern}
1321 @itemx --remove-section=@var{sectionpattern}
1322 Remove any section matching @var{sectionpattern} from the output file.
1323 This option may be given more than once. Note that using this option
1324 inappropriately may make the output file unusable. Wildcard
1325 characters are accepted in @var{sectionpattern}. Using both the
1326 @option{-j} and @option{-R} options together results in undefined
1329 If the first character of @var{sectionpattern} is the exclamation
1330 point (!) then matching sections will not be removed even if an
1331 earlier use of @option{--remove-section} on the same command line
1332 would otherwise remove it. For example:
1335 --remove-section=.text.* --remove-section=!.text.foo
1338 will remove all sections matching the pattern '.text.*', but will not
1339 remove the section '.text.foo'.
1341 @item --remove-relocations=@var{sectionpattern}
1342 Remove non-dynamic relocations from the output file for any section
1343 matching @var{sectionpattern}. This option may be given more than
1344 once. Note that using this option inappropriately may make the output
1345 file unusable, and attempting to remove a dynamic relocation section
1346 such as @samp{.rela.plt} from an executable or shared library with
1347 @option{--remove-relocations=.plt} will not work. Wildcard characters
1348 are accepted in @var{sectionpattern}.
1352 --remove-relocations=.text.*
1355 will remove the relocations for all sections matching the pattern
1358 If the first character of @var{sectionpattern} is the exclamation
1359 point (!) then matching sections will not have their relocation
1360 removed even if an earlier use of @option{--remove-relocations} on the
1361 same command line would otherwise cause the relocations to be removed.
1365 --remove-relocations=.text.* --remove-relocations=!.text.foo
1368 will remove all relocations for sections matching the pattern
1369 '.text.*', but will not remove relocations for the section
1374 Do not copy relocation and symbol information from the source file.
1377 @itemx --strip-debug
1378 Do not copy debugging symbols or sections from the source file.
1380 @item --strip-unneeded
1381 Strip all symbols that are not needed for relocation processing.
1383 @item -K @var{symbolname}
1384 @itemx --keep-symbol=@var{symbolname}
1385 When stripping symbols, keep symbol @var{symbolname} even if it would
1386 normally be stripped. This option may be given more than once.
1388 @item -N @var{symbolname}
1389 @itemx --strip-symbol=@var{symbolname}
1390 Do not copy symbol @var{symbolname} from the source file. This option
1391 may be given more than once.
1393 @item --strip-unneeded-symbol=@var{symbolname}
1394 Do not copy symbol @var{symbolname} from the source file unless it is needed
1395 by a relocation. This option may be given more than once.
1397 @item -G @var{symbolname}
1398 @itemx --keep-global-symbol=@var{symbolname}
1399 Keep only symbol @var{symbolname} global. Make all other symbols local
1400 to the file, so that they are not visible externally. This option may
1401 be given more than once. Note: this option cannot be used in
1402 conjunction with the @option{--globalize-symbol} or
1403 @option{--globalize-symbols} options.
1405 @item --localize-hidden
1406 In an ELF object, mark all symbols that have hidden or internal visibility
1407 as local. This option applies on top of symbol-specific localization options
1408 such as @option{-L}.
1410 @item -L @var{symbolname}
1411 @itemx --localize-symbol=@var{symbolname}
1412 Convert a global or weak symbol called @var{symbolname} into a local
1413 symbol, so that it is not visible externally. This option may be
1414 given more than once. Note - unique symbols are not converted.
1416 @item -W @var{symbolname}
1417 @itemx --weaken-symbol=@var{symbolname}
1418 Make symbol @var{symbolname} weak. This option may be given more than once.
1420 @item --globalize-symbol=@var{symbolname}
1421 Give symbol @var{symbolname} global scoping so that it is visible
1422 outside of the file in which it is defined. This option may be given
1423 more than once. Note: this option cannot be used in conjunction with
1424 the @option{-G} or @option{--keep-global-symbol} options.
1428 Permit regular expressions in @var{symbolname}s used in other command
1429 line options. The question mark (?), asterisk (*), backslash (\) and
1430 square brackets ([]) operators can be used anywhere in the symbol
1431 name. If the first character of the symbol name is the exclamation
1432 point (!) then the sense of the switch is reversed for that symbol.
1439 would cause objcopy to weaken all symbols that start with ``fo''
1440 except for the symbol ``foo''.
1443 @itemx --discard-all
1444 Do not copy non-global symbols from the source file.
1445 @c FIXME any reason to prefer "non-global" to "local" here?
1448 @itemx --discard-locals
1449 Do not copy compiler-generated local symbols.
1450 (These usually start with @samp{L} or @samp{.}.)
1453 @itemx --byte=@var{byte}
1454 If interleaving has been enabled via the @option{--interleave} option
1455 then start the range of bytes to keep at the @var{byte}th byte.
1456 @var{byte} can be in the range from 0 to @var{breadth}-1, where
1457 @var{breadth} is the value given by the @option{--interleave} option.
1459 @item -i [@var{breadth}]
1460 @itemx --interleave[=@var{breadth}]
1461 Only copy a range out of every @var{breadth} bytes. (Header data is
1462 not affected). Select which byte in the range begins the copy with
1463 the @option{--byte} option. Select the width of the range with the
1464 @option{--interleave-width} option.
1466 This option is useful for creating files to program @sc{rom}. It is
1467 typically used with an @code{srec} output target. Note that
1468 @command{objcopy} will complain if you do not specify the
1469 @option{--byte} option as well.
1471 The default interleave breadth is 4, so with @option{--byte} set to 0,
1472 @command{objcopy} would copy the first byte out of every four bytes
1473 from the input to the output.
1475 @item --interleave-width=@var{width}
1476 When used with the @option{--interleave} option, copy @var{width}
1477 bytes at a time. The start of the range of bytes to be copied is set
1478 by the @option{--byte} option, and the extent of the range is set with
1479 the @option{--interleave} option.
1481 The default value for this option is 1. The value of @var{width} plus
1482 the @var{byte} value set by the @option{--byte} option must not exceed
1483 the interleave breadth set by the @option{--interleave} option.
1485 This option can be used to create images for two 16-bit flashes interleaved
1486 in a 32-bit bus by passing @option{-b 0 -i 4 --interleave-width=2}
1487 and @option{-b 2 -i 4 --interleave-width=2} to two @command{objcopy}
1488 commands. If the input was '12345678' then the outputs would be
1489 '1256' and '3478' respectively.
1492 @itemx --preserve-dates
1493 Set the access and modification dates of the output file to be the same
1494 as those of the input file.
1497 @itemx --enable-deterministic-archives
1498 @cindex deterministic archives
1499 @kindex --enable-deterministic-archives
1500 Operate in @emph{deterministic} mode. When copying archive members
1501 and writing the archive index, use zero for UIDs, GIDs, timestamps,
1502 and use consistent file modes for all files.
1504 If @file{binutils} was configured with
1505 @option{--enable-deterministic-archives}, then this mode is on by default.
1506 It can be disabled with the @samp{-U} option, below.
1509 @itemx --disable-deterministic-archives
1510 @cindex deterministic archives
1511 @kindex --enable-deterministic-archives
1512 Do @emph{not} operate in @emph{deterministic} mode. This is the
1513 inverse of the @option{-D} option, above: when copying archive members
1514 and writing the archive index, use their actual UID, GID, timestamp,
1515 and file mode values.
1517 This is the default unless @file{binutils} was configured with
1518 @option{--enable-deterministic-archives}.
1521 Convert debugging information, if possible. This is not the default
1522 because only certain debugging formats are supported, and the
1523 conversion process can be time consuming.
1525 @item --gap-fill @var{val}
1526 Fill gaps between sections with @var{val}. This operation applies to
1527 the @emph{load address} (LMA) of the sections. It is done by increasing
1528 the size of the section with the lower address, and filling in the extra
1529 space created with @var{val}.
1531 @item --pad-to @var{address}
1532 Pad the output file up to the load address @var{address}. This is
1533 done by increasing the size of the last section. The extra space is
1534 filled in with the value specified by @option{--gap-fill} (default zero).
1536 @item --set-start @var{val}
1537 Set the start address of the new file to @var{val}. Not all object file
1538 formats support setting the start address.
1540 @item --change-start @var{incr}
1541 @itemx --adjust-start @var{incr}
1542 @cindex changing start address
1543 Change the start address by adding @var{incr}. Not all object file
1544 formats support setting the start address.
1546 @item --change-addresses @var{incr}
1547 @itemx --adjust-vma @var{incr}
1548 @cindex changing object addresses
1549 Change the VMA and LMA addresses of all sections, as well as the start
1550 address, by adding @var{incr}. Some object file formats do not permit
1551 section addresses to be changed arbitrarily. Note that this does not
1552 relocate the sections; if the program expects sections to be loaded at a
1553 certain address, and this option is used to change the sections such
1554 that they are loaded at a different address, the program may fail.
1556 @item --change-section-address @var{sectionpattern}@{=,+,-@}@var{val}
1557 @itemx --adjust-section-vma @var{sectionpattern}@{=,+,-@}@var{val}
1558 @cindex changing section address
1559 Set or change both the VMA address and the LMA address of any section
1560 matching @var{sectionpattern}. If @samp{=} is used, the section
1561 address is set to @var{val}. Otherwise, @var{val} is added to or
1562 subtracted from the section address. See the comments under
1563 @option{--change-addresses}, above. If @var{sectionpattern} does not
1564 match any sections in the input file, a warning will be issued, unless
1565 @option{--no-change-warnings} is used.
1567 @item --change-section-lma @var{sectionpattern}@{=,+,-@}@var{val}
1568 @cindex changing section LMA
1569 Set or change the LMA address of any sections matching
1570 @var{sectionpattern}. The LMA address is the address where the
1571 section will be loaded into memory at program load time. Normally
1572 this is the same as the VMA address, which is the address of the
1573 section at program run time, but on some systems, especially those
1574 where a program is held in ROM, the two can be different. If @samp{=}
1575 is used, the section address is set to @var{val}. Otherwise,
1576 @var{val} is added to or subtracted from the section address. See the
1577 comments under @option{--change-addresses}, above. If
1578 @var{sectionpattern} does not match any sections in the input file, a
1579 warning will be issued, unless @option{--no-change-warnings} is used.
1581 @item --change-section-vma @var{sectionpattern}@{=,+,-@}@var{val}
1582 @cindex changing section VMA
1583 Set or change the VMA address of any section matching
1584 @var{sectionpattern}. The VMA address is the address where the
1585 section will be located once the program has started executing.
1586 Normally this is the same as the LMA address, which is the address
1587 where the section will be loaded into memory, but on some systems,
1588 especially those where a program is held in ROM, the two can be
1589 different. If @samp{=} is used, the section address is set to
1590 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1591 section address. See the comments under @option{--change-addresses},
1592 above. If @var{sectionpattern} does not match any sections in the
1593 input file, a warning will be issued, unless
1594 @option{--no-change-warnings} is used.
1596 @item --change-warnings
1597 @itemx --adjust-warnings
1598 If @option{--change-section-address} or @option{--change-section-lma} or
1599 @option{--change-section-vma} is used, and the section pattern does not
1600 match any sections, issue a warning. This is the default.
1602 @item --no-change-warnings
1603 @itemx --no-adjust-warnings
1604 Do not issue a warning if @option{--change-section-address} or
1605 @option{--adjust-section-lma} or @option{--adjust-section-vma} is used, even
1606 if the section pattern does not match any sections.
1608 @item --set-section-flags @var{sectionpattern}=@var{flags}
1609 Set the flags for any sections matching @var{sectionpattern}. The
1610 @var{flags} argument is a comma separated string of flag names. The
1611 recognized names are @samp{alloc}, @samp{contents}, @samp{load},
1612 @samp{noload}, @samp{readonly}, @samp{code}, @samp{data}, @samp{rom},
1613 @samp{share}, and @samp{debug}. You can set the @samp{contents} flag
1614 for a section which does not have contents, but it is not meaningful
1615 to clear the @samp{contents} flag of a section which does have
1616 contents--just remove the section instead. Not all flags are
1617 meaningful for all object file formats.
1619 @item --add-section @var{sectionname}=@var{filename}
1620 Add a new section named @var{sectionname} while copying the file. The
1621 contents of the new section are taken from the file @var{filename}. The
1622 size of the section will be the size of the file. This option only
1623 works on file formats which can support sections with arbitrary names.
1624 Note - it may be necessary to use the @option{--set-section-flags}
1625 option to set the attributes of the newly created section.
1627 @item --dump-section @var{sectionname}=@var{filename}
1628 Place the contents of section named @var{sectionname} into the file
1629 @var{filename}, overwriting any contents that may have been there
1630 previously. This option is the inverse of @option{--add-section}.
1631 This option is similar to the @option{--only-section} option except
1632 that it does not create a formatted file, it just dumps the contents
1633 as raw binary data, without applying any relocations. The option can
1634 be specified more than once.
1636 @item --update-section @var{sectionname}=@var{filename}
1637 Replace the existing contents of a section named @var{sectionname}
1638 with the contents of file @var{filename}. The size of the section
1639 will be adjusted to the size of the file. The section flags for
1640 @var{sectionname} will be unchanged. For ELF format files the section
1641 to segment mapping will also remain unchanged, something which is not
1642 possible using @option{--remove-section} followed by
1643 @option{--add-section}. The option can be specified more than once.
1645 Note - it is possible to use @option{--rename-section} and
1646 @option{--update-section} to both update and rename a section from one
1647 command line. In this case, pass the original section name to
1648 @option{--update-section}, and the original and new section names to
1649 @option{--rename-section}.
1651 @item --add-symbol @var{name}=[@var{section}:]@var{value}[,@var{flags}]
1652 Add a new symbol named @var{name} while copying the file. This option may be
1653 specified multiple times. If the @var{section} is given, the symbol will be
1654 associated with and relative to that section, otherwise it will be an ABS
1655 symbol. Specifying an undefined section will result in a fatal error. There
1656 is no check for the value, it will be taken as specified. Symbol flags can
1657 be specified and not all flags will be meaningful for all object file
1658 formats. By default, the symbol will be global. The special flag
1659 'before=@var{othersym}' will insert the new symbol in front of the specified
1660 @var{othersym}, otherwise the symbol(s) will be added at the end of the
1661 symbol table in the order they appear.
1663 @item --rename-section @var{oldname}=@var{newname}[,@var{flags}]
1664 Rename a section from @var{oldname} to @var{newname}, optionally
1665 changing the section's flags to @var{flags} in the process. This has
1666 the advantage over using a linker script to perform the rename in that
1667 the output stays as an object file and does not become a linked
1670 This option is particularly helpful when the input format is binary,
1671 since this will always create a section called .data. If for example,
1672 you wanted instead to create a section called .rodata containing binary
1673 data you could use the following command line to achieve it:
1676 objcopy -I binary -O <output_format> -B <architecture> \
1677 --rename-section .data=.rodata,alloc,load,readonly,data,contents \
1678 <input_binary_file> <output_object_file>
1681 @item --long-section-names @{enable,disable,keep@}
1682 Controls the handling of long section names when processing @code{COFF}
1683 and @code{PE-COFF} object formats. The default behaviour, @samp{keep},
1684 is to preserve long section names if any are present in the input file.
1685 The @samp{enable} and @samp{disable} options forcibly enable or disable
1686 the use of long section names in the output object; when @samp{disable}
1687 is in effect, any long section names in the input object will be truncated.
1688 The @samp{enable} option will only emit long section names if any are
1689 present in the inputs; this is mostly the same as @samp{keep}, but it
1690 is left undefined whether the @samp{enable} option might force the
1691 creation of an empty string table in the output file.
1693 @item --change-leading-char
1694 Some object file formats use special characters at the start of
1695 symbols. The most common such character is underscore, which compilers
1696 often add before every symbol. This option tells @command{objcopy} to
1697 change the leading character of every symbol when it converts between
1698 object file formats. If the object file formats use the same leading
1699 character, this option has no effect. Otherwise, it will add a
1700 character, or remove a character, or change a character, as
1703 @item --remove-leading-char
1704 If the first character of a global symbol is a special symbol leading
1705 character used by the object file format, remove the character. The
1706 most common symbol leading character is underscore. This option will
1707 remove a leading underscore from all global symbols. This can be useful
1708 if you want to link together objects of different file formats with
1709 different conventions for symbol names. This is different from
1710 @option{--change-leading-char} because it always changes the symbol name
1711 when appropriate, regardless of the object file format of the output
1714 @item --reverse-bytes=@var{num}
1715 Reverse the bytes in a section with output contents. A section length must
1716 be evenly divisible by the value given in order for the swap to be able to
1717 take place. Reversing takes place before the interleaving is performed.
1719 This option is used typically in generating ROM images for problematic
1720 target systems. For example, on some target boards, the 32-bit words
1721 fetched from 8-bit ROMs are re-assembled in little-endian byte order
1722 regardless of the CPU byte order. Depending on the programming model, the
1723 endianness of the ROM may need to be modified.
1725 Consider a simple file with a section containing the following eight
1726 bytes: @code{12345678}.
1728 Using @samp{--reverse-bytes=2} for the above example, the bytes in the
1729 output file would be ordered @code{21436587}.
1731 Using @samp{--reverse-bytes=4} for the above example, the bytes in the
1732 output file would be ordered @code{43218765}.
1734 By using @samp{--reverse-bytes=2} for the above example, followed by
1735 @samp{--reverse-bytes=4} on the output file, the bytes in the second
1736 output file would be ordered @code{34127856}.
1738 @item --srec-len=@var{ival}
1739 Meaningful only for srec output. Set the maximum length of the Srecords
1740 being produced to @var{ival}. This length covers both address, data and
1743 @item --srec-forceS3
1744 Meaningful only for srec output. Avoid generation of S1/S2 records,
1745 creating S3-only record format.
1747 @item --redefine-sym @var{old}=@var{new}
1748 Change the name of a symbol @var{old}, to @var{new}. This can be useful
1749 when one is trying link two things together for which you have no
1750 source, and there are name collisions.
1752 @item --redefine-syms=@var{filename}
1753 Apply @option{--redefine-sym} to each symbol pair "@var{old} @var{new}"
1754 listed in the file @var{filename}. @var{filename} is simply a flat file,
1755 with one symbol pair per line. Line comments may be introduced by the hash
1756 character. This option may be given more than once.
1759 Change all global symbols in the file to be weak. This can be useful
1760 when building an object which will be linked against other objects using
1761 the @option{-R} option to the linker. This option is only effective when
1762 using an object file format which supports weak symbols.
1764 @item --keep-symbols=@var{filename}
1765 Apply @option{--keep-symbol} option to each symbol listed in the file
1766 @var{filename}. @var{filename} is simply a flat file, with one symbol
1767 name per line. Line comments may be introduced by the hash character.
1768 This option may be given more than once.
1770 @item --strip-symbols=@var{filename}
1771 Apply @option{--strip-symbol} option to each symbol listed in the file
1772 @var{filename}. @var{filename} is simply a flat file, with one symbol
1773 name per line. Line comments may be introduced by the hash character.
1774 This option may be given more than once.
1776 @item --strip-unneeded-symbols=@var{filename}
1777 Apply @option{--strip-unneeded-symbol} option to each symbol listed in
1778 the file @var{filename}. @var{filename} is simply a flat file, with one
1779 symbol name per line. Line comments may be introduced by the hash
1780 character. This option may be given more than once.
1782 @item --keep-global-symbols=@var{filename}
1783 Apply @option{--keep-global-symbol} option to each symbol listed in the
1784 file @var{filename}. @var{filename} is simply a flat file, with one
1785 symbol name per line. Line comments may be introduced by the hash
1786 character. This option may be given more than once.
1788 @item --localize-symbols=@var{filename}
1789 Apply @option{--localize-symbol} option to each symbol listed in the file
1790 @var{filename}. @var{filename} is simply a flat file, with one symbol
1791 name per line. Line comments may be introduced by the hash character.
1792 This option may be given more than once.
1794 @item --globalize-symbols=@var{filename}
1795 Apply @option{--globalize-symbol} option to each symbol listed in the file
1796 @var{filename}. @var{filename} is simply a flat file, with one symbol
1797 name per line. Line comments may be introduced by the hash character.
1798 This option may be given more than once. Note: this option cannot be
1799 used in conjunction with the @option{-G} or @option{--keep-global-symbol}
1802 @item --weaken-symbols=@var{filename}
1803 Apply @option{--weaken-symbol} option to each symbol listed in the file
1804 @var{filename}. @var{filename} is simply a flat file, with one symbol
1805 name per line. Line comments may be introduced by the hash character.
1806 This option may be given more than once.
1808 @item --alt-machine-code=@var{index}
1809 If the output architecture has alternate machine codes, use the
1810 @var{index}th code instead of the default one. This is useful in case
1811 a machine is assigned an official code and the tool-chain adopts the
1812 new code, but other applications still depend on the original code
1813 being used. For ELF based architectures if the @var{index}
1814 alternative does not exist then the value is treated as an absolute
1815 number to be stored in the e_machine field of the ELF header.
1817 @item --writable-text
1818 Mark the output text as writable. This option isn't meaningful for all
1819 object file formats.
1821 @item --readonly-text
1822 Make the output text write protected. This option isn't meaningful for all
1823 object file formats.
1826 Mark the output file as demand paged. This option isn't meaningful for all
1827 object file formats.
1830 Mark the output file as impure. This option isn't meaningful for all
1831 object file formats.
1833 @item --prefix-symbols=@var{string}
1834 Prefix all symbols in the output file with @var{string}.
1836 @item --prefix-sections=@var{string}
1837 Prefix all section names in the output file with @var{string}.
1839 @item --prefix-alloc-sections=@var{string}
1840 Prefix all the names of all allocated sections in the output file with
1843 @item --add-gnu-debuglink=@var{path-to-file}
1844 Creates a .gnu_debuglink section which contains a reference to
1845 @var{path-to-file} and adds it to the output file. Note: the file at
1846 @var{path-to-file} must exist. Part of the process of adding the
1847 .gnu_debuglink section involves embedding a checksum of the contents
1848 of the debug info file into the section.
1850 If the debug info file is built in one location but it is going to be
1851 installed at a later time into a different location then do not use
1852 the path to the installed location. The @option{--add-gnu-debuglink}
1853 option will fail because the installed file does not exist yet.
1854 Instead put the debug info file in the current directory and use the
1855 @option{--add-gnu-debuglink} option without any directory components,
1859 objcopy --add-gnu-debuglink=foo.debug
1862 At debug time the debugger will attempt to look for the separate debug
1863 info file in a set of known locations. The exact set of these
1864 locations varies depending upon the distribution being used, but it
1869 @item * The same directory as the executable.
1871 @item * A sub-directory of the directory containing the executable
1874 @item * A global debug directory such as /usr/lib/debug.
1877 As long as the debug info file has been installed into one of these
1878 locations before the debugger is run everything should work
1881 @item --keep-file-symbols
1882 When stripping a file, perhaps with @option{--strip-debug} or
1883 @option{--strip-unneeded}, retain any symbols specifying source file names,
1884 which would otherwise get stripped.
1886 @item --only-keep-debug
1887 Strip a file, removing contents of any sections that would not be
1888 stripped by @option{--strip-debug} and leaving the debugging sections
1889 intact. In ELF files, this preserves all note sections in the output.
1891 Note - the section headers of the stripped sections are preserved,
1892 including their sizes, but the contents of the section are discarded.
1893 The section headers are preserved so that other tools can match up the
1894 debuginfo file with the real executable, even if that executable has
1895 been relocated to a different address space.
1897 The intention is that this option will be used in conjunction with
1898 @option{--add-gnu-debuglink} to create a two part executable. One a
1899 stripped binary which will occupy less space in RAM and in a
1900 distribution and the second a debugging information file which is only
1901 needed if debugging abilities are required. The suggested procedure
1902 to create these files is as follows:
1905 @item Link the executable as normal. Assuming that it is called
1907 @item Run @code{objcopy --only-keep-debug foo foo.dbg} to
1908 create a file containing the debugging info.
1909 @item Run @code{objcopy --strip-debug foo} to create a
1910 stripped executable.
1911 @item Run @code{objcopy --add-gnu-debuglink=foo.dbg foo}
1912 to add a link to the debugging info into the stripped executable.
1915 Note---the choice of @code{.dbg} as an extension for the debug info
1916 file is arbitrary. Also the @code{--only-keep-debug} step is
1917 optional. You could instead do this:
1920 @item Link the executable as normal.
1921 @item Copy @code{foo} to @code{foo.full}
1922 @item Run @code{objcopy --strip-debug foo}
1923 @item Run @code{objcopy --add-gnu-debuglink=foo.full foo}
1926 i.e., the file pointed to by the @option{--add-gnu-debuglink} can be the
1927 full executable. It does not have to be a file created by the
1928 @option{--only-keep-debug} switch.
1930 Note---this switch is only intended for use on fully linked files. It
1931 does not make sense to use it on object files where the debugging
1932 information may be incomplete. Besides the gnu_debuglink feature
1933 currently only supports the presence of one filename containing
1934 debugging information, not multiple filenames on a one-per-object-file
1938 Remove the contents of all DWARF .dwo sections, leaving the
1939 remaining debugging sections and all symbols intact.
1940 This option is intended for use by the compiler as part of
1941 the @option{-gsplit-dwarf} option, which splits debug information
1942 between the .o file and a separate .dwo file. The compiler
1943 generates all debug information in the same file, then uses
1944 the @option{--extract-dwo} option to copy the .dwo sections to
1945 the .dwo file, then the @option{--strip-dwo} option to remove
1946 those sections from the original .o file.
1949 Extract the contents of all DWARF .dwo sections. See the
1950 @option{--strip-dwo} option for more information.
1952 @item --file-alignment @var{num}
1953 Specify the file alignment. Sections in the file will always begin at
1954 file offsets which are multiples of this number. This defaults to
1956 [This option is specific to PE targets.]
1958 @item --heap @var{reserve}
1959 @itemx --heap @var{reserve},@var{commit}
1960 Specify the number of bytes of memory to reserve (and optionally commit)
1961 to be used as heap for this program.
1962 [This option is specific to PE targets.]
1964 @item --image-base @var{value}
1965 Use @var{value} as the base address of your program or dll. This is
1966 the lowest memory location that will be used when your program or dll
1967 is loaded. To reduce the need to relocate and improve performance of
1968 your dlls, each should have a unique base address and not overlap any
1969 other dlls. The default is 0x400000 for executables, and 0x10000000
1971 [This option is specific to PE targets.]
1973 @item --section-alignment @var{num}
1974 Sets the section alignment. Sections in memory will always begin at
1975 addresses which are a multiple of this number. Defaults to 0x1000.
1976 [This option is specific to PE targets.]
1978 @item --stack @var{reserve}
1979 @itemx --stack @var{reserve},@var{commit}
1980 Specify the number of bytes of memory to reserve (and optionally commit)
1981 to be used as stack for this program.
1982 [This option is specific to PE targets.]
1984 @item --subsystem @var{which}
1985 @itemx --subsystem @var{which}:@var{major}
1986 @itemx --subsystem @var{which}:@var{major}.@var{minor}
1987 Specifies the subsystem under which your program will execute. The
1988 legal values for @var{which} are @code{native}, @code{windows},
1989 @code{console}, @code{posix}, @code{efi-app}, @code{efi-bsd},
1990 @code{efi-rtd}, @code{sal-rtd}, and @code{xbox}. You may optionally set
1991 the subsystem version also. Numeric values are also accepted for
1993 [This option is specific to PE targets.]
1995 @item --extract-symbol
1996 Keep the file's section flags and symbols but remove all section data.
1997 Specifically, the option:
2000 @item removes the contents of all sections;
2001 @item sets the size of every section to zero; and
2002 @item sets the file's start address to zero.
2005 This option is used to build a @file{.sym} file for a VxWorks kernel.
2006 It can also be a useful way of reducing the size of a @option{--just-symbols}
2009 @item --compress-debug-sections
2010 Compress DWARF debug sections using zlib with SHF_COMPRESSED from the
2011 ELF ABI. Note - if compression would actually make a section
2012 @emph{larger}, then it is not compressed.
2014 @item --compress-debug-sections=none
2015 @itemx --compress-debug-sections=zlib
2016 @itemx --compress-debug-sections=zlib-gnu
2017 @itemx --compress-debug-sections=zlib-gabi
2018 For ELF files, these options control how DWARF debug sections are
2019 compressed. @option{--compress-debug-sections=none} is equivalent
2020 to @option{--decompress-debug-sections}.
2021 @option{--compress-debug-sections=zlib} and
2022 @option{--compress-debug-sections=zlib-gabi} are equivalent to
2023 @option{--compress-debug-sections}.
2024 @option{--compress-debug-sections=zlib-gnu} compresses DWARF debug
2025 sections using zlib. The debug sections are renamed to begin with
2026 @samp{.zdebug} instead of @samp{.debug}. Note - if compression would
2027 actually make a section @emph{larger}, then it is not compressed nor
2030 @item --decompress-debug-sections
2031 Decompress DWARF debug sections using zlib. The original section
2032 names of the compressed sections are restored.
2034 @item --elf-stt-common=yes
2035 @itemx --elf-stt-common=no
2036 For ELF files, these options control whether common symbols should be
2037 converted to the @code{STT_COMMON} or @code{STT_OBJECT} type.
2038 @option{--elf-stt-common=yes} converts common symbol type to
2039 @code{STT_COMMON}. @option{--elf-stt-common=no} converts common symbol
2040 type to @code{STT_OBJECT}.
2043 @itemx --no-merge-notes
2044 For ELF files, attempt (or do not attempt) to reduce the size of any
2045 SHT_NOTE type sections by removing duplicate notes.
2049 Show the version number of @command{objcopy}.
2053 Verbose output: list all object files modified. In the case of
2054 archives, @samp{objcopy -V} lists all members of the archive.
2057 Show a summary of the options to @command{objcopy}.
2060 Display a list showing all architectures and object formats available.
2066 @c man begin SEEALSO objcopy
2067 ld(1), objdump(1), and the Info entries for @file{binutils}.
2074 @cindex object file information
2077 @c man title objdump display information from object files.
2080 @c man begin SYNOPSIS objdump
2081 objdump [@option{-a}|@option{--archive-headers}]
2082 [@option{-b} @var{bfdname}|@option{--target=@var{bfdname}}]
2083 [@option{-C}|@option{--demangle}[=@var{style}] ]
2084 [@option{-d}|@option{--disassemble}[=@var{symbol}]]
2085 [@option{-D}|@option{--disassemble-all}]
2086 [@option{-z}|@option{--disassemble-zeroes}]
2087 [@option{-EB}|@option{-EL}|@option{--endian=}@{big | little @}]
2088 [@option{-f}|@option{--file-headers}]
2089 [@option{-F}|@option{--file-offsets}]
2090 [@option{--file-start-context}]
2091 [@option{-g}|@option{--debugging}]
2092 [@option{-e}|@option{--debugging-tags}]
2093 [@option{-h}|@option{--section-headers}|@option{--headers}]
2094 [@option{-i}|@option{--info}]
2095 [@option{-j} @var{section}|@option{--section=}@var{section}]
2096 [@option{-l}|@option{--line-numbers}]
2097 [@option{-S}|@option{--source}]
2098 [@option{-m} @var{machine}|@option{--architecture=}@var{machine}]
2099 [@option{-M} @var{options}|@option{--disassembler-options=}@var{options}]
2100 [@option{-p}|@option{--private-headers}]
2101 [@option{-P} @var{options}|@option{--private=}@var{options}]
2102 [@option{-r}|@option{--reloc}]
2103 [@option{-R}|@option{--dynamic-reloc}]
2104 [@option{-s}|@option{--full-contents}]
2105 [@option{-W[lLiaprmfFsoRtUuTgAckK]}|
2106 @option{--dwarf}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]]
2107 [@option{-G}|@option{--stabs}]
2108 [@option{-t}|@option{--syms}]
2109 [@option{-T}|@option{--dynamic-syms}]
2110 [@option{-x}|@option{--all-headers}]
2111 [@option{-w}|@option{--wide}]
2112 [@option{--start-address=}@var{address}]
2113 [@option{--stop-address=}@var{address}]
2114 [@option{--prefix-addresses}]
2115 [@option{--[no-]show-raw-insn}]
2116 [@option{--adjust-vma=}@var{offset}]
2117 [@option{--dwarf-depth=@var{n}}]
2118 [@option{--dwarf-start=@var{n}}]
2119 [@option{--no-recurse-limit}|@option{--recurse-limit}]
2120 [@option{--special-syms}]
2121 [@option{--prefix=}@var{prefix}]
2122 [@option{--prefix-strip=}@var{level}]
2123 [@option{--insn-width=}@var{width}]
2124 [@option{-V}|@option{--version}]
2125 [@option{-H}|@option{--help}]
2126 @var{objfile}@dots{}
2130 @c man begin DESCRIPTION objdump
2132 @command{objdump} displays information about one or more object files.
2133 The options control what particular information to display. This
2134 information is mostly useful to programmers who are working on the
2135 compilation tools, as opposed to programmers who just want their
2136 program to compile and work.
2138 @var{objfile}@dots{} are the object files to be examined. When you
2139 specify archives, @command{objdump} shows information on each of the member
2144 @c man begin OPTIONS objdump
2146 The long and short forms of options, shown here as alternatives, are
2147 equivalent. At least one option from the list
2148 @option{-a,-d,-D,-e,-f,-g,-G,-h,-H,-p,-P,-r,-R,-s,-S,-t,-T,-V,-x} must be given.
2152 @itemx --archive-header
2153 @cindex archive headers
2154 If any of the @var{objfile} files are archives, display the archive
2155 header information (in a format similar to @samp{ls -l}). Besides the
2156 information you could list with @samp{ar tv}, @samp{objdump -a} shows
2157 the object file format of each archive member.
2159 @item --adjust-vma=@var{offset}
2160 @cindex section addresses in objdump
2161 @cindex VMA in objdump
2162 When dumping information, first add @var{offset} to all the section
2163 addresses. This is useful if the section addresses do not correspond to
2164 the symbol table, which can happen when putting sections at particular
2165 addresses when using a format which can not represent section addresses,
2168 @item -b @var{bfdname}
2169 @itemx --target=@var{bfdname}
2170 @cindex object code format
2171 Specify that the object-code format for the object files is
2172 @var{bfdname}. This option may not be necessary; @var{objdump} can
2173 automatically recognize many formats.
2177 objdump -b oasys -m vax -h fu.o
2180 displays summary information from the section headers (@option{-h}) of
2181 @file{fu.o}, which is explicitly identified (@option{-m}) as a VAX object
2182 file in the format produced by Oasys compilers. You can list the
2183 formats available with the @option{-i} option.
2184 @xref{Target Selection}, for more information.
2187 @itemx --demangle[=@var{style}]
2188 @cindex demangling in objdump
2189 Decode (@dfn{demangle}) low-level symbol names into user-level names.
2190 Besides removing any initial underscore prepended by the system, this
2191 makes C++ function names readable. Different compilers have different
2192 mangling styles. The optional demangling style argument can be used to
2193 choose an appropriate demangling style for your compiler. @xref{c++filt},
2194 for more information on demangling.
2196 @item --recurse-limit
2197 @itemx --no-recurse-limit
2198 @itemx --recursion-limit
2199 @itemx --no-recursion-limit
2200 Enables or disables a limit on the amount of recursion performed
2201 whilst demangling strings. Since the name mangling formats allow for
2202 an inifinite level of recursion it is possible to create strings whose
2203 decoding will exhaust the amount of stack space available on the host
2204 machine, triggering a memory fault. The limit tries to prevent this
2205 from happening by restricting recursion to 2048 levels of nesting.
2207 The default is for this limit to be enabled, but disabling it may be
2208 necessary in order to demangle truly complicated names. Note however
2209 that if the recursion limit is disabled then stack exhaustion is
2210 possible and any bug reports about such an event will be rejected.
2214 Display debugging information. This attempts to parse STABS
2215 debugging format information stored in the file and print it out using
2216 a C like syntax. If no STABS debuging was found this option
2217 falls back on the @option{-W} option to print any DWARF information in
2221 @itemx --debugging-tags
2222 Like @option{-g}, but the information is generated in a format compatible
2226 @itemx --disassemble
2227 @itemx --disassemble=@var{symbol}
2228 @cindex disassembling object code
2229 @cindex machine instructions
2230 Display the assembler mnemonics for the machine instructions from the
2231 input file. This option only disassembles those sections which are
2232 expected to contain instructions. If the optional @var{symbol}
2233 argument is given, then display the assembler mnemonics starting at
2234 @var{symbol}. If @var{symbol} is a function name then disassembly
2235 will stop at the end of the function, otherwise it will stop when the
2236 next symbol is encountered. If there are no matches for @var{symbol}
2237 then nothing will be displayed.
2239 Note if the @option{--dwarf=follow-links} option has also been enabled
2240 then any symbol tables in linked debug info files will be read in and
2241 used when disassembling.
2244 @itemx --disassemble-all
2245 Like @option{-d}, but disassemble the contents of all sections, not just
2246 those expected to contain instructions.
2248 This option also has a subtle effect on the disassembly of
2249 instructions in code sections. When option @option{-d} is in effect
2250 objdump will assume that any symbols present in a code section occur
2251 on the boundary between instructions and it will refuse to disassemble
2252 across such a boundary. When option @option{-D} is in effect however
2253 this assumption is supressed. This means that it is possible for the
2254 output of @option{-d} and @option{-D} to differ if, for example, data
2255 is stored in code sections.
2257 If the target is an ARM architecture this switch also has the effect
2258 of forcing the disassembler to decode pieces of data found in code
2259 sections as if they were instructions.
2261 Note if the @option{--dwarf=follow-links} option has also been enabled
2262 then any symbol tables in linked debug info files will be read in and
2263 used when disassembling.
2265 @item --prefix-addresses
2266 When disassembling, print the complete address on each line. This is
2267 the older disassembly format.
2271 @itemx --endian=@{big|little@}
2273 @cindex disassembly endianness
2274 Specify the endianness of the object files. This only affects
2275 disassembly. This can be useful when disassembling a file format which
2276 does not describe endianness information, such as S-records.
2279 @itemx --file-headers
2280 @cindex object file header
2281 Display summary information from the overall header of
2282 each of the @var{objfile} files.
2285 @itemx --file-offsets
2286 @cindex object file offsets
2287 When disassembling sections, whenever a symbol is displayed, also
2288 display the file offset of the region of data that is about to be
2289 dumped. If zeroes are being skipped, then when disassembly resumes,
2290 tell the user how many zeroes were skipped and the file offset of the
2291 location from where the disassembly resumes. When dumping sections,
2292 display the file offset of the location from where the dump starts.
2294 @item --file-start-context
2295 @cindex source code context
2296 Specify that when displaying interlisted source code/disassembly
2297 (assumes @option{-S}) from a file that has not yet been displayed, extend the
2298 context to the start of the file.
2301 @itemx --section-headers
2303 @cindex section headers
2304 Display summary information from the section headers of the
2307 File segments may be relocated to nonstandard addresses, for example by
2308 using the @option{-Ttext}, @option{-Tdata}, or @option{-Tbss} options to
2309 @command{ld}. However, some object file formats, such as a.out, do not
2310 store the starting address of the file segments. In those situations,
2311 although @command{ld} relocates the sections correctly, using @samp{objdump
2312 -h} to list the file section headers cannot show the correct addresses.
2313 Instead, it shows the usual addresses, which are implicit for the
2316 Note, in some cases it is possible for a section to have both the
2317 READONLY and the NOREAD attributes set. In such cases the NOREAD
2318 attribute takes precedence, but @command{objdump} will report both
2319 since the exact setting of the flag bits might be important.
2323 Print a summary of the options to @command{objdump} and exit.
2327 @cindex architectures available
2328 @cindex object formats available
2329 Display a list showing all architectures and object formats available
2330 for specification with @option{-b} or @option{-m}.
2333 @itemx --section=@var{name}
2334 @cindex section information
2335 Display information only for section @var{name}.
2338 @itemx --line-numbers
2339 @cindex source filenames for object files
2340 Label the display (using debugging information) with the filename and
2341 source line numbers corresponding to the object code or relocs shown.
2342 Only useful with @option{-d}, @option{-D}, or @option{-r}.
2344 @item -m @var{machine}
2345 @itemx --architecture=@var{machine}
2346 @cindex architecture
2347 @cindex disassembly architecture
2348 Specify the architecture to use when disassembling object files. This
2349 can be useful when disassembling object files which do not describe
2350 architecture information, such as S-records. You can list the available
2351 architectures with the @option{-i} option.
2353 If the target is an ARM architecture then this switch has an
2354 additional effect. It restricts the disassembly to only those
2355 instructions supported by the architecture specified by @var{machine}.
2356 If it is necessary to use this switch because the input file does not
2357 contain any architecture information, but it is also desired to
2358 disassemble all the instructions use @option{-marm}.
2360 @item -M @var{options}
2361 @itemx --disassembler-options=@var{options}
2362 Pass target specific information to the disassembler. Only supported on
2363 some targets. If it is necessary to specify more than one
2364 disassembler option then multiple @option{-M} options can be used or
2365 can be placed together into a comma separated list.
2367 For ARC, @option{dsp} controls the printing of DSP instructions,
2368 @option{spfp} selects the printing of FPX single precision FP
2369 instructions, @option{dpfp} selects the printing of FPX double
2370 precision FP instructions, @option{quarkse_em} selects the printing of
2371 special QuarkSE-EM instructions, @option{fpuda} selects the printing
2372 of double precision assist instructions, @option{fpus} selects the
2373 printing of FPU single precision FP instructions, while @option{fpud}
2374 selects the printing of FPU double precision FP instructions.
2375 Additionally, one can choose to have all the immediates printed in
2376 hexadecimal using @option{hex}. By default, the short immediates are
2377 printed using the decimal representation, while the long immediate
2378 values are printed as hexadecimal.
2380 @option{cpu=...} allows to enforce a particular ISA when disassembling
2381 instructions, overriding the @option{-m} value or whatever is in the ELF file.
2382 This might be useful to select ARC EM or HS ISA, because architecture is same
2383 for those and disassembler relies on private ELF header data to decide if code
2384 is for EM or HS. This option might be specified multiple times - only the
2385 latest value will be used. Valid values are same as for the assembler
2386 @option{-mcpu=...} option.
2388 If the target is an ARM architecture then this switch can be used to
2389 select which register name set is used during disassembler. Specifying
2390 @option{-M reg-names-std} (the default) will select the register names as
2391 used in ARM's instruction set documentation, but with register 13 called
2392 'sp', register 14 called 'lr' and register 15 called 'pc'. Specifying
2393 @option{-M reg-names-apcs} will select the name set used by the ARM
2394 Procedure Call Standard, whilst specifying @option{-M reg-names-raw} will
2395 just use @samp{r} followed by the register number.
2397 There are also two variants on the APCS register naming scheme enabled
2398 by @option{-M reg-names-atpcs} and @option{-M reg-names-special-atpcs} which
2399 use the ARM/Thumb Procedure Call Standard naming conventions. (Either
2400 with the normal register names or the special register names).
2402 This option can also be used for ARM architectures to force the
2403 disassembler to interpret all instructions as Thumb instructions by
2404 using the switch @option{--disassembler-options=force-thumb}. This can be
2405 useful when attempting to disassemble thumb code produced by other
2408 For AArch64 targets this switch can be used to set whether instructions are
2409 disassembled as the most general instruction using the @option{-M no-aliases}
2410 option or whether instruction notes should be generated as comments in the
2411 disasssembly using @option{-M notes}.
2413 For the x86, some of the options duplicate functions of the @option{-m}
2414 switch, but allow finer grained control. Multiple selections from the
2415 following may be specified as a comma separated string.
2420 Select disassembly for the given architecture.
2424 Select between intel syntax mode and AT&T syntax mode.
2428 Select between AMD64 ISA and Intel64 ISA.
2430 @item intel-mnemonic
2432 Select between intel mnemonic mode and AT&T mnemonic mode.
2433 Note: @code{intel-mnemonic} implies @code{intel} and
2434 @code{att-mnemonic} implies @code{att}.
2441 Specify the default address size and operand size. These four options
2442 will be overridden if @code{x86-64}, @code{i386} or @code{i8086}
2443 appear later in the option string.
2446 When in AT&T mode, instructs the disassembler to print a mnemonic
2447 suffix even when the suffix could be inferred by the operands.
2450 For PowerPC, the @option{-M} argument @option{raw} selects
2451 disasssembly of hardware insns rather than aliases. For example, you
2452 will see @code{rlwinm} rather than @code{clrlwi}, and @code{addi}
2453 rather than @code{li}. All of the @option{-m} arguments for
2454 @command{gas} that select a CPU are supported. These are:
2455 @option{403}, @option{405}, @option{440}, @option{464}, @option{476},
2456 @option{601}, @option{603}, @option{604}, @option{620}, @option{7400},
2457 @option{7410}, @option{7450}, @option{7455}, @option{750cl},
2458 @option{821}, @option{850}, @option{860}, @option{a2}, @option{booke},
2459 @option{booke32}, @option{cell}, @option{com}, @option{e200z4},
2460 @option{e300}, @option{e500}, @option{e500mc}, @option{e500mc64},
2461 @option{e500x2}, @option{e5500}, @option{e6500}, @option{efs},
2462 @option{power4}, @option{power5}, @option{power6}, @option{power7},
2463 @option{power8}, @option{power9}, @option{ppc}, @option{ppc32},
2464 @option{ppc64}, @option{ppc64bridge}, @option{ppcps}, @option{pwr},
2465 @option{pwr2}, @option{pwr4}, @option{pwr5}, @option{pwr5x},
2466 @option{pwr6}, @option{pwr7}, @option{pwr8}, @option{pwr9},
2467 @option{pwrx}, @option{titan}, and @option{vle}.
2468 @option{32} and @option{64} modify the default or a prior CPU
2469 selection, disabling and enabling 64-bit insns respectively. In
2470 addition, @option{altivec}, @option{any}, @option{htm}, @option{vsx},
2471 and @option{spe} add capabilities to a previous @emph{or later} CPU
2472 selection. @option{any} will disassemble any opcode known to
2473 binutils, but in cases where an opcode has two different meanings or
2474 different arguments, you may not see the disassembly you expect.
2475 If you disassemble without giving a CPU selection, a default will be
2476 chosen from information gleaned by BFD from the object files headers,
2477 but the result again may not be as you expect.
2479 For MIPS, this option controls the printing of instruction mnemonic
2480 names and register names in disassembled instructions. Multiple
2481 selections from the following may be specified as a comma separated
2482 string, and invalid options are ignored:
2486 Print the 'raw' instruction mnemonic instead of some pseudo
2487 instruction mnemonic. I.e., print 'daddu' or 'or' instead of 'move',
2488 'sll' instead of 'nop', etc.
2491 Disassemble MSA instructions.
2494 Disassemble the virtualization ASE instructions.
2497 Disassemble the eXtended Physical Address (XPA) ASE instructions.
2499 @item gpr-names=@var{ABI}
2500 Print GPR (general-purpose register) names as appropriate
2501 for the specified ABI. By default, GPR names are selected according to
2502 the ABI of the binary being disassembled.
2504 @item fpr-names=@var{ABI}
2505 Print FPR (floating-point register) names as
2506 appropriate for the specified ABI. By default, FPR numbers are printed
2509 @item cp0-names=@var{ARCH}
2510 Print CP0 (system control coprocessor; coprocessor 0) register names
2511 as appropriate for the CPU or architecture specified by
2512 @var{ARCH}. By default, CP0 register names are selected according to
2513 the architecture and CPU of the binary being disassembled.
2515 @item hwr-names=@var{ARCH}
2516 Print HWR (hardware register, used by the @code{rdhwr} instruction) names
2517 as appropriate for the CPU or architecture specified by
2518 @var{ARCH}. By default, HWR names are selected according to
2519 the architecture and CPU of the binary being disassembled.
2521 @item reg-names=@var{ABI}
2522 Print GPR and FPR names as appropriate for the selected ABI.
2524 @item reg-names=@var{ARCH}
2525 Print CPU-specific register names (CP0 register and HWR names)
2526 as appropriate for the selected CPU or architecture.
2529 For any of the options listed above, @var{ABI} or
2530 @var{ARCH} may be specified as @samp{numeric} to have numbers printed
2531 rather than names, for the selected types of registers.
2532 You can list the available values of @var{ABI} and @var{ARCH} using
2533 the @option{--help} option.
2535 For VAX, you can specify function entry addresses with @option{-M
2536 entry:0xf00ba}. You can use this multiple times to properly
2537 disassemble VAX binary files that don't contain symbol tables (like
2538 ROM dumps). In these cases, the function entry mask would otherwise
2539 be decoded as VAX instructions, which would probably lead the rest
2540 of the function being wrongly disassembled.
2543 @itemx --private-headers
2544 Print information that is specific to the object file format. The exact
2545 information printed depends upon the object file format. For some
2546 object file formats, no additional information is printed.
2548 @item -P @var{options}
2549 @itemx --private=@var{options}
2550 Print information that is specific to the object file format. The
2551 argument @var{options} is a comma separated list that depends on the
2552 format (the lists of options is displayed with the help).
2554 For XCOFF, the available options are:
2570 Not all object formats support this option. In particular the ELF
2571 format does not use it.
2575 @cindex relocation entries, in object file
2576 Print the relocation entries of the file. If used with @option{-d} or
2577 @option{-D}, the relocations are printed interspersed with the
2581 @itemx --dynamic-reloc
2582 @cindex dynamic relocation entries, in object file
2583 Print the dynamic relocation entries of the file. This is only
2584 meaningful for dynamic objects, such as certain types of shared
2585 libraries. As for @option{-r}, if used with @option{-d} or
2586 @option{-D}, the relocations are printed interspersed with the
2590 @itemx --full-contents
2591 @cindex sections, full contents
2592 @cindex object file sections
2593 Display the full contents of any sections requested. By default all
2594 non-empty sections are displayed.
2598 @cindex source disassembly
2599 @cindex disassembly, with source
2600 Display source code intermixed with disassembly, if possible. Implies
2603 @item --prefix=@var{prefix}
2604 @cindex Add prefix to absolute paths
2605 Specify @var{prefix} to add to the absolute paths when used with
2608 @item --prefix-strip=@var{level}
2609 @cindex Strip absolute paths
2610 Indicate how many initial directory names to strip off the hardwired
2611 absolute paths. It has no effect without @option{--prefix=}@var{prefix}.
2613 @item --show-raw-insn
2614 When disassembling instructions, print the instruction in hex as well as
2615 in symbolic form. This is the default except when
2616 @option{--prefix-addresses} is used.
2618 @item --no-show-raw-insn
2619 When disassembling instructions, do not print the instruction bytes.
2620 This is the default when @option{--prefix-addresses} is used.
2622 @item --insn-width=@var{width}
2623 @cindex Instruction width
2624 Display @var{width} bytes on a single line when disassembling
2627 @item -W[lLiaprmfFsoRtUuTgAckK]
2628 @itemx --dwarf[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]
2629 @include debug.options.texi
2632 Enable additional checks for consistency of Dwarf information.
2638 @cindex debug symbols
2639 @cindex ELF object file format
2640 Display the full contents of any sections requested. Display the
2641 contents of the .stab and .stab.index and .stab.excl sections from an
2642 ELF file. This is only useful on systems (such as Solaris 2.0) in which
2643 @code{.stab} debugging symbol-table entries are carried in an ELF
2644 section. In most other file formats, debugging symbol-table entries are
2645 interleaved with linkage symbols, and are visible in the @option{--syms}
2648 @item --start-address=@var{address}
2649 @cindex start-address
2650 Start displaying data at the specified address. This affects the output
2651 of the @option{-d}, @option{-r} and @option{-s} options.
2653 @item --stop-address=@var{address}
2654 @cindex stop-address
2655 Stop displaying data at the specified address. This affects the output
2656 of the @option{-d}, @option{-r} and @option{-s} options.
2660 @cindex symbol table entries, printing
2661 Print the symbol table entries of the file.
2662 This is similar to the information provided by the @samp{nm} program,
2663 although the display format is different. The format of the output
2664 depends upon the format of the file being dumped, but there are two main
2665 types. One looks like this:
2668 [ 4](sec 3)(fl 0x00)(ty 0)(scl 3) (nx 1) 0x00000000 .bss
2669 [ 6](sec 1)(fl 0x00)(ty 0)(scl 2) (nx 0) 0x00000000 fred
2672 where the number inside the square brackets is the number of the entry
2673 in the symbol table, the @var{sec} number is the section number, the
2674 @var{fl} value are the symbol's flag bits, the @var{ty} number is the
2675 symbol's type, the @var{scl} number is the symbol's storage class and
2676 the @var{nx} value is the number of auxilary entries associated with
2677 the symbol. The last two fields are the symbol's value and its name.
2679 The other common output format, usually seen with ELF based files,
2683 00000000 l d .bss 00000000 .bss
2684 00000000 g .text 00000000 fred
2687 Here the first number is the symbol's value (sometimes refered to as
2688 its address). The next field is actually a set of characters and
2689 spaces indicating the flag bits that are set on the symbol. These
2690 characters are described below. Next is the section with which the
2691 symbol is associated or @emph{*ABS*} if the section is absolute (ie
2692 not connected with any section), or @emph{*UND*} if the section is
2693 referenced in the file being dumped, but not defined there.
2695 After the section name comes another field, a number, which for common
2696 symbols is the alignment and for other symbol is the size. Finally
2697 the symbol's name is displayed.
2699 The flag characters are divided into 7 groups as follows:
2705 The symbol is a local (l), global (g), unique global (u), neither
2706 global nor local (a space) or both global and local (!). A
2707 symbol can be neither local or global for a variety of reasons, e.g.,
2708 because it is used for debugging, but it is probably an indication of
2709 a bug if it is ever both local and global. Unique global symbols are
2710 a GNU extension to the standard set of ELF symbol bindings. For such
2711 a symbol the dynamic linker will make sure that in the entire process
2712 there is just one symbol with this name and type in use.
2715 The symbol is weak (w) or strong (a space).
2718 The symbol denotes a constructor (C) or an ordinary symbol (a space).
2721 The symbol is a warning (W) or a normal symbol (a space). A warning
2722 symbol's name is a message to be displayed if the symbol following the
2723 warning symbol is ever referenced.
2727 The symbol is an indirect reference to another symbol (I), a function
2728 to be evaluated during reloc processing (i) or a normal symbol (a
2733 The symbol is a debugging symbol (d) or a dynamic symbol (D) or a
2734 normal symbol (a space).
2739 The symbol is the name of a function (F) or a file (f) or an object
2740 (O) or just a normal symbol (a space).
2744 @itemx --dynamic-syms
2745 @cindex dynamic symbol table entries, printing
2746 Print the dynamic symbol table entries of the file. This is only
2747 meaningful for dynamic objects, such as certain types of shared
2748 libraries. This is similar to the information provided by the @samp{nm}
2749 program when given the @option{-D} (@option{--dynamic}) option.
2751 The output format is similar to that produced by the @option{--syms}
2752 option, except that an extra field is inserted before the symbol's
2753 name, giving the version information associated with the symbol.
2754 If the version is the default version to be used when resolving
2755 unversioned references to the symbol then it's displayed as is,
2756 otherwise it's put into parentheses.
2758 @item --special-syms
2759 When displaying symbols include those which the target considers to be
2760 special in some way and which would not normally be of interest to the
2765 Print the version number of @command{objdump} and exit.
2768 @itemx --all-headers
2769 @cindex all header information, object file
2770 @cindex header information, all
2771 Display all available header information, including the symbol table and
2772 relocation entries. Using @option{-x} is equivalent to specifying all of
2773 @option{-a -f -h -p -r -t}.
2777 @cindex wide output, printing
2778 Format some lines for output devices that have more than 80 columns.
2779 Also do not truncate symbol names when they are displayed.
2782 @itemx --disassemble-zeroes
2783 Normally the disassembly output will skip blocks of zeroes. This
2784 option directs the disassembler to disassemble those blocks, just like
2791 @c man begin SEEALSO objdump
2792 nm(1), readelf(1), and the Info entries for @file{binutils}.
2800 @cindex archive contents
2801 @cindex symbol index
2803 @c man title ranlib generate index to archive.
2806 @c man begin SYNOPSIS ranlib
2807 ranlib [@option{--plugin} @var{name}] [@option{-DhHvVt}] @var{archive}
2811 @c man begin DESCRIPTION ranlib
2813 @command{ranlib} generates an index to the contents of an archive and
2814 stores it in the archive. The index lists each symbol defined by a
2815 member of an archive that is a relocatable object file.
2817 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
2819 An archive with such an index speeds up linking to the library and
2820 allows routines in the library to call each other without regard to
2821 their placement in the archive.
2823 The @sc{gnu} @command{ranlib} program is another form of @sc{gnu} @command{ar}; running
2824 @command{ranlib} is completely equivalent to executing @samp{ar -s}.
2829 @c man begin OPTIONS ranlib
2835 Show usage information for @command{ranlib}.
2840 Show the version number of @command{ranlib}.
2843 @cindex deterministic archives
2844 @kindex --enable-deterministic-archives
2845 Operate in @emph{deterministic} mode. The symbol map archive member's
2846 header will show zero for the UID, GID, and timestamp. When this
2847 option is used, multiple runs will produce identical output files.
2849 If @file{binutils} was configured with
2850 @option{--enable-deterministic-archives}, then this mode is on by
2851 default. It can be disabled with the @samp{-U} option, described
2855 Update the timestamp of the symbol map of an archive.
2858 @cindex deterministic archives
2859 @kindex --enable-deterministic-archives
2860 Do @emph{not} operate in @emph{deterministic} mode. This is the
2861 inverse of the @samp{-D} option, above: the archive index will get
2862 actual UID, GID, timestamp, and file mode values.
2864 If @file{binutils} was configured @emph{without}
2865 @option{--enable-deterministic-archives}, then this mode is on by
2873 @c man begin SEEALSO ranlib
2874 ar(1), nm(1), and the Info entries for @file{binutils}.
2882 @cindex section sizes
2884 @c man title size list section sizes and total size.
2887 @c man begin SYNOPSIS size
2888 size [@option{-A}|@option{-B}|@option{-G}|@option{--format=}@var{compatibility}]
2890 [@option{-d}|@option{-o}|@option{-x}|@option{--radix=}@var{number}]
2892 [@option{-t}|@option{--totals}]
2893 [@option{--target=}@var{bfdname}] [@option{-V}|@option{--version}]
2894 [@var{objfile}@dots{}]
2898 @c man begin DESCRIPTION size
2900 The @sc{gnu} @command{size} utility lists the section sizes---and the total
2901 size---for each of the object or archive files @var{objfile} in its
2902 argument list. By default, one line of output is generated for each
2903 object file or each module in an archive.
2905 @var{objfile}@dots{} are the object files to be examined.
2906 If none are specified, the file @code{a.out} will be used.
2910 @c man begin OPTIONS size
2912 The command-line options have the following meanings:
2918 @itemx --format=@var{compatibility}
2919 @cindex @command{size} display format
2920 Using one of these options, you can choose whether the output from @sc{gnu}
2921 @command{size} resembles output from System V @command{size} (using @option{-A},
2922 or @option{--format=sysv}), or Berkeley @command{size} (using @option{-B}, or
2923 @option{--format=berkeley}). The default is the one-line format similar to
2924 Berkeley's. Alternatively, you can choose the GNU format output
2925 (using @option{-G}, or @option{--format=gnu}), this is similar to
2926 Berkeley's output format, but sizes are counted differently.
2927 @c Bonus for doc-source readers: you can also say --format=strange (or
2928 @c anything else that starts with 's') for sysv, and --format=boring (or
2929 @c anything else that starts with 'b') for Berkeley.
2931 Here is an example of the Berkeley (default) format of output from
2934 $ size --format=Berkeley ranlib size
2935 text data bss dec hex filename
2936 294880 81920 11592 388392 5ed28 ranlib
2937 294880 81920 11888 388688 5ee50 size
2940 The Berkeley style output counts read only data in the @code{text}
2941 column, not in the @code{data} column, the @code{dec} and @code{hex}
2942 columns both display the sum of the @code{text}, @code{data}, and
2943 @code{bss} columns in decimal and hexadecimal respectively.
2945 The GNU format counts read only data in the @code{data} column, not
2946 the @code{text} column, and only displays the sum of the @code{text},
2947 @code{data}, and @code{bss} columns once, in the @code{total} column.
2948 The @option{--radix} option can be used to change the number base for
2949 all columns. Here is the same data displayed with GNU conventions:
2952 $ size --format=GNU ranlib size
2953 text data bss total filename
2954 279880 96920 11592 388392 ranlib
2955 279880 96920 11888 388688 size
2959 This is the same data, but displayed closer to System V conventions:
2962 $ size --format=SysV ranlib size
2980 Show a summary of acceptable arguments and options.
2985 @itemx --radix=@var{number}
2986 @cindex @command{size} number format
2987 @cindex radix for section sizes
2988 Using one of these options, you can control whether the size of each
2989 section is given in decimal (@option{-d}, or @option{--radix=10}); octal
2990 (@option{-o}, or @option{--radix=8}); or hexadecimal (@option{-x}, or
2991 @option{--radix=16}). In @option{--radix=@var{number}}, only the three
2992 values (8, 10, 16) are supported. The total size is always given in two
2993 radices; decimal and hexadecimal for @option{-d} or @option{-x} output, or
2994 octal and hexadecimal if you're using @option{-o}.
2997 Print total size of common symbols in each file. When using Berkeley
2998 or GNU format these are included in the bss size.
3002 Show totals of all objects listed (Berkeley or GNU format mode only).
3004 @item --target=@var{bfdname}
3005 @cindex object code format
3006 Specify that the object-code format for @var{objfile} is
3007 @var{bfdname}. This option may not be necessary; @command{size} can
3008 automatically recognize many formats.
3009 @xref{Target Selection}, for more information.
3013 Display the version number of @command{size}.
3019 @c man begin SEEALSO size
3020 ar(1), objdump(1), readelf(1), and the Info entries for @file{binutils}.
3027 @cindex listings strings
3028 @cindex printing strings
3029 @cindex strings, printing
3031 @c man title strings print the strings of printable characters in files.
3034 @c man begin SYNOPSIS strings
3035 strings [@option{-afovV}] [@option{-}@var{min-len}]
3036 [@option{-n} @var{min-len}] [@option{--bytes=}@var{min-len}]
3037 [@option{-t} @var{radix}] [@option{--radix=}@var{radix}]
3038 [@option{-e} @var{encoding}] [@option{--encoding=}@var{encoding}]
3039 [@option{-}] [@option{--all}] [@option{--print-file-name}]
3040 [@option{-T} @var{bfdname}] [@option{--target=}@var{bfdname}]
3041 [@option{-w}] [@option{--include-all-whitespace}]
3042 [@option{-s}] [@option{--output-separator}@var{sep_string}]
3043 [@option{--help}] [@option{--version}] @var{file}@dots{}
3047 @c man begin DESCRIPTION strings
3049 For each @var{file} given, @sc{gnu} @command{strings} prints the
3050 printable character sequences that are at least 4 characters long (or
3051 the number given with the options below) and are followed by an
3052 unprintable character.
3054 Depending upon how the strings program was configured it will default
3055 to either displaying all the printable sequences that it can find in
3056 each file, or only those sequences that are in loadable, initialized
3057 data sections. If the file type in unrecognizable, or if strings is
3058 reading from stdin then it will always display all of the printable
3059 sequences that it can find.
3061 For backwards compatibility any file that occurs after a command-line
3062 option of just @option{-} will also be scanned in full, regardless of
3063 the presence of any @option{-d} option.
3065 @command{strings} is mainly useful for determining the contents of
3070 @c man begin OPTIONS strings
3076 Scan the whole file, regardless of what sections it contains or
3077 whether those sections are loaded or initialized. Normally this is
3078 the default behaviour, but strings can be configured so that the
3079 @option{-d} is the default instead.
3081 The @option{-} option is position dependent and forces strings to
3082 perform full scans of any file that is mentioned after the @option{-}
3083 on the command line, even if the @option{-d} option has been
3088 Only print strings from initialized, loaded data sections in the
3089 file. This may reduce the amount of garbage in the output, but it
3090 also exposes the strings program to any security flaws that may be
3091 present in the BFD library used to scan and load sections. Strings
3092 can be configured so that this option is the default behaviour. In
3093 such cases the @option{-a} option can be used to avoid using the BFD
3094 library and instead just print all of the strings found in the file.
3097 @itemx --print-file-name
3098 Print the name of the file before each string.
3101 Print a summary of the program usage on the standard output and exit.
3103 @item -@var{min-len}
3104 @itemx -n @var{min-len}
3105 @itemx --bytes=@var{min-len}
3106 Print sequences of characters that are at least @var{min-len} characters
3107 long, instead of the default 4.
3110 Like @samp{-t o}. Some other versions of @command{strings} have @option{-o}
3111 act like @samp{-t d} instead. Since we can not be compatible with both
3112 ways, we simply chose one.
3114 @item -t @var{radix}
3115 @itemx --radix=@var{radix}
3116 Print the offset within the file before each string. The single
3117 character argument specifies the radix of the offset---@samp{o} for
3118 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
3120 @item -e @var{encoding}
3121 @itemx --encoding=@var{encoding}
3122 Select the character encoding of the strings that are to be found.
3123 Possible values for @var{encoding} are: @samp{s} = single-7-bit-byte
3124 characters (ASCII, ISO 8859, etc., default), @samp{S} =
3125 single-8-bit-byte characters, @samp{b} = 16-bit bigendian, @samp{l} =
3126 16-bit littleendian, @samp{B} = 32-bit bigendian, @samp{L} = 32-bit
3127 littleendian. Useful for finding wide character strings. (@samp{l}
3128 and @samp{b} apply to, for example, Unicode UTF-16/UCS-2 encodings).
3130 @item -T @var{bfdname}
3131 @itemx --target=@var{bfdname}
3132 @cindex object code format
3133 Specify an object code format other than your system's default format.
3134 @xref{Target Selection}, for more information.
3139 Print the program version number on the standard output and exit.
3142 @itemx --include-all-whitespace
3143 By default tab and space characters are included in the strings that
3144 are displayed, but other whitespace characters, such a newlines and
3145 carriage returns, are not. The @option{-w} option changes this so
3146 that all whitespace characters are considered to be part of a string.
3149 @itemx --output-separator
3150 By default, output strings are delimited by a new-line. This option
3151 allows you to supply any string to be used as the output record
3152 separator. Useful with --include-all-whitespace where strings
3153 may contain new-lines internally.
3159 @c man begin SEEALSO strings
3160 ar(1), nm(1), objdump(1), ranlib(1), readelf(1)
3161 and the Info entries for @file{binutils}.
3169 @cindex removing symbols
3170 @cindex discarding symbols
3171 @cindex symbols, discarding
3173 @c man title strip Discard symbols from object files.
3176 @c man begin SYNOPSIS strip
3177 strip [@option{-F} @var{bfdname} |@option{--target=}@var{bfdname}]
3178 [@option{-I} @var{bfdname} |@option{--input-target=}@var{bfdname}]
3179 [@option{-O} @var{bfdname} |@option{--output-target=}@var{bfdname}]
3180 [@option{-s}|@option{--strip-all}]
3181 [@option{-S}|@option{-g}|@option{-d}|@option{--strip-debug}]
3182 [@option{--strip-dwo}]
3183 [@option{-K} @var{symbolname}|@option{--keep-symbol=}@var{symbolname}]
3184 [@option{-M}|@option{--merge-notes}][@option{--no-merge-notes}]
3185 [@option{-N} @var{symbolname} |@option{--strip-symbol=}@var{symbolname}]
3186 [@option{-w}|@option{--wildcard}]
3187 [@option{-x}|@option{--discard-all}] [@option{-X} |@option{--discard-locals}]
3188 [@option{-R} @var{sectionname} |@option{--remove-section=}@var{sectionname}]
3189 [@option{--remove-relocations=}@var{sectionpattern}]
3190 [@option{-o} @var{file}] [@option{-p}|@option{--preserve-dates}]
3191 [@option{-D}|@option{--enable-deterministic-archives}]
3192 [@option{-U}|@option{--disable-deterministic-archives}]
3193 [@option{--keep-file-symbols}]
3194 [@option{--only-keep-debug}]
3195 [@option{-v} |@option{--verbose}] [@option{-V}|@option{--version}]
3196 [@option{--help}] [@option{--info}]
3197 @var{objfile}@dots{}
3201 @c man begin DESCRIPTION strip
3203 @sc{gnu} @command{strip} discards all symbols from object files
3204 @var{objfile}. The list of object files may include archives.
3205 At least one object file must be given.
3207 @command{strip} modifies the files named in its argument,
3208 rather than writing modified copies under different names.
3212 @c man begin OPTIONS strip
3215 @item -F @var{bfdname}
3216 @itemx --target=@var{bfdname}
3217 Treat the original @var{objfile} as a file with the object
3218 code format @var{bfdname}, and rewrite it in the same format.
3219 @xref{Target Selection}, for more information.
3222 Show a summary of the options to @command{strip} and exit.
3225 Display a list showing all architectures and object formats available.
3227 @item -I @var{bfdname}
3228 @itemx --input-target=@var{bfdname}
3229 Treat the original @var{objfile} as a file with the object
3230 code format @var{bfdname}.
3231 @xref{Target Selection}, for more information.
3233 @item -O @var{bfdname}
3234 @itemx --output-target=@var{bfdname}
3235 Replace @var{objfile} with a file in the output format @var{bfdname}.
3236 @xref{Target Selection}, for more information.
3238 @item -R @var{sectionname}
3239 @itemx --remove-section=@var{sectionname}
3240 Remove any section named @var{sectionname} from the output file, in
3241 addition to whatever sections would otherwise be removed. This
3242 option may be given more than once. Note that using this option
3243 inappropriately may make the output file unusable. The wildcard
3244 character @samp{*} may be given at the end of @var{sectionname}. If
3245 so, then any section starting with @var{sectionname} will be removed.
3247 If the first character of @var{sectionpattern} is the exclamation
3248 point (!) then matching sections will not be removed even if an
3249 earlier use of @option{--remove-section} on the same command line
3250 would otherwise remove it. For example:
3253 --remove-section=.text.* --remove-section=!.text.foo
3256 will remove all sections matching the pattern '.text.*', but will not
3257 remove the section '.text.foo'.
3259 @item --remove-relocations=@var{sectionpattern}
3260 Remove relocations from the output file for any section matching
3261 @var{sectionpattern}. This option may be given more than once. Note
3262 that using this option inappropriately may make the output file
3263 unusable. Wildcard characters are accepted in @var{sectionpattern}.
3267 --remove-relocations=.text.*
3270 will remove the relocations for all sections matching the patter
3273 If the first character of @var{sectionpattern} is the exclamation
3274 point (!) then matching sections will not have their relocation
3275 removed even if an earlier use of @option{--remove-relocations} on the
3276 same command line would otherwise cause the relocations to be removed.
3280 --remove-relocations=.text.* --remove-relocations=!.text.foo
3283 will remove all relocations for sections matching the pattern
3284 '.text.*', but will not remove relocations for the section
3294 @itemx --strip-debug
3295 Remove debugging symbols only.
3298 Remove the contents of all DWARF .dwo sections, leaving the
3299 remaining debugging sections and all symbols intact.
3300 See the description of this option in the @command{objcopy} section
3301 for more information.
3303 @item --strip-unneeded
3304 Remove all symbols that are not needed for relocation processing.
3306 @item -K @var{symbolname}
3307 @itemx --keep-symbol=@var{symbolname}
3308 When stripping symbols, keep symbol @var{symbolname} even if it would
3309 normally be stripped. This option may be given more than once.
3312 @itemx --merge-notes
3313 @itemx --no-merge-notes
3314 For ELF files, attempt (or do not attempt) to reduce the size of any
3315 SHT_NOTE type sections by removing duplicate notes. The default is to
3316 attempt this reduction.
3318 @item -N @var{symbolname}
3319 @itemx --strip-symbol=@var{symbolname}
3320 Remove symbol @var{symbolname} from the source file. This option may be
3321 given more than once, and may be combined with strip options other than
3325 Put the stripped output in @var{file}, rather than replacing the
3326 existing file. When this argument is used, only one @var{objfile}
3327 argument may be specified.
3330 @itemx --preserve-dates
3331 Preserve the access and modification dates of the file.
3334 @itemx --enable-deterministic-archives
3335 @cindex deterministic archives
3336 @kindex --enable-deterministic-archives
3337 Operate in @emph{deterministic} mode. When copying archive members
3338 and writing the archive index, use zero for UIDs, GIDs, timestamps,
3339 and use consistent file modes for all files.
3341 If @file{binutils} was configured with
3342 @option{--enable-deterministic-archives}, then this mode is on by default.
3343 It can be disabled with the @samp{-U} option, below.
3346 @itemx --disable-deterministic-archives
3347 @cindex deterministic archives
3348 @kindex --enable-deterministic-archives
3349 Do @emph{not} operate in @emph{deterministic} mode. This is the
3350 inverse of the @option{-D} option, above: when copying archive members
3351 and writing the archive index, use their actual UID, GID, timestamp,
3352 and file mode values.
3354 This is the default unless @file{binutils} was configured with
3355 @option{--enable-deterministic-archives}.
3359 Permit regular expressions in @var{symbolname}s used in other command
3360 line options. The question mark (?), asterisk (*), backslash (\) and
3361 square brackets ([]) operators can be used anywhere in the symbol
3362 name. If the first character of the symbol name is the exclamation
3363 point (!) then the sense of the switch is reversed for that symbol.
3370 would cause strip to only keep symbols that start with the letters
3371 ``fo'', but to discard the symbol ``foo''.
3374 @itemx --discard-all
3375 Remove non-global symbols.
3378 @itemx --discard-locals
3379 Remove compiler-generated local symbols.
3380 (These usually start with @samp{L} or @samp{.}.)
3382 @item --keep-file-symbols
3383 When stripping a file, perhaps with @option{--strip-debug} or
3384 @option{--strip-unneeded}, retain any symbols specifying source file names,
3385 which would otherwise get stripped.
3387 @item --only-keep-debug
3388 Strip a file, emptying the contents of any sections that would not be
3389 stripped by @option{--strip-debug} and leaving the debugging sections
3390 intact. In ELF files, this preserves all the note sections in the
3393 Note - the section headers of the stripped sections are preserved,
3394 including their sizes, but the contents of the section are discarded.
3395 The section headers are preserved so that other tools can match up the
3396 debuginfo file with the real executable, even if that executable has
3397 been relocated to a different address space.
3399 The intention is that this option will be used in conjunction with
3400 @option{--add-gnu-debuglink} to create a two part executable. One a
3401 stripped binary which will occupy less space in RAM and in a
3402 distribution and the second a debugging information file which is only
3403 needed if debugging abilities are required. The suggested procedure
3404 to create these files is as follows:
3407 @item Link the executable as normal. Assuming that it is called
3409 @item Run @code{objcopy --only-keep-debug foo foo.dbg} to
3410 create a file containing the debugging info.
3411 @item Run @code{objcopy --strip-debug foo} to create a
3412 stripped executable.
3413 @item Run @code{objcopy --add-gnu-debuglink=foo.dbg foo}
3414 to add a link to the debugging info into the stripped executable.
3417 Note---the choice of @code{.dbg} as an extension for the debug info
3418 file is arbitrary. Also the @code{--only-keep-debug} step is
3419 optional. You could instead do this:
3422 @item Link the executable as normal.
3423 @item Copy @code{foo} to @code{foo.full}
3424 @item Run @code{strip --strip-debug foo}
3425 @item Run @code{objcopy --add-gnu-debuglink=foo.full foo}
3428 i.e., the file pointed to by the @option{--add-gnu-debuglink} can be the
3429 full executable. It does not have to be a file created by the
3430 @option{--only-keep-debug} switch.
3432 Note---this switch is only intended for use on fully linked files. It
3433 does not make sense to use it on object files where the debugging
3434 information may be incomplete. Besides the gnu_debuglink feature
3435 currently only supports the presence of one filename containing
3436 debugging information, not multiple filenames on a one-per-object-file
3441 Show the version number for @command{strip}.
3445 Verbose output: list all object files modified. In the case of
3446 archives, @samp{strip -v} lists all members of the archive.
3452 @c man begin SEEALSO strip
3453 the Info entries for @file{binutils}.
3457 @node c++filt, addr2line, strip, Top
3461 @cindex demangling C++ symbols
3463 @c man title cxxfilt Demangle C++ and Java symbols.
3466 @c man begin SYNOPSIS cxxfilt
3467 c++filt [@option{-_}|@option{--strip-underscore}]
3468 [@option{-n}|@option{--no-strip-underscore}]
3469 [@option{-p}|@option{--no-params}]
3470 [@option{-t}|@option{--types}]
3471 [@option{-i}|@option{--no-verbose}]
3472 [@option{-r}|@option{--no-recurse-limit}]
3473 [@option{-R}|@option{--recurse-limit}]
3474 [@option{-s} @var{format}|@option{--format=}@var{format}]
3475 [@option{--help}] [@option{--version}] [@var{symbol}@dots{}]
3479 @c man begin DESCRIPTION cxxfilt
3482 The C++ and Java languages provide function overloading, which means
3483 that you can write many functions with the same name, providing that
3484 each function takes parameters of different types. In order to be
3485 able to distinguish these similarly named functions C++ and Java
3486 encode them into a low-level assembler name which uniquely identifies
3487 each different version. This process is known as @dfn{mangling}. The
3489 @footnote{MS-DOS does not allow @kbd{+} characters in file names, so on
3490 MS-DOS this program is named @command{CXXFILT}.}
3491 program does the inverse mapping: it decodes (@dfn{demangles}) low-level
3492 names into user-level names so that they can be read.
3494 Every alphanumeric word (consisting of letters, digits, underscores,
3495 dollars, or periods) seen in the input is a potential mangled name.
3496 If the name decodes into a C++ name, the C++ name replaces the
3497 low-level name in the output, otherwise the original word is output.
3498 In this way you can pass an entire assembler source file, containing
3499 mangled names, through @command{c++filt} and see the same source file
3500 containing demangled names.
3502 You can also use @command{c++filt} to decipher individual symbols by
3503 passing them on the command line:
3506 c++filt @var{symbol}
3509 If no @var{symbol} arguments are given, @command{c++filt} reads symbol
3510 names from the standard input instead. All the results are printed on
3511 the standard output. The difference between reading names from the
3512 command line versus reading names from the standard input is that
3513 command-line arguments are expected to be just mangled names and no
3514 checking is performed to separate them from surrounding text. Thus
3521 will work and demangle the name to ``f()'' whereas:
3527 will not work. (Note the extra comma at the end of the mangled
3528 name which makes it invalid). This command however will work:
3531 echo _Z1fv, | c++filt -n
3534 and will display ``f(),'', i.e., the demangled name followed by a
3535 trailing comma. This behaviour is because when the names are read
3536 from the standard input it is expected that they might be part of an
3537 assembler source file where there might be extra, extraneous
3538 characters trailing after a mangled name. For example:
3541 .type _Z1fv, @@function
3546 @c man begin OPTIONS cxxfilt
3550 @itemx --strip-underscore
3551 On some systems, both the C and C++ compilers put an underscore in front
3552 of every name. For example, the C name @code{foo} gets the low-level
3553 name @code{_foo}. This option removes the initial underscore. Whether
3554 @command{c++filt} removes the underscore by default is target dependent.
3557 @itemx --no-strip-underscore
3558 Do not remove the initial underscore.
3562 When demangling the name of a function, do not display the types of
3563 the function's parameters.
3567 Attempt to demangle types as well as function names. This is disabled
3568 by default since mangled types are normally only used internally in
3569 the compiler, and they can be confused with non-mangled names. For example,
3570 a function called ``a'' treated as a mangled type name would be
3571 demangled to ``signed char''.
3575 Do not include implementation details (if any) in the demangled
3580 @itemx --recurse-limit
3581 @itemx --no-recurse-limit
3582 @itemx --recursion-limit
3583 @itemx --no-recursion-limit
3584 Enables or disables a limit on the amount of recursion performed
3585 whilst demangling strings. Since the name mangling formats allow for
3586 an inifinite level of recursion it is possible to create strings whose
3587 decoding will exhaust the amount of stack space available on the host
3588 machine, triggering a memory fault. The limit tries to prevent this
3589 from happening by restricting recursion to 2048 levels of nesting.
3591 The default is for this limit to be enabled, but disabling it may be
3592 necessary in order to demangle truly complicated names. Note however
3593 that if the recursion limit is disabled then stack exhaustion is
3594 possible and any bug reports about such an event will be rejected.
3596 The @option{-r} option is a synonym for the
3597 @option{--no-recurse-limit} option. The @option{-R} option is a
3598 synonym for the @option{--recurse-limit} option.
3600 @item -s @var{format}
3601 @itemx --format=@var{format}
3602 @command{c++filt} can decode various methods of mangling, used by
3603 different compilers. The argument to this option selects which
3608 Automatic selection based on executable (the default method)
3610 the one used by the @sc{gnu} C++ compiler (g++)
3612 the one used by the Lucid compiler (lcc)
3614 the one specified by the C++ Annotated Reference Manual
3616 the one used by the HP compiler (aCC)
3618 the one used by the EDG compiler
3620 the one used by the @sc{gnu} C++ compiler (g++) with the V3 ABI.
3622 the one used by the @sc{gnu} Java compiler (gcj)
3624 the one used by the @sc{gnu} Ada compiler (GNAT).
3628 Print a summary of the options to @command{c++filt} and exit.
3631 Print the version number of @command{c++filt} and exit.
3637 @c man begin SEEALSO cxxfilt
3638 the Info entries for @file{binutils}.
3643 @emph{Warning:} @command{c++filt} is a new utility, and the details of its
3644 user interface are subject to change in future releases. In particular,
3645 a command-line option may be required in the future to decode a name
3646 passed as an argument on the command line; in other words,
3649 c++filt @var{symbol}
3653 may in a future release become
3656 c++filt @var{option} @var{symbol}
3664 @cindex address to file name and line number
3666 @c man title addr2line convert addresses into file names and line numbers.
3669 @c man begin SYNOPSIS addr2line
3670 addr2line [@option{-a}|@option{--addresses}]
3671 [@option{-b} @var{bfdname}|@option{--target=}@var{bfdname}]
3672 [@option{-C}|@option{--demangle}[=@var{style}]]
3673 [@option{-r}|@option{--no-recurse-limit}]
3674 [@option{-R}|@option{--recurse-limit}]
3675 [@option{-e} @var{filename}|@option{--exe=}@var{filename}]
3676 [@option{-f}|@option{--functions}] [@option{-s}|@option{--basename}]
3677 [@option{-i}|@option{--inlines}]
3678 [@option{-p}|@option{--pretty-print}]
3679 [@option{-j}|@option{--section=}@var{name}]
3680 [@option{-H}|@option{--help}] [@option{-V}|@option{--version}]
3685 @c man begin DESCRIPTION addr2line
3687 @command{addr2line} translates addresses into file names and line numbers.
3688 Given an address in an executable or an offset in a section of a relocatable
3689 object, it uses the debugging information to figure out which file name and
3690 line number are associated with it.
3692 The executable or relocatable object to use is specified with the @option{-e}
3693 option. The default is the file @file{a.out}. The section in the relocatable
3694 object to use is specified with the @option{-j} option.
3696 @command{addr2line} has two modes of operation.
3698 In the first, hexadecimal addresses are specified on the command line,
3699 and @command{addr2line} displays the file name and line number for each
3702 In the second, @command{addr2line} reads hexadecimal addresses from
3703 standard input, and prints the file name and line number for each
3704 address on standard output. In this mode, @command{addr2line} may be used
3705 in a pipe to convert dynamically chosen addresses.
3707 The format of the output is @samp{FILENAME:LINENO}. By default
3708 each input address generates one line of output.
3710 Two options can generate additional lines before each
3711 @samp{FILENAME:LINENO} line (in that order).
3713 If the @option{-a} option is used then a line with the input address
3716 If the @option{-f} option is used, then a line with the
3717 @samp{FUNCTIONNAME} is displayed. This is the name of the function
3718 containing the address.
3720 One option can generate additional lines after the
3721 @samp{FILENAME:LINENO} line.
3723 If the @option{-i} option is used and the code at the given address is
3724 present there because of inlining by the compiler then additional
3725 lines are displayed afterwards. One or two extra lines (if the
3726 @option{-f} option is used) are displayed for each inlined function.
3728 Alternatively if the @option{-p} option is used then each input
3729 address generates a single, long, output line containing the address,
3730 the function name, the file name and the line number. If the
3731 @option{-i} option has also been used then any inlined functions will
3732 be displayed in the same manner, but on separate lines, and prefixed
3733 by the text @samp{(inlined by)}.
3735 If the file name or function name can not be determined,
3736 @command{addr2line} will print two question marks in their place. If the
3737 line number can not be determined, @command{addr2line} will print 0.
3741 @c man begin OPTIONS addr2line
3743 The long and short forms of options, shown here as alternatives, are
3749 Display the address before the function name, file and line number
3750 information. The address is printed with a @samp{0x} prefix to easily
3753 @item -b @var{bfdname}
3754 @itemx --target=@var{bfdname}
3755 @cindex object code format
3756 Specify that the object-code format for the object files is
3760 @itemx --demangle[=@var{style}]
3761 @cindex demangling in objdump
3762 Decode (@dfn{demangle}) low-level symbol names into user-level names.
3763 Besides removing any initial underscore prepended by the system, this
3764 makes C++ function names readable. Different compilers have different
3765 mangling styles. The optional demangling style argument can be used to
3766 choose an appropriate demangling style for your compiler. @xref{c++filt},
3767 for more information on demangling.
3769 @item -e @var{filename}
3770 @itemx --exe=@var{filename}
3771 Specify the name of the executable for which addresses should be
3772 translated. The default file is @file{a.out}.
3776 Display function names as well as file and line number information.
3780 Display only the base of each file name.
3784 If the address belongs to a function that was inlined, the source
3785 information for all enclosing scopes back to the first non-inlined
3786 function will also be printed. For example, if @code{main} inlines
3787 @code{callee1} which inlines @code{callee2}, and address is from
3788 @code{callee2}, the source information for @code{callee1} and @code{main}
3789 will also be printed.
3793 Read offsets relative to the specified section instead of absolute addresses.
3796 @itemx --pretty-print
3797 Make the output more human friendly: each location are printed on one line.
3798 If option @option{-i} is specified, lines for all enclosing scopes are
3799 prefixed with @samp{(inlined by)}.
3803 @itemx --recurse-limit
3804 @itemx --no-recurse-limit
3805 @itemx --recursion-limit
3806 @itemx --no-recursion-limit
3807 Enables or disables a limit on the amount of recursion performed
3808 whilst demangling strings. Since the name mangling formats allow for
3809 an inifinite level of recursion it is possible to create strings whose
3810 decoding will exhaust the amount of stack space available on the host
3811 machine, triggering a memory fault. The limit tries to prevent this
3812 from happening by restricting recursion to 2048 levels of nesting.
3814 The default is for this limit to be enabled, but disabling it may be
3815 necessary in order to demangle truly complicated names. Note however
3816 that if the recursion limit is disabled then stack exhaustion is
3817 possible and any bug reports about such an event will be rejected.
3819 The @option{-r} option is a synonym for the
3820 @option{--no-recurse-limit} option. The @option{-R} option is a
3821 synonym for the @option{--recurse-limit} option.
3823 Note this option is only effective if the @option{-C} or
3824 @option{--demangle} option has been enabled.
3831 @c man begin SEEALSO addr2line
3832 Info entries for @file{binutils}.
3839 @command{windmc} may be used to generator Windows message resources.
3842 @emph{Warning:} @command{windmc} is not always built as part of the binary
3843 utilities, since it is only useful for Windows targets.
3846 @c man title windmc generates Windows message resources.
3849 @c man begin SYNOPSIS windmc
3850 windmc [options] input-file
3854 @c man begin DESCRIPTION windmc
3856 @command{windmc} reads message definitions from an input file (.mc) and
3857 translate them into a set of output files. The output files may be of
3862 A C header file containing the message definitions.
3865 A resource file compilable by the @command{windres} tool.
3868 One or more binary files containing the resource data for a specific
3872 A C include file that maps message id's to their symbolic name.
3875 The exact description of these different formats is available in
3876 documentation from Microsoft.
3878 When @command{windmc} converts from the @code{mc} format to the @code{bin}
3879 format, @code{rc}, @code{h}, and optional @code{dbg} it is acting like the
3880 Windows Message Compiler.
3884 @c man begin OPTIONS windmc
3889 Specifies that the input file specified is ASCII. This is the default
3894 Specifies that messages in the output @code{bin} files should be in ASCII
3899 Specifies that @code{bin} filenames should have to be prefixed by the
3900 basename of the source file.
3904 Sets the customer bit in all message id's.
3906 @item -C @var{codepage}
3907 @itemx --codepage_in @var{codepage}
3908 Sets the default codepage to be used to convert input file to UTF16. The
3909 default is ocdepage 1252.
3912 @itemx --decimal_values
3913 Outputs the constants in the header file in decimal. Default is using
3917 @itemx --extension @var{ext}
3918 The extension for the header file. The default is .h extension.
3920 @item -F @var{target}
3921 @itemx --target @var{target}
3922 Specify the BFD format to use for a bin file as output. This
3923 is a BFD target name; you can use the @option{--help} option to see a list
3924 of supported targets. Normally @command{windmc} will use the default
3925 format, which is the first one listed by the @option{--help} option.
3927 @ref{Target Selection}.
3931 @itemx --headerdir @var{path}
3932 The target directory of the generated header file. The default is the
3937 Displays a list of command-line options and then exits.
3939 @item -m @var{characters}
3940 @itemx --maxlength @var{characters}
3941 Instructs @command{windmc} to generate a warning if the length
3942 of any message exceeds the number specified.
3945 @itemx --nullterminate
3946 Terminate message text in @code{bin} files by zero. By default they are
3947 terminated by CR/LF.
3950 @itemx --hresult_use
3951 Not yet implemented. Instructs @code{windmc} to generate an OLE2 header
3952 file, using HRESULT definitions. Status codes are used if the flag is not
3955 @item -O @var{codepage}
3956 @itemx --codepage_out @var{codepage}
3957 Sets the default codepage to be used to output text files. The default
3961 @itemx --rcdir @var{path}
3962 The target directory for the generated @code{rc} script and the generated
3963 @code{bin} files that the resource compiler script includes. The default
3964 is the current directory.
3968 Specifies that the input file is UTF16.
3971 @itemx --unicode_out
3972 Specifies that messages in the output @code{bin} file should be in UTF16
3973 format. This is the default behaviour.
3977 Enable verbose mode.
3981 Prints the version number for @command{windmc}.
3984 @itemx --xdgb @var{path}
3985 The path of the @code{dbg} C include file that maps message id's to the
3986 symbolic name. No such file is generated without specifying the switch.
3992 @c man begin SEEALSO windmc
3993 the Info entries for @file{binutils}.
4000 @command{windres} may be used to manipulate Windows resources.
4003 @emph{Warning:} @command{windres} is not always built as part of the binary
4004 utilities, since it is only useful for Windows targets.
4007 @c man title windres manipulate Windows resources.
4010 @c man begin SYNOPSIS windres
4011 windres [options] [input-file] [output-file]
4015 @c man begin DESCRIPTION windres
4017 @command{windres} reads resources from an input file and copies them into
4018 an output file. Either file may be in one of three formats:
4022 A text format read by the Resource Compiler.
4025 A binary format generated by the Resource Compiler.
4028 A COFF object or executable.
4031 The exact description of these different formats is available in
4032 documentation from Microsoft.
4034 When @command{windres} converts from the @code{rc} format to the @code{res}
4035 format, it is acting like the Windows Resource Compiler. When
4036 @command{windres} converts from the @code{res} format to the @code{coff}
4037 format, it is acting like the Windows @code{CVTRES} program.
4039 When @command{windres} generates an @code{rc} file, the output is similar
4040 but not identical to the format expected for the input. When an input
4041 @code{rc} file refers to an external filename, an output @code{rc} file
4042 will instead include the file contents.
4044 If the input or output format is not specified, @command{windres} will
4045 guess based on the file name, or, for the input file, the file contents.
4046 A file with an extension of @file{.rc} will be treated as an @code{rc}
4047 file, a file with an extension of @file{.res} will be treated as a
4048 @code{res} file, and a file with an extension of @file{.o} or
4049 @file{.exe} will be treated as a @code{coff} file.
4051 If no output file is specified, @command{windres} will print the resources
4052 in @code{rc} format to standard output.
4054 The normal use is for you to write an @code{rc} file, use @command{windres}
4055 to convert it to a COFF object file, and then link the COFF file into
4056 your application. This will make the resources described in the
4057 @code{rc} file available to Windows.
4061 @c man begin OPTIONS windres
4064 @item -i @var{filename}
4065 @itemx --input @var{filename}
4066 The name of the input file. If this option is not used, then
4067 @command{windres} will use the first non-option argument as the input file
4068 name. If there are no non-option arguments, then @command{windres} will
4069 read from standard input. @command{windres} can not read a COFF file from
4072 @item -o @var{filename}
4073 @itemx --output @var{filename}
4074 The name of the output file. If this option is not used, then
4075 @command{windres} will use the first non-option argument, after any used
4076 for the input file name, as the output file name. If there is no
4077 non-option argument, then @command{windres} will write to standard output.
4078 @command{windres} can not write a COFF file to standard output. Note,
4079 for compatibility with @command{rc} the option @option{-fo} is also
4080 accepted, but its use is not recommended.
4082 @item -J @var{format}
4083 @itemx --input-format @var{format}
4084 The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
4085 @samp{coff}. If no input format is specified, @command{windres} will
4086 guess, as described above.
4088 @item -O @var{format}
4089 @itemx --output-format @var{format}
4090 The output format to generate. @var{format} may be @samp{res},
4091 @samp{rc}, or @samp{coff}. If no output format is specified,
4092 @command{windres} will guess, as described above.
4094 @item -F @var{target}
4095 @itemx --target @var{target}
4096 Specify the BFD format to use for a COFF file as input or output. This
4097 is a BFD target name; you can use the @option{--help} option to see a list
4098 of supported targets. Normally @command{windres} will use the default
4099 format, which is the first one listed by the @option{--help} option.
4101 @ref{Target Selection}.
4104 @item --preprocessor @var{program}
4105 When @command{windres} reads an @code{rc} file, it runs it through the C
4106 preprocessor first. This option may be used to specify the preprocessor
4107 to use, including any leading arguments. The default preprocessor
4108 argument is @code{gcc -E -xc-header -DRC_INVOKED}.
4110 @item --preprocessor-arg @var{option}
4111 When @command{windres} reads an @code{rc} file, it runs it through
4112 the C preprocessor first. This option may be used to specify additional
4113 text to be passed to preprocessor on its command line.
4114 This option can be used multiple times to add multiple options to the
4115 preprocessor command line.
4117 @item -I @var{directory}
4118 @itemx --include-dir @var{directory}
4119 Specify an include directory to use when reading an @code{rc} file.
4120 @command{windres} will pass this to the preprocessor as an @option{-I}
4121 option. @command{windres} will also search this directory when looking for
4122 files named in the @code{rc} file. If the argument passed to this command
4123 matches any of the supported @var{formats} (as described in the @option{-J}
4124 option), it will issue a deprecation warning, and behave just like the
4125 @option{-J} option. New programs should not use this behaviour. If a
4126 directory happens to match a @var{format}, simple prefix it with @samp{./}
4127 to disable the backward compatibility.
4129 @item -D @var{target}
4130 @itemx --define @var{sym}[=@var{val}]
4131 Specify a @option{-D} option to pass to the preprocessor when reading an
4134 @item -U @var{target}
4135 @itemx --undefine @var{sym}
4136 Specify a @option{-U} option to pass to the preprocessor when reading an
4140 Ignored for compatibility with rc.
4143 Enable verbose mode. This tells you what the preprocessor is if you
4147 @item --codepage @var{val}
4148 Specify the default codepage to use when reading an @code{rc} file.
4149 @var{val} should be a hexadecimal prefixed by @samp{0x} or decimal
4150 codepage code. The valid range is from zero up to 0xffff, but the
4151 validity of the codepage is host and configuration dependent.
4154 @item --language @var{val}
4155 Specify the default language to use when reading an @code{rc} file.
4156 @var{val} should be a hexadecimal language code. The low eight bits are
4157 the language, and the high eight bits are the sublanguage.
4159 @item --use-temp-file
4160 Use a temporary file to instead of using popen to read the output of
4161 the preprocessor. Use this option if the popen implementation is buggy
4162 on the host (eg., certain non-English language versions of Windows 95 and
4163 Windows 98 are known to have buggy popen where the output will instead
4166 @item --no-use-temp-file
4167 Use popen, not a temporary file, to read the output of the preprocessor.
4168 This is the default behaviour.
4172 Prints a usage summary.
4176 Prints the version number for @command{windres}.
4179 If @command{windres} is compiled with @code{YYDEBUG} defined as @code{1},
4180 this will turn on parser debugging.
4186 @c man begin SEEALSO windres
4187 the Info entries for @file{binutils}.
4196 @command{dlltool} is used to create the files needed to create dynamic
4197 link libraries (DLLs) on systems which understand PE format image
4198 files such as Windows. A DLL contains an export table which contains
4199 information that the runtime loader needs to resolve references from a
4200 referencing program.
4202 The export table is generated by this program by reading in a
4203 @file{.def} file or scanning the @file{.a} and @file{.o} files which
4204 will be in the DLL. A @file{.o} file can contain information in
4205 special @samp{.drectve} sections with export information.
4208 @emph{Note:} @command{dlltool} is not always built as part of the
4209 binary utilities, since it is only useful for those targets which
4213 @c man title dlltool Create files needed to build and use DLLs.
4216 @c man begin SYNOPSIS dlltool
4217 dlltool [@option{-d}|@option{--input-def} @var{def-file-name}]
4218 [@option{-b}|@option{--base-file} @var{base-file-name}]
4219 [@option{-e}|@option{--output-exp} @var{exports-file-name}]
4220 [@option{-z}|@option{--output-def} @var{def-file-name}]
4221 [@option{-l}|@option{--output-lib} @var{library-file-name}]
4222 [@option{-y}|@option{--output-delaylib} @var{library-file-name}]
4223 [@option{--export-all-symbols}] [@option{--no-export-all-symbols}]
4224 [@option{--exclude-symbols} @var{list}]
4225 [@option{--no-default-excludes}]
4226 [@option{-S}|@option{--as} @var{path-to-assembler}] [@option{-f}|@option{--as-flags} @var{options}]
4227 [@option{-D}|@option{--dllname} @var{name}] [@option{-m}|@option{--machine} @var{machine}]
4228 [@option{-a}|@option{--add-indirect}]
4229 [@option{-U}|@option{--add-underscore}] [@option{--add-stdcall-underscore}]
4230 [@option{-k}|@option{--kill-at}] [@option{-A}|@option{--add-stdcall-alias}]
4231 [@option{-p}|@option{--ext-prefix-alias} @var{prefix}]
4232 [@option{-x}|@option{--no-idata4}] [@option{-c}|@option{--no-idata5}]
4233 [@option{--use-nul-prefixed-import-tables}]
4234 [@option{-I}|@option{--identify} @var{library-file-name}] [@option{--identify-strict}]
4235 [@option{-i}|@option{--interwork}]
4236 [@option{-n}|@option{--nodelete}] [@option{-t}|@option{--temp-prefix} @var{prefix}]
4237 [@option{-v}|@option{--verbose}]
4238 [@option{-h}|@option{--help}] [@option{-V}|@option{--version}]
4239 [@option{--no-leading-underscore}] [@option{--leading-underscore}]
4240 [object-file @dots{}]
4244 @c man begin DESCRIPTION dlltool
4246 @command{dlltool} reads its inputs, which can come from the @option{-d} and
4247 @option{-b} options as well as object files specified on the command
4248 line. It then processes these inputs and if the @option{-e} option has
4249 been specified it creates a exports file. If the @option{-l} option
4250 has been specified it creates a library file and if the @option{-z} option
4251 has been specified it creates a def file. Any or all of the @option{-e},
4252 @option{-l} and @option{-z} options can be present in one invocation of
4255 When creating a DLL, along with the source for the DLL, it is necessary
4256 to have three other files. @command{dlltool} can help with the creation of
4259 The first file is a @file{.def} file which specifies which functions are
4260 exported from the DLL, which functions the DLL imports, and so on. This
4261 is a text file and can be created by hand, or @command{dlltool} can be used
4262 to create it using the @option{-z} option. In this case @command{dlltool}
4263 will scan the object files specified on its command line looking for
4264 those functions which have been specially marked as being exported and
4265 put entries for them in the @file{.def} file it creates.
4267 In order to mark a function as being exported from a DLL, it needs to
4268 have an @option{-export:<name_of_function>} entry in the @samp{.drectve}
4269 section of the object file. This can be done in C by using the
4273 asm (".section .drectve");
4274 asm (".ascii \"-export:my_func\"");
4276 int my_func (void) @{ @dots{} @}
4279 The second file needed for DLL creation is an exports file. This file
4280 is linked with the object files that make up the body of the DLL and it
4281 handles the interface between the DLL and the outside world. This is a
4282 binary file and it can be created by giving the @option{-e} option to
4283 @command{dlltool} when it is creating or reading in a @file{.def} file.
4285 The third file needed for DLL creation is the library file that programs
4286 will link with in order to access the functions in the DLL (an `import
4287 library'). This file can be created by giving the @option{-l} option to
4288 dlltool when it is creating or reading in a @file{.def} file.
4290 If the @option{-y} option is specified, dlltool generates a delay-import
4291 library that can be used instead of the normal import library to allow
4292 a program to link to the dll only as soon as an imported function is
4293 called for the first time. The resulting executable will need to be
4294 linked to the static delayimp library containing __delayLoadHelper2(),
4295 which in turn will import LoadLibraryA and GetProcAddress from kernel32.
4297 @command{dlltool} builds the library file by hand, but it builds the
4298 exports file by creating temporary files containing assembler statements
4299 and then assembling these. The @option{-S} command-line option can be
4300 used to specify the path to the assembler that dlltool will use,
4301 and the @option{-f} option can be used to pass specific flags to that
4302 assembler. The @option{-n} can be used to prevent dlltool from deleting
4303 these temporary assembler files when it is done, and if @option{-n} is
4304 specified twice then this will prevent dlltool from deleting the
4305 temporary object files it used to build the library.
4307 Here is an example of creating a DLL from a source file @samp{dll.c} and
4308 also creating a program (from an object file called @samp{program.o})
4313 dlltool -e exports.o -l dll.lib dll.o
4314 gcc dll.o exports.o -o dll.dll
4315 gcc program.o dll.lib -o program
4319 @command{dlltool} may also be used to query an existing import library
4320 to determine the name of the DLL to which it is associated. See the
4321 description of the @option{-I} or @option{--identify} option.
4325 @c man begin OPTIONS dlltool
4327 The command-line options have the following meanings:
4331 @item -d @var{filename}
4332 @itemx --input-def @var{filename}
4333 @cindex input .def file
4334 Specifies the name of a @file{.def} file to be read in and processed.
4336 @item -b @var{filename}
4337 @itemx --base-file @var{filename}
4339 Specifies the name of a base file to be read in and processed. The
4340 contents of this file will be added to the relocation section in the
4341 exports file generated by dlltool.
4343 @item -e @var{filename}
4344 @itemx --output-exp @var{filename}
4345 Specifies the name of the export file to be created by dlltool.
4347 @item -z @var{filename}
4348 @itemx --output-def @var{filename}
4349 Specifies the name of the @file{.def} file to be created by dlltool.
4351 @item -l @var{filename}
4352 @itemx --output-lib @var{filename}
4353 Specifies the name of the library file to be created by dlltool.
4355 @item -y @var{filename}
4356 @itemx --output-delaylib @var{filename}
4357 Specifies the name of the delay-import library file to be created by dlltool.
4359 @item --export-all-symbols
4360 Treat all global and weak defined symbols found in the input object
4361 files as symbols to be exported. There is a small list of symbols which
4362 are not exported by default; see the @option{--no-default-excludes}
4363 option. You may add to the list of symbols to not export by using the
4364 @option{--exclude-symbols} option.
4366 @item --no-export-all-symbols
4367 Only export symbols explicitly listed in an input @file{.def} file or in
4368 @samp{.drectve} sections in the input object files. This is the default
4369 behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
4370 attributes in the source code.
4372 @item --exclude-symbols @var{list}
4373 Do not export the symbols in @var{list}. This is a list of symbol names
4374 separated by comma or colon characters. The symbol names should not
4375 contain a leading underscore. This is only meaningful when
4376 @option{--export-all-symbols} is used.
4378 @item --no-default-excludes
4379 When @option{--export-all-symbols} is used, it will by default avoid
4380 exporting certain special symbols. The current list of symbols to avoid
4381 exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
4382 @samp{impure_ptr}. You may use the @option{--no-default-excludes} option
4383 to go ahead and export these special symbols. This is only meaningful
4384 when @option{--export-all-symbols} is used.
4387 @itemx --as @var{path}
4388 Specifies the path, including the filename, of the assembler to be used
4389 to create the exports file.
4391 @item -f @var{options}
4392 @itemx --as-flags @var{options}
4393 Specifies any specific command-line options to be passed to the
4394 assembler when building the exports file. This option will work even if
4395 the @option{-S} option is not used. This option only takes one argument,
4396 and if it occurs more than once on the command line, then later
4397 occurrences will override earlier occurrences. So if it is necessary to
4398 pass multiple options to the assembler they should be enclosed in
4402 @itemx --dll-name @var{name}
4403 Specifies the name to be stored in the @file{.def} file as the name of
4404 the DLL when the @option{-e} option is used. If this option is not
4405 present, then the filename given to the @option{-e} option will be
4406 used as the name of the DLL.
4408 @item -m @var{machine}
4409 @itemx -machine @var{machine}
4410 Specifies the type of machine for which the library file should be
4411 built. @command{dlltool} has a built in default type, depending upon how
4412 it was created, but this option can be used to override that. This is
4413 normally only useful when creating DLLs for an ARM processor, when the
4414 contents of the DLL are actually encode using Thumb instructions.
4417 @itemx --add-indirect
4418 Specifies that when @command{dlltool} is creating the exports file it
4419 should add a section which allows the exported functions to be
4420 referenced without using the import library. Whatever the hell that
4424 @itemx --add-underscore
4425 Specifies that when @command{dlltool} is creating the exports file it
4426 should prepend an underscore to the names of @emph{all} exported symbols.
4428 @item --no-leading-underscore
4429 @item --leading-underscore
4430 Specifies whether standard symbol should be forced to be prefixed, or
4433 @item --add-stdcall-underscore
4434 Specifies that when @command{dlltool} is creating the exports file it
4435 should prepend an underscore to the names of exported @emph{stdcall}
4436 functions. Variable names and non-stdcall function names are not modified.
4437 This option is useful when creating GNU-compatible import libs for third
4438 party DLLs that were built with MS-Windows tools.
4442 Specifies that @samp{@@<number>} suffixes should be omitted from the names
4443 of stdcall functions that will be imported from the DLL. This is
4444 useful when creating an import library for a DLL which exports stdcall
4445 functions but without the usual @samp{@@<number>} symbol name suffix.
4447 This does not change the naming of symbols provided by the import library
4448 to programs linked against it, but only the entries in the import table
4449 (ie the .idata section).
4452 @itemx --add-stdcall-alias
4453 Specifies that when @command{dlltool} is creating the exports file it
4454 should add aliases for stdcall symbols without @samp{@@ <number>}
4455 in addition to the symbols with @samp{@@ <number>}.
4458 @itemx --ext-prefix-alias @var{prefix}
4459 Causes @command{dlltool} to create external aliases for all DLL
4460 imports with the specified prefix. The aliases are created for both
4461 external and import symbols with no leading underscore.
4465 Specifies that when @command{dlltool} is creating the exports and library
4466 files it should omit the @code{.idata4} section. This is for compatibility
4467 with certain operating systems.
4469 @item --use-nul-prefixed-import-tables
4470 Specifies that when @command{dlltool} is creating the exports and library
4471 files it should prefix the @code{.idata4} and @code{.idata5} by zero an
4472 element. This emulates old gnu import library generation of
4473 @code{dlltool}. By default this option is turned off.
4477 Specifies that when @command{dlltool} is creating the exports and library
4478 files it should omit the @code{.idata5} section. This is for compatibility
4479 with certain operating systems.
4481 @item -I @var{filename}
4482 @itemx --identify @var{filename}
4483 Specifies that @command{dlltool} should inspect the import library
4484 indicated by @var{filename} and report, on @code{stdout}, the name(s)
4485 of the associated DLL(s). This can be performed in addition to any
4486 other operations indicated by the other options and arguments.
4487 @command{dlltool} fails if the import library does not exist or is not
4488 actually an import library. See also @option{--identify-strict}.
4490 @item --identify-strict
4491 Modifies the behavior of the @option{--identify} option, such
4492 that an error is reported if @var{filename} is associated with
4497 Specifies that @command{dlltool} should mark the objects in the library
4498 file and exports file that it produces as supporting interworking
4499 between ARM and Thumb code.
4503 Makes @command{dlltool} preserve the temporary assembler files it used to
4504 create the exports file. If this option is repeated then dlltool will
4505 also preserve the temporary object files it uses to create the library
4508 @item -t @var{prefix}
4509 @itemx --temp-prefix @var{prefix}
4510 Makes @command{dlltool} use @var{prefix} when constructing the names of
4511 temporary assembler and object files. By default, the temp file prefix
4512 is generated from the pid.
4516 Make dlltool describe what it is doing.
4520 Displays a list of command-line options and then exits.
4524 Displays dlltool's version number and then exits.
4531 * def file format:: The format of the dlltool @file{.def} file
4534 @node def file format
4535 @section The format of the @command{dlltool} @file{.def} file
4537 A @file{.def} file contains any number of the following commands:
4541 @item @code{NAME} @var{name} @code{[ ,} @var{base} @code{]}
4542 The result is going to be named @var{name}@code{.exe}.
4544 @item @code{LIBRARY} @var{name} @code{[ ,} @var{base} @code{]}
4545 The result is going to be named @var{name}@code{.dll}.
4546 Note: If you want to use LIBRARY as name then you need to quote. Otherwise
4547 this will fail due a necessary hack for libtool (see PR binutils/13710 for more
4550 @item @code{EXPORTS ( ( (} @var{name1} @code{[ = } @var{name2} @code{] ) | ( } @var{name1} @code{=} @var{module-name} @code{.} @var{external-name} @code{) ) [ == } @var{its_name} @code{]}
4551 @item @code{[} @var{integer} @code{] [ NONAME ] [ CONSTANT ] [ DATA ] [ PRIVATE ] ) *}
4552 Declares @var{name1} as an exported symbol from the DLL, with optional
4553 ordinal number @var{integer}, or declares @var{name1} as an alias
4554 (forward) of the function @var{external-name} in the DLL.
4555 If @var{its_name} is specified, this name is used as string in export table.
4557 Note: The @code{EXPORTS} has to be the last command in .def file, as keywords
4558 are treated - beside @code{LIBRARY} - as simple name-identifiers.
4559 If you want to use LIBRARY as name then you need to quote it.
4561 @item @code{IMPORTS ( (} @var{internal-name} @code{=} @var{module-name} @code{.} @var{integer} @code{) | [} @var{internal-name} @code{= ]} @var{module-name} @code{.} @var{external-name} @code{) [ == ) @var{its_name} @code{]} *}
4562 Declares that @var{external-name} or the exported function whose
4563 ordinal number is @var{integer} is to be imported from the file
4564 @var{module-name}. If @var{internal-name} is specified then this is
4565 the name that the imported function will be referred to in the body of
4567 If @var{its_name} is specified, this name is used as string in import table.
4568 Note: The @code{IMPORTS} has to be the last command in .def file, as keywords
4569 are treated - beside @code{LIBRARY} - as simple name-identifiers.
4570 If you want to use LIBRARY as name then you need to quote it.
4572 @item @code{DESCRIPTION} @var{string}
4573 Puts @var{string} into the output @file{.exp} file in the
4574 @code{.rdata} section.
4576 @item @code{STACKSIZE} @var{number-reserve} @code{[, } @var{number-commit} @code{]}
4577 @item @code{HEAPSIZE} @var{number-reserve} @code{[, } @var{number-commit} @code{]}
4578 Generates @code{--stack} or @code{--heap}
4579 @var{number-reserve},@var{number-commit} in the output @code{.drectve}
4580 section. The linker will see this and act upon it.
4582 @item @code{CODE} @var{attr} @code{+}
4583 @item @code{DATA} @var{attr} @code{+}
4584 @item @code{SECTIONS (} @var{section-name} @var{attr}@code{ + ) *}
4585 Generates @code{--attr} @var{section-name} @var{attr} in the output
4586 @code{.drectve} section, where @var{attr} is one of @code{READ},
4587 @code{WRITE}, @code{EXECUTE} or @code{SHARED}. The linker will see
4588 this and act upon it.
4593 @c man begin SEEALSO dlltool
4594 The Info pages for @file{binutils}.
4601 @cindex ELF file information
4604 @c man title readelf Displays information about ELF files.
4607 @c man begin SYNOPSIS readelf
4608 readelf [@option{-a}|@option{--all}]
4609 [@option{-h}|@option{--file-header}]
4610 [@option{-l}|@option{--program-headers}|@option{--segments}]
4611 [@option{-S}|@option{--section-headers}|@option{--sections}]
4612 [@option{-g}|@option{--section-groups}]
4613 [@option{-t}|@option{--section-details}]
4614 [@option{-e}|@option{--headers}]
4615 [@option{-s}|@option{--syms}|@option{--symbols}]
4616 [@option{--dyn-syms}]
4617 [@option{-n}|@option{--notes}]
4618 [@option{-r}|@option{--relocs}]
4619 [@option{-u}|@option{--unwind}]
4620 [@option{-d}|@option{--dynamic}]
4621 [@option{-V}|@option{--version-info}]
4622 [@option{-A}|@option{--arch-specific}]
4623 [@option{-D}|@option{--use-dynamic}]
4624 [@option{-x} <number or name>|@option{--hex-dump=}<number or name>]
4625 [@option{-p} <number or name>|@option{--string-dump=}<number or name>]
4626 [@option{-R} <number or name>|@option{--relocated-dump=}<number or name>]
4627 [@option{-z}|@option{--decompress}]
4628 [@option{-c}|@option{--archive-index}]
4629 [@option{-w[lLiaprmfFsoRtUuTgAckK]}|
4630 @option{--debug-dump}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]]
4631 [@option{--dwarf-depth=@var{n}}]
4632 [@option{--dwarf-start=@var{n}}]
4633 [@option{-I}|@option{--histogram}]
4634 [@option{-v}|@option{--version}]
4635 [@option{-W}|@option{--wide}]
4636 [@option{-H}|@option{--help}]
4637 @var{elffile}@dots{}
4641 @c man begin DESCRIPTION readelf
4643 @command{readelf} displays information about one or more ELF format object
4644 files. The options control what particular information to display.
4646 @var{elffile}@dots{} are the object files to be examined. 32-bit and
4647 64-bit ELF files are supported, as are archives containing ELF files.
4649 This program performs a similar function to @command{objdump} but it
4650 goes into more detail and it exists independently of the @sc{bfd}
4651 library, so if there is a bug in @sc{bfd} then readelf will not be
4656 @c man begin OPTIONS readelf
4658 The long and short forms of options, shown here as alternatives, are
4659 equivalent. At least one option besides @samp{-v} or @samp{-H} must be
4665 Equivalent to specifying @option{--file-header},
4666 @option{--program-headers}, @option{--sections}, @option{--symbols},
4667 @option{--relocs}, @option{--dynamic}, @option{--notes},
4668 @option{--version-info}, @option{--arch-specific}, @option{--unwind},
4669 @option{--section-groups} and @option{--histogram}.
4671 Note - this option does not enable @option{--use-dynamic} itself, so
4672 if that option is not present on the command line then dynamic symbols
4673 and dynamic relocs will not be displayed.
4676 @itemx --file-header
4677 @cindex ELF file header information
4678 Displays the information contained in the ELF header at the start of the
4682 @itemx --program-headers
4684 @cindex ELF program header information
4685 @cindex ELF segment information
4686 Displays the information contained in the file's segment headers, if it
4691 @itemx --section-headers
4692 @cindex ELF section information
4693 Displays the information contained in the file's section headers, if it
4697 @itemx --section-groups
4698 @cindex ELF section group information
4699 Displays the information contained in the file's section groups, if it
4703 @itemx --section-details
4704 @cindex ELF section information
4705 Displays the detailed section information. Implies @option{-S}.
4710 @cindex ELF symbol table information
4711 Displays the entries in symbol table section of the file, if it has one.
4712 If a symbol has version information associated with it then this is
4713 displayed as well. The version string is displayed as a suffix to the
4714 symbol name, preceeded by an @@ character. For example
4715 @samp{foo@@VER_1}. If the version is the default version to be used
4716 when resolving unversioned references to the symbol then it is
4717 displayed as a suffix preceeded by two @@ characters. For example
4718 @samp{foo@@@@VER_2}.
4721 @cindex ELF dynamic symbol table information
4722 Displays the entries in dynamic symbol table section of the file, if it
4723 has one. The output format is the same as the format used by the
4724 @option{--syms} option.
4728 Display all the headers in the file. Equivalent to @option{-h -l -S}.
4733 Displays the contents of the NOTE segments and/or sections, if any.
4737 @cindex ELF reloc information
4738 Displays the contents of the file's relocation section, if it has one.
4742 @cindex unwind information
4743 Displays the contents of the file's unwind section, if it has one. Only
4744 the unwind sections for IA64 ELF files, as well as ARM unwind tables
4745 (@code{.ARM.exidx} / @code{.ARM.extab}) are currently supported. If
4746 support is not yet implemented for your architecture you could try
4747 dumping the contents of the @var{.eh_frames} section using the
4748 @option{--debug-dump=frames} or @option{--debug-dump=frames-interp}
4753 @cindex ELF dynamic section information
4754 Displays the contents of the file's dynamic section, if it has one.
4757 @itemx --version-info
4758 @cindex ELF version sections information
4759 Displays the contents of the version sections in the file, it they
4763 @itemx --arch-specific
4764 Displays architecture-specific information in the file, if there
4768 @itemx --use-dynamic
4769 When displaying symbols, this option makes @command{readelf} use the
4770 symbol hash tables in the file's dynamic section, rather than the
4771 symbol table sections.
4773 When displaying relocations, this option makes @command{readelf}
4774 display the dynamic relocations rather than the static relocations.
4776 @item -x <number or name>
4777 @itemx --hex-dump=<number or name>
4778 Displays the contents of the indicated section as a hexadecimal bytes.
4779 A number identifies a particular section by index in the section table;
4780 any other string identifies all sections with that name in the object file.
4782 @item -R <number or name>
4783 @itemx --relocated-dump=<number or name>
4784 Displays the contents of the indicated section as a hexadecimal
4785 bytes. A number identifies a particular section by index in the
4786 section table; any other string identifies all sections with that name
4787 in the object file. The contents of the section will be relocated
4788 before they are displayed.
4790 @item -p <number or name>
4791 @itemx --string-dump=<number or name>
4792 Displays the contents of the indicated section as printable strings.
4793 A number identifies a particular section by index in the section table;
4794 any other string identifies all sections with that name in the object file.
4798 Requests that the section(s) being dumped by @option{x}, @option{R} or
4799 @option{p} options are decompressed before being displayed. If the
4800 section(s) are not compressed then they are displayed as is.
4803 @itemx --archive-index
4804 @cindex Archive file symbol index information
4805 Displays the file symbol index information contained in the header part
4806 of binary archives. Performs the same function as the @option{t}
4807 command to @command{ar}, but without using the BFD library. @xref{ar}.
4809 @item -w[lLiaprmfFsoRtUuTgAckK]
4810 @itemx --debug-dump[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]
4811 @include debug.options.texi
4815 Display a histogram of bucket list lengths when displaying the contents
4816 of the symbol tables.
4820 Display the version number of readelf.
4824 Don't break output lines to fit into 80 columns. By default
4825 @command{readelf} breaks section header and segment listing lines for
4826 64-bit ELF files, so that they fit into 80 columns. This option causes
4827 @command{readelf} to print each section header resp. each segment one a
4828 single line, which is far more readable on terminals wider than 80 columns.
4832 Display the command-line options understood by @command{readelf}.
4839 @c man begin SEEALSO readelf
4840 objdump(1), and the Info entries for @file{binutils}.
4847 @cindex Update ELF header
4850 @c man title elfedit Update ELF header and program property of ELF files.
4853 @c man begin SYNOPSIS elfedit
4854 elfedit [@option{--input-mach=}@var{machine}]
4855 [@option{--input-type=}@var{type}]
4856 [@option{--input-osabi=}@var{osabi}]
4857 @option{--output-mach=}@var{machine}
4858 @option{--output-type=}@var{type}
4859 @option{--output-osabi=}@var{osabi}
4860 @option{--enable-x86-feature=}@var{feature}
4861 @option{--disable-x86-feature=}@var{feature}
4862 [@option{-v}|@option{--version}]
4863 [@option{-h}|@option{--help}]
4864 @var{elffile}@dots{}
4868 @c man begin DESCRIPTION elfedit
4870 @command{elfedit} updates the ELF header and program property of ELF
4871 files which have the matching ELF machine and file types. The options
4872 control how and which fields in the ELF header and program property
4875 @var{elffile}@dots{} are the ELF files to be updated. 32-bit and
4876 64-bit ELF files are supported, as are archives containing ELF files.
4879 @c man begin OPTIONS elfedit
4881 The long and short forms of options, shown here as alternatives, are
4882 equivalent. At least one of the @option{--output-mach},
4883 @option{--output-type}, @option{--output-osabi},
4884 @option{--enable-x86-feature} and @option{--disable-x86-feature}
4885 options must be given.
4889 @item --input-mach=@var{machine}
4890 Set the matching input ELF machine type to @var{machine}. If
4891 @option{--input-mach} isn't specified, it will match any ELF
4894 The supported ELF machine types are, @var{i386}, @var{IAMCU}, @var{L1OM},
4895 @var{K1OM} and @var{x86-64}.
4897 @item --output-mach=@var{machine}
4898 Change the ELF machine type in the ELF header to @var{machine}. The
4899 supported ELF machine types are the same as @option{--input-mach}.
4901 @item --input-type=@var{type}
4902 Set the matching input ELF file type to @var{type}. If
4903 @option{--input-type} isn't specified, it will match any ELF file types.
4905 The supported ELF file types are, @var{rel}, @var{exec} and @var{dyn}.
4907 @item --output-type=@var{type}
4908 Change the ELF file type in the ELF header to @var{type}. The
4909 supported ELF types are the same as @option{--input-type}.
4911 @item --input-osabi=@var{osabi}
4912 Set the matching input ELF file OSABI to @var{osabi}. If
4913 @option{--input-osabi} isn't specified, it will match any ELF OSABIs.
4915 The supported ELF OSABIs are, @var{none}, @var{HPUX}, @var{NetBSD},
4916 @var{GNU}, @var{Linux} (alias for @var{GNU}),
4917 @var{Solaris}, @var{AIX}, @var{Irix},
4918 @var{FreeBSD}, @var{TRU64}, @var{Modesto}, @var{OpenBSD}, @var{OpenVMS},
4919 @var{NSK}, @var{AROS} and @var{FenixOS}.
4921 @item --output-osabi=@var{osabi}
4922 Change the ELF OSABI in the ELF header to @var{osabi}. The
4923 supported ELF OSABI are the same as @option{--input-osabi}.
4925 @item --enable-x86-feature=@var{feature}
4926 Set the @var{feature} bit in program property in @var{exec} or @var{dyn}
4927 ELF files with machine types of @var{i386} or @var{x86-64}. The
4928 supported features are, @var{ibt} and @var{shstk}.
4930 @item --disable-x86-feature=@var{feature}
4931 Clear the @var{feature} bit in program property in @var{exec} or
4932 @var{dyn} ELF files with machine types of @var{i386} or @var{x86-64}.
4933 The supported features are the same as @option{--enable-x86-feature}.
4935 Note: @option{--enable-x86-feature} and @option{--disable-x86-feature}
4936 are available only on hosts with @samp{mmap} support.
4940 Display the version number of @command{elfedit}.
4944 Display the command-line options understood by @command{elfedit}.
4951 @c man begin SEEALSO elfedit
4952 readelf(1), and the Info entries for @file{binutils}.
4956 @node Common Options
4957 @chapter Common Options
4959 The following command-line options are supported by all of the
4960 programs described in this manual.
4962 @c man begin OPTIONS
4964 @include at-file.texi
4968 Display the command-line options supported by the program.
4971 Display the version number of the program.
4973 @c man begin OPTIONS
4977 @node Selecting the Target System
4978 @chapter Selecting the Target System
4980 You can specify two aspects of the target system to the @sc{gnu}
4981 binary file utilities, each in several ways:
4991 In the following summaries, the lists of ways to specify values are in
4992 order of decreasing precedence. The ways listed first override those
4995 The commands to list valid values only list the values for which the
4996 programs you are running were configured. If they were configured with
4997 @option{--enable-targets=all}, the commands list most of the available
4998 values, but a few are left out; not all targets can be configured in at
4999 once because some of them can only be configured @dfn{native} (on hosts
5000 with the same type as the target system).
5003 * Target Selection::
5004 * Architecture Selection::
5007 @node Target Selection
5008 @section Target Selection
5010 A @dfn{target} is an object file format. A given target may be
5011 supported for multiple architectures (@pxref{Architecture Selection}).
5012 A target selection may also have variations for different operating
5013 systems or architectures.
5015 The command to list valid target values is @samp{objdump -i}
5016 (the first column of output contains the relevant information).
5018 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
5019 @samp{a.out-sunos-big}.
5021 You can also specify a target using a configuration triplet. This is
5022 the same sort of name that is passed to @file{configure} to specify a
5023 target. When you use a configuration triplet as an argument, it must be
5024 fully canonicalized. You can see the canonical version of a triplet by
5025 running the shell script @file{config.sub} which is included with the
5028 Some sample configuration triplets are: @samp{m68k-hp-bsd},
5029 @samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
5031 @subheading @command{objdump} Target
5037 command-line option: @option{-b} or @option{--target}
5040 environment variable @code{GNUTARGET}
5043 deduced from the input file
5046 @subheading @command{objcopy} and @command{strip} Input Target
5052 command-line options: @option{-I} or @option{--input-target}, or @option{-F} or @option{--target}
5055 environment variable @code{GNUTARGET}
5058 deduced from the input file
5061 @subheading @command{objcopy} and @command{strip} Output Target
5067 command-line options: @option{-O} or @option{--output-target}, or @option{-F} or @option{--target}
5070 the input target (see ``@command{objcopy} and @command{strip} Input Target'' above)
5073 environment variable @code{GNUTARGET}
5076 deduced from the input file
5079 @subheading @command{nm}, @command{size}, and @command{strings} Target
5085 command-line option: @option{--target}
5088 environment variable @code{GNUTARGET}
5091 deduced from the input file
5094 @node Architecture Selection
5095 @section Architecture Selection
5097 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
5098 to run. Its name may contain a colon, separating the name of the
5099 processor family from the name of the particular @sc{cpu}.
5101 The command to list valid architecture values is @samp{objdump -i} (the
5102 second column contains the relevant information).
5104 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
5106 @subheading @command{objdump} Architecture
5112 command-line option: @option{-m} or @option{--architecture}
5115 deduced from the input file
5118 @subheading @command{objcopy}, @command{nm}, @command{size}, @command{strings} Architecture
5124 deduced from the input file
5127 @node Reporting Bugs
5128 @chapter Reporting Bugs
5130 @cindex reporting bugs
5132 Your bug reports play an essential role in making the binary utilities
5135 Reporting a bug may help you by bringing a solution to your problem, or
5136 it may not. But in any case the principal function of a bug report is
5137 to help the entire community by making the next version of the binary
5138 utilities work better. Bug reports are your contribution to their
5141 In order for a bug report to serve its purpose, you must include the
5142 information that enables us to fix the bug.
5145 * Bug Criteria:: Have you found a bug?
5146 * Bug Reporting:: How to report bugs
5150 @section Have You Found a Bug?
5151 @cindex bug criteria
5153 If you are not sure whether you have found a bug, here are some guidelines:
5156 @cindex fatal signal
5159 If a binary utility gets a fatal signal, for any input whatever, that is
5160 a bug. Reliable utilities never crash.
5162 @cindex error on valid input
5164 If a binary utility produces an error message for valid input, that is a
5168 If you are an experienced user of binary utilities, your suggestions for
5169 improvement are welcome in any case.
5173 @section How to Report Bugs
5175 @cindex bugs, reporting
5177 A number of companies and individuals offer support for @sc{gnu}
5178 products. If you obtained the binary utilities from a support
5179 organization, we recommend you contact that organization first.
5181 You can find contact information for many support companies and
5182 individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
5186 In any event, we also recommend that you send bug reports for the binary
5187 utilities to @value{BUGURL}.
5190 The fundamental principle of reporting bugs usefully is this:
5191 @strong{report all the facts}. If you are not sure whether to state a
5192 fact or leave it out, state it!
5194 Often people omit facts because they think they know what causes the
5195 problem and assume that some details do not matter. Thus, you might
5196 assume that the name of a file you use in an example does not matter.
5197 Well, probably it does not, but one cannot be sure. Perhaps the bug is
5198 a stray memory reference which happens to fetch from the location where
5199 that pathname is stored in memory; perhaps, if the pathname were
5200 different, the contents of that location would fool the utility into
5201 doing the right thing despite the bug. Play it safe and give a
5202 specific, complete example. That is the easiest thing for you to do,
5203 and the most helpful.
5205 Keep in mind that the purpose of a bug report is to enable us to fix the bug if
5206 it is new to us. Therefore, always write your bug reports on the assumption
5207 that the bug has not been reported previously.
5209 Sometimes people give a few sketchy facts and ask, ``Does this ring a
5210 bell?'' This cannot help us fix a bug, so it is basically useless. We
5211 respond by asking for enough details to enable us to investigate.
5212 You might as well expedite matters by sending them to begin with.
5214 To enable us to fix the bug, you should include all these things:
5218 The version of the utility. Each utility announces it if you start it
5219 with the @option{--version} argument.
5221 Without this, we will not know whether there is any point in looking for
5222 the bug in the current version of the binary utilities.
5225 Any patches you may have applied to the source, including any patches
5226 made to the @code{BFD} library.
5229 The type of machine you are using, and the operating system name and
5233 What compiler (and its version) was used to compile the utilities---e.g.
5237 The command arguments you gave the utility to observe the bug. To
5238 guarantee you will not omit something important, list them all. A copy
5239 of the Makefile (or the output from make) is sufficient.
5241 If we were to try to guess the arguments, we would probably guess wrong
5242 and then we might not encounter the bug.
5245 A complete input file, or set of input files, that will reproduce the
5246 bug. If the utility is reading an object file or files, then it is
5247 generally most helpful to send the actual object files.
5249 If the source files were produced exclusively using @sc{gnu} programs
5250 (e.g., @command{gcc}, @command{gas}, and/or the @sc{gnu} @command{ld}), then it
5251 may be OK to send the source files rather than the object files. In
5252 this case, be sure to say exactly what version of @command{gcc}, or
5253 whatever, was used to produce the object files. Also say how
5254 @command{gcc}, or whatever, was configured.
5257 A description of what behavior you observe that you believe is
5258 incorrect. For example, ``It gets a fatal signal.''
5260 Of course, if the bug is that the utility gets a fatal signal, then we
5261 will certainly notice it. But if the bug is incorrect output, we might
5262 not notice unless it is glaringly wrong. You might as well not give us
5263 a chance to make a mistake.
5265 Even if the problem you experience is a fatal signal, you should still
5266 say so explicitly. Suppose something strange is going on, such as your
5267 copy of the utility is out of sync, or you have encountered a bug in
5268 the C library on your system. (This has happened!) Your copy might
5269 crash and ours would not. If you told us to expect a crash, then when
5270 ours fails to crash, we would know that the bug was not happening for
5271 us. If you had not told us to expect a crash, then we would not be able
5272 to draw any conclusion from our observations.
5275 If you wish to suggest changes to the source, send us context diffs, as
5276 generated by @command{diff} with the @option{-u}, @option{-c}, or @option{-p}
5277 option. Always send diffs from the old file to the new file. If you
5278 wish to discuss something in the @command{ld} source, refer to it by
5279 context, not by line number.
5281 The line numbers in our development sources will not match those in your
5282 sources. Your line numbers would convey no useful information to us.
5285 Here are some things that are not necessary:
5289 A description of the envelope of the bug.
5291 Often people who encounter a bug spend a lot of time investigating
5292 which changes to the input file will make the bug go away and which
5293 changes will not affect it.
5295 This is often time consuming and not very useful, because the way we
5296 will find the bug is by running a single example under the debugger
5297 with breakpoints, not by pure deduction from a series of examples.
5298 We recommend that you save your time for something else.
5300 Of course, if you can find a simpler example to report @emph{instead}
5301 of the original one, that is a convenience for us. Errors in the
5302 output will be easier to spot, running under the debugger will take
5303 less time, and so on.
5305 However, simplification is not vital; if you do not want to do this,
5306 report the bug anyway and send us the entire test case you used.
5309 A patch for the bug.
5311 A patch for the bug does help us if it is a good one. But do not omit
5312 the necessary information, such as the test case, on the assumption that
5313 a patch is all we need. We might see problems with your patch and decide
5314 to fix the problem another way, or we might not understand it at all.
5316 Sometimes with programs as complicated as the binary utilities it is
5317 very hard to construct an example that will make the program follow a
5318 certain path through the code. If you do not send us the example, we
5319 will not be able to construct one, so we will not be able to verify that
5322 And if we cannot understand what bug you are trying to fix, or why your
5323 patch should be an improvement, we will not install it. A test case will
5324 help us to understand.
5327 A guess about what the bug is or what it depends on.
5329 Such guesses are usually wrong. Even we cannot guess right about such
5330 things without first using the debugger to find the facts.
5333 @node GNU Free Documentation License
5334 @appendix GNU Free Documentation License
5338 @node Binutils Index
5339 @unnumbered Binutils Index