1 \input texinfo @c -*- Texinfo -*-
2 @setfilename binutils.info
8 * Binutils: (binutils). The GNU binary utilities "ar", "objcopy",
9 "objdump", "nm", "nlmconv", "size",
10 "strings", "strip", and "ranlib".
16 Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.
18 Permission is granted to make and distribute verbatim copies of
19 this manual provided the copyright notice and this permission notice
20 are preserved on all copies.
23 Permission is granted to process this file through TeX and print the
24 results, provided the printed document carries a copying permission
25 notice identical to this one except for the removal of this paragraph
26 (this paragraph not being relevant to the printed manual).
30 Permission is granted to copy and distribute modified versions of this
31 manual under the conditions for verbatim copying, provided also that
32 the entire resulting derived work is distributed under the terms of a
33 permission notice identical to this one.
35 Permission is granted to copy and distribute translations of this manual
36 into another language, under the above conditions for modified versions.
41 @c This file documents the GNU binary utilities "ar", "ld", "objcopy",
42 @c "objdump", "nm", "size", "strings", "strip", and "ranlib".
44 @c Copyright (C) 1991, 92, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.
46 @c This text may be freely distributed under the terms of the GNU
47 @c General Public License.
50 @setchapternewpage odd
51 @settitle @sc{gnu} Binary Utilities
54 @title The @sc{gnu} Binary Utilities
55 @subtitle Version @value{VERSION}
58 @author Roland H. Pesch
59 @author Jeffrey M. Osier
60 @author Cygnus Support
64 {\parskip=0pt \hfill Cygnus Support\par \hfill
65 \TeX{}info \texinfoversion\par }
68 @vskip 0pt plus 1filll
69 Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.
71 Permission is granted to make and distribute verbatim copies of
72 this manual provided the copyright notice and this permission notice
73 are preserved on all copies.
75 Permission is granted to copy and distribute modified versions of this
76 manual under the conditions for verbatim copying, provided also that
77 the entire resulting derived work is distributed under the terms of a
78 permission notice identical to this one.
80 Permission is granted to copy and distribute translations of this manual
81 into another language, under the above conditions for modified versions.
88 This brief manual contains preliminary documentation for the @sc{gnu} binary
89 utilities (collectively version @value{VERSION}):
94 Create, modify, and extract from archives
97 List symbols from object files
100 Copy and translate object files
103 Display information from object files
106 Generate index to archive contents
109 List file section sizes and total size
112 List printable strings from files
118 Demangle encoded C++ symbols
121 Convert object code into a Netware Loadable Module
126 * ar:: Create, modify, and extract from archives
127 * nm:: List symbols from object files
128 * objcopy:: Copy and translate object files
129 * objdump:: Display information from object files
130 * ranlib:: Generate index to archive contents
131 * size:: List section sizes and total size
132 * strings:: List printable strings from files
133 * strip:: Discard symbols
134 * c++filt:: Filter to demangle encoded C++ symbols
135 * nlmconv:: Converts object code into an NLM
136 * Selecting The Target System:: How these utilities determine the target.
137 * Reporting Bugs:: Reporting Bugs
146 @cindex collections of files
148 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
149 ar -M [ <mri-script ]
152 The @sc{gnu} @code{ar} program creates, modifies, and extracts from
153 archives. An @dfn{archive} is a single file holding a collection of
154 other files in a structure that makes it possible to retrieve
155 the original individual files (called @dfn{members} of the archive).
157 The original files' contents, mode (permissions), timestamp, owner, and
158 group are preserved in the archive, and can be restored on
162 @sc{gnu} @code{ar} can maintain archives whose members have names of any
163 length; however, depending on how @code{ar} is configured on your
164 system, a limit on member-name length may be imposed for compatibility
165 with archive formats maintained with other tools. If it exists, the
166 limit is often 15 characters (typical of formats related to a.out) or 16
167 characters (typical of formats related to coff).
170 @code{ar} is considered a binary utility because archives of this sort
171 are most often used as @dfn{libraries} holding commonly needed
175 @code{ar} creates an index to the symbols defined in relocatable
176 object modules in the archive when you specify the modifier @samp{s}.
177 Once created, this index is updated in the archive whenever @code{ar}
178 makes a change to its contents (save for the @samp{q} update operation).
179 An archive with such an index speeds up linking to the library, and
180 allows routines in the library to call each other without regard to
181 their placement in the archive.
183 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
184 table. If an archive lacks the table, another form of @code{ar} called
185 @code{ranlib} can be used to add just the table.
187 @cindex compatibility, @code{ar}
188 @cindex @code{ar} compatibility
189 @sc{gnu} @code{ar} is designed to be compatible with two different
190 facilities. You can control its activity using command-line options,
191 like the different varieties of @code{ar} on Unix systems; or, if you
192 specify the single command-line option @samp{-M}, you can control it
193 with a script supplied via standard input, like the MRI ``librarian''
197 * ar cmdline:: Controlling @code{ar} on the command line
198 * ar scripts:: Controlling @code{ar} with a script
203 @section Controlling @code{ar} on the command line
206 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
209 @cindex Unix compatibility, @code{ar}
210 When you use @code{ar} in the Unix style, @code{ar} insists on at least two
211 arguments to execute: one keyletter specifying the @emph{operation}
212 (optionally accompanied by other keyletters specifying
213 @emph{modifiers}), and the archive name to act on.
215 Most operations can also accept further @var{member} arguments,
216 specifying particular files to operate on.
218 @sc{gnu} @code{ar} allows you to mix the operation code @var{p} and modifier
219 flags @var{mod} in any order, within the first command-line argument.
221 If you wish, you may begin the first command-line argument with a
224 @cindex operations on archive
225 The @var{p} keyletter specifies what operation to execute; it may be
226 any of the following, but you must specify only one of them:
230 @cindex deleting from archive
231 @emph{Delete} modules from the archive. Specify the names of modules to
232 be deleted as @var{member}@dots{}; the archive is untouched if you
233 specify no files to delete.
235 If you specify the @samp{v} modifier, @code{ar} lists each module
239 @cindex moving in archive
240 Use this operation to @emph{move} members in an archive.
242 The ordering of members in an archive can make a difference in how
243 programs are linked using the library, if a symbol is defined in more
246 If no modifiers are used with @code{m}, any members you name in the
247 @var{member} arguments are moved to the @emph{end} of the archive;
248 you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
249 specified place instead.
252 @cindex printing from archive
253 @emph{Print} the specified members of the archive, to the standard
254 output file. If the @samp{v} modifier is specified, show the member
255 name before copying its contents to standard output.
257 If you specify no @var{member} arguments, all the files in the archive are
261 @cindex quick append to archive
262 @emph{Quick append}; add the files @var{member}@dots{} to the end of
263 @var{archive}, without checking for replacement.
265 The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
266 operation; new members are always placed at the end of the archive.
268 The modifier @samp{v} makes @code{ar} list each file as it is appended.
270 Since the point of this operation is speed, the archive's symbol table
271 index is not updated, even if it already existed; you can use @samp{ar s} or
272 @code{ranlib} explicitly to update the symbol table index.
275 @cindex replacement in archive
276 Insert the files @var{member}@dots{} into @var{archive} (with
277 @emph{replacement}). This operation differs from @samp{q} in that any
278 previously existing members are deleted if their names match those being
281 If one of the files named in @var{member}@dots{} does not exist, @code{ar}
282 displays an error message, and leaves undisturbed any existing members
283 of the archive matching that name.
285 By default, new members are added at the end of the file; but you may
286 use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
287 placement relative to some existing member.
289 The modifier @samp{v} used with this operation elicits a line of
290 output for each file inserted, along with one of the letters @samp{a} or
291 @samp{r} to indicate whether the file was appended (no old member
292 deleted) or replaced.
295 @cindex contents of archive
296 Display a @emph{table} listing the contents of @var{archive}, or those
297 of the files listed in @var{member}@dots{} that are present in the
298 archive. Normally only the member name is shown; if you also want to
299 see the modes (permissions), timestamp, owner, group, and size, you can
300 request that by also specifying the @samp{v} modifier.
302 If you do not specify a @var{member}, all files in the archive
305 @cindex repeated names in archive
306 @cindex name duplication in archive
307 If there is more than one file with the same name (say, @samp{fie}) in
308 an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
309 first instance; to see them all, you must ask for a complete
310 listing---in our example, @samp{ar t b.a}.
311 @c WRS only; per Gumby, this is implementation-dependent, and in a more
312 @c recent case in fact works the other way.
315 @cindex extract from archive
316 @emph{Extract} members (named @var{member}) from the archive. You can
317 use the @samp{v} modifier with this operation, to request that
318 @code{ar} list each name as it extracts it.
320 If you do not specify a @var{member}, all files in the archive
325 A number of modifiers (@var{mod}) may immediately follow the @var{p}
326 keyletter, to specify variations on an operation's behavior:
330 @cindex relative placement in archive
331 Add new files @emph{after} an existing member of the
332 archive. If you use the modifier @samp{a}, the name of an existing archive
333 member must be present as the @var{relpos} argument, before the
334 @var{archive} specification.
337 Add new files @emph{before} an existing member of the
338 archive. If you use the modifier @samp{b}, the name of an existing archive
339 member must be present as the @var{relpos} argument, before the
340 @var{archive} specification. (same as @samp{i}).
343 @cindex creating archives
344 @emph{Create} the archive. The specified @var{archive} is always
345 created if it did not exist, when you request an update. But a warning is
346 issued unless you specify in advance that you expect to create it, by
350 Truncate names in the archive. @sc{gnu} @code{ar} will normally permit file
351 names of any length. This will cause it to create archives which are
352 not compatible with the native @code{ar} program on some systems. If
353 this is a concern, the @samp{f} modifier may be used to truncate file
354 names when putting them in the archive.
357 Insert new files @emph{before} an existing member of the
358 archive. If you use the modifier @samp{i}, the name of an existing archive
359 member must be present as the @var{relpos} argument, before the
360 @var{archive} specification. (same as @samp{b}).
363 This modifier is accepted but not used.
364 @c whaffor ar l modifier??? presumably compat; with
365 @c what???---doc@@cygnus.com, 25jan91
368 @cindex dates in archive
369 Preserve the @emph{original} dates of members when extracting them. If
370 you do not specify this modifier, files extracted from the archive
371 are stamped with the time of extraction.
374 @cindex writing archive index
375 Write an object-file index into the archive, or update an existing one,
376 even if no other change is made to the archive. You may use this modifier
377 flag either with any operation, or alone. Running @samp{ar s} on an
378 archive is equivalent to running @samp{ranlib} on it.
381 @cindex updating an archive
382 Normally, @samp{ar r}@dots{} inserts all files
383 listed into the archive. If you would like to insert @emph{only} those
384 of the files you list that are newer than existing members of the same
385 names, use this modifier. The @samp{u} modifier is allowed only for the
386 operation @samp{r} (replace). In particular, the combination @samp{qu} is
387 not allowed, since checking the timestamps would lose any speed
388 advantage from the operation @samp{q}.
391 This modifier requests the @emph{verbose} version of an operation. Many
392 operations display additional information, such as filenames processed,
393 when the modifier @samp{v} is appended.
396 This modifier shows the version number of @code{ar}.
400 @section Controlling @code{ar} with a script
403 ar -M [ <@var{script} ]
406 @cindex MRI compatibility, @code{ar}
407 @cindex scripts, @code{ar}
408 If you use the single command-line option @samp{-M} with @code{ar}, you
409 can control its operation with a rudimentary command language. This
410 form of @code{ar} operates interactively if standard input is coming
411 directly from a terminal. During interactive use, @code{ar} prompts for
412 input (the prompt is @samp{AR >}), and continues executing even after
413 errors. If you redirect standard input to a script file, no prompts are
414 issued, and @code{ar} abandons execution (with a nonzero exit code)
417 The @code{ar} command language is @emph{not} designed to be equivalent
418 to the command-line options; in fact, it provides somewhat less control
419 over archives. The only purpose of the command language is to ease the
420 transition to @sc{gnu} @code{ar} for developers who already have scripts
421 written for the MRI ``librarian'' program.
423 The syntax for the @code{ar} command language is straightforward:
426 commands are recognized in upper or lower case; for example, @code{LIST}
427 is the same as @code{list}. In the following descriptions, commands are
428 shown in upper case for clarity.
431 a single command may appear on each line; it is the first word on the
435 empty lines are allowed, and have no effect.
438 comments are allowed; text after either of the characters @samp{*}
439 or @samp{;} is ignored.
442 Whenever you use a list of names as part of the argument to an @code{ar}
443 command, you can separate the individual names with either commas or
444 blanks. Commas are shown in the explanations below, for clarity.
447 @samp{+} is used as a line continuation character; if @samp{+} appears
448 at the end of a line, the text on the following line is considered part
449 of the current command.
452 Here are the commands you can use in @code{ar} scripts, or when using
453 @code{ar} interactively. Three of them have special significance:
455 @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
456 a temporary file required for most of the other commands.
458 @code{SAVE} commits the changes so far specified by the script. Prior
459 to @code{SAVE}, commands affect only the temporary copy of the current
463 @item ADDLIB @var{archive}
464 @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
465 Add all the contents of @var{archive} (or, if specified, each named
466 @var{module} from @var{archive}) to the current archive.
468 Requires prior use of @code{OPEN} or @code{CREATE}.
470 @item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
471 @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
472 @c else like "ar q..."
473 Add each named @var{member} as a module in the current archive.
475 Requires prior use of @code{OPEN} or @code{CREATE}.
478 Discard the contents of the current archive, cancelling the effect of
479 any operations since the last @code{SAVE}. May be executed (with no
480 effect) even if no current archive is specified.
482 @item CREATE @var{archive}
483 Creates an archive, and makes it the current archive (required for many
484 other commands). The new archive is created with a temporary name; it
485 is not actually saved as @var{archive} until you use @code{SAVE}.
486 You can overwrite existing archives; similarly, the contents of any
487 existing file named @var{archive} will not be destroyed until @code{SAVE}.
489 @item DELETE @var{module}, @var{module}, @dots{} @var{module}
490 Delete each listed @var{module} from the current archive; equivalent to
491 @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
493 Requires prior use of @code{OPEN} or @code{CREATE}.
495 @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
496 @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
497 List each named @var{module} present in @var{archive}. The separate
498 command @code{VERBOSE} specifies the form of the output: when verbose
499 output is off, output is like that of @samp{ar -t @var{archive}
500 @var{module}@dots{}}. When verbose output is on, the listing is like
501 @samp{ar -tv @var{archive} @var{module}@dots{}}.
503 Output normally goes to the standard output stream; however, if you
504 specify @var{outputfile} as a final argument, @code{ar} directs the
508 Exit from @code{ar}, with a @code{0} exit code to indicate successful
509 completion. This command does not save the output file; if you have
510 changed the current archive since the last @code{SAVE} command, those
513 @item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
514 Extract each named @var{module} from the current archive, writing them
515 into the current directory as separate files. Equivalent to @samp{ar -x
516 @var{archive} @var{module}@dots{}}.
518 Requires prior use of @code{OPEN} or @code{CREATE}.
521 @c FIXME Tokens but no commands???
528 Display full contents of the current archive, in ``verbose'' style
529 regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
530 tv @var{archive}}). (This single command is a @sc{gnu} @code{ld}
531 enhancement, rather than present for MRI compatibility.)
533 Requires prior use of @code{OPEN} or @code{CREATE}.
535 @item OPEN @var{archive}
536 Opens an existing archive for use as the current archive (required for
537 many other commands). Any changes as the result of subsequent commands
538 will not actually affect @var{archive} until you next use @code{SAVE}.
540 @item REPLACE @var{module}, @var{module}, @dots{} @var{module}
541 In the current archive, replace each existing @var{module} (named in
542 the @code{REPLACE} arguments) from files in the current working directory.
543 To execute this command without errors, both the file, and the module in
544 the current archive, must exist.
546 Requires prior use of @code{OPEN} or @code{CREATE}.
549 Toggle an internal flag governing the output from @code{DIRECTORY}.
550 When the flag is on, @code{DIRECTORY} output matches output from
551 @samp{ar -tv }@dots{}.
554 Commit your changes to the current archive, and actually save it as a
555 file with the name specified in the last @code{CREATE} or @code{OPEN}
558 Requires prior use of @code{OPEN} or @code{CREATE}.
567 The @sc{gnu} linker @code{ld} is now described in a separate manual.
568 @xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
577 nm [ -a | --debug-syms ] [ -g | --extern-only ]
578 [ -B ] [ -C | --demangle ] [ -D | --dynamic ]
579 [ -s | --print-armap ] [ -A | -o | --print-file-name ]
580 [ -n | -v | --numeric-sort ] [ -p | --no-sort ]
581 [ -r | --reverse-sort ] [ --size-sort ] [ -u | --undefined-only ]
582 [ -t @var{radix} | --radix=@var{radix} ] [ -P | --portability ]
583 [ --target=@var{bfdname} ] [ -f @var{format} | --format=@var{format} ]
584 [ --defined-only ] [-l | --line-numbers ]
585 [ --no-demangle ] [ -V | --version ] [ --help ] [ @var{objfile}@dots{} ]
588 @sc{gnu} @code{nm} lists the symbols from object files @var{objfile}@dots{}.
589 If no object files are listed as arguments, @code{nm} assumes
592 For each symbol, @code{nm} shows:
596 The symbol value, in the radix selected by options (see below), or
597 hexadecimal by default.
600 The symbol type. At least the following types are used; others are, as
601 well, depending on the object file format. If lowercase, the symbol is
602 local; if uppercase, the symbol is global (external).
604 @c Some more detail on exactly what these symbol types are used for
608 The symbol's value is absolute, and will not be changed by further
612 The symbol is in the uninitialized data section (known as BSS).
615 The symbol is common. Common symbols are uninitialized data. When
616 linking, multiple common symbols may appear with the same name. If the
617 symbol is defined anywhere, the common symbols are treated as undefined
618 references. For more details on common symbols, see the discussion of
619 --warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
622 The symbol is in the initialized data section.
625 The symbol is in an initialized data section for small objects. Some
626 object file formats permit more efficient access to small data objects,
627 such as a global int variable as opposed to a large global array.
630 The symbol is an indirect reference to another symbol. This is a GNU
631 extension to the a.out object file format which is rarely used.
634 The symbol is a debugging symbol.
637 The symbol is in a read only data section.
640 The symbol is in an uninitialized data section for small objects.
643 The symbol is in the text (code) section.
646 The symbol is undefined.
649 The symbol is weak. When a weak defined symbol is linked with a normal
650 defined symbol, the normal defined symbol is used with no error. When a
651 weak undefined symbol is linked and the symbol is not defined, the value
652 of the weak symbol becomes zero with no error.
655 The symbol is a stabs symbol in an a.out object file. In this case, the
656 next values printed are the stabs other field, the stabs desc field, and
657 the stab type. Stabs symbols are used to hold debugging information;
658 for more information, see @ref{Top,Stabs,Stabs Overview,stabs.info, The
659 ``stabs'' debug format}.
662 The symbol type is unknown, or object file format specific.
669 The long and short forms of options, shown here as alternatives, are
675 @itemx --print-file-name
676 @cindex input file name
678 @cindex source file name
679 Precede each symbol by the name of the input file (or archive element)
680 in which it was found, rather than identifying the input file once only,
681 before all of its symbols.
685 @cindex debugging symbols
686 Display all symbols, even debugger-only symbols; normally these are not
690 @cindex @code{nm} format
691 @cindex @code{nm} compatibility
692 The same as @samp{--format=bsd} (for compatibility with the MIPS @code{nm}).
696 @cindex demangling C++ symbols
697 Decode (@dfn{demangle}) low-level symbol names into user-level names.
698 Besides removing any initial underscore prepended by the system, this
699 makes C++ function names readable. @xref{c++filt}, for more information
703 Do not demangle low-level symbol names. This is the default.
707 @cindex dynamic symbols
708 Display the dynamic symbols rather than the normal symbols. This is
709 only meaningful for dynamic objects, such as certain types of shared
712 @item -f @var{format}
713 @itemx --format=@var{format}
714 @cindex @code{nm} format
715 @cindex @code{nm} compatibility
716 Use the output format @var{format}, which can be @code{bsd},
717 @code{sysv}, or @code{posix}. The default is @code{bsd}.
718 Only the first character of @var{format} is significant; it can be
719 either upper or lower case.
723 @cindex external symbols
724 Display only external symbols.
727 @itemx --line-numbers
728 @cindex symbol line numbers
729 For each symbol, use debugging information to try to find a filename and
730 line number. For a defined symbol, look for the line number of the
731 address of the symbol. For an undefined symbol, look for the line
732 number of a relocation entry which refers to the symbol. If line number
733 information can be found, print it after the other symbol information.
737 @itemx --numeric-sort
738 Sort symbols numerically by their addresses, rather than alphabetically
743 @cindex sorting symbols
744 Do not bother to sort the symbols in any order; print them in the order
749 Use the POSIX.2 standard output format instead of the default format.
750 Equivalent to @samp{-f posix}.
754 @cindex symbol index, listing
755 When listing symbols from archive members, include the index: a mapping
756 (stored in the archive by @code{ar} or @code{ranlib}) of which modules
757 contain definitions for which names.
760 @itemx --reverse-sort
761 Reverse the order of the sort (whether numeric or alphabetic); let the
765 Sort symbols by size. The size is computed as the difference between
766 the value of the symbol and the value of the symbol with the next higher
767 value. The size of the symbol is printed, rather than the value.
770 @itemx --radix=@var{radix}
771 Use @var{radix} as the radix for printing the symbol values. It must be
772 @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
774 @item --target=@var{bfdname}
775 @cindex object code format
776 Specify an object code format other than your system's default format.
777 @xref{Target Selection}, for more information.
780 @itemx --undefined-only
781 @cindex external symbols
782 @cindex undefined symbols
783 Display only undefined symbols (those external to each object file).
786 @cindex external symbols
787 @cindex undefined symbols
788 Display only defined symbols for each object file.
792 Show the version number of @code{nm} and exit.
795 Show a summary of the options to @code{nm} and exit.
802 objcopy [ -F @var{bfdname} | --target=@var{bfdname} ]
803 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
804 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
805 [ -S | --strip-all ] [ -g | --strip-debug ]
806 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
807 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
808 [ -x | --discard-all ] [ -X | --discard-locals ]
809 [ -b @var{byte} | --byte=@var{byte} ]
810 [ -i @var{interleave} | --interleave=@var{interleave} ]
811 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
813 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
814 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
815 [ --adjust-vma=@var{incr} ]
816 [ --adjust-section-vma=@var{section}@{=,+,-@}@var{val} ]
817 [ --adjust-warnings ] [ --no-adjust-warnings ]
818 [ --set-section-flags=@var{section}=@var{flags} ]
819 [ --add-section=@var{sectionname}=@var{filename} ]
820 [ --change-leading-char ] [ --remove-leading-char ]
822 [ -v | --verbose ] [ -V | --version ] [ --help ]
823 @var{infile} [@var{outfile}]
826 The @sc{gnu} @code{objcopy} utility copies the contents of an object
827 file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
828 read and write the object files. It can write the destination object
829 file in a format different from that of the source object file. The
830 exact behavior of @code{objcopy} is controlled by command-line options.
832 @code{objcopy} creates temporary files to do its translations and
833 deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
834 translation work; it has access to all the formats described in @sc{bfd}
835 and thus is able to recognize most formats without being told
836 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
838 @code{objcopy} can be used to generate S-records by using an output
839 target of @samp{srec} (e.g., use @samp{-O srec}).
841 @code{objcopy} can be used to generate a raw binary file by using an
842 output target of @samp{binary} (e.g., use @samp{-O binary}). When
843 @code{objcopy} generates a raw binary file, it will essentially produce
844 a memory dump of the contents of the input object file. All symbols and
845 relocation information will be discarded. The memory dump will start at
846 the load address of the lowest section copied into the output file.
848 When generating an S-record or a raw binary file, it may be helpful to
849 use @samp{-S} to remove sections containing debugging information. In
850 some cases @samp{-R} will be useful to remove sections which contain
851 information which is not needed by the binary file.
856 The source and output files, respectively.
857 If you do not specify @var{outfile}, @code{objcopy} creates a
858 temporary file and destructively renames the result with
859 the name of @var{infile}.
861 @item -I @var{bfdname}
862 @itemx --input-target=@var{bfdname}
863 Consider the source file's object format to be @var{bfdname}, rather than
864 attempting to deduce it. @xref{Target Selection}, for more information.
866 @item -O @var{bfdname}
867 @itemx --output-target=@var{bfdname}
868 Write the output file using the object format @var{bfdname}.
869 @xref{Target Selection}, for more information.
871 @item -F @var{bfdname}
872 @itemx --target=@var{bfdname}
873 Use @var{bfdname} as the object format for both the input and the output
874 file; i.e., simply transfer data from source to destination with no
875 translation. @xref{Target Selection}, for more information.
877 @item -R @var{sectionname}
878 @itemx --remove-section=@var{sectionname}
879 Remove any section named @var{sectionname} from the output file. This
880 option may be given more than once. Note that using this option
881 inappropriately may make the output file unusable.
885 Do not copy relocation and symbol information from the source file.
889 Do not copy debugging symbols from the source file.
891 @item --strip-unneeded
892 Strip all symbols that are not needed for relocation processing.
894 @item -K @var{symbolname}
895 @itemx --keep-symbol=@var{symbolname}
896 Copy only symbol @var{symbolname} from the source file. This option may
897 be given more than once.
899 @item -N @var{symbolname}
900 @itemx --strip-symbol=@var{symbolname}
901 Do not copy symbol @var{symbolname} from the source file. This option
902 may be given more than once, and may be combined with strip options
903 other than @code{-K}.
907 Do not copy non-global symbols from the source file.
908 @c FIXME any reason to prefer "non-global" to "local" here?
911 @itemx --discard-locals
912 Do not copy compiler-generated local symbols.
913 (These usually start with @samp{L} or @samp{.}.)
916 @itemx --byte=@var{byte}
917 Keep only every @var{byte}th byte of the input file (header data is not
918 affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
919 where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
920 option, or the default of 4. This option is useful for creating files
921 to program @sc{rom}. It is typically used with an @code{srec} output
924 @item -i @var{interleave}
925 @itemx --interleave=@var{interleave}
926 Only copy one out of every @var{interleave} bytes. Select which byte to
927 copy with the @var{-b} or @samp{--byte} option. The default is 4.
928 @code{objcopy} ignores this option if you do not specify either @samp{-b} or
932 Convert debugging information, if possible. This is not the default
933 because only certain debugging formats are supported, and the
934 conversion process can be time consuming.
936 @item --gap-fill @var{val}
937 Fill gaps between sections with @var{val}. This is done by increasing
938 the size of the section with the lower address, and filling in the extra
939 space created with @var{val}.
941 @item --pad-to @var{address}
942 Pad the output file up to the virtual address @var{address}. This is
943 done by increasing the size of the last section. The extra space is
944 filled in with the value specified by @samp{--gap-fill} (default zero).
946 @item --set-start @var{val}
947 Set the address of the new file to @var{val}. Not all object file
948 formats support setting the start address.
950 @item --adjust-start @var{incr}
951 Adjust the start address by adding @var{incr}. Not all object file
952 formats support setting the start address.
954 @item --adjust-vma @var{incr}
955 Adjust the address of all sections, as well as the start address, by
956 adding @var{incr}. Some object file formats do not permit section
957 addresses to be changed arbitrarily. Note that this does not relocate
958 the sections; if the program expects sections to be loaded at a certain
959 address, and this option is used to change the sections such that they
960 are loaded at a different address, the program may fail.
962 @item --adjust-section-vma @var{section}@{=,+,-@}@var{val}
963 Set or adjust the address of the named @var{section}. If @samp{=} is
964 used, the section address is set to @var{val}. Otherwise, @var{val} is
965 added to or subtracted from the section address. See the comments under
966 @samp{--adjust-vma}, above. If @var{section} does not exist in the
967 input file, a warning will be issued, unless @samp{--no-adjust-warnings}
970 @item --adjust-warnings
971 If @samp{--adjust-section-vma} is used, and the named section does not
972 exist, issue a warning. This is the default.
974 @item --no-adjust-warnings
975 Do not issue a warning if @samp{--adjust-section-vma} is used, even if
976 the named section does not exist.
978 @item --set-section-flags @var{section}=@var{flags}
979 Set the flags for the named section. The @var{flags} argument is a
980 comma separated string of flag names. The recognized names are
981 @samp{alloc}, @samp{load}, @samp{readonly}, @samp{code}, @samp{data},
982 and @samp{rom}. Not all flags are meaningful for all object file
985 @item --add-section @var{sectionname}=@var{filename}
986 Add a new section named @var{sectionname} while copying the file. The
987 contents of the new section are taken from the file @var{filename}. The
988 size of the section will be the size of the file. This option only
989 works on file formats which can support sections with arbitrary names.
991 @item --change-leading-char
992 Some object file formats use special characters at the start of
993 symbols. The most common such character is underscore, which compilers
994 often add before every symbol. This option tells @code{objcopy} to
995 change the leading character of every symbol when it converts between
996 object file formats. If the object file formats use the same leading
997 character, this option has no effect. Otherwise, it will add a
998 character, or remove a character, or change a character, as
1001 @item --remove-leading-char
1002 If the first character of a global symbol is a special symbol leading
1003 character used by the object file format, remove the character. The
1004 most common symbol leading character is underscore. This option will
1005 remove a leading underscore from all global symbols. This can be useful
1006 if you want to link together objects of different file formats with
1007 different conventions for symbol names. This is different from
1008 @code{--change-leading-char} because it always changes the symbol name
1009 when appropriate, regardless of the object file format of the output
1013 Change all global symbols in the file to be weak. This can be useful
1014 when building an object which will be linked against other objects using
1015 the @code{-R} option to the linker. This option is only effective when
1016 using an object file format which supports weak symbols.
1020 Show the version number of @code{objcopy}.
1024 Verbose output: list all object files modified. In the case of
1025 archives, @samp{objcopy -V} lists all members of the archive.
1028 Show a summary of the options to @code{objcopy}.
1034 @cindex object file information
1038 objdump [ -a | --archive-headers ]
1039 [ -b @var{bfdname} | --target=@var{bfdname} ] [ --debugging ]
1040 [ -d | --disassemble ] [ -D | --disassemble-all ]
1041 [ --disassemble-zeroes ]
1042 [ -EB | -EL | --endian=@{big | little @} ]
1043 [ -f | --file-headers ]
1044 [ -h | --section-headers | --headers ] [ -i | --info ]
1045 [ -j @var{section} | --section=@var{section} ]
1046 [ -l | --line-numbers ] [ -S | --source ]
1047 [ -m @var{machine} | --architecture=@var{machine} ]
1048 [ -r | --reloc ] [ -R | --dynamic-reloc ]
1049 [ -s | --full-contents ] [ --stabs ]
1050 [ -t | --syms ] [ -T | --dynamic-syms ] [ -x | --all-headers ]
1051 [ -w | --wide ] [ --start-address=@var{address} ]
1052 [ --stop-address=@var{address} ]
1053 [ --prefix-addresses] [ --[no-]show-raw-insn ]
1054 [ --adjust-vma=@var{offset} ]
1055 [ --version ] [ --help ]
1056 @var{objfile}@dots{}
1059 @code{objdump} displays information about one or more object files.
1060 The options control what particular information to display. This
1061 information is mostly useful to programmers who are working on the
1062 compilation tools, as opposed to programmers who just want their
1063 program to compile and work.
1065 @var{objfile}@dots{} are the object files to be examined. When you
1066 specify archives, @code{objdump} shows information on each of the member
1069 The long and short forms of options, shown here as alternatives, are
1070 equivalent. At least one option besides @samp{-l} must be given.
1074 @itemx --archive-header
1075 @cindex archive headers
1076 If any of the @var{objfile} files are archives, display the archive
1077 header information (in a format similar to @samp{ls -l}). Besides the
1078 information you could list with @samp{ar tv}, @samp{objdump -a} shows
1079 the object file format of each archive member.
1081 @item --adjust-vma=@var{offset}
1082 @cindex section addresses in objdump
1083 @cindex VMA in objdump
1084 When dumping information, first add @var{offset} to all the section
1085 addresses. This is useful if the section addresses do not correspond to
1086 the symbol table, which can happen when putting sections at particular
1087 addresses when using a format which can not represent section addresses,
1090 @item -b @var{bfdname}
1091 @itemx --target=@var{bfdname}
1092 @cindex object code format
1093 Specify that the object-code format for the object files is
1094 @var{bfdname}. This option may not be necessary; @var{objdump} can
1095 automatically recognize many formats.
1099 objdump -b oasys -m vax -h fu.o
1102 displays summary information from the section headers (@samp{-h}) of
1103 @file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1104 file in the format produced by Oasys compilers. You can list the
1105 formats available with the @samp{-i} option.
1106 @xref{Target Selection}, for more information.
1109 Display debugging information. This attempts to parse debugging
1110 information stored in the file and print it out using a C like syntax.
1111 Only certain types of debugging information have been implemented.
1114 @itemx --disassemble
1115 @cindex disassembling object code
1116 @cindex machine instructions
1117 Display the assembler mnemonics for the machine instructions from
1118 @var{objfile}. This option only disassembles those sections which are
1119 expected to contain instructions.
1122 @itemx --disassemble-all
1123 Like @samp{-d}, but disassemble the contents of all sections, not just
1124 those expected to contain instructions.
1126 @item --prefix-addresses
1127 When disassembling, print the complete address on each line. This is
1128 the older disassembly format.
1130 @item --disassemble-zeroes
1131 Normally the disassembly output will skip blocks of zeroes. This
1132 option directs the disassembler to disassemble those blocks, just like
1137 @itemx --endian=@{big|little@}
1139 @cindex disassembly endianness
1140 Specify the endianness of the object files. This only affects
1141 disassembly. This can be useful when disassembling a file format which
1142 does not describe endianness information, such as S-records.
1145 @itemx --file-header
1146 @cindex object file header
1147 Display summary information from the overall header of
1148 each of the @var{objfile} files.
1151 @itemx --section-header
1153 @cindex section headers
1154 Display summary information from the section headers of the
1157 File segments may be relocated to nonstandard addresses, for example by
1158 using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1159 @code{ld}. However, some object file formats, such as a.out, do not
1160 store the starting address of the file segments. In those situations,
1161 although @code{ld} relocates the sections correctly, using @samp{objdump
1162 -h} to list the file section headers cannot show the correct addresses.
1163 Instead, it shows the usual addresses, which are implicit for the
1167 Print a summary of the options to @code{objdump} and exit.
1171 @cindex architectures available
1172 @cindex object formats available
1173 Display a list showing all architectures and object formats available
1174 for specification with @samp{-b} or @samp{-m}.
1177 @itemx --section=@var{name}
1178 @cindex section information
1179 Display information only for section @var{name}.
1182 @itemx --line-numbers
1183 @cindex source filenames for object files
1184 Label the display (using debugging information) with the filename and
1185 source line numbers corresponding to the object code or relocs shown.
1186 Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1188 @item -m @var{machine}
1189 @itemx --architecture=@var{machine}
1190 @cindex architecture
1191 @cindex disassembly architecture
1192 Specify the architecture to use when disassembling object files. This
1193 can be useful when disasembling object files which do not describe
1194 architecture information, such as S-records. You can list the available
1195 architectures with the @samp{-i} option.
1199 @cindex relocation entries, in object file
1200 Print the relocation entries of the file. If used with @samp{-d} or
1201 @samp{-D}, the relocations are printed interspersed with the
1205 @itemx --dynamic-reloc
1206 @cindex dynamic relocation entries, in object file
1207 Print the dynamic relocation entries of the file. This is only
1208 meaningful for dynamic objects, such as certain types of shared
1212 @itemx --full-contents
1213 @cindex sections, full contents
1214 @cindex object file sections
1215 Display the full contents of any sections requested.
1219 @cindex source disassembly
1220 @cindex disassembly, with source
1221 Display source code intermixed with disassembly, if possible. Implies
1224 @item --show-raw-insn
1225 When disassembling instructions, print the instruction in hex as well as
1226 in symbolic form. This is the default except when
1227 @code{--prefix-addresses} is used.
1229 @item --no-show-raw-insn
1230 When disassembling instructions, do not print the instruction bytes.
1231 This is the default when @code{--prefix-addresses} is used.
1236 @cindex debug symbols
1237 @cindex ELF object file format
1238 Display the full contents of any sections requested. Display the
1239 contents of the .stab and .stab.index and .stab.excl sections from an
1240 ELF file. This is only useful on systems (such as Solaris 2.0) in which
1241 @code{.stab} debugging symbol-table entries are carried in an ELF
1242 section. In most other file formats, debugging symbol-table entries are
1243 interleaved with linkage symbols, and are visible in the @samp{--syms}
1244 output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1245 Overview,stabs.info, The ``stabs'' debug format}.
1247 @item --start-address=@var{address}
1248 @cindex start-address
1249 Start displaying data at the specified address. This affects the output
1250 of the @code{-d}, @code{-r} and @code{-s} options.
1252 @item --stop-address=@var{address}
1253 @cindex stop-address
1254 Stop displaying data at the specified address. This affects the output
1255 of the @code{-d}, @code{-r} and @code{-s} options.
1259 @cindex symbol table entries, printing
1260 Print the symbol table entries of the file.
1261 This is similar to the information provided by the @samp{nm} program.
1264 @itemx --dynamic-syms
1265 @cindex dynamic symbol table entries, printing
1266 Print the dynamic symbol table entries of the file. This is only
1267 meaningful for dynamic objects, such as certain types of shared
1268 libraries. This is similar to the information provided by the @samp{nm}
1269 program when given the @samp{-D} (@samp{--dynamic}) option.
1272 Print the version number of @code{objdump} and exit.
1276 @cindex all header information, object file
1277 @cindex header information, all
1278 Display all available header information, including the symbol table and
1279 relocation entries. Using @samp{-x} is equivalent to specifying all of
1280 @samp{-a -f -h -r -t}.
1284 @cindex wide output, printing
1285 Format some lines for output devices that have more than 80 columns.
1292 @cindex archive contents
1293 @cindex symbol index
1296 ranlib [-vV] @var{archive}
1299 @code{ranlib} generates an index to the contents of an archive and
1300 stores it in the archive. The index lists each symbol defined by a
1301 member of an archive that is a relocatable object file.
1303 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1305 An archive with such an index speeds up linking to the library and
1306 allows routines in the library to call each other without regard to
1307 their placement in the archive.
1309 The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1310 @code{ranlib} is completely equivalent to executing @samp{ar -s}.
1316 Show the version number of @code{ranlib}.
1323 @cindex section sizes
1326 size [ -A | -B | --format=@var{compatibility} ]
1327 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1328 [ --target=@var{bfdname} ] [ -V | --version ]
1329 @var{objfile}@dots{}
1332 The @sc{gnu} @code{size} utility lists the section sizes---and the total
1333 size---for each of the object or archive files @var{objfile} in its
1334 argument list. By default, one line of output is generated for each
1335 object file or each module in an archive.
1337 @var{objfile}@dots{} are the object files to be examined.
1339 The command line options have the following meanings:
1344 @itemx --format=@var{compatibility}
1345 @cindex @code{size} display format
1346 Using one of these options, you can choose whether the output from @sc{gnu}
1347 @code{size} resembles output from System V @code{size} (using @samp{-A},
1348 or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1349 @samp{--format=berkeley}). The default is the one-line format similar to
1351 @c Bonus for doc-source readers: you can also say --format=strange (or
1352 @c anything else that starts with 's') for sysv, and --format=boring (or
1353 @c anything else that starts with 'b') for Berkeley.
1355 Here is an example of the Berkeley (default) format of output from
1358 size --format=Berkeley ranlib size
1359 text data bss dec hex filename
1360 294880 81920 11592 388392 5ed28 ranlib
1361 294880 81920 11888 388688 5ee50 size
1365 This is the same data, but displayed closer to System V conventions:
1368 size --format=SysV ranlib size
1386 Show a summary of acceptable arguments and options.
1391 @itemx --radix=@var{number}
1392 @cindex @code{size} number format
1393 @cindex radix for section sizes
1394 Using one of these options, you can control whether the size of each
1395 section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1396 (@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1397 @samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1398 values (8, 10, 16) are supported. The total size is always given in two
1399 radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1400 octal and hexadecimal if you're using @samp{-o}.
1402 @item --target=@var{bfdname}
1403 @cindex object code format
1404 Specify that the object-code format for @var{objfile} is
1405 @var{bfdname}. This option may not be necessary; @code{size} can
1406 automatically recognize many formats.
1407 @xref{Target Selection}, for more information.
1411 Display the version number of @code{size}.
1417 @cindex listings strings
1418 @cindex printing strings
1419 @cindex strings, printing
1422 strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1423 [--all] [--print-file-name] [--bytes=@var{min-len}]
1424 [--radix=@var{radix}] [--target=@var{bfdname}]
1425 [--help] [--version] @var{file}@dots{}
1428 For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1429 character sequences that are at least 4 characters long (or the number
1430 given with the options below) and are followed by an unprintable
1431 character. By default, it only prints the strings from the initialized
1432 and loaded sections of object files; for other types of files, it prints
1433 the strings from the whole file.
1435 @code{strings} is mainly useful for determining the contents of non-text
1442 Do not scan only the initialized and loaded sections of object files;
1443 scan the whole files.
1446 @itemx --print-file-name
1447 Print the name of the file before each string.
1450 Print a summary of the program usage on the standard output and exit.
1452 @itemx -@var{min-len}
1453 @item -n @var{min-len}
1454 @itemx --bytes=@var{min-len}
1455 Print sequences of characters that are at least @var{min-len} characters
1456 long, instead of the default 4.
1459 Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1460 act like @samp{-t d} instead. Since we can not be compatible with both
1461 ways, we simply chose one.
1463 @item -t @var{radix}
1464 @itemx --radix=@var{radix}
1465 Print the offset within the file before each string. The single
1466 character argument specifies the radix of the offset---@samp{o} for
1467 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1469 @item --target=@var{bfdname}
1470 @cindex object code format
1471 Specify an object code format other than your system's default format.
1472 @xref{Target Selection}, for more information.
1476 Print the program version number on the standard output and exit.
1483 @cindex removing symbols
1484 @cindex discarding symbols
1485 @cindex symbols, discarding
1488 strip [ -F @var{bfdname} | --target=@var{bfdname} | --target=@var{bfdname} ]
1489 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1490 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1491 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1492 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1493 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1494 [ -x | --discard-all ] [ -X | --discard-locals ]
1495 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1497 [ -v | --verbose ] [ -V | --version ] [ --help ]
1498 @var{objfile}@dots{}
1501 @sc{gnu} @code{strip} discards all symbols from object files
1502 @var{objfile}. The list of object files may include archives.
1503 At least one object file must be given.
1505 @code{strip} modifies the files named in its argument,
1506 rather than writing modified copies under different names.
1509 @item -F @var{bfdname}
1510 @itemx --target=@var{bfdname}
1511 Treat the original @var{objfile} as a file with the object
1512 code format @var{bfdname}, and rewrite it in the same format.
1513 @xref{Target Selection}, for more information.
1516 Show a summary of the options to @code{strip} and exit.
1518 @item -I @var{bfdname}
1519 @itemx --input-target=@var{bfdname}
1520 Treat the original @var{objfile} as a file with the object
1521 code format @var{bfdname}.
1522 @xref{Target Selection}, for more information.
1524 @item -O @var{bfdname}
1525 @itemx --output-target=@var{bfdname}
1526 Replace @var{objfile} with a file in the output format @var{bfdname}.
1527 @xref{Target Selection}, for more information.
1529 @item -R @var{sectionname}
1530 @itemx --remove-section=@var{sectionname}
1531 Remove any section named @var{sectionname} from the output file. This
1532 option may be given more than once. Note that using this option
1533 inappropriately may make the output file unusable.
1541 @itemx --strip-debug
1542 Remove debugging symbols only.
1544 @item --strip-unneeded
1545 Remove all symbols that are not needed for relocation processing.
1547 @item -K @var{symbolname}
1548 @itemx --keep-symbol=@var{symbolname}
1549 Keep only symbol @var{symbolname} from the source file. This option may
1550 be given more than once.
1552 @item -N @var{symbolname}
1553 @itemx --strip-symbol=@var{symbolname}
1554 Remove symbol @var{symbolname} from the source file. This option may be
1555 given more than once, and may be combined with strip options other than
1559 Put the stripped output in @var{file}, rather than replacing the
1560 existing file. When this argument is used, only one @var{objfile}
1561 argument may be specified.
1564 @itemx --discard-all
1565 Remove non-global symbols.
1568 @itemx --discard-locals
1569 Remove compiler-generated local symbols.
1570 (These usually start with @samp{L} or @samp{.}.)
1574 Show the version number for @code{strip}.
1578 Verbose output: list all object files modified. In the case of
1579 archives, @samp{strip -v} lists all members of the archive.
1586 @cindex demangling C++ symbols
1589 c++filt [ -_ | --strip-underscores ]
1590 [ -n | --no-strip-underscores ]
1591 [ -s @var{format} | --format=@var{format} ]
1592 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1595 The C++ language provides function overloading, which means that you can
1596 write many functions with the same name (providing each takes parameters
1597 of different types). All C++ function names are encoded into a
1598 low-level assembly label (this process is known as
1599 @dfn{mangling}). The @code{c++filt} program does the inverse mapping: it
1600 decodes (@dfn{demangles}) low-level names into user-level names so that
1601 the linker can keep these overloaded functions from clashing.
1603 Every alphanumeric word (consisting of letters, digits, underscores,
1604 dollars, or periods) seen in the input is a potential label. If the
1605 label decodes into a C++ name, the C++ name replaces the low-level
1608 You can use @code{c++filt} to decipher individual symbols:
1611 c++filt @var{symbol}
1614 If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1615 names from the standard input and writes the demangled names to the
1616 standard output. All results are printed on the standard output.
1620 @itemx --strip-underscores
1621 On some systems, both the C and C++ compilers put an underscore in front
1622 of every name. For example, the C name @code{foo} gets the low-level
1623 name @code{_foo}. This option removes the initial underscore. Whether
1624 @code{c++filt} removes the underscore by default is target dependent.
1627 @itemx --no-strip-underscores
1628 Do not remove the initial underscore.
1630 @item -s @var{format}
1631 @itemx --format=@var{format}
1632 @sc{gnu} @code{nm} can decode three different methods of mangling, used by
1633 different C++ compilers. The argument to this option selects which
1638 the one used by the @sc{gnu} compiler (the default method)
1640 the one used by the Lucid compiler
1642 the one specified by the C++ Annotated Reference Manual
1646 Print a summary of the options to @code{c++filt} and exit.
1649 Print the version number of @code{c++filt} and exit.
1653 @emph{Warning:} @code{c++filt} is a new utility, and the details of its
1654 user interface are subject to change in future releases. In particular,
1655 a command-line option may be required in the the future to decode a name
1656 passed as an argument on the command line; in other words,
1659 c++filt @var{symbol}
1663 may in a future release become
1666 c++filt @var{option} @var{symbol}
1673 @code{nlmconv} converts a relocatable object file into a NetWare
1677 @code{nlmconv} currently works with @samp{i386} object
1678 files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1679 object files in @sc{elf}, or @code{a.out} format@footnote{
1680 @code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1681 format in the Binary File Descriptor library. It has only been tested
1682 with the above formats.}.
1686 @emph{Warning:} @code{nlmconv} is not always built as part of the binary
1687 utilities, since it is only useful for NLM targets.
1691 nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1692 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1693 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1694 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1695 [ -h | --help ] [ -V | --version ]
1696 @var{infile} @var{outfile}
1699 @code{nlmconv} converts the relocatable @samp{i386} object file
1700 @var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1701 reading @var{headerfile} for NLM header information. For instructions
1702 on writing the NLM command file language used in header files, see the
1703 @samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1704 Development and Tools Overview}, which is part of the NLM Software
1705 Developer's Kit (``NLM SDK''), available from Novell, Inc.
1706 @code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1707 @var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1710 @code{nlmconv} can perform a link step. In other words, you can list
1711 more than one object file for input if you list them in the definitions
1712 file (rather than simply specifying one input file on the command line).
1713 In this case, @code{nlmconv} calls the linker for you.
1716 @item -I @var{bfdname}
1717 @itemx --input-target=@var{bfdname}
1718 Object format of the input file. @code{nlmconv} can usually determine
1719 the format of a given file (so no default is necessary).
1720 @xref{Target Selection}, for more information.
1722 @item -O @var{bfdname}
1723 @itemx --output-target=@var{bfdname}
1724 Object format of the output file. @code{nlmconv} infers the output
1725 format based on the input format, e.g. for a @samp{i386} input file the
1726 output format is @samp{nlm32-i386}.
1727 @xref{Target Selection}, for more information.
1729 @item -T @var{headerfile}
1730 @itemx --header-file=@var{headerfile}
1731 Reads @var{headerfile} for NLM header information. For instructions on
1732 writing the NLM command file language used in header files, see@ see the
1733 @samp{linkers} section, of the @cite{NLM Development and Tools
1734 Overview}, which is part of the NLM Software Developer's Kit, available
1739 Displays (on standard error) the linker command line used by @code{nlmconv}.
1741 @item -l @var{linker}
1742 @itemx --linker=@var{linker}
1743 Use @var{linker} for any linking. @var{linker} can be an abosolute or a
1748 Prints a usage summary.
1752 Prints the version number for @code{nlmconv}.
1755 @node Selecting The Target System
1756 @chapter Selecting the target system
1758 You can specify three aspects of the target system to the @sc{gnu}
1759 binary file utilities, each in several ways:
1769 the linker emulation (which applies to the linker only)
1772 In the following summaries, the lists of ways to specify values are in
1773 order of decreasing precedence. The ways listed first override those
1776 The commands to list valid values only list the values for which the
1777 programs you are running were configured. If they were configured with
1778 @samp{--enable-targets=all}, the commands list most of the available
1779 values, but a few are left out; not all targets can be configured in at
1780 once because some of them can only be configured @dfn{native} (on hosts
1781 with the same type as the target system).
1784 * Target Selection::
1785 * Architecture Selection::
1786 * Linker Emulation Selection::
1789 @node Target Selection
1790 @section Target Selection
1792 A @dfn{target} is an object file format. A given target may be
1793 supported for multiple architectures (@pxref{Architecture Selection}).
1794 A target selection may also have variations for different operating
1795 systems or architectures.
1797 The command to list valid target values is @samp{objdump -i}
1798 (the first column of output contains the relevant information).
1800 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
1801 @samp{a.out-sunos-big}.
1803 You can also specify a target using a configuration triplet. This is
1804 the same sort of name that is passed to configure to specify a target.
1805 When you use a configuration triplet as an argument, it must be fully
1806 canonicalized. You can see the canonical version of a triplet by
1807 running the shell script @file{config.sub} which is included with the
1810 Some sample configuration triplets are: @samp{m68k-hp-bsd},
1811 @samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
1813 @subheading @code{objdump} Target
1819 command line option: @samp{-b} or @samp{--target}
1822 environment variable @code{GNUTARGET}
1825 deduced from the input file
1828 @subheading @code{objcopy} and @code{strip} Input Target
1834 command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
1837 environment variable @code{GNUTARGET}
1840 deduced from the input file
1843 @subheading @code{objcopy} and @code{strip} Output Target
1849 command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
1852 the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
1855 environment variable @code{GNUTARGET}
1858 deduced from the input file
1861 @subheading @code{nm}, @code{size}, and @code{strings} Target
1867 command line option: @samp{--target}
1870 environment variable @code{GNUTARGET}
1873 deduced from the input file
1876 @subheading Linker Input Target
1882 command line option: @samp{-b} or @samp{--format}
1883 (@pxref{Options,,Options,ld.info,Using LD})
1886 script command @code{TARGET}
1887 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
1890 environment variable @code{GNUTARGET}
1891 (@pxref{Environment,,Environment,ld.info,Using LD})
1894 the default target of the selected linker emulation
1895 (@pxref{Linker Emulation Selection})
1898 @subheading Linker Output Target
1904 command line option: @samp{-oformat}
1905 (@pxref{Options,,Options,ld.info,Using LD})
1908 script command @code{OUTPUT_FORMAT}
1909 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
1912 the linker input target (see ``Linker Input Target'' above)
1915 @node Architecture Selection
1916 @section Architecture selection
1918 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
1919 to run. Its name may contain a colon, separating the name of the
1920 processor family from the name of the particular @sc{cpu}.
1922 The command to list valid architecture values is @samp{objdump -i} (the
1923 second column contains the relevant information).
1925 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
1927 @subheading @code{objdump} Architecture
1933 command line option: @samp{-m} or @samp{--architecture}
1936 deduced from the input file
1939 @subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
1945 deduced from the input file
1948 @subheading Linker Input Architecture
1954 deduced from the input file
1957 @subheading Linker Output Architecture
1963 script command @code{OUTPUT_ARCH}
1964 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
1967 the default architecture from the linker output target
1968 (@pxref{Target Selection})
1971 @node Linker Emulation Selection
1972 @section Linker emulation selection
1974 A linker @dfn{emulation} is a ``personality'' of the linker, which gives
1975 the linker default values for the other aspects of the target system.
1976 In particular, it consists of
1986 several ``hook'' functions that are run at certain stages of the linking
1987 process to do special things that some targets require
1990 The command to list valid linker emulation values is @samp{ld -V}.
1992 Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
1998 command line option: @samp{-m}
1999 (@pxref{Options,,Options,ld.info,Using LD})
2002 environment variable @code{LDEMULATION}
2005 compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2006 which comes from @code{EMUL} in @file{config/@var{target}.mt}
2009 @node Reporting Bugs
2010 @chapter Reporting Bugs
2012 @cindex reporting bugs
2014 Your bug reports play an essential role in making the binary utilities
2017 Reporting a bug may help you by bringing a solution to your problem, or
2018 it may not. But in any case the principal function of a bug report is
2019 to help the entire community by making the next version of the binary
2020 utilities work better. Bug reports are your contribution to their
2023 In order for a bug report to serve its purpose, you must include the
2024 information that enables us to fix the bug.
2027 * Bug Criteria:: Have you found a bug?
2028 * Bug Reporting:: How to report bugs
2032 @section Have you found a bug?
2033 @cindex bug criteria
2035 If you are not sure whether you have found a bug, here are some guidelines:
2038 @cindex fatal signal
2041 If a binary utility gets a fatal signal, for any input whatever, that is
2042 a bug. Reliable utilities never crash.
2044 @cindex error on valid input
2046 If a binary utility produces an error message for valid input, that is a
2050 If you are an experienced user of binary utilities, your suggestions for
2051 improvement are welcome in any case.
2055 @section How to report bugs
2057 @cindex bugs, reporting
2059 A number of companies and individuals offer support for @sc{gnu}
2060 products. If you obtained the binary utilities from a support
2061 organization, we recommend you contact that organization first.
2063 You can find contact information for many support companies and
2064 individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2067 In any event, we also recommend that you send bug reports for the binary
2068 utilities to @samp{bug-gnu-utils@@prep.ai.mit.edu}.
2070 The fundamental principle of reporting bugs usefully is this:
2071 @strong{report all the facts}. If you are not sure whether to state a
2072 fact or leave it out, state it!
2074 Often people omit facts because they think they know what causes the
2075 problem and assume that some details do not matter. Thus, you might
2076 assume that the name of a file you use in an example does not matter.
2077 Well, probably it does not, but one cannot be sure. Perhaps the bug is
2078 a stray memory reference which happens to fetch from the location where
2079 that pathname is stored in memory; perhaps, if the pathname were
2080 different, the contents of that location would fool the utility into
2081 doing the right thing despite the bug. Play it safe and give a
2082 specific, complete example. That is the easiest thing for you to do,
2083 and the most helpful.
2085 Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2086 it is new to us. Therefore, always write your bug reports on the assumption
2087 that the bug has not been reported previously.
2089 Sometimes people give a few sketchy facts and ask, ``Does this ring a
2090 bell?'' Those bug reports are useless, and we urge everyone to
2091 @emph{refuse to respond to them} except to chide the sender to report
2094 To enable us to fix the bug, you should include all these things:
2098 The version of the utility. Each utility announces it if you start it
2099 with the @samp{--version} argument.
2101 Without this, we will not know whether there is any point in looking for
2102 the bug in the current version of the binary utilities.
2105 Any patches you may have applied to the source, including any patches
2106 made to the @code{BFD} library.
2109 The type of machine you are using, and the operating system name and
2113 What compiler (and its version) was used to compile the utilities---e.g.
2117 The command arguments you gave the utility to observe the bug. To
2118 guarantee you will not omit something important, list them all. A copy
2119 of the Makefile (or the output from make) is sufficient.
2121 If we were to try to guess the arguments, we would probably guess wrong
2122 and then we might not encounter the bug.
2125 A complete input file, or set of input files, that will reproduce the
2126 bug. If the utility is reading an object file or files, then it is
2127 generally most helpful to send the actual object files, uuencoded if
2128 necessary to get them through the mail system. Making them available
2129 for anonymous FTP is not as good, but may be the only reasonable choice
2130 for large object files.
2132 If the source files were produced exclusively using @sc{gnu} programs
2133 (e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2134 may be OK to send the source files rather than the object files. In
2135 this case, be sure to say exactly what version of @code{gcc}, or
2136 whatever, was used to produce the object files. Also say how
2137 @code{gcc}, or whatever, was configured.
2140 A description of what behavior you observe that you believe is
2141 incorrect. For example, ``It gets a fatal signal.''
2143 Of course, if the bug is that the utility gets a fatal signal, then we
2144 will certainly notice it. But if the bug is incorrect output, we might
2145 not notice unless it is glaringly wrong. You might as well not give us
2146 a chance to make a mistake.
2148 Even if the problem you experience is a fatal signal, you should still
2149 say so explicitly. Suppose something strange is going on, such as, your
2150 copy of the utility is out of synch, or you have encountered a bug in
2151 the C library on your system. (This has happened!) Your copy might
2152 crash and ours would not. If you told us to expect a crash, then when
2153 ours fails to crash, we would know that the bug was not happening for
2154 us. If you had not told us to expect a crash, then we would not be able
2155 to draw any conclusion from our observations.
2158 If you wish to suggest changes to the source, send us context diffs, as
2159 generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2160 option. Always send diffs from the old file to the new file. If you
2161 even discuss something in the @code{ld} source, refer to it by context,
2164 The line numbers in our development sources will not match those in your
2165 sources. Your line numbers would convey no useful information to us.
2168 Here are some things that are not necessary:
2172 A description of the envelope of the bug.
2174 Often people who encounter a bug spend a lot of time investigating
2175 which changes to the input file will make the bug go away and which
2176 changes will not affect it.
2178 This is often time consuming and not very useful, because the way we
2179 will find the bug is by running a single example under the debugger
2180 with breakpoints, not by pure deduction from a series of examples.
2181 We recommend that you save your time for something else.
2183 Of course, if you can find a simpler example to report @emph{instead}
2184 of the original one, that is a convenience for us. Errors in the
2185 output will be easier to spot, running under the debugger will take
2186 less time, and so on.
2188 However, simplification is not vital; if you do not want to do this,
2189 report the bug anyway and send us the entire test case you used.
2192 A patch for the bug.
2194 A patch for the bug does help us if it is a good one. But do not omit
2195 the necessary information, such as the test case, on the assumption that
2196 a patch is all we need. We might see problems with your patch and decide
2197 to fix the problem another way, or we might not understand it at all.
2199 Sometimes with programs as complicated as the binary utilities it is
2200 very hard to construct an example that will make the program follow a
2201 certain path through the code. If you do not send us the example, we
2202 will not be able to construct one, so we will not be able to verify that
2205 And if we cannot understand what bug you are trying to fix, or why your
2206 patch should be an improvement, we will not install it. A test case will
2207 help us to understand.
2210 A guess about what the bug is or what it depends on.
2212 Such guesses are usually wrong. Even we cannot guess right about such
2213 things without first using the debugger to find the facts.