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", "ranlib" and "dlltool".
16 Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 1998 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, 97, 1998 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, 97, 1998 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 addresses into file names and line numbers
124 Convert object code into a Netware Loadable Module
127 Manipulate Windows resources
130 Create the files needed to build and use Dynamic Link Libraries
135 * ar:: Create, modify, and extract from archives
136 * nm:: List symbols from object files
137 * objcopy:: Copy and translate object files
138 * objdump:: Display information from object files
139 * ranlib:: Generate index to archive contents
140 * size:: List section sizes and total size
141 * strings:: List printable strings from files
142 * strip:: Discard symbols
143 * c++filt:: Filter to demangle encoded C++ symbols
144 * addr2line:: Convert addresses to file and line
145 * nlmconv:: Converts object code into an NLM
146 * windres:: Manipulate Windows resources
147 * dlltool:: Create files needed to build and use DLLs
148 * Selecting The Target System:: How these utilities determine the target.
149 * Reporting Bugs:: Reporting Bugs
158 @cindex collections of files
160 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
161 ar -M [ <mri-script ]
164 The @sc{gnu} @code{ar} program creates, modifies, and extracts from
165 archives. An @dfn{archive} is a single file holding a collection of
166 other files in a structure that makes it possible to retrieve
167 the original individual files (called @dfn{members} of the archive).
169 The original files' contents, mode (permissions), timestamp, owner, and
170 group are preserved in the archive, and can be restored on
174 @sc{gnu} @code{ar} can maintain archives whose members have names of any
175 length; however, depending on how @code{ar} is configured on your
176 system, a limit on member-name length may be imposed for compatibility
177 with archive formats maintained with other tools. If it exists, the
178 limit is often 15 characters (typical of formats related to a.out) or 16
179 characters (typical of formats related to coff).
182 @code{ar} is considered a binary utility because archives of this sort
183 are most often used as @dfn{libraries} holding commonly needed
187 @code{ar} creates an index to the symbols defined in relocatable
188 object modules in the archive when you specify the modifier @samp{s}.
189 Once created, this index is updated in the archive whenever @code{ar}
190 makes a change to its contents (save for the @samp{q} update operation).
191 An archive with such an index speeds up linking to the library, and
192 allows routines in the library to call each other without regard to
193 their placement in the archive.
195 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
196 table. If an archive lacks the table, another form of @code{ar} called
197 @code{ranlib} can be used to add just the table.
199 @cindex compatibility, @code{ar}
200 @cindex @code{ar} compatibility
201 @sc{gnu} @code{ar} is designed to be compatible with two different
202 facilities. You can control its activity using command-line options,
203 like the different varieties of @code{ar} on Unix systems; or, if you
204 specify the single command-line option @samp{-M}, you can control it
205 with a script supplied via standard input, like the MRI ``librarian''
209 * ar cmdline:: Controlling @code{ar} on the command line
210 * ar scripts:: Controlling @code{ar} with a script
215 @section Controlling @code{ar} on the command line
218 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
221 @cindex Unix compatibility, @code{ar}
222 When you use @code{ar} in the Unix style, @code{ar} insists on at least two
223 arguments to execute: one keyletter specifying the @emph{operation}
224 (optionally accompanied by other keyletters specifying
225 @emph{modifiers}), and the archive name to act on.
227 Most operations can also accept further @var{member} arguments,
228 specifying particular files to operate on.
230 @sc{gnu} @code{ar} allows you to mix the operation code @var{p} and modifier
231 flags @var{mod} in any order, within the first command-line argument.
233 If you wish, you may begin the first command-line argument with a
236 @cindex operations on archive
237 The @var{p} keyletter specifies what operation to execute; it may be
238 any of the following, but you must specify only one of them:
242 @cindex deleting from archive
243 @emph{Delete} modules from the archive. Specify the names of modules to
244 be deleted as @var{member}@dots{}; the archive is untouched if you
245 specify no files to delete.
247 If you specify the @samp{v} modifier, @code{ar} lists each module
251 @cindex moving in archive
252 Use this operation to @emph{move} members in an archive.
254 The ordering of members in an archive can make a difference in how
255 programs are linked using the library, if a symbol is defined in more
258 If no modifiers are used with @code{m}, any members you name in the
259 @var{member} arguments are moved to the @emph{end} of the archive;
260 you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
261 specified place instead.
264 @cindex printing from archive
265 @emph{Print} the specified members of the archive, to the standard
266 output file. If the @samp{v} modifier is specified, show the member
267 name before copying its contents to standard output.
269 If you specify no @var{member} arguments, all the files in the archive are
273 @cindex quick append to archive
274 @emph{Quick append}; Historically, add the files @var{member}@dots{} to the end of
275 @var{archive}, without checking for replacement.
277 The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
278 operation; new members are always placed at the end of the archive.
280 The modifier @samp{v} makes @code{ar} list each file as it is appended.
282 Since the point of this operation is speed, the archive's symbol table
283 index is not updated, even if it already existed; you can use @samp{ar s} or
284 @code{ranlib} explicitly to update the symbol table index.
286 However, too many different systems assume quick append rebuilds the
287 index, so GNU ar implements @code{q} as a synonym for @code{r}.
290 @cindex replacement in archive
291 Insert the files @var{member}@dots{} into @var{archive} (with
292 @emph{replacement}). This operation differs from @samp{q} in that any
293 previously existing members are deleted if their names match those being
296 If one of the files named in @var{member}@dots{} does not exist, @code{ar}
297 displays an error message, and leaves undisturbed any existing members
298 of the archive matching that name.
300 By default, new members are added at the end of the file; but you may
301 use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
302 placement relative to some existing member.
304 The modifier @samp{v} used with this operation elicits a line of
305 output for each file inserted, along with one of the letters @samp{a} or
306 @samp{r} to indicate whether the file was appended (no old member
307 deleted) or replaced.
310 @cindex contents of archive
311 Display a @emph{table} listing the contents of @var{archive}, or those
312 of the files listed in @var{member}@dots{} that are present in the
313 archive. Normally only the member name is shown; if you also want to
314 see the modes (permissions), timestamp, owner, group, and size, you can
315 request that by also specifying the @samp{v} modifier.
317 If you do not specify a @var{member}, all files in the archive
320 @cindex repeated names in archive
321 @cindex name duplication in archive
322 If there is more than one file with the same name (say, @samp{fie}) in
323 an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
324 first instance; to see them all, you must ask for a complete
325 listing---in our example, @samp{ar t b.a}.
326 @c WRS only; per Gumby, this is implementation-dependent, and in a more
327 @c recent case in fact works the other way.
330 @cindex extract from archive
331 @emph{Extract} members (named @var{member}) from the archive. You can
332 use the @samp{v} modifier with this operation, to request that
333 @code{ar} list each name as it extracts it.
335 If you do not specify a @var{member}, all files in the archive
340 A number of modifiers (@var{mod}) may immediately follow the @var{p}
341 keyletter, to specify variations on an operation's behavior:
345 @cindex relative placement in archive
346 Add new files @emph{after} an existing member of the
347 archive. If you use the modifier @samp{a}, the name of an existing archive
348 member must be present as the @var{relpos} argument, before the
349 @var{archive} specification.
352 Add new files @emph{before} an existing member of the
353 archive. If you use the modifier @samp{b}, the name of an existing archive
354 member must be present as the @var{relpos} argument, before the
355 @var{archive} specification. (same as @samp{i}).
358 @cindex creating archives
359 @emph{Create} the archive. The specified @var{archive} is always
360 created if it did not exist, when you request an update. But a warning is
361 issued unless you specify in advance that you expect to create it, by
365 Truncate names in the archive. @sc{gnu} @code{ar} will normally permit file
366 names of any length. This will cause it to create archives which are
367 not compatible with the native @code{ar} program on some systems. If
368 this is a concern, the @samp{f} modifier may be used to truncate file
369 names when putting them in the archive.
372 Insert new files @emph{before} an existing member of the
373 archive. If you use the modifier @samp{i}, the name of an existing archive
374 member must be present as the @var{relpos} argument, before the
375 @var{archive} specification. (same as @samp{b}).
378 This modifier is accepted but not used.
379 @c whaffor ar l modifier??? presumably compat; with
380 @c what???---doc@@cygnus.com, 25jan91
383 @cindex dates in archive
384 Preserve the @emph{original} dates of members when extracting them. If
385 you do not specify this modifier, files extracted from the archive
386 are stamped with the time of extraction.
389 @cindex writing archive index
390 Write an object-file index into the archive, or update an existing one,
391 even if no other change is made to the archive. You may use this modifier
392 flag either with any operation, or alone. Running @samp{ar s} on an
393 archive is equivalent to running @samp{ranlib} on it.
396 @cindex not writing archive index
397 Do not generate an archive symbol table. This can speed up building a
398 large library in several steps. The resulting archive can not be used
399 with the linker. In order to build a symbol table, you must omit the
400 @samp{S} modifier on the last execution of @samp{ar}, or you must run
401 @samp{ranlib} on the archive.
404 @cindex updating an archive
405 Normally, @samp{ar r}@dots{} inserts all files
406 listed into the archive. If you would like to insert @emph{only} those
407 of the files you list that are newer than existing members of the same
408 names, use this modifier. The @samp{u} modifier is allowed only for the
409 operation @samp{r} (replace). In particular, the combination @samp{qu} is
410 not allowed, since checking the timestamps would lose any speed
411 advantage from the operation @samp{q}.
414 This modifier requests the @emph{verbose} version of an operation. Many
415 operations display additional information, such as filenames processed,
416 when the modifier @samp{v} is appended.
419 This modifier shows the version number of @code{ar}.
423 @section Controlling @code{ar} with a script
426 ar -M [ <@var{script} ]
429 @cindex MRI compatibility, @code{ar}
430 @cindex scripts, @code{ar}
431 If you use the single command-line option @samp{-M} with @code{ar}, you
432 can control its operation with a rudimentary command language. This
433 form of @code{ar} operates interactively if standard input is coming
434 directly from a terminal. During interactive use, @code{ar} prompts for
435 input (the prompt is @samp{AR >}), and continues executing even after
436 errors. If you redirect standard input to a script file, no prompts are
437 issued, and @code{ar} abandons execution (with a nonzero exit code)
440 The @code{ar} command language is @emph{not} designed to be equivalent
441 to the command-line options; in fact, it provides somewhat less control
442 over archives. The only purpose of the command language is to ease the
443 transition to @sc{gnu} @code{ar} for developers who already have scripts
444 written for the MRI ``librarian'' program.
446 The syntax for the @code{ar} command language is straightforward:
449 commands are recognized in upper or lower case; for example, @code{LIST}
450 is the same as @code{list}. In the following descriptions, commands are
451 shown in upper case for clarity.
454 a single command may appear on each line; it is the first word on the
458 empty lines are allowed, and have no effect.
461 comments are allowed; text after either of the characters @samp{*}
462 or @samp{;} is ignored.
465 Whenever you use a list of names as part of the argument to an @code{ar}
466 command, you can separate the individual names with either commas or
467 blanks. Commas are shown in the explanations below, for clarity.
470 @samp{+} is used as a line continuation character; if @samp{+} appears
471 at the end of a line, the text on the following line is considered part
472 of the current command.
475 Here are the commands you can use in @code{ar} scripts, or when using
476 @code{ar} interactively. Three of them have special significance:
478 @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
479 a temporary file required for most of the other commands.
481 @code{SAVE} commits the changes so far specified by the script. Prior
482 to @code{SAVE}, commands affect only the temporary copy of the current
486 @item ADDLIB @var{archive}
487 @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
488 Add all the contents of @var{archive} (or, if specified, each named
489 @var{module} from @var{archive}) to the current archive.
491 Requires prior use of @code{OPEN} or @code{CREATE}.
493 @item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
494 @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
495 @c else like "ar q..."
496 Add each named @var{member} as a module in the current archive.
498 Requires prior use of @code{OPEN} or @code{CREATE}.
501 Discard the contents of the current archive, canceling the effect of
502 any operations since the last @code{SAVE}. May be executed (with no
503 effect) even if no current archive is specified.
505 @item CREATE @var{archive}
506 Creates an archive, and makes it the current archive (required for many
507 other commands). The new archive is created with a temporary name; it
508 is not actually saved as @var{archive} until you use @code{SAVE}.
509 You can overwrite existing archives; similarly, the contents of any
510 existing file named @var{archive} will not be destroyed until @code{SAVE}.
512 @item DELETE @var{module}, @var{module}, @dots{} @var{module}
513 Delete each listed @var{module} from the current archive; equivalent to
514 @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
516 Requires prior use of @code{OPEN} or @code{CREATE}.
518 @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
519 @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
520 List each named @var{module} present in @var{archive}. The separate
521 command @code{VERBOSE} specifies the form of the output: when verbose
522 output is off, output is like that of @samp{ar -t @var{archive}
523 @var{module}@dots{}}. When verbose output is on, the listing is like
524 @samp{ar -tv @var{archive} @var{module}@dots{}}.
526 Output normally goes to the standard output stream; however, if you
527 specify @var{outputfile} as a final argument, @code{ar} directs the
531 Exit from @code{ar}, with a @code{0} exit code to indicate successful
532 completion. This command does not save the output file; if you have
533 changed the current archive since the last @code{SAVE} command, those
536 @item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
537 Extract each named @var{module} from the current archive, writing them
538 into the current directory as separate files. Equivalent to @samp{ar -x
539 @var{archive} @var{module}@dots{}}.
541 Requires prior use of @code{OPEN} or @code{CREATE}.
544 @c FIXME Tokens but no commands???
551 Display full contents of the current archive, in ``verbose'' style
552 regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
553 tv @var{archive}}). (This single command is a @sc{gnu} @code{ld}
554 enhancement, rather than present for MRI compatibility.)
556 Requires prior use of @code{OPEN} or @code{CREATE}.
558 @item OPEN @var{archive}
559 Opens an existing archive for use as the current archive (required for
560 many other commands). Any changes as the result of subsequent commands
561 will not actually affect @var{archive} until you next use @code{SAVE}.
563 @item REPLACE @var{module}, @var{module}, @dots{} @var{module}
564 In the current archive, replace each existing @var{module} (named in
565 the @code{REPLACE} arguments) from files in the current working directory.
566 To execute this command without errors, both the file, and the module in
567 the current archive, must exist.
569 Requires prior use of @code{OPEN} or @code{CREATE}.
572 Toggle an internal flag governing the output from @code{DIRECTORY}.
573 When the flag is on, @code{DIRECTORY} output matches output from
574 @samp{ar -tv }@dots{}.
577 Commit your changes to the current archive, and actually save it as a
578 file with the name specified in the last @code{CREATE} or @code{OPEN}
581 Requires prior use of @code{OPEN} or @code{CREATE}.
590 The @sc{gnu} linker @code{ld} is now described in a separate manual.
591 @xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
600 nm [ -a | --debug-syms ] [ -g | --extern-only ]
601 [ -B ] [ -C | --demangle ] [ -D | --dynamic ]
602 [ -s | --print-armap ] [ -A | -o | --print-file-name ]
603 [ -n | -v | --numeric-sort ] [ -p | --no-sort ]
604 [ -r | --reverse-sort ] [ --size-sort ] [ -u | --undefined-only ]
605 [ -t @var{radix} | --radix=@var{radix} ] [ -P | --portability ]
606 [ --target=@var{bfdname} ] [ -f @var{format} | --format=@var{format} ]
607 [ --defined-only ] [-l | --line-numbers ]
608 [ --no-demangle ] [ -V | --version ] [ --help ] [ @var{objfile}@dots{} ]
611 @sc{gnu} @code{nm} lists the symbols from object files @var{objfile}@dots{}.
612 If no object files are listed as arguments, @code{nm} assumes
615 For each symbol, @code{nm} shows:
619 The symbol value, in the radix selected by options (see below), or
620 hexadecimal by default.
623 The symbol type. At least the following types are used; others are, as
624 well, depending on the object file format. If lowercase, the symbol is
625 local; if uppercase, the symbol is global (external).
627 @c Some more detail on exactly what these symbol types are used for
631 The symbol's value is absolute, and will not be changed by further
635 The symbol is in the uninitialized data section (known as BSS).
638 The symbol is common. Common symbols are uninitialized data. When
639 linking, multiple common symbols may appear with the same name. If the
640 symbol is defined anywhere, the common symbols are treated as undefined
641 references. For more details on common symbols, see the discussion of
642 --warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
645 The symbol is in the initialized data section.
648 The symbol is in an initialized data section for small objects. Some
649 object file formats permit more efficient access to small data objects,
650 such as a global int variable as opposed to a large global array.
653 The symbol is an indirect reference to another symbol. This is a GNU
654 extension to the a.out object file format which is rarely used.
657 The symbol is a debugging symbol.
660 The symbol is in a read only data section.
663 The symbol is in an uninitialized data section for small objects.
666 The symbol is in the text (code) section.
669 The symbol is undefined.
672 The symbol is weak. When a weak defined symbol is linked with a normal
673 defined symbol, the normal defined symbol is used with no error. When a
674 weak undefined symbol is linked and the symbol is not defined, the value
675 of the weak symbol becomes zero with no error.
678 The symbol is a stabs symbol in an a.out object file. In this case, the
679 next values printed are the stabs other field, the stabs desc field, and
680 the stab type. Stabs symbols are used to hold debugging information;
681 for more information, see @ref{Top,Stabs,Stabs Overview,stabs.info, The
682 ``stabs'' debug format}.
685 The symbol type is unknown, or object file format specific.
692 The long and short forms of options, shown here as alternatives, are
698 @itemx --print-file-name
699 @cindex input file name
701 @cindex source file name
702 Precede each symbol by the name of the input file (or archive element)
703 in which it was found, rather than identifying the input file once only,
704 before all of its symbols.
708 @cindex debugging symbols
709 Display all symbols, even debugger-only symbols; normally these are not
713 @cindex @code{nm} format
714 @cindex @code{nm} compatibility
715 The same as @samp{--format=bsd} (for compatibility with the MIPS @code{nm}).
719 @cindex demangling in nm
720 Decode (@dfn{demangle}) low-level symbol names into user-level names.
721 Besides removing any initial underscore prepended by the system, this
722 makes C++ function names readable. @xref{c++filt}, for more information
726 Do not demangle low-level symbol names. This is the default.
730 @cindex dynamic symbols
731 Display the dynamic symbols rather than the normal symbols. This is
732 only meaningful for dynamic objects, such as certain types of shared
735 @item -f @var{format}
736 @itemx --format=@var{format}
737 @cindex @code{nm} format
738 @cindex @code{nm} compatibility
739 Use the output format @var{format}, which can be @code{bsd},
740 @code{sysv}, or @code{posix}. The default is @code{bsd}.
741 Only the first character of @var{format} is significant; it can be
742 either upper or lower case.
746 @cindex external symbols
747 Display only external symbols.
750 @itemx --line-numbers
751 @cindex symbol line numbers
752 For each symbol, use debugging information to try to find a filename and
753 line number. For a defined symbol, look for the line number of the
754 address of the symbol. For an undefined symbol, look for the line
755 number of a relocation entry which refers to the symbol. If line number
756 information can be found, print it after the other symbol information.
760 @itemx --numeric-sort
761 Sort symbols numerically by their addresses, rather than alphabetically
766 @cindex sorting symbols
767 Do not bother to sort the symbols in any order; print them in the order
772 Use the POSIX.2 standard output format instead of the default format.
773 Equivalent to @samp{-f posix}.
777 @cindex symbol index, listing
778 When listing symbols from archive members, include the index: a mapping
779 (stored in the archive by @code{ar} or @code{ranlib}) of which modules
780 contain definitions for which names.
783 @itemx --reverse-sort
784 Reverse the order of the sort (whether numeric or alphabetic); let the
788 Sort symbols by size. The size is computed as the difference between
789 the value of the symbol and the value of the symbol with the next higher
790 value. The size of the symbol is printed, rather than the value.
793 @itemx --radix=@var{radix}
794 Use @var{radix} as the radix for printing the symbol values. It must be
795 @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
797 @item --target=@var{bfdname}
798 @cindex object code format
799 Specify an object code format other than your system's default format.
800 @xref{Target Selection}, for more information.
803 @itemx --undefined-only
804 @cindex external symbols
805 @cindex undefined symbols
806 Display only undefined symbols (those external to each object file).
809 @cindex external symbols
810 @cindex undefined symbols
811 Display only defined symbols for each object file.
815 Show the version number of @code{nm} and exit.
818 Show a summary of the options to @code{nm} and exit.
825 objcopy [ -F @var{bfdname} | --target=@var{bfdname} ]
826 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
827 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
828 [ -S | --strip-all ] [ -g | --strip-debug ]
829 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
830 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
831 [ -L @var{symbolname} | --localize-symbol=@var{symbolname} ]
832 [ -W @var{symbolname} | --weaken-symbol=@var{symbolname} ]
833 [ -x | --discard-all ] [ -X | --discard-locals ]
834 [ -b @var{byte} | --byte=@var{byte} ]
835 [ -i @var{interleave} | --interleave=@var{interleave} ]
836 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
837 [ -p | --preserve-dates ] [ --debugging ]
838 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
839 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
840 [ --change-addresses=@var{incr} ]
841 [ --change-section-address=@var{section}@{=,+,-@}@var{val} ]
842 [ --change-section-lma=@var{section}@{=,+,-@}@var{val} ]
843 [ --change-section-vma=@var{section}@{=,+,-@}@var{val} ]
844 [ --change-warnings ] [ --no-change-warnings ]
845 [ --set-section-flags=@var{section}=@var{flags} ]
846 [ --add-section=@var{sectionname}=@var{filename} ]
847 [ --change-leading-char ] [ --remove-leading-char ]
849 [ -v | --verbose ] [ -V | --version ] [ --help ]
850 @var{infile} [@var{outfile}]
853 The @sc{gnu} @code{objcopy} utility copies the contents of an object
854 file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
855 read and write the object files. It can write the destination object
856 file in a format different from that of the source object file. The
857 exact behavior of @code{objcopy} is controlled by command-line options.
859 @code{objcopy} creates temporary files to do its translations and
860 deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
861 translation work; it has access to all the formats described in @sc{bfd}
862 and thus is able to recognize most formats without being told
863 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
865 @code{objcopy} can be used to generate S-records by using an output
866 target of @samp{srec} (e.g., use @samp{-O srec}).
868 @code{objcopy} can be used to generate a raw binary file by using an
869 output target of @samp{binary} (e.g., use @samp{-O binary}). When
870 @code{objcopy} generates a raw binary file, it will essentially produce
871 a memory dump of the contents of the input object file. All symbols and
872 relocation information will be discarded. The memory dump will start at
873 the load address of the lowest section copied into the output file.
875 When generating an S-record or a raw binary file, it may be helpful to
876 use @samp{-S} to remove sections containing debugging information. In
877 some cases @samp{-R} will be useful to remove sections which contain
878 information which is not needed by the binary file.
883 The source and output files, respectively.
884 If you do not specify @var{outfile}, @code{objcopy} creates a
885 temporary file and destructively renames the result with
886 the name of @var{infile}.
888 @item -I @var{bfdname}
889 @itemx --input-target=@var{bfdname}
890 Consider the source file's object format to be @var{bfdname}, rather than
891 attempting to deduce it. @xref{Target Selection}, for more information.
893 @item -O @var{bfdname}
894 @itemx --output-target=@var{bfdname}
895 Write the output file using the object format @var{bfdname}.
896 @xref{Target Selection}, for more information.
898 @item -F @var{bfdname}
899 @itemx --target=@var{bfdname}
900 Use @var{bfdname} as the object format for both the input and the output
901 file; i.e., simply transfer data from source to destination with no
902 translation. @xref{Target Selection}, for more information.
904 @item -R @var{sectionname}
905 @itemx --remove-section=@var{sectionname}
906 Remove any section named @var{sectionname} from the output file. This
907 option may be given more than once. Note that using this option
908 inappropriately may make the output file unusable.
912 Do not copy relocation and symbol information from the source file.
916 Do not copy debugging symbols from the source file.
918 @item --strip-unneeded
919 Strip all symbols that are not needed for relocation processing.
921 @item -K @var{symbolname}
922 @itemx --keep-symbol=@var{symbolname}
923 Copy only symbol @var{symbolname} from the source file. This option may
924 be given more than once.
926 @item -N @var{symbolname}
927 @itemx --strip-symbol=@var{symbolname}
928 Do not copy symbol @var{symbolname} from the source file. This option
929 may be given more than once.
931 @item -L @var{symbolname}
932 @itemx --localize-symbol=@var{symbolname}
933 Make symbol @var{symbolname} local to the file, so that it is not
934 visible externally. This option may be given more than once.
936 @item -W @var{symbolname}
937 @itemx --weaken-symbol=@var{symbolname}
938 Make symbol @var{symbolname} weak. This option may be given more than once.
942 Do not copy non-global symbols from the source file.
943 @c FIXME any reason to prefer "non-global" to "local" here?
946 @itemx --discard-locals
947 Do not copy compiler-generated local symbols.
948 (These usually start with @samp{L} or @samp{.}.)
951 @itemx --byte=@var{byte}
952 Keep only every @var{byte}th byte of the input file (header data is not
953 affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
954 where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
955 option, or the default of 4. This option is useful for creating files
956 to program @sc{rom}. It is typically used with an @code{srec} output
959 @item -i @var{interleave}
960 @itemx --interleave=@var{interleave}
961 Only copy one out of every @var{interleave} bytes. Select which byte to
962 copy with the @var{-b} or @samp{--byte} option. The default is 4.
963 @code{objcopy} ignores this option if you do not specify either @samp{-b} or
967 @itemx --preserve-dates
968 Set the access and modification dates of the output file to be the same
969 as those of the input file.
972 Convert debugging information, if possible. This is not the default
973 because only certain debugging formats are supported, and the
974 conversion process can be time consuming.
976 @item --gap-fill @var{val}
977 Fill gaps between sections with @var{val}. This operation applies to
978 the @emph{load address} (LMA) of the sections. It is done by increasing
979 the size of the section with the lower address, and filling in the extra
980 space created with @var{val}.
982 @item --pad-to @var{address}
983 Pad the output file up to the load address @var{address}. This is
984 done by increasing the size of the last section. The extra space is
985 filled in with the value specified by @samp{--gap-fill} (default zero).
987 @item --set-start @var{val}
988 Set the address of the new file to @var{val}. Not all object file
989 formats support setting the start address.
991 @item --change-start @var{incr}
992 @itemx --adjust-start @var{incr}
993 @cindex changing start address
994 Change the start address by adding @var{incr}. Not all object file
995 formats support setting the start address.
997 @item --change-addresses @var{incr}
998 @itemx --adjust-vma @var{incr}
999 @cindex changing object addresses
1000 Change the VMA and LMA addresses of all sections, as well as the start
1001 address, by adding @var{incr}. Some object file formats do not permit
1002 section addresses to be changed arbitrarily. Note that this does not
1003 relocate the sections; if the program expects sections to be loaded at a
1004 certain address, and this option is used to change the sections such
1005 that they are loaded at a different address, the program may fail.
1007 @item --change-section-address @var{section}@{=,+,-@}@var{val}
1008 @itemx --adjust-section-vma @var{section}@{=,+,-@}@var{val}
1009 @cindex changing section address
1010 Set or change both the VMA address and the LMA address of the named
1011 @var{section}. If @samp{=} is used, the section address is set to
1012 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1013 section address. See the comments under @samp{--change-addresses},
1014 above. If @var{section} does not exist in the input file, a warning will
1015 be issued, unless @samp{--no-change-warnings} is used.
1017 @item --change-section-lma @var{section}@{=,+,-@}@var{val}
1018 @cindex changing section LMA
1019 Set or change the LMA address of the named @var{section}. The LMA
1020 address is the address where the section will be loaded into memory at
1021 program load time. Normally this is the same as the VMA address, which
1022 is the address of the section at program run time, but on some systems,
1023 especially those where a program is held in ROM, the two can be
1024 different. If @samp{=} is used, the section address is set to
1025 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1026 section address. See the comments under @samp{--change-addresses},
1027 above. If @var{section} does not exist in the input file, a warning
1028 will be issued, unless @samp{--no-change-warnings} is used.
1030 @item --change-section-vma @var{section}@{=,+,-@}@var{val}
1031 @cindex changing section VMA
1032 Set or change the VMA address of the named @var{section}. The VMA
1033 address is the address where the section will be located once the
1034 program has started executing. Normally this is the same as the LMA
1035 address, which is the address where the section will be loaded into
1036 memory, but on some systems, especially those where a program is held in
1037 ROM, the two can be different. If @samp{=} is used, the section address
1038 is set to @var{val}. Otherwise, @var{val} is added to or subtracted
1039 from the section address. See the comments under
1040 @samp{--change-addresses}, above. If @var{section} does not exist in
1041 the input file, a warning will be issued, unless
1042 @samp{--no-change-warnings} is used.
1044 @item --change-warnings
1045 @itemx --adjust-warnings
1046 If @samp{--change-section-address} or @samp{--change-section-lma} or
1047 @samp{--change-section-vma} is used, and the named section does not
1048 exist, issue a warning. This is the default.
1050 @item --no-change-warnings
1051 @itemx --no-adjust-warnings
1052 Do not issue a warning if @samp{--change-section-address} or
1053 @samp{--adjust-section-lma} or @samp{--adjust-section-vma} is used, even
1054 if the named section does not exist.
1056 @item --set-section-flags @var{section}=@var{flags}
1057 Set the flags for the named section. The @var{flags} argument is a
1058 comma separated string of flag names. The recognized names are
1059 @samp{alloc}, @samp{contents}, @samp{load}, @samp{readonly},
1060 @samp{code}, @samp{data}, and @samp{rom}. You can set the
1061 @samp{contents} flag for a section which does not have contents, but it
1062 is not meaningful to clear the @samp{contents} flag of a section which
1063 does have contents--just remove the section instead. Not all flags are
1064 meaningful for all object file formats.
1066 @item --add-section @var{sectionname}=@var{filename}
1067 Add a new section named @var{sectionname} while copying the file. The
1068 contents of the new section are taken from the file @var{filename}. The
1069 size of the section will be the size of the file. This option only
1070 works on file formats which can support sections with arbitrary names.
1072 @item --change-leading-char
1073 Some object file formats use special characters at the start of
1074 symbols. The most common such character is underscore, which compilers
1075 often add before every symbol. This option tells @code{objcopy} to
1076 change the leading character of every symbol when it converts between
1077 object file formats. If the object file formats use the same leading
1078 character, this option has no effect. Otherwise, it will add a
1079 character, or remove a character, or change a character, as
1082 @item --remove-leading-char
1083 If the first character of a global symbol is a special symbol leading
1084 character used by the object file format, remove the character. The
1085 most common symbol leading character is underscore. This option will
1086 remove a leading underscore from all global symbols. This can be useful
1087 if you want to link together objects of different file formats with
1088 different conventions for symbol names. This is different from
1089 @code{--change-leading-char} because it always changes the symbol name
1090 when appropriate, regardless of the object file format of the output
1094 Change all global symbols in the file to be weak. This can be useful
1095 when building an object which will be linked against other objects using
1096 the @code{-R} option to the linker. This option is only effective when
1097 using an object file format which supports weak symbols.
1101 Show the version number of @code{objcopy}.
1105 Verbose output: list all object files modified. In the case of
1106 archives, @samp{objcopy -V} lists all members of the archive.
1109 Show a summary of the options to @code{objcopy}.
1115 @cindex object file information
1119 objdump [ -a | --archive-headers ]
1120 [ -b @var{bfdname} | --target=@var{bfdname} ] [ --debugging ]
1121 [ -C | --demangle ] [ -d | --disassemble ]
1122 [ -D | --disassemble-all ] [ --disassemble-zeroes ]
1123 [ -EB | -EL | --endian=@{big | little @} ]
1124 [ -f | --file-headers ]
1125 [ -h | --section-headers | --headers ] [ -i | --info ]
1126 [ -j @var{section} | --section=@var{section} ]
1127 [ -l | --line-numbers ] [ -S | --source ]
1128 [ -m @var{machine} | --architecture=@var{machine} ]
1129 [ -r | --reloc ] [ -R | --dynamic-reloc ]
1130 [ -s | --full-contents ] [ --stabs ]
1131 [ -t | --syms ] [ -T | --dynamic-syms ] [ -x | --all-headers ]
1132 [ -w | --wide ] [ --start-address=@var{address} ]
1133 [ --stop-address=@var{address} ]
1134 [ --prefix-addresses] [ --[no-]show-raw-insn ]
1135 [ --adjust-vma=@var{offset} ]
1136 [ --version ] [ --help ]
1137 @var{objfile}@dots{}
1140 @code{objdump} displays information about one or more object files.
1141 The options control what particular information to display. This
1142 information is mostly useful to programmers who are working on the
1143 compilation tools, as opposed to programmers who just want their
1144 program to compile and work.
1146 @var{objfile}@dots{} are the object files to be examined. When you
1147 specify archives, @code{objdump} shows information on each of the member
1150 The long and short forms of options, shown here as alternatives, are
1151 equivalent. At least one option besides @samp{-l} must be given.
1155 @itemx --archive-header
1156 @cindex archive headers
1157 If any of the @var{objfile} files are archives, display the archive
1158 header information (in a format similar to @samp{ls -l}). Besides the
1159 information you could list with @samp{ar tv}, @samp{objdump -a} shows
1160 the object file format of each archive member.
1162 @item --adjust-vma=@var{offset}
1163 @cindex section addresses in objdump
1164 @cindex VMA in objdump
1165 When dumping information, first add @var{offset} to all the section
1166 addresses. This is useful if the section addresses do not correspond to
1167 the symbol table, which can happen when putting sections at particular
1168 addresses when using a format which can not represent section addresses,
1171 @item -b @var{bfdname}
1172 @itemx --target=@var{bfdname}
1173 @cindex object code format
1174 Specify that the object-code format for the object files is
1175 @var{bfdname}. This option may not be necessary; @var{objdump} can
1176 automatically recognize many formats.
1180 objdump -b oasys -m vax -h fu.o
1183 displays summary information from the section headers (@samp{-h}) of
1184 @file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1185 file in the format produced by Oasys compilers. You can list the
1186 formats available with the @samp{-i} option.
1187 @xref{Target Selection}, for more information.
1191 @cindex demangling in objdump
1192 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1193 Besides removing any initial underscore prepended by the system, this
1194 makes C++ function names readable. @xref{c++filt}, for more information
1198 Display debugging information. This attempts to parse debugging
1199 information stored in the file and print it out using a C like syntax.
1200 Only certain types of debugging information have been implemented.
1203 @itemx --disassemble
1204 @cindex disassembling object code
1205 @cindex machine instructions
1206 Display the assembler mnemonics for the machine instructions from
1207 @var{objfile}. This option only disassembles those sections which are
1208 expected to contain instructions.
1211 @itemx --disassemble-all
1212 Like @samp{-d}, but disassemble the contents of all sections, not just
1213 those expected to contain instructions.
1215 @item --prefix-addresses
1216 When disassembling, print the complete address on each line. This is
1217 the older disassembly format.
1219 @item --disassemble-zeroes
1220 Normally the disassembly output will skip blocks of zeroes. This
1221 option directs the disassembler to disassemble those blocks, just like
1226 @itemx --endian=@{big|little@}
1228 @cindex disassembly endianness
1229 Specify the endianness of the object files. This only affects
1230 disassembly. This can be useful when disassembling a file format which
1231 does not describe endianness information, such as S-records.
1234 @itemx --file-header
1235 @cindex object file header
1236 Display summary information from the overall header of
1237 each of the @var{objfile} files.
1240 @itemx --section-header
1242 @cindex section headers
1243 Display summary information from the section headers of the
1246 File segments may be relocated to nonstandard addresses, for example by
1247 using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1248 @code{ld}. However, some object file formats, such as a.out, do not
1249 store the starting address of the file segments. In those situations,
1250 although @code{ld} relocates the sections correctly, using @samp{objdump
1251 -h} to list the file section headers cannot show the correct addresses.
1252 Instead, it shows the usual addresses, which are implicit for the
1256 Print a summary of the options to @code{objdump} and exit.
1260 @cindex architectures available
1261 @cindex object formats available
1262 Display a list showing all architectures and object formats available
1263 for specification with @samp{-b} or @samp{-m}.
1266 @itemx --section=@var{name}
1267 @cindex section information
1268 Display information only for section @var{name}.
1271 @itemx --line-numbers
1272 @cindex source filenames for object files
1273 Label the display (using debugging information) with the filename and
1274 source line numbers corresponding to the object code or relocs shown.
1275 Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1277 @item -m @var{machine}
1278 @itemx --architecture=@var{machine}
1279 @cindex architecture
1280 @cindex disassembly architecture
1281 Specify the architecture to use when disassembling object files. This
1282 can be useful when disassembling object files which do not describe
1283 architecture information, such as S-records. You can list the available
1284 architectures with the @samp{-i} option.
1288 @cindex relocation entries, in object file
1289 Print the relocation entries of the file. If used with @samp{-d} or
1290 @samp{-D}, the relocations are printed interspersed with the
1294 @itemx --dynamic-reloc
1295 @cindex dynamic relocation entries, in object file
1296 Print the dynamic relocation entries of the file. This is only
1297 meaningful for dynamic objects, such as certain types of shared
1301 @itemx --full-contents
1302 @cindex sections, full contents
1303 @cindex object file sections
1304 Display the full contents of any sections requested.
1308 @cindex source disassembly
1309 @cindex disassembly, with source
1310 Display source code intermixed with disassembly, if possible. Implies
1313 @item --show-raw-insn
1314 When disassembling instructions, print the instruction in hex as well as
1315 in symbolic form. This is the default except when
1316 @code{--prefix-addresses} is used.
1318 @item --no-show-raw-insn
1319 When disassembling instructions, do not print the instruction bytes.
1320 This is the default when @code{--prefix-addresses} is used.
1325 @cindex debug symbols
1326 @cindex ELF object file format
1327 Display the full contents of any sections requested. Display the
1328 contents of the .stab and .stab.index and .stab.excl sections from an
1329 ELF file. This is only useful on systems (such as Solaris 2.0) in which
1330 @code{.stab} debugging symbol-table entries are carried in an ELF
1331 section. In most other file formats, debugging symbol-table entries are
1332 interleaved with linkage symbols, and are visible in the @samp{--syms}
1333 output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1334 Overview,stabs.info, The ``stabs'' debug format}.
1336 @item --start-address=@var{address}
1337 @cindex start-address
1338 Start displaying data at the specified address. This affects the output
1339 of the @code{-d}, @code{-r} and @code{-s} options.
1341 @item --stop-address=@var{address}
1342 @cindex stop-address
1343 Stop displaying data at the specified address. This affects the output
1344 of the @code{-d}, @code{-r} and @code{-s} options.
1348 @cindex symbol table entries, printing
1349 Print the symbol table entries of the file.
1350 This is similar to the information provided by the @samp{nm} program.
1353 @itemx --dynamic-syms
1354 @cindex dynamic symbol table entries, printing
1355 Print the dynamic symbol table entries of the file. This is only
1356 meaningful for dynamic objects, such as certain types of shared
1357 libraries. This is similar to the information provided by the @samp{nm}
1358 program when given the @samp{-D} (@samp{--dynamic}) option.
1361 Print the version number of @code{objdump} and exit.
1365 @cindex all header information, object file
1366 @cindex header information, all
1367 Display all available header information, including the symbol table and
1368 relocation entries. Using @samp{-x} is equivalent to specifying all of
1369 @samp{-a -f -h -r -t}.
1373 @cindex wide output, printing
1374 Format some lines for output devices that have more than 80 columns.
1381 @cindex archive contents
1382 @cindex symbol index
1385 ranlib [-vV] @var{archive}
1388 @code{ranlib} generates an index to the contents of an archive and
1389 stores it in the archive. The index lists each symbol defined by a
1390 member of an archive that is a relocatable object file.
1392 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1394 An archive with such an index speeds up linking to the library and
1395 allows routines in the library to call each other without regard to
1396 their placement in the archive.
1398 The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1399 @code{ranlib} is completely equivalent to executing @samp{ar -s}.
1405 Show the version number of @code{ranlib}.
1412 @cindex section sizes
1415 size [ -A | -B | --format=@var{compatibility} ]
1416 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1417 [ --target=@var{bfdname} ] [ -V | --version ]
1418 [ @var{objfile}@dots{} ]
1421 The @sc{gnu} @code{size} utility lists the section sizes---and the total
1422 size---for each of the object or archive files @var{objfile} in its
1423 argument list. By default, one line of output is generated for each
1424 object file or each module in an archive.
1426 @var{objfile}@dots{} are the object files to be examined.
1427 If none are specified, the file @code{a.out} will be used.
1429 The command line options have the following meanings:
1434 @itemx --format=@var{compatibility}
1435 @cindex @code{size} display format
1436 Using one of these options, you can choose whether the output from @sc{gnu}
1437 @code{size} resembles output from System V @code{size} (using @samp{-A},
1438 or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1439 @samp{--format=berkeley}). The default is the one-line format similar to
1441 @c Bonus for doc-source readers: you can also say --format=strange (or
1442 @c anything else that starts with 's') for sysv, and --format=boring (or
1443 @c anything else that starts with 'b') for Berkeley.
1445 Here is an example of the Berkeley (default) format of output from
1448 size --format=Berkeley ranlib size
1449 text data bss dec hex filename
1450 294880 81920 11592 388392 5ed28 ranlib
1451 294880 81920 11888 388688 5ee50 size
1455 This is the same data, but displayed closer to System V conventions:
1458 size --format=SysV ranlib size
1476 Show a summary of acceptable arguments and options.
1481 @itemx --radix=@var{number}
1482 @cindex @code{size} number format
1483 @cindex radix for section sizes
1484 Using one of these options, you can control whether the size of each
1485 section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1486 (@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1487 @samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1488 values (8, 10, 16) are supported. The total size is always given in two
1489 radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1490 octal and hexadecimal if you're using @samp{-o}.
1492 @item --target=@var{bfdname}
1493 @cindex object code format
1494 Specify that the object-code format for @var{objfile} is
1495 @var{bfdname}. This option may not be necessary; @code{size} can
1496 automatically recognize many formats.
1497 @xref{Target Selection}, for more information.
1501 Display the version number of @code{size}.
1507 @cindex listings strings
1508 @cindex printing strings
1509 @cindex strings, printing
1512 strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1513 [--all] [--print-file-name] [--bytes=@var{min-len}]
1514 [--radix=@var{radix}] [--target=@var{bfdname}]
1515 [--help] [--version] @var{file}@dots{}
1518 For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1519 character sequences that are at least 4 characters long (or the number
1520 given with the options below) and are followed by an unprintable
1521 character. By default, it only prints the strings from the initialized
1522 and loaded sections of object files; for other types of files, it prints
1523 the strings from the whole file.
1525 @code{strings} is mainly useful for determining the contents of non-text
1532 Do not scan only the initialized and loaded sections of object files;
1533 scan the whole files.
1536 @itemx --print-file-name
1537 Print the name of the file before each string.
1540 Print a summary of the program usage on the standard output and exit.
1542 @item -@var{min-len}
1543 @itemx -n @var{min-len}
1544 @itemx --bytes=@var{min-len}
1545 Print sequences of characters that are at least @var{min-len} characters
1546 long, instead of the default 4.
1549 Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1550 act like @samp{-t d} instead. Since we can not be compatible with both
1551 ways, we simply chose one.
1553 @item -t @var{radix}
1554 @itemx --radix=@var{radix}
1555 Print the offset within the file before each string. The single
1556 character argument specifies the radix of the offset---@samp{o} for
1557 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1559 @item --target=@var{bfdname}
1560 @cindex object code format
1561 Specify an object code format other than your system's default format.
1562 @xref{Target Selection}, for more information.
1566 Print the program version number on the standard output and exit.
1573 @cindex removing symbols
1574 @cindex discarding symbols
1575 @cindex symbols, discarding
1578 strip [ -F @var{bfdname} | --target=@var{bfdname} ]
1579 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1580 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1581 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1582 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1583 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1584 [ -x | --discard-all ] [ -X | --discard-locals ]
1585 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1586 [ -o @var{file} ] [ -p | --preserve-dates ]
1587 [ -v | --verbose ] [ -V | --version ] [ --help ]
1588 @var{objfile}@dots{}
1591 @sc{gnu} @code{strip} discards all symbols from object files
1592 @var{objfile}. The list of object files may include archives.
1593 At least one object file must be given.
1595 @code{strip} modifies the files named in its argument,
1596 rather than writing modified copies under different names.
1599 @item -F @var{bfdname}
1600 @itemx --target=@var{bfdname}
1601 Treat the original @var{objfile} as a file with the object
1602 code format @var{bfdname}, and rewrite it in the same format.
1603 @xref{Target Selection}, for more information.
1606 Show a summary of the options to @code{strip} and exit.
1608 @item -I @var{bfdname}
1609 @itemx --input-target=@var{bfdname}
1610 Treat the original @var{objfile} as a file with the object
1611 code format @var{bfdname}.
1612 @xref{Target Selection}, for more information.
1614 @item -O @var{bfdname}
1615 @itemx --output-target=@var{bfdname}
1616 Replace @var{objfile} with a file in the output format @var{bfdname}.
1617 @xref{Target Selection}, for more information.
1619 @item -R @var{sectionname}
1620 @itemx --remove-section=@var{sectionname}
1621 Remove any section named @var{sectionname} from the output file. This
1622 option may be given more than once. Note that using this option
1623 inappropriately may make the output file unusable.
1631 @itemx --strip-debug
1632 Remove debugging symbols only.
1634 @item --strip-unneeded
1635 Remove all symbols that are not needed for relocation processing.
1637 @item -K @var{symbolname}
1638 @itemx --keep-symbol=@var{symbolname}
1639 Keep only symbol @var{symbolname} from the source file. This option may
1640 be given more than once.
1642 @item -N @var{symbolname}
1643 @itemx --strip-symbol=@var{symbolname}
1644 Remove symbol @var{symbolname} from the source file. This option may be
1645 given more than once, and may be combined with strip options other than
1649 Put the stripped output in @var{file}, rather than replacing the
1650 existing file. When this argument is used, only one @var{objfile}
1651 argument may be specified.
1654 @itemx --preserve-dates
1655 Preserve the access and modification dates of the file.
1658 @itemx --discard-all
1659 Remove non-global symbols.
1662 @itemx --discard-locals
1663 Remove compiler-generated local symbols.
1664 (These usually start with @samp{L} or @samp{.}.)
1668 Show the version number for @code{strip}.
1672 Verbose output: list all object files modified. In the case of
1673 archives, @samp{strip -v} lists all members of the archive.
1680 @cindex demangling C++ symbols
1683 c++filt [ -_ | --strip-underscores ]
1684 [ -n | --no-strip-underscores ]
1685 [ -s @var{format} | --format=@var{format} ]
1686 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1689 The C++ language provides function overloading, which means that you can
1690 write many functions with the same name (providing each takes parameters
1691 of different types). All C++ function names are encoded into a
1692 low-level assembly label (this process is known as
1693 @dfn{mangling}). The @code{c++filt} program does the inverse mapping: it
1694 decodes (@dfn{demangles}) low-level names into user-level names so that
1695 the linker can keep these overloaded functions from clashing.
1697 Every alphanumeric word (consisting of letters, digits, underscores,
1698 dollars, or periods) seen in the input is a potential label. If the
1699 label decodes into a C++ name, the C++ name replaces the low-level
1702 You can use @code{c++filt} to decipher individual symbols:
1705 c++filt @var{symbol}
1708 If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1709 names from the standard input and writes the demangled names to the
1710 standard output. All results are printed on the standard output.
1714 @itemx --strip-underscores
1715 On some systems, both the C and C++ compilers put an underscore in front
1716 of every name. For example, the C name @code{foo} gets the low-level
1717 name @code{_foo}. This option removes the initial underscore. Whether
1718 @code{c++filt} removes the underscore by default is target dependent.
1721 @itemx --no-strip-underscores
1722 Do not remove the initial underscore.
1724 @item -s @var{format}
1725 @itemx --format=@var{format}
1726 @sc{gnu} @code{nm} can decode three different methods of mangling, used by
1727 different C++ compilers. The argument to this option selects which
1732 the one used by the @sc{gnu} compiler (the default method)
1734 the one used by the Lucid compiler
1736 the one specified by the C++ Annotated Reference Manual
1740 Print a summary of the options to @code{c++filt} and exit.
1743 Print the version number of @code{c++filt} and exit.
1747 @emph{Warning:} @code{c++filt} is a new utility, and the details of its
1748 user interface are subject to change in future releases. In particular,
1749 a command-line option may be required in the the future to decode a name
1750 passed as an argument on the command line; in other words,
1753 c++filt @var{symbol}
1757 may in a future release become
1760 c++filt @var{option} @var{symbol}
1768 @cindex address to file name and line number
1771 addr2line [ -b @var{bfdname} | --target=@var{bfdname} ]
1773 [ -e @var{filename} | --exe=@var{filename} ]
1774 [ -f | --functions ] [ -s | --basename ]
1775 [ -H | --help ] [ -V | --version ]
1779 @code{addr2line} translates program addresses into file names and line
1780 numbers. Given an address and an executable, it uses the debugging
1781 information in the executable to figure out which file name and line
1782 number are associated with a given address.
1784 The executable to use is specified with the @code{-e} option. The
1785 default is @file{a.out}.
1787 @code{addr2line} has two modes of operation.
1789 In the first, hexadecimal addresses are specified on the command line,
1790 and @code{addr2line} displays the file name and line number for each
1793 In the second, @code{addr2line} reads hexadecimal addresses from
1794 standard input, and prints the file name and line number for each
1795 address on standard output. In this mode, @code{addr2line} may be used
1796 in a pipe to convert dynamically chosen addresses.
1798 The format of the output is @samp{FILENAME:LINENO}. The file name and
1799 line number for each address is printed on a separate line. If the
1800 @code{-f} option is used, then each @samp{FILENAME:LINENO} line is
1801 preceded by a @samp{FUNCTIONNAME} line which is the name of the function
1802 containing the address.
1804 If the file name or function name can not be determined,
1805 @code{addr2line} will print two question marks in their place. If the
1806 line number can not be determined, @code{addr2line} will print 0.
1808 The long and short forms of options, shown here as alternatives, are
1812 @item -b @var{bfdname}
1813 @itemx --target=@var{bfdname}
1814 @cindex object code format
1815 Specify that the object-code format for the object files is
1820 @cindex demangling in objdump
1821 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1822 Besides removing any initial underscore prepended by the system, this
1823 makes C++ function names readable. @xref{c++filt}, for more information
1826 @item -e @var{filename}
1827 @itemx --exe=@var{filename}
1828 Specify the name of the executable for which addresses should be
1829 translated. The default file is @file{a.out}.
1833 Display function names as well as file and line number information.
1837 Display only the base of each file name.
1843 @code{nlmconv} converts a relocatable object file into a NetWare
1847 @code{nlmconv} currently works with @samp{i386} object
1848 files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1849 object files in @sc{elf}, or @code{a.out} format@footnote{
1850 @code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1851 format in the Binary File Descriptor library. It has only been tested
1852 with the above formats.}.
1856 @emph{Warning:} @code{nlmconv} is not always built as part of the binary
1857 utilities, since it is only useful for NLM targets.
1861 nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1862 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1863 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1864 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1865 [ -h | --help ] [ -V | --version ]
1866 @var{infile} @var{outfile}
1869 @code{nlmconv} converts the relocatable @samp{i386} object file
1870 @var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1871 reading @var{headerfile} for NLM header information. For instructions
1872 on writing the NLM command file language used in header files, see the
1873 @samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1874 Development and Tools Overview}, which is part of the NLM Software
1875 Developer's Kit (``NLM SDK''), available from Novell, Inc.
1876 @code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1877 @var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1880 @code{nlmconv} can perform a link step. In other words, you can list
1881 more than one object file for input if you list them in the definitions
1882 file (rather than simply specifying one input file on the command line).
1883 In this case, @code{nlmconv} calls the linker for you.
1886 @item -I @var{bfdname}
1887 @itemx --input-target=@var{bfdname}
1888 Object format of the input file. @code{nlmconv} can usually determine
1889 the format of a given file (so no default is necessary).
1890 @xref{Target Selection}, for more information.
1892 @item -O @var{bfdname}
1893 @itemx --output-target=@var{bfdname}
1894 Object format of the output file. @code{nlmconv} infers the output
1895 format based on the input format, e.g. for a @samp{i386} input file the
1896 output format is @samp{nlm32-i386}.
1897 @xref{Target Selection}, for more information.
1899 @item -T @var{headerfile}
1900 @itemx --header-file=@var{headerfile}
1901 Reads @var{headerfile} for NLM header information. For instructions on
1902 writing the NLM command file language used in header files, see@ see the
1903 @samp{linkers} section, of the @cite{NLM Development and Tools
1904 Overview}, which is part of the NLM Software Developer's Kit, available
1909 Displays (on standard error) the linker command line used by @code{nlmconv}.
1911 @item -l @var{linker}
1912 @itemx --linker=@var{linker}
1913 Use @var{linker} for any linking. @var{linker} can be an absolute or a
1918 Prints a usage summary.
1922 Prints the version number for @code{nlmconv}.
1928 @code{windres} may be used to manipulate Windows resources.
1931 @emph{Warning:} @code{windres} is not always built as part of the binary
1932 utilities, since it is only useful for Windows targets.
1936 windres [options] [input-file] [output-file]
1939 @code{windres} reads resources from an input file and copies them into
1940 an output file. Either file may be in one of three formats:
1944 A text format read by the Resource Compiler.
1947 A binary format generated by the Resource Compiler.
1950 A COFF object or executable.
1953 The exact description of these different formats is available in
1954 documentation from Microsoft.
1956 When @code{windres} converts from the @code{rc} format to the @code{res}
1957 format, it is acting like the Windows Resource Compiler. When
1958 @code{windres} converts from the @code{res} format to the @code{coff}
1959 format, it is acting like the Windows @code{CVTRES} program.
1961 When @code{windres} generates an @code{rc} file, the output is similar
1962 but not identical to the format expected for the input. When an input
1963 @code{rc} file refers to an external filename, an output @code{rc} file
1964 will instead include the file contents.
1966 If the input or output format is not specified, @code{windres} will
1967 guess based on the file name, or, for the input file, the file contents.
1968 A file with an extension of @file{.rc} will be treated as an @code{rc}
1969 file, a file with an extension of @file{.res} will be treated as a
1970 @code{res} file, and a file with an extension of @file{.o} or
1971 @file{.exe} will be treated as a @code{coff} file.
1973 If no output file is specified, @code{windres} will print the resources
1974 in @code{rc} format to standard output.
1976 The normal use is for you to write an @code{rc} file, use @code{windres}
1977 to convert it to a COFF object file, and then link the COFF file into
1978 your application. This will make the resources described in the
1979 @code{rc} file available to Windows.
1982 @item -i @var{filename}
1983 @itemx --input @var{filename}
1984 The name of the input file. If this option is not used, then
1985 @code{windres} will use the first non-option argument as the input file
1986 name. If there are no non-option arguments, then @code{windres} will
1987 read from standard input. @code{windres} can not read a COFF file from
1990 @item -o @var{filename}
1991 @itemx --output @var{filename}
1992 The name of the output file. If this option is not used, then
1993 @code{windres} will use the first non-option argument, after any used
1994 for the input file name, as the output file name. If there is no
1995 non-option argument, then @code{windres} will write to standard output.
1996 @code{windres} can not write a COFF file to standard output.
1998 @item -I @var{format}
1999 @itemx --input-format @var{format}
2000 The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
2001 @samp{coff}. If no input format is specified, @code{windres} will
2002 guess, as described above.
2004 @item -O @var{format}
2005 @itemx --output-format @var{format}
2006 The output format to generate. @var{format} may be @samp{res},
2007 @samp{rc}, or @samp{coff}. If no output format is specified,
2008 @code{windres} will guess, as described above.
2010 @item -F @var{target}
2011 @itemx --target @var{target}
2012 Specify the BFD format to use for a COFF file as input or output. This
2013 is a BFD target name; you can use the @code{--help} option to see a list
2014 of supported targets. Normally @code{windres} will use the default
2015 format, which is the first one listed by the @code{--help} option.
2016 @ref{Target Selection}.
2018 @item --preprocessor @var{program}
2019 When @code{windres} reads an @code{rc} file, it runs it through the C
2020 preprocessor first. This option may be used to specify the preprocessor
2021 to use, including any leading arguments. The default preprocessor
2022 argument is @code{gcc -E -xc-header -DRC_INVOKED}.
2024 @item --include-dir @var{directory}
2025 Specify an include directory to use when reading an @code{rc} file.
2026 @code{windres} will pass this to the preprocessor as an @code{-I}
2027 option. @code{windres} will also search this directory when looking for
2028 files named in the @code{rc} file.
2030 @item --define @var{sym[=val]}
2031 Specify a @code{-D} option to pass to the preprocessor when reading an
2034 @item --language @var{val}
2035 Specify the default language to use when reading an @code{rc} file.
2036 @var{val} should be a hexadecimal language code. The low eight bits are
2037 the language, and the high eight bits are the sublanguage.
2040 Prints a usage summary.
2043 Prints the version number for @code{windres}.
2046 If @code{windres} is compiled with @code{YYDEBUG} defined as @code{1},
2047 this will turn on parser debugging.
2052 @chapter Create files needed to build and use DLLs
2056 @code{dlltool} may be used to create the files needed to build and use
2057 dynamic link libraries (DLLs).
2060 @emph{Warning:} @code{dlltool} is not always built as part of the binary
2061 utilities, since it is only useful for those targets which support DLLs.
2065 dlltool [-d|--input-def <def-file-name>]
2066 [-b|--base-file <base-file-name>]
2067 [-e|--output-exp <exports-file-name>]
2068 [-z|--output-def <def-file-name>]
2069 [-l|--output-lib <library-file-name>]
2070 [-S|--as <path-to-assembler>] [-f|--as-flags <options>]
2071 [-D|--dllname <name>] [-m|--machine <machine>]
2072 [-a|--add-indirect] [-U|--add-underscore] [-k|--kill-at]
2073 [-x|--no-idata4] [-c|--no-idata5] [-i|--interwork]
2074 [-n|--nodelete] [-v|--verbose] [-h|--help] [-V|--version]
2075 [object-file @dots{}]
2078 @code{dlltool} reads its inputs, which can come from the @samp{-d} and
2079 @samp{-b} options as well as object files specified on the command
2080 line. It then processes these inputs and if the @samp{-e} option has
2081 been specified it creates a exports file. If the @samp{-l} option
2082 has been specified it creates a library file and if the @samp{-z} option
2083 has been specified it creates a def file. Any or all of the -e, -l
2084 and -z options can be present in one invocation of dlltool.
2086 When creating a DLL, along with the source for the DLL, it is necessary
2087 to have three other files. @code{dlltool} can help with the creation of
2090 The first file is a @samp{.def} file which specifies which functions are
2091 exported from the DLL, which functions the DLL imports, and so on. This
2092 is a text file and can be created by hand, or @code{dlltool} can be used
2093 to create it using the @samp{-z} option. In this case @code{dlltool}
2094 will scan the object files specified on its command line looking for
2095 those functions which have been specially marked as being exported and
2096 put entries for them in the .def file it creates.
2098 In order to mark a function as being exported from a DLL, it needs to
2099 have an @samp{-export:<name_of_function>} entry in the @samp{.drective}
2100 section of the object file. This can be done in C by using the
2104 asm (".section .drective");
2105 asm (".ascii \"-export:my_func\"");
2107 int my_func (void) @{ @dots{} @}
2110 The second file needed for DLL creation is an exports file. This file
2111 is linked with the object files that make up the body of the DLL and it
2112 handles the interface between the DLL and the outside world. This is a
2113 binary file and it can be created by giving the @samp{-e} option to
2114 @code{dlltool} when it is creating or reading in a .def file.
2116 The third file needed for DLL creation is the library file that programs
2117 will link with in order to access the functions in the DLL. This file
2118 can be created by giving the @samp{-l} option to dlltool when it
2119 is creating or reading in a .def file.
2121 @code{dlltool} builds the library file by hand, but it builds the
2122 exports file by creating temporary files containing assembler statements
2123 and then assembling these. The @samp{-S} command line option can be
2124 used to specify the path to the assembler that dlltool will use,
2125 and the @samp{-f} option can be used to pass specific flags to that
2126 assembler. The @samp{-n} can be used to prevent dlltool from deleting
2127 these temporary assembler files when it is done, and if @samp{-n} is
2128 specified twice then this will prevent dlltool from deleting the
2129 temporary object files it used to build the library.
2131 Here is an example of creating a DLL from a source file @samp{dll.c} and
2132 also creating a program (from an object file called @samp{program.o})
2137 dlltool -e exports.o -l dll.lib dll.o
2138 gcc dll.o exports.o -o dll.dll
2139 gcc program.o dll.lib -o program
2142 The command line options have the following meanings:
2147 @itemx --input-def FILENAME
2148 @cindex input .def file
2149 Specifies the name of a .def file to be read in and processed.
2152 @itemx --base-file FILENAME
2154 Specifies the name of a base file to be read in and processed. The
2155 contents of this file will be added to the relocation section in the
2156 exports file generated by dlltool.
2159 @itemx --output-exp FILENAME
2160 Specifies the name of the export file to be created by dlltool.
2163 @itemx --output-def FILENAME
2164 Specifies the name of the .def file to be created by dlltool.
2167 @itemx --output-lib FILENAME
2168 Specifies the name of the library file to be created by dlltool.
2172 Specifies the path, including the filename, of the assembler to be used
2173 to create the exports file.
2176 @itemx --as-flags SWITCHES
2177 Specifies any specific command line switches to be passed to the
2178 assembler when building the exports file. This option will work even if
2179 the @samp{-S} option is not used. This option only takes one argument,
2180 and if it occurs more than once on the command line, then later
2181 occurrences will override earlier occurrences. So if it is necessary to
2182 pass multiple switches to the assembler they should be enclosed in
2186 @itemx --dll-name NAME
2187 Specifies the name to be stored in the .def file as the name of the DLL
2188 when the @samp{-e} option is used. If this option is not present, then
2189 the filename given to the @samp{-e} option will be used as the name of
2193 @itemx -machine MACHINE
2194 Specifies the type of machine for which the library file should be
2195 built. @code{dlltool} has a built in default type, depending upon how
2196 it was created, but this option can be used to override that. This is
2197 normally only useful when creating DLLs for an ARM processor, when the
2198 contents of the DLL are actually encode using THUMB instructions.
2201 @itemx --add-indirect
2202 Specifies that when @code{dlltool} is creating the exports file it
2203 should add a section which allows the exported functions to be
2204 referenced without using the import library. Whatever the hell that
2208 @itemx --add-underscore
2209 Specifies that when @code{dlltool} is creating the exports file it
2210 should prepend an underscore to the names of the exported functions.
2214 Specifies that when @code{dlltool} is creating the exports file it
2215 should not append the string @samp{@@ <number>}. These numbers are
2216 called ordinal numbers and they represent another way of accessing the
2217 function in a DLL, other than by name.
2221 Specifies that when @code{dlltool} is creating the exports and library
2222 files it should omit the .idata4 section. This is for compatibility
2223 with certain operating systems.
2227 Specifies that when @code{dlltool} is creating the exports and library
2228 files it should omit the .idata5 section. This is for compatibility
2229 with certain operating systems.
2233 Specifies that @code{dlltool} should mark the objects in the library
2234 file and exports file that it produces as supporting interworking
2235 between ARM and THUMB code.
2239 Makes @code{dlltool} preserve the temporary assembler files it used to
2240 create the exports file. If this option is repeated then dlltool will
2241 also preserve the temporary object files it uses to create the library
2246 Make dlltool describe what it is doing.
2250 Displays a list of command line options and then exits.
2254 Displays dlltool's version number and then exits.
2260 @node Selecting The Target System
2261 @chapter Selecting the target system
2263 You can specify three aspects of the target system to the @sc{gnu}
2264 binary file utilities, each in several ways:
2274 the linker emulation (which applies to the linker only)
2277 In the following summaries, the lists of ways to specify values are in
2278 order of decreasing precedence. The ways listed first override those
2281 The commands to list valid values only list the values for which the
2282 programs you are running were configured. If they were configured with
2283 @samp{--enable-targets=all}, the commands list most of the available
2284 values, but a few are left out; not all targets can be configured in at
2285 once because some of them can only be configured @dfn{native} (on hosts
2286 with the same type as the target system).
2289 * Target Selection::
2290 * Architecture Selection::
2291 * Linker Emulation Selection::
2294 @node Target Selection
2295 @section Target Selection
2297 A @dfn{target} is an object file format. A given target may be
2298 supported for multiple architectures (@pxref{Architecture Selection}).
2299 A target selection may also have variations for different operating
2300 systems or architectures.
2302 The command to list valid target values is @samp{objdump -i}
2303 (the first column of output contains the relevant information).
2305 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
2306 @samp{a.out-sunos-big}.
2308 You can also specify a target using a configuration triplet. This is
2309 the same sort of name that is passed to configure to specify a target.
2310 When you use a configuration triplet as an argument, it must be fully
2311 canonicalized. You can see the canonical version of a triplet by
2312 running the shell script @file{config.sub} which is included with the
2315 Some sample configuration triplets are: @samp{m68k-hp-bsd},
2316 @samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
2318 @subheading @code{objdump} Target
2324 command line option: @samp{-b} or @samp{--target}
2327 environment variable @code{GNUTARGET}
2330 deduced from the input file
2333 @subheading @code{objcopy} and @code{strip} Input Target
2339 command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
2342 environment variable @code{GNUTARGET}
2345 deduced from the input file
2348 @subheading @code{objcopy} and @code{strip} Output Target
2354 command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
2357 the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
2360 environment variable @code{GNUTARGET}
2363 deduced from the input file
2366 @subheading @code{nm}, @code{size}, and @code{strings} Target
2372 command line option: @samp{--target}
2375 environment variable @code{GNUTARGET}
2378 deduced from the input file
2381 @subheading Linker Input Target
2387 command line option: @samp{-b} or @samp{--format}
2388 (@pxref{Options,,Options,ld.info,Using LD})
2391 script command @code{TARGET}
2392 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2395 environment variable @code{GNUTARGET}
2396 (@pxref{Environment,,Environment,ld.info,Using LD})
2399 the default target of the selected linker emulation
2400 (@pxref{Linker Emulation Selection})
2403 @subheading Linker Output Target
2409 command line option: @samp{-oformat}
2410 (@pxref{Options,,Options,ld.info,Using LD})
2413 script command @code{OUTPUT_FORMAT}
2414 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2417 the linker input target (see ``Linker Input Target'' above)
2420 @node Architecture Selection
2421 @section Architecture selection
2423 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
2424 to run. Its name may contain a colon, separating the name of the
2425 processor family from the name of the particular @sc{cpu}.
2427 The command to list valid architecture values is @samp{objdump -i} (the
2428 second column contains the relevant information).
2430 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
2432 @subheading @code{objdump} Architecture
2438 command line option: @samp{-m} or @samp{--architecture}
2441 deduced from the input file
2444 @subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
2450 deduced from the input file
2453 @subheading Linker Input Architecture
2459 deduced from the input file
2462 @subheading Linker Output Architecture
2468 script command @code{OUTPUT_ARCH}
2469 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2472 the default architecture from the linker output target
2473 (@pxref{Target Selection})
2476 @node Linker Emulation Selection
2477 @section Linker emulation selection
2479 A linker @dfn{emulation} is a ``personality'' of the linker, which gives
2480 the linker default values for the other aspects of the target system.
2481 In particular, it consists of
2491 several ``hook'' functions that are run at certain stages of the linking
2492 process to do special things that some targets require
2495 The command to list valid linker emulation values is @samp{ld -V}.
2497 Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
2503 command line option: @samp{-m}
2504 (@pxref{Options,,Options,ld.info,Using LD})
2507 environment variable @code{LDEMULATION}
2510 compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2511 which comes from @code{EMUL} in @file{config/@var{target}.mt}
2514 @node Reporting Bugs
2515 @chapter Reporting Bugs
2517 @cindex reporting bugs
2519 Your bug reports play an essential role in making the binary utilities
2522 Reporting a bug may help you by bringing a solution to your problem, or
2523 it may not. But in any case the principal function of a bug report is
2524 to help the entire community by making the next version of the binary
2525 utilities work better. Bug reports are your contribution to their
2528 In order for a bug report to serve its purpose, you must include the
2529 information that enables us to fix the bug.
2532 * Bug Criteria:: Have you found a bug?
2533 * Bug Reporting:: How to report bugs
2537 @section Have you found a bug?
2538 @cindex bug criteria
2540 If you are not sure whether you have found a bug, here are some guidelines:
2543 @cindex fatal signal
2546 If a binary utility gets a fatal signal, for any input whatever, that is
2547 a bug. Reliable utilities never crash.
2549 @cindex error on valid input
2551 If a binary utility produces an error message for valid input, that is a
2555 If you are an experienced user of binary utilities, your suggestions for
2556 improvement are welcome in any case.
2560 @section How to report bugs
2562 @cindex bugs, reporting
2564 A number of companies and individuals offer support for @sc{gnu}
2565 products. If you obtained the binary utilities from a support
2566 organization, we recommend you contact that organization first.
2568 You can find contact information for many support companies and
2569 individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2572 In any event, we also recommend that you send bug reports for the binary
2573 utilities to @samp{bug-gnu-utils@@gnu.org}.
2575 The fundamental principle of reporting bugs usefully is this:
2576 @strong{report all the facts}. If you are not sure whether to state a
2577 fact or leave it out, state it!
2579 Often people omit facts because they think they know what causes the
2580 problem and assume that some details do not matter. Thus, you might
2581 assume that the name of a file you use in an example does not matter.
2582 Well, probably it does not, but one cannot be sure. Perhaps the bug is
2583 a stray memory reference which happens to fetch from the location where
2584 that pathname is stored in memory; perhaps, if the pathname were
2585 different, the contents of that location would fool the utility into
2586 doing the right thing despite the bug. Play it safe and give a
2587 specific, complete example. That is the easiest thing for you to do,
2588 and the most helpful.
2590 Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2591 it is new to us. Therefore, always write your bug reports on the assumption
2592 that the bug has not been reported previously.
2594 Sometimes people give a few sketchy facts and ask, ``Does this ring a
2595 bell?'' Those bug reports are useless, and we urge everyone to
2596 @emph{refuse to respond to them} except to chide the sender to report
2599 To enable us to fix the bug, you should include all these things:
2603 The version of the utility. Each utility announces it if you start it
2604 with the @samp{--version} argument.
2606 Without this, we will not know whether there is any point in looking for
2607 the bug in the current version of the binary utilities.
2610 Any patches you may have applied to the source, including any patches
2611 made to the @code{BFD} library.
2614 The type of machine you are using, and the operating system name and
2618 What compiler (and its version) was used to compile the utilities---e.g.
2622 The command arguments you gave the utility to observe the bug. To
2623 guarantee you will not omit something important, list them all. A copy
2624 of the Makefile (or the output from make) is sufficient.
2626 If we were to try to guess the arguments, we would probably guess wrong
2627 and then we might not encounter the bug.
2630 A complete input file, or set of input files, that will reproduce the
2631 bug. If the utility is reading an object file or files, then it is
2632 generally most helpful to send the actual object files, uuencoded if
2633 necessary to get them through the mail system. Making them available
2634 for anonymous FTP is not as good, but may be the only reasonable choice
2635 for large object files.
2637 If the source files were produced exclusively using @sc{gnu} programs
2638 (e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2639 may be OK to send the source files rather than the object files. In
2640 this case, be sure to say exactly what version of @code{gcc}, or
2641 whatever, was used to produce the object files. Also say how
2642 @code{gcc}, or whatever, was configured.
2645 A description of what behavior you observe that you believe is
2646 incorrect. For example, ``It gets a fatal signal.''
2648 Of course, if the bug is that the utility gets a fatal signal, then we
2649 will certainly notice it. But if the bug is incorrect output, we might
2650 not notice unless it is glaringly wrong. You might as well not give us
2651 a chance to make a mistake.
2653 Even if the problem you experience is a fatal signal, you should still
2654 say so explicitly. Suppose something strange is going on, such as, your
2655 copy of the utility is out of synch, or you have encountered a bug in
2656 the C library on your system. (This has happened!) Your copy might
2657 crash and ours would not. If you told us to expect a crash, then when
2658 ours fails to crash, we would know that the bug was not happening for
2659 us. If you had not told us to expect a crash, then we would not be able
2660 to draw any conclusion from our observations.
2663 If you wish to suggest changes to the source, send us context diffs, as
2664 generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2665 option. Always send diffs from the old file to the new file. If you
2666 even discuss something in the @code{ld} source, refer to it by context,
2669 The line numbers in our development sources will not match those in your
2670 sources. Your line numbers would convey no useful information to us.
2673 Here are some things that are not necessary:
2677 A description of the envelope of the bug.
2679 Often people who encounter a bug spend a lot of time investigating
2680 which changes to the input file will make the bug go away and which
2681 changes will not affect it.
2683 This is often time consuming and not very useful, because the way we
2684 will find the bug is by running a single example under the debugger
2685 with breakpoints, not by pure deduction from a series of examples.
2686 We recommend that you save your time for something else.
2688 Of course, if you can find a simpler example to report @emph{instead}
2689 of the original one, that is a convenience for us. Errors in the
2690 output will be easier to spot, running under the debugger will take
2691 less time, and so on.
2693 However, simplification is not vital; if you do not want to do this,
2694 report the bug anyway and send us the entire test case you used.
2697 A patch for the bug.
2699 A patch for the bug does help us if it is a good one. But do not omit
2700 the necessary information, such as the test case, on the assumption that
2701 a patch is all we need. We might see problems with your patch and decide
2702 to fix the problem another way, or we might not understand it at all.
2704 Sometimes with programs as complicated as the binary utilities it is
2705 very hard to construct an example that will make the program follow a
2706 certain path through the code. If you do not send us the example, we
2707 will not be able to construct one, so we will not be able to verify that
2710 And if we cannot understand what bug you are trying to fix, or why your
2711 patch should be an improvement, we will not install it. A test case will
2712 help us to understand.
2715 A guess about what the bug is or what it depends on.
2717 Such guesses are usually wrong. Even we cannot guess right about such
2718 things without first using the debugger to find the facts.