1 \input texinfo @c -*- Texinfo -*-
2 @setfilename binutils.info
8 * Binutils: (binutils). The GNU binary utilities "ar", "objcopy",
9 "objdump", "nm", "nlmconv", "size", "readelf"
10 "strings", "strip", "ranlib" and "dlltool".
16 Copyright @copyright{} 1991, 92, 93, 94, 95, 96, 97, 98, 1999 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", "readelf" and "ranlib".
44 @c Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 1999 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 Display the contents of ELF format files.
112 List file section sizes and total size
115 List printable strings from files
121 Demangle encoded C++ symbols
124 Convert addresses into file names and line numbers
127 Convert object code into a Netware Loadable Module
130 Manipulate Windows resources
133 Create the files needed to build and use Dynamic Link Libraries
138 * ar:: Create, modify, and extract from archives
139 * nm:: List symbols from object files
140 * objcopy:: Copy and translate object files
141 * objdump:: Display information from object files
142 * ranlib:: Generate index to archive contents
143 * readelf:: Display the contents of ELF format files.
144 * size:: List section sizes and total size
145 * strings:: List printable strings from files
146 * strip:: Discard symbols
147 * c++filt:: Filter to demangle encoded C++ symbols
148 * addr2line:: Convert addresses to file and line
149 * nlmconv:: Converts object code into an NLM
150 * windres:: Manipulate Windows resources
151 * dlltool:: Create files needed to build and use DLLs
152 * Selecting The Target System:: How these utilities determine the target.
153 * Reporting Bugs:: Reporting Bugs
162 @cindex collections of files
164 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
165 ar -M [ <mri-script ]
168 The @sc{gnu} @code{ar} program creates, modifies, and extracts from
169 archives. An @dfn{archive} is a single file holding a collection of
170 other files in a structure that makes it possible to retrieve
171 the original individual files (called @dfn{members} of the archive).
173 The original files' contents, mode (permissions), timestamp, owner, and
174 group are preserved in the archive, and can be restored on
178 @sc{gnu} @code{ar} can maintain archives whose members have names of any
179 length; however, depending on how @code{ar} is configured on your
180 system, a limit on member-name length may be imposed for compatibility
181 with archive formats maintained with other tools. If it exists, the
182 limit is often 15 characters (typical of formats related to a.out) or 16
183 characters (typical of formats related to coff).
186 @code{ar} is considered a binary utility because archives of this sort
187 are most often used as @dfn{libraries} holding commonly needed
191 @code{ar} creates an index to the symbols defined in relocatable
192 object modules in the archive when you specify the modifier @samp{s}.
193 Once created, this index is updated in the archive whenever @code{ar}
194 makes a change to its contents (save for the @samp{q} update operation).
195 An archive with such an index speeds up linking to the library, and
196 allows routines in the library to call each other without regard to
197 their placement in the archive.
199 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
200 table. If an archive lacks the table, another form of @code{ar} called
201 @code{ranlib} can be used to add just the table.
203 @cindex compatibility, @code{ar}
204 @cindex @code{ar} compatibility
205 @sc{gnu} @code{ar} is designed to be compatible with two different
206 facilities. You can control its activity using command-line options,
207 like the different varieties of @code{ar} on Unix systems; or, if you
208 specify the single command-line option @samp{-M}, you can control it
209 with a script supplied via standard input, like the MRI ``librarian''
213 * ar cmdline:: Controlling @code{ar} on the command line
214 * ar scripts:: Controlling @code{ar} with a script
219 @section Controlling @code{ar} on the command line
222 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
225 @cindex Unix compatibility, @code{ar}
226 When you use @code{ar} in the Unix style, @code{ar} insists on at least two
227 arguments to execute: one keyletter specifying the @emph{operation}
228 (optionally accompanied by other keyletters specifying
229 @emph{modifiers}), and the archive name to act on.
231 Most operations can also accept further @var{member} arguments,
232 specifying particular files to operate on.
234 @sc{gnu} @code{ar} allows you to mix the operation code @var{p} and modifier
235 flags @var{mod} in any order, within the first command-line argument.
237 If you wish, you may begin the first command-line argument with a
240 @cindex operations on archive
241 The @var{p} keyletter specifies what operation to execute; it may be
242 any of the following, but you must specify only one of them:
246 @cindex deleting from archive
247 @emph{Delete} modules from the archive. Specify the names of modules to
248 be deleted as @var{member}@dots{}; the archive is untouched if you
249 specify no files to delete.
251 If you specify the @samp{v} modifier, @code{ar} lists each module
255 @cindex moving in archive
256 Use this operation to @emph{move} members in an archive.
258 The ordering of members in an archive can make a difference in how
259 programs are linked using the library, if a symbol is defined in more
262 If no modifiers are used with @code{m}, any members you name in the
263 @var{member} arguments are moved to the @emph{end} of the archive;
264 you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
265 specified place instead.
268 @cindex printing from archive
269 @emph{Print} the specified members of the archive, to the standard
270 output file. If the @samp{v} modifier is specified, show the member
271 name before copying its contents to standard output.
273 If you specify no @var{member} arguments, all the files in the archive are
277 @cindex quick append to archive
278 @emph{Quick append}; Historically, add the files @var{member}@dots{} to the end of
279 @var{archive}, without checking for replacement.
281 The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
282 operation; new members are always placed at the end of the archive.
284 The modifier @samp{v} makes @code{ar} list each file as it is appended.
286 Since the point of this operation is speed, the archive's symbol table
287 index is not updated, even if it already existed; you can use @samp{ar s} or
288 @code{ranlib} explicitly to update the symbol table index.
290 However, too many different systems assume quick append rebuilds the
291 index, so GNU ar implements @code{q} as a synonym for @code{r}.
294 @cindex replacement in archive
295 Insert the files @var{member}@dots{} into @var{archive} (with
296 @emph{replacement}). This operation differs from @samp{q} in that any
297 previously existing members are deleted if their names match those being
300 If one of the files named in @var{member}@dots{} does not exist, @code{ar}
301 displays an error message, and leaves undisturbed any existing members
302 of the archive matching that name.
304 By default, new members are added at the end of the file; but you may
305 use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
306 placement relative to some existing member.
308 The modifier @samp{v} used with this operation elicits a line of
309 output for each file inserted, along with one of the letters @samp{a} or
310 @samp{r} to indicate whether the file was appended (no old member
311 deleted) or replaced.
314 @cindex contents of archive
315 Display a @emph{table} listing the contents of @var{archive}, or those
316 of the files listed in @var{member}@dots{} that are present in the
317 archive. Normally only the member name is shown; if you also want to
318 see the modes (permissions), timestamp, owner, group, and size, you can
319 request that by also specifying the @samp{v} modifier.
321 If you do not specify a @var{member}, all files in the archive
324 @cindex repeated names in archive
325 @cindex name duplication in archive
326 If there is more than one file with the same name (say, @samp{fie}) in
327 an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
328 first instance; to see them all, you must ask for a complete
329 listing---in our example, @samp{ar t b.a}.
330 @c WRS only; per Gumby, this is implementation-dependent, and in a more
331 @c recent case in fact works the other way.
334 @cindex extract from archive
335 @emph{Extract} members (named @var{member}) from the archive. You can
336 use the @samp{v} modifier with this operation, to request that
337 @code{ar} list each name as it extracts it.
339 If you do not specify a @var{member}, all files in the archive
344 A number of modifiers (@var{mod}) may immediately follow the @var{p}
345 keyletter, to specify variations on an operation's behavior:
349 @cindex relative placement in archive
350 Add new files @emph{after} an existing member of the
351 archive. If you use the modifier @samp{a}, the name of an existing archive
352 member must be present as the @var{relpos} argument, before the
353 @var{archive} specification.
356 Add new files @emph{before} an existing member of the
357 archive. If you use the modifier @samp{b}, the name of an existing archive
358 member must be present as the @var{relpos} argument, before the
359 @var{archive} specification. (same as @samp{i}).
362 @cindex creating archives
363 @emph{Create} the archive. The specified @var{archive} is always
364 created if it did not exist, when you request an update. But a warning is
365 issued unless you specify in advance that you expect to create it, by
369 Truncate names in the archive. @sc{gnu} @code{ar} will normally permit file
370 names of any length. This will cause it to create archives which are
371 not compatible with the native @code{ar} program on some systems. If
372 this is a concern, the @samp{f} modifier may be used to truncate file
373 names when putting them in the archive.
376 Insert new files @emph{before} an existing member of the
377 archive. If you use the modifier @samp{i}, the name of an existing archive
378 member must be present as the @var{relpos} argument, before the
379 @var{archive} specification. (same as @samp{b}).
382 This modifier is accepted but not used.
383 @c whaffor ar l modifier??? presumably compat; with
384 @c what???---doc@@cygnus.com, 25jan91
387 @cindex dates in archive
388 Preserve the @emph{original} dates of members when extracting them. If
389 you do not specify this modifier, files extracted from the archive
390 are stamped with the time of extraction.
393 @cindex writing archive index
394 Write an object-file index into the archive, or update an existing one,
395 even if no other change is made to the archive. You may use this modifier
396 flag either with any operation, or alone. Running @samp{ar s} on an
397 archive is equivalent to running @samp{ranlib} on it.
400 @cindex not writing archive index
401 Do not generate an archive symbol table. This can speed up building a
402 large library in several steps. The resulting archive can not be used
403 with the linker. In order to build a symbol table, you must omit the
404 @samp{S} modifier on the last execution of @samp{ar}, or you must run
405 @samp{ranlib} on the archive.
408 @cindex updating an archive
409 Normally, @samp{ar r}@dots{} inserts all files
410 listed into the archive. If you would like to insert @emph{only} those
411 of the files you list that are newer than existing members of the same
412 names, use this modifier. The @samp{u} modifier is allowed only for the
413 operation @samp{r} (replace). In particular, the combination @samp{qu} is
414 not allowed, since checking the timestamps would lose any speed
415 advantage from the operation @samp{q}.
418 This modifier requests the @emph{verbose} version of an operation. Many
419 operations display additional information, such as filenames processed,
420 when the modifier @samp{v} is appended.
423 This modifier shows the version number of @code{ar}.
427 @section Controlling @code{ar} with a script
430 ar -M [ <@var{script} ]
433 @cindex MRI compatibility, @code{ar}
434 @cindex scripts, @code{ar}
435 If you use the single command-line option @samp{-M} with @code{ar}, you
436 can control its operation with a rudimentary command language. This
437 form of @code{ar} operates interactively if standard input is coming
438 directly from a terminal. During interactive use, @code{ar} prompts for
439 input (the prompt is @samp{AR >}), and continues executing even after
440 errors. If you redirect standard input to a script file, no prompts are
441 issued, and @code{ar} abandons execution (with a nonzero exit code)
444 The @code{ar} command language is @emph{not} designed to be equivalent
445 to the command-line options; in fact, it provides somewhat less control
446 over archives. The only purpose of the command language is to ease the
447 transition to @sc{gnu} @code{ar} for developers who already have scripts
448 written for the MRI ``librarian'' program.
450 The syntax for the @code{ar} command language is straightforward:
453 commands are recognized in upper or lower case; for example, @code{LIST}
454 is the same as @code{list}. In the following descriptions, commands are
455 shown in upper case for clarity.
458 a single command may appear on each line; it is the first word on the
462 empty lines are allowed, and have no effect.
465 comments are allowed; text after either of the characters @samp{*}
466 or @samp{;} is ignored.
469 Whenever you use a list of names as part of the argument to an @code{ar}
470 command, you can separate the individual names with either commas or
471 blanks. Commas are shown in the explanations below, for clarity.
474 @samp{+} is used as a line continuation character; if @samp{+} appears
475 at the end of a line, the text on the following line is considered part
476 of the current command.
479 Here are the commands you can use in @code{ar} scripts, or when using
480 @code{ar} interactively. Three of them have special significance:
482 @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
483 a temporary file required for most of the other commands.
485 @code{SAVE} commits the changes so far specified by the script. Prior
486 to @code{SAVE}, commands affect only the temporary copy of the current
490 @item ADDLIB @var{archive}
491 @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
492 Add all the contents of @var{archive} (or, if specified, each named
493 @var{module} from @var{archive}) to the current archive.
495 Requires prior use of @code{OPEN} or @code{CREATE}.
497 @item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
498 @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
499 @c else like "ar q..."
500 Add each named @var{member} as a module in the current archive.
502 Requires prior use of @code{OPEN} or @code{CREATE}.
505 Discard the contents of the current archive, canceling the effect of
506 any operations since the last @code{SAVE}. May be executed (with no
507 effect) even if no current archive is specified.
509 @item CREATE @var{archive}
510 Creates an archive, and makes it the current archive (required for many
511 other commands). The new archive is created with a temporary name; it
512 is not actually saved as @var{archive} until you use @code{SAVE}.
513 You can overwrite existing archives; similarly, the contents of any
514 existing file named @var{archive} will not be destroyed until @code{SAVE}.
516 @item DELETE @var{module}, @var{module}, @dots{} @var{module}
517 Delete each listed @var{module} from the current archive; equivalent to
518 @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
520 Requires prior use of @code{OPEN} or @code{CREATE}.
522 @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
523 @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
524 List each named @var{module} present in @var{archive}. The separate
525 command @code{VERBOSE} specifies the form of the output: when verbose
526 output is off, output is like that of @samp{ar -t @var{archive}
527 @var{module}@dots{}}. When verbose output is on, the listing is like
528 @samp{ar -tv @var{archive} @var{module}@dots{}}.
530 Output normally goes to the standard output stream; however, if you
531 specify @var{outputfile} as a final argument, @code{ar} directs the
535 Exit from @code{ar}, with a @code{0} exit code to indicate successful
536 completion. This command does not save the output file; if you have
537 changed the current archive since the last @code{SAVE} command, those
540 @item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
541 Extract each named @var{module} from the current archive, writing them
542 into the current directory as separate files. Equivalent to @samp{ar -x
543 @var{archive} @var{module}@dots{}}.
545 Requires prior use of @code{OPEN} or @code{CREATE}.
548 @c FIXME Tokens but no commands???
555 Display full contents of the current archive, in ``verbose'' style
556 regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
557 tv @var{archive}}). (This single command is a @sc{gnu} @code{ld}
558 enhancement, rather than present for MRI compatibility.)
560 Requires prior use of @code{OPEN} or @code{CREATE}.
562 @item OPEN @var{archive}
563 Opens an existing archive for use as the current archive (required for
564 many other commands). Any changes as the result of subsequent commands
565 will not actually affect @var{archive} until you next use @code{SAVE}.
567 @item REPLACE @var{module}, @var{module}, @dots{} @var{module}
568 In the current archive, replace each existing @var{module} (named in
569 the @code{REPLACE} arguments) from files in the current working directory.
570 To execute this command without errors, both the file, and the module in
571 the current archive, must exist.
573 Requires prior use of @code{OPEN} or @code{CREATE}.
576 Toggle an internal flag governing the output from @code{DIRECTORY}.
577 When the flag is on, @code{DIRECTORY} output matches output from
578 @samp{ar -tv }@dots{}.
581 Commit your changes to the current archive, and actually save it as a
582 file with the name specified in the last @code{CREATE} or @code{OPEN}
585 Requires prior use of @code{OPEN} or @code{CREATE}.
594 The @sc{gnu} linker @code{ld} is now described in a separate manual.
595 @xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
604 nm [ -a | --debug-syms ] [ -g | --extern-only ]
605 [ -B ] [ -C | --demangle ] [ -D | --dynamic ]
606 [ -s | --print-armap ] [ -A | -o | --print-file-name ]
607 [ -n | -v | --numeric-sort ] [ -p | --no-sort ]
608 [ -r | --reverse-sort ] [ --size-sort ] [ -u | --undefined-only ]
609 [ -t @var{radix} | --radix=@var{radix} ] [ -P | --portability ]
610 [ --target=@var{bfdname} ] [ -f @var{format} | --format=@var{format} ]
611 [ --defined-only ] [-l | --line-numbers ]
612 [ --no-demangle ] [ -V | --version ] [ --help ] [ @var{objfile}@dots{} ]
615 @sc{gnu} @code{nm} lists the symbols from object files @var{objfile}@dots{}.
616 If no object files are listed as arguments, @code{nm} assumes
619 For each symbol, @code{nm} shows:
623 The symbol value, in the radix selected by options (see below), or
624 hexadecimal by default.
627 The symbol type. At least the following types are used; others are, as
628 well, depending on the object file format. If lowercase, the symbol is
629 local; if uppercase, the symbol is global (external).
631 @c Some more detail on exactly what these symbol types are used for
635 The symbol's value is absolute, and will not be changed by further
639 The symbol is in the uninitialized data section (known as BSS).
642 The symbol is common. Common symbols are uninitialized data. When
643 linking, multiple common symbols may appear with the same name. If the
644 symbol is defined anywhere, the common symbols are treated as undefined
645 references. For more details on common symbols, see the discussion of
646 --warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.
649 The symbol is in the initialized data section.
652 The symbol is in an initialized data section for small objects. Some
653 object file formats permit more efficient access to small data objects,
654 such as a global int variable as opposed to a large global array.
657 The symbol is an indirect reference to another symbol. This is a GNU
658 extension to the a.out object file format which is rarely used.
661 The symbol is a debugging symbol.
664 The symbol is in a read only data section.
667 The symbol is in an uninitialized data section for small objects.
670 The symbol is in the text (code) section.
673 The symbol is undefined.
676 The symbol is weak. When a weak defined symbol is linked with a normal
677 defined symbol, the normal defined symbol is used with no error. When a
678 weak undefined symbol is linked and the symbol is not defined, the value
679 of the weak symbol becomes zero with no error.
682 The symbol is a stabs symbol in an a.out object file. In this case, the
683 next values printed are the stabs other field, the stabs desc field, and
684 the stab type. Stabs symbols are used to hold debugging information;
685 for more information, see @ref{Top,Stabs,Stabs Overview,stabs.info, The
686 ``stabs'' debug format}.
689 The symbol type is unknown, or object file format specific.
696 The long and short forms of options, shown here as alternatives, are
702 @itemx --print-file-name
703 @cindex input file name
705 @cindex source file name
706 Precede each symbol by the name of the input file (or archive element)
707 in which it was found, rather than identifying the input file once only,
708 before all of its symbols.
712 @cindex debugging symbols
713 Display all symbols, even debugger-only symbols; normally these are not
717 @cindex @code{nm} format
718 @cindex @code{nm} compatibility
719 The same as @samp{--format=bsd} (for compatibility with the MIPS @code{nm}).
723 @cindex demangling in nm
724 Decode (@dfn{demangle}) low-level symbol names into user-level names.
725 Besides removing any initial underscore prepended by the system, this
726 makes C++ function names readable. @xref{c++filt}, for more information
730 Do not demangle low-level symbol names. This is the default.
734 @cindex dynamic symbols
735 Display the dynamic symbols rather than the normal symbols. This is
736 only meaningful for dynamic objects, such as certain types of shared
739 @item -f @var{format}
740 @itemx --format=@var{format}
741 @cindex @code{nm} format
742 @cindex @code{nm} compatibility
743 Use the output format @var{format}, which can be @code{bsd},
744 @code{sysv}, or @code{posix}. The default is @code{bsd}.
745 Only the first character of @var{format} is significant; it can be
746 either upper or lower case.
750 @cindex external symbols
751 Display only external symbols.
754 @itemx --line-numbers
755 @cindex symbol line numbers
756 For each symbol, use debugging information to try to find a filename and
757 line number. For a defined symbol, look for the line number of the
758 address of the symbol. For an undefined symbol, look for the line
759 number of a relocation entry which refers to the symbol. If line number
760 information can be found, print it after the other symbol information.
764 @itemx --numeric-sort
765 Sort symbols numerically by their addresses, rather than alphabetically
770 @cindex sorting symbols
771 Do not bother to sort the symbols in any order; print them in the order
776 Use the POSIX.2 standard output format instead of the default format.
777 Equivalent to @samp{-f posix}.
781 @cindex symbol index, listing
782 When listing symbols from archive members, include the index: a mapping
783 (stored in the archive by @code{ar} or @code{ranlib}) of which modules
784 contain definitions for which names.
787 @itemx --reverse-sort
788 Reverse the order of the sort (whether numeric or alphabetic); let the
792 Sort symbols by size. The size is computed as the difference between
793 the value of the symbol and the value of the symbol with the next higher
794 value. The size of the symbol is printed, rather than the value.
797 @itemx --radix=@var{radix}
798 Use @var{radix} as the radix for printing the symbol values. It must be
799 @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
801 @item --target=@var{bfdname}
802 @cindex object code format
803 Specify an object code format other than your system's default format.
804 @xref{Target Selection}, for more information.
807 @itemx --undefined-only
808 @cindex external symbols
809 @cindex undefined symbols
810 Display only undefined symbols (those external to each object file).
813 @cindex external symbols
814 @cindex undefined symbols
815 Display only defined symbols for each object file.
819 Show the version number of @code{nm} and exit.
822 Show a summary of the options to @code{nm} and exit.
829 objcopy [ -F @var{bfdname} | --target=@var{bfdname} ]
830 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
831 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
832 [ -S | --strip-all ] [ -g | --strip-debug ]
833 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
834 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
835 [ -L @var{symbolname} | --localize-symbol=@var{symbolname} ]
836 [ -W @var{symbolname} | --weaken-symbol=@var{symbolname} ]
837 [ -x | --discard-all ] [ -X | --discard-locals ]
838 [ -b @var{byte} | --byte=@var{byte} ]
839 [ -i @var{interleave} | --interleave=@var{interleave} ]
840 [ -j @var{sectionname} | --only-section=@var{sectionname} ]
841 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
842 [ -p | --preserve-dates ] [ --debugging ]
843 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
844 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
845 [ --change-addresses=@var{incr} ]
846 [ --change-section-address=@var{section}@{=,+,-@}@var{val} ]
847 [ --change-section-lma=@var{section}@{=,+,-@}@var{val} ]
848 [ --change-section-vma=@var{section}@{=,+,-@}@var{val} ]
849 [ --change-warnings ] [ --no-change-warnings ]
850 [ --set-section-flags=@var{section}=@var{flags} ]
851 [ --add-section=@var{sectionname}=@var{filename} ]
852 [ --change-leading-char ] [ --remove-leading-char ]
854 [ -v | --verbose ] [ -V | --version ] [ --help ]
855 @var{infile} [@var{outfile}]
858 The @sc{gnu} @code{objcopy} utility copies the contents of an object
859 file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
860 read and write the object files. It can write the destination object
861 file in a format different from that of the source object file. The
862 exact behavior of @code{objcopy} is controlled by command-line options.
864 @code{objcopy} creates temporary files to do its translations and
865 deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
866 translation work; it has access to all the formats described in @sc{bfd}
867 and thus is able to recognize most formats without being told
868 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
870 @code{objcopy} can be used to generate S-records by using an output
871 target of @samp{srec} (e.g., use @samp{-O srec}).
873 @code{objcopy} can be used to generate a raw binary file by using an
874 output target of @samp{binary} (e.g., use @samp{-O binary}). When
875 @code{objcopy} generates a raw binary file, it will essentially produce
876 a memory dump of the contents of the input object file. All symbols and
877 relocation information will be discarded. The memory dump will start at
878 the load address of the lowest section copied into the output file.
880 When generating an S-record or a raw binary file, it may be helpful to
881 use @samp{-S} to remove sections containing debugging information. In
882 some cases @samp{-R} will be useful to remove sections which contain
883 information which is not needed by the binary file.
888 The source and output files, respectively.
889 If you do not specify @var{outfile}, @code{objcopy} creates a
890 temporary file and destructively renames the result with
891 the name of @var{infile}.
893 @item -I @var{bfdname}
894 @itemx --input-target=@var{bfdname}
895 Consider the source file's object format to be @var{bfdname}, rather than
896 attempting to deduce it. @xref{Target Selection}, for more information.
898 @item -O @var{bfdname}
899 @itemx --output-target=@var{bfdname}
900 Write the output file using the object format @var{bfdname}.
901 @xref{Target Selection}, for more information.
903 @item -F @var{bfdname}
904 @itemx --target=@var{bfdname}
905 Use @var{bfdname} as the object format for both the input and the output
906 file; i.e., simply transfer data from source to destination with no
907 translation. @xref{Target Selection}, for more information.
909 @item -j @var{sectionname}
910 @itemx --only-section=@var{sectionname}
911 Copy only the named section from the input file to the output file.
912 This option may be given more than once. Note that using this option
913 inappropriately may make the output file unusable.
915 @item -R @var{sectionname}
916 @itemx --remove-section=@var{sectionname}
917 Remove any section named @var{sectionname} from the output file. This
918 option may be given more than once. Note that using this option
919 inappropriately may make the output file unusable.
923 Do not copy relocation and symbol information from the source file.
927 Do not copy debugging symbols from the source file.
929 @item --strip-unneeded
930 Strip all symbols that are not needed for relocation processing.
932 @item -K @var{symbolname}
933 @itemx --keep-symbol=@var{symbolname}
934 Copy only symbol @var{symbolname} from the source file. This option may
935 be given more than once.
937 @item -N @var{symbolname}
938 @itemx --strip-symbol=@var{symbolname}
939 Do not copy symbol @var{symbolname} from the source file. This option
940 may be given more than once.
942 @item -L @var{symbolname}
943 @itemx --localize-symbol=@var{symbolname}
944 Make symbol @var{symbolname} local to the file, so that it is not
945 visible externally. This option may be given more than once.
947 @item -W @var{symbolname}
948 @itemx --weaken-symbol=@var{symbolname}
949 Make symbol @var{symbolname} weak. This option may be given more than once.
953 Do not copy non-global symbols from the source file.
954 @c FIXME any reason to prefer "non-global" to "local" here?
957 @itemx --discard-locals
958 Do not copy compiler-generated local symbols.
959 (These usually start with @samp{L} or @samp{.}.)
962 @itemx --byte=@var{byte}
963 Keep only every @var{byte}th byte of the input file (header data is not
964 affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
965 where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
966 option, or the default of 4. This option is useful for creating files
967 to program @sc{rom}. It is typically used with an @code{srec} output
970 @item -i @var{interleave}
971 @itemx --interleave=@var{interleave}
972 Only copy one out of every @var{interleave} bytes. Select which byte to
973 copy with the @var{-b} or @samp{--byte} option. The default is 4.
974 @code{objcopy} ignores this option if you do not specify either @samp{-b} or
978 @itemx --preserve-dates
979 Set the access and modification dates of the output file to be the same
980 as those of the input file.
983 Convert debugging information, if possible. This is not the default
984 because only certain debugging formats are supported, and the
985 conversion process can be time consuming.
987 @item --gap-fill @var{val}
988 Fill gaps between sections with @var{val}. This operation applies to
989 the @emph{load address} (LMA) of the sections. It is done by increasing
990 the size of the section with the lower address, and filling in the extra
991 space created with @var{val}.
993 @item --pad-to @var{address}
994 Pad the output file up to the load address @var{address}. This is
995 done by increasing the size of the last section. The extra space is
996 filled in with the value specified by @samp{--gap-fill} (default zero).
998 @item --set-start @var{val}
999 Set the address of the new file to @var{val}. Not all object file
1000 formats support setting the start address.
1002 @item --change-start @var{incr}
1003 @itemx --adjust-start @var{incr}
1004 @cindex changing start address
1005 Change the start address by adding @var{incr}. Not all object file
1006 formats support setting the start address.
1008 @item --change-addresses @var{incr}
1009 @itemx --adjust-vma @var{incr}
1010 @cindex changing object addresses
1011 Change the VMA and LMA addresses of all sections, as well as the start
1012 address, by adding @var{incr}. Some object file formats do not permit
1013 section addresses to be changed arbitrarily. Note that this does not
1014 relocate the sections; if the program expects sections to be loaded at a
1015 certain address, and this option is used to change the sections such
1016 that they are loaded at a different address, the program may fail.
1018 @item --change-section-address @var{section}@{=,+,-@}@var{val}
1019 @itemx --adjust-section-vma @var{section}@{=,+,-@}@var{val}
1020 @cindex changing section address
1021 Set or change both the VMA address and the LMA address of the named
1022 @var{section}. If @samp{=} is used, the section address is set to
1023 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1024 section address. See the comments under @samp{--change-addresses},
1025 above. If @var{section} does not exist in the input file, a warning will
1026 be issued, unless @samp{--no-change-warnings} is used.
1028 @item --change-section-lma @var{section}@{=,+,-@}@var{val}
1029 @cindex changing section LMA
1030 Set or change the LMA address of the named @var{section}. The LMA
1031 address is the address where the section will be loaded into memory at
1032 program load time. Normally this is the same as the VMA address, which
1033 is the address of the section at program run time, but on some systems,
1034 especially those where a program is held in ROM, the two can be
1035 different. If @samp{=} is used, the section address is set to
1036 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1037 section address. See the comments under @samp{--change-addresses},
1038 above. If @var{section} does not exist in the input file, a warning
1039 will be issued, unless @samp{--no-change-warnings} is used.
1041 @item --change-section-vma @var{section}@{=,+,-@}@var{val}
1042 @cindex changing section VMA
1043 Set or change the VMA address of the named @var{section}. The VMA
1044 address is the address where the section will be located once the
1045 program has started executing. Normally this is the same as the LMA
1046 address, which is the address where the section will be loaded into
1047 memory, but on some systems, especially those where a program is held in
1048 ROM, the two can be different. If @samp{=} is used, the section address
1049 is set to @var{val}. Otherwise, @var{val} is added to or subtracted
1050 from the section address. See the comments under
1051 @samp{--change-addresses}, above. If @var{section} does not exist in
1052 the input file, a warning will be issued, unless
1053 @samp{--no-change-warnings} is used.
1055 @item --change-warnings
1056 @itemx --adjust-warnings
1057 If @samp{--change-section-address} or @samp{--change-section-lma} or
1058 @samp{--change-section-vma} is used, and the named section does not
1059 exist, issue a warning. This is the default.
1061 @item --no-change-warnings
1062 @itemx --no-adjust-warnings
1063 Do not issue a warning if @samp{--change-section-address} or
1064 @samp{--adjust-section-lma} or @samp{--adjust-section-vma} is used, even
1065 if the named section does not exist.
1067 @item --set-section-flags @var{section}=@var{flags}
1068 Set the flags for the named section. The @var{flags} argument is a
1069 comma separated string of flag names. The recognized names are
1070 @samp{alloc}, @samp{contents}, @samp{load}, @samp{readonly},
1071 @samp{code}, @samp{data}, and @samp{rom}. You can set the
1072 @samp{contents} flag for a section which does not have contents, but it
1073 is not meaningful to clear the @samp{contents} flag of a section which
1074 does have contents--just remove the section instead. Not all flags are
1075 meaningful for all object file formats.
1077 @item --add-section @var{sectionname}=@var{filename}
1078 Add a new section named @var{sectionname} while copying the file. The
1079 contents of the new section are taken from the file @var{filename}. The
1080 size of the section will be the size of the file. This option only
1081 works on file formats which can support sections with arbitrary names.
1083 @item --change-leading-char
1084 Some object file formats use special characters at the start of
1085 symbols. The most common such character is underscore, which compilers
1086 often add before every symbol. This option tells @code{objcopy} to
1087 change the leading character of every symbol when it converts between
1088 object file formats. If the object file formats use the same leading
1089 character, this option has no effect. Otherwise, it will add a
1090 character, or remove a character, or change a character, as
1093 @item --remove-leading-char
1094 If the first character of a global symbol is a special symbol leading
1095 character used by the object file format, remove the character. The
1096 most common symbol leading character is underscore. This option will
1097 remove a leading underscore from all global symbols. This can be useful
1098 if you want to link together objects of different file formats with
1099 different conventions for symbol names. This is different from
1100 @code{--change-leading-char} because it always changes the symbol name
1101 when appropriate, regardless of the object file format of the output
1105 Change all global symbols in the file to be weak. This can be useful
1106 when building an object which will be linked against other objects using
1107 the @code{-R} option to the linker. This option is only effective when
1108 using an object file format which supports weak symbols.
1112 Show the version number of @code{objcopy}.
1116 Verbose output: list all object files modified. In the case of
1117 archives, @samp{objcopy -V} lists all members of the archive.
1120 Show a summary of the options to @code{objcopy}.
1126 @cindex object file information
1130 objdump [ -a | --archive-headers ]
1131 [ -b @var{bfdname} | --target=@var{bfdname} ] [ --debugging ]
1132 [ -C | --demangle ] [ -d | --disassemble ]
1133 [ -D | --disassemble-all ] [ --disassemble-zeroes ]
1134 [ -EB | -EL | --endian=@{big | little @} ]
1135 [ -f | --file-headers ]
1136 [ -h | --section-headers | --headers ] [ -i | --info ]
1137 [ -j @var{section} | --section=@var{section} ]
1138 [ -l | --line-numbers ] [ -S | --source ]
1139 [ -m @var{machine} | --architecture=@var{machine} ]
1140 [ -p | --private-headers ]
1141 [ -r | --reloc ] [ -R | --dynamic-reloc ]
1142 [ -s | --full-contents ] [ --stabs ]
1143 [ -t | --syms ] [ -T | --dynamic-syms ] [ -x | --all-headers ]
1144 [ -w | --wide ] [ --start-address=@var{address} ]
1145 [ --stop-address=@var{address} ]
1146 [ --prefix-addresses] [ --[no-]show-raw-insn ]
1147 [ --adjust-vma=@var{offset} ]
1148 [ --version ] [ --help ]
1149 @var{objfile}@dots{}
1152 @code{objdump} displays information about one or more object files.
1153 The options control what particular information to display. This
1154 information is mostly useful to programmers who are working on the
1155 compilation tools, as opposed to programmers who just want their
1156 program to compile and work.
1158 @var{objfile}@dots{} are the object files to be examined. When you
1159 specify archives, @code{objdump} shows information on each of the member
1162 The long and short forms of options, shown here as alternatives, are
1163 equivalent. At least one option besides @samp{-l} must be given.
1167 @itemx --archive-header
1168 @cindex archive headers
1169 If any of the @var{objfile} files are archives, display the archive
1170 header information (in a format similar to @samp{ls -l}). Besides the
1171 information you could list with @samp{ar tv}, @samp{objdump -a} shows
1172 the object file format of each archive member.
1174 @item --adjust-vma=@var{offset}
1175 @cindex section addresses in objdump
1176 @cindex VMA in objdump
1177 When dumping information, first add @var{offset} to all the section
1178 addresses. This is useful if the section addresses do not correspond to
1179 the symbol table, which can happen when putting sections at particular
1180 addresses when using a format which can not represent section addresses,
1183 @item -b @var{bfdname}
1184 @itemx --target=@var{bfdname}
1185 @cindex object code format
1186 Specify that the object-code format for the object files is
1187 @var{bfdname}. This option may not be necessary; @var{objdump} can
1188 automatically recognize many formats.
1192 objdump -b oasys -m vax -h fu.o
1195 displays summary information from the section headers (@samp{-h}) of
1196 @file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1197 file in the format produced by Oasys compilers. You can list the
1198 formats available with the @samp{-i} option.
1199 @xref{Target Selection}, for more information.
1203 @cindex demangling in objdump
1204 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1205 Besides removing any initial underscore prepended by the system, this
1206 makes C++ function names readable. @xref{c++filt}, for more information
1210 Display debugging information. This attempts to parse debugging
1211 information stored in the file and print it out using a C like syntax.
1212 Only certain types of debugging information have been implemented.
1215 @itemx --disassemble
1216 @cindex disassembling object code
1217 @cindex machine instructions
1218 Display the assembler mnemonics for the machine instructions from
1219 @var{objfile}. This option only disassembles those sections which are
1220 expected to contain instructions.
1223 @itemx --disassemble-all
1224 Like @samp{-d}, but disassemble the contents of all sections, not just
1225 those expected to contain instructions.
1227 @item --prefix-addresses
1228 When disassembling, print the complete address on each line. This is
1229 the older disassembly format.
1231 @item --disassemble-zeroes
1232 Normally the disassembly output will skip blocks of zeroes. This
1233 option directs the disassembler to disassemble those blocks, just like
1238 @itemx --endian=@{big|little@}
1240 @cindex disassembly endianness
1241 Specify the endianness of the object files. This only affects
1242 disassembly. This can be useful when disassembling a file format which
1243 does not describe endianness information, such as S-records.
1246 @itemx --file-header
1247 @cindex object file header
1248 Display summary information from the overall header of
1249 each of the @var{objfile} files.
1252 @itemx --section-header
1254 @cindex section headers
1255 Display summary information from the section headers of the
1258 File segments may be relocated to nonstandard addresses, for example by
1259 using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1260 @code{ld}. However, some object file formats, such as a.out, do not
1261 store the starting address of the file segments. In those situations,
1262 although @code{ld} relocates the sections correctly, using @samp{objdump
1263 -h} to list the file section headers cannot show the correct addresses.
1264 Instead, it shows the usual addresses, which are implicit for the
1268 Print a summary of the options to @code{objdump} and exit.
1272 @cindex architectures available
1273 @cindex object formats available
1274 Display a list showing all architectures and object formats available
1275 for specification with @samp{-b} or @samp{-m}.
1278 @itemx --section=@var{name}
1279 @cindex section information
1280 Display information only for section @var{name}.
1283 @itemx --line-numbers
1284 @cindex source filenames for object files
1285 Label the display (using debugging information) with the filename and
1286 source line numbers corresponding to the object code or relocs shown.
1287 Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1289 @item -m @var{machine}
1290 @itemx --architecture=@var{machine}
1291 @cindex architecture
1292 @cindex disassembly architecture
1293 Specify the architecture to use when disassembling object files. This
1294 can be useful when disassembling object files which do not describe
1295 architecture information, such as S-records. You can list the available
1296 architectures with the @samp{-i} option.
1299 @itemx --private-headers
1300 Print information that is specific to the object file format. The exact
1301 information printed depends upon the object file format. For some
1302 object file formats, no additional information is printed.
1306 @cindex relocation entries, in object file
1307 Print the relocation entries of the file. If used with @samp{-d} or
1308 @samp{-D}, the relocations are printed interspersed with the
1312 @itemx --dynamic-reloc
1313 @cindex dynamic relocation entries, in object file
1314 Print the dynamic relocation entries of the file. This is only
1315 meaningful for dynamic objects, such as certain types of shared
1319 @itemx --full-contents
1320 @cindex sections, full contents
1321 @cindex object file sections
1322 Display the full contents of any sections requested.
1326 @cindex source disassembly
1327 @cindex disassembly, with source
1328 Display source code intermixed with disassembly, if possible. Implies
1331 @item --show-raw-insn
1332 When disassembling instructions, print the instruction in hex as well as
1333 in symbolic form. This is the default except when
1334 @code{--prefix-addresses} is used.
1336 @item --no-show-raw-insn
1337 When disassembling instructions, do not print the instruction bytes.
1338 This is the default when @code{--prefix-addresses} is used.
1343 @cindex debug symbols
1344 @cindex ELF object file format
1345 Display the full contents of any sections requested. Display the
1346 contents of the .stab and .stab.index and .stab.excl sections from an
1347 ELF file. This is only useful on systems (such as Solaris 2.0) in which
1348 @code{.stab} debugging symbol-table entries are carried in an ELF
1349 section. In most other file formats, debugging symbol-table entries are
1350 interleaved with linkage symbols, and are visible in the @samp{--syms}
1351 output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1352 Overview,stabs.info, The ``stabs'' debug format}.
1354 @item --start-address=@var{address}
1355 @cindex start-address
1356 Start displaying data at the specified address. This affects the output
1357 of the @code{-d}, @code{-r} and @code{-s} options.
1359 @item --stop-address=@var{address}
1360 @cindex stop-address
1361 Stop displaying data at the specified address. This affects the output
1362 of the @code{-d}, @code{-r} and @code{-s} options.
1366 @cindex symbol table entries, printing
1367 Print the symbol table entries of the file.
1368 This is similar to the information provided by the @samp{nm} program.
1371 @itemx --dynamic-syms
1372 @cindex dynamic symbol table entries, printing
1373 Print the dynamic symbol table entries of the file. This is only
1374 meaningful for dynamic objects, such as certain types of shared
1375 libraries. This is similar to the information provided by the @samp{nm}
1376 program when given the @samp{-D} (@samp{--dynamic}) option.
1379 Print the version number of @code{objdump} and exit.
1383 @cindex all header information, object file
1384 @cindex header information, all
1385 Display all available header information, including the symbol table and
1386 relocation entries. Using @samp{-x} is equivalent to specifying all of
1387 @samp{-a -f -h -r -t}.
1391 @cindex wide output, printing
1392 Format some lines for output devices that have more than 80 columns.
1399 @cindex archive contents
1400 @cindex symbol index
1403 ranlib [-vV] @var{archive}
1406 @code{ranlib} generates an index to the contents of an archive and
1407 stores it in the archive. The index lists each symbol defined by a
1408 member of an archive that is a relocatable object file.
1410 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1412 An archive with such an index speeds up linking to the library and
1413 allows routines in the library to call each other without regard to
1414 their placement in the archive.
1416 The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1417 @code{ranlib} is completely equivalent to executing @samp{ar -s}.
1423 Show the version number of @code{ranlib}.
1430 @cindex section sizes
1433 size [ -A | -B | --format=@var{compatibility} ]
1434 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1435 [ --target=@var{bfdname} ] [ -V | --version ]
1436 [ @var{objfile}@dots{} ]
1439 The @sc{gnu} @code{size} utility lists the section sizes---and the total
1440 size---for each of the object or archive files @var{objfile} in its
1441 argument list. By default, one line of output is generated for each
1442 object file or each module in an archive.
1444 @var{objfile}@dots{} are the object files to be examined.
1445 If none are specified, the file @code{a.out} will be used.
1447 The command line options have the following meanings:
1452 @itemx --format=@var{compatibility}
1453 @cindex @code{size} display format
1454 Using one of these options, you can choose whether the output from @sc{gnu}
1455 @code{size} resembles output from System V @code{size} (using @samp{-A},
1456 or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1457 @samp{--format=berkeley}). The default is the one-line format similar to
1459 @c Bonus for doc-source readers: you can also say --format=strange (or
1460 @c anything else that starts with 's') for sysv, and --format=boring (or
1461 @c anything else that starts with 'b') for Berkeley.
1463 Here is an example of the Berkeley (default) format of output from
1466 size --format=Berkeley ranlib size
1467 text data bss dec hex filename
1468 294880 81920 11592 388392 5ed28 ranlib
1469 294880 81920 11888 388688 5ee50 size
1473 This is the same data, but displayed closer to System V conventions:
1476 size --format=SysV ranlib size
1494 Show a summary of acceptable arguments and options.
1499 @itemx --radix=@var{number}
1500 @cindex @code{size} number format
1501 @cindex radix for section sizes
1502 Using one of these options, you can control whether the size of each
1503 section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1504 (@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1505 @samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1506 values (8, 10, 16) are supported. The total size is always given in two
1507 radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1508 octal and hexadecimal if you're using @samp{-o}.
1510 @item --target=@var{bfdname}
1511 @cindex object code format
1512 Specify that the object-code format for @var{objfile} is
1513 @var{bfdname}. This option may not be necessary; @code{size} can
1514 automatically recognize many formats.
1515 @xref{Target Selection}, for more information.
1519 Display the version number of @code{size}.
1525 @cindex listings strings
1526 @cindex printing strings
1527 @cindex strings, printing
1530 strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1531 [--all] [--print-file-name] [--bytes=@var{min-len}]
1532 [--radix=@var{radix}] [--target=@var{bfdname}]
1533 [--help] [--version] @var{file}@dots{}
1536 For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1537 character sequences that are at least 4 characters long (or the number
1538 given with the options below) and are followed by an unprintable
1539 character. By default, it only prints the strings from the initialized
1540 and loaded sections of object files; for other types of files, it prints
1541 the strings from the whole file.
1543 @code{strings} is mainly useful for determining the contents of non-text
1550 Do not scan only the initialized and loaded sections of object files;
1551 scan the whole files.
1554 @itemx --print-file-name
1555 Print the name of the file before each string.
1558 Print a summary of the program usage on the standard output and exit.
1560 @item -@var{min-len}
1561 @itemx -n @var{min-len}
1562 @itemx --bytes=@var{min-len}
1563 Print sequences of characters that are at least @var{min-len} characters
1564 long, instead of the default 4.
1567 Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1568 act like @samp{-t d} instead. Since we can not be compatible with both
1569 ways, we simply chose one.
1571 @item -t @var{radix}
1572 @itemx --radix=@var{radix}
1573 Print the offset within the file before each string. The single
1574 character argument specifies the radix of the offset---@samp{o} for
1575 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1577 @item --target=@var{bfdname}
1578 @cindex object code format
1579 Specify an object code format other than your system's default format.
1580 @xref{Target Selection}, for more information.
1584 Print the program version number on the standard output and exit.
1591 @cindex removing symbols
1592 @cindex discarding symbols
1593 @cindex symbols, discarding
1596 strip [ -F @var{bfdname} | --target=@var{bfdname} ]
1597 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1598 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1599 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1600 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1601 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1602 [ -x | --discard-all ] [ -X | --discard-locals ]
1603 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1604 [ -o @var{file} ] [ -p | --preserve-dates ]
1605 [ -v | --verbose ] [ -V | --version ] [ --help ]
1606 @var{objfile}@dots{}
1609 @sc{gnu} @code{strip} discards all symbols from object files
1610 @var{objfile}. The list of object files may include archives.
1611 At least one object file must be given.
1613 @code{strip} modifies the files named in its argument,
1614 rather than writing modified copies under different names.
1617 @item -F @var{bfdname}
1618 @itemx --target=@var{bfdname}
1619 Treat the original @var{objfile} as a file with the object
1620 code format @var{bfdname}, and rewrite it in the same format.
1621 @xref{Target Selection}, for more information.
1624 Show a summary of the options to @code{strip} and exit.
1626 @item -I @var{bfdname}
1627 @itemx --input-target=@var{bfdname}
1628 Treat the original @var{objfile} as a file with the object
1629 code format @var{bfdname}.
1630 @xref{Target Selection}, for more information.
1632 @item -O @var{bfdname}
1633 @itemx --output-target=@var{bfdname}
1634 Replace @var{objfile} with a file in the output format @var{bfdname}.
1635 @xref{Target Selection}, for more information.
1637 @item -R @var{sectionname}
1638 @itemx --remove-section=@var{sectionname}
1639 Remove any section named @var{sectionname} from the output file. This
1640 option may be given more than once. Note that using this option
1641 inappropriately may make the output file unusable.
1649 @itemx --strip-debug
1650 Remove debugging symbols only.
1652 @item --strip-unneeded
1653 Remove all symbols that are not needed for relocation processing.
1655 @item -K @var{symbolname}
1656 @itemx --keep-symbol=@var{symbolname}
1657 Keep only symbol @var{symbolname} from the source file. This option may
1658 be given more than once.
1660 @item -N @var{symbolname}
1661 @itemx --strip-symbol=@var{symbolname}
1662 Remove symbol @var{symbolname} from the source file. This option may be
1663 given more than once, and may be combined with strip options other than
1667 Put the stripped output in @var{file}, rather than replacing the
1668 existing file. When this argument is used, only one @var{objfile}
1669 argument may be specified.
1672 @itemx --preserve-dates
1673 Preserve the access and modification dates of the file.
1676 @itemx --discard-all
1677 Remove non-global symbols.
1680 @itemx --discard-locals
1681 Remove compiler-generated local symbols.
1682 (These usually start with @samp{L} or @samp{.}.)
1686 Show the version number for @code{strip}.
1690 Verbose output: list all object files modified. In the case of
1691 archives, @samp{strip -v} lists all members of the archive.
1698 @cindex demangling C++ symbols
1701 c++filt [ -_ | --strip-underscores ]
1703 [ -n | --no-strip-underscores ]
1704 [ -s @var{format} | --format=@var{format} ]
1705 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1708 The C++ and Java languages provides function overloading, which means
1709 that you can write many functions with the same name (providing each
1710 takes parameters of different types). All C++ and Java function names
1711 are encoded into a low-level assembly label (this process is known as
1712 @dfn{mangling}). The @code{c++filt} program does the inverse mapping: it
1713 decodes (@dfn{demangles}) low-level names into user-level names so that
1714 the linker can keep these overloaded functions from clashing.
1716 Every alphanumeric word (consisting of letters, digits, underscores,
1717 dollars, or periods) seen in the input is a potential label. If the
1718 label decodes into a C++ name, the C++ name replaces the low-level
1721 You can use @code{c++filt} to decipher individual symbols:
1724 c++filt @var{symbol}
1727 If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1728 names from the standard input and writes the demangled names to the
1729 standard output. All results are printed on the standard output.
1733 @itemx --strip-underscores
1734 On some systems, both the C and C++ compilers put an underscore in front
1735 of every name. For example, the C name @code{foo} gets the low-level
1736 name @code{_foo}. This option removes the initial underscore. Whether
1737 @code{c++filt} removes the underscore by default is target dependent.
1741 Prints demangled names using Java syntax. The default is to use C++
1745 @itemx --no-strip-underscores
1746 Do not remove the initial underscore.
1748 @item -s @var{format}
1749 @itemx --format=@var{format}
1750 @sc{gnu} @code{nm} can decode three different methods of mangling, used by
1751 different C++ compilers. The argument to this option selects which
1756 the one used by the @sc{gnu} compiler (the default method)
1758 the one used by the Lucid compiler
1760 the one specified by the C++ Annotated Reference Manual
1762 the one used by the HP compiler
1764 the one used by the EDG compiler
1768 Print a summary of the options to @code{c++filt} and exit.
1771 Print the version number of @code{c++filt} and exit.
1775 @emph{Warning:} @code{c++filt} is a new utility, and the details of its
1776 user interface are subject to change in future releases. In particular,
1777 a command-line option may be required in the the future to decode a name
1778 passed as an argument on the command line; in other words,
1781 c++filt @var{symbol}
1785 may in a future release become
1788 c++filt @var{option} @var{symbol}
1796 @cindex address to file name and line number
1799 addr2line [ -b @var{bfdname} | --target=@var{bfdname} ]
1801 [ -e @var{filename} | --exe=@var{filename} ]
1802 [ -f | --functions ] [ -s | --basename ]
1803 [ -H | --help ] [ -V | --version ]
1807 @code{addr2line} translates program addresses into file names and line
1808 numbers. Given an address and an executable, it uses the debugging
1809 information in the executable to figure out which file name and line
1810 number are associated with a given address.
1812 The executable to use is specified with the @code{-e} option. The
1813 default is @file{a.out}.
1815 @code{addr2line} has two modes of operation.
1817 In the first, hexadecimal addresses are specified on the command line,
1818 and @code{addr2line} displays the file name and line number for each
1821 In the second, @code{addr2line} reads hexadecimal addresses from
1822 standard input, and prints the file name and line number for each
1823 address on standard output. In this mode, @code{addr2line} may be used
1824 in a pipe to convert dynamically chosen addresses.
1826 The format of the output is @samp{FILENAME:LINENO}. The file name and
1827 line number for each address is printed on a separate line. If the
1828 @code{-f} option is used, then each @samp{FILENAME:LINENO} line is
1829 preceded by a @samp{FUNCTIONNAME} line which is the name of the function
1830 containing the address.
1832 If the file name or function name can not be determined,
1833 @code{addr2line} will print two question marks in their place. If the
1834 line number can not be determined, @code{addr2line} will print 0.
1836 The long and short forms of options, shown here as alternatives, are
1840 @item -b @var{bfdname}
1841 @itemx --target=@var{bfdname}
1842 @cindex object code format
1843 Specify that the object-code format for the object files is
1848 @cindex demangling in objdump
1849 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1850 Besides removing any initial underscore prepended by the system, this
1851 makes C++ function names readable. @xref{c++filt}, for more information
1854 @item -e @var{filename}
1855 @itemx --exe=@var{filename}
1856 Specify the name of the executable for which addresses should be
1857 translated. The default file is @file{a.out}.
1861 Display function names as well as file and line number information.
1865 Display only the base of each file name.
1871 @code{nlmconv} converts a relocatable object file into a NetWare
1875 @code{nlmconv} currently works with @samp{i386} object
1876 files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1877 object files in @sc{elf}, or @code{a.out} format@footnote{
1878 @code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1879 format in the Binary File Descriptor library. It has only been tested
1880 with the above formats.}.
1884 @emph{Warning:} @code{nlmconv} is not always built as part of the binary
1885 utilities, since it is only useful for NLM targets.
1889 nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1890 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1891 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1892 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1893 [ -h | --help ] [ -V | --version ]
1894 @var{infile} @var{outfile}
1897 @code{nlmconv} converts the relocatable @samp{i386} object file
1898 @var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1899 reading @var{headerfile} for NLM header information. For instructions
1900 on writing the NLM command file language used in header files, see the
1901 @samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1902 Development and Tools Overview}, which is part of the NLM Software
1903 Developer's Kit (``NLM SDK''), available from Novell, Inc.
1904 @code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1905 @var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1908 @code{nlmconv} can perform a link step. In other words, you can list
1909 more than one object file for input if you list them in the definitions
1910 file (rather than simply specifying one input file on the command line).
1911 In this case, @code{nlmconv} calls the linker for you.
1914 @item -I @var{bfdname}
1915 @itemx --input-target=@var{bfdname}
1916 Object format of the input file. @code{nlmconv} can usually determine
1917 the format of a given file (so no default is necessary).
1918 @xref{Target Selection}, for more information.
1920 @item -O @var{bfdname}
1921 @itemx --output-target=@var{bfdname}
1922 Object format of the output file. @code{nlmconv} infers the output
1923 format based on the input format, e.g. for a @samp{i386} input file the
1924 output format is @samp{nlm32-i386}.
1925 @xref{Target Selection}, for more information.
1927 @item -T @var{headerfile}
1928 @itemx --header-file=@var{headerfile}
1929 Reads @var{headerfile} for NLM header information. For instructions on
1930 writing the NLM command file language used in header files, see@ see the
1931 @samp{linkers} section, of the @cite{NLM Development and Tools
1932 Overview}, which is part of the NLM Software Developer's Kit, available
1937 Displays (on standard error) the linker command line used by @code{nlmconv}.
1939 @item -l @var{linker}
1940 @itemx --linker=@var{linker}
1941 Use @var{linker} for any linking. @var{linker} can be an absolute or a
1946 Prints a usage summary.
1950 Prints the version number for @code{nlmconv}.
1956 @code{windres} may be used to manipulate Windows resources.
1959 @emph{Warning:} @code{windres} is not always built as part of the binary
1960 utilities, since it is only useful for Windows targets.
1964 windres [options] [input-file] [output-file]
1967 @code{windres} reads resources from an input file and copies them into
1968 an output file. Either file may be in one of three formats:
1972 A text format read by the Resource Compiler.
1975 A binary format generated by the Resource Compiler.
1978 A COFF object or executable.
1981 The exact description of these different formats is available in
1982 documentation from Microsoft.
1984 When @code{windres} converts from the @code{rc} format to the @code{res}
1985 format, it is acting like the Windows Resource Compiler. When
1986 @code{windres} converts from the @code{res} format to the @code{coff}
1987 format, it is acting like the Windows @code{CVTRES} program.
1989 When @code{windres} generates an @code{rc} file, the output is similar
1990 but not identical to the format expected for the input. When an input
1991 @code{rc} file refers to an external filename, an output @code{rc} file
1992 will instead include the file contents.
1994 If the input or output format is not specified, @code{windres} will
1995 guess based on the file name, or, for the input file, the file contents.
1996 A file with an extension of @file{.rc} will be treated as an @code{rc}
1997 file, a file with an extension of @file{.res} will be treated as a
1998 @code{res} file, and a file with an extension of @file{.o} or
1999 @file{.exe} will be treated as a @code{coff} file.
2001 If no output file is specified, @code{windres} will print the resources
2002 in @code{rc} format to standard output.
2004 The normal use is for you to write an @code{rc} file, use @code{windres}
2005 to convert it to a COFF object file, and then link the COFF file into
2006 your application. This will make the resources described in the
2007 @code{rc} file available to Windows.
2010 @item -i @var{filename}
2011 @itemx --input @var{filename}
2012 The name of the input file. If this option is not used, then
2013 @code{windres} will use the first non-option argument as the input file
2014 name. If there are no non-option arguments, then @code{windres} will
2015 read from standard input. @code{windres} can not read a COFF file from
2018 @item -o @var{filename}
2019 @itemx --output @var{filename}
2020 The name of the output file. If this option is not used, then
2021 @code{windres} will use the first non-option argument, after any used
2022 for the input file name, as the output file name. If there is no
2023 non-option argument, then @code{windres} will write to standard output.
2024 @code{windres} can not write a COFF file to standard output.
2026 @item -I @var{format}
2027 @itemx --input-format @var{format}
2028 The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
2029 @samp{coff}. If no input format is specified, @code{windres} will
2030 guess, as described above.
2032 @item -O @var{format}
2033 @itemx --output-format @var{format}
2034 The output format to generate. @var{format} may be @samp{res},
2035 @samp{rc}, or @samp{coff}. If no output format is specified,
2036 @code{windres} will guess, as described above.
2038 @item -F @var{target}
2039 @itemx --target @var{target}
2040 Specify the BFD format to use for a COFF file as input or output. This
2041 is a BFD target name; you can use the @code{--help} option to see a list
2042 of supported targets. Normally @code{windres} will use the default
2043 format, which is the first one listed by the @code{--help} option.
2044 @ref{Target Selection}.
2046 @item --preprocessor @var{program}
2047 When @code{windres} reads an @code{rc} file, it runs it through the C
2048 preprocessor first. This option may be used to specify the preprocessor
2049 to use, including any leading arguments. The default preprocessor
2050 argument is @code{gcc -E -xc-header -DRC_INVOKED}.
2052 @item --include-dir @var{directory}
2053 Specify an include directory to use when reading an @code{rc} file.
2054 @code{windres} will pass this to the preprocessor as an @code{-I}
2055 option. @code{windres} will also search this directory when looking for
2056 files named in the @code{rc} file.
2058 @item -D @var{target}
2059 @item --define @var{sym[=val]}
2060 Specify a @code{-D} option to pass to the preprocessor when reading an
2064 Enable verbose mode. This tells you what the preprocessor is if you
2067 @item --language @var{val}
2068 Specify the default language to use when reading an @code{rc} file.
2069 @var{val} should be a hexadecimal language code. The low eight bits are
2070 the language, and the high eight bits are the sublanguage.
2073 Prints a usage summary.
2076 Prints the version number for @code{windres}.
2079 If @code{windres} is compiled with @code{YYDEBUG} defined as @code{1},
2080 this will turn on parser debugging.
2085 @chapter Create files needed to build and use DLLs
2089 @code{dlltool} may be used to create the files needed to build and use
2090 dynamic link libraries (DLLs).
2093 @emph{Warning:} @code{dlltool} is not always built as part of the binary
2094 utilities, since it is only useful for those targets which support DLLs.
2098 dlltool [-d|--input-def @var{def-file-name}]
2099 [-b|--base-file @var{base-file-name}]
2100 [-e|--output-exp @var{exports-file-name}]
2101 [-z|--output-def @var{def-file-name}]
2102 [-l|--output-lib @var{library-file-name}]
2103 [--export-all-symbols] [--no-export-all-symbols]
2104 [--exclude-symbols @var{list}]
2105 [--no-default-excludes]
2106 [-S|--as @var{path-to-assembler}] [-f|--as-flags @var{options}]
2107 [-D|--dllname @var{name}] [-m|--machine @var{machine}]
2108 [-a|--add-indirect] [-U|--add-underscore] [-k|--kill-at]
2109 [-A|--add-stdcall-alias]
2110 [-x|--no-idata4] [-c|--no-idata5] [-i|--interwork]
2111 [-n|--nodelete] [-v|--verbose] [-h|--help] [-V|--version]
2112 [object-file @dots{}]
2115 @code{dlltool} reads its inputs, which can come from the @samp{-d} and
2116 @samp{-b} options as well as object files specified on the command
2117 line. It then processes these inputs and if the @samp{-e} option has
2118 been specified it creates a exports file. If the @samp{-l} option
2119 has been specified it creates a library file and if the @samp{-z} option
2120 has been specified it creates a def file. Any or all of the -e, -l
2121 and -z options can be present in one invocation of dlltool.
2123 When creating a DLL, along with the source for the DLL, it is necessary
2124 to have three other files. @code{dlltool} can help with the creation of
2127 The first file is a @samp{.def} file which specifies which functions are
2128 exported from the DLL, which functions the DLL imports, and so on. This
2129 is a text file and can be created by hand, or @code{dlltool} can be used
2130 to create it using the @samp{-z} option. In this case @code{dlltool}
2131 will scan the object files specified on its command line looking for
2132 those functions which have been specially marked as being exported and
2133 put entries for them in the .def file it creates.
2135 In order to mark a function as being exported from a DLL, it needs to
2136 have an @samp{-export:<name_of_function>} entry in the @samp{.drectve}
2137 section of the object file. This can be done in C by using the
2141 asm (".section .drectve");
2142 asm (".ascii \"-export:my_func\"");
2144 int my_func (void) @{ @dots{} @}
2147 The second file needed for DLL creation is an exports file. This file
2148 is linked with the object files that make up the body of the DLL and it
2149 handles the interface between the DLL and the outside world. This is a
2150 binary file and it can be created by giving the @samp{-e} option to
2151 @code{dlltool} when it is creating or reading in a .def file.
2153 The third file needed for DLL creation is the library file that programs
2154 will link with in order to access the functions in the DLL. This file
2155 can be created by giving the @samp{-l} option to dlltool when it
2156 is creating or reading in a .def file.
2158 @code{dlltool} builds the library file by hand, but it builds the
2159 exports file by creating temporary files containing assembler statements
2160 and then assembling these. The @samp{-S} command line option can be
2161 used to specify the path to the assembler that dlltool will use,
2162 and the @samp{-f} option can be used to pass specific flags to that
2163 assembler. The @samp{-n} can be used to prevent dlltool from deleting
2164 these temporary assembler files when it is done, and if @samp{-n} is
2165 specified twice then this will prevent dlltool from deleting the
2166 temporary object files it used to build the library.
2168 Here is an example of creating a DLL from a source file @samp{dll.c} and
2169 also creating a program (from an object file called @samp{program.o})
2174 dlltool -e exports.o -l dll.lib dll.o
2175 gcc dll.o exports.o -o dll.dll
2176 gcc program.o dll.lib -o program
2179 The command line options have the following meanings:
2183 @item -d @var{filename}
2184 @itemx --input-def @var{filename}
2185 @cindex input .def file
2186 Specifies the name of a .def file to be read in and processed.
2188 @item -b @var{filename}
2189 @itemx --base-file @var{filename}
2191 Specifies the name of a base file to be read in and processed. The
2192 contents of this file will be added to the relocation section in the
2193 exports file generated by dlltool.
2195 @item -e @var{filename}
2196 @itemx --output-exp @var{filename}
2197 Specifies the name of the export file to be created by dlltool.
2199 @item -z @var{filename}
2200 @itemx --output-def @var{filename}
2201 Specifies the name of the .def file to be created by dlltool.
2203 @item -l @var{filename}
2204 @itemx --output-lib @var{filename}
2205 Specifies the name of the library file to be created by dlltool.
2207 @item --export-all-symbols
2208 Treat all global and weak defined symbols found in the input object
2209 files as symbols to be exported. There is a small list of symbols which
2210 are not exported by default; see the @code{--no-default-excludes}
2211 option. You may add to the list of symbols to not export by using the
2212 @code{--exclude-symbols} option.
2214 @item --no-export-all-symbols
2215 Only export symbols explicitly listed in an input .def file or in
2216 @samp{.drectve} sections in the input object files. This is the default
2217 behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
2218 attributes in the source code.
2220 @item --exclude-symbols @var{list}
2221 Do not export the symbols in @var{list}. This is a list of symbol names
2222 separated by comma or colon characters. The symbol names should not
2223 contain a leading underscore. This is only meaningful when
2224 @code{--export-all-symbols} is used.
2226 @item --no-default-excludes
2227 When @code{--export-all-symbols} is used, it will by default avoid
2228 exporting certain special symbols. The current list of symbols to avoid
2229 exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
2230 @samp{impure_ptr}. You may use the @code{--no-default-excludes} option
2231 to go ahead and export these special symbols. This is only meaningful
2232 when @code{--export-all-symbols} is used.
2235 @itemx --as @var{path}
2236 Specifies the path, including the filename, of the assembler to be used
2237 to create the exports file.
2239 @item -f @var{switches}
2240 @itemx --as-flags @var{switches}
2241 Specifies any specific command line switches to be passed to the
2242 assembler when building the exports file. This option will work even if
2243 the @samp{-S} option is not used. This option only takes one argument,
2244 and if it occurs more than once on the command line, then later
2245 occurrences will override earlier occurrences. So if it is necessary to
2246 pass multiple switches to the assembler they should be enclosed in
2250 @itemx --dll-name @var{name}
2251 Specifies the name to be stored in the .def file as the name of the DLL
2252 when the @samp{-e} option is used. If this option is not present, then
2253 the filename given to the @samp{-e} option will be used as the name of
2256 @item -m @var{machine}
2257 @itemx -machine @var{machine}
2258 Specifies the type of machine for which the library file should be
2259 built. @code{dlltool} has a built in default type, depending upon how
2260 it was created, but this option can be used to override that. This is
2261 normally only useful when creating DLLs for an ARM processor, when the
2262 contents of the DLL are actually encode using THUMB instructions.
2265 @itemx --add-indirect
2266 Specifies that when @code{dlltool} is creating the exports file it
2267 should add a section which allows the exported functions to be
2268 referenced without using the import library. Whatever the hell that
2272 @itemx --add-underscore
2273 Specifies that when @code{dlltool} is creating the exports file it
2274 should prepend an underscore to the names of the exported functions.
2278 Specifies that when @code{dlltool} is creating the exports file it
2279 should not append the string @samp{@@ <number>}. These numbers are
2280 called ordinal numbers and they represent another way of accessing the
2281 function in a DLL, other than by name.
2284 @itemx --add-stdcall-alias
2285 Specifies that when @code{dlltool} is creating the exports file it
2286 should add aliases for stdcall symbols without @samp{@@ <number>}
2287 in addition to the symbols with @samp{@@ <number>}.
2291 Specifies that when @code{dlltool} is creating the exports and library
2292 files it should omit the .idata4 section. This is for compatibility
2293 with certain operating systems.
2297 Specifies that when @code{dlltool} is creating the exports and library
2298 files it should omit the .idata5 section. This is for compatibility
2299 with certain operating systems.
2303 Specifies that @code{dlltool} should mark the objects in the library
2304 file and exports file that it produces as supporting interworking
2305 between ARM and THUMB code.
2309 Makes @code{dlltool} preserve the temporary assembler files it used to
2310 create the exports file. If this option is repeated then dlltool will
2311 also preserve the temporary object files it uses to create the library
2316 Make dlltool describe what it is doing.
2320 Displays a list of command line options and then exits.
2324 Displays dlltool's version number and then exits.
2331 @cindex ELF file information
2335 readelf [ -a | --all ]
2336 [ -h | --file-header]
2337 [ -l | --program-headers | --segments]
2338 [ -S | --section-headers | --sections]
2340 [ -s | --syms | --symbols]
2343 [ -V | --version-info]
2344 [ -D | --use-dynamic]
2345 [ -x <number> | --hex-dump=<number>]
2346 [ -w[liapr] | --debug-dump[=info,=line,=abbrev,=pubnames,=ranges]]
2350 @var{elffile}@dots{}
2353 @code{readelf} displays information about one or more ELF format object
2354 files. The options control what particular information to display.
2356 @var{elffile}@dots{} are the object files to be examined. At the
2357 moment, @code{readelf} does not support examining archives, nor does it
2358 support examing 64 bit ELF files.
2360 The long and short forms of options, shown here as alternatives, are
2361 equivalent. At least one option besides @samp{-v} or @samp{-H} must be
2367 Equivalent to specifiying @samp{--file-header},
2368 @samp{--program-headers}, @samp{--sections}, @samp{--symbols},
2369 @samp{--relocs}, @samp{--dynamic} and @samp{--version-info}.
2372 @itemx --file-header
2373 @cindex ELF file header information
2374 Displays the information contained in the ELF header at the start of the
2378 @itemx --program-headers
2380 @cindex ELF program header information
2381 @cindex ELF segment information
2382 Displays the information contained in the file's segment headers, if it
2387 @itemx --section-headers
2388 @cindex ELF section information
2389 Displays the information contained in the file's section headers, if it
2395 @cindex ELF symbol table information
2396 Displays the entries in symbol table section of the file, if it has one.
2400 Display all the headers in the file. Equivalent to @samp{-h -l -S}.
2404 @cindex ELF reloc information
2405 Displays the contents of the file's relocation section, if it ha one.
2409 @cindex ELF dynamic section information
2410 Displays the contents of the file's dynamic section, if it has one.
2413 @itemx --version-info
2414 @cindex ELF version sections informations
2415 Displays the contents of the version sections in the file, it they
2419 @itemx --use-dynamic
2420 When displaying symbols, this option makes @code{readelf} use the
2421 symblol table in the file's dynamic section, rather than the one in the
2425 @itemx --hex-dump=<number>
2426 Displays the contents of the indicated section as a hexadecimal dump.
2429 @itemx --debug-dump[=line,=info,=abbrev,=pubnames,=ranges]
2430 Displays the contents of the debug sections in the file, if any are
2431 present. If one of the optional letters or words follows the switch
2432 then only data found in those specific sections will be dumped.
2435 Display a histogram of bucket list lengths when displaying the contents
2436 of the symbol tables.
2440 Display the version number of readelf.
2444 Display the command line options understood by @code{readelf}.
2449 @node Selecting The Target System
2450 @chapter Selecting the target system
2452 You can specify three aspects of the target system to the @sc{gnu}
2453 binary file utilities, each in several ways:
2463 the linker emulation (which applies to the linker only)
2466 In the following summaries, the lists of ways to specify values are in
2467 order of decreasing precedence. The ways listed first override those
2470 The commands to list valid values only list the values for which the
2471 programs you are running were configured. If they were configured with
2472 @samp{--enable-targets=all}, the commands list most of the available
2473 values, but a few are left out; not all targets can be configured in at
2474 once because some of them can only be configured @dfn{native} (on hosts
2475 with the same type as the target system).
2478 * Target Selection::
2479 * Architecture Selection::
2480 * Linker Emulation Selection::
2483 @node Target Selection
2484 @section Target Selection
2486 A @dfn{target} is an object file format. A given target may be
2487 supported for multiple architectures (@pxref{Architecture Selection}).
2488 A target selection may also have variations for different operating
2489 systems or architectures.
2491 The command to list valid target values is @samp{objdump -i}
2492 (the first column of output contains the relevant information).
2494 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
2495 @samp{a.out-sunos-big}.
2497 You can also specify a target using a configuration triplet. This is
2498 the same sort of name that is passed to configure to specify a target.
2499 When you use a configuration triplet as an argument, it must be fully
2500 canonicalized. You can see the canonical version of a triplet by
2501 running the shell script @file{config.sub} which is included with the
2504 Some sample configuration triplets are: @samp{m68k-hp-bsd},
2505 @samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
2507 @subheading @code{objdump} Target
2513 command line option: @samp{-b} or @samp{--target}
2516 environment variable @code{GNUTARGET}
2519 deduced from the input file
2522 @subheading @code{objcopy} and @code{strip} Input Target
2528 command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
2531 environment variable @code{GNUTARGET}
2534 deduced from the input file
2537 @subheading @code{objcopy} and @code{strip} Output Target
2543 command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
2546 the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
2549 environment variable @code{GNUTARGET}
2552 deduced from the input file
2555 @subheading @code{nm}, @code{size}, and @code{strings} Target
2561 command line option: @samp{--target}
2564 environment variable @code{GNUTARGET}
2567 deduced from the input file
2570 @subheading Linker Input Target
2576 command line option: @samp{-b} or @samp{--format}
2577 (@pxref{Options,,Options,ld.info,Using LD})
2580 script command @code{TARGET}
2581 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2584 environment variable @code{GNUTARGET}
2585 (@pxref{Environment,,Environment,ld.info,Using LD})
2588 the default target of the selected linker emulation
2589 (@pxref{Linker Emulation Selection})
2592 @subheading Linker Output Target
2598 command line option: @samp{-oformat}
2599 (@pxref{Options,,Options,ld.info,Using LD})
2602 script command @code{OUTPUT_FORMAT}
2603 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2606 the linker input target (see ``Linker Input Target'' above)
2609 @node Architecture Selection
2610 @section Architecture selection
2612 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
2613 to run. Its name may contain a colon, separating the name of the
2614 processor family from the name of the particular @sc{cpu}.
2616 The command to list valid architecture values is @samp{objdump -i} (the
2617 second column contains the relevant information).
2619 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
2621 @subheading @code{objdump} Architecture
2627 command line option: @samp{-m} or @samp{--architecture}
2630 deduced from the input file
2633 @subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
2639 deduced from the input file
2642 @subheading Linker Input Architecture
2648 deduced from the input file
2651 @subheading Linker Output Architecture
2657 script command @code{OUTPUT_ARCH}
2658 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2661 the default architecture from the linker output target
2662 (@pxref{Target Selection})
2665 @node Linker Emulation Selection
2666 @section Linker emulation selection
2668 A linker @dfn{emulation} is a ``personality'' of the linker, which gives
2669 the linker default values for the other aspects of the target system.
2670 In particular, it consists of
2680 several ``hook'' functions that are run at certain stages of the linking
2681 process to do special things that some targets require
2684 The command to list valid linker emulation values is @samp{ld -V}.
2686 Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
2692 command line option: @samp{-m}
2693 (@pxref{Options,,Options,ld.info,Using LD})
2696 environment variable @code{LDEMULATION}
2699 compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2700 which comes from @code{EMUL} in @file{config/@var{target}.mt}
2703 @node Reporting Bugs
2704 @chapter Reporting Bugs
2706 @cindex reporting bugs
2708 Your bug reports play an essential role in making the binary utilities
2711 Reporting a bug may help you by bringing a solution to your problem, or
2712 it may not. But in any case the principal function of a bug report is
2713 to help the entire community by making the next version of the binary
2714 utilities work better. Bug reports are your contribution to their
2717 In order for a bug report to serve its purpose, you must include the
2718 information that enables us to fix the bug.
2721 * Bug Criteria:: Have you found a bug?
2722 * Bug Reporting:: How to report bugs
2726 @section Have you found a bug?
2727 @cindex bug criteria
2729 If you are not sure whether you have found a bug, here are some guidelines:
2732 @cindex fatal signal
2735 If a binary utility gets a fatal signal, for any input whatever, that is
2736 a bug. Reliable utilities never crash.
2738 @cindex error on valid input
2740 If a binary utility produces an error message for valid input, that is a
2744 If you are an experienced user of binary utilities, your suggestions for
2745 improvement are welcome in any case.
2749 @section How to report bugs
2751 @cindex bugs, reporting
2753 A number of companies and individuals offer support for @sc{gnu}
2754 products. If you obtained the binary utilities from a support
2755 organization, we recommend you contact that organization first.
2757 You can find contact information for many support companies and
2758 individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2761 In any event, we also recommend that you send bug reports for the binary
2762 utilities to @samp{bug-gnu-utils@@gnu.org}.
2764 The fundamental principle of reporting bugs usefully is this:
2765 @strong{report all the facts}. If you are not sure whether to state a
2766 fact or leave it out, state it!
2768 Often people omit facts because they think they know what causes the
2769 problem and assume that some details do not matter. Thus, you might
2770 assume that the name of a file you use in an example does not matter.
2771 Well, probably it does not, but one cannot be sure. Perhaps the bug is
2772 a stray memory reference which happens to fetch from the location where
2773 that pathname is stored in memory; perhaps, if the pathname were
2774 different, the contents of that location would fool the utility into
2775 doing the right thing despite the bug. Play it safe and give a
2776 specific, complete example. That is the easiest thing for you to do,
2777 and the most helpful.
2779 Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2780 it is new to us. Therefore, always write your bug reports on the assumption
2781 that the bug has not been reported previously.
2783 Sometimes people give a few sketchy facts and ask, ``Does this ring a
2784 bell?'' Those bug reports are useless, and we urge everyone to
2785 @emph{refuse to respond to them} except to chide the sender to report
2788 To enable us to fix the bug, you should include all these things:
2792 The version of the utility. Each utility announces it if you start it
2793 with the @samp{--version} argument.
2795 Without this, we will not know whether there is any point in looking for
2796 the bug in the current version of the binary utilities.
2799 Any patches you may have applied to the source, including any patches
2800 made to the @code{BFD} library.
2803 The type of machine you are using, and the operating system name and
2807 What compiler (and its version) was used to compile the utilities---e.g.
2811 The command arguments you gave the utility to observe the bug. To
2812 guarantee you will not omit something important, list them all. A copy
2813 of the Makefile (or the output from make) is sufficient.
2815 If we were to try to guess the arguments, we would probably guess wrong
2816 and then we might not encounter the bug.
2819 A complete input file, or set of input files, that will reproduce the
2820 bug. If the utility is reading an object file or files, then it is
2821 generally most helpful to send the actual object files, uuencoded if
2822 necessary to get them through the mail system. Making them available
2823 for anonymous FTP is not as good, but may be the only reasonable choice
2824 for large object files.
2826 If the source files were produced exclusively using @sc{gnu} programs
2827 (e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2828 may be OK to send the source files rather than the object files. In
2829 this case, be sure to say exactly what version of @code{gcc}, or
2830 whatever, was used to produce the object files. Also say how
2831 @code{gcc}, or whatever, was configured.
2834 A description of what behavior you observe that you believe is
2835 incorrect. For example, ``It gets a fatal signal.''
2837 Of course, if the bug is that the utility gets a fatal signal, then we
2838 will certainly notice it. But if the bug is incorrect output, we might
2839 not notice unless it is glaringly wrong. You might as well not give us
2840 a chance to make a mistake.
2842 Even if the problem you experience is a fatal signal, you should still
2843 say so explicitly. Suppose something strange is going on, such as, your
2844 copy of the utility is out of synch, or you have encountered a bug in
2845 the C library on your system. (This has happened!) Your copy might
2846 crash and ours would not. If you told us to expect a crash, then when
2847 ours fails to crash, we would know that the bug was not happening for
2848 us. If you had not told us to expect a crash, then we would not be able
2849 to draw any conclusion from our observations.
2852 If you wish to suggest changes to the source, send us context diffs, as
2853 generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2854 option. Always send diffs from the old file to the new file. If you
2855 even discuss something in the @code{ld} source, refer to it by context,
2858 The line numbers in our development sources will not match those in your
2859 sources. Your line numbers would convey no useful information to us.
2862 Here are some things that are not necessary:
2866 A description of the envelope of the bug.
2868 Often people who encounter a bug spend a lot of time investigating
2869 which changes to the input file will make the bug go away and which
2870 changes will not affect it.
2872 This is often time consuming and not very useful, because the way we
2873 will find the bug is by running a single example under the debugger
2874 with breakpoints, not by pure deduction from a series of examples.
2875 We recommend that you save your time for something else.
2877 Of course, if you can find a simpler example to report @emph{instead}
2878 of the original one, that is a convenience for us. Errors in the
2879 output will be easier to spot, running under the debugger will take
2880 less time, and so on.
2882 However, simplification is not vital; if you do not want to do this,
2883 report the bug anyway and send us the entire test case you used.
2886 A patch for the bug.
2888 A patch for the bug does help us if it is a good one. But do not omit
2889 the necessary information, such as the test case, on the assumption that
2890 a patch is all we need. We might see problems with your patch and decide
2891 to fix the problem another way, or we might not understand it at all.
2893 Sometimes with programs as complicated as the binary utilities it is
2894 very hard to construct an example that will make the program follow a
2895 certain path through the code. If you do not send us the example, we
2896 will not be able to construct one, so we will not be able to verify that
2899 And if we cannot understand what bug you are trying to fix, or why your
2900 patch should be an improvement, we will not install it. A test case will
2901 help us to understand.
2904 A guess about what the bug is or what it depends on.
2906 Such guesses are usually wrong. Even we cannot guess right about such
2907 things without first using the debugger to find the facts.