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 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
841 [ -p | --preserve-dates ] [ --debugging ]
842 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
843 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
844 [ --change-addresses=@var{incr} ]
845 [ --change-section-address=@var{section}@{=,+,-@}@var{val} ]
846 [ --change-section-lma=@var{section}@{=,+,-@}@var{val} ]
847 [ --change-section-vma=@var{section}@{=,+,-@}@var{val} ]
848 [ --change-warnings ] [ --no-change-warnings ]
849 [ --set-section-flags=@var{section}=@var{flags} ]
850 [ --add-section=@var{sectionname}=@var{filename} ]
851 [ --change-leading-char ] [ --remove-leading-char ]
853 [ -v | --verbose ] [ -V | --version ] [ --help ]
854 @var{infile} [@var{outfile}]
857 The @sc{gnu} @code{objcopy} utility copies the contents of an object
858 file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
859 read and write the object files. It can write the destination object
860 file in a format different from that of the source object file. The
861 exact behavior of @code{objcopy} is controlled by command-line options.
863 @code{objcopy} creates temporary files to do its translations and
864 deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
865 translation work; it has access to all the formats described in @sc{bfd}
866 and thus is able to recognize most formats without being told
867 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
869 @code{objcopy} can be used to generate S-records by using an output
870 target of @samp{srec} (e.g., use @samp{-O srec}).
872 @code{objcopy} can be used to generate a raw binary file by using an
873 output target of @samp{binary} (e.g., use @samp{-O binary}). When
874 @code{objcopy} generates a raw binary file, it will essentially produce
875 a memory dump of the contents of the input object file. All symbols and
876 relocation information will be discarded. The memory dump will start at
877 the load address of the lowest section copied into the output file.
879 When generating an S-record or a raw binary file, it may be helpful to
880 use @samp{-S} to remove sections containing debugging information. In
881 some cases @samp{-R} will be useful to remove sections which contain
882 information which is not needed by the binary file.
887 The source and output files, respectively.
888 If you do not specify @var{outfile}, @code{objcopy} creates a
889 temporary file and destructively renames the result with
890 the name of @var{infile}.
892 @item -I @var{bfdname}
893 @itemx --input-target=@var{bfdname}
894 Consider the source file's object format to be @var{bfdname}, rather than
895 attempting to deduce it. @xref{Target Selection}, for more information.
897 @item -O @var{bfdname}
898 @itemx --output-target=@var{bfdname}
899 Write the output file using the object format @var{bfdname}.
900 @xref{Target Selection}, for more information.
902 @item -F @var{bfdname}
903 @itemx --target=@var{bfdname}
904 Use @var{bfdname} as the object format for both the input and the output
905 file; i.e., simply transfer data from source to destination with no
906 translation. @xref{Target Selection}, for more information.
908 @item -R @var{sectionname}
909 @itemx --remove-section=@var{sectionname}
910 Remove any section named @var{sectionname} from the output file. This
911 option may be given more than once. Note that using this option
912 inappropriately may make the output file unusable.
916 Do not copy relocation and symbol information from the source file.
920 Do not copy debugging symbols from the source file.
922 @item --strip-unneeded
923 Strip all symbols that are not needed for relocation processing.
925 @item -K @var{symbolname}
926 @itemx --keep-symbol=@var{symbolname}
927 Copy only symbol @var{symbolname} from the source file. This option may
928 be given more than once.
930 @item -N @var{symbolname}
931 @itemx --strip-symbol=@var{symbolname}
932 Do not copy symbol @var{symbolname} from the source file. This option
933 may be given more than once.
935 @item -L @var{symbolname}
936 @itemx --localize-symbol=@var{symbolname}
937 Make symbol @var{symbolname} local to the file, so that it is not
938 visible externally. This option may be given more than once.
940 @item -W @var{symbolname}
941 @itemx --weaken-symbol=@var{symbolname}
942 Make symbol @var{symbolname} weak. This option may be given more than once.
946 Do not copy non-global symbols from the source file.
947 @c FIXME any reason to prefer "non-global" to "local" here?
950 @itemx --discard-locals
951 Do not copy compiler-generated local symbols.
952 (These usually start with @samp{L} or @samp{.}.)
955 @itemx --byte=@var{byte}
956 Keep only every @var{byte}th byte of the input file (header data is not
957 affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
958 where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
959 option, or the default of 4. This option is useful for creating files
960 to program @sc{rom}. It is typically used with an @code{srec} output
963 @item -i @var{interleave}
964 @itemx --interleave=@var{interleave}
965 Only copy one out of every @var{interleave} bytes. Select which byte to
966 copy with the @var{-b} or @samp{--byte} option. The default is 4.
967 @code{objcopy} ignores this option if you do not specify either @samp{-b} or
971 @itemx --preserve-dates
972 Set the access and modification dates of the output file to be the same
973 as those of the input file.
976 Convert debugging information, if possible. This is not the default
977 because only certain debugging formats are supported, and the
978 conversion process can be time consuming.
980 @item --gap-fill @var{val}
981 Fill gaps between sections with @var{val}. This operation applies to
982 the @emph{load address} (LMA) of the sections. It is done by increasing
983 the size of the section with the lower address, and filling in the extra
984 space created with @var{val}.
986 @item --pad-to @var{address}
987 Pad the output file up to the load address @var{address}. This is
988 done by increasing the size of the last section. The extra space is
989 filled in with the value specified by @samp{--gap-fill} (default zero).
991 @item --set-start @var{val}
992 Set the address of the new file to @var{val}. Not all object file
993 formats support setting the start address.
995 @item --change-start @var{incr}
996 @itemx --adjust-start @var{incr}
997 @cindex changing start address
998 Change the start address by adding @var{incr}. Not all object file
999 formats support setting the start address.
1001 @item --change-addresses @var{incr}
1002 @itemx --adjust-vma @var{incr}
1003 @cindex changing object addresses
1004 Change the VMA and LMA addresses of all sections, as well as the start
1005 address, by adding @var{incr}. Some object file formats do not permit
1006 section addresses to be changed arbitrarily. Note that this does not
1007 relocate the sections; if the program expects sections to be loaded at a
1008 certain address, and this option is used to change the sections such
1009 that they are loaded at a different address, the program may fail.
1011 @item --change-section-address @var{section}@{=,+,-@}@var{val}
1012 @itemx --adjust-section-vma @var{section}@{=,+,-@}@var{val}
1013 @cindex changing section address
1014 Set or change both the VMA address and the LMA address of the named
1015 @var{section}. If @samp{=} is used, the section address is set to
1016 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1017 section address. See the comments under @samp{--change-addresses},
1018 above. If @var{section} does not exist in the input file, a warning will
1019 be issued, unless @samp{--no-change-warnings} is used.
1021 @item --change-section-lma @var{section}@{=,+,-@}@var{val}
1022 @cindex changing section LMA
1023 Set or change the LMA address of the named @var{section}. The LMA
1024 address is the address where the section will be loaded into memory at
1025 program load time. Normally this is the same as the VMA address, which
1026 is the address of the section at program run time, but on some systems,
1027 especially those where a program is held in ROM, the two can be
1028 different. If @samp{=} is used, the section address is set to
1029 @var{val}. Otherwise, @var{val} is added to or subtracted from the
1030 section address. See the comments under @samp{--change-addresses},
1031 above. If @var{section} does not exist in the input file, a warning
1032 will be issued, unless @samp{--no-change-warnings} is used.
1034 @item --change-section-vma @var{section}@{=,+,-@}@var{val}
1035 @cindex changing section VMA
1036 Set or change the VMA address of the named @var{section}. The VMA
1037 address is the address where the section will be located once the
1038 program has started executing. Normally this is the same as the LMA
1039 address, which is the address where the section will be loaded into
1040 memory, but on some systems, especially those where a program is held in
1041 ROM, the two can be different. If @samp{=} is used, the section address
1042 is set to @var{val}. Otherwise, @var{val} is added to or subtracted
1043 from the section address. See the comments under
1044 @samp{--change-addresses}, above. If @var{section} does not exist in
1045 the input file, a warning will be issued, unless
1046 @samp{--no-change-warnings} is used.
1048 @item --change-warnings
1049 @itemx --adjust-warnings
1050 If @samp{--change-section-address} or @samp{--change-section-lma} or
1051 @samp{--change-section-vma} is used, and the named section does not
1052 exist, issue a warning. This is the default.
1054 @item --no-change-warnings
1055 @itemx --no-adjust-warnings
1056 Do not issue a warning if @samp{--change-section-address} or
1057 @samp{--adjust-section-lma} or @samp{--adjust-section-vma} is used, even
1058 if the named section does not exist.
1060 @item --set-section-flags @var{section}=@var{flags}
1061 Set the flags for the named section. The @var{flags} argument is a
1062 comma separated string of flag names. The recognized names are
1063 @samp{alloc}, @samp{contents}, @samp{load}, @samp{readonly},
1064 @samp{code}, @samp{data}, and @samp{rom}. You can set the
1065 @samp{contents} flag for a section which does not have contents, but it
1066 is not meaningful to clear the @samp{contents} flag of a section which
1067 does have contents--just remove the section instead. Not all flags are
1068 meaningful for all object file formats.
1070 @item --add-section @var{sectionname}=@var{filename}
1071 Add a new section named @var{sectionname} while copying the file. The
1072 contents of the new section are taken from the file @var{filename}. The
1073 size of the section will be the size of the file. This option only
1074 works on file formats which can support sections with arbitrary names.
1076 @item --change-leading-char
1077 Some object file formats use special characters at the start of
1078 symbols. The most common such character is underscore, which compilers
1079 often add before every symbol. This option tells @code{objcopy} to
1080 change the leading character of every symbol when it converts between
1081 object file formats. If the object file formats use the same leading
1082 character, this option has no effect. Otherwise, it will add a
1083 character, or remove a character, or change a character, as
1086 @item --remove-leading-char
1087 If the first character of a global symbol is a special symbol leading
1088 character used by the object file format, remove the character. The
1089 most common symbol leading character is underscore. This option will
1090 remove a leading underscore from all global symbols. This can be useful
1091 if you want to link together objects of different file formats with
1092 different conventions for symbol names. This is different from
1093 @code{--change-leading-char} because it always changes the symbol name
1094 when appropriate, regardless of the object file format of the output
1098 Change all global symbols in the file to be weak. This can be useful
1099 when building an object which will be linked against other objects using
1100 the @code{-R} option to the linker. This option is only effective when
1101 using an object file format which supports weak symbols.
1105 Show the version number of @code{objcopy}.
1109 Verbose output: list all object files modified. In the case of
1110 archives, @samp{objcopy -V} lists all members of the archive.
1113 Show a summary of the options to @code{objcopy}.
1119 @cindex object file information
1123 objdump [ -a | --archive-headers ]
1124 [ -b @var{bfdname} | --target=@var{bfdname} ] [ --debugging ]
1125 [ -C | --demangle ] [ -d | --disassemble ]
1126 [ -D | --disassemble-all ] [ --disassemble-zeroes ]
1127 [ -EB | -EL | --endian=@{big | little @} ]
1128 [ -f | --file-headers ]
1129 [ -h | --section-headers | --headers ] [ -i | --info ]
1130 [ -j @var{section} | --section=@var{section} ]
1131 [ -l | --line-numbers ] [ -S | --source ]
1132 [ -m @var{machine} | --architecture=@var{machine} ]
1133 [ -p | --private-headers ]
1134 [ -r | --reloc ] [ -R | --dynamic-reloc ]
1135 [ -s | --full-contents ] [ --stabs ]
1136 [ -t | --syms ] [ -T | --dynamic-syms ] [ -x | --all-headers ]
1137 [ -w | --wide ] [ --start-address=@var{address} ]
1138 [ --stop-address=@var{address} ]
1139 [ --prefix-addresses] [ --[no-]show-raw-insn ]
1140 [ --adjust-vma=@var{offset} ]
1141 [ --version ] [ --help ]
1142 @var{objfile}@dots{}
1145 @code{objdump} displays information about one or more object files.
1146 The options control what particular information to display. This
1147 information is mostly useful to programmers who are working on the
1148 compilation tools, as opposed to programmers who just want their
1149 program to compile and work.
1151 @var{objfile}@dots{} are the object files to be examined. When you
1152 specify archives, @code{objdump} shows information on each of the member
1155 The long and short forms of options, shown here as alternatives, are
1156 equivalent. At least one option besides @samp{-l} must be given.
1160 @itemx --archive-header
1161 @cindex archive headers
1162 If any of the @var{objfile} files are archives, display the archive
1163 header information (in a format similar to @samp{ls -l}). Besides the
1164 information you could list with @samp{ar tv}, @samp{objdump -a} shows
1165 the object file format of each archive member.
1167 @item --adjust-vma=@var{offset}
1168 @cindex section addresses in objdump
1169 @cindex VMA in objdump
1170 When dumping information, first add @var{offset} to all the section
1171 addresses. This is useful if the section addresses do not correspond to
1172 the symbol table, which can happen when putting sections at particular
1173 addresses when using a format which can not represent section addresses,
1176 @item -b @var{bfdname}
1177 @itemx --target=@var{bfdname}
1178 @cindex object code format
1179 Specify that the object-code format for the object files is
1180 @var{bfdname}. This option may not be necessary; @var{objdump} can
1181 automatically recognize many formats.
1185 objdump -b oasys -m vax -h fu.o
1188 displays summary information from the section headers (@samp{-h}) of
1189 @file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1190 file in the format produced by Oasys compilers. You can list the
1191 formats available with the @samp{-i} option.
1192 @xref{Target Selection}, for more information.
1196 @cindex demangling in objdump
1197 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1198 Besides removing any initial underscore prepended by the system, this
1199 makes C++ function names readable. @xref{c++filt}, for more information
1203 Display debugging information. This attempts to parse debugging
1204 information stored in the file and print it out using a C like syntax.
1205 Only certain types of debugging information have been implemented.
1208 @itemx --disassemble
1209 @cindex disassembling object code
1210 @cindex machine instructions
1211 Display the assembler mnemonics for the machine instructions from
1212 @var{objfile}. This option only disassembles those sections which are
1213 expected to contain instructions.
1216 @itemx --disassemble-all
1217 Like @samp{-d}, but disassemble the contents of all sections, not just
1218 those expected to contain instructions.
1220 @item --prefix-addresses
1221 When disassembling, print the complete address on each line. This is
1222 the older disassembly format.
1224 @item --disassemble-zeroes
1225 Normally the disassembly output will skip blocks of zeroes. This
1226 option directs the disassembler to disassemble those blocks, just like
1231 @itemx --endian=@{big|little@}
1233 @cindex disassembly endianness
1234 Specify the endianness of the object files. This only affects
1235 disassembly. This can be useful when disassembling a file format which
1236 does not describe endianness information, such as S-records.
1239 @itemx --file-header
1240 @cindex object file header
1241 Display summary information from the overall header of
1242 each of the @var{objfile} files.
1245 @itemx --section-header
1247 @cindex section headers
1248 Display summary information from the section headers of the
1251 File segments may be relocated to nonstandard addresses, for example by
1252 using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1253 @code{ld}. However, some object file formats, such as a.out, do not
1254 store the starting address of the file segments. In those situations,
1255 although @code{ld} relocates the sections correctly, using @samp{objdump
1256 -h} to list the file section headers cannot show the correct addresses.
1257 Instead, it shows the usual addresses, which are implicit for the
1261 Print a summary of the options to @code{objdump} and exit.
1265 @cindex architectures available
1266 @cindex object formats available
1267 Display a list showing all architectures and object formats available
1268 for specification with @samp{-b} or @samp{-m}.
1271 @itemx --section=@var{name}
1272 @cindex section information
1273 Display information only for section @var{name}.
1276 @itemx --line-numbers
1277 @cindex source filenames for object files
1278 Label the display (using debugging information) with the filename and
1279 source line numbers corresponding to the object code or relocs shown.
1280 Only useful with @samp{-d}, @samp{-D}, or @samp{-r}.
1282 @item -m @var{machine}
1283 @itemx --architecture=@var{machine}
1284 @cindex architecture
1285 @cindex disassembly architecture
1286 Specify the architecture to use when disassembling object files. This
1287 can be useful when disassembling object files which do not describe
1288 architecture information, such as S-records. You can list the available
1289 architectures with the @samp{-i} option.
1292 @itemx --private-headers
1293 Print information that is specific to the object file format. The exact
1294 information printed depends upon the object file format. For some
1295 object file formats, no additional information is printed.
1299 @cindex relocation entries, in object file
1300 Print the relocation entries of the file. If used with @samp{-d} or
1301 @samp{-D}, the relocations are printed interspersed with the
1305 @itemx --dynamic-reloc
1306 @cindex dynamic relocation entries, in object file
1307 Print the dynamic relocation entries of the file. This is only
1308 meaningful for dynamic objects, such as certain types of shared
1312 @itemx --full-contents
1313 @cindex sections, full contents
1314 @cindex object file sections
1315 Display the full contents of any sections requested.
1319 @cindex source disassembly
1320 @cindex disassembly, with source
1321 Display source code intermixed with disassembly, if possible. Implies
1324 @item --show-raw-insn
1325 When disassembling instructions, print the instruction in hex as well as
1326 in symbolic form. This is the default except when
1327 @code{--prefix-addresses} is used.
1329 @item --no-show-raw-insn
1330 When disassembling instructions, do not print the instruction bytes.
1331 This is the default when @code{--prefix-addresses} is used.
1336 @cindex debug symbols
1337 @cindex ELF object file format
1338 Display the full contents of any sections requested. Display the
1339 contents of the .stab and .stab.index and .stab.excl sections from an
1340 ELF file. This is only useful on systems (such as Solaris 2.0) in which
1341 @code{.stab} debugging symbol-table entries are carried in an ELF
1342 section. In most other file formats, debugging symbol-table entries are
1343 interleaved with linkage symbols, and are visible in the @samp{--syms}
1344 output. For more information on stabs symbols, see @ref{Top,Stabs,Stabs
1345 Overview,stabs.info, The ``stabs'' debug format}.
1347 @item --start-address=@var{address}
1348 @cindex start-address
1349 Start displaying data at the specified address. This affects the output
1350 of the @code{-d}, @code{-r} and @code{-s} options.
1352 @item --stop-address=@var{address}
1353 @cindex stop-address
1354 Stop displaying data at the specified address. This affects the output
1355 of the @code{-d}, @code{-r} and @code{-s} options.
1359 @cindex symbol table entries, printing
1360 Print the symbol table entries of the file.
1361 This is similar to the information provided by the @samp{nm} program.
1364 @itemx --dynamic-syms
1365 @cindex dynamic symbol table entries, printing
1366 Print the dynamic symbol table entries of the file. This is only
1367 meaningful for dynamic objects, such as certain types of shared
1368 libraries. This is similar to the information provided by the @samp{nm}
1369 program when given the @samp{-D} (@samp{--dynamic}) option.
1372 Print the version number of @code{objdump} and exit.
1376 @cindex all header information, object file
1377 @cindex header information, all
1378 Display all available header information, including the symbol table and
1379 relocation entries. Using @samp{-x} is equivalent to specifying all of
1380 @samp{-a -f -h -r -t}.
1384 @cindex wide output, printing
1385 Format some lines for output devices that have more than 80 columns.
1392 @cindex archive contents
1393 @cindex symbol index
1396 ranlib [-vV] @var{archive}
1399 @code{ranlib} generates an index to the contents of an archive and
1400 stores it in the archive. The index lists each symbol defined by a
1401 member of an archive that is a relocatable object file.
1403 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1405 An archive with such an index speeds up linking to the library and
1406 allows routines in the library to call each other without regard to
1407 their placement in the archive.
1409 The @sc{gnu} @code{ranlib} program is another form of @sc{gnu} @code{ar}; running
1410 @code{ranlib} is completely equivalent to executing @samp{ar -s}.
1416 Show the version number of @code{ranlib}.
1423 @cindex section sizes
1426 size [ -A | -B | --format=@var{compatibility} ]
1427 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1428 [ --target=@var{bfdname} ] [ -V | --version ]
1429 [ @var{objfile}@dots{} ]
1432 The @sc{gnu} @code{size} utility lists the section sizes---and the total
1433 size---for each of the object or archive files @var{objfile} in its
1434 argument list. By default, one line of output is generated for each
1435 object file or each module in an archive.
1437 @var{objfile}@dots{} are the object files to be examined.
1438 If none are specified, the file @code{a.out} will be used.
1440 The command line options have the following meanings:
1445 @itemx --format=@var{compatibility}
1446 @cindex @code{size} display format
1447 Using one of these options, you can choose whether the output from @sc{gnu}
1448 @code{size} resembles output from System V @code{size} (using @samp{-A},
1449 or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1450 @samp{--format=berkeley}). The default is the one-line format similar to
1452 @c Bonus for doc-source readers: you can also say --format=strange (or
1453 @c anything else that starts with 's') for sysv, and --format=boring (or
1454 @c anything else that starts with 'b') for Berkeley.
1456 Here is an example of the Berkeley (default) format of output from
1459 size --format=Berkeley ranlib size
1460 text data bss dec hex filename
1461 294880 81920 11592 388392 5ed28 ranlib
1462 294880 81920 11888 388688 5ee50 size
1466 This is the same data, but displayed closer to System V conventions:
1469 size --format=SysV ranlib size
1487 Show a summary of acceptable arguments and options.
1492 @itemx --radix=@var{number}
1493 @cindex @code{size} number format
1494 @cindex radix for section sizes
1495 Using one of these options, you can control whether the size of each
1496 section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1497 (@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1498 @samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1499 values (8, 10, 16) are supported. The total size is always given in two
1500 radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1501 octal and hexadecimal if you're using @samp{-o}.
1503 @item --target=@var{bfdname}
1504 @cindex object code format
1505 Specify that the object-code format for @var{objfile} is
1506 @var{bfdname}. This option may not be necessary; @code{size} can
1507 automatically recognize many formats.
1508 @xref{Target Selection}, for more information.
1512 Display the version number of @code{size}.
1518 @cindex listings strings
1519 @cindex printing strings
1520 @cindex strings, printing
1523 strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1524 [--all] [--print-file-name] [--bytes=@var{min-len}]
1525 [--radix=@var{radix}] [--target=@var{bfdname}]
1526 [--help] [--version] @var{file}@dots{}
1529 For each @var{file} given, @sc{gnu} @code{strings} prints the printable
1530 character sequences that are at least 4 characters long (or the number
1531 given with the options below) and are followed by an unprintable
1532 character. By default, it only prints the strings from the initialized
1533 and loaded sections of object files; for other types of files, it prints
1534 the strings from the whole file.
1536 @code{strings} is mainly useful for determining the contents of non-text
1543 Do not scan only the initialized and loaded sections of object files;
1544 scan the whole files.
1547 @itemx --print-file-name
1548 Print the name of the file before each string.
1551 Print a summary of the program usage on the standard output and exit.
1553 @item -@var{min-len}
1554 @itemx -n @var{min-len}
1555 @itemx --bytes=@var{min-len}
1556 Print sequences of characters that are at least @var{min-len} characters
1557 long, instead of the default 4.
1560 Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1561 act like @samp{-t d} instead. Since we can not be compatible with both
1562 ways, we simply chose one.
1564 @item -t @var{radix}
1565 @itemx --radix=@var{radix}
1566 Print the offset within the file before each string. The single
1567 character argument specifies the radix of the offset---@samp{o} for
1568 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1570 @item --target=@var{bfdname}
1571 @cindex object code format
1572 Specify an object code format other than your system's default format.
1573 @xref{Target Selection}, for more information.
1577 Print the program version number on the standard output and exit.
1584 @cindex removing symbols
1585 @cindex discarding symbols
1586 @cindex symbols, discarding
1589 strip [ -F @var{bfdname} | --target=@var{bfdname} ]
1590 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1591 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1592 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1593 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1594 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1595 [ -x | --discard-all ] [ -X | --discard-locals ]
1596 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1597 [ -o @var{file} ] [ -p | --preserve-dates ]
1598 [ -v | --verbose ] [ -V | --version ] [ --help ]
1599 @var{objfile}@dots{}
1602 @sc{gnu} @code{strip} discards all symbols from object files
1603 @var{objfile}. The list of object files may include archives.
1604 At least one object file must be given.
1606 @code{strip} modifies the files named in its argument,
1607 rather than writing modified copies under different names.
1610 @item -F @var{bfdname}
1611 @itemx --target=@var{bfdname}
1612 Treat the original @var{objfile} as a file with the object
1613 code format @var{bfdname}, and rewrite it in the same format.
1614 @xref{Target Selection}, for more information.
1617 Show a summary of the options to @code{strip} and exit.
1619 @item -I @var{bfdname}
1620 @itemx --input-target=@var{bfdname}
1621 Treat the original @var{objfile} as a file with the object
1622 code format @var{bfdname}.
1623 @xref{Target Selection}, for more information.
1625 @item -O @var{bfdname}
1626 @itemx --output-target=@var{bfdname}
1627 Replace @var{objfile} with a file in the output format @var{bfdname}.
1628 @xref{Target Selection}, for more information.
1630 @item -R @var{sectionname}
1631 @itemx --remove-section=@var{sectionname}
1632 Remove any section named @var{sectionname} from the output file. This
1633 option may be given more than once. Note that using this option
1634 inappropriately may make the output file unusable.
1642 @itemx --strip-debug
1643 Remove debugging symbols only.
1645 @item --strip-unneeded
1646 Remove all symbols that are not needed for relocation processing.
1648 @item -K @var{symbolname}
1649 @itemx --keep-symbol=@var{symbolname}
1650 Keep only symbol @var{symbolname} from the source file. This option may
1651 be given more than once.
1653 @item -N @var{symbolname}
1654 @itemx --strip-symbol=@var{symbolname}
1655 Remove symbol @var{symbolname} from the source file. This option may be
1656 given more than once, and may be combined with strip options other than
1660 Put the stripped output in @var{file}, rather than replacing the
1661 existing file. When this argument is used, only one @var{objfile}
1662 argument may be specified.
1665 @itemx --preserve-dates
1666 Preserve the access and modification dates of the file.
1669 @itemx --discard-all
1670 Remove non-global symbols.
1673 @itemx --discard-locals
1674 Remove compiler-generated local symbols.
1675 (These usually start with @samp{L} or @samp{.}.)
1679 Show the version number for @code{strip}.
1683 Verbose output: list all object files modified. In the case of
1684 archives, @samp{strip -v} lists all members of the archive.
1691 @cindex demangling C++ symbols
1694 c++filt [ -_ | --strip-underscores ]
1696 [ -n | --no-strip-underscores ]
1697 [ -s @var{format} | --format=@var{format} ]
1698 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1701 The C++ and Java languages provides function overloading, which means
1702 that you can write many functions with the same name (providing each
1703 takes parameters of different types). All C++ and Java function names
1704 are encoded into a low-level assembly label (this process is known as
1705 @dfn{mangling}). The @code{c++filt} program does the inverse mapping: it
1706 decodes (@dfn{demangles}) low-level names into user-level names so that
1707 the linker can keep these overloaded functions from clashing.
1709 Every alphanumeric word (consisting of letters, digits, underscores,
1710 dollars, or periods) seen in the input is a potential label. If the
1711 label decodes into a C++ name, the C++ name replaces the low-level
1714 You can use @code{c++filt} to decipher individual symbols:
1717 c++filt @var{symbol}
1720 If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1721 names from the standard input and writes the demangled names to the
1722 standard output. All results are printed on the standard output.
1726 @itemx --strip-underscores
1727 On some systems, both the C and C++ compilers put an underscore in front
1728 of every name. For example, the C name @code{foo} gets the low-level
1729 name @code{_foo}. This option removes the initial underscore. Whether
1730 @code{c++filt} removes the underscore by default is target dependent.
1734 Prints demangled names using Java syntax. The default is to use C++
1738 @itemx --no-strip-underscores
1739 Do not remove the initial underscore.
1741 @item -s @var{format}
1742 @itemx --format=@var{format}
1743 @sc{gnu} @code{nm} can decode three different methods of mangling, used by
1744 different C++ compilers. The argument to this option selects which
1749 the one used by the @sc{gnu} compiler (the default method)
1751 the one used by the Lucid compiler
1753 the one specified by the C++ Annotated Reference Manual
1755 the one used by the HP compiler
1757 the one used by the EDG compiler
1761 Print a summary of the options to @code{c++filt} and exit.
1764 Print the version number of @code{c++filt} and exit.
1768 @emph{Warning:} @code{c++filt} is a new utility, and the details of its
1769 user interface are subject to change in future releases. In particular,
1770 a command-line option may be required in the the future to decode a name
1771 passed as an argument on the command line; in other words,
1774 c++filt @var{symbol}
1778 may in a future release become
1781 c++filt @var{option} @var{symbol}
1789 @cindex address to file name and line number
1792 addr2line [ -b @var{bfdname} | --target=@var{bfdname} ]
1794 [ -e @var{filename} | --exe=@var{filename} ]
1795 [ -f | --functions ] [ -s | --basename ]
1796 [ -H | --help ] [ -V | --version ]
1800 @code{addr2line} translates program addresses into file names and line
1801 numbers. Given an address and an executable, it uses the debugging
1802 information in the executable to figure out which file name and line
1803 number are associated with a given address.
1805 The executable to use is specified with the @code{-e} option. The
1806 default is @file{a.out}.
1808 @code{addr2line} has two modes of operation.
1810 In the first, hexadecimal addresses are specified on the command line,
1811 and @code{addr2line} displays the file name and line number for each
1814 In the second, @code{addr2line} reads hexadecimal addresses from
1815 standard input, and prints the file name and line number for each
1816 address on standard output. In this mode, @code{addr2line} may be used
1817 in a pipe to convert dynamically chosen addresses.
1819 The format of the output is @samp{FILENAME:LINENO}. The file name and
1820 line number for each address is printed on a separate line. If the
1821 @code{-f} option is used, then each @samp{FILENAME:LINENO} line is
1822 preceded by a @samp{FUNCTIONNAME} line which is the name of the function
1823 containing the address.
1825 If the file name or function name can not be determined,
1826 @code{addr2line} will print two question marks in their place. If the
1827 line number can not be determined, @code{addr2line} will print 0.
1829 The long and short forms of options, shown here as alternatives, are
1833 @item -b @var{bfdname}
1834 @itemx --target=@var{bfdname}
1835 @cindex object code format
1836 Specify that the object-code format for the object files is
1841 @cindex demangling in objdump
1842 Decode (@dfn{demangle}) low-level symbol names into user-level names.
1843 Besides removing any initial underscore prepended by the system, this
1844 makes C++ function names readable. @xref{c++filt}, for more information
1847 @item -e @var{filename}
1848 @itemx --exe=@var{filename}
1849 Specify the name of the executable for which addresses should be
1850 translated. The default file is @file{a.out}.
1854 Display function names as well as file and line number information.
1858 Display only the base of each file name.
1864 @code{nlmconv} converts a relocatable object file into a NetWare
1868 @code{nlmconv} currently works with @samp{i386} object
1869 files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1870 object files in @sc{elf}, or @code{a.out} format@footnote{
1871 @code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1872 format in the Binary File Descriptor library. It has only been tested
1873 with the above formats.}.
1877 @emph{Warning:} @code{nlmconv} is not always built as part of the binary
1878 utilities, since it is only useful for NLM targets.
1882 nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1883 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1884 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1885 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1886 [ -h | --help ] [ -V | --version ]
1887 @var{infile} @var{outfile}
1890 @code{nlmconv} converts the relocatable @samp{i386} object file
1891 @var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1892 reading @var{headerfile} for NLM header information. For instructions
1893 on writing the NLM command file language used in header files, see the
1894 @samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1895 Development and Tools Overview}, which is part of the NLM Software
1896 Developer's Kit (``NLM SDK''), available from Novell, Inc.
1897 @code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1898 @var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1901 @code{nlmconv} can perform a link step. In other words, you can list
1902 more than one object file for input if you list them in the definitions
1903 file (rather than simply specifying one input file on the command line).
1904 In this case, @code{nlmconv} calls the linker for you.
1907 @item -I @var{bfdname}
1908 @itemx --input-target=@var{bfdname}
1909 Object format of the input file. @code{nlmconv} can usually determine
1910 the format of a given file (so no default is necessary).
1911 @xref{Target Selection}, for more information.
1913 @item -O @var{bfdname}
1914 @itemx --output-target=@var{bfdname}
1915 Object format of the output file. @code{nlmconv} infers the output
1916 format based on the input format, e.g. for a @samp{i386} input file the
1917 output format is @samp{nlm32-i386}.
1918 @xref{Target Selection}, for more information.
1920 @item -T @var{headerfile}
1921 @itemx --header-file=@var{headerfile}
1922 Reads @var{headerfile} for NLM header information. For instructions on
1923 writing the NLM command file language used in header files, see@ see the
1924 @samp{linkers} section, of the @cite{NLM Development and Tools
1925 Overview}, which is part of the NLM Software Developer's Kit, available
1930 Displays (on standard error) the linker command line used by @code{nlmconv}.
1932 @item -l @var{linker}
1933 @itemx --linker=@var{linker}
1934 Use @var{linker} for any linking. @var{linker} can be an absolute or a
1939 Prints a usage summary.
1943 Prints the version number for @code{nlmconv}.
1949 @code{windres} may be used to manipulate Windows resources.
1952 @emph{Warning:} @code{windres} is not always built as part of the binary
1953 utilities, since it is only useful for Windows targets.
1957 windres [options] [input-file] [output-file]
1960 @code{windres} reads resources from an input file and copies them into
1961 an output file. Either file may be in one of three formats:
1965 A text format read by the Resource Compiler.
1968 A binary format generated by the Resource Compiler.
1971 A COFF object or executable.
1974 The exact description of these different formats is available in
1975 documentation from Microsoft.
1977 When @code{windres} converts from the @code{rc} format to the @code{res}
1978 format, it is acting like the Windows Resource Compiler. When
1979 @code{windres} converts from the @code{res} format to the @code{coff}
1980 format, it is acting like the Windows @code{CVTRES} program.
1982 When @code{windres} generates an @code{rc} file, the output is similar
1983 but not identical to the format expected for the input. When an input
1984 @code{rc} file refers to an external filename, an output @code{rc} file
1985 will instead include the file contents.
1987 If the input or output format is not specified, @code{windres} will
1988 guess based on the file name, or, for the input file, the file contents.
1989 A file with an extension of @file{.rc} will be treated as an @code{rc}
1990 file, a file with an extension of @file{.res} will be treated as a
1991 @code{res} file, and a file with an extension of @file{.o} or
1992 @file{.exe} will be treated as a @code{coff} file.
1994 If no output file is specified, @code{windres} will print the resources
1995 in @code{rc} format to standard output.
1997 The normal use is for you to write an @code{rc} file, use @code{windres}
1998 to convert it to a COFF object file, and then link the COFF file into
1999 your application. This will make the resources described in the
2000 @code{rc} file available to Windows.
2003 @item -i @var{filename}
2004 @itemx --input @var{filename}
2005 The name of the input file. If this option is not used, then
2006 @code{windres} will use the first non-option argument as the input file
2007 name. If there are no non-option arguments, then @code{windres} will
2008 read from standard input. @code{windres} can not read a COFF file from
2011 @item -o @var{filename}
2012 @itemx --output @var{filename}
2013 The name of the output file. If this option is not used, then
2014 @code{windres} will use the first non-option argument, after any used
2015 for the input file name, as the output file name. If there is no
2016 non-option argument, then @code{windres} will write to standard output.
2017 @code{windres} can not write a COFF file to standard output.
2019 @item -I @var{format}
2020 @itemx --input-format @var{format}
2021 The input format to read. @var{format} may be @samp{res}, @samp{rc}, or
2022 @samp{coff}. If no input format is specified, @code{windres} will
2023 guess, as described above.
2025 @item -O @var{format}
2026 @itemx --output-format @var{format}
2027 The output format to generate. @var{format} may be @samp{res},
2028 @samp{rc}, or @samp{coff}. If no output format is specified,
2029 @code{windres} will guess, as described above.
2031 @item -F @var{target}
2032 @itemx --target @var{target}
2033 Specify the BFD format to use for a COFF file as input or output. This
2034 is a BFD target name; you can use the @code{--help} option to see a list
2035 of supported targets. Normally @code{windres} will use the default
2036 format, which is the first one listed by the @code{--help} option.
2037 @ref{Target Selection}.
2039 @item --preprocessor @var{program}
2040 When @code{windres} reads an @code{rc} file, it runs it through the C
2041 preprocessor first. This option may be used to specify the preprocessor
2042 to use, including any leading arguments. The default preprocessor
2043 argument is @code{gcc -E -xc-header -DRC_INVOKED}.
2045 @item --include-dir @var{directory}
2046 Specify an include directory to use when reading an @code{rc} file.
2047 @code{windres} will pass this to the preprocessor as an @code{-I}
2048 option. @code{windres} will also search this directory when looking for
2049 files named in the @code{rc} file.
2051 @item -D @var{target}
2052 @item --define @var{sym[=val]}
2053 Specify a @code{-D} option to pass to the preprocessor when reading an
2057 Enable verbose mode. This tells you what the preprocessor is if you
2060 @item --language @var{val}
2061 Specify the default language to use when reading an @code{rc} file.
2062 @var{val} should be a hexadecimal language code. The low eight bits are
2063 the language, and the high eight bits are the sublanguage.
2066 Prints a usage summary.
2069 Prints the version number for @code{windres}.
2072 If @code{windres} is compiled with @code{YYDEBUG} defined as @code{1},
2073 this will turn on parser debugging.
2078 @chapter Create files needed to build and use DLLs
2082 @code{dlltool} may be used to create the files needed to build and use
2083 dynamic link libraries (DLLs).
2086 @emph{Warning:} @code{dlltool} is not always built as part of the binary
2087 utilities, since it is only useful for those targets which support DLLs.
2091 dlltool [-d|--input-def @var{def-file-name}]
2092 [-b|--base-file @var{base-file-name}]
2093 [-e|--output-exp @var{exports-file-name}]
2094 [-z|--output-def @var{def-file-name}]
2095 [-l|--output-lib @var{library-file-name}]
2096 [--export-all-symbols] [--no-export-all-symbols]
2097 [--exclude-symbols @var{list}]
2098 [--no-default-excludes]
2099 [-S|--as @var{path-to-assembler}] [-f|--as-flags @var{options}]
2100 [-D|--dllname @var{name}] [-m|--machine @var{machine}]
2101 [-a|--add-indirect] [-U|--add-underscore] [-k|--kill-at]
2102 [-A|--add-stdcall-alias]
2103 [-x|--no-idata4] [-c|--no-idata5] [-i|--interwork]
2104 [-n|--nodelete] [-v|--verbose] [-h|--help] [-V|--version]
2105 [object-file @dots{}]
2108 @code{dlltool} reads its inputs, which can come from the @samp{-d} and
2109 @samp{-b} options as well as object files specified on the command
2110 line. It then processes these inputs and if the @samp{-e} option has
2111 been specified it creates a exports file. If the @samp{-l} option
2112 has been specified it creates a library file and if the @samp{-z} option
2113 has been specified it creates a def file. Any or all of the -e, -l
2114 and -z options can be present in one invocation of dlltool.
2116 When creating a DLL, along with the source for the DLL, it is necessary
2117 to have three other files. @code{dlltool} can help with the creation of
2120 The first file is a @samp{.def} file which specifies which functions are
2121 exported from the DLL, which functions the DLL imports, and so on. This
2122 is a text file and can be created by hand, or @code{dlltool} can be used
2123 to create it using the @samp{-z} option. In this case @code{dlltool}
2124 will scan the object files specified on its command line looking for
2125 those functions which have been specially marked as being exported and
2126 put entries for them in the .def file it creates.
2128 In order to mark a function as being exported from a DLL, it needs to
2129 have an @samp{-export:<name_of_function>} entry in the @samp{.drectve}
2130 section of the object file. This can be done in C by using the
2134 asm (".section .drectve");
2135 asm (".ascii \"-export:my_func\"");
2137 int my_func (void) @{ @dots{} @}
2140 The second file needed for DLL creation is an exports file. This file
2141 is linked with the object files that make up the body of the DLL and it
2142 handles the interface between the DLL and the outside world. This is a
2143 binary file and it can be created by giving the @samp{-e} option to
2144 @code{dlltool} when it is creating or reading in a .def file.
2146 The third file needed for DLL creation is the library file that programs
2147 will link with in order to access the functions in the DLL. This file
2148 can be created by giving the @samp{-l} option to dlltool when it
2149 is creating or reading in a .def file.
2151 @code{dlltool} builds the library file by hand, but it builds the
2152 exports file by creating temporary files containing assembler statements
2153 and then assembling these. The @samp{-S} command line option can be
2154 used to specify the path to the assembler that dlltool will use,
2155 and the @samp{-f} option can be used to pass specific flags to that
2156 assembler. The @samp{-n} can be used to prevent dlltool from deleting
2157 these temporary assembler files when it is done, and if @samp{-n} is
2158 specified twice then this will prevent dlltool from deleting the
2159 temporary object files it used to build the library.
2161 Here is an example of creating a DLL from a source file @samp{dll.c} and
2162 also creating a program (from an object file called @samp{program.o})
2167 dlltool -e exports.o -l dll.lib dll.o
2168 gcc dll.o exports.o -o dll.dll
2169 gcc program.o dll.lib -o program
2172 The command line options have the following meanings:
2176 @item -d @var{filename}
2177 @itemx --input-def @var{filename}
2178 @cindex input .def file
2179 Specifies the name of a .def file to be read in and processed.
2181 @item -b @var{filename}
2182 @itemx --base-file @var{filename}
2184 Specifies the name of a base file to be read in and processed. The
2185 contents of this file will be added to the relocation section in the
2186 exports file generated by dlltool.
2188 @item -e @var{filename}
2189 @itemx --output-exp @var{filename}
2190 Specifies the name of the export file to be created by dlltool.
2192 @item -z @var{filename}
2193 @itemx --output-def @var{filename}
2194 Specifies the name of the .def file to be created by dlltool.
2196 @item -l @var{filename}
2197 @itemx --output-lib @var{filename}
2198 Specifies the name of the library file to be created by dlltool.
2200 @item --export-all-symbols
2201 Treat all global and weak defined symbols found in the input object
2202 files as symbols to be exported. There is a small list of symbols which
2203 are not exported by default; see the @code{--no-default-excludes}
2204 option. You may add to the list of symbols to not export by using the
2205 @code{--exclude-symbols} option.
2207 @item --no-export-all-symbols
2208 Only export symbols explicitly listed in an input .def file or in
2209 @samp{.drectve} sections in the input object files. This is the default
2210 behaviour. The @samp{.drectve} sections are created by @samp{dllexport}
2211 attributes in the source code.
2213 @item --exclude-symbols @var{list}
2214 Do not export the symbols in @var{list}. This is a list of symbol names
2215 separated by comma or colon characters. The symbol names should not
2216 contain a leading underscore. This is only meaningful when
2217 @code{--export-all-symbols} is used.
2219 @item --no-default-excludes
2220 When @code{--export-all-symbols} is used, it will by default avoid
2221 exporting certain special symbols. The current list of symbols to avoid
2222 exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0},
2223 @samp{impure_ptr}. You may use the @code{--no-default-excludes} option
2224 to go ahead and export these special symbols. This is only meaningful
2225 when @code{--export-all-symbols} is used.
2228 @itemx --as @var{path}
2229 Specifies the path, including the filename, of the assembler to be used
2230 to create the exports file.
2232 @item -f @var{switches}
2233 @itemx --as-flags @var{switches}
2234 Specifies any specific command line switches to be passed to the
2235 assembler when building the exports file. This option will work even if
2236 the @samp{-S} option is not used. This option only takes one argument,
2237 and if it occurs more than once on the command line, then later
2238 occurrences will override earlier occurrences. So if it is necessary to
2239 pass multiple switches to the assembler they should be enclosed in
2243 @itemx --dll-name @var{name}
2244 Specifies the name to be stored in the .def file as the name of the DLL
2245 when the @samp{-e} option is used. If this option is not present, then
2246 the filename given to the @samp{-e} option will be used as the name of
2249 @item -m @var{machine}
2250 @itemx -machine @var{machine}
2251 Specifies the type of machine for which the library file should be
2252 built. @code{dlltool} has a built in default type, depending upon how
2253 it was created, but this option can be used to override that. This is
2254 normally only useful when creating DLLs for an ARM processor, when the
2255 contents of the DLL are actually encode using THUMB instructions.
2258 @itemx --add-indirect
2259 Specifies that when @code{dlltool} is creating the exports file it
2260 should add a section which allows the exported functions to be
2261 referenced without using the import library. Whatever the hell that
2265 @itemx --add-underscore
2266 Specifies that when @code{dlltool} is creating the exports file it
2267 should prepend an underscore to the names of the exported functions.
2271 Specifies that when @code{dlltool} is creating the exports file it
2272 should not append the string @samp{@@ <number>}. These numbers are
2273 called ordinal numbers and they represent another way of accessing the
2274 function in a DLL, other than by name.
2277 @itemx --add-stdcall-alias
2278 Specifies that when @code{dlltool} is creating the exports file it
2279 should add aliases for stdcall symbols without @samp{@@ <number>}
2280 in addition to the symbols with @samp{@@ <number>}.
2284 Specifies that when @code{dlltool} is creating the exports and library
2285 files it should omit the .idata4 section. This is for compatibility
2286 with certain operating systems.
2290 Specifies that when @code{dlltool} is creating the exports and library
2291 files it should omit the .idata5 section. This is for compatibility
2292 with certain operating systems.
2296 Specifies that @code{dlltool} should mark the objects in the library
2297 file and exports file that it produces as supporting interworking
2298 between ARM and THUMB code.
2302 Makes @code{dlltool} preserve the temporary assembler files it used to
2303 create the exports file. If this option is repeated then dlltool will
2304 also preserve the temporary object files it uses to create the library
2309 Make dlltool describe what it is doing.
2313 Displays a list of command line options and then exits.
2317 Displays dlltool's version number and then exits.
2324 @cindex ELF file information
2328 readelf [ -a | --all ]
2329 [ -h | --file-header]
2330 [ -l | --program-headers | --segments]
2331 [ -S | --section-headers | --sections]
2333 [ -s | --syms | --symbols]
2336 [ -V | --version-info]
2337 [ -D | --use-dynamic]
2338 [ -x <number> | --hex-dump=<number>]
2339 [ -w[liapr] | --debug-dump[=info,=line,=abbrev,=pubnames,=ranges]]
2343 @var{elffile}@dots{}
2346 @code{readelf} displays information about one or more ELF format object
2347 files. The options control what particular information to display.
2349 @var{elffile}@dots{} are the object files to be examined. At the
2350 moment, @code{readelf} does not support examining archives, nor does it
2351 support examing 64 bit ELF files.
2353 The long and short forms of options, shown here as alternatives, are
2354 equivalent. At least one option besides @samp{-v} or @samp{-H} must be
2360 Equivalent to specifiying @samp{--file-header},
2361 @samp{--program-headers}, @samp{--sections}, @samp{--symbols},
2362 @samp{--relocs}, @samp{--dynamic} and @samp{--version-info}.
2365 @itemx --file-header
2366 @cindex ELF file header information
2367 Displays the information contained in the ELF header at the start of the
2371 @itemx --program-headers
2373 @cindex ELF program header information
2374 @cindex ELF segment information
2375 Displays the information contained in the file's segment headers, if it
2380 @itemx --section-headers
2381 @cindex ELF section information
2382 Displays the information contained in the file's section headers, if it
2388 @cindex ELF symbol table information
2389 Displays the entries in symbol table section of the file, if it has one.
2393 Display all the headers in the file. Equivalent to @samp{-h -l -S}.
2397 @cindex ELF reloc information
2398 Displays the contents of the file's relocation section, if it ha one.
2402 @cindex ELF dynamic section information
2403 Displays the contents of the file's dynamic section, if it has one.
2406 @itemx --version-info
2407 @cindex ELF version sections informations
2408 Displays the contents of the version sections in the file, it they
2412 @itemx --use-dynamic
2413 When displaying symbols, this option makes @code{readelf} use the
2414 symblol table in the file's dynamic section, rather than the one in the
2418 @itemx --hex-dump=<number>
2419 Displays the contents of the indicated section as a hexadecimal dump.
2422 @itemx --debug-dump[=line,=info,=abbrev,=pubnames,=ranges]
2423 Displays the contents of the debug sections in the file, if any are
2424 present. If one of the optional letters or words follows the switch
2425 then only data found in those specific sections will be dumped.
2428 Display a histogram of bucket list lengths when displaying the contents
2429 of the symbol tables.
2433 Display the version number of readelf.
2437 Display the command line options understood by @code{readelf}.
2442 @node Selecting The Target System
2443 @chapter Selecting the target system
2445 You can specify three aspects of the target system to the @sc{gnu}
2446 binary file utilities, each in several ways:
2456 the linker emulation (which applies to the linker only)
2459 In the following summaries, the lists of ways to specify values are in
2460 order of decreasing precedence. The ways listed first override those
2463 The commands to list valid values only list the values for which the
2464 programs you are running were configured. If they were configured with
2465 @samp{--enable-targets=all}, the commands list most of the available
2466 values, but a few are left out; not all targets can be configured in at
2467 once because some of them can only be configured @dfn{native} (on hosts
2468 with the same type as the target system).
2471 * Target Selection::
2472 * Architecture Selection::
2473 * Linker Emulation Selection::
2476 @node Target Selection
2477 @section Target Selection
2479 A @dfn{target} is an object file format. A given target may be
2480 supported for multiple architectures (@pxref{Architecture Selection}).
2481 A target selection may also have variations for different operating
2482 systems or architectures.
2484 The command to list valid target values is @samp{objdump -i}
2485 (the first column of output contains the relevant information).
2487 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
2488 @samp{a.out-sunos-big}.
2490 You can also specify a target using a configuration triplet. This is
2491 the same sort of name that is passed to configure to specify a target.
2492 When you use a configuration triplet as an argument, it must be fully
2493 canonicalized. You can see the canonical version of a triplet by
2494 running the shell script @file{config.sub} which is included with the
2497 Some sample configuration triplets are: @samp{m68k-hp-bsd},
2498 @samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}.
2500 @subheading @code{objdump} Target
2506 command line option: @samp{-b} or @samp{--target}
2509 environment variable @code{GNUTARGET}
2512 deduced from the input file
2515 @subheading @code{objcopy} and @code{strip} Input Target
2521 command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
2524 environment variable @code{GNUTARGET}
2527 deduced from the input file
2530 @subheading @code{objcopy} and @code{strip} Output Target
2536 command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
2539 the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
2542 environment variable @code{GNUTARGET}
2545 deduced from the input file
2548 @subheading @code{nm}, @code{size}, and @code{strings} Target
2554 command line option: @samp{--target}
2557 environment variable @code{GNUTARGET}
2560 deduced from the input file
2563 @subheading Linker Input Target
2569 command line option: @samp{-b} or @samp{--format}
2570 (@pxref{Options,,Options,ld.info,Using LD})
2573 script command @code{TARGET}
2574 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2577 environment variable @code{GNUTARGET}
2578 (@pxref{Environment,,Environment,ld.info,Using LD})
2581 the default target of the selected linker emulation
2582 (@pxref{Linker Emulation Selection})
2585 @subheading Linker Output Target
2591 command line option: @samp{-oformat}
2592 (@pxref{Options,,Options,ld.info,Using LD})
2595 script command @code{OUTPUT_FORMAT}
2596 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2599 the linker input target (see ``Linker Input Target'' above)
2602 @node Architecture Selection
2603 @section Architecture selection
2605 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
2606 to run. Its name may contain a colon, separating the name of the
2607 processor family from the name of the particular @sc{cpu}.
2609 The command to list valid architecture values is @samp{objdump -i} (the
2610 second column contains the relevant information).
2612 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
2614 @subheading @code{objdump} Architecture
2620 command line option: @samp{-m} or @samp{--architecture}
2623 deduced from the input file
2626 @subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
2632 deduced from the input file
2635 @subheading Linker Input Architecture
2641 deduced from the input file
2644 @subheading Linker Output Architecture
2650 script command @code{OUTPUT_ARCH}
2651 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
2654 the default architecture from the linker output target
2655 (@pxref{Target Selection})
2658 @node Linker Emulation Selection
2659 @section Linker emulation selection
2661 A linker @dfn{emulation} is a ``personality'' of the linker, which gives
2662 the linker default values for the other aspects of the target system.
2663 In particular, it consists of
2673 several ``hook'' functions that are run at certain stages of the linking
2674 process to do special things that some targets require
2677 The command to list valid linker emulation values is @samp{ld -V}.
2679 Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
2685 command line option: @samp{-m}
2686 (@pxref{Options,,Options,ld.info,Using LD})
2689 environment variable @code{LDEMULATION}
2692 compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
2693 which comes from @code{EMUL} in @file{config/@var{target}.mt}
2696 @node Reporting Bugs
2697 @chapter Reporting Bugs
2699 @cindex reporting bugs
2701 Your bug reports play an essential role in making the binary utilities
2704 Reporting a bug may help you by bringing a solution to your problem, or
2705 it may not. But in any case the principal function of a bug report is
2706 to help the entire community by making the next version of the binary
2707 utilities work better. Bug reports are your contribution to their
2710 In order for a bug report to serve its purpose, you must include the
2711 information that enables us to fix the bug.
2714 * Bug Criteria:: Have you found a bug?
2715 * Bug Reporting:: How to report bugs
2719 @section Have you found a bug?
2720 @cindex bug criteria
2722 If you are not sure whether you have found a bug, here are some guidelines:
2725 @cindex fatal signal
2728 If a binary utility gets a fatal signal, for any input whatever, that is
2729 a bug. Reliable utilities never crash.
2731 @cindex error on valid input
2733 If a binary utility produces an error message for valid input, that is a
2737 If you are an experienced user of binary utilities, your suggestions for
2738 improvement are welcome in any case.
2742 @section How to report bugs
2744 @cindex bugs, reporting
2746 A number of companies and individuals offer support for @sc{gnu}
2747 products. If you obtained the binary utilities from a support
2748 organization, we recommend you contact that organization first.
2750 You can find contact information for many support companies and
2751 individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs
2754 In any event, we also recommend that you send bug reports for the binary
2755 utilities to @samp{bug-gnu-utils@@gnu.org}.
2757 The fundamental principle of reporting bugs usefully is this:
2758 @strong{report all the facts}. If you are not sure whether to state a
2759 fact or leave it out, state it!
2761 Often people omit facts because they think they know what causes the
2762 problem and assume that some details do not matter. Thus, you might
2763 assume that the name of a file you use in an example does not matter.
2764 Well, probably it does not, but one cannot be sure. Perhaps the bug is
2765 a stray memory reference which happens to fetch from the location where
2766 that pathname is stored in memory; perhaps, if the pathname were
2767 different, the contents of that location would fool the utility into
2768 doing the right thing despite the bug. Play it safe and give a
2769 specific, complete example. That is the easiest thing for you to do,
2770 and the most helpful.
2772 Keep in mind that the purpose of a bug report is to enable us to fix the bug if
2773 it is new to us. Therefore, always write your bug reports on the assumption
2774 that the bug has not been reported previously.
2776 Sometimes people give a few sketchy facts and ask, ``Does this ring a
2777 bell?'' Those bug reports are useless, and we urge everyone to
2778 @emph{refuse to respond to them} except to chide the sender to report
2781 To enable us to fix the bug, you should include all these things:
2785 The version of the utility. Each utility announces it if you start it
2786 with the @samp{--version} argument.
2788 Without this, we will not know whether there is any point in looking for
2789 the bug in the current version of the binary utilities.
2792 Any patches you may have applied to the source, including any patches
2793 made to the @code{BFD} library.
2796 The type of machine you are using, and the operating system name and
2800 What compiler (and its version) was used to compile the utilities---e.g.
2804 The command arguments you gave the utility to observe the bug. To
2805 guarantee you will not omit something important, list them all. A copy
2806 of the Makefile (or the output from make) is sufficient.
2808 If we were to try to guess the arguments, we would probably guess wrong
2809 and then we might not encounter the bug.
2812 A complete input file, or set of input files, that will reproduce the
2813 bug. If the utility is reading an object file or files, then it is
2814 generally most helpful to send the actual object files, uuencoded if
2815 necessary to get them through the mail system. Making them available
2816 for anonymous FTP is not as good, but may be the only reasonable choice
2817 for large object files.
2819 If the source files were produced exclusively using @sc{gnu} programs
2820 (e.g., @code{gcc}, @code{gas}, and/or the @sc{gnu} @code{ld}), then it
2821 may be OK to send the source files rather than the object files. In
2822 this case, be sure to say exactly what version of @code{gcc}, or
2823 whatever, was used to produce the object files. Also say how
2824 @code{gcc}, or whatever, was configured.
2827 A description of what behavior you observe that you believe is
2828 incorrect. For example, ``It gets a fatal signal.''
2830 Of course, if the bug is that the utility gets a fatal signal, then we
2831 will certainly notice it. But if the bug is incorrect output, we might
2832 not notice unless it is glaringly wrong. You might as well not give us
2833 a chance to make a mistake.
2835 Even if the problem you experience is a fatal signal, you should still
2836 say so explicitly. Suppose something strange is going on, such as, your
2837 copy of the utility is out of synch, or you have encountered a bug in
2838 the C library on your system. (This has happened!) Your copy might
2839 crash and ours would not. If you told us to expect a crash, then when
2840 ours fails to crash, we would know that the bug was not happening for
2841 us. If you had not told us to expect a crash, then we would not be able
2842 to draw any conclusion from our observations.
2845 If you wish to suggest changes to the source, send us context diffs, as
2846 generated by @code{diff} with the @samp{-u}, @samp{-c}, or @samp{-p}
2847 option. Always send diffs from the old file to the new file. If you
2848 even discuss something in the @code{ld} source, refer to it by context,
2851 The line numbers in our development sources will not match those in your
2852 sources. Your line numbers would convey no useful information to us.
2855 Here are some things that are not necessary:
2859 A description of the envelope of the bug.
2861 Often people who encounter a bug spend a lot of time investigating
2862 which changes to the input file will make the bug go away and which
2863 changes will not affect it.
2865 This is often time consuming and not very useful, because the way we
2866 will find the bug is by running a single example under the debugger
2867 with breakpoints, not by pure deduction from a series of examples.
2868 We recommend that you save your time for something else.
2870 Of course, if you can find a simpler example to report @emph{instead}
2871 of the original one, that is a convenience for us. Errors in the
2872 output will be easier to spot, running under the debugger will take
2873 less time, and so on.
2875 However, simplification is not vital; if you do not want to do this,
2876 report the bug anyway and send us the entire test case you used.
2879 A patch for the bug.
2881 A patch for the bug does help us if it is a good one. But do not omit
2882 the necessary information, such as the test case, on the assumption that
2883 a patch is all we need. We might see problems with your patch and decide
2884 to fix the problem another way, or we might not understand it at all.
2886 Sometimes with programs as complicated as the binary utilities it is
2887 very hard to construct an example that will make the program follow a
2888 certain path through the code. If you do not send us the example, we
2889 will not be able to construct one, so we will not be able to verify that
2892 And if we cannot understand what bug you are trying to fix, or why your
2893 patch should be an improvement, we will not install it. A test case will
2894 help us to understand.
2897 A guess about what the bug is or what it depends on.
2899 Such guesses are usually wrong. Even we cannot guess right about such
2900 things without first using the debugger to find the facts.