\input texinfo @c -*- Texinfo -*- @setfilename binutils.info @settitle @sc{gnu} Binary Utilities @finalout @synindex ky cp @c man begin INCLUDE @include bfdver.texi @c man end @copying @c man begin COPYRIGHT Copyright @copyright{} 1991-2020 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''. @c man end @end copying @dircategory Software development @direntry * Binutils: (binutils). The GNU binary utilities. @end direntry @dircategory Individual utilities @direntry * addr2line: (binutils)addr2line. Convert addresses to file and line. * ar: (binutils)ar. Create, modify, and extract from archives. * c++filt: (binutils)c++filt. Filter to demangle encoded C++ symbols. * cxxfilt: (binutils)c++filt. MS-DOS name for c++filt. * dlltool: (binutils)dlltool. Create files needed to build and use DLLs. * nm: (binutils)nm. List symbols from object files. * objcopy: (binutils)objcopy. Copy and translate object files. * objdump: (binutils)objdump. Display information from object files. * ranlib: (binutils)ranlib. Generate index to archive contents. * readelf: (binutils)readelf. Display the contents of ELF format files. * size: (binutils)size. List section sizes and total size. * strings: (binutils)strings. List printable strings from files. * strip: (binutils)strip. Discard symbols. * elfedit: (binutils)elfedit. Update ELF header and property of ELF files. * windmc: (binutils)windmc. Generator for Windows message resources. * windres: (binutils)windres. Manipulate Windows resources. @end direntry @titlepage @title The @sc{gnu} Binary Utilities @ifset VERSION_PACKAGE @subtitle @value{VERSION_PACKAGE} @end ifset @subtitle Version @value{VERSION} @sp 1 @subtitle @value{UPDATED} @author Roland H. Pesch @author Jeffrey M. Osier @author Cygnus Support @page @tex {\parskip=0pt \hfill Cygnus Support\par \hfill Texinfo \texinfoversion\par } @end tex @vskip 0pt plus 1filll @insertcopying @end titlepage @contents @node Top @top Introduction @cindex version This brief manual contains documentation for the @sc{gnu} binary utilities @ifset VERSION_PACKAGE @value{VERSION_PACKAGE} @end ifset version @value{VERSION}: @iftex @table @code @item ar Create, modify, and extract from archives @item nm List symbols from object files @item objcopy Copy and translate object files @item objdump Display information from object files @item ranlib Generate index to archive contents @item readelf Display the contents of ELF format files. @item size List file section sizes and total size @item strings List printable strings from files @item strip Discard symbols @item elfedit Update the ELF header and program property of ELF files. @item c++filt Demangle encoded C++ symbols (on MS-DOS, this program is named @code{cxxfilt}) @item addr2line Convert addresses into file names and line numbers @item windres Manipulate Windows resources @item windmc Generator for Windows message resources @item dlltool Create the files needed to build and use Dynamic Link Libraries @end table @end iftex This document is distributed under the terms of the GNU Free Documentation License version 1.3. A copy of the license is included in the section entitled ``GNU Free Documentation License''. @menu * ar:: Create, modify, and extract from archives * nm:: List symbols from object files * objcopy:: Copy and translate object files * objdump:: Display information from object files * ranlib:: Generate index to archive contents * size:: List section sizes and total size * strings:: List printable strings from files * strip:: Discard symbols * c++filt:: Filter to demangle encoded C++ symbols * cxxfilt: c++filt. MS-DOS name for c++filt * addr2line:: Convert addresses to file and line * windmc:: Generator for Windows message resources * windres:: Manipulate Windows resources * dlltool:: Create files needed to build and use DLLs * readelf:: Display the contents of ELF format files * elfedit:: Update ELF header and property of ELF files * Common Options:: Command-line options for all utilities * Selecting the Target System:: How these utilities determine the target * debuginfod:: Using binutils with debuginfod * Reporting Bugs:: Reporting Bugs * GNU Free Documentation License:: GNU Free Documentation License * Binutils Index:: Binutils Index @end menu @node ar @chapter ar @kindex ar @cindex archives @cindex collections of files @c man title ar create, modify, and extract from archives @smallexample ar [-]@var{p}[@var{mod}] [@option{--plugin} @var{name}] [@option{--target} @var{bfdname}] [@option{--output} @var{dirname}] [@var{relpos}] [@var{count}] @var{archive} [@var{member}@dots{}] ar -M [ }), and continues executing even after errors. If you redirect standard input to a script file, no prompts are issued, and @command{ar} abandons execution (with a nonzero exit code) on any error. The @command{ar} command language is @emph{not} designed to be equivalent to the command-line options; in fact, it provides somewhat less control over archives. The only purpose of the command language is to ease the transition to @sc{gnu} @command{ar} for developers who already have scripts written for the MRI ``librarian'' program. The syntax for the @command{ar} command language is straightforward: @itemize @bullet @item commands are recognized in upper or lower case; for example, @code{LIST} is the same as @code{list}. In the following descriptions, commands are shown in upper case for clarity. @item a single command may appear on each line; it is the first word on the line. @item empty lines are allowed, and have no effect. @item comments are allowed; text after either of the characters @samp{*} or @samp{;} is ignored. @item Whenever you use a list of names as part of the argument to an @command{ar} command, you can separate the individual names with either commas or blanks. Commas are shown in the explanations below, for clarity. @item @samp{+} is used as a line continuation character; if @samp{+} appears at the end of a line, the text on the following line is considered part of the current command. @end itemize Here are the commands you can use in @command{ar} scripts, or when using @command{ar} interactively. Three of them have special significance: @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is a temporary file required for most of the other commands. @code{SAVE} commits the changes so far specified by the script. Prior to @code{SAVE}, commands affect only the temporary copy of the current archive. @table @code @item ADDLIB @var{archive} @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module}) Add all the contents of @var{archive} (or, if specified, each named @var{module} from @var{archive}) to the current archive. Requires prior use of @code{OPEN} or @code{CREATE}. @item ADDMOD @var{member}, @var{member}, @dots{} @var{member} @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}" @c else like "ar q..." Add each named @var{member} as a module in the current archive. Requires prior use of @code{OPEN} or @code{CREATE}. @item CLEAR Discard the contents of the current archive, canceling the effect of any operations since the last @code{SAVE}. May be executed (with no effect) even if no current archive is specified. @item CREATE @var{archive} Creates an archive, and makes it the current archive (required for many other commands). The new archive is created with a temporary name; it is not actually saved as @var{archive} until you use @code{SAVE}. You can overwrite existing archives; similarly, the contents of any existing file named @var{archive} will not be destroyed until @code{SAVE}. @item DELETE @var{module}, @var{module}, @dots{} @var{module} Delete each listed @var{module} from the current archive; equivalent to @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}. Requires prior use of @code{OPEN} or @code{CREATE}. @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile} List each named @var{module} present in @var{archive}. The separate command @code{VERBOSE} specifies the form of the output: when verbose output is off, output is like that of @samp{ar -t @var{archive} @var{module}@dots{}}. When verbose output is on, the listing is like @samp{ar -tv @var{archive} @var{module}@dots{}}. Output normally goes to the standard output stream; however, if you specify @var{outputfile} as a final argument, @command{ar} directs the output to that file. @item END Exit from @command{ar}, with a @code{0} exit code to indicate successful completion. This command does not save the output file; if you have changed the current archive since the last @code{SAVE} command, those changes are lost. @item EXTRACT @var{module}, @var{module}, @dots{} @var{module} Extract each named @var{module} from the current archive, writing them into the current directory as separate files. Equivalent to @samp{ar -x @var{archive} @var{module}@dots{}}. Requires prior use of @code{OPEN} or @code{CREATE}. @ignore @c FIXME Tokens but no commands??? @item FULLDIR @item HELP @end ignore @item LIST Display full contents of the current archive, in ``verbose'' style regardless of the state of @code{VERBOSE}. The effect is like @samp{ar tv @var{archive}}. (This single command is a @sc{gnu} @command{ar} enhancement, rather than present for MRI compatibility.) Requires prior use of @code{OPEN} or @code{CREATE}. @item OPEN @var{archive} Opens an existing archive for use as the current archive (required for many other commands). Any changes as the result of subsequent commands will not actually affect @var{archive} until you next use @code{SAVE}. @item REPLACE @var{module}, @var{module}, @dots{} @var{module} In the current archive, replace each existing @var{module} (named in the @code{REPLACE} arguments) from files in the current working directory. To execute this command without errors, both the file, and the module in the current archive, must exist. Requires prior use of @code{OPEN} or @code{CREATE}. @item VERBOSE Toggle an internal flag governing the output from @code{DIRECTORY}. When the flag is on, @code{DIRECTORY} output matches output from @samp{ar -tv }@dots{}. @item SAVE Commit your changes to the current archive, and actually save it as a file with the name specified in the last @code{CREATE} or @code{OPEN} command. Requires prior use of @code{OPEN} or @code{CREATE}. @end table @iftex @node ld @chapter ld @cindex linker @kindex ld The @sc{gnu} linker @command{ld} is now described in a separate manual. @xref{Top,, Overview,, Using LD: the @sc{gnu} linker}. @end iftex @node nm @chapter nm @cindex symbols @kindex nm @c man title nm list symbols from object files @smallexample @c man begin SYNOPSIS nm nm [@option{-A}|@option{-o}|@option{--print-file-name}] [@option{-a}|@option{--debug-syms}] [@option{-B}|@option{--format=bsd}] [@option{-C}|@option{--demangle}[=@var{style}]] [@option{-D}|@option{--dynamic}] [@option{-f}@var{format}|@option{--format=}@var{format}] [@option{-g}|@option{--extern-only}] [@option{-h}|@option{--help}] [@option{-l}|@option{--line-numbers}] [@option{--inlines}] [@option{-n}|@option{-v}|@option{--numeric-sort}] [@option{-P}|@option{--portability}] [@option{-p}|@option{--no-sort}] [@option{-r}|@option{--reverse-sort}] [@option{-S}|@option{--print-size}] [@option{-s}|@option{--print-armap}] [@option{-t} @var{radix}|@option{--radix=}@var{radix}] [@option{-u}|@option{--undefined-only}] [@option{-V}|@option{--version}] [@option{-X 32_64}] [@option{--defined-only}] [@option{--no-demangle}] [@option{--plugin} @var{name}] [@option{--no-recurse-limit}|@option{--recurse-limit}]] [@option{--size-sort}] [@option{--special-syms}] [@option{--synthetic}] [@option{--with-symbol-versions}] [@option{--target=}@var{bfdname}] [@var{objfile}@dots{}] @c man end @end smallexample @c man begin DESCRIPTION nm @sc{gnu} @command{nm} lists the symbols from object files @var{objfile}@dots{}. If no object files are listed as arguments, @command{nm} assumes the file @file{a.out}. For each symbol, @command{nm} shows: @itemize @bullet @item The symbol value, in the radix selected by options (see below), or hexadecimal by default. @item The symbol type. At least the following types are used; others are, as well, depending on the object file format. If lowercase, the symbol is usually local; if uppercase, the symbol is global (external). There are however a few lowercase symbols that are shown for special global symbols (@code{u}, @code{v} and @code{w}). @c Some more detail on exactly what these symbol types are used for @c would be nice. @table @code @item A The symbol's value is absolute, and will not be changed by further linking. @item B @itemx b The symbol is in the BSS data section. This section typically contains zero-initialized or uninitialized data, although the exact behavior is system dependent. @item C The symbol is common. Common symbols are uninitialized data. When linking, multiple common symbols may appear with the same name. If the symbol is defined anywhere, the common symbols are treated as undefined references. @ifclear man For more details on common symbols, see the discussion of --warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}. @end ifclear @item D @itemx d The symbol is in the initialized data section. @item G @itemx g The symbol is in an initialized data section for small objects. Some object file formats permit more efficient access to small data objects, such as a global int variable as opposed to a large global array. @item i For PE format files this indicates that the symbol is in a section specific to the implementation of DLLs. For ELF format files this indicates that the symbol is an indirect function. This is a GNU extension to the standard set of ELF symbol types. It indicates a symbol which if referenced by a relocation does not evaluate to its address, but instead must be invoked at runtime. The runtime execution will then return the value to be used in the relocation. @item I The symbol is an indirect reference to another symbol. @item N The symbol is a debugging symbol. @item n The symbol is in the read-only data section. @item p The symbol is in a stack unwind section. @item R @itemx r The symbol is in a read only data section. @item S @itemx s The symbol is in an uninitialized or zero-initialized data section for small objects. @item T @itemx t The symbol is in the text (code) section. @item U The symbol is undefined. @item u The symbol is a unique global symbol. This is a GNU extension to the standard set of ELF symbol bindings. For such a symbol the dynamic linker will make sure that in the entire process there is just one symbol with this name and type in use. @item V @itemx v The symbol is a weak object. When a weak defined symbol is linked with a normal defined symbol, the normal defined symbol is used with no error. When a weak undefined symbol is linked and the symbol is not defined, the value of the weak symbol becomes zero with no error. On some systems, uppercase indicates that a default value has been specified. @item W @itemx w The symbol is a weak symbol that has not been specifically tagged as a weak object symbol. When a weak defined symbol is linked with a normal defined symbol, the normal defined symbol is used with no error. When a weak undefined symbol is linked and the symbol is not defined, the value of the symbol is determined in a system-specific manner without error. On some systems, uppercase indicates that a default value has been specified. @item - The symbol is a stabs symbol in an a.out object file. In this case, the next values printed are the stabs other field, the stabs desc field, and the stab type. Stabs symbols are used to hold debugging information. @item ? The symbol type is unknown, or object file format specific. @end table @item The symbol name. @end itemize @c man end @c man begin OPTIONS nm The long and short forms of options, shown here as alternatives, are equivalent. @table @env @item -A @itemx -o @itemx --print-file-name @cindex input file name @cindex file name @cindex source file name Precede each symbol by the name of the input file (or archive member) in which it was found, rather than identifying the input file once only, before all of its symbols. @item -a @itemx --debug-syms @cindex debugging symbols Display all symbols, even debugger-only symbols; normally these are not listed. @item -B @cindex @command{nm} format @cindex @command{nm} compatibility The same as @option{--format=bsd} (for compatibility with the MIPS @command{nm}). @item -C @itemx --demangle[=@var{style}] @cindex demangling in nm Decode (@dfn{demangle}) low-level symbol names into user-level names. Besides removing any initial underscore prepended by the system, this makes C++ function names readable. Different compilers have different mangling styles. The optional demangling style argument can be used to choose an appropriate demangling style for your compiler. @xref{c++filt}, for more information on demangling. @item --no-demangle Do not demangle low-level symbol names. This is the default. @item --recurse-limit @itemx --no-recurse-limit @itemx --recursion-limit @itemx --no-recursion-limit Enables or disables a limit on the amount of recursion performed whilst demangling strings. Since the name mangling formats allow for an inifinite level of recursion it is possible to create strings whose decoding will exhaust the amount of stack space available on the host machine, triggering a memory fault. The limit tries to prevent this from happening by restricting recursion to 2048 levels of nesting. The default is for this limit to be enabled, but disabling it may be necessary in order to demangle truly complicated names. Note however that if the recursion limit is disabled then stack exhaustion is possible and any bug reports about such an event will be rejected. @item -D @itemx --dynamic @cindex dynamic symbols Display the dynamic symbols rather than the normal symbols. This is only meaningful for dynamic objects, such as certain types of shared libraries. @item -f @var{format} @itemx --format=@var{format} @cindex @command{nm} format @cindex @command{nm} compatibility Use the output format @var{format}, which can be @code{bsd}, @code{sysv}, or @code{posix}. The default is @code{bsd}. Only the first character of @var{format} is significant; it can be either upper or lower case. @item -g @itemx --extern-only @cindex external symbols Display only external symbols. @item -h @itemx --help Show a summary of the options to @command{nm} and exit. @item -l @itemx --line-numbers @cindex symbol line numbers For each symbol, use debugging information to try to find a filename and line number. For a defined symbol, look for the line number of the address of the symbol. For an undefined symbol, look for the line number of a relocation entry which refers to the symbol. If line number information can be found, print it after the other symbol information. @item --inlines @cindex objdump inlines When option @option{-l} is active, if the address belongs to a function that was inlined, then this option causes the source information for all enclosing scopes back to the first non-inlined function to be printed as well. For example, if @code{main} inlines @code{callee1} which inlines @code{callee2}, and address is from @code{callee2}, the source information for @code{callee1} and @code{main} will also be printed. @item -n @itemx -v @itemx --numeric-sort Sort symbols numerically by their addresses, rather than alphabetically by their names. @item -p @itemx --no-sort @cindex sorting symbols Do not bother to sort the symbols in any order; print them in the order encountered. @item -P @itemx --portability Use the POSIX.2 standard output format instead of the default format. Equivalent to @samp{-f posix}. @item -r @itemx --reverse-sort Reverse the order of the sort (whether numeric or alphabetic); let the last come first. @item -S @itemx --print-size Print both value and size of defined symbols for the @code{bsd} output style. This option has no effect for object formats that do not record symbol sizes, unless @samp{--size-sort} is also used in which case a calculated size is displayed. @item -s @itemx --print-armap @cindex symbol index, listing When listing symbols from archive members, include the index: a mapping (stored in the archive by @command{ar} or @command{ranlib}) of which modules contain definitions for which names. @item -t @var{radix} @itemx --radix=@var{radix} Use @var{radix} as the radix for printing the symbol values. It must be @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal. @item -u @itemx --undefined-only @cindex external symbols @cindex undefined symbols Display only undefined symbols (those external to each object file). @item -V @itemx --version Show the version number of @command{nm} and exit. @item -X This option is ignored for compatibility with the AIX version of @command{nm}. It takes one parameter which must be the string @option{32_64}. The default mode of AIX @command{nm} corresponds to @option{-X 32}, which is not supported by @sc{gnu} @command{nm}. @item --defined-only @cindex external symbols @cindex undefined symbols Display only defined symbols for each object file. @item --plugin @var{name} @cindex plugins Load the plugin called @var{name} to add support for extra target types. This option is only available if the toolchain has been built with plugin support enabled. If @option{--plugin} is not provided, but plugin support has been enabled then @command{nm} iterates over the files in @file{$@{libdir@}/bfd-plugins} in alphabetic order and the first plugin that claims the object in question is used. Please note that this plugin search directory is @emph{not} the one used by @command{ld}'s @option{-plugin} option. In order to make @command{nm} use the linker plugin it must be copied into the @file{$@{libdir@}/bfd-plugins} directory. For GCC based compilations the linker plugin is called @file{liblto_plugin.so.0.0.0}. For Clang based compilations it is called @file{LLVMgold.so}. The GCC plugin is always backwards compatible with earlier versions, so it is sufficient to just copy the newest one. @item --size-sort Sort symbols by size. For ELF objects symbol sizes are read from the ELF, for other object types the symbol sizes are computed as the difference between the value of the symbol and the value of the symbol with the next higher value. If the @code{bsd} output format is used the size of the symbol is printed, rather than the value, and @samp{-S} must be used in order both size and value to be printed. @item --special-syms Display symbols which have a target-specific special meaning. These symbols are usually used by the target for some special processing and are not normally helpful when included in the normal symbol lists. For example for ARM targets this option would skip the mapping symbols used to mark transitions between ARM code, THUMB code and data. @item --synthetic Include synthetic symbols in the output. These are special symbols created by the linker for various purposes. They are not shown by default since they are not part of the binary's original source code. @item --with-symbol-versions Enables the display of symbol version information if any exists. The version string is displayed as a suffix to the symbol name, preceeded by an @@ character. For example @samp{foo@@VER_1}. If the version is the default version to be used when resolving unversioned references to the symbol then it is displayed as a suffix preceeded by two @@ characters. For example @samp{foo@@@@VER_2}. @item --target=@var{bfdname} @cindex object code format Specify an object code format other than your system's default format. @xref{Target Selection}, for more information. @end table @c man end @ignore @c man begin SEEALSO nm ar(1), objdump(1), ranlib(1), and the Info entries for @file{binutils}. @c man end @end ignore @node objcopy @chapter objcopy @c man title objcopy copy and translate object files @smallexample @c man begin SYNOPSIS objcopy objcopy [@option{-F} @var{bfdname}|@option{--target=}@var{bfdname}] [@option{-I} @var{bfdname}|@option{--input-target=}@var{bfdname}] [@option{-O} @var{bfdname}|@option{--output-target=}@var{bfdname}] [@option{-B} @var{bfdarch}|@option{--binary-architecture=}@var{bfdarch}] [@option{-S}|@option{--strip-all}] [@option{-g}|@option{--strip-debug}] [@option{--strip-unneeded}] [@option{-K} @var{symbolname}|@option{--keep-symbol=}@var{symbolname}] [@option{-N} @var{symbolname}|@option{--strip-symbol=}@var{symbolname}] [@option{--strip-unneeded-symbol=}@var{symbolname}] [@option{-G} @var{symbolname}|@option{--keep-global-symbol=}@var{symbolname}] [@option{--localize-hidden}] [@option{-L} @var{symbolname}|@option{--localize-symbol=}@var{symbolname}] [@option{--globalize-symbol=}@var{symbolname}] [@option{--globalize-symbols=}@var{filename}] [@option{-W} @var{symbolname}|@option{--weaken-symbol=}@var{symbolname}] [@option{-w}|@option{--wildcard}] [@option{-x}|@option{--discard-all}] [@option{-X}|@option{--discard-locals}] [@option{-b} @var{byte}|@option{--byte=}@var{byte}] [@option{-i} [@var{breadth}]|@option{--interleave}[=@var{breadth}]] [@option{--interleave-width=}@var{width}] [@option{-j} @var{sectionpattern}|@option{--only-section=}@var{sectionpattern}] [@option{-R} @var{sectionpattern}|@option{--remove-section=}@var{sectionpattern}] [@option{--keep-section=}@var{sectionpattern}] [@option{--remove-relocations=}@var{sectionpattern}] [@option{-p}|@option{--preserve-dates}] [@option{-D}|@option{--enable-deterministic-archives}] [@option{-U}|@option{--disable-deterministic-archives}] [@option{--debugging}] [@option{--gap-fill=}@var{val}] [@option{--pad-to=}@var{address}] [@option{--set-start=}@var{val}] [@option{--adjust-start=}@var{incr}] [@option{--change-addresses=}@var{incr}] [@option{--change-section-address} @var{sectionpattern}@{=,+,-@}@var{val}] [@option{--change-section-lma} @var{sectionpattern}@{=,+,-@}@var{val}] [@option{--change-section-vma} @var{sectionpattern}@{=,+,-@}@var{val}] [@option{--change-warnings}] [@option{--no-change-warnings}] [@option{--set-section-flags} @var{sectionpattern}=@var{flags}] [@option{--set-section-alignment} @var{sectionpattern}=@var{align}] [@option{--add-section} @var{sectionname}=@var{filename}] [@option{--dump-section} @var{sectionname}=@var{filename}] [@option{--update-section} @var{sectionname}=@var{filename}] [@option{--rename-section} @var{oldname}=@var{newname}[,@var{flags}]] [@option{--long-section-names} @{enable,disable,keep@}] [@option{--change-leading-char}] [@option{--remove-leading-char}] [@option{--reverse-bytes=}@var{num}] [@option{--srec-len=}@var{ival}] [@option{--srec-forceS3}] [@option{--redefine-sym} @var{old}=@var{new}] [@option{--redefine-syms=}@var{filename}] [@option{--weaken}] [@option{--keep-symbols=}@var{filename}] [@option{--strip-symbols=}@var{filename}] [@option{--strip-unneeded-symbols=}@var{filename}] [@option{--keep-global-symbols=}@var{filename}] [@option{--localize-symbols=}@var{filename}] [@option{--weaken-symbols=}@var{filename}] [@option{--add-symbol} @var{name}=[@var{section}:]@var{value}[,@var{flags}]] [@option{--alt-machine-code=}@var{index}] [@option{--prefix-symbols=}@var{string}] [@option{--prefix-sections=}@var{string}] [@option{--prefix-alloc-sections=}@var{string}] [@option{--add-gnu-debuglink=}@var{path-to-file}] [@option{--keep-file-symbols}] [@option{--only-keep-debug}] [@option{--strip-dwo}] [@option{--extract-dwo}] [@option{--extract-symbol}] [@option{--writable-text}] [@option{--readonly-text}] [@option{--pure}] [@option{--impure}] [@option{--file-alignment=}@var{num}] [@option{--heap=}@var{size}] [@option{--image-base=}@var{address}] [@option{--section-alignment=}@var{num}] [@option{--stack=}@var{size}] [@option{--subsystem=}@var{which}:@var{major}.@var{minor}] [@option{--compress-debug-sections}] [@option{--decompress-debug-sections}] [@option{--elf-stt-common=@var{val}}] [@option{--merge-notes}] [@option{--no-merge-notes}] [@option{--verilog-data-width=@var{val}}] [@option{-v}|@option{--verbose}] [@option{-V}|@option{--version}] [@option{--help}] [@option{--info}] @var{infile} [@var{outfile}] @c man end @end smallexample @c man begin DESCRIPTION objcopy The @sc{gnu} @command{objcopy} utility copies the contents of an object file to another. @command{objcopy} uses the @sc{gnu} @sc{bfd} Library to read and write the object files. It can write the destination object file in a format different from that of the source object file. The exact behavior of @command{objcopy} is controlled by command-line options. Note that @command{objcopy} should be able to copy a fully linked file between any two formats. However, copying a relocatable object file between any two formats may not work as expected. @command{objcopy} creates temporary files to do its translations and deletes them afterward. @command{objcopy} uses @sc{bfd} to do all its translation work; it has access to all the formats described in @sc{bfd} and thus is able to recognize most formats without being told explicitly. @xref{BFD,,BFD,ld.info,Using LD}. @command{objcopy} can be used to generate S-records by using an output target of @samp{srec} (e.g., use @samp{-O srec}). @command{objcopy} can be used to generate a raw binary file by using an output target of @samp{binary} (e.g., use @option{-O binary}). When @command{objcopy} generates a raw binary file, it will essentially produce a memory dump of the contents of the input object file. All symbols and relocation information will be discarded. The memory dump will start at the load address of the lowest section copied into the output file. When generating an S-record or a raw binary file, it may be helpful to use @option{-S} to remove sections containing debugging information. In some cases @option{-R} will be useful to remove sections which contain information that is not needed by the binary file. Note---@command{objcopy} is not able to change the endianness of its input files. If the input format has an endianness (some formats do not), @command{objcopy} can only copy the inputs into file formats that have the same endianness or which have no endianness (e.g., @samp{srec}). (However, see the @option{--reverse-bytes} option.) @c man end @c man begin OPTIONS objcopy @table @env @item @var{infile} @itemx @var{outfile} The input and output files, respectively. If you do not specify @var{outfile}, @command{objcopy} creates a temporary file and destructively renames the result with the name of @var{infile}. @item -I @var{bfdname} @itemx --input-target=@var{bfdname} Consider the source file's object format to be @var{bfdname}, rather than attempting to deduce it. @xref{Target Selection}, for more information. @item -O @var{bfdname} @itemx --output-target=@var{bfdname} Write the output file using the object format @var{bfdname}. @xref{Target Selection}, for more information. @item -F @var{bfdname} @itemx --target=@var{bfdname} Use @var{bfdname} as the object format for both the input and the output file; i.e., simply transfer data from source to destination with no translation. @xref{Target Selection}, for more information. @item -B @var{bfdarch} @itemx --binary-architecture=@var{bfdarch} Useful when transforming a architecture-less input file into an object file. In this case the output architecture can be set to @var{bfdarch}. This option will be ignored if the input file has a known @var{bfdarch}. You can access this binary data inside a program by referencing the special symbols that are created by the conversion process. These symbols are called _binary_@var{objfile}_start, _binary_@var{objfile}_end and _binary_@var{objfile}_size. e.g. you can transform a picture file into an object file and then access it in your code using these symbols. @item -j @var{sectionpattern} @itemx --only-section=@var{sectionpattern} Copy only the indicated sections from the input file to the output file. This option may be given more than once. Note that using this option inappropriately may make the output file unusable. Wildcard characters are accepted in @var{sectionpattern}. If the first character of @var{sectionpattern} is the exclamation point (!) then matching sections will not be copied, even if earlier use of @option{--only-section} on the same command line would otherwise copy it. For example: @smallexample --only-section=.text.* --only-section=!.text.foo @end smallexample will copy all sectinos maching '.text.*' but not the section '.text.foo'. @item -R @var{sectionpattern} @itemx --remove-section=@var{sectionpattern} Remove any section matching @var{sectionpattern} from the output file. This option may be given more than once. Note that using this option inappropriately may make the output file unusable. Wildcard characters are accepted in @var{sectionpattern}. Using both the @option{-j} and @option{-R} options together results in undefined behaviour. If the first character of @var{sectionpattern} is the exclamation point (!) then matching sections will not be removed even if an earlier use of @option{--remove-section} on the same command line would otherwise remove it. For example: @smallexample --remove-section=.text.* --remove-section=!.text.foo @end smallexample will remove all sections matching the pattern '.text.*', but will not remove the section '.text.foo'. @item --keep-section=@var{sectionpattern} When removing sections from the output file, keep sections that match @var{sectionpattern}. @item --remove-relocations=@var{sectionpattern} Remove non-dynamic relocations from the output file for any section matching @var{sectionpattern}. This option may be given more than once. Note that using this option inappropriately may make the output file unusable, and attempting to remove a dynamic relocation section such as @samp{.rela.plt} from an executable or shared library with @option{--remove-relocations=.plt} will not work. Wildcard characters are accepted in @var{sectionpattern}. For example: @smallexample --remove-relocations=.text.* @end smallexample will remove the relocations for all sections matching the pattern '.text.*'. If the first character of @var{sectionpattern} is the exclamation point (!) then matching sections will not have their relocation removed even if an earlier use of @option{--remove-relocations} on the same command line would otherwise cause the relocations to be removed. For example: @smallexample --remove-relocations=.text.* --remove-relocations=!.text.foo @end smallexample will remove all relocations for sections matching the pattern '.text.*', but will not remove relocations for the section '.text.foo'. @item -S @itemx --strip-all Do not copy relocation and symbol information from the source file. @item -g @itemx --strip-debug Do not copy debugging symbols or sections from the source file. @item --strip-unneeded Strip all symbols that are not needed for relocation processing. @item -K @var{symbolname} @itemx --keep-symbol=@var{symbolname} When stripping symbols, keep symbol @var{symbolname} even if it would normally be stripped. This option may be given more than once. @item -N @var{symbolname} @itemx --strip-symbol=@var{symbolname} Do not copy symbol @var{symbolname} from the source file. This option may be given more than once. @item --strip-unneeded-symbol=@var{symbolname} Do not copy symbol @var{symbolname} from the source file unless it is needed by a relocation. This option may be given more than once. @item -G @var{symbolname} @itemx --keep-global-symbol=@var{symbolname} Keep only symbol @var{symbolname} global. Make all other symbols local to the file, so that they are not visible externally. This option may be given more than once. Note: this option cannot be used in conjunction with the @option{--globalize-symbol} or @option{--globalize-symbols} options. @item --localize-hidden In an ELF object, mark all symbols that have hidden or internal visibility as local. This option applies on top of symbol-specific localization options such as @option{-L}. @item -L @var{symbolname} @itemx --localize-symbol=@var{symbolname} Convert a global or weak symbol called @var{symbolname} into a local symbol, so that it is not visible externally. This option may be given more than once. Note - unique symbols are not converted. @item -W @var{symbolname} @itemx --weaken-symbol=@var{symbolname} Make symbol @var{symbolname} weak. This option may be given more than once. @item --globalize-symbol=@var{symbolname} Give symbol @var{symbolname} global scoping so that it is visible outside of the file in which it is defined. This option may be given more than once. Note: this option cannot be used in conjunction with the @option{-G} or @option{--keep-global-symbol} options. @item -w @itemx --wildcard Permit regular expressions in @var{symbolname}s used in other command line options. The question mark (?), asterisk (*), backslash (\) and square brackets ([]) operators can be used anywhere in the symbol name. If the first character of the symbol name is the exclamation point (!) then the sense of the switch is reversed for that symbol. For example: @smallexample -w -W !foo -W fo* @end smallexample would cause objcopy to weaken all symbols that start with ``fo'' except for the symbol ``foo''. @item -x @itemx --discard-all Do not copy non-global symbols from the source file. @c FIXME any reason to prefer "non-global" to "local" here? @item -X @itemx --discard-locals Do not copy compiler-generated local symbols. (These usually start with @samp{L} or @samp{.}.) @item -b @var{byte} @itemx --byte=@var{byte} If interleaving has been enabled via the @option{--interleave} option then start the range of bytes to keep at the @var{byte}th byte. @var{byte} can be in the range from 0 to @var{breadth}-1, where @var{breadth} is the value given by the @option{--interleave} option. @item -i [@var{breadth}] @itemx --interleave[=@var{breadth}] Only copy a range out of every @var{breadth} bytes. (Header data is not affected). Select which byte in the range begins the copy with the @option{--byte} option. Select the width of the range with the @option{--interleave-width} option. This option is useful for creating files to program @sc{rom}. It is typically used with an @code{srec} output target. Note that @command{objcopy} will complain if you do not specify the @option{--byte} option as well. The default interleave breadth is 4, so with @option{--byte} set to 0, @command{objcopy} would copy the first byte out of every four bytes from the input to the output. @item --interleave-width=@var{width} When used with the @option{--interleave} option, copy @var{width} bytes at a time. The start of the range of bytes to be copied is set by the @option{--byte} option, and the extent of the range is set with the @option{--interleave} option. The default value for this option is 1. The value of @var{width} plus the @var{byte} value set by the @option{--byte} option must not exceed the interleave breadth set by the @option{--interleave} option. This option can be used to create images for two 16-bit flashes interleaved in a 32-bit bus by passing @option{-b 0 -i 4 --interleave-width=2} and @option{-b 2 -i 4 --interleave-width=2} to two @command{objcopy} commands. If the input was '12345678' then the outputs would be '1256' and '3478' respectively. @item -p @itemx --preserve-dates Set the access and modification dates of the output file to be the same as those of the input file. @item -D @itemx --enable-deterministic-archives @cindex deterministic archives @kindex --enable-deterministic-archives Operate in @emph{deterministic} mode. When copying archive members and writing the archive index, use zero for UIDs, GIDs, timestamps, and use consistent file modes for all files. If @file{binutils} was configured with @option{--enable-deterministic-archives}, then this mode is on by default. It can be disabled with the @samp{-U} option, below. @item -U @itemx --disable-deterministic-archives @cindex deterministic archives @kindex --enable-deterministic-archives Do @emph{not} operate in @emph{deterministic} mode. This is the inverse of the @option{-D} option, above: when copying archive members and writing the archive index, use their actual UID, GID, timestamp, and file mode values. This is the default unless @file{binutils} was configured with @option{--enable-deterministic-archives}. @item --debugging Convert debugging information, if possible. This is not the default because only certain debugging formats are supported, and the conversion process can be time consuming. @item --gap-fill @var{val} Fill gaps between sections with @var{val}. This operation applies to the @emph{load address} (LMA) of the sections. It is done by increasing the size of the section with the lower address, and filling in the extra space created with @var{val}. @item --pad-to @var{address} Pad the output file up to the load address @var{address}. This is done by increasing the size of the last section. The extra space is filled in with the value specified by @option{--gap-fill} (default zero). @item --set-start @var{val} Set the start address of the new file to @var{val}. Not all object file formats support setting the start address. @item --change-start @var{incr} @itemx --adjust-start @var{incr} @cindex changing start address Change the start address by adding @var{incr}. Not all object file formats support setting the start address. @item --change-addresses @var{incr} @itemx --adjust-vma @var{incr} @cindex changing object addresses Change the VMA and LMA addresses of all sections, as well as the start address, by adding @var{incr}. Some object file formats do not permit section addresses to be changed arbitrarily. Note that this does not relocate the sections; if the program expects sections to be loaded at a certain address, and this option is used to change the sections such that they are loaded at a different address, the program may fail. @item --change-section-address @var{sectionpattern}@{=,+,-@}@var{val} @itemx --adjust-section-vma @var{sectionpattern}@{=,+,-@}@var{val} @cindex changing section address Set or change both the VMA address and the LMA address of any section matching @var{sectionpattern}. If @samp{=} is used, the section address is set to @var{val}. Otherwise, @var{val} is added to or subtracted from the section address. See the comments under @option{--change-addresses}, above. If @var{sectionpattern} does not match any sections in the input file, a warning will be issued, unless @option{--no-change-warnings} is used. @item --change-section-lma @var{sectionpattern}@{=,+,-@}@var{val} @cindex changing section LMA Set or change the LMA address of any sections matching @var{sectionpattern}. The LMA address is the address where the section will be loaded into memory at program load time. Normally this is the same as the VMA address, which is the address of the section at program run time, but on some systems, especially those where a program is held in ROM, the two can be different. If @samp{=} is used, the section address is set to @var{val}. Otherwise, @var{val} is added to or subtracted from the section address. See the comments under @option{--change-addresses}, above. If @var{sectionpattern} does not match any sections in the input file, a warning will be issued, unless @option{--no-change-warnings} is used. @item --change-section-vma @var{sectionpattern}@{=,+,-@}@var{val} @cindex changing section VMA Set or change the VMA address of any section matching @var{sectionpattern}. The VMA address is the address where the section will be located once the program has started executing. Normally this is the same as the LMA address, which is the address where the section will be loaded into memory, but on some systems, especially those where a program is held in ROM, the two can be different. If @samp{=} is used, the section address is set to @var{val}. Otherwise, @var{val} is added to or subtracted from the section address. See the comments under @option{--change-addresses}, above. If @var{sectionpattern} does not match any sections in the input file, a warning will be issued, unless @option{--no-change-warnings} is used. @item --change-warnings @itemx --adjust-warnings If @option{--change-section-address} or @option{--change-section-lma} or @option{--change-section-vma} is used, and the section pattern does not match any sections, issue a warning. This is the default. @item --no-change-warnings @itemx --no-adjust-warnings Do not issue a warning if @option{--change-section-address} or @option{--adjust-section-lma} or @option{--adjust-section-vma} is used, even if the section pattern does not match any sections. @item --set-section-flags @var{sectionpattern}=@var{flags} Set the flags for any sections matching @var{sectionpattern}. The @var{flags} argument is a comma separated string of flag names. The recognized names are @samp{alloc}, @samp{contents}, @samp{load}, @samp{noload}, @samp{readonly}, @samp{code}, @samp{data}, @samp{rom}, @samp{exclude}, @samp{share}, and @samp{debug}. You can set the @samp{contents} flag for a section which does not have contents, but it is not meaningful to clear the @samp{contents} flag of a section which does have contents--just remove the section instead. Not all flags are meaningful for all object file formats. @item --set-section-alignment @var{sectionpattern}=@var{align} Set the alignment for any sections matching @var{sectionpattern}. @var{align} specifies the alignment in bytes and must be a power of two, i.e. 1, 2, 4, 8@dots{}. @item --add-section @var{sectionname}=@var{filename} Add a new section named @var{sectionname} while copying the file. The contents of the new section are taken from the file @var{filename}. The size of the section will be the size of the file. This option only works on file formats which can support sections with arbitrary names. Note - it may be necessary to use the @option{--set-section-flags} option to set the attributes of the newly created section. @item --dump-section @var{sectionname}=@var{filename} Place the contents of section named @var{sectionname} into the file @var{filename}, overwriting any contents that may have been there previously. This option is the inverse of @option{--add-section}. This option is similar to the @option{--only-section} option except that it does not create a formatted file, it just dumps the contents as raw binary data, without applying any relocations. The option can be specified more than once. @item --update-section @var{sectionname}=@var{filename} Replace the existing contents of a section named @var{sectionname} with the contents of file @var{filename}. The size of the section will be adjusted to the size of the file. The section flags for @var{sectionname} will be unchanged. For ELF format files the section to segment mapping will also remain unchanged, something which is not possible using @option{--remove-section} followed by @option{--add-section}. The option can be specified more than once. Note - it is possible to use @option{--rename-section} and @option{--update-section} to both update and rename a section from one command line. In this case, pass the original section name to @option{--update-section}, and the original and new section names to @option{--rename-section}. @item --add-symbol @var{name}=[@var{section}:]@var{value}[,@var{flags}] Add a new symbol named @var{name} while copying the file. This option may be specified multiple times. If the @var{section} is given, the symbol will be associated with and relative to that section, otherwise it will be an ABS symbol. Specifying an undefined section will result in a fatal error. There is no check for the value, it will be taken as specified. Symbol flags can be specified and not all flags will be meaningful for all object file formats. By default, the symbol will be global. The special flag 'before=@var{othersym}' will insert the new symbol in front of the specified @var{othersym}, otherwise the symbol(s) will be added at the end of the symbol table in the order they appear. @item --rename-section @var{oldname}=@var{newname}[,@var{flags}] Rename a section from @var{oldname} to @var{newname}, optionally changing the section's flags to @var{flags} in the process. This has the advantage over using a linker script to perform the rename in that the output stays as an object file and does not become a linked executable. This option is particularly helpful when the input format is binary, since this will always create a section called .data. If for example, you wanted instead to create a section called .rodata containing binary data you could use the following command line to achieve it: @smallexample objcopy -I binary -O -B \ --rename-section .data=.rodata,alloc,load,readonly,data,contents \ @end smallexample @item --long-section-names @{enable,disable,keep@} Controls the handling of long section names when processing @code{COFF} and @code{PE-COFF} object formats. The default behaviour, @samp{keep}, is to preserve long section names if any are present in the input file. The @samp{enable} and @samp{disable} options forcibly enable or disable the use of long section names in the output object; when @samp{disable} is in effect, any long section names in the input object will be truncated. The @samp{enable} option will only emit long section names if any are present in the inputs; this is mostly the same as @samp{keep}, but it is left undefined whether the @samp{enable} option might force the creation of an empty string table in the output file. @item --change-leading-char Some object file formats use special characters at the start of symbols. The most common such character is underscore, which compilers often add before every symbol. This option tells @command{objcopy} to change the leading character of every symbol when it converts between object file formats. If the object file formats use the same leading character, this option has no effect. Otherwise, it will add a character, or remove a character, or change a character, as appropriate. @item --remove-leading-char If the first character of a global symbol is a special symbol leading character used by the object file format, remove the character. The most common symbol leading character is underscore. This option will remove a leading underscore from all global symbols. This can be useful if you want to link together objects of different file formats with different conventions for symbol names. This is different from @option{--change-leading-char} because it always changes the symbol name when appropriate, regardless of the object file format of the output file. @item --reverse-bytes=@var{num} Reverse the bytes in a section with output contents. A section length must be evenly divisible by the value given in order for the swap to be able to take place. Reversing takes place before the interleaving is performed. This option is used typically in generating ROM images for problematic target systems. For example, on some target boards, the 32-bit words fetched from 8-bit ROMs are re-assembled in little-endian byte order regardless of the CPU byte order. Depending on the programming model, the endianness of the ROM may need to be modified. Consider a simple file with a section containing the following eight bytes: @code{12345678}. Using @samp{--reverse-bytes=2} for the above example, the bytes in the output file would be ordered @code{21436587}. Using @samp{--reverse-bytes=4} for the above example, the bytes in the output file would be ordered @code{43218765}. By using @samp{--reverse-bytes=2} for the above example, followed by @samp{--reverse-bytes=4} on the output file, the bytes in the second output file would be ordered @code{34127856}. @item --srec-len=@var{ival} Meaningful only for srec output. Set the maximum length of the Srecords being produced to @var{ival}. This length covers both address, data and crc fields. @item --srec-forceS3 Meaningful only for srec output. Avoid generation of S1/S2 records, creating S3-only record format. @item --redefine-sym @var{old}=@var{new} Change the name of a symbol @var{old}, to @var{new}. This can be useful when one is trying link two things together for which you have no source, and there are name collisions. @item --redefine-syms=@var{filename} Apply @option{--redefine-sym} to each symbol pair "@var{old} @var{new}" listed in the file @var{filename}. @var{filename} is simply a flat file, with one symbol pair per line. Line comments may be introduced by the hash character. This option may be given more than once. @item --weaken Change all global symbols in the file to be weak. This can be useful when building an object which will be linked against other objects using the @option{-R} option to the linker. This option is only effective when using an object file format which supports weak symbols. @item --keep-symbols=@var{filename} Apply @option{--keep-symbol} option to each symbol listed in the file @var{filename}. @var{filename} is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. @item --strip-symbols=@var{filename} Apply @option{--strip-symbol} option to each symbol listed in the file @var{filename}. @var{filename} is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. @item --strip-unneeded-symbols=@var{filename} Apply @option{--strip-unneeded-symbol} option to each symbol listed in the file @var{filename}. @var{filename} is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. @item --keep-global-symbols=@var{filename} Apply @option{--keep-global-symbol} option to each symbol listed in the file @var{filename}. @var{filename} is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. @item --localize-symbols=@var{filename} Apply @option{--localize-symbol} option to each symbol listed in the file @var{filename}. @var{filename} is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. @item --globalize-symbols=@var{filename} Apply @option{--globalize-symbol} option to each symbol listed in the file @var{filename}. @var{filename} is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. Note: this option cannot be used in conjunction with the @option{-G} or @option{--keep-global-symbol} options. @item --weaken-symbols=@var{filename} Apply @option{--weaken-symbol} option to each symbol listed in the file @var{filename}. @var{filename} is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. @item --alt-machine-code=@var{index} If the output architecture has alternate machine codes, use the @var{index}th code instead of the default one. This is useful in case a machine is assigned an official code and the tool-chain adopts the new code, but other applications still depend on the original code being used. For ELF based architectures if the @var{index} alternative does not exist then the value is treated as an absolute number to be stored in the e_machine field of the ELF header. @item --writable-text Mark the output text as writable. This option isn't meaningful for all object file formats. @item --readonly-text Make the output text write protected. This option isn't meaningful for all object file formats. @item --pure Mark the output file as demand paged. This option isn't meaningful for all object file formats. @item --impure Mark the output file as impure. This option isn't meaningful for all object file formats. @item --prefix-symbols=@var{string} Prefix all symbols in the output file with @var{string}. @item --prefix-sections=@var{string} Prefix all section names in the output file with @var{string}. @item --prefix-alloc-sections=@var{string} Prefix all the names of all allocated sections in the output file with @var{string}. @item --add-gnu-debuglink=@var{path-to-file} Creates a .gnu_debuglink section which contains a reference to @var{path-to-file} and adds it to the output file. Note: the file at @var{path-to-file} must exist. Part of the process of adding the .gnu_debuglink section involves embedding a checksum of the contents of the debug info file into the section. If the debug info file is built in one location but it is going to be installed at a later time into a different location then do not use the path to the installed location. The @option{--add-gnu-debuglink} option will fail because the installed file does not exist yet. Instead put the debug info file in the current directory and use the @option{--add-gnu-debuglink} option without any directory components, like this: @smallexample objcopy --add-gnu-debuglink=foo.debug @end smallexample At debug time the debugger will attempt to look for the separate debug info file in a set of known locations. The exact set of these locations varies depending upon the distribution being used, but it typically includes: @table @code @item * The same directory as the executable. @item * A sub-directory of the directory containing the executable called .debug @item * A global debug directory such as /usr/lib/debug. @end table As long as the debug info file has been installed into one of these locations before the debugger is run everything should work correctly. @item --keep-file-symbols When stripping a file, perhaps with @option{--strip-debug} or @option{--strip-unneeded}, retain any symbols specifying source file names, which would otherwise get stripped. @item --only-keep-debug Strip a file, removing contents of any sections that would not be stripped by @option{--strip-debug} and leaving the debugging sections intact. In ELF files, this preserves all note sections in the output. Note - the section headers of the stripped sections are preserved, including their sizes, but the contents of the section are discarded. The section headers are preserved so that other tools can match up the debuginfo file with the real executable, even if that executable has been relocated to a different address space. The intention is that this option will be used in conjunction with @option{--add-gnu-debuglink} to create a two part executable. One a stripped binary which will occupy less space in RAM and in a distribution and the second a debugging information file which is only needed if debugging abilities are required. The suggested procedure to create these files is as follows: @enumerate @item Link the executable as normal. Assuming that it is called @code{foo} then... @item Run @code{objcopy --only-keep-debug foo foo.dbg} to create a file containing the debugging info. @item Run @code{objcopy --strip-debug foo} to create a stripped executable. @item Run @code{objcopy --add-gnu-debuglink=foo.dbg foo} to add a link to the debugging info into the stripped executable. @end enumerate Note---the choice of @code{.dbg} as an extension for the debug info file is arbitrary. Also the @code{--only-keep-debug} step is optional. You could instead do this: @enumerate @item Link the executable as normal. @item Copy @code{foo} to @code{foo.full} @item Run @code{objcopy --strip-debug foo} @item Run @code{objcopy --add-gnu-debuglink=foo.full foo} @end enumerate i.e., the file pointed to by the @option{--add-gnu-debuglink} can be the full executable. It does not have to be a file created by the @option{--only-keep-debug} switch. Note---this switch is only intended for use on fully linked files. It does not make sense to use it on object files where the debugging information may be incomplete. Besides the gnu_debuglink feature currently only supports the presence of one filename containing debugging information, not multiple filenames on a one-per-object-file basis. @item --strip-dwo Remove the contents of all DWARF .dwo sections, leaving the remaining debugging sections and all symbols intact. This option is intended for use by the compiler as part of the @option{-gsplit-dwarf} option, which splits debug information between the .o file and a separate .dwo file. The compiler generates all debug information in the same file, then uses the @option{--extract-dwo} option to copy the .dwo sections to the .dwo file, then the @option{--strip-dwo} option to remove those sections from the original .o file. @item --extract-dwo Extract the contents of all DWARF .dwo sections. See the @option{--strip-dwo} option for more information. @item --file-alignment @var{num} Specify the file alignment. Sections in the file will always begin at file offsets which are multiples of this number. This defaults to 512. [This option is specific to PE targets.] @item --heap @var{reserve} @itemx --heap @var{reserve},@var{commit} Specify the number of bytes of memory to reserve (and optionally commit) to be used as heap for this program. [This option is specific to PE targets.] @item --image-base @var{value} Use @var{value} as the base address of your program or dll. This is the lowest memory location that will be used when your program or dll is loaded. To reduce the need to relocate and improve performance of your dlls, each should have a unique base address and not overlap any other dlls. The default is 0x400000 for executables, and 0x10000000 for dlls. [This option is specific to PE targets.] @item --section-alignment @var{num} Sets the section alignment field in the PE header. Sections in memory will always begin at addresses which are a multiple of this number. Defaults to 0x1000. [This option is specific to PE targets.] @item --stack @var{reserve} @itemx --stack @var{reserve},@var{commit} Specify the number of bytes of memory to reserve (and optionally commit) to be used as stack for this program. [This option is specific to PE targets.] @item --subsystem @var{which} @itemx --subsystem @var{which}:@var{major} @itemx --subsystem @var{which}:@var{major}.@var{minor} Specifies the subsystem under which your program will execute. The legal values for @var{which} are @code{native}, @code{windows}, @code{console}, @code{posix}, @code{efi-app}, @code{efi-bsd}, @code{efi-rtd}, @code{sal-rtd}, and @code{xbox}. You may optionally set the subsystem version also. Numeric values are also accepted for @var{which}. [This option is specific to PE targets.] @item --extract-symbol Keep the file's section flags and symbols but remove all section data. Specifically, the option: @itemize @item removes the contents of all sections; @item sets the size of every section to zero; and @item sets the file's start address to zero. @end itemize This option is used to build a @file{.sym} file for a VxWorks kernel. It can also be a useful way of reducing the size of a @option{--just-symbols} linker input file. @item --compress-debug-sections Compress DWARF debug sections using zlib with SHF_COMPRESSED from the ELF ABI. Note - if compression would actually make a section @emph{larger}, then it is not compressed. @item --compress-debug-sections=none @itemx --compress-debug-sections=zlib @itemx --compress-debug-sections=zlib-gnu @itemx --compress-debug-sections=zlib-gabi For ELF files, these options control how DWARF debug sections are compressed. @option{--compress-debug-sections=none} is equivalent to @option{--decompress-debug-sections}. @option{--compress-debug-sections=zlib} and @option{--compress-debug-sections=zlib-gabi} are equivalent to @option{--compress-debug-sections}. @option{--compress-debug-sections=zlib-gnu} compresses DWARF debug sections using zlib. The debug sections are renamed to begin with @samp{.zdebug} instead of @samp{.debug}. Note - if compression would actually make a section @emph{larger}, then it is not compressed nor renamed. @item --decompress-debug-sections Decompress DWARF debug sections using zlib. The original section names of the compressed sections are restored. @item --elf-stt-common=yes @itemx --elf-stt-common=no For ELF files, these options control whether common symbols should be converted to the @code{STT_COMMON} or @code{STT_OBJECT} type. @option{--elf-stt-common=yes} converts common symbol type to @code{STT_COMMON}. @option{--elf-stt-common=no} converts common symbol type to @code{STT_OBJECT}. @item --merge-notes @itemx --no-merge-notes For ELF files, attempt (or do not attempt) to reduce the size of any SHT_NOTE type sections by removing duplicate notes. @item -V @itemx --version Show the version number of @command{objcopy}. @item --verilog-data-width=@var{bytes} For Verilog output, this options controls the number of bytes converted for each output data element. The input target controls the endianness of the conversion. @item -v @itemx --verbose Verbose output: list all object files modified. In the case of archives, @samp{objcopy -V} lists all members of the archive. @item --help Show a summary of the options to @command{objcopy}. @item --info Display a list showing all architectures and object formats available. @end table @c man end @ignore @c man begin SEEALSO objcopy ld(1), objdump(1), and the Info entries for @file{binutils}. @c man end @end ignore @node objdump @chapter objdump @cindex object file information @kindex objdump @c man title objdump display information from object files @smallexample @c man begin SYNOPSIS objdump objdump [@option{-a}|@option{--archive-headers}] [@option{-b} @var{bfdname}|@option{--target=@var{bfdname}}] [@option{-C}|@option{--demangle}[=@var{style}] ] [@option{-d}|@option{--disassemble}[=@var{symbol}]] [@option{-D}|@option{--disassemble-all}] [@option{-z}|@option{--disassemble-zeroes}] [@option{-EB}|@option{-EL}|@option{--endian=}@{big | little @}] [@option{-f}|@option{--file-headers}] [@option{-F}|@option{--file-offsets}] [@option{--file-start-context}] [@option{-g}|@option{--debugging}] [@option{-e}|@option{--debugging-tags}] [@option{-h}|@option{--section-headers}|@option{--headers}] [@option{-i}|@option{--info}] [@option{-j} @var{section}|@option{--section=}@var{section}] [@option{-l}|@option{--line-numbers}] [@option{-S}|@option{--source}] [@option{--source-comment}[=@var{text}]] [@option{-m} @var{machine}|@option{--architecture=}@var{machine}] [@option{-M} @var{options}|@option{--disassembler-options=}@var{options}] [@option{-p}|@option{--private-headers}] [@option{-P} @var{options}|@option{--private=}@var{options}] [@option{-r}|@option{--reloc}] [@option{-R}|@option{--dynamic-reloc}] [@option{-s}|@option{--full-contents}] [@option{-W[lLiaprmfFsoRtUuTgAckK]}| @option{--dwarf}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]] [@option{--ctf=}@var{section}] [@option{-G}|@option{--stabs}] [@option{-t}|@option{--syms}] [@option{-T}|@option{--dynamic-syms}] [@option{-x}|@option{--all-headers}] [@option{-w}|@option{--wide}] [@option{--start-address=}@var{address}] [@option{--stop-address=}@var{address}] [@option{--prefix-addresses}] [@option{--[no-]show-raw-insn}] [@option{--adjust-vma=}@var{offset}] [@option{--dwarf-depth=@var{n}}] [@option{--dwarf-start=@var{n}}] [@option{--ctf-parent=}@var{section}] [@option{--no-recurse-limit}|@option{--recurse-limit}] [@option{--special-syms}] [@option{--prefix=}@var{prefix}] [@option{--prefix-strip=}@var{level}] [@option{--insn-width=}@var{width}] [@option{--visualize-jumps[=color|=extended-color|=off]} [@option{-V}|@option{--version}] [@option{-H}|@option{--help}] @var{objfile}@dots{} @c man end @end smallexample @c man begin DESCRIPTION objdump @command{objdump} displays information about one or more object files. The options control what particular information to display. This information is mostly useful to programmers who are working on the compilation tools, as opposed to programmers who just want their program to compile and work. @var{objfile}@dots{} are the object files to be examined. When you specify archives, @command{objdump} shows information on each of the member object files. @c man end @c man begin OPTIONS objdump The long and short forms of options, shown here as alternatives, are equivalent. At least one option from the list @option{-a,-d,-D,-e,-f,-g,-G,-h,-H,-p,-P,-r,-R,-s,-S,-t,-T,-V,-x} must be given. @table @env @item -a @itemx --archive-header @cindex archive headers If any of the @var{objfile} files are archives, display the archive header information (in a format similar to @samp{ls -l}). Besides the information you could list with @samp{ar tv}, @samp{objdump -a} shows the object file format of each archive member. @item --adjust-vma=@var{offset} @cindex section addresses in objdump @cindex VMA in objdump When dumping information, first add @var{offset} to all the section addresses. This is useful if the section addresses do not correspond to the symbol table, which can happen when putting sections at particular addresses when using a format which can not represent section addresses, such as a.out. @item -b @var{bfdname} @itemx --target=@var{bfdname} @cindex object code format Specify that the object-code format for the object files is @var{bfdname}. This option may not be necessary; @var{objdump} can automatically recognize many formats. For example, @example objdump -b oasys -m vax -h fu.o @end example @noindent displays summary information from the section headers (@option{-h}) of @file{fu.o}, which is explicitly identified (@option{-m}) as a VAX object file in the format produced by Oasys compilers. You can list the formats available with the @option{-i} option. @xref{Target Selection}, for more information. @item -C @itemx --demangle[=@var{style}] @cindex demangling in objdump Decode (@dfn{demangle}) low-level symbol names into user-level names. Besides removing any initial underscore prepended by the system, this makes C++ function names readable. Different compilers have different mangling styles. The optional demangling style argument can be used to choose an appropriate demangling style for your compiler. @xref{c++filt}, for more information on demangling. @item --recurse-limit @itemx --no-recurse-limit @itemx --recursion-limit @itemx --no-recursion-limit Enables or disables a limit on the amount of recursion performed whilst demangling strings. Since the name mangling formats allow for an inifinite level of recursion it is possible to create strings whose decoding will exhaust the amount of stack space available on the host machine, triggering a memory fault. The limit tries to prevent this from happening by restricting recursion to 2048 levels of nesting. The default is for this limit to be enabled, but disabling it may be necessary in order to demangle truly complicated names. Note however that if the recursion limit is disabled then stack exhaustion is possible and any bug reports about such an event will be rejected. @item -g @itemx --debugging Display debugging information. This attempts to parse STABS debugging format information stored in the file and print it out using a C like syntax. If no STABS debuging was found this option falls back on the @option{-W} option to print any DWARF information in the file. @item -e @itemx --debugging-tags Like @option{-g}, but the information is generated in a format compatible with ctags tool. @item -d @itemx --disassemble @itemx --disassemble=@var{symbol} @cindex disassembling object code @cindex machine instructions Display the assembler mnemonics for the machine instructions from the input file. This option only disassembles those sections which are expected to contain instructions. If the optional @var{symbol} argument is given, then display the assembler mnemonics starting at @var{symbol}. If @var{symbol} is a function name then disassembly will stop at the end of the function, otherwise it will stop when the next symbol is encountered. If there are no matches for @var{symbol} then nothing will be displayed. Note if the @option{--dwarf=follow-links} option has also been enabled then any symbol tables in linked debug info files will be read in and used when disassembling. @item -D @itemx --disassemble-all Like @option{-d}, but disassemble the contents of all sections, not just those expected to contain instructions. This option also has a subtle effect on the disassembly of instructions in code sections. When option @option{-d} is in effect objdump will assume that any symbols present in a code section occur on the boundary between instructions and it will refuse to disassemble across such a boundary. When option @option{-D} is in effect however this assumption is supressed. This means that it is possible for the output of @option{-d} and @option{-D} to differ if, for example, data is stored in code sections. If the target is an ARM architecture this switch also has the effect of forcing the disassembler to decode pieces of data found in code sections as if they were instructions. Note if the @option{--dwarf=follow-links} option has also been enabled then any symbol tables in linked debug info files will be read in and used when disassembling. @item --prefix-addresses When disassembling, print the complete address on each line. This is the older disassembly format. @item -EB @itemx -EL @itemx --endian=@{big|little@} @cindex endianness @cindex disassembly endianness Specify the endianness of the object files. This only affects disassembly. This can be useful when disassembling a file format which does not describe endianness information, such as S-records. @item -f @itemx --file-headers @cindex object file header Display summary information from the overall header of each of the @var{objfile} files. @item -F @itemx --file-offsets @cindex object file offsets When disassembling sections, whenever a symbol is displayed, also display the file offset of the region of data that is about to be dumped. If zeroes are being skipped, then when disassembly resumes, tell the user how many zeroes were skipped and the file offset of the location from where the disassembly resumes. When dumping sections, display the file offset of the location from where the dump starts. @item --file-start-context @cindex source code context Specify that when displaying interlisted source code/disassembly (assumes @option{-S}) from a file that has not yet been displayed, extend the context to the start of the file. @item -h @itemx --section-headers @itemx --headers @cindex section headers Display summary information from the section headers of the object file. File segments may be relocated to nonstandard addresses, for example by using the @option{-Ttext}, @option{-Tdata}, or @option{-Tbss} options to @command{ld}. However, some object file formats, such as a.out, do not store the starting address of the file segments. In those situations, although @command{ld} relocates the sections correctly, using @samp{objdump -h} to list the file section headers cannot show the correct addresses. Instead, it shows the usual addresses, which are implicit for the target. Note, in some cases it is possible for a section to have both the READONLY and the NOREAD attributes set. In such cases the NOREAD attribute takes precedence, but @command{objdump} will report both since the exact setting of the flag bits might be important. @item -H @itemx --help Print a summary of the options to @command{objdump} and exit. @item -i @itemx --info @cindex architectures available @cindex object formats available Display a list showing all architectures and object formats available for specification with @option{-b} or @option{-m}. @item -j @var{name} @itemx --section=@var{name} @cindex section information Display information only for section @var{name}. @item -l @itemx --line-numbers @cindex source filenames for object files Label the display (using debugging information) with the filename and source line numbers corresponding to the object code or relocs shown. Only useful with @option{-d}, @option{-D}, or @option{-r}. @item -m @var{machine} @itemx --architecture=@var{machine} @cindex architecture @cindex disassembly architecture Specify the architecture to use when disassembling object files. This can be useful when disassembling object files which do not describe architecture information, such as S-records. You can list the available architectures with the @option{-i} option. If the target is an ARM architecture then this switch has an additional effect. It restricts the disassembly to only those instructions supported by the architecture specified by @var{machine}. If it is necessary to use this switch because the input file does not contain any architecture information, but it is also desired to disassemble all the instructions use @option{-marm}. @item -M @var{options} @itemx --disassembler-options=@var{options} Pass target specific information to the disassembler. Only supported on some targets. If it is necessary to specify more than one disassembler option then multiple @option{-M} options can be used or can be placed together into a comma separated list. For ARC, @option{dsp} controls the printing of DSP instructions, @option{spfp} selects the printing of FPX single precision FP instructions, @option{dpfp} selects the printing of FPX double precision FP instructions, @option{quarkse_em} selects the printing of special QuarkSE-EM instructions, @option{fpuda} selects the printing of double precision assist instructions, @option{fpus} selects the printing of FPU single precision FP instructions, while @option{fpud} selects the printing of FPU double precision FP instructions. Additionally, one can choose to have all the immediates printed in hexadecimal using @option{hex}. By default, the short immediates are printed using the decimal representation, while the long immediate values are printed as hexadecimal. @option{cpu=...} allows to enforce a particular ISA when disassembling instructions, overriding the @option{-m} value or whatever is in the ELF file. This might be useful to select ARC EM or HS ISA, because architecture is same for those and disassembler relies on private ELF header data to decide if code is for EM or HS. This option might be specified multiple times - only the latest value will be used. Valid values are same as for the assembler @option{-mcpu=...} option. If the target is an ARM architecture then this switch can be used to select which register name set is used during disassembler. Specifying @option{-M reg-names-std} (the default) will select the register names as used in ARM's instruction set documentation, but with register 13 called 'sp', register 14 called 'lr' and register 15 called 'pc'. Specifying @option{-M reg-names-apcs} will select the name set used by the ARM Procedure Call Standard, whilst specifying @option{-M reg-names-raw} will just use @samp{r} followed by the register number. There are also two variants on the APCS register naming scheme enabled by @option{-M reg-names-atpcs} and @option{-M reg-names-special-atpcs} which use the ARM/Thumb Procedure Call Standard naming conventions. (Either with the normal register names or the special register names). This option can also be used for ARM architectures to force the disassembler to interpret all instructions as Thumb instructions by using the switch @option{--disassembler-options=force-thumb}. This can be useful when attempting to disassemble thumb code produced by other compilers. For AArch64 targets this switch can be used to set whether instructions are disassembled as the most general instruction using the @option{-M no-aliases} option or whether instruction notes should be generated as comments in the disasssembly using @option{-M notes}. For the x86, some of the options duplicate functions of the @option{-m} switch, but allow finer grained control. Multiple selections from the following may be specified as a comma separated string. @table @code @item x86-64 @itemx i386 @itemx i8086 Select disassembly for the given architecture. @item intel @itemx att Select between intel syntax mode and AT&T syntax mode. @item amd64 @itemx intel64 Select between AMD64 ISA and Intel64 ISA. @item intel-mnemonic @itemx att-mnemonic Select between intel mnemonic mode and AT&T mnemonic mode. Note: @code{intel-mnemonic} implies @code{intel} and @code{att-mnemonic} implies @code{att}. @item addr64 @itemx addr32 @itemx addr16 @itemx data32 @itemx data16 Specify the default address size and operand size. These five options will be overridden if @code{x86-64}, @code{i386} or @code{i8086} appear later in the option string. @item suffix When in AT&T mode, instructs the disassembler to print a mnemonic suffix even when the suffix could be inferred by the operands. @end table For PowerPC, the @option{-M} argument @option{raw} selects disasssembly of hardware insns rather than aliases. For example, you will see @code{rlwinm} rather than @code{clrlwi}, and @code{addi} rather than @code{li}. All of the @option{-m} arguments for @command{gas} that select a CPU are supported. These are: @option{403}, @option{405}, @option{440}, @option{464}, @option{476}, @option{601}, @option{603}, @option{604}, @option{620}, @option{7400}, @option{7410}, @option{7450}, @option{7455}, @option{750cl}, @option{821}, @option{850}, @option{860}, @option{a2}, @option{booke}, @option{booke32}, @option{cell}, @option{com}, @option{e200z4}, @option{e300}, @option{e500}, @option{e500mc}, @option{e500mc64}, @option{e500x2}, @option{e5500}, @option{e6500}, @option{efs}, @option{power4}, @option{power5}, @option{power6}, @option{power7}, @option{power8}, @option{power9}, @option{ppc}, @option{ppc32}, @option{ppc64}, @option{ppc64bridge}, @option{ppcps}, @option{pwr}, @option{pwr2}, @option{pwr4}, @option{pwr5}, @option{pwr5x}, @option{pwr6}, @option{pwr7}, @option{pwr8}, @option{pwr9}, @option{pwrx}, @option{titan}, and @option{vle}. @option{32} and @option{64} modify the default or a prior CPU selection, disabling and enabling 64-bit insns respectively. In addition, @option{altivec}, @option{any}, @option{htm}, @option{vsx}, and @option{spe} add capabilities to a previous @emph{or later} CPU selection. @option{any} will disassemble any opcode known to binutils, but in cases where an opcode has two different meanings or different arguments, you may not see the disassembly you expect. If you disassemble without giving a CPU selection, a default will be chosen from information gleaned by BFD from the object files headers, but the result again may not be as you expect. For MIPS, this option controls the printing of instruction mnemonic names and register names in disassembled instructions. Multiple selections from the following may be specified as a comma separated string, and invalid options are ignored: @table @code @item no-aliases Print the 'raw' instruction mnemonic instead of some pseudo instruction mnemonic. I.e., print 'daddu' or 'or' instead of 'move', 'sll' instead of 'nop', etc. @item msa Disassemble MSA instructions. @item virt Disassemble the virtualization ASE instructions. @item xpa Disassemble the eXtended Physical Address (XPA) ASE instructions. @item gpr-names=@var{ABI} Print GPR (general-purpose register) names as appropriate for the specified ABI. By default, GPR names are selected according to the ABI of the binary being disassembled. @item fpr-names=@var{ABI} Print FPR (floating-point register) names as appropriate for the specified ABI. By default, FPR numbers are printed rather than names. @item cp0-names=@var{ARCH} Print CP0 (system control coprocessor; coprocessor 0) register names as appropriate for the CPU or architecture specified by @var{ARCH}. By default, CP0 register names are selected according to the architecture and CPU of the binary being disassembled. @item hwr-names=@var{ARCH} Print HWR (hardware register, used by the @code{rdhwr} instruction) names as appropriate for the CPU or architecture specified by @var{ARCH}. By default, HWR names are selected according to the architecture and CPU of the binary being disassembled. @item reg-names=@var{ABI} Print GPR and FPR names as appropriate for the selected ABI. @item reg-names=@var{ARCH} Print CPU-specific register names (CP0 register and HWR names) as appropriate for the selected CPU or architecture. @end table For any of the options listed above, @var{ABI} or @var{ARCH} may be specified as @samp{numeric} to have numbers printed rather than names, for the selected types of registers. You can list the available values of @var{ABI} and @var{ARCH} using the @option{--help} option. For VAX, you can specify function entry addresses with @option{-M entry:0xf00ba}. You can use this multiple times to properly disassemble VAX binary files that don't contain symbol tables (like ROM dumps). In these cases, the function entry mask would otherwise be decoded as VAX instructions, which would probably lead the rest of the function being wrongly disassembled. @item -p @itemx --private-headers Print information that is specific to the object file format. The exact information printed depends upon the object file format. For some object file formats, no additional information is printed. @item -P @var{options} @itemx --private=@var{options} Print information that is specific to the object file format. The argument @var{options} is a comma separated list that depends on the format (the lists of options is displayed with the help). For XCOFF, the available options are: @table @code @item header @item aout @item sections @item syms @item relocs @item lineno, @item loader @item except @item typchk @item traceback @item toc @item ldinfo @end table Not all object formats support this option. In particular the ELF format does not use it. @item -r @itemx --reloc @cindex relocation entries, in object file Print the relocation entries of the file. If used with @option{-d} or @option{-D}, the relocations are printed interspersed with the disassembly. @item -R @itemx --dynamic-reloc @cindex dynamic relocation entries, in object file Print the dynamic relocation entries of the file. This is only meaningful for dynamic objects, such as certain types of shared libraries. As for @option{-r}, if used with @option{-d} or @option{-D}, the relocations are printed interspersed with the disassembly. @item -s @itemx --full-contents @cindex sections, full contents @cindex object file sections Display the full contents of any sections requested. By default all non-empty sections are displayed. @item -S @itemx --source @cindex source disassembly @cindex disassembly, with source Display source code intermixed with disassembly, if possible. Implies @option{-d}. @item --source-comment[=@var{txt}] @cindex source disassembly @cindex disassembly, with source Like the @option{-S} option, but all source code lines are displayed with a prefix of @var{txt}. Typically @var{txt} will be a comment string which can be used to distinguish the assembler code from the source code. If @var{txt} is not provided then a default string of @var{``# ``} (hash followed by a space), will be used. @item --prefix=@var{prefix} @cindex Add prefix to absolute paths Specify @var{prefix} to add to the absolute paths when used with @option{-S}. @item --prefix-strip=@var{level} @cindex Strip absolute paths Indicate how many initial directory names to strip off the hardwired absolute paths. It has no effect without @option{--prefix=}@var{prefix}. @item --show-raw-insn When disassembling instructions, print the instruction in hex as well as in symbolic form. This is the default except when @option{--prefix-addresses} is used. @item --no-show-raw-insn When disassembling instructions, do not print the instruction bytes. This is the default when @option{--prefix-addresses} is used. @item --insn-width=@var{width} @cindex Instruction width Display @var{width} bytes on a single line when disassembling instructions. @item --visualize-jumps[=color|=extended-color|=off] Visualize jumps that stay inside a function by drawing ASCII art between the start and target addresses. The optional @option{=color} argument adds color to the output using simple terminal colors. Alternatively the @option{=extended-color} argument will add color using 8bit colors, but these might not work on all terminals. If it is necessary to disable the @option{visualize-jumps} option after it has previously been enabled then use @option{visualize-jumps=off}. @item -W[lLiaprmfFsoRtUuTgAckK] @itemx --dwarf[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links] @include debug.options.texi @item --dwarf-check Enable additional checks for consistency of Dwarf information. @include ctf.options.texi @item -G @itemx --stabs @cindex stab @cindex .stab @cindex debug symbols @cindex ELF object file format Display the full contents of any sections requested. Display the contents of the .stab and .stab.index and .stab.excl sections from an ELF file. This is only useful on systems (such as Solaris 2.0) in which @code{.stab} debugging symbol-table entries are carried in an ELF section. In most other file formats, debugging symbol-table entries are interleaved with linkage symbols, and are visible in the @option{--syms} output. @item --start-address=@var{address} @cindex start-address Start displaying data at the specified address. This affects the output of the @option{-d}, @option{-r} and @option{-s} options. @item --stop-address=@var{address} @cindex stop-address Stop displaying data at the specified address. This affects the output of the @option{-d}, @option{-r} and @option{-s} options. @item -t @itemx --syms @cindex symbol table entries, printing Print the symbol table entries of the file. This is similar to the information provided by the @samp{nm} program, although the display format is different. The format of the output depends upon the format of the file being dumped, but there are two main types. One looks like this: @smallexample [ 4](sec 3)(fl 0x00)(ty 0)(scl 3) (nx 1) 0x00000000 .bss [ 6](sec 1)(fl 0x00)(ty 0)(scl 2) (nx 0) 0x00000000 fred @end smallexample where the number inside the square brackets is the number of the entry in the symbol table, the @var{sec} number is the section number, the @var{fl} value are the symbol's flag bits, the @var{ty} number is the symbol's type, the @var{scl} number is the symbol's storage class and the @var{nx} value is the number of auxilary entries associated with the symbol. The last two fields are the symbol's value and its name. The other common output format, usually seen with ELF based files, looks like this: @smallexample 00000000 l d .bss 00000000 .bss 00000000 g .text 00000000 fred @end smallexample Here the first number is the symbol's value (sometimes refered to as its address). The next field is actually a set of characters and spaces indicating the flag bits that are set on the symbol. These characters are described below. Next is the section with which the symbol is associated or @emph{*ABS*} if the section is absolute (ie not connected with any section), or @emph{*UND*} if the section is referenced in the file being dumped, but not defined there. After the section name comes another field, a number, which for common symbols is the alignment and for other symbol is the size. Finally the symbol's name is displayed. The flag characters are divided into 7 groups as follows: @table @code @item l @itemx g @itemx u @itemx ! The symbol is a local (l), global (g), unique global (u), neither global nor local (a space) or both global and local (!). A symbol can be neither local or global for a variety of reasons, e.g., because it is used for debugging, but it is probably an indication of a bug if it is ever both local and global. Unique global symbols are a GNU extension to the standard set of ELF symbol bindings. For such a symbol the dynamic linker will make sure that in the entire process there is just one symbol with this name and type in use. @item w The symbol is weak (w) or strong (a space). @item C The symbol denotes a constructor (C) or an ordinary symbol (a space). @item W The symbol is a warning (W) or a normal symbol (a space). A warning symbol's name is a message to be displayed if the symbol following the warning symbol is ever referenced. @item I @item i The symbol is an indirect reference to another symbol (I), a function to be evaluated during reloc processing (i) or a normal symbol (a space). @item d @itemx D The symbol is a debugging symbol (d) or a dynamic symbol (D) or a normal symbol (a space). @item F @item f @item O The symbol is the name of a function (F) or a file (f) or an object (O) or just a normal symbol (a space). @end table @item -T @itemx --dynamic-syms @cindex dynamic symbol table entries, printing Print the dynamic symbol table entries of the file. This is only meaningful for dynamic objects, such as certain types of shared libraries. This is similar to the information provided by the @samp{nm} program when given the @option{-D} (@option{--dynamic}) option. The output format is similar to that produced by the @option{--syms} option, except that an extra field is inserted before the symbol's name, giving the version information associated with the symbol. If the version is the default version to be used when resolving unversioned references to the symbol then it's displayed as is, otherwise it's put into parentheses. @item --special-syms When displaying symbols include those which the target considers to be special in some way and which would not normally be of interest to the user. @item -V @itemx --version Print the version number of @command{objdump} and exit. @item -x @itemx --all-headers @cindex all header information, object file @cindex header information, all Display all available header information, including the symbol table and relocation entries. Using @option{-x} is equivalent to specifying all of @option{-a -f -h -p -r -t}. @item -w @itemx --wide @cindex wide output, printing Format some lines for output devices that have more than 80 columns. Also do not truncate symbol names when they are displayed. @item -z @itemx --disassemble-zeroes Normally the disassembly output will skip blocks of zeroes. This option directs the disassembler to disassemble those blocks, just like any other data. @end table @c man end @ignore @c man begin SEEALSO objdump nm(1), readelf(1), and the Info entries for @file{binutils}. @c man end @end ignore @node ranlib @chapter ranlib @kindex ranlib @cindex archive contents @cindex symbol index @c man title ranlib generate an index to an archive @smallexample @c man begin SYNOPSIS ranlib ranlib [@option{--plugin} @var{name}] [@option{-DhHvVt}] @var{archive} @c man end @end smallexample @c man begin DESCRIPTION ranlib @command{ranlib} generates an index to the contents of an archive and stores it in the archive. The index lists each symbol defined by a member of an archive that is a relocatable object file. You may use @samp{nm -s} or @samp{nm --print-armap} to list this index. An archive with such an index speeds up linking to the library and allows routines in the library to call each other without regard to their placement in the archive. The @sc{gnu} @command{ranlib} program is another form of @sc{gnu} @command{ar}; running @command{ranlib} is completely equivalent to executing @samp{ar -s}. @xref{ar}. @c man end @c man begin OPTIONS ranlib @table @env @item -h @itemx -H @itemx --help Show usage information for @command{ranlib}. @item -v @itemx -V @itemx --version Show the version number of @command{ranlib}. @item -D @cindex deterministic archives @kindex --enable-deterministic-archives Operate in @emph{deterministic} mode. The symbol map archive member's header will show zero for the UID, GID, and timestamp. When this option is used, multiple runs will produce identical output files. If @file{binutils} was configured with @option{--enable-deterministic-archives}, then this mode is on by default. It can be disabled with the @samp{-U} option, described below. @item -t Update the timestamp of the symbol map of an archive. @item -U @cindex deterministic archives @kindex --enable-deterministic-archives Do @emph{not} operate in @emph{deterministic} mode. This is the inverse of the @samp{-D} option, above: the archive index will get actual UID, GID, timestamp, and file mode values. If @file{binutils} was configured @emph{without} @option{--enable-deterministic-archives}, then this mode is on by default. @end table @c man end @ignore @c man begin SEEALSO ranlib ar(1), nm(1), and the Info entries for @file{binutils}. @c man end @end ignore @node size @chapter size @kindex size @cindex section sizes @c man title size list section sizes and total size of binary files @smallexample @c man begin SYNOPSIS size size [@option{-A}|@option{-B}|@option{-G}|@option{--format=}@var{compatibility}] [@option{--help}] [@option{-d}|@option{-o}|@option{-x}|@option{--radix=}@var{number}] [@option{--common}] [@option{-t}|@option{--totals}] [@option{--target=}@var{bfdname}] [@option{-V}|@option{--version}] [@var{objfile}@dots{}] @c man end @end smallexample @c man begin DESCRIPTION size The @sc{gnu} @command{size} utility lists the section sizes and the total size for each of the binary files @var{objfile} on its argument list. By default, one line of output is generated for each file or each module if the file is an archive. @var{objfile}@dots{} are the files to be examined. If none are specified, the file @code{a.out} will be used instead. @c man end @c man begin OPTIONS size The command-line options have the following meanings: @table @env @item -A @itemx -B @itemx -G @itemx --format=@var{compatibility} @cindex @command{size} display format Using one of these options, you can choose whether the output from @sc{gnu} @command{size} resembles output from System V @command{size} (using @option{-A}, or @option{--format=sysv}), or Berkeley @command{size} (using @option{-B}, or @option{--format=berkeley}). The default is the one-line format similar to Berkeley's. Alternatively, you can choose the GNU format output (using @option{-G}, or @option{--format=gnu}), this is similar to Berkeley's output format, but sizes are counted differently. @c Bonus for doc-source readers: you can also say --format=strange (or @c anything else that starts with 's') for sysv, and --format=boring (or @c anything else that starts with 'b') for Berkeley. Here is an example of the Berkeley (default) format of output from @command{size}: @smallexample $ size --format=Berkeley ranlib size text data bss dec hex filename 294880 81920 11592 388392 5ed28 ranlib 294880 81920 11888 388688 5ee50 size @end smallexample The Berkeley style output counts read only data in the @code{text} column, not in the @code{data} column, the @code{dec} and @code{hex} columns both display the sum of the @code{text}, @code{data}, and @code{bss} columns in decimal and hexadecimal respectively. The GNU format counts read only data in the @code{data} column, not the @code{text} column, and only displays the sum of the @code{text}, @code{data}, and @code{bss} columns once, in the @code{total} column. The @option{--radix} option can be used to change the number base for all columns. Here is the same data displayed with GNU conventions: @smallexample $ size --format=GNU ranlib size text data bss total filename 279880 96920 11592 388392 ranlib 279880 96920 11888 388688 size @end smallexample @noindent This is the same data, but displayed closer to System V conventions: @smallexample $ size --format=SysV ranlib size ranlib : section size addr .text 294880 8192 .data 81920 303104 .bss 11592 385024 Total 388392 size : section size addr .text 294880 8192 .data 81920 303104 .bss 11888 385024 Total 388688 @end smallexample @item --help Show a summary of acceptable arguments and options. @item -d @itemx -o @itemx -x @itemx --radix=@var{number} @cindex @command{size} number format @cindex radix for section sizes Using one of these options, you can control whether the size of each section is given in decimal (@option{-d}, or @option{--radix=10}); octal (@option{-o}, or @option{--radix=8}); or hexadecimal (@option{-x}, or @option{--radix=16}). In @option{--radix=@var{number}}, only the three values (8, 10, 16) are supported. The total size is always given in two radices; decimal and hexadecimal for @option{-d} or @option{-x} output, or octal and hexadecimal if you're using @option{-o}. @item --common Print total size of common symbols in each file. When using Berkeley or GNU format these are included in the bss size. @item -t @itemx --totals Show totals of all objects listed (Berkeley or GNU format mode only). @item --target=@var{bfdname} @cindex object code format Specify that the object-code format for @var{objfile} is @var{bfdname}. This option may not be necessary; @command{size} can automatically recognize many formats. @xref{Target Selection}, for more information. @item -V @itemx --version Display the version number of @command{size}. @end table @c man end @ignore @c man begin SEEALSO size ar(1), objdump(1), readelf(1), and the Info entries for @file{binutils}. @c man end @end ignore @node strings @chapter strings @kindex strings @cindex listings strings @cindex printing strings @cindex strings, printing @c man title strings print the sequences of printable characters in files @smallexample @c man begin SYNOPSIS strings strings [@option{-afovV}] [@option{-}@var{min-len}] [@option{-n} @var{min-len}] [@option{--bytes=}@var{min-len}] [@option{-t} @var{radix}] [@option{--radix=}@var{radix}] [@option{-e} @var{encoding}] [@option{--encoding=}@var{encoding}] [@option{-}] [@option{--all}] [@option{--print-file-name}] [@option{-T} @var{bfdname}] [@option{--target=}@var{bfdname}] [@option{-w}] [@option{--include-all-whitespace}] [@option{-s}] [@option{--output-separator}@var{sep_string}] [@option{--help}] [@option{--version}] @var{file}@dots{} @c man end @end smallexample @c man begin DESCRIPTION strings For each @var{file} given, @sc{gnu} @command{strings} prints the printable character sequences that are at least 4 characters long (or the number given with the options below) and are followed by an unprintable character. Depending upon how the strings program was configured it will default to either displaying all the printable sequences that it can find in each file, or only those sequences that are in loadable, initialized data sections. If the file type in unrecognizable, or if strings is reading from stdin then it will always display all of the printable sequences that it can find. For backwards compatibility any file that occurs after a command-line option of just @option{-} will also be scanned in full, regardless of the presence of any @option{-d} option. @command{strings} is mainly useful for determining the contents of non-text files. @c man end @c man begin OPTIONS strings @table @env @item -a @itemx --all @itemx - Scan the whole file, regardless of what sections it contains or whether those sections are loaded or initialized. Normally this is the default behaviour, but strings can be configured so that the @option{-d} is the default instead. The @option{-} option is position dependent and forces strings to perform full scans of any file that is mentioned after the @option{-} on the command line, even if the @option{-d} option has been specified. @item -d @itemx --data Only print strings from initialized, loaded data sections in the file. This may reduce the amount of garbage in the output, but it also exposes the strings program to any security flaws that may be present in the BFD library used to scan and load sections. Strings can be configured so that this option is the default behaviour. In such cases the @option{-a} option can be used to avoid using the BFD library and instead just print all of the strings found in the file. @item -f @itemx --print-file-name Print the name of the file before each string. @item --help Print a summary of the program usage on the standard output and exit. @item -@var{min-len} @itemx -n @var{min-len} @itemx --bytes=@var{min-len} Print sequences of characters that are at least @var{min-len} characters long, instead of the default 4. @item -o Like @samp{-t o}. Some other versions of @command{strings} have @option{-o} act like @samp{-t d} instead. Since we can not be compatible with both ways, we simply chose one. @item -t @var{radix} @itemx --radix=@var{radix} Print the offset within the file before each string. The single character argument specifies the radix of the offset---@samp{o} for octal, @samp{x} for hexadecimal, or @samp{d} for decimal. @item -e @var{encoding} @itemx --encoding=@var{encoding} Select the character encoding of the strings that are to be found. Possible values for @var{encoding} are: @samp{s} = single-7-bit-byte characters (ASCII, ISO 8859, etc., default), @samp{S} = single-8-bit-byte characters, @samp{b} = 16-bit bigendian, @samp{l} = 16-bit littleendian, @samp{B} = 32-bit bigendian, @samp{L} = 32-bit littleendian. Useful for finding wide character strings. (@samp{l} and @samp{b} apply to, for example, Unicode UTF-16/UCS-2 encodings). @item -T @var{bfdname} @itemx --target=@var{bfdname} @cindex object code format Specify an object code format other than your system's default format. @xref{Target Selection}, for more information. @item -v @itemx -V @itemx --version Print the program version number on the standard output and exit. @item -w @itemx --include-all-whitespace By default tab and space characters are included in the strings that are displayed, but other whitespace characters, such a newlines and carriage returns, are not. The @option{-w} option changes this so that all whitespace characters are considered to be part of a string. @item -s @itemx --output-separator By default, output strings are delimited by a new-line. This option allows you to supply any string to be used as the output record separator. Useful with --include-all-whitespace where strings may contain new-lines internally. @end table @c man end @ignore @c man begin SEEALSO strings ar(1), nm(1), objdump(1), ranlib(1), readelf(1) and the Info entries for @file{binutils}. @c man end @end ignore @node strip @chapter strip @kindex strip @cindex removing symbols @cindex discarding symbols @cindex symbols, discarding @c man title strip discard symbols and other data from object files @smallexample @c man begin SYNOPSIS strip strip [@option{-F} @var{bfdname} |@option{--target=}@var{bfdname}] [@option{-I} @var{bfdname} |@option{--input-target=}@var{bfdname}] [@option{-O} @var{bfdname} |@option{--output-target=}@var{bfdname}] [@option{-s}|@option{--strip-all}] [@option{-S}|@option{-g}|@option{-d}|@option{--strip-debug}] [@option{--strip-dwo}] [@option{-K} @var{symbolname}|@option{--keep-symbol=}@var{symbolname}] [@option{-M}|@option{--merge-notes}][@option{--no-merge-notes}] [@option{-N} @var{symbolname} |@option{--strip-symbol=}@var{symbolname}] [@option{-w}|@option{--wildcard}] [@option{-x}|@option{--discard-all}] [@option{-X} |@option{--discard-locals}] [@option{-R} @var{sectionname} |@option{--remove-section=}@var{sectionname}] [@option{--keep-section=}@var{sectionpattern}] [@option{--remove-relocations=}@var{sectionpattern}] [@option{-o} @var{file}] [@option{-p}|@option{--preserve-dates}] [@option{-D}|@option{--enable-deterministic-archives}] [@option{-U}|@option{--disable-deterministic-archives}] [@option{--keep-file-symbols}] [@option{--only-keep-debug}] [@option{-v} |@option{--verbose}] [@option{-V}|@option{--version}] [@option{--help}] [@option{--info}] @var{objfile}@dots{} @c man end @end smallexample @c man begin DESCRIPTION strip @sc{gnu} @command{strip} discards all symbols from object files @var{objfile}. The list of object files may include archives. At least one object file must be given. @command{strip} modifies the files named in its argument, rather than writing modified copies under different names. @c man end @c man begin OPTIONS strip @table @env @item -F @var{bfdname} @itemx --target=@var{bfdname} Treat the original @var{objfile} as a file with the object code format @var{bfdname}, and rewrite it in the same format. @xref{Target Selection}, for more information. @item --help Show a summary of the options to @command{strip} and exit. @item --info Display a list showing all architectures and object formats available. @item -I @var{bfdname} @itemx --input-target=@var{bfdname} Treat the original @var{objfile} as a file with the object code format @var{bfdname}. @xref{Target Selection}, for more information. @item -O @var{bfdname} @itemx --output-target=@var{bfdname} Replace @var{objfile} with a file in the output format @var{bfdname}. @xref{Target Selection}, for more information. @item -R @var{sectionname} @itemx --remove-section=@var{sectionname} Remove any section named @var{sectionname} from the output file, in addition to whatever sections would otherwise be removed. This option may be given more than once. Note that using this option inappropriately may make the output file unusable. The wildcard character @samp{*} may be given at the end of @var{sectionname}. If so, then any section starting with @var{sectionname} will be removed. If the first character of @var{sectionpattern} is the exclamation point (!) then matching sections will not be removed even if an earlier use of @option{--remove-section} on the same command line would otherwise remove it. For example: @smallexample --remove-section=.text.* --remove-section=!.text.foo @end smallexample will remove all sections matching the pattern '.text.*', but will not remove the section '.text.foo'. @item --keep-section=@var{sectionpattern} When removing sections from the output file, keep sections that match @var{sectionpattern}. @item --remove-relocations=@var{sectionpattern} Remove relocations from the output file for any section matching @var{sectionpattern}. This option may be given more than once. Note that using this option inappropriately may make the output file unusable. Wildcard characters are accepted in @var{sectionpattern}. For example: @smallexample --remove-relocations=.text.* @end smallexample will remove the relocations for all sections matching the patter '.text.*'. If the first character of @var{sectionpattern} is the exclamation point (!) then matching sections will not have their relocation removed even if an earlier use of @option{--remove-relocations} on the same command line would otherwise cause the relocations to be removed. For example: @smallexample --remove-relocations=.text.* --remove-relocations=!.text.foo @end smallexample will remove all relocations for sections matching the pattern '.text.*', but will not remove relocations for the section '.text.foo'. @item -s @itemx --strip-all Remove all symbols. @item -g @itemx -S @itemx -d @itemx --strip-debug Remove debugging symbols only. @item --strip-dwo Remove the contents of all DWARF .dwo sections, leaving the remaining debugging sections and all symbols intact. See the description of this option in the @command{objcopy} section for more information. @item --strip-unneeded Remove all symbols that are not needed for relocation processing. @item -K @var{symbolname} @itemx --keep-symbol=@var{symbolname} When stripping symbols, keep symbol @var{symbolname} even if it would normally be stripped. This option may be given more than once. @item -M @itemx --merge-notes @itemx --no-merge-notes For ELF files, attempt (or do not attempt) to reduce the size of any SHT_NOTE type sections by removing duplicate notes. The default is to attempt this reduction unless stripping debug or DWO information. @item -N @var{symbolname} @itemx --strip-symbol=@var{symbolname} Remove symbol @var{symbolname} from the source file. This option may be given more than once, and may be combined with strip options other than @option{-K}. @item -o @var{file} Put the stripped output in @var{file}, rather than replacing the existing file. When this argument is used, only one @var{objfile} argument may be specified. @item -p @itemx --preserve-dates Preserve the access and modification dates of the file. @item -D @itemx --enable-deterministic-archives @cindex deterministic archives @kindex --enable-deterministic-archives Operate in @emph{deterministic} mode. When copying archive members and writing the archive index, use zero for UIDs, GIDs, timestamps, and use consistent file modes for all files. If @file{binutils} was configured with @option{--enable-deterministic-archives}, then this mode is on by default. It can be disabled with the @samp{-U} option, below. @item -U @itemx --disable-deterministic-archives @cindex deterministic archives @kindex --enable-deterministic-archives Do @emph{not} operate in @emph{deterministic} mode. This is the inverse of the @option{-D} option, above: when copying archive members and writing the archive index, use their actual UID, GID, timestamp, and file mode values. This is the default unless @file{binutils} was configured with @option{--enable-deterministic-archives}. @item -w @itemx --wildcard Permit regular expressions in @var{symbolname}s used in other command line options. The question mark (?), asterisk (*), backslash (\) and square brackets ([]) operators can be used anywhere in the symbol name. If the first character of the symbol name is the exclamation point (!) then the sense of the switch is reversed for that symbol. For example: @smallexample -w -K !foo -K fo* @end smallexample would cause strip to only keep symbols that start with the letters ``fo'', but to discard the symbol ``foo''. @item -x @itemx --discard-all Remove non-global symbols. @item -X @itemx --discard-locals Remove compiler-generated local symbols. (These usually start with @samp{L} or @samp{.}.) @item --keep-file-symbols When stripping a file, perhaps with @option{--strip-debug} or @option{--strip-unneeded}, retain any symbols specifying source file names, which would otherwise get stripped. @item --only-keep-debug Strip a file, emptying the contents of any sections that would not be stripped by @option{--strip-debug} and leaving the debugging sections intact. In ELF files, this preserves all the note sections in the output as well. Note - the section headers of the stripped sections are preserved, including their sizes, but the contents of the section are discarded. The section headers are preserved so that other tools can match up the debuginfo file with the real executable, even if that executable has been relocated to a different address space. The intention is that this option will be used in conjunction with @option{--add-gnu-debuglink} to create a two part executable. One a stripped binary which will occupy less space in RAM and in a distribution and the second a debugging information file which is only needed if debugging abilities are required. The suggested procedure to create these files is as follows: @enumerate @item Link the executable as normal. Assuming that it is called @code{foo} then... @item Run @code{objcopy --only-keep-debug foo foo.dbg} to create a file containing the debugging info. @item Run @code{objcopy --strip-debug foo} to create a stripped executable. @item Run @code{objcopy --add-gnu-debuglink=foo.dbg foo} to add a link to the debugging info into the stripped executable. @end enumerate Note---the choice of @code{.dbg} as an extension for the debug info file is arbitrary. Also the @code{--only-keep-debug} step is optional. You could instead do this: @enumerate @item Link the executable as normal. @item Copy @code{foo} to @code{foo.full} @item Run @code{strip --strip-debug foo} @item Run @code{objcopy --add-gnu-debuglink=foo.full foo} @end enumerate i.e., the file pointed to by the @option{--add-gnu-debuglink} can be the full executable. It does not have to be a file created by the @option{--only-keep-debug} switch. Note---this switch is only intended for use on fully linked files. It does not make sense to use it on object files where the debugging information may be incomplete. Besides the gnu_debuglink feature currently only supports the presence of one filename containing debugging information, not multiple filenames on a one-per-object-file basis. @item -V @itemx --version Show the version number for @command{strip}. @item -v @itemx --verbose Verbose output: list all object files modified. In the case of archives, @samp{strip -v} lists all members of the archive. @end table @c man end @ignore @c man begin SEEALSO strip the Info entries for @file{binutils}. @c man end @end ignore @node c++filt, addr2line, strip, Top @chapter c++filt @kindex c++filt @cindex demangling C++ symbols @c man title cxxfilt demangle C++ and Java symbols @smallexample @c man begin SYNOPSIS cxxfilt c++filt [@option{-_}|@option{--strip-underscore}] [@option{-n}|@option{--no-strip-underscore}] [@option{-p}|@option{--no-params}] [@option{-t}|@option{--types}] [@option{-i}|@option{--no-verbose}] [@option{-r}|@option{--no-recurse-limit}] [@option{-R}|@option{--recurse-limit}] [@option{-s} @var{format}|@option{--format=}@var{format}] [@option{--help}] [@option{--version}] [@var{symbol}@dots{}] @c man end @end smallexample @c man begin DESCRIPTION cxxfilt @kindex cxxfilt The C++ and Java languages provide function overloading, which means that you can write many functions with the same name, providing that each function takes parameters of different types. In order to be able to distinguish these similarly named functions C++ and Java encode them into a low-level assembler name which uniquely identifies each different version. This process is known as @dfn{mangling}. The @command{c++filt} @footnote{MS-DOS does not allow @kbd{+} characters in file names, so on MS-DOS this program is named @command{CXXFILT}.} program does the inverse mapping: it decodes (@dfn{demangles}) low-level names into user-level names so that they can be read. Every alphanumeric word (consisting of letters, digits, underscores, dollars, or periods) seen in the input is a potential mangled name. If the name decodes into a C++ name, the C++ name replaces the low-level name in the output, otherwise the original word is output. In this way you can pass an entire assembler source file, containing mangled names, through @command{c++filt} and see the same source file containing demangled names. You can also use @command{c++filt} to decipher individual symbols by passing them on the command line: @example c++filt @var{symbol} @end example If no @var{symbol} arguments are given, @command{c++filt} reads symbol names from the standard input instead. All the results are printed on the standard output. The difference between reading names from the command line versus reading names from the standard input is that command-line arguments are expected to be just mangled names and no checking is performed to separate them from surrounding text. Thus for example: @smallexample c++filt -n _Z1fv @end smallexample will work and demangle the name to ``f()'' whereas: @smallexample c++filt -n _Z1fv, @end smallexample will not work. (Note the extra comma at the end of the mangled name which makes it invalid). This command however will work: @smallexample echo _Z1fv, | c++filt -n @end smallexample and will display ``f(),'', i.e., the demangled name followed by a trailing comma. This behaviour is because when the names are read from the standard input it is expected that they might be part of an assembler source file where there might be extra, extraneous characters trailing after a mangled name. For example: @smallexample .type _Z1fv, @@function @end smallexample @c man end @c man begin OPTIONS cxxfilt @table @env @item -_ @itemx --strip-underscore On some systems, both the C and C++ compilers put an underscore in front of every name. For example, the C name @code{foo} gets the low-level name @code{_foo}. This option removes the initial underscore. Whether @command{c++filt} removes the underscore by default is target dependent. @item -n @itemx --no-strip-underscore Do not remove the initial underscore. @item -p @itemx --no-params When demangling the name of a function, do not display the types of the function's parameters. @item -t @itemx --types Attempt to demangle types as well as function names. This is disabled by default since mangled types are normally only used internally in the compiler, and they can be confused with non-mangled names. For example, a function called ``a'' treated as a mangled type name would be demangled to ``signed char''. @item -i @itemx --no-verbose Do not include implementation details (if any) in the demangled output. @item -r @itemx -R @itemx --recurse-limit @itemx --no-recurse-limit @itemx --recursion-limit @itemx --no-recursion-limit Enables or disables a limit on the amount of recursion performed whilst demangling strings. Since the name mangling formats allow for an inifinite level of recursion it is possible to create strings whose decoding will exhaust the amount of stack space available on the host machine, triggering a memory fault. The limit tries to prevent this from happening by restricting recursion to 2048 levels of nesting. The default is for this limit to be enabled, but disabling it may be necessary in order to demangle truly complicated names. Note however that if the recursion limit is disabled then stack exhaustion is possible and any bug reports about such an event will be rejected. The @option{-r} option is a synonym for the @option{--no-recurse-limit} option. The @option{-R} option is a synonym for the @option{--recurse-limit} option. @item -s @var{format} @itemx --format=@var{format} @command{c++filt} can decode various methods of mangling, used by different compilers. The argument to this option selects which method it uses: @table @code @item auto Automatic selection based on executable (the default method) @item gnu the one used by the @sc{gnu} C++ compiler (g++) @item lucid the one used by the Lucid compiler (lcc) @item arm the one specified by the C++ Annotated Reference Manual @item hp the one used by the HP compiler (aCC) @item edg the one used by the EDG compiler @item gnu-v3 the one used by the @sc{gnu} C++ compiler (g++) with the V3 ABI. @item java the one used by the @sc{gnu} Java compiler (gcj) @item gnat the one used by the @sc{gnu} Ada compiler (GNAT). @end table @item --help Print a summary of the options to @command{c++filt} and exit. @item --version Print the version number of @command{c++filt} and exit. @end table @c man end @ignore @c man begin SEEALSO cxxfilt the Info entries for @file{binutils}. @c man end @end ignore @quotation @emph{Warning:} @command{c++filt} is a new utility, and the details of its user interface are subject to change in future releases. In particular, a command-line option may be required in the future to decode a name passed as an argument on the command line; in other words, @example c++filt @var{symbol} @end example @noindent may in a future release become @example c++filt @var{option} @var{symbol} @end example @end quotation @node addr2line @chapter addr2line @kindex addr2line @cindex address to file name and line number @c man title addr2line convert addresses into file names and line numbers @smallexample @c man begin SYNOPSIS addr2line addr2line [@option{-a}|@option{--addresses}] [@option{-b} @var{bfdname}|@option{--target=}@var{bfdname}] [@option{-C}|@option{--demangle}[=@var{style}]] [@option{-r}|@option{--no-recurse-limit}] [@option{-R}|@option{--recurse-limit}] [@option{-e} @var{filename}|@option{--exe=}@var{filename}] [@option{-f}|@option{--functions}] [@option{-s}|@option{--basename}] [@option{-i}|@option{--inlines}] [@option{-p}|@option{--pretty-print}] [@option{-j}|@option{--section=}@var{name}] [@option{-H}|@option{--help}] [@option{-V}|@option{--version}] [addr addr @dots{}] @c man end @end smallexample @c man begin DESCRIPTION addr2line @command{addr2line} translates addresses into file names and line numbers. Given an address in an executable or an offset in a section of a relocatable object, it uses the debugging information to figure out which file name and line number are associated with it. The executable or relocatable object to use is specified with the @option{-e} option. The default is the file @file{a.out}. The section in the relocatable object to use is specified with the @option{-j} option. @command{addr2line} has two modes of operation. In the first, hexadecimal addresses are specified on the command line, and @command{addr2line} displays the file name and line number for each address. In the second, @command{addr2line} reads hexadecimal addresses from standard input, and prints the file name and line number for each address on standard output. In this mode, @command{addr2line} may be used in a pipe to convert dynamically chosen addresses. The format of the output is @samp{FILENAME:LINENO}. By default each input address generates one line of output. Two options can generate additional lines before each @samp{FILENAME:LINENO} line (in that order). If the @option{-a} option is used then a line with the input address is displayed. If the @option{-f} option is used, then a line with the @samp{FUNCTIONNAME} is displayed. This is the name of the function containing the address. One option can generate additional lines after the @samp{FILENAME:LINENO} line. If the @option{-i} option is used and the code at the given address is present there because of inlining by the compiler then additional lines are displayed afterwards. One or two extra lines (if the @option{-f} option is used) are displayed for each inlined function. Alternatively if the @option{-p} option is used then each input address generates a single, long, output line containing the address, the function name, the file name and the line number. If the @option{-i} option has also been used then any inlined functions will be displayed in the same manner, but on separate lines, and prefixed by the text @samp{(inlined by)}. If the file name or function name can not be determined, @command{addr2line} will print two question marks in their place. If the line number can not be determined, @command{addr2line} will print 0. @c man end @c man begin OPTIONS addr2line The long and short forms of options, shown here as alternatives, are equivalent. @table @env @item -a @itemx --addresses Display the address before the function name, file and line number information. The address is printed with a @samp{0x} prefix to easily identify it. @item -b @var{bfdname} @itemx --target=@var{bfdname} @cindex object code format Specify that the object-code format for the object files is @var{bfdname}. @item -C @itemx --demangle[=@var{style}] @cindex demangling in objdump Decode (@dfn{demangle}) low-level symbol names into user-level names. Besides removing any initial underscore prepended by the system, this makes C++ function names readable. Different compilers have different mangling styles. The optional demangling style argument can be used to choose an appropriate demangling style for your compiler. @xref{c++filt}, for more information on demangling. @item -e @var{filename} @itemx --exe=@var{filename} Specify the name of the executable for which addresses should be translated. The default file is @file{a.out}. @item -f @itemx --functions Display function names as well as file and line number information. @item -s @itemx --basenames Display only the base of each file name. @item -i @itemx --inlines If the address belongs to a function that was inlined, the source information for all enclosing scopes back to the first non-inlined function will also be printed. For example, if @code{main} inlines @code{callee1} which inlines @code{callee2}, and address is from @code{callee2}, the source information for @code{callee1} and @code{main} will also be printed. @item -j @itemx --section Read offsets relative to the specified section instead of absolute addresses. @item -p @itemx --pretty-print Make the output more human friendly: each location are printed on one line. If option @option{-i} is specified, lines for all enclosing scopes are prefixed with @samp{(inlined by)}. @item -r @itemx -R @itemx --recurse-limit @itemx --no-recurse-limit @itemx --recursion-limit @itemx --no-recursion-limit Enables or disables a limit on the amount of recursion performed whilst demangling strings. Since the name mangling formats allow for an inifinite level of recursion it is possible to create strings whose decoding will exhaust the amount of stack space available on the host machine, triggering a memory fault. The limit tries to prevent this from happening by restricting recursion to 2048 levels of nesting. The default is for this limit to be enabled, but disabling it may be necessary in order to demangle truly complicated names. Note however that if the recursion limit is disabled then stack exhaustion is possible and any bug reports about such an event will be rejected. The @option{-r} option is a synonym for the @option{--no-recurse-limit} option. The @option{-R} option is a synonym for the @option{--recurse-limit} option. Note this option is only effective if the @option{-C} or @option{--demangle} option has been enabled. @end table @c man end @ignore @c man begin SEEALSO addr2line Info entries for @file{binutils}. @c man end @end ignore @node windmc @chapter windmc @command{windmc} may be used to generator Windows message resources. @quotation @emph{Warning:} @command{windmc} is not always built as part of the binary utilities, since it is only useful for Windows targets. @end quotation @c man title windmc generates Windows message resources @smallexample @c man begin SYNOPSIS windmc windmc [options] input-file @c man end @end smallexample @c man begin DESCRIPTION windmc @command{windmc} reads message definitions from an input file (.mc) and translate them into a set of output files. The output files may be of four kinds: @table @code @item h A C header file containing the message definitions. @item rc A resource file compilable by the @command{windres} tool. @item bin One or more binary files containing the resource data for a specific message language. @item dbg A C include file that maps message id's to their symbolic name. @end table The exact description of these different formats is available in documentation from Microsoft. When @command{windmc} converts from the @code{mc} format to the @code{bin} format, @code{rc}, @code{h}, and optional @code{dbg} it is acting like the Windows Message Compiler. @c man end @c man begin OPTIONS windmc @table @env @item -a @itemx --ascii_in Specifies that the input file specified is ASCII. This is the default behaviour. @item -A @itemx --ascii_out Specifies that messages in the output @code{bin} files should be in ASCII format. @item -b @itemx --binprefix Specifies that @code{bin} filenames should have to be prefixed by the basename of the source file. @item -c @itemx --customflag Sets the customer bit in all message id's. @item -C @var{codepage} @itemx --codepage_in @var{codepage} Sets the default codepage to be used to convert input file to UTF16. The default is ocdepage 1252. @item -d @itemx --decimal_values Outputs the constants in the header file in decimal. Default is using hexadecimal output. @item -e @var{ext} @itemx --extension @var{ext} The extension for the header file. The default is .h extension. @item -F @var{target} @itemx --target @var{target} Specify the BFD format to use for a bin file as output. This is a BFD target name; you can use the @option{--help} option to see a list of supported targets. Normally @command{windmc} will use the default format, which is the first one listed by the @option{--help} option. @ifclear man @ref{Target Selection}. @end ifclear @item -h @var{path} @itemx --headerdir @var{path} The target directory of the generated header file. The default is the current directory. @item -H @itemx --help Displays a list of command-line options and then exits. @item -m @var{characters} @itemx --maxlength @var{characters} Instructs @command{windmc} to generate a warning if the length of any message exceeds the number specified. @item -n @itemx --nullterminate Terminate message text in @code{bin} files by zero. By default they are terminated by CR/LF. @item -o @itemx --hresult_use Not yet implemented. Instructs @code{windmc} to generate an OLE2 header file, using HRESULT definitions. Status codes are used if the flag is not specified. @item -O @var{codepage} @itemx --codepage_out @var{codepage} Sets the default codepage to be used to output text files. The default is ocdepage 1252. @item -r @var{path} @itemx --rcdir @var{path} The target directory for the generated @code{rc} script and the generated @code{bin} files that the resource compiler script includes. The default is the current directory. @item -u @itemx --unicode_in Specifies that the input file is UTF16. @item -U @itemx --unicode_out Specifies that messages in the output @code{bin} file should be in UTF16 format. This is the default behaviour. @item -v @item --verbose Enable verbose mode. @item -V @item --version Prints the version number for @command{windmc}. @item -x @var{path} @itemx --xdgb @var{path} The path of the @code{dbg} C include file that maps message id's to the symbolic name. No such file is generated without specifying the switch. @end table @c man end @ignore @c man begin SEEALSO windmc the Info entries for @file{binutils}. @c man end @end ignore @node windres @chapter windres @command{windres} may be used to manipulate Windows resources. @quotation @emph{Warning:} @command{windres} is not always built as part of the binary utilities, since it is only useful for Windows targets. @end quotation @c man title windres manipulate Windows resources @smallexample @c man begin SYNOPSIS windres windres [options] [input-file] [output-file] @c man end @end smallexample @c man begin DESCRIPTION windres @command{windres} reads resources from an input file and copies them into an output file. Either file may be in one of three formats: @table @code @item rc A text format read by the Resource Compiler. @item res A binary format generated by the Resource Compiler. @item coff A COFF object or executable. @end table The exact description of these different formats is available in documentation from Microsoft. When @command{windres} converts from the @code{rc} format to the @code{res} format, it is acting like the Windows Resource Compiler. When @command{windres} converts from the @code{res} format to the @code{coff} format, it is acting like the Windows @code{CVTRES} program. When @command{windres} generates an @code{rc} file, the output is similar but not identical to the format expected for the input. When an input @code{rc} file refers to an external filename, an output @code{rc} file will instead include the file contents. If the input or output format is not specified, @command{windres} will guess based on the file name, or, for the input file, the file contents. A file with an extension of @file{.rc} will be treated as an @code{rc} file, a file with an extension of @file{.res} will be treated as a @code{res} file, and a file with an extension of @file{.o} or @file{.exe} will be treated as a @code{coff} file. If no output file is specified, @command{windres} will print the resources in @code{rc} format to standard output. The normal use is for you to write an @code{rc} file, use @command{windres} to convert it to a COFF object file, and then link the COFF file into your application. This will make the resources described in the @code{rc} file available to Windows. @c man end @c man begin OPTIONS windres @table @env @item -i @var{filename} @itemx --input @var{filename} The name of the input file. If this option is not used, then @command{windres} will use the first non-option argument as the input file name. If there are no non-option arguments, then @command{windres} will read from standard input. @command{windres} can not read a COFF file from standard input. @item -o @var{filename} @itemx --output @var{filename} The name of the output file. If this option is not used, then @command{windres} will use the first non-option argument, after any used for the input file name, as the output file name. If there is no non-option argument, then @command{windres} will write to standard output. @command{windres} can not write a COFF file to standard output. Note, for compatibility with @command{rc} the option @option{-fo} is also accepted, but its use is not recommended. @item -J @var{format} @itemx --input-format @var{format} The input format to read. @var{format} may be @samp{res}, @samp{rc}, or @samp{coff}. If no input format is specified, @command{windres} will guess, as described above. @item -O @var{format} @itemx --output-format @var{format} The output format to generate. @var{format} may be @samp{res}, @samp{rc}, or @samp{coff}. If no output format is specified, @command{windres} will guess, as described above. @item -F @var{target} @itemx --target @var{target} Specify the BFD format to use for a COFF file as input or output. This is a BFD target name; you can use the @option{--help} option to see a list of supported targets. Normally @command{windres} will use the default format, which is the first one listed by the @option{--help} option. @ifclear man @ref{Target Selection}. @end ifclear @item --preprocessor @var{program} When @command{windres} reads an @code{rc} file, it runs it through the C preprocessor first. This option may be used to specify the preprocessor to use, including any leading arguments. The default preprocessor argument is @code{gcc -E -xc-header -DRC_INVOKED}. @item --preprocessor-arg @var{option} When @command{windres} reads an @code{rc} file, it runs it through the C preprocessor first. This option may be used to specify additional text to be passed to preprocessor on its command line. This option can be used multiple times to add multiple options to the preprocessor command line. @item -I @var{directory} @itemx --include-dir @var{directory} Specify an include directory to use when reading an @code{rc} file. @command{windres} will pass this to the preprocessor as an @option{-I} option. @command{windres} will also search this directory when looking for files named in the @code{rc} file. If the argument passed to this command matches any of the supported @var{formats} (as described in the @option{-J} option), it will issue a deprecation warning, and behave just like the @option{-J} option. New programs should not use this behaviour. If a directory happens to match a @var{format}, simple prefix it with @samp{./} to disable the backward compatibility. @item -D @var{target} @itemx --define @var{sym}[=@var{val}] Specify a @option{-D} option to pass to the preprocessor when reading an @code{rc} file. @item -U @var{target} @itemx --undefine @var{sym} Specify a @option{-U} option to pass to the preprocessor when reading an @code{rc} file. @item -r Ignored for compatibility with rc. @item -v Enable verbose mode. This tells you what the preprocessor is if you didn't specify one. @item -c @var{val} @item --codepage @var{val} Specify the default codepage to use when reading an @code{rc} file. @var{val} should be a hexadecimal prefixed by @samp{0x} or decimal codepage code. The valid range is from zero up to 0xffff, but the validity of the codepage is host and configuration dependent. @item -l @var{val} @item --language @var{val} Specify the default language to use when reading an @code{rc} file. @var{val} should be a hexadecimal language code. The low eight bits are the language, and the high eight bits are the sublanguage. @item --use-temp-file Use a temporary file to instead of using popen to read the output of the preprocessor. Use this option if the popen implementation is buggy on the host (eg., certain non-English language versions of Windows 95 and Windows 98 are known to have buggy popen where the output will instead go the console). @item --no-use-temp-file Use popen, not a temporary file, to read the output of the preprocessor. This is the default behaviour. @item -h @item --help Prints a usage summary. @item -V @item --version Prints the version number for @command{windres}. @item --yydebug If @command{windres} is compiled with @code{YYDEBUG} defined as @code{1}, this will turn on parser debugging. @end table @c man end @ignore @c man begin SEEALSO windres the Info entries for @file{binutils}. @c man end @end ignore @node dlltool @chapter dlltool @cindex DLL @kindex dlltool @command{dlltool} is used to create the files needed to create dynamic link libraries (DLLs) on systems which understand PE format image files such as Windows. A DLL contains an export table which contains information that the runtime loader needs to resolve references from a referencing program. The export table is generated by this program by reading in a @file{.def} file or scanning the @file{.a} and @file{.o} files which will be in the DLL. A @file{.o} file can contain information in special @samp{.drectve} sections with export information. @quotation @emph{Note:} @command{dlltool} is not always built as part of the binary utilities, since it is only useful for those targets which support DLLs. @end quotation @c man title dlltool create files needed to build and use DLLs @smallexample @c man begin SYNOPSIS dlltool dlltool [@option{-d}|@option{--input-def} @var{def-file-name}] [@option{-b}|@option{--base-file} @var{base-file-name}] [@option{-e}|@option{--output-exp} @var{exports-file-name}] [@option{-z}|@option{--output-def} @var{def-file-name}] [@option{-l}|@option{--output-lib} @var{library-file-name}] [@option{-y}|@option{--output-delaylib} @var{library-file-name}] [@option{--export-all-symbols}] [@option{--no-export-all-symbols}] [@option{--exclude-symbols} @var{list}] [@option{--no-default-excludes}] [@option{-S}|@option{--as} @var{path-to-assembler}] [@option{-f}|@option{--as-flags} @var{options}] [@option{-D}|@option{--dllname} @var{name}] [@option{-m}|@option{--machine} @var{machine}] [@option{-a}|@option{--add-indirect}] [@option{-U}|@option{--add-underscore}] [@option{--add-stdcall-underscore}] [@option{-k}|@option{--kill-at}] [@option{-A}|@option{--add-stdcall-alias}] [@option{-p}|@option{--ext-prefix-alias} @var{prefix}] [@option{-x}|@option{--no-idata4}] [@option{-c}|@option{--no-idata5}] [@option{--use-nul-prefixed-import-tables}] [@option{-I}|@option{--identify} @var{library-file-name}] [@option{--identify-strict}] [@option{-i}|@option{--interwork}] [@option{-n}|@option{--nodelete}] [@option{-t}|@option{--temp-prefix} @var{prefix}] [@option{-v}|@option{--verbose}] [@option{-h}|@option{--help}] [@option{-V}|@option{--version}] [@option{--no-leading-underscore}] [@option{--leading-underscore}] [object-file @dots{}] @c man end @end smallexample @c man begin DESCRIPTION dlltool @command{dlltool} reads its inputs, which can come from the @option{-d} and @option{-b} options as well as object files specified on the command line. It then processes these inputs and if the @option{-e} option has been specified it creates a exports file. If the @option{-l} option has been specified it creates a library file and if the @option{-z} option has been specified it creates a def file. Any or all of the @option{-e}, @option{-l} and @option{-z} options can be present in one invocation of dlltool. When creating a DLL, along with the source for the DLL, it is necessary to have three other files. @command{dlltool} can help with the creation of these files. The first file is a @file{.def} file which specifies which functions are exported from the DLL, which functions the DLL imports, and so on. This is a text file and can be created by hand, or @command{dlltool} can be used to create it using the @option{-z} option. In this case @command{dlltool} will scan the object files specified on its command line looking for those functions which have been specially marked as being exported and put entries for them in the @file{.def} file it creates. In order to mark a function as being exported from a DLL, it needs to have an @option{-export:} entry in the @samp{.drectve} section of the object file. This can be done in C by using the asm() operator: @smallexample asm (".section .drectve"); asm (".ascii \"-export:my_func\""); int my_func (void) @{ @dots{} @} @end smallexample The second file needed for DLL creation is an exports file. This file is linked with the object files that make up the body of the DLL and it handles the interface between the DLL and the outside world. This is a binary file and it can be created by giving the @option{-e} option to @command{dlltool} when it is creating or reading in a @file{.def} file. The third file needed for DLL creation is the library file that programs will link with in order to access the functions in the DLL (an `import library'). This file can be created by giving the @option{-l} option to dlltool when it is creating or reading in a @file{.def} file. If the @option{-y} option is specified, dlltool generates a delay-import library that can be used instead of the normal import library to allow a program to link to the dll only as soon as an imported function is called for the first time. The resulting executable will need to be linked to the static delayimp library containing __delayLoadHelper2(), which in turn will import LoadLibraryA and GetProcAddress from kernel32. @command{dlltool} builds the library file by hand, but it builds the exports file by creating temporary files containing assembler statements and then assembling these. The @option{-S} command-line option can be used to specify the path to the assembler that dlltool will use, and the @option{-f} option can be used to pass specific flags to that assembler. The @option{-n} can be used to prevent dlltool from deleting these temporary assembler files when it is done, and if @option{-n} is specified twice then this will prevent dlltool from deleting the temporary object files it used to build the library. Here is an example of creating a DLL from a source file @samp{dll.c} and also creating a program (from an object file called @samp{program.o}) that uses that DLL: @smallexample gcc -c dll.c dlltool -e exports.o -l dll.lib dll.o gcc dll.o exports.o -o dll.dll gcc program.o dll.lib -o program @end smallexample @command{dlltool} may also be used to query an existing import library to determine the name of the DLL to which it is associated. See the description of the @option{-I} or @option{--identify} option. @c man end @c man begin OPTIONS dlltool The command-line options have the following meanings: @table @env @item -d @var{filename} @itemx --input-def @var{filename} @cindex input .def file Specifies the name of a @file{.def} file to be read in and processed. @item -b @var{filename} @itemx --base-file @var{filename} @cindex base files Specifies the name of a base file to be read in and processed. The contents of this file will be added to the relocation section in the exports file generated by dlltool. @item -e @var{filename} @itemx --output-exp @var{filename} Specifies the name of the export file to be created by dlltool. @item -z @var{filename} @itemx --output-def @var{filename} Specifies the name of the @file{.def} file to be created by dlltool. @item -l @var{filename} @itemx --output-lib @var{filename} Specifies the name of the library file to be created by dlltool. @item -y @var{filename} @itemx --output-delaylib @var{filename} Specifies the name of the delay-import library file to be created by dlltool. @item --export-all-symbols Treat all global and weak defined symbols found in the input object files as symbols to be exported. There is a small list of symbols which are not exported by default; see the @option{--no-default-excludes} option. You may add to the list of symbols to not export by using the @option{--exclude-symbols} option. @item --no-export-all-symbols Only export symbols explicitly listed in an input @file{.def} file or in @samp{.drectve} sections in the input object files. This is the default behaviour. The @samp{.drectve} sections are created by @samp{dllexport} attributes in the source code. @item --exclude-symbols @var{list} Do not export the symbols in @var{list}. This is a list of symbol names separated by comma or colon characters. The symbol names should not contain a leading underscore. This is only meaningful when @option{--export-all-symbols} is used. @item --no-default-excludes When @option{--export-all-symbols} is used, it will by default avoid exporting certain special symbols. The current list of symbols to avoid exporting is @samp{DllMain@@12}, @samp{DllEntryPoint@@0}, @samp{impure_ptr}. You may use the @option{--no-default-excludes} option to go ahead and export these special symbols. This is only meaningful when @option{--export-all-symbols} is used. @item -S @var{path} @itemx --as @var{path} Specifies the path, including the filename, of the assembler to be used to create the exports file. @item -f @var{options} @itemx --as-flags @var{options} Specifies any specific command-line options to be passed to the assembler when building the exports file. This option will work even if the @option{-S} option is not used. This option only takes one argument, and if it occurs more than once on the command line, then later occurrences will override earlier occurrences. So if it is necessary to pass multiple options to the assembler they should be enclosed in double quotes. @item -D @var{name} @itemx --dll-name @var{name} Specifies the name to be stored in the @file{.def} file as the name of the DLL when the @option{-e} option is used. If this option is not present, then the filename given to the @option{-e} option will be used as the name of the DLL. @item -m @var{machine} @itemx -machine @var{machine} Specifies the type of machine for which the library file should be built. @command{dlltool} has a built in default type, depending upon how it was created, but this option can be used to override that. This is normally only useful when creating DLLs for an ARM processor, when the contents of the DLL are actually encode using Thumb instructions. @item -a @itemx --add-indirect Specifies that when @command{dlltool} is creating the exports file it should add a section which allows the exported functions to be referenced without using the import library. Whatever the hell that means! @item -U @itemx --add-underscore Specifies that when @command{dlltool} is creating the exports file it should prepend an underscore to the names of @emph{all} exported symbols. @item --no-leading-underscore @item --leading-underscore Specifies whether standard symbol should be forced to be prefixed, or not. @item --add-stdcall-underscore Specifies that when @command{dlltool} is creating the exports file it should prepend an underscore to the names of exported @emph{stdcall} functions. Variable names and non-stdcall function names are not modified. This option is useful when creating GNU-compatible import libs for third party DLLs that were built with MS-Windows tools. @item -k @itemx --kill-at Specifies that @samp{@@} suffixes should be omitted from the names of stdcall functions that will be imported from the DLL. This is useful when creating an import library for a DLL which exports stdcall functions but without the usual @samp{@@} symbol name suffix. This does not change the naming of symbols provided by the import library to programs linked against it, but only the entries in the import table (ie the .idata section). @item -A @itemx --add-stdcall-alias Specifies that when @command{dlltool} is creating the exports file it should add aliases for stdcall symbols without @samp{@@ } in addition to the symbols with @samp{@@ }. @item -p @itemx --ext-prefix-alias @var{prefix} Causes @command{dlltool} to create external aliases for all DLL imports with the specified prefix. The aliases are created for both external and import symbols with no leading underscore. @item -x @itemx --no-idata4 Specifies that when @command{dlltool} is creating the exports and library files it should omit the @code{.idata4} section. This is for compatibility with certain operating systems. @item --use-nul-prefixed-import-tables Specifies that when @command{dlltool} is creating the exports and library files it should prefix the @code{.idata4} and @code{.idata5} by zero an element. This emulates old gnu import library generation of @code{dlltool}. By default this option is turned off. @item -c @itemx --no-idata5 Specifies that when @command{dlltool} is creating the exports and library files it should omit the @code{.idata5} section. This is for compatibility with certain operating systems. @item -I @var{filename} @itemx --identify @var{filename} Specifies that @command{dlltool} should inspect the import library indicated by @var{filename} and report, on @code{stdout}, the name(s) of the associated DLL(s). This can be performed in addition to any other operations indicated by the other options and arguments. @command{dlltool} fails if the import library does not exist or is not actually an import library. See also @option{--identify-strict}. @item --identify-strict Modifies the behavior of the @option{--identify} option, such that an error is reported if @var{filename} is associated with more than one DLL. @item -i @itemx --interwork Specifies that @command{dlltool} should mark the objects in the library file and exports file that it produces as supporting interworking between ARM and Thumb code. @item -n @itemx --nodelete Makes @command{dlltool} preserve the temporary assembler files it used to create the exports file. If this option is repeated then dlltool will also preserve the temporary object files it uses to create the library file. @item -t @var{prefix} @itemx --temp-prefix @var{prefix} Makes @command{dlltool} use @var{prefix} when constructing the names of temporary assembler and object files. By default, the temp file prefix is generated from the pid. @item -v @itemx --verbose Make dlltool describe what it is doing. @item -h @itemx --help Displays a list of command-line options and then exits. @item -V @itemx --version Displays dlltool's version number and then exits. @end table @c man end @menu * def file format:: The format of the dlltool @file{.def} file @end menu @node def file format @section The format of the @command{dlltool} @file{.def} file A @file{.def} file contains any number of the following commands: @table @asis @item @code{NAME} @var{name} @code{[ ,} @var{base} @code{]} The result is going to be named @var{name}@code{.exe}. @item @code{LIBRARY} @var{name} @code{[ ,} @var{base} @code{]} The result is going to be named @var{name}@code{.dll}. Note: If you want to use LIBRARY as name then you need to quote. Otherwise this will fail due a necessary hack for libtool (see PR binutils/13710 for more details). @item @code{EXPORTS ( ( (} @var{name1} @code{[ = } @var{name2} @code{] ) | ( } @var{name1} @code{=} @var{module-name} @code{.} @var{external-name} @code{) ) [ == } @var{its_name} @code{]} @item @code{[} @var{integer} @code{] [ NONAME ] [ CONSTANT ] [ DATA ] [ PRIVATE ] ) *} Declares @var{name1} as an exported symbol from the DLL, with optional ordinal number @var{integer}, or declares @var{name1} as an alias (forward) of the function @var{external-name} in the DLL. If @var{its_name} is specified, this name is used as string in export table. @var{module-name}. Note: The @code{EXPORTS} has to be the last command in .def file, as keywords are treated - beside @code{LIBRARY} - as simple name-identifiers. If you want to use LIBRARY as name then you need to quote it. @item @code{IMPORTS ( (} @var{internal-name} @code{=} @var{module-name} @code{.} @var{integer} @code{) | [} @var{internal-name} @code{= ]} @var{module-name} @code{.} @var{external-name} @code{) [ == ) @var{its_name} @code{]} *} Declares that @var{external-name} or the exported function whose ordinal number is @var{integer} is to be imported from the file @var{module-name}. If @var{internal-name} is specified then this is the name that the imported function will be referred to in the body of the DLL. If @var{its_name} is specified, this name is used as string in import table. Note: The @code{IMPORTS} has to be the last command in .def file, as keywords are treated - beside @code{LIBRARY} - as simple name-identifiers. If you want to use LIBRARY as name then you need to quote it. @item @code{DESCRIPTION} @var{string} Puts @var{string} into the output @file{.exp} file in the @code{.rdata} section. @item @code{STACKSIZE} @var{number-reserve} @code{[, } @var{number-commit} @code{]} @item @code{HEAPSIZE} @var{number-reserve} @code{[, } @var{number-commit} @code{]} Generates @code{--stack} or @code{--heap} @var{number-reserve},@var{number-commit} in the output @code{.drectve} section. The linker will see this and act upon it. @item @code{CODE} @var{attr} @code{+} @item @code{DATA} @var{attr} @code{+} @item @code{SECTIONS (} @var{section-name} @var{attr}@code{ + ) *} Generates @code{--attr} @var{section-name} @var{attr} in the output @code{.drectve} section, where @var{attr} is one of @code{READ}, @code{WRITE}, @code{EXECUTE} or @code{SHARED}. The linker will see this and act upon it. @end table @ignore @c man begin SEEALSO dlltool The Info pages for @file{binutils}. @c man end @end ignore @node readelf @chapter readelf @cindex ELF file information @kindex readelf @c man title readelf display information about ELF files @smallexample @c man begin SYNOPSIS readelf readelf [@option{-a}|@option{--all}] [@option{-h}|@option{--file-header}] [@option{-l}|@option{--program-headers}|@option{--segments}] [@option{-S}|@option{--section-headers}|@option{--sections}] [@option{-g}|@option{--section-groups}] [@option{-t}|@option{--section-details}] [@option{-e}|@option{--headers}] [@option{-s}|@option{--syms}|@option{--symbols}] [@option{--dyn-syms}] [@option{-n}|@option{--notes}] [@option{-r}|@option{--relocs}] [@option{-u}|@option{--unwind}] [@option{-d}|@option{--dynamic}] [@option{-V}|@option{--version-info}] [@option{-A}|@option{--arch-specific}] [@option{-D}|@option{--use-dynamic}] [@option{-x} |@option{--hex-dump=}] [@option{-p} |@option{--string-dump=}] [@option{-R} |@option{--relocated-dump=}] [@option{-z}|@option{--decompress}] [@option{-c}|@option{--archive-index}] [@option{-w[lLiaprmfFsoRtUuTgAckK]}| @option{--debug-dump}[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]] [@option{--dwarf-depth=@var{n}}] [@option{--dwarf-start=@var{n}}] [@option{--ctf=}@var{section}] [@option{--ctf-parent=}@var{section}] [@option{--ctf-symbols=}@var{section}] [@option{--ctf-strings=}@var{section}] [@option{-I}|@option{--histogram}] [@option{-v}|@option{--version}] [@option{-W}|@option{--wide}] [@option{-H}|@option{--help}] @var{elffile}@dots{} @c man end @end smallexample @c man begin DESCRIPTION readelf @command{readelf} displays information about one or more ELF format object files. The options control what particular information to display. @var{elffile}@dots{} are the object files to be examined. 32-bit and 64-bit ELF files are supported, as are archives containing ELF files. This program performs a similar function to @command{objdump} but it goes into more detail and it exists independently of the @sc{bfd} library, so if there is a bug in @sc{bfd} then readelf will not be affected. @c man end @c man begin OPTIONS readelf The long and short forms of options, shown here as alternatives, are equivalent. At least one option besides @samp{-v} or @samp{-H} must be given. @table @env @item -a @itemx --all Equivalent to specifying @option{--file-header}, @option{--program-headers}, @option{--sections}, @option{--symbols}, @option{--relocs}, @option{--dynamic}, @option{--notes}, @option{--version-info}, @option{--arch-specific}, @option{--unwind}, @option{--section-groups} and @option{--histogram}. Note - this option does not enable @option{--use-dynamic} itself, so if that option is not present on the command line then dynamic symbols and dynamic relocs will not be displayed. @item -h @itemx --file-header @cindex ELF file header information Displays the information contained in the ELF header at the start of the file. @item -l @itemx --program-headers @itemx --segments @cindex ELF program header information @cindex ELF segment information Displays the information contained in the file's segment headers, if it has any. @item -S @itemx --sections @itemx --section-headers @cindex ELF section information Displays the information contained in the file's section headers, if it has any. @item -g @itemx --section-groups @cindex ELF section group information Displays the information contained in the file's section groups, if it has any. @item -t @itemx --section-details @cindex ELF section information Displays the detailed section information. Implies @option{-S}. @item -s @itemx --symbols @itemx --syms @cindex ELF symbol table information Displays the entries in symbol table section of the file, if it has one. If a symbol has version information associated with it then this is displayed as well. The version string is displayed as a suffix to the symbol name, preceeded by an @@ character. For example @samp{foo@@VER_1}. If the version is the default version to be used when resolving unversioned references to the symbol then it is displayed as a suffix preceeded by two @@ characters. For example @samp{foo@@@@VER_2}. @item --dyn-syms @cindex ELF dynamic symbol table information Displays the entries in dynamic symbol table section of the file, if it has one. The output format is the same as the format used by the @option{--syms} option. @item -e @itemx --headers Display all the headers in the file. Equivalent to @option{-h -l -S}. @item -n @itemx --notes @cindex ELF notes Displays the contents of the NOTE segments and/or sections, if any. @item -r @itemx --relocs @cindex ELF reloc information Displays the contents of the file's relocation section, if it has one. @item -u @itemx --unwind @cindex unwind information Displays the contents of the file's unwind section, if it has one. Only the unwind sections for IA64 ELF files, as well as ARM unwind tables (@code{.ARM.exidx} / @code{.ARM.extab}) are currently supported. If support is not yet implemented for your architecture you could try dumping the contents of the @var{.eh_frames} section using the @option{--debug-dump=frames} or @option{--debug-dump=frames-interp} options. @item -d @itemx --dynamic @cindex ELF dynamic section information Displays the contents of the file's dynamic section, if it has one. @item -V @itemx --version-info @cindex ELF version sections information Displays the contents of the version sections in the file, it they exist. @item -A @itemx --arch-specific Displays architecture-specific information in the file, if there is any. @item -D @itemx --use-dynamic When displaying symbols, this option makes @command{readelf} use the symbol hash tables in the file's dynamic section, rather than the symbol table sections. When displaying relocations, this option makes @command{readelf} display the dynamic relocations rather than the static relocations. @item -x @itemx --hex-dump= Displays the contents of the indicated section as a hexadecimal bytes. A number identifies a particular section by index in the section table; any other string identifies all sections with that name in the object file. @item -R @itemx --relocated-dump= Displays the contents of the indicated section as a hexadecimal bytes. A number identifies a particular section by index in the section table; any other string identifies all sections with that name in the object file. The contents of the section will be relocated before they are displayed. @item -p @itemx --string-dump= Displays the contents of the indicated section as printable strings. A number identifies a particular section by index in the section table; any other string identifies all sections with that name in the object file. @item -z @itemx --decompress Requests that the section(s) being dumped by @option{x}, @option{R} or @option{p} options are decompressed before being displayed. If the section(s) are not compressed then they are displayed as is. @item -c @itemx --archive-index @cindex Archive file symbol index information Displays the file symbol index information contained in the header part of binary archives. Performs the same function as the @option{t} command to @command{ar}, but without using the BFD library. @xref{ar}. @item -w[lLiaprmfFsoRtUuTgAckK] @itemx --debug-dump[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links] @include debug.options.texi @include ctf.options.texi @item --ctf-symbols=@var{section} @item --ctf-strings=@var{section} Specify the name of another section from which the CTF file can inherit strings and symbols. By default, the @code{.symtab} and its linked string table are used. If either of @option{--ctf-symbols} or @option{--ctf-strings} is specified, the other must be specified as well. @item -I @itemx --histogram Display a histogram of bucket list lengths when displaying the contents of the symbol tables. @item -v @itemx --version Display the version number of readelf. @item -W @itemx --wide Don't break output lines to fit into 80 columns. By default @command{readelf} breaks section header and segment listing lines for 64-bit ELF files, so that they fit into 80 columns. This option causes @command{readelf} to print each section header resp. each segment one a single line, which is far more readable on terminals wider than 80 columns. @item -H @itemx --help Display the command-line options understood by @command{readelf}. @end table @c man end @ignore @c man begin SEEALSO readelf objdump(1), and the Info entries for @file{binutils}. @c man end @end ignore @node elfedit @chapter elfedit @cindex Update ELF header @kindex elfedit @c man title elfedit update ELF header and program property of ELF files @smallexample @c man begin SYNOPSIS elfedit elfedit [@option{--input-mach=}@var{machine}] [@option{--input-type=}@var{type}] [@option{--input-osabi=}@var{osabi}] @option{--output-mach=}@var{machine} @option{--output-type=}@var{type} @option{--output-osabi=}@var{osabi} @option{--enable-x86-feature=}@var{feature} @option{--disable-x86-feature=}@var{feature} [@option{-v}|@option{--version}] [@option{-h}|@option{--help}] @var{elffile}@dots{} @c man end @end smallexample @c man begin DESCRIPTION elfedit @command{elfedit} updates the ELF header and program property of ELF files which have the matching ELF machine and file types. The options control how and which fields in the ELF header and program property should be updated. @var{elffile}@dots{} are the ELF files to be updated. 32-bit and 64-bit ELF files are supported, as are archives containing ELF files. @c man end @c man begin OPTIONS elfedit The long and short forms of options, shown here as alternatives, are equivalent. At least one of the @option{--output-mach}, @option{--output-type}, @option{--output-osabi}, @option{--enable-x86-feature} and @option{--disable-x86-feature} options must be given. @table @env @item --input-mach=@var{machine} Set the matching input ELF machine type to @var{machine}. If @option{--input-mach} isn't specified, it will match any ELF machine types. The supported ELF machine types are, @var{i386}, @var{IAMCU}, @var{L1OM}, @var{K1OM} and @var{x86-64}. @item --output-mach=@var{machine} Change the ELF machine type in the ELF header to @var{machine}. The supported ELF machine types are the same as @option{--input-mach}. @item --input-type=@var{type} Set the matching input ELF file type to @var{type}. If @option{--input-type} isn't specified, it will match any ELF file types. The supported ELF file types are, @var{rel}, @var{exec} and @var{dyn}. @item --output-type=@var{type} Change the ELF file type in the ELF header to @var{type}. The supported ELF types are the same as @option{--input-type}. @item --input-osabi=@var{osabi} Set the matching input ELF file OSABI to @var{osabi}. If @option{--input-osabi} isn't specified, it will match any ELF OSABIs. The supported ELF OSABIs are, @var{none}, @var{HPUX}, @var{NetBSD}, @var{GNU}, @var{Linux} (alias for @var{GNU}), @var{Solaris}, @var{AIX}, @var{Irix}, @var{FreeBSD}, @var{TRU64}, @var{Modesto}, @var{OpenBSD}, @var{OpenVMS}, @var{NSK}, @var{AROS} and @var{FenixOS}. @item --output-osabi=@var{osabi} Change the ELF OSABI in the ELF header to @var{osabi}. The supported ELF OSABI are the same as @option{--input-osabi}. @item --enable-x86-feature=@var{feature} Set the @var{feature} bit in program property in @var{exec} or @var{dyn} ELF files with machine types of @var{i386} or @var{x86-64}. The supported features are, @var{ibt} and @var{shstk}. @item --disable-x86-feature=@var{feature} Clear the @var{feature} bit in program property in @var{exec} or @var{dyn} ELF files with machine types of @var{i386} or @var{x86-64}. The supported features are the same as @option{--enable-x86-feature}. Note: @option{--enable-x86-feature} and @option{--disable-x86-feature} are available only on hosts with @samp{mmap} support. @item -v @itemx --version Display the version number of @command{elfedit}. @item -h @itemx --help Display the command-line options understood by @command{elfedit}. @end table @c man end @ignore @c man begin SEEALSO elfedit readelf(1), and the Info entries for @file{binutils}. @c man end @end ignore @node Common Options @chapter Common Options The following command-line options are supported by all of the programs described in this manual. @c man begin OPTIONS @table @env @include at-file.texi @c man end @item --help Display the command-line options supported by the program. @item --version Display the version number of the program. @c man begin OPTIONS @end table @c man end @node Selecting the Target System @chapter Selecting the Target System You can specify two aspects of the target system to the @sc{gnu} binary file utilities, each in several ways: @itemize @bullet @item the target @item the architecture @end itemize In the following summaries, the lists of ways to specify values are in order of decreasing precedence. The ways listed first override those listed later. The commands to list valid values only list the values for which the programs you are running were configured. If they were configured with @option{--enable-targets=all}, the commands list most of the available values, but a few are left out; not all targets can be configured in at once because some of them can only be configured @dfn{native} (on hosts with the same type as the target system). @menu * Target Selection:: * Architecture Selection:: @end menu @node Target Selection @section Target Selection A @dfn{target} is an object file format. A given target may be supported for multiple architectures (@pxref{Architecture Selection}). A target selection may also have variations for different operating systems or architectures. The command to list valid target values is @samp{objdump -i} (the first column of output contains the relevant information). Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips}, @samp{a.out-sunos-big}. You can also specify a target using a configuration triplet. This is the same sort of name that is passed to @file{configure} to specify a target. When you use a configuration triplet as an argument, it must be fully canonicalized. You can see the canonical version of a triplet by running the shell script @file{config.sub} which is included with the sources. Some sample configuration triplets are: @samp{m68k-hp-bsd}, @samp{mips-dec-ultrix}, @samp{sparc-sun-sunos}. @subheading @command{objdump} Target Ways to specify: @enumerate @item command-line option: @option{-b} or @option{--target} @item environment variable @code{GNUTARGET} @item deduced from the input file @end enumerate @subheading @command{objcopy} and @command{strip} Input Target Ways to specify: @enumerate @item command-line options: @option{-I} or @option{--input-target}, or @option{-F} or @option{--target} @item environment variable @code{GNUTARGET} @item deduced from the input file @end enumerate @subheading @command{objcopy} and @command{strip} Output Target Ways to specify: @enumerate @item command-line options: @option{-O} or @option{--output-target}, or @option{-F} or @option{--target} @item the input target (see ``@command{objcopy} and @command{strip} Input Target'' above) @item environment variable @code{GNUTARGET} @item deduced from the input file @end enumerate @subheading @command{nm}, @command{size}, and @command{strings} Target Ways to specify: @enumerate @item command-line option: @option{--target} @item environment variable @code{GNUTARGET} @item deduced from the input file @end enumerate @node Architecture Selection @section Architecture Selection An @dfn{architecture} is a type of @sc{cpu} on which an object file is to run. Its name may contain a colon, separating the name of the processor family from the name of the particular @sc{cpu}. The command to list valid architecture values is @samp{objdump -i} (the second column contains the relevant information). Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}. @subheading @command{objdump} Architecture Ways to specify: @enumerate @item command-line option: @option{-m} or @option{--architecture} @item deduced from the input file @end enumerate @subheading @command{objcopy}, @command{nm}, @command{size}, @command{strings} Architecture Ways to specify: @enumerate @item deduced from the input file @end enumerate @node debuginfod @chapter debuginfod @cindex separate debug files debuginfod is a web service that indexes ELF/DWARF debugging resources by build-id and serves them over HTTP. Binutils can be built with the debuginfod client library @code{libdebuginfod} using the @option{--with-debuginfod} configure option. This option is enabled by default if @code{libdebuginfod} is installed and found at configure time. This allows @command{objdump} and @command{readelf} to automatically query debuginfod servers for separate debug files when the files are otherwise not found. debuginfod is packaged with elfutils, starting with version 0.178. You can get the latest version from `https://sourceware.org/elfutils/'. @node Reporting Bugs @chapter Reporting Bugs @cindex bugs @cindex reporting bugs Your bug reports play an essential role in making the binary utilities reliable. Reporting a bug may help you by bringing a solution to your problem, or it may not. But in any case the principal function of a bug report is to help the entire community by making the next version of the binary utilities work better. Bug reports are your contribution to their maintenance. In order for a bug report to serve its purpose, you must include the information that enables us to fix the bug. @menu * Bug Criteria:: Have you found a bug? * Bug Reporting:: How to report bugs @end menu @node Bug Criteria @section Have You Found a Bug? @cindex bug criteria If you are not sure whether you have found a bug, here are some guidelines: @itemize @bullet @cindex fatal signal @cindex crash @item If a binary utility gets a fatal signal, for any input whatever, that is a bug. Reliable utilities never crash. @cindex error on valid input @item If a binary utility produces an error message for valid input, that is a bug. @item If you are an experienced user of binary utilities, your suggestions for improvement are welcome in any case. @end itemize @node Bug Reporting @section How to Report Bugs @cindex bug reports @cindex bugs, reporting A number of companies and individuals offer support for @sc{gnu} products. If you obtained the binary utilities from a support organization, we recommend you contact that organization first. You can find contact information for many support companies and individuals in the file @file{etc/SERVICE} in the @sc{gnu} Emacs distribution. @ifset BUGURL In any event, we also recommend that you send bug reports for the binary utilities to @value{BUGURL}. @end ifset The fundamental principle of reporting bugs usefully is this: @strong{report all the facts}. If you are not sure whether to state a fact or leave it out, state it! Often people omit facts because they think they know what causes the problem and assume that some details do not matter. Thus, you might assume that the name of a file you use in an example does not matter. Well, probably it does not, but one cannot be sure. Perhaps the bug is a stray memory reference which happens to fetch from the location where that pathname is stored in memory; perhaps, if the pathname were different, the contents of that location would fool the utility into doing the right thing despite the bug. Play it safe and give a specific, complete example. That is the easiest thing for you to do, and the most helpful. Keep in mind that the purpose of a bug report is to enable us to fix the bug if it is new to us. Therefore, always write your bug reports on the assumption that the bug has not been reported previously. Sometimes people give a few sketchy facts and ask, ``Does this ring a bell?'' This cannot help us fix a bug, so it is basically useless. We respond by asking for enough details to enable us to investigate. You might as well expedite matters by sending them to begin with. To enable us to fix the bug, you should include all these things: @itemize @bullet @item The version of the utility. Each utility announces it if you start it with the @option{--version} argument. Without this, we will not know whether there is any point in looking for the bug in the current version of the binary utilities. @item Any patches you may have applied to the source, including any patches made to the @code{BFD} library. @item The type of machine you are using, and the operating system name and version number. @item What compiler (and its version) was used to compile the utilities---e.g. ``@code{gcc-2.7}''. @item The command arguments you gave the utility to observe the bug. To guarantee you will not omit something important, list them all. A copy of the Makefile (or the output from make) is sufficient. If we were to try to guess the arguments, we would probably guess wrong and then we might not encounter the bug. @item A complete input file, or set of input files, that will reproduce the bug. If the utility is reading an object file or files, then it is generally most helpful to send the actual object files. If the source files were produced exclusively using @sc{gnu} programs (e.g., @command{gcc}, @command{gas}, and/or the @sc{gnu} @command{ld}), then it may be OK to send the source files rather than the object files. In this case, be sure to say exactly what version of @command{gcc}, or whatever, was used to produce the object files. Also say how @command{gcc}, or whatever, was configured. @item A description of what behavior you observe that you believe is incorrect. For example, ``It gets a fatal signal.'' Of course, if the bug is that the utility gets a fatal signal, then we will certainly notice it. But if the bug is incorrect output, we might not notice unless it is glaringly wrong. You might as well not give us a chance to make a mistake. Even if the problem you experience is a fatal signal, you should still say so explicitly. Suppose something strange is going on, such as your copy of the utility is out of sync, or you have encountered a bug in the C library on your system. (This has happened!) Your copy might crash and ours would not. If you told us to expect a crash, then when ours fails to crash, we would know that the bug was not happening for us. If you had not told us to expect a crash, then we would not be able to draw any conclusion from our observations. @item If you wish to suggest changes to the source, send us context diffs, as generated by @command{diff} with the @option{-u}, @option{-c}, or @option{-p} option. Always send diffs from the old file to the new file. If you wish to discuss something in the @command{ld} source, refer to it by context, not by line number. The line numbers in our development sources will not match those in your sources. Your line numbers would convey no useful information to us. @end itemize Here are some things that are not necessary: @itemize @bullet @item A description of the envelope of the bug. Often people who encounter a bug spend a lot of time investigating which changes to the input file will make the bug go away and which changes will not affect it. This is often time consuming and not very useful, because the way we will find the bug is by running a single example under the debugger with breakpoints, not by pure deduction from a series of examples. We recommend that you save your time for something else. Of course, if you can find a simpler example to report @emph{instead} of the original one, that is a convenience for us. Errors in the output will be easier to spot, running under the debugger will take less time, and so on. However, simplification is not vital; if you do not want to do this, report the bug anyway and send us the entire test case you used. @item A patch for the bug. A patch for the bug does help us if it is a good one. But do not omit the necessary information, such as the test case, on the assumption that a patch is all we need. We might see problems with your patch and decide to fix the problem another way, or we might not understand it at all. Sometimes with programs as complicated as the binary utilities it is very hard to construct an example that will make the program follow a certain path through the code. If you do not send us the example, we will not be able to construct one, so we will not be able to verify that the bug is fixed. And if we cannot understand what bug you are trying to fix, or why your patch should be an improvement, we will not install it. A test case will help us to understand. @item A guess about what the bug is or what it depends on. Such guesses are usually wrong. Even we cannot guess right about such things without first using the debugger to find the facts. @end itemize @node GNU Free Documentation License @appendix GNU Free Documentation License @include fdl.texi @node Binutils Index @unnumbered Binutils Index @printindex cp @bye