This brief manual contains documentation for the gnu binary utilities (collectively version 2.15):
This document is distributed under the terms of the GNU Free Documentation License. A copy of the license is included in the section entitled "GNU Free Documentation License".
ar [-]p[mod [relpos] [count]] archive [member...]
ar -M [ <mri-script ]
The gnu ar program creates, modifies, and extracts from archives. An archive is a single file holding a collection of other files in a structure that makes it possible to retrieve the original individual files (called members of the archive).
The original files' contents, mode (permissions), timestamp, owner, and group are preserved in the archive, and can be restored on extraction.
gnu ar can maintain archives whose members have names of any length; however, depending on how ar is configured on your system, a limit on member-name length may be imposed for compatibility with archive formats maintained with other tools. If it exists, the limit is often 15 characters (typical of formats related to a.out) or 16 characters (typical of formats related to coff).
ar is considered a binary utility because archives of this sort are most often used as libraries holding commonly needed subroutines.
ar creates an index to the symbols defined in relocatable object modules in the archive when you specify the modifier `s'. Once created, this index is updated in the archive whenever ar makes a change to its contents (save for the `q' update operation). 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.
You may use `nm -s' or `nm --print-armap' to list this index table. If an archive lacks the table, another form of ar called ranlib can be used to add just the table.
gnu ar is designed to be compatible with two different facilities. You can control its activity using command-line options, like the different varieties of ar on Unix systems; or, if you specify the single command-line option -M, you can control it with a script supplied via standard input, like the MRI “librarian” program.
ar [-X32_64] [-]p[mod [relpos] [count]] archive [member...]
When you use ar in the Unix style, ar insists on at least two arguments to execute: one keyletter specifying the operation (optionally accompanied by other keyletters specifying modifiers), and the archive name to act on.
Most operations can also accept further member arguments, specifying particular files to operate on.
gnu ar allows you to mix the operation code p and modifier flags mod in any order, within the first command-line argument.
If you wish, you may begin the first command-line argument with a dash.
The p keyletter specifies what operation to execute; it may be any of the following, but you must specify only one of them:
If you specify the `v' modifier, ar lists each module
as it is deleted.
The ordering of members in an archive can make a difference in how programs are linked using the library, if a symbol is defined in more than one member.
If no modifiers are used with m, any members you name in the
member arguments are moved to the end of the archive;
you can use the `a', `b', or `i' modifiers to move them to a
specified place instead.
If you specify no member arguments, all the files in the archive are
printed.
The modifiers `a', `b', and `i' do not affect this operation; new members are always placed at the end of the archive.
The modifier `v' makes ar list each file as it is appended.
Since the point of this operation is speed, the archive's symbol table index is not updated, even if it already existed; you can use `ar s' or ranlib explicitly to update the symbol table index.
However, too many different systems assume quick append rebuilds the
index, so gnu ar implements `q' as a synonym for `r'.
If one of the files named in member... does not exist, ar displays an error message, and leaves undisturbed any existing members of the archive matching that name.
By default, new members are added at the end of the file; but you may use one of the modifiers `a', `b', or `i' to request placement relative to some existing member.
The modifier `v' used with this operation elicits a line of
output for each file inserted, along with one of the letters `a' or
`r' to indicate whether the file was appended (no old member
deleted) or replaced.
If you do not specify a member, all files in the archive are listed.
If there is more than one file with the same name (say, `fie') in
an archive (say `b.a'), `ar t b.a fie' lists only the
first instance; to see them all, you must ask for a complete
listing—in our example, `ar t b.a'.
If you do not specify a member, all files in the archive are extracted.
A number of modifiers (mod) may immediately follow the p keyletter, to specify variations on an operation's behavior:
ar ignores an initial option spelt `-X32_64', for compatibility with AIX. The behaviour produced by this option is the default for gnu ar. ar does not support any of the other `-X' options; in particular, it does not support -X32 which is the default for AIX ar.
ar -M [ <script ]
If you use the single command-line option `-M' with ar, you can control its operation with a rudimentary command language. This form of ar operates interactively if standard input is coming directly from a terminal. During interactive use, ar prompts for input (the prompt is `AR >'), and continues executing even after errors. If you redirect standard input to a script file, no prompts are issued, and ar abandons execution (with a nonzero exit code) on any error.
The ar command language is 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 gnu ar for developers who already have scripts written for the MRI “librarian” program.
The syntax for the ar command language is straightforward:
LIST
is the same as list. In the following descriptions, commands are
shown in upper case for clarity.
Here are the commands you can use in ar scripts, or when using ar interactively. Three of them have special significance:
OPEN or CREATE specify a current archive, which is
a temporary file required for most of the other commands.
SAVE commits the changes so far specified by the script. Prior
to SAVE, commands affect only the temporary copy of the current
archive.
ADDLIB archiveADDLIB archive (module, module, ... module)Requires prior use of OPEN or CREATE.
ADDMOD member, member, ... memberRequires prior use of OPEN or CREATE.
CLEARSAVE. May be executed (with no
effect) even if no current archive is specified.
CREATE archiveSAVE.
You can overwrite existing archives; similarly, the contents of any
existing file named archive will not be destroyed until SAVE.
DELETE module, module, ... moduleRequires prior use of OPEN or CREATE.
DIRECTORY archive (module, ... module)DIRECTORY archive (module, ... module) outputfileVERBOSE specifies the form of the output: when verbose
output is off, output is like that of `ar -t archive
module...'. When verbose output is on, the listing is like
`ar -tv archive module...'.
Output normally goes to the standard output stream; however, if you
specify outputfile as a final argument, ar directs the
output to that file.
END0 exit code to indicate successful
completion. This command does not save the output file; if you have
changed the current archive since the last SAVE command, those
changes are lost.
EXTRACT module, module, ... moduleRequires prior use of OPEN or CREATE.
LISTVERBOSE. The effect is like `ar
tv archive'. (This single command is a gnu ar
enhancement, rather than present for MRI compatibility.)
Requires prior use of OPEN or CREATE.
OPEN archiveSAVE.
REPLACE module, module, ... moduleREPLACE 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 OPEN or CREATE.
VERBOSEDIRECTORY.
When the flag is on, DIRECTORY output matches output from
`ar -tv '....
SAVECREATE or OPEN
command.
Requires prior use of OPEN or CREATE.
nm [-a|--debug-syms] [-g|--extern-only]
[-B] [-C|--demangle[=style]] [-D|--dynamic]
[-S|--print-size] [-s|--print-armap]
[-A|-o|--print-file-name]
[-n|-v|--numeric-sort] [-p|--no-sort]
[-r|--reverse-sort] [--size-sort] [-u|--undefined-only]
[-t radix|--radix=radix] [-P|--portability]
[--target=bfdname] [-fformat|--format=format]
[--defined-only] [-l|--line-numbers] [--no-demangle]
[-V|--version] [-X 32_64] [--help] [objfile...]
gnu nm lists the symbols from object files objfile.... If no object files are listed as arguments, nm assumes the file a.out.
For each symbol, nm shows:
ABCDGINRSTUVW-?The long and short forms of options, shown here as alternatives, are equivalent.
bsd,
sysv, or posix. The default is bsd.
Only the first character of format is significant; it can be
either upper or lower case.
bsd output format.
bsd output format is used the size of the symbol
is printed, rather than the value, and `-S' must be used in order
both size and value to be printed.
objcopy [-F bfdname|--target=bfdname]
[-I bfdname|--input-target=bfdname]
[-O bfdname|--output-target=bfdname]
[-B bfdarch|--binary-architecture=bfdarch]
[-S|--strip-all]
[-g|--strip-debug]
[-K symbolname|--keep-symbol=symbolname]
[-N symbolname|--strip-symbol=symbolname]
[-G symbolname|--keep-global-symbol=symbolname]
[-L symbolname|--localize-symbol=symbolname]
[-W symbolname|--weaken-symbol=symbolname]
[-w|--wildcard]
[-x|--discard-all]
[-X|--discard-locals]
[-b byte|--byte=byte]
[-i interleave|--interleave=interleave]
[-j sectionname|--only-section=sectionname]
[-R sectionname|--remove-section=sectionname]
[-p|--preserve-dates]
[--debugging]
[--gap-fill=val]
[--pad-to=address]
[--set-start=val]
[--adjust-start=incr]
[--change-addresses=incr]
[--change-section-address section{=,+,-}val]
[--change-section-lma section{=,+,-}val]
[--change-section-vma section{=,+,-}val]
[--change-warnings] [--no-change-warnings]
[--set-section-flags section=flags]
[--add-section sectionname=filename]
[--rename-section oldname=newname[,flags]]
[--change-leading-char] [--remove-leading-char]
[--srec-len=ival] [--srec-forceS3]
[--redefine-sym old=new]
[--redefine-syms=filename]
[--weaken]
[--keep-symbols=filename]
[--strip-symbols=filename]
[--keep-global-symbols=filename]
[--localize-symbols=filename]
[--weaken-symbols=filename]
[--alt-machine-code=index]
[--prefix-symbols=string]
[--prefix-sections=string]
[--prefix-alloc-sections=string]
[--add-gnu-debuglink=path-to-file]
[--only-keep-debug]
[--writable-text]
[--readonly-text]
[--pure]
[--impure]
[-v|--verbose]
[-V|--version]
[--help] [--info]
infile [outfile]
The gnu objcopy utility copies the contents of an object file to another. objcopy uses the gnu 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 objcopy is controlled by command-line options. Note that 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.
objcopy creates temporary files to do its translations and deletes them afterward. objcopy uses bfd to do all its translation work; it has access to all the formats described in bfd and thus is able to recognize most formats without being told explicitly. See BFD.
objcopy can be used to generate S-records by using an output target of `srec' (e.g., use `-O srec').
objcopy can be used to generate a raw binary file by using an output target of `binary' (e.g., use -O binary). When 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 -S to remove sections containing debugging information. In some cases -R will be useful to remove sections which contain information that is not needed by the binary file.
Note—objcopy is not able to change the endianness of its input files. If the input format has an endianness (some formats do not), objcopy can only copy the inputs into file formats that have the same endianness or which have no endianness (e.g., `srec').
-w -W !foo -W fo*
would cause objcopy to weaken all symbols that start with “fo”
except for the symbol “foo”.
srec output
target.
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:
objcopy -I binary -O <output_format> -B <architecture> \
--rename-section .data=.rodata,alloc,load,readonly,data,contents \
<input_binary_file> <output_object_file>
The intention is that this option will be used in conjunction with --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:
foo then...
objcopy --only-keep-debug foo foo.dbg to
create a file containing the debugging info.
objcopy --strip-debug foo to create a
stripped executable.
objcopy --add-gnu-debuglink=foo.dbg foo
to add a link to the debugging info into the stripped executable.
Note - the choice of .dbg as an extension for the debug info
file is arbitrary. Also the --only-keep-debug step is
optional. You could instead do this:
foo to foo.full
objcopy --strip-debug foo
objcopy --add-gnu-debuglink=foo.full foo
ie the file pointed to by the --add-gnu-debuglink can be the
full executable. It does not have to be a file created by the
--only-keep-debug switch.
objdump [-a|--archive-headers]
[-b bfdname|--target=bfdname]
[-C|--demangle[=style] ]
[-d|--disassemble]
[-D|--disassemble-all]
[-z|--disassemble-zeroes]
[-EB|-EL|--endian={big | little }]
[-f|--file-headers]
[--file-start-context]
[-g|--debugging]
[-e|--debugging-tags]
[-h|--section-headers|--headers]
[-i|--info]
[-j section|--section=section]
[-l|--line-numbers]
[-S|--source]
[-m machine|--architecture=machine]
[-M options|--disassembler-options=options]
[-p|--private-headers]
[-r|--reloc]
[-R|--dynamic-reloc]
[-s|--full-contents]
[-G|--stabs]
[-t|--syms]
[-T|--dynamic-syms]
[-x|--all-headers]
[-w|--wide]
[--start-address=address]
[--stop-address=address]
[--prefix-addresses]
[--[no-]show-raw-insn]
[--adjust-vma=offset]
[-V|--version]
[-H|--help]
objfile...
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.
objfile... are the object files to be examined. When you specify archives, objdump shows information on each of the member object files.
The long and short forms of options, shown here as alternatives, are equivalent. At least one option from the list -a,-d,-D,-e,-f,-g,-G,-h,-H,-p,-r,-R,-s,-S,-t,-T,-V,-x must be given.
For example,
objdump -b oasys -m vax -h fu.o
displays summary information from the section headers (-h) of
fu.o, which is explicitly identified (-m) as a VAX object
file in the format produced by Oasys compilers. You can list the
formats available with the -i option.
See Target Selection, for more information.
File segments may be relocated to nonstandard addresses, for example by
using the -Ttext, -Tdata, or -Tbss options to
ld. However, some object file formats, such as a.out, do not
store the starting address of the file segments. In those situations,
although ld relocates the sections correctly, using `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.
If the target is an ARM architecture then this switch can be used to select which register name set is used during disassembler. Specifying -M reg-name-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 -M reg-names-apcs will select the name set used by the ARM Procedure Call Standard, whilst specifying -M reg-names-raw will just use `r' followed by the register number.
There are also two variants on the APCS register naming scheme enabled by -M reg-names-atpcs and -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 --disassembler-options=force-thumb. This can be useful when attempting to disassemble thumb code produced by other compilers.
For the x86, some of the options duplicate functions of the -m switch, but allow finer grained control. Multiple selections from the following may be specified as a comma separated string. x86-64, i386 and i8086 select disassembly for the given architecture. intel and att select between intel syntax mode and AT&T syntax mode. addr32, addr16, data32 and data16 specify the default address size and operand size. These four options will be overridden if x86-64, i386 or i8086 appear later in the option string. Lastly, suffix, when in AT&T mode, instructs the disassembler to print a mnemonic suffix even when the suffix could be inferred by the operands.
For PPC, booke, booke32 and booke64 select disassembly of BookE instructions. 32 and 64 select PowerPC and PowerPC64 disassembly, respectively.
For MIPS, this option controls the printing of register names in disassembled instructions. Multiple selections from the following may be specified as a comma separated string, and invalid options are ignored:
gpr-names=ABIfpr-names=ABIcp0-names=ARCHhwr-names=ARCHrdhwr instruction) names
as appropriate for the CPU or architecture specified by
ARCH. By default, HWR names are selected according to
the architecture and CPU of the binary being disassembled.
reg-names=ABIreg-names=ARCHFor any of the options listed above, ABI or
ARCH may be specified as `numeric' to have numbers printed
rather than names, for the selected types of registers.
You can list the available values of ABI and ARCH using
the --help option.
.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 --syms
output.
For more information on stabs symbols, see Stabs.
ranlib [-vV] archive
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 `nm -s' or `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 gnu ranlib program is another form of gnu ar; running ranlib is completely equivalent to executing `ar -s'. See ar.
size [-A|-B|--format=compatibility]
[--help]
[-d|-o|-x|--radix=number]
[-t|--totals]
[--target=bfdname] [-V|--version]
[objfile...]
The gnu size utility lists the section sizes—and the total size—for each of the object or archive files objfile in its argument list. By default, one line of output is generated for each object file or each module in an archive.
objfile... are the object files to be examined.
If none are specified, the file a.out will be used.
The command line options have the following meanings:
Here is an example of the Berkeley (default) format of output from size:
$ size --format=Berkeley ranlib size
text data bss dec hex filename
294880 81920 11592 388392 5ed28 ranlib
294880 81920 11888 388688 5ee50 size
This is the same data, but displayed closer to System V conventions:
$ 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
strings [-afov] [-min-len]
[-n min-len] [--bytes=min-len]
[-t radix] [--radix=radix]
[-e encoding] [--encoding=encoding]
[-] [--all] [--print-file-name]
[--target=bfdname]
[--help] [--version] file...
For each file given, gnu 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. By default, it only prints the strings from the initialized and loaded sections of object files; for other types of files, it prints the strings from the whole file.
strings is mainly useful for determining the contents of non-text files.
strip [-F bfdname |--target=bfdname]
[-I bfdname |--input-target=bfdname]
[-O bfdname |--output-target=bfdname]
[-s|--strip-all]
[-S|-g|-d|--strip-debug]
[-K symbolname |--keep-symbol=symbolname]
[-N symbolname |--strip-symbol=symbolname]
[-w|--wildcard]
[-x|--discard-all] [-X |--discard-locals]
[-R sectionname |--remove-section=sectionname]
[-o file] [-p|--preserve-dates]
[--only-keep-debug]
[-v |--verbose] [-V|--version]
[--help] [--info]
objfile...
gnu strip discards all symbols from object files objfile. The list of object files may include archives. At least one object file must be given.
strip modifies the files named in its argument, rather than writing modified copies under different names.
-w -K !foo -K fo*
would cause strip to only keep symbols that start with the letters
“fo”, but to discard the symbol “foo”.
The intention is that this option will be used in conjunction with --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:
foo then...
objcopy --only-keep-debug foo foo.dbg to
create a file containing the debugging info.
objcopy --strip-debug foo to create a
stripped executable.
objcopy --add-gnu-debuglink=foo.dbg foo
to add a link to the debugging info into the stripped executable.
Note - the choice of .dbg as an extension for the debug info
file is arbitrary. Also the --only-keep-debug step is
optional. You could instead do this:
foo to foo.full
strip --strip-debug foo
objcopy --add-gnu-debuglink=foo.full foo
ie the file pointed to by the --add-gnu-debuglink can be the
full executable. It does not have to be a file created by the
--only-keep-debug switch.
c++filt [-_|--strip-underscores]
[-j|--java]
[-n|--no-strip-underscores]
[-p|--no-params]
[-s format|--format=format]
[--help] [--version] [symbol...]
The C++ and Java languages provides function overloading, which means that you can write many functions with the same name (providing each takes parameters of different types). All C++ and Java function names are encoded into a low-level assembly label (this process is known as mangling). The c++filt 1 program does the inverse mapping: it decodes (demangles) low-level names into user-level names so that the linker can keep these overloaded functions from clashing.
Every alphanumeric word (consisting of letters, digits, underscores, dollars, or periods) seen in the input is a potential label. If the label decodes into a C++ name, the C++ name replaces the low-level name in the output.
You can use c++filt to decipher individual symbols:
c++filt symbol
If no symbol arguments are given, c++filt reads symbol names from the standard input and writes the demangled names to the standard output. All results are printed on the standard output.
foo gets the low-level
name _foo. This option removes the initial underscore. Whether
c++filt removes the underscore by default is target dependent.
autognulucidarmhpedggnu-v3javagnatWarning: 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 the future to decode a name passed as an argument on the command line; in other words,c++filt symbolmay in a future release become
c++filt option symbol
addr2line [-b bfdname|--target=bfdname]
[-C|--demangle[=style]]
[-e filename|--exe=filename]
[-f|--functions] [-s|--basename]
[-H|--help] [-V|--version]
[addr addr ...]
addr2line translates program addresses into file names and line numbers. Given an address and an executable, it uses the debugging information in the executable to figure out which file name and line number are associated with a given address.
The executable to use is specified with the -e option. The default is the file a.out.
addr2line has two modes of operation.
In the first, hexadecimal addresses are specified on the command line, and addr2line displays the file name and line number for each address.
In the second, addr2line reads hexadecimal addresses from standard input, and prints the file name and line number for each address on standard output. In this mode, addr2line may be used in a pipe to convert dynamically chosen addresses.
The format of the output is `FILENAME:LINENO'. The file name and line number for each address is printed on a separate line. If the -f option is used, then each `FILENAME:LINENO' line is preceded by a `FUNCTIONNAME' line which is the name of the function containing the address.
If the file name or function name can not be determined, addr2line will print two question marks in their place. If the line number can not be determined, addr2line will print 0.
The long and short forms of options, shown here as alternatives, are equivalent.
nlmconv converts a relocatable object file into a NetWare Loadable Module.
Warning: nlmconv is not always built as part of the binary utilities, since it is only useful for NLM targets.
nlmconv [-I bfdname|--input-target=bfdname]
[-O bfdname|--output-target=bfdname]
[-T headerfile|--header-file=headerfile]
[-d|--debug] [-l linker|--linker=linker]
[-h|--help] [-V|--version]
infile outfile
nlmconv converts the relocatable `i386' object file infile into the NetWare Loadable Module outfile, optionally reading headerfile for NLM header information. For instructions on writing the NLM command file language used in header files, see the `linkers' section, `NLMLINK' in particular, of the NLM Development and Tools Overview, which is part of the NLM Software Developer's Kit (“NLM SDK”), available from Novell, Inc. nlmconv uses the gnu Binary File Descriptor library to read infile; see BFD, for more information.
nlmconv can perform a link step. In other words, you can list more than one object file for input if you list them in the definitions file (rather than simply specifying one input file on the command line). In this case, nlmconv calls the linker for you.
windres may be used to manipulate Windows resources.
Warning: windres is not always built as part of the binary utilities, since it is only useful for Windows targets.
windres [options] [input-file] [output-file]
windres reads resources from an input file and copies them into an output file. Either file may be in one of three formats:
rcrescoffThe exact description of these different formats is available in documentation from Microsoft.
When windres converts from the rc format to the res
format, it is acting like the Windows Resource Compiler. When
windres converts from the res format to the coff
format, it is acting like the Windows CVTRES program.
When windres generates an rc file, the output is similar
but not identical to the format expected for the input. When an input
rc file refers to an external filename, an output rc file
will instead include the file contents.
If the input or output format is not specified, windres will
guess based on the file name, or, for the input file, the file contents.
A file with an extension of .rc will be treated as an rc
file, a file with an extension of .res will be treated as a
res file, and a file with an extension of .o or
.exe will be treated as a coff file.
If no output file is specified, windres will print the resources
in rc format to standard output.
The normal use is for you to write an rc file, use 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
rc file available to Windows.
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 gcc -E -xc-header -DRC_INVOKED.
rc file.
windres will pass this to the preprocessor as an -I
option. windres will also search this directory when looking for
files named in the rc file. If the argument passed to this command
matches any of the supported formats (as descrived in the -J
option), it will issue a deprecation warning, and behave just like the
-J option. New programs should not use this behaviour. If a
directory happens to match a format, simple prefix it with `./'
to disable the backward compatibility.
rc file.
rc file.
rc file.
val should be a hexadecimal language code. The low eight bits are
the language, and the high eight bits are the sublanguage.
YYDEBUG defined as 1,
this will turn on parser debugging.
dlltool may be used to create the files needed to build and use dynamic link libraries (DLLs).
Warning: dlltool is not always built as part of the binary utilities, since it is only useful for those targets which support DLLs.
dlltool [-d|--input-def def-file-name]
[-b|--base-file base-file-name]
[-e|--output-exp exports-file-name]
[-z|--output-def def-file-name]
[-l|--output-lib library-file-name]
[--export-all-symbols] [--no-export-all-symbols]
[--exclude-symbols list]
[--no-default-excludes]
[-S|--as path-to-assembler] [-f|--as-flags options]
[-D|--dllname name] [-m|--machine machine]
[-a|--add-indirect] [-U|--add-underscore] [-k|--kill-at]
[-A|--add-stdcall-alias]
[-x|--no-idata4] [-c|--no-idata5] [-i|--interwork]
[-n|--nodelete] [-t|--temp-prefix prefix]
[-v|--verbose]
[-h|--help] [-V|--version]
[object-file ...]
dlltool reads its inputs, which can come from the -d and -b options as well as object files specified on the command line. It then processes these inputs and if the -e option has been specified it creates a exports file. If the -l option has been specified it creates a library file and if the -z option has been specified it creates a def file. Any or all of the -e, -l and -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. dlltool can help with the creation of these files.
The first file is a `.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 dlltool can be used to create it using the -z option. In this case 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 .def file it creates.
In order to mark a function as being exported from a DLL, it needs to have an -export:<name_of_function> entry in the `.drectve' section of the object file. This can be done in C by using the asm() operator:
asm (".section .drectve");
asm (".ascii \"-export:my_func\"");
int my_func (void) { ... }
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 -e option to dlltool when it is creating or reading in a .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. This file can be created by giving the -l option to dlltool when it is creating or reading in a .def file.
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 -S command line option can be used to specify the path to the assembler that dlltool will use, and the -f option can be used to pass specific flags to that assembler. The -n can be used to prevent dlltool from deleting these temporary assembler files when it is done, and if -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 `dll.c' and also creating a program (from an object file called `program.o') that uses that DLL:
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
The command line options have the following meanings:
.idata4 section. This is for compatibility
with certain operating systems.
.idata5 section. This is for compatibility
with certain operating systems.
readelf [-a|--all]
[-h|--file-header]
[-l|--program-headers|--segments]
[-S|--section-headers|--sections]
[-e|--headers]
[-s|--syms|--symbols]
[-n|--notes]
[-r|--relocs]
[-u|--unwind]
[-d|--dynamic]
[-V|--version-info]
[-A|--arch-specific]
[-D|--use-dynamic]
[-x <number>|--hex-dump=<number>]
[-w[liaprmfFso]|
--debug-dump[=line,=info,=abbrev,=pubnames,=ranges,=macro,=frames,=frames-interp,=str,=loc]]
[-I|-histogram]
[-v|--version]
[-W|--wide]
[-H|--help]
elffile...
readelf displays information about one or more ELF format object files. The options control what particular information to display.
elffile... 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 objdump but it goes into more detail and it exists independently of the bfd library, so if there is a bug in bfd then readelf will not be affected.
The long and short forms of options, shown here as alternatives, are equivalent. At least one option besides `-v' or `-H' must be given.
You can specify two aspects of the target system to the gnu binary file utilities, each in several ways:
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 --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 native (on hosts with the same type as the target system).
A target is an object file format. A given target may be supported for multiple architectures (see Architecture Selection). A target selection may also have variations for different operating systems or architectures.
The command to list valid target values is `objdump -i' (the first column of output contains the relevant information).
Some sample values are: `a.out-hp300bsd', `ecoff-littlemips', `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 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 config.sub which is included with the sources.
Some sample configuration triplets are: `m68k-hp-bsd', `mips-dec-ultrix', `sparc-sun-sunos'.
Ways to specify:
GNUTARGET
Ways to specify:
GNUTARGET
Ways to specify:
GNUTARGET
Ways to specify:
GNUTARGET
An architecture is a type of 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 cpu.
The command to list valid architecture values is `objdump -i' (the second column contains the relevant information).
Sample values: `m68k:68020', `mips:3000', `sparc'.
Ways to specify:
Ways to specify:
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.
If you are not sure whether you have found a bug, here are some guidelines:
A number of companies and individuals offer support for 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 etc/SERVICE in the gnu Emacs distribution.
In any event, we also recommend that you send bug reports for the binary utilities to `bug-binutils@gnu.org'.
The fundamental principle of reporting bugs usefully is this: 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:
Without this, we will not know whether there is any point in looking for the bug in the current version of the binary utilities.
BFD library.
gcc-2.7”.
If we were to try to guess the arguments, we would probably guess wrong and then we might not encounter the bug.
If the source files were produced exclusively using gnu programs (e.g., gcc, gas, and/or the gnu 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 gcc, or whatever, was used to produce the object files. Also say how gcc, or whatever, was configured.
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 synch, 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.
The line numbers in our development sources will not match those in your sources. Your line numbers would convey no useful information to us.
Here are some things that are not necessary:
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 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.
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.
Such guesses are usually wrong. Even we cannot guess right about such things without first using the debugger to find the facts.
Copyright (C) 2000 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
The purpose of this License is to make a manual, textbook, or other written document “free” in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.
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This License applies to any manual or other work that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. The “Document”, below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as “you.”
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Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1
or any later version published by the Free Software Foundation;
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Front-Cover Texts being list, and with the Back-Cover Texts being list.
A copy of the license is included in the section entitled "GNU
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If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.
addr2line: addr2linear: arc++filt: c++filtcxxfilt: c++filtdlltool: dlltoolnm: nmobjdump: objdumpranlib: ranlibreadelf: readelfsize: sizestrings: stringsstrip: strip[1] MS-DOS does not allow + characters in file names, so on MS-DOS this program is named cxxfilt.