This is binutils.info, produced by makeinfo version 4.0 from binutils.texi. START-INFO-DIR-ENTRY * Binutils: (binutils). The GNU binary utilities. * ar: (binutils)ar. Create, modify, and extract from archives * 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 * c++filt: (binutils)c++filt. Filter to demangle encoded C++ symbols * cxxfilt: (binutils)c++filt. MS-DOS name for c++filt * addr2line: (binutils)addr2line. Convert addresses to file and line * nlmconv: (binutils)nlmconv. Converts object code into an NLM * windres: (binutils)windres. Manipulate Windows resources * dlltool: (binutils)dlltool. Create files needed to build and use DLLs END-INFO-DIR-ENTRY Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions.  File: binutils.info, Node: size, Next: strings, Prev: readelf, Up: Top size **** size [ -A | -B | --format=COMPATIBILITY ] [ --help ] [ -d | -o | -x | --radix=NUMBER ] [ --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: `-A' `-B' `--format=COMPATIBILITY' Using one of these options, you can choose whether the output from GNU `size' resembles output from System V `size' (using `-A', or `--format=sysv'), or Berkeley `size' (using `-B', or `--format=berkeley'). The default is the one-line format similar to Berkeley's. 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 `--help' Show a summary of acceptable arguments and options. `-d' `-o' `-x' `--radix=NUMBER' Using one of these options, you can control whether the size of each section is given in decimal (`-d', or `--radix=10'); octal (`-o', or `--radix=8'); or hexadecimal (`-x', or `--radix=16'). In `--radix=NUMBER', only the three values (8, 10, 16) are supported. The total size is always given in two radices; decimal and hexadecimal for `-d' or `-x' output, or octal and hexadecimal if you're using `-o'. `--target=BFDNAME' Specify that the object-code format for OBJFILE is BFDNAME. This option may not be necessary; `size' can automatically recognize many formats. *Note Target Selection::, for more information. `-V' `--version' Display the version number of `size'.  File: binutils.info, Node: strings, Next: strip, Prev: size, Up: Top strings ******* strings [-afov] [-MIN-LEN] [-n MIN-LEN] [-t RADIX] [-] [--all] [--print-file-name] [--bytes=MIN-LEN] [--radix=RADIX] [--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. `-a' `--all' `-' Do not scan only the initialized and loaded sections of object files; scan the whole files. `-f' `--print-file-name' Print the name of the file before each string. `--help' Print a summary of the program usage on the standard output and exit. `-MIN-LEN' `-n MIN-LEN' `--bytes=MIN-LEN' Print sequences of characters that are at least MIN-LEN characters long, instead of the default 4. `-o' Like `-t o'. Some other versions of `strings' have `-o' act like `-t d' instead. Since we can not be compatible with both ways, we simply chose one. `-t RADIX' `--radix=RADIX' Print the offset within the file before each string. The single character argument specifies the radix of the offset--`o' for octal, `x' for hexadecimal, or `d' for decimal. `--target=BFDNAME' Specify an object code format other than your system's default format. *Note Target Selection::, for more information. `-v' `--version' Print the program version number on the standard output and exit.  File: binutils.info, Node: strip, Next: c++filt, Prev: strings, Up: Top strip ***** strip [ -F BFDNAME | --target=BFDNAME ] [ -I BFDNAME | --input-target=BFDNAME ] [ -O BFDNAME | --output-target=BFDNAME ] [ -s | --strip-all ] [ -S | -g | --strip-debug ] [ -K SYMBOLNAME | --keep-symbol=SYMBOLNAME ] [ -N SYMBOLNAME | --strip-symbol=SYMBOLNAME ] [ -x | --discard-all ] [ -X | --discard-locals ] [ -R SECTIONNAME | --remove-section=SECTIONNAME ] [ -o FILE ] [ -p | --preserve-dates ] [ -v | --verbose ] [ -V | --version ] [ --help ] 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. `-F BFDNAME' `--target=BFDNAME' Treat the original OBJFILE as a file with the object code format BFDNAME, and rewrite it in the same format. *Note Target Selection::, for more information. `--help' Show a summary of the options to `strip' and exit. `-I BFDNAME' `--input-target=BFDNAME' Treat the original OBJFILE as a file with the object code format BFDNAME. *Note Target Selection::, for more information. `-O BFDNAME' `--output-target=BFDNAME' Replace OBJFILE with a file in the output format BFDNAME. *Note Target Selection::, for more information. `-R SECTIONNAME' `--remove-section=SECTIONNAME' Remove any section named SECTIONNAME from the output file. This option may be given more than once. Note that using this option inappropriately may make the output file unusable. `-s' `--strip-all' Remove all symbols. `-g' `-S' `--strip-debug' Remove debugging symbols only. `--strip-unneeded' Remove all symbols that are not needed for relocation processing. `-K SYMBOLNAME' `--keep-symbol=SYMBOLNAME' Keep only symbol SYMBOLNAME from the source file. This option may be given more than once. `-N SYMBOLNAME' `--strip-symbol=SYMBOLNAME' Remove symbol SYMBOLNAME from the source file. This option may be given more than once, and may be combined with strip options other than `-K'. `-o FILE' Put the stripped output in FILE, rather than replacing the existing file. When this argument is used, only one OBJFILE argument may be specified. `-p' `--preserve-dates' Preserve the access and modification dates of the file. `-x' `--discard-all' Remove non-global symbols. `-X' `--discard-locals' Remove compiler-generated local symbols. (These usually start with `L' or `.'.) `-V' `--version' Show the version number for `strip'. `-v' `--verbose' Verbose output: list all object files modified. In the case of archives, `strip -v' lists all members of the archive.  File: binutils.info, Node: c++filt, Next: addr2line, Prev: strip, Up: Top c++filt ******* c++filt [ -_ | --strip-underscores ] [ -j | --java ] [ -n | --no-strip-underscores ] [ -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. `-_' `--strip-underscores' On some systems, both the C and C++ compilers put an underscore in front of every name. For example, the C name `foo' gets the low-level name `_foo'. This option removes the initial underscore. Whether `c++filt' removes the underscore by default is target dependent. `-j' `--java' Prints demangled names using Java syntax. The default is to use C++ syntax. `-n' `--no-strip-underscores' Do not remove the initial underscore. `-s FORMAT' `--format=FORMAT' GNU `nm' can decode three different methods of mangling, used by different C++ compilers. The argument to this option selects which method it uses: `gnu' the one used by the GNU compiler (the default method) `lucid' the one used by the Lucid compiler `arm' the one specified by the C++ Annotated Reference Manual `hp' the one used by the HP compiler `edg' the one used by the EDG compiler `--help' Print a summary of the options to `c++filt' and exit. `--version' Print the version number of `c++filt' and exit. _Warning:_ `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 SYMBOL may in a future release become c++filt OPTION SYMBOL ---------- Footnotes ---------- (1) MS-DOS does not allow `+' characters in file names, so on MS-DOS this program is named `cxxfilt'.  File: binutils.info, Node: addr2line, Next: nlmconv, Prev: c++filt, Up: Top addr2line ********* addr2line [ -b BFDNAME | --target=BFDNAME ] [ -C | --demangle ] [ -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. `-b BFDNAME' `--target=BFDNAME' Specify that the object-code format for the object files is BFDNAME. `-C' `--demangle' Decode ("demangle") low-level symbol names into user-level names. Besides removing any initial underscore prepended by the system, this makes C++ function names readable. *Note c++filt::, for more information on demangling. `-e FILENAME' `--exe=FILENAME' Specify the name of the executable for which addresses should be translated. The default file is `a.out'. `-f' `--functions' Display function names as well as file and line number information. `-s' `--basenames' Display only the base of each file name.  File: binutils.info, Node: nlmconv, Next: windres, Prev: addr2line, Up: Top nlmconv ******* `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 *Note BFD: (ld.info)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. `-I BFDNAME' `--input-target=BFDNAME' Object format of the input file. `nlmconv' can usually determine the format of a given file (so no default is necessary). *Note Target Selection::, for more information. `-O BFDNAME' `--output-target=BFDNAME' Object format of the output file. `nlmconv' infers the output format based on the input format, e.g. for a `i386' input file the output format is `nlm32-i386'. *Note Target Selection::, for more information. `-T HEADERFILE' `--header-file=HEADERFILE' Reads HEADERFILE for NLM header information. For instructions on writing the NLM command file language used in header files, see see the `linkers' section, of the `NLM Development and Tools Overview', which is part of the NLM Software Developer's Kit, available from Novell, Inc. `-d' `--debug' Displays (on standard error) the linker command line used by `nlmconv'. `-l LINKER' `--linker=LINKER' Use LINKER for any linking. LINKER can be an absolute or a relative pathname. `-h' `--help' Prints a usage summary. `-V' `--version' Prints the version number for `nlmconv'.  File: binutils.info, Node: windres, Next: dlltool, Prev: nlmconv, Up: Top windres ******* `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: `rc' A text format read by the Resource Compiler. `res' A binary format generated by the Resource Compiler. `coff' A COFF object or executable. The 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. `-i FILENAME' `--input FILENAME' The name of the input file. If this option is not used, then `windres' will use the first non-option argument as the input file name. If there are no non-option arguments, then `windres' will read from standard input. `windres' can not read a COFF file from standard input. `-o FILENAME' `--output FILENAME' The name of the output file. If this option is not used, then `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 `windres' will write to standard output. `windres' can not write a COFF file to standard output. `-I FORMAT' `--input-format FORMAT' The input format to read. FORMAT may be `res', `rc', or `coff'. If no input format is specified, `windres' will guess, as described above. `-O FORMAT' `--output-format FORMAT' The output format to generate. FORMAT may be `res', `rc', or `coff'. If no output format is specified, `windres' will guess, as described above. `-F TARGET' `--target 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 `--help' option to see a list of supported targets. Normally `windres' will use the default format, which is the first one listed by the `--help' option. *Note Target Selection::. `--preprocessor PROGRAM' When `windres' reads an `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'. `--include-dir DIRECTORY' Specify an include directory to use when reading an `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. `-D TARGET' `--define SYM[=VAL]' Specify a `-D' option to pass to the preprocessor when reading an `rc' file. `-v' Enable verbose mode. This tells you what the preprocessor is if you didn't specify one. `--language VAL' Specify the default language to use when reading an `rc' file. VAL should be a hexadecimal language code. The low eight bits are the language, and the high eight bits are the sublanguage. `--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). `--no-use-temp-file' Use popen, not a temporary file, to read the output of the preprocessor. This is the default behaviour. `--help' Prints a usage summary. `--version' Prints the version number for `windres'. `--yydebug' If `windres' is compiled with `YYDEBUG' defined as `1', this will turn on parser debugging.  File: binutils.info, Node: dlltool, Next: Selecting The Target System, Prev: windres, Up: Top Create files needed to build and use DLLs ***************************************** `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] [-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:' 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: `-d FILENAME' `--input-def FILENAME' Specifies the name of a .def file to be read in and processed. `-b FILENAME' `--base-file FILENAME' 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. `-e FILENAME' `--output-exp FILENAME' Specifies the name of the export file to be created by dlltool. `-z FILENAME' `--output-def FILENAME' Specifies the name of the .def file to be created by dlltool. `-l FILENAME' `--output-lib FILENAME' Specifies the name of the library file to be created by dlltool. `--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 `--no-default-excludes' option. You may add to the list of symbols to not export by using the `--exclude-symbols' option. `--no-export-all-symbols' Only export symbols explicitly listed in an input .def file or in `.drectve' sections in the input object files. This is the default behaviour. The `.drectve' sections are created by `dllexport' attributes in the source code. `--exclude-symbols LIST' Do not export the symbols in 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 `--export-all-symbols' is used. `--no-default-excludes' When `--export-all-symbols' is used, it will by default avoid exporting certain special symbols. The current list of symbols to avoid exporting is `DllMain@12', `DllEntryPoint@0', `impure_ptr'. You may use the `--no-default-excludes' option to go ahead and export these special symbols. This is only meaningful when `--export-all-symbols' is used. `-S PATH' `--as PATH' Specifies the path, including the filename, of the assembler to be used to create the exports file. `-f SWITCHES' `--as-flags SWITCHES' Specifies any specific command line switches to be passed to the assembler when building the exports file. This option will work even if the `-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 switches to the assembler they should be enclosed in double quotes. `-D NAME' `--dll-name NAME' Specifies the name to be stored in the .def file as the name of the DLL when the `-e' option is used. If this option is not present, then the filename given to the `-e' option will be used as the name of the DLL. `-m MACHINE' `-machine MACHINE' Specifies the type of machine for which the library file should be built. `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. `-a' `--add-indirect' Specifies that when `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! `-U' `--add-underscore' Specifies that when `dlltool' is creating the exports file it should prepend an underscore to the names of the exported functions. `-k' `--kill-at' Specifies that when `dlltool' is creating the exports file it should not append the string `@ '. These numbers are called ordinal numbers and they represent another way of accessing the function in a DLL, other than by name. `-A' `--add-stdcall-alias' Specifies that when `dlltool' is creating the exports file it should add aliases for stdcall symbols without `@ ' in addition to the symbols with `@ '. `-x' `--no-idata4' Specifies that when `dlltool' is creating the exports and library files it should omit the .idata4 section. This is for compatibility with certain operating systems. `-c' `--no-idata5' Specifies that when `dlltool' is creating the exports and library files it should omit the .idata5 section. This is for compatibility with certain operating systems. `-i' `--interwork' Specifies that `dlltool' should mark the objects in the library file and exports file that it produces as supporting interworking between ARM and THUMB code. `-n' `--nodelete' Makes `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. `-v' `--verbose' Make dlltool describe what it is doing. `-h' `--help' Displays a list of command line options and then exits. `-V' `--version' Displays dlltool's version number and then exits.  File: binutils.info, Node: readelf, Next: size, Prev: ranlib, Up: Top readelf ******* readelf [ -a | --all ] [ -h | --file-header] [ -l | --program-headers | --segments] [ -S | --section-headers | --sections] [ -e | --headers] [ -s | --syms | --symbols] [ -n | --notes] [ -r | --relocs] [ -d | --dynamic] [ -V | --version-info] [ -D | --use-dynamic] [ -x | --hex-dump=] [ -w[liapr] | --debug-dump[=info,=line,=abbrev,=pubnames,=ranges]] [ --histogram] [ -v | --version] [ -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. At the moment, `readelf' does not support examining archives, nor does it support examing 64 bit ELF files. The long and short forms of options, shown here as alternatives, are equivalent. At least one option besides `-v' or `-H' must be given. `-a' `--all' Equivalent to specifiying `--file-header', `--program-headers', `--sections', `--symbols', `--relocs', `--dynamic', `--notes' and `--version-info'. `-h' `--file-header' Displays the information contained in the ELF header at the start of the file. `-l' `--program-headers' `--segments' Displays the information contained in the file's segment headers, if it has any. `-S' `--sections' `--section-headers' Displays the information contained in the file's section headers, if it has any. `-s' `--symbols' `--syms' Displays the entries in symbol table section of the file, if it has one. `-e' `--headers' Display all the headers in the file. Equivalent to `-h -l -S'. `-n' `--notes' Displays the contents of the NOTE segment, if it exists. `-r' `--relocs' Displays the contents of the file's relocation section, if it ha one. `-d' `--dynamic' Displays the contents of the file's dynamic section, if it has one. `-V' `--version-info' Displays the contents of the version sections in the file, it they exist. `-D' `--use-dynamic' When displaying symbols, this option makes `readelf' use the symblol table in the file's dynamic section, rather than the one in the symbols section. `-x ' `--hex-dump=' Displays the contents of the indicated section as a hexadecimal dump. `-w[liapr]' `--debug-dump[=line,=info,=abbrev,=pubnames,=ranges]' Displays the contents of the debug sections in the file, if any are present. If one of the optional letters or words follows the switch then only data found in those specific sections will be dumped. `--histogram' Display a histogram of bucket list lengths when displaying the contents of the symbol tables. `-v' `--version' Display the version number of readelf. `-H' `--help' Display the command line options understood by `readelf'.  File: binutils.info, Node: Selecting The Target System, Next: Reporting Bugs, Prev: dlltool, Up: Top Selecting the target system *************************** You can specify three aspects of the target system to the GNU binary file utilities, each in several ways: * the target * the architecture * the linker emulation (which applies to the linker only) 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). * Menu: * Target Selection:: * Architecture Selection:: * Linker Emulation Selection::  File: binutils.info, Node: Target Selection, Next: Architecture Selection, Up: Selecting The Target System Target Selection ================ A "target" is an object file format. A given target may be supported for multiple architectures (*note 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'. `objdump' Target ---------------- Ways to specify: 1. command line option: `-b' or `--target' 2. environment variable `GNUTARGET' 3. deduced from the input file `objcopy' and `strip' Input Target ---------------------------------- Ways to specify: 1. command line options: `-I' or `--input-target', or `-F' or `--target' 2. environment variable `GNUTARGET' 3. deduced from the input file `objcopy' and `strip' Output Target ----------------------------------- Ways to specify: 1. command line options: `-O' or `--output-target', or `-F' or `--target' 2. the input target (see "`objcopy' and `strip' Input Target" above) 3. environment variable `GNUTARGET' 4. deduced from the input file `nm', `size', and `strings' Target ---------------------------------- Ways to specify: 1. command line option: `--target' 2. environment variable `GNUTARGET' 3. deduced from the input file Linker Input Target ------------------- Ways to specify: 1. command line option: `-b' or `--format' (*note Options: (ld.info)Options.) 2. script command `TARGET' (*note Option Commands: (ld.info)Option Commands.) 3. environment variable `GNUTARGET' (*note Environment: (ld.info)Environment.) 4. the default target of the selected linker emulation (*note Linker Emulation Selection::) Linker Output Target -------------------- Ways to specify: 1. command line option: `-oformat' (*note Options: (ld.info)Options.) 2. script command `OUTPUT_FORMAT' (*note Option Commands: (ld.info)Option Commands.) 3. the linker input target (see "Linker Input Target" above)  File: binutils.info, Node: Architecture Selection, Next: Linker Emulation Selection, Prev: Target Selection, Up: Selecting The Target System Architecture selection ====================== 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'. `objdump' Architecture ---------------------- Ways to specify: 1. command line option: `-m' or `--architecture' 2. deduced from the input file `objcopy', `nm', `size', `strings' Architecture ----------------------------------------------- Ways to specify: 1. deduced from the input file Linker Input Architecture ------------------------- Ways to specify: 1. deduced from the input file Linker Output Architecture -------------------------- Ways to specify: 1. script command `OUTPUT_ARCH' (*note Option Commands: (ld.info)Option Commands.) 2. the default architecture from the linker output target (*note Target Selection::)  File: binutils.info, Node: Linker Emulation Selection, Prev: Architecture Selection, Up: Selecting The Target System Linker emulation selection ========================== A linker "emulation" is a "personality" of the linker, which gives the linker default values for the other aspects of the target system. In particular, it consists of * the linker script * the target * several "hook" functions that are run at certain stages of the linking process to do special things that some targets require The command to list valid linker emulation values is `ld -V'. Sample values: `hp300bsd', `mipslit', `sun4'. Ways to specify: 1. command line option: `-m' (*note Options: (ld.info)Options.) 2. environment variable `LDEMULATION' 3. compiled-in `DEFAULT_EMULATION' from `Makefile', which comes from `EMUL' in `config/TARGET.mt'  File: binutils.info, Node: Reporting Bugs, Next: Index, Prev: Selecting The Target System, Up: Top 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  File: binutils.info, Node: Bug Criteria, Next: Bug Reporting, Up: Reporting Bugs Have you found a bug? ===================== If you are not sure whether you have found a bug, here are some guidelines: * If a binary utility gets a fatal signal, for any input whatever, that is a bug. Reliable utilities never crash. * If a binary utility produces an error message for valid input, that is a bug. * If you are an experienced user of binary utilities, your suggestions for improvement are welcome in any case.  File: binutils.info, Node: Bug Reporting, Prev: Bug Criteria, Up: Reporting Bugs How to report bugs ================== 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-gnu-utils@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?" Those bug reports are useless, and we urge everyone to _refuse to respond to them_ except to chide the sender to report bugs properly. To enable us to fix the bug, you should include all these things: * The version of the utility. Each utility announces it if you start it with the `--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. * Any patches you may have applied to the source, including any patches made to the `BFD' library. * The type of machine you are using, and the operating system name and version number. * What compiler (and its version) was used to compile the utilities--e.g. "`gcc-2.7'". * 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. * 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, uuencoded if necessary to get them through the mail system. Note that `bug-gnu-utils@gnu.org' is a mailing list, so you should avoid sending very large files to it. Making the files available for anonymous FTP is OK. 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. * 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 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. * If you wish to suggest changes to the source, send us context diffs, as generated by `diff' with the `-u', `-c', or `-p' option. Always send diffs from the old file to the new file. If you wish to discuss something in the `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. Here are some things that are not necessary: * 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 _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. 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. * 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.