Computer Science
objdump(1) GNU Development Tools objdump(1)
NAME
objdump - display information from object files.
SYNOPSIS
objdump
[-a|--archive-headers] [-b bfdname |
--target=bfdname] [-C|--demangle] [--debugging]
[-d|--disassemble] [-D|--disassemble-all]
[--disassemble-zeroes]
[-EB|-EL|--endian={big|little}] [-f|--file-headers]
[-h|--section-headers | --headers] [-i|--info]
[-j section | --section=section]
[-l|--line-numbers] [-m machine |
--architecture=machine] [--prefix-addresses]
[-r|--reloc] [-R|--dynamic-reloc]
[-s|--full-contents] [-S|--source]
[--[no-]show-raw-insn] [--stabs] [-t|--syms]
[-T|--dynamic-syms] [-x|--all-headers]
[--start-address=address] [--stop-address=address]
[--adjust-vma=offset] [--version] [--help]
objfile...
DESCRIPTION
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.
OPTIONS
Where long and short forms of an option are shown togeth-
er, they are equivalent. At least one option besides -l
(--line-numbers) must be given.
-a
--archive-headers
If any files from objfile are archives, display the
archive header information (in a format similar to
`ls -l'). Besides the information you could list
with `ar tv', `objdump -a' shows the object file
format of each archive member.
--adjust-vma=offset
When dumping information, first add offset to all
the section addresses. This is useful if the sec-
tion 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.
-b bfdname
--target=bfdname
Specify the object-code format for the object files
to be bfdname. This may not be necessary; objdump
can automatically recognize many formats. For ex-
ample,
objdump -b oasys -m vax -h fu.o
display summary information from the section head-
ers (`-h') of `fu.o', which is explicitly identi-
fied (`-m') as a Vax object file in the format pro-
duced by Oasys compilers. You can list the formats
available with the `-i' option.
-C
--demangle
Decode (demangle) low-level symbol names into user-
level names. Besides removing any initial under-
score prepended by the system, this makes C++ func-
tion names readable.
--debugging
Display debugging information. This attempts to
parse debugging information stored in the file and
print it out using a C like syntax. Only certain
types of debugging information have been implement-
ed.
-d
--disassemble
Display the assembler mnemonics for the machine in-
structions from objfile. This option only disas-
sembles those sections which are expected to con-
tain instructions.
-D
--disassemble-all
Like -d, but disassemble the contents of all sec-
tions, not just those expected to contain instruc-
tions.
--prefix-addresses
When disassembling, print the complete address on
each line. This is the older disassembly format.
--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.
-EB
-EL
--endian={big|little}
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.
-f
--file-headers
Display summary information from the overall header
of each file in objfile.
-h
--section-headers
--headers
Display summary information from the section head-
ers of the object file.
--help Print a summary of the options to objdump and exit.
-i
--info Display a list showing all architectures and object
formats available for specification with -b or -m.
-j name
--section=name
Display information only for section name.
-l
--line-numbers
Label the display (using debugging information)
with the filename and source line numbers corre-
sponding to the object code shown. Only useful
with -d, -D, or -r.
-m machine
--architecture=machine
Specify the architecture to use when disassembling
object files. This can be useful when disassem-
bling object files which do not describe architec-
ture information, such as S-records. You can list
the available architectures with the -i option.
-r
--reloc
Print the relocation entries of the file. If used
with -d or -d, the relocations are printed inter-
spersed with the disassembly.
-R
--dynamic-reloc
Print the dynamic relocation entries of the file.
This is only meaningful for dynamic objects, such
as certain types of shared libraries.
-s
--full-contents
Display the full contents of any sections request-
ed.
-S
--source
Display source code intermixed with disassembly, if
possible. Implies -d.
--show-raw-insn
When disassembling instructions, print the instruc-
tion in hex as well as in symbolic form. This is
the default except when --prefix-addresses is used.
--no-show-raw-insn
When disassembling instructions, do not print the
instruction bytes. This is the default when --pre-
fix-addresses is used.
--stabs
Display the contents of the .stab, .stab.index, and
.stab.excl sections from an ELF file. This is only
useful on systems (such as Solaris 2.0) in which
.stab debugging symbol-table entries are carried in
an ELF section. In most other file formats, debug-
ging symbol-table entries are interleaved with
linkage symbols, and are visible in the --syms out-
put.
--start-address=address
Start displaying data at the specified address.
This affects the output of the -d, -r and -s op-
tions.
--stop-address=address
Stop displaying data at the specified address.
This affects the output of the -d, -r and -s op-
tions.
-t
--syms Symbol Table. Print the symbol table entries of
the file. This is similar to the information pro-
vided by the `nm' program.
-T
--dynamic-syms
Dynamic Symbol Table. 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 informa-
tion provided by the `nm' program when given the -D
(--dynamic) option.
--version
Print the version number of objdump and exit.
-x
--all-headers
Display all available header information, including
the symbol table and relocation entries. Using
`-x' is equivalent to specifying all of `-a -f -h
-r -t'.
SEE ALSO
`binutils' entry in info; The GNU Binary Utilities, Roland
H. Pesch (October 1991); nm(1).
COPYING
Copyright (c) 1991, 92, 93, 94, 95, 1996 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 ver-
sions of this manual under the conditions for verbatim
copying, provided 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 con-
ditions for modified versions, except that this permission
notice may be included in translations approved by the
Free Software Foundation instead of in the original En-
glish.
cygnus support 5 November 1991 1
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