freebsd-skq/contrib/elftoolchain/nm/nm.1
Ed Maste ae500c1ff8 Update to ELF Tool Chain r3668
Highlights:
- Make sure that only TLS sections are sorted into TLS segment.
- Fixed multiple errors in "Section to Segment mapping".
- Man page updates
- ar improvements
- elfcopy: avoid filter_reloc uninitialized variable for rela
- elfcopy: avoid stripping relocations from static binaries
- readelf: avoid printing directory in front of absolute path
- readelf: add NT_FREEBSD_FEATURE_CTL FreeBSD note type
- test improvements

NOTES:

Some of these changes originated in FreeBSD and simply reduce diffs
between contrib and vendor.

ELF Tool Chain ar is not (currently) used in FreeBSD, and there are
improvements in both FreeBSD and ELF Tool Chain ar that are not in
the other.

Sponsored by:	The FreeBSD Foundation
2019-01-10 14:35:23 +00:00

341 lines
7.8 KiB
Groff

.\" Copyright (c) 2007 Hyogeol Lee <hyogeollee@gmail.com>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer
.\" in this position and unchanged.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $Id: nm.1 3642 2018-10-14 14:24:28Z jkoshy $
.\"
.Dd September 13, 2017
.Dt NM 1
.Os
.Sh NAME
.Nm nm
.Nd display symbolic information in object files
.Sh SYNOPSIS
.Nm
.Op Fl -debug-syms
.Op Fl -defined-only
.Op Fl -demangle Ns Op = Ns style
.Op Fl -dynamic
.Op Fl -extern-only
.Op Fl -help
.Op Fl -line-numbers
.Op Fl -no-demangle
.Op Fl -no-sort
.Op Fl -numeric-sort
.Op Fl -print-armap
.Op Fl -print-file-name
.Op Fl -print-size
.Op Fl -radix= Ns Ar format
.Op Fl -reverse-sort
.Op Fl -size-sort
.Op Fl -undefined-only
.Op Fl -version
.Op Fl A
.Op Fl B
.Op Fl C Op Ar style
.Op Fl D
.Op Fl P
.Op Fl V
.Op Fl a
.Op Fl e
.Op Fl g
.Op Fl h
.Op Fl l
.Op Fl n
.Op Fl o
.Op Fl p
.Op Fl r
.Op Fl S
.Op Fl s
.Op Fl t Ar format
.Op Fl u
.Op Fl x
.Ar
.Sh DESCRIPTION
The
.Nm
utility displays symbolic information in the object files,
executables, and object library files named by its arguments.
Lack of symbolic information in an otherwise valid input
file, is not considered to be an error.
If no files are specified on the command line,
.Nm
will attempt to read
.Pa a.out .
.Pp
The
.Nm
utility recognizes the following options:
.Bl -tag -width ".Fl d Ar argument"
.It Fl -debug-syms
Display all symbols, including debugger-only symbols.
.It Fl -defined-only
Display only defined symbols.
.It Fl -demangle Ns Op = Ns Ar style
Decode (demangle) low-level symbol names into human-readable names.
Supported values for argument
.Ar style
are
.Sq auto ,
.Sq gnu-v2 ,
.Sq gnu-v3
and
.Sq arm.
If argument
.Ar style
is not specified, it is taken to be
.Sq auto .
.It Fl -dynamic
Only display dynamic symbols.
This option is only meaningful for shared libraries.
.It Fl -extern-only
Only display information about global (external) symbols.
.It Fl -help
Display a help message and exit.
.It Fl -format Ns = Ns Ar format
Display output in the format specified by argument
.Ar format .
Supported values for the format argument are
.Sq bsd ,
.Sq sysv ,
and
.Sq posix .
The default output format is
.Sq bsd .
.It Fl -line-numbers
Display the filename and line number associated a symbol using
any debugging information present in the input file.
For defined symbols, look up the line number associated with
the address of the symbol.
For undefined symbols, look up the line number associated with
a relocation entry that refers to the symbol.
If line number information can be determined, it is displayed after
other symbol information.
.It Fl -no-demangle
Do not demangle symbol names (default).
.It Fl -no-sort
Do not sort symbols.
.It Fl -numeric-sort
Sort symbols numerically by address instead of alphabetically by name.
.It Fl -print-armap
For
.Xr ar 1
archives, include the index of the archive's members.
.It Fl -print-file-name
Write the full pathname or library name of an object on each line,
before the rest of the information for a symbol.
If this option is not specified,
.Nm
will only identify an input file once, before its symbols are
listed.
.It Fl -print-size
Print the size of each symbol instead of its value.
.It Fl -radix Ns = Ns Ar radix
Print numeric values using the specified radix.
Supported values for argument
.Ar radix
are
.Sq d
for decimal,
.Sq o
for octal, and
.Sq x
for hexadecimal.
.It Fl -reverse-sort
Reverse the order of the sort.
.It Fl -size-sort
Sort symbols by size instead of alphabetically by name.
.It Fl -undefined-only
Display only undefined symbols.
.It Fl -version
Display the version identifier for
.Nm
and exit.
.It Fl A
Equivalent to specifying option
.Fl -print-file-name .
.It Fl B
Equivalent to specifying option
.Fl -format= Ns Ar bsd .
.It Fl C Op Ar style
Equivalent to specifying option
.Fl -demangle Ns Op = Ns Ar style .
.It Fl D
Equivalent to specifying option
.Fl -dynamic .
.It Fl F Ar format
Equivalent to specifying option
.Fl -format Ns = Ns Ar format .
.It Fl P
Equivalent to specifying option
.Fl -format Ns = Ns Ar posix .
.It Fl S
Equivalent to specifying option
.Fl -print-size .
.It Fl V
Equivalent to specifying option
.Fl -version .
.It Fl a
Equivalent to specifying option
.Fl -debug-syms .
.It Fl e
Only display information for global and static symbols.
.It Fl f
Produce full output (default).
.It Fl g
Equivalent to specifying option
.Fl -extern-only .
.It Fl h
Equivalent to specifying option
.Fl -help .
.It Fl l
Equivalent to specifying option
.Fl -line-numbers .
.It Fl n
Equivalent to specifying option
.Fl -numeric-sort .
.It Fl o
If POSIX output was specified using the
.Fl F Ar posix
or
.Fl P
options, this option is equivalent to specifying
.Fl -radix Ns = Ns Sq Ar o .
If POSIX output was not specified, this option
acts as a synonym for the
.Fl -print-file-name
option.
.It Fl p
Equivalent to specifying option
.Fl -no-sort .
.It Fl v
Equivalent to option
.Fl n .
.It Fl r
Equivalent to specifying option
.Fl -reverse-sort
.It Fl s
Equivalent to specifying option
.Fl -print-armap .
.It Fl t Ar radix
Equivalent to specifying option
.Fl -radix= Ns Ar radix .
.It Fl u
Equivalent to specifying option
.Fl -undefined-only .
.It Fl x
Write numeric values in hexadecimal (equivalent to -t x).
.El
.Sh OUTPUT FORMAT
.Pp
The
.Nm
utility can present its information in a number of formats, numeric
radices and sort orders.
By default
.Nm
uses BSD style output, a hexadecimal radix, without output sorted
alphabetically by name and without demangling of names.
.Pp
For each symbol listed,
.Nm
presents the following information:
.Bl -bullet -compact
.It
The library or object name, if options
.Fl A
or
.Fl -print-file-name
were specified.
.It
The symbol name.
.It
The type of the symbol denoted by a single character as below:
.Bl -tag -compact -width indent
.It A
A global, absolute symbol.
.It B
A global
.Dq bss
(uninitialized data) symbol.
.It C
A
.Dq common
symbol, representing uninitialized data.
.It D
A global symbol naming initialized data.
.It N
A debugger symbol.
.It R
A read-only data symbol.
.It T
A global text symbol.
.It U
An undefined symbol.
.It V
A weak object.
.It W
A weak reference.
.It a
A local absolute symbol.
.It b
A local
.Dq bss
(uninitialized data) symbol.
.It d
A local data symbol.
.It r
A local read-only data symbol.
.It t
A local text symbol.
.It v
A weak object that is undefined.
.It w
A weak symbol that is undefined.
.It ?
None of the above.
.El
.It
The value of the symbol.
.It
The size of the symbol if applicable.
.It
Line number information, if available and if options
.Fl l
or
.Fl -line-numbers
were specified.
.El
.Sh EXIT STATUS
.Ex -std
.Sh SEE ALSO
.Xr ar 1 ,
.Xr objdump 1 ,
.Xr ranlib 1 ,
.Xr elf 3
.Sh AUTHORS
The
.Nm
utility and this manual page were written by
.An Hyogeol Lee Aq Mt hyogeollee@gmail.com .