ld.1

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.B OUTPUT_FORMAT
can also specify the output format, but this option overrides it.

.TP
.BI "\-R " "filename"
Read symbol names and their addresses from \c
.I filename\c
\&, but do not
relocate it or include it in the output.  This allows your output file
to refer symbolically to absolute locations of memory defined in other
programs.

.TP
.B \-relax
An option with machine dependent effects.  Currently this option is only
supported on the H8/300.

On some platforms, use this option to perform global optimizations that
become possible when the linker resolves addressing in your program, such
as relaxing address modes and synthesizing new instructions in the
output object file.  

On platforms where this is not supported, `\|\c
.B \-relax\c
\&\|' is accepted, but has no effect.

.TP
.B \-r 
Generates relocatable output\(em\&i.e., generate an output file that can in
turn serve as input to \c
.B ld\c
\&.  This is often called \c
.I partial
linking\c
\&.  As a side effect, in environments that support standard Unix
magic numbers, this option also sets the output file's magic number to
\c
.B OMAGIC\c
\&.
If this option is not specified, an absolute file is produced.  When
linking C++ programs, this option \c
.I will not\c
\& resolve references to
constructors; \c
.B \-Ur\c
\& is an alternative. 

This option does the same as \c
.B \-i\c
\&.

.TP
.B \-rpath\ \fIdirectory
Add a directory to the runtime library search path.  This is used when
linking an ELF executable with shared objects.  All 
.B \-rpath
arguments are concatenated and passed to the runtime linker, which uses
them to locate shared objects at runtime.  The
.B \-rpath
option is also used when locating shared objects which are needed by
shared objects explicitly included in the link; see the description of
the
.B \-rpath\-link
option.  If
.B \-rpath
is not used when linking an ELF executable, the contents of the
environment variable
.B LD_RUN_PATH
will be used if it is defined.

The
.B \-rpath
option may also be used on SunOS.  By default, on SunOS, the linker
will form a runtime search path out of all the
.B \-L
options it is given.  If a
.B \-rpath
option is used, the runtime search path will be formed exclusively
using the
.B \-rpath
options, ignoring
the
.B \-L
options.  This can be useful when using gcc, which adds many
.B \-L
options which may be on NFS mounted filesystems.

.TP
.B \-rpath\-link\ \fIdirectory
When using ELF or SunOS, one shared library may require another.  This
happens when an
.B ld\ \-shared
link includes a shared library as one of the input files.

When the linker encounters such a dependency when doing a non-shared,
non-relocateable link, it will automatically try to locate the required
shared library and include it in the link, if it is not included
explicitly.  In such a case, the
.B \-rpath\-link
option specifies the first set of directories to search.  The
.B \-rpath\-link
option may specify a sequence of directory names either by specifying
a list of names separated by colons, or by appearing multiple times.

If the required shared library is not found, the linker will issue a
warning and continue with the link.

.TP
.B \-S 
Omits debugger symbol information (but not all symbols) from the output file.

.TP
.B \-s 
Omits all symbol information from the output file.

.TP
.B \-shared
Create a shared library.  This is currently only supported on ELF and
SunOS platforms (on SunOS it is not required, as the linker will
automatically create a shared library when there are undefined symbols
and the
.B \-e
option is not used).

.TP
.B \-sort\-common
Normally, when
.B ld
places the global common symbols in the appropriate output sections,
it sorts them by size.  First come all the one byte symbols, then all
the two bytes, then all the four bytes, and then everything else.
This is to prevent gaps between symbols due to
alignment constraints.  This option disables that sorting.

.TP
.B \-split\-by\-reloc\ \fIcount
Trys to creates extra sections in the output file so that no single
output section in the file contains more than
.I count
relocations.
This is useful when generating huge relocatable for downloading into
certain real time kernels with the COFF object file format; since COFF
cannot represent more than 65535 relocations in a single section.
Note that this will fail to work with object file formats which do not
support arbitrary sections.  The linker will not split up individual
input sections for redistribution, so if a single input section
contains more than
.I count
relocations one output section will contain that many relocations.

.TP
.B \-split\-by\-file
Similar to
.B \-split\-by\-reloc
but creates a new output section for each input file.

.TP
.BI "--section-start " "sectionname" "\fR=\fP"org
Locate a section in the output file at the absolute
address given by \c
.I org\c
\&.  \c
\c
.I org\c
\& must be a hexadecimal integer.
You may use this option as many
times as necessary to locate multiple sections in the command
line.  If you need more elaborate expressions, consider
using the linker command language from a script.

.TP
.BI "\-Tbss " "org"\c
.TP
.BI "\-Tdata " "org"\c
.TP
.BI "\-Ttext " "org"\c
Use \c
.I org\c
\& as the starting address for\(em\&respectively\(em\&the
\c
.B bss\c
\&, \c
.B data\c
\&, or the \c
.B text\c
\& segment of the output file.
\c
.I org\c
\& must be a hexadecimal integer.

.TP
.BI "\-T " "commandfile"
Equivalent to \c
.B \-c \c
.I commandfile\c
\&\c
\&; supported for compatibility with
other tools.  

.TP
.B \-t 
Prints names of input files as \c
.B ld\c
\& processes them.

.TP
.BI "\-u " "sym"
Forces \c
.I sym\c
\& to be entered in the output file as an undefined symbol.
This may, for example, trigger linking of additional modules from
standard libraries.  \c
.B \-u\c
\& may be repeated with different option
arguments to enter additional undefined symbols.

.TP
.B \-Ur 
For anything other than C++ programs, this option is equivalent to
\c
.B \-r\c
\&: it generates relocatable output\(em\&i.e., an output file that can in
turn serve as input to \c
.B ld\c
\&.  When linking C++ programs, \c
.B \-Ur
.I will\c
\& resolve references to constructors, unlike \c
.B \-r\c
\&.

.TP
.B \-\-verbose
Display the version number for \c
.B ld
and list the supported emulations.
Display which input files can and can not be opened.

.TP
.B \-v, \-V
Display the version number for \c
.B ld\c
\&.
The
.B \-V
option also lists the supported emulations.

.TP
.B \-\-version
Display the version number for \c
.B ld
and exit.

.TP
.B \-warn\-common
Warn when a common symbol is combined with another common symbol or with
a symbol definition.  Unix linkers allow this somewhat sloppy practice,
but linkers on some other operating systems do not.  This option allows
you to find potential problems from combining global symbols.

.TP
.B \-warn\-constructors
Warn if any global constructors are used.  This is only useful for a
few object file formats.  For formats like COFF or ELF, the linker can
not detect the use of global constructors.

.TP
.B \-warn\-multiple\-gp
Warn if the output file requires multiple global-pointer values.  This
option is only meaningful for certain processors, such as the Alpha.

.TP
.B \-warn\-once
Only warn once for each undefined symbol, rather than once per module
which refers to it.

.TP
.B \-warn\-section\-align
Warn if the address of an output section is changed because of
alignment.  Typically, the alignment will be set by an input section.
The address will only be changed if it not explicitly specified; that
is, if the SECTIONS command does not specify a start address for the
section.

.TP
.B \-\-whole\-archive
For each archive mentioned on the command line after the
.B \-\-whole\-archive
option, include every object file in the archive in the link, rather
than searching the archive for the required object files.  This is
normally used to turn an archive file into a shared library, forcing
every object to be included in the resulting shared library.

.TP
.B \-\-no\-whole\-archive
Turn off the effect of the
.B \-\-whole\-archive
option for archives which appear later on the command line.

.TP
.BI "--wrap " "symbol"
Use a wrapper function for 
.I symbol.
Any undefined reference to
.I symbol
will be resolved to
.BI "__wrap_" "symbol".
Any undefined reference to
.BI "__real_" "symbol"
will be resolved to
.I symbol.

.TP
.B \-X 
Delete all temporary local symbols.  For most targets, this is all local
symbols whose names begin with `\|\c
.B L\c
\|'.

.TP
.B \-x
Delete all local symbols.

.PP

.SH ENVIRONMENT
\c
You can change the behavior of
.B ld\c
\& with the environment variable \c
.B GNUTARGET\c
\&.

\c
.B GNUTARGET\c
\& determines the input-file object format if you don't
use \c
.B \-b\c
\& (or its synonym \c
.B \-format\c
\&).  Its value should be one
of the BFD names for an input format.  If there is no
\c
.B GNUTARGET\c
\& in the environment, \c
.B ld\c
\& uses the natural format
of the host. If \c
.B GNUTARGET\c
\& is set to \c
.B default\c
\& then BFD attempts to discover the
input format by examining binary input files; this method often
succeeds, but there are potential ambiguities, since there is no method
of ensuring that the magic number used to flag object-file formats is
unique.  However, the configuration procedure for BFD on each system
places the conventional format for that system first in the search-list,
so ambiguities are resolved in favor of convention.

.PP

.SH "SEE ALSO"

.BR objdump ( 1 )
.br
.br
.RB "`\|" ld "\|' and `\|" binutils "\|'"
entries in
.B info\c
.br
.I 
ld: the GNU linker\c
, Steve Chamberlain and Roland Pesch;
.I
The GNU Binary Utilities\c
, Roland H. Pesch.

.SH COPYING