1029 lines
21 KiB
Groff
1029 lines
21 KiB
Groff
.\" Copyright (c) 1991, 1992 Free Software Foundation
|
|
.\" See section COPYING for conditions for redistribution
|
|
.\" $Id$
|
|
.TH gld 1 "23 January 1992" "cygnus support" "GNU Development Tools"
|
|
.de BP
|
|
.sp
|
|
.ti \-.2i
|
|
\(**
|
|
..
|
|
|
|
.SH NAME
|
|
gld \- the GNU linker
|
|
|
|
.SH SYNOPSIS
|
|
.hy 0
|
|
.na
|
|
.TP
|
|
.B gld
|
|
.RB "[\|" \-o "
|
|
.I output\c
|
|
\&\|] \c
|
|
.I objfiles\c
|
|
\&.\|.\|.
|
|
.br
|
|
.RB "[\|" \-A\c
|
|
.I architecture\c
|
|
\&\|]
|
|
.RB "[\|" "\-b\ "\c
|
|
.I input-format\c
|
|
\&\|]
|
|
.RB "[\|" \-Bstatic "\|]"
|
|
.RB "[\|" "\-c\ "\c
|
|
.I commandfile\c
|
|
\&\|]
|
|
.RB "[\|" \-d | \-dc | \-dp\c
|
|
\|]
|
|
.br
|
|
.RB "[\|" "\-defsym\ "\c
|
|
.I symbol\c
|
|
\& = \c
|
|
.I expression\c
|
|
\&\|]
|
|
.RB "[\|" "\-e\ "\c
|
|
.I entry\c
|
|
\&\|]
|
|
.RB "[\|" \-F "\|]"
|
|
.RB "[\|" "\-F\ "\c
|
|
.I format\c
|
|
\&\|]
|
|
.RB "[\|" "\-format\ "\c
|
|
.I input-format\c
|
|
\&\|]
|
|
.RB "[\|" \-g "\|]"
|
|
.RB "[\|" \-i "\|]"
|
|
.RB "[\|" \-l\c
|
|
.I ar\c
|
|
\&\|]
|
|
.RB "[\|" \-L\c
|
|
.I searchdir\c
|
|
\&\|]
|
|
.RB "[\|" \-M | \-m "\|]"
|
|
.RB "[\|" \-n "\|]"
|
|
.RB "[\|" \-noinhibit-exec "\|]"
|
|
.RB "[\|" "\-R\ "\c
|
|
.I filename\c
|
|
\&\|]
|
|
.RB "[\|" \-relax "\|]"
|
|
.RB "[\|" \-r | \-Ur "\|]"
|
|
.RB "[\|" \-S "\|]"
|
|
.RB "[\|" \-s "\|]"
|
|
.RB "[\|" "\-T\ "\c
|
|
.I commandfile\c
|
|
\&\|]
|
|
.RB "[\|" "\-Ttext\ "\c
|
|
.I textorg\c
|
|
\&\|]
|
|
.RB "[\|" "\-Tdata\ "\c
|
|
.I dataorg\c
|
|
\&\|]
|
|
.RB "[\|" "\-Tbss\ "\c
|
|
.I bssorg\c
|
|
\&\|]
|
|
.RB "[\|" \-t "\|]"
|
|
.RB "[\|" "\-u\ "\c
|
|
.I sym\c
|
|
\&]
|
|
.RB "[\|" \-v "\|]"
|
|
.RB "[\|" \-X "\|]"
|
|
.RB "[\|" \-x "\|]"
|
|
.RB "[\|" { \c
|
|
.I script\c
|
|
.BR } "\|]"
|
|
.ad b
|
|
.hy 1
|
|
.SH DESCRIPTION
|
|
\c
|
|
.B gld\c
|
|
\& combines a number of object and archive files, relocates
|
|
their data and ties up symbol references. Often the last step in
|
|
building a new compiled program to run is a call to \c
|
|
.B gld\c
|
|
\&.
|
|
|
|
\c
|
|
.B gld\c
|
|
\& accepts Linker Command Language files
|
|
to provide explicit and total control over the linking process.
|
|
This man page does not describe the command language; see the `\|\c
|
|
.B ld\c
|
|
\|' entry in `\|\c
|
|
.B info\c
|
|
\|', or the manual
|
|
.I
|
|
gld: the GNU linker
|
|
\&, for full details on the command language and on other aspects of
|
|
the GNU linker.
|
|
|
|
This version of \c
|
|
.B gld\c
|
|
\& uses the general purpose BFD libraries
|
|
to operate on object files. This allows \c
|
|
.B gld\c
|
|
\& to read, combine, and
|
|
write object files in many different formats\(em\&for example, COFF or
|
|
\c
|
|
.B a.out\c
|
|
\&. Different formats may be linked together to produce any
|
|
available kind of object file. You can use `\|\c
|
|
.B objdump \-i\c
|
|
\|' to get a list of formats supported on various architectures; see
|
|
.BR objdump ( 1 ).
|
|
|
|
Aside from its flexibility, the GNU linker is more helpful than other
|
|
linkers in providing diagnostic information. Many linkers abandon
|
|
execution immediately upon encountering an error; whenever possible,
|
|
\c
|
|
.B gld\c
|
|
\& continues executing, allowing you to identify other errors
|
|
(or, in some cases, to get an output file in spite of the error).
|
|
|
|
The GNU linker \c
|
|
.B gld\c
|
|
\& is meant to cover a broad range of situations,
|
|
and to be as compatible as possible with other linkers. As a result,
|
|
you have many choices to control its behavior through the command line,
|
|
and through environment variables.
|
|
|
|
.SH OPTIONS
|
|
The plethora of command-line options may seem intimidating, but in
|
|
actual practice few of them are used in any particular context.
|
|
For instance, a frequent use of \c
|
|
.B gld\c
|
|
\& is to link standard Unix
|
|
object files on a standard, supported Unix system. On such a system, to
|
|
link a file \c
|
|
.B hello.o\c
|
|
\&:
|
|
.sp
|
|
.br
|
|
$\ gld\ \-o\ output\ /lib/crt0.o\ hello.o\ \-lc
|
|
.br
|
|
.sp
|
|
This tells \c
|
|
.B gld\c
|
|
\& to produce a file called \c
|
|
.B output\c
|
|
\& as the
|
|
result of linking the file \c
|
|
.B /lib/crt0.o\c
|
|
\& with \c
|
|
.B hello.o\c
|
|
\& and
|
|
the library \c
|
|
.B libc.a\c
|
|
\& which will come from the standard search
|
|
directories.
|
|
|
|
The command-line options to \c
|
|
.B gld\c
|
|
\& may be specified in any order, and
|
|
may be repeated at will. For the most part, repeating an option with a
|
|
different argument will either have no further effect, or override prior
|
|
occurrences (those further to the left on the command line) of an
|
|
option.
|
|
|
|
The exceptions\(em\&which may meaningfully be used more than once\(em\&are
|
|
\c
|
|
.B \-A\c
|
|
\&, \c
|
|
.B \-b\c
|
|
\& (or its synonym \c
|
|
.B \-format\c
|
|
\&), \c
|
|
.B \-defsym\c
|
|
\&,
|
|
\c
|
|
.B \-L\c
|
|
\&, \c
|
|
.B \-l\c
|
|
\&, \c
|
|
.B \-R\c
|
|
\&, and \c
|
|
.B \-u\c
|
|
\&.
|
|
|
|
The list of object files to be linked together, shown as \c
|
|
.I objfiles\c
|
|
\&,
|
|
may follow, precede, or be mixed in with command-line options; save that
|
|
an \c
|
|
.I objfiles\c
|
|
\& argument may not be placed between an option flag and
|
|
its argument.
|
|
|
|
Usually the linker is invoked with at least one object file, but other
|
|
forms of binary input files can also be specified with \c
|
|
.B \-l\c
|
|
\&,
|
|
\c
|
|
.B \-R\c
|
|
\&, and the script command language. If \c
|
|
.I no\c
|
|
\& binary input
|
|
files at all are specified, the linker does not produce any output, and
|
|
issues the message `\|\c
|
|
.B No input files\c
|
|
\|'.
|
|
|
|
Option arguments must either follow the option letter without intervening
|
|
whitespace, or be given as separate arguments immediately following the
|
|
option that requires them.
|
|
|
|
.TP
|
|
.IR "objfiles" .\|.\|.
|
|
The object files \c
|
|
.I objfiles\c
|
|
\& to be linked.
|
|
|
|
.TP
|
|
.BI "-A" "architecture"\c
|
|
\&
|
|
In the current release of \c
|
|
.B gld\c
|
|
\&, this option is useful only for the
|
|
Intel 960 family of architectures. In that \c
|
|
.B gld\c
|
|
\& configuration, the
|
|
\c
|
|
.I architecture\c
|
|
\& argument is one of the two-letter names identifying
|
|
members of the 960 family; the option specifies the desired output
|
|
target, and warns of any incompatible instructions in the input files.
|
|
It also modifies the linker's search strategy for archive libraries, to
|
|
support the use of libraries specific to each particular
|
|
architecture, by including in the search loop names suffixed with the
|
|
string identifying the architecture.
|
|
|
|
For example, if your \c
|
|
.B gld\c
|
|
\& command line included `\|\c
|
|
.B \-ACA\c
|
|
\|' as
|
|
well as `\|\c
|
|
.B \-ltry\c
|
|
\|', the linker would look (in its built-in search
|
|
paths, and in any paths you specify with \c
|
|
.B \-L\c
|
|
\&) for a library with
|
|
the names
|
|
.sp
|
|
.br
|
|
try
|
|
.br
|
|
libtry.a
|
|
.br
|
|
tryca
|
|
.br
|
|
libtryca.a
|
|
.br
|
|
.sp
|
|
|
|
The first two possibilities would be considered in any event; the last
|
|
two are due to the use of `\|\c
|
|
.B \-ACA\c
|
|
\|'.
|
|
|
|
Future releases of \c
|
|
.B gld\c
|
|
\& may support similar functionality for
|
|
other architecture families.
|
|
|
|
You can meaningfully use \c
|
|
.B \-A\c
|
|
\& more than once on a command line, if
|
|
an architecture family allows combination of target architectures; each
|
|
use will add another pair of name variants to search for when \c
|
|
.B \-l\c
|
|
\&
|
|
specifies a library.
|
|
|
|
.TP
|
|
.BI "-b " "input-format"\c
|
|
\&
|
|
Specify the binary format for input object files that follow this option
|
|
on the command line. You don't usually need to specify this, as
|
|
\c
|
|
.B gld\c
|
|
\& is configured to expect as a default input format the most
|
|
usual format on each machine. \c
|
|
.I input-format\c
|
|
\& is a text string, the
|
|
name of a particular format supported by the BFD libraries.
|
|
\c
|
|
.B \-format \c
|
|
.I input-format\c
|
|
\&\c
|
|
\& has the same effect.
|
|
|
|
You may want to use this option if you are linking files with an unusual
|
|
binary format. You can also use \c
|
|
.B \-b\c
|
|
\& to switch formats explicitly (when
|
|
linking object files of different formats), by including
|
|
\c
|
|
.B \-b \c
|
|
.I input-format\c
|
|
\&\c
|
|
\& before each group of object files in a
|
|
particular format.
|
|
|
|
The default format is taken from the environment variable
|
|
.B GNUTARGET\c
|
|
\&. You can also define the input
|
|
format from a script, using the command \c
|
|
.B TARGET\c
|
|
\&.
|
|
|
|
.TP
|
|
.B \-Bstatic
|
|
This flag is accepted for command-line compatibility with the SunOS linker,
|
|
but has no effect on \c
|
|
.B gld\c
|
|
\&.
|
|
|
|
.TP
|
|
.BI "-c " "commandfile"\c
|
|
\&
|
|
Directs \c
|
|
.B gld\c
|
|
\& to read link commands from the file
|
|
\c
|
|
.I commandfile\c
|
|
\&. These commands will completely override \c
|
|
.B gld\c
|
|
\&'s
|
|
default link format (rather than adding to it); \c
|
|
.I commandfile\c
|
|
\& must
|
|
specify everything necessary to describe the target format.
|
|
|
|
|
|
You may also include a script of link commands directly in the command
|
|
line by bracketing it between `\|\c
|
|
.B {\c
|
|
\|' and `\|\c
|
|
.B }\c
|
|
\|' characters.
|
|
|
|
.TP
|
|
.B \-d
|
|
.TP
|
|
.B \-dc
|
|
.TP
|
|
.B \-dp
|
|
These three options are equivalent; multiple forms are supported for
|
|
compatibility with other linkers. Use any of them to make \c
|
|
.B ld\c
|
|
\&
|
|
assign space to common symbols even if a relocatable output file is
|
|
specified (\c
|
|
.B \-r\c
|
|
\&). The script command
|
|
\c
|
|
.B FORCE_COMMON_ALLOCATION\c
|
|
\& has the same effect.
|
|
|
|
.TP
|
|
.BI "-defsym " "symbol"\c
|
|
\& = \c
|
|
.I expression\c
|
|
\&
|
|
Create a global symbol in the output file, containing the absolute
|
|
address given by \c
|
|
.I expression\c
|
|
\&. You may use this option as many
|
|
times as necessary to define multiple symbols in the command line. A
|
|
limited form of arithmetic is supported for the \c
|
|
.I expression\c
|
|
\& in this
|
|
context: you may give a hexadecimal constant or the name of an existing
|
|
symbol, or use \c
|
|
.B +\c
|
|
\& and \c
|
|
.B \-\c
|
|
\& to add or subtract hexadecimal
|
|
constants or symbols. If you need more elaborate expressions, consider
|
|
using the linker command language from a script.
|
|
|
|
.TP
|
|
.BI "-e " "entry"\c
|
|
\&
|
|
Use \c
|
|
.I entry\c
|
|
\& as the explicit symbol for beginning execution of your
|
|
program, rather than the default entry point. for a
|
|
discussion of defaults and other ways of specifying the
|
|
entry point.
|
|
|
|
.TP
|
|
.B \-F
|
|
.TP
|
|
.BI "-F" "format"\c
|
|
\&
|
|
Some older linkers used this option throughout a compilation toolchain
|
|
for specifying object-file format for both input and output object
|
|
files. \c
|
|
.B gld\c
|
|
\&'s mechanisms (the \c
|
|
.B \-b\c
|
|
\& or \c
|
|
.B \-format\c
|
|
\& options
|
|
for input files, the \c
|
|
.B TARGET\c
|
|
\& command in linker scripts for output
|
|
files, the \c
|
|
.B GNUTARGET\c
|
|
\& environment variable) are more flexible, but
|
|
but it accepts (and ignores) the \c
|
|
.B \-F\c
|
|
\& option flag for compatibility
|
|
with scripts written to call the old linker.
|
|
|
|
.TP
|
|
.BI "-format " "input-format"\c
|
|
\&
|
|
Synonym for \c
|
|
.B \-b\c
|
|
\& \c
|
|
.I input-format\c
|
|
\&.
|
|
|
|
.TP
|
|
.B \-g
|
|
Accepted, but ignored; provided for compatibility with other tools.
|
|
|
|
.TP
|
|
.B \-i
|
|
Perform an incremental link (same as option \c
|
|
.B \-r\c
|
|
\&).
|
|
|
|
.TP
|
|
.BI "-l" "ar"\c
|
|
\&
|
|
Add an archive file \c
|
|
.I ar\c
|
|
\& to the list of files to link. This
|
|
option may be used any number of times. \c
|
|
.B ld\c
|
|
\& will search its
|
|
path-list for occurrences of \c
|
|
.B lib\c
|
|
.I ar\c
|
|
\&.a\c
|
|
\& for every \c
|
|
.I ar\c
|
|
\&
|
|
specified.
|
|
|
|
.TP
|
|
.BI "-L" "searchdir"\c
|
|
\&
|
|
This command adds path \c
|
|
.I searchdir\c
|
|
\& to the list of paths that
|
|
\c
|
|
.B gld\c
|
|
\& will search for archive libraries. You may use this option
|
|
any number of times.
|
|
|
|
The default set of paths searched (without being specified with
|
|
\c
|
|
.B \-L\c
|
|
\&) depends on what emulation mode \c
|
|
.B gld\c
|
|
\& is using, and in
|
|
some cases also on how it was configured. The
|
|
paths can also be specified in a link script with the \c
|
|
.B SEARCH_DIR\c
|
|
\&
|
|
command.
|
|
|
|
.TP
|
|
.B \-M
|
|
.TP
|
|
.B \-m
|
|
Print (to the standard output file) a link map\(em\&diagnostic information
|
|
about where symbols are mapped by \c
|
|
.B ld\c
|
|
\&, and information on global
|
|
common storage allocation.
|
|
|
|
.TP
|
|
.B \-n
|
|
sets the text segment to be read only, and \c
|
|
.B NMAGIC\c
|
|
\& is written
|
|
if possible.
|
|
|
|
.TP
|
|
.B \-noinhibit-exec
|
|
Normally, the linker will not produce an output file if it encounters
|
|
errors during the link process. With this flag, you can specify that
|
|
you wish the output file retained even after non-fatal errors.
|
|
|
|
.TP
|
|
.BI "-o " "output"\c
|
|
\&
|
|
.I output\c
|
|
\&
|
|
\c
|
|
.I output\c
|
|
\& is a name for the program produced by \c
|
|
.B ld\c
|
|
\&; if this
|
|
option is not specified, the name `\|\c
|
|
.B a.out\c
|
|
\|' is used by default. The
|
|
script command \c
|
|
.B OUTPUT\c
|
|
\& can also specify the output file name.
|
|
|
|
.TP
|
|
.BI "-R " "filename"\c
|
|
\&
|
|
.I file\c
|
|
\&
|
|
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 gld\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 \-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
|
|
.BI "{ " "script" " }"
|
|
You can, if you wish, include a script of linker commands directly in
|
|
the command line instead of referring to it via an input file. When the
|
|
character `\|\c
|
|
.B {\c
|
|
\|' occurs on the command line, the linker switches to
|
|
interpreting the command language until the end of the list of commands
|
|
is reached\(em\&flagged with a closing brace `\|\c
|
|
.B }\c
|
|
\|'. Other command-line
|
|
options will not be recognized while parsing the script.
|
|
for a description of the command language.
|
|
|
|
.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 textorg\c
|
|
\& must be a hexadecimal integer.
|
|
|
|
.TP
|
|
.BI "-T " "commandfile"\c
|
|
\&
|
|
.TP
|
|
.BI "-T" "commandfile"\c
|
|
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"\c
|
|
\&
|
|
.I sym\c
|
|
\&
|
|
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 gld\c
|
|
\&. When linking C++ programs, \c
|
|
.B \-Ur\c
|
|
\&
|
|
\c
|
|
.I will\c
|
|
\& resolve references to constructors, unlike \c
|
|
.B \-r\c
|
|
\&.
|
|
|
|
.TP
|
|
.B \-v
|
|
Display the version number for \c
|
|
.B gld\c
|
|
\&.
|
|
|
|
.TP
|
|
.B \-X
|
|
If \c
|
|
.B \-s\c
|
|
\& or \c
|
|
.B \-S\c
|
|
\& is also specified, delete only local symbols
|
|
beginning with `\|\c
|
|
.B L\c
|
|
\|'.
|
|
|
|
.TP
|
|
.B \-x
|
|
If \c
|
|
.B \-s\c
|
|
\& or \c
|
|
.B \-S\c
|
|
\& is also specified, delete all local symbols,
|
|
not just those beginning with `\|\c
|
|
.B L\c
|
|
\|'.
|
|
|
|
.PP
|
|
|
|
.SH ENVIRONMENT
|
|
\c
|
|
.B gld\c
|
|
\& always consults two environment variables: \c
|
|
.B GNUTARGET\c
|
|
\&
|
|
and \c
|
|
.B LDEMULATION\c
|
|
\&. Depending on the setting of the latter, other
|
|
environment variables may be used as well.
|
|
|
|
\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 gld\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.
|
|
|
|
\c
|
|
.B LDEMULATION\c
|
|
\& controls some aspects of \c
|
|
.B gld\c
|
|
\&'s dominant
|
|
personality. Although \c
|
|
.B gld\c
|
|
\& is flexible enough to permit its use
|
|
in many contexts regardless of configuration, you can use this variable
|
|
to make it act more like one or another older linker by default.
|
|
|
|
In particular, the value of \c
|
|
.B LDEMULATION\c
|
|
\& controls what default
|
|
linker script is used (thereby controlling the default input and output
|
|
formats; ; what default paths are searched for
|
|
archive libraries; and in some cases whether additional linker script
|
|
commands are available.
|
|
|
|
Here is the current set of emulations available:
|
|
|
|
.TP
|
|
.B LDEMULATION=gld
|
|
Emulate the older GNU linker. When this emulation is selected, the
|
|
default library search paths are
|
|
.sp
|
|
.br
|
|
/lib
|
|
.br
|
|
/usr/lib
|
|
.br
|
|
/usr/local/lib/lib
|
|
.br
|
|
.sp
|
|
|
|
The default output format is set to \c
|
|
.B a.out-generic-big\c
|
|
\&, and the
|
|
default machine is the system's configured BFD default.
|
|
|
|
.TP
|
|
.B LDEMULATION=gld68k
|
|
A variant of the \c
|
|
.B gld\c
|
|
\& emulation; only differs in specifically
|
|
setting the default BFD machine as \c
|
|
.B m68k\c
|
|
\&.
|
|
|
|
.TP
|
|
.B LDEMULATION=gld960
|
|
Emulate the Intel port of the older \c
|
|
.B gld\c
|
|
\& for the i960
|
|
architectures. The default library search paths are taken from two
|
|
other environment variables, \c
|
|
.B G960LIB\c
|
|
\& and \c
|
|
.B G960BASE\c
|
|
\&. The
|
|
default architecture is \c
|
|
.B i960\c
|
|
\&. The default output format is set
|
|
to \c
|
|
.B b.out.big\c
|
|
\&, and in fact the default output file name (if
|
|
\c
|
|
.B \-o\c
|
|
\& is not specified) is \c
|
|
.B b.out\c
|
|
\&, to reflect this variant
|
|
format, for this emulation.
|
|
|
|
This emulation can behave slightly differently depending on the setting
|
|
of the \c
|
|
.B gld\c
|
|
\& compile-time switch \c
|
|
.B GNU960\c
|
|
\&. If \c
|
|
.B gld\c
|
|
\& is
|
|
compiled with \c
|
|
.B GNU960\c
|
|
\& defined, then an additional environment
|
|
variable\(em\&\c
|
|
.B GNUTARGET\c
|
|
\&\(em\&is available; its value, if available,
|
|
specifies some other default output format than \c
|
|
.B b.out.big\c
|
|
\&.
|
|
|
|
.TP
|
|
.B LDEMULATION=gldm88kbcs
|
|
Sets the output format to \c
|
|
.B m88kbcs\c
|
|
\& and the architecture to
|
|
\c
|
|
.B m88k\c
|
|
\&. Default library search paths are
|
|
.sp
|
|
.br
|
|
/lib
|
|
.br
|
|
/usr/lib
|
|
.br
|
|
/usr/local/lib
|
|
.br
|
|
.sp
|
|
|
|
.TP
|
|
.B LDEMULATION=lnk960
|
|
Emulate the Intel linker \c
|
|
.B lnk960\c
|
|
\&. The default output format is
|
|
\c
|
|
.B coff-Intel-big\c
|
|
\&. With this emulation, \c
|
|
.B gld\c
|
|
\&
|
|
supports the additional script commands \c
|
|
.B HLL\c
|
|
\& and \c
|
|
.B SYSLIB\c
|
|
\& for
|
|
specification of library archives. This is the only emulation with
|
|
extensive support for the \c
|
|
.B \-A\c
|
|
\& (architecture) command-line option.
|
|
By default, the architecture \c
|
|
.B CORE\c
|
|
\& is assumed, but you can choose
|
|
additional features from the i960 architecture family by using one of
|
|
the following with \c
|
|
.B \-A\c
|
|
\& (or by using the \c
|
|
.B OUTPUT_ARCH\c
|
|
\& command
|
|
from a script):
|
|
.sp
|
|
.br
|
|
CORE
|
|
.br
|
|
KB
|
|
.br
|
|
SB
|
|
.br
|
|
MC
|
|
.br
|
|
XA
|
|
.br
|
|
CA
|
|
.br
|
|
KA
|
|
.br
|
|
SA
|
|
.br
|
|
.sp
|
|
|
|
The default libraries are chosen with some attention to the architecture
|
|
selected; the core library `\|\c
|
|
.B cg\c
|
|
\|' is always included, but the library
|
|
\c
|
|
.B fpg\c
|
|
\& is also used if you've specified any of the architectures
|
|
\c
|
|
.B KA\c
|
|
\&, \c
|
|
.B SA\c
|
|
\&, or \c
|
|
.B CA\c
|
|
\&.
|
|
|
|
Like \c
|
|
.B gld960\c
|
|
\&, this emulation uses additional environment variables
|
|
to set the default library search paths. Also like \c
|
|
.B gld960\c
|
|
\&, the
|
|
behavior of this emulation is slightly different depending on whether
|
|
\c
|
|
.B gld\c
|
|
\& itself was compiled with \c
|
|
.B GNU960\c
|
|
\& defined.
|
|
|
|
If your \c
|
|
.B gld\c
|
|
\& was compiled with \c
|
|
.B GNU960\c
|
|
\& defined, the default
|
|
paths are taken from all three of \c
|
|
.B G960LIB\c
|
|
\&, \c
|
|
.B G960BASE\c
|
|
\&, and
|
|
\c
|
|
.B I960BASE\c
|
|
\&. For the first two, paths you supply are automatically
|
|
suffixed with `\|\c
|
|
.B /lib/libcoff\c
|
|
\|'; for the last, your path is
|
|
automatically suffixed with `\|\c
|
|
.B /lib\c
|
|
\|'.
|
|
|
|
If your \c
|
|
.B gld\c
|
|
\& was \c
|
|
.I not\c
|
|
\& compiled with \c
|
|
.B GNU960\c
|
|
\& defined,
|
|
the default paths are taken from \c
|
|
.B I960BASE\c
|
|
\&, and \c
|
|
.B G960BASE\c
|
|
\& is
|
|
only consulted if \c
|
|
.B I960BASE\c
|
|
\& is undefined. In this case
|
|
\c
|
|
.B G960LIB\c
|
|
\& is not used at all.
|
|
|
|
.TP
|
|
.B LDEMULATION=vanilla
|
|
This is the least specific setting for \c
|
|
.B gld\c
|
|
\&. You can set
|
|
\c
|
|
.B LDEMULATION=vanilla\c
|
|
\& to disable emulation of other linkers. This
|
|
setting makes \c
|
|
.B gld\c
|
|
\& take the default machine from the BFD
|
|
configuration on your system; \c
|
|
.B a.out-generic-big\c
|
|
\& is the default
|
|
target. No other defaults are specified.
|
|
|
|
.PP
|
|
|
|
.SH "SEE ALSO"
|
|
|
|
.BR objdump ( 1 )
|
|
.br
|
|
.br
|
|
.RB "`\|" ld "\|' and `\|" binutils "\|'"
|
|
entries in
|
|
.B info\c
|
|
.br
|
|
.I
|
|
gld: the GNU linker\c
|
|
, Steve Chamberlain and Roland Pesch;
|
|
.I
|
|
The GNU Binary Utilities\c
|
|
, Roland H. Pesch.
|
|
|
|
.SH COPYING
|
|
Copyright (c) 1991, 1992 Free Software Foundation, Inc.
|
|
.PP
|
|
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.
|
|
.PP
|
|
Permission is granted to copy and distribute modified versions 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.
|
|
.PP
|
|
Permission is granted to copy and distribute translations of this
|
|
manual into another language, under the above conditions for modified
|
|
versions, except that this permission notice may be included in
|
|
translations approved by the Free Software Foundation instead of in
|
|
the original English.
|