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LD(1)			     GNU Development Tools			 LD(1)

NAME
       ld - Using LD, the GNU linker

SYNOPSIS
       ld [options] objfile ...

DESCRIPTION
       ld combines a number of object and archive files, relocates their data
       and ties up symbol references. Usually the last step in compiling a
       program is to run ld.

       ld accepts Linker Command Language files written in a superset of
       AT&T's Link Editor Command Language syntax, to provide explicit and
       total control over the linking process.

       This man page does not describe the command language; see the ld entry
       in "info", or the manual ld: the GNU linker, for full details on the
       command language and on other aspects of the GNU linker.

       This version of ld uses the general purpose BFD libraries to operate on
       object files. This allows ld to read, combine, and write object files
       in many different formats---for example, COFF or "a.out".  Different
       formats may be linked together to produce any available kind of object
       file.

       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, ld
       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 ld 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.

OPTIONS
       The linker supports a plethora of command-line options, but in actual
       practice few of them are used in any particular context.	 For instance,
       a frequent use of ld is to link standard Unix object files on a
       standard, supported Unix system.	 On such a system, to link a file
       "hello.o":

	       ld -o <output> /lib/crt0.o hello.o -lc

       This tells ld to produce a file called output as the result of linking
       the file "/lib/crt0.o" with "hello.o" and the library "libc.a", which
       will come from the standard search directories.	(See the discussion of
       the -l option below.)

       Some of the command-line options to ld may be specified at any point in
       the command line.  However, options which refer to files, such as -l or
       -T, cause the file to be read at the point at which the option appears
       in the command line, relative to the object files and other file
       options.	 Repeating non-file options with a different argument will
       either have no further effect, or override prior occurrences (those
       further to the left on the command line) of that option.	 Options which
       may be meaningfully specified more than once are noted in the
       descriptions below.

       Non-option arguments are object files or archives which are to be
       linked together.	 They may follow, precede, or be mixed in with
       command-line options, except that an object file argument may not be
       placed between an option and its argument.

       Usually the linker is invoked with at least one object file, but you
       can specify other forms of binary input files using -l, -R, and the
       script command language.	 If no binary input files at all are
       specified, the linker does not produce any output, and issues the
       message No input files.

       If the linker cannot recognize the format of an object file, it will
       assume that it is a linker script.  A script specified in this way
       augments the main linker script used for the link (either the default
       linker script or the one specified by using -T).	 This feature permits
       the linker to link against a file which appears to be an object or an
       archive, but actually merely defines some symbol values, or uses
       "INPUT" or "GROUP" to load other objects.  Note that specifying a
       script in this way merely augments the main linker script; use the -T
       option to replace the default linker script entirely.

       For options whose names are a single letter, option arguments must
       either follow the option letter without intervening whitespace, or be
       given as separate arguments immediately following the option that
       requires them.

       For options whose names are multiple letters, either one dash or two
       can precede the option name; for example, -trace-symbol and
       --trace-symbol are equivalent.  Note---there is one exception to this
       rule.  Multiple letter options that start with a lower case 'o' can
       only be preceeded by two dashes.	 This is to reduce confusion with the
       -o option.  So for example -omagic sets the output file name to magic
       whereas --omagic sets the NMAGIC flag on the output.

       Arguments to multiple-letter options must either be separated from the
       option name by an equals sign, or be given as separate arguments
       immediately following the option that requires them.  For example,
       --trace-symbol foo and --trace-symbol=foo are equivalent.  Unique
       abbreviations of the names of multiple-letter options are accepted.

       Note---if the linker is being invoked indirectly, via a compiler driver
       (e.g. gcc) then all the linker command line options should be prefixed
       by -Wl, (or whatever is appropriate for the particular compiler driver)
       like this:

		 gcc -Wl,--startgroup foo.o bar.o -Wl,--endgroup

       This is important, because otherwise the compiler driver program may
       silently drop the linker options, resulting in a bad link.

       Here is a table of the generic command line switches accepted by the
       GNU linker:

       -akeyword
	   This option is supported for HP/UX compatibility.  The keyword
	   argument must be one of the strings archive, shared, or default.
	   -aarchive is functionally equivalent to -Bstatic, and the other two
	   keywords are functionally equivalent to -Bdynamic.  This option may
	   be used any number of times.

       -Aarchitecture

       --architecture=architecture
	   In the current release of ld, this option is useful only for the
	   Intel 960 family of architectures.  In that ld configuration, the
	   architecture argument identifies the particular architecture in the
	   960 family, enabling some safeguards and modifying the
	   archive-library search path.

	   Future releases of ld may support similar functionality for other
	   architecture families.

       -b input-format

       --format=input-format
	   ld may be configured to support more than one kind of object file.
	   If your ld is configured this way, you can use the -b option to
	   specify the binary format for input object files that follow this
	   option on the command line.	Even when ld is configured to support
	   alternative object formats, you don't usually need to specify this,
	   as ld should be configured to expect as a default input format the
	   most usual format on each machine.  input-format is a text string,
	   the name of a particular format supported by the BFD libraries.
	   (You can list the available binary formats with objdump -i.)

	   You may want to use this option if you are linking files with an
	   unusual binary format.  You can also use -b to switch formats
	   explicitly (when linking object files of different formats), by
	   including -b input-format before each group of object files in a
	   particular format.

	   The default format is taken from the environment variable
	   "GNUTARGET".

	   You can also define the input format from a script, using the
	   command "TARGET";

       -c MRI-commandfile

       --mri-script=MRI-commandfile
	   For compatibility with linkers produced by MRI, ld accepts script
	   files written in an alternate, restricted command language,
	   described in the MRI Compatible Script Files section of GNU ld
	   documentation.  Introduce MRI script files with the option -c; use
	   the -T option to run linker scripts written in the general-purpose
	   ld scripting language.  If MRI-cmdfile does not exist, ld looks for
	   it in the directories specified by any -L options.

       -d

       -dc

       -dp These three options are equivalent; multiple forms are supported
	   for compatibility with other linkers.  They assign space to common
	   symbols even if a relocatable output file is specified (with -r).
	   The script command "FORCE_COMMON_ALLOCATION" has the same effect.

       -e entry

       --entry=entry
	   Use entry as the explicit symbol for beginning execution of your
	   program, rather than the default entry point.  If there is no
	   symbol named entry, the linker will try to parse entry as a number,
	   and use that as the entry address (the number will be interpreted
	   in base 10; you may use a leading 0x for base 16, or a leading 0
	   for base 8).

       -E

       --export-dynamic
	   When creating a dynamically linked executable, add all symbols to
	   the dynamic symbol table.  The dynamic symbol table is the set of
	   symbols which are visible from dynamic objects at run time.

	   If you do not use this option, the dynamic symbol table will
	   normally contain only those symbols which are referenced by some
	   dynamic object mentioned in the link.

	   If you use "dlopen" to load a dynamic object which needs to refer
	   back to the symbols defined by the program, rather than some other
	   dynamic object, then you will probably need to use this option when
	   linking the program itself.

	   You can also use the version script to control what symbols should
	   be added to the dynamic symbol table if the output format supports
	   it.	See the description of --version-script in @ref{VERSION}.

       -EB Link big-endian objects.  This affects the default output format.

       -EL Link little-endian objects.	This affects the default output
	   format.

       -f

       --auxiliary name
	   When creating an ELF shared object, set the internal DT_AUXILIARY
	   field to the specified name.	 This tells the dynamic linker that
	   the symbol table of the shared object should be used as an
	   auxiliary filter on the symbol table of the shared object name.

	   If you later link a program against this filter object, then, when
	   you run the program, the dynamic linker will see the DT_AUXILIARY
	   field.  If the dynamic linker resolves any symbols from the filter
	   object, it will first check whether there is a definition in the
	   shared object name.	If there is one, it will be used instead of
	   the definition in the filter object.	 The shared object name need
	   not exist.  Thus the shared object name may be used to provide an
	   alternative implementation of certain functions, perhaps for
	   debugging or for machine specific performance.

	   This option may be specified more than once.	 The DT_AUXILIARY
	   entries will be created in the order in which they appear on the
	   command line.

       -F name

       --filter name
	   When creating an ELF shared object, set the internal DT_FILTER
	   field to the specified name.	 This tells the dynamic linker that
	   the symbol table of the shared object which is being created should
	   be used as a filter on the symbol table of the shared object name.

	   If you later link a program against this filter object, then, when
	   you run the program, the dynamic linker will see the DT_FILTER
	   field.  The dynamic linker will resolve symbols according to the
	   symbol table of the filter object as usual, but it will actually
	   link to the definitions found in the shared object name.  Thus the
	   filter object can be used to select a subset of the symbols
	   provided by the object name.

	   Some older linkers used the -F option throughout a compilation
	   toolchain for specifying object-file format for both input and
	   output object files.	 The GNU linker uses other mechanisms for this
	   purpose: the -b, --format, --oformat options, the "TARGET" command
	   in linker scripts, and the "GNUTARGET" environment variable.	 The
	   GNU linker will ignore the -F option when not creating an ELF
	   shared object.

       -fini name
	   When creating an ELF executable or shared object, call NAME when
	   the executable or shared object is unloaded, by setting DT_FINI to
	   the address of the function.	 By default, the linker uses "_fini"
	   as the function to call.

       -g  Ignored.  Provided for compatibility with other tools.

       -Gvalue

       --gpsize=value
	   Set the maximum size of objects to be optimized using the GP
	   register to size.  This is only meaningful for object file formats
	   such as MIPS ECOFF which supports putting large and small objects
	   into different sections.  This is ignored for other object file
	   formats.

       -hname

       -soname=name
	   When creating an ELF shared object, set the internal DT_SONAME
	   field to the specified name.	 When an executable is linked with a
	   shared object which has a DT_SONAME field, then when the executable
	   is run the dynamic linker will attempt to load the shared object
	   specified by the DT_SONAME field rather than the using the file
	   name given to the linker.

       -i  Perform an incremental link (same as option -r).

       -init name
	   When creating an ELF executable or shared object, call NAME when
	   the executable or shared object is loaded, by setting DT_INIT to
	   the address of the function.	 By default, the linker uses "_init"
	   as the function to call.

       -larchive

       --library=archive
	   Add archive file archive to the list of files to link.  This option
	   may be used any number of times.  ld will search its path-list for
	   occurrences of "libarchive.a" for every archive specified.

	   On systems which support shared libraries, ld may also search for
	   libraries with extensions other than ".a".  Specifically, on ELF
	   and SunOS systems, ld will search a directory for a library with an
	   extension of ".so" before searching for one with an extension of
	   ".a".  By convention, a ".so" extension indicates a shared library.

	   The linker will search an archive only once, at the location where
	   it is specified on the command line.	 If the archive defines a
	   symbol which was undefined in some object which appeared before the
	   archive on the command line, the linker will include the
	   appropriate file(s) from the archive.  However, an undefined symbol
	   in an object appearing later on the command line will not cause the
	   linker to search the archive again.

	   See the -( option for a way to force the linker to search archives
	   multiple times.

	   You may list the same archive multiple times on the command line.

	   This type of archive searching is standard for Unix linkers.
	   However, if you are using ld on AIX, note that it is different from
	   the behaviour of the AIX linker.

       -Lsearchdir

       --library-path=searchdir
	   Add path searchdir to the list of paths that ld will search for
	   archive libraries and ld control scripts.  You may use this option
	   any number of times.	 The directories are searched in the order in
	   which they are specified on the command line.  Directories
	   specified on the command line are searched before the default
	   directories.	 All -L options apply to all -l options, regardless of
	   the order in which the options appear.

	   If searchdir begins with "=", then the "=" will be replaced by the
	   sysroot prefix, a path specified when the linker is configured.

	   The default set of paths searched (without being specified with -L)
	   depends on which emulation mode ld is using, and in some cases also
	   on how it was configured.

	   The paths can also be specified in a link script with the
	   "SEARCH_DIR" command.  Directories specified this way are searched
	   at the point in which the linker script appears in the command
	   line.

       -memulation
	   Emulate the emulation linker.  You can list the available
	   emulations with the --verbose or -V options.

	   If the -m option is not used, the emulation is taken from the
	   "LDEMULATION" environment variable, if that is defined.

	   Otherwise, the default emulation depends upon how the linker was
	   configured.

       -M

       --print-map
	   Print a link map to the standard output.  A link map provides
	   information about the link, including the following:
	   o   Where object files and symbols are mapped into memory.

	   o   How common symbols are allocated.

	   o   All archive members included in the link, with a mention of the
	       symbol which caused the archive member to be brought in.

       -n

       --nmagic
	   Turn off page alignment of sections, and mark the output as
	   "NMAGIC" if possible.

       -N

       --omagic
	   Set the text and data sections to be readable and writable.	Also,
	   do not page-align the data segment, and disable linking against
	   shared libraries.  If the output format supports Unix style magic
	   numbers, mark the output as "OMAGIC". Note: Although a writable
	   text section is allowed for PE-COFF targets, it does not conform to
	   the format specification published by Microsoft.

       --no-omagic
	   This option negates most of the effects of the -N option.  It sets
	   the text section to be read-only, and forces the data segment to be
	   page-aligned.  Note - this option does not enable linking against
	   shared libraries.  Use -Bdynamic for this.

       -o output

       --output=output
	   Use output as the name for the program produced by ld; if this
	   option is not specified, the name a.out is used by default.	The
	   script command "OUTPUT" can also specify the output file name.

       -O level
	   If level is a numeric values greater than zero ld optimizes the
	   output.  This might take significantly longer and therefore
	   probably should only be enabled for the final binary.

       -q

       --emit-relocs
	   Leave relocation sections and contents in fully linked
	   exececutables.  Post link analysis and optimization tools may need
	   this information in order to perform correct modifications of
	   executables.	 This results in larger executables.

	   This option is currently only supported on ELF platforms.

       -r

       --relocatable
	   Generate relocatable output---i.e., generate an output file that
	   can in turn serve as input to ld.  This is often called partial
	   linking.  As a side effect, in environments that support standard
	   Unix magic numbers, this option also sets the output file's magic
	   number to "OMAGIC".	If this option is not specified, an absolute
	   file is produced.  When linking C++ programs, this option will not
	   resolve references to constructors; to do that, use -Ur.

	   When an input file does not have the same format as the output
	   file, partial linking is only supported if that input file does not
	   contain any relocations.  Different output formats can have further
	   restrictions; for example some "a.out"-based formats do not support
	   partial linking with input files in other formats at all.

	   This option does the same thing as -i.

       -R filename

       --just-symbols=filename
	   Read symbol names and their addresses from filename, 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.  You may use this option more than once.

	   For compatibility with other ELF linkers, if the -R option is
	   followed by a directory name, rather than a file name, it is
	   treated as the -rpath option.

       -s

       --strip-all
	   Omit all symbol information from the output file.

       -S

       --strip-debug
	   Omit debugger symbol information (but not all symbols) from the
	   output file.

       -t

       --trace
	   Print the names of the input files as ld processes them.

       -T scriptfile

       --script=scriptfile
	   Use scriptfile as the linker script.	 This script replaces ld's
	   default linker script (rather than adding to it), so commandfile
	   must specify everything necessary to describe the output file.
	   If scriptfile does not exist in the current directory, "ld" looks
	   for it in the directories specified by any preceding -L options.
	   Multiple -T options accumulate.

       -u symbol

       --undefined=symbol
	   Force symbol to be entered in the output file as an undefined
	   symbol.  Doing this may, for example, trigger linking of additional
	   modules from standard libraries.  -u may be repeated with different
	   option arguments to enter additional undefined symbols.  This
	   option is equivalent to the "EXTERN" linker script command.

       -Ur For anything other than C++ programs, this option is equivalent to
	   -r: it generates relocatable output---i.e., an output file that can
	   in turn serve as input to ld.  When linking C++ programs, -Ur does
	   resolve references to constructors, unlike -r.  It does not work to
	   use -Ur on files that were themselves linked with -Ur; once the
	   constructor table has been built, it cannot be added to.  Use -Ur
	   only for the last partial link, and -r for the others.

       --unique[=SECTION]
	   Creates a separate output section for every input section matching
	   SECTION, or if the optional wildcard SECTION argument is missing,
	   for every orphan input section.  An orphan section is one not
	   specifically mentioned in a linker script.  You may use this option
	   multiple times on the command line;	It prevents the normal merging
	   of input sections with the same name, overriding output section
	   assignments in a linker script.

       -v

       --version

       -V  Display the version number for ld.  The -V option also lists the
	   supported emulations.

       -x

       --discard-all
	   Delete all local symbols.

       -X

       --discard-locals
	   Delete all temporary local symbols.	For most targets, this is all
	   local symbols whose names begin with L.

       -y symbol

       --trace-symbol=symbol
	   Print the name of each linked file in which symbol appears.	This
	   option may be given any number of times.  On many systems it is
	   necessary to prepend an underscore.

	   This option is useful when you have an undefined symbol in your
	   link but don't know where the reference is coming from.

       -Y path
	   Add path to the default library search path.	 This option exists
	   for Solaris compatibility.

       -z keyword
	   The recognized keywords are:
	   combreloc
	       Combines multiple reloc sections and sorts them to make dynamic
	       symbol lookup caching possible.

	   defs
	       Disallows undefined symbols in object files.  Undefined symbols
	       in shared libraries are still allowed.

	   initfirst
	       This option is only meaningful when building a shared object.
	       It marks the object so that its runtime initialization will
	       occur before the runtime initialization of any other objects
	       brought into the process at the same time.  Similarly the
	       runtime finalization of the object will occur after the runtime
	       finalization of any other objects.

	   interpose
	       Marks the object that its symbol table interposes before all
	       symbols but the primary executable.

	   loadfltr
	       Marks  the object that its filters be processed immediately at
	       runtime.

	   muldefs
	       Allows multiple definitions.

	   nocombreloc
	       Disables multiple reloc sections combining.

	   nocopyreloc
	       Disables production of copy relocs.

	   nodefaultlib
	       Marks the object that the search for dependencies of this
	       object will ignore any default library search paths.

	   nodelete
	       Marks the object shouldn't be unloaded at runtime.

	   nodlopen
	       Marks the object not available to "dlopen".

	   nodump
	       Marks the object can not be dumped by "dldump".

	   now When generating an executable or shared library, mark it to
	       tell the dynamic linker to resolve all symbols when the program
	       is started, or when the shared library is linked to using
	       dlopen, instead of deferring function call resolution to the
	       point when the function is first called.

	   origin
	       Marks the object may contain $ORIGIN.

	   Other keywords are ignored for Solaris compatibility.

       -Z  Produce 'Standard' executables, disables Writable XOR Executable
	   features in resulting binaries.

       -( archives -)

       --start-group archives --end-group
	   The archives should be a list of archive files.  They may be either
	   explicit file names, or -l options.

	   The specified archives are searched repeatedly until no new
	   undefined references are created.  Normally, an archive is searched
	   only once in the order that it is specified on the command line.
	   If a symbol in that archive is needed to resolve an undefined
	   symbol referred to by an object in an archive that appears later on
	   the command line, the linker would not be able to resolve that
	   reference.  By grouping the archives, they all be searched
	   repeatedly until all possible references are resolved.

	   Using this option has a significant performance cost.  It is best
	   to use it only when there are unavoidable circular references
	   between two or more archives.

       --accept-unknown-input-arch

       --no-accept-unknown-input-arch
	   Tells the linker to accept input files whose architecture cannot be
	   recognised.	The assumption is that the user knows what they are
	   doing and deliberately wants to link in these unknown input files.
	   This was the default behaviour of the linker, before release 2.14.
	   The default behaviour from release 2.14 onwards is to reject such
	   input files, and so the --accept-unknown-input-arch option has been
	   added to restore the old behaviour.

       --as-needed

       --no-as-needed
	   This option affects ELF DT_NEEDED tags for dynamic libraries
	   mentioned on the command line after the --as-needed option.
	   Normally, the linker will add a DT_NEEDED tag for each dynamic
	   library mentioned on the command line, regardless of whether the
	   library is actually needed. --as-needed causes DT_NEEDED tags to
	   only be emitted for libraries that satisfy some reference from
	   regular objects.  --no-as-needed restores the default behaviour.

       -assert keyword
	   This option is ignored for SunOS compatibility.

       -Bdynamic

       -dy

       -call_shared
	   Link against dynamic libraries.  This is only meaningful on
	   platforms for which shared libraries are supported.	This option is
	   normally the default on such platforms.  The different variants of
	   this option are for compatibility with various systems.  You may
	   use this option multiple times on the command line: it affects
	   library searching for -l options which follow it.

       -Bgroup
	   Set the "DF_1_GROUP" flag in the "DT_FLAGS_1" entry in the dynamic
	   section.  This causes the runtime linker to handle lookups in this
	   object and its dependencies to be performed only inside the group.
	   --unresolved-symbols=report-all is implied.	This option is only
	   meaningful on ELF platforms which support shared libraries.

       -Bstatic

       -dn

       -non_shared

       -static
	   Do not link against shared libraries.  This is only meaningful on
	   platforms for which shared libraries are supported.	The different
	   variants of this option are for compatibility with various systems.
	   You may use this option multiple times on the command line: it
	   affects library searching for -l options which follow it.  This
	   option also implies --unresolved-symbols=report-all.

       -Bsymbolic
	   When creating a shared library, bind references to global symbols
	   to the definition within the shared library, if any.	 Normally, it
	   is possible for a program linked against a shared library to
	   override the definition within the shared library.  This option is
	   only meaningful on ELF platforms which support shared libraries.

       --check-sections

       --no-check-sections
	   Asks the linker not to check section addresses after they have been
	   assigned to see if there any overlaps.  Normally the linker will
	   perform this check, and if it finds any overlaps it will produce
	   suitable error messages.  The linker does know about, and does make
	   allowances for sections in overlays.	 The default behaviour can be
	   restored by using the command line switch --check-sections.

       --cref
	   Output a cross reference table.  If a linker map file is being
	   generated, the cross reference table is printed to the map file.
	   Otherwise, it is printed on the standard output.

	   The format of the table is intentionally simple, so that it may be
	   easily processed by a script if necessary.  The symbols are printed
	   out, sorted by name.	 For each symbol, a list of file names is
	   given.  If the symbol is defined, the first file listed is the
	   location of the definition.	The remaining files contain references
	   to the symbol.

       --no-define-common
	   This option inhibits the assignment of addresses to common symbols.
	   The script command "INHIBIT_COMMON_ALLOCATION" has the same effect.

	   The --no-define-common option allows decoupling the decision to
	   assign addresses to Common symbols from the choice of the output
	   file type; otherwise a non-Relocatable output type forces assigning
	   addresses to Common symbols.	 Using --no-define-common allows
	   Common symbols that are referenced from a shared library to be
	   assigned addresses only in the main program.	 This eliminates the
	   unused duplicate space in the shared library, and also prevents any
	   possible confusion over resolving to the wrong duplicate when there
	   are many dynamic modules with specialized search paths for runtime
	   symbol resolution.

       --defsym symbol=expression
	   Create a global symbol in the output file, containing the absolute
	   address given by expression.	 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 expression in this
	   context: you may give a hexadecimal constant or the name of an
	   existing symbol, or use "+" and "-" to add or subtract hexadecimal
	   constants or symbols.  If you need more elaborate expressions,
	   consider using the linker command language from a script.  Note:
	   there should be no white space between symbol, the equals sign
	   (``=''), and expression.

       --demangle[=style]

       --no-demangle
	   These options control whether to demangle symbol names in error
	   messages and other output.  When the linker is told to demangle, it
	   tries to present symbol names in a readable fashion: it strips
	   leading underscores if they are used by the object file format, and
	   converts C++ mangled symbol names into user readable names.
	   Different compilers have different mangling styles.	The optional
	   demangling style argument can be used to choose an appropriate
	   demangling style for your compiler.	The linker will demangle by
	   default unless the environment variable COLLECT_NO_DEMANGLE is set.
	   These options may be used to override the default.

       --dynamic-linker file
	   Set the name of the dynamic linker.	This is only meaningful when
	   generating dynamically linked ELF executables.  The default dynamic
	   linker is normally correct; don't use this unless you know what you
	   are doing.

       --embedded-relocs
	   This option is only meaningful when linking MIPS embedded PIC code,
	   generated by the -membedded-pic option to the GNU compiler and
	   assembler.  It causes the linker to create a table which may be
	   used at runtime to relocate any data which was statically
	   initialized to pointer values.  See the code in testsuite/ld-empic
	   for details.

       --fatal-warnings
	   Treat all warnings as errors.

       --force-exe-suffix
	   Make sure that an output file has a .exe suffix.

	   If a successfully built fully linked output file does not have a
	   ".exe" or ".dll" suffix, this option forces the linker to copy the
	   output file to one of the same name with a ".exe" suffix. This
	   option is useful when using unmodified Unix makefiles on a
	   Microsoft Windows host, since some versions of Windows won't run an
	   image unless it ends in a ".exe" suffix.

       --no-gc-sections

       --gc-sections
	   Enable garbage collection of unused input sections.	It is ignored
	   on targets that do not support this option.	This option is not
	   compatible with -r, nor should it be used with dynamic linking.
	   The default behaviour (of not performing this garbage collection)
	   can be restored by specifying --no-gc-sections on the command line.

       --help
	   Print a summary of the command-line options on the standard output
	   and exit.

       --target-help
	   Print a summary of all target specific options on the standard
	   output and exit.

       -Map mapfile
	   Print a link map to the file mapfile.  See the description of the
	   -M option, above.

       --no-keep-memory
	   ld normally optimizes for speed over memory usage by caching the
	   symbol tables of input files in memory.  This option tells ld to
	   instead optimize for memory usage, by rereading the symbol tables
	   as necessary.  This may be required if ld runs out of memory space
	   while linking a large executable.

       --no-undefined

       -z defs
	   Report unresolved symbol references from regular object files.
	   This is done even if the linker is creating a non-symbolic shared
	   library.  The switch --[no-]allow-shlib-undefined controls the
	   behaviour for reporting unresolved references found in shared
	   libraries being linked in.

       --allow-multiple-definition

       -z muldefs
	   Normally when a symbol is defined multiple times, the linker will
	   report a fatal error. These options allow multiple definitions and
	   the first definition will be used.

       --allow-shlib-undefined

       --no-allow-shlib-undefined
	   Allows (the default) or disallows undefined symbols in shared
	   libraries.  This switch is similar to --no-undefined except that it
	   determines the behaviour when the undefined symbols are in a shared
	   library rather than a regular object file.  It does not affect how
	   undefined symbols in regular object files are handled.

	   The reason that --allow-shlib-undefined is the default is that the
	   shared library being specified at link time may not be the same as
	   the one that is available at load time, so the symbols might
	   actually be resolvable at load time.	 Plus there are some systems,
	   (eg BeOS) where undefined symbols in shared libraries is normal.
	   (The kernel patches them at load time to select which function is
	   most appropriate for the current architecture.  This is used for
	   example to dynamically select an appropriate memset function).
	   Apparently it is also normal for HPPA shared libraries to have
	   undefined symbols.

       --no-undefined-version
	   Normally when a symbol has an undefined version, the linker will
	   ignore it. This option disallows symbols with undefined version and
	   a fatal error will be issued instead.

       --no-warn-mismatch
	   Normally ld will give an error if you try to link together input
	   files that are mismatched for some reason, perhaps because they
	   have been compiled for different processors or for different
	   endiannesses.  This option tells ld that it should silently permit
	   such possible errors.  This option should only be used with care,
	   in cases when you have taken some special action that ensures that
	   the linker errors are inappropriate.

       --no-whole-archive
	   Turn off the effect of the --whole-archive option for subsequent
	   archive files.

       --noinhibit-exec
	   Retain the executable output file whenever it is still usable.
	   Normally, the linker will not produce an output file if it
	   encounters errors during the link process; it exits without writing
	   an output file when it issues any error whatsoever.

       -nostdlib
	   Only search library directories explicitly specified on the command
	   line.  Library directories specified in linker scripts (including
	   linker scripts specified on the command line) are ignored.

       --oformat output-format
	   ld may be configured to support more than one kind of object file.
	   If your ld is configured this way, you can use the --oformat option
	   to specify the binary format for the output object file.  Even when
	   ld is configured to support alternative object formats, you don't
	   usually need to specify this, as ld should be configured to produce
	   as a default output format the most usual format on each machine.
	   output-format is a text string, the name of a particular format
	   supported by the BFD libraries.  (You can list the available binary
	   formats with objdump -i.)  The script command "OUTPUT_FORMAT" can
	   also specify the output format, but this option overrides it.

       -pie

       --pic-executable
	   Create a position independent executable.  This is currently only
	   supported on ELF platforms.	Position independent executables are
	   similar to shared libraries in that they are relocated by the
	   dynamic linker to the virtual address the OS chooses for them
	   (which can vary between invocations).  Like normal dynamically
	   linked executables they can be executed and symbols defined in the
	   executable cannot be overridden by shared libraries.

       -qmagic
	   This option is ignored for Linux compatibility.

       -Qy This option is ignored for SVR4 compatibility.

       --relax
	   An option with machine dependent effects.  This option is only
	   supported on a few targets.

	   On some platforms, the --relax option performs global optimizations
	   that become possible when the linker resolves addressing in the
	   program, such as relaxing address modes and synthesizing new
	   instructions in the output object file.

	   On some platforms these link time global optimizations may make
	   symbolic debugging of the resulting executable impossible.  This is
	   known to be the case for the Matsushita MN10200 and MN10300 family
	   of processors.

	   On platforms where this is not supported, --relax is accepted, but
	   ignored.

       --retain-symbols-file filename
	   Retain only the symbols listed in the file filename, discarding all
	   others.  filename is simply a flat file, with one symbol name per
	   line.  This option is especially useful in environments (such as
	   VxWorks) where a large global symbol table is accumulated
	   gradually, to conserve run-time memory.

	   --retain-symbols-file does not discard undefined symbols, or
	   symbols needed for relocations.

	   You may only specify --retain-symbols-file once in the command
	   line.  It overrides -s and -S.

       -rpath dir
	   Add a directory to the runtime library search path.	This is used
	   when linking an ELF executable with shared objects.	All -rpath
	   arguments are concatenated and passed to the runtime linker, which
	   uses them to locate shared objects at runtime.  The -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 -rpath-link option.  If -rpath is not used when linking an
	   ELF executable, the contents of the environment variable
	   "LD_RUN_PATH" will be used if it is defined.

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

	   For compatibility with other ELF linkers, if the -R option is
	   followed by a directory name, rather than a file name, it is
	   treated as the -rpath option.

       -rpath-link DIR
	   When using ELF or SunOS, one shared library may require another.
	   This happens when an "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-relocatable 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 -rpath-link
	   option specifies the first set of directories to search.  The
	   -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.

	   This option should be used with caution as it overrides the search
	   path that may have been hard compiled into a shared library. In
	   such a case it is possible to use unintentionally a different
	   search path than the runtime linker would do.

	   The linker uses the following search paths to locate required
	   shared libraries.
	   1.  Any directories specified by -rpath-link options.

	   2.  Any directories specified by -rpath options.  The difference
	       between -rpath and -rpath-link is that directories specified by
	       -rpath options are included in the executable and used at
	       runtime, whereas the -rpath-link option is only effective at
	       link time. It is for the native linker only.

	   3.  On an ELF system, if the -rpath and "rpath-link" options were
	       not used, search the contents of the environment variable
	       "LD_RUN_PATH". It is for the native linker only.

	   4.  On SunOS, if the -rpath option was not used, search any
	       directories specified using -L options.

	   5.  For a native linker, the contents of the environment variable
	       "LD_LIBRARY_PATH".

	   6.  For a native ELF linker, the directories in "DT_RUNPATH" or
	       "DT_RPATH" of a shared library are searched for shared
	       libraries needed by it. The "DT_RPATH" entries are ignored if
	       "DT_RUNPATH" entries exist.

	   7.  The default directories, normally /lib and /usr/lib.

	   8.  For a native linker on an ELF system, if the file
	       /etc/ld.so.conf exists, the list of directories found in that
	       file.

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

       -shared

       -Bshareable
	   Create a shared library.  This is currently only supported on ELF,
	   XCOFF and SunOS platforms.  On SunOS, the linker will automatically
	   create a shared library if the -e option is not used and there are
	   undefined symbols in the link.

       --sort-common
	   This option tells ld to sort the common symbols by size when it
	   places them in the appropriate output sections.  First come all the
	   one byte symbols, then all the two byte, then all the four byte,
	   and then everything else.  This is to prevent gaps between symbols
	   due to alignment constraints.

       --split-by-file [size]
	   Similar to --split-by-reloc but creates a new output section for
	   each input file when size is reached.  size defaults to a size of 1
	   if not given.

       --split-by-reloc [count]
	   Tries to creates extra sections in the output file so that no
	   single output section in the file contains more than count
	   relocations.	 This is useful when generating huge relocatable files
	   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
	   count relocations one output section will contain that many
	   relocations.	 count defaults to a value of 32768.

       --stats
	   Compute and display statistics about the operation of the linker,
	   such as execution time and memory usage.

       --traditional-format
	   For some targets, the output of ld is different in some ways from
	   the output of some existing linker.	This switch requests ld to use
	   the traditional format instead.

	   For example, on SunOS, ld combines duplicate entries in the symbol
	   string table.  This can reduce the size of an output file with full
	   debugging information by over 30 percent.  Unfortunately, the SunOS
	   "dbx" program can not read the resulting program ("gdb" has no
	   trouble).  The --traditional-format switch tells ld to not combine
	   duplicate entries.

       --section-start sectionname=org
	   Locate a section in the output file at the absolute address given
	   by org.  You may use this option as many times as necessary to
	   locate multiple sections in the command line.  org must be a single
	   hexadecimal integer; for compatibility with other linkers, you may
	   omit the leading 0x usually associated with hexadecimal values.
	   Note: there should be no white space between sectionname, the
	   equals sign (``=''), and org.

       -Tbss org

       -Tdata org

       -Ttext org
	   Same as --section-start, with ".bss", ".data" or ".text" as the
	   sectionname.

       --unresolved-symbols=method
	   Determine how to handle unresolved symbols.	There are four
	   possible values for method:
	   ignore-all
	       Do not report any unresolved symbols.

	   report-all
	       Report all unresolved symbols.  This is the default.

	   ignore-in-object-files
	       Report unresolved symbols that are contained in shared
	       libraries, but ignore them if they come from regular object
	       files.

	   ignore-in-shared-libs
	       Report unresolved symbols that come from regular object files,
	       but ignore them if they come from shared libraries.  This can
	       be useful when creating a dynamic binary and it is known that
	       all the shared libraries that it should be referencing are
	       included on the linker's command line.

	   The behaviour for shared libraries on their own can also be
	   controlled by the --[no-]allow-shlib-undefined option.

	   Normally the linker will generate an error message for each
	   reported unresolved symbol but the option --warn-unresolved-symbols
	   can change this to a warning.

       --dll-verbose

       --verbose
	   Display the version number for ld and list the linker emulations
	   supported.  Display which input files can and cannot be opened.
	   Display the linker script being used by the linker.

       --version-script=version-scriptfile
	   Specify the name of a version script to the linker.	This is
	   typically used when creating shared libraries to specify additional
	   information about the version hierarchy for the library being
	   created.  This option is only meaningful on ELF platforms which
	   support shared libraries.

       --warn-common
	   Warn when a common symbol is combined with another common symbol or
	   with a symbol definition.  Unix linkers allow this somewhat sloppy
	   practise, but linkers on some other operating systems do not.  This
	   option allows you to find potential problems from combining global
	   symbols.  Unfortunately, some C libraries use this practise, so you
	   may get some warnings about symbols in the libraries as well as in
	   your programs.

	   There are three kinds of global symbols, illustrated here by C
	   examples:
	   int i = 1;
	       A definition, which goes in the initialized data section of the
	       output file.

	   extern int i;
	       An undefined reference, which does not allocate space.  There
	       must be either a definition or a common symbol for the variable
	       somewhere.

	   int i;
	       A common symbol.	 If there are only (one or more) common
	       symbols for a variable, it goes in the uninitialized data area
	       of the output file.  The linker merges multiple common symbols
	       for the same variable into a single symbol.  If they are of
	       different sizes, it picks the largest size.  The linker turns a
	       common symbol into a declaration, if there is a definition of
	       the same variable.

	   The --warn-common option can produce five kinds of warnings.	 Each
	   warning consists of a pair of lines: the first describes the symbol
	   just encountered, and the second describes the previous symbol
	   encountered with the same name.  One or both of the two symbols
	   will be a common symbol.

	   1.  Turning a common symbol into a reference, because there is
	       already a definition for the symbol.

		       <file>(<section>): warning: common of `<symbol>'
			  overridden by definition
		       <file>(<section>): warning: defined here

	   2.  Turning a common symbol into a reference, because a later
	       definition for the symbol is encountered.  This is the same as
	       the previous case, except that the symbols are encountered in a
	       different order.

		       <file>(<section>): warning: definition of `<symbol>'
			  overriding common
		       <file>(<section>): warning: common is here

	   3.  Merging a common symbol with a previous same-sized common
	       symbol.

		       <file>(<section>): warning: multiple common
			  of `<symbol>'
		       <file>(<section>): warning: previous common is here

	   4.  Merging a common symbol with a previous larger common symbol.

		       <file>(<section>): warning: common of `<symbol>'
			  overridden by larger common
		       <file>(<section>): warning: larger common is here

	   5.  Merging a common symbol with a previous smaller common symbol.
	       This is the same as the previous case, except that the symbols
	       are encountered in a different order.

		       <file>(<section>): warning: common of `<symbol>'
			  overriding smaller common
		       <file>(<section>): warning: smaller common is here

       --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.

       --warn-multiple-gp
	   Warn if multiple global pointer values are required in the output
	   file.  This is only meaningful for certain processors, such as the
	   Alpha.  Specifically, some processors put large-valued constants in
	   a special section.  A special register (the global pointer) points
	   into the middle of this section, so that constants can be loaded
	   efficiently via a base-register relative addressing mode.  Since
	   the offset in base-register relative mode is fixed and relatively
	   small (e.g., 16 bits), this limits the maximum size of the constant
	   pool.  Thus, in large programs, it is often necessary to use
	   multiple global pointer values in order to be able to address all
	   possible constants.	This option causes a warning to be issued
	   whenever this case occurs.

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

       --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.

       --warn-unresolved-symbols
	   If the linker is going to report an unresolved symbol (see the
	   option --unresolved-symbols) it will normally generate an error.
	   This option makes it generate a warning instead.

       --error-unresolved-symbols
	   This restores the linker's default behaviour of generating errors
	   when it is reporting unresolved symbols.

       --whole-archive
	   For each archive mentioned on the command line after the
	   --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.  This option may be used more than once.

	   Two notes when using this option from gcc: First, gcc doesn't know
	   about this option, so you have to use -Wl,-whole-archive.  Second,
	   don't forget to use -Wl,-no-whole-archive after your list of
	   archives, because gcc will add its own list of archives to your
	   link and you may not want this flag to affect those as well.

       --wrap symbol
	   Use a wrapper function for symbol.  Any undefined reference to
	   symbol will be resolved to "__wrap_symbol".	Any undefined
	   reference to "__real_symbol" will be resolved to symbol.

	   This can be used to provide a wrapper for a system function.	 The
	   wrapper function should be called "__wrap_symbol".  If it wishes to
	   call the system function, it should call "__real_symbol".

	   Here is a trivial example:

		   void *
		   __wrap_malloc (size_t c)
		   {
		     printf ("malloc called with %zu\n", c);
		     return __real_malloc (c);
		   }

	   If you link other code with this file using --wrap malloc, then all
	   calls to "malloc" will call the function "__wrap_malloc" instead.
	   The call to "__real_malloc" in "__wrap_malloc" will call the real
	   "malloc" function.

	   You may wish to provide a "__real_malloc" function as well, so that
	   links without the --wrap option will succeed.  If you do this, you
	   should not put the definition of "__real_malloc" in the same file
	   as "__wrap_malloc"; if you do, the assembler may resolve the call
	   before the linker has a chance to wrap it to "malloc".

       --enable-new-dtags

       --disable-new-dtags
	   This linker can create the new dynamic tags in ELF. But the older
	   ELF systems may not understand them. If you specify
	   --enable-new-dtags, the dynamic tags will be created as needed.  If
	   you specify --disable-new-dtags, no new dynamic tags will be
	   created. By default, the new dynamic tags are not created. Note
	   that those options are only available for ELF systems.

       The i386 PE linker supports the -shared option, which causes the output
       to be a dynamically linked library (DLL) instead of a normal
       executable.  You should name the output "*.dll" when you use this
       option.	In addition, the linker fully supports the standard "*.def"
       files, which may be specified on the linker command line like an object
       file (in fact, it should precede archives it exports symbols from, to
       ensure that they get linked in, just like a normal object file).

       In addition to the options common to all targets, the i386 PE linker
       support additional command line options that are specific to the i386
       PE target.  Options that take values may be separated from their values
       by either a space or an equals sign.

       --add-stdcall-alias
	   If given, symbols with a stdcall suffix (@nn) will be exported
	   as-is and also with the suffix stripped.  [This option is specific
	   to the i386 PE targeted port of the linker]

       --base-file file
	   Use file as the name of a file in which to save the base addresses
	   of all the relocations needed for generating DLLs with dlltool.
	   [This is an i386 PE specific option]

       --dll
	   Create a DLL instead of a regular executable.  You may also use
	   -shared or specify a "LIBRARY" in a given ".def" file.  [This
	   option is specific to the i386 PE targeted port of the linker]

       --enable-stdcall-fixup

       --disable-stdcall-fixup
	   If the link finds a symbol that it cannot resolve, it will attempt
	   to do ``fuzzy linking'' by looking for another defined symbol that
	   differs only in the format of the symbol name (cdecl vs stdcall)
	   and will resolve that symbol by linking to the match.  For example,
	   the undefined symbol "_foo" might be linked to the function
	   "_foo@12", or the undefined symbol "_bar@16" might be linked to the
	   function "_bar".  When the linker does this, it prints a warning,
	   since it normally should have failed to link, but sometimes import
	   libraries generated from third-party dlls may need this feature to
	   be usable.  If you specify --enable-stdcall-fixup, this feature is
	   fully enabled and warnings are not printed.	If you specify
	   --disable-stdcall-fixup, this feature is disabled and such
	   mismatches are considered to be errors.  [This option is specific
	   to the i386 PE targeted port of the linker]

       --export-all-symbols
	   If given, all global symbols in the objects used to build a DLL
	   will be exported by the DLL.	 Note that this is the default if
	   there otherwise wouldn't be any exported symbols.  When symbols are
	   explicitly exported via DEF files or implicitly exported via
	   function attributes, the default is to not export anything else
	   unless this option is given.	 Note that the symbols "DllMain@12",
	   "DllEntryPoint@0", "DllMainCRTStartup@12", and "impure_ptr" will
	   not be automatically exported.  Also, symbols imported from other
	   DLLs will not be re-exported, nor will symbols specifying the DLL's
	   internal layout such as those beginning with "_head_" or ending
	   with "_iname".  In addition, no symbols from "libgcc", "libstd++",
	   "libmingw32", or "crtX.o" will be exported.	Symbols whose names
	   begin with "__rtti_" or "__builtin_" will not be exported, to help
	   with C++ DLLs.  Finally, there is an extensive list of
	   cygwin-private symbols that are not exported (obviously, this
	   applies on when building DLLs for cygwin targets).  These
	   cygwin-excludes are: "_cygwin_dll_entry@12",
	   "_cygwin_crt0_common@8", "_cygwin_noncygwin_dll_entry@12",
	   "_fmode", "_impure_ptr", "cygwin_attach_dll", "cygwin_premain0",
	   "cygwin_premain1", "cygwin_premain2", "cygwin_premain3", and
	   "environ".  [This option is specific to the i386 PE targeted port
	   of the linker]

       --exclude-symbols symbol,symbol,...
	   Specifies a list of symbols which should not be automatically
	   exported.  The symbol names may be delimited by commas or colons.
	   [This option is specific to the i386 PE targeted port of the
	   linker]

       --exclude-libs lib,lib,...
	   Specifies a list of archive libraries from which symbols should not
	   be automatically exported. The library names may be delimited by
	   commas or colons.  Specifying "--exclude-libs ALL" excludes symbols
	   in all archive libraries from automatic export. Symbols explicitly
	   listed in a .def file are still exported, regardless of this
	   option.  [This option is specific to the i386 PE targeted port of
	   the linker]

       --file-alignment
	   Specify the file alignment.	Sections in the file will always begin
	   at file offsets which are multiples of this number.	This defaults
	   to 512.  [This option is specific to the i386 PE targeted port of
	   the linker]

       --heap reserve

       --heap reserve,commit
	   Specify the amount of memory to reserve (and optionally commit) to
	   be used as heap for this program.  The default is 1Mb reserved, 4K
	   committed.  [This option is specific to the i386 PE targeted port
	   of the linker]

       --image-base value
	   Use value as the base address of your program or dll.  This is the
	   lowest memory location that will be used when your program or dll
	   is loaded.  To reduce the need to relocate and improve performance
	   of your dlls, each should have a unique base address and not
	   overlap any other dlls.  The default is 0x400000 for executables,
	   and 0x10000000 for dlls.  [This option is specific to the i386 PE
	   targeted port of the linker]

       --kill-at
	   If given, the stdcall suffixes (@nn) will be stripped from symbols
	   before they are exported.  [This option is specific to the i386 PE
	   targeted port of the linker]

       --major-image-version value
	   Sets the major number of the ``image version''.  Defaults to 1.
	   [This option is specific to the i386 PE targeted port of the
	   linker]

       --major-os-version value
	   Sets the major number of the ``os version''.	 Defaults to 4.	 [This
	   option is specific to the i386 PE targeted port of the linker]

       --major-subsystem-version value
	   Sets the major number of the ``subsystem version''.	Defaults to 4.
	   [This option is specific to the i386 PE targeted port of the
	   linker]

       --minor-image-version value
	   Sets the minor number of the ``image version''.  Defaults to 0.
	   [This option is specific to the i386 PE targeted port of the
	   linker]

       --minor-os-version value
	   Sets the minor number of the ``os version''.	 Defaults to 0.	 [This
	   option is specific to the i386 PE targeted port of the linker]

       --minor-subsystem-version value
	   Sets the minor number of the ``subsystem version''.	Defaults to 0.
	   [This option is specific to the i386 PE targeted port of the
	   linker]

       --output-def file
	   The linker will create the file file which will contain a DEF file
	   corresponding to the DLL the linker is generating.  This DEF file
	   (which should be called "*.def") may be used to create an import
	   library with "dlltool" or may be used as a reference to
	   automatically or implicitly exported symbols.  [This option is
	   specific to the i386 PE targeted port of the linker]

       --out-implib file
	   The linker will create the file file which will contain an import
	   lib corresponding to the DLL the linker is generating. This import
	   lib (which should be called "*.dll.a" or "*.a" may be used to link
	   clients against the generated DLL; this behaviour makes it possible
	   to skip a separate "dlltool" import library creation step.  [This
	   option is specific to the i386 PE targeted port of the linker]

       --enable-auto-image-base
	   Automatically choose the image base for DLLs, unless one is
	   specified using the "--image-base" argument.	 By using a hash
	   generated from the dllname to create unique image bases for each
	   DLL, in-memory collisions and relocations which can delay program
	   execution are avoided.  [This option is specific to the i386 PE
	   targeted port of the linker]

       --disable-auto-image-base
	   Do not automatically generate a unique image base.  If there is no
	   user-specified image base ("--image-base") then use the platform
	   default.  [This option is specific to the i386 PE targeted port of
	   the linker]

       --dll-search-prefix string
	   When linking dynamically to a dll without an import library, search
	   for "<string><basename>.dll" in preference to "lib<basename>.dll".
	   This behaviour allows easy distinction between DLLs built for the
	   various "subplatforms": native, cygwin, uwin, pw, etc.  For
	   instance, cygwin DLLs typically use "--dll-search-prefix=cyg".
	   [This option is specific to the i386 PE targeted port of the
	   linker]

       --enable-auto-import
	   Do sophisticated linking of "_symbol" to "__imp__symbol" for DATA
	   imports from DLLs, and create the necessary thunking symbols when
	   building the import libraries with those DATA exports. Note: Use of
	   the 'auto-import' extension will cause the text section of the
	   image file to be made writable. This does not conform to the
	   PE-COFF format specification published by Microsoft.

	   Using 'auto-import' generally will 'just work' O- but sometimes you
	   may see this message:

	   "variable '<var>' can't be auto-imported. Please read the
	   documentation for ld's "--enable-auto-import" for details."

	   This message occurs when some (sub)expression accesses an address
	   ultimately given by the sum of two constants (Win32 import tables
	   only allow one).  Instances where this may occur include accesses
	   to member fields of struct variables imported from a DLL, as well
	   as using a constant index into an array variable imported from a
	   DLL.	 Any multiword variable (arrays, structs, long long, etc) may
	   trigger this error condition.  However, regardless of the exact
	   data type of the offending exported variable, ld will always detect
	   it, issue the warning, and exit.

	   There are several ways to address this difficulty, regardless of
	   the data type of the exported variable:

	   One way is to use --enable-runtime-pseudo-reloc switch. This leaves
	   the task of adjusting references in your client code for runtime
	   environment, so this method works only when runtime environment
	   supports this feature.

	   A second solution is to force one of the 'constants' to be a
	   variable O- that is, unknown and un-optimizable at compile time.
	   For arrays, there are two possibilities: a) make the indexee (the
	   array's address) a variable, or b) make the 'constant' index a
	   variable.  Thus:

		   extern type extern_array[];
		   extern_array[1] -->
		      { volatile type *t=extern_array; t[1] }

	   or

		   extern type extern_array[];
		   extern_array[1] -->
		      { volatile int t=1; extern_array[t] }

	   For structs (and most other multiword data types) the only option
	   is to make the struct itself (or the long long, or the ...)
	   variable:

		   extern struct s extern_struct;
		   extern_struct.field -->
		      { volatile struct s *t=&extern_struct; t->field }

	   or

		   extern long long extern_ll;
		   extern_ll -->
		     { volatile long long * local_ll=&extern_ll; *local_ll }

	   A third method of dealing with this difficulty is to abandon
	   'auto-import' for the offending symbol and mark it with
	   "__declspec(dllimport)".  However, in practise that requires using
	   compile-time #defines to indicate whether you are building a DLL,
	   building client code that will link to the DLL, or merely
	   building/linking to a static library.   In making the choice
	   between the various methods of resolving the 'direct address with
	   constant offset' problem, you should consider typical real-world
	   usage:

	   Original:

		   --foo.h
		   extern int arr[];
		   --foo.c
		   #include "foo.h"
		   void main(int argc, char **argv){
		     printf("%d\n",arr[1]);
		   }

	   Solution 1:

		   --foo.h
		   extern int arr[];
		   --foo.c
		   #include "foo.h"
		   void main(int argc, char **argv){
		     /* This workaround is for win32 and cygwin; do not "optimize" */
		     volatile int *parr = arr;
		     printf("%d\n",parr[1]);
		   }

	   Solution 2:

		   --foo.h
		   /* Note: auto-export is assumed (no __declspec(dllexport)) */
		   #if (defined(_WIN32) || defined(__CYGWIN__)) && \
		     !(defined(FOO_BUILD_DLL) || defined(FOO_STATIC))
		   #define FOO_IMPORT __declspec(dllimport)
		   #else
		   #define FOO_IMPORT
		   #endif
		   extern FOO_IMPORT int arr[];
		   --foo.c
		   #include "foo.h"
		   void main(int argc, char **argv){
		     printf("%d\n",arr[1]);
		   }

	   A fourth way to avoid this problem is to re-code your library to
	   use a functional interface rather than a data interface for the
	   offending variables (e.g. set_foo() and get_foo() accessor
	   functions).	[This option is specific to the i386 PE targeted port
	   of the linker]

       --disable-auto-import
	   Do not attempt to do sophisticated linking of "_symbol" to
	   "__imp__symbol" for DATA imports from DLLs.	[This option is
	   specific to the i386 PE targeted port of the linker]

       --enable-runtime-pseudo-reloc
	   If your code contains expressions described in --enable-auto-import
	   section, that is, DATA imports from DLL with non-zero offset, this
	   switch will create a vector of 'runtime pseudo relocations' which
	   can be used by runtime environment to adjust references to such
	   data in your client code.  [This option is specific to the i386 PE
	   targeted port of the linker]

       --disable-runtime-pseudo-reloc
	   Do not create pseudo relocations for non-zero offset DATA imports
	   from DLLs.  This is the default.  [This option is specific to the
	   i386 PE targeted port of the linker]

       --enable-extra-pe-debug
	   Show additional debug info related to auto-import symbol thunking.
	   [This option is specific to the i386 PE targeted port of the
	   linker]

       --section-alignment
	   Sets the section alignment.	Sections in memory will always begin
	   at addresses which are a multiple of this number.  Defaults to
	   0x1000.  [This option is specific to the i386 PE targeted port of
	   the linker]

       --stack reserve

       --stack reserve,commit
	   Specify the amount of memory to reserve (and optionally commit) to
	   be used as stack for this program.  The default is 2Mb reserved, 4K
	   committed.  [This option is specific to the i386 PE targeted port
	   of the linker]

       --subsystem which

       --subsystem which:major

       --subsystem which:major.minor
	   Specifies the subsystem under which your program will execute.  The
	   legal values for which are "native", "windows", "console", and
	   "posix".  You may optionally set the subsystem version also.	 [This
	   option is specific to the i386 PE targeted port of the linker]

ENVIRONMENT
       You can change the behaviour of ld with the environment variables
       "GNUTARGET", "LDEMULATION" and "COLLECT_NO_DEMANGLE".

       "GNUTARGET" determines the input-file object format if you don't use -b
       (or its synonym --format).  Its value should be one of the BFD names
       for an input format.  If there is no "GNUTARGET" in the environment, ld
       uses the natural format of the target. If "GNUTARGET" is set to
       "default" 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 specify 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.

       "LDEMULATION" determines the default emulation if you don't use the -m
       option.	The emulation can affect various aspects of linker behaviour,
       particularly the default linker script.	You can list the available
       emulations with the --verbose or -V options.  If the -m option is not
       used, and the "LDEMULATION" environment variable is not defined, the
       default emulation depends upon how the linker was configured.

       Normally, the linker will default to demangling symbols.	 However, if
       "COLLECT_NO_DEMANGLE" is set in the environment, then it will default
       to not demangling symbols.  This environment variable is used in a
       similar fashion by the "gcc" linker wrapper program.  The default may
       be overridden by the --demangle and --no-demangle options.

SEE ALSO
       ar(1), nm(1), objcopy(1), objdump(1), readelf(1) and the Info entries
       for binutils and ld.

COPYRIGHT
       Copyright (c) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002,
       2003, 2004 Free Software Foundation, Inc.

       Permission is granted to copy, distribute and/or modify this document
       under the terms of the GNU Free Documentation License, Version 1.1 or
       any later version published by the Free Software Foundation; with no
       Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
       Texts.  A copy of the license is included in the section entitled ``GNU
       Free Documentation License''.

binutils-2.15							 March 1, 2011
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