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  • LINUX man pages
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    The following form allows you to view linux man pages.

    Command:

    ld

    
    
    

    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" 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
    
           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.  Specifying a script in this
           way merely augments the main linker script, with the extra commands
           placed after the main script; use the -T option to replace the default
           linker script entirely, but note the effect of the "INSERT" command.
    
           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 preceded 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,--start-group foo.o bar.o -Wl,--end-group
    
           This is important, because otherwise the compiler driver program may
           silently drop the linker options, resulting in a bad link.  Confusion
           may also arise when passing options that require values through a
           driver, as the use of a space between option and argument acts as a
           separator, and causes the driver to pass only the option to the linker
           and the argument to the compiler.  In this case, it is simplest to use
           the joined forms of both single- and multiple-letter options, such as:
    
                     gcc foo.o bar.o -Wl,-eENTRY -Wl,-Map=a.map
    
           Here is a table of the generic command line switches accepted by the
           GNU linker:
    
           @file
               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.
    
           --audit AUDITLIB
               Adds AUDITLIB to the "DT_AUDIT" entry of the dynamic section.
               AUDITLIB is not checked for existence, nor will it use the
               DT_SONAME specified in the library.  If specified multiple times
               "DT_AUDIT" will contain a colon separated list of audit interfaces
               to use. If the linker finds an object with an audit entry while
               searching for shared libraries, it will add a corresponding
               "DT_DEPAUDIT" entry in the output file.  This option is only
               meaningful on ELF platforms supporting the rtld-audit interface.
    
           -A architecture
           --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
    
           --depaudit AUDITLIB
           -P AUDITLIB
               Adds AUDITLIB to the "DT_DEPAUDIT" entry of the dynamic section.
               AUDITLIB is not checked for existence, nor will it use the
               DT_SONAME specified in the library.  If specified multiple times
               "DT_DEPAUDIT" will contain a colon separated list of audit
               interfaces to use.  This option is only meaningful on ELF platforms
               supporting the rtld-audit interface.  The -P option is provided for
               Solaris compatibility.
    
           -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).
    
           --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.  This option is
               available only for the i386 PE targeted port of the linker and for
               ELF targeted ports.  For i386 PE, symbols explicitly listed in a
               .def file are still exported, regardless of this option.  For ELF
               targeted ports, symbols affected by this option will be treated as
               hidden.
    
           --exclude-modules-for-implib module,module,...
               Specifies a list of object files or archive members, from which
               symbols should not be automatically exported, but which should be
               copied wholesale into the import library being generated during the
               link.  The module names may be delimited by commas or colons, and
               must match exactly the filenames used by ld to open the files; for
               archive members, this is simply the member name, but for object
               files the name listed must include and match precisely any path
               used to specify the input file on the linker's command-line.  This
               option is available only for the i386 PE targeted port of the
               linker.  Symbols explicitly listed in a .def file are still
               exported, regardless of this option.
    
           -E
           --export-dynamic
           --no-export-dynamic
               When creating a dynamically linked executable, using the -E option
               or the --export-dynamic option causes the linker to 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.
    
               Note that this option is specific to ELF targeted ports.  PE
               targets support a similar function to export all symbols from a DLL
               or EXE; see the description of --export-all-symbols below.
    
           -EB Link big-endian objects.  This affects the default output format.
    
           -EL Link little-endian objects.  This affects the default output
               format.
    
           -f name
           --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.
               into different sections.  This is ignored for other object file
               formats.
    
           -h name
           -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.
    
           -l namespec
           --library=namespec
               Add the archive or object file specified by namespec to the list of
               files to link.  This option may be used any number of times.  If
               namespec is of the form :filename, ld will search the library path
               for a file called filename, otherwise it will search the library
               path for a file called libnamespec.a.
    
               On systems which support shared libraries, ld may also search for
               files other than libnamespec.a.  Specifically, on ELF and SunOS
               systems, ld will search a directory for a library called
               libnamespec.so before searching for one called libnamespec.a.  (By
               convention, a ".so" extension indicates a shared library.)  Note
               that this behavior does not apply to :filename, which always
               specifies a file called filename.
    
               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.
    
               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.
    
           -m emulation
               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:
    
               ?   Where object files are mapped into memory.
    
               ?   How common symbols are allocated.
    
               ?   All archive members included in the link, with a mention of the
                   symbol which caused the archive member to be brought in.
    
               ?   The values assigned to symbols.
    
                   Note - symbols whose values are computed by an expression which
                   involves a reference to a previous value of the same symbol may
                   not have correct result displayed in the link map.  This is
                   because the linker discards intermediate results and only
                   retains the final value of an expression.  Under such
                   circumstances the linker will display the final value enclosed
                   by square brackets.  Thus for example a linker script
                   containing:
    
                              foo = 1
                              foo = foo * 4
                              foo = foo + 8
    
                   will produce the following output in the link map if the -M
                   option is used:
    
                              0x00000001                foo = 0x1
                              [0x0000000c]                foo = (foo * 0x4)
    
               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.  At the
               moment this option only affects ELF shared library generation.
               Future releases of the linker may make more use of this option.
               Also currently there is no difference in the linker's behaviour for
               different non-zero values of this option.  Again this may change
               with future releases.
    
           -q
           --emit-relocs
               Leave relocation sections and contents in fully linked executables.
               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.
    
           --force-dynamic
               Force the output file to have dynamic sections.  This option is
               specific to VxWorks targets.
    
           -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
               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.
    
           -dT scriptfile
           --default-script=scriptfile
               Use scriptfile as the default linker script.
    
               This option is similar to the --script option except that
               processing of the script is delayed until after the rest of the
               command line has been processed.  This allows options placed after
               the --default-script option on the command line to affect the
               behaviour of the linker script, which can be important when the
               linker command line cannot be directly controlled by the user.  (eg
               because the command line is being constructed by another tool, such
               as gcc).
    
           -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
               supported emulations.
    
           -x
           --discard-all
               Delete all local symbols.
    
           -X
           --discard-locals
               Delete all temporary local symbols.  (These symbols start with
               system-specific local label prefixes, typically .L for ELF systems
               or L for traditional a.out systems.)
    
           -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.
    
               execstack
                   Marks the object as requiring executable stack.
    
               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.
    
               lazy
    
               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".
    
               noexecstack
                   Marks the object as not requiring executable stack.
    
               norelro
                   Don't create an ELF "PT_GNU_RELRO" segment header in the
                   object.
    
               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.
    
               relro
                   Create an ELF "PT_GNU_RELRO" segment header in the object.
    
               max-page-size=value
                   Set the emulation maximum page size to value.
    
               common-page-size=value
                   Set the emulation common page size to value.
    
               Other keywords are ignored for Solaris compatibility.
    
           -( 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.
               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 or not.  --as-needed causes a DT_NEEDED
               tag to only be emitted for a library that satisfies an undefined
               symbol reference from a regular object file or, if the library is
               not found in the DT_NEEDED lists of other libraries linked up to
               that point, an undefined symbol reference from another dynamic
               library.  --no-as-needed restores the default behaviour.
    
           --add-needed
           --no-add-needed
               These two options have been deprecated because of the similarity of
               their names to the --as-needed and --no-as-needed options.  They
               have been replaced by --copy-dt-needed-entries and
               --no-copy-dt-needed-entries.
    
           -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
    
           -Bsymbolic-functions
               When creating a shared library, bind references to global function
               symbols to the definition within the shared library, if any.  This
               option is only meaningful on ELF platforms which support shared
               libraries.
    
           --dynamic-list=dynamic-list-file
               Specify the name of a dynamic list file to the linker.  This is
               typically used when creating shared libraries to specify a list of
               global symbols whose references shouldn't be bound to the
               definition within the shared library, or creating dynamically
               linked executables to specify a list of symbols which should be
               added to the symbol table in the executable.  This option is only
               meaningful on ELF platforms which support shared libraries.
    
               The format of the dynamic list is the same as the version node
               without scope and node name.  See VERSION for more information.
    
           --dynamic-list-data
               Include all global data symbols to the dynamic list.
    
           --dynamic-list-cpp-new
               Provide the builtin dynamic list for C++ operator new and delete.
               It is mainly useful for building shared libstdc++.
    
           --dynamic-list-cpp-typeinfo
               Provide the builtin dynamic list for C++ runtime type
               identification.
    
           --check-sections
           --no-check-sections
               Asks the linker not to check section addresses after they have been
               assigned to see if there are 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.  Section overlap is not usually checked for
               relocatable links.  You can force checking in that case by using
               the --check-sections option.
    
           --copy-dt-needed-entries
           --no-copy-dt-needed-entries
               This option affects the treatment of dynamic libraries referred to
               by DT_NEEDED tags inside ELF dynamic libraries mentioned on the
               command line.  Normally the linker will add a DT_NEEDED tag to the
               output binary for each library mentioned in a DT_NEEDED tag in an
               input dynamic library.  With --no-copy-dt-needed-entries specified
               on the command line however any dynamic libraries that follow it
               will have their DT_NEEDED entries ignored.  The default behaviour
               can be restored with --copy-dt-needed-entries.
    
               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.
    
           -Ifile
           --dynamic-linker=file
               Set the name of the dynamic linker.  This is only meaningful when
               generating dynamically linked ELF executables.  The default dynamic
               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.
    
           --gc-sections
           --no-gc-sections
               Enable garbage collection of unused input sections.  It is ignored
               on targets that do not support this option.  The default behaviour
               (of not performing this garbage collection) can be restored by
               specifying --no-gc-sections on the command line.
    
               --gc-sections decides which input sections are used by examining
               symbols and relocations.  The section containing the entry symbol
               and all sections containing symbols undefined on the command-line
               will be kept, as will sections containing symbols referenced by
               dynamic objects.  Note that when building shared libraries, the
               linker must assume that any visible symbol is referenced.  Once
               this initial set of sections has been determined, the linker
               recursively marks as used any section referenced by their
               relocations.  See --entry and --undefined.
    
               This option can be set when doing a partial link (enabled with
               option -r).  In this case the root of symbols kept must be
               explicitely specified either by an --entry or --undefined option or
               by a "ENTRY" command in the linker script.
    
           --print-gc-sections
           --no-print-gc-sections
               List all sections removed by garbage collection.  The listing is
               printed on stderr.  This option is only effective if garbage
               collection has been enabled via the --gc-sections) option.  The
               default behaviour (of not listing the sections that are removed)
               can be restored by specifying --no-print-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
               the first definition will be used.
    
           --allow-shlib-undefined
           --no-allow-shlib-undefined
               Allows 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 default behaviour is to report errors for any undefined symbols
               referenced in shared libraries if the linker is being used to
               create an executable, but to allow them if the linker is being used
               to create a shared library.
    
               The reasons for allowing undefined symbol references in shared
               libraries specified at link time are that:
    
               ?   A shared library specified at link time may not be the same as
                   the one that is available at load time, so the symbol might
                   actually be resolvable at load time.
    
               ?   There are some operating systems, eg BeOS and HPPA, where
                   undefined symbols in shared libraries are normal.
    
                   The BeOS kernel for example patches shared libraries at load
                   time to select whichever function is most appropriate for the
                   current architecture.  This is used, for example, to
                   dynamically select an appropriate memset function.
    
           --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.
    
           --default-symver
               Create and use a default symbol version (the soname) for
               unversioned exported symbols.
    
           --default-imported-symver
               Create and use a default symbol version (the soname) for
               unversioned imported symbols.
    
           --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.
    
           -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
               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 file systems.
    
               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. Searching -rpath in this way is only supported by
                   native linkers and cross linkers which have been configured
                   with the --with-sysroot option.
    
               3.  On an ELF system, for native linkers, if the -rpath and
                   -rpath-link options were not used, search the contents of the
    
               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
           --sort-common=ascending
           --sort-common=descending
               This option tells ld to sort the common symbols by alignment in
               ascending or descending order when it places them in the
               appropriate output sections.  The symbol alignments considered are
               sixteen-byte or larger, eight-byte, four-byte, two-byte, and one-
               byte. This is to prevent gaps between symbols due to alignment
               constraints.  If no sorting order is specified, then descending
               order is assumed.
    
           --sort-section=name
               This option will apply "SORT_BY_NAME" to all wildcard section
               patterns in the linker script.
    
           --sort-section=alignment
               This option will apply "SORT_BY_ALIGNMENT" to all wildcard section
               patterns in the linker script.
    
           --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.
    
               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.
    
           -Ttext-segment=org
               When creating an ELF executable or shared object, it will set the
               address of the first byte of the text segment.
    
           --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
               which support shared libraries; see VERSION.  It is partially
               supported on PE platforms, which can use version scripts to filter
               symbol visibility in auto-export mode: any symbols marked local in
               the version script will not be exported.
    
           --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: 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-shared-textrel
               Warn if the linker adds a DT_TEXTREL to a shared object.
    
           --warn-alternate-em
               Warn if an object has alternate ELF machine code.
    
           --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.
               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".
    
           --eh-frame-hdr
               Request creation of ".eh_frame_hdr" section and ELF
               "PT_GNU_EH_FRAME" segment header.
    
           --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.
    
           --hash-size=number
               Set the default size of the linker's hash tables to a prime number
               close to number.  Increasing this value can reduce the length of
               time it takes the linker to perform its tasks, at the expense of
               increasing the linker's memory requirements.  Similarly reducing
    
               Another effect of the switch is to set the default hash table size
               to 1021, which again saves memory at the cost of lengthening the
               linker's run time.  This is not done however if the --hash-size
               switch has been used.
    
               The --reduce-memory-overheads switch may be also be used to enable
               other tradeoffs in future versions of the linker.
    
           --build-id
           --build-id=style
               Request creation of ".note.gnu.build-id" ELF note section.  The
               contents of the note are unique bits identifying this linked file.
               style can be "uuid" to use 128 random bits, "sha1" to use a 160-bit
               SHA1 hash on the normative parts of the output contents, "md5" to
               use a 128-bit MD5 hash on the normative parts of the output
               contents, or "0xhexstring" to use a chosen bit string specified as
               an even number of hexadecimal digits ("-" and ":" characters
               between digit pairs are ignored).  If style is omitted, "sha1" is
               used.
    
               The "md5" and "sha1" styles produces an identifier that is always
               the same in an identical output file, but will be unique among all
               nonidentical output files.  It is not intended to be compared as a
               checksum for the file's contents.  A linked file may be changed
               later by other tools, but the build ID bit string identifying the
               original linked file does not change.
    
               Passing "none" for style disables the setting from any "--build-id"
               options earlier on the command line.
    
           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.
               extension, it is possible to allow their use in executable images
               as well, or to (probably pointlessly!)  disallow it in object
               files, by using these two options.  Executable images generated
               with these long section names are slightly non-standard, carrying
               as they do a string table, and may generate confusing output when
               examined with non-GNU PE-aware tools, such as file viewers and
               dumpers.  However, GDB relies on the use of PE long section names
               to find Dwarf-2 debug information sections in an executable image
               at runtime, and so if neither option is specified on the command-
               line, ld will enable long section names, overriding the default and
               technically correct behaviour, when it finds the presence of debug
               information while linking an executable image and not stripping
               symbols.  [This option is valid for all PE targeted ports 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",
    
           --heap reserve
           --heap reserve,commit
               Specify the number of bytes 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]
    
           --large-address-aware
               If given, the appropriate bit in the "Characteristics" field of the
               COFF header is set to indicate that this executable supports
               virtual addresses greater than 2 gigabytes.  This should be used in
               conjunction with the /3GB or /USERVA=value megabytes switch in the
               "[operating systems]" section of the BOOT.INI.  Otherwise, this bit
               has no effect.  [This option is specific to PE targeted ports 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
    
           --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.
    
               Note - use of the 'auto-import' extension will also cause read only
               data which would normally be placed into the .rdata section to be
               placed into the .data section instead.  This is in order to work
               around a problem with consts that is described here:
               http://www.cygwin.com/ml/cygwin/2004-09/msg01101.html
    
               Using 'auto-import' generally will 'just work' -- 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."
    
               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 -- 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 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]
    
               specific to the i386 PE targeted port of the linker]
    
               The following options set flags in the "DllCharacteristics" field
               of the PE file header: [These options are specific to PE targeted
               ports of the linker]
    
           --dynamicbase
               The image base address may be relocated using address space layout
               randomization (ASLR).  This feature was introduced with MS Windows
               Vista for i386 PE targets.
    
           --forceinteg
               Code integrity checks are enforced.
    
           --nxcompat
               The image is compatible with the Data Execution Prevention.  This
               feature was introduced with MS Windows XP SP2 for i386 PE targets.
    
           --no-isolation
               Although the image understands isolation, do not isolate the image.
    
           --no-seh
               The image does not use SEH. No SE handler may be called from this
               image.
    
           --no-bind
               Do not bind this image.
    
           --wdmdriver
               The driver uses the MS Windows Driver Model.
    
           --tsaware
               The image is Terminal Server aware.
    
           The 68HC11 and 68HC12 linkers support specific options to control the
           memory bank switching mapping and trampoline code generation.
    
           --no-trampoline
               This option disables the generation of trampoline. By default a
               trampoline is generated for each far function which is called using
               a "jsr" instruction (this happens when a pointer to a far function
               is taken).
    
           --bank-window name
               This option indicates to the linker the name of the memory region
               in the MEMORY specification that describes the memory bank window.
               The definition of such region is then used by the linker to compute
               paging and addresses within the memory window.
    
           The following options are supported to control handling of GOT
           generation when linking for 68K targets.
    
           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, 2005, 2006, 2007, 2008, 2009 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 1.3 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-2.20.51.0.2 2015-07-23 LD(1)

    
    
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