LD(1)LD(1)NAMEld - link editor
SYNOPSISld [ option ] ... file ...
DESCRIPTION
Ld, the link editor, links Elf object files. The archive format ld uses
is the one created by the archiver ar(1).
ld is normally invoked by cc(1), although it can be run separately. When
ld is used as part of a cc compilation, the ld options must be passed via
the -Wl mechanism. See cc(1) for details of -Wl.
The ld command combines several object files into one, performs
relocation, resolves external symbols, builds tables and relocation
information for run-time linkage in case of shared linking, and supports
symbol table information for symbolic debugging. In the simplest case,
the names of several object files are given. ld combines them, producing
an object module that can be executed or used as input for a subsequent
ld run. (In the latter case, the -r option must be given to preserve the
relocation entries.) The output of ld is left in a.out. By default,
this file is a dynamic executable if no errors occurred during the link.
Usually, ld is invoked by the compiler driver as the final step in
compilation. Only under special circumstances is it necessary to run it
separately.
The sections within the argument object files are combined, some by
merging and others by concatenation. The order in which this is done may
be specified. The entry point of the output is the first instruction in
the text segment (unless the -e option is specified).
If any argument is a library, it is searched exactly once at the point it
is encountered in the argument list. There are two kinds of libraries,
archives and dynamic shared objects. When linking with archives, only
those routines defining an unresolved external reference are loaded.
Shared objects are used only if the output is to be dynamic. In that
case, only the name is used for external resolution, no object is
included as part of the output object file. Note, unresolved symbols are
not considered an error when linking -shared. The library (archive)
symbol table (see ar(1)) is a hash table and is searched to resolved
external references that can be satisfied by library members. The
ordering of library members is NOT important.
Linking against a dynamic shared object will normally cause that object
to be loaded at runtime (see rld(1) and dso(5)) whenever the object being
created is loaded, thus resolving the symbols supplied by that object.
The loading of a dynamic shared object can be delayed using the
-delay_load option. In this case the object is not loaded until a symbol
supplied by the object is actually referenced. Symbols from a delay
loaded object do not preempt symbols from other libraries; they are
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resolved as if the object was last on the link line.
When searching for ucode libraries the default directories searched are
/usr/lib/, /lib/ and /usr/local/lib/. Note that, although archives will
be found in /usr/local/lib/, shared objects should not be installed
there, as they will not be found by rld(1). When searching for 64bit
libraries the default directories searched are /usr/lib64/, /lib64/ and
/usr/local/lib64/. When searching for n32 libraries the default
directories searched are /usr/lib32/, /lib32/ and /usr/local/lib32/.
Reserved Symbols
The symbols `.bss', `.comment', `.data', `.fini', `.init', `.lit4',
`.lit8', `.rdata', `.sbss', `.sdata', `.text', `_BASE_ADDRESS',
`_DYNAMIC', `_DYNAMIC_LINK', `_DYNAMIC_LINKING', `_GOT_OFFSET',
`__dso_displacement', `__elf_header', `__fstart', `__istart',
`__lcldta_address', `__lcldta_size', `__program_header_table',
`__rld_obj_head', `__start', `__unwind', `_data_init_table', `_edata',
`_end', `_etext', `_fbss', `_fdata', `_ftext', `_gp', `_gp_disp',
`_lib_version', `_procedure_string_table', `_procedure_table',
`_procedure_table_size', `_rld_new_interface', `_rt_symbol_string_table',
`_rt_symbol_table', `_rt_symbol_table_size', and all symbols beginning
with the prefixes `__elf_vaddr' and `__elf_size' are reserved. It is
erroneous to define these symbols. In ANSI C the symbols `end', `edata',
and `etext' may be user defined. (see the description of -std below.) If
they are not defined (but only referenced) they are assigned the same
values as `_end', `_edata', and `_etext' respectively. More information
on these symbols is available in end(3C).
Symbol Resolution / Input Searchpath Options
-lx Search a library libx.{so,a}, where x is a string. A shared object
or an archive is searched when its name is encountered, so the
placement of a -l is significant.
-L dir
Change the algorithm of searching for libx.{so,a} or libx.b to look
in dir before looking in the default directories. This option is
effective only if it precedes the -l options on the command line.
Repeating for emphasis: dir must be a directory.
-Ldir
The same as -L dir.
-L Change the algorithm of searching for libx.{so,a} or libx.b to never
look in the default directories. This is useful when the default
directories for libraries should not be searched and only the
directories specified by -Ldir are to be searched. This option may
be dropped from some future release in favor of the -nostdlib
option.
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LD(1)LD(1)-nostdlib
Change the algorithm of searching for libx.a or libx.b to never look
in the default directories. This is useful when the default
directories for libraries should not be searched and only the
directories specified by -L dir are to be searched.
-B [static|dynamic|symbolic]
In dynamic mode (the default), ld searches each directory specified
in the library search path for a file libx.so, and if not available
then libx.a. When -B static is specified, ld selects only the files
ending in .a (except for libc). If it is desired to link with
static libraries, but not all of the needed .a files are available:
cc prog.o -o prog -B static -lXm -lXt -B dynamic -lX11 -lgen
When -B symbolic is specified, ld inserts the element DT_SYMBOLIC
into the .dynamic section of a shared object library and this alters
the dynamic linker's symbol resolution algorithm for references
within the library. Instead of starting a symbol search with the
executable file, the dynamic linker starts from the shared object
itself. If the shared object fails to supply the referenced symbol,
the dynamic linker then searches the executable file and other
shared objects as usual.
-u symname
Enter symname as an undefined in the symbol table. This is useful
for loading entirely from a library, since initially the symbol
table is empty and an unresolved reference is needed to force the
loading of the first routine.
-std Specifies that the linker should not define certain symbol names,
e.g. `end`, `edata`, and `etext`.
-cckr
Specifies that the linker should set the value of the variable
`_lib_version` to specify non-ansi semantics to see end(3).
-cxx Specifies special handling of certain symbols needed for proper
linkage and execution of C++ programs.
Input Specification Options-from optionlistfile
This allows one to specify arguments to ld in a file. Read the file
optionlistfile as if it appeared on the command line in the same
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position as the -from option. Newlines in optionlistfile are
treated as if they were ordinary spaces.
-objectlist objectlistfile
Read the file objectlistfile to obtain a list of files. By putting
the list of files in objectlistfile instead of on the command line
one avoids exceeding the limit on the length of a command line.
This is primarily useful when linking very large programs with many
objects and long filenames. The objectlistfile is a list of file
or archive names, one file per line. Blank lines are silently
ignored. Leading white space is ignored. A filename is considered
ended by the next whitespace character. Characters after the
filename are ignored. Any leading ``-'' in an objectlistfile line
is considered part of a filename: nothing in the file is taken as an
option. Lines are in the file are limited to BUFSIZ*2 characters
(16K bytes) each.
-all Link in all of the objects from all archives following this flag.
This option is commonly used in conjunction with -shared option to
create a shared object out of an existing archive.
-notall
Turns off -all. This still allows objects to be pulled out of the
archive into a DSO if these objects resolve unresolved symbols in
the already included object, but these objects are included without
exporting their symbols by default.
-exclude object
Used in conjunction with -all and -shared. The object specified will
be excluded in making the shared object.
-no_archive
Requires that -l references must resolve to shared objects.
Normally, if the shared object as specified by the -l is not found,
the linker attempts to find the corresponding archive to resolve
undefines. This option disallow using those archives. This is a
synonym of -Bdynamic.
Debugging Options-aoutkeep
By default, ld removes the output file if there are link errors.
But when this flag is set, the output file will be rename to a.out .
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LD(1)LD(1)-m Produce a map or listing of the input/output sections on the
standard output (UNIX system V-like map).
-M Produce a primitive load map, listing the names of the files that
will be loaded (UNIX 4.3bsd-like map).
-gpinfo
Produce a listing of short data section components (page pointers,
GOT pointers, small data, and small literals). This may be useful in
identifying modules with large gp relative sections. In cases where
-multigot won't work, recompiling these modules with -G0 may allow a
successful link.
-v Set verbose mode. Print the name of each file as it is processed.
-quickstart_info
Prints extra information regarding the quickstart status of the
executable file created, including a full list of conflict symbols
and their objects of origin.
-ysym
Indicate each file in which sym appears, sym's type and whether the
file defines or references sym. Many such options may be given to
trace many symbols. Each -ysym applies to those files listed after
this option on the command line.
-V Print a message giving information about the version of ld being
used.
-f fill
Set the fill pattern for ``holes'' within an output section. The
argument fill is a four-byte hexadecimal constant.
-show_unref
Defined but unreferenced symbols will be listed. This flag is
useful for finding out "dead code" in a program. Note that it is
normal behavior for many library routines to define symbols that
might not be referenced by all programs. Also, in the case of weak
and strong symbol pair where two different symbols point to the same
virtual address, if only one of them is referenced, the other symbol
is still listed. This does not necessarily mean the specified
function is never used.
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LD(1)LD(1)Message Options
-LD_MSG:[msgtype=numlist][:msgtype=numlist]..
General message handling interface for ld that allows the user to
select the message type of the specified message numbers. The
numlist is a comma (',') or dash ('-') separated list of message
numbers.
error=numlist
Treat each message on the numlist as an error.
warning=numlist
Treat each message on the numlist as a warning.
info=numlist
Treat each message on the numlist as an info message.
verbose=numlist
Treat each message on the numlist as a verbose message.
off=numlist
Ignore each message on the numlist.
For example, -LD_MSG:warning=33 tells the linker to treat message
33, which by default is an error, as a warning. Similarly,
-LD_MSG:warning=33:off=47-68 tells the linker to treat message 33 as
a warning and to ignore all messages from 47 to 68 inclusive.
Fatal errors can not be modified by -LD_MSG:
-U Undefined symbols are not considered an error when this is supplied.
As a result, one can create an executable with undefined symbols.
Referencing an undefined symbol during execution may cause a
segmentation fault and a core dump.
-woff numlist
This allows a user to specify a comma-separated list of numbers of
warnings which the linker is to suppress. For example, -woff
5,17,23 turns off warnings numbered 5, 17 and 23. If you are
linking using the cc(1) command, this flag should be passed to the
linker with, -Wl,-woff,5 -Wl,-woff,17 -Wl,-woff,23.
-w This flag specifies that all warnings are to be suppressed.
-info
Enable the linker to print out messages of an informational nature
which might highlight unusual, but not illegal situations. This is
on by default.
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LD(1)LD(1)-noinfo
Disable the -info level of error messages as described above.
-demangle
Specifies that demangling of C++ names should take place when
printing other messages.
-ignore_unresolved
This option causes an executable or DSO to be produced and ld to
exit with zero status even if there are unresolved symbols;
resolution of these symbols will be completed by rld . If linking
-call_shared, a list of the unresolved symbols will be output (as it
always is for -call_shared). If linking -shared, no such list will
be output. If linking -non_shared, this option is ignored (and
-no_unresolved is used, as it always is for -non_shared). This
option is the default for -shared linking, but not for -call_shared
or -non_shared.
-no_unresolved
Unresolved symbols will be listed. If linking -shared, a DSO will
still be produced (as it always is for -shared) and ld will exit
with zero status. If linking -call_shared or -non_shared, ld will
exit with nonzero status and no executable will be produced. This
option is the default for -call_shared and -non_shared link, but not
for -shared.
-warn_unused
This flag specifies that the linker should issue a warning if it
finds that some object has not been used in a link. The semantics
of dynamic linking dictate that this cannot be determined absolutely
at static link time, but it is usually quite reliable. This is the
default.
-dont_warn_unused
Turns off the warning specified by -warn_unused.
-allow_missing
When using an ELF layout specification file with the
Stripping Options-s Strip the symbolic information from the output object file.
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LD(1)LD(1)-x Do not preserve local (non-global) symbols in the output symbol
table; enter external and static symbols only. This option saves
some space in the output file.
Output Object Format Options-r Retain relocation entries in the output file. Relocation entries
must be saved if the output file is to become an input file in a
subsequent ld run. This option also prevents final definitions from
being given to common symbols, and suppresses the `undefined symbol'
diagnostics.
-elf Produce ELF output object file. This is the default and currently
the only file format supported.
-non_shared
Produce a static executable. The output object created will not use
any shared objects during execution. This declares that you are
doing non-PIC loading.
-shared
Produce a dynamic shared object. This includes creating all of the
tables for run-time linking and resolving references to other
specified shared objects. The object created may be used by the
linker to make dynamic executables.
-call_shared
Produce a dynamic executable. The object created may use shared
objects at run-time. This is the default.
-o32 or -32
Specifies that the object to be linked (and the input objects) are
to be 32-bit ucode objects.
-n32 Specifies that the object to be linked (and the input objects) are
to be 32-bit n32 objects.
-64 Specifies that the object to be linked (and the input objects) are
to be 64-bit objects.
-mips1
Specifies that the linker should try to produce a binary that
conforms to the MIPS 1 ISA. If ld finds object files that are MIPS
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2, the resulting binary will silently be marked as being a -mips2
binary. ( NOTE: Because all -o32 format object files shipped by SGI
are built -mips2 , it may not be possible to produce a -mips1
executable.)
-mips2
Specifies that the linker should try to produce a binary that
conforms to the MIPS 2 ISA.
-mips3
Specifies that the linker should try to produce a binary that
conforms to the MIPS 3 ISA. If ld finds object files that are MIPS
4, the resulting binary will silently be marked as being a -mips4
binary.
-mips4
Specifies that the linker should try to produce a binary that
conforms to the MIPS 4 ISA.
Layout Options
-LD_LAYOUT:[type=arg][:type=arg]..
Commands that affect object layout.
seglign=alignval
Defines the minimum segment alignment to be alignval. This
value needs to be both 0x1000 or greater and a power of 2.
-d Force definition of common storage and define loader defined
symbols even if -r is present.
-z Arrange that the process pages are loaded on demand from the
resulting executable file rather than preloaded, and that the
text pages are shared among all users. This is the default.
-multigot Create multiple Global Offset Tables. All entries in the GOT
need to be accessible from a 16 bit offset from a common GP
(Global Pointer). If the GOT grows too big you may get a "gp
out of range" error at link time. This option will allow the
linker to create multiple GOTs and GPs thus avoiding the error.
This is position dependent and should appear before any objects
on the command line. Having multiple GOTs will neither increase
code size nor affect performance. This option is only usable
with PIC code: it is not appropriate or useful with code
compiled or linked -non_shared.
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LD(1)LD(1)-n Arrange that when the output file is executed, the entire text
and data portions of the executables are preloaded. This
involves moving the data areas up to the first possible
pagesize byte boundary following the end of the text. User
must specify -non_shared when -n is used.
-N Place the data segment immediately after the text and do not
make the text portion read only or sharable. Only objects
compiled -non_shared can be linked with -N.
-T num Set the text segment origin. The argument num is a hexadecimal
number.
-D num Set the data segment origin. The argument num is a hexadecimal
number. Please note that this switch is non-standard, and may
not be supported across product lines.
-B num Set the bss segment origin. The argument num is a hexadecimal
number. Please note that this switch is non-standard, and may
not be supported across product lines.
-G num If the flag -_SYSTYPE_SVR4 has been specified, this flag is a
synonym for -shared, and takes no numerical argument.
Otherwise, The argument num is taken to be a decimal number
that is the largest size in bytes of a .comm item that is to be
allocated in the small bss section for reference off the global
pointer. The default is 8 bytes. Please note that this switch
is non-standard, and may not be supported across product lines.
-rdata_writable
Puts .rodata into the "data" segment, which has the "WRITE"
permission. This is the default.
-rdata_shared
Puts .rodata into the "text" segment, where it will be shared
across processes, and will be read-only.
-ivpad Improves cache behavior by causing the linker to perform
intervariable padding of some large variables.
-noivpad Turns off -ivpad.
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LD(1)LD(1)-Xlocal name,...
Assigns the named global bss (uninitialized data) symbols to a
special local data section in the a.out. This is useful for
hand-parallelized Fortran programs that require this symbol to
be private for each thread.
A symbol assigned to the small bss or small data section of an
object file cannot be moved to the special section. If the
symbol gets assigned to one of small bss/data section, then
either recompile with a smaller -G number or use the following
pragma in your source code:
#pragma section_non_gp(name) in C or
c*$*section_non_gp(name) in Fortran.
-elspec elsfile
This flag specifies a file to serve as an ELF layout
specification file. This file and its syntax are described in
elspec(5).
-elsmap This flag specifies that the linker should emit a layout map in
the form of an ELF layout specification. The output from this
specification can be used with the -elspec flag without
modification.
-check_registry location_file
Check the location of this shared object's segments and make
sure they stay out of the way of others in the location_file.
A single registry file, either with -check_registry or
-update_registry is allowed. This option is used with -shared.
-update_registry location_file
Register the location of this shared object's segments and make
sure they stay out of the way of others in the location_file.
Location_file is updated if it is writable. A single registry
file, either with -check_registry or -update_registry is
allowed. This option is used with -shared. The default
registry file is /usr/lib{,32,64}/so_locations. See the dso(5)
manpage for details on so_locations.
Dynamic Options-e epsym
Set the default entry point address for the output file to be that
of the symbol epsym.
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LD(1)LD(1)-I path_name
The path_name is a path name for the system to invoke as a program
interpreter. This option writes the path name into the .interp
section.
-default_delay_load
When creating a dynamic shared object using -shared, it marks that
shared object as default delay load.
-delay_load
Indicates that the next specified object, if it is a dynamic shared
object, should be delay loaded.
-force_load
Forces the normal loading of the next specified object, overriding
any default delay load attribute associated with that object.
This flag is used when creating a dynamic object ( -shared or
-call_shared). It indicates that symbols from the next object,
archive, or dynamic shared object will be exported by the object
being created. This is the default behavior for linking in an object
but not for archives or dynamic shared objects.
-hides
This flag is used when creating a dynamic object ( -shared or
-call_shared). It indicates that symbols from the next object,
archive, or dynamic shared object will be hidden by the object being
created. This is the default behavior for linking in archives or
dynamic shared objects, but not for objects.
-exported_symbol name,...
Used in conjunction with -shared or -call_shared. This marks the
symbol given by the list of names as exported. If you specify any
exported symbols, then all unspecified symbols are automatically
hidden.
-exports_file filename
Used in conjunction with -shared or -call_shared. The file given by
filename contains a list of symbols that should be exported. The
list is space separated (including newlines). Any symbols not
specifically exported will be automatically hidden.
-hidden_symbolname,...
Used in conjunction with -shared or -call_shared. This marks the
symbol given by the list of names as hidden. This is ignored if any
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symbols are specifically marked as exported using the
-exported_symbol or -exports_file options.
-hiddens_file filename
Used in conjunction with -shared or -call_shared. The file given by
filename contains a list of symbols that should be hidden. The list
is space separated (including newlines). This list is ignored if
any symbols are specifically marked as exported using
-exported_symbol or -exports_file options.
-transitive_link
Normally, every shared object and every executable has a dependency
list of shared objects which are needed for correct execution. The
runtime linker rld(1) will load these objects, when any process is
run. If the depended-upon shared objects have more objects which
they in turn depend upon, rld will add them at the end of the list,
and so on, performing a transitive closure.
By default a similar operation is performed at static (ld) link
time. Any shared object which is listed on the command line is put
on a.out's dependency list. Then any new shared objects from the
dependency lists of the already-processed shared objects are also
processed and checked for conflicting definitions of symbols, but
are not added to the list of shared objects needed by the object
being built. This is the default behavior.
-no_transitive_link
Some applications may find it desirable to hide some of their
dependent libraries. This flag cancels the upward propagation of
libraries to facilitate such hiding. Executables and shared objects
built in this way may experience slightly slower startup. If you are
linking using the cc(1) command, this flag should be passed both to
the driver and the linker, e.g. both -no_transitive_link and
-Wl,-no_transitive_link should be used.
-set_version version_string
Sets the value of DT_MIPS_IVERSION field in the dynamic section of
the shared object to "version_string". The version string is a
series of version strings separated by colons(:).
-exact_version
Set the LL_EXACT_MATCH flag in .liblist flags field. This indicates
to rld that this shared object must match the timestamp and checksum
from the .liblist section in addition to the interface version.
This means that all DSOs run against must match, exactly, the
version, timestamp, and checksum against which the app was linked
(or rqs-d). This means that if the object is copied to another
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machine it will not run unless the object is first rqs-d (because
the other machine will surely have a different checksum/timestamp
for things on the liblist of this object. Such as libc.so.1). Even
more surprising: on a mips4 machine (such as R10000) cc t.c -n32
-mips3 -Wl,-exact_version ; ./a.out will not execute. rld will
report a fatal error because the mips3 libc.so.1 linked against is
not the same as the mips4 libc.so.1 against which the executable
will run on that machine.
-ignore_version
Sets the LL_IGNORE_VERSION flag in the liblist flags field. For
subsequent shared objects in the liblist. rld will not try to match
the interface version as specified at link time.
-require_minor
Set the LL_REQUIRE_MINOR flag in the .liblist flags field for shared
objects listed subsequently on the link line. This indicates to rld
that the shared object used at runtime must have the exact same
minor (and major) version number as that at static link time.
Otherwise, execution will abort. See the dso(5) manpage for details
on major and minor version numbers.
-ignore_minor
Clear the LL_REQUIRE_MINOR flag in the .liblist flags field for
shared objects listed subsequently on the link line. This allows
rld to use a shared object at runtime which has a different minor
version number. This is the default behavior. See the dso(5)
manpage for details on major and minor version numbers.
-no_library_replacement
Turns on a flag in the dynamic section so that rld does not allow
execution time or runtime changing of the path (except for super
user) to find the shared objects. Typically, used for security
purposes on system utilities.
-rpath library_path
Sets the rpath (see the generic abi ) to the specified string.
Meaningful only for shared linkage.
-soname shared_object_name
Sets DT_SONAME for a shared object. Use in conjunction with -shared
option. The name may be a single component name (e.g. libc.a), a
full (starting with a slash), or relative pathname (containing a
slash). Single component name use rpath, LD_LIBRARY_PATH and the
default paths to resolve their locations.
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LD(1)LD(1)-init ifuncsymbol
Put a call to ifuncsymbol in the code rld will exercise before the
main program begins. This contains initialization code to be called
before control is passed to main. In the case of a dlopen'd or
sgidladd'd DSO, this initialization function is called after the DSO
is loaded but before it is referenced. Only a single -init option
is effective in a given DSO or executable (if multiple are provided,
the last is used). -init is only meaningful when creating a DSO or
creating a call-shared executable. -init has no affect on non-
shared links.
-fini ffuncsymbol
Put a call to ffuncsymbol in the code rld will exercise after the
main program exits. This contains termination code to be called
after the main program exits. In the case of a dlclose'd DSO which
is no longer referenced, this function is called before the DSO is
unmapped. Only a single -fini option is effective in a given DSO or
executable (if multiple are provided, the last is used). -fini is
only meaningful when creating a DSO or creating a call-shared
executable. -fini has no affect on non-shared links.
I/O Options
-mmap
This specifies that the linker will use mmap(2) as its preferred
mode for reading object files. This usually results in better I/O
performances, except when using NFS mounted files with high network
latencies. This is the default.
-read
This specifies that the linker is to use the open(2) , lseek(2) ,
and read(2) as its preferred mode for reading object files. Setting
this option when many object files are remotely mounted with high
network latency often improves performance.
Hardware Patch Options-no_r5k_jump_at_eop
Works around an R5000 bug present in 1.1 silicon. This option tries
to prevent certain classes of branch instructions from being the
second to last instruction on an even page of virtual memory. This
option is on by default. The hinv(1) command can be used to
determine what rev of R5000 is present in the system.
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LD(1)LD(1)-allow_r5k_jump_at_eop
Disables the work around for the R5000 bug. When this flag is
present, no adjustment is attempted. The work around is enabled by
default, the presence of this flag before any object files will turn
it off. Turning off this option will result in code that is not
compatible across platforms and may also result in a performance
penalty some R5000 systems.
-no_jump_at_eop
Works around an R4000 bug present in 2.1 and 2.2 silicon. This
option tries to prevent certain classes of branch instructions from
being the last instruction on a page of virtual memory. This option
is on by default for links of MIPS3 or lower programs. The hinv(1)
command can be used to determine what rev of R4000 is present in the
system.
-allow_jump_at_eop
Disables the work around for the R4000 bug. When this flag is
present, no adjustment is attempted. The work around is enabled by
default, the presence of this flag before any object files will turn
it off. Turning off this option will result in code that is not
compatible across platforms and may also result in a performance
penalty on some R4000 systems.
Miscellaneous Options-o outfile
Produce an output object file by the name outfile. The name of the
default object file is a.out. In the event that outfile has
undefined references at the end of the link editor run, and the -r
option was not used, and the -aoutkeep option was used outfile will
be renamed a.out. If there are undefined references and the
-aoutkeep option was not used there will be no output from ld.
-VS num
Use num as the decimal version stamp to identify the a.out file that
is produced. The version stamp is stored in the optional and
symbolic headers.
-_SYSTYPE_SVR4
This flag alters the meaning of the -G flag to conform to the Unix
System V Release 4 usage. See the description below.
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LD(1)LD(1)Synonym Options-ajeop
This is a synonym for -allow_jump_at_eop
-Ldir
The same as -L dir.
-L Change the algorithm of searching for libx.{so,a} or libx.b to never
look in the default directories. This is useful when the default
directories for libraries should not be searched and only the
directories specified by -Ldir are to be searched. This option may
be dropped from some future release in favor of the -nostdlib
option.
-G If the flag -_SYSTYPE_SVR4 has been specified, this flag is a
synonym for -shared, and takes no numerical argument.
-Wx,-G num
This is a synonym for the non-SVR4 meaning of -G
-h This is a synonym for -soname
-dy This is a synonym for -call_shared
-dn This is a synonym for -non_shared
-a This is a synonym of -non_shared.
-hides_file filename
This is the obsolete version of the -hiddens_file option and will
disappear in future releases of the linker. Please change your
makefiles to reflect this change.
-none
Same as -notall
FILES
/lib/lib*.so
/lib/lib*.a
/usr/lib/lib*.so
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LD(1)LD(1)
/usr/lib/lib*.a
/usr/lib/so_locations
/usr/local/lib/lib*.a libraries
/lib32/lib*.so
/lib32/lib*.a
/usr/lib32/lib*.so
/usr/lib32/lib*.a
/usr/lib32/so_locations
/usr/local/lib32/lib*.a libraries
/lib64/lib*.so
/lib64/lib*.a
/usr/lib64/lib*.so
/usr/lib64/lib*.a
/usr/lib64/so_locations
/usr/local/lib64/lib*.a libraries
a.out output file
SEE ALSOcc(1), pc(1), f77(1), as(1), uld(1), ar(1), end(3), collide(1), rqs(1),
dso(5)NOTES
An object's segments must not overlap and all of the object's addresses
must be less than 0x80000000. The stack starts at 0x80000000 and grows
down through lower addresses therefore space should be left for it. The
default text segment address is 0x10000000 with the data segment
immediately following the text segment. The default is that the bss
segment follows the data segment.
When creating an executable object runnable on Unix, a.out,
/usr/lib/crt1.o Should be the first object loaded and /usr/lib/crtn.o
should be last following any libraries. The compiler drivers (cc(1),
f77(1), and pc(1)) automatically load these object files in the proper
order. Note that if ld is invoked directly, those two objects will not be
loaded automatically. It is the user's responsibility to specify them
explicitly.
A single registry file, either with -check_registry or -update_registry
is allowed. If multiple registry files are provided, all except the last
one are silently ignored.
Be careful when using -delay_load or when linking against an object that
was built -default_delay_load as the symbol preemption rules are
different: symbols are resolved from the delay loaded object as if the
object were last on the link line.
Archives that are built with -C produce COFF style archive headers. The
linker will no longer recognize such archives.
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LD(1)LD(1)
The following group of options have been superseded by the -elspec
functionality: -Xnobsschange, -Xnosortbss, -Xsortbss, -Xndblock,
-Xblock, -Xblockrange, -Xndlocaldata, -Xalignbss, -Xnoalignbss,
-Xcachemisalign, -Xcachesize, -Xcachelinesize, -Xdefmovemax, -Xsetalign,
-Xdebug. The flag -Xlocaldata has been replaced by the flag -Xlocal.
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