Интерактивная система просмотра системных руководств (man-ов)
>> ld (1) ( Solaris man: Команды и прикладные программы пользовательского уровня ) ld (1) ( FreeBSD man: Команды и прикладные программы пользовательского уровня ) ld (1) ( Linux man: Команды и прикладные программы пользовательского уровня )
ld - link-editor for object files
ld [-64] [-a | -r] [-b] [-Bdirect | nodirect]
[-B dynamic | static] [-B eliminate] [-B group] [-B local]
[-B reduce] [-B symbolic] [-c name] [-C] [-d y | n]
[-D token,...] [-e epsym] [-f name | -F name] [-G] [-h name]
[-i] [-I name] [-l x] [-L path] [-m] [-M mapfile]
[-N string] [-o outfile] [-p auditlib] [-P auditlib]
[-Q y | n] [-R path] [-s] [-S supportlib] [-t]
[-u symname] [-V] [-Y P,dirlist] [-z absexec]
[-z allextract | defaultextract | weakextract ]
[-z altexec64] [-z combreloc | nocombreloc ] [-z defs | nodefs]
[-z direct | nodirect] [-z endfiltee] [-z finiarray=function]
[-z globalaudit] [-z groupperm | nogroupperm] [-z help ]
[-z ignore | record] [-z initarray=function] [-z initfirst]
[-z interpose] [-z lazyload | nolazyload]
[-z ld32=arg1,arg2,...] [-z ld64=arg1,arg2,...]
[-z loadfltr] [-z muldefs] [-z nocompstrtab] [-z nodefaultlib]
[-z nodelete] [-z nodlopen] [-z nodump] [-z noldynsym]
[-z nopartial] [-z noversion] [-z now] [-z origin]
[-z preinitarray=function] [-z redlocsym] [-z relaxreloc]
[-z rescan-now] [-z recan] [-z rescan-start ... -z rescan-end]]
[-z target=sparc|x86] [-z text | textwarn | textoff]
[-z verbose] filename...
The link-editor, ld, combines relocatable object
files by resolving symbol references to symbol definitions, together with
performing relocations. ld operates in two modes, static
or dynamic, as governed by the -d option. In all cases, the
output of ld is left in the file a.out by
default. See NOTES.
In dynamic mode, -dy, the default, relocatable object
files that are provided as arguments are combined to produce an executable
object file. This file is linked at execution with any shared object files
that are provided as arguments. If the -G option is specified,
relocatable object files are combined to produce a shared object. Without
the -G option, a dynamic executable is created.
In static mode, -dn, relocatable object files that are
provided as arguments are combined to produce a static executable file. If
the -r option is specified, relocatable object files are combined
to produce one relocatable object file. See Static Executables.
Dynamic linking is the most common model for combining relocatable objects,
and the eventual creation of processes within Solaris. This environment tightly
couples the work of the link-editor and the runtime linker, ld.so.1(1). Both of these utilities,
together with their related technologies and utilities, are extensively documented
in the Linker and Libraries Guide.
If any argument is a library, ld by default searches
the library exactly once at the point the library is encountered on the argument
list. The library can be either a shared object or relocatable archive. See ar.h(3HEAD)).
A shared object consists of an indivisible, whole unit that has been
generated by a previous link-edit of one or more input files. When the link-editor
processes a shared object, the entire contents of the shared object become
a logical part of the resulting output file image. The shared object is not
physically copied during the link-edit as its actual inclusion is deferred
until process execution. This logical inclusion means that all symbol entries
defined in the shared object are made available to the link-editing process.
See Chapter 4, Shared Objects, in Linker and Libraries Guide
For an archive library, ld loads only those routines
that define an unresolved external reference. ld searches
the symbol table of the archive library sequentially to resolve external references
that can be satisfied by library members. This search is repeated until no
external references can be resolved by the archive. Thus, the order of members
in the library is functionally unimportant, unless multiple library members
exist that define the same external symbol. Archive libraries that have interdependencies
can require multiple command line definitions, or the use of one of the -z rescan options. See Archive Processing in Linker and Libraries Guide.
ld is a cross link-editor, able to link 32-bit
objects or 64-bit objects, for Sparc or x86 targets. ld uses
the ELF class and machine type of the first relocatable
object on the command line to govern the mode in which to operate. The mixing
of 32-bit objects and 64-bit objects is not permitted. Similarly,
only objects of a single machine type are allowed. See the -64 and -z target options, and the LD_NOEXEC_64 environment
The creation of static executables has been discouraged for many releases.
In fact, 64-bit system archive libraries have never been provided. Because
a static executable is built against system archive libraries, the executable
contains system implementation details. This self-containment has a number
The executable is immune to the benefits of system patches
delivered as shared objects. The executable therefore, must be rebuilt to
take advantage of many system improvements.
The ability of the executable to run on future releases can
The duplication of system implementation details negatively
affects system performance.
With Solaris 10, 32-bit system archive libraries are no longer
provided. Without these libraries, specifically libc.a,
the creation of static executables is no longer achievable without specialized
system knowledge. However, the capability of ld to process
static linking options, and the processing of archive libraries, remains unchanged.
The following options are supported.
Creates a 64-bit object. By default, the class of the
object being generated is determined from the first ELF object
processed from the command line. This option is useful when creating an object
directly with ld whose input is solely from an archive
library or a mapfile. See The 32-bit link-editor and 64-bit link-editor in Linker and Libraries Guide.
In static mode only, produces an executable object file. Undefined
references are not permitted. This option is the default behavior for static
mode. The -a option can not be used with the -r option.
See Static Executables under DESCRIPTION.
In dynamic mode only, provides no special processing for dynamic
executable relocations that reference symbols in shared objects. Without the -b option, the link-editor applies techniques within a dynamic executable
so that the text segment can remain read-only. One technique is the creation
of special position-independent relocations for references to functions that
are defined in shared objects. Another technique arranges for data objects
that are defined in shared objects to be copied into the memory image of an
executable at runtime.
The -b option is intended for specialized dynamic objects
and is not recommended for general use. Its use suppresses all specialized
processing required to ensure an object's shareability, and can even prevent
the relocation of 64-bit executables.
-B direct | nodirect
These options govern direct binding. -B direct establishes direct binding information by recording the relationship
between each symbol reference together with the dependency that provides the
definition. In addition, direct binding information is established between
each symbol reference and an associated definition within the object being
created. The runtime linker uses this information to search directly for a
symbol in the associated object rather than to carry out a default symbol
Direct binding information can only be established to dependencies specified
with the link-edit. Thus, you should use the -z defs option.
Objects that wish to interpose on symbols in a direct binding environment
should identify themselves as interposers with the -z interpose option. The use of -B direct enables -z lazyload for all dependencies.
The -B nodirect option prevents any
direct binding to the interfaces offered by the object being created. The
object being created can continue to directly bind to external interfaces
by specifying the -z direct option. See Appendix D, Direct Bindings, in Linker and Libraries Guide.
-B dynamic | static
Options governing library inclusion. -B dynamic is valid in dynamic mode only. These options can be specified
any number of times on the command line as toggles: if the -B static option is given, no shared objects are accepted until -B dynamic is seen. See the -l option.
Causes any global symbols, not assigned to a version definition,
to be eliminated from the symbol table. Version definitions can be supplied
by means of a mapfile to indicate the global symbols
that should remain visible in the generated object. This option achieves the
same symbol elimination as the auto-elimination directive
that is available as part of a mapfile version definition.
This option can be useful when combining versioned and non-versioned relocatable
objects. See also the -B local option and
the -B reduce option. See Defining Additional Symbols with a mapfile in Linker and Libraries Guide.
Establishes a shared object and its dependencies as a group.
Objects within the group are bound to other members of the group at runtime.
This mode is similar to adding the object to the process by using dlopen(3C) with the RTLD_GROUP mode.
An object that has an explicit dependency on a object identified as a group,
becomes a member of the group.
As the group must be self contained, use of the -B group option also asserts the -z defs option.
Causes any global symbols, not assigned to a version definition,
to be reduced to local. Version definitions can be supplied by means of a mapfile to indicate the global symbols that should remain visible
in the generated object. This option achieves the same symbol reduction as
the auto-reduction directive that is available
as part of a mapfile version definition. This option
can be useful when combining versioned and non-versioned relocatable objects.
See also the -B eliminate option and the -B reduce option. See Defining Additional Symbols with a mapfile in Linker and Libraries Guide.
When generating a relocatable object, causes the reduction
of symbolic information defined by any version definitions. Version definitions
can be supplied by means of a mapfile to indicate the
global symbols that should remain visible in the generated object. By default,
when a relocatable object is generated, version definitions are only recorded
in the output image. The actual reduction of symbolic information is carried
out when the object is used in the construction of a dynamic executable or
shared object. The -B reduce option is
applied automatically when a dynamic executable or shared object is created.
In dynamic mode only. When building a shared object, binds
references to global symbols to their definitions, if available, within the
object. Normally, references to global symbols within shared objects are not
bound until runtime, even if definitions are available. This model allows
definitions of the same symbol in an executable or other shared object to
override the object's own definition. ld issues warnings
for undefined symbols unless -z defs overrides.
The -B symbolic option is intended
for specialized dynamic objects and is not recommended for general use. To
reduce the runtime relocation processing that is required an object, the creation
of a version definition is recommended.
Records the configuration file name for
use at runtime. Configuration files can be employed to alter default search
paths, provide a directory cache, together with providing alternative object
dependencies. See crle(1).
Demangles C++ symbol names displayed in diagnostic
-d y | n
When -d y, the default,
is specified, ld uses dynamic linking. When -d n is specified, ld uses static linking. See Static Executables under DESCRIPTION, and -B dynamic|static.
Prints debugging information as specified by each token, to the standard error. The special token help indicates
the full list of tokens available. See Debugging Aids in Linker and Libraries Guide.
Sets the entry point address for the output file to be the
Useful only when building a shared object. Specifies that
the symbol table of the shared object is used as an auxiliary filter on the
symbol table of the shared object specified by name.
Multiple instances of this option are allowed. This option can not be combined
with the -F option. See Generating Auxiliary Filters in Linker and Libraries Guide.
Useful only when building a shared object. Specifies that
the symbol table of the shared object is used as a filter on the symbol table
of the shared object specified by name. Multiple
instances of this option are allowed. This option can not be combined with
the -f option. See Generating Standard Filters in Linker and Libraries Guide.
In dynamic mode only, produces a shared object. Undefined
symbols are allowed. See Chapter 4, Shared Objects, in Linker and Libraries Guide.
In dynamic mode only, when building a shared object, records name in the object's dynamic section. name is
recorded in any dynamic objects that are linked with this object rather than
the object's file system name. Accordingly, name is
used by the runtime linker as the name of the shared object to search for
at runtime. See Recording a Shared Object Name in Linker and Libraries Guide.
Ignores LD_LIBRARY_PATH. This option is useful
when an LD_LIBRARY_PATH setting is in effect to influence the
runtime library search, which would interfere with the link-editing being
When building an executable, uses name as
the path name of the interpreter to be written into the program header. The
default in static mode is no interpreter. In dynamic mode, the default is
the name of the runtime linker, ld.so.1(1).
Either case can be overridden by -I name. exec(2) loads this interpreter when
the a.out is loaded, and passes control to the interpreter
rather than to the a.out directly.
Searches a library libx.so or libx.a,
the conventional names for shared object and archive libraries, respectively.
In dynamic mode, unless the -B static option
is in effect, ld searches each directory specified in the
library search path for a libx.so or libx.a file.
The directory search stops at the first directory containing either. ld chooses
the file ending in .so if -lx expands
to two files with names of the form libx.so and libx.a.
If no libx.so is
found, then ld accepts libx.a. In static mode, or when the -B static option
is in effect, ld selects only the file ending in .a. ld searches a library when the library is encountered, so the placement
of -l is significant. See Linking With Additional Libraries in Linker and Libraries Guide.
Adds path to the library search
directories. ld searches for libraries first in any directories
specified by the -L options and then in the standard directories.
This option is useful only if the option precedes the -l options
to which the -L option applies. See Directories Searched by the Link-Editor in Linker and Libraries Guide.
The environment variable LD_LIBRARY_PATH can be used
to supplement the library search path, however the -L option
is recommended, as the environment variable is also interpreted by the runtime
environment. See LD_LIBRARY_PATH under ENVIRONMENT VARIABLES.
Produces a memory map or listing of the input/output sections,
together with any non-fatal multiply-defined symbols, on the standard output.
Reads mapfile as a
text file of directives to ld. This option can be specified
multiple times. If mapfile is a directory, then
all regular files, as defined by stat(2),
within the directory are processed. See Chapter 9, Mapfile Option, in Linker and Libraries Guide. Example mapfiles are provided in /usr/lib/ld. See FILES.
This option causes a DT_NEEDED entry to
be added to the .dynamic section of the object being built.
The value of the DT_NEEDED string is the string that
is specified on the command line. This option is position dependent, and the DT_NEEDED .dynamic entry is relative to the other
dynamic dependencies discovered on the link-edit line. This option is useful
for specifying dependencies within device driver relocatable objects when
combined with the -dy and -r options.
Produces an output object file that is named outfile. The name of the default object file is a.out.
Identifies an audit library, auditlib.
This audit library is used to audit the object being created at runtime. A
shared object identified as requiring auditing with the -p option,
has this requirement inherited by any object that specifies the shared object
as a dependency. See the -P option. See Runtime Linker Auditing Interface in Linker and Libraries Guide.
Identifies an audit library, auditlib.
This audit library is used to audit the dependencies of the object being created
at runtime. Dependency auditing can also be inherited from dependencies that
are identified as requiring auditing. See the -p option, and
the -z globalaudit option. See Runtime Linker Auditing Interface in Linker and Libraries Guide.
-Q y | n
Under -Q y, an ident string
is added to the .comment section of the output file. This
string identifies the version of the ld used to create
the file. This results in multiple ld idents when
there have been multiple linking steps, such as when using ld -r. This identification is identical with the default action of the cc command. -Q n suppresses version
identification. .comment sections can be manipulated by
the mcs(1) utility.
Combines relocatable object files to produce one relocatable
object file. ld does not complain about unresolved references.
This option cannot be used with the -a option.
A colon-separated list of directories used to specify library
search directories to the runtime linker. If present and not NULL, the path
is recorded in the output object file and passed to the runtime linker. Multiple
instances of this option are concatenated together with each path separated
by a colon. See Directories Searched by the Runtime Linker in Linker and Libraries Guide.
The use of a runpath within an associated object is
preferable to setting global search paths such as through the LD_LIBRARY_PATH environment variable. Only the runpaths that are
necessary to find the objects dependencies should be recorded. ldd(1) can also be used to discover
unused runpaths in dynamic objects, when used with the -U option.
Various tokens can also be supplied with a runpath that
provide a flexible means of identifying system capabilities or an objects
location. See Appendix C, Establishing Dependencies with Dynamic String Tokens, in Linker and Libraries Guide. The $ORIGIN token is especially useful in allowing dynamic objects to be relocated
to different locations in the file system.
Strips symbolic information from the output file. Any debugging
information, that is, .line, .debug*,
and .stab* sections, and their associated relocation entries
are removed. Except for relocatable files, a symbol table SHT_SYMTAB and
its associated string table section are not created in the output object file.
The elimination of a SHT_SYMTAB symbol table can reduce
the .stab* debugging information that is generated using
the compiler drivers -g option. See the -z redlocsym and -z noldynsym options.
The shared object supportlib is
loaded with ld and given information regarding the linking
process. Shared objects that are defined by using the -S option
can also be supplied using the SGS_SUPPORT environment variable.
See Link-Editor Support Interface in Linker and Libraries Guide.
Turns off the warning for multiply-defined symbols that have
different sizes or different alignments.
Enters symname as an undefined
symbol in the symbol table. This option is useful for loading entirely from
an archive library. In this instance, an unresolved reference is needed to
force the loading of the first routine. The placement of this option on the
command line is significant. This option must be placed before the library
that defines the symbol. See Defining Additional Symbols with the u option in Linker and Libraries Guide.
Outputs a message giving information about the version of ld being used.
Changes the default directories used for finding libraries. dirlist is a colon-separated path list.
Useful only when building a dynamic executable. Specifies
that references to external absolute symbols should be resolved immediately
instead of being left for resolution at runtime. In very specialized circumstances,
this option removes text relocations that can result in excessive swap space
demands by an executable.
-z allextract | defaultextract | weakextract
--whole-archive | --no-whole-archive
Alters the extraction criteria of objects from any archives
that follow. By default, archive members are extracted to satisfy undefined
references and to promote tentative definitions with data definitions. Weak
symbol references do not trigger extraction. Under the -z allextract or --whole-archive options, all archive
members are extracted from the archive. Under -z weakextract, weak references trigger archive extraction. The -z defaultextract or --no-whole-archive options provide
a means of returning to the default following use of the former extract options.
See Archive Processing in Linker and Libraries Guide.
Execute the 64-bit ld. The creation
of very large 32-bit objects can exhaust the virtual memory that is
available to the 32-bit ld. The -z altexec64 option can be used to force the use of the associated
64-bit ld. The 64-bit ld provides
a larger virtual address space for building 32-bit objects. See The 32-bit link-editor and 64-bit link-editor in Linker and Libraries Guide.
-z combreloc | nocombreloc
By default, ld combines multiple relocation
sections when building executables or shared objects. This section combination
differs from relocatable objects, in which relocation sections are maintained
in a one-to-one relationship with the sections to which the relocations must
be applied. The -z nocombreloc option disables
this merging of relocation sections, and preserves the one-to-one relationship
found in the original relocatable objects.
ld sorts the entries of data relocation sections
by their symbol reference. This sorting reduces runtime symbol lookup. When
multiple relocation sections are combined, this sorting produces the least
possible relocation overhead when objects are loaded into memory, and speeds
the runtime loading of dynamic objects.
Historically, the individual relocation sections were carried over to
any executable or shared object, and the -z combreloc option
was required to enable the relocation section merging previously described.
Relocation section merging is now the default. The -z combreloc option is still accepted for the benefit of old build environments,
but the option is unnecessary, and has no effect.
-z defs | nodefs
The -z defs option and
the --no-undefined option force a fatal error if any undefined
symbols remain at the end of the link. This mode is the default when an executable
is built. For historic reasons, this mode is not the
default when building a shared object. Use of the -z defs option is recommended, as this mode assures the object being built
is self-contained. A self-contained object has all symbolic references resolved
internally, or to the object's immediate dependencies.
The -z nodefs option allows undefined
symbols. For historic reasons, this mode is the default when a shared object
is built. When used with executables, the behavior of references to such undefined
symbols is unspecified. Use of the -z nodefs option
is not recommended.
-z direct | nodirect
Enables or disables direct binding to any dependencies that
follow on the command line. These options allow finer control over direct
binding than the global counterpart -B direct.
The -z direct option also differs from
the -B direct option in the following areas.
Direct binding information is not established between a symbol reference and
an associated definition within the object being created. Lazy loading is
Marks a filtee so that when processed by
a filter, the filtee terminates any further filtee searches
by the filter. See Reducing Filtee Searches in Linker and Libraries Guide.
Appends an entry to the .finiarray section
of the object being built. If no .finiarray section is
present, a section is created. The new entry is initialized to point to function. See Initialization and Termination Sections in Linker and Libraries Guide.
This option supplements an audit library definition that has
been recorded with the -P option. This option is only meaningful
when building a dynamic executable. Audit libraries that are defined within
an object with the -P option typically allow for the auditing
of the immediate dependencies of the object. The -z globalaudit promotes the auditor to a global auditor, thus allowing the auditing
of all dependencies. See Invoking the Auditing Interface in Linker and Libraries Guide.
An auditor established with the -P option and the -z globalaudit option, is equivalent to the auditor
being established with the LD_AUDIT environment variable. See ld.so.1(1).
-z groupperm | nogroupperm
Assigns, or deassigns each dependency that
follows to a unique group. The assignment of a dependency to a group has the
same effect as if the dependency had been built using the -B group option.
Print a summary of the command line options on the standard
output and exit.
-z ignore | record
Ignores, or records, dynamic dependencies that are not referenced
as part of the link-edit. Ignores, or records, unreferenced ELF sections
from the relocatable objects that are read as part of the link-edit. By default, -z record is in effect.
If an ELF section is ignored, the section is eliminated
from the output file being generated. A section is ignored when three conditions
are true. The eliminated section must contribute to an allocatable segment.
The eliminated section must provide no global symbols. No other section from
any object that contributes to the link-edit, must reference an eliminated
Appends an entry to the .initarray section
of the object being built. If no .initarray section is
present, a section is created. The new entry is initialized to point to function. See Initialization and Termination Sections in Linker and Libraries Guide.
Marks the object so that its runtime initialization occurs
before the runtime initialization of any other objects brought into the process
at the same time. In addition, the object runtime finalization occurs after
the runtime finalization of any other objects removed from the process at
the same time. This option is only meaningful when building a shared object.
Marks the object as an interposer. At runtime, an object is
identified as an explicit interposer if the object has been tagged using the -z interpose option. An explicit interposer is also established when
an object is loaded using the LD_PRELOAD environment variable.
Implicit interposition can occur because of the load order of objects, however,
this implicit interposition is unknown to the runtime linker. Explicit interposition
can ensure that interposition takes place regardless of the order in which
objects are loaded. Explicit interposition also ensures that the runtime linker
searches for symbols in any explicit interposers when direct bindings are
-z lazyload | nolazyload
Enables or disables the marking of dynamic dependencies to
be lazily loaded. Dynamic dependencies which are marked lazyload are
not loaded at initial process start-up. These dependencies are delayed until
the first binding to the object is made. Note: Lazy loading
requires the correct declaration of dependencies, together with associated runpaths for each dynamic object used within a process. See Lazy Loading of Dynamic Dependencies in Linker and Libraries Guide.
The class of the link-editor is affected by the class of the
output file being created and by the capabilities of the underlying operating
system. The -z ld[32|64] options provide a means of defining any link-editor argument.
The defined argument is only interpreted, respectively, by the 32-bit
class or 64-bit class of the link-editor.
For example, support libraries are class specific, so the correct class
of support library can be ensured using:
ld ... -z ld32=-Saudit32.so.1 -z ld64=-Saudit64.so.1 ...
The class of link-editor that is invoked is determined from the ELF class of the first relocatable file that is seen on the command
line. This determination is carried out prior to any -z ld[32|64]
Marks a filter to indicate that filtees must
be processed immediately at runtime. Normally, filter processing is delayed
until a symbol reference is bound to the filter. The runtime processing of
an object that contains this flag mimics that which occurs if the LD_LOADFLTR environment variable is in effect. See the ld.so.1(1).
Allows multiple symbol definitions. By default, multiple symbol
definitions that occur between relocatable objects result in a fatal error
condition. This option, suppresses the error condition, allowing the first
symbol definition to be taken.
Disables the compression of ELF string
tables. By default, string compression is applied to SHT_STRTAB sections,
and to SHT_PROGBITS sections that have their SHF_MERGE and SHF_STRINGS section flags set.
Marks the object so that the runtime default library search
path, used after any LD_LIBRARY_PATH or runpaths,
is ignored. This option implies that all dependencies of the object can be
satisfied from its runpath.
Marks the object as non-deletable at runtime. This mode is
similar to adding the object to the process by using dlopen(3C) with the RTLD_NODELETE mode.
Marks the object as not available to dlopen(3C), either as the object specified
by the dlopen(), or as any form of dependency required
by the object specified by the dlopen(). This option is
only meaningful when building a shared object.
Marks the object as not available to dldump(3C).
Prevents the inclusion of a .SUNW_ldynsym section
in dynamic executables or sharable libraries. The .SUNW_ldynsym section
augments the .dynsym section by providing symbols for local
functions. Local function symbols allow debuggers to display local function
names in stack traces from stripped programs. Similarly, dladdr(3C) is able to supply more accurate
The -z noldynsym option also prevents
the inclusion of the two symbol sort sections that are related to the .SUNW_ldynsym section. The .SUNW_dynsymsort section provides
sorted access to regular function and variable symbols. The .SUNW_dyntlssort section provides sorted access to thread local storage (TLS)
The .SUNW_ldynsym, .SUNW_dynsymsort,
and .SUNW_dyntlssort sections, which becomes part of the
allocable text segment of the resulting file, cannot be removed by strip(1). Therefore, the -z noldynsym option is the only way to prevent their inclusion. See
the -s and -z redlocsym options.
Partially initialized symbols, that are defined within relocatable
object files, are expanded in the output file being generated.
Does not record any versioning sections. Any version sections
or associated .dynamic section entries are not generated
in the output image.
Marks the object as requiring non-lazy runtime binding. This
mode is similar to adding the object to the process by using dlopen(3C) with the RTLD_NOW mode.
This mode is also similar to having the LD_BIND_NOW environment
variable in effect. See ld.so.1(1).
Marks the object as requiring immediate $ORIGIN processing
at runtime. This option is only maintained for historic compatibility, as
the runtime analysis of objects to provide for $ORIGIN processing
is now default.
Appends an entry to the .preinitarray section
of the object being built. If no .preinitarray section
is present, a section is created. The new entry is initialized to point to function. See Initialization and Termination Sections in Linker and Libraries Guide.
Eliminates all local symbols except for the SECT symbols
from the symbol table SHT_SYMTAB. All relocations that
refer to local symbols are updated to refer to the corresponding SECT symbol.
This option allows specialized objects to greatly reduce their symbol table
sizes. Eliminated local symbols can reduce the .stab* debugging
information that is generated using the compiler drivers -g option.
See the -s and -z noldynsym options.
ld normally issues a fatal error upon encountering
a relocation using a symbol that references an eliminated COMDAT section.
If -z relaxreloc is enabled, ld instead
redirects such relocations to the equivalent symbol in the COMDAT section
that was kept. -z relaxreloc is a specialized
option, mainly of interest to compiler authors, and is not intended for general
These options rescan the archive files that are provided to
the link-edit. By default, archives are processed once as the archives appear
on the command line. Archives are traditionally specified at the end of the
command line so that their symbol definitions resolve any preceding references.
However, specifying archives multiple times to satisfy their own interdependencies
can be necessary.
-z rescan-now is a positional option,
and is processed by the link-editor immediately when encountered on the command
line. All archives seen on the command line up to that point are immediately
reprocessed in an attempt to locate additional archive members that resolve
symbol references. This archive rescanning is repeated until a pass over the
archives occurs in which no new members are extracted.
-z rescan is a position independent
option. The link-editor defers the rescan operation until after it has processed
the entire command line, and then initiates a final rescan operation over
all archives seen on the command line. The -z rescan operation
can interact incorrectly with objects that contain initialization
(.init) or finalization (.fini) sections, preventing the code in those sections
from running. For this reason, -z rescan is
deprecated, and use of -z rescan-now is
-z rescan-start ... -z rescan-end
--start-group ... --end-group
-( ... -)
Defines an archive rescan group. This is a positional construct,
and is processed by the link-editor immediately upon encountering the closing
delimiter option. Archives found within the group delimiter options are reprocessed
as a group in an attempt to locate additional archive members that resolve
symbol references. This archive rescanning is repeated until a pass over
the archives On the occurs in which no new members are extracted. Archive
rescan groups cannot be nested.
Specifies the machine type for the output object. Supported
targets are Sparc and x86. The 32-bit machine type for the specified
target is used unless the -64 option is also present, in which
case the corresponding 64-bit machine type is used. By default, the
machine type of the object being generated is determined from the first ELF object processed from the command line. This option is useful
when creating an object directly with ld whose input is
solely from an archive library or a mapfile. See the -M option. See The 32-bit link-editor and 64-bit link-editor in Linker and Libraries Guide.
In dynamic mode only, forces a fatal error if any relocations
against non-writable, allocatable sections remain. For historic reasons, this
mode is not the default when building an executable or shared object. However,
its use is recommended to ensure that the text segment of the dynamic object
being built is shareable between multiple running processes. A shared text
segment incurs the least relocation overhead when loaded into memory. See Position-Independent Code in Linker and Libraries Guide.
In dynamic mode only, allows relocations against all allocatable
sections, including non-writable ones. This mode is the default when building
a shared object.
In dynamic mode only, lists a warning if any relocations against
non-writable, allocatable sections remain. This mode is the default when building
This option provides additional warning diagnostics during
a link-edit. Presently, this option conveys suspicious use of displacement
relocations. This option also conveys the restricted use of static TLS relocations
when building shared objects. In future, this option might be enhanced to
provide additional diagnostics that are deemed too noisy to be generated by
An alternative link-editor path name. ld executes,
and passes control to this alternative link-editor. This environment variable
provides a generic means of overriding the default link-editor that is called
from the various compiler drivers. See the -z altexec64 option.
A list of directories in which to search for the libraries
specified using the -l option. Multiple directories are separated
by a colon. In the most general case, this environment variable contains two
directory lists separated by a semicolon:
If ld is called with any number of occurrences of -L, as in:
ld ... -Lpath1 ... -Lpathn ...
then the search path ordering is:
dirlist1 path1 ... pathn dirlist2 LIBPATH
When the list of directories does not contain a semicolon, the list
is interpreted as dirlist2.
The LD_LIBRARY_PATH environment variable also affects
the runtime linkers search for dynamic dependencies.
This environment variable can be specified with a _32 or _64 suffix.
This makes the environment variable specific, respectively, to 32-bit
or 64-bit processes and overrides any non-suffixed version of the environment
variable that is in effect.
Suppresses the automatic execution of the 64-bit link-editor.
By default, the link-editor executes the 64-bit version when the ELF class of the first relocatable file identifies a 64-bit object.
The 64-bit image that a 32-bit link-editor can create, has some
limitations. However, some link-edits might find the use of the 32-bit
A default set of options to ld. LD_OPTIONS is interpreted by ld just as though its value
had been placed on the command line, immediately following the name used to
invoke ld, as in:
ld $LD_OPTIONS ... other-arguments ...
An alternative mechanism for specifying a runpath to
the link-editor. See the -R option. If both LD_RUN_PATH and
the -R option are specified, -R supersedes.
Provides a colon-separated list of shared objects that are
loaded with the link-editor and given information regarding the linking process.
This environment variable can be specified with a _32 or _64 suffix. This
makes the environment variable specific, respectively, to the 32-bit
or 64-bit class of ld and overrides any non-suffixed
version of the environment variable that is in effect. See the -S option.
Notice that environment variable-names that begin with the characters
'LD_' are reserved for possible future enhancements to ld and ld.so.1(1).
shared object libraries.
default output file.
For 32-bit libraries, the default search path is /usr/ccs/lib, followed by /lib, and finally /usr/lib. For 64-bit libraries, the default search path is /lib/64, followed by /usr/lib/64.
A directory containing several mapfiles that
can be used during link-editing. These mapfiles provide
various capabilities, such as defining memory layouts, aligning bss, and defining
See attributes(5) for
descriptions of the following attributes:
|ATTRIBUTE TYPE||ATTRIBUTE VALUE|
as(1), crle(1), gprof(1), ld.so.1(1), ldd(1), mcs(1), pvs(1), exec(2), stat(2), dlopen(3C), dldump(3C), elf(3ELF), ar.h(3HEAD), a.out(4), attributes(5)
Linker and Libraries Guide
Default options applied by ld are maintained for
historic reasons. In today's programming environment, where dynamic objects
dominate, alternative defaults would often make more sense. However, historic
defaults must be maintained to ensure compatibility with existing program
development environments. Historic defaults are called out wherever possible
in this manual. For a description of the current recommended options, see Appendix A, Link-Editor Quick Reference, in Linker and Libraries Guide.
If the file being created by ld already exists, the
file is unlinked after all input files have been processed. A new file with
the specified name is then created. This allows ld to create
a new version of the file, while simultaneously allowing existing processes
that are accessing the old file contents to continue running. If the old file
has no other links, the disk space of the removed file is freed when the last
process referencing the file terminates.
The behavior of ld when the file being created already
exists was changed with SXCE build 43.
In older versions, the existing file was rewritten in place, an approach with
the potential to corrupt any running processes that is using the file. This
change has an implication for output files that have multiple hard links in
the file system. Previously, all links would remain intact, with all links
accessing the new file contents. The new ld behavior breaks such links, with the result that only the specified output
file name references the new file. All the other links continue to reference
the old file. To ensure consistent behavior, applications that rely on multiple
hard links to linker output files should explicitly remove and relink the
other file names.
- Static Executables
- ENVIRONMENT VARIABLES
- SEE ALSO