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STANDARD Printed by: Nora Chuang [nchuang] STANDARD

/build/1111/BRICK/man1/!!!intro.1

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ld(1) ld(1)

libraries

Dump info about libraries searched.

procelim

Dump info about sections that have been rejected by the +Oprocelim option

sections

Dump info about each input section added to the output ﬁle.

symbols

Dump info about global symbols referenced/deﬁned from/in the input ﬁles.

all Dumps all of the above info. Same as -v.

Defaults

Unless otherwise directed, ld names its output a.out. The -o option overrides this. Executable output

ﬁles are of type SHARE_MAGIC . The default state of -a is to search shared libraries if available, archive

libraries otherwise. The default bind behavior is deferred.

The default value of the -Z/-z option is -Z.

For 64-bit mode, +std is on by default.

Incremental linking with ld (64-bit Mode ONLY)

In the edit-compile-link-debug development cycle, link time is a signiﬁcant component. The incremental

linker (available through the +ild and +ildrelink options) can reduce the link time by taking advan-

tage of the fact that you can reuse most of the previous version of the program and that the unchanged

object ﬁles do not need to be processed. The incremental linker allows you to insert object code into an out-

put ﬁle (executable or shared library) that you created earlier, without relinking the unmodiﬁed object ﬁles.

The time required to relink after the initial incremental link depends on the number of modules you

modify.

The linker performs the following different modes of linking:

• normal link: the default operation mode in which the linker links all modules.

• initial incremental link: the mode entered when you request an incremental link, but the output

module created by the incremental linker does not exist, or it exists but the incremental linker is

unable to perform an incremental update.

• incremental link: the mode entered when you request an incremental link, an output module created

by the incremental linker exists, and the incremental linker does not require an initial incremental

link.

Incremental links are usually much faster than regular links. On the initial link, the incremental linker

requires about the same amount of time that a normal link process requires, but subsequent incremental

links can be much faster than a normal link. A change in one object ﬁle in a moderate size link (tens of

ﬁles, several megabytes total) normally is about 10 times faster than a regular ld link. The incremental

linker perform as many incremental links as allocated padding space and other constrains permit. The cost

of the reduced link time is an increase in the size of the executable or shared library.

The incremental linker allocates padding space for all components of the output ﬁle. Padding makes

modules larger than those modules linked by ld. As object ﬁles increase in size during successive incre-

mental links, the incremental linker can exhaust the available padding. If this occurs, it displays a warning

message and does a complete initialincremental link of the module. When an object ﬁle changes, the incre-

mental linker not only replaces the content of that ﬁle in the executable or shared library being linked, but

also adjusts references to all symbols deﬁned in the object ﬁle and referenced by other objects. This is done

by looking at relocation records saved in the incrementally linked executable or shared library.

On the initial incremental link, the linker processes the input object ﬁles and libraries in the same way as

the normal link. In addition to the normal linking process, the incremental linker saves information about

object ﬁles, global symbols, and relocations, and pads sections in the output ﬁle for expansion. On subse-

quent incremental links, the linker uses timestamps and ﬁle sizes to determine which object ﬁles have

changed, and updates those modules.

Under certain conditions, the incremental linker cannot perform incremental links. When this occurs, the

incremental linker automatically performs an initial incremental link to restore the process. In the follow-

ing situations, the linker automatically performs an initialincremental link of the output ﬁle:

Section 1−−434 − 12 − HP-UX Release 11i: December 2000

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