NAME
ld - link editor
SYNOPSIS
ld [ -sulxrdni ] name ...
DESCRIPTION
Ld combines several object programs into one; resolves
external references; and searches libraries. In the sim-
plest case the names of several object programs are given,
and ld combines them, producing an object module which can
be either executed or become the input for a further ld run.
(In the latter case, the -r option must be given to preserve
the relocation bits.) The output of ld is left on a.out.
This file is made executable only if no errors occurred dur-
ing the load.
The argument routines are concatenated in the order speci-
fied. The entry point of the output is the beginning of the
first routine.
If any argument is a library, it is searched exactly once at
the point it is encountered in the argument list. Only
those routines defining an unresolved external reference are
loaded. If a routine from a library references another rou-
tine in the library, the referenced routine must appear
after the referencing routine in the library. Thus the
order of programs within libraries is important.
Ld understands several flag arguments which are written pre-
ceded by a `-'. Except for -l, they should appear before
the file names.
-s `squash' the output, that is, remove the symbol table
and relocation bits to save space (but impair the use-
fulness of the debugger). This information can also be
removed by strip.
-u take the following argument as a symbol and enter it as
undefined in the symbol table. This is useful for load-
ing wholly from a library, since initially the symbol
table is empty and an unresolved reference is needed to
force the loading of the first routine.
-l This option is an abbreviation for a library name. -l
alone stands for `/lib/liba.a', which is the standard
system library for assembly language programs. -lx
stands for `/lib/libx.a' where x is any character. A
library is searched when its name is encountered, so the
placement of a -l is significant.
-x do not preserve local (non-.globl) symbols in the output
symbol table; only enter external symbols. This option
1
saves some space in the output file.
-X Save local symbols except for those whose names begin
with `L'. This option is used by cc to discard inter-
nally generated labels while retaining symbols local to
routines.
-r generate relocation bits in the output file so that it
can be the subject of another ld run. This flag also
prevents final definitions from being given to common
symbols, and suppresses the `undefined symbol' diagnos-
tics.
-d force definition of common storage even if the -r flag
is present.
-n Arrange that when the output file is executed, the text
portion will be read-only and shared among all users
executing the file. This involves moving the data areas
up the the first possible 4K word boundary following the
end of the text.
-i When the output file is executed, the program text and
data areas will live in separate address spaces. The
only difference between this option and -n is that here
the data starts at location 0.
FILES
/lib/lib?.a libraries
a.out output file
SEE ALSO
as (I), ar (I)
BUGS
2