LD(I) 8/16/73 LD(I)
ld - link editor
ld [ -sulxrdni ] name ...
Ld combines several object programs into one; resolves
external references; and searches libraries. In the
simplest 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 during the load.
The argument routines are concatenated in the order
specified. 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
routine 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
preceded 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
usefulness 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
loading 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 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
internally 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'
-d force definition of common storage even if the -r flag
-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.
a.out output file
as (I), ar (I)