32v 1m ld
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LD(1) UNIX Programmer's Manual LD(1)
ld - link editor
ld [ option ] ... file ...
_L_d combines several object programs into one, resolves external references, and searches libraries. In the sim- plest case several object _f_i_l_e_s are given, and _l_d combines them, producing an object module which can be either exe- cuted or become the input for a further _l_d run. (In the latter case, the -r option must be given to preserve the relocation bits.) The output of _l_d 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 speci- fied. The entry point of the output is the beginning of the first routine (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. 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.
The symbols `_etext', `_edata' and `_end' (`etext', `edata' and `end' in C) are reserved, and if referred to, are set to the first location above the program, the first location above initialized data, and the first location above all data respectively. It is erroneous to define these symbols.
_L_d understands several options. Except for -l, they should appear before the file names.
-D Take the next argument as a hexadecimal number and pad the data segment with zero bytes to the indicated length.
-d Force definition of common storage even if the -r flag is present.
-e The following argument is taken to be the name of the entry point of the loaded program; location 0 is the default.
-l_x This option is an abbreviation for the library name `/lib/lib_x.a', where _x is a string. If that does not exist, _l_d tries `/usr/lib/lib_x.a' A library is searched when its name is encountered, so the placement of a -l is significant.
-N Do not make the text portion read only or sharable. (Use "magic number" 0407.)
-n Arrange (by giving the output file a 0410 "magic number") 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 to the first possible 512 byte boundary following the end of the text. This option is the default under UNIX/32V; the only other choice is -N.
-o The _n_a_m_e argument after -o is used as the name of the _l_d output file, instead of a.out.
-r Generate relocation bits in the output file so that it can be the subject of another _l_d run. This flag also prevents final definitions from being given to common symbols, and suppresses the `undefined symbol' diagnos- tics.
-S `Strip' the output by removing all symbols except locals and globals.
-s `Strip' 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 _s_t_r_i_p(1).
-T The next argument is a hexadecimal number which sets the text segment origin. The default origin is 0.
-t ("trace") Print the name of each file as it is pro- cessed.
-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 sym- bol table is empty and an unresolved reference is needed to force the loading of the first routine.
-X Save local symbols except for those whose names begin with `L'. This option is used by _c_c(1) to discard internally-generated labels while retaining symbols local to routines.
-x Do not preserve local (non-.globl) symbols in the out- put symbol table; only enter external symbols. This option saves some space in the output file.
/lib/lib*.a libraries /usr/lib/lib*.a more libraries a.out output file