Return to ld CVS log

Up to [MW Coherent from dump] / coherent / a / usr / man / MULTI

Annotation of coherent/a/usr/man/MULTI/ld, revision 1.1

1.1     ! root        1: 
        !             2: 
        !             3: ld                           Command                           ld
        !             4: 
        !             5: 
        !             6: 
        !             7: 
        !             8: Link relocatable object files
        !             9: 
        !            10: lldd [_o_p_t_i_o_n ...] _f_i_l_e ...
        !            11: 
        !            12: A compiler  translates a file  of source code  into a relocatable
        !            13: object.  This  relocatable object  cannot be executed  by itself,
        !            14: for  calls to  routines  stored in  libraries have  not yet  been
        !            15: resolved.  ld  combines, or links, relocatable  object files with
        !            16: routines stored in libraries  produced by the archiver ar to con-
        !            17: struct  an executable  file.  For  this  reason, ld  is sometimes
        !            18: called a linker, a link editor, or a loader.
        !            19: 
        !            20: ld scans  its arguments  in order  and interprets each  option as
        !            21: described below.   Each non-option argument is  either a relocat-
        !            22: able object file, produced by cc, as, or ld, or a library archive
        !            23: produced  by ar.   It rejects  all other  arguments and  prints a
        !            24: diagnostic message.
        !            25: 
        !            26: Each relocatable  file argument is bound into  the output file if
        !            27: its machine  type matches the  machine type of the  first file so
        !            28: bound; if it does not,  ld prints a diagnostic message.  The sym-
        !            29: bol table of the file is  merged into the output symbol table and
        !            30: the list of  defined and undefined symbols updated appropriately.
        !            31: If  the  file redefines  a  symbol defined  in  an earlier  bound
        !            32: module, the redefinition is reported and the link continues.  The
        !            33: last such redefinition  determines the value that the symbol will
        !            34: have in the output file,  which may be acceptable but is probably
        !            35: an error.
        !            36: 
        !            37: Each  library archive  argument is searched  only to  resolve un-
        !            38: defined references, i.e.,  if there are no undefined symbols, the
        !            39: linker  goes to  the next argument  immediately.  The  library is
        !            40: searched from  first module to last and  any module that resolves
        !            41: one or more undefined symbols is bound into the output exactly as
        !            42: an explicitly  named relocatable file  is bound.  The  library is
        !            43: searched repeatedly until an  entire scan adds nothing to the ex-
        !            44: ecutable file.
        !            45: 
        !            46: The order  of modules in a library is  important in two respects:
        !            47: it will  affect the time required to search  the library, and, if
        !            48: more than  one module resolves an undefined  symbol, it can alter
        !            49: the set of library modules bound into the output.
        !            50: 
        !            51: A library will link faster  if the undefined symbols in any given
        !            52: library module are resolved  by a library module that comes later
        !            53: in the library.   Thus, the low-level library modules, those with
        !            54: no  undefined symbols,  should come  at the  end of  the library,
        !            55: whereas the higher-level  modules, those with many undefined sym-
        !            56: bols,  should come  at the  beginning.   The library  module ran-
        !            57: lib.sym, which  is maintained by  the ar s  modifier, provides ld
        !            58: with a  compressed index to  the symbols defined  in the library.
        !            59: But even with the index, the library will link much faster if the
        !            60: modules occur in top-down rather than bottom-up order.
        !            61: 
        !            62: 
        !            63: 
        !            64: COHERENT Lexicon                                           Page 1
        !            65: 
        !            66: 
        !            67: 
        !            68: 
        !            69: ld                           Command                           ld
        !            70: 
        !            71: 
        !            72: 
        !            73: A library can be constructed to provide a type of ``conditional''
        !            74: linking  if alternate  resolutions of  undefined symbols  are ar-
        !            75: chived in  a carefully  thought-out order.  For  instance, libc.a
        !            76: contains the modules
        !            77: 
        !            78: 
        !            79:              finit.o
        !            80:              exit.o
        !            81:              _finish.o
        !            82: 
        !            83: 
        !            84: in precisely  the order given, though some  other modules may in-
        !            85: tervene.   finit.o contains  most of the  internals of  the STDIO
        !            86: library, exit.o contains  the exit() function, and _finish.o con-
        !            87: tains  an empty  version of _finish(),  the function  that exit()
        !            88: calls to  close STDIO streams  before process termination.   If a
        !            89: program uses  any STDIO routines,  macros, or data,  then finit.o
        !            90: will be bound into the output with its version of finish().  If a
        !            91: program uses no STDIO, then the ``dummy'' _finish.o will be bound
        !            92: into  the output  because  it is  the first  module that  defines
        !            93: _finish() that  the linker encounters  after exit.o adds  the un-
        !            94: defined reference.  This saves approximately 3,000 bytes.  To set
        !            95: the order of routines within a library, use the archiver ar.
        !            96: 
        !            97: The available options are as follows:
        !            98: 
        !            99: -dd    Define common  regions  even if  relocation information  is
        !           100:      retained.  By  default, ld leaves common  areas undefined if
        !           101:      there  are  undefined   symbols  or  if  the  -r  option  is
        !           102:      specified.
        !           103: 
        !           104: -ee _e_n_t_r_y
        !           105:      Specify the  entry point of  the output module,  either as a
        !           106:      symbol or as an absolute octal address.
        !           107: 
        !           108: -kk[_s_y_s_t_e_m]
        !           109:      Bind the output as a kernel process or linkable driver.  The
        !           110:      starting address depends on the target machine, and ld scans
        !           111:      the system link file  symbol table for symbols that are cur-
        !           112:      rently undefined.  system defaults to /coherent.
        !           113: 
        !           114: -ll _n_a_m_e
        !           115:      An   abbreviation   for   the  library   /lliibb/lliibb_n_a_m_e.aa   or
        !           116:      /uussrr/lliibb/lliibb_n_a_m_e.aa if the first is not found.
        !           117: 
        !           118: -mm   This option tells  ld to perform in-memory load if possible.
        !           119:      This requires more memory, but is faster than using a buffer
        !           120:      file.
        !           121: 
        !           122: -nn   Bind  the output with separate  shared and private segments,
        !           123:      and with  each starting on  a hardware segment  boundary, so
        !           124:      that several  processes can use a single  copy of the shared
        !           125:      segment simultaneously.
        !           126: 
        !           127: 
        !           128: 
        !           129: 
        !           130: COHERENT Lexicon                                           Page 2
        !           131: 
        !           132: 
        !           133: 
        !           134: 
        !           135: ld                           Command                           ld
        !           136: 
        !           137: 
        !           138: 
        !           139: -oo _f_i_l_e
        !           140:      Write output to file (default, ll.oouutt.)
        !           141: 
        !           142: -RR _v_a_l_u_e
        !           143:      Relocation  base option.  By  default, ld  links executeable
        !           144:      files to  run at the user-base for  the computer.  In almost
        !           145:      all cases, the user-base is zero.  If the -R option is used,
        !           146:      ld will  link the executeable to run at  value instead of at
        !           147:      zero.  value  can be  set to any  C-style constant, or  to a
        !           148:      symbol name  that ld  can find in  the object files  and ar-
        !           149:      chives  being linked;  remember that  a  C-accessible symbol
        !           150:      must end  with an underscore character  `_'.  This option is
        !           151:      used primarily  to produce output  files that can  be burned
        !           152:      into ROM.  These programs must make their own provisions for
        !           153:      relocating initialized data and other tasks.
        !           154: 
        !           155: -rr   Retain  relocation information in  the output, and  issue no
        !           156:      diagnostic  message for  undefined symbols.   By  default ld
        !           157:      discards relocation information from the output if there are
        !           158:      no undefined symbols.
        !           159: 
        !           160: -ss   Strip the symbol table from the output.  The same effect may
        !           161:      be obtained  by using the command strip.  The  -s and -r op-
        !           162:      tions are mutually exclusive.
        !           163: 
        !           164: -uu _s_y_m_b_o_l
        !           165:      Add symbol  to the symbol table as  a global reference, usu-
        !           166:      ally to force the linking of a particular library module.
        !           167: 
        !           168: -XX   Discard local compiler-generated symbols of the form `LL...'.
        !           169: 
        !           170: -xx   Discard all local symbols.
        !           171: 
        !           172: ***** Files *****
        !           173: 
        !           174: ll.oouutt -- Default output
        !           175: /ccoohheerreenntt for -kk option
        !           176: /lliibb/lliibb*.aa -- Libraries
        !           177: /uussrr/lliibb/lliibb*.aa -- More libraries
        !           178: 
        !           179: ***** See Also *****
        !           180: 
        !           181: ar, ar.h, as, cc, commands, l.out.h, strip
        !           182: 
        !           183: ***** Notes *****
        !           184: 
        !           185: By  default,  COHERENT  allocates two  kilobytes  of  stack to  a
        !           186: process.  This  is sufficient for most  processes.  To change the
        !           187: amount of stack used by  a given executable program, use the com-
        !           188: mand fixstack.   See its Lexicon  entry for details.   If you are
        !           189: linking a program by hand (that is, running ld independently from
        !           190: the  cc command),  be sure  to  include the  appropriate run-time
        !           191: start-up routine with the ld command line; otherwise, the program
        !           192: will not link correctly.
        !           193: 
        !           194: 
        !           195: 
        !           196: COHERENT Lexicon                                           Page 3
        !           197: 
        !           198: 

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.