gcc/ada/link.c

   1 /****************************************************************************
   2  *                                                                          *
   3  *                         GNAT COMPILER COMPONENTS                         *
   4  *                                                                          *
   5  *                                 L I N K                                  *
   6  *                                                                          *
   7  *                                                                          *
   8  *                          C Implementation File                           *
   9  *                                                                          *
  10  *          Copyright (C) 1992-2001, Free Software Foundation, Inc.         *
  11  *                                                                          *
  12  * GNAT is free software;  you can  redistribute it  and/or modify it under *
  13  * terms of the  GNU General Public License as published  by the Free Soft- *
  14  * ware  Foundation;  either version 2,  or (at your option) any later ver- *
  15  * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *
  16  * OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY *
  17  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License *
  18  * for  more details.  You should have  received  a copy of the GNU General *
  19  * Public License  distributed with GNAT;  see file COPYING.  If not, write *
  20  * to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, *
  21  * MA 02111-1307, USA.                                                      *
  22  *                                                                          *
  23  * As a  special  exception,  if you  link  this file  with other  files to *
  24  * produce an executable,  this file does not by itself cause the resulting *
  25  * executable to be covered by the GNU General Public License. This except- *
  26  * ion does not  however invalidate  any other reasons  why the  executable *
  27  * file might be covered by the  GNU Public License.                        *
  28  *                                                                          *
  29  * GNAT was originally developed  by the GNAT team at  New York University. *
  30  * Extensive contributions were provided by Ada Core Technologies Inc.      *
  31  *                                                                          *
  32  ****************************************************************************/
  33
  34 /*  This file contains parameterizations used by gnatlink.adb in handling   */
  35 /*  very long linker lines in systems where there are limitations on the    */
  36 /*  argument length when the command line is used to pass items to the      */
  37 /*  linker                                                                  */
  38
  39 #include <string.h>
  40
  41 /*  objlist_file_supported is set to 1 when the system linker allows        */
  42 /*  response file, that is a file that contains the list of object files.   */
  43 /*  This is useful on systems where the command line length is limited,     */
  44 /*  meaning that putting all the object files on the command line can       */
  45 /*  result in an unacceptable limit on the number of files.                 */
  46
  47 /*  object_file_option denotes the system dependent linker option which     */
  48 /*  allows object file names to be placed in a file and then passed to      */
  49 /*  the linker. object_file_option must be set if objlist_file_supported    */
  50 /*  is set to 1.                                                            */
  51
  52 /*  link_max is a conservative system specific threshold (in bytes) of the  */
  53 /*  argument length passed to the linker which will trigger a file being    */
  54 /*  used instead of the command line directly. If the argument length is    */
  55 /*  greater than this threshhold, then an objlist_file will be generated    */
  56 /*  and object_file_option and objlist_file_supported must be set. If       */
  57 /*  objlist_file_supported is set to 0 (unsupported), then link_max is      */
  58 /*  set to 2**31-1 so that the limit will never be exceeded.                */
  59
  60 /*  run_path_option is the system dependent linker option which specifies   */
  61 /*  the run time path to use when loading dynamic libraries. This should    */
  62 /*  be set to the null string if the system does not support dynmamic       */
  63 /*  loading of libraries.                                                   */
  64
  65 /*  shared_libgnat_default gives the system dependent link method that      */
  66 /*  be used by default for linking libgnat (shared or static)               */
  67
  68 /*  using_gnu_linker is set to 1 when the GNU linker is used under this     */
  69 /*  target.                                                                 */
  70
  71 /*  RESPONSE FILE & GNU LINKER                                              */
  72 /*  --------------------------                                              */
  73 /*  objlist_file_supported and using_gnu_link used together tell gnatlink   */
  74 /*  to generate a GNU style response file. Note that object_file_option     */
  75 /*  must be set to "" in this case, since no option is required for a       */
  76 /*  response file to be passed to GNU ld. With a GNU linker we use the      */
  77 /*  linker script to implement the response file feature. Any file passed   */
  78 /*  in the GNU ld command line with an unknown extension is supposed to be  */
  79 /*  a linker script. Each linker script augment the current configuration.  */
  80 /*  The format of such response file is as follow :                         */
  81 /*  INPUT (obj1.p obj2.o ...)                                               */
  82
  83 #define SHARED 'H'
  84 #define STATIC 'T'
  85
  86 #if defined (__osf__)
  87 const char *object_file_option = "-Wl,-input,";
  88 const char *run_path_option = "-Wl,-rpath,";
  89 int link_max = 10000;
  90 unsigned char objlist_file_supported = 1;
  91 char shared_libgnat_default = STATIC;
  92 unsigned char using_gnu_linker = 0;
  93 const char *object_library_extension = ".a";
  94
  95 #elif defined (sgi)
  96 const char *object_file_option = "-Wl,-objectlist,";
  97 const char *run_path_option = "-Wl,-rpath,";
  98 int link_max = 5000;
  99 unsigned char objlist_file_supported = 1;
 100 char shared_libgnat_default = SHARED;
 101 unsigned char using_gnu_linker = 0;
 102 const char *object_library_extension = ".a";
 103
 104 #elif defined (__WIN32)
 105 const char *object_file_option = "";
 106 const char *run_path_option = "";
 107 int link_max = 30000;
 108 unsigned char objlist_file_supported = 1;
 109 char shared_libgnat_default = STATIC;
 110 unsigned char using_gnu_linker = 1;
 111 const char *object_library_extension = ".a";
 112
 113 #elif defined (__INTERIX)
 114 const char *object_file_option = "";
 115 const char *run_path_option = "";
 116 int link_max = 5000;
 117 unsigned char objlist_file_supported = 1;
 118 char shared_libgnat_default = STATIC;
 119 unsigned char using_gnu_linker = 1;
 120 const char *object_library_extension = ".a";
 121
 122 #elif defined (hpux)
 123 const char *object_file_option = "-Wl,-c,";
 124 const char *run_path_option = "-Wl,+b,";
 125 int link_max = 5000;
 126 unsigned char objlist_file_supported = 1;
 127 char shared_libgnat_default = STATIC;
 128 unsigned char using_gnu_linker = 0;
 129 const char *object_library_extension = ".a";
 130
 131 #elif defined (_AIX)
 132 const char *object_file_option = "-Wl,-f,";
 133 const char *run_path_option = "";
 134 int link_max = 15000;
 135 cnonst unsigned char objlist_file_supported = 1;
 136 char shared_libgnat_default = STATIC;
 137 unsigned char using_gnu_linker = 0;
 138 const char *object_library_extension = ".a";
 139
 140 #elif defined (VMS)
 141 const char *object_file_option = "";
 142 const char *run_path_option = "";
 143 char shared_libgnat_default = SHARED;
 144 int link_max = 2147483647;
 145 unsigned char objlist_file_supported = 0;
 146 unsigned char using_gnu_linker = 0;
 147 const char *object_library_extension = ".olb";
 148
 149 #elif defined (sun)
 150 const char *object_file_option = "";
 151 const char *run_path_option = "-R";
 152 char shared_libgnat_default = STATIC;
 153 int link_max = 2147483647;
 154 unsigned char objlist_file_supported = 0;
 155 unsigned char using_gnu_linker = 0;
 156 const char *object_library_extension = ".a";
 157
 158 #elif defined (linux)
 159 const char *object_file_option = "";
 160 const char *run_path_option = "-Wl,-rpath,";
 161 char shared_libgnat_default = STATIC;
 162 int link_max = 2147483647;
 163 unsigned char objlist_file_supported = 0;
 164 unsigned char using_gnu_linker = 0;
 165 const char *object_library_extension = ".a";
 166
 167 #elif defined (__svr4__) && defined (i386)
 168 const char *object_file_option = "";
 169 const char *run_path_option = "";
 170 char shared_libgnat_default = STATIC;
 171 int link_max = 2147483647;
 172 unsigned char objlist_file_supported = 0;
 173 unsigned char using_gnu_linker = 0;
 174 const char *object_library_extension = ".a";
 175
 176 #else
 177
 178 /*  These are the default settings for all other systems. No response file
 179     is supported, the shared library default is STATIC.  */
 180 const char *run_path_option = "";
 181 const char *object_file_option = "";
 182 char shared_libgnat_default = STATIC;
 183 int link_max = 2147483647;
 184 unsigned char objlist_file_supported = 0;
 185 unsigned char using_gnu_linker = 0;
 186 const char *object_library_extension = ".a";
 187 #endif