ld/ldemul.c

   1 /* ldemul.c -- clearing house for ld emulation states
   2    Copyright (C) 1991-2019 Free Software Foundation, Inc.
   3
   4    This file is part of the GNU Binutils.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 #include "sysdep.h"
  22 #include "bfd.h"
  23 #include "getopt.h"
  24 #include "bfdlink.h"
  25
  26 #include "ld.h"
  27 #include "ldmisc.h"
  28 #include "ldexp.h"
  29 #include "ldlang.h"
  30 #include "ldfile.h"
  31 #include "ldemul.h"
  32 #include "ldmain.h"
  33 #include "ldemul-list.h"
  34
  35 static ld_emulation_xfer_type *ld_emulation;
  36
  37 void
  38 ldemul_hll (char *name)
  39 {
  40   ld_emulation->hll (name);
  41 }
  42
  43 void
  44 ldemul_syslib (char *name)
  45 {
  46   ld_emulation->syslib (name);
  47 }
  48
  49 void
  50 ldemul_after_parse (void)
  51 {
  52   ld_emulation->after_parse ();
  53 }
  54
  55 void
  56 ldemul_before_parse (void)
  57 {
  58   ld_emulation->before_parse ();
  59 }
  60
  61 void
  62 ldemul_after_open (void)
  63 {
  64   ld_emulation->after_open ();
  65 }
  66
  67 void
  68 ldemul_after_check_relocs (void)
  69 {
  70   ld_emulation->after_check_relocs ();
  71 }
  72
  73 void
  74 ldemul_after_allocation (void)
  75 {
  76   ld_emulation->after_allocation ();
  77 }
  78
  79 void
  80 ldemul_before_allocation (void)
  81 {
  82   ld_emulation->before_allocation ();
  83 }
  84
  85 void
  86 ldemul_set_output_arch (void)
  87 {
  88   ld_emulation->set_output_arch ();
  89 }
  90
  91 void
  92 ldemul_finish (void)
  93 {
  94   ld_emulation->finish ();
  95 }
  96
  97 void
  98 ldemul_set_symbols (void)
  99 {
 100   if (ld_emulation->set_symbols)
 101     ld_emulation->set_symbols ();
 102 }
 103
 104 void
 105 ldemul_create_output_section_statements (void)
 106 {
 107   if (ld_emulation->create_output_section_statements)
 108     ld_emulation->create_output_section_statements ();
 109 }
 110
 111 char *
 112 ldemul_get_script (int *isfile)
 113 {
 114   return ld_emulation->get_script (isfile);
 115 }
 116
 117 bfd_boolean
 118 ldemul_open_dynamic_archive (const char *arch, search_dirs_type *search,
 119                              lang_input_statement_type *entry)
 120 {
 121   if (ld_emulation->open_dynamic_archive)
 122     return (*ld_emulation->open_dynamic_archive) (arch, search, entry);
 123   return FALSE;
 124 }
 125
 126 lang_output_section_statement_type *
 127 ldemul_place_orphan (asection *s, const char *name, int constraint)
 128 {
 129   if (ld_emulation->place_orphan)
 130     return (*ld_emulation->place_orphan) (s, name, constraint);
 131   return NULL;
 132 }
 133
 134 void
 135 ldemul_add_options (int ns, char **shortopts, int nl,
 136                     struct option **longopts, int nrl,
 137                     struct option **really_longopts)
 138 {
 139   if (ld_emulation->add_options)
 140     (*ld_emulation->add_options) (ns, shortopts, nl, longopts,
 141                                   nrl, really_longopts);
 142 }
 143
 144 bfd_boolean
 145 ldemul_handle_option (int optc)
 146 {
 147   if (ld_emulation->handle_option)
 148     return (*ld_emulation->handle_option) (optc);
 149   return FALSE;
 150 }
 151
 152 bfd_boolean
 153 ldemul_parse_args (int argc, char **argv)
 154 {
 155   /* Try and use the emulation parser if there is one.  */
 156   if (ld_emulation->parse_args)
 157     return (*ld_emulation->parse_args) (argc, argv);
 158   return FALSE;
 159 }
 160
 161 /* Let the emulation code handle an unrecognized file.  */
 162
 163 bfd_boolean
 164 ldemul_unrecognized_file (lang_input_statement_type *entry)
 165 {
 166   if (ld_emulation->unrecognized_file)
 167     return (*ld_emulation->unrecognized_file) (entry);
 168   return FALSE;
 169 }
 170
 171 /* Let the emulation code handle a recognized file.  */
 172
 173 bfd_boolean
 174 ldemul_recognized_file (lang_input_statement_type *entry)
 175 {
 176   if (ld_emulation->recognized_file)
 177     return (*ld_emulation->recognized_file) (entry);
 178   return FALSE;
 179 }
 180
 181 char *
 182 ldemul_choose_target (int argc, char **argv)
 183 {
 184   return ld_emulation->choose_target (argc, argv);
 185 }
 186
 187
 188 /* The default choose_target function.  */
 189
 190 char *
 191 ldemul_default_target (int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED)
 192 {
 193   char *from_outside = getenv (TARGET_ENVIRON);
 194   if (from_outside != (char *) NULL)
 195     return from_outside;
 196   return ld_emulation->target_name;
 197 }
 198
 199 /* If the entry point was not specified as an address, then add the
 200    symbol as undefined.  This will cause ld to extract an archive
 201    element defining the entry if ld is linking against such an archive.
 202
 203    We don't do this when generating shared libraries unless given -e
 204    on the command line, because most shared libs are not designed to
 205    be run as an executable.  However, some are, eg. glibc ld.so and
 206    may rely on the default linker script supplying ENTRY.  So we can't
 207    remove the ENTRY from the script, but would rather not insert
 208    undefined _start syms.  */
 209
 210 void
 211 after_parse_default (void)
 212 {
 213   if (entry_symbol.name != NULL
 214       && (bfd_link_executable (&link_info) || entry_from_cmdline))
 215     {
 216       bfd_boolean is_vma = FALSE;
 217
 218       if (entry_from_cmdline)
 219         {
 220           const char *send;
 221
 222           bfd_scan_vma (entry_symbol.name, &send, 0);
 223           is_vma = *send == '\0';
 224         }
 225       if (!is_vma)
 226         ldlang_add_undef (entry_symbol.name, entry_from_cmdline);
 227     }
 228   if (config.maxpagesize == 0)
 229     config.maxpagesize = bfd_emul_get_maxpagesize (default_target);
 230   if (config.commonpagesize == 0)
 231     config.commonpagesize = bfd_emul_get_commonpagesize (default_target,
 232                                                          link_info.relro);
 233 }
 234
 235 void
 236 after_open_default (void)
 237 {
 238 }
 239
 240 void
 241 after_check_relocs_default (void)
 242 {
 243 }
 244
 245 void
 246 after_allocation_default (void)
 247 {
 248   lang_relax_sections (FALSE);
 249 }
 250
 251 void
 252 before_allocation_default (void)
 253 {
 254   if (!bfd_link_relocatable (&link_info))
 255     strip_excluded_output_sections ();
 256 }
 257
 258 void
 259 finish_default (void)
 260 {
 261   if (!bfd_link_relocatable (&link_info))
 262     _bfd_fix_excluded_sec_syms (link_info.output_bfd, &link_info);
 263 }
 264
 265 void
 266 set_output_arch_default (void)
 267 {
 268   /* Set the output architecture and machine if possible.  */
 269   bfd_set_arch_mach (link_info.output_bfd,
 270                      ldfile_output_architecture, ldfile_output_machine);
 271
 272   bfd_emul_set_maxpagesize (output_target, config.maxpagesize);
 273   bfd_emul_set_commonpagesize (output_target, config.commonpagesize);
 274 }
 275
 276 void
 277 syslib_default (char *ignore ATTRIBUTE_UNUSED)
 278 {
 279   info_msg (_("%pS SYSLIB ignored\n"), NULL);
 280 }
 281
 282 void
 283 hll_default (char *ignore ATTRIBUTE_UNUSED)
 284 {
 285   info_msg (_("%pS HLL ignored\n"), NULL);
 286 }
 287
 288 ld_emulation_xfer_type *ld_emulations[] = { EMULATION_LIST };
 289
 290 void
 291 ldemul_choose_mode (char *target)
 292 {
 293   ld_emulation_xfer_type **eptr = ld_emulations;
 294   /* Ignore "gld" prefix.  */
 295   if (target[0] == 'g' && target[1] == 'l' && target[2] == 'd')
 296     target += 3;
 297   for (; *eptr; eptr++)
 298     {
 299       if (strcmp (target, (*eptr)->emulation_name) == 0)
 300         {
 301           ld_emulation = *eptr;
 302           return;
 303         }
 304     }
 305   einfo (_("%P: unrecognised emulation mode: %s\n"), target);
 306   einfo (_("Supported emulations: "));
 307   ldemul_list_emulations (stderr);
 308   einfo ("%F\n");
 309 }
 310
 311 void
 312 ldemul_list_emulations (FILE *f)
 313 {
 314   ld_emulation_xfer_type **eptr = ld_emulations;
 315   bfd_boolean first = TRUE;
 316
 317   for (; *eptr; eptr++)
 318     {
 319       if (first)
 320         first = FALSE;
 321       else
 322         fprintf (f, " ");
 323       fprintf (f, "%s", (*eptr)->emulation_name);
 324     }
 325 }
 326
 327 void
 328 ldemul_list_emulation_options (FILE *f)
 329 {
 330   ld_emulation_xfer_type **eptr;
 331   int options_found = 0;
 332
 333   for (eptr = ld_emulations; *eptr; eptr++)
 334     {
 335       ld_emulation_xfer_type *emul = *eptr;
 336
 337       if (emul->list_options)
 338         {
 339           fprintf (f, "%s: \n", emul->emulation_name);
 340
 341           emul->list_options (f);
 342
 343           options_found = 1;
 344         }
 345     }
 346
 347   if (!options_found)
 348     fprintf (f, _("  no emulation specific options.\n"));
 349 }
 350
 351 int
 352 ldemul_find_potential_libraries (char *name, lang_input_statement_type *entry)
 353 {
 354   if (ld_emulation->find_potential_libraries)
 355     return ld_emulation->find_potential_libraries (name, entry);
 356
 357   return 0;
 358 }
 359
 360 struct bfd_elf_version_expr *
 361 ldemul_new_vers_pattern (struct bfd_elf_version_expr *entry)
 362 {
 363   if (ld_emulation->new_vers_pattern)
 364     entry = (*ld_emulation->new_vers_pattern) (entry);
 365   return entry;
 366 }
 367
 368 void
 369 ldemul_extra_map_file_text (bfd *abfd, struct bfd_link_info *info, FILE *mapf)
 370 {
 371   if (ld_emulation->extra_map_file_text)
 372     ld_emulation->extra_map_file_text (abfd, info, mapf);
 373 }