ld/emultempl/ppc64elf.em

   1 # This shell script emits a C file. -*- C -*-
   2 # Copyright 2002, 2003, 2004, 2005, 2007, 2008
   3 # Free Software Foundation, Inc.
   4 #
   5 # This file is part of the GNU Binutils.
   6 #
   7 # This program is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; either version 3 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program; if not, write to the Free Software
  19 # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  20 # MA 02110-1301, USA.
  21 #
  22
  23 # This file is sourced from elf32.em, and defines extra powerpc64-elf
  24 # specific routines.
  25 #
  26 fragment <<EOF
  27
  28 #include "ldctor.h"
  29 #include "libbfd.h"
  30 #include "elf-bfd.h"
  31 #include "elf64-ppc.h"
  32
  33 /* Fake input file for stubs.  */
  34 static lang_input_statement_type *stub_file;
  35 static int stub_added = 0;
  36
  37 /* Whether we need to call ppc_layout_sections_again.  */
  38 static int need_laying_out = 0;
  39
  40 /* Maximum size of a group of input sections that can be handled by
  41    one stub section.  A value of +/-1 indicates the bfd back-end
  42    should use a suitable default size.  */
  43 static bfd_signed_vma group_size = 1;
  44
  45 /* Whether to add ".foo" entries for each "foo" in a version script.  */
  46 static int dotsyms = 1;
  47
  48 /* Whether to run tls optimization.  */
  49 static int no_tls_opt = 0;
  50
  51 /* Whether to run opd optimization.  */
  52 static int no_opd_opt = 0;
  53
  54 /* Whether to run toc optimization.  */
  55 static int no_toc_opt = 0;
  56
  57 /* Whether to allow multiple toc sections.  */
  58 static int no_multi_toc = 0;
  59
  60 /* Whether to emit symbols for stubs.  */
  61 static int emit_stub_syms = 0;
  62
  63 static asection *toc_section = 0;
  64
  65 /* Whether to canonicalize .opd so that there are no overlapping
  66    .opd entries.  */
  67 static int non_overlapping_opd = 0;
  68
  69 /* This is called before the input files are opened.  We create a new
  70    fake input file to hold the stub sections.  */
  71
  72 static void
  73 ppc_create_output_section_statements (void)
  74 {
  75   if (!(bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour
  76         && elf_object_id (link_info.output_bfd) == PPC64_ELF_TDATA))
  77     return;
  78
  79   link_info.wrap_char = '.';
  80
  81   stub_file = lang_add_input_file ("linker stubs",
  82                                    lang_input_file_is_fake_enum,
  83                                    NULL);
  84   stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
  85   if (stub_file->the_bfd == NULL
  86       || !bfd_set_arch_mach (stub_file->the_bfd,
  87                              bfd_get_arch (link_info.output_bfd),
  88                              bfd_get_mach (link_info.output_bfd)))
  89     {
  90       einfo ("%F%P: can not create BFD %E\n");
  91       return;
  92     }
  93
  94   stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
  95   ldlang_add_file (stub_file);
  96   ppc64_elf_init_stub_bfd (stub_file->the_bfd, &link_info);
  97 }
  98
  99 static void
 100 ppc_before_allocation (void)
 101 {
 102   if (stub_file != NULL)
 103     {
 104       if (!no_opd_opt
 105           && !ppc64_elf_edit_opd (link_info.output_bfd, &link_info,
 106                                   non_overlapping_opd))
 107         einfo ("%X%P: can not edit %s %E\n", "opd");
 108
 109       if (ppc64_elf_tls_setup (link_info.output_bfd, &link_info)
 110           && !no_tls_opt)
 111         {
 112           /* Size the sections.  This is premature, but we want to know the
 113              TLS segment layout so that certain optimizations can be done.  */
 114           expld.phase = lang_mark_phase_enum;
 115           expld.dataseg.phase = exp_dataseg_none;
 116           one_lang_size_sections_pass (NULL, TRUE);
 117
 118           if (!ppc64_elf_tls_optimize (link_info.output_bfd, &link_info))
 119             einfo ("%X%P: TLS problem %E\n");
 120
 121           /* We must not cache anything from the preliminary sizing.  */
 122           lang_reset_memory_regions ();
 123         }
 124
 125       if (!no_toc_opt
 126           && !link_info.relocatable
 127           && !ppc64_elf_edit_toc (link_info.output_bfd, &link_info))
 128         einfo ("%X%P: can not edit %s %E\n", "toc");
 129     }
 130
 131   gld${EMULATION_NAME}_before_allocation ();
 132 }
 133
 134 struct hook_stub_info
 135 {
 136   lang_statement_list_type add;
 137   asection *input_section;
 138 };
 139
 140 /* Traverse the linker tree to find the spot where the stub goes.  */
 141
 142 static bfd_boolean
 143 hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
 144 {
 145   lang_statement_union_type *l;
 146   bfd_boolean ret;
 147
 148   for (; (l = *lp) != NULL; lp = &l->header.next)
 149     {
 150       switch (l->header.type)
 151         {
 152         case lang_constructors_statement_enum:
 153           ret = hook_in_stub (info, &constructor_list.head);
 154           if (ret)
 155             return ret;
 156           break;
 157
 158         case lang_output_section_statement_enum:
 159           ret = hook_in_stub (info,
 160                               &l->output_section_statement.children.head);
 161           if (ret)
 162             return ret;
 163           break;
 164
 165         case lang_wild_statement_enum:
 166           ret = hook_in_stub (info, &l->wild_statement.children.head);
 167           if (ret)
 168             return ret;
 169           break;
 170
 171         case lang_group_statement_enum:
 172           ret = hook_in_stub (info, &l->group_statement.children.head);
 173           if (ret)
 174             return ret;
 175           break;
 176
 177         case lang_input_section_enum:
 178           if (l->input_section.section == info->input_section)
 179             {
 180               /* We've found our section.  Insert the stub immediately
 181                  before its associated input section.  */
 182               *lp = info->add.head;
 183               *(info->add.tail) = l;
 184               return TRUE;
 185             }
 186           break;
 187
 188         case lang_data_statement_enum:
 189         case lang_reloc_statement_enum:
 190         case lang_object_symbols_statement_enum:
 191         case lang_output_statement_enum:
 192         case lang_target_statement_enum:
 193         case lang_input_statement_enum:
 194         case lang_assignment_statement_enum:
 195         case lang_padding_statement_enum:
 196         case lang_address_statement_enum:
 197         case lang_fill_statement_enum:
 198           break;
 199
 200         default:
 201           FAIL ();
 202           break;
 203         }
 204     }
 205   return FALSE;
 206 }
 207
 208
 209 /* Call-back for ppc64_elf_size_stubs.  */
 210
 211 /* Create a new stub section, and arrange for it to be linked
 212    immediately before INPUT_SECTION.  */
 213
 214 static asection *
 215 ppc_add_stub_section (const char *stub_sec_name, asection *input_section)
 216 {
 217   asection *stub_sec;
 218   flagword flags;
 219   asection *output_section;
 220   const char *secname;
 221   lang_output_section_statement_type *os;
 222   struct hook_stub_info info;
 223
 224   flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
 225            | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_KEEP);
 226   stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
 227                                                  stub_sec_name, flags);
 228   if (stub_sec == NULL)
 229     goto err_ret;
 230
 231   output_section = input_section->output_section;
 232   secname = bfd_get_section_name (output_section->owner, output_section);
 233   os = lang_output_section_find (secname);
 234
 235   info.input_section = input_section;
 236   lang_list_init (&info.add);
 237   lang_add_section (&info.add, stub_sec, os);
 238
 239   if (info.add.head == NULL)
 240     goto err_ret;
 241
 242   stub_added = 1;
 243   if (hook_in_stub (&info, &os->children.head))
 244     return stub_sec;
 245
 246  err_ret:
 247   einfo ("%X%P: can not make stub section: %E\n");
 248   return NULL;
 249 }
 250
 251
 252 /* Another call-back for ppc64_elf_size_stubs.  */
 253
 254 static void
 255 ppc_layout_sections_again (void)
 256 {
 257   /* If we have changed sizes of the stub sections, then we need
 258      to recalculate all the section offsets.  This may mean we need to
 259      add even more stubs.  */
 260   gld${EMULATION_NAME}_map_segments (TRUE);
 261   need_laying_out = -1;
 262 }
 263
 264
 265 /* Call the back-end function to set TOC base after we have placed all
 266    the sections.  */
 267 static void
 268 gld${EMULATION_NAME}_after_allocation (void)
 269 {
 270   if (!link_info.relocatable)
 271     _bfd_set_gp_value (link_info.output_bfd,
 272                        ppc64_elf_toc (link_info.output_bfd));
 273 }
 274
 275
 276 static void
 277 build_toc_list (lang_statement_union_type *statement)
 278 {
 279   if (statement->header.type == lang_input_section_enum)
 280     {
 281       asection *i = statement->input_section.section;
 282
 283       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 284           && (i->flags & SEC_EXCLUDE) == 0
 285           && i->output_section == toc_section)
 286         ppc64_elf_next_toc_section (&link_info, i);
 287     }
 288 }
 289
 290
 291 static void
 292 build_section_lists (lang_statement_union_type *statement)
 293 {
 294   if (statement->header.type == lang_input_section_enum)
 295     {
 296       asection *i = statement->input_section.section;
 297
 298       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 299           && (i->flags & SEC_EXCLUDE) == 0
 300           && i->output_section != NULL
 301           && i->output_section->owner == link_info.output_bfd)
 302         {
 303           if (!ppc64_elf_next_input_section (&link_info, i))
 304             einfo ("%X%P: can not size stub section: %E\n");
 305         }
 306     }
 307 }
 308
 309
 310 /* Final emulation specific call.  */
 311
 312 static void
 313 gld${EMULATION_NAME}_finish (void)
 314 {
 315   /* e_entry on PowerPC64 points to the function descriptor for
 316      _start.  If _start is missing, default to the first function
 317      descriptor in the .opd section.  */
 318   entry_section = ".opd";
 319
 320   /* bfd_elf_discard_info just plays with debugging sections,
 321      ie. doesn't affect any code, so we can delay resizing the
 322      sections.  It's likely we'll resize everything in the process of
 323      adding stubs.  */
 324   if (bfd_elf_discard_info (link_info.output_bfd, &link_info))
 325     need_laying_out = 1;
 326
 327   /* If generating a relocatable output file, then we don't have any
 328      stubs.  */
 329   if (stub_file != NULL && !link_info.relocatable)
 330     {
 331       int ret = ppc64_elf_setup_section_lists (link_info.output_bfd,
 332                                                &link_info,
 333                                                no_multi_toc);
 334       if (ret < 0)
 335         einfo ("%X%P: can not size stub section: %E\n");
 336       else if (ret > 0)
 337         {
 338           toc_section = bfd_get_section_by_name (link_info.output_bfd, ".got");
 339           if (toc_section != NULL)
 340             lang_for_each_statement (build_toc_list);
 341
 342           ppc64_elf_reinit_toc (link_info.output_bfd, &link_info);
 343
 344           lang_for_each_statement (build_section_lists);
 345
 346           /* Call into the BFD backend to do the real work.  */
 347           if (!ppc64_elf_size_stubs (link_info.output_bfd,
 348                                      &link_info,
 349                                      group_size,
 350                                      &ppc_add_stub_section,
 351                                      &ppc_layout_sections_again))
 352             einfo ("%X%P: can not size stub section: %E\n");
 353         }
 354     }
 355
 356   if (need_laying_out != -1)
 357     gld${EMULATION_NAME}_map_segments (need_laying_out);
 358
 359   if (link_info.relocatable)
 360     {
 361       asection *toc = bfd_get_section_by_name (link_info.output_bfd, ".toc");
 362       if (toc != NULL
 363           && bfd_section_size (link_info.output_bfd, toc) > 0x10000)
 364         einfo ("%X%P: TOC section size exceeds 64k\n");
 365     }
 366
 367   if (stub_added)
 368     {
 369       char *msg = NULL;
 370       char *line, *endline;
 371
 372       emit_stub_syms |= link_info.emitrelocations;
 373       if (!ppc64_elf_build_stubs (emit_stub_syms, &link_info,
 374                                   config.stats ? &msg : NULL))
 375         einfo ("%X%P: can not build stubs: %E\n");
 376
 377       for (line = msg; line != NULL; line = endline)
 378         {
 379           endline = strchr (line, '\n');
 380           if (endline != NULL)
 381             *endline++ = '\0';
 382           fprintf (stderr, "%s: %s\n", program_name, line);
 383         }
 384       if (msg != NULL)
 385         free (msg);
 386     }
 387
 388   ppc64_elf_restore_symbols (&link_info);
 389   finish_default ();
 390 }
 391
 392
 393 /* Add a pattern matching ".foo" for every "foo" in a version script.
 394
 395    The reason for doing this is that many shared library version
 396    scripts export a selected set of functions or data symbols, forcing
 397    others local.  eg.
 398
 399    . VERS_1 {
 400    .       global:
 401    .               this; that; some; thing;
 402    .       local:
 403    .               *;
 404    .   };
 405
 406    To make the above work for PowerPC64, we need to export ".this",
 407    ".that" and so on, otherwise only the function descriptor syms are
 408    exported.  Lack of an exported function code sym may cause a
 409    definition to be pulled in from a static library.  */
 410
 411 static struct bfd_elf_version_expr *
 412 gld${EMULATION_NAME}_new_vers_pattern (struct bfd_elf_version_expr *entry)
 413 {
 414   struct bfd_elf_version_expr *dot_entry;
 415   unsigned int len;
 416   char *dot_pat;
 417
 418   if (!dotsyms
 419       || entry->pattern[0] == '.'
 420       || (!entry->literal && entry->pattern[0] == '*'))
 421     return entry;
 422
 423   dot_entry = xmalloc (sizeof *dot_entry);
 424   *dot_entry = *entry;
 425   dot_entry->next = entry;
 426   len = strlen (entry->pattern) + 2;
 427   dot_pat = xmalloc (len);
 428   dot_pat[0] = '.';
 429   memcpy (dot_pat + 1, entry->pattern, len - 1);
 430   dot_entry->pattern = dot_pat;
 431   return dot_entry;
 432 }
 433
 434
 435 /* Avoid processing the fake stub_file in vercheck, stat_needed and
 436    check_needed routines.  */
 437
 438 static void (*real_func) (lang_input_statement_type *);
 439
 440 static void ppc_for_each_input_file_wrapper (lang_input_statement_type *l)
 441 {
 442   if (l != stub_file)
 443     (*real_func) (l);
 444 }
 445
 446 static void
 447 ppc_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
 448 {
 449   real_func = func;
 450   lang_for_each_input_file (&ppc_for_each_input_file_wrapper);
 451 }
 452
 453 #define lang_for_each_input_file ppc_lang_for_each_input_file
 454
 455 EOF
 456
 457 if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
 458   fragment <<EOF
 459 /* Special handling for embedded SPU executables.  */
 460 extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
 461 static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
 462
 463 static bfd_boolean
 464 ppc64_recognized_file (lang_input_statement_type *entry)
 465 {
 466   if (embedded_spu_file (entry, "-m64"))
 467     return TRUE;
 468
 469   return gld${EMULATION_NAME}_load_symbols (entry);
 470 }
 471 EOF
 472 LDEMUL_RECOGNIZED_FILE=ppc64_recognized_file
 473 fi
 474
 475 # Define some shell vars to insert bits of code into the standard elf
 476 # parse_args and list_options functions.
 477 #
 478 PARSE_AND_LIST_PROLOGUE='
 479 #define OPTION_STUBGROUP_SIZE           301
 480 #define OPTION_STUBSYMS                 (OPTION_STUBGROUP_SIZE + 1)
 481 #define OPTION_DOTSYMS                  (OPTION_STUBSYMS + 1)
 482 #define OPTION_NO_DOTSYMS               (OPTION_DOTSYMS + 1)
 483 #define OPTION_NO_TLS_OPT               (OPTION_NO_DOTSYMS + 1)
 484 #define OPTION_NO_OPD_OPT               (OPTION_NO_TLS_OPT + 1)
 485 #define OPTION_NO_TOC_OPT               (OPTION_NO_OPD_OPT + 1)
 486 #define OPTION_NO_MULTI_TOC             (OPTION_NO_TOC_OPT + 1)
 487 #define OPTION_NON_OVERLAPPING_OPD      (OPTION_NO_MULTI_TOC + 1)
 488 '
 489
 490 PARSE_AND_LIST_LONGOPTS='
 491   { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
 492   { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
 493   { "dotsyms", no_argument, NULL, OPTION_DOTSYMS },
 494   { "no-dotsyms", no_argument, NULL, OPTION_NO_DOTSYMS },
 495   { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
 496   { "no-opd-optimize", no_argument, NULL, OPTION_NO_OPD_OPT },
 497   { "no-toc-optimize", no_argument, NULL, OPTION_NO_TOC_OPT },
 498   { "no-multi-toc", no_argument, NULL, OPTION_NO_MULTI_TOC },
 499   { "non-overlapping-opd", no_argument, NULL, OPTION_NON_OVERLAPPING_OPD },
 500 '
 501
 502 PARSE_AND_LIST_OPTIONS='
 503   fprintf (file, _("\
 504   --stub-group-size=N         Maximum size of a group of input sections that\n\
 505                                 can be handled by one stub section.  A negative\n\
 506                                 value locates all stubs before their branches\n\
 507                                 (with a group size of -N), while a positive\n\
 508                                 value allows two groups of input sections, one\n\
 509                                 before, and one after each stub section.\n\
 510                                 Values of +/-1 indicate the linker should\n\
 511                                 choose suitable defaults.\n"
 512                    ));
 513   fprintf (file, _("\
 514   --emit-stub-syms            Label linker stubs with a symbol.\n"
 515                    ));
 516   fprintf (file, _("\
 517   --dotsyms                   For every version pattern \"foo\" in a version\n\
 518                                 script, add \".foo\" so that function code\n\
 519                                 symbols are treated the same as function\n\
 520                                 descriptor symbols.  Defaults to on.\n"
 521                    ));
 522   fprintf (file, _("\
 523   --no-dotsyms                Don'\''t do anything special in version scripts.\n"
 524                    ));
 525   fprintf (file, _("\
 526   --no-tls-optimize           Don'\''t try to optimize TLS accesses.\n"
 527                    ));
 528   fprintf (file, _("\
 529   --no-opd-optimize           Don'\''t optimize the OPD section.\n"
 530                    ));
 531   fprintf (file, _("\
 532   --no-toc-optimize           Don'\''t optimize the TOC section.\n"
 533                    ));
 534   fprintf (file, _("\
 535   --no-multi-toc              Disallow automatic multiple toc sections.\n"
 536                    ));
 537   fprintf (file, _("\
 538   --non-overlapping-opd       Canonicalize .opd, so that there are no\n\
 539                                 overlapping .opd entries.\n"
 540                    ));
 541 '
 542
 543 PARSE_AND_LIST_ARGS_CASES='
 544     case OPTION_STUBGROUP_SIZE:
 545       {
 546         const char *end;
 547         group_size = bfd_scan_vma (optarg, &end, 0);
 548         if (*end)
 549           einfo (_("%P%F: invalid number `%s'\''\n"), optarg);
 550       }
 551       break;
 552
 553     case OPTION_STUBSYMS:
 554       emit_stub_syms = 1;
 555       break;
 556
 557     case OPTION_DOTSYMS:
 558       dotsyms = 1;
 559       break;
 560
 561     case OPTION_NO_DOTSYMS:
 562       dotsyms = 0;
 563       break;
 564
 565     case OPTION_NO_TLS_OPT:
 566       no_tls_opt = 1;
 567       break;
 568
 569     case OPTION_NO_OPD_OPT:
 570       no_opd_opt = 1;
 571       break;
 572
 573     case OPTION_NO_TOC_OPT:
 574       no_toc_opt = 1;
 575       break;
 576
 577     case OPTION_NO_MULTI_TOC:
 578       no_multi_toc = 1;
 579       break;
 580
 581     case OPTION_NON_OVERLAPPING_OPD:
 582       non_overlapping_opd = 1;
 583       break;
 584 '
 585
 586 # Put these extra ppc64elf routines in ld_${EMULATION_NAME}_emulation
 587 #
 588 LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
 589 LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
 590 LDEMUL_FINISH=gld${EMULATION_NAME}_finish
 591 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_create_output_section_statements
 592 LDEMUL_NEW_VERS_PATTERN=gld${EMULATION_NAME}_new_vers_pattern