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   stub_sec = bfd_make_section_anyway (stub_file->the_bfd, stub_sec_name);
 225   if (stub_sec == NULL)
 226     goto err_ret;
 227
 228   flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
 229            | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_KEEP);
 230   if (!bfd_set_section_flags (stub_file->the_bfd, stub_sec, flags))
 231     goto err_ret;
 232
 233   output_section = input_section->output_section;
 234   secname = bfd_get_section_name (output_section->owner, output_section);
 235   os = lang_output_section_find (secname);
 236
 237   info.input_section = input_section;
 238   lang_list_init (&info.add);
 239   lang_add_section (&info.add, stub_sec, os);
 240
 241   if (info.add.head == NULL)
 242     goto err_ret;
 243
 244   stub_added = 1;
 245   if (hook_in_stub (&info, &os->children.head))
 246     return stub_sec;
 247
 248  err_ret:
 249   einfo ("%X%P: can not make stub section: %E\n");
 250   return NULL;
 251 }
 252
 253
 254 /* Another call-back for ppc64_elf_size_stubs.  */
 255
 256 static void
 257 ppc_layout_sections_again (void)
 258 {
 259   /* If we have changed sizes of the stub sections, then we need
 260      to recalculate all the section offsets.  This may mean we need to
 261      add even more stubs.  */
 262   gld${EMULATION_NAME}_map_segments (TRUE);
 263   need_laying_out = -1;
 264 }
 265
 266
 267 /* Call the back-end function to set TOC base after we have placed all
 268    the sections.  */
 269 static void
 270 gld${EMULATION_NAME}_after_allocation (void)
 271 {
 272   if (!link_info.relocatable)
 273     _bfd_set_gp_value (link_info.output_bfd,
 274                        ppc64_elf_toc (link_info.output_bfd));
 275 }
 276
 277
 278 static void
 279 build_toc_list (lang_statement_union_type *statement)
 280 {
 281   if (statement->header.type == lang_input_section_enum)
 282     {
 283       asection *i = statement->input_section.section;
 284
 285       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 286           && (i->flags & SEC_EXCLUDE) == 0
 287           && i->output_section == toc_section)
 288         ppc64_elf_next_toc_section (&link_info, i);
 289     }
 290 }
 291
 292
 293 static void
 294 build_section_lists (lang_statement_union_type *statement)
 295 {
 296   if (statement->header.type == lang_input_section_enum)
 297     {
 298       asection *i = statement->input_section.section;
 299
 300       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 301           && (i->flags & SEC_EXCLUDE) == 0
 302           && i->output_section != NULL
 303           && i->output_section->owner == link_info.output_bfd)
 304         {
 305           if (!ppc64_elf_next_input_section (&link_info, i))
 306             einfo ("%X%P: can not size stub section: %E\n");
 307         }
 308     }
 309 }
 310
 311
 312 /* Final emulation specific call.  */
 313
 314 static void
 315 gld${EMULATION_NAME}_finish (void)
 316 {
 317   /* e_entry on PowerPC64 points to the function descriptor for
 318      _start.  If _start is missing, default to the first function
 319      descriptor in the .opd section.  */
 320   entry_section = ".opd";
 321
 322   /* bfd_elf_discard_info just plays with debugging sections,
 323      ie. doesn't affect any code, so we can delay resizing the
 324      sections.  It's likely we'll resize everything in the process of
 325      adding stubs.  */
 326   if (bfd_elf_discard_info (link_info.output_bfd, &link_info))
 327     need_laying_out = 1;
 328
 329   /* If generating a relocatable output file, then we don't have any
 330      stubs.  */
 331   if (stub_file != NULL && !link_info.relocatable)
 332     {
 333       int ret = ppc64_elf_setup_section_lists (link_info.output_bfd,
 334                                                &link_info,
 335                                                no_multi_toc);
 336       if (ret < 0)
 337         einfo ("%X%P: can not size stub section: %E\n");
 338       else if (ret > 0)
 339         {
 340           toc_section = bfd_get_section_by_name (link_info.output_bfd, ".got");
 341           if (toc_section != NULL)
 342             lang_for_each_statement (build_toc_list);
 343
 344           ppc64_elf_reinit_toc (link_info.output_bfd, &link_info);
 345
 346           lang_for_each_statement (build_section_lists);
 347
 348           /* Call into the BFD backend to do the real work.  */
 349           if (!ppc64_elf_size_stubs (link_info.output_bfd,
 350                                      &link_info,
 351                                      group_size,
 352                                      &ppc_add_stub_section,
 353                                      &ppc_layout_sections_again))
 354             einfo ("%X%P: can not size stub section: %E\n");
 355         }
 356     }
 357
 358   if (need_laying_out != -1)
 359     gld${EMULATION_NAME}_map_segments (need_laying_out);
 360
 361   if (link_info.relocatable)
 362     {
 363       asection *toc = bfd_get_section_by_name (link_info.output_bfd, ".toc");
 364       if (toc != NULL
 365           && bfd_section_size (link_info.output_bfd, toc) > 0x10000)
 366         einfo ("%X%P: TOC section size exceeds 64k\n");
 367     }
 368
 369   if (stub_added)
 370     {
 371       char *msg = NULL;
 372       char *line, *endline;
 373
 374       emit_stub_syms |= link_info.emitrelocations;
 375       if (!ppc64_elf_build_stubs (emit_stub_syms, &link_info,
 376                                   config.stats ? &msg : NULL))
 377         einfo ("%X%P: can not build stubs: %E\n");
 378
 379       for (line = msg; line != NULL; line = endline)
 380         {
 381           endline = strchr (line, '\n');
 382           if (endline != NULL)
 383             *endline++ = '\0';
 384           fprintf (stderr, "%s: %s\n", program_name, line);
 385         }
 386       if (msg != NULL)
 387         free (msg);
 388     }
 389
 390   ppc64_elf_restore_symbols (&link_info);
 391   finish_default ();
 392 }
 393
 394
 395 /* Add a pattern matching ".foo" for every "foo" in a version script.
 396
 397    The reason for doing this is that many shared library version
 398    scripts export a selected set of functions or data symbols, forcing
 399    others local.  eg.
 400
 401    . VERS_1 {
 402    .       global:
 403    .               this; that; some; thing;
 404    .       local:
 405    .               *;
 406    .   };
 407
 408    To make the above work for PowerPC64, we need to export ".this",
 409    ".that" and so on, otherwise only the function descriptor syms are
 410    exported.  Lack of an exported function code sym may cause a
 411    definition to be pulled in from a static library.  */
 412
 413 static struct bfd_elf_version_expr *
 414 gld${EMULATION_NAME}_new_vers_pattern (struct bfd_elf_version_expr *entry)
 415 {
 416   struct bfd_elf_version_expr *dot_entry;
 417   unsigned int len;
 418   char *dot_pat;
 419
 420   if (!dotsyms
 421       || (entry->pattern != NULL
 422           && (entry->pattern[0] == '*' || entry->pattern[0] == '.')))
 423     return entry;
 424
 425   dot_entry = xmalloc (sizeof *dot_entry);
 426   *dot_entry = *entry;
 427   dot_entry->next = entry;
 428   if (entry->pattern != NULL)
 429     {
 430       len = strlen (entry->pattern) + 2;
 431       dot_pat = xmalloc (len);
 432       dot_pat[0] = '.';
 433       memcpy (dot_pat + 1, entry->pattern, len - 1);
 434       dot_entry->pattern = dot_pat;
 435     }
 436   if (entry->symbol != NULL)
 437     {
 438       len = strlen (entry->symbol) + 2;
 439       dot_pat = xmalloc (len);
 440       dot_pat[0] = '.';
 441       memcpy (dot_pat + 1, entry->symbol, len - 1);
 442       dot_entry->symbol = dot_pat;
 443     }
 444   return dot_entry;
 445 }
 446
 447
 448 /* Avoid processing the fake stub_file in vercheck, stat_needed and
 449    check_needed routines.  */
 450
 451 static void (*real_func) (lang_input_statement_type *);
 452
 453 static void ppc_for_each_input_file_wrapper (lang_input_statement_type *l)
 454 {
 455   if (l != stub_file)
 456     (*real_func) (l);
 457 }
 458
 459 static void
 460 ppc_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
 461 {
 462   real_func = func;
 463   lang_for_each_input_file (&ppc_for_each_input_file_wrapper);
 464 }
 465
 466 #define lang_for_each_input_file ppc_lang_for_each_input_file
 467
 468 EOF
 469
 470 if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
 471   fragment <<EOF
 472 /* Special handling for embedded SPU executables.  */
 473 extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
 474 static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
 475
 476 static bfd_boolean
 477 ppc64_recognized_file (lang_input_statement_type *entry)
 478 {
 479   if (embedded_spu_file (entry, "-m64"))
 480     return TRUE;
 481
 482   return gld${EMULATION_NAME}_load_symbols (entry);
 483 }
 484 EOF
 485 LDEMUL_RECOGNIZED_FILE=ppc64_recognized_file
 486 fi
 487
 488 # Define some shell vars to insert bits of code into the standard elf
 489 # parse_args and list_options functions.
 490 #
 491 PARSE_AND_LIST_PROLOGUE='
 492 #define OPTION_STUBGROUP_SIZE           301
 493 #define OPTION_STUBSYMS                 (OPTION_STUBGROUP_SIZE + 1)
 494 #define OPTION_DOTSYMS                  (OPTION_STUBSYMS + 1)
 495 #define OPTION_NO_DOTSYMS               (OPTION_DOTSYMS + 1)
 496 #define OPTION_NO_TLS_OPT               (OPTION_NO_DOTSYMS + 1)
 497 #define OPTION_NO_OPD_OPT               (OPTION_NO_TLS_OPT + 1)
 498 #define OPTION_NO_TOC_OPT               (OPTION_NO_OPD_OPT + 1)
 499 #define OPTION_NO_MULTI_TOC             (OPTION_NO_TOC_OPT + 1)
 500 #define OPTION_NON_OVERLAPPING_OPD      (OPTION_NO_MULTI_TOC + 1)
 501 '
 502
 503 PARSE_AND_LIST_LONGOPTS='
 504   { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
 505   { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
 506   { "dotsyms", no_argument, NULL, OPTION_DOTSYMS },
 507   { "no-dotsyms", no_argument, NULL, OPTION_NO_DOTSYMS },
 508   { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
 509   { "no-opd-optimize", no_argument, NULL, OPTION_NO_OPD_OPT },
 510   { "no-toc-optimize", no_argument, NULL, OPTION_NO_TOC_OPT },
 511   { "no-multi-toc", no_argument, NULL, OPTION_NO_MULTI_TOC },
 512   { "non-overlapping-opd", no_argument, NULL, OPTION_NON_OVERLAPPING_OPD },
 513 '
 514
 515 PARSE_AND_LIST_OPTIONS='
 516   fprintf (file, _("\
 517   --stub-group-size=N         Maximum size of a group of input sections that\n\
 518                                 can be handled by one stub section.  A negative\n\
 519                                 value locates all stubs before their branches\n\
 520                                 (with a group size of -N), while a positive\n\
 521                                 value allows two groups of input sections, one\n\
 522                                 before, and one after each stub section.\n\
 523                                 Values of +/-1 indicate the linker should\n\
 524                                 choose suitable defaults.\n"
 525                    ));
 526   fprintf (file, _("\
 527   --emit-stub-syms            Label linker stubs with a symbol.\n"
 528                    ));
 529   fprintf (file, _("\
 530   --dotsyms                   For every version pattern \"foo\" in a version\n\
 531                                 script, add \".foo\" so that function code\n\
 532                                 symbols are treated the same as function\n\
 533                                 descriptor symbols.  Defaults to on.\n"
 534                    ));
 535   fprintf (file, _("\
 536   --no-dotsyms                Don'\''t do anything special in version scripts.\n"
 537                    ));
 538   fprintf (file, _("\
 539   --no-tls-optimize           Don'\''t try to optimize TLS accesses.\n"
 540                    ));
 541   fprintf (file, _("\
 542   --no-opd-optimize           Don'\''t optimize the OPD section.\n"
 543                    ));
 544   fprintf (file, _("\
 545   --no-toc-optimize           Don'\''t optimize the TOC section.\n"
 546                    ));
 547   fprintf (file, _("\
 548   --no-multi-toc              Disallow automatic multiple toc sections.\n"
 549                    ));
 550   fprintf (file, _("\
 551   --non-overlapping-opd       Canonicalize .opd, so that there are no\n\
 552                                 overlapping .opd entries.\n"
 553                    ));
 554 '
 555
 556 PARSE_AND_LIST_ARGS_CASES='
 557     case OPTION_STUBGROUP_SIZE:
 558       {
 559         const char *end;
 560         group_size = bfd_scan_vma (optarg, &end, 0);
 561         if (*end)
 562           einfo (_("%P%F: invalid number `%s'\''\n"), optarg);
 563       }
 564       break;
 565
 566     case OPTION_STUBSYMS:
 567       emit_stub_syms = 1;
 568       break;
 569
 570     case OPTION_DOTSYMS:
 571       dotsyms = 1;
 572       break;
 573
 574     case OPTION_NO_DOTSYMS:
 575       dotsyms = 0;
 576       break;
 577
 578     case OPTION_NO_TLS_OPT:
 579       no_tls_opt = 1;
 580       break;
 581
 582     case OPTION_NO_OPD_OPT:
 583       no_opd_opt = 1;
 584       break;
 585
 586     case OPTION_NO_TOC_OPT:
 587       no_toc_opt = 1;
 588       break;
 589
 590     case OPTION_NO_MULTI_TOC:
 591       no_multi_toc = 1;
 592       break;
 593
 594     case OPTION_NON_OVERLAPPING_OPD:
 595       non_overlapping_opd = 1;
 596       break;
 597 '
 598
 599 # Put these extra ppc64elf routines in ld_${EMULATION_NAME}_emulation
 600 #
 601 LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
 602 LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
 603 LDEMUL_FINISH=gld${EMULATION_NAME}_finish
 604 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_create_output_section_statements
 605 LDEMUL_NEW_VERS_PATTERN=gld${EMULATION_NAME}_new_vers_pattern