ld/emultempl/ppc64elf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright 2002, 2003, 2004, 2005, 2007 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
  22 # This file is sourced from elf32.em, and defines extra powerpc64-elf
  23 # specific routines.
  24 #
  25 fragment <<EOF
  26
  27 #include "ldctor.h"
  28 #include "libbfd.h"
  29 #include "elf-bfd.h"
  30 #include "elf64-ppc.h"
  31
  32 /* Fake input file for stubs.  */
  33 static lang_input_statement_type *stub_file;
  34 static int stub_added = 0;
  35
  36 /* Whether we need to call ppc_layout_sections_again.  */
  37 static int need_laying_out = 0;
  38
  39 /* Maximum size of a group of input sections that can be handled by
  40    one stub section.  A value of +/-1 indicates the bfd back-end
  41    should use a suitable default size.  */
  42 static bfd_signed_vma group_size = 1;
  43
  44 /* Whether to add ".foo" entries for each "foo" in a version script.  */
  45 static int dotsyms = 1;
  46
  47 /* Whether to run tls optimization.  */
  48 static int no_tls_opt = 0;
  49
  50 /* Whether to run opd optimization.  */
  51 static int no_opd_opt = 0;
  52
  53 /* Whether to run toc optimization.  */
  54 static int no_toc_opt = 0;
  55
  56 /* Whether to allow multiple toc sections.  */
  57 static int no_multi_toc = 0;
  58
  59 /* Whether to emit symbols for stubs.  */
  60 static int emit_stub_syms = 0;
  61
  62 static asection *toc_section = 0;
  63
  64 /* Whether to canonicalize .opd so that there are no overlapping
  65    .opd entries.  */
  66 static int non_overlapping_opd = 0;
  67
  68 /* This is called before the input files are opened.  We create a new
  69    fake input file to hold the stub sections.  */
  70
  71 static void
  72 ppc_create_output_section_statements (void)
  73 {
  74   extern const bfd_target bfd_elf64_powerpc_vec;
  75   extern const bfd_target bfd_elf64_powerpcle_vec;
  76
  77   if (link_info.hash->creator != &bfd_elf64_powerpc_vec
  78       && link_info.hash->creator != &bfd_elf64_powerpcle_vec)
  79     return;
  80
  81   link_info.wrap_char = '.';
  82
  83   stub_file = lang_add_input_file ("linker stubs",
  84                                    lang_input_file_is_fake_enum,
  85                                    NULL);
  86   stub_file->the_bfd = bfd_create ("linker stubs", output_bfd);
  87   if (stub_file->the_bfd == NULL
  88       || !bfd_set_arch_mach (stub_file->the_bfd,
  89                              bfd_get_arch (output_bfd),
  90                              bfd_get_mach (output_bfd)))
  91     {
  92       einfo ("%F%P: can not create BFD %E\n");
  93       return;
  94     }
  95
  96   stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
  97   ldlang_add_file (stub_file);
  98   ppc64_elf_init_stub_bfd (stub_file->the_bfd, &link_info);
  99 }
 100
 101 static void
 102 ppc_before_allocation (void)
 103 {
 104   if (stub_file != NULL)
 105     {
 106       if (!ppc64_elf_edit_opd (output_bfd, &link_info, no_opd_opt,
 107                                non_overlapping_opd))
 108         einfo ("%X%P: can not edit %s %E\n", "opd");
 109
 110       if (ppc64_elf_tls_setup (output_bfd, &link_info) && !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 (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 (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${EMULATION_NAME}_after_allocation (void)
 271 {
 272   if (!link_info.relocatable)
 273     _bfd_set_gp_value (output_bfd, ppc64_elf_toc (output_bfd));
 274 }
 275
 276
 277 static void
 278 build_toc_list (lang_statement_union_type *statement)
 279 {
 280   if (statement->header.type == lang_input_section_enum)
 281     {
 282       asection *i = statement->input_section.section;
 283
 284       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 285           && (i->flags & SEC_EXCLUDE) == 0
 286           && i->output_section == toc_section)
 287         ppc64_elf_next_toc_section (&link_info, i);
 288     }
 289 }
 290
 291
 292 static void
 293 build_section_lists (lang_statement_union_type *statement)
 294 {
 295   if (statement->header.type == lang_input_section_enum)
 296     {
 297       asection *i = statement->input_section.section;
 298
 299       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 300           && (i->flags & SEC_EXCLUDE) == 0
 301           && i->output_section != NULL
 302           && i->output_section->owner == output_bfd)
 303         {
 304           if (!ppc64_elf_next_input_section (&link_info, i))
 305             einfo ("%X%P: can not size stub section: %E\n");
 306         }
 307     }
 308 }
 309
 310
 311 /* Final emulation specific call.  */
 312
 313 static void
 314 gld${EMULATION_NAME}_finish (void)
 315 {
 316   /* e_entry on PowerPC64 points to the function descriptor for
 317      _start.  If _start is missing, default to the first function
 318      descriptor in the .opd section.  */
 319   entry_section = ".opd";
 320
 321   /* bfd_elf_discard_info just plays with debugging sections,
 322      ie. doesn't affect any code, so we can delay resizing the
 323      sections.  It's likely we'll resize everything in the process of
 324      adding stubs.  */
 325   if (bfd_elf_discard_info (output_bfd, &link_info))
 326     need_laying_out = 1;
 327
 328   /* If generating a relocatable output file, then we don't have any
 329      stubs.  */
 330   if (stub_file != NULL && !link_info.relocatable)
 331     {
 332       int ret = ppc64_elf_setup_section_lists (output_bfd, &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 (output_bfd, ".got");
 339           if (toc_section != NULL)
 340             lang_for_each_statement (build_toc_list);
 341
 342           ppc64_elf_reinit_toc (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 (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${EMULATION_NAME}_map_segments (need_laying_out);
 358
 359   if (link_info.relocatable)
 360     {
 361       asection *toc = bfd_get_section_by_name (output_bfd, ".toc");
 362       if (toc != NULL
 363           && bfd_section_size (output_bfd, toc) > 0x10000)
 364         einfo ("%X%P: TOC section size exceeds 64k\n");
 365     }
 366
 367   if (stub_added)
 368     {
 369       char *msg = NULL;
 370       char *line, *endline;
 371
 372       emit_stub_syms |= link_info.emitrelocations;
 373       if (!ppc64_elf_build_stubs (emit_stub_syms, &link_info,
 374                                   config.stats ? &msg : NULL))
 375         einfo ("%X%P: can not build stubs: %E\n");
 376
 377       for (line = msg; line != NULL; line = endline)
 378         {
 379           endline = strchr (line, '\n');
 380           if (endline != NULL)
 381             *endline++ = '\0';
 382           fprintf (stderr, "%s: %s\n", program_name, line);
 383         }
 384       if (msg != NULL)
 385         free (msg);
 386     }
 387
 388   ppc64_elf_restore_symbols (&link_info);
 389   finish_default ();
 390 }
 391
 392
 393 /* Add a pattern matching ".foo" for every "foo" in a version script.
 394
 395    The reason for doing this is that many shared library version
 396    scripts export a selected set of functions or data symbols, forcing
 397    others local.  eg.
 398
 399    . VERS_1 {
 400    .       global:
 401    .               this; that; some; thing;
 402    .       local:
 403    .               *;
 404    .   };
 405
 406    To make the above work for PowerPC64, we need to export ".this",
 407    ".that" and so on, otherwise only the function descriptor syms are
 408    exported.  Lack of an exported function code sym may cause a
 409    definition to be pulled in from a static library.  */
 410
 411 static struct bfd_elf_version_expr *
 412 gld${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 != NULL
 420           && (entry->pattern[0] == '*' || entry->pattern[0] == '.')))
 421     return entry;
 422
 423   dot_entry = xmalloc (sizeof *dot_entry);
 424   *dot_entry = *entry;
 425   dot_entry->next = entry;
 426   if (entry->pattern != NULL)
 427     {
 428       len = strlen (entry->pattern) + 2;
 429       dot_pat = xmalloc (len);
 430       dot_pat[0] = '.';
 431       memcpy (dot_pat + 1, entry->pattern, len - 1);
 432       dot_entry->pattern = dot_pat;
 433     }
 434   if (entry->symbol != NULL)
 435     {
 436       len = strlen (entry->symbol) + 2;
 437       dot_pat = xmalloc (len);
 438       dot_pat[0] = '.';
 439       memcpy (dot_pat + 1, entry->symbol, len - 1);
 440       dot_entry->symbol = dot_pat;
 441     }
 442   return dot_entry;
 443 }
 444
 445
 446 /* Avoid processing the fake stub_file in vercheck, stat_needed and
 447    check_needed routines.  */
 448
 449 static void (*real_func) (lang_input_statement_type *);
 450
 451 static void ppc_for_each_input_file_wrapper (lang_input_statement_type *l)
 452 {
 453   if (l != stub_file)
 454     (*real_func) (l);
 455 }
 456
 457 static void
 458 ppc_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
 459 {
 460   real_func = func;
 461   lang_for_each_input_file (&ppc_for_each_input_file_wrapper);
 462 }
 463
 464 #define lang_for_each_input_file ppc_lang_for_each_input_file
 465
 466 EOF
 467
 468 if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
 469   fragment <<EOF
 470 /* Special handling for embedded SPU executables.  */
 471 extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
 472 static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
 473
 474 static bfd_boolean
 475 ppc64_recognized_file (lang_input_statement_type *entry)
 476 {
 477   if (embedded_spu_file (entry, "-m64"))
 478     return TRUE;
 479
 480   return gld${EMULATION_NAME}_load_symbols (entry);
 481 }
 482 EOF
 483 LDEMUL_RECOGNIZED_FILE=ppc64_recognized_file
 484 fi
 485
 486 # Define some shell vars to insert bits of code into the standard elf
 487 # parse_args and list_options functions.
 488 #
 489 PARSE_AND_LIST_PROLOGUE='
 490 #define OPTION_STUBGROUP_SIZE           301
 491 #define OPTION_STUBSYMS                 (OPTION_STUBGROUP_SIZE + 1)
 492 #define OPTION_DOTSYMS                  (OPTION_STUBSYMS + 1)
 493 #define OPTION_NO_DOTSYMS               (OPTION_DOTSYMS + 1)
 494 #define OPTION_NO_TLS_OPT               (OPTION_NO_DOTSYMS + 1)
 495 #define OPTION_NO_OPD_OPT               (OPTION_NO_TLS_OPT + 1)
 496 #define OPTION_NO_TOC_OPT               (OPTION_NO_OPD_OPT + 1)
 497 #define OPTION_NO_MULTI_TOC             (OPTION_NO_TOC_OPT + 1)
 498 #define OPTION_NON_OVERLAPPING_OPD      (OPTION_NO_MULTI_TOC + 1)
 499 '
 500
 501 PARSE_AND_LIST_LONGOPTS='
 502   { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
 503   { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
 504   { "dotsyms", no_argument, NULL, OPTION_DOTSYMS },
 505   { "no-dotsyms", no_argument, NULL, OPTION_NO_DOTSYMS },
 506   { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
 507   { "no-opd-optimize", no_argument, NULL, OPTION_NO_OPD_OPT },
 508   { "no-toc-optimize", no_argument, NULL, OPTION_NO_TOC_OPT },
 509   { "no-multi-toc", no_argument, NULL, OPTION_NO_MULTI_TOC },
 510   { "non-overlapping-opd", no_argument, NULL, OPTION_NON_OVERLAPPING_OPD },
 511 '
 512
 513 PARSE_AND_LIST_OPTIONS='
 514   fprintf (file, _("\
 515   --stub-group-size=N   Maximum size of a group of input sections that can be\n\
 516                           handled by one stub section.  A negative value\n\
 517                           locates all stubs before their branches (with a\n\
 518                           group size of -N), while a positive value allows\n\
 519                           two groups of input sections, one before, and one\n\
 520                           after each stub section.  Values of +/-1 indicate\n\
 521                           the linker should choose suitable defaults.\n"
 522                    ));
 523   fprintf (file, _("\
 524   --emit-stub-syms      Label linker stubs with a symbol.\n"
 525                    ));
 526   fprintf (file, _("\
 527   --dotsyms             For every version pattern \"foo\" in a version script,\n\
 528                           add \".foo\" so that function code symbols are\n\
 529                           treated the same as function descriptor symbols.\n\
 530                           Defaults to on.\n"
 531                    ));
 532   fprintf (file, _("\
 533   --no-dotsyms          Don'\''t do anything special in version scripts.\n"
 534                    ));
 535   fprintf (file, _("\
 536   --no-tls-optimize     Don'\''t try to optimize TLS accesses.\n"
 537                    ));
 538   fprintf (file, _("\
 539   --no-opd-optimize     Don'\''t optimize the OPD section.\n"
 540                    ));
 541   fprintf (file, _("\
 542   --no-toc-optimize     Don'\''t optimize the TOC section.\n"
 543                    ));
 544   fprintf (file, _("\
 545   --no-multi-toc        Disallow automatic multiple toc sections.\n"
 546                    ));
 547   fprintf (file, _("\
 548   --non-overlapping-opd Canonicalize .opd, so that there are no overlapping\n\
 549                           .opd entries.\n"
 550                    ));
 551 '
 552
 553 PARSE_AND_LIST_ARGS_CASES='
 554     case OPTION_STUBGROUP_SIZE:
 555       {
 556         const char *end;
 557         group_size = bfd_scan_vma (optarg, &end, 0);
 558         if (*end)
 559           einfo (_("%P%F: invalid number `%s'\''\n"), optarg);
 560       }
 561       break;
 562
 563     case OPTION_STUBSYMS:
 564       emit_stub_syms = 1;
 565       break;
 566
 567     case OPTION_DOTSYMS:
 568       dotsyms = 1;
 569       break;
 570
 571     case OPTION_NO_DOTSYMS:
 572       dotsyms = 0;
 573       break;
 574
 575     case OPTION_NO_TLS_OPT:
 576       no_tls_opt = 1;
 577       break;
 578
 579     case OPTION_NO_OPD_OPT:
 580       no_opd_opt = 1;
 581       break;
 582
 583     case OPTION_NO_TOC_OPT:
 584       no_toc_opt = 1;
 585       break;
 586
 587     case OPTION_NO_MULTI_TOC:
 588       no_multi_toc = 1;
 589       break;
 590
 591     case OPTION_NON_OVERLAPPING_OPD:
 592       non_overlapping_opd = 1;
 593       break;
 594 '
 595
 596 # Put these extra ppc64elf routines in ld_${EMULATION_NAME}_emulation
 597 #
 598 LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
 599 LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
 600 LDEMUL_FINISH=gld${EMULATION_NAME}_finish
 601 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_create_output_section_statements
 602 LDEMUL_NEW_VERS_PATTERN=gld${EMULATION_NAME}_new_vers_pattern