ld/emultempl/ppc64elf.em

   1 # This shell script emits a C file. -*- C -*-
   2 # Copyright 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   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 static int no_tls_get_addr_opt = 0;
  51
  52 /* Whether to run opd optimization.  */
  53 static int no_opd_opt = 0;
  54
  55 /* Whether to run toc optimization.  */
  56 static int no_toc_opt = 0;
  57
  58 /* Whether to allow multiple toc sections.  */
  59 static int no_multi_toc = 0;
  60
  61 /* Whether to emit symbols for stubs.  */
  62 static int emit_stub_syms = 0;
  63
  64 static asection *toc_section = 0;
  65
  66 /* Whether to canonicalize .opd so that there are no overlapping
  67    .opd entries.  */
  68 static int non_overlapping_opd = 0;
  69
  70 /* This is called before the input files are opened.  We create a new
  71    fake input file to hold the stub sections.  */
  72
  73 static void
  74 ppc_create_output_section_statements (void)
  75 {
  76   if (!(bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour
  77         && elf_object_id (link_info.output_bfd) == PPC64_ELF_TDATA))
  78     return;
  79
  80   link_info.wrap_char = '.';
  81
  82   stub_file = lang_add_input_file ("linker stubs",
  83                                    lang_input_file_is_fake_enum,
  84                                    NULL);
  85   stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
  86   if (stub_file->the_bfd == NULL
  87       || !bfd_set_arch_mach (stub_file->the_bfd,
  88                              bfd_get_arch (link_info.output_bfd),
  89                              bfd_get_mach (link_info.output_bfd)))
  90     {
  91       einfo ("%F%P: can not create BFD %E\n");
  92       return;
  93     }
  94
  95   stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
  96   ldlang_add_file (stub_file);
  97   ppc64_elf_init_stub_bfd (stub_file->the_bfd, &link_info);
  98 }
  99
 100 static void
 101 ppc_before_allocation (void)
 102 {
 103   if (stub_file != NULL)
 104     {
 105       if (!no_opd_opt
 106           && !ppc64_elf_edit_opd (link_info.output_bfd, &link_info,
 107                                   non_overlapping_opd))
 108         einfo ("%X%P: can not edit %s %E\n", "opd");
 109
 110       if (ppc64_elf_tls_setup (link_info.output_bfd, &link_info,
 111                                no_tls_get_addr_opt)
 112           && !no_tls_opt)
 113         {
 114           /* Size the sections.  This is premature, but we want to know the
 115              TLS segment layout so that certain optimizations can be done.  */
 116           expld.phase = lang_mark_phase_enum;
 117           expld.dataseg.phase = exp_dataseg_none;
 118           one_lang_size_sections_pass (NULL, TRUE);
 119
 120           if (!ppc64_elf_tls_optimize (link_info.output_bfd, &link_info))
 121             einfo ("%X%P: TLS problem %E\n");
 122
 123           /* We must not cache anything from the preliminary sizing.  */
 124           lang_reset_memory_regions ();
 125         }
 126
 127       if (!no_toc_opt
 128           && !link_info.relocatable
 129           && !ppc64_elf_edit_toc (link_info.output_bfd, &link_info))
 130         einfo ("%X%P: can not edit %s %E\n", "toc");
 131     }
 132
 133   gld${EMULATION_NAME}_before_allocation ();
 134 }
 135
 136 struct hook_stub_info
 137 {
 138   lang_statement_list_type add;
 139   asection *input_section;
 140 };
 141
 142 /* Traverse the linker tree to find the spot where the stub goes.  */
 143
 144 static bfd_boolean
 145 hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
 146 {
 147   lang_statement_union_type *l;
 148   bfd_boolean ret;
 149
 150   for (; (l = *lp) != NULL; lp = &l->header.next)
 151     {
 152       switch (l->header.type)
 153         {
 154         case lang_constructors_statement_enum:
 155           ret = hook_in_stub (info, &constructor_list.head);
 156           if (ret)
 157             return ret;
 158           break;
 159
 160         case lang_output_section_statement_enum:
 161           ret = hook_in_stub (info,
 162                               &l->output_section_statement.children.head);
 163           if (ret)
 164             return ret;
 165           break;
 166
 167         case lang_wild_statement_enum:
 168           ret = hook_in_stub (info, &l->wild_statement.children.head);
 169           if (ret)
 170             return ret;
 171           break;
 172
 173         case lang_group_statement_enum:
 174           ret = hook_in_stub (info, &l->group_statement.children.head);
 175           if (ret)
 176             return ret;
 177           break;
 178
 179         case lang_input_section_enum:
 180           if (l->input_section.section == info->input_section)
 181             {
 182               /* We've found our section.  Insert the stub immediately
 183                  before its associated input section.  */
 184               *lp = info->add.head;
 185               *(info->add.tail) = l;
 186               return TRUE;
 187             }
 188           break;
 189
 190         case lang_data_statement_enum:
 191         case lang_reloc_statement_enum:
 192         case lang_object_symbols_statement_enum:
 193         case lang_output_statement_enum:
 194         case lang_target_statement_enum:
 195         case lang_input_statement_enum:
 196         case lang_assignment_statement_enum:
 197         case lang_padding_statement_enum:
 198         case lang_address_statement_enum:
 199         case lang_fill_statement_enum:
 200           break;
 201
 202         default:
 203           FAIL ();
 204           break;
 205         }
 206     }
 207   return FALSE;
 208 }
 209
 210
 211 /* Call-back for ppc64_elf_size_stubs.  */
 212
 213 /* Create a new stub section, and arrange for it to be linked
 214    immediately before INPUT_SECTION.  */
 215
 216 static asection *
 217 ppc_add_stub_section (const char *stub_sec_name, asection *input_section)
 218 {
 219   asection *stub_sec;
 220   flagword flags;
 221   asection *output_section;
 222   const char *secname;
 223   lang_output_section_statement_type *os;
 224   struct hook_stub_info info;
 225
 226   flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
 227            | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_KEEP);
 228   stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
 229                                                  stub_sec_name, flags);
 230   if (stub_sec == NULL)
 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
 264   if (!link_info.relocatable)
 265     _bfd_set_gp_value (link_info.output_bfd,
 266                        ppc64_elf_toc (link_info.output_bfd));
 267
 268   need_laying_out = -1;
 269 }
 270
 271
 272 static void
 273 build_toc_list (lang_statement_union_type *statement)
 274 {
 275   if (statement->header.type == lang_input_section_enum)
 276     {
 277       asection *i = statement->input_section.section;
 278
 279       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 280           && (i->flags & SEC_EXCLUDE) == 0
 281           && i->output_section == toc_section)
 282         ppc64_elf_next_toc_section (&link_info, i);
 283     }
 284 }
 285
 286
 287 static void
 288 build_section_lists (lang_statement_union_type *statement)
 289 {
 290   if (statement->header.type == lang_input_section_enum)
 291     {
 292       asection *i = statement->input_section.section;
 293
 294       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 295           && (i->flags & SEC_EXCLUDE) == 0
 296           && i->output_section != NULL
 297           && i->output_section->owner == link_info.output_bfd)
 298         {
 299           if (!ppc64_elf_next_input_section (&link_info, i))
 300             einfo ("%X%P: can not size stub section: %E\n");
 301         }
 302     }
 303 }
 304
 305
 306 /* Call the back-end function to set TOC base after we have placed all
 307    the sections.  */
 308 static void
 309 gld${EMULATION_NAME}_after_allocation (void)
 310 {
 311   /* bfd_elf_discard_info just plays with data and debugging sections,
 312      ie. doesn't affect code size, so we can delay resizing the
 313      sections.  It's likely we'll resize everything in the process of
 314      adding stubs.  */
 315   if (bfd_elf_discard_info (link_info.output_bfd, &link_info))
 316     need_laying_out = 1;
 317
 318   /* If generating a relocatable output file, then we don't have any
 319      stubs.  */
 320   if (stub_file != NULL && !link_info.relocatable)
 321     {
 322       int ret = ppc64_elf_setup_section_lists (link_info.output_bfd,
 323                                                &link_info,
 324                                                no_multi_toc);
 325       if (ret < 0)
 326         einfo ("%X%P: can not size stub section: %E\n");
 327       else if (ret > 0)
 328         {
 329           toc_section = bfd_get_section_by_name (link_info.output_bfd, ".got");
 330           if (toc_section != NULL)
 331             lang_for_each_statement (build_toc_list);
 332
 333           ppc64_elf_reinit_toc (link_info.output_bfd, &link_info);
 334
 335           lang_for_each_statement (build_section_lists);
 336
 337           /* Call into the BFD backend to do the real work.  */
 338           if (!ppc64_elf_size_stubs (link_info.output_bfd,
 339                                      &link_info,
 340                                      group_size,
 341                                      &ppc_add_stub_section,
 342                                      &ppc_layout_sections_again))
 343             einfo ("%X%P: can not size stub section: %E\n");
 344         }
 345     }
 346
 347   if (need_laying_out != -1)
 348     {
 349       gld${EMULATION_NAME}_map_segments (need_laying_out);
 350
 351       if (!link_info.relocatable)
 352         _bfd_set_gp_value (link_info.output_bfd,
 353                            ppc64_elf_toc (link_info.output_bfd));
 354     }
 355 }
 356
 357
 358 /* Final emulation specific call.  */
 359
 360 static void
 361 gld${EMULATION_NAME}_finish (void)
 362 {
 363   /* e_entry on PowerPC64 points to the function descriptor for
 364      _start.  If _start is missing, default to the first function
 365      descriptor in the .opd section.  */
 366   entry_section = ".opd";
 367
 368   if (link_info.relocatable)
 369     {
 370       asection *toc = bfd_get_section_by_name (link_info.output_bfd, ".toc");
 371       if (toc != NULL
 372           && bfd_section_size (link_info.output_bfd, toc) > 0x10000)
 373         einfo ("%X%P: TOC section size exceeds 64k\n");
 374     }
 375
 376   if (stub_added)
 377     {
 378       char *msg = NULL;
 379       char *line, *endline;
 380
 381       emit_stub_syms |= link_info.emitrelocations;
 382       if (!ppc64_elf_build_stubs (emit_stub_syms, &link_info,
 383                                   config.stats ? &msg : NULL))
 384         einfo ("%X%P: can not build stubs: %E\n");
 385
 386       for (line = msg; line != NULL; line = endline)
 387         {
 388           endline = strchr (line, '\n');
 389           if (endline != NULL)
 390             *endline++ = '\0';
 391           fprintf (stderr, "%s: %s\n", program_name, line);
 392         }
 393       if (msg != NULL)
 394         free (msg);
 395     }
 396
 397   ppc64_elf_restore_symbols (&link_info);
 398   finish_default ();
 399 }
 400
 401
 402 /* Add a pattern matching ".foo" for every "foo" in a version script.
 403
 404    The reason for doing this is that many shared library version
 405    scripts export a selected set of functions or data symbols, forcing
 406    others local.  eg.
 407
 408    . VERS_1 {
 409    .       global:
 410    .               this; that; some; thing;
 411    .       local:
 412    .               *;
 413    .   };
 414
 415    To make the above work for PowerPC64, we need to export ".this",
 416    ".that" and so on, otherwise only the function descriptor syms are
 417    exported.  Lack of an exported function code sym may cause a
 418    definition to be pulled in from a static library.  */
 419
 420 static struct bfd_elf_version_expr *
 421 gld${EMULATION_NAME}_new_vers_pattern (struct bfd_elf_version_expr *entry)
 422 {
 423   struct bfd_elf_version_expr *dot_entry;
 424   unsigned int len;
 425   char *dot_pat;
 426
 427   if (!dotsyms
 428       || entry->pattern[0] == '.'
 429       || (!entry->literal && entry->pattern[0] == '*'))
 430     return entry;
 431
 432   dot_entry = xmalloc (sizeof *dot_entry);
 433   *dot_entry = *entry;
 434   dot_entry->next = entry;
 435   len = strlen (entry->pattern) + 2;
 436   dot_pat = xmalloc (len);
 437   dot_pat[0] = '.';
 438   memcpy (dot_pat + 1, entry->pattern, len - 1);
 439   dot_entry->pattern = dot_pat;
 440   return dot_entry;
 441 }
 442
 443
 444 /* Avoid processing the fake stub_file in vercheck, stat_needed and
 445    check_needed routines.  */
 446
 447 static void (*real_func) (lang_input_statement_type *);
 448
 449 static void ppc_for_each_input_file_wrapper (lang_input_statement_type *l)
 450 {
 451   if (l != stub_file)
 452     (*real_func) (l);
 453 }
 454
 455 static void
 456 ppc_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
 457 {
 458   real_func = func;
 459   lang_for_each_input_file (&ppc_for_each_input_file_wrapper);
 460 }
 461
 462 #define lang_for_each_input_file ppc_lang_for_each_input_file
 463
 464 EOF
 465
 466 if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
 467   fragment <<EOF
 468 /* Special handling for embedded SPU executables.  */
 469 extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
 470 static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
 471
 472 static bfd_boolean
 473 ppc64_recognized_file (lang_input_statement_type *entry)
 474 {
 475   if (embedded_spu_file (entry, "-m64"))
 476     return TRUE;
 477
 478   return gld${EMULATION_NAME}_load_symbols (entry);
 479 }
 480 EOF
 481 LDEMUL_RECOGNIZED_FILE=ppc64_recognized_file
 482 fi
 483
 484 # Define some shell vars to insert bits of code into the standard elf
 485 # parse_args and list_options functions.
 486 #
 487 PARSE_AND_LIST_PROLOGUE='
 488 #define OPTION_STUBGROUP_SIZE           301
 489 #define OPTION_STUBSYMS                 (OPTION_STUBGROUP_SIZE + 1)
 490 #define OPTION_DOTSYMS                  (OPTION_STUBSYMS + 1)
 491 #define OPTION_NO_DOTSYMS               (OPTION_DOTSYMS + 1)
 492 #define OPTION_NO_TLS_OPT               (OPTION_NO_DOTSYMS + 1)
 493 #define OPTION_NO_TLS_GET_ADDR_OPT      (OPTION_NO_TLS_OPT + 1)
 494 #define OPTION_NO_OPD_OPT               (OPTION_NO_TLS_GET_ADDR_OPT + 1)
 495 #define OPTION_NO_TOC_OPT               (OPTION_NO_OPD_OPT + 1)
 496 #define OPTION_NO_MULTI_TOC             (OPTION_NO_TOC_OPT + 1)
 497 #define OPTION_NON_OVERLAPPING_OPD      (OPTION_NO_MULTI_TOC + 1)
 498 '
 499
 500 PARSE_AND_LIST_LONGOPTS='
 501   { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
 502   { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
 503   { "dotsyms", no_argument, NULL, OPTION_DOTSYMS },
 504   { "no-dotsyms", no_argument, NULL, OPTION_NO_DOTSYMS },
 505   { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
 506   { "no-tls-get-addr-optimize", no_argument, NULL, OPTION_NO_TLS_GET_ADDR_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\n\
 516                                 can be handled by one stub section.  A negative\n\
 517                                 value locates all stubs before their branches\n\
 518                                 (with a group size of -N), while a positive\n\
 519                                 value allows two groups of input sections, one\n\
 520                                 before, and one after each stub section.\n\
 521                                 Values of +/-1 indicate the linker should\n\
 522                                 choose suitable defaults.\n"
 523                    ));
 524   fprintf (file, _("\
 525   --emit-stub-syms            Label linker stubs with a symbol.\n"
 526                    ));
 527   fprintf (file, _("\
 528   --dotsyms                   For every version pattern \"foo\" in a version\n\
 529                                 script, add \".foo\" so that function code\n\
 530                                 symbols are treated the same as function\n\
 531                                 descriptor symbols.  Defaults to on.\n"
 532                    ));
 533   fprintf (file, _("\
 534   --no-dotsyms                Don'\''t do anything special in version scripts.\n"
 535                    ));
 536   fprintf (file, _("\
 537   --no-tls-optimize           Don'\''t try to optimize TLS accesses.\n"
 538                    ));
 539   fprintf (file, _("\
 540   --no-tls-get-addr-optimize  Don'\''t use a special __tls_get_addr call.\n"
 541                    ));
 542   fprintf (file, _("\
 543   --no-opd-optimize           Don'\''t optimize the OPD section.\n"
 544                    ));
 545   fprintf (file, _("\
 546   --no-toc-optimize           Don'\''t optimize the TOC section.\n"
 547                    ));
 548   fprintf (file, _("\
 549   --no-multi-toc              Disallow automatic multiple toc sections.\n"
 550                    ));
 551   fprintf (file, _("\
 552   --non-overlapping-opd       Canonicalize .opd, so that there are no\n\
 553                                 overlapping .opd entries.\n"
 554                    ));
 555 '
 556
 557 PARSE_AND_LIST_ARGS_CASES='
 558     case OPTION_STUBGROUP_SIZE:
 559       {
 560         const char *end;
 561         group_size = bfd_scan_vma (optarg, &end, 0);
 562         if (*end)
 563           einfo (_("%P%F: invalid number `%s'\''\n"), optarg);
 564       }
 565       break;
 566
 567     case OPTION_STUBSYMS:
 568       emit_stub_syms = 1;
 569       break;
 570
 571     case OPTION_DOTSYMS:
 572       dotsyms = 1;
 573       break;
 574
 575     case OPTION_NO_DOTSYMS:
 576       dotsyms = 0;
 577       break;
 578
 579     case OPTION_NO_TLS_OPT:
 580       no_tls_opt = 1;
 581       break;
 582
 583     case OPTION_NO_TLS_GET_ADDR_OPT:
 584       no_tls_get_addr_opt = 1;
 585       break;
 586
 587     case OPTION_NO_OPD_OPT:
 588       no_opd_opt = 1;
 589       break;
 590
 591     case OPTION_NO_TOC_OPT:
 592       no_toc_opt = 1;
 593       break;
 594
 595     case OPTION_NO_MULTI_TOC:
 596       no_multi_toc = 1;
 597       break;
 598
 599     case OPTION_NON_OVERLAPPING_OPD:
 600       non_overlapping_opd = 1;
 601       break;
 602 '
 603
 604 # Put these extra ppc64elf routines in ld_${EMULATION_NAME}_emulation
 605 #
 606 LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
 607 LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
 608 LDEMUL_FINISH=gld${EMULATION_NAME}_finish
 609 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_create_output_section_statements
 610 LDEMUL_NEW_VERS_PATTERN=gld${EMULATION_NAME}_new_vers_pattern