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   extern const bfd_target bfd_elf64_powerpc_vec;
  76   extern const bfd_target bfd_elf64_powerpcle_vec;
  77
  78   if (link_info.hash->creator != &bfd_elf64_powerpc_vec
  79       && link_info.hash->creator != &bfd_elf64_powerpcle_vec)
  80     return;
  81
  82   link_info.wrap_char = '.';
  83
  84   stub_file = lang_add_input_file ("linker stubs",
  85                                    lang_input_file_is_fake_enum,
  86                                    NULL);
  87   stub_file->the_bfd = bfd_create ("linker stubs", output_bfd);
  88   if (stub_file->the_bfd == NULL
  89       || !bfd_set_arch_mach (stub_file->the_bfd,
  90                              bfd_get_arch (output_bfd),
  91                              bfd_get_mach (output_bfd)))
  92     {
  93       einfo ("%F%P: can not create BFD %E\n");
  94       return;
  95     }
  96
  97   stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
  98   ldlang_add_file (stub_file);
  99   ppc64_elf_init_stub_bfd (stub_file->the_bfd, &link_info);
 100 }
 101
 102 static void
 103 ppc_before_allocation (void)
 104 {
 105   if (stub_file != NULL)
 106     {
 107       if (!no_opd_opt
 108           && !ppc64_elf_edit_opd (output_bfd, &link_info, non_overlapping_opd))
 109         einfo ("%X%P: can not edit %s %E\n", "opd");
 110
 111       if (ppc64_elf_tls_setup (output_bfd, &link_info) && !no_tls_opt)
 112         {
 113           /* Size the sections.  This is premature, but we want to know the
 114              TLS segment layout so that certain optimizations can be done.  */
 115           expld.phase = lang_mark_phase_enum;
 116           expld.dataseg.phase = exp_dataseg_none;
 117           one_lang_size_sections_pass (NULL, TRUE);
 118
 119           if (!ppc64_elf_tls_optimize (output_bfd, &link_info))
 120             einfo ("%X%P: TLS problem %E\n");
 121
 122           /* We must not cache anything from the preliminary sizing.  */
 123           lang_reset_memory_regions ();
 124         }
 125
 126       if (!no_toc_opt
 127           && !link_info.relocatable
 128           && !ppc64_elf_edit_toc (output_bfd, &link_info))
 129         einfo ("%X%P: can not edit %s %E\n", "toc");
 130     }
 131
 132   gld${EMULATION_NAME}_before_allocation ();
 133 }
 134
 135 struct hook_stub_info
 136 {
 137   lang_statement_list_type add;
 138   asection *input_section;
 139 };
 140
 141 /* Traverse the linker tree to find the spot where the stub goes.  */
 142
 143 static bfd_boolean
 144 hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
 145 {
 146   lang_statement_union_type *l;
 147   bfd_boolean ret;
 148
 149   for (; (l = *lp) != NULL; lp = &l->header.next)
 150     {
 151       switch (l->header.type)
 152         {
 153         case lang_constructors_statement_enum:
 154           ret = hook_in_stub (info, &constructor_list.head);
 155           if (ret)
 156             return ret;
 157           break;
 158
 159         case lang_output_section_statement_enum:
 160           ret = hook_in_stub (info,
 161                               &l->output_section_statement.children.head);
 162           if (ret)
 163             return ret;
 164           break;
 165
 166         case lang_wild_statement_enum:
 167           ret = hook_in_stub (info, &l->wild_statement.children.head);
 168           if (ret)
 169             return ret;
 170           break;
 171
 172         case lang_group_statement_enum:
 173           ret = hook_in_stub (info, &l->group_statement.children.head);
 174           if (ret)
 175             return ret;
 176           break;
 177
 178         case lang_input_section_enum:
 179           if (l->input_section.section == info->input_section)
 180             {
 181               /* We've found our section.  Insert the stub immediately
 182                  before its associated input section.  */
 183               *lp = info->add.head;
 184               *(info->add.tail) = l;
 185               return TRUE;
 186             }
 187           break;
 188
 189         case lang_data_statement_enum:
 190         case lang_reloc_statement_enum:
 191         case lang_object_symbols_statement_enum:
 192         case lang_output_statement_enum:
 193         case lang_target_statement_enum:
 194         case lang_input_statement_enum:
 195         case lang_assignment_statement_enum:
 196         case lang_padding_statement_enum:
 197         case lang_address_statement_enum:
 198         case lang_fill_statement_enum:
 199           break;
 200
 201         default:
 202           FAIL ();
 203           break;
 204         }
 205     }
 206   return FALSE;
 207 }
 208
 209
 210 /* Call-back for ppc64_elf_size_stubs.  */
 211
 212 /* Create a new stub section, and arrange for it to be linked
 213    immediately before INPUT_SECTION.  */
 214
 215 static asection *
 216 ppc_add_stub_section (const char *stub_sec_name, asection *input_section)
 217 {
 218   asection *stub_sec;
 219   flagword flags;
 220   asection *output_section;
 221   const char *secname;
 222   lang_output_section_statement_type *os;
 223   struct hook_stub_info info;
 224
 225   stub_sec = bfd_make_section_anyway (stub_file->the_bfd, stub_sec_name);
 226   if (stub_sec == NULL)
 227     goto err_ret;
 228
 229   flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
 230            | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_KEEP);
 231   if (!bfd_set_section_flags (stub_file->the_bfd, stub_sec, flags))
 232     goto err_ret;
 233
 234   output_section = input_section->output_section;
 235   secname = bfd_get_section_name (output_section->owner, output_section);
 236   os = lang_output_section_find (secname);
 237
 238   info.input_section = input_section;
 239   lang_list_init (&info.add);
 240   lang_add_section (&info.add, stub_sec, os);
 241
 242   if (info.add.head == NULL)
 243     goto err_ret;
 244
 245   stub_added = 1;
 246   if (hook_in_stub (&info, &os->children.head))
 247     return stub_sec;
 248
 249  err_ret:
 250   einfo ("%X%P: can not make stub section: %E\n");
 251   return NULL;
 252 }
 253
 254
 255 /* Another call-back for ppc64_elf_size_stubs.  */
 256
 257 static void
 258 ppc_layout_sections_again (void)
 259 {
 260   /* If we have changed sizes of the stub sections, then we need
 261      to recalculate all the section offsets.  This may mean we need to
 262      add even more stubs.  */
 263   gld${EMULATION_NAME}_map_segments (TRUE);
 264   need_laying_out = -1;
 265 }
 266
 267
 268 /* Call the back-end function to set TOC base after we have placed all
 269    the sections.  */
 270 static void
 271 gld${EMULATION_NAME}_after_allocation (void)
 272 {
 273   if (!link_info.relocatable)
 274     _bfd_set_gp_value (output_bfd, ppc64_elf_toc (output_bfd));
 275 }
 276
 277
 278 static void
 279 build_toc_list (lang_statement_union_type *statement)
 280 {
 281   if (statement->header.type == lang_input_section_enum)
 282     {
 283       asection *i = statement->input_section.section;
 284
 285       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 286           && (i->flags & SEC_EXCLUDE) == 0
 287           && i->output_section == toc_section)
 288         ppc64_elf_next_toc_section (&link_info, i);
 289     }
 290 }
 291
 292
 293 static void
 294 build_section_lists (lang_statement_union_type *statement)
 295 {
 296   if (statement->header.type == lang_input_section_enum)
 297     {
 298       asection *i = statement->input_section.section;
 299
 300       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 301           && (i->flags & SEC_EXCLUDE) == 0
 302           && i->output_section != NULL
 303           && i->output_section->owner == output_bfd)
 304         {
 305           if (!ppc64_elf_next_input_section (&link_info, i))
 306             einfo ("%X%P: can not size stub section: %E\n");
 307         }
 308     }
 309 }
 310
 311
 312 /* Final emulation specific call.  */
 313
 314 static void
 315 gld${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 (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 (output_bfd, &link_info,
 334                                                no_multi_toc);
 335       if (ret < 0)
 336         einfo ("%X%P: can not size stub section: %E\n");
 337       else if (ret > 0)
 338         {
 339           toc_section = bfd_get_section_by_name (output_bfd, ".got");
 340           if (toc_section != NULL)
 341             lang_for_each_statement (build_toc_list);
 342
 343           ppc64_elf_reinit_toc (output_bfd, &link_info);
 344
 345           lang_for_each_statement (build_section_lists);
 346
 347           /* Call into the BFD backend to do the real work.  */
 348           if (!ppc64_elf_size_stubs (output_bfd,
 349                                      &link_info,
 350                                      group_size,
 351                                      &ppc_add_stub_section,
 352                                      &ppc_layout_sections_again))
 353             einfo ("%X%P: can not size stub section: %E\n");
 354         }
 355     }
 356
 357   if (need_laying_out != -1)
 358     gld${EMULATION_NAME}_map_segments (need_laying_out);
 359
 360   if (link_info.relocatable)
 361     {
 362       asection *toc = bfd_get_section_by_name (output_bfd, ".toc");
 363       if (toc != NULL
 364           && bfd_section_size (output_bfd, toc) > 0x10000)
 365         einfo ("%X%P: TOC section size exceeds 64k\n");
 366     }
 367
 368   if (stub_added)
 369     {
 370       char *msg = NULL;
 371       char *line, *endline;
 372
 373       emit_stub_syms |= link_info.emitrelocations;
 374       if (!ppc64_elf_build_stubs (emit_stub_syms, &link_info,
 375                                   config.stats ? &msg : NULL))
 376         einfo ("%X%P: can not build stubs: %E\n");
 377
 378       for (line = msg; line != NULL; line = endline)
 379         {
 380           endline = strchr (line, '\n');
 381           if (endline != NULL)
 382             *endline++ = '\0';
 383           fprintf (stderr, "%s: %s\n", program_name, line);
 384         }
 385       if (msg != NULL)
 386         free (msg);
 387     }
 388
 389   ppc64_elf_restore_symbols (&link_info);
 390   finish_default ();
 391 }
 392
 393
 394 /* Add a pattern matching ".foo" for every "foo" in a version script.
 395
 396    The reason for doing this is that many shared library version
 397    scripts export a selected set of functions or data symbols, forcing
 398    others local.  eg.
 399
 400    . VERS_1 {
 401    .       global:
 402    .               this; that; some; thing;
 403    .       local:
 404    .               *;
 405    .   };
 406
 407    To make the above work for PowerPC64, we need to export ".this",
 408    ".that" and so on, otherwise only the function descriptor syms are
 409    exported.  Lack of an exported function code sym may cause a
 410    definition to be pulled in from a static library.  */
 411
 412 static struct bfd_elf_version_expr *
 413 gld${EMULATION_NAME}_new_vers_pattern (struct bfd_elf_version_expr *entry)
 414 {
 415   struct bfd_elf_version_expr *dot_entry;
 416   unsigned int len;
 417   char *dot_pat;
 418
 419   if (!dotsyms
 420       || (entry->pattern != NULL
 421           && (entry->pattern[0] == '*' || entry->pattern[0] == '.')))
 422     return entry;
 423
 424   dot_entry = xmalloc (sizeof *dot_entry);
 425   *dot_entry = *entry;
 426   dot_entry->next = entry;
 427   if (entry->pattern != NULL)
 428     {
 429       len = strlen (entry->pattern) + 2;
 430       dot_pat = xmalloc (len);
 431       dot_pat[0] = '.';
 432       memcpy (dot_pat + 1, entry->pattern, len - 1);
 433       dot_entry->pattern = dot_pat;
 434     }
 435   if (entry->symbol != NULL)
 436     {
 437       len = strlen (entry->symbol) + 2;
 438       dot_pat = xmalloc (len);
 439       dot_pat[0] = '.';
 440       memcpy (dot_pat + 1, entry->symbol, len - 1);
 441       dot_entry->symbol = dot_pat;
 442     }
 443   return dot_entry;
 444 }
 445
 446
 447 /* Avoid processing the fake stub_file in vercheck, stat_needed and
 448    check_needed routines.  */
 449
 450 static void (*real_func) (lang_input_statement_type *);
 451
 452 static void ppc_for_each_input_file_wrapper (lang_input_statement_type *l)
 453 {
 454   if (l != stub_file)
 455     (*real_func) (l);
 456 }
 457
 458 static void
 459 ppc_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
 460 {
 461   real_func = func;
 462   lang_for_each_input_file (&ppc_for_each_input_file_wrapper);
 463 }
 464
 465 #define lang_for_each_input_file ppc_lang_for_each_input_file
 466
 467 EOF
 468
 469 if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
 470   fragment <<EOF
 471 /* Special handling for embedded SPU executables.  */
 472 extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
 473 static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
 474
 475 static bfd_boolean
 476 ppc64_recognized_file (lang_input_statement_type *entry)
 477 {
 478   if (embedded_spu_file (entry, "-m64"))
 479     return TRUE;
 480
 481   return gld${EMULATION_NAME}_load_symbols (entry);
 482 }
 483 EOF
 484 LDEMUL_RECOGNIZED_FILE=ppc64_recognized_file
 485 fi
 486
 487 # Define some shell vars to insert bits of code into the standard elf
 488 # parse_args and list_options functions.
 489 #
 490 PARSE_AND_LIST_PROLOGUE='
 491 #define OPTION_STUBGROUP_SIZE           301
 492 #define OPTION_STUBSYMS                 (OPTION_STUBGROUP_SIZE + 1)
 493 #define OPTION_DOTSYMS                  (OPTION_STUBSYMS + 1)
 494 #define OPTION_NO_DOTSYMS               (OPTION_DOTSYMS + 1)
 495 #define OPTION_NO_TLS_OPT               (OPTION_NO_DOTSYMS + 1)
 496 #define OPTION_NO_OPD_OPT               (OPTION_NO_TLS_OPT + 1)
 497 #define OPTION_NO_TOC_OPT               (OPTION_NO_OPD_OPT + 1)
 498 #define OPTION_NO_MULTI_TOC             (OPTION_NO_TOC_OPT + 1)
 499 #define OPTION_NON_OVERLAPPING_OPD      (OPTION_NO_MULTI_TOC + 1)
 500 '
 501
 502 PARSE_AND_LIST_LONGOPTS='
 503   { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
 504   { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
 505   { "dotsyms", no_argument, NULL, OPTION_DOTSYMS },
 506   { "no-dotsyms", no_argument, NULL, OPTION_NO_DOTSYMS },
 507   { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
 508   { "no-opd-optimize", no_argument, NULL, OPTION_NO_OPD_OPT },
 509   { "no-toc-optimize", no_argument, NULL, OPTION_NO_TOC_OPT },
 510   { "no-multi-toc", no_argument, NULL, OPTION_NO_MULTI_TOC },
 511   { "non-overlapping-opd", no_argument, NULL, OPTION_NON_OVERLAPPING_OPD },
 512 '
 513
 514 PARSE_AND_LIST_OPTIONS='
 515   fprintf (file, _("\
 516   --stub-group-size=N         Maximum size of a group of input sections that\n\
 517                                 can be handled by one stub section.  A negative\n\
 518                                 value locates all stubs before their branches\n\
 519                                 (with a group size of -N), while a positive\n\
 520                                 value allows two groups of input sections, one\n\
 521                                 before, and one after each stub section.\n\
 522                                 Values of +/-1 indicate the linker should\n\
 523                                 choose suitable defaults.\n"
 524                    ));
 525   fprintf (file, _("\
 526   --emit-stub-syms            Label linker stubs with a symbol.\n"
 527                    ));
 528   fprintf (file, _("\
 529   --dotsyms                   For every version pattern \"foo\" in a version\n\
 530                                 script, add \".foo\" so that function code\n\
 531                                 symbols are treated the same as function\n\
 532                                 descriptor symbols.  Defaults to on.\n"
 533                    ));
 534   fprintf (file, _("\
 535   --no-dotsyms                Don'\''t do anything special in version scripts.\n"
 536                    ));
 537   fprintf (file, _("\
 538   --no-tls-optimize           Don'\''t try to optimize TLS accesses.\n"
 539                    ));
 540   fprintf (file, _("\
 541   --no-opd-optimize           Don'\''t optimize the OPD section.\n"
 542                    ));
 543   fprintf (file, _("\
 544   --no-toc-optimize           Don'\''t optimize the TOC section.\n"
 545                    ));
 546   fprintf (file, _("\
 547   --no-multi-toc              Disallow automatic multiple toc sections.\n"
 548                    ));
 549   fprintf (file, _("\
 550   --non-overlapping-opd       Canonicalize .opd, so that there are no\n\
 551                                 overlapping .opd entries.\n"
 552                    ));
 553 '
 554
 555 PARSE_AND_LIST_ARGS_CASES='
 556     case OPTION_STUBGROUP_SIZE:
 557       {
 558         const char *end;
 559         group_size = bfd_scan_vma (optarg, &end, 0);
 560         if (*end)
 561           einfo (_("%P%F: invalid number `%s'\''\n"), optarg);
 562       }
 563       break;
 564
 565     case OPTION_STUBSYMS:
 566       emit_stub_syms = 1;
 567       break;
 568
 569     case OPTION_DOTSYMS:
 570       dotsyms = 1;
 571       break;
 572
 573     case OPTION_NO_DOTSYMS:
 574       dotsyms = 0;
 575       break;
 576
 577     case OPTION_NO_TLS_OPT:
 578       no_tls_opt = 1;
 579       break;
 580
 581     case OPTION_NO_OPD_OPT:
 582       no_opd_opt = 1;
 583       break;
 584
 585     case OPTION_NO_TOC_OPT:
 586       no_toc_opt = 1;
 587       break;
 588
 589     case OPTION_NO_MULTI_TOC:
 590       no_multi_toc = 1;
 591       break;
 592
 593     case OPTION_NON_OVERLAPPING_OPD:
 594       non_overlapping_opd = 1;
 595       break;
 596 '
 597
 598 # Put these extra ppc64elf routines in ld_${EMULATION_NAME}_emulation
 599 #
 600 LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
 601 LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
 602 LDEMUL_FINISH=gld${EMULATION_NAME}_finish
 603 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_create_output_section_statements
 604 LDEMUL_NEW_VERS_PATTERN=gld${EMULATION_NAME}_new_vers_pattern