ld/emultempl/ppc64elf.em

   1 # This shell script emits a C file. -*- C -*-
   2 # Copyright 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
   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 = -1;
  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_DATA))
  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         {
 283           if (!ppc64_elf_next_toc_section (&link_info, i))
 284             einfo ("%X%P: linker script separates .got and .toc\n");
 285         }
 286     }
 287 }
 288
 289
 290 static void
 291 build_section_lists (lang_statement_union_type *statement)
 292 {
 293   if (statement->header.type == lang_input_section_enum)
 294     {
 295       asection *i = statement->input_section.section;
 296
 297       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 298           && (i->flags & SEC_EXCLUDE) == 0
 299           && i->output_section != NULL
 300           && i->output_section->owner == link_info.output_bfd)
 301         {
 302           if (!ppc64_elf_next_input_section (&link_info, i))
 303             einfo ("%X%P: can not size stub section: %E\n");
 304         }
 305     }
 306 }
 307
 308
 309 /* Call the back-end function to set TOC base after we have placed all
 310    the sections.  */
 311 static void
 312 gld${EMULATION_NAME}_after_allocation (void)
 313 {
 314   /* bfd_elf_discard_info just plays with data and debugging sections,
 315      ie. doesn't affect code size, so we can delay resizing the
 316      sections.  It's likely we'll resize everything in the process of
 317      adding stubs.  */
 318   if (bfd_elf_discard_info (link_info.output_bfd, &link_info))
 319     need_laying_out = 1;
 320
 321   /* If generating a relocatable output file, then we don't have any
 322      stubs.  */
 323   if (stub_file != NULL && !link_info.relocatable)
 324     {
 325       int ret = ppc64_elf_setup_section_lists (&link_info,
 326                                                &ppc_add_stub_section,
 327                                                &ppc_layout_sections_again);
 328       if (ret < 0)
 329         einfo ("%X%P: can not size stub section: %E\n");
 330       else if (ret > 0)
 331         {
 332           ppc64_elf_start_multitoc_partition (&link_info);
 333
 334           if (!no_multi_toc)
 335             {
 336               toc_section = bfd_get_section_by_name (link_info.output_bfd,
 337                                                      ".got");
 338               if (toc_section != NULL)
 339                 lang_for_each_statement (build_toc_list);
 340             }
 341
 342           if (ppc64_elf_layout_multitoc (&link_info)
 343               && !no_multi_toc
 344               && toc_section != NULL)
 345             lang_for_each_statement (build_toc_list);
 346
 347           ppc64_elf_finish_multitoc_partition (&link_info);
 348
 349           lang_for_each_statement (build_section_lists);
 350
 351           /* Call into the BFD backend to do the real work.  */
 352           if (!ppc64_elf_size_stubs (&link_info, group_size))
 353             einfo ("%X%P: can not size stub section: %E\n");
 354         }
 355     }
 356
 357   if (need_laying_out != -1)
 358     {
 359       gld${EMULATION_NAME}_map_segments (need_laying_out);
 360
 361       if (!link_info.relocatable)
 362         _bfd_set_gp_value (link_info.output_bfd,
 363                            ppc64_elf_toc (link_info.output_bfd));
 364     }
 365 }
 366
 367
 368 /* Final emulation specific call.  */
 369
 370 static void
 371 gld${EMULATION_NAME}_finish (void)
 372 {
 373   /* e_entry on PowerPC64 points to the function descriptor for
 374      _start.  If _start is missing, default to the first function
 375      descriptor in the .opd section.  */
 376   entry_section = ".opd";
 377
 378   if (link_info.relocatable)
 379     {
 380       asection *toc = bfd_get_section_by_name (link_info.output_bfd, ".toc");
 381       if (toc != NULL
 382           && bfd_section_size (link_info.output_bfd, toc) > 0x10000)
 383         einfo ("%X%P: TOC section size exceeds 64k\n");
 384     }
 385
 386   if (stub_added)
 387     {
 388       char *msg = NULL;
 389       char *line, *endline;
 390
 391       if (emit_stub_syms < 0)
 392         emit_stub_syms = 1;
 393       if (!ppc64_elf_build_stubs (emit_stub_syms, &link_info,
 394                                   config.stats ? &msg : NULL))
 395         einfo ("%X%P: can not build stubs: %E\n");
 396
 397       for (line = msg; line != NULL; line = endline)
 398         {
 399           endline = strchr (line, '\n');
 400           if (endline != NULL)
 401             *endline++ = '\0';
 402           fprintf (stderr, "%s: %s\n", program_name, line);
 403         }
 404       if (msg != NULL)
 405         free (msg);
 406     }
 407
 408   ppc64_elf_restore_symbols (&link_info);
 409   finish_default ();
 410 }
 411
 412
 413 /* Add a pattern matching ".foo" for every "foo" in a version script.
 414
 415    The reason for doing this is that many shared library version
 416    scripts export a selected set of functions or data symbols, forcing
 417    others local.  eg.
 418
 419    . VERS_1 {
 420    .       global:
 421    .               this; that; some; thing;
 422    .       local:
 423    .               *;
 424    .   };
 425
 426    To make the above work for PowerPC64, we need to export ".this",
 427    ".that" and so on, otherwise only the function descriptor syms are
 428    exported.  Lack of an exported function code sym may cause a
 429    definition to be pulled in from a static library.  */
 430
 431 static struct bfd_elf_version_expr *
 432 gld${EMULATION_NAME}_new_vers_pattern (struct bfd_elf_version_expr *entry)
 433 {
 434   struct bfd_elf_version_expr *dot_entry;
 435   unsigned int len;
 436   char *dot_pat;
 437
 438   if (!dotsyms
 439       || entry->pattern[0] == '.'
 440       || (!entry->literal && entry->pattern[0] == '*'))
 441     return entry;
 442
 443   dot_entry = xmalloc (sizeof *dot_entry);
 444   *dot_entry = *entry;
 445   dot_entry->next = entry;
 446   len = strlen (entry->pattern) + 2;
 447   dot_pat = xmalloc (len);
 448   dot_pat[0] = '.';
 449   memcpy (dot_pat + 1, entry->pattern, len - 1);
 450   dot_entry->pattern = dot_pat;
 451   return dot_entry;
 452 }
 453
 454
 455 /* Avoid processing the fake stub_file in vercheck, stat_needed and
 456    check_needed routines.  */
 457
 458 static void (*real_func) (lang_input_statement_type *);
 459
 460 static void ppc_for_each_input_file_wrapper (lang_input_statement_type *l)
 461 {
 462   if (l != stub_file)
 463     (*real_func) (l);
 464 }
 465
 466 static void
 467 ppc_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
 468 {
 469   real_func = func;
 470   lang_for_each_input_file (&ppc_for_each_input_file_wrapper);
 471 }
 472
 473 #define lang_for_each_input_file ppc_lang_for_each_input_file
 474
 475 EOF
 476
 477 if grep -q 'ld_elf32_spu_emulation' ldemul-list.h; then
 478   fragment <<EOF
 479 /* Special handling for embedded SPU executables.  */
 480 extern bfd_boolean embedded_spu_file (lang_input_statement_type *, const char *);
 481 static bfd_boolean gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *);
 482
 483 static bfd_boolean
 484 ppc64_recognized_file (lang_input_statement_type *entry)
 485 {
 486   if (embedded_spu_file (entry, "-m64"))
 487     return TRUE;
 488
 489   return gld${EMULATION_NAME}_load_symbols (entry);
 490 }
 491 EOF
 492 LDEMUL_RECOGNIZED_FILE=ppc64_recognized_file
 493 fi
 494
 495 # Define some shell vars to insert bits of code into the standard elf
 496 # parse_args and list_options functions.
 497 #
 498 PARSE_AND_LIST_PROLOGUE='
 499 #define OPTION_STUBGROUP_SIZE           301
 500 #define OPTION_STUBSYMS                 (OPTION_STUBGROUP_SIZE + 1)
 501 #define OPTION_NO_STUBSYMS              (OPTION_STUBSYMS + 1)
 502 #define OPTION_DOTSYMS                  (OPTION_NO_STUBSYMS + 1)
 503 #define OPTION_NO_DOTSYMS               (OPTION_DOTSYMS + 1)
 504 #define OPTION_NO_TLS_OPT               (OPTION_NO_DOTSYMS + 1)
 505 #define OPTION_NO_TLS_GET_ADDR_OPT      (OPTION_NO_TLS_OPT + 1)
 506 #define OPTION_NO_OPD_OPT               (OPTION_NO_TLS_GET_ADDR_OPT + 1)
 507 #define OPTION_NO_TOC_OPT               (OPTION_NO_OPD_OPT + 1)
 508 #define OPTION_NO_MULTI_TOC             (OPTION_NO_TOC_OPT + 1)
 509 #define OPTION_NON_OVERLAPPING_OPD      (OPTION_NO_MULTI_TOC + 1)
 510 '
 511
 512 PARSE_AND_LIST_LONGOPTS='
 513   { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
 514   { "emit-stub-syms", no_argument, NULL, OPTION_STUBSYMS },
 515   { "no-emit-stub-syms", no_argument, NULL, OPTION_NO_STUBSYMS },
 516   { "dotsyms", no_argument, NULL, OPTION_DOTSYMS },
 517   { "no-dotsyms", no_argument, NULL, OPTION_NO_DOTSYMS },
 518   { "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
 519   { "no-tls-get-addr-optimize", no_argument, NULL, OPTION_NO_TLS_GET_ADDR_OPT },
 520   { "no-opd-optimize", no_argument, NULL, OPTION_NO_OPD_OPT },
 521   { "no-toc-optimize", no_argument, NULL, OPTION_NO_TOC_OPT },
 522   { "no-multi-toc", no_argument, NULL, OPTION_NO_MULTI_TOC },
 523   { "non-overlapping-opd", no_argument, NULL, OPTION_NON_OVERLAPPING_OPD },
 524 '
 525
 526 PARSE_AND_LIST_OPTIONS='
 527   fprintf (file, _("\
 528   --stub-group-size=N         Maximum size of a group of input sections that\n\
 529                                 can be handled by one stub section.  A negative\n\
 530                                 value locates all stubs before their branches\n\
 531                                 (with a group size of -N), while a positive\n\
 532                                 value allows two groups of input sections, one\n\
 533                                 before, and one after each stub section.\n\
 534                                 Values of +/-1 indicate the linker should\n\
 535                                 choose suitable defaults.\n"
 536                    ));
 537   fprintf (file, _("\
 538   --emit-stub-syms            Label linker stubs with a symbol.\n"
 539                    ));
 540   fprintf (file, _("\
 541   --no-emit-stub-syms         Don'\''t label linker stubs with a symbol.\n"
 542                    ));
 543   fprintf (file, _("\
 544   --dotsyms                   For every version pattern \"foo\" in a version\n\
 545                                 script, add \".foo\" so that function code\n\
 546                                 symbols are treated the same as function\n\
 547                                 descriptor symbols.  Defaults to on.\n"
 548                    ));
 549   fprintf (file, _("\
 550   --no-dotsyms                Don'\''t do anything special in version scripts.\n"
 551                    ));
 552   fprintf (file, _("\
 553   --no-tls-optimize           Don'\''t try to optimize TLS accesses.\n"
 554                    ));
 555   fprintf (file, _("\
 556   --no-tls-get-addr-optimize  Don'\''t use a special __tls_get_addr call.\n"
 557                    ));
 558   fprintf (file, _("\
 559   --no-opd-optimize           Don'\''t optimize the OPD section.\n"
 560                    ));
 561   fprintf (file, _("\
 562   --no-toc-optimize           Don'\''t optimize the TOC section.\n"
 563                    ));
 564   fprintf (file, _("\
 565   --no-multi-toc              Disallow automatic multiple toc sections.\n"
 566                    ));
 567   fprintf (file, _("\
 568   --non-overlapping-opd       Canonicalize .opd, so that there are no\n\
 569                                 overlapping .opd entries.\n"
 570                    ));
 571 '
 572
 573 PARSE_AND_LIST_ARGS_CASES='
 574     case OPTION_STUBGROUP_SIZE:
 575       {
 576         const char *end;
 577         group_size = bfd_scan_vma (optarg, &end, 0);
 578         if (*end)
 579           einfo (_("%P%F: invalid number `%s'\''\n"), optarg);
 580       }
 581       break;
 582
 583     case OPTION_STUBSYMS:
 584       emit_stub_syms = 1;
 585       break;
 586
 587     case OPTION_NO_STUBSYMS:
 588       emit_stub_syms = 0;
 589       break;
 590
 591     case OPTION_DOTSYMS:
 592       dotsyms = 1;
 593       break;
 594
 595     case OPTION_NO_DOTSYMS:
 596       dotsyms = 0;
 597       break;
 598
 599     case OPTION_NO_TLS_OPT:
 600       no_tls_opt = 1;
 601       break;
 602
 603     case OPTION_NO_TLS_GET_ADDR_OPT:
 604       no_tls_get_addr_opt = 1;
 605       break;
 606
 607     case OPTION_NO_OPD_OPT:
 608       no_opd_opt = 1;
 609       break;
 610
 611     case OPTION_NO_TOC_OPT:
 612       no_toc_opt = 1;
 613       break;
 614
 615     case OPTION_NO_MULTI_TOC:
 616       no_multi_toc = 1;
 617       break;
 618
 619     case OPTION_NON_OVERLAPPING_OPD:
 620       non_overlapping_opd = 1;
 621       break;
 622 '
 623
 624 # Put these extra ppc64elf routines in ld_${EMULATION_NAME}_emulation
 625 #
 626 LDEMUL_BEFORE_ALLOCATION=ppc_before_allocation
 627 LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
 628 LDEMUL_FINISH=gld${EMULATION_NAME}_finish
 629 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=ppc_create_output_section_statements
 630 LDEMUL_NEW_VERS_PATTERN=gld${EMULATION_NAME}_new_vers_pattern