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