ld/emultempl/armelf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright 1991, 1993, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
   3 #   2004, 2005, 2007, 2008
   4 #   Free Software Foundation, Inc.
   5 #
   6 # This file is part of the GNU Binutils.
   7 #
   8 # This program is free software; you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation; either version 3 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # This program is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program; if not, write to the Free Software
  20 # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 # MA 02110-1301, USA.
  22 #
  23
  24 # This file is sourced from elf32.em, and defines extra arm-elf
  25 # specific routines.
  26 #
  27 test -z "$TARGET2_TYPE" && TARGET2_TYPE="rel"
  28 fragment <<EOF
  29
  30 #include "ldctor.h"
  31 #include "elf/arm.h"
  32
  33 static char *thumb_entry_symbol = NULL;
  34 static int byteswap_code = 0;
  35 static int target1_is_rel = 0${TARGET1_IS_REL};
  36 static char *target2_type = "${TARGET2_TYPE}";
  37 static int fix_v4bx = 0;
  38 static int use_blx = 0;
  39 static bfd_arm_vfp11_fix vfp11_denorm_fix = BFD_ARM_VFP11_FIX_DEFAULT;
  40 static int no_enum_size_warning = 0;
  41 static int no_wchar_size_warning = 0;
  42 static int pic_veneer = 0;
  43
  44 static void
  45 gld${EMULATION_NAME}_before_parse (void)
  46 {
  47 #ifndef TARGET_                 /* I.e., if not generic.  */
  48   ldfile_set_output_arch ("`echo ${ARCH}`", bfd_arch_unknown);
  49 #endif /* not TARGET_ */
  50   config.dynamic_link = ${DYNAMIC_LINK-TRUE};
  51   config.has_shared = `if test -n "$GENERATE_SHLIB_SCRIPT" ; then echo TRUE ; else echo FALSE ; fi`;
  52 }
  53
  54 static void
  55 arm_elf_before_allocation (void)
  56 {
  57   bfd_elf32_arm_set_byteswap_code (&link_info, byteswap_code);
  58
  59   /* Choose type of VFP11 erratum fix, or warn if specified fix is unnecessary
  60      due to architecture version.  */
  61   bfd_elf32_arm_set_vfp11_fix (link_info.output_bfd, &link_info);
  62
  63   /* We should be able to set the size of the interworking stub section.  We
  64      can't do it until later if we have dynamic sections, though.  */
  65   if (! elf_hash_table (&link_info)->dynamic_sections_created)
  66     {
  67       /* Here we rummage through the found bfds to collect glue information.  */
  68       LANG_FOR_EACH_INPUT_STATEMENT (is)
  69         {
  70           /* Initialise mapping tables for code/data.  */
  71           bfd_elf32_arm_init_maps (is->the_bfd);
  72
  73           if (!bfd_elf32_arm_process_before_allocation (is->the_bfd,
  74                                                         &link_info)
  75               || !bfd_elf32_arm_vfp11_erratum_scan (is->the_bfd, &link_info))
  76             /* xgettext:c-format */
  77             einfo (_("Errors encountered processing file %s"), is->filename);
  78         }
  79
  80       /* We have seen it all.  Allocate it, and carry on.  */
  81       bfd_elf32_arm_allocate_interworking_sections (& link_info);
  82     }
  83
  84   /* Call the standard elf routine.  */
  85   gld${EMULATION_NAME}_before_allocation ();
  86 }
  87
  88 static void
  89 arm_elf_after_allocation (void)
  90 {
  91   /* Call the standard elf routine.  */
  92   after_allocation_default ();
  93
  94   {
  95     LANG_FOR_EACH_INPUT_STATEMENT (is)
  96       {
  97         /* Figure out where VFP11 erratum veneers (and the labels returning
  98            from same) have been placed.  */
  99         bfd_elf32_arm_vfp11_fix_veneer_locations (is->the_bfd, &link_info);
 100       }
 101   }
 102 }
 103
 104 /* Fake input file for stubs.  */
 105 static lang_input_statement_type *stub_file;
 106
 107 /* Whether we need to call gldarm_layout_sections_again.  */
 108 static int need_laying_out = 0;
 109
 110 /* Maximum size of a group of input sections that can be handled by
 111    one stub section.  A value of +/-1 indicates the bfd back-end
 112    should use a suitable default size.  */
 113 static bfd_signed_vma group_size = 1;
 114
 115 struct hook_stub_info
 116 {
 117   lang_statement_list_type add;
 118   asection *input_section;
 119 };
 120
 121 /* Traverse the linker tree to find the spot where the stub goes.  */
 122
 123 static bfd_boolean
 124 hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
 125 {
 126   lang_statement_union_type *l;
 127   bfd_boolean ret;
 128
 129   for (; (l = *lp) != NULL; lp = &l->header.next)
 130     {
 131       switch (l->header.type)
 132         {
 133         case lang_constructors_statement_enum:
 134           ret = hook_in_stub (info, &constructor_list.head);
 135           if (ret)
 136             return ret;
 137           break;
 138
 139         case lang_output_section_statement_enum:
 140           ret = hook_in_stub (info,
 141                               &l->output_section_statement.children.head);
 142           if (ret)
 143             return ret;
 144           break;
 145
 146         case lang_wild_statement_enum:
 147           ret = hook_in_stub (info, &l->wild_statement.children.head);
 148           if (ret)
 149             return ret;
 150           break;
 151
 152         case lang_group_statement_enum:
 153           ret = hook_in_stub (info, &l->group_statement.children.head);
 154           if (ret)
 155             return ret;
 156           break;
 157
 158         case lang_input_section_enum:
 159           if (l->input_section.section == info->input_section)
 160             {
 161               /* We've found our section.  Insert the stub immediately
 162                  after its associated input section.  */
 163               *(info->add.tail) = l->header.next;
 164               l->header.next = info->add.head;
 165               return TRUE;
 166             }
 167           break;
 168
 169         case lang_data_statement_enum:
 170         case lang_reloc_statement_enum:
 171         case lang_object_symbols_statement_enum:
 172         case lang_output_statement_enum:
 173         case lang_target_statement_enum:
 174         case lang_input_statement_enum:
 175         case lang_assignment_statement_enum:
 176         case lang_padding_statement_enum:
 177         case lang_address_statement_enum:
 178         case lang_fill_statement_enum:
 179           break;
 180
 181         default:
 182           FAIL ();
 183           break;
 184         }
 185     }
 186   return FALSE;
 187 }
 188
 189
 190 /* Call-back for elf32_arm_size_stubs.  */
 191
 192 /* Create a new stub section, and arrange for it to be linked
 193    immediately after INPUT_SECTION.  */
 194
 195 static asection *
 196 elf32_arm_add_stub_section (const char *stub_sec_name,
 197                             asection *input_section)
 198 {
 199   asection *stub_sec;
 200   flagword flags;
 201   asection *output_section;
 202   const char *secname;
 203   lang_output_section_statement_type *os;
 204   struct hook_stub_info info;
 205
 206   flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
 207            | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
 208   stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
 209                                                  stub_sec_name, flags);
 210   if (stub_sec == NULL)
 211     goto err_ret;
 212
 213   bfd_set_section_alignment (stub_file->the_bfd, stub_sec, 3);
 214
 215   output_section = input_section->output_section;
 216   secname = bfd_get_section_name (output_section->owner, output_section);
 217   os = lang_output_section_find (secname);
 218
 219   info.input_section = input_section;
 220   lang_list_init (&info.add);
 221   lang_add_section (&info.add, stub_sec, os);
 222
 223   if (info.add.head == NULL)
 224     goto err_ret;
 225
 226   if (hook_in_stub (&info, &os->children.head))
 227     return stub_sec;
 228
 229  err_ret:
 230   einfo ("%X%P: can not make stub section: %E\n");
 231   return NULL;
 232 }
 233
 234 /* Another call-back for elf_arm_size_stubs.  */
 235
 236 static void
 237 gldarm_layout_sections_again (void)
 238 {
 239   /* If we have changed sizes of the stub sections, then we need
 240      to recalculate all the section offsets.  This may mean we need to
 241      add even more stubs.  */
 242   gld${EMULATION_NAME}_map_segments (TRUE);
 243   need_laying_out = -1;
 244 }
 245
 246 static void
 247 build_section_lists (lang_statement_union_type *statement)
 248 {
 249   if (statement->header.type == lang_input_section_enum)
 250     {
 251       asection *i = statement->input_section.section;
 252
 253       if (!((lang_input_statement_type *) i->owner->usrdata)->just_syms_flag
 254           && (i->flags & SEC_EXCLUDE) == 0
 255           && i->output_section != NULL
 256           && i->output_section->owner == link_info.output_bfd)
 257         elf32_arm_next_input_section (& link_info, i);
 258     }
 259 }
 260
 261 static void
 262 gld${EMULATION_NAME}_finish (void)
 263 {
 264   struct bfd_link_hash_entry * h;
 265
 266   /* bfd_elf32_discard_info just plays with debugging sections,
 267      ie. doesn't affect any code, so we can delay resizing the
 268      sections.  It's likely we'll resize everything in the process of
 269      adding stubs.  */
 270   if (bfd_elf_discard_info (link_info.output_bfd, & link_info))
 271     need_laying_out = 1;
 272
 273   /* If generating a relocatable output file, then we don't
 274      have to examine the relocs.  */
 275   if (stub_file != NULL && !link_info.relocatable)
 276     {
 277       int  ret = elf32_arm_setup_section_lists (link_info.output_bfd, & link_info);
 278
 279       if (ret != 0)
 280         {
 281           if (ret < 0)
 282             {
 283               einfo ("%X%P: could not compute sections lists for stub generation: %E\n");
 284               return;
 285             }
 286
 287           lang_for_each_statement (build_section_lists);
 288
 289           /* Call into the BFD backend to do the real work.  */
 290           if (! elf32_arm_size_stubs (link_info.output_bfd,
 291                                       stub_file->the_bfd,
 292                                       & link_info,
 293                                       group_size,
 294                                       & elf32_arm_add_stub_section,
 295                                       & gldarm_layout_sections_again))
 296             {
 297               einfo ("%X%P: cannot size stub section: %E\n");
 298               return;
 299             }
 300         }
 301     }
 302
 303   if (need_laying_out != -1)
 304     gld${EMULATION_NAME}_map_segments (need_laying_out);
 305
 306   if (! link_info.relocatable)
 307     {
 308       /* Now build the linker stubs.  */
 309       if (stub_file->the_bfd->sections != NULL)
 310         {
 311           if (! elf32_arm_build_stubs (& link_info))
 312             einfo ("%X%P: can not build stubs: %E\n");
 313         }
 314     }
 315
 316   finish_default ();
 317
 318   if (thumb_entry_symbol)
 319     {
 320       h = bfd_link_hash_lookup (link_info.hash, thumb_entry_symbol,
 321                                 FALSE, FALSE, TRUE);
 322     }
 323   else
 324     {
 325       struct elf_link_hash_entry * eh;
 326
 327       if (!entry_symbol.name)
 328         return;
 329
 330       h = bfd_link_hash_lookup (link_info.hash, entry_symbol.name,
 331                                 FALSE, FALSE, TRUE);
 332       eh = (struct elf_link_hash_entry *)h;
 333       if (!h || ELF_ST_TYPE(eh->type) != STT_ARM_TFUNC)
 334         return;
 335     }
 336
 337
 338   if (h != (struct bfd_link_hash_entry *) NULL
 339       && (h->type == bfd_link_hash_defined
 340           || h->type == bfd_link_hash_defweak)
 341       && h->u.def.section->output_section != NULL)
 342     {
 343       static char buffer[32];
 344       bfd_vma val;
 345
 346       /* Special procesing is required for a Thumb entry symbol.  The
 347          bottom bit of its address must be set.  */
 348       val = (h->u.def.value
 349              + bfd_get_section_vma (link_info.output_bfd,
 350                                     h->u.def.section->output_section)
 351              + h->u.def.section->output_offset);
 352
 353       val |= 1;
 354
 355       /* Now convert this value into a string and store it in entry_symbol
 356          where the lang_finish() function will pick it up.  */
 357       buffer[0] = '0';
 358       buffer[1] = 'x';
 359
 360       sprintf_vma (buffer + 2, val);
 361
 362       if (thumb_entry_symbol != NULL && entry_symbol.name != NULL
 363           && entry_from_cmdline)
 364         einfo (_("%P: warning: '--thumb-entry %s' is overriding '-e %s'\n"),
 365                thumb_entry_symbol, entry_symbol.name);
 366       entry_symbol.name = buffer;
 367     }
 368   else
 369     einfo (_("%P: warning: cannot find thumb start symbol %s\n"),
 370            thumb_entry_symbol);
 371 }
 372
 373 /* This is a convenient point to tell BFD about target specific flags.
 374    After the output has been created, but before inputs are read.  */
 375 static void
 376 arm_elf_create_output_section_statements (void)
 377 {
 378   if (strstr (bfd_get_target (link_info.output_bfd), "arm") == NULL)
 379     {
 380       /* The arm backend needs special fields in the output hash structure.
 381          These will only be created if the output format is an arm format,
 382          hence we do not support linking and changing output formats at the
 383          same time.  Use a link followed by objcopy to change output formats.  */
 384       einfo ("%F%X%P: error: Cannot change output format whilst linking ARM binaries.\n");
 385       return;
 386     }
 387
 388   bfd_elf32_arm_set_target_relocs (link_info.output_bfd, &link_info,
 389                                    target1_is_rel,
 390                                    target2_type, fix_v4bx, use_blx,
 391                                    vfp11_denorm_fix, no_enum_size_warning,
 392                                    no_wchar_size_warning,
 393                                    pic_veneer);
 394
 395   stub_file = lang_add_input_file ("linker stubs",
 396                                    lang_input_file_is_fake_enum,
 397                                    NULL);
 398   stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
 399   if (stub_file->the_bfd == NULL
 400       || ! bfd_set_arch_mach (stub_file->the_bfd,
 401                               bfd_get_arch (link_info.output_bfd),
 402                               bfd_get_mach (link_info.output_bfd)))
 403     {
 404       einfo ("%X%P: can not create BFD %E\n");
 405       return;
 406     }
 407
 408   stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
 409   ldlang_add_file (stub_file);
 410
 411   /* Also use the stub file for stubs placed in a single output section.  */
 412   bfd_elf32_arm_add_glue_sections_to_bfd (stub_file->the_bfd, &link_info);
 413   bfd_elf32_arm_get_bfd_for_interworking (stub_file->the_bfd, &link_info);
 414 }
 415
 416 /* Avoid processing the fake stub_file in vercheck, stat_needed and
 417    check_needed routines.  */
 418
 419 static void (*real_func) (lang_input_statement_type *);
 420
 421 static void arm_for_each_input_file_wrapper (lang_input_statement_type *l)
 422 {
 423   if (l != stub_file)
 424     (*real_func) (l);
 425 }
 426
 427 static void
 428 arm_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
 429 {
 430   real_func = func;
 431   lang_for_each_input_file (&arm_for_each_input_file_wrapper);
 432 }
 433
 434 #define lang_for_each_input_file arm_lang_for_each_input_file
 435
 436 EOF
 437
 438 # Define some shell vars to insert bits of code into the standard elf
 439 # parse_args and list_options functions.
 440 #
 441 PARSE_AND_LIST_PROLOGUE='
 442 #define OPTION_THUMB_ENTRY              301
 443 #define OPTION_BE8                      302
 444 #define OPTION_TARGET1_REL              303
 445 #define OPTION_TARGET1_ABS              304
 446 #define OPTION_TARGET2                  305
 447 #define OPTION_FIX_V4BX                 306
 448 #define OPTION_USE_BLX                  307
 449 #define OPTION_VFP11_DENORM_FIX         308
 450 #define OPTION_NO_ENUM_SIZE_WARNING     309
 451 #define OPTION_PIC_VENEER               310
 452 #define OPTION_FIX_V4BX_INTERWORKING    311
 453 #define OPTION_STUBGROUP_SIZE           312
 454 #define OPTION_NO_WCHAR_SIZE_WARNING    313
 455 '
 456
 457 PARSE_AND_LIST_SHORTOPTS=p
 458
 459 PARSE_AND_LIST_LONGOPTS='
 460   { "no-pipeline-knowledge", no_argument, NULL, '\'p\''},
 461   { "thumb-entry", required_argument, NULL, OPTION_THUMB_ENTRY},
 462   { "be8", no_argument, NULL, OPTION_BE8},
 463   { "target1-rel", no_argument, NULL, OPTION_TARGET1_REL},
 464   { "target1-abs", no_argument, NULL, OPTION_TARGET1_ABS},
 465   { "target2", required_argument, NULL, OPTION_TARGET2},
 466   { "fix-v4bx", no_argument, NULL, OPTION_FIX_V4BX},
 467   { "fix-v4bx-interworking", no_argument, NULL, OPTION_FIX_V4BX_INTERWORKING},
 468   { "use-blx", no_argument, NULL, OPTION_USE_BLX},
 469   { "vfp11-denorm-fix", required_argument, NULL, OPTION_VFP11_DENORM_FIX},
 470   { "no-enum-size-warning", no_argument, NULL, OPTION_NO_ENUM_SIZE_WARNING},
 471   { "pic-veneer", no_argument, NULL, OPTION_PIC_VENEER},
 472   { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
 473   { "no-wchar-size-warning", no_argument, NULL, OPTION_NO_WCHAR_SIZE_WARNING},
 474 '
 475
 476 PARSE_AND_LIST_OPTIONS='
 477   fprintf (file, _("  --thumb-entry=<sym>         Set the entry point to be Thumb symbol <sym>\n"));
 478   fprintf (file, _("  --be8                       Output BE8 format image\n"));
 479   fprintf (file, _("  --target1=rel               Interpret R_ARM_TARGET1 as R_ARM_REL32\n"));
 480   fprintf (file, _("  --target1=abs               Interpret R_ARM_TARGET1 as R_ARM_ABS32\n"));
 481   fprintf (file, _("  --target2=<type>            Specify definition of R_ARM_TARGET2\n"));
 482   fprintf (file, _("  --fix-v4bx                  Rewrite BX rn as MOV pc, rn for ARMv4\n"));
 483   fprintf (file, _("  --fix-v4bx-interworking     Rewrite BX rn branch to ARMv4 interworking veneer\n"));
 484   fprintf (file, _("  --use-blx                   Enable use of BLX instructions\n"));
 485   fprintf (file, _("  --vfp11-denorm-fix          Specify how to fix VFP11 denorm erratum\n"));
 486   fprintf (file, _("  --no-enum-size-warning      Don'\''t warn about objects with incompatible\n"
 487                    "                                enum sizes\n"));
 488   fprintf (file, _("  --no-wchar-size-warning     Don'\''t warn about objects with incompatible"
 489                    "                                wchar_t sizes\n"));
 490   fprintf (file, _("  --pic-veneer                Always generate PIC interworking veneers\n"));
 491   fprintf (file, _("\
 492    --stub-group-size=N   Maximum size of a group of input sections that can be\n\
 493                            handled by one stub section.  A negative value\n\
 494                            locates all stubs after their branches (with a\n\
 495                            group size of -N), while a positive value allows\n\
 496                            two groups of input sections, one before, and one\n\
 497                            after each stub section.  Values of +/-1 indicate\n\
 498                            the linker should choose suitable defaults.\n"
 499                    ));
 500 '
 501
 502 PARSE_AND_LIST_ARGS_CASES='
 503     case '\'p\'':
 504       /* Only here for backwards compatibility.  */
 505       break;
 506
 507     case OPTION_THUMB_ENTRY:
 508       thumb_entry_symbol = optarg;
 509       break;
 510
 511     case OPTION_BE8:
 512       byteswap_code = 1;
 513       break;
 514
 515     case OPTION_TARGET1_REL:
 516       target1_is_rel = 1;
 517       break;
 518
 519     case OPTION_TARGET1_ABS:
 520       target1_is_rel = 0;
 521       break;
 522
 523     case OPTION_TARGET2:
 524       target2_type = optarg;
 525       break;
 526
 527     case OPTION_FIX_V4BX:
 528       fix_v4bx = 1;
 529       break;
 530
 531     case OPTION_FIX_V4BX_INTERWORKING:
 532       fix_v4bx = 2;
 533       break;
 534
 535     case OPTION_USE_BLX:
 536       use_blx = 1;
 537       break;
 538
 539     case OPTION_VFP11_DENORM_FIX:
 540       if (strcmp (optarg, "none") == 0)
 541         vfp11_denorm_fix = BFD_ARM_VFP11_FIX_NONE;
 542       else if (strcmp (optarg, "scalar") == 0)
 543         vfp11_denorm_fix = BFD_ARM_VFP11_FIX_SCALAR;
 544       else if (strcmp (optarg, "vector") == 0)
 545         vfp11_denorm_fix = BFD_ARM_VFP11_FIX_VECTOR;
 546       else
 547         einfo (_("Unrecognized VFP11 fix type '\''%s'\''.\n"), optarg);
 548       break;
 549
 550     case OPTION_NO_ENUM_SIZE_WARNING:
 551       no_enum_size_warning = 1;
 552       break;
 553
 554     case OPTION_NO_WCHAR_SIZE_WARNING:
 555       no_wchar_size_warning = 1;
 556       break;
 557
 558     case OPTION_PIC_VENEER:
 559       pic_veneer = 1;
 560       break;
 561
 562     case OPTION_STUBGROUP_SIZE:
 563       {
 564         const char *end;
 565
 566         group_size = bfd_scan_vma (optarg, &end, 0);
 567         if (*end)
 568           einfo (_("%P%F: invalid number `%s'\''\n"), optarg);
 569       }
 570       break;
 571 '
 572
 573 # We have our own before_allocation etc. functions, but they call
 574 # the standard routines, so give them a different name.
 575 LDEMUL_BEFORE_ALLOCATION=arm_elf_before_allocation
 576 LDEMUL_AFTER_ALLOCATION=arm_elf_after_allocation
 577 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=arm_elf_create_output_section_statements
 578
 579 # Replace the elf before_parse function with our own.
 580 LDEMUL_BEFORE_PARSE=gld"${EMULATION_NAME}"_before_parse
 581
 582 # Call the extra arm-elf function
 583 LDEMUL_FINISH=gld${EMULATION_NAME}_finish