ld/emultempl/aarch64elf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright (C) 2009-2017 Free Software Foundation, Inc.
   3 #   Contributed by ARM Ltd.
   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; see the file COPYING3. If not,
  19 # see <http://www.gnu.org/licenses/>.
  20 #
  21
  22 # This file is sourced from elf32.em, and defines extra aarch64-elf
  23 # specific routines.
  24 #
  25 fragment <<EOF
  26
  27 #include "ldctor.h"
  28 #include "elf/aarch64.h"
  29
  30 static int no_enum_size_warning = 0;
  31 static int no_wchar_size_warning = 0;
  32 static int pic_veneer = 0;
  33 static int fix_erratum_835769 = 0;
  34 static int fix_erratum_843419 = 0;
  35 static int no_apply_dynamic_relocs = 0;
  36
  37 static void
  38 gld${EMULATION_NAME}_before_parse (void)
  39 {
  40 #ifndef TARGET_                 /* I.e., if not generic.  */
  41   ldfile_set_output_arch ("`echo ${ARCH}`", bfd_arch_unknown);
  42 #endif /* not TARGET_ */
  43   input_flags.dynamic = ${DYNAMIC_LINK-TRUE};
  44   config.has_shared = `if test -n "$GENERATE_SHLIB_SCRIPT" ; then echo TRUE ; else echo FALSE ; fi`;
  45   config.separate_code = `if test "x${SEPARATE_CODE}" = xyes ; then echo TRUE ; else echo FALSE ; fi`;
  46   link_info.relro = DEFAULT_LD_Z_RELRO;
  47 }
  48
  49 static void
  50 aarch64_elf_before_allocation (void)
  51 {
  52   /* We should be able to set the size of the interworking stub section.  We
  53      can't do it until later if we have dynamic sections, though.  */
  54   if (! elf_hash_table (&link_info)->dynamic_sections_created)
  55     {
  56       /* Here we rummage through the found bfds to collect information.  */
  57       LANG_FOR_EACH_INPUT_STATEMENT (is)
  58       {
  59         /* Initialise mapping tables for code/data.  */
  60         bfd_elf${ELFSIZE}_aarch64_init_maps (is->the_bfd);
  61       }
  62     }
  63
  64   /* Call the standard elf routine.  */
  65   gld${EMULATION_NAME}_before_allocation ();
  66 }
  67
  68 /* Fake input file for stubs.  */
  69 static lang_input_statement_type *stub_file;
  70
  71 /* Whether we need to call gldarm_layout_sections_again.  */
  72 static int need_laying_out = 0;
  73
  74 /* Maximum size of a group of input sections that can be handled by
  75    one stub section.  A value of +/-1 indicates the bfd back-end
  76    should use a suitable default size.  */
  77 static bfd_signed_vma group_size = 1;
  78
  79 struct hook_stub_info
  80 {
  81   lang_statement_list_type add;
  82   asection *input_section;
  83 };
  84
  85 /* Traverse the linker tree to find the spot where the stub goes.  */
  86
  87 static bfd_boolean
  88 hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
  89 {
  90   lang_statement_union_type *l;
  91   bfd_boolean ret;
  92
  93   for (; (l = *lp) != NULL; lp = &l->header.next)
  94     {
  95       switch (l->header.type)
  96         {
  97         case lang_constructors_statement_enum:
  98           ret = hook_in_stub (info, &constructor_list.head);
  99           if (ret)
 100             return ret;
 101           break;
 102
 103         case lang_output_section_statement_enum:
 104           ret = hook_in_stub (info,
 105                               &l->output_section_statement.children.head);
 106           if (ret)
 107             return ret;
 108           break;
 109
 110         case lang_wild_statement_enum:
 111           ret = hook_in_stub (info, &l->wild_statement.children.head);
 112           if (ret)
 113             return ret;
 114           break;
 115
 116         case lang_group_statement_enum:
 117           ret = hook_in_stub (info, &l->group_statement.children.head);
 118           if (ret)
 119             return ret;
 120           break;
 121
 122         case lang_input_section_enum:
 123           if (l->input_section.section == info->input_section)
 124             {
 125               /* We've found our section.  Insert the stub immediately
 126                  after its associated input section.  */
 127               *(info->add.tail) = l->header.next;
 128               l->header.next = info->add.head;
 129               return TRUE;
 130             }
 131           break;
 132
 133         case lang_data_statement_enum:
 134         case lang_reloc_statement_enum:
 135         case lang_object_symbols_statement_enum:
 136         case lang_output_statement_enum:
 137         case lang_target_statement_enum:
 138         case lang_input_statement_enum:
 139         case lang_assignment_statement_enum:
 140         case lang_padding_statement_enum:
 141         case lang_address_statement_enum:
 142         case lang_fill_statement_enum:
 143           break;
 144
 145         default:
 146           FAIL ();
 147           break;
 148         }
 149     }
 150   return FALSE;
 151 }
 152
 153
 154 /* Call-back for elf${ELFSIZE}_aarch64_size_stubs.  */
 155
 156 /* Create a new stub section, and arrange for it to be linked
 157    immediately after INPUT_SECTION.  */
 158
 159 static asection *
 160 elf${ELFSIZE}_aarch64_add_stub_section (const char *stub_sec_name,
 161                                         asection *input_section)
 162 {
 163   asection *stub_sec;
 164   flagword flags;
 165   asection *output_section;
 166   lang_output_section_statement_type *os;
 167   struct hook_stub_info info;
 168
 169   flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
 170            | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
 171   stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
 172                                                  stub_sec_name, flags);
 173   if (stub_sec == NULL)
 174     goto err_ret;
 175
 176   bfd_set_section_alignment (stub_file->the_bfd, stub_sec, 2);
 177
 178   output_section = input_section->output_section;
 179   os = lang_output_section_get (output_section);
 180
 181   info.input_section = input_section;
 182   lang_list_init (&info.add);
 183   lang_add_section (&info.add, stub_sec, NULL, os);
 184
 185   if (info.add.head == NULL)
 186     goto err_ret;
 187
 188   if (hook_in_stub (&info, &os->children.head))
 189     return stub_sec;
 190
 191  err_ret:
 192   einfo (_("%X%P: can not make stub section: %E\n"));
 193   return NULL;
 194 }
 195
 196 /* Another call-back for elf${ELFSIZE}_aarch64_size_stubs.  */
 197
 198 static void
 199 gldaarch64_layout_sections_again (void)
 200 {
 201   /* If we have changed sizes of the stub sections, then we need
 202      to recalculate all the section offsets.  This may mean we need to
 203      add even more stubs.  */
 204   gld${EMULATION_NAME}_map_segments (TRUE);
 205   need_laying_out = -1;
 206 }
 207
 208 static void
 209 build_section_lists (lang_statement_union_type *statement)
 210 {
 211   if (statement->header.type == lang_input_section_enum)
 212     {
 213       asection *i = statement->input_section.section;
 214
 215       if (!((lang_input_statement_type *) i->owner->usrdata)->flags.just_syms
 216           && (i->flags & SEC_EXCLUDE) == 0
 217           && i->output_section != NULL
 218           && i->output_section->owner == link_info.output_bfd)
 219         elf${ELFSIZE}_aarch64_next_input_section (& link_info, i);
 220     }
 221 }
 222
 223 static void
 224 gld${EMULATION_NAME}_after_allocation (void)
 225 {
 226   int ret;
 227
 228   /* bfd_elf32_discard_info just plays with debugging sections,
 229      ie. doesn't affect any code, so we can delay resizing the
 230      sections.  It's likely we'll resize everything in the process of
 231      adding stubs.  */
 232   ret = bfd_elf_discard_info (link_info.output_bfd, & link_info);
 233   if (ret < 0)
 234     {
 235       einfo (_("%X%P: .eh_frame/.stab edit: %E\n"));
 236       return;
 237     }
 238   else if (ret > 0)
 239     need_laying_out = 1;
 240
 241   /* If generating a relocatable output file, then we don't
 242      have to examine the relocs.  */
 243   if (stub_file != NULL && !bfd_link_relocatable (&link_info))
 244     {
 245       ret = elf${ELFSIZE}_aarch64_setup_section_lists (link_info.output_bfd,
 246                                                        &link_info);
 247       if (ret != 0)
 248         {
 249           if (ret < 0)
 250             {
 251               einfo (_("%X%P: could not compute sections lists "
 252                        "for stub generation: %E\n"));
 253               return;
 254             }
 255
 256           lang_for_each_statement (build_section_lists);
 257
 258           /* Call into the BFD backend to do the real work.  */
 259           if (! elf${ELFSIZE}_aarch64_size_stubs (link_info.output_bfd,
 260                                           stub_file->the_bfd,
 261                                           & link_info,
 262                                           group_size,
 263                                           & elf${ELFSIZE}_aarch64_add_stub_section,
 264                                           & gldaarch64_layout_sections_again))
 265             {
 266               einfo (_("%X%P: cannot size stub section: %E\n"));
 267               return;
 268             }
 269         }
 270     }
 271
 272   if (need_laying_out != -1)
 273     gld${EMULATION_NAME}_map_segments (need_laying_out);
 274 }
 275
 276 static void
 277 gld${EMULATION_NAME}_finish (void)
 278 {
 279   if (!bfd_link_relocatable (&link_info))
 280     {
 281       /* Now build the linker stubs.  */
 282       if (stub_file->the_bfd->sections != NULL)
 283         {
 284           if (! elf${ELFSIZE}_aarch64_build_stubs (& link_info))
 285             einfo (_("%X%P: can not build stubs: %E\n"));
 286         }
 287     }
 288
 289   finish_default ();
 290 }
 291
 292 /* This is a convenient point to tell BFD about target specific flags.
 293    After the output has been created, but before inputs are read.  */
 294 static void
 295 aarch64_elf_create_output_section_statements (void)
 296 {
 297   if (strstr (bfd_get_target (link_info.output_bfd), "aarch64") == NULL)
 298     {
 299       /* The arm backend needs special fields in the output hash structure.
 300          These will only be created if the output format is an arm format,
 301          hence we do not support linking and changing output formats at the
 302          same time.  Use a link followed by objcopy to change output formats.  */
 303       einfo (_("%F%X%P: error: Cannot change output format "
 304                "whilst linking AArch64 binaries.\n"));
 305       return;
 306     }
 307
 308   bfd_elf${ELFSIZE}_aarch64_set_options (link_info.output_bfd, &link_info,
 309                                  no_enum_size_warning,
 310                                  no_wchar_size_warning,
 311                                  pic_veneer,
 312                                  fix_erratum_835769, fix_erratum_843419,
 313                                  no_apply_dynamic_relocs);
 314
 315   stub_file = lang_add_input_file ("linker stubs",
 316                                    lang_input_file_is_fake_enum,
 317                                    NULL);
 318   stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
 319   if (stub_file->the_bfd == NULL
 320       || ! bfd_set_arch_mach (stub_file->the_bfd,
 321                               bfd_get_arch (link_info.output_bfd),
 322                               bfd_get_mach (link_info.output_bfd)))
 323     {
 324       einfo (_("%X%P: can not create BFD %E\n"));
 325       return;
 326     }
 327
 328   stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
 329   ldlang_add_file (stub_file);
 330 }
 331
 332 /* Avoid processing the fake stub_file in vercheck, stat_needed and
 333    check_needed routines.  */
 334
 335 static void (*real_func) (lang_input_statement_type *);
 336
 337 static void aarch64_for_each_input_file_wrapper (lang_input_statement_type *l)
 338 {
 339   if (l != stub_file)
 340     (*real_func) (l);
 341 }
 342
 343 static void
 344 aarch64_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
 345 {
 346   real_func = func;
 347   lang_for_each_input_file (&aarch64_for_each_input_file_wrapper);
 348 }
 349
 350 #define lang_for_each_input_file aarch64_lang_for_each_input_file
 351
 352 EOF
 353
 354 # Define some shell vars to insert bits of code into the standard elf
 355 # parse_args and list_options functions.
 356 #
 357 PARSE_AND_LIST_PROLOGUE='
 358 #define OPTION_NO_ENUM_SIZE_WARNING     309
 359 #define OPTION_PIC_VENEER               310
 360 #define OPTION_STUBGROUP_SIZE           311
 361 #define OPTION_NO_WCHAR_SIZE_WARNING    312
 362 #define OPTION_FIX_ERRATUM_835769       313
 363 #define OPTION_FIX_ERRATUM_843419       314
 364 #define OPTION_NO_APPLY_DYNAMIC_RELOCS  315
 365 '
 366
 367 PARSE_AND_LIST_SHORTOPTS=p
 368
 369 PARSE_AND_LIST_LONGOPTS='
 370   { "no-pipeline-knowledge", no_argument, NULL, '\'p\''},
 371   { "no-enum-size-warning", no_argument, NULL, OPTION_NO_ENUM_SIZE_WARNING},
 372   { "pic-veneer", no_argument, NULL, OPTION_PIC_VENEER},
 373   { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
 374   { "no-wchar-size-warning", no_argument, NULL, OPTION_NO_WCHAR_SIZE_WARNING},
 375   { "fix-cortex-a53-835769", no_argument, NULL, OPTION_FIX_ERRATUM_835769},
 376   { "fix-cortex-a53-843419", no_argument, NULL, OPTION_FIX_ERRATUM_843419},
 377   { "no-apply-dynamic-relocs", no_argument, NULL, OPTION_NO_APPLY_DYNAMIC_RELOCS},
 378 '
 379
 380 PARSE_AND_LIST_OPTIONS='
 381   fprintf (file, _("  --no-enum-size-warning      Don'\''t warn about objects with incompatible\n"
 382                    "                                enum sizes\n"));
 383   fprintf (file, _("  --no-wchar-size-warning     Don'\''t warn about objects with incompatible"
 384                    "                                wchar_t sizes\n"));
 385   fprintf (file, _("  --pic-veneer                Always generate PIC interworking veneers\n"));
 386   fprintf (file, _("\
 387    --stub-group-size=N   Maximum size of a group of input sections that can be\n\
 388                            handled by one stub section.  A negative value\n\
 389                            locates all stubs after their branches (with a\n\
 390                            group size of -N), while a positive value allows\n\
 391                            two groups of input sections, one before, and one\n\
 392                            after each stub section.  Values of +/-1 indicate\n\
 393                            the linker should choose suitable defaults.\n"
 394                    ));
 395   fprintf (file, _("  --fix-cortex-a53-835769      Fix erratum 835769\n"));
 396   fprintf (file, _("  --fix-cortex-a53-843419      Fix erratum 843419\n"));
 397   fprintf (file, _("  --no-apply-dynamic-relocs    Do not apply link-time values for dynamic relocations\n"));
 398 '
 399
 400 PARSE_AND_LIST_ARGS_CASES='
 401     case '\'p\'':
 402       /* Only here for backwards compatibility.  */
 403       break;
 404
 405     case OPTION_NO_ENUM_SIZE_WARNING:
 406       no_enum_size_warning = 1;
 407       break;
 408
 409     case OPTION_NO_WCHAR_SIZE_WARNING:
 410       no_wchar_size_warning = 1;
 411       break;
 412
 413     case OPTION_PIC_VENEER:
 414       pic_veneer = 1;
 415       break;
 416
 417     case OPTION_FIX_ERRATUM_835769:
 418       fix_erratum_835769 = 1;
 419       break;
 420
 421     case OPTION_FIX_ERRATUM_843419:
 422       fix_erratum_843419 = 1;
 423       break;
 424
 425     case OPTION_NO_APPLY_DYNAMIC_RELOCS:
 426       no_apply_dynamic_relocs = 1;
 427       break;
 428
 429     case OPTION_STUBGROUP_SIZE:
 430       {
 431         const char *end;
 432
 433         group_size = bfd_scan_vma (optarg, &end, 0);
 434         if (*end)
 435           einfo (_("%P%F: invalid number `%s'\''\n"), optarg);
 436       }
 437       break;
 438 '
 439
 440 # We have our own before_allocation etc. functions, but they call
 441 # the standard routines, so give them a different name.
 442 LDEMUL_BEFORE_ALLOCATION=aarch64_elf_before_allocation
 443 LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
 444 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=aarch64_elf_create_output_section_statements
 445
 446 # Replace the elf before_parse function with our own.
 447 LDEMUL_BEFORE_PARSE=gld"${EMULATION_NAME}"_before_parse
 448
 449 # Call the extra arm-elf function
 450 LDEMUL_FINISH=gld${EMULATION_NAME}_finish