ld/emultempl/mipself.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright (C) 2004-2017 Free Software Foundation, Inc.
   3 #
   4 # This file is part of the GNU Binutils.
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  19 # MA 02110-1301, USA.
  20
  21 fragment <<EOF
  22
  23 #include "ldctor.h"
  24 #include "elf/mips.h"
  25 #include "elfxx-mips.h"
  26
  27 #define is_mips_elf(bfd)                                \
  28   (bfd_get_flavour (bfd) == bfd_target_elf_flavour      \
  29    && elf_tdata (bfd) != NULL                           \
  30    && elf_object_id (bfd) == MIPS_ELF_DATA)
  31
  32 /* Fake input file for stubs.  */
  33 static lang_input_statement_type *stub_file;
  34 static bfd *stub_bfd;
  35
  36 static bfd_boolean insn32;
  37
  38 static void
  39 mips_after_parse (void)
  40 {
  41   /* .gnu.hash and the MIPS ABI require .dynsym to be sorted in different
  42      ways.  .gnu.hash needs symbols to be grouped by hash code whereas the
  43      MIPS ABI requires a mapping between the GOT and the symbol table.  */
  44   if (link_info.emit_gnu_hash)
  45     {
  46       einfo ("%X%P: .gnu.hash is incompatible with the MIPS ABI\n");
  47       link_info.emit_hash = TRUE;
  48       link_info.emit_gnu_hash = FALSE;
  49     }
  50   gld${EMULATION_NAME}_after_parse ();
  51 }
  52
  53 struct hook_stub_info
  54 {
  55   lang_statement_list_type add;
  56   asection *input_section;
  57 };
  58
  59 /* Traverse the linker tree to find the spot where the stub goes.  */
  60
  61 static bfd_boolean
  62 hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
  63 {
  64   lang_statement_union_type *l;
  65   bfd_boolean ret;
  66
  67   for (; (l = *lp) != NULL; lp = &l->header.next)
  68     {
  69       switch (l->header.type)
  70         {
  71         case lang_constructors_statement_enum:
  72           ret = hook_in_stub (info, &constructor_list.head);
  73           if (ret)
  74             return ret;
  75           break;
  76
  77         case lang_output_section_statement_enum:
  78           ret = hook_in_stub (info,
  79                               &l->output_section_statement.children.head);
  80           if (ret)
  81             return ret;
  82           break;
  83
  84         case lang_wild_statement_enum:
  85           ret = hook_in_stub (info, &l->wild_statement.children.head);
  86           if (ret)
  87             return ret;
  88           break;
  89
  90         case lang_group_statement_enum:
  91           ret = hook_in_stub (info, &l->group_statement.children.head);
  92           if (ret)
  93             return ret;
  94           break;
  95
  96         case lang_input_section_enum:
  97           if (info->input_section == NULL
  98               || l->input_section.section == info->input_section)
  99             {
 100               /* We've found our section.  Insert the stub immediately
 101                  before its associated input section.  */
 102               *lp = info->add.head;
 103               *(info->add.tail) = l;
 104               return TRUE;
 105             }
 106           break;
 107
 108         case lang_data_statement_enum:
 109         case lang_reloc_statement_enum:
 110         case lang_object_symbols_statement_enum:
 111         case lang_output_statement_enum:
 112         case lang_target_statement_enum:
 113         case lang_input_statement_enum:
 114         case lang_assignment_statement_enum:
 115         case lang_padding_statement_enum:
 116         case lang_address_statement_enum:
 117         case lang_fill_statement_enum:
 118           break;
 119
 120         default:
 121           FAIL ();
 122           break;
 123         }
 124     }
 125   return FALSE;
 126 }
 127
 128 /* Create a new stub section called STUB_SEC_NAME and arrange for it to
 129    be linked in OUTPUT_SECTION.  The section should go at the beginning of
 130    OUTPUT_SECTION if INPUT_SECTION is null, otherwise it must go immediately
 131    before INPUT_SECTION.  */
 132
 133 static asection *
 134 mips_add_stub_section (const char *stub_sec_name, asection *input_section,
 135                        asection *output_section)
 136 {
 137   asection *stub_sec;
 138   flagword flags;
 139   lang_output_section_statement_type *os;
 140   struct hook_stub_info info;
 141
 142   /* PR 12845: If the input section has been garbage collected it will
 143      not have its output section set to *ABS*.  */
 144   if (bfd_is_abs_section (output_section))
 145     return NULL;
 146
 147   /* Create the stub file, if we haven't already.  */
 148   if (stub_file == NULL)
 149     {
 150       stub_file = lang_add_input_file ("linker stubs",
 151                                        lang_input_file_is_fake_enum,
 152                                        NULL);
 153       stub_bfd = bfd_create ("linker stubs", link_info.output_bfd);
 154       if (stub_bfd == NULL
 155           || !bfd_set_arch_mach (stub_bfd,
 156                                  bfd_get_arch (link_info.output_bfd),
 157                                  bfd_get_mach (link_info.output_bfd)))
 158         {
 159           einfo ("%F%P: can not create BFD %E\n");
 160           return NULL;
 161         }
 162       stub_bfd->flags |= BFD_LINKER_CREATED;
 163       stub_file->the_bfd = stub_bfd;
 164       ldlang_add_file (stub_file);
 165     }
 166
 167   /* Create the section.  */
 168   stub_sec = bfd_make_section_anyway (stub_bfd, stub_sec_name);
 169   if (stub_sec == NULL)
 170     goto err_ret;
 171
 172   /* Set the flags.  */
 173   flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
 174            | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_KEEP);
 175   if (!bfd_set_section_flags (stub_bfd, stub_sec, flags))
 176     goto err_ret;
 177
 178   os = lang_output_section_get (output_section);
 179
 180   /* Initialize a statement list that contains only the new statement.  */
 181   lang_list_init (&info.add);
 182   lang_add_section (&info.add, stub_sec, NULL, os);
 183   if (info.add.head == NULL)
 184     goto err_ret;
 185
 186   /* Insert the new statement in the appropriate place.  */
 187   info.input_section = input_section;
 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 /* This is called before the input files are opened.  */
 197
 198 static void
 199 mips_create_output_section_statements (void)
 200 {
 201   struct elf_link_hash_table *htab;
 202
 203   htab = elf_hash_table (&link_info);
 204   if (is_elf_hash_table (htab) && is_mips_elf (link_info.output_bfd))
 205     _bfd_mips_elf_insn32 (&link_info, insn32);
 206
 207   if (is_mips_elf (link_info.output_bfd))
 208     _bfd_mips_elf_init_stubs (&link_info, mips_add_stub_section);
 209 }
 210
 211 /* This is called after we have merged the private data of the input bfds.  */
 212
 213 static void
 214 mips_before_allocation (void)
 215 {
 216   flagword flags;
 217
 218   flags = elf_elfheader (link_info.output_bfd)->e_flags;
 219   if (!bfd_link_pic (&link_info)
 220       && !link_info.nocopyreloc
 221       && (flags & (EF_MIPS_PIC | EF_MIPS_CPIC)) == EF_MIPS_CPIC)
 222     _bfd_mips_elf_use_plts_and_copy_relocs (&link_info);
 223
 224   gld${EMULATION_NAME}_before_allocation ();
 225 }
 226
 227 /* Avoid processing the fake stub_file in vercheck, stat_needed and
 228    check_needed routines.  */
 229
 230 static void (*real_func) (lang_input_statement_type *);
 231
 232 static void mips_for_each_input_file_wrapper (lang_input_statement_type *l)
 233 {
 234   if (l != stub_file)
 235     (*real_func) (l);
 236 }
 237
 238 static void
 239 mips_lang_for_each_input_file (void (*func) (lang_input_statement_type *))
 240 {
 241   real_func = func;
 242   lang_for_each_input_file (&mips_for_each_input_file_wrapper);
 243 }
 244
 245 #define lang_for_each_input_file mips_lang_for_each_input_file
 246
 247 EOF
 248
 249 # Define some shell vars to insert bits of code into the standard elf
 250 # parse_args and list_options functions.
 251 #
 252 PARSE_AND_LIST_PROLOGUE='
 253 enum
 254   {
 255     OPTION_INSN32 = 301,
 256     OPTION_NO_INSN32
 257   };
 258 '
 259
 260 PARSE_AND_LIST_LONGOPTS='
 261   { "insn32", no_argument, NULL, OPTION_INSN32 },
 262   { "no-insn32", no_argument, NULL, OPTION_NO_INSN32 },
 263 '
 264
 265 PARSE_AND_LIST_OPTIONS='
 266   fprintf (file, _("\
 267   --insn32                    Only generate 32-bit microMIPS instructions\n"
 268                    ));
 269   fprintf (file, _("\
 270   --no-insn32                 Generate all microMIPS instructions\n"
 271                    ));
 272 '
 273
 274 PARSE_AND_LIST_ARGS_CASES='
 275     case OPTION_INSN32:
 276       insn32 = TRUE;
 277       break;
 278
 279     case OPTION_NO_INSN32:
 280       insn32 = FALSE;
 281       break;
 282 '
 283
 284 LDEMUL_AFTER_PARSE=mips_after_parse
 285 LDEMUL_BEFORE_ALLOCATION=mips_before_allocation
 286 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=mips_create_output_section_statements