ld/emultempl/m68kelf.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright 2000, 2001, 2003, 2005, 2007, 2008, 2009
   3 #   Free Software Foundation, Inc.
   4 #   Written by Michael Sokolov <msokolov@ivan.Harhan.ORG>, based on armelf.em
   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 some extra routines for m68k
  25 # embedded systems using ELF and for some other systems using m68k ELF.  While
  26 # it is sourced from elf32.em for all m68k ELF configurations, here we include
  27 # only the features we want depending on the configuration.
  28
  29 case ${target} in
  30   m68*-*-elf)
  31     echo "#define SUPPORT_EMBEDDED_RELOCS" >>e${EMULATION_NAME}.c
  32     ;;
  33 esac
  34
  35 case ${target} in
  36   *-linux*)
  37 # Don't use multi-GOT by default due to glibc linker's assumption
  38 # that GOT pointer points to GOT[0].
  39 #   got_handling_target_default=GOT_HANDLING_MULTIGOT
  40     got_handling_target_default=GOT_HANDLING_SINGLE
  41     ;;
  42   *)
  43     got_handling_target_default=GOT_HANDLING_SINGLE
  44     ;;
  45 esac
  46
  47 fragment <<EOF
  48
  49 #define GOT_HANDLING_SINGLE   (0)
  50 #define GOT_HANDLING_NEGATIVE (1)
  51 #define GOT_HANDLING_MULTIGOT (2)
  52 #define GOT_HANDLING_TARGET_DEFAULT ${got_handling_target_default}
  53
  54 /* How to generate GOT.  */
  55 static int got_handling = GOT_HANDLING_DEFAULT;
  56
  57 #ifdef SUPPORT_EMBEDDED_RELOCS
  58 static void check_sections (bfd *, asection *, void *);
  59 #endif
  60
  61 /* This function is run after all the input files have been opened.  */
  62
  63 static void
  64 m68k_elf_after_open (void)
  65 {
  66   /* Call the standard elf routine.  */
  67   gld${EMULATION_NAME}_after_open ();
  68
  69 #ifdef SUPPORT_EMBEDDED_RELOCS
  70   if (command_line.embedded_relocs
  71       && (! link_info.relocatable))
  72     {
  73       bfd *abfd;
  74
  75       /* In the embedded relocs mode we create a .emreloc section for each
  76          input file with a nonzero .data section.  The BFD backend will fill in
  77          these sections with magic numbers which can be used to relocate the
  78          data section at run time.  */
  79       for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link_next)
  80         {
  81           asection *datasec;
  82
  83           /* As first-order business, make sure that each input BFD is either
  84              COFF or ELF.  We need to call a special BFD backend function to
  85              generate the embedded relocs, and we have such functions only for
  86              COFF and ELF.  */
  87           if (bfd_get_flavour (abfd) != bfd_target_coff_flavour
  88               && bfd_get_flavour (abfd) != bfd_target_elf_flavour)
  89             einfo ("%F%B: all input objects must be COFF or ELF for --embedded-relocs\n");
  90
  91           datasec = bfd_get_section_by_name (abfd, ".data");
  92
  93           /* Note that we assume that the reloc_count field has already
  94              been set up.  We could call bfd_get_reloc_upper_bound, but
  95              that returns the size of a memory buffer rather than a reloc
  96              count.  We do not want to call bfd_canonicalize_reloc,
  97              because although it would always work it would force us to
  98              read in the relocs into BFD canonical form, which would waste
  99              a significant amount of time and memory.  */
 100           if (datasec != NULL && datasec->reloc_count > 0)
 101             {
 102               asection *relsec;
 103
 104               relsec = bfd_make_section_with_flags (abfd, ".emreloc",
 105                                                     (SEC_ALLOC
 106                                                     | SEC_LOAD
 107                                                     | SEC_HAS_CONTENTS
 108                                                     | SEC_IN_MEMORY));
 109               if (relsec == NULL
 110                   || ! bfd_set_section_alignment (abfd, relsec, 2)
 111                   || ! bfd_set_section_size (abfd, relsec,
 112                                              datasec->reloc_count * 12))
 113                 einfo ("%F%B: can not create .emreloc section: %E\n");
 114             }
 115
 116           /* Double check that all other data sections are empty, as is
 117              required for embedded PIC code.  */
 118           bfd_map_over_sections (abfd, check_sections, datasec);
 119         }
 120     }
 121 #endif /* SUPPORT_EMBEDDED_RELOCS */
 122 }
 123
 124 #ifdef SUPPORT_EMBEDDED_RELOCS
 125 /* Check that of the data sections, only the .data section has
 126    relocs.  This is called via bfd_map_over_sections.  */
 127
 128 static void
 129 check_sections (bfd *abfd, asection *sec, void *datasec)
 130 {
 131   if ((bfd_get_section_flags (abfd, sec) & SEC_DATA)
 132       && sec != datasec
 133       && sec->reloc_count != 0)
 134     einfo ("%B%X: section %s has relocs; can not use --embedded-relocs\n",
 135            abfd, bfd_get_section_name (abfd, sec));
 136 }
 137
 138 #endif /* SUPPORT_EMBEDDED_RELOCS */
 139
 140 /* This function is called after the section sizes and offsets have
 141    been set.  */
 142
 143 static void
 144 m68k_elf_after_allocation (void)
 145 {
 146   /* Call the standard elf routine.  */
 147   gld${EMULATION_NAME}_after_allocation ();
 148
 149 #ifdef SUPPORT_EMBEDDED_RELOCS
 150   if (command_line.embedded_relocs
 151       && (! link_info.relocatable))
 152     {
 153       bfd *abfd;
 154
 155       /* If we are generating embedded relocs, call a special BFD backend
 156          routine to do the work.  */
 157       for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link_next)
 158         {
 159           asection *datasec, *relsec;
 160           char *errmsg;
 161
 162           datasec = bfd_get_section_by_name (abfd, ".data");
 163
 164           if (datasec == NULL || datasec->reloc_count == 0)
 165             continue;
 166
 167           relsec = bfd_get_section_by_name (abfd, ".emreloc");
 168           ASSERT (relsec != NULL);
 169
 170           if (bfd_get_flavour (abfd) == bfd_target_coff_flavour)
 171             {
 172               if (! bfd_m68k_coff_create_embedded_relocs (abfd, &link_info,
 173                                                           datasec, relsec,
 174                                                           &errmsg))
 175                 {
 176                   if (errmsg == NULL)
 177                     einfo ("%B%X: can not create runtime reloc information: %E\n",
 178                            abfd);
 179                   else
 180                     einfo ("%X%B: can not create runtime reloc information: %s\n",
 181                            abfd, errmsg);
 182                 }
 183             }
 184           else if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
 185             {
 186               if (! bfd_m68k_elf32_create_embedded_relocs (abfd, &link_info,
 187                                                            datasec, relsec,
 188                                                            &errmsg))
 189                 {
 190                   if (errmsg == NULL)
 191                     einfo ("%B%X: can not create runtime reloc information: %E\n",
 192                            abfd);
 193                   else
 194                     einfo ("%X%B: can not create runtime reloc information: %s\n",
 195                            abfd, errmsg);
 196                 }
 197             }
 198           else
 199             abort ();
 200         }
 201     }
 202 #endif /* SUPPORT_EMBEDDED_RELOCS */
 203 }
 204
 205 /* This is a convenient point to tell BFD about target specific flags.
 206    After the output has been created, but before inputs are read.  */
 207
 208 static void
 209 elf_m68k_create_output_section_statements (void)
 210 {
 211   bfd_elf_m68k_set_target_options (&link_info, got_handling);
 212 }
 213
 214 EOF
 215
 216 # Define some shell vars to insert bits of code into the standard elf
 217 # parse_args and list_options functions.
 218 #
 219 PARSE_AND_LIST_PROLOGUE='
 220 #define OPTION_GOT      301
 221 '
 222
 223 PARSE_AND_LIST_LONGOPTS='
 224   { "got", required_argument, NULL, OPTION_GOT},
 225 '
 226
 227 PARSE_AND_LIST_OPTIONS='
 228   fprintf (file, _("  --got=<type>                Specify GOT handling scheme\n"));
 229 '
 230
 231 PARSE_AND_LIST_ARGS_CASES='
 232     case OPTION_GOT:
 233       if (strcmp (optarg, "target") == 0)
 234         got_handling = GOT_HANDLING_TARGET_DEFAULT;
 235       else if (strcmp (optarg, "single") == 0)
 236         got_handling = 0;
 237       else if (strcmp (optarg, "negative") == 0)
 238         got_handling = 1;
 239       else if (strcmp (optarg, "multigot") == 0)
 240         got_handling = 2;
 241       else
 242         einfo (_("Unrecognized --got argument '\''%s'\''.\n"), optarg);
 243       break;
 244 '
 245
 246 # We have our own after_open and after_allocation functions, but they call
 247 # the standard routines, so give them a different name.
 248 LDEMUL_AFTER_OPEN=m68k_elf_after_open
 249 LDEMUL_AFTER_ALLOCATION=m68k_elf_after_allocation
 250 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=elf_m68k_create_output_section_statements