ld/emultempl/cr16elf.em

   1 # This shell script emits a C file. -*- C -*-
   2 # Copyright (C) 2007-2019 Free Software Foundation, Inc.
   3 # Contributed by M R Swami Reddy <MR.Swami.Reddy@nsc.com>
   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 elf.em, and defines extra cr16-elf
  24 # specific routines.
  25 #
  26 fragment <<EOF
  27
  28 #include "ldctor.h"
  29
  30 static void check_sections (bfd *, asection *, void *);
  31
  32
  33 /* This function is run after all the input files have been opened.  */
  34
  35 static void
  36 cr16_elf_after_open (void)
  37 {
  38   /* Call the standard elf routine.  */
  39   gld${EMULATION_NAME}_after_open ();
  40
  41   if (command_line.embedded_relocs
  42       && !bfd_link_relocatable (&link_info))
  43     {
  44       bfd *abfd;
  45
  46       /* In the embedded relocs mode we create a .emreloc section for each
  47          input file with a nonzero .data section.  The BFD backend will fill in
  48          these sections with magic numbers which can be used to relocate the
  49          data section at run time.  */
  50       for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link.next)
  51         {
  52           asection *datasec;
  53
  54           /* As first-order business, make sure that each input BFD is either
  55              COFF or ELF.  We need to call a special BFD backend function to
  56              generate the embedded relocs, and we have such functions only for
  57              COFF and ELF.  */
  58           if (bfd_get_flavour (abfd) != bfd_target_coff_flavour
  59               && bfd_get_flavour (abfd) != bfd_target_elf_flavour)
  60             einfo (_("%F%P: %pB: all input objects must be COFF or ELF "
  61                      "for --embedded-relocs\n"));
  62
  63           datasec = bfd_get_section_by_name (abfd, ".data.rel");
  64
  65           /* Note that we assume that the reloc_count field has already
  66              been set up.  We could call bfd_get_reloc_upper_bound, but
  67              that returns the size of a memory buffer rather than a reloc
  68              count.  We do not want to call bfd_canonicalize_reloc,
  69              because although it would always work it would force us to
  70              read in the relocs into BFD canonical form, which would waste
  71              a significant amount of time and memory.  */
  72           if (datasec != NULL && datasec->reloc_count > 0)
  73             {
  74               asection *relsec;
  75
  76               relsec = bfd_make_section (abfd, ".emreloc");
  77               if (relsec == NULL
  78                   || !bfd_set_section_flags (relsec, (SEC_ALLOC
  79                                                       | SEC_LOAD
  80                                                       | SEC_HAS_CONTENTS
  81                                                       | SEC_IN_MEMORY))
  82                   || !bfd_set_section_alignment (relsec, 2)
  83                   || !bfd_set_section_size (relsec, datasec->reloc_count * 8))
  84                 einfo (_("%F%P: %pB: can not create .emreloc section: %E\n"));
  85             }
  86
  87           /* Double check that all other data sections are empty, as is
  88              required for embedded PIC code.  */
  89           bfd_map_over_sections (abfd, check_sections, datasec);
  90         }
  91     }
  92 }
  93
  94 /* Check that of the data sections, only the .data section has
  95    relocs.  This is called via bfd_map_over_sections.  */
  96
  97 static void
  98 check_sections (bfd *abfd, asection *sec, void *datasec)
  99 {
 100   if ((strncmp (bfd_section_name (sec), ".data.rel", 9) == 0)
 101       && sec != datasec
 102       && sec->reloc_count == 0 )
 103     einfo (_("%X%P: %pB: section %s has relocs; can not use --embedded-relocs\n"),
 104            abfd, bfd_section_name (sec));
 105 }
 106
 107 static void
 108 cr16elf_after_parse (void)
 109 {
 110   /* Always behave as if called with --sort-common command line
 111      option.
 112      This is to emulate the CRTools' method of keeping variables
 113      of different alignment in separate sections.  */
 114   config.sort_common = TRUE;
 115
 116   /* Don't create a demand-paged executable, since this feature isn't
 117      meaninful in CR16 embedded systems. Moreover, when magic_demand_paged
 118      is true the link sometimes fails.  */
 119   config.magic_demand_paged = FALSE;
 120
 121   ldelf_after_parse ();
 122 }
 123
 124 /* This is called after the sections have been attached to output
 125    sections, but before any sizes or addresses have been set.  */
 126
 127 static void
 128 cr16elf_before_allocation (void)
 129 {
 130   /* Call the default first.  */
 131   gld${EMULATION_NAME}_before_allocation ();
 132
 133   if (command_line.embedded_relocs
 134       && (!bfd_link_relocatable (&link_info)))
 135     {
 136
 137       bfd *abfd;
 138
 139       /* If we are generating embedded relocs, call a special BFD backend
 140          routine to do the work.  */
 141       for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link.next)
 142         {
 143           asection *datasec, *relsec;
 144           char *errmsg;
 145
 146           datasec = bfd_get_section_by_name (abfd, ".data.rel");
 147
 148           if (datasec == NULL || datasec->reloc_count == 0)
 149             continue;
 150
 151           relsec = bfd_get_section_by_name (abfd, ".emreloc");
 152           ASSERT (relsec != NULL);
 153
 154           if (! bfd_cr16_elf32_create_embedded_relocs (abfd, &link_info,
 155                                                        datasec, relsec,
 156                                                        &errmsg))
 157             {
 158               if (errmsg == NULL)
 159                 einfo (_("%X%P: %pB: can not create runtime reloc information: %E\n"),
 160                        abfd);
 161               else
 162                 einfo (_("%X%P: %pB: can not create runtime reloc information: %s\n"),
 163                        abfd, errmsg);
 164             }
 165         }
 166     }
 167
 168   /* Enable relaxation by default if the "--no-relax" option was not
 169      specified.  This is done here instead of in the before_parse hook
 170      because there is a check in main() to prohibit use of --relax and
 171      -r together.  */
 172   if (RELAXATION_DISABLED_BY_DEFAULT)
 173     ENABLE_RELAXATION;
 174 }
 175
 176 EOF
 177
 178 # Put these extra cr16-elf routines in ld_${EMULATION_NAME}_emulation
 179 #
 180 LDEMUL_AFTER_OPEN=cr16_elf_after_open
 181 LDEMUL_AFTER_PARSE=cr16elf_after_parse
 182 LDEMUL_BEFORE_ALLOCATION=cr16elf_before_allocation