ld/emultempl/mmo.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
   3 #
   4 # This file is part of GLD, the Gnu Linker.
   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 2 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, MA 02110-1301, USA.
  19 #
  20
  21 # This file is sourced from generic.em
  22
  23 cat >>e${EMULATION_NAME}.c <<EOF
  24 /* Need to have this define before mmix-elfnmmo, which includes
  25    needrelax.em which uses this name for the before_allocation function,
  26    normally defined in elf32.em.  */
  27 #define gldmmo_before_allocation before_allocation_default
  28
  29 #include "elf-bfd.h"
  30 EOF
  31
  32 . ${srcdir}/emultempl/elf-generic.em
  33 . ${srcdir}/emultempl/mmix-elfnmmo.em
  34
  35 cat >>e${EMULATION_NAME}.c <<EOF
  36
  37 /* Place an orphan section.  We use this to put random SEC_CODE or
  38    SEC_READONLY sections right after MMO_TEXT_SECTION_NAME.  Much borrowed
  39    from elf32.em.  */
  40
  41 static bfd_boolean
  42 mmo_place_orphan (asection *s)
  43 {
  44   static struct orphan_save hold_text =
  45     {
  46       MMO_TEXT_SECTION_NAME,
  47       SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE,
  48       0, 0, 0, 0
  49     };
  50   struct orphan_save *place;
  51   const char *secname;
  52   lang_output_section_statement_type *after;
  53   lang_output_section_statement_type *os;
  54
  55   /* We have nothing to say for anything other than a final link.  */
  56   if (link_info.relocatable
  57       || (s->flags & (SEC_EXCLUDE | SEC_LOAD)) != SEC_LOAD)
  58     return FALSE;
  59
  60   /* Only care for sections we're going to load.  */
  61   secname = s->name;
  62   os = lang_output_section_find (secname);
  63
  64   /* We have an output section by this name.  Place the section inside it
  65      (regardless of whether the linker script lists it as input).  */
  66   if (os != NULL)
  67     {
  68       lang_add_section (&os->children, s, os);
  69       return TRUE;
  70     }
  71
  72   /* If this section does not have .text-type section flags or there's no
  73      MMO_TEXT_SECTION_NAME, we don't have anything to say.  */
  74   if ((s->flags & (SEC_CODE | SEC_READONLY)) == 0)
  75     return FALSE;
  76
  77   if (hold_text.os == NULL)
  78     hold_text.os = lang_output_section_find (hold_text.name);
  79
  80   place = &hold_text;
  81   if (hold_text.os != NULL)
  82     after = hold_text.os;
  83   else
  84     after = &lang_output_section_statement.head->output_section_statement;
  85
  86   /* If there's an output section by this name, we'll use it, regardless
  87      of section flags, in contrast to what's done in elf32.em.  */
  88   os = lang_insert_orphan (s, secname, after, place, NULL, NULL);
  89
  90   /* We need an output section for .text as a root, so if there was none
  91      (might happen with a peculiar linker script such as in "map
  92      addresses", map-address.exp), we grab the output section created
  93      above.  */
  94   if (hold_text.os == NULL)
  95     hold_text.os = os;
  96
  97   return TRUE;
  98 }
  99
 100 /* Remove the spurious settings of SEC_RELOC that make it to the output at
 101    link time.  We are as confused as elflink.h:elf_bfd_final_link, and
 102    paper over the bug similarly.  */
 103
 104 static void
 105 mmo_wipe_sec_reloc_flag (bfd *abfd, asection *sec, void *ptr ATTRIBUTE_UNUSED)
 106 {
 107   bfd_set_section_flags (abfd, sec,
 108                          bfd_get_section_flags (abfd, sec) & ~SEC_RELOC);
 109 }
 110
 111 /* Iterate with bfd_map_over_sections over mmo_wipe_sec_reloc_flag... */
 112
 113 static void
 114 mmo_finish (void)
 115 {
 116   bfd_map_over_sections (output_bfd, mmo_wipe_sec_reloc_flag, NULL);
 117   gld${EMULATION_NAME}_map_segments (FALSE);
 118   finish_default ();
 119 }
 120 \f
 121 /* To get on-demand global register allocation right, we need to parse the
 122    relocs, like what happens when linking to ELF.  It needs to be done
 123    before all input sections are supposed to be present.  When linking to
 124    ELF, it's done when reading symbols.  When linking to mmo, we do it
 125    when all input files are seen, which is equivalent.  */
 126
 127 static void
 128 mmo_after_open (void)
 129 {
 130   /* When there's a mismatch between the output format and the emulation
 131      (using weird combinations like "-m mmo --oformat elf64-mmix" for
 132      example), we'd count relocs twice because they'd also be counted
 133      along the usual route for ELF-only linking, which would lead to an
 134      internal accounting error.  */
 135   if (bfd_get_flavour (output_bfd) != bfd_target_elf_flavour)
 136     {
 137       LANG_FOR_EACH_INPUT_STATEMENT (is)
 138         {
 139           if (bfd_get_flavour (is->the_bfd) == bfd_target_elf_flavour
 140               && !_bfd_mmix_check_all_relocs (is->the_bfd, &link_info))
 141             einfo ("%X%P: Internal problems scanning %B after opening it",
 142                    is->the_bfd);
 143         }
 144     }
 145 }
 146 EOF
 147
 148 LDEMUL_PLACE_ORPHAN=mmo_place_orphan
 149 LDEMUL_FINISH=mmo_finish
 150 LDEMUL_AFTER_OPEN=mmo_after_open