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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19 #
  20
  21 # This file is sourced from elf32.em and mmo.em, used to define
  22 # linker MMIX-specifics common to ELF and MMO.
  23
  24 cat >>e${EMULATION_NAME}.c <<EOF
  25 /* Need to have this define before mmix-elfnmmo, which includes
  26    needrelax.em which uses this name for the before_allocation function,
  27    normally defined in elf32.em.  */
  28 #define gldmmo_before_allocation before_allocation_default
  29 EOF
  30
  31 . ${srcdir}/emultempl/mmix-elfnmmo.em
  32
  33 cat >>e${EMULATION_NAME}.c <<EOF
  34
  35 /* Place an orphan section.  We use this to put random SEC_CODE or
  36    SEC_READONLY sections right after MMO_TEXT_SECTION_NAME.  Much borrowed
  37    from elf32.em.  */
  38
  39 static bfd_boolean
  40 mmo_place_orphan (lang_input_statement_type *file, asection *s)
  41 {
  42   static struct orphan_save hold_text =
  43     {
  44       MMO_TEXT_SECTION_NAME,
  45       SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE,
  46       0, 0, 0, 0
  47     };
  48   struct orphan_save *place;
  49   const char *secname;
  50   lang_output_section_statement_type *after;
  51   lang_output_section_statement_type *os;
  52
  53   /* We have nothing to say for anything other than a final link.  */
  54   if (link_info.relocatable
  55       || (s->flags & (SEC_EXCLUDE | SEC_LOAD)) != SEC_LOAD)
  56     return FALSE;
  57
  58   /* Only care for sections we're going to load.  */
  59   secname = s->name;
  60   os = lang_output_section_find (secname);
  61
  62   /* We have an output section by this name.  Place the section inside it
  63      (regardless of whether the linker script lists it as input).  */
  64   if (os != NULL)
  65     {
  66       lang_add_section (&os->children, s, os, file);
  67       return TRUE;
  68     }
  69
  70   /* If this section does not have .text-type section flags or there's no
  71      MMO_TEXT_SECTION_NAME, we don't have anything to say.  */
  72   if ((s->flags & (SEC_CODE | SEC_READONLY)) == 0)
  73     return FALSE;
  74
  75   if (hold_text.os == NULL)
  76     hold_text.os = lang_output_section_find (hold_text.name);
  77
  78   place = &hold_text;
  79   if (hold_text.os != NULL)
  80     after = hold_text.os;
  81   else
  82     after = &lang_output_section_statement.head->output_section_statement;
  83
  84   /* If there's an output section by this name, we'll use it, regardless
  85      of section flags, in contrast to what's done in elf32.em.  */
  86   os = lang_insert_orphan (file, s, secname, after, place, NULL, NULL);
  87
  88   /* We need an output section for .text as a root, so if there was none
  89      (might happen with a peculiar linker script such as in "map
  90      addresses", map-address.exp), we grab the output section created
  91      above.  */
  92   if (hold_text.os == NULL)
  93     hold_text.os = os;
  94
  95   return TRUE;
  96 }
  97
  98 /* Remove the spurious settings of SEC_RELOC that make it to the output at
  99    link time.  We are as confused as elflink.h:elf_bfd_final_link, and
 100    paper over the bug similarly.  */
 101
 102 static void
 103 mmo_wipe_sec_reloc_flag (bfd *abfd, asection *sec, void *ptr ATTRIBUTE_UNUSED)
 104 {
 105   bfd_set_section_flags (abfd, sec,
 106                          bfd_get_section_flags (abfd, sec) & ~SEC_RELOC);
 107 }
 108
 109 /* Iterate with bfd_map_over_sections over mmo_wipe_sec_reloc_flag... */
 110
 111 static void
 112 mmo_finish (void)
 113 {
 114   bfd_map_over_sections (output_bfd, mmo_wipe_sec_reloc_flag, NULL);
 115 }
 116 \f
 117 /* To get on-demand global register allocation right, we need to parse the
 118    relocs, like what happens when linking to ELF.  It needs to be done
 119    before all input sections are supposed to be present.  When linking to
 120    ELF, it's done when reading symbols.  When linking to mmo, we do it
 121    when all input files are seen, which is equivalent.  */
 122
 123 static void
 124 mmo_after_open (void)
 125 {
 126   /* When there's a mismatch between the output format and the emulation
 127      (using weird combinations like "-m mmo --oformat elf64-mmix" for
 128      example), we'd count relocs twice because they'd also be counted
 129      along the usual route for ELF-only linking, which would lead to an
 130      internal accounting error.  */
 131   if (bfd_get_flavour (output_bfd) != bfd_target_elf_flavour)
 132     {
 133       LANG_FOR_EACH_INPUT_STATEMENT (is)
 134         {
 135           if (bfd_get_flavour (is->the_bfd) == bfd_target_elf_flavour
 136               && !_bfd_mmix_check_all_relocs (is->the_bfd, &link_info))
 137             einfo ("%X%P: Internal problems scanning %B after opening it",
 138                    is->the_bfd);
 139         }
 140     }
 141 }
 142 EOF
 143
 144 LDEMUL_PLACE_ORPHAN=mmo_place_orphan
 145 LDEMUL_FINISH=mmo_finish
 146 LDEMUL_AFTER_OPEN=mmo_after_open