ld/emultempl/mmo.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright 2001, 2002, 2003, 2004, 2006, 2007, 2008
   3 #   Free Software Foundation, Inc.
   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 generic.em.
  24
  25 fragment <<EOF
  26 /* Need to have this macro defined before mmix-elfnmmo, which uses the
  27    name for the before_allocation function, defined in ldemul.c (for
  28    the mmo "emulation") or in elf32.em (for the elf64mmix
  29    "emulation").  */
  30 #define gldmmo_before_allocation before_allocation_default
  31
  32 /* We include this header *not* because we expect to handle ELF here
  33    but because we re-use the map_segments function in elf-generic.em,
  34    a file which is rightly somewhat ELF-centric.  But this is only to
  35    get a weird testcase right; ld-mmix/bpo-22, forcing ELF to be
  36    output from the mmo emulation: -m mmo --oformat elf64-mmix!  */
  37 #include "elf-bfd.h"
  38 EOF
  39
  40 source_em ${srcdir}/emultempl/elf-generic.em
  41 source_em ${srcdir}/emultempl/mmix-elfnmmo.em
  42
  43 fragment <<EOF
  44
  45 /* Place an orphan section.  We use this to put random SEC_CODE or
  46    SEC_READONLY sections right after MMO_TEXT_SECTION_NAME.  Much borrowed
  47    from elf32.em.  */
  48
  49 static bfd_boolean
  50 mmo_place_orphan (asection *s)
  51 {
  52   static struct orphan_save hold_text =
  53     {
  54       MMO_TEXT_SECTION_NAME,
  55       SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE,
  56       0, 0, 0, 0
  57     };
  58   struct orphan_save *place;
  59   const char *secname;
  60   lang_output_section_statement_type *after;
  61   lang_output_section_statement_type *os;
  62
  63   /* We have nothing to say for anything other than a final link.  */
  64   if (link_info.relocatable
  65       || (s->flags & (SEC_EXCLUDE | SEC_LOAD)) != SEC_LOAD)
  66     return FALSE;
  67
  68   /* Only care for sections we're going to load.  */
  69   secname = s->name;
  70   os = lang_output_section_find (secname);
  71
  72   /* We have an output section by this name.  Place the section inside it
  73      (regardless of whether the linker script lists it as input).  */
  74   if (os != NULL)
  75     {
  76       lang_add_section (&os->children, s, os);
  77       return TRUE;
  78     }
  79
  80   /* If this section does not have .text-type section flags or there's no
  81      MMO_TEXT_SECTION_NAME, we don't have anything to say.  */
  82   if ((s->flags & (SEC_CODE | SEC_READONLY)) == 0)
  83     return FALSE;
  84
  85   if (hold_text.os == NULL)
  86     hold_text.os = lang_output_section_find (hold_text.name);
  87
  88   place = &hold_text;
  89   if (hold_text.os != NULL)
  90     after = hold_text.os;
  91   else
  92     after = &lang_output_section_statement.head->output_section_statement;
  93
  94   /* If there's an output section by this name, we'll use it, regardless
  95      of section flags, in contrast to what's done in elf32.em.  */
  96   os = lang_insert_orphan (s, secname, after, place, NULL, NULL);
  97
  98   /* We need an output section for .text as a root, so if there was none
  99      (might happen with a peculiar linker script such as in "map
 100      addresses", map-address.exp), we grab the output section created
 101      above.  */
 102   if (hold_text.os == NULL)
 103     hold_text.os = os;
 104
 105   return TRUE;
 106 }
 107
 108 /* Remove the spurious settings of SEC_RELOC that make it to the output at
 109    link time.  We are as confused as elflink.h:elf_bfd_final_link, and
 110    paper over the bug similarly.  */
 111
 112 static void
 113 mmo_wipe_sec_reloc_flag (bfd *abfd, asection *sec, void *ptr ATTRIBUTE_UNUSED)
 114 {
 115   bfd_set_section_flags (abfd, sec,
 116                          bfd_get_section_flags (abfd, sec) & ~SEC_RELOC);
 117 }
 118
 119 /* Iterate with bfd_map_over_sections over mmo_wipe_sec_reloc_flag... */
 120
 121 static void
 122 mmo_finish (void)
 123 {
 124   bfd_map_over_sections (link_info.output_bfd, mmo_wipe_sec_reloc_flag, NULL);
 125   gld${EMULATION_NAME}_map_segments (FALSE);
 126   finish_default ();
 127 }
 128 \f
 129 /* To get on-demand global register allocation right, we need to parse the
 130    relocs, like what happens when linking to ELF.  It needs to be done
 131    before all input sections are supposed to be present.  When linking to
 132    ELF, it's done when reading symbols.  When linking to mmo, we do it
 133    when all input files are seen, which is equivalent.  */
 134
 135 static void
 136 mmo_after_open (void)
 137 {
 138   /* When there's a mismatch between the output format and the emulation
 139      (using weird combinations like "-m mmo --oformat elf64-mmix" for
 140      example), we'd count relocs twice because they'd also be counted
 141      along the usual route for ELF-only linking, which would lead to an
 142      internal accounting error.  */
 143   if (bfd_get_flavour (link_info.output_bfd) != bfd_target_elf_flavour)
 144     {
 145       LANG_FOR_EACH_INPUT_STATEMENT (is)
 146         {
 147           if (bfd_get_flavour (is->the_bfd) == bfd_target_elf_flavour
 148               && !_bfd_mmix_check_all_relocs (is->the_bfd, &link_info))
 149             einfo ("%X%P: Internal problems scanning %B after opening it",
 150                    is->the_bfd);
 151         }
 152     }
 153 }
 154 EOF
 155
 156 LDEMUL_PLACE_ORPHAN=mmo_place_orphan
 157 LDEMUL_FINISH=mmo_finish
 158 LDEMUL_AFTER_OPEN=mmo_after_open