ld/emultempl/mmo.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright 2001, 2002, 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
   3 #
   4 # This file is part of the GNU Binutils.
   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 3 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,
  19 # MA 02110-1301, USA.
  20 #
  21
  22 # This file is sourced from generic.em.
  23
  24 fragment <<EOF
  25 /* Need to have this macro defined before mmix-elfnmmo, which uses the
  26    name for the before_allocation function, defined in ldemul.c (for
  27    the mmo "emulation") or in elf32.em (for the elf64mmix
  28    "emulation").  */
  29 #define gldmmo_before_allocation before_allocation_default
  30
  31 /* We include this header *not* because we expect to handle ELF here
  32    but because we re-use the map_segments function in elf-generic.em,
  33    a file which is rightly somewhat ELF-centric.  But this is only to
  34    get a weird testcase right; ld-mmix/bpo-22, forcing ELF to be
  35    output from the mmo emulation: -m mmo --oformat elf64-mmix!  */
  36 #include "elf-bfd.h"
  37 EOF
  38
  39 source_em ${srcdir}/emultempl/elf-generic.em
  40 source_em ${srcdir}/emultempl/mmix-elfnmmo.em
  41
  42 fragment <<EOF
  43
  44 /* Place an orphan section.  We use this to put random SEC_CODE or
  45    SEC_READONLY sections right after MMO_TEXT_SECTION_NAME.  Much borrowed
  46    from elf32.em.  */
  47
  48 static bfd_boolean
  49 mmo_place_orphan (asection *s)
  50 {
  51   static struct orphan_save hold_text =
  52     {
  53       MMO_TEXT_SECTION_NAME,
  54       SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE,
  55       0, 0, 0, 0
  56     };
  57   struct orphan_save *place;
  58   const char *secname;
  59   lang_output_section_statement_type *after;
  60   lang_output_section_statement_type *os;
  61
  62   /* We have nothing to say for anything other than a final link.  */
  63   if (link_info.relocatable
  64       || (s->flags & (SEC_EXCLUDE | SEC_LOAD)) != SEC_LOAD)
  65     return FALSE;
  66
  67   /* Only care for sections we're going to load.  */
  68   secname = s->name;
  69   os = lang_output_section_find (secname);
  70
  71   /* We have an output section by this name.  Place the section inside it
  72      (regardless of whether the linker script lists it as input).  */
  73   if (os != NULL)
  74     {
  75       lang_add_section (&os->children, s, os);
  76       return TRUE;
  77     }
  78
  79   /* If this section does not have .text-type section flags or there's no
  80      MMO_TEXT_SECTION_NAME, we don't have anything to say.  */
  81   if ((s->flags & (SEC_CODE | SEC_READONLY)) == 0)
  82     return FALSE;
  83
  84   if (hold_text.os == NULL)
  85     hold_text.os = lang_output_section_find (hold_text.name);
  86
  87   place = &hold_text;
  88   if (hold_text.os != NULL)
  89     after = hold_text.os;
  90   else
  91     after = &lang_output_section_statement.head->output_section_statement;
  92
  93   /* If there's an output section by this name, we'll use it, regardless
  94      of section flags, in contrast to what's done in elf32.em.  */
  95   os = lang_insert_orphan (s, secname, after, place, NULL, NULL);
  96
  97   /* We need an output section for .text as a root, so if there was none
  98      (might happen with a peculiar linker script such as in "map
  99      addresses", map-address.exp), we grab the output section created
 100      above.  */
 101   if (hold_text.os == NULL)
 102     hold_text.os = os;
 103
 104   return TRUE;
 105 }
 106
 107 /* Remove the spurious settings of SEC_RELOC that make it to the output at
 108    link time.  We are as confused as elflink.h:elf_bfd_final_link, and
 109    paper over the bug similarly.  */
 110
 111 static void
 112 mmo_wipe_sec_reloc_flag (bfd *abfd, asection *sec, void *ptr ATTRIBUTE_UNUSED)
 113 {
 114   bfd_set_section_flags (abfd, sec,
 115                          bfd_get_section_flags (abfd, sec) & ~SEC_RELOC);
 116 }
 117
 118 /* Iterate with bfd_map_over_sections over mmo_wipe_sec_reloc_flag... */
 119
 120 static void
 121 mmo_finish (void)
 122 {
 123   bfd_map_over_sections (output_bfd, mmo_wipe_sec_reloc_flag, NULL);
 124   gld${EMULATION_NAME}_map_segments (FALSE);
 125   finish_default ();
 126 }
 127 \f
 128 /* To get on-demand global register allocation right, we need to parse the
 129    relocs, like what happens when linking to ELF.  It needs to be done
 130    before all input sections are supposed to be present.  When linking to
 131    ELF, it's done when reading symbols.  When linking to mmo, we do it
 132    when all input files are seen, which is equivalent.  */
 133
 134 static void
 135 mmo_after_open (void)
 136 {
 137   /* When there's a mismatch between the output format and the emulation
 138      (using weird combinations like "-m mmo --oformat elf64-mmix" for
 139      example), we'd count relocs twice because they'd also be counted
 140      along the usual route for ELF-only linking, which would lead to an
 141      internal accounting error.  */
 142   if (bfd_get_flavour (output_bfd) != bfd_target_elf_flavour)
 143     {
 144       LANG_FOR_EACH_INPUT_STATEMENT (is)
 145         {
 146           if (bfd_get_flavour (is->the_bfd) == bfd_target_elf_flavour
 147               && !_bfd_mmix_check_all_relocs (is->the_bfd, &link_info))
 148             einfo ("%X%P: Internal problems scanning %B after opening it",
 149                    is->the_bfd);
 150         }
 151     }
 152 }
 153 EOF
 154
 155 LDEMUL_PLACE_ORPHAN=mmo_place_orphan
 156 LDEMUL_FINISH=mmo_finish
 157 LDEMUL_AFTER_OPEN=mmo_after_open