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