ld/emultempl/mmo.em

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