ld/emultempl/mmix-elfnmmo.em

   1 # This shell script emits a C file. -*- C -*-
   2 #   Copyright (C) 2001-2015 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 elf32.em and mmo.em, used to define
  23 # MMIX-specific things common to ELF and MMO.
  24
  25 fragment <<EOF
  26 #include "elf/mmix.h"
  27
  28 /* Set up handling of linker-allocated global registers.  */
  29
  30 static void
  31 mmix_before_allocation (void)
  32 {
  33   /* Call the default first.  */
  34   gld${EMULATION_NAME}_before_allocation ();
  35
  36   /* There's a needrelax.em which uses this ..._before_allocation-hook and
  37      just has the statement below as payload.  It's more of a hassle to
  38      use that than to just include these two lines and take the
  39      maintenance burden to keep them in sync.  (Of course we lose the
  40      maintenance burden of checking that it still does what we need.)  */
  41
  42   /* Force -relax on (regardless of whether we're doing a relocatable
  43      link).  */
  44   ENABLE_RELAXATION;
  45
  46   if (!_bfd_mmix_before_linker_allocation (link_info.output_bfd, &link_info))
  47     einfo ("%X%P: Internal problems setting up section %s",
  48            MMIX_LD_ALLOCATED_REG_CONTENTS_SECTION_NAME);
  49 }
  50
  51 /* We need to set the VMA of the .MMIX.reg_contents section when it has
  52    been allocated, and produce the final settings for the linker-generated
  53    GREGs.  */
  54
  55 static void
  56 mmix_after_allocation (void)
  57 {
  58   asection *sec;
  59   bfd_signed_vma regvma;
  60
  61   gld${EMULATION_NAME}_after_allocation ();
  62
  63   /* If there's no register section, we don't need to do anything.  On the
  64      other hand, if there's a non-standard linker-script without a mapping
  65      from MMIX_LD_ALLOCATED_REG_CONTENTS_SECTION_NAME when that section is
  66      present (as in the ld test "NOCROSSREFS 2"), that section (1) will be
  67      orphaned; not inserted in MMIX_REG_CONTENTS_SECTION_NAME and (2) we
  68      will not do the necessary preparations for those relocations that
  69      caused it to be created.  We'll SEGV from the latter error.  The
  70      former error in separation will result in a non-working binary, but
  71      that's expected when you play tricks with linker scripts.  The
  72      "NOCROSSREFS 2" test does not run the output so it does not matter
  73      there.  */
  74   sec = bfd_get_section_by_name (link_info.output_bfd,
  75                                  MMIX_REG_CONTENTS_SECTION_NAME);
  76   if (sec == NULL)
  77     sec
  78       = bfd_get_section_by_name (link_info.output_bfd,
  79                                  MMIX_LD_ALLOCATED_REG_CONTENTS_SECTION_NAME);
  80   if (sec == NULL)
  81     return;
  82
  83   regvma = 256 * 8 - sec->size - 8;
  84
  85   /* If we start on a local register, we have too many global registers.
  86      We treat this error as nonfatal (meaning processing will continue in
  87      search for other errors), because it's a link error in the same way
  88      as an undefined symbol.  */
  89   if (regvma < 32 * 8)
  90     {
  91       einfo ("%X%P: Too many global registers: %u, max 223\n",
  92              (unsigned) sec->size / 8);
  93       regvma = 32 * 8;
  94     }
  95
  96   /* Set vma to correspond to first such register number * 8.  */
  97   bfd_set_section_vma (link_info.output_bfd, sec, (bfd_vma) regvma);
  98
  99   /* Simplify symbol output for the register section (without contents;
 100      created for register symbols) by setting the output offset to 0.
 101      This section is only present when there are register symbols.  */
 102   sec = bfd_get_section_by_name (link_info.output_bfd, MMIX_REG_SECTION_NAME);
 103   if (sec != NULL)
 104     bfd_set_section_vma (sec->owner, sec, 0);
 105
 106   if (!_bfd_mmix_after_linker_allocation (link_info.output_bfd, &link_info))
 107     {
 108       /* This is a fatal error; make einfo call not return.  */
 109       einfo ("%F%P: Can't finalize linker-allocated global registers\n");
 110     }
 111 }
 112 EOF
 113
 114 LDEMUL_AFTER_ALLOCATION=mmix_after_allocation
 115 LDEMUL_BEFORE_ALLOCATION=mmix_before_allocation