bfd/simple.c

   1 /* simple.c -- BFD simple client routines
   2    Copyright 2002, 2003, 2004, 2005
   3    Free Software Foundation, Inc.
   4    Contributed by MontaVista Software, Inc.
   5
   6    This file is part of BFD, the Binary File Descriptor library.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
  21
  22 #include "bfd.h"
  23 #include "sysdep.h"
  24 #include "libbfd.h"
  25 #include "bfdlink.h"
  26
  27 static bfd_boolean
  28 simple_dummy_warning (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
  29                       const char *warning ATTRIBUTE_UNUSED,
  30                       const char *symbol ATTRIBUTE_UNUSED,
  31                       bfd *abfd ATTRIBUTE_UNUSED,
  32                       asection *section ATTRIBUTE_UNUSED,
  33                       bfd_vma address ATTRIBUTE_UNUSED)
  34 {
  35   return TRUE;
  36 }
  37
  38 static bfd_boolean
  39 simple_dummy_undefined_symbol (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
  40                                const char *name ATTRIBUTE_UNUSED,
  41                                bfd *abfd ATTRIBUTE_UNUSED,
  42                                asection *section ATTRIBUTE_UNUSED,
  43                                bfd_vma address ATTRIBUTE_UNUSED,
  44                                bfd_boolean fatal ATTRIBUTE_UNUSED)
  45 {
  46   return TRUE;
  47 }
  48
  49 static bfd_boolean
  50 simple_dummy_reloc_overflow (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
  51                              struct bfd_link_hash_entry *entry ATTRIBUTE_UNUSED,
  52                              const char *name ATTRIBUTE_UNUSED,
  53                              const char *reloc_name ATTRIBUTE_UNUSED,
  54                              bfd_vma addend ATTRIBUTE_UNUSED,
  55                              bfd *abfd ATTRIBUTE_UNUSED,
  56                              asection *section ATTRIBUTE_UNUSED,
  57                              bfd_vma address ATTRIBUTE_UNUSED)
  58 {
  59   return TRUE;
  60 }
  61
  62 static bfd_boolean
  63 simple_dummy_reloc_dangerous (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
  64                               const char *message ATTRIBUTE_UNUSED,
  65                               bfd *abfd ATTRIBUTE_UNUSED,
  66                               asection *section ATTRIBUTE_UNUSED,
  67                               bfd_vma address ATTRIBUTE_UNUSED)
  68 {
  69   return TRUE;
  70 }
  71
  72 static bfd_boolean
  73 simple_dummy_unattached_reloc (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
  74                                const char *name ATTRIBUTE_UNUSED,
  75                                bfd *abfd ATTRIBUTE_UNUSED,
  76                                asection *section ATTRIBUTE_UNUSED,
  77                                bfd_vma address ATTRIBUTE_UNUSED)
  78 {
  79   return TRUE;
  80 }
  81
  82 static bfd_boolean
  83 simple_dummy_multiple_definition (struct bfd_link_info *link_info ATTRIBUTE_UNUSED,
  84                                   const char *name ATTRIBUTE_UNUSED,
  85                                   bfd *obfd ATTRIBUTE_UNUSED,
  86                                   asection *osec ATTRIBUTE_UNUSED,
  87                                   bfd_vma oval ATTRIBUTE_UNUSED,
  88                                   bfd *nbfd ATTRIBUTE_UNUSED,
  89                                   asection *nsec ATTRIBUTE_UNUSED,
  90                                   bfd_vma nval ATTRIBUTE_UNUSED)
  91 {
  92   return TRUE;
  93 }
  94
  95 static void
  96 simple_dummy_einfo (const char *fmt ATTRIBUTE_UNUSED, ...)
  97 {
  98 }
  99
 100 struct saved_output_info
 101 {
 102   bfd_vma offset;
 103   asection *section;
 104 };
 105
 106 static void
 107 simple_save_output_info (bfd *abfd ATTRIBUTE_UNUSED,
 108                          asection *section,
 109                          void *ptr)
 110 {
 111   struct saved_output_info *output_info = ptr;
 112   output_info[section->index].offset = section->output_offset;
 113   output_info[section->index].section = section->output_section;
 114   if ((section->flags & SEC_DEBUGGING) != 0
 115       || section->output_section == NULL)
 116     {
 117       section->output_offset = 0;
 118       section->output_section = section;
 119     }
 120 }
 121
 122 static void
 123 simple_restore_output_info (bfd *abfd ATTRIBUTE_UNUSED,
 124                             asection *section,
 125                             void *ptr)
 126 {
 127   struct saved_output_info *output_info = ptr;
 128   section->output_offset = output_info[section->index].offset;
 129   section->output_section = output_info[section->index].section;
 130 }
 131
 132 /*
 133 FUNCTION
 134         bfd_simple_relocate_secton
 135
 136 SYNOPSIS
 137         bfd_byte *bfd_simple_get_relocated_section_contents
 138           (bfd *abfd, asection *sec, bfd_byte *outbuf, asymbol **symbol_table);
 139
 140 DESCRIPTION
 141         Returns the relocated contents of section @var{sec}.  The symbols in
 142         @var{symbol_table} will be used, or the symbols from @var{abfd} if
 143         @var{symbol_table} is NULL.  The output offsets for debug sections will
 144         be temporarily reset to 0.  The result will be stored at @var{outbuf}
 145         or allocated with @code{bfd_malloc} if @var{outbuf} is @code{NULL}.
 146
 147         Returns @code{NULL} on a fatal error; ignores errors applying
 148         particular relocations.
 149 */
 150
 151 bfd_byte *
 152 bfd_simple_get_relocated_section_contents (bfd *abfd,
 153                                            asection *sec,
 154                                            bfd_byte *outbuf,
 155                                            asymbol **symbol_table)
 156 {
 157   struct bfd_link_info link_info;
 158   struct bfd_link_order link_order;
 159   struct bfd_link_callbacks callbacks;
 160   bfd_byte *contents, *data;
 161   int storage_needed;
 162   void *saved_offsets;
 163
 164   if (! (sec->flags & SEC_RELOC))
 165     {
 166       bfd_size_type amt = sec->rawsize > sec->size ? sec->rawsize : sec->size;
 167       bfd_size_type size = sec->rawsize ? sec->rawsize : sec->size;
 168
 169       if (outbuf == NULL)
 170         contents = bfd_malloc (amt);
 171       else
 172         contents = outbuf;
 173
 174       if (contents)
 175         bfd_get_section_contents (abfd, sec, contents, 0, size);
 176
 177       return contents;
 178     }
 179
 180   /* In order to use bfd_get_relocated_section_contents, we need
 181      to forge some data structures that it expects.  */
 182
 183   /* Fill in the bare minimum number of fields for our purposes.  */
 184   memset (&link_info, 0, sizeof (link_info));
 185   link_info.input_bfds = abfd;
 186
 187   link_info.hash = _bfd_generic_link_hash_table_create (abfd);
 188   link_info.callbacks = &callbacks;
 189   callbacks.warning = simple_dummy_warning;
 190   callbacks.undefined_symbol = simple_dummy_undefined_symbol;
 191   callbacks.reloc_overflow = simple_dummy_reloc_overflow;
 192   callbacks.reloc_dangerous = simple_dummy_reloc_dangerous;
 193   callbacks.unattached_reloc = simple_dummy_unattached_reloc;
 194   callbacks.multiple_definition = simple_dummy_multiple_definition;
 195   callbacks.einfo = simple_dummy_einfo;
 196
 197   memset (&link_order, 0, sizeof (link_order));
 198   link_order.next = NULL;
 199   link_order.type = bfd_indirect_link_order;
 200   link_order.offset = 0;
 201   link_order.size = sec->size;
 202   link_order.u.indirect.section = sec;
 203
 204   data = NULL;
 205   if (outbuf == NULL)
 206     {
 207       data = bfd_malloc (sec->size);
 208       if (data == NULL)
 209         return NULL;
 210       outbuf = data;
 211     }
 212
 213   /* The sections in ABFD may already have output sections and offsets set.
 214      Because this function is primarily for debug sections, and GCC uses the
 215      knowledge that debug sections will generally have VMA 0 when emitting
 216      relocations between DWARF-2 sections (which are supposed to be
 217      section-relative offsets anyway), we need to reset the output offsets
 218      to zero.  We also need to arrange for section->output_section->vma plus
 219      section->output_offset to equal section->vma, which we do by setting
 220      section->output_section to point back to section.  Save the original
 221      output offset and output section to restore later.  */
 222   saved_offsets = malloc (sizeof (struct saved_output_info)
 223                           * abfd->section_count);
 224   if (saved_offsets == NULL)
 225     {
 226       if (data)
 227         free (data);
 228       return NULL;
 229     }
 230   bfd_map_over_sections (abfd, simple_save_output_info, saved_offsets);
 231
 232   if (symbol_table == NULL)
 233     {
 234       _bfd_generic_link_add_symbols (abfd, &link_info);
 235
 236       storage_needed = bfd_get_symtab_upper_bound (abfd);
 237       symbol_table = bfd_malloc (storage_needed);
 238       bfd_canonicalize_symtab (abfd, symbol_table);
 239     }
 240   else
 241     storage_needed = 0;
 242
 243   contents = bfd_get_relocated_section_contents (abfd,
 244                                                  &link_info,
 245                                                  &link_order,
 246                                                  outbuf,
 247                                                  0,
 248                                                  symbol_table);
 249   if (contents == NULL && data != NULL)
 250     free (data);
 251
 252   bfd_map_over_sections (abfd, simple_restore_output_info, saved_offsets);
 253   free (saved_offsets);
 254
 255   _bfd_generic_link_hash_table_free (link_info.hash);
 256   return contents;
 257 }