bfd/simple.c

   1 /* simple.c -- BFD simple client routines
   2    Copyright 2002, 2003
   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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  21
  22 #include "bfd.h"
  23 #include "sysdep.h"
  24 #include "libbfd.h"
  25 #include "bfdlink.h"
  26
  27 static bfd_boolean simple_dummy_warning
  28   PARAMS ((struct bfd_link_info *, const char *, const char *, bfd *,
  29            asection *, bfd_vma));
  30
  31 static bfd_boolean simple_dummy_undefined_symbol
  32   PARAMS ((struct bfd_link_info *, const char *, bfd *, asection *,
  33            bfd_vma, bfd_boolean));
  34
  35 static bfd_boolean simple_dummy_reloc_overflow
  36   PARAMS ((struct bfd_link_info *, const char *, const char *, bfd_vma,
  37            bfd *, asection *, bfd_vma));
  38
  39 static bfd_boolean simple_dummy_reloc_dangerous
  40   PARAMS ((struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma));
  41
  42 static bfd_boolean simple_dummy_unattached_reloc
  43   PARAMS ((struct bfd_link_info *, const char *, bfd *, asection *, bfd_vma));
  44
  45 static void simple_save_output_info
  46   PARAMS ((bfd *, asection *, PTR));
  47
  48 static void simple_restore_output_info
  49   PARAMS ((bfd *, asection *, PTR));
  50
  51 bfd_byte * bfd_simple_get_relocated_section_contents
  52   PARAMS ((bfd *, asection *, bfd_byte *, asymbol **));
  53
  54 static bfd_boolean
  55 simple_dummy_warning (link_info, warning, symbol, abfd, section, address)
  56      struct bfd_link_info *link_info ATTRIBUTE_UNUSED;
  57      const char *warning ATTRIBUTE_UNUSED;
  58      const char *symbol ATTRIBUTE_UNUSED;
  59      bfd *abfd ATTRIBUTE_UNUSED;
  60      asection *section ATTRIBUTE_UNUSED;
  61      bfd_vma address ATTRIBUTE_UNUSED;
  62 {
  63   return TRUE;
  64 }
  65
  66 static bfd_boolean
  67 simple_dummy_undefined_symbol (link_info, name, abfd, section, address, fatal)
  68      struct bfd_link_info *link_info ATTRIBUTE_UNUSED;
  69      const char *name ATTRIBUTE_UNUSED;
  70      bfd *abfd ATTRIBUTE_UNUSED;
  71      asection *section ATTRIBUTE_UNUSED;
  72      bfd_vma address ATTRIBUTE_UNUSED;
  73      bfd_boolean fatal ATTRIBUTE_UNUSED;
  74 {
  75   return TRUE;
  76 }
  77
  78 static bfd_boolean
  79 simple_dummy_reloc_overflow (link_info, name, reloc_name, addend, abfd,
  80                              section, address)
  81      struct bfd_link_info *link_info ATTRIBUTE_UNUSED;
  82      const char *name ATTRIBUTE_UNUSED;
  83      const char *reloc_name ATTRIBUTE_UNUSED;
  84      bfd_vma addend ATTRIBUTE_UNUSED;
  85      bfd *abfd ATTRIBUTE_UNUSED;
  86      asection *section ATTRIBUTE_UNUSED;
  87      bfd_vma address ATTRIBUTE_UNUSED;
  88 {
  89   return TRUE;
  90 }
  91
  92 static bfd_boolean
  93 simple_dummy_reloc_dangerous (link_info, message, abfd, section, address)
  94      struct bfd_link_info *link_info ATTRIBUTE_UNUSED;
  95      const char *message ATTRIBUTE_UNUSED;
  96      bfd *abfd ATTRIBUTE_UNUSED;
  97      asection *section ATTRIBUTE_UNUSED;
  98      bfd_vma address ATTRIBUTE_UNUSED;
  99 {
 100   return TRUE;
 101 }
 102
 103 static bfd_boolean
 104 simple_dummy_unattached_reloc (link_info, name, abfd, section, address)
 105      struct bfd_link_info *link_info ATTRIBUTE_UNUSED;
 106      const char *name ATTRIBUTE_UNUSED;
 107      bfd *abfd ATTRIBUTE_UNUSED;
 108      asection *section ATTRIBUTE_UNUSED;
 109      bfd_vma address ATTRIBUTE_UNUSED;
 110 {
 111   return TRUE;
 112 }
 113
 114 struct saved_output_info
 115 {
 116   bfd_vma offset;
 117   asection *section;
 118 };
 119
 120 static void
 121 simple_save_output_info (abfd, section, ptr)
 122      bfd *abfd ATTRIBUTE_UNUSED;
 123      asection *section;
 124      PTR ptr;
 125 {
 126   struct saved_output_info *output_info = (struct saved_output_info *) ptr;
 127   output_info[section->index].offset = section->output_offset;
 128   output_info[section->index].section = section->output_section;
 129   section->output_offset = 0;
 130   section->output_section = section;
 131 }
 132
 133 static void
 134 simple_restore_output_info (abfd, section, ptr)
 135      bfd *abfd ATTRIBUTE_UNUSED;
 136      asection *section;
 137      PTR ptr;
 138 {
 139   struct saved_output_info *output_info = (struct saved_output_info *) ptr;
 140   section->output_offset = output_info[section->index].offset;
 141   section->output_section = output_info[section->index].section;
 142 }
 143
 144 /*
 145 FUNCTION
 146         bfd_simple_relocate_secton
 147
 148 SYNOPSIS
 149         bfd_byte *bfd_simple_get_relocated_section_contents (bfd *abfd, asection *sec, bfd_byte *outbuf, asymbol **symbol_table);
 150
 151 DESCRIPTION
 152         Returns the relocated contents of section @var{sec}.  The symbols in
 153         @var{symbol_table} will be used, or the symbols from @var{abfd} if
 154         @var{symbol_table} is NULL.  The output offsets for all sections will
 155         be temporarily reset to 0.  The result will be stored at @var{outbuf}
 156         or allocated with @code{bfd_malloc} if @var{outbuf} is @code{NULL}.
 157
 158         Generally all sections in @var{abfd} should have their
 159         @code{output_section} pointing back to the original section.
 160
 161         Returns @code{NULL} on a fatal error; ignores errors applying
 162         particular relocations.
 163 */
 164
 165 bfd_byte *
 166 bfd_simple_get_relocated_section_contents (abfd, sec, outbuf, symbol_table)
 167      bfd *abfd;
 168      asection *sec;
 169      bfd_byte *outbuf;
 170      asymbol **symbol_table;
 171 {
 172   struct bfd_link_info link_info;
 173   struct bfd_link_order link_order;
 174   struct bfd_link_callbacks callbacks;
 175   bfd_byte *contents, *data;
 176   int storage_needed;
 177   PTR saved_offsets;
 178
 179   if (! (sec->flags & SEC_RELOC))
 180     {
 181       bfd_size_type size = bfd_section_size (abfd, sec);
 182
 183       if (outbuf == NULL)
 184         contents = bfd_malloc (size);
 185       else
 186         contents = outbuf;
 187
 188       if (contents)
 189         bfd_get_section_contents (abfd, sec, contents, 0, size);
 190
 191       return contents;
 192     }
 193
 194   /* In order to use bfd_get_relocated_section_contents, we need
 195      to forge some data structures that it expects.  */
 196
 197   /* Fill in the bare minimum number of fields for our purposes.  */
 198   memset (&link_info, 0, sizeof (link_info));
 199   link_info.input_bfds = abfd;
 200
 201   link_info.hash = bfd_link_hash_table_create (abfd);
 202   link_info.callbacks = &callbacks;
 203   callbacks.warning = simple_dummy_warning;
 204   callbacks.undefined_symbol = simple_dummy_undefined_symbol;
 205   callbacks.reloc_overflow = simple_dummy_reloc_overflow;
 206   callbacks.reloc_dangerous = simple_dummy_reloc_dangerous;
 207   callbacks.unattached_reloc = simple_dummy_unattached_reloc;
 208
 209   memset (&link_order, 0, sizeof (link_order));
 210   link_order.next = NULL;
 211   link_order.type = bfd_indirect_link_order;
 212   link_order.offset = 0;
 213   link_order.size = bfd_section_size (abfd, sec);
 214   link_order.u.indirect.section = sec;
 215
 216   data = NULL;
 217   if (outbuf == NULL)
 218     {
 219       data = bfd_malloc (bfd_section_size (abfd, sec));
 220       if (data == NULL)
 221         return NULL;
 222       outbuf = data;
 223     }
 224
 225   /* The sections in ABFD may already have output sections and offsets set.
 226      Because this function is primarily for debug sections, and GCC uses the
 227      knowledge that debug sections will generally have VMA 0 when emiting
 228      relocations between DWARF-2 sections (which are supposed to be
 229      section-relative offsets anyway), we need to reset the output offsets
 230      to zero.  We also need to arrange for section->output_section->vma plus
 231      section->output_offset to equal section->vma, which we do by setting
 232      section->output_section to point back to section.  Save the original
 233      output offset and output section to restore later.  */
 234   saved_offsets = malloc (sizeof (struct saved_output_info)
 235                           * abfd->section_count);
 236   if (saved_offsets == NULL)
 237     {
 238       if (data)
 239         free (data);
 240       return NULL;
 241     }
 242   bfd_map_over_sections (abfd, simple_save_output_info, saved_offsets);
 243
 244   if (symbol_table == NULL)
 245     {
 246       _bfd_generic_link_add_symbols (abfd, &link_info);
 247
 248       storage_needed = bfd_get_symtab_upper_bound (abfd);
 249       symbol_table = (asymbol **) bfd_malloc (storage_needed);
 250       bfd_canonicalize_symtab (abfd, symbol_table);
 251     }
 252   else
 253     storage_needed = 0;
 254
 255   contents = bfd_get_relocated_section_contents (abfd,
 256                                                  &link_info,
 257                                                  &link_order,
 258                                                  outbuf,
 259                                                  0,
 260                                                  symbol_table);
 261   if (contents == NULL && data != NULL)
 262     free (data);
 263
 264 #if 0
 265   /* NOTE: cagney/2003-04-05: This free, which was introduced on
 266      2003-03-31 to stop a memory leak, caused a memory corruption
 267      between GDB and BFD.  The problem, which is stabs specific, can
 268      be identified by a bunch of failures in relocate.exp vis:
 269
 270        gdb.base/relocate.exp: get address of static_bar
 271
 272      Details of the problem can be found on the binutils@ mailing
 273      list, see the discussion thread: "gdb.mi/mi-cli.exp failures".  */
 274   if (storage_needed != 0)
 275     free (symbol_table);
 276 #endif
 277
 278   bfd_map_over_sections (abfd, simple_restore_output_info, saved_offsets);
 279   free (saved_offsets);
 280
 281   /* Foul hack to prevent bfd_section_size aborts.  This flag only controls
 282      that macro (and the related size macros), selecting between _raw_size
 283      and _cooked_size.  Debug sections won't change size while we're only
 284      relocating.  There may be trouble here someday if it tries to run
 285      relaxation unexpectedly, so make sure.  */
 286   BFD_ASSERT (sec->_raw_size == sec->_cooked_size);
 287   sec->reloc_done = 0;
 288
 289   bfd_link_hash_table_free (abfd, link_info.hash);
 290
 291   return contents;
 292 }