gdb/dwarf2/comp-unit.c

   1 /* DWARF 2 debugging format support for GDB.
   2
   3    Copyright (C) 1994-2020 Free Software Foundation, Inc.
   4
   5    Adapted by Gary Funck (gary@intrepid.com), Intrepid Technology,
   6    Inc.  with support from Florida State University (under contract
   7    with the Ada Joint Program Office), and Silicon Graphics, Inc.
   8    Initial contribution by Brent Benson, Harris Computer Systems, Inc.,
   9    based on Fred Fish's (Cygnus Support) implementation of DWARF 1
  10    support.
  11
  12    This file is part of GDB.
  13
  14    This program is free software; you can redistribute it and/or modify
  15    it under the terms of the GNU General Public License as published by
  16    the Free Software Foundation; either version 3 of the License, or
  17    (at your option) any later version.
  18
  19    This program is distributed in the hope that it will be useful,
  20    but WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22    GNU General Public License for more details.
  23
  24    You should have received a copy of the GNU General Public License
  25    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  26
  27 #include "defs.h"
  28 #include "dwarf2/comp-unit.h"
  29 #include "dwarf2/leb.h"
  30 #include "dwarf2/read.h"
  31 #include "dwarf2/section.h"
  32
  33 /* Convert a unit type to corresponding DW_UT name.  */
  34
  35 static const char *
  36 dwarf_unit_type_name (int unit_type)
  37 {
  38   switch (unit_type)
  39     {
  40       case 0x01:
  41         return "DW_UT_compile (0x01)";
  42       case 0x02:
  43         return "DW_UT_type (0x02)";
  44       case 0x03:
  45         return "DW_UT_partial (0x03)";
  46       case 0x04:
  47         return "DW_UT_skeleton (0x04)";
  48       case 0x05:
  49         return "DW_UT_split_compile (0x05)";
  50       case 0x06:
  51         return "DW_UT_split_type (0x06)";
  52       case 0x80:
  53         return "DW_UT_lo_user (0x80)";
  54       case 0xff:
  55         return "DW_UT_hi_user (0xff)";
  56       default:
  57         return nullptr;
  58     }
  59 }
  60
  61 /* See comp-unit.h.  */
  62
  63 const gdb_byte *
  64 read_comp_unit_head (struct comp_unit_head *cu_header,
  65                      const gdb_byte *info_ptr,
  66                      struct dwarf2_section_info *section,
  67                      rcuh_kind section_kind)
  68 {
  69   int signed_addr;
  70   unsigned int bytes_read;
  71   const char *filename = section->get_file_name ();
  72   bfd *abfd = section->get_bfd_owner ();
  73
  74   cu_header->length = read_initial_length (abfd, info_ptr, &bytes_read);
  75   cu_header->initial_length_size = bytes_read;
  76   cu_header->offset_size = (bytes_read == 4) ? 4 : 8;
  77   info_ptr += bytes_read;
  78   cu_header->version = read_2_bytes (abfd, info_ptr);
  79   if (cu_header->version < 2 || cu_header->version > 5)
  80     error (_("Dwarf Error: wrong version in compilation unit header "
  81            "(is %d, should be 2, 3, 4 or 5) [in module %s]"),
  82            cu_header->version, filename);
  83   info_ptr += 2;
  84   if (cu_header->version < 5)
  85     switch (section_kind)
  86       {
  87       case rcuh_kind::COMPILE:
  88         cu_header->unit_type = DW_UT_compile;
  89         break;
  90       case rcuh_kind::TYPE:
  91         cu_header->unit_type = DW_UT_type;
  92         break;
  93       default:
  94         internal_error (__FILE__, __LINE__,
  95                         _("read_comp_unit_head: invalid section_kind"));
  96       }
  97   else
  98     {
  99       cu_header->unit_type = static_cast<enum dwarf_unit_type>
 100                                                  (read_1_byte (abfd, info_ptr));
 101       info_ptr += 1;
 102       switch (cu_header->unit_type)
 103         {
 104         case DW_UT_compile:
 105         case DW_UT_partial:
 106         case DW_UT_skeleton:
 107         case DW_UT_split_compile:
 108           if (section_kind != rcuh_kind::COMPILE)
 109             error (_("Dwarf Error: wrong unit_type in compilation unit header "
 110                    "(is %s, should be %s) [in module %s]"),
 111                    dwarf_unit_type_name (cu_header->unit_type),
 112                    dwarf_unit_type_name (DW_UT_type), filename);
 113           break;
 114         case DW_UT_type:
 115         case DW_UT_split_type:
 116           section_kind = rcuh_kind::TYPE;
 117           break;
 118         default:
 119           error (_("Dwarf Error: wrong unit_type in compilation unit header "
 120                  "(is %#04x, should be one of: %s, %s, %s, %s or %s) "
 121                  "[in module %s]"), cu_header->unit_type,
 122                  dwarf_unit_type_name (DW_UT_compile),
 123                  dwarf_unit_type_name (DW_UT_skeleton),
 124                  dwarf_unit_type_name (DW_UT_split_compile),
 125                  dwarf_unit_type_name (DW_UT_type),
 126                  dwarf_unit_type_name (DW_UT_split_type), filename);
 127         }
 128
 129       cu_header->addr_size = read_1_byte (abfd, info_ptr);
 130       info_ptr += 1;
 131     }
 132   cu_header->abbrev_sect_off
 133     = (sect_offset) cu_header->read_offset (abfd, info_ptr, &bytes_read);
 134   info_ptr += bytes_read;
 135   if (cu_header->version < 5)
 136     {
 137       cu_header->addr_size = read_1_byte (abfd, info_ptr);
 138       info_ptr += 1;
 139     }
 140   signed_addr = bfd_get_sign_extend_vma (abfd);
 141   if (signed_addr < 0)
 142     internal_error (__FILE__, __LINE__,
 143                     _("read_comp_unit_head: dwarf from non elf file"));
 144   cu_header->signed_addr_p = signed_addr;
 145
 146   bool header_has_signature = section_kind == rcuh_kind::TYPE
 147     || cu_header->unit_type == DW_UT_skeleton
 148     || cu_header->unit_type == DW_UT_split_compile;
 149
 150   if (header_has_signature)
 151     {
 152       cu_header->signature = read_8_bytes (abfd, info_ptr);
 153       info_ptr += 8;
 154     }
 155
 156   if (section_kind == rcuh_kind::TYPE)
 157     {
 158       LONGEST type_offset;
 159       type_offset = cu_header->read_offset (abfd, info_ptr, &bytes_read);
 160       info_ptr += bytes_read;
 161       cu_header->type_cu_offset_in_tu = (cu_offset) type_offset;
 162       if (to_underlying (cu_header->type_cu_offset_in_tu) != type_offset)
 163         error (_("Dwarf Error: Too big type_offset in compilation unit "
 164                "header (is %s) [in module %s]"), plongest (type_offset),
 165                filename);
 166     }
 167
 168   return info_ptr;
 169 }
 170
 171 /* Subroutine of read_and_check_comp_unit_head and
 172    read_and_check_type_unit_head to simplify them.
 173    Perform various error checking on the header.  */
 174
 175 static void
 176 error_check_comp_unit_head (dwarf2_per_objfile *per_objfile,
 177                             struct comp_unit_head *header,
 178                             struct dwarf2_section_info *section,
 179                             struct dwarf2_section_info *abbrev_section)
 180 {
 181   const char *filename = section->get_file_name ();
 182
 183   if (to_underlying (header->abbrev_sect_off)
 184       >= abbrev_section->get_size (per_objfile->objfile))
 185     error (_("Dwarf Error: bad offset (%s) in compilation unit header "
 186            "(offset %s + 6) [in module %s]"),
 187            sect_offset_str (header->abbrev_sect_off),
 188            sect_offset_str (header->sect_off),
 189            filename);
 190
 191   /* Cast to ULONGEST to use 64-bit arithmetic when possible to
 192      avoid potential 32-bit overflow.  */
 193   if (((ULONGEST) header->sect_off + header->get_length ())
 194       > section->size)
 195     error (_("Dwarf Error: bad length (0x%x) in compilation unit header "
 196            "(offset %s + 0) [in module %s]"),
 197            header->length, sect_offset_str (header->sect_off),
 198            filename);
 199 }
 200
 201 /* See comp-unit.h.  */
 202
 203 const gdb_byte *
 204 read_and_check_comp_unit_head (dwarf2_per_objfile *per_objfile,
 205                                struct comp_unit_head *header,
 206                                struct dwarf2_section_info *section,
 207                                struct dwarf2_section_info *abbrev_section,
 208                                const gdb_byte *info_ptr,
 209                                rcuh_kind section_kind)
 210 {
 211   const gdb_byte *beg_of_comp_unit = info_ptr;
 212
 213   header->sect_off = (sect_offset) (beg_of_comp_unit - section->buffer);
 214
 215   info_ptr = read_comp_unit_head (header, info_ptr, section, section_kind);
 216
 217   header->first_die_cu_offset = (cu_offset) (info_ptr - beg_of_comp_unit);
 218
 219   error_check_comp_unit_head (per_objfile, header, section, abbrev_section);
 220
 221   return info_ptr;
 222 }
 223
 224 CORE_ADDR
 225 comp_unit_head::read_address (bfd *abfd, const gdb_byte *buf,
 226                               unsigned int *bytes_read) const
 227 {
 228   CORE_ADDR retval = 0;
 229
 230   if (signed_addr_p)
 231     {
 232       switch (addr_size)
 233         {
 234         case 2:
 235           retval = bfd_get_signed_16 (abfd, buf);
 236           break;
 237         case 4:
 238           retval = bfd_get_signed_32 (abfd, buf);
 239           break;
 240         case 8:
 241           retval = bfd_get_signed_64 (abfd, buf);
 242           break;
 243         default:
 244           internal_error (__FILE__, __LINE__,
 245                           _("read_address: bad switch, signed [in module %s]"),
 246                           bfd_get_filename (abfd));
 247         }
 248     }
 249   else
 250     {
 251       switch (addr_size)
 252         {
 253         case 2:
 254           retval = bfd_get_16 (abfd, buf);
 255           break;
 256         case 4:
 257           retval = bfd_get_32 (abfd, buf);
 258           break;
 259         case 8:
 260           retval = bfd_get_64 (abfd, buf);
 261           break;
 262         default:
 263           internal_error (__FILE__, __LINE__,
 264                           _("read_address: bad switch, "
 265                             "unsigned [in module %s]"),
 266                           bfd_get_filename (abfd));
 267         }
 268     }
 269
 270   *bytes_read = addr_size;
 271   return retval;
 272 }