gdb/dwarf2/attribute.c

   1 /* DWARF attributes
   2
   3    Copyright (C) 1994-2022 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/attribute.h"
  29 #include "dwarf2/stringify.h"
  30 #include "complaints.h"
  31
  32 /* See attribute.h.  */
  33
  34 CORE_ADDR
  35 attribute::as_address () const
  36 {
  37   CORE_ADDR addr;
  38
  39   gdb_assert (!requires_reprocessing);
  40
  41   if (form != DW_FORM_addr && form != DW_FORM_addrx
  42       && form != DW_FORM_GNU_addr_index)
  43     {
  44       /* Aside from a few clearly defined exceptions, attributes that
  45          contain an address must always be in DW_FORM_addr form.
  46          Unfortunately, some compilers happen to be violating this
  47          requirement by encoding addresses using other forms, such
  48          as DW_FORM_data4 for example.  For those broken compilers,
  49          we try to do our best, without any guarantee of success,
  50          to interpret the address correctly.  It would also be nice
  51          to generate a complaint, but that would require us to maintain
  52          a list of legitimate cases where a non-address form is allowed,
  53          as well as update callers to pass in at least the CU's DWARF
  54          version.  This is more overhead than what we're willing to
  55          expand for a pretty rare case.  */
  56       addr = u.unsnd;
  57     }
  58   else
  59     addr = u.addr;
  60
  61   return addr;
  62 }
  63
  64 /* See attribute.h.  */
  65
  66 bool
  67 attribute::form_is_string () const
  68 {
  69   return (form == DW_FORM_strp || form == DW_FORM_line_strp
  70           || form == DW_FORM_string
  71           || form == DW_FORM_strx
  72           || form == DW_FORM_strx1
  73           || form == DW_FORM_strx2
  74           || form == DW_FORM_strx3
  75           || form == DW_FORM_strx4
  76           || form == DW_FORM_GNU_str_index
  77           || form == DW_FORM_GNU_strp_alt);
  78 }
  79
  80 /* See attribute.h.  */
  81
  82 const char *
  83 attribute::as_string () const
  84 {
  85   gdb_assert (!requires_reprocessing);
  86   if (form_is_string ())
  87     return u.str;
  88   return nullptr;
  89 }
  90
  91 /* See attribute.h.  */
  92
  93 bool
  94 attribute::form_is_block () const
  95 {
  96   return (form == DW_FORM_block1
  97           || form == DW_FORM_block2
  98           || form == DW_FORM_block4
  99           || form == DW_FORM_block
 100           || form == DW_FORM_exprloc
 101           || form == DW_FORM_data16);
 102 }
 103
 104 /* See attribute.h.  */
 105
 106 bool
 107 attribute::form_is_section_offset () const
 108 {
 109   return (form == DW_FORM_data4
 110           || form == DW_FORM_data8
 111           || form == DW_FORM_sec_offset
 112           || form == DW_FORM_loclistx);
 113 }
 114
 115 /* See attribute.h.  */
 116
 117 bool
 118 attribute::form_is_constant () const
 119 {
 120   switch (form)
 121     {
 122     case DW_FORM_sdata:
 123     case DW_FORM_udata:
 124     case DW_FORM_data1:
 125     case DW_FORM_data2:
 126     case DW_FORM_data4:
 127     case DW_FORM_data8:
 128     case DW_FORM_implicit_const:
 129       return true;
 130     default:
 131       return false;
 132     }
 133 }
 134
 135 /* See attribute.h.  */
 136
 137 void
 138 attribute::get_ref_die_offset_complaint () const
 139 {
 140   complaint (_("unsupported die ref attribute form: '%s'"),
 141              dwarf_form_name (form));
 142 }
 143
 144 /* See attribute.h.  */
 145
 146 LONGEST
 147 attribute::constant_value (int default_value) const
 148 {
 149   if (form == DW_FORM_sdata || form == DW_FORM_implicit_const)
 150     return u.snd;
 151   else if (form == DW_FORM_udata
 152            || form == DW_FORM_data1
 153            || form == DW_FORM_data2
 154            || form == DW_FORM_data4
 155            || form == DW_FORM_data8)
 156     return u.unsnd;
 157   else
 158     {
 159       /* For DW_FORM_data16 see attribute::form_is_constant.  */
 160       complaint (_("Attribute value is not a constant (%s)"),
 161                  dwarf_form_name (form));
 162       return default_value;
 163     }
 164 }
 165
 166 /* See attribute.h.  */
 167
 168 bool
 169 attribute::form_is_unsigned () const
 170 {
 171   return (form == DW_FORM_ref_addr
 172           || form == DW_FORM_GNU_ref_alt
 173           || form == DW_FORM_data2
 174           || form == DW_FORM_data4
 175           || form == DW_FORM_data8
 176           || form == DW_FORM_sec_offset
 177           || form == DW_FORM_data1
 178           || form == DW_FORM_flag
 179           || form == DW_FORM_flag_present
 180           || form == DW_FORM_udata
 181           || form == DW_FORM_rnglistx
 182           || form == DW_FORM_loclistx
 183           || form == DW_FORM_ref1
 184           || form == DW_FORM_ref2
 185           || form == DW_FORM_ref4
 186           || form == DW_FORM_ref8
 187           || form == DW_FORM_ref_udata);
 188 }
 189
 190 /* See attribute.h.  */
 191
 192 bool
 193 attribute::form_is_signed () const
 194 {
 195   return form == DW_FORM_sdata || form == DW_FORM_implicit_const;
 196 }
 197
 198 /* See attribute.h.  */
 199
 200 bool
 201 attribute::form_requires_reprocessing () const
 202 {
 203   return (form == DW_FORM_strx
 204           || form == DW_FORM_strx1
 205           || form == DW_FORM_strx2
 206           || form == DW_FORM_strx3
 207           || form == DW_FORM_strx4
 208           || form == DW_FORM_GNU_str_index
 209           || form == DW_FORM_addrx
 210           || form == DW_FORM_GNU_addr_index
 211           || form == DW_FORM_rnglistx
 212           || form == DW_FORM_loclistx);
 213 }
 214
 215 /* See attribute.h.  */
 216
 217 dwarf_defaulted_attribute
 218 attribute::defaulted () const
 219 {
 220   LONGEST value = constant_value (-1);
 221
 222   switch (value)
 223     {
 224     case DW_DEFAULTED_no:
 225     case DW_DEFAULTED_in_class:
 226     case DW_DEFAULTED_out_of_class:
 227       return (dwarf_defaulted_attribute) value;
 228     }
 229
 230   /* If the form was not constant, we already complained in
 231      constant_value, so there's no need to complain again.  */
 232   if (form_is_constant ())
 233     complaint (_("unrecognized DW_AT_defaulted value (%s)"),
 234                plongest (value));
 235   return DW_DEFAULTED_no;
 236 }
 237
 238 /* See attribute.h.  */
 239
 240 dwarf_virtuality_attribute
 241 attribute::as_virtuality () const
 242 {
 243   LONGEST value = constant_value (-1);
 244
 245   switch (value)
 246     {
 247     case DW_VIRTUALITY_none:
 248     case DW_VIRTUALITY_virtual:
 249     case DW_VIRTUALITY_pure_virtual:
 250       return (dwarf_virtuality_attribute) value;
 251     }
 252
 253   /* If the form was not constant, we already complained in
 254      constant_value, so there's no need to complain again.  */
 255   if (form_is_constant ())
 256     complaint (_("unrecognized DW_AT_virtuality value (%s)"),
 257                plongest (value));
 258   return DW_VIRTUALITY_none;
 259 }
 260
 261 /* See attribute.h.  */
 262
 263 bool
 264 attribute::as_boolean () const
 265 {
 266   if (form == DW_FORM_flag_present)
 267     return true;
 268   else if (form == DW_FORM_flag)
 269     return u.unsnd != 0;
 270   return constant_value (0) != 0;
 271 }