1 /* DWARF attributes 2 3 Copyright (C) 1994-2023 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 } 272