1 /* Compute size of an aggregate type from DWARF. 2 Copyright (C) 2010, 2014 Red Hat, Inc. 3 This file is part of elfutils. 4 5 This file is free software; you can redistribute it and/or modify 6 it under the terms of either 7 8 * the GNU Lesser General Public License as published by the Free 9 Software Foundation; either version 3 of the License, or (at 10 your option) any later version 11 12 or 13 14 * the GNU General Public License as published by the Free 15 Software Foundation; either version 2 of the License, or (at 16 your option) any later version 17 18 or both in parallel, as here. 19 20 elfutils is distributed in the hope that it will be useful, but 21 WITHOUT ANY WARRANTY; without even the implied warranty of 22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 23 General Public License for more details. 24 25 You should have received copies of the GNU General Public License and 26 the GNU Lesser General Public License along with this program. If 27 not, see <http://www.gnu.org/licenses/>. */ 28 29 #ifdef HAVE_CONFIG_H 30 # include <config.h> 31 #endif 32 33 #include <dwarf.h> 34 #include "libdwP.h" 35 36 37 static Dwarf_Die * 38 get_type (Dwarf_Die *die, Dwarf_Attribute *attr_mem, Dwarf_Die *type_mem) 39 { 40 Dwarf_Die *type = INTUSE(dwarf_formref_die) 41 (INTUSE(dwarf_attr_integrate) (die, DW_AT_type, attr_mem), type_mem); 42 43 if (INTUSE(dwarf_peel_type) (type, type) != 0) 44 return NULL; 45 46 return type; 47 } 48 49 static int 50 array_size (Dwarf_Die *die, Dwarf_Word *size, 51 Dwarf_Attribute *attr_mem, Dwarf_Die *type_mem) 52 { 53 Dwarf_Word eltsize; 54 if (INTUSE(dwarf_aggregate_size) (get_type (die, attr_mem, type_mem), 55 &eltsize) != 0) 56 return -1; 57 58 /* An array can have DW_TAG_subrange_type or DW_TAG_enumeration_type 59 children instead that give the size of each dimension. */ 60 61 Dwarf_Die child; 62 if (INTUSE(dwarf_child) (die, &child) != 0) 63 return -1; 64 65 bool any = false; 66 Dwarf_Word total = 0; 67 do 68 { 69 Dwarf_Word count; 70 switch (INTUSE(dwarf_tag) (&child)) 71 { 72 case DW_TAG_subrange_type: 73 /* This has either DW_AT_count or DW_AT_upper_bound. */ 74 if (INTUSE(dwarf_attr_integrate) (&child, DW_AT_count, 75 attr_mem) != NULL) 76 { 77 if (INTUSE(dwarf_formudata) (attr_mem, &count) != 0) 78 return -1; 79 } 80 else 81 { 82 Dwarf_Sword upper; 83 Dwarf_Sword lower; 84 if (INTUSE(dwarf_formsdata) (INTUSE(dwarf_attr_integrate) 85 (&child, DW_AT_upper_bound, 86 attr_mem), &upper) != 0) 87 return -1; 88 89 /* Having DW_AT_lower_bound is optional. */ 90 if (INTUSE(dwarf_attr_integrate) (&child, DW_AT_lower_bound, 91 attr_mem) != NULL) 92 { 93 if (INTUSE(dwarf_formsdata) (attr_mem, &lower) != 0) 94 return -1; 95 } 96 else 97 { 98 /* Determine default lower bound from language, 99 as per "4.12 Subrange Type Entries". */ 100 Dwarf_Die cu = CUDIE (die->cu); 101 switch (INTUSE(dwarf_srclang) (&cu)) 102 { 103 case DW_LANG_C: 104 case DW_LANG_C89: 105 case DW_LANG_C99: 106 case DW_LANG_C11: 107 case DW_LANG_C_plus_plus: 108 case DW_LANG_C_plus_plus_11: 109 case DW_LANG_C_plus_plus_14: 110 case DW_LANG_ObjC: 111 case DW_LANG_ObjC_plus_plus: 112 case DW_LANG_Java: 113 case DW_LANG_D: 114 case DW_LANG_UPC: 115 case DW_LANG_Go: 116 lower = 0; 117 break; 118 119 case DW_LANG_Ada83: 120 case DW_LANG_Ada95: 121 case DW_LANG_Cobol74: 122 case DW_LANG_Cobol85: 123 case DW_LANG_Fortran77: 124 case DW_LANG_Fortran90: 125 case DW_LANG_Fortran95: 126 case DW_LANG_Fortran03: 127 case DW_LANG_Fortran08: 128 case DW_LANG_Pascal83: 129 case DW_LANG_Modula2: 130 case DW_LANG_PL1: 131 lower = 1; 132 break; 133 134 default: 135 return -1; 136 } 137 } 138 if (unlikely (lower > upper)) 139 return -1; 140 count = upper - lower + 1; 141 } 142 break; 143 144 case DW_TAG_enumeration_type: 145 /* We have to find the DW_TAG_enumerator child with the 146 highest value to know the array's element count. */ 147 count = 0; 148 Dwarf_Die enum_child; 149 int has_children = INTUSE(dwarf_child) (die, &enum_child); 150 if (has_children < 0) 151 return -1; 152 if (has_children > 0) 153 do 154 if (INTUSE(dwarf_tag) (&enum_child) == DW_TAG_enumerator) 155 { 156 Dwarf_Word value; 157 if (INTUSE(dwarf_formudata) (INTUSE(dwarf_attr_integrate) 158 (&enum_child, DW_AT_const_value, 159 attr_mem), &value) != 0) 160 return -1; 161 if (value >= count) 162 count = value + 1; 163 } 164 while (INTUSE(dwarf_siblingof) (&enum_child, &enum_child) > 0); 165 break; 166 167 default: 168 continue; 169 } 170 171 /* This is a subrange_type or enumeration_type and we've set COUNT. 172 Now determine the stride for this array dimension. */ 173 Dwarf_Word stride = eltsize; 174 if (INTUSE(dwarf_attr_integrate) (&child, DW_AT_byte_stride, 175 attr_mem) != NULL) 176 { 177 if (INTUSE(dwarf_formudata) (attr_mem, &stride) != 0) 178 return -1; 179 } 180 else if (INTUSE(dwarf_attr_integrate) (&child, DW_AT_bit_stride, 181 attr_mem) != NULL) 182 { 183 if (INTUSE(dwarf_formudata) (attr_mem, &stride) != 0) 184 return -1; 185 if (stride % 8) /* XXX maybe compute in bits? */ 186 return -1; 187 stride /= 8; 188 } 189 190 any = true; 191 total += stride * count; 192 } 193 while (INTUSE(dwarf_siblingof) (&child, &child) == 0); 194 195 if (!any) 196 return -1; 197 198 *size = total; 199 return 0; 200 } 201 202 static int 203 aggregate_size (Dwarf_Die *die, Dwarf_Word *size, Dwarf_Die *type_mem) 204 { 205 Dwarf_Attribute attr_mem; 206 207 if (INTUSE(dwarf_attr_integrate) (die, DW_AT_byte_size, &attr_mem) != NULL) 208 return INTUSE(dwarf_formudata) (&attr_mem, size); 209 210 switch (INTUSE(dwarf_tag) (die)) 211 { 212 case DW_TAG_subrange_type: 213 return aggregate_size (get_type (die, &attr_mem, type_mem), 214 size, type_mem); /* Tail call. */ 215 216 case DW_TAG_array_type: 217 return array_size (die, size, &attr_mem, type_mem); 218 219 /* Assume references and pointers have pointer size if not given an 220 explicit DW_AT_byte_size. */ 221 case DW_TAG_pointer_type: 222 case DW_TAG_reference_type: 223 case DW_TAG_rvalue_reference_type: 224 *size = die->cu->address_size; 225 return 0; 226 } 227 228 /* Most types must give their size directly. */ 229 return -1; 230 } 231 232 int 233 dwarf_aggregate_size (Dwarf_Die *die, Dwarf_Word *size) 234 { 235 Dwarf_Die type_mem; 236 237 if (INTUSE (dwarf_peel_type) (die, die) != 0) 238 return -1; 239 240 return aggregate_size (die, size, &type_mem); 241 } 242 INTDEF (dwarf_aggregate_size) 243 OLD_VERSION (dwarf_aggregate_size, ELFUTILS_0.144) 244 NEW_VERSION (dwarf_aggregate_size, ELFUTILS_0.161) 245
