1/* Compute size of an aggregate type from DWARF. 2 Copyright (C) 2010 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 5 Red Hat elfutils is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by the 7 Free Software Foundation; version 2 of the License. 8 9 Red Hat elfutils is distributed in the hope that it will be useful, but 10 WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 General Public License for more details. 13 14 You should have received a copy of the GNU General Public License along 15 with Red Hat elfutils; if not, write to the Free Software Foundation, 16 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 17 18 In addition, as a special exception, Red Hat, Inc. gives You the 19 additional right to link the code of Red Hat elfutils with code licensed 20 under any Open Source Initiative certified open source license 21 (http://www.opensource.org/licenses/index.php) which requires the 22 distribution of source code with any binary distribution and to 23 distribute linked combinations of the two. Non-GPL Code permitted under 24 this exception must only link to the code of Red Hat elfutils through 25 those well defined interfaces identified in the file named EXCEPTION 26 found in the source code files (the "Approved Interfaces"). The files 27 of Non-GPL Code may instantiate templates or use macros or inline 28 functions from the Approved Interfaces without causing the resulting 29 work to be covered by the GNU General Public License. Only Red Hat, 30 Inc. may make changes or additions to the list of Approved Interfaces. 31 Red Hat's grant of this exception is conditioned upon your not adding 32 any new exceptions. If you wish to add a new Approved Interface or 33 exception, please contact Red Hat. You must obey the GNU General Public 34 License in all respects for all of the Red Hat elfutils code and other 35 code used in conjunction with Red Hat elfutils except the Non-GPL Code 36 covered by this exception. If you modify this file, you may extend this 37 exception to your version of the file, but you are not obligated to do 38 so. If you do not wish to provide this exception without modification, 39 you must delete this exception statement from your version and license 40 this file solely under the GPL without exception. 41 42 Red Hat elfutils is an included package of the Open Invention Network. 43 An included package of the Open Invention Network is a package for which 44 Open Invention Network licensees cross-license their patents. No patent 45 license is granted, either expressly or impliedly, by designation as an 46 included package. Should you wish to participate in the Open Invention 47 Network licensing program, please visit www.openinventionnetwork.com 48 <http://www.openinventionnetwork.com>. */ 49 50#ifdef HAVE_CONFIG_H 51# include <config.h> 52#endif 53 54#include <dwarf.h> 55#include "libdwP.h" 56 57 58static Dwarf_Die * 59get_type (Dwarf_Die *die, Dwarf_Attribute *attr_mem, Dwarf_Die *type_mem) 60{ 61 return INTUSE(dwarf_formref_die) 62 (INTUSE(dwarf_attr_integrate) (die, DW_AT_type, attr_mem), type_mem); 63} 64 65static int 66array_size (Dwarf_Die *die, Dwarf_Word *size, 67 Dwarf_Attribute *attr_mem, Dwarf_Die *type_mem) 68{ 69 Dwarf_Word eltsize; 70 if (INTUSE(dwarf_aggregate_size) (get_type (die, attr_mem, type_mem), 71 &eltsize) != 0) 72 return -1; 73 74 /* An array can have DW_TAG_subrange_type or DW_TAG_enumeration_type 75 children instead that give the size of each dimension. */ 76 77 Dwarf_Die child; 78 if (INTUSE(dwarf_child) (die, &child) != 0) 79 return -1; 80 81 bool any = false; 82 Dwarf_Word total = 0; 83 do 84 { 85 Dwarf_Word count; 86 switch (INTUSE(dwarf_tag) (&child)) 87 { 88 case DW_TAG_subrange_type: 89 /* This has either DW_AT_count or DW_AT_upper_bound. */ 90 if (INTUSE(dwarf_attr_integrate) (&child, DW_AT_count, 91 attr_mem) != NULL) 92 { 93 if (INTUSE(dwarf_formudata) (attr_mem, &count) != 0) 94 return -1; 95 } 96 else 97 { 98 Dwarf_Sword upper; 99 Dwarf_Sword lower; 100 if (INTUSE(dwarf_formsdata) (INTUSE(dwarf_attr_integrate) 101 (&child, DW_AT_upper_bound, 102 attr_mem), &upper) != 0) 103 return -1; 104 105 /* Having DW_AT_lower_bound is optional. */ 106 if (INTUSE(dwarf_attr_integrate) (&child, DW_AT_lower_bound, 107 attr_mem) != NULL) 108 { 109 if (INTUSE(dwarf_formsdata) (attr_mem, &lower) != 0) 110 return -1; 111 } 112 else 113 { 114 /* Determine default lower bound from language, 115 as per "4.12 Subrange Type Entries". */ 116 Dwarf_Die cu = CUDIE (die->cu); 117 switch (INTUSE(dwarf_srclang) (&cu)) 118 { 119 case DW_LANG_C: 120 case DW_LANG_C89: 121 case DW_LANG_C99: 122 case DW_LANG_C_plus_plus: 123 case DW_LANG_Objc: 124 case DW_LANG_ObjC_plus_plus: 125 case DW_LANG_Java: 126 case DW_LANG_D: 127 case DW_LANG_UPC: 128 lower = 0; 129 break; 130 131 case DW_LANG_Ada83: 132 case DW_LANG_Ada95: 133 case DW_LANG_Cobol74: 134 case DW_LANG_Cobol85: 135 case DW_LANG_Fortran77: 136 case DW_LANG_Fortran90: 137 case DW_LANG_Fortran95: 138 case DW_LANG_Pascal83: 139 case DW_LANG_Modula2: 140 case DW_LANG_PL1: 141 lower = 1; 142 break; 143 144 default: 145 return -1; 146 } 147 } 148 if (unlikely (lower > upper)) 149 return -1; 150 count = upper - lower + 1; 151 } 152 break; 153 154 case DW_TAG_enumeration_type: 155 /* We have to find the DW_TAG_enumerator child with the 156 highest value to know the array's element count. */ 157 count = 0; 158 Dwarf_Die enum_child; 159 int has_children = INTUSE(dwarf_child) (die, &enum_child); 160 if (has_children < 0) 161 return -1; 162 if (has_children > 0) 163 do 164 if (INTUSE(dwarf_tag) (&enum_child) == DW_TAG_enumerator) 165 { 166 Dwarf_Word value; 167 if (INTUSE(dwarf_formudata) (INTUSE(dwarf_attr_integrate) 168 (&enum_child, DW_AT_const_value, 169 attr_mem), &value) != 0) 170 return -1; 171 if (value >= count) 172 count = value + 1; 173 } 174 while (INTUSE(dwarf_siblingof) (&enum_child, &enum_child) > 0); 175 break; 176 177 default: 178 continue; 179 } 180 181 /* This is a subrange_type or enumeration_type and we've set COUNT. 182 Now determine the stride for this array dimension. */ 183 Dwarf_Word stride = eltsize; 184 if (INTUSE(dwarf_attr_integrate) (&child, DW_AT_byte_stride, 185 attr_mem) != NULL) 186 { 187 if (INTUSE(dwarf_formudata) (attr_mem, &stride) != 0) 188 return -1; 189 } 190 else if (INTUSE(dwarf_attr_integrate) (&child, DW_AT_bit_stride, 191 attr_mem) != NULL) 192 { 193 if (INTUSE(dwarf_formudata) (attr_mem, &stride) != 0) 194 return -1; 195 if (stride % 8) /* XXX maybe compute in bits? */ 196 return -1; 197 stride /= 8; 198 } 199 200 any = true; 201 total += stride * count; 202 } 203 while (INTUSE(dwarf_siblingof) (&child, &child) == 0); 204 205 if (!any) 206 return -1; 207 208 *size = total; 209 return 0; 210} 211 212static int 213aggregate_size (Dwarf_Die *die, Dwarf_Word *size, Dwarf_Die *type_mem) 214{ 215 Dwarf_Attribute attr_mem; 216 217 if (INTUSE(dwarf_attr_integrate) (die, DW_AT_byte_size, &attr_mem) != NULL) 218 return INTUSE(dwarf_formudata) (&attr_mem, size); 219 220 switch (INTUSE(dwarf_tag) (die)) 221 { 222 case DW_TAG_typedef: 223 case DW_TAG_subrange_type: 224 return aggregate_size (get_type (die, &attr_mem, type_mem), 225 size, type_mem); /* Tail call. */ 226 227 case DW_TAG_array_type: 228 return array_size (die, size, &attr_mem, type_mem); 229 } 230 231 /* Most types must give their size directly. */ 232 return -1; 233} 234 235int 236dwarf_aggregate_size (die, size) 237 Dwarf_Die *die; 238 Dwarf_Word *size; 239{ 240 Dwarf_Die type_mem; 241 return aggregate_size (die, size, &type_mem); 242} 243INTDEF (dwarf_aggregate_size) 244