1 /* Return unsigned constant represented by attribute. 2 Copyright (C) 2003-2012 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 Written by Ulrich Drepper <drepper (at) redhat.com>, 2003. 5 6 Red Hat elfutils is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by the 8 Free Software Foundation; version 2 of the License. 9 10 Red Hat elfutils is distributed in the hope that it will be useful, but 11 WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 General Public License for more details. 14 15 You should have received a copy of the GNU General Public License along 16 with Red Hat elfutils; if not, write to the Free Software Foundation, 17 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 18 19 In addition, as a special exception, Red Hat, Inc. gives You the 20 additional right to link the code of Red Hat elfutils with code licensed 21 under any Open Source Initiative certified open source license 22 (http://www.opensource.org/licenses/index.php) which requires the 23 distribution of source code with any binary distribution and to 24 distribute linked combinations of the two. Non-GPL Code permitted under 25 this exception must only link to the code of Red Hat elfutils through 26 those well defined interfaces identified in the file named EXCEPTION 27 found in the source code files (the "Approved Interfaces"). The files 28 of Non-GPL Code may instantiate templates or use macros or inline 29 functions from the Approved Interfaces without causing the resulting 30 work to be covered by the GNU General Public License. Only Red Hat, 31 Inc. may make changes or additions to the list of Approved Interfaces. 32 Red Hat's grant of this exception is conditioned upon your not adding 33 any new exceptions. If you wish to add a new Approved Interface or 34 exception, please contact Red Hat. You must obey the GNU General Public 35 License in all respects for all of the Red Hat elfutils code and other 36 code used in conjunction with Red Hat elfutils except the Non-GPL Code 37 covered by this exception. If you modify this file, you may extend this 38 exception to your version of the file, but you are not obligated to do 39 so. If you do not wish to provide this exception without modification, 40 you must delete this exception statement from your version and license 41 this file solely under the GPL without exception. 42 43 Red Hat elfutils is an included package of the Open Invention Network. 44 An included package of the Open Invention Network is a package for which 45 Open Invention Network licensees cross-license their patents. No patent 46 license is granted, either expressly or impliedly, by designation as an 47 included package. Should you wish to participate in the Open Invention 48 Network licensing program, please visit www.openinventionnetwork.com 49 <http://www.openinventionnetwork.com>. */ 50 51 #ifdef HAVE_CONFIG_H 52 # include <config.h> 53 #endif 54 55 #include <dwarf.h> 56 #include "libdwP.h" 57 58 internal_function unsigned char * 59 __libdw_formptr (Dwarf_Attribute *attr, int sec_index, 60 int err_nodata, unsigned char **endpp, 61 Dwarf_Off *offsetp) 62 { 63 if (attr == NULL) 64 return NULL; 65 66 const Elf_Data *d = attr->cu->dbg->sectiondata[sec_index]; 67 if (unlikely (d == NULL)) 68 { 69 __libdw_seterrno (err_nodata); 70 return NULL; 71 } 72 73 Dwarf_Word offset; 74 if (attr->form == DW_FORM_sec_offset) 75 { 76 if (__libdw_read_offset (attr->cu->dbg, cu_sec_idx (attr->cu), attr->valp, 77 attr->cu->offset_size, &offset, sec_index, 0)) 78 return NULL; 79 } 80 else if (attr->cu->version > 3) 81 goto invalid; 82 else 83 switch (attr->form) 84 { 85 case DW_FORM_data4: 86 case DW_FORM_data8: 87 if (__libdw_read_offset (attr->cu->dbg, cu_sec_idx (attr->cu), 88 attr->valp, 89 attr->form == DW_FORM_data4 ? 4 : 8, 90 &offset, sec_index, 0)) 91 return NULL; 92 break; 93 94 default: 95 if (INTUSE(dwarf_formudata) (attr, &offset)) 96 return NULL; 97 }; 98 99 unsigned char *readp = d->d_buf + offset; 100 unsigned char *endp = d->d_buf + d->d_size; 101 if (unlikely (readp >= endp)) 102 { 103 invalid: 104 __libdw_seterrno (DWARF_E_INVALID_DWARF); 105 return NULL; 106 } 107 108 if (endpp != NULL) 109 *endpp = endp; 110 if (offsetp != NULL) 111 *offsetp = offset; 112 return readp; 113 } 114 115 int 116 dwarf_formudata (attr, return_uval) 117 Dwarf_Attribute *attr; 118 Dwarf_Word *return_uval; 119 { 120 if (attr == NULL) 121 return -1; 122 123 const unsigned char *datap; 124 125 switch (attr->form) 126 { 127 case DW_FORM_data1: 128 *return_uval = *attr->valp; 129 break; 130 131 case DW_FORM_data2: 132 *return_uval = read_2ubyte_unaligned (attr->cu->dbg, attr->valp); 133 break; 134 135 case DW_FORM_data4: 136 case DW_FORM_data8: 137 case DW_FORM_sec_offset: 138 /* Before DWARF4 data4 and data8 are pure constants unless the 139 attribute also allows offsets (*ptr classes), since DWARF4 140 they are always just constants (start_scope is special though, 141 since it only could express a rangelist since DWARF4). */ 142 if (attr->form == DW_FORM_sec_offset 143 || (attr->cu->version < 4 && attr->code != DW_AT_start_scope)) 144 { 145 switch (attr->code) 146 { 147 case DW_AT_data_member_location: 148 case DW_AT_frame_base: 149 case DW_AT_location: 150 case DW_AT_return_addr: 151 case DW_AT_segment: 152 case DW_AT_static_link: 153 case DW_AT_string_length: 154 case DW_AT_use_location: 155 case DW_AT_vtable_elem_location: 156 /* loclistptr */ 157 if (__libdw_formptr (attr, IDX_debug_loc, 158 DWARF_E_NO_LOCLIST, NULL, 159 return_uval) == NULL) 160 return -1; 161 break; 162 163 case DW_AT_macro_info: 164 /* macptr */ 165 if (__libdw_formptr (attr, IDX_debug_macinfo, 166 DWARF_E_NO_ENTRY, NULL, 167 return_uval) == NULL) 168 return -1; 169 break; 170 171 case DW_AT_ranges: 172 case DW_AT_start_scope: 173 /* rangelistptr */ 174 if (__libdw_formptr (attr, IDX_debug_ranges, 175 DWARF_E_NO_DEBUG_RANGES, NULL, 176 return_uval) == NULL) 177 return -1; 178 break; 179 180 case DW_AT_stmt_list: 181 /* lineptr */ 182 if (__libdw_formptr (attr, IDX_debug_line, 183 DWARF_E_NO_DEBUG_LINE, NULL, 184 return_uval) == NULL) 185 return -1; 186 break; 187 188 default: 189 /* sec_offset can only be used by one of the above attrs. */ 190 if (attr->form == DW_FORM_sec_offset) 191 { 192 __libdw_seterrno (DWARF_E_INVALID_DWARF); 193 return -1; 194 } 195 196 /* Not one of the special attributes, just a constant. */ 197 if (__libdw_read_address (attr->cu->dbg, cu_sec_idx (attr->cu), 198 attr->valp, 199 attr->form == DW_FORM_data4 ? 4 : 8, 200 return_uval)) 201 return -1; 202 break; 203 } 204 } 205 else 206 { 207 /* We are dealing with a constant data4 or data8. */ 208 if (__libdw_read_address (attr->cu->dbg, cu_sec_idx (attr->cu), 209 attr->valp, 210 attr->form == DW_FORM_data4 ? 4 : 8, 211 return_uval)) 212 return -1; 213 } 214 break; 215 216 case DW_FORM_sdata: 217 datap = attr->valp; 218 get_sleb128 (*return_uval, datap); 219 break; 220 221 case DW_FORM_udata: 222 datap = attr->valp; 223 get_uleb128 (*return_uval, datap); 224 break; 225 226 default: 227 __libdw_seterrno (DWARF_E_NO_CONSTANT); 228 return -1; 229 } 230 231 return 0; 232 } 233 INTDEF(dwarf_formudata) 234
