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1 : : /* Return DWARF attribute associated with a location expression op. 2 : : Copyright (C) 2013, 2014, 2017, 2018 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 : : static Dwarf_CU * 37 : 43215 : attr_form_cu (Dwarf_Attribute *attr) 38 : : { 39 : : /* If the attribute has block/expr form the data comes from the 40 : : .debug_info from the same cu as the attr. Otherwise it comes from 41 : : the .debug_loc or .debug_loclists data section. */ 42 [ + + ]: 43215 : switch (attr->form) 43 : : { 44 : 2560 : case DW_FORM_block1: 45 : : case DW_FORM_block2: 46 : : case DW_FORM_block4: 47 : : case DW_FORM_block: 48 : : case DW_FORM_exprloc: 49 : 2560 : return attr->cu; 50 : 40655 : default: 51 : 40655 : return (attr->cu->version < 5 52 : 40637 : ? attr->cu->dbg->fake_loc_cu 53 [ + + ]: 40655 : : attr->cu->dbg->fake_loclists_cu); 54 : : } 55 : : } 56 : : 57 : : static unsigned char * 58 : 41 : addr_valp (Dwarf_CU *cu, Dwarf_Word index) 59 : : { 60 : 41 : Elf_Data *debug_addr = cu->dbg->sectiondata[IDX_debug_addr]; 61 [ - + ]: 41 : if (debug_addr == NULL) 62 : : { 63 : 0 : __libdw_seterrno (DWARF_E_NO_DEBUG_ADDR); 64 : 0 : return NULL; 65 : : } 66 : : 67 : 41 : Dwarf_Word offset = __libdw_cu_addr_base (cu) + (index * cu->address_size); 68 : 41 : return (unsigned char *) debug_addr->d_buf + offset; 69 : : } 70 : : 71 : : int 72 : 47404 : dwarf_getlocation_attr (Dwarf_Attribute *attr, const Dwarf_Op *op, Dwarf_Attribute *result) 73 : : { 74 [ + - ]: 47404 : if (attr == NULL) 75 : : return -1; 76 : : 77 [ + + + + : 47404 : switch (op->atom) + - + - ] 78 : : { 79 : 1160 : case DW_OP_implicit_value: 80 : 1160 : result->code = DW_AT_const_value; 81 : 1160 : result->form = DW_FORM_block; 82 : 1160 : result->valp = (unsigned char *) (uintptr_t) op->number2; 83 : 1160 : result->cu = attr_form_cu (attr); 84 : 1160 : break; 85 : : 86 : 41940 : case DW_OP_entry_value: 87 : : case DW_OP_GNU_entry_value: 88 : 41940 : result->code = DW_AT_location; 89 : 41940 : result->form = DW_FORM_exprloc; 90 : 41940 : result->valp = (unsigned char *) (uintptr_t) op->number2; 91 : 41940 : result->cu = attr_form_cu (attr); 92 : 41940 : break; 93 : : 94 : 115 : case DW_OP_const_type: 95 : : case DW_OP_GNU_const_type: 96 : 115 : result->code = DW_AT_const_value; 97 : 115 : result->form = DW_FORM_block1; 98 : 115 : result->valp = (unsigned char *) (uintptr_t) op->number2; 99 : 115 : result->cu = attr_form_cu (attr); 100 : 115 : break; 101 : : 102 : 18 : case DW_OP_GNU_const_index: 103 : : case DW_OP_constx: 104 : 18 : result->code = DW_AT_const_value; 105 [ - + ]: 18 : if (attr->cu->address_size == 4) 106 : 0 : result->form = DW_FORM_data4; 107 : : else 108 : 18 : result->form = DW_FORM_data8; 109 : 18 : result->valp = addr_valp (attr->cu, op->number); 110 [ + - ]: 18 : if (result->valp == NULL) 111 : : return -1; 112 : 18 : result->cu = attr->cu->dbg->fake_addr_cu; 113 : 18 : break; 114 : : 115 : 23 : case DW_OP_GNU_addr_index: 116 : : case DW_OP_addrx: 117 : 23 : result->code = DW_AT_low_pc; 118 : 23 : result->form = DW_FORM_addr; 119 : 23 : result->valp = addr_valp (attr->cu, op->number); 120 [ + - ]: 23 : if (result->valp == NULL) 121 : : return -1; 122 : 23 : result->cu = attr->cu->dbg->fake_addr_cu; 123 : 23 : break; 124 : : 125 : 0 : case DW_OP_call2: 126 : : case DW_OP_call4: 127 : : case DW_OP_call_ref: 128 : : { 129 : 0 : Dwarf_Die die; 130 [ # # ]: 0 : if (INTUSE(dwarf_getlocation_die) (attr, op, &die) != 0) 131 : 0 : return -1; 132 [ # # ]: 0 : if (INTUSE(dwarf_attr) (&die, DW_AT_location, result) == NULL) 133 : : { 134 : 0 : __libdw_empty_loc_attr (result); 135 : 0 : return 0; 136 : : } 137 : : } 138 : 0 : break; 139 : : 140 : 4148 : case DW_OP_implicit_pointer: 141 : : case DW_OP_GNU_implicit_pointer: 142 : : case DW_OP_GNU_variable_value: 143 : : { 144 : 4148 : Dwarf_Die die; 145 [ + - ]: 4148 : if (INTUSE(dwarf_getlocation_die) (attr, op, &die) != 0) 146 : 6 : return -1; 147 [ + + ]: 4148 : if (INTUSE(dwarf_attr) (&die, DW_AT_location, result) == NULL 148 [ + - ]: 6 : && INTUSE(dwarf_attr) (&die, DW_AT_const_value, result) == NULL) 149 : : { 150 : 6 : __libdw_empty_loc_attr (result); 151 : 6 : return 0; 152 : : } 153 : : } 154 : 4142 : break; 155 : : 156 : 0 : default: 157 : 0 : __libdw_seterrno (DWARF_E_INVALID_ACCESS); 158 : 0 : return -1; 159 : : } 160 : : 161 : : return 0; 162 : : }