1 /* Find CU for given offset. 2 Copyright (C) 2003-2010, 2014 Red Hat, Inc. 3 This file is part of elfutils. 4 Written by Ulrich Drepper <drepper (at) redhat.com>, 2003. 5 6 This file is free software; you can redistribute it and/or modify 7 it under the terms of either 8 9 * the GNU Lesser General Public License as published by the Free 10 Software Foundation; either version 3 of the License, or (at 11 your option) any later version 12 13 or 14 15 * the GNU General Public License as published by the Free 16 Software Foundation; either version 2 of the License, or (at 17 your option) any later version 18 19 or both in parallel, as here. 20 21 elfutils is distributed in the hope that it will be useful, but 22 WITHOUT ANY WARRANTY; without even the implied warranty of 23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 24 General Public License for more details. 25 26 You should have received copies of the GNU General Public License and 27 the GNU Lesser General Public License along with this program. If 28 not, see <http://www.gnu.org/licenses/>. */ 29 30 #ifdef HAVE_CONFIG_H 31 # include <config.h> 32 #endif 33 34 #include <assert.h> 35 #include <search.h> 36 #include "libdwP.h" 37 38 static int 39 findcu_cb (const void *arg1, const void *arg2) 40 { 41 struct Dwarf_CU *cu1 = (struct Dwarf_CU *) arg1; 42 struct Dwarf_CU *cu2 = (struct Dwarf_CU *) arg2; 43 44 /* Find out which of the two arguments is the search value. It has 45 end offset 0. */ 46 if (cu1->end == 0) 47 { 48 if (cu1->start < cu2->start) 49 return -1; 50 if (cu1->start >= cu2->end) 51 return 1; 52 } 53 else 54 { 55 if (cu2->start < cu1->start) 56 return 1; 57 if (cu2->start >= cu1->end) 58 return -1; 59 } 60 61 return 0; 62 } 63 64 struct Dwarf_CU * 65 internal_function 66 __libdw_intern_next_unit (dbg, debug_types) 67 Dwarf *dbg; 68 bool debug_types; 69 { 70 Dwarf_Off *const offsetp 71 = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset; 72 void **tree = debug_types ? &dbg->tu_tree : &dbg->cu_tree; 73 74 Dwarf_Off oldoff = *offsetp; 75 uint16_t version; 76 uint8_t address_size; 77 uint8_t offset_size; 78 Dwarf_Off abbrev_offset; 79 uint64_t type_sig8 = 0; 80 Dwarf_Off type_offset = 0; 81 82 if (INTUSE(dwarf_next_unit) (dbg, oldoff, offsetp, NULL, 83 &version, &abbrev_offset, 84 &address_size, &offset_size, 85 debug_types ? &type_sig8 : NULL, 86 debug_types ? &type_offset : NULL) != 0) 87 /* No more entries. */ 88 return NULL; 89 90 /* We only know how to handle the DWARF version 2 through 4 formats. */ 91 if (unlikely (version < 2) || unlikely (version > 4)) 92 { 93 __libdw_seterrno (DWARF_E_INVALID_DWARF); 94 return NULL; 95 } 96 97 /* Invalid or truncated debug section data? */ 98 Elf_Data *data = dbg->sectiondata[debug_types 99 ? IDX_debug_types : IDX_debug_info]; 100 if (unlikely (*offsetp > data->d_size)) 101 *offsetp = data->d_size; 102 103 /* Create an entry for this CU. */ 104 struct Dwarf_CU *newp = libdw_typed_alloc (dbg, struct Dwarf_CU); 105 106 newp->dbg = dbg; 107 newp->start = oldoff; 108 newp->end = *offsetp; 109 newp->address_size = address_size; 110 newp->offset_size = offset_size; 111 newp->version = version; 112 newp->type_sig8 = type_sig8; 113 newp->type_offset = type_offset; 114 Dwarf_Abbrev_Hash_init (&newp->abbrev_hash, 41); 115 newp->orig_abbrev_offset = newp->last_abbrev_offset = abbrev_offset; 116 newp->lines = NULL; 117 newp->locs = NULL; 118 119 if (debug_types) 120 Dwarf_Sig8_Hash_insert (&dbg->sig8_hash, type_sig8, newp); 121 122 newp->startp = data->d_buf + newp->start; 123 newp->endp = data->d_buf + newp->end; 124 125 /* Add the new entry to the search tree. */ 126 if (tsearch (newp, tree, findcu_cb) == NULL) 127 { 128 /* Something went wrong. Undo the operation. */ 129 *offsetp = oldoff; 130 __libdw_seterrno (DWARF_E_NOMEM); 131 return NULL; 132 } 133 134 return newp; 135 } 136 137 struct Dwarf_CU * 138 __libdw_findcu (dbg, start, debug_types) 139 Dwarf *dbg; 140 Dwarf_Off start; 141 bool debug_types; 142 { 143 void **tree = debug_types ? &dbg->tu_tree : &dbg->cu_tree; 144 Dwarf_Off *next_offset 145 = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset; 146 147 /* Maybe we already know that CU. */ 148 struct Dwarf_CU fake = { .start = start, .end = 0 }; 149 struct Dwarf_CU **found = tfind (&fake, tree, findcu_cb); 150 if (found != NULL) 151 return *found; 152 153 if (start < *next_offset) 154 { 155 __libdw_seterrno (DWARF_E_INVALID_DWARF); 156 return NULL; 157 } 158 159 /* No. Then read more CUs. */ 160 while (1) 161 { 162 struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg, debug_types); 163 if (newp == NULL) 164 return NULL; 165 166 /* Is this the one we are looking for? */ 167 if (start < *next_offset) 168 // XXX Match exact offset. 169 return newp; 170 } 171 /* NOTREACHED */ 172 } 173
