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 (Dwarf *dbg, bool debug_types) 67 { 68 Dwarf_Off *const offsetp 69 = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset; 70 void **tree = debug_types ? &dbg->tu_tree : &dbg->cu_tree; 71 72 Dwarf_Off oldoff = *offsetp; 73 uint16_t version; 74 uint8_t address_size; 75 uint8_t offset_size; 76 Dwarf_Off abbrev_offset; 77 uint64_t type_sig8 = 0; 78 Dwarf_Off type_offset = 0; 79 80 if (INTUSE(dwarf_next_unit) (dbg, oldoff, offsetp, NULL, 81 &version, &abbrev_offset, 82 &address_size, &offset_size, 83 debug_types ? &type_sig8 : NULL, 84 debug_types ? &type_offset : NULL) != 0) 85 /* No more entries. */ 86 return NULL; 87 88 /* We only know how to handle the DWARF version 2 through 4 formats. */ 89 if (unlikely (version < 2) || unlikely (version > 4)) 90 { 91 __libdw_seterrno (DWARF_E_INVALID_DWARF); 92 return NULL; 93 } 94 95 /* Invalid or truncated debug section data? */ 96 Elf_Data *data = dbg->sectiondata[debug_types 97 ? IDX_debug_types : IDX_debug_info]; 98 if (unlikely (*offsetp > data->d_size)) 99 *offsetp = data->d_size; 100 101 /* Create an entry for this CU. */ 102 struct Dwarf_CU *newp = libdw_typed_alloc (dbg, struct Dwarf_CU); 103 104 newp->dbg = dbg; 105 newp->start = oldoff; 106 newp->end = *offsetp; 107 newp->address_size = address_size; 108 newp->offset_size = offset_size; 109 newp->version = version; 110 newp->type_sig8 = type_sig8; 111 newp->type_offset = type_offset; 112 Dwarf_Abbrev_Hash_init (&newp->abbrev_hash, 41); 113 newp->orig_abbrev_offset = newp->last_abbrev_offset = abbrev_offset; 114 newp->lines = NULL; 115 newp->locs = NULL; 116 117 if (debug_types) 118 Dwarf_Sig8_Hash_insert (&dbg->sig8_hash, type_sig8, newp); 119 120 newp->startp = data->d_buf + newp->start; 121 newp->endp = data->d_buf + newp->end; 122 123 /* Add the new entry to the search tree. */ 124 if (tsearch (newp, tree, findcu_cb) == NULL) 125 { 126 /* Something went wrong. Undo the operation. */ 127 *offsetp = oldoff; 128 __libdw_seterrno (DWARF_E_NOMEM); 129 return NULL; 130 } 131 132 return newp; 133 } 134 135 struct Dwarf_CU * 136 internal_function 137 __libdw_findcu (Dwarf *dbg, Dwarf_Off start, bool debug_types) 138 { 139 void **tree = debug_types ? &dbg->tu_tree : &dbg->cu_tree; 140 Dwarf_Off *next_offset 141 = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset; 142 143 /* Maybe we already know that CU. */ 144 struct Dwarf_CU fake = { .start = start, .end = 0 }; 145 struct Dwarf_CU **found = tfind (&fake, tree, findcu_cb); 146 if (found != NULL) 147 return *found; 148 149 if (start < *next_offset) 150 { 151 __libdw_seterrno (DWARF_E_INVALID_DWARF); 152 return NULL; 153 } 154 155 /* No. Then read more CUs. */ 156 while (1) 157 { 158 struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg, debug_types); 159 if (newp == NULL) 160 return NULL; 161 162 /* Is this the one we are looking for? */ 163 if (start < *next_offset) 164 // XXX Match exact offset. 165 return newp; 166 } 167 /* NOTREACHED */ 168 } 169
