1 /* Find CU for given offset. 2 Copyright (C) 2003, 2004, 2005, 2007 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 <assert.h> 56 #include <search.h> 57 #include "libdwP.h" 58 59 60 static int 61 findcu_cb (const void *arg1, const void *arg2) 62 { 63 struct Dwarf_CU *cu1 = (struct Dwarf_CU *) arg1; 64 struct Dwarf_CU *cu2 = (struct Dwarf_CU *) arg2; 65 66 /* Find out which of the two arguments is the search value. It has 67 end offset 0. */ 68 if (cu1->end == 0) 69 { 70 if (cu1->start < cu2->start) 71 return -1; 72 if (cu1->start >= cu2->end) 73 return 1; 74 } 75 else 76 { 77 if (cu2->start < cu1->start) 78 return 1; 79 if (cu2->start >= cu1->end) 80 return -1; 81 } 82 83 return 0; 84 } 85 86 87 struct Dwarf_CU * 88 __libdw_findcu (dbg, start) 89 Dwarf *dbg; 90 Dwarf_Off start; 91 { 92 /* Maybe we already know that CU. */ 93 struct Dwarf_CU fake = { .start = start, .end = 0 }; 94 struct Dwarf_CU **found = tfind (&fake, &dbg->cu_tree, findcu_cb); 95 if (found != NULL) 96 return *found; 97 98 if (start < dbg->next_cu_offset) 99 { 100 invalid: 101 __libdw_seterrno (DWARF_E_INVALID_DWARF); 102 return NULL; 103 } 104 105 /* No. Then read more CUs. */ 106 while (1) 107 { 108 Dwarf_Off oldoff = dbg->next_cu_offset; 109 uint8_t address_size; 110 uint8_t offset_size; 111 Dwarf_Off abbrev_offset; 112 113 if (INTUSE(dwarf_nextcu) (dbg, oldoff, &dbg->next_cu_offset, NULL, 114 &abbrev_offset, &address_size, &offset_size) 115 != 0) 116 /* No more entries. */ 117 return NULL; 118 119 /* XXX We need the version number but dwarf_nextcu swallows it. */ 120 const char *bytes = (dbg->sectiondata[IDX_debug_info]->d_buf + oldoff 121 + (2 * offset_size - 4)); 122 uint16_t version = read_2ubyte_unaligned (dbg, bytes); 123 124 /* We only know how to handle the DWARF version 2 and 3 formats. */ 125 if (unlikely (version != 2) && unlikely (version != 3)) 126 goto invalid; 127 128 /* Create an entry for this CU. */ 129 struct Dwarf_CU *newp = libdw_typed_alloc (dbg, struct Dwarf_CU); 130 131 newp->dbg = dbg; 132 newp->start = oldoff; 133 newp->end = dbg->next_cu_offset; 134 newp->address_size = address_size; 135 newp->offset_size = offset_size; 136 newp->version = version; 137 Dwarf_Abbrev_Hash_init (&newp->abbrev_hash, 41); 138 newp->orig_abbrev_offset = newp->last_abbrev_offset = abbrev_offset; 139 newp->lines = NULL; 140 newp->locs = NULL; 141 142 /* Add the new entry to the search tree. */ 143 if (tsearch (newp, &dbg->cu_tree, findcu_cb) == NULL) 144 { 145 /* Something went wrong. Unfo the operation. */ 146 dbg->next_cu_offset = oldoff; 147 __libdw_seterrno (DWARF_E_NOMEM); 148 return NULL; 149 } 150 151 /* Is this the one we are looking for? */ 152 if (start < dbg->next_cu_offset) 153 // XXX Match exact offset. 154 return newp; 155 } 156 /* NOTREACHED */ 157 } 158
