Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame^] | 1 | /* Find CU for given offset. |
| 2 | Copyright (C) 2003-2010 Red Hat, Inc. |
| 3 | This file is part of Red Hat elfutils. |
| 4 | Written by Ulrich Drepper <drepper@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 |
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| 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 |
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| 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 | struct Dwarf_CU * |
| 61 | internal_function |
| 62 | __libdw_intern_next_unit (dbg, debug_types) |
| 63 | Dwarf *dbg; |
| 64 | bool debug_types; |
| 65 | { |
| 66 | Dwarf_Off *const offsetp |
| 67 | = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset; |
| 68 | |
| 69 | Dwarf_Off oldoff = *offsetp; |
| 70 | uint16_t version; |
| 71 | uint8_t address_size; |
| 72 | uint8_t offset_size; |
| 73 | Dwarf_Off abbrev_offset; |
| 74 | uint64_t type_sig8 = 0; |
| 75 | Dwarf_Off type_offset = 0; |
| 76 | |
| 77 | if (INTUSE(dwarf_next_unit) (dbg, oldoff, offsetp, NULL, |
| 78 | &version, &abbrev_offset, |
| 79 | &address_size, &offset_size, |
| 80 | debug_types ? &type_sig8 : NULL, |
| 81 | debug_types ? &type_offset : NULL) != 0) |
| 82 | /* No more entries. */ |
| 83 | return NULL; |
| 84 | |
| 85 | /* We only know how to handle the DWARF version 2 through 4 formats. */ |
| 86 | if (unlikely (version < 2) || unlikely (version > 4)) |
| 87 | { |
| 88 | __libdw_seterrno (DWARF_E_INVALID_DWARF); |
| 89 | return NULL; |
| 90 | } |
| 91 | |
| 92 | /* Create an entry for this CU. */ |
| 93 | struct Dwarf_CU *newp = libdw_typed_alloc (dbg, struct Dwarf_CU); |
| 94 | |
| 95 | newp->dbg = dbg; |
| 96 | newp->start = oldoff; |
| 97 | newp->end = *offsetp; |
| 98 | newp->address_size = address_size; |
| 99 | newp->offset_size = offset_size; |
| 100 | newp->version = version; |
| 101 | newp->type_sig8 = type_sig8; |
| 102 | newp->type_offset = type_offset; |
| 103 | Dwarf_Abbrev_Hash_init (&newp->abbrev_hash, 41); |
| 104 | newp->orig_abbrev_offset = newp->last_abbrev_offset = abbrev_offset; |
| 105 | newp->lines = NULL; |
| 106 | newp->locs = NULL; |
| 107 | |
| 108 | return newp; |
| 109 | } |
| 110 | |
| 111 | |
| 112 | static int |
| 113 | findcu_cb (const void *arg1, const void *arg2) |
| 114 | { |
| 115 | struct Dwarf_CU *cu1 = (struct Dwarf_CU *) arg1; |
| 116 | struct Dwarf_CU *cu2 = (struct Dwarf_CU *) arg2; |
| 117 | |
| 118 | /* Find out which of the two arguments is the search value. It has |
| 119 | end offset 0. */ |
| 120 | if (cu1->end == 0) |
| 121 | { |
| 122 | if (cu1->start < cu2->start) |
| 123 | return -1; |
| 124 | if (cu1->start >= cu2->end) |
| 125 | return 1; |
| 126 | } |
| 127 | else |
| 128 | { |
| 129 | if (cu2->start < cu1->start) |
| 130 | return 1; |
| 131 | if (cu2->start >= cu1->end) |
| 132 | return -1; |
| 133 | } |
| 134 | |
| 135 | return 0; |
| 136 | } |
| 137 | |
| 138 | struct Dwarf_CU * |
| 139 | __libdw_findcu (dbg, start, debug_types) |
| 140 | Dwarf *dbg; |
| 141 | Dwarf_Off start; |
| 142 | bool debug_types; |
| 143 | { |
| 144 | void **tree = debug_types ? &dbg->tu_tree : &dbg->cu_tree; |
| 145 | Dwarf_Off *next_offset |
| 146 | = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset; |
| 147 | |
| 148 | /* Maybe we already know that CU. */ |
| 149 | struct Dwarf_CU fake = { .start = start, .end = 0 }; |
| 150 | struct Dwarf_CU **found = tfind (&fake, tree, findcu_cb); |
| 151 | if (found != NULL) |
| 152 | return *found; |
| 153 | |
| 154 | if (start < *next_offset) |
| 155 | { |
| 156 | __libdw_seterrno (DWARF_E_INVALID_DWARF); |
| 157 | return NULL; |
| 158 | } |
| 159 | |
| 160 | /* No. Then read more CUs. */ |
| 161 | while (1) |
| 162 | { |
| 163 | Dwarf_Off oldoff = *next_offset; |
| 164 | struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg, debug_types); |
| 165 | if (newp == NULL) |
| 166 | return NULL; |
| 167 | |
| 168 | /* Add the new entry to the search tree. */ |
| 169 | if (tsearch (newp, tree, findcu_cb) == NULL) |
| 170 | { |
| 171 | /* Something went wrong. Undo the operation. */ |
| 172 | *next_offset = oldoff; |
| 173 | __libdw_seterrno (DWARF_E_NOMEM); |
| 174 | return NULL; |
| 175 | } |
| 176 | |
| 177 | /* Is this the one we are looking for? */ |
| 178 | if (start < *next_offset) |
| 179 | // XXX Match exact offset. |
| 180 | return newp; |
| 181 | } |
| 182 | /* NOTREACHED */ |
| 183 | } |