toolkit/crashreporter/google-breakpad/src/processor/contained_range_map-inl.h

Wed, 31 Dec 2014 06:09:35 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Wed, 31 Dec 2014 06:09:35 +0100
changeset 0
6474c204b198
permissions
-rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

michael@0 1 // Copyright (c) 2006, Google Inc.
michael@0 2 // All rights reserved.
michael@0 3 //
michael@0 4 // Redistribution and use in source and binary forms, with or without
michael@0 5 // modification, are permitted provided that the following conditions are
michael@0 6 // met:
michael@0 7 //
michael@0 8 // * Redistributions of source code must retain the above copyright
michael@0 9 // notice, this list of conditions and the following disclaimer.
michael@0 10 // * Redistributions in binary form must reproduce the above
michael@0 11 // copyright notice, this list of conditions and the following disclaimer
michael@0 12 // in the documentation and/or other materials provided with the
michael@0 13 // distribution.
michael@0 14 // * Neither the name of Google Inc. nor the names of its
michael@0 15 // contributors may be used to endorse or promote products derived from
michael@0 16 // this software without specific prior written permission.
michael@0 17 //
michael@0 18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0 19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0 20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0 21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
michael@0 22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
michael@0 23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
michael@0 24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0 25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0 26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0 27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
michael@0 28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0 29
michael@0 30 // contained_range_map-inl.h: Hierarchically-organized range map implementation.
michael@0 31 //
michael@0 32 // See contained_range_map.h for documentation.
michael@0 33 //
michael@0 34 // Author: Mark Mentovai
michael@0 35
michael@0 36 #ifndef PROCESSOR_CONTAINED_RANGE_MAP_INL_H__
michael@0 37 #define PROCESSOR_CONTAINED_RANGE_MAP_INL_H__
michael@0 38
michael@0 39 #include "processor/contained_range_map.h"
michael@0 40
michael@0 41 #include <assert.h>
michael@0 42
michael@0 43 #include "common/logging.h"
michael@0 44
michael@0 45
michael@0 46 namespace google_breakpad {
michael@0 47
michael@0 48
michael@0 49 template<typename AddressType, typename EntryType>
michael@0 50 ContainedRangeMap<AddressType, EntryType>::~ContainedRangeMap() {
michael@0 51 // Clear frees the children pointed to by the map, and frees the map itself.
michael@0 52 Clear();
michael@0 53 }
michael@0 54
michael@0 55
michael@0 56 template<typename AddressType, typename EntryType>
michael@0 57 bool ContainedRangeMap<AddressType, EntryType>::StoreRange(
michael@0 58 const AddressType &base, const AddressType &size, const EntryType &entry) {
michael@0 59 AddressType high = base + size - 1;
michael@0 60
michael@0 61 // Check for undersize or overflow.
michael@0 62 if (size <= 0 || high < base) {
michael@0 63 //TODO(nealsid) We are commenting this out in order to prevent
michael@0 64 // excessive logging. We plan to move to better logging as this
michael@0 65 // failure happens quite often and is expected(see comment in
michael@0 66 // basic_source_line_resolver.cc:671).
michael@0 67 // BPLOG(INFO) << "StoreRange failed, " << HexString(base) << "+"
michael@0 68 // << HexString(size) << ", " << HexString(high);
michael@0 69 return false;
michael@0 70 }
michael@0 71
michael@0 72 if (!map_)
michael@0 73 map_ = new AddressToRangeMap();
michael@0 74
michael@0 75 MapIterator iterator_base = map_->lower_bound(base);
michael@0 76 MapIterator iterator_high = map_->lower_bound(high);
michael@0 77 MapIterator iterator_end = map_->end();
michael@0 78
michael@0 79 if (iterator_base == iterator_high && iterator_base != iterator_end &&
michael@0 80 base >= iterator_base->second->base_) {
michael@0 81 // The new range is entirely within an existing child range.
michael@0 82
michael@0 83 // If the new range's geometry is exactly equal to an existing child
michael@0 84 // range's, it violates the containment rules, and an attempt to store
michael@0 85 // it must fail. iterator_base->first contains the key, which was the
michael@0 86 // containing child's high address.
michael@0 87 if (iterator_base->second->base_ == base && iterator_base->first == high) {
michael@0 88 // TODO(nealsid): See the TODO above on why this is commented out.
michael@0 89 // BPLOG(INFO) << "StoreRange failed, identical range is already "
michael@0 90 // "present: " << HexString(base) << "+" << HexString(size);
michael@0 91 return false;
michael@0 92 }
michael@0 93
michael@0 94 // Pass the new range on to the child to attempt to store.
michael@0 95 return iterator_base->second->StoreRange(base, size, entry);
michael@0 96 }
michael@0 97
michael@0 98 // iterator_high might refer to an irrelevant range: one whose base address
michael@0 99 // is higher than the new range's high address. Set contains_high to true
michael@0 100 // only if iterator_high refers to a range that is at least partially
michael@0 101 // within the new range.
michael@0 102 bool contains_high = iterator_high != iterator_end &&
michael@0 103 high >= iterator_high->second->base_;
michael@0 104
michael@0 105 // If the new range encompasses any existing child ranges, it must do so
michael@0 106 // fully. Partial containment isn't allowed.
michael@0 107 if ((iterator_base != iterator_end && base > iterator_base->second->base_) ||
michael@0 108 (contains_high && high < iterator_high->first)) {
michael@0 109 // TODO(mmentovai): Some symbol files will trip this check frequently
michael@0 110 // on STACK lines. Too many messages will be produced. These are more
michael@0 111 // suitable for a DEBUG channel than an INFO channel.
michael@0 112 // BPLOG(INFO) << "StoreRange failed, new range partially contains "
michael@0 113 // "existing range: " << HexString(base) << "+" <<
michael@0 114 // HexString(size);
michael@0 115 return false;
michael@0 116 }
michael@0 117
michael@0 118 // When copying and erasing contained ranges, the "end" iterator needs to
michael@0 119 // point one past the last item of the range to copy. If contains_high is
michael@0 120 // false, the iterator's already in the right place; the increment is safe
michael@0 121 // because contains_high can't be true if iterator_high == iterator_end.
michael@0 122 if (contains_high)
michael@0 123 ++iterator_high;
michael@0 124
michael@0 125 // Optimization: if the iterators are equal, no child ranges would be
michael@0 126 // moved. Create the new child range with a NULL map to conserve space
michael@0 127 // in leaf nodes, of which there will be many.
michael@0 128 AddressToRangeMap *child_map = NULL;
michael@0 129
michael@0 130 if (iterator_base != iterator_high) {
michael@0 131 // The children of this range that are contained by the new range must
michael@0 132 // be transferred over to the new range. Create the new child range map
michael@0 133 // and copy the pointers to range maps it should contain into it.
michael@0 134 child_map = new AddressToRangeMap(iterator_base, iterator_high);
michael@0 135
michael@0 136 // Remove the copied child pointers from this range's map of children.
michael@0 137 map_->erase(iterator_base, iterator_high);
michael@0 138 }
michael@0 139
michael@0 140 // Store the new range in the map by its high address. Any children that
michael@0 141 // the new child range contains were formerly children of this range but
michael@0 142 // are now this range's grandchildren. Ownership of these is transferred
michael@0 143 // to the new child range.
michael@0 144 map_->insert(MapValue(high,
michael@0 145 new ContainedRangeMap(base, entry, child_map)));
michael@0 146 return true;
michael@0 147 }
michael@0 148
michael@0 149
michael@0 150 template<typename AddressType, typename EntryType>
michael@0 151 bool ContainedRangeMap<AddressType, EntryType>::RetrieveRange(
michael@0 152 const AddressType &address, EntryType *entry) const {
michael@0 153 BPLOG_IF(ERROR, !entry) << "ContainedRangeMap::RetrieveRange requires "
michael@0 154 "|entry|";
michael@0 155 assert(entry);
michael@0 156
michael@0 157 // If nothing was ever stored, then there's nothing to retrieve.
michael@0 158 if (!map_)
michael@0 159 return false;
michael@0 160
michael@0 161 // Get an iterator to the child range whose high address is equal to or
michael@0 162 // greater than the supplied address. If the supplied address is higher
michael@0 163 // than all of the high addresses in the range, then this range does not
michael@0 164 // contain a child at address, so return false. If the supplied address
michael@0 165 // is lower than the base address of the child range, then it is not within
michael@0 166 // the child range, so return false.
michael@0 167 MapConstIterator iterator = map_->lower_bound(address);
michael@0 168 if (iterator == map_->end() || address < iterator->second->base_)
michael@0 169 return false;
michael@0 170
michael@0 171 // The child in iterator->second contains the specified address. Find out
michael@0 172 // if it has a more-specific descendant that also contains it. If it does,
michael@0 173 // it will set |entry| appropriately. If not, set |entry| to the child.
michael@0 174 if (!iterator->second->RetrieveRange(address, entry))
michael@0 175 *entry = iterator->second->entry_;
michael@0 176
michael@0 177 return true;
michael@0 178 }
michael@0 179
michael@0 180
michael@0 181 template<typename AddressType, typename EntryType>
michael@0 182 void ContainedRangeMap<AddressType, EntryType>::Clear() {
michael@0 183 if (map_) {
michael@0 184 MapConstIterator end = map_->end();
michael@0 185 for (MapConstIterator child = map_->begin(); child != end; ++child)
michael@0 186 delete child->second;
michael@0 187
michael@0 188 delete map_;
michael@0 189 map_ = NULL;
michael@0 190 }
michael@0 191 }
michael@0 192
michael@0 193
michael@0 194 } // namespace google_breakpad
michael@0 195
michael@0 196
michael@0 197 #endif // PROCESSOR_CONTAINED_RANGE_MAP_INL_H__

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