Handle frame pointer omission (#21), part 1: ContainedRangeMap. r=bryner.

- ContainedRangeMap is the data structure that will be used to store and
   look up debugging information for frames by instruction address.  The
   debugging information includes a way to locate the calling frame in
   the absence of a saved frame pointer.
 - Restructure RangeMap into an -inl file to match ContainedRangeMap.

http://groups.google.com/group/airbag-dev/browse_thread/thread/c5823bfc1828ed42


git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@29 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/processor/contained_range_map-inl.h

@@ -0,0 +1,157 @@
+// Copyright (C) 2006 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// contained_range_map-inl.h: Hierarchically-organized range map implementation.
+//
+// See contained_range_map.h for documentation.
+//
+// Author: Mark Mentovai
+
+#ifndef PROCESSOR_CONTAINED_RANGE_MAP_INL_H__
+#define PROCESSOR_CONTAINED_RANGE_MAP_INL_H__
+
+
+#include "processor/contained_range_map.h"
+
+
+namespace google_airbag {
+
+
+template<typename AddressType, typename EntryType>
+ContainedRangeMap<AddressType, EntryType>::~ContainedRangeMap() {
+  // Clear frees the children pointed to by the map, and frees the map itself.
+  Clear();
+}
+
+
+template<typename AddressType, typename EntryType>
+bool ContainedRangeMap<AddressType, EntryType>::StoreRange(
+    const AddressType &base, const AddressType &size, const EntryType &entry) {
+  AddressType high = base + size - 1;
+
+  // Check for undersize or overflow.
+  if (size <= 0 || high < base)
+    return false;
+
+  if (!map_)
+    map_ = new AddressToRangeMap();
+
+  MapIterator iterator_base = map_->lower_bound(base);
+  MapIterator iterator_high = map_->lower_bound(high);
+  MapConstIterator iterator_end = map_->end();
+
+  if (iterator_base == iterator_high && iterator_base != iterator_end &&
+      base >= iterator_base->second->base_) {
+    // The new range is entirely within an existing child range.
+
+    // If the new range's geometry is exactly equal to an existing child
+    // range's, it violates the containment rules, and an attempt to store
+    // it must fail.  iterator_base->first contains the key, which was the
+    // containing child's high address.
+    if (iterator_base->second->base_ == base && iterator_base->first == high)
+      return false;
+
+    // Pass the new range on to the child to attempt to store.
+    return iterator_base->second->StoreRange(base, size, entry);
+  }
+
+  // iterator_high might refer to an irrelevant range: one whose base address
+  // is higher than the new range's high address.  Set contains_high to true
+  // only if iterator_high refers to a range that is at least partially
+  // within the new range.
+  bool contains_high = iterator_high != iterator_end &&
+                       high >= iterator_high->second->base_;
+
+  // If the new range encompasses any existing child ranges, it must do so
+  // fully.  Partial containment isn't allowed.
+  if ((iterator_base != iterator_end && base > iterator_base->second->base_) ||
+      (contains_high && high < iterator_high->first)) {
+    return false;
+  }
+
+  // When copying and erasing contained ranges, the "end" iterator needs to
+  // point one past the last item of the range to copy.  If contains_high is
+  // false, the iterator's already in the right place; the increment is safe
+  // because contains_high can't be true if iterator_high == iterator_end.
+  if (contains_high)
+    ++iterator_high;
+
+  // Optimization: if the iterators are equal, no child ranges would be
+  // moved.  Create the new child range with a NULL map to conserve space
+  // in leaf nodes, of which there will be many.
+  AddressToRangeMap *child_map = NULL;
+
+  if (iterator_base != iterator_high) {
+    // The children of this range that are contained by the new range must
+    // be transferred over to the new range.  Create the new child range map
+    // and copy the pointers to range maps it should contain into it.
+    child_map = new AddressToRangeMap(iterator_base, iterator_high);
+
+    // Remove the copied child pointers from this range's map of children.
+    map_->erase(iterator_base, iterator_high);
+  }
+
+  // Store the new range in the map by its high address.  Any children that
+  // the new child range contains were formerly children of this range but
+  // are now this range's grandchildren.  Ownership of these is transferred
+  // to the new child range.
+  map_->insert(MapValue(high,
+                        new ContainedRangeMap(base, entry, child_map)));
+  return true;
+}
+
+
+template<typename AddressType, typename EntryType>
+bool ContainedRangeMap<AddressType, EntryType>::RetrieveRange(
+    const AddressType &address, EntryType *entry) const {
+  if (!entry || !map_)
+    return false;
+
+  // Get an iterator to the child range whose high address is equal to or
+  // greater than the supplied address.  If the supplied address is higher
+  // than all of the high addresses in the range, then this range does not
+  // contain a child at address, so return false.  If the supplied address
+  // is lower than the base address of the child range, then it is not within
+  // the child range, so return false.
+  MapConstIterator iterator = map_->lower_bound(address);
+  if (iterator == map_->end() || address < iterator->second->base_)
+    return false;
+
+  // The child in iterator->second contains the specified address.  Find out
+  // if it has a more-specific descendant that also contains it.  If it does,
+  // it will set |entry| appropriately.  If not, set |entry| to the child.
+  if (!iterator->second->RetrieveRange(address, entry))
+    *entry = iterator->second->entry_;
+
+  return true;
+}
+
+
+template<typename AddressType, typename EntryType>
+void ContainedRangeMap<AddressType, EntryType>::Clear() {
+  if (map_) {
+    MapConstIterator end = map_->end();
+    for (MapConstIterator child = map_->begin(); child != end; ++child)
+      delete child->second;
+
+    delete map_;
+    map_ = NULL;
+  }
+}
+
+
+}  // namespace google_airbag
+
+
+#endif  // PROCESSOR_CONTAINED_RANGE_MAP_INL_H__