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- // Copyright 2017 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #include "components/zucchini/image_index.h"
- #include <algorithm>
- #include <utility>
- #include "components/zucchini/algorithm.h"
- #include "components/zucchini/disassembler.h"
- namespace zucchini {
- ImageIndex::ImageIndex(ConstBufferView image)
- : image_(image), type_tags_(image.size(), kNoTypeTag) {}
- ImageIndex::ImageIndex(ImageIndex&&) = default;
- ImageIndex::~ImageIndex() = default;
- bool ImageIndex::Initialize(Disassembler* disasm) {
- std::vector<ReferenceGroup> ref_groups = disasm->MakeReferenceGroups();
- for (const auto& group : ref_groups) {
- // Build pool-to-type mapping.
- DCHECK_NE(kNoPoolTag, group.pool_tag());
- TargetPool& target_pool = target_pools_[group.pool_tag()];
- target_pool.AddType(group.type_tag());
- target_pool.InsertTargets(std::move(*group.GetReader(disasm)));
- }
- for (const auto& group : ref_groups) {
- // Find and store all references for each type, returns false on finding
- // any overlap, to signal error.
- if (!InsertReferences(group.traits(),
- std::move(*group.GetReader(disasm)))) {
- return false;
- }
- }
- return true;
- }
- bool ImageIndex::IsToken(offset_t location) const {
- TypeTag type = LookupType(location);
- // |location| points into raw data.
- if (type == kNoTypeTag)
- return true;
- // |location| points into a Reference.
- Reference reference = refs(type).at(location);
- // Only the first byte of a reference is a token.
- return location == reference.location;
- }
- bool ImageIndex::InsertReferences(const ReferenceTypeTraits& traits,
- ReferenceReader&& ref_reader) {
- // Store ReferenceSet for current type (of |group|).
- DCHECK_NE(kNoTypeTag, traits.type_tag);
- auto result = reference_sets_.emplace(
- traits.type_tag, ReferenceSet(traits, pool(traits.pool_tag)));
- DCHECK(result.second);
- result.first->second.InitReferences(std::move(ref_reader));
- for (auto ref : reference_sets_.at(traits.type_tag)) {
- DCHECK(RangeIsBounded(ref.location, traits.width, size()));
- auto cur_type_tag = type_tags_.begin() + ref.location;
- // Check for overlap with existing reference. If found, then invalidate.
- if (std::any_of(cur_type_tag, cur_type_tag + traits.width,
- [](TypeTag type) { return type != kNoTypeTag; })) {
- return false;
- }
- std::fill(cur_type_tag, cur_type_tag + traits.width, traits.type_tag);
- }
- return true;
- }
- } // namespace zucchini
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