// 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 #include #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 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