| // 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 |