1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
// 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
|
