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
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
|
// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_PARSING_PREPARSE_DATA_IMPL_H_
#define V8_PARSING_PREPARSE_DATA_IMPL_H_
#include "src/parsing/preparse-data.h"
#include <memory>
#include "src/common/assert-scope.h"
namespace v8 {
namespace internal {
// Classes which are internal to prepared-scope-data.cc, but are exposed in
// a header for tests.
// Wraps a ZoneVector<uint8_t> to have with functions named the same as
// PodArray<uint8_t>.
class ZoneVectorWrapper {
public:
ZoneVectorWrapper() = default;
explicit ZoneVectorWrapper(ZoneVector<uint8_t>* data) : data_(data) {}
int data_length() const { return static_cast<int>(data_->size()); }
uint8_t get(int index) const { return data_->at(index); }
private:
ZoneVector<uint8_t>* data_ = nullptr;
};
template <class Data>
class BaseConsumedPreparseData : public ConsumedPreparseData {
public:
class ByteData : public PreparseByteDataConstants {
public:
ByteData() {}
// Reading from the ByteData is only allowed when a ReadingScope is on the
// stack. This ensures that we have a DisallowHeapAllocation in place
// whenever ByteData holds a raw pointer into the heap.
class ReadingScope {
public:
ReadingScope(ByteData* consumed_data, Data data)
: consumed_data_(consumed_data) {
consumed_data->data_ = data;
#ifdef DEBUG
consumed_data->has_data_ = true;
#endif
}
explicit ReadingScope(BaseConsumedPreparseData<Data>* parent)
: ReadingScope(parent->scope_data_.get(), parent->GetScopeData()) {}
~ReadingScope() {
#ifdef DEBUG
consumed_data_->has_data_ = false;
#endif
}
private:
ByteData* consumed_data_;
DISALLOW_HEAP_ALLOCATION(no_gc)
};
void SetPosition(int position) {
DCHECK_LE(position, data_.data_length());
index_ = position;
}
size_t RemainingBytes() const {
DCHECK(has_data_);
DCHECK_LE(index_, data_.data_length());
return data_.data_length() - index_;
}
bool HasRemainingBytes(size_t bytes) const {
DCHECK(has_data_);
return index_ <= data_.data_length() && bytes <= RemainingBytes();
}
int32_t ReadUint32() {
DCHECK(has_data_);
DCHECK(HasRemainingBytes(kUint32Size));
// Check that there indeed is an integer following.
DCHECK_EQ(data_.get(index_++), kUint32Size);
int32_t result = data_.get(index_) + (data_.get(index_ + 1) << 8) +
(data_.get(index_ + 2) << 16) +
(data_.get(index_ + 3) << 24);
index_ += 4;
stored_quarters_ = 0;
return result;
}
int32_t ReadVarint32() {
DCHECK(HasRemainingBytes(kVarint32MinSize));
DCHECK_EQ(data_.get(index_++), kVarint32MinSize);
int32_t value = 0;
bool has_another_byte;
unsigned shift = 0;
do {
uint8_t byte = data_.get(index_++);
value |= static_cast<int32_t>(byte & 0x7F) << shift;
shift += 7;
has_another_byte = byte & 0x80;
} while (has_another_byte);
DCHECK_EQ(data_.get(index_++), kVarint32EndMarker);
stored_quarters_ = 0;
return value;
}
uint8_t ReadUint8() {
DCHECK(has_data_);
DCHECK(HasRemainingBytes(kUint8Size));
// Check that there indeed is a byte following.
DCHECK_EQ(data_.get(index_++), kUint8Size);
stored_quarters_ = 0;
return data_.get(index_++);
}
uint8_t ReadQuarter() {
DCHECK(has_data_);
if (stored_quarters_ == 0) {
DCHECK(HasRemainingBytes(kUint8Size));
// Check that there indeed are quarters following.
DCHECK_EQ(data_.get(index_++), kQuarterMarker);
stored_byte_ = data_.get(index_++);
stored_quarters_ = 4;
}
// Read the first 2 bits from stored_byte_.
uint8_t result = (stored_byte_ >> 6) & 3;
DCHECK_LE(result, 3);
--stored_quarters_;
stored_byte_ <<= 2;
return result;
}
private:
Data data_ = {};
int index_ = 0;
uint8_t stored_quarters_ = 0;
uint8_t stored_byte_ = 0;
#ifdef DEBUG
bool has_data_ = false;
#endif
};
BaseConsumedPreparseData() : scope_data_(new ByteData()), child_index_(0) {}
virtual Data GetScopeData() = 0;
virtual ProducedPreparseData* GetChildData(Zone* zone, int child_index) = 0;
ProducedPreparseData* GetDataForSkippableFunction(
Zone* zone, int start_position, int* end_position, int* num_parameters,
int* function_length, int* num_inner_functions, bool* uses_super_property,
LanguageMode* language_mode) final;
void RestoreScopeAllocationData(DeclarationScope* scope,
AstValueFactory* ast_value_factory) final;
#ifdef DEBUG
bool VerifyDataStart();
#endif
private:
void RestoreDataForScope(Scope* scope, AstValueFactory* ast_value_factory);
void RestoreDataForVariable(Variable* var);
void RestoreDataForInnerScopes(Scope* scope,
AstValueFactory* ast_value_factory);
std::unique_ptr<ByteData> scope_data_;
// When consuming the data, these indexes point to the data we're going to
// consume next.
int child_index_;
DISALLOW_COPY_AND_ASSIGN(BaseConsumedPreparseData);
};
// Implementation of ConsumedPreparseData for on-heap data.
class OnHeapConsumedPreparseData final
: public BaseConsumedPreparseData<PreparseData> {
public:
OnHeapConsumedPreparseData(Isolate* isolate, Handle<PreparseData> data);
PreparseData GetScopeData() final;
ProducedPreparseData* GetChildData(Zone* zone, int child_index) final;
private:
Isolate* isolate_;
Handle<PreparseData> data_;
};
// A serialized PreparseData in zone memory (as apposed to being on-heap).
class ZonePreparseData : public ZoneObject {
public:
V8_EXPORT_PRIVATE ZonePreparseData(Zone* zone, Vector<uint8_t>* byte_data,
int child_length);
Handle<PreparseData> Serialize(Isolate* isolate);
Handle<PreparseData> Serialize(OffThreadIsolate* isolate);
int children_length() const { return static_cast<int>(children_.size()); }
ZonePreparseData* get_child(int index) { return children_[index]; }
void set_child(int index, ZonePreparseData* child) {
DCHECK_NOT_NULL(child);
children_[index] = child;
}
ZoneVector<uint8_t>* byte_data() { return &byte_data_; }
private:
ZoneVector<uint8_t> byte_data_;
ZoneVector<ZonePreparseData*> children_;
DISALLOW_COPY_AND_ASSIGN(ZonePreparseData);
};
ZonePreparseData* PreparseDataBuilder::ByteData::CopyToZone(
Zone* zone, int children_length) {
DCHECK(is_finalized_);
return new (zone) ZonePreparseData(zone, &zone_byte_data_, children_length);
}
// Implementation of ConsumedPreparseData for PreparseData
// serialized into zone memory.
class ZoneConsumedPreparseData final
: public BaseConsumedPreparseData<ZoneVectorWrapper> {
public:
ZoneConsumedPreparseData(Zone* zone, ZonePreparseData* data);
ZoneVectorWrapper GetScopeData() final;
ProducedPreparseData* GetChildData(Zone* zone, int child_index) final;
private:
ZonePreparseData* data_;
ZoneVectorWrapper scope_data_wrapper_;
};
} // namespace internal
} // namespace v8
#endif // V8_PARSING_PREPARSE_DATA_IMPL_H_
|