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
|
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "frontend/PropOpEmitter.h"
#include "frontend/BytecodeEmitter.h"
#include "frontend/SharedContext.h"
#include "vm/Opcodes.h"
#include "vm/StringType.h"
#include "vm/ThrowMsgKind.h" // ThrowMsgKind
using namespace js;
using namespace js::frontend;
PropOpEmitter::PropOpEmitter(BytecodeEmitter* bce, Kind kind, ObjKind objKind)
: bce_(bce), kind_(kind), objKind_(objKind) {}
bool PropOpEmitter::prepareAtomIndex(const ParserAtom* prop) {
return bce_->makeAtomIndex(prop, &propAtomIndex_);
}
bool PropOpEmitter::prepareForObj() {
MOZ_ASSERT(state_ == State::Start);
#ifdef DEBUG
state_ = State::Obj;
#endif
return true;
}
bool PropOpEmitter::emitGet(const ParserAtom* prop) {
MOZ_ASSERT(state_ == State::Obj);
if (!prepareAtomIndex(prop)) {
return false;
}
if (isCall()) {
if (!bce_->emit1(JSOp::Dup)) {
// [stack] # if Super
// [stack] THIS THIS
// [stack] # otherwise
// [stack] OBJ OBJ
return false;
}
}
if (isSuper()) {
if (!bce_->emitSuperBase()) {
// [stack] THIS? THIS SUPERBASE
return false;
}
}
if (isIncDec() || isCompoundAssignment()) {
if (isSuper()) {
if (!bce_->emit1(JSOp::Dup2)) {
// [stack] THIS SUPERBASE THIS SUPERBASE
return false;
}
} else {
if (!bce_->emit1(JSOp::Dup)) {
// [stack] OBJ OBJ
return false;
}
}
}
JSOp op = isSuper() ? JSOp::GetPropSuper : JSOp::GetProp;
if (!bce_->emitAtomOp(op, propAtomIndex_, ShouldInstrument::Yes)) {
// [stack] # if Get
// [stack] PROP
// [stack] # if Call
// [stack] THIS PROP
// [stack] # if Inc/Dec/Compound, Super]
// [stack] THIS SUPERBASE PROP
// [stack] # if Inc/Dec/Compound, other
// [stack] OBJ PROP
return false;
}
if (isCall()) {
if (!bce_->emit1(JSOp::Swap)) {
// [stack] PROP THIS
return false;
}
}
#ifdef DEBUG
state_ = State::Get;
#endif
return true;
}
bool PropOpEmitter::prepareForRhs() {
MOZ_ASSERT(isSimpleAssignment() || isPropInit() || isCompoundAssignment());
MOZ_ASSERT_IF(isSimpleAssignment() || isPropInit(), state_ == State::Obj);
MOZ_ASSERT_IF(isCompoundAssignment(), state_ == State::Get);
if (isSimpleAssignment() || isPropInit()) {
// For CompoundAssignment, SuperBase is already emitted by emitGet.
if (isSuper()) {
if (!bce_->emitSuperBase()) {
// [stack] THIS SUPERBASE
return false;
}
}
}
#ifdef DEBUG
state_ = State::Rhs;
#endif
return true;
}
bool PropOpEmitter::skipObjAndRhs() {
MOZ_ASSERT(state_ == State::Start);
MOZ_ASSERT(isSimpleAssignment() || isPropInit());
#ifdef DEBUG
state_ = State::Rhs;
#endif
return true;
}
bool PropOpEmitter::emitDelete(const ParserAtom* prop) {
MOZ_ASSERT_IF(!isSuper(), state_ == State::Obj);
MOZ_ASSERT_IF(isSuper(), state_ == State::Start);
MOZ_ASSERT(isDelete());
if (!prepareAtomIndex(prop)) {
return false;
}
if (isSuper()) {
if (!bce_->emitSuperBase()) {
// [stack] THIS SUPERBASE
return false;
}
// Unconditionally throw when attempting to delete a super-reference.
if (!bce_->emit2(JSOp::ThrowMsg, uint8_t(ThrowMsgKind::CantDeleteSuper))) {
// [stack] THIS SUPERBASE
return false;
}
// Another wrinkle: Balance the stack from the emitter's point of view.
// Execution will not reach here, as the last bytecode threw.
if (!bce_->emit1(JSOp::Pop)) {
// [stack] THIS
return false;
}
} else {
JSOp op = bce_->sc->strict() ? JSOp::StrictDelProp : JSOp::DelProp;
if (!bce_->emitAtomOp(op, propAtomIndex_)) {
// [stack] SUCCEEDED
return false;
}
}
#ifdef DEBUG
state_ = State::Delete;
#endif
return true;
}
bool PropOpEmitter::emitAssignment(const ParserAtom* prop) {
MOZ_ASSERT(isSimpleAssignment() || isPropInit() || isCompoundAssignment());
MOZ_ASSERT(state_ == State::Rhs);
if (isSimpleAssignment() || isPropInit()) {
if (!prepareAtomIndex(prop)) {
return false;
}
}
MOZ_ASSERT_IF(isPropInit(), !isSuper());
JSOp setOp = isPropInit() ? JSOp::InitProp
: isSuper() ? bce_->sc->strict() ? JSOp::StrictSetPropSuper
: JSOp::SetPropSuper
: bce_->sc->strict() ? JSOp::StrictSetProp
: JSOp::SetProp;
if (!bce_->emitAtomOp(setOp, propAtomIndex_, ShouldInstrument::Yes)) {
// [stack] VAL
return false;
}
#ifdef DEBUG
state_ = State::Assignment;
#endif
return true;
}
bool PropOpEmitter::emitIncDec(const ParserAtom* prop) {
MOZ_ASSERT(state_ == State::Obj);
MOZ_ASSERT(isIncDec());
if (!emitGet(prop)) {
return false;
}
MOZ_ASSERT(state_ == State::Get);
JSOp incOp = isInc() ? JSOp::Inc : JSOp::Dec;
if (!bce_->emit1(JSOp::ToNumeric)) {
// [stack] ... N
return false;
}
if (isPostIncDec()) {
// [stack] OBJ SUPERBASE? N
if (!bce_->emit1(JSOp::Dup)) {
// [stack] .. N N
return false;
}
if (!bce_->emit2(JSOp::Unpick, 2 + isSuper())) {
// [stack] N OBJ SUPERBASE? N
return false;
}
}
if (!bce_->emit1(incOp)) {
// [stack] ... N+1
return false;
}
JSOp setOp = isSuper() ? bce_->sc->strict() ? JSOp::StrictSetPropSuper
: JSOp::SetPropSuper
: bce_->sc->strict() ? JSOp::StrictSetProp
: JSOp::SetProp;
if (!bce_->emitAtomOp(setOp, propAtomIndex_, ShouldInstrument::Yes)) {
// [stack] N? N+1
return false;
}
if (isPostIncDec()) {
if (!bce_->emit1(JSOp::Pop)) {
// [stack] N
return false;
}
}
#ifdef DEBUG
state_ = State::IncDec;
#endif
return true;
}
|
