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
|
/* -*- 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/WhileEmitter.h"
#include "frontend/BytecodeEmitter.h"
#include "vm/Opcodes.h"
#include "vm/StencilEnums.h" // TryNoteKind
using namespace js;
using namespace js::frontend;
WhileEmitter::WhileEmitter(BytecodeEmitter* bce) : bce_(bce) {}
bool WhileEmitter::emitCond(uint32_t whilePos, uint32_t condPos,
uint32_t endPos) {
MOZ_ASSERT(state_ == State::Start);
// If we have a single-line while, like "while (x) ;", we want to emit the
// line note before the loop, so that the debugger sees a single entry point.
// This way, if there is a breakpoint on the line, it will only fire once; and
// "next"ing will skip the whole loop. However, for the multi-line case we
// want to emit the line note for the JSOp::LoopHead, so that "cont" stops on
// each iteration -- but without a stop before the first iteration.
if (bce_->errorReporter().lineAt(whilePos) ==
bce_->errorReporter().lineAt(endPos)) {
if (!bce_->updateSourceCoordNotes(whilePos)) {
return false;
}
// Emit a Nop to ensure the source position is not part of the loop.
if (!bce_->emit1(JSOp::Nop)) {
return false;
}
}
loopInfo_.emplace(bce_, StatementKind::WhileLoop);
if (!loopInfo_->emitLoopHead(bce_, mozilla::Some(condPos))) {
return false;
}
#ifdef DEBUG
state_ = State::Cond;
#endif
return true;
}
bool WhileEmitter::emitBody() {
MOZ_ASSERT(state_ == State::Cond);
if (!bce_->emitJump(JSOp::JumpIfFalse, &loopInfo_->breaks)) {
return false;
}
tdzCacheForBody_.emplace(bce_);
#ifdef DEBUG
state_ = State::Body;
#endif
return true;
}
bool WhileEmitter::emitEnd() {
MOZ_ASSERT(state_ == State::Body);
tdzCacheForBody_.reset();
if (!loopInfo_->emitContinueTarget(bce_)) {
return false;
}
if (!loopInfo_->emitLoopEnd(bce_, JSOp::Goto, TryNoteKind::Loop)) {
return false;
}
loopInfo_.reset();
#ifdef DEBUG
state_ = State::End;
#endif
return true;
}
#ifdef ENABLE_DECORATORS
bool InternalWhileEmitter::emitCond() {
MOZ_ASSERT(state_ == State::Start);
loopInfo_.emplace(bce_, StatementKind::WhileLoop);
if (!loopInfo_->emitLoopHead(bce_, mozilla::Nothing())) {
return false;
}
# ifdef DEBUG
state_ = State::Cond;
# endif
return true;
}
#endif
|
