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Bug 1460126 - Part 2: Merge TryEmitter::{ShouldUseRetVal,ShouldUseControl} into TryEmitter::ControlKind. r=jwalden

This commit is contained in:
Tooru Fujisawa 2018-05-31 15:15:50 +09:00
Родитель 855b95adc1
Коммит dabf454e17
1 изменённых файлов: 43 добавлений и 48 удалений
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91
js/src/frontend/BytecodeEmitter.cpp
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@ -1507,7 +1507,8 @@ BytecodeEmitter::TDZCheckCache::noteTDZCheck(BytecodeEmitter* bce, JSAtom* name,
// Usage: (check for the return value is omitted for simplicity)
//
// `try { try_block } catch (ex) { catch_block }`
// TryEmitter tryCatch(this, TryEmitter::Kind::TryCatch);
// TryEmitter tryCatch(this, TryEmitter::Kind::TryCatch,
// TryEmitter::ControlKind::Syntactic);
// tryCatch.emitTry();
// emit(try_block);
// tryCatch.emitCatch();
@ -1515,7 +1516,8 @@ BytecodeEmitter::TDZCheckCache::noteTDZCheck(BytecodeEmitter* bce, JSAtom* name,
// tryCatch.emitEnd();
//
// `try { try_block } finally { finally_block }`
// TryEmitter tryCatch(this, TryEmitter::Kind::TryFinally);
// TryEmitter tryCatch(this, TryEmitter::Kind::TryFinally,
// TryEmitter::ControlKind::Syntactic);
// tryCatch.emitTry();
// emit(try_block);
// // finally_pos: The "{" character's position in the source code text.
@ -1524,7 +1526,8 @@ BytecodeEmitter::TDZCheckCache::noteTDZCheck(BytecodeEmitter* bce, JSAtom* name,
// tryCatch.emitEnd();
//
// `try { try_block } catch (ex) {catch_block} finally { finally_block }`
// TryEmitter tryCatch(this, TryEmitter::Kind::TryCatchFinally);
// TryEmitter tryCatch(this, TryEmitter::Kind::TryCatchFinally,
// TryEmitter::ControlKind::Syntactic);
// tryCatch.emitTry();
// emit(try_block);
// tryCatch.emitCatch();
@ -1542,11 +1545,17 @@ class MOZ_STACK_CLASS TryEmitter
TryFinally
};
// Whether the catch and finally blocks handle the frame's return value.
// If UseRetVal is specified, the bytecode marked with "*" are emitted
// to clear return value with `undefined` before the catch block and the
// finally block, and also to save/restore the return value before/after
// the finally block.
// Syntactic try-catch-finally and internally used non-syntactic
// try-catch-finally behave differently for 2 points.
//
// The first one is whether TryFinallyControl is used or not.
// See the comment for `controlInfo_`.
//
// The second one is whether the catch and finally blocks handle the frame's
// return value. For syntactic try-catch-finally, the bytecode marked with
// "*" are emitted to clear return value with `undefined` before the catch
// block and the finally block, and also to save/restore the return value
// before/after the finally block.
//
// JSOP_TRY
//
@ -1581,27 +1590,17 @@ class MOZ_STACK_CLASS TryEmitter
// end:
// JSOP_JUMPTARGET
//
// For syntactic try-catch-finally, UseRetVal should be used.
// For non-syntactic try-catch-finally, DontUseRetVal should be used.
enum ShouldUseRetVal {
UseRetVal,
DontUseRetVal
};
// Whether this class should use TryFinallyControl.
// See the comment for `controlInfo_`.
//
// For syntactic try-catch-finally, UseControl should be used.
// For non-syntactic try-catch-finally, DontUseControl should be used.
enum ShouldUseControl {
UseControl,
DontUseControl,
// For syntactic try-catch-finally, Syntactic should be used.
// For non-syntactic try-catch-finally, NonSyntactic should be used.
enum class ControlKind {
Syntactic,
NonSyntactic
};
private:
BytecodeEmitter* bce_;
Kind kind_;
ShouldUseRetVal retValKind_;
ControlKind controlKind_;
// Track jumps-over-catches and gosubs-to-finally for later fixup.
//
@ -1609,19 +1608,17 @@ class MOZ_STACK_CLASS TryEmitter
// jumps-over-catches) result in a GOSUB being written into the bytecode
// stream and fixed-up later.
//
// If ShouldUseControl is DontUseControl, all that handling is skipped.
// DontUseControl is used by yield* and the internal try-catch around
// IteratorClose. These internal uses must:
// For non-syntactic try-catch-finally, all that handling is skipped.
// The non-syntactic try-catch-finally must:
// * have only one catch block
// * have JSOP_GOTO at the end of catch-block
// * have no non-local-jump
// * don't use finally block for normal completion of try-block and
// catch-block
//
// Additionally, a finally block may be emitted when ShouldUseControl is
// DontUseControl, even if the kind is not TryCatchFinally or TryFinally,
// because GOSUBs are not emitted. This internal use shares the
// requirements as above.
// Additionally, a finally block may be emitted for non-syntactic
// try-catch-finally, even if the kind is TryCatch, because GOSUBs are not
// emitted.
Maybe<TryFinallyControl> controlInfo_;
// The stack depth before emitting JSOP_TRY.
@ -1679,17 +1676,16 @@ class MOZ_STACK_CLASS TryEmitter
}
public:
TryEmitter(BytecodeEmitter* bce, Kind kind, ShouldUseRetVal retValKind = UseRetVal,
ShouldUseControl controlKind = UseControl)
TryEmitter(BytecodeEmitter* bce, Kind kind, ControlKind controlKind)
: bce_(bce),
kind_(kind),
retValKind_(retValKind),
controlKind_(controlKind),
depth_(0),
noteIndex_(0),
tryStart_(0),
state_(State::Start)
{
if (controlKind == UseControl)
if (controlKind_ == ControlKind::Syntactic)
controlInfo_.emplace(bce_, hasFinally() ? StatementKind::Finally : StatementKind::Try);
finallyStart_.offset = 0;
}
@ -1758,7 +1754,7 @@ class MOZ_STACK_CLASS TryEmitter
MOZ_ASSERT(bce_->stackDepth == depth_);
if (retValKind_ == UseRetVal) {
if (controlKind_ == ControlKind::Syntactic) {
// Clear the frame's return value that might have been set by the
// try block:
//
@ -1802,9 +1798,10 @@ class MOZ_STACK_CLASS TryEmitter
bool emitFinally(const Maybe<uint32_t>& finallyPos = Nothing()) {
// If we are using controlInfo_ (i.e., emitting a syntactic try
// blocks), we must have specified up front if there will be a finally
// close. For internal try blocks, like those emitted for yield* and
// IteratorClose inside for-of loops, we can emitFinally even without
// specifying up front, since the internal try blocks emit no GOSUBs.
// close. For internal non-syntactic try blocks, like those emitted for
// yield* and IteratorClose inside for-of loops, we can emitFinally even
// without specifying up front, since the internal non-syntactic try
// blocks emit no GOSUBs.
if (!controlInfo_) {
if (kind_ == Kind::TryCatch)
kind_ = Kind::TryCatchFinally;
@ -1841,7 +1838,7 @@ class MOZ_STACK_CLASS TryEmitter
if (!bce_->emit1(JSOP_FINALLY))
return false;
if (retValKind_ == UseRetVal) {
if (controlKind_ == ControlKind::Syntactic) {
if (!bce_->emit1(JSOP_GETRVAL))
return false;
@ -1863,7 +1860,7 @@ class MOZ_STACK_CLASS TryEmitter
bool emitFinallyEnd() {
MOZ_ASSERT(state_ == State::Finally);
if (retValKind_ == UseRetVal) {
if (controlKind_ == ControlKind::Syntactic) {
if (!bce_->emit1(JSOP_SETRVAL))
return false;
}
@ -2263,8 +2260,7 @@ class ForOfLoopControl : public LoopControl
}
bool emitBeginCodeNeedingIteratorClose(BytecodeEmitter* bce) {
tryCatch_.emplace(bce, TryEmitter::Kind::TryCatch, TryEmitter::DontUseRetVal,
TryEmitter::DontUseControl);
tryCatch_.emplace(bce, TryEmitter::Kind::TryCatch, TryEmitter::ControlKind::NonSyntactic);
if (!tryCatch_->emitTry())
return false;
@ -5536,8 +5532,7 @@ BytecodeEmitter::emitIteratorCloseInScope(EmitterScope& currentScope,
Maybe<TryEmitter> tryCatch;
if (completionKind == CompletionKind::Throw) {
tryCatch.emplace(this, TryEmitter::Kind::TryCatch, TryEmitter::DontUseRetVal,
TryEmitter::DontUseControl);
tryCatch.emplace(this, TryEmitter::Kind::TryCatch, TryEmitter::ControlKind::NonSyntactic);
// Mutate stack to balance stack for try-catch.
if (!emit1(JSOP_UNDEFINED)) // ... RET ITER UNDEF
@ -6872,7 +6867,7 @@ BytecodeEmitter::emitTry(ParseNode* pn)
MOZ_ASSERT(finallyNode);
kind = TryEmitter::Kind::TryFinally;
}
TryEmitter tryCatch(this, kind);
TryEmitter tryCatch(this, kind, TryEmitter::ControlKind::Syntactic);
if (!tryCatch.emitTry())
return false;
@ -8618,8 +8613,8 @@ BytecodeEmitter::emitYieldStar(ParseNode* iter)
int32_t startDepth = stackDepth;
MOZ_ASSERT(startDepth >= 3);
TryEmitter tryCatch(this, TryEmitter::Kind::TryCatchFinally, TryEmitter::DontUseRetVal,
TryEmitter::DontUseControl);
TryEmitter tryCatch(this, TryEmitter::Kind::TryCatchFinally,
TryEmitter::ControlKind::NonSyntactic);
if (!tryCatch.emitJumpOverCatchAndFinally()) // NEXT ITER RESULT
return false;