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-rw-r--r--js/src/frontend/BytecodeEmitter.cpp619
-rw-r--r--js/src/frontend/BytecodeEmitter.h6
2 files changed, 461 insertions, 164 deletions
diff --git a/js/src/frontend/BytecodeEmitter.cpp b/js/src/frontend/BytecodeEmitter.cpp
index a4cfeb753..fb141e92d 100644
--- a/js/src/frontend/BytecodeEmitter.cpp
+++ b/js/src/frontend/BytecodeEmitter.cpp
@@ -58,6 +58,7 @@ using mozilla::Some;
class BreakableControl;
class LabelControl;
class LoopControl;
+class ForOfLoopControl;
class TryFinallyControl;
static bool
@@ -152,6 +153,13 @@ BytecodeEmitter::NestableControl::is<LoopControl>() const
template <>
bool
+BytecodeEmitter::NestableControl::is<ForOfLoopControl>() const
+{
+ return kind_ == StatementKind::ForOfLoop;
+}
+
+template <>
+bool
BytecodeEmitter::NestableControl::is<TryFinallyControl>() const
{
return kind_ == StatementKind::Try || kind_ == StatementKind::Finally;
@@ -270,6 +278,64 @@ class LoopControl : public BreakableControl
}
};
+class ForOfLoopControl : public LoopControl
+{
+ // The stack depth of the iterator.
+ int32_t iterDepth_;
+
+ // for-of loops, when throwing from non-iterator code (i.e. from the body
+ // or from evaluating the LHS of the loop condition), need to call
+ // IteratorClose. If IteratorClose itself throws, we must not re-call
+ // IteratorClose. Since non-local jumps like break and return call
+ // IteratorClose, whenever a non-local jump is emitted, we must terminate
+ // the current JSTRY_ITERCLOSE note to skip the non-local jump code, then
+ // start a new one.
+ //
+ // Visually,
+ //
+ // for (x of y) {
+ // ... instantiate ForOfLoopControl
+ // ... + <-- iterCloseTryStart_ points to right before
+ // ... assignment to loop variable
+ // ... ^
+ // ... |
+ // if (...) v
+ // + call finishIterCloseTryNote before |break|
+ // above range is noted with JSTRY_ITERCLOSE
+ //
+ // break; <-- break and IteratorClose are not inside
+ // JSTRY_ITERCLOSE note
+ //
+ // call startNewIterCloseTryNote after |break|
+ // + <-- next iterCloseTryStart_ points here
+ // ... |
+ // ... ~
+ // }
+ ptrdiff_t iterCloseTryStart_;
+
+ public:
+ ForOfLoopControl(BytecodeEmitter* bce, int32_t iterDepth)
+ : LoopControl(bce, StatementKind::ForOfLoop),
+ iterDepth_(iterDepth),
+ iterCloseTryStart_(-1)
+ {
+ MOZ_ASSERT(bce->stackDepth >= iterDepth);
+ }
+
+ MOZ_MUST_USE bool finishIterCloseTryNote(BytecodeEmitter* bce) {
+ ptrdiff_t end = bce->offset();
+ MOZ_ASSERT(end >= iterCloseTryStart_);
+ if (end != iterCloseTryStart_)
+ return bce->tryNoteList.append(JSTRY_ITERCLOSE, iterDepth_, iterCloseTryStart_, end);
+ return true;
+ }
+
+ void startNewIterCloseTryNote(BytecodeEmitter* bce) {
+ MOZ_ASSERT(bce->offset() > iterCloseTryStart_);
+ iterCloseTryStart_ = bce->offset();
+ }
+};
+
class TryFinallyControl : public BytecodeEmitter::NestableControl
{
bool emittingSubroutine_;
@@ -1497,6 +1563,156 @@ BytecodeEmitter::TDZCheckCache::noteTDZCheck(BytecodeEmitter* bce, JSAtom* name,
return true;
}
+class MOZ_STACK_CLASS IfThenElseEmitter
+{
+ BytecodeEmitter* bce_;
+ JumpList jumpAroundThen_;
+ JumpList jumpsAroundElse_;
+ unsigned noteIndex_;
+ int32_t thenDepth_;
+#ifdef DEBUG
+ int32_t pushed_;
+ bool calculatedPushed_;
+#endif
+ enum State {
+ Start,
+ If,
+ Cond,
+ IfElse,
+ Else,
+ End
+ };
+ State state_;
+
+ public:
+ explicit IfThenElseEmitter(BytecodeEmitter* bce)
+ : bce_(bce),
+ noteIndex_(-1),
+ thenDepth_(0),
+#ifdef DEBUG
+ pushed_(0),
+ calculatedPushed_(false),
+#endif
+ state_(Start)
+ {}
+
+ ~IfThenElseEmitter()
+ {}
+
+ private:
+ bool emitIf(State nextState) {
+ MOZ_ASSERT(state_ == Start || state_ == Else);
+ MOZ_ASSERT(nextState == If || nextState == IfElse || nextState == Cond);
+
+ // Clear jumpAroundThen_ offset that points previous JSOP_IFEQ.
+ if (state_ == Else)
+ jumpAroundThen_ = JumpList();
+
+ // Emit an annotated branch-if-false around the then part.
+ SrcNoteType type = nextState == If ? SRC_IF : nextState == IfElse ? SRC_IF_ELSE : SRC_COND;
+ if (!bce_->newSrcNote(type, &noteIndex_))
+ return false;
+ if (!bce_->emitJump(JSOP_IFEQ, &jumpAroundThen_))
+ return false;
+
+ // To restore stack depth in else part, save depth of the then part.
+#ifdef DEBUG
+ // If DEBUG, this is also necessary to calculate |pushed_|.
+ thenDepth_ = bce_->stackDepth;
+#else
+ if (nextState == IfElse || nextState == Cond)
+ thenDepth_ = bce_->stackDepth;
+#endif
+ state_ = nextState;
+ return true;
+ }
+
+ public:
+ bool emitIf() {
+ return emitIf(If);
+ }
+
+ bool emitCond() {
+ return emitIf(Cond);
+ }
+
+ bool emitIfElse() {
+ return emitIf(IfElse);
+ }
+
+ bool emitElse() {
+ MOZ_ASSERT(state_ == IfElse || state_ == Cond);
+
+ calculateOrCheckPushed();
+
+ // Emit a jump from the end of our then part around the else part. The
+ // patchJumpsToTarget call at the bottom of this function will fix up
+ // the offset with jumpsAroundElse value.
+ if (!bce_->emitJump(JSOP_GOTO, &jumpsAroundElse_))
+ return false;
+
+ // Ensure the branch-if-false comes here, then emit the else.
+ if (!bce_->emitJumpTargetAndPatch(jumpAroundThen_))
+ return false;
+
+ // Annotate SRC_IF_ELSE or SRC_COND with the offset from branch to
+ // jump, for IonMonkey's benefit. We can't just "back up" from the pc
+ // of the else clause, because we don't know whether an extended
+ // jump was required to leap from the end of the then clause over
+ // the else clause.
+ if (!bce_->setSrcNoteOffset(noteIndex_, 0,
+ jumpsAroundElse_.offset - jumpAroundThen_.offset))
+ {
+ return false;
+ }
+
+ // Restore stack depth of the then part.
+ bce_->stackDepth = thenDepth_;
+ state_ = Else;
+ return true;
+ }
+
+ bool emitEnd() {
+ MOZ_ASSERT(state_ == If || state_ == Else);
+
+ calculateOrCheckPushed();
+
+ if (state_ == If) {
+ // No else part, fixup the branch-if-false to come here.
+ if (!bce_->emitJumpTargetAndPatch(jumpAroundThen_))
+ return false;
+ }
+
+ // Patch all the jumps around else parts.
+ if (!bce_->emitJumpTargetAndPatch(jumpsAroundElse_))
+ return false;
+
+ state_ = End;
+ return true;
+ }
+
+ void calculateOrCheckPushed() {
+#ifdef DEBUG
+ if (!calculatedPushed_) {
+ pushed_ = bce_->stackDepth - thenDepth_;
+ calculatedPushed_ = true;
+ } else {
+ MOZ_ASSERT(pushed_ == bce_->stackDepth - thenDepth_);
+ }
+#endif
+ }
+
+#ifdef DEBUG
+ int32_t pushed() const {
+ return pushed_;
+ }
+
+ int32_t popped() const {
+ return -pushed_;
+ }
+#endif
+};
+
BytecodeEmitter::BytecodeEmitter(BytecodeEmitter* parent,
Parser<FullParseHandler>* parser, SharedContext* sc,
HandleScript script, Handle<LazyScript*> lazyScript,
@@ -2013,22 +2229,43 @@ BytecodeEmitter::flushPops(int* npops)
namespace {
-class NonLocalExitControl {
+class NonLocalExitControl
+{
+ public:
+ enum Kind
+ {
+ // IteratorClose is handled especially inside the exception unwinder.
+ Throw,
+
+ // A 'continue' statement does not call IteratorClose for the loop it
+ // is continuing, i.e. excluding the target loop.
+ Continue,
+
+ // A 'break' or 'return' statement does call IteratorClose for the
+ // loop it is breaking out of or returning from, i.e. including the
+ // target loop.
+ Break,
+ Return
+ };
+
+ private:
BytecodeEmitter* bce_;
const uint32_t savedScopeNoteIndex_;
const int savedDepth_;
uint32_t openScopeNoteIndex_;
+ Kind kind_;
NonLocalExitControl(const NonLocalExitControl&) = delete;
MOZ_MUST_USE bool leaveScope(BytecodeEmitter::EmitterScope* scope);
public:
- explicit NonLocalExitControl(BytecodeEmitter* bce)
+ NonLocalExitControl(BytecodeEmitter* bce, Kind kind)
: bce_(bce),
savedScopeNoteIndex_(bce->scopeNoteList.length()),
savedDepth_(bce->stackDepth),
- openScopeNoteIndex_(bce->innermostEmitterScope->noteIndex())
+ openScopeNoteIndex_(bce->innermostEmitterScope->noteIndex()),
+ kind_(kind)
{ }
~NonLocalExitControl() {
@@ -2075,6 +2312,14 @@ NonLocalExitControl::prepareForNonLocalJump(BytecodeEmitter::NestableControl* ta
EmitterScope* es = bce_->innermostEmitterScope;
int npops = 0;
+ bool hasForOfLoopsWithIteratorClose = false;
+
+ // IteratorClose is handled specially in the exception unwinder. For
+ // 'continue', 'break', and 'return' statements, emit IteratorClose
+ // bytecode inline. 'continue' statements do not call IteratorClose for
+ // the loop they are continuing.
+ bool emitIteratorClose = kind_ == Continue || kind_ == Break || kind_ == Return;
+ bool emitIteratorCloseAtTarget = emitIteratorClose && kind_ != Continue;
auto flushPops = [&npops](BytecodeEmitter* bce) {
if (npops && !bce->flushPops(&npops))
@@ -2114,15 +2359,29 @@ NonLocalExitControl::prepareForNonLocalJump(BytecodeEmitter::NestableControl* ta
}
case StatementKind::ForOfLoop:
- npops += 2;
+ // The iterator and the current value are on the stack.
+ //
+ if (emitIteratorClose) {
+ hasForOfLoopsWithIteratorClose = true;
+ if (!control->as<ForOfLoopControl>().finishIterCloseTryNote(bce_))
+ return false;
+ if (!bce_->emit1(JSOP_POP)) // ... ITER
+ return false;
+ if (!bce_->emitIteratorClose()) // ...
+ return false;
+ } else {
+ if (!bce_->emit1(JSOP_POP)) // ... ITER
+ return false;
+ if (!bce_->emit1(JSOP_POP)) // ...
+ return false;
+ }
break;
case StatementKind::ForInLoop:
- /* The iterator and the current value are on the stack. */
- npops += 1;
- if (!flushPops(bce_))
+ // The iterator and the current value are on the stack.
+ if (!bce_->emit1(JSOP_POP)) // ... ITER
return false;
- if (!bce_->emit1(JSOP_ENDITER))
+ if (!bce_->emit1(JSOP_ENDITER)) // ...
return false;
break;
@@ -2131,13 +2390,45 @@ NonLocalExitControl::prepareForNonLocalJump(BytecodeEmitter::NestableControl* ta
}
}
+ if (target && target->is<ForOfLoopControl>() && emitIteratorCloseAtTarget) {
+ hasForOfLoopsWithIteratorClose = true;
+ if (!target->as<ForOfLoopControl>().finishIterCloseTryNote(bce_))
+ return false;
+
+ // The iterator and the current value are on the stack. At the level
+ // of the target block, there's bytecode after the loop that will pop
+ // the iterator and the value, so duplicate the iterator and call
+ // IteratorClose.
+ if (!bce_->emitDupAt(1)) // ... ITER RESULT ITER
+ return false;
+ if (!bce_->emitIteratorClose()) // ... ITER RESULT
+ return false;
+ }
+
EmitterScope* targetEmitterScope = target ? target->emitterScope() : bce_->varEmitterScope;
for (; es != targetEmitterScope; es = es->enclosingInFrame()) {
if (!leaveScope(es))
return false;
}
- return flushPops(bce_);
+ if (!flushPops(bce_))
+ return false;
+
+ // See comment in ForOfLoopControl.
+ if (hasForOfLoopsWithIteratorClose) {
+ for (NestableControl* control = bce_->innermostNestableControl;
+ control != target;
+ control = control->enclosing())
+ {
+ if (control->is<ForOfLoopControl>())
+ control->as<ForOfLoopControl>().startNewIterCloseTryNote(bce_);
+ }
+
+ if (target && target->is<ForOfLoopControl>() && emitIteratorCloseAtTarget)
+ target->as<ForOfLoopControl>().startNewIterCloseTryNote(bce_);
+ }
+
+ return true;
}
} // anonymous namespace
@@ -2145,7 +2436,9 @@ NonLocalExitControl::prepareForNonLocalJump(BytecodeEmitter::NestableControl* ta
bool
BytecodeEmitter::emitGoto(NestableControl* target, JumpList* jumplist, SrcNoteType noteType)
{
- NonLocalExitControl nle(this);
+ NonLocalExitControl nle(this, noteType == SRC_CONTINUE
+ ? NonLocalExitControl::Continue
+ : NonLocalExitControl::Break);
if (!nle.prepareForNonLocalJump(target))
return false;
@@ -4530,6 +4823,144 @@ BytecodeEmitter::emitIteratorNext(ParseNode* pn, bool allowSelfHosted)
}
bool
+BytecodeEmitter::emitIteratorClose(Maybe<JumpTarget> yieldStarTryStart, bool allowSelfHosted)
+{
+ MOZ_ASSERT(allowSelfHosted || emitterMode != BytecodeEmitter::SelfHosting,
+ ".close() on iterators is prohibited in self-hosted code because it "
+ "can run user-modifiable iteration code");
+
+ // Generate inline logic corresponding to IteratorClose (ES 7.4.6).
+ //
+ // Callers need to ensure that the iterator object is at the top of the
+ // stack.
+
+ if (!emit1(JSOP_DUP)) // ... ITER ITER
+ return false;
+
+ // Step 3.
+ //
+ // Get the "return" method.
+ if (!emitAtomOp(cx->names().return_, JSOP_CALLPROP)) // ... ITER RET
+ return false;
+
+ // Step 4.
+ //
+ // Do nothing if "return" is null or undefined.
+ IfThenElseEmitter ifReturnMethodIsDefined(this);
+ if (!emit1(JSOP_DUP)) // ... ITER RET RET
+ return false;
+ if (!emit1(JSOP_UNDEFINED)) // ... ITER RET RET UNDEFINED
+ return false;
+ if (!emit1(JSOP_NE)) // ... ITER RET ?NEQL
+ return false;
+ if (!ifReturnMethodIsDefined.emitIfElse())
+ return false;
+
+ // Steps 5, 8.
+ //
+ // Call "return" if it is not undefined or null, and check that it returns
+ // an Object.
+ if (!emit1(JSOP_SWAP)) // ... RET ITER
+ return false;
+
+ // ES 14.4.13, yield * AssignmentExpression, step 5.c
+ //
+ // When emitting iterator.return() for yield* forced return, we need to
+ // pass the argument passed to Generator.prototype.return to the return
+ // method.
+ if (yieldStarTryStart) {
+ IfThenElseEmitter ifGeneratorClosing(this);
+ if (!emitDupAt(2)) // ... FTYPE FVALUE RET ITER FVALUE
+ return false;
+ if (!emit1(JSOP_ISGENCLOSING)) // ... FTYPE FVALUE RET ITER FVALUE CLOSING
+ return false;
+ if (!emit1(JSOP_SWAP)) // ... FTYPE FVALUE RET ITER CLOSING FVALUE
+ return false;
+ if (!emit1(JSOP_POP)) // ... FTYPE FVALUE RET ITER CLOSING
+ return false;
+ if (!ifGeneratorClosing.emitIfElse()) // ... FTYPE FVALUE RET ITER
+ return false;
+
+ if (!emit1(JSOP_GETRVAL)) // ... FTYPE FVALUE RET ITER RVAL
+ return false;
+ if (!emitAtomOp(cx->names().value, JSOP_GETPROP)) // ... FTYPE FVALUE RET ITER VALUE
+ return false;
+ if (!emitCall(JSOP_CALL, 1)) // ... FTYPE FVALUE RESULT
+ return false;
+ checkTypeSet(JSOP_CALL);
+ if (!emitCheckIsObj(CheckIsObjectKind::IteratorReturn)) // ... FTYPE FVALUE RESULT
+ return false;
+
+ IfThenElseEmitter ifReturnDone(this);
+ if (!emit1(JSOP_DUP)) // ITER OLDRESULT FTYPE FVALUE RESULT RESULT
+ return false;
+ if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ITER OLDRESULT FTYPE FVALUE RESULT DONE
+ return false;
+ if (!ifReturnDone.emitIfElse()) // ITER OLDRESULT FTYPE FVALUE RESULT
+ return false;
+ if (!emit1(JSOP_DUP)) // ITER OLDRESULT FTYPE FVALUE RESULT RESULT
+ return false;
+ if (!emit1(JSOP_SETRVAL)) // ITER OLDRESULT FTYPE FVALUE RESULT
+ return false;
+ if (!ifReturnDone.emitElse()) // ITER OLDRESULT FTYPE FVALUE RESULT
+ return false;
+ int32_t savedDepth = this->stackDepth;
+ if (!emit2(JSOP_UNPICK, 3)) // ITER RESULT OLDRESULT FTYPE FVALUE
+ return false;
+ if (!emitUint16Operand(JSOP_POPN, 3)) // ITER RESULT
+ return false;
+ JumpList beq;
+ JumpTarget breakTarget{ -1 };
+ if (!emitBackwardJump(JSOP_GOTO, *yieldStarTryStart, &beq, &breakTarget)) // ITER RESULT
+ return false;
+ this->stackDepth = savedDepth;
+ if (!ifReturnDone.emitEnd())
+ return false;
+
+ if (!ifGeneratorClosing.emitElse()) // ... FTYPE FVALUE RET ITER
+ return false;
+ if (!emitCall(JSOP_CALL, 0)) // ... FTYPE FVALUE RESULT
+ return false;
+ checkTypeSet(JSOP_CALL);
+ if (!emitCheckIsObj(CheckIsObjectKind::IteratorReturn)) // ... FTYPE FVALUE RESULT
+ return false;
+
+ if (!ifGeneratorClosing.emitEnd())
+ return false;
+ } else {
+ if (!emitCall(JSOP_CALL, 0)) // ... RESULT
+ return false;
+ checkTypeSet(JSOP_CALL);
+ if (!emitCheckIsObj(CheckIsObjectKind::IteratorReturn)) // ... RESULT
+ return false;
+ }
+
+ if (!ifReturnMethodIsDefined.emitElse())
+ return false;
+ if (!emit1(JSOP_POP)) // ... ITER
+ return false;
+ if (!ifReturnMethodIsDefined.emitEnd())
+ return false;
+
+ return emit1(JSOP_POP); // ...
+}
+
+template <typename InnerEmitter>
+bool
+BytecodeEmitter::wrapWithIteratorCloseTryNote(int32_t iterDepth, InnerEmitter emitter)
+{
+ MOZ_ASSERT(this->stackDepth >= iterDepth);
+
+ ptrdiff_t start = offset();
+ if (!emitter(this))
+ return false;
+ ptrdiff_t end = offset();
+ if (start != end)
+ return tryNoteList.append(JSTRY_ITERCLOSE, iterDepth, start, end);
+ return true;
+}
+
+bool
BytecodeEmitter::emitDefault(ParseNode* defaultExpr, ParseNode* pattern)
{
if (!emit1(JSOP_DUP)) // VALUE VALUE
@@ -4617,156 +5048,6 @@ BytecodeEmitter::emitInitializerInBranch(ParseNode* initializer, ParseNode* patt
return emitInitializer(initializer, pattern);
}
-class MOZ_STACK_CLASS IfThenElseEmitter
-{
- BytecodeEmitter* bce_;
- JumpList jumpAroundThen_;
- JumpList jumpsAroundElse_;
- unsigned noteIndex_;
- int32_t thenDepth_;
-#ifdef DEBUG
- int32_t pushed_;
- bool calculatedPushed_;
-#endif
- enum State {
- Start,
- If,
- Cond,
- IfElse,
- Else,
- End
- };
- State state_;
-
- public:
- explicit IfThenElseEmitter(BytecodeEmitter* bce)
- : bce_(bce),
- noteIndex_(-1),
- thenDepth_(0),
-#ifdef DEBUG
- pushed_(0),
- calculatedPushed_(false),
-#endif
- state_(Start)
- {}
-
- ~IfThenElseEmitter()
- {}
-
- private:
- bool emitIf(State nextState) {
- MOZ_ASSERT(state_ == Start || state_ == Else);
- MOZ_ASSERT(nextState == If || nextState == IfElse || nextState == Cond);
-
- // Clear jumpAroundThen_ offset that points previous JSOP_IFEQ.
- if (state_ == Else)
- jumpAroundThen_ = JumpList();
-
- // Emit an annotated branch-if-false around the then part.
- SrcNoteType type = nextState == If ? SRC_IF : nextState == IfElse ? SRC_IF_ELSE : SRC_COND;
- if (!bce_->newSrcNote(type, &noteIndex_))
- return false;
- if (!bce_->emitJump(JSOP_IFEQ, &jumpAroundThen_))
- return false;
-
- // To restore stack depth in else part, save depth of the then part.
-#ifdef DEBUG
- // If DEBUG, this is also necessary to calculate |pushed_|.
- thenDepth_ = bce_->stackDepth;
-#else
- if (nextState == IfElse || nextState == Cond)
- thenDepth_ = bce_->stackDepth;
-#endif
- state_ = nextState;
- return true;
- }
-
- public:
- bool emitIf() {
- return emitIf(If);
- }
-
- bool emitCond() {
- return emitIf(Cond);
- }
-
- bool emitIfElse() {
- return emitIf(IfElse);
- }
-
- bool emitElse() {
- MOZ_ASSERT(state_ == IfElse || state_ == Cond);
-
- calculateOrCheckPushed();
-
- // Emit a jump from the end of our then part around the else part. The
- // patchJumpsToTarget call at the bottom of this function will fix up
- // the offset with jumpsAroundElse value.
- if (!bce_->emitJump(JSOP_GOTO, &jumpsAroundElse_))
- return false;
-
- // Ensure the branch-if-false comes here, then emit the else.
- if (!bce_->emitJumpTargetAndPatch(jumpAroundThen_))
- return false;
-
- // Annotate SRC_IF_ELSE or SRC_COND with the offset from branch to
- // jump, for IonMonkey's benefit. We can't just "back up" from the pc
- // of the else clause, because we don't know whether an extended
- // jump was required to leap from the end of the then clause over
- // the else clause.
- if (!bce_->setSrcNoteOffset(noteIndex_, 0,
- jumpsAroundElse_.offset - jumpAroundThen_.offset))
- {
- return false;
- }
-
- // Restore stack depth of the then part.
- bce_->stackDepth = thenDepth_;
- state_ = Else;
- return true;
- }
-
- bool emitEnd() {
- MOZ_ASSERT(state_ == If || state_ == Else);
-
- calculateOrCheckPushed();
-
- if (state_ == If) {
- // No else part, fixup the branch-if-false to come here.
- if (!bce_->emitJumpTargetAndPatch(jumpAroundThen_))
- return false;
- }
-
- // Patch all the jumps around else parts.
- if (!bce_->emitJumpTargetAndPatch(jumpsAroundElse_))
- return false;
-
- state_ = End;
- return true;
- }
-
- void calculateOrCheckPushed() {
-#ifdef DEBUG
- if (!calculatedPushed_) {
- pushed_ = bce_->stackDepth - thenDepth_;
- calculatedPushed_ = true;
- } else {
- MOZ_ASSERT(pushed_ == bce_->stackDepth - thenDepth_);
- }
-#endif
- }
-
-#ifdef DEBUG
- int32_t pushed() const {
- return pushed_;
- }
-
- int32_t popped() const {
- return -pushed_;
- }
-#endif
-};
-
bool
BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlavor flav)
{
@@ -5710,7 +5991,7 @@ BytecodeEmitter::emitCatch(ParseNode* pn)
return false;
{
- NonLocalExitControl nle(this);
+ NonLocalExitControl nle(this, NonLocalExitControl::Throw);
// Move exception back to cx->exception to prepare for
// the next catch.
@@ -6303,12 +6584,14 @@ BytecodeEmitter::emitForOf(ParseNode* forOfLoop, EmitterScope* headLexicalEmitte
if (!emitIterator()) // ITER
return false;
+ int32_t iterDepth = stackDepth;
+
// For-of loops have both the iterator and the value on the stack. Push
// undefined to balance the stack.
if (!emit1(JSOP_UNDEFINED)) // ITER RESULT
return false;
- LoopControl loopInfo(this, StatementKind::ForOfLoop);
+ ForOfLoopControl loopInfo(this, iterDepth);
// Annotate so IonMonkey can find the loop-closing jump.
unsigned noteIndex;
@@ -6354,18 +6637,23 @@ BytecodeEmitter::emitForOf(ParseNode* forOfLoop, EmitterScope* headLexicalEmitte
#endif
// Emit code to assign result.value to the iteration variable.
+ //
+ // Note that ES 13.7.5.13, step 5.c says getting result.value does not
+ // call IteratorClose, so start JSTRY_ITERCLOSE after the GETPROP.
if (!emit1(JSOP_DUP)) // ITER RESULT RESULT
return false;
if (!emitAtomOp(cx->names().value, JSOP_GETPROP)) // ITER RESULT VALUE
return false;
+ loopInfo.startNewIterCloseTryNote(this);
+
if (!emitInitializeForInOrOfTarget(forOfHead)) // ITER RESULT VALUE
return false;
if (!emit1(JSOP_POP)) // ITER RESULT
return false;
- MOZ_ASSERT(this->stackDepth == loopDepth,
+ MOZ_ASSERT(stackDepth == loopDepth,
"the stack must be balanced around the initializing "
"operation");
@@ -6374,6 +6662,9 @@ BytecodeEmitter::emitForOf(ParseNode* forOfLoop, EmitterScope* headLexicalEmitte
if (!emitTree(forBody)) // ITER RESULT
return false;
+ if (!loopInfo.finishIterCloseTryNote(this))
+ return false;
+
// Set offset for continues.
loopInfo.continueTarget = { offset() };
@@ -7609,7 +7900,7 @@ BytecodeEmitter::emitReturn(ParseNode* pn)
return false;
}
- NonLocalExitControl nle(this);
+ NonLocalExitControl nle(this, NonLocalExitControl::Return);
if (!nle.prepareForNonLocalJumpToOutermost())
return false;
diff --git a/js/src/frontend/BytecodeEmitter.h b/js/src/frontend/BytecodeEmitter.h
index 066c06672..6b39069de 100644
--- a/js/src/frontend/BytecodeEmitter.h
+++ b/js/src/frontend/BytecodeEmitter.h
@@ -679,6 +679,12 @@ struct MOZ_STACK_CLASS BytecodeEmitter
// Pops iterator from the top of the stack. Pushes the result of |.next()|
// onto the stack.
MOZ_MUST_USE bool emitIteratorNext(ParseNode* pn, bool allowSelfHosted = false);
+ MOZ_MUST_USE bool emitIteratorClose(
+ mozilla::Maybe<JumpTarget> yieldStarTryStart = mozilla::Nothing(),
+ bool allowSelfHosted = false);
+
+ template <typename InnerEmitter>
+ MOZ_MUST_USE bool wrapWithIteratorCloseTryNote(int32_t iterDepth, InnerEmitter emitter);
// Check if the value on top of the stack is "undefined". If so, replace
// that value on the stack with the value defined by |defaultExpr|.
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-15 19:21:54 +0000