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-rw-r--r--js/src/frontend/BytecodeEmitter.cpp453
-rw-r--r--js/src/frontend/BytecodeEmitter.h6
-rw-r--r--js/src/jit-test/tests/auto-regress/for-of-iterator-close-debugger.js15
-rw-r--r--js/src/jit/BaselineBailouts.cpp14
-rw-r--r--js/src/jit/JitFrames.cpp15
-rw-r--r--js/src/jsapi.h9
-rw-r--r--js/src/jsscript.h1
-rw-r--r--js/src/shell/js.cpp2
-rw-r--r--js/src/vm/Interpreter.cpp34
-rw-r--r--js/src/vm/Interpreter.h7
-rw-r--r--js/src/vm/Opcodes.h11
11 files changed, 378 insertions, 189 deletions
diff --git a/js/src/frontend/BytecodeEmitter.cpp b/js/src/frontend/BytecodeEmitter.cpp
index 4a60f1cf1..4d6ff6305 100644
--- a/js/src/frontend/BytecodeEmitter.cpp
+++ b/js/src/frontend/BytecodeEmitter.cpp
@@ -244,9 +244,9 @@ class LoopControl : public BreakableControl
loopDepth_ = enclosingLoop ? enclosingLoop->loopDepth_ + 1 : 1;
int loopSlots;
- if (loopKind == StatementKind::Spread)
+ if (loopKind == StatementKind::Spread || loopKind == StatementKind::ForOfLoop)
loopSlots = 3;
- else if (loopKind == StatementKind::ForInLoop || loopKind == StatementKind::ForOfLoop)
+ else if (loopKind == StatementKind::ForInLoop)
loopSlots = 2;
else
loopSlots = 0;
@@ -278,64 +278,6 @@ 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_;
@@ -2025,6 +1967,144 @@ class MOZ_STACK_CLASS IfThenElseEmitter
#endif
};
+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. This is done by enclosing non-iterator code with
+ // try-catch and call IteratorClose in `catch` block.
+ // 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 tell catch block not to perform
+ // IteratorClose.
+ //
+ // for (x of y) {
+ // // Operations for iterator (IteratorNext etc) are outside of
+ // // try-block.
+ // try {
+ // ...
+ // if (...) {
+ // // Before non-local jump, clear iterator on the stack to tell
+ // // catch block not to perform IteratorClose.
+ // tmpIterator = iterator;
+ // iterator = undefined;
+ // IteratorClose(tmpIterator, { break });
+ // break;
+ // }
+ // ...
+ // } catch (e) {
+ // // Just throw again when iterator is cleared by non-local jump.
+ // if (iterator === undefined)
+ // throw e;
+ // IteratorClose(iterator, { throw, e });
+ // }
+ // }
+ Maybe<TryEmitter> tryCatch_;
+
+ bool allowSelfHosted_;
+
+ public:
+ ForOfLoopControl(BytecodeEmitter* bce, int32_t iterDepth, bool allowSelfHosted)
+ : LoopControl(bce, StatementKind::ForOfLoop),
+ iterDepth_(iterDepth),
+ allowSelfHosted_(allowSelfHosted)
+ {
+ }
+
+ bool emitBeginCodeNeedingIteratorClose(BytecodeEmitter* bce) {
+ tryCatch_.emplace(bce, TryEmitter::TryCatch, TryEmitter::DontUseRetVal);
+
+ if (!tryCatch_->emitTry())
+ return false;
+ return true;
+ }
+
+ bool emitEndCodeNeedingIteratorClose(BytecodeEmitter* bce) {
+ if (!tryCatch_->emitCatch()) // ITER ...
+ return false;
+
+ if (!bce->emit1(JSOP_EXCEPTION)) // ITER ... EXCEPTION
+ return false;
+ unsigned slotFromTop = bce->stackDepth - iterDepth_;
+ if (!bce->emitDupAt(slotFromTop)) // ITER ... EXCEPTION ITER
+ return false;
+
+ // If ITER is undefined, it means the exception is thrown by
+ // IteratorClose for non-local jump, and we should't perform
+ // IteratorClose again here.
+ if (!bce->emit1(JSOP_UNDEFINED)) // ITER ... EXCEPTION ITER UNDEF
+ return false;
+ if (!bce->emit1(JSOP_STRICTNE)) // ITER ... EXCEPTION NE
+ return false;
+
+ IfThenElseEmitter ifIteratorIsNotClosed(bce);
+ if (!ifIteratorIsNotClosed.emitIf()) // ITER ... EXCEPTION
+ return false;
+
+ MOZ_ASSERT(slotFromTop == unsigned(bce->stackDepth - iterDepth_));
+ if (!bce->emitDupAt(slotFromTop)) // ITER ... EXCEPTION ITER
+ return false;
+ if (!emitIteratorClose(bce, CompletionKind::Throw)) // ITER ... EXCEPTION
+ return false;
+
+ if (!ifIteratorIsNotClosed.emitEnd()) // ITER ... EXCEPTION
+ return false;
+
+ if (!bce->emit1(JSOP_THROW)) // ITER ...
+ return false;
+
+ if (!tryCatch_->emitEnd())
+ return false;
+
+ tryCatch_.reset();
+ return true;
+ }
+
+ bool emitIteratorClose(BytecodeEmitter* bce,
+ CompletionKind completionKind = CompletionKind::Normal) {
+ return bce->emitIteratorClose(completionKind, allowSelfHosted_);
+ }
+
+ bool emitPrepareForNonLocalJump(BytecodeEmitter* bce, bool isTarget) {
+ // Pop unnecessary values from the stack. Effectively this means
+ // leaving try-catch block. However, the performing IteratorClose can
+ // reach the depth for try-catch, and effectively re-enter the
+ // try-catch block.
+ if (!bce->emit1(JSOP_POP)) // ITER RESULT
+ return false;
+ if (!bce->emit1(JSOP_POP)) // ITER
+ return false;
+
+ // Clear ITER slot on the stack to tell catch block to avoid performing
+ // IteratorClose again.
+ if (!bce->emit1(JSOP_UNDEFINED)) // ITER UNDEF
+ return false;
+ if (!bce->emit1(JSOP_SWAP)) // UNDEF ITER
+ return false;
+
+ if (!emitIteratorClose(bce)) // UNDEF
+ return false;
+
+ if (isTarget) {
+ // At the level of the target block, there's bytecode after the
+ // loop that will pop the iterator and the value, so push
+ // undefineds to balance the stack.
+ if (!bce->emit1(JSOP_UNDEFINED)) // UNDEF UNDEF
+ return false;
+ if (!bce->emit1(JSOP_UNDEFINED)) // UNDEF UNDEF UNDEF
+ return false;
+ } else {
+ if (!bce->emit1(JSOP_POP)) //
+ return false;
+ }
+
+ return true;
+ }
+};
+
BytecodeEmitter::BytecodeEmitter(BytecodeEmitter* parent,
Parser<FullParseHandler>* parser, SharedContext* sc,
HandleScript script, Handle<LazyScript*> lazyScript,
@@ -2383,6 +2463,12 @@ BytecodeEmitter::emitCheckIsObj(CheckIsObjectKind kind)
return emit2(JSOP_CHECKISOBJ, uint8_t(kind));
}
+bool
+BytecodeEmitter::emitCheckIsCallable(CheckIsCallableKind kind)
+{
+ return emit2(JSOP_CHECKISCALLABLE, uint8_t(kind));
+}
+
static inline unsigned
LengthOfSetLine(unsigned line)
{
@@ -2624,10 +2710,8 @@ 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
+ // 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;
@@ -2664,31 +2748,22 @@ NonLocalExitControl::prepareForNonLocalJump(BytecodeEmitter::NestableControl* ta
} else {
if (!flushPops(bce_))
return false;
- if (!bce_->emitJump(JSOP_GOSUB, &finallyControl.gosubs))
+ if (!bce_->emitJump(JSOP_GOSUB, &finallyControl.gosubs)) // ...
return false;
}
break;
}
case StatementKind::ForOfLoop:
- if (!flushPops(bce_))
- return false;
-
- // 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
+ if (!flushPops(bce_))
return false;
- if (!bce_->emitIteratorClose()) // ...
+
+ ForOfLoopControl& loopinfo = control->as<ForOfLoopControl>();
+ if (!loopinfo.emitPrepareForNonLocalJump(bce_, /* isTarget = */ false)) // ...
return false;
} else {
- if (!bce_->emit1(JSOP_POP)) // ... ITER
- return false;
- if (!bce_->emit1(JSOP_POP)) // ...
- return false;
+ npops += 3;
}
break;
@@ -2711,18 +2786,9 @@ NonLocalExitControl::prepareForNonLocalJump(BytecodeEmitter::NestableControl* ta
if (!flushPops(bce_))
return false;
- 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
+ if (target && emitIteratorCloseAtTarget && target->is<ForOfLoopControl>()) {
+ ForOfLoopControl& loopinfo = target->as<ForOfLoopControl>();
+ if (!loopinfo.emitPrepareForNonLocalJump(bce_, /* isTarget = */ true)) // ... UNDEF UNDEF UNDEF
return false;
}
@@ -2732,20 +2798,6 @@ NonLocalExitControl::prepareForNonLocalJump(BytecodeEmitter::NestableControl* ta
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;
}
@@ -5120,7 +5172,7 @@ BytecodeEmitter::emitSetOrInitializeDestructuring(ParseNode* target, Destructuri
}
bool
-BytecodeEmitter::emitIteratorNext(ParseNode* pn, bool allowSelfHosted)
+BytecodeEmitter::emitIteratorNext(ParseNode* pn, bool allowSelfHosted /* = false */)
{
MOZ_ASSERT(allowSelfHosted || emitterMode != BytecodeEmitter::SelfHosting,
".next() iteration is prohibited in self-hosted code because it "
@@ -5141,7 +5193,8 @@ BytecodeEmitter::emitIteratorNext(ParseNode* pn, bool allowSelfHosted)
}
bool
-BytecodeEmitter::emitIteratorClose(bool allowSelfHosted)
+BytecodeEmitter::emitIteratorClose(CompletionKind completionKind /* = CompletionKind::Normal */,
+ bool allowSelfHosted /* = false */)
{
MOZ_ASSERT(allowSelfHosted || emitterMode != BytecodeEmitter::SelfHosting,
".close() on iterators is prohibited in self-hosted code because it "
@@ -5174,17 +5227,86 @@ BytecodeEmitter::emitIteratorClose(bool allowSelfHosted)
if (!ifReturnMethodIsDefined.emitIfElse())
return false;
+ if (completionKind == CompletionKind::Throw) {
+ // 7.4.6 IteratorClose ( iterator, completion )
+ // ...
+ // 3. Let return be ? GetMethod(iterator, "return").
+ // 4. If return is undefined, return Completion(completion).
+ // 5. Let innerResult be Call(return, iterator, « »).
+ // 6. If completion.[[Type]] is throw, return Completion(completion).
+ // 7. If innerResult.[[Type]] is throw, return
+ // Completion(innerResult).
+ //
+ // For CompletionKind::Normal case, JSOP_CALL for step 5 checks if RET
+ // is callable, and throws if not. Since step 6 doesn't match and
+ // error handling in step 3 and step 7 can be merged.
+ //
+ // For CompletionKind::Throw case, an error thrown by JSOP_CALL for
+ // step 5 is ignored by try-catch. So we should check if RET is
+ // callable here, outside of try-catch, and the throw immediately if
+ // not.
+ CheckIsCallableKind kind = CheckIsCallableKind::IteratorReturn;
+ if (!emitCheckIsCallable(kind)) // ... ITER RET
+ 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;
- if (!emitCall(JSOP_CALL, 0)) // ... RESULT
+
+ Maybe<TryEmitter> tryCatch;
+
+ if (completionKind == CompletionKind::Throw) {
+ tryCatch.emplace(this, TryEmitter::TryCatch, TryEmitter::DontUseRetVal,
+ TryEmitter::DontUseControl);
+
+ // Mutate stack to balance stack for try-catch.
+ if (!emit1(JSOP_UNDEFINED)) // ... RET ITER UNDEF
+ return false;
+ if (!tryCatch->emitTry()) // ... RET ITER UNDEF
+ return false;
+ if (!emitDupAt(2)) // ... RET ITER UNDEF RET
+ return false;
+ if (!emitDupAt(2)) // ... RET ITER UNDEF RET ITER
+ return false;
+ }
+
+ if (!emitCall(JSOP_CALL, 0)) // ... ... RESULT
return false;
checkTypeSet(JSOP_CALL);
- if (!emitCheckIsObj(CheckIsObjectKind::IteratorReturn)) // ... RESULT
- return false;
+
+ if (completionKind == CompletionKind::Throw) {
+ if (!emit1(JSOP_SWAP)) // ... RET ITER RESULT UNDEF
+ return false;
+ if (!emit1(JSOP_POP)) // ... RET ITER RESULT
+ return false;
+
+ if (!tryCatch->emitCatch()) // ... RET ITER RESULT
+ return false;
+
+ // Just ignore the exception thrown by call.
+ if (!emit1(JSOP_EXCEPTION)) // ... RET ITER RESULT EXC
+ return false;
+ if (!emit1(JSOP_POP)) // ... RET ITER RESULT
+ return false;
+
+ if (!tryCatch->emitEnd()) // ... RET ITER RESULT
+ return false;
+
+ // Restore stack.
+ if (!emit2(JSOP_UNPICK, 2)) // ... RESULT RET ITER
+ return false;
+ if (!emit1(JSOP_POP)) // ... RESULT RET
+ return false;
+ if (!emit1(JSOP_POP)) // ... RESULT
+ return false;
+ } else {
+ if (!emitCheckIsObj(CheckIsObjectKind::IteratorReturn)) // ... RESULT
+ return false;
+ }
if (!ifReturnMethodIsDefined.emitElse())
return false;
@@ -6749,8 +6871,19 @@ BytecodeEmitter::emitForOf(ParseNode* forOfLoop, EmitterScope* headLexicalEmitte
MOZ_ASSERT(forOfHead->isKind(PNK_FOROF));
MOZ_ASSERT(forOfHead->isArity(PN_TERNARY));
- // Evaluate the expression being iterated.
ParseNode* forHeadExpr = forOfHead->pn_kid3;
+
+ // Certain builtins (e.g. Array.from) are implemented in self-hosting
+ // as for-of loops.
+ bool allowSelfHostedIter = false;
+ if (emitterMode == BytecodeEmitter::SelfHosting &&
+ forHeadExpr->isKind(PNK_CALL) &&
+ forHeadExpr->pn_head->name() == cx->names().allowContentIter)
+ {
+ allowSelfHostedIter = true;
+ }
+
+ // Evaluate the expression being iterated.
if (!emitTree(forHeadExpr)) // ITERABLE
return false;
if (!emitIterator()) // ITER
@@ -6758,12 +6891,14 @@ BytecodeEmitter::emitForOf(ParseNode* forOfLoop, EmitterScope* headLexicalEmitte
int32_t iterDepth = stackDepth;
- // For-of loops have both the iterator and the value on the stack. Push
- // undefined to balance the stack.
+ // For-of loops have both the iterator, the result, and the result.value
+ // on the stack. Push undefineds to balance the stack.
if (!emit1(JSOP_UNDEFINED)) // ITER RESULT
return false;
+ if (!emit1(JSOP_UNDEFINED)) // ITER RESULT UNDEF
+ return false;
- ForOfLoopControl loopInfo(this, iterDepth);
+ ForOfLoopControl loopInfo(this, iterDepth, allowSelfHostedIter);
// Annotate so IonMonkey can find the loop-closing jump.
unsigned noteIndex;
@@ -6771,11 +6906,11 @@ BytecodeEmitter::emitForOf(ParseNode* forOfLoop, EmitterScope* headLexicalEmitte
return false;
JumpList initialJump;
- if (!emitJump(JSOP_GOTO, &initialJump)) // ITER RESULT
+ if (!emitJump(JSOP_GOTO, &initialJump)) // ITER RESULT UNDEF
return false;
JumpTarget top{ -1 };
- if (!emitLoopHead(nullptr, &top)) // ITER RESULT
+ if (!emitLoopHead(nullptr, &top)) // ITER RESULT UNDEF
return false;
// If the loop had an escaping lexical declaration, replace the current
@@ -6792,7 +6927,7 @@ BytecodeEmitter::emitForOf(ParseNode* forOfLoop, EmitterScope* headLexicalEmitte
MOZ_ASSERT(headLexicalEmitterScope->scope(this)->kind() == ScopeKind::Lexical);
if (headLexicalEmitterScope->hasEnvironment()) {
- if (!emit1(JSOP_RECREATELEXICALENV)) // ITER RESULT
+ if (!emit1(JSOP_RECREATELEXICALENV)) // ITER RESULT UNDEF
return false;
}
@@ -6812,61 +6947,66 @@ BytecodeEmitter::emitForOf(ParseNode* forOfLoop, EmitterScope* headLexicalEmitte
//
// 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_POP)) // ITER RESULT
+ return false;
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
+ if (!loopInfo.emitBeginCodeNeedingIteratorClose(this))
return false;
- if (!emit1(JSOP_POP)) // ITER RESULT
+ if (!emitInitializeForInOrOfTarget(forOfHead)) // ITER RESULT VALUE
return false;
MOZ_ASSERT(stackDepth == loopDepth,
"the stack must be balanced around the initializing "
"operation");
+ // Remove VALUE from the stack to release it.
+ if (!emit1(JSOP_POP)) // ITER RESULT
+ return false;
+ if (!emit1(JSOP_UNDEFINED)) // ITER RESULT UNDEF
+ return false;
+
// Perform the loop body.
ParseNode* forBody = forOfLoop->pn_right;
- if (!emitTree(forBody)) // ITER RESULT
+ if (!emitTree(forBody)) // ITER RESULT UNDEF
return false;
- if (!loopInfo.finishIterCloseTryNote(this))
+ MOZ_ASSERT(stackDepth == loopDepth,
+ "the stack must be balanced around the for-of body");
+
+ if (!loopInfo.emitEndCodeNeedingIteratorClose(this))
return false;
// Set offset for continues.
loopInfo.continueTarget = { offset() };
- if (!emitLoopEntry(forHeadExpr, initialJump)) // ITER RESULT
+ if (!emitLoopEntry(forHeadExpr, initialJump)) // ITER RESULT UNDEF
return false;
- if (!emit1(JSOP_POP)) // ITER
+ if (!emit1(JSOP_SWAP)) // ITER UNDEF RESULT
+ return false;
+ if (!emit1(JSOP_POP)) // ITER UNDEF
return false;
- if (!emit1(JSOP_DUP)) // ITER ITER
+ if (!emitDupAt(1)) // ITER UNDEF ITER
return false;
- // Certain builtins (e.g. Array.from) are implemented in self-hosting
- // as for-of loops.
- bool allowSelfHostedIter = false;
- if (emitterMode == BytecodeEmitter::SelfHosting &&
- forHeadExpr->isKind(PNK_CALL) &&
- forHeadExpr->pn_head->name() == cx->names().allowContentIter)
- {
- allowSelfHostedIter = true;
- }
+ if (!emitIteratorNext(forOfHead, allowSelfHostedIter)) // ITER UNDEF RESULT
+ return false;
- if (!emitIteratorNext(forOfHead, allowSelfHostedIter)) // ITER RESULT
+ if (!emit1(JSOP_SWAP)) // ITER RESULT UNDEF
return false;
- if (!emit1(JSOP_DUP)) // ITER RESULT RESULT
+
+ if (!emitDupAt(1)) // ITER RESULT UNDEF RESULT
return false;
- if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ITER RESULT DONE
+ if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ITER RESULT UNDEF DONE
return false;
if (!emitBackwardJump(JSOP_IFEQ, top, &beq, &breakTarget))
- return false; // ITER RESULT
+ return false; // ITER RESULT UNDEF
MOZ_ASSERT(this->stackDepth == loopDepth);
}
@@ -6881,7 +7021,7 @@ BytecodeEmitter::emitForOf(ParseNode* forOfLoop, EmitterScope* headLexicalEmitte
if (!tryNoteList.append(JSTRY_FOR_OF, stackDepth, top.offset, breakTarget.offset))
return false;
- return emitUint16Operand(JSOP_POPN, 2); //
+ return emitUint16Operand(JSOP_POPN, 3); //
}
bool
@@ -7291,6 +7431,8 @@ BytecodeEmitter::emitComprehensionForOf(ParseNode* pn)
// Push a dummy result so that we properly enter iteration midstream.
if (!emit1(JSOP_UNDEFINED)) // ITER RESULT
return false;
+ if (!emit1(JSOP_UNDEFINED)) // ITER RESULT VALUE
+ return false;
// Enter the block before the loop body, after evaluating the obj.
// Initialize let bindings with undefined when entering, as the name
@@ -7328,42 +7470,59 @@ BytecodeEmitter::emitComprehensionForOf(ParseNode* pn)
#endif
// Emit code to assign result.value to the iteration variable.
+ if (!emit1(JSOP_POP)) // ITER RESULT
+ return false;
if (!emit1(JSOP_DUP)) // ITER RESULT RESULT
return false;
if (!emitAtomOp(cx->names().value, JSOP_GETPROP)) // ITER RESULT VALUE
return false;
+
+ // Notice: Comprehension for-of doesn't perform IteratorClose, since it's
+ // not in the spec.
+
if (!emitAssignment(loopVariableName, JSOP_NOP, nullptr)) // ITER RESULT VALUE
return false;
+
+ // Remove VALUE from the stack to release it.
if (!emit1(JSOP_POP)) // ITER RESULT
return false;
+ if (!emit1(JSOP_UNDEFINED)) // ITER RESULT UNDEF
+ return false;
// The stack should be balanced around the assignment opcode sequence.
MOZ_ASSERT(this->stackDepth == loopDepth);
// Emit code for the loop body.
- if (!emitTree(forBody))
+ if (!emitTree(forBody)) // ITER RESULT UNDEF
return false;
+ // The stack should be balanced around the assignment opcode sequence.
+ MOZ_ASSERT(this->stackDepth == loopDepth);
+
// Set offset for continues.
loopInfo.continueTarget = { offset() };
if (!emitLoopEntry(forHeadExpr, jmp))
return false;
- if (!emit1(JSOP_POP)) // ITER
+ if (!emit1(JSOP_SWAP)) // ITER UNDEF RESULT
return false;
- if (!emit1(JSOP_DUP)) // ITER ITER
+ if (!emit1(JSOP_POP)) // ITER UNDEF
return false;
- if (!emitIteratorNext(forHead)) // ITER RESULT
+ if (!emitDupAt(1)) // ITER UNDEF ITER
return false;
- if (!emit1(JSOP_DUP)) // ITER RESULT RESULT
+ if (!emitIteratorNext(forHead)) // ITER UNDEF RESULT
+ return false;
+ if (!emit1(JSOP_SWAP)) // ITER RESULT UNDEF
+ return false;
+ if (!emitDupAt(1)) // ITER RESULT UNDEF RESULT
return false;
- if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ITER RESULT DONE
+ if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ITER RESULT UNDEF DONE
return false;
JumpList beq;
JumpTarget breakTarget{ -1 };
- if (!emitBackwardJump(JSOP_IFEQ, top, &beq, &breakTarget)) // ITER RESULT
+ if (!emitBackwardJump(JSOP_IFEQ, top, &beq, &breakTarget)) // ITER RESULT UNDEF
return false;
MOZ_ASSERT(this->stackDepth == loopDepth);
@@ -7385,7 +7544,7 @@ BytecodeEmitter::emitComprehensionForOf(ParseNode* pn)
}
// Pop the result and the iter.
- return emitUint16Operand(JSOP_POPN, 2); //
+ return emitUint16Operand(JSOP_POPN, 3); //
}
bool
diff --git a/js/src/frontend/BytecodeEmitter.h b/js/src/frontend/BytecodeEmitter.h
index 2ab6c6fef..7ff40b462 100644
--- a/js/src/frontend/BytecodeEmitter.h
+++ b/js/src/frontend/BytecodeEmitter.h
@@ -473,6 +473,9 @@ struct MOZ_STACK_CLASS BytecodeEmitter
// Helper to emit JSOP_CHECKISOBJ.
MOZ_MUST_USE bool emitCheckIsObj(CheckIsObjectKind kind);
+ // Helper to emit JSOP_CHECKISCALLABLE.
+ MOZ_MUST_USE bool emitCheckIsCallable(CheckIsCallableKind kind);
+
// Emit a bytecode followed by an uint16 immediate operand stored in
// big-endian order.
MOZ_MUST_USE bool emitUint16Operand(JSOp op, uint32_t operand);
@@ -679,7 +682,8 @@ 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(bool allowSelfHosted = false);
+ MOZ_MUST_USE bool emitIteratorClose(CompletionKind completionKind = CompletionKind::Normal,
+ bool allowSelfHosted = false);
template <typename InnerEmitter>
MOZ_MUST_USE bool wrapWithDestructuringIteratorCloseTryNote(int32_t iterDepth,
diff --git a/js/src/jit-test/tests/auto-regress/for-of-iterator-close-debugger.js b/js/src/jit-test/tests/auto-regress/for-of-iterator-close-debugger.js
new file mode 100644
index 000000000..a4d0bf654
--- /dev/null
+++ b/js/src/jit-test/tests/auto-regress/for-of-iterator-close-debugger.js
@@ -0,0 +1,15 @@
+// |jit-test| error:ReferenceError
+
+// for-of should close iterator even if the exception is once caught by the
+// debugger.
+
+var g = newGlobal();
+g.parent = this;
+g.eval("new Debugger(parent).onExceptionUnwind = function () { };");
+// jsfunfuzz-generated
+for (var x of []) {};
+for (var l of [0]) {
+ for (var y = 0; y < 1; y++) {
+ g2;
+ }
+}
diff --git a/js/src/jit/BaselineBailouts.cpp b/js/src/jit/BaselineBailouts.cpp
index 161e1aa4c..3ab722b3d 100644
--- a/js/src/jit/BaselineBailouts.cpp
+++ b/js/src/jit/BaselineBailouts.cpp
@@ -509,16 +509,10 @@ HasLiveStackValueAtDepth(JSScript* script, jsbytecode* pc, uint32_t stackDepth)
break;
case JSTRY_FOR_OF:
- // For-of loops have both the iterator and the result object on
- // stack. The iterator is below the result object.
- if (stackDepth == tn->stackDepth - 1)
- return true;
- break;
-
- case JSTRY_ITERCLOSE:
- // Code that need to call IteratorClose have the iterator on the
- // stack.
- if (stackDepth == tn->stackDepth)
+ // For-of loops have the iterator, the result object, and the value
+ // of the result object on stack. The iterator is below the result
+ // object and the value.
+ if (stackDepth == tn->stackDepth - 2)
return true;
break;
diff --git a/js/src/jit/JitFrames.cpp b/js/src/jit/JitFrames.cpp
index 7c3f0d120..a70356ad4 100644
--- a/js/src/jit/JitFrames.cpp
+++ b/js/src/jit/JitFrames.cpp
@@ -331,7 +331,6 @@ static void
CloseLiveIteratorIon(JSContext* cx, const InlineFrameIterator& frame, JSTryNote* tn)
{
MOZ_ASSERT(tn->kind == JSTRY_FOR_IN ||
- tn->kind == JSTRY_ITERCLOSE ||
tn->kind == JSTRY_DESTRUCTURING_ITERCLOSE);
bool isDestructuring = tn->kind == JSTRY_DESTRUCTURING_ITERCLOSE;
@@ -442,7 +441,6 @@ HandleExceptionIon(JSContext* cx, const InlineFrameIterator& frame, ResumeFromEx
switch (tn->kind) {
case JSTRY_FOR_IN:
- case JSTRY_ITERCLOSE:
case JSTRY_DESTRUCTURING_ITERCLOSE:
MOZ_ASSERT_IF(tn->kind == JSTRY_FOR_IN,
JSOp(*(script->main() + tn->start + tn->length)) == JSOP_ENDITER);
@@ -637,19 +635,6 @@ ProcessTryNotesBaseline(JSContext* cx, const JitFrameIterator& frame, Environmen
break;
}
- case JSTRY_ITERCLOSE: {
- uint8_t* framePointer;
- uint8_t* stackPointer;
- BaselineFrameAndStackPointersFromTryNote(tn, frame, &framePointer, &stackPointer);
- Value iterValue(*reinterpret_cast<Value*>(stackPointer));
- RootedObject iterObject(cx, &iterValue.toObject());
- if (!IteratorCloseForException(cx, iterObject)) {
- SettleOnTryNote(cx, tn, frame, ei, rfe, pc);
- return false;
- }
- break;
- }
-
case JSTRY_DESTRUCTURING_ITERCLOSE: {
uint8_t* framePointer;
uint8_t* stackPointer;
diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index cbef0f8fb..5523dfa1d 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -6622,5 +6622,14 @@ SetGetPerformanceGroupsCallback(JSContext*, GetGroupsCallback, void*);
} /* namespace js */
+namespace js {
+
+enum class CompletionKind {
+ Normal,
+ Return,
+ Throw
+};
+
+} /* namespace js */
#endif /* jsapi_h */
diff --git a/js/src/jsscript.h b/js/src/jsscript.h
index 8bba3ec39..9cb7c538f 100644
--- a/js/src/jsscript.h
+++ b/js/src/jsscript.h
@@ -85,7 +85,6 @@ enum JSTryNoteKind {
JSTRY_FOR_IN,
JSTRY_FOR_OF,
JSTRY_LOOP,
- JSTRY_ITERCLOSE,
JSTRY_DESTRUCTURING_ITERCLOSE
};
diff --git a/js/src/shell/js.cpp b/js/src/shell/js.cpp
index 6fe01de22..5d6508d59 100644
--- a/js/src/shell/js.cpp
+++ b/js/src/shell/js.cpp
@@ -2599,8 +2599,6 @@ TryNoteName(JSTryNoteKind kind)
return "for-of";
case JSTRY_LOOP:
return "loop";
- case JSTRY_ITERCLOSE:
- return "iterclose";
case JSTRY_DESTRUCTURING_ITERCLOSE:
return "dstr-iterclose";
}
diff --git a/js/src/vm/Interpreter.cpp b/js/src/vm/Interpreter.cpp
index 7f8ff8445..eb3000e07 100644
--- a/js/src/vm/Interpreter.cpp
+++ b/js/src/vm/Interpreter.cpp
@@ -1189,17 +1189,6 @@ ProcessTryNotes(JSContext* cx, EnvironmentIter& ei, InterpreterRegs& regs)
break;
}
- case JSTRY_ITERCLOSE: {
- // The iterator object is at the top of the stack.
- Value* sp = regs.spForStackDepth(tn->stackDepth);
- RootedObject iterObject(cx, &sp[-1].toObject());
- if (!IteratorCloseForException(cx, iterObject)) {
- SettleOnTryNote(cx, tn, ei, regs);
- return ErrorReturnContinuation;
- }
- break;
- }
-
case JSTRY_DESTRUCTURING_ITERCLOSE: {
// Whether the destructuring iterator is done is at the top of the
// stack. The iterator object is second from the top.
@@ -1892,7 +1881,6 @@ CASE(JSOP_UNUSED192)
CASE(JSOP_UNUSED209)
CASE(JSOP_UNUSED210)
CASE(JSOP_UNUSED211)
-CASE(JSOP_UNUSED219)
CASE(JSOP_UNUSED220)
CASE(JSOP_UNUSED221)
CASE(JSOP_UNUSED222)
@@ -2637,6 +2625,15 @@ CASE(JSOP_CHECKISOBJ)
}
END_CASE(JSOP_CHECKISOBJ)
+CASE(JSOP_CHECKISCALLABLE)
+{
+ if (!IsCallable(REGS.sp[-1])) {
+ MOZ_ALWAYS_FALSE(ThrowCheckIsCallable(cx, CheckIsCallableKind(GET_UINT8(REGS.pc))));
+ goto error;
+ }
+}
+END_CASE(JSOP_CHECKISCALLABLE)
+
CASE(JSOP_CHECKTHIS)
{
if (REGS.sp[-1].isMagic(JS_UNINITIALIZED_LEXICAL)) {
@@ -5095,6 +5092,19 @@ js::ThrowCheckIsObject(JSContext* cx, CheckIsObjectKind kind)
}
bool
+js::ThrowCheckIsCallable(JSContext* cx, CheckIsCallableKind kind)
+{
+ switch (kind) {
+ case CheckIsCallableKind::IteratorReturn:
+ JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_RETURN_NOT_CALLABLE);
+ break;
+ default:
+ MOZ_CRASH("Unknown kind");
+ }
+ return false;
+}
+
+bool
js::ThrowUninitializedThis(JSContext* cx, AbstractFramePtr frame)
{
RootedFunction fun(cx);
diff --git a/js/src/vm/Interpreter.h b/js/src/vm/Interpreter.h
index 38e23ec06..330dbef5f 100644
--- a/js/src/vm/Interpreter.h
+++ b/js/src/vm/Interpreter.h
@@ -570,6 +570,13 @@ enum class CheckIsObjectKind : uint8_t {
bool
ThrowCheckIsObject(JSContext* cx, CheckIsObjectKind kind);
+enum class CheckIsCallableKind : uint8_t {
+ IteratorReturn
+};
+
+bool
+ThrowCheckIsCallable(JSContext* cx, CheckIsCallableKind kind);
+
bool
ThrowUninitializedThis(JSContext* cx, AbstractFramePtr frame);
diff --git a/js/src/vm/Opcodes.h b/js/src/vm/Opcodes.h
index 84f08c4d5..3848445ff 100644
--- a/js/src/vm/Opcodes.h
+++ b/js/src/vm/Opcodes.h
@@ -2201,7 +2201,16 @@
*/ \
macro(JSOP_HOLE, 218, "hole", NULL, 1, 0, 1, JOF_BYTE) \
\
- macro(JSOP_UNUSED219, 219,"unused219", NULL, 1, 0, 0, JOF_BYTE) \
+ /*
+ * Checks that the top value on the stack is callable, and throws a
+ * TypeError if not. The operand 'kind' is used only to generate an
+ * appropriate error message.
+ * Category: Statements
+ * Type: Function
+ * Operands: uint8_t kind
+ * Stack: result => result, callable
+ */ \
+ macro(JSOP_CHECKISCALLABLE, 219, "checkiscallable", NULL, 2, 1, 1, JOF_UINT8) \
macro(JSOP_UNUSED220, 220,"unused220", NULL, 1, 0, 0, JOF_BYTE) \
macro(JSOP_UNUSED221, 221,"unused221", NULL, 1, 0, 0, JOF_BYTE) \
macro(JSOP_UNUSED222, 222,"unused222", NULL, 1, 0, 0, JOF_BYTE) \
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 13:56:37 +0000