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-rw-r--r--js/src/frontend/BytecodeEmitter.cpp257
-rw-r--r--js/src/frontend/BytecodeEmitter.h1
2 files changed, 119 insertions, 139 deletions
diff --git a/js/src/frontend/BytecodeEmitter.cpp b/js/src/frontend/BytecodeEmitter.cpp
index ee26d0c43..a68fe8538 100644
--- a/js/src/frontend/BytecodeEmitter.cpp
+++ b/js/src/frontend/BytecodeEmitter.cpp
@@ -4463,13 +4463,6 @@ BytecodeEmitter::emitDestructuringLHS(ParseNode* target, DestructuringFlavor fla
}
bool
-BytecodeEmitter::emitDestructuringLHSInBranch(ParseNode* target, DestructuringFlavor flav)
-{
- TDZCheckCache tdzCache(this);
- return emitDestructuringLHS(target, flav);
-}
-
-bool
BytecodeEmitter::emitIteratorNext(ParseNode* pn, bool allowSelfHosted)
{
MOZ_ASSERT(allowSelfHosted || emitterMode != BytecodeEmitter::SelfHosting,
@@ -4739,7 +4732,7 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav
//
// let x, y;
// let a, b, c, d;
- // let tmp, done, iter, result; // stack values
+ // let iter, result, done, value; // stack values
//
// iter = x[Symbol.iterator]();
//
@@ -4747,115 +4740,113 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav
// result = iter.next();
// done = result.done;
//
- // if (done) {
- // a = undefined;
- //
- // result = undefined;
- // done = true;
- // } else {
- // a = result.value;
+ // if (done)
+ // value = undefined;
+ // else
+ // value = result.value;
//
- // // Do next element's .next() and .done access here
- // result = iter.next();
- // done = result.done;
- // }
+ // a = value;
//
// // ==== emitted by loop for b ====
// if (done) {
- // b = undefined;
- //
- // result = undefined;
- // done = true;
+ // value = undefined;
// } else {
- // b = result.value;
- //
// result = iter.next();
// done = result.done;
+ // if (done)
+ // value = undefined;
+ // else
+ // value = result.value;
// }
//
+ // b = value;
+ //
// // ==== emitted by loop for elision ====
// if (done) {
- // result = undefined
- // done = true
+ // value = undefined;
// } else {
- // result.value;
- //
// result = iter.next();
// done = result.done;
+ // if (done)
+ // value = undefined;
+ // else
+ // value = result.value;
// }
//
// // ==== emitted by loop for c ====
// if (done) {
- // c = y;
+ // value = undefined;
// } else {
- // tmp = result.value;
- // if (tmp === undefined)
- // tmp = y;
- // c = tmp;
- //
- // // Don't do next element's .next() and .done access if
- // // this is the last non-spread element.
+ // result = iter.next();
+ // done = result.done;
+ // if (done)
+ // value = undefined;
+ // else
+ // value = result.value;
// }
//
+ // if (value === undefined)
+ // value = y;
+ //
+ // c = value;
+ //
// // ==== emitted by loop for d ====
- // if (done) {
- // // Assing empty array when completed
- // d = [];
- // } else {
- // d = [...iter];
- // }
+ // if (done)
+ // value = [];
+ // else
+ // value = [...iter];
+ //
+ // d = value;
- /*
- * Use an iterator to destructure the RHS, instead of index lookup. We
- * must leave the *original* value on the stack.
- */
+ // Use an iterator to destructure the RHS, instead of index lookup. We
+ // must leave the *original* value on the stack.
if (!emit1(JSOP_DUP)) // ... OBJ OBJ
return false;
- if (!emitIterator()) // ... OBJ? ITER
+ if (!emitIterator()) // ... OBJ ITER
return false;
- bool needToPopIterator = true;
for (ParseNode* member = pattern->pn_head; member; member = member->pn_next) {
bool isHead = member == pattern->pn_head;
+ bool hasNext = !!member->pn_next;
+
if (member->isKind(PNK_SPREAD)) {
IfThenElseEmitter ifThenElse(this);
if (!isHead) {
// If spread is not the first element of the pattern,
// iterator can already be completed.
- if (!ifThenElse.emitIfElse()) // ... OBJ? ITER
+ // ... OBJ ITER DONE
+ if (!ifThenElse.emitIfElse()) // ... OBJ ITER
return false;
- if (!emit1(JSOP_POP)) // ... OBJ?
- return false;
- if (!emitUint32Operand(JSOP_NEWARRAY, 0)) // ... OBJ? ARRAY
+ if (!emitUint32Operand(JSOP_NEWARRAY, 0)) // ... OBJ ITER ARRAY
return false;
- if (!emitDestructuringLHSInBranch(member, flav)) // ... OBJ?
- return false;
-
- if (!ifThenElse.emitElse()) // ... OBJ? ITER
+ if (!ifThenElse.emitElse()) // ... OBJ ITER
return false;
}
// If iterator is not completed, create a new array with the rest
// of the iterator.
- if (!emitUint32Operand(JSOP_NEWARRAY, 0)) // ... OBJ? ITER ARRAY
+ if (!emit1(JSOP_DUP)) // ... OBJ ITER
return false;
- if (!emitNumberOp(0)) // ... OBJ? ITER ARRAY INDEX
+ if (!emitUint32Operand(JSOP_NEWARRAY, 0)) // ... OBJ ITER ITER ARRAY
return false;
- if (!emitSpread()) // ... OBJ? ARRAY INDEX
+ if (!emitNumberOp(0)) // ... OBJ ITER ITER ARRAY INDEX
return false;
- if (!emit1(JSOP_POP)) // ... OBJ? ARRAY
+ if (!emitSpread()) // ... OBJ ITER ARRAY INDEX
return false;
- if (!emitDestructuringLHSInBranch(member, flav)) // ... OBJ?
+ if (!emit1(JSOP_POP)) // ... OBJ ITER ARRAY
return false;
if (!isHead) {
if (!ifThenElse.emitEnd())
return false;
- MOZ_ASSERT(ifThenElse.popped() == 1);
+ MOZ_ASSERT(ifThenElse.pushed() == 1);
}
- needToPopIterator = false;
- MOZ_ASSERT(!member->pn_next);
+
+ if (!emitDestructuringLHS(member, flav)) // ... OBJ ITER
+ return false;
+
+ MOZ_ASSERT(!hasNext);
break;
}
@@ -4867,110 +4858,100 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav
}
bool isElision = subpattern->isKind(PNK_ELISION);
- bool hasNextNonSpread = member->pn_next && !member->pn_next->isKind(PNK_SPREAD);
- bool hasNextSpread = member->pn_next && member->pn_next->isKind(PNK_SPREAD);
MOZ_ASSERT(!subpattern->isKind(PNK_SPREAD));
- auto emitNext = [pattern](ExclusiveContext* cx, BytecodeEmitter* bce) {
- if (!bce->emit1(JSOP_DUP)) // ... OBJ? ITER ITER
- return false;
- if (!bce->emitIteratorNext(pattern)) // ... OBJ? ITER RESULT
+ IfThenElseEmitter ifAlreadyDone(this);
+ if (!isHead) {
+ // If this element is not the first element of the pattern,
+ // iterator can already be completed.
+ // ... OBJ ITER DONE
+ if (hasNext) {
+ if (!emit1(JSOP_DUP)) // ... OBJ ITER DONE DONE
+ return false;
+ }
+ if (!ifAlreadyDone.emitIfElse()) // ... OBJ ITER ?DONE
return false;
- if (!bce->emit1(JSOP_DUP)) // ... OBJ? ITER RESULT RESULT
+
+ if (!emit1(JSOP_UNDEFINED)) // ... OBJ ITER ?DONE UNDEF
return false;
- if (!bce->emitAtomOp(cx->names().done, JSOP_GETPROP)) // ... OBJ? ITER RESULT DONE?
+ if (!emit1(JSOP_NOP_DESTRUCTURING)) // ... OBJ ITER ?DONE UNDEF
return false;
- return true;
- };
- if (isHead) {
- if (!emitNext(cx, this)) // ... OBJ? ITER RESULT DONE?
+ if (!ifAlreadyDone.emitElse()) // ... OBJ ITER ?DONE
return false;
+
+ if (hasNext) {
+ if (!emit1(JSOP_POP)) // ... OBJ ITER
+ return false;
+ }
}
- IfThenElseEmitter ifThenElse(this);
- if (!ifThenElse.emitIfElse()) // ... OBJ? ITER RESULT
+ if (!emit1(JSOP_DUP)) // ... OBJ ITER ITER
return false;
-
- if (!emit1(JSOP_POP)) // ... OBJ? ITER
+ if (!emitIteratorNext(pattern)) // ... OBJ ITER RESULT
return false;
- if (pndefault) {
- // Emit only pndefault tree here, as undefined check in emitDefault
- // should always be true.
- if (!emitInitializerInBranch(pndefault, subpattern)) // ... OBJ? ITER VALUE
+ if (!emit1(JSOP_DUP)) // ... OBJ ITER RESULT RESULT
+ return false;
+ if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ... OBJ ITER RESULT DONE
+ return false;
+
+ if (hasNext) {
+ if (!emit1(JSOP_DUP)) // ... OBJ ITER RESULT DONE DONE
return false;
- } else {
- if (!isElision) {
- if (!emit1(JSOP_UNDEFINED)) // ... OBJ? ITER UNDEFINED
- return false;
- if (!emit1(JSOP_NOP_DESTRUCTURING))
- return false;
- }
}
- if (!isElision) {
- if (!emitDestructuringLHSInBranch(subpattern, flav)) // ... OBJ? ITER
- return false;
- } else if (pndefault) {
- if (!emit1(JSOP_POP)) // ... OBJ? ITER
+
+ IfThenElseEmitter ifDone(this);
+ if (!ifDone.emitIfElse()) // ... OBJ ITER RESULT ?DONE
+ return false;
+
+ if (hasNext) {
+ if (!emit1(JSOP_SWAP)) // ... OBJ ITER ?DONE RESULT
return false;
}
+ if (!emit1(JSOP_POP)) // ... OBJ ITER ?DONE
+ return false;
+ if (!emit1(JSOP_UNDEFINED)) // ... OBJ ITER ?DONE UNDEF
+ return false;
+ if (!emit1(JSOP_NOP_DESTRUCTURING)) // ... OBJ ITER ?DONE UNDEF
+ return false;
- // Setup next element's result when the iterator is done.
- if (hasNextNonSpread) {
- if (!emit1(JSOP_UNDEFINED)) // ... OBJ? ITER RESULT
- return false;
- if (!emit1(JSOP_NOP_DESTRUCTURING))
- return false;
- if (!emit1(JSOP_TRUE)) // ... OBJ? ITER RESULT DONE?
- return false;
- } else if (hasNextSpread) {
- if (!emit1(JSOP_TRUE)) // ... OBJ? ITER DONE?
+ if (!ifDone.emitElse()) // ... OBJ ITER RESULT ?DONE
+ return false;
+
+ if (hasNext) {
+ if (!emit1(JSOP_SWAP)) // ... OBJ ITER ?DONE RESULT
return false;
}
-
- if (!ifThenElse.emitElse()) // ... OBJ? ITER RESULT
+ if (!emitAtomOp(cx->names().value, JSOP_GETPROP)) // ... OBJ ITER ?DONE VALUE
return false;
- if (!emitAtomOp(cx->names().value, JSOP_GETPROP)) // ... OBJ? ITER VALUE
+ if (!ifDone.emitEnd())
return false;
+ MOZ_ASSERT(ifDone.pushed() == 0);
- if (pndefault) {
- if (!emitDefault(pndefault, subpattern)) // ... OBJ? ITER VALUE
+ if (!isHead) {
+ if (!ifAlreadyDone.emitEnd())
return false;
+ MOZ_ASSERT(ifAlreadyDone.pushed() == 1);
}
- if (!isElision) {
- if (!emitDestructuringLHSInBranch(subpattern, flav)) // ... OBJ? ITER
- return false;
- } else {
- if (!emit1(JSOP_POP)) // ... OBJ? ITER
+ if (pndefault) {
+ if (!emitDefault(pndefault, subpattern)) // ... OBJ ITER ?DONE VALUE
return false;
}
- // Setup next element's result when the iterator is not done.
- if (hasNextNonSpread) {
- if (!emitNext(cx, this)) // ... OBJ? ITER RESULT DONE?
+ if (!isElision) {
+ if (!emitDestructuringLHS(subpattern, flav)) // ... OBJ ITER ?DONE
return false;
- } else if (hasNextSpread) {
- if (!emit1(JSOP_FALSE)) // ... OBJ? ITER DONE?
+ } else {
+ if (!emit1(JSOP_POP)) // ... OBJ ITER ?DONE
return false;
}
-
- if (!ifThenElse.emitEnd())
- return false;
- if (hasNextNonSpread)
- MOZ_ASSERT(ifThenElse.pushed() == 1);
- else if (hasNextSpread)
- MOZ_ASSERT(ifThenElse.pushed() == 0);
- else
- MOZ_ASSERT(ifThenElse.popped() == 1);
}
- if (needToPopIterator) {
- if (!emit1(JSOP_POP)) // ... OBJ?
- return false;
- }
+ if (!emit1(JSOP_POP)) // ... OBJ
+ return false;
return true;
}
@@ -6118,7 +6099,7 @@ BytecodeEmitter::emitSpread(bool allowSelfHosted)
return false;
if (!emit1(JSOP_DUP)) // ITER ARR I RESULT RESULT
return false;
- if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ITER ARR I RESULT DONE?
+ if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ITER ARR I RESULT DONE
return false;
if (!emitBackwardJump(JSOP_IFEQ, top, &beq, &breakTarget)) // ITER ARR I RESULT
@@ -6307,7 +6288,7 @@ BytecodeEmitter::emitForOf(ParseNode* forOfLoop, EmitterScope* headLexicalEmitte
return false;
if (!emit1(JSOP_DUP)) // ITER RESULT RESULT
return false;
- if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ITER RESULT DONE?
+ if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ITER RESULT DONE
return false;
if (!emitBackwardJump(JSOP_IFEQ, top, &beq, &breakTarget))
@@ -6803,7 +6784,7 @@ BytecodeEmitter::emitComprehensionForOf(ParseNode* pn)
return false;
if (!emit1(JSOP_DUP)) // ITER RESULT RESULT
return false;
- if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ITER RESULT DONE?
+ if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ITER RESULT DONE
return false;
JumpList beq;
diff --git a/js/src/frontend/BytecodeEmitter.h b/js/src/frontend/BytecodeEmitter.h
index 4b3750dd5..f09b529ed 100644
--- a/js/src/frontend/BytecodeEmitter.h
+++ b/js/src/frontend/BytecodeEmitter.h
@@ -646,7 +646,6 @@ struct MOZ_STACK_CLASS BytecodeEmitter
// the stack and emits code to destructure a single lhs expression (either a
// name or a compound []/{} expression).
MOZ_MUST_USE bool emitDestructuringLHS(ParseNode* target, DestructuringFlavor flav);
- MOZ_MUST_USE bool emitDestructuringLHSInBranch(ParseNode* target, DestructuringFlavor flav);
// emitDestructuringOps assumes the to-be-destructured value has been
// pushed on the stack and emits code to destructure each part of a [] or
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-18 14:47:50 +0000