diff options
Diffstat (limited to 'js/src/frontend')
| -rw-r--r-- | js/src/frontend/BytecodeEmitter.cpp | 277 | ||||
| -rw-r--r-- | js/src/frontend/BytecodeEmitter.h | 18 |
2 files changed, 202 insertions, 93 deletions
diff --git a/js/src/frontend/BytecodeEmitter.cpp b/js/src/frontend/BytecodeEmitter.cpp index a68fe8538..a4cfeb753 100644 --- a/js/src/frontend/BytecodeEmitter.cpp +++ b/js/src/frontend/BytecodeEmitter.cpp @@ -4325,7 +4325,69 @@ BytecodeEmitter::emitDestructuringDeclsWithEmitter(ParseNode* pattern, NameEmitt } bool -BytecodeEmitter::emitDestructuringLHS(ParseNode* target, DestructuringFlavor flav) +BytecodeEmitter::emitDestructuringLHSRef(ParseNode* target, size_t* emitted) +{ + *emitted = 0; + + if (target->isKind(PNK_SPREAD)) + target = target->pn_kid; + else if (target->isKind(PNK_ASSIGN)) + target = target->pn_left; + + // No need to recur into PNK_ARRAY and PNK_OBJECT subpatterns here, since + // emitSetOrInitializeDestructuring does the recursion when setting or + // initializing value. Getting reference doesn't recur. + if (target->isKind(PNK_NAME) || target->isKind(PNK_ARRAY) || target->isKind(PNK_OBJECT)) + return true; + +#ifdef DEBUG + int depth = stackDepth; +#endif + + switch (target->getKind()) { + case PNK_DOT: { + if (target->as<PropertyAccess>().isSuper()) { + if (!emitSuperPropLHS(&target->as<PropertyAccess>().expression())) + return false; + *emitted = 2; + } else { + if (!emitTree(target->pn_expr)) + return false; + *emitted = 1; + } + break; + } + + case PNK_ELEM: { + if (target->as<PropertyByValue>().isSuper()) { + if (!emitSuperElemOperands(target, EmitElemOption::Ref)) + return false; + *emitted = 3; + } else { + if (!emitElemOperands(target, EmitElemOption::Ref)) + return false; + *emitted = 2; + } + break; + } + + case PNK_CALL: + MOZ_ASSERT_UNREACHABLE("Parser::reportIfNotValidSimpleAssignmentTarget " + "rejects function calls as assignment " + "targets in destructuring assignments"); + break; + + default: + MOZ_CRASH("emitDestructuringLHSRef: bad lhs kind"); + } + + MOZ_ASSERT(stackDepth == depth + int(*emitted)); + + return true; +} + +bool +BytecodeEmitter::emitSetOrInitializeDestructuring(ParseNode* target, DestructuringFlavor flav) { // Now emit the lvalue opcode sequence. If the lvalue is a nested // destructuring initialiser-form, call ourselves to handle it, then pop @@ -4401,44 +4463,28 @@ BytecodeEmitter::emitDestructuringLHS(ParseNode* target, DestructuringFlavor fla } case PNK_DOT: { - // See the (PNK_NAME, JSOP_SETNAME) case above. - // - // In `a.x = b`, `a` is evaluated first, then `b`, then a - // JSOP_SETPROP instruction. - // - // In `[a.x] = [b]`, per spec, `b` is evaluated before `a`. Then we - // need a property set -- but the operands are on the stack in the - // wrong order for JSOP_SETPROP, so we have to add a JSOP_SWAP. + // The reference is already pushed by emitDestructuringLHSRef. JSOp setOp; - if (target->as<PropertyAccess>().isSuper()) { - if (!emitSuperPropLHS(&target->as<PropertyAccess>().expression())) - return false; - if (!emit2(JSOP_PICK, 2)) - return false; + if (target->as<PropertyAccess>().isSuper()) setOp = sc->strict() ? JSOP_STRICTSETPROP_SUPER : JSOP_SETPROP_SUPER; - } else { - if (!emitTree(target->pn_expr)) - return false; - if (!emit1(JSOP_SWAP)) - return false; + else setOp = sc->strict() ? JSOP_STRICTSETPROP : JSOP_SETPROP; - } if (!emitAtomOp(target, setOp)) return false; break; } case PNK_ELEM: { - // See the comment at `case PNK_DOT:` above. This case, - // `[a[x]] = [b]`, is handled much the same way. The JSOP_SWAP - // is emitted by emitElemOperands. + // The reference is already pushed by emitDestructuringLHSRef. if (target->as<PropertyByValue>().isSuper()) { JSOp setOp = sc->strict() ? JSOP_STRICTSETELEM_SUPER : JSOP_SETELEM_SUPER; - if (!emitSuperElemOp(target, setOp)) + // emitDestructuringLHSRef already did emitSuperElemOperands + // part of emitSuperElemOp. Perform remaining part here. + if (!emitElemOpBase(setOp)) return false; } else { JSOp setOp = sc->strict() ? JSOP_STRICTSETELEM : JSOP_SETELEM; - if (!emitElemOp(target, setOp)) + if (!emitElemOpBase(setOp)) return false; } break; @@ -4451,7 +4497,7 @@ BytecodeEmitter::emitDestructuringLHS(ParseNode* target, DestructuringFlavor fla break; default: - MOZ_CRASH("emitDestructuringLHS: bad lhs kind"); + MOZ_CRASH("emitSetOrInitializeDestructuring: bad lhs kind"); } // Pop the assigned value. @@ -4732,11 +4778,13 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav // // let x, y; // let a, b, c, d; - // let iter, result, done, value; // stack values + // let iter, lref, result, done, value; // stack values // // iter = x[Symbol.iterator](); // // // ==== emitted by loop for a ==== + // lref = GetReference(a); + // // result = iter.next(); // done = result.done; // @@ -4745,9 +4793,11 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav // else // value = result.value; // - // a = value; + // SetOrInitialize(lref, value); // // // ==== emitted by loop for b ==== + // lref = GetReference(b); + // // if (done) { // value = undefined; // } else { @@ -4759,7 +4809,7 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav // value = result.value; // } // - // b = value; + // SetOrInitialize(lref, value); // // // ==== emitted by loop for elision ==== // if (done) { @@ -4774,6 +4824,8 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav // } // // // ==== emitted by loop for c ==== + // lref = GetReference(c); + // // if (done) { // value = undefined; // } else { @@ -4788,15 +4840,17 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav // if (value === undefined) // value = y; // - // c = value; + // SetOrInitialize(lref, value); // // // ==== emitted by loop for d ==== + // lref = GetReference(d); + // // if (done) // value = []; // else // value = [...iter]; // - // d = value; + // SetOrInitialize(lref, value); // Use an iterator to destructure the RHS, instead of index lookup. We // must leave the *original* value on the stack. @@ -4810,31 +4864,40 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav bool hasNext = !!member->pn_next; if (member->isKind(PNK_SPREAD)) { + size_t emitted = 0; + if (!emitDestructuringLHSRef(member, &emitted)) // ... OBJ ITER ?DONE *LREF + return false; + IfThenElseEmitter ifThenElse(this); if (!isHead) { // If spread is not the first element of the pattern, // iterator can already be completed. - // ... OBJ ITER DONE - if (!ifThenElse.emitIfElse()) // ... OBJ ITER + // ... OBJ ITER DONE *LREF + if (emitted) { + if (!emit2(JSOP_PICK, emitted)) // ... OBJ ITER *LREF DONE + return false; + } + + if (!ifThenElse.emitIfElse()) // ... OBJ ITER *LREF return false; - if (!emitUint32Operand(JSOP_NEWARRAY, 0)) // ... OBJ ITER ARRAY + if (!emitUint32Operand(JSOP_NEWARRAY, 0)) // ... OBJ ITER *LREF ARRAY return false; - if (!ifThenElse.emitElse()) // ... OBJ ITER + if (!ifThenElse.emitElse()) // ... OBJ ITER *LREF return false; } // If iterator is not completed, create a new array with the rest // of the iterator. - if (!emit1(JSOP_DUP)) // ... OBJ ITER + if (!emitDupAt(emitted)) // ... OBJ ITER *LREF ITER return false; - if (!emitUint32Operand(JSOP_NEWARRAY, 0)) // ... OBJ ITER ITER ARRAY + if (!emitUint32Operand(JSOP_NEWARRAY, 0)) // ... OBJ ITER *LREF ITER ARRAY return false; - if (!emitNumberOp(0)) // ... OBJ ITER ITER ARRAY INDEX + if (!emitNumberOp(0)) // ... OBJ ITER *LREF ITER ARRAY INDEX return false; - if (!emitSpread()) // ... OBJ ITER ARRAY INDEX + if (!emitSpread()) // ... OBJ ITER *LREF ARRAY INDEX return false; - if (!emit1(JSOP_POP)) // ... OBJ ITER ARRAY + if (!emit1(JSOP_POP)) // ... OBJ ITER *LREF ARRAY return false; if (!isHead) { @@ -4843,7 +4906,7 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav MOZ_ASSERT(ifThenElse.pushed() == 1); } - if (!emitDestructuringLHS(member, flav)) // ... OBJ ITER + if (!emitSetOrInitializeDestructuring(member, flav)) // ... OBJ ITER return false; MOZ_ASSERT(!hasNext); @@ -4861,69 +4924,91 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav MOZ_ASSERT(!subpattern->isKind(PNK_SPREAD)); + size_t emitted = 0; + if (!isElision) { + if (!emitDestructuringLHSRef(subpattern, &emitted)) // ... OBJ ITER ?DONE *LREF + return false; + } + 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; + // ... OBJ ITER DONE *LREF + if (emitted) { + if (hasNext) { + if (!emitDupAt(emitted)) // ... OBJ ITER DONE *LREF DONE + return false; + } else { + if (!emit2(JSOP_PICK, emitted)) // ... OBJ ITER *LREF DONE + return false; + } + } else { + if (hasNext) { + // The position of LREF in the following stack comment + // isn't accurate for the operation, but it's equivalent + // since LREF is nothing + if (!emit1(JSOP_DUP)) // ... OBJ ITER DONE *LREF DONE + return false; + } } - if (!ifAlreadyDone.emitIfElse()) // ... OBJ ITER ?DONE + if (!ifAlreadyDone.emitIfElse()) // ... OBJ ITER ?DONE *LREF return false; - if (!emit1(JSOP_UNDEFINED)) // ... OBJ ITER ?DONE UNDEF + if (!emit1(JSOP_UNDEFINED)) // ... OBJ ITER ?DONE *LREF UNDEF return false; - if (!emit1(JSOP_NOP_DESTRUCTURING)) // ... OBJ ITER ?DONE UNDEF + if (!emit1(JSOP_NOP_DESTRUCTURING)) // ... OBJ ITER ?DONE *LREF UNDEF return false; - if (!ifAlreadyDone.emitElse()) // ... OBJ ITER ?DONE + if (!ifAlreadyDone.emitElse()) // ... OBJ ITER ?DONE *LREF return false; if (hasNext) { - if (!emit1(JSOP_POP)) // ... OBJ ITER + if (emitted) { + if (!emit2(JSOP_PICK, emitted)) // ... OBJ ITER *LREF DONE + return false; + } + if (!emit1(JSOP_POP)) // ... OBJ ITER *LREF return false; } } - if (!emit1(JSOP_DUP)) // ... OBJ ITER ITER - return false; - if (!emitIteratorNext(pattern)) // ... OBJ ITER RESULT + if (emitted) { + if (!emitDupAt(emitted)) // ... OBJ ITER *LREF ITER + return false; + } else { + if (!emit1(JSOP_DUP)) // ... OBJ ITER *LREF ITER + return false; + } + if (!emitIteratorNext(pattern)) // ... OBJ ITER *LREF RESULT return false; - if (!emit1(JSOP_DUP)) // ... OBJ ITER RESULT RESULT + if (!emit1(JSOP_DUP)) // ... OBJ ITER *LREF RESULT RESULT return false; - if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ... OBJ ITER RESULT DONE + if (!emitAtomOp(cx->names().done, JSOP_GETPROP)) // ... OBJ ITER *LREF RESULT DONE return false; if (hasNext) { - if (!emit1(JSOP_DUP)) // ... OBJ ITER RESULT DONE DONE + if (!emit1(JSOP_DUP)) // ... OBJ ITER *LREF RESULT DONE DONE + return false; + if (!emit2(JSOP_UNPICK, emitted + 2)) // ... OBJ ITER DONE *LREF RESULT DONE return false; } IfThenElseEmitter ifDone(this); - if (!ifDone.emitIfElse()) // ... OBJ ITER RESULT ?DONE + if (!ifDone.emitIfElse()) // ... OBJ ITER ?DONE *LREF RESULT return false; - if (hasNext) { - if (!emit1(JSOP_SWAP)) // ... OBJ ITER ?DONE RESULT - return false; - } - if (!emit1(JSOP_POP)) // ... OBJ ITER ?DONE + if (!emit1(JSOP_POP)) // ... OBJ ITER ?DONE *LREF return false; - if (!emit1(JSOP_UNDEFINED)) // ... OBJ ITER ?DONE UNDEF + if (!emit1(JSOP_UNDEFINED)) // ... OBJ ITER ?DONE *LREF UNDEF return false; - if (!emit1(JSOP_NOP_DESTRUCTURING)) // ... OBJ ITER ?DONE UNDEF + if (!emit1(JSOP_NOP_DESTRUCTURING)) // ... OBJ ITER ?DONE *LREF UNDEF return false; - if (!ifDone.emitElse()) // ... OBJ ITER RESULT ?DONE + if (!ifDone.emitElse()) // ... OBJ ITER ?DONE *LREF RESULT return false; - if (hasNext) { - if (!emit1(JSOP_SWAP)) // ... OBJ ITER ?DONE RESULT - return false; - } - if (!emitAtomOp(cx->names().value, JSOP_GETPROP)) // ... OBJ ITER ?DONE VALUE + if (!emitAtomOp(cx->names().value, JSOP_GETPROP)) // ... OBJ ITER ?DONE *LREF VALUE return false; if (!ifDone.emitEnd()) @@ -4937,13 +5022,16 @@ BytecodeEmitter::emitDestructuringOpsArray(ParseNode* pattern, DestructuringFlav } if (pndefault) { - if (!emitDefault(pndefault, subpattern)) // ... OBJ ITER ?DONE VALUE + if (!emitDefault(pndefault, subpattern)) // ... OBJ ITER ?DONE *LREF VALUE return false; } if (!isElision) { - if (!emitDestructuringLHS(subpattern, flav)) // ... OBJ ITER ?DONE + if (!emitSetOrInitializeDestructuring(subpattern, + flav)) // ... OBJ ITER ?DONE + { return false; + } } else { if (!emit1(JSOP_POP)) // ... OBJ ITER ?DONE return false; @@ -4975,27 +5063,43 @@ BytecodeEmitter::emitDestructuringOpsObject(ParseNode* pattern, DestructuringFla return false; for (ParseNode* member = pattern->pn_head; member; member = member->pn_next) { - // Duplicate the value being destructured to use as a reference base. - if (!emit1(JSOP_DUP)) // ... RHS RHS + ParseNode* subpattern; + if (member->isKind(PNK_MUTATEPROTO)) + subpattern = member->pn_kid; + else + subpattern = member->pn_right; + ParseNode* lhs = subpattern; + if (lhs->isKind(PNK_ASSIGN)) + lhs = lhs->pn_left; + + size_t emitted; + if (!emitDestructuringLHSRef(lhs, &emitted)) // ... RHS *LREF return false; + // Duplicate the value being destructured to use as a reference base. + if (emitted) { + if (!emitDupAt(emitted)) // ... RHS *LREF RHS + return false; + } else { + if (!emit1(JSOP_DUP)) // ... RHS RHS + return false; + } + // Now push the property name currently being matched, which is the // current property name "label" on the left of a colon in the object // initialiser. bool needsGetElem = true; - ParseNode* subpattern; if (member->isKind(PNK_MUTATEPROTO)) { - if (!emitAtomOp(cx->names().proto, JSOP_GETPROP)) // ... RHS PROP + if (!emitAtomOp(cx->names().proto, JSOP_GETPROP)) // ... RHS *LREF PROP return false; needsGetElem = false; - subpattern = member->pn_kid; } else { MOZ_ASSERT(member->isKind(PNK_COLON) || member->isKind(PNK_SHORTHAND)); ParseNode* key = member->pn_left; if (key->isKind(PNK_NUMBER)) { - if (!emitNumberOp(key->pn_dval)) // ... RHS RHS KEY + if (!emitNumberOp(key->pn_dval)) // ... RHS *LREF RHS KEY return false; } else if (key->isKind(PNK_OBJECT_PROPERTY_NAME) || key->isKind(PNK_STRING)) { PropertyName* name = key->pn_atom->asPropertyName(); @@ -5005,33 +5109,30 @@ BytecodeEmitter::emitDestructuringOpsObject(ParseNode* pattern, DestructuringFla // as indexes for simplification of downstream analysis. jsid id = NameToId(name); if (id != IdToTypeId(id)) { - if (!emitTree(key)) // ... RHS RHS KEY + if (!emitTree(key)) // ... RHS *LREF RHS KEY return false; } else { - if (!emitAtomOp(name, JSOP_GETPROP)) // ...RHS PROP + if (!emitAtomOp(name, JSOP_GETPROP)) // ... RHS *LREF PROP return false; needsGetElem = false; } } else { - if (!emitComputedPropertyName(key)) // ... RHS RHS KEY + if (!emitComputedPropertyName(key)) // ... RHS *LREF RHS KEY return false; } - - subpattern = member->pn_right; } // Get the property value if not done already. - if (needsGetElem && !emitElemOpBase(JSOP_GETELEM)) // ... RHS PROP + if (needsGetElem && !emitElemOpBase(JSOP_GETELEM)) // ... RHS *LREF PROP return false; if (subpattern->isKind(PNK_ASSIGN)) { - if (!emitDefault(subpattern->pn_right, subpattern->pn_left)) + if (!emitDefault(subpattern->pn_right, lhs)) // ... RHS *LREF VALUE return false; - subpattern = subpattern->pn_left; } - // Destructure PROP per this member's subpattern. - if (!emitDestructuringLHS(subpattern, flav)) + // Destructure PROP per this member's lhs. + if (!emitSetOrInitializeDestructuring(subpattern, flav)) // ... RHS return false; } diff --git a/js/src/frontend/BytecodeEmitter.h b/js/src/frontend/BytecodeEmitter.h index f09b529ed..066c06672 100644 --- a/js/src/frontend/BytecodeEmitter.h +++ b/js/src/frontend/BytecodeEmitter.h @@ -609,7 +609,7 @@ struct MOZ_STACK_CLASS BytecodeEmitter // Emit bytecode to put operands for a JSOP_GETELEM/CALLELEM/SETELEM/DELELEM // opcode onto the stack in the right order. In the case of SETELEM, the // value to be assigned must already be pushed. - enum class EmitElemOption { Get, Set, Call, IncDec, CompoundAssign }; + enum class EmitElemOption { Get, Set, Call, IncDec, CompoundAssign, Ref }; MOZ_MUST_USE bool emitElemOperands(ParseNode* pn, EmitElemOption opts); MOZ_MUST_USE bool emitElemOpBase(JSOp op); @@ -642,10 +642,18 @@ struct MOZ_STACK_CLASS BytecodeEmitter DestructuringAssignment }; - // emitDestructuringLHS assumes the to-be-destructured value has been pushed on - // 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); + // emitDestructuringLHSRef emits the lhs expression's reference. + // If the lhs expression is object property |OBJ.prop|, it emits |OBJ|. + // If it's object element |OBJ[ELEM]|, it emits |OBJ| and |ELEM|. + // If there's nothing to evaluate for the reference, it emits nothing. + // |emitted| parameter receives the number of values pushed onto the stack. + MOZ_MUST_USE bool emitDestructuringLHSRef(ParseNode* target, size_t* emitted); + + // emitSetOrInitializeDestructuring assumes the lhs expression's reference + // and the to-be-destructured value has been pushed on the stack. It emits + // code to destructure a single lhs expression (either a name or a compound + // []/{} expression). + MOZ_MUST_USE bool emitSetOrInitializeDestructuring(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 |