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Diffstat (limited to 'js/src/frontend/PropOpEmitter.cpp')
| -rw-r--r-- | js/src/frontend/PropOpEmitter.cpp | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/js/src/frontend/PropOpEmitter.cpp b/js/src/frontend/PropOpEmitter.cpp new file mode 100644 index 0000000000..fd00024e7c --- /dev/null +++ b/js/src/frontend/PropOpEmitter.cpp @@ -0,0 +1,275 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- + * vim: set ts=8 sts=4 et sw=4 tw=99: + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "frontend/PropOpEmitter.h" + +#include "frontend/BytecodeEmitter.h" +#include "frontend/SharedContext.h" +#include "vm/Opcodes.h" +#include "vm/String.h" + +using namespace js; +using namespace js::frontend; + +PropOpEmitter::PropOpEmitter(BytecodeEmitter* bce, Kind kind, ObjKind objKind) + : bce_(bce), + kind_(kind), + objKind_(objKind) +{} + +bool +PropOpEmitter::prepareAtomIndex(JSAtom* prop) +{ + if (!bce_->makeAtomIndex(prop, &propAtomIndex_)) { + return false; + } + isLength_ = prop == bce_->cx->names().length; + + return true; +} + +bool +PropOpEmitter::prepareForObj() +{ + MOZ_ASSERT(state_ == State::Start); + +#ifdef DEBUG + state_ = State::Obj; +#endif + return true; +} + +bool +PropOpEmitter::emitGet(JSAtom* prop) +{ + MOZ_ASSERT(state_ == State::Obj); + + if (!prepareAtomIndex(prop)) { + return false; + } + if (isCall()) { + if (!bce_->emit1(JSOP_DUP)) { // [Super] + // // THIS THIS + // // [Other] + // // OBJ OBJ + return false; + } + } + if (isSuper()) { + if (!bce_->emit1(JSOP_SUPERBASE)) { // THIS? THIS SUPERBASE + return false; + } + } + if (isIncDec() || isCompoundAssignment()) { + if (isSuper()) { + if (!bce_->emit1(JSOP_DUP2)) { // THIS SUPERBASE THIS SUPERBASE + return false; + } + } else { + if (!bce_->emit1(JSOP_DUP)) { // OBJ OBJ + return false; + } + } + } + + JSOp op; + if (isSuper()) { + op = JSOP_GETPROP_SUPER; + } else if (isCall()) { + op = JSOP_CALLPROP; + } else { + op = isLength_ ? JSOP_LENGTH : JSOP_GETPROP; + } + if (!bce_->emitAtomOp(propAtomIndex_, op)) { // [Get] + // // PROP + // // [Call] + // // THIS PROP + // // [Inc/Dec/Compound, + // // Super] + // // THIS SUPERBASE PROP + // // [Inc/Dec/Compound, + // // Other] + // // OBJ PROP + return false; + } + if (isCall()) { + if (!bce_->emit1(JSOP_SWAP)) { // PROP THIS + return false; + } + } + +#ifdef DEBUG + state_ = State::Get; +#endif + return true; +} + +bool +PropOpEmitter::prepareForRhs() +{ + MOZ_ASSERT(isSimpleAssignment() || isCompoundAssignment()); + MOZ_ASSERT_IF(isSimpleAssignment(), state_ == State::Obj); + MOZ_ASSERT_IF(isCompoundAssignment(), state_ == State::Get); + + if (isSimpleAssignment()) { + // For CompoundAssignment, SUPERBASE is already emitted by emitGet. + if (isSuper()) { + if (!bce_->emit1(JSOP_SUPERBASE)) { // THIS SUPERBASE + return false; + } + } + } + +#ifdef DEBUG + state_ = State::Rhs; +#endif + return true; +} + +bool +PropOpEmitter::skipObjAndRhs() +{ + MOZ_ASSERT(state_ == State::Start); + MOZ_ASSERT(isSimpleAssignment()); + +#ifdef DEBUG + state_ = State::Rhs; +#endif + return true; +} + +bool +PropOpEmitter::emitDelete(JSAtom* prop) +{ + MOZ_ASSERT_IF(!isSuper(), state_ == State::Obj); + MOZ_ASSERT_IF(isSuper(), state_ == State::Start); + MOZ_ASSERT(isDelete()); + + if (!prepareAtomIndex(prop)) { + return false; + } + if (isSuper()) { + if (!bce_->emit1(JSOP_SUPERBASE)) { // THIS SUPERBASE + return false; + } + + // Unconditionally throw when attempting to delete a super-reference. + if (!bce_->emitUint16Operand(JSOP_THROWMSG, JSMSG_CANT_DELETE_SUPER)) { + return false; // THIS SUPERBASE + } + + // Another wrinkle: Balance the stack from the emitter's point of view. + // Execution will not reach here, as the last bytecode threw. + if (!bce_->emit1(JSOP_POP)) { // THIS + return false; + } + } else { + JSOp op = bce_->sc->strict() ? JSOP_STRICTDELPROP : JSOP_DELPROP; + if (!bce_->emitAtomOp(propAtomIndex_, op)) { // SUCCEEDED + return false; + } + } + +#ifdef DEBUG + state_ = State::Delete; +#endif + return true; +} + +bool +PropOpEmitter::emitAssignment(JSAtom* prop) +{ + MOZ_ASSERT(isSimpleAssignment() || isCompoundAssignment()); + MOZ_ASSERT(state_ == State::Rhs); + + if (isSimpleAssignment()) { + if (!prepareAtomIndex(prop)) { + return false; + } + } + + JSOp setOp = isSuper() + ? bce_->sc->strict() ? JSOP_STRICTSETPROP_SUPER : JSOP_SETPROP_SUPER + : bce_->sc->strict() ? JSOP_STRICTSETPROP : JSOP_SETPROP; + if (!bce_->emitAtomOp(propAtomIndex_, setOp)) { // VAL + return false; + } + +#ifdef DEBUG + state_ = State::Assignment; +#endif + return true; +} + +bool +PropOpEmitter::emitIncDec(JSAtom* prop) +{ + MOZ_ASSERT(state_ == State::Obj); + MOZ_ASSERT(isIncDec()); + + if (!emitGet(prop)) { + return false; + } + + MOZ_ASSERT(state_ == State::Get); + + JSOp binOp = isInc() ? JSOP_ADD : JSOP_SUB; + + if (!bce_->emit1(JSOP_POS)) { // ... N + return false; + } + if (isPostIncDec()) { + if (!bce_->emit1(JSOP_DUP)) { // ... N N + return false; + } + } + if (!bce_->emit1(JSOP_ONE)) { // ... N? N 1 + return false; + } + if (!bce_->emit1(binOp)) { // ... N? N+1 + return false; + } + if (isPostIncDec()) { + if (isSuper()) { // THIS OBJ N N+1 + if (!bce_->emit2(JSOP_PICK, 3)) { // OBJ N N+1 THIS + return false; + } + if (!bce_->emit1(JSOP_SWAP)) { // OBJ N THIS N+1 + return false; + } + if (!bce_->emit2(JSOP_PICK, 3)) { // N THIS N+1 OBJ + return false; + } + if (!bce_->emit1(JSOP_SWAP)) { // N THIS OBJ N+1 + return false; + } + } else { // OBJ N N+1 + if (!bce_->emit2(JSOP_PICK, 2)) { // N N+1 OBJ + return false; + } + if (!bce_->emit1(JSOP_SWAP)) { // N OBJ N+1 + return false; + } + } + } + + JSOp setOp = isSuper() + ? bce_->sc->strict() ? JSOP_STRICTSETPROP_SUPER : JSOP_SETPROP_SUPER + : bce_->sc->strict() ? JSOP_STRICTSETPROP : JSOP_SETPROP; + if (!bce_->emitAtomOp(propAtomIndex_, setOp)) { // N? N+1 + return false; + } + if (isPostIncDec()) { + if (!bce_->emit1(JSOP_POP)) { // N + return false; + } + } + +#ifdef DEBUG + state_ = State::IncDec; +#endif + return true; +} |