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Diffstat (limited to 'js/src/frontend/PropOpEmitter.cpp')
| -rw-r--r-- | js/src/frontend/PropOpEmitter.cpp | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/js/src/frontend/PropOpEmitter.cpp b/js/src/frontend/PropOpEmitter.cpp new file mode 100644 index 0000000000..ff08bd8580 --- /dev/null +++ b/js/src/frontend/PropOpEmitter.cpp @@ -0,0 +1,244 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * 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/ParserAtom.h" // ParserAtom +#include "frontend/SharedContext.h" +#include "vm/Opcodes.h" +#include "vm/ThrowMsgKind.h" // ThrowMsgKind + +using namespace js; +using namespace js::frontend; + +PropOpEmitter::PropOpEmitter(BytecodeEmitter* bce, Kind kind, ObjKind objKind) + : bce_(bce), kind_(kind), objKind_(objKind) {} + +bool PropOpEmitter::prepareAtomIndex(TaggedParserAtomIndex prop) { + return bce_->makeAtomIndex(prop, ParserAtom::Atomize::Yes, &propAtomIndex_); +} + +bool PropOpEmitter::prepareForObj() { + MOZ_ASSERT(state_ == State::Start); + +#ifdef DEBUG + state_ = State::Obj; +#endif + return true; +} + +bool PropOpEmitter::emitGet(TaggedParserAtomIndex prop) { + MOZ_ASSERT(state_ == State::Obj); + + if (!prepareAtomIndex(prop)) { + return false; + } + if (isCall()) { + if (!bce_->emit1(JSOp::Dup)) { + // [stack] # if Super + // [stack] THIS THIS + // [stack] # otherwise + // [stack] OBJ OBJ + return false; + } + } + if (isSuper()) { + if (!bce_->emitSuperBase()) { + // [stack] THIS? THIS SUPERBASE + return false; + } + } + if (isIncDec() || isCompoundAssignment()) { + if (isSuper()) { + if (!bce_->emit1(JSOp::Dup2)) { + // [stack] THIS SUPERBASE THIS SUPERBASE + return false; + } + } else { + if (!bce_->emit1(JSOp::Dup)) { + // [stack] OBJ OBJ + return false; + } + } + } + + JSOp op = isSuper() ? JSOp::GetPropSuper : JSOp::GetProp; + if (!bce_->emitAtomOp(op, propAtomIndex_)) { + // [stack] # if Get + // [stack] PROP + // [stack] # if Call + // [stack] THIS PROP + // [stack] # if Inc/Dec/Compound, Super] + // [stack] THIS SUPERBASE PROP + // [stack] # if Inc/Dec/Compound, other + // [stack] OBJ PROP + return false; + } + if (isCall()) { + if (!bce_->emit1(JSOp::Swap)) { + // [stack] PROP THIS + return false; + } + } + +#ifdef DEBUG + state_ = State::Get; +#endif + return true; +} + +bool PropOpEmitter::prepareForRhs() { + MOZ_ASSERT(isSimpleAssignment() || isPropInit() || isCompoundAssignment()); + MOZ_ASSERT_IF(isSimpleAssignment() || isPropInit(), state_ == State::Obj); + MOZ_ASSERT_IF(isCompoundAssignment(), state_ == State::Get); + + if (isSimpleAssignment() || isPropInit()) { + // For CompoundAssignment, SuperBase is already emitted by emitGet. + if (isSuper()) { + if (!bce_->emitSuperBase()) { + // [stack] THIS SUPERBASE + return false; + } + } + } + +#ifdef DEBUG + state_ = State::Rhs; +#endif + return true; +} + +bool PropOpEmitter::skipObjAndRhs() { + MOZ_ASSERT(state_ == State::Start); + MOZ_ASSERT(isSimpleAssignment() || isPropInit()); + +#ifdef DEBUG + state_ = State::Rhs; +#endif + return true; +} + +bool PropOpEmitter::emitDelete(TaggedParserAtomIndex 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_->emitSuperBase()) { + // [stack] THIS SUPERBASE + return false; + } + + // Unconditionally throw when attempting to delete a super-reference. + if (!bce_->emit2(JSOp::ThrowMsg, uint8_t(ThrowMsgKind::CantDeleteSuper))) { + // [stack] THIS SUPERBASE + return false; + } + + // 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)) { + // [stack] THIS + return false; + } + } else { + JSOp op = bce_->sc->strict() ? JSOp::StrictDelProp : JSOp::DelProp; + if (!bce_->emitAtomOp(op, propAtomIndex_)) { + // [stack] SUCCEEDED + return false; + } + } + +#ifdef DEBUG + state_ = State::Delete; +#endif + return true; +} + +bool PropOpEmitter::emitAssignment(TaggedParserAtomIndex prop) { + MOZ_ASSERT(isSimpleAssignment() || isPropInit() || isCompoundAssignment()); + MOZ_ASSERT(state_ == State::Rhs); + + if (isSimpleAssignment() || isPropInit()) { + if (!prepareAtomIndex(prop)) { + return false; + } + } + + MOZ_ASSERT_IF(isPropInit(), !isSuper()); + JSOp setOp = isPropInit() ? JSOp::InitProp + : isSuper() ? bce_->sc->strict() ? JSOp::StrictSetPropSuper + : JSOp::SetPropSuper + : bce_->sc->strict() ? JSOp::StrictSetProp + : JSOp::SetProp; + if (!bce_->emitAtomOp(setOp, propAtomIndex_)) { + // [stack] VAL + return false; + } + +#ifdef DEBUG + state_ = State::Assignment; +#endif + return true; +} + +bool PropOpEmitter::emitIncDec(TaggedParserAtomIndex prop, + ValueUsage valueUsage) { + MOZ_ASSERT(state_ == State::Obj); + MOZ_ASSERT(isIncDec()); + + if (!emitGet(prop)) { + return false; + } + + MOZ_ASSERT(state_ == State::Get); + + JSOp incOp = isInc() ? JSOp::Inc : JSOp::Dec; + + if (!bce_->emit1(JSOp::ToNumeric)) { + // [stack] ... N + return false; + } + if (isPostIncDec() && valueUsage == ValueUsage::WantValue) { + // [stack] OBJ SUPERBASE? N + if (!bce_->emit1(JSOp::Dup)) { + // [stack] .. N N + return false; + } + if (!bce_->emit2(JSOp::Unpick, 2 + isSuper())) { + // [stack] N OBJ SUPERBASE? N + return false; + } + } + if (!bce_->emit1(incOp)) { + // [stack] ... N+1 + return false; + } + + JSOp setOp = isSuper() ? bce_->sc->strict() ? JSOp::StrictSetPropSuper + : JSOp::SetPropSuper + : bce_->sc->strict() ? JSOp::StrictSetProp + : JSOp::SetProp; + if (!bce_->emitAtomOp(setOp, propAtomIndex_)) { + // [stack] N? N+1 + return false; + } + if (isPostIncDec() && valueUsage == ValueUsage::WantValue) { + if (!bce_->emit1(JSOp::Pop)) { + // [stack] N + return false; + } + } + +#ifdef DEBUG + state_ = State::IncDec; +#endif + return true; +} |