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/* -*- 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
#include "frontend/NameOpEmitter.h"
#include "frontend/AbstractScopePtr.h"
#include "frontend/BytecodeEmitter.h"
#include "frontend/ParserAtom.h" // ParserAtom
#include "frontend/SharedContext.h"
#include "frontend/TDZCheckCache.h"
#include "frontend/ValueUsage.h"
#include "js/Value.h"
#include "vm/Opcodes.h"
using namespace js;
using namespace js::frontend;
NameOpEmitter::NameOpEmitter(BytecodeEmitter* bce, TaggedParserAtomIndex name,
Kind kind)
: bce_(bce), kind_(kind), name_(name), loc_(bce_->lookupName(name_)) {}
NameOpEmitter::NameOpEmitter(BytecodeEmitter* bce, TaggedParserAtomIndex name,
const NameLocation& loc, Kind kind)
: bce_(bce), kind_(kind), name_(name), loc_(loc) {}
bool NameOpEmitter::emitGet() {
MOZ_ASSERT(state_ == State::Start);
switch (loc_.kind()) {
case NameLocation::Kind::Dynamic:
if (!bce_->emitAtomOp(JSOp::GetName, name_)) {
// [stack] VAL
return false;
}
break;
case NameLocation::Kind::Global: {
MOZ_ASSERT(bce_->outermostScope().hasNonSyntacticScopeOnChain() ==
bce_->sc->hasNonSyntacticScope());
if (bce_->sc->hasNonSyntacticScope()) {
if (!bce_->emitAtomOp(JSOp::GetName, name_)) {
// [stack] VAL
return false;
}
} else {
// Some names on the global are not configurable and have fixed values
// which we can emit instead.
if (name_ == TaggedParserAtomIndex::WellKnown::undefined()) {
if (!bce_->emit1(JSOp::Undefined)) {
return false;
}
} else if (name_ == TaggedParserAtomIndex::WellKnown::NaN()) {
if (!bce_->emitDouble(JS::GenericNaN())) {
return false;
}
} else if (name_ == TaggedParserAtomIndex::WellKnown::Infinity()) {
if (!bce_->emitDouble(JS::Infinity())) {
return false;
}
} else {
if (!bce_->emitAtomOp(JSOp::GetGName, name_)) {
// [stack] VAL
return false;
}
}
}
break;
}
case NameLocation::Kind::Intrinsic:
if (name_ == TaggedParserAtomIndex::WellKnown::undefined()) {
if (!bce_->emit1(JSOp::Undefined)) {
// [stack] Undefined
return false;
}
} else {
if (!bce_->emitAtomOp(JSOp::GetIntrinsic, name_)) {
// [stack] VAL
return false;
}
}
break;
case NameLocation::Kind::NamedLambdaCallee:
if (!bce_->emit1(JSOp::Callee)) {
// [stack] VAL
return false;
}
break;
case NameLocation::Kind::Import:
if (!bce_->emitAtomOp(JSOp::GetImport, name_)) {
// [stack] VAL
return false;
}
break;
case NameLocation::Kind::ArgumentSlot:
if (!bce_->emitArgOp(JSOp::GetArg, loc_.argumentSlot())) {
// [stack] VAL
return false;
}
break;
case NameLocation::Kind::FrameSlot:
if (!bce_->emitLocalOp(JSOp::GetLocal, loc_.frameSlot())) {
// [stack] VAL
return false;
}
if (loc_.isLexical()) {
if (!bce_->emitTDZCheckIfNeeded(name_, loc_, ValueIsOnStack::Yes)) {
// [stack] VAL
return false;
}
}
break;
case NameLocation::Kind::EnvironmentCoordinate:
case NameLocation::Kind::DebugEnvironmentCoordinate:
if (!bce_->emitEnvCoordOp(
loc_.kind() == NameLocation::Kind::EnvironmentCoordinate
? JSOp::GetAliasedVar
: JSOp::GetAliasedDebugVar,
loc_.environmentCoordinate())) {
// [stack] VAL
return false;
}
if (loc_.isLexical()) {
if (!bce_->emitTDZCheckIfNeeded(name_, loc_, ValueIsOnStack::Yes)) {
// [stack] VAL
return false;
}
}
break;
case NameLocation::Kind::DynamicAnnexBVar:
MOZ_CRASH(
"Synthesized vars for Annex B.3.3 should only be used in "
"initialization");
}
if (isCall()) {
MOZ_ASSERT(bce_->outermostScope().hasNonSyntacticScopeOnChain() ==
bce_->sc->hasNonSyntacticScope());
switch (loc_.kind()) {
case NameLocation::Kind::Dynamic:
case NameLocation::Kind::Global:
MOZ_ASSERT(bce_->emitterMode != BytecodeEmitter::SelfHosting);
if (bce_->needsImplicitThis() || bce_->sc->hasNonSyntacticScope()) {
MOZ_ASSERT_IF(bce_->needsImplicitThis(),
loc_.kind() == NameLocation::Kind::Dynamic);
if (!bce_->emitAtomOp(JSOp::ImplicitThis, name_)) {
// [stack] CALLEE THIS
return false;
}
} else {
if (!bce_->emit1(JSOp::Undefined)) {
// [stack] CALLEE UNDEF
return false;
}
}
break;
case NameLocation::Kind::Intrinsic:
case NameLocation::Kind::NamedLambdaCallee:
case NameLocation::Kind::Import:
case NameLocation::Kind::ArgumentSlot:
case NameLocation::Kind::FrameSlot:
case NameLocation::Kind::EnvironmentCoordinate:
if (bce_->emitterMode == BytecodeEmitter::SelfHosting) {
if (!bce_->emitDebugCheckSelfHosted()) {
// [stack] CALLEE
return false;
}
}
if (!bce_->emit1(JSOp::Undefined)) {
// [stack] CALLEE UNDEF
return false;
}
break;
case NameLocation::Kind::DebugEnvironmentCoordinate:
MOZ_CRASH(
"DebugEnvironmentCoordinate should only be used to get the private "
"brand, and so should never call.");
break;
case NameLocation::Kind::DynamicAnnexBVar:
MOZ_CRASH(
"Synthesized vars for Annex B.3.3 should only be used in "
"initialization");
}
}
#ifdef DEBUG
state_ = State::Get;
#endif
return true;
}
bool NameOpEmitter::prepareForRhs() {
MOZ_ASSERT(state_ == State::Start);
switch (loc_.kind()) {
case NameLocation::Kind::Dynamic:
case NameLocation::Kind::Import:
case NameLocation::Kind::DynamicAnnexBVar:
if (!bce_->makeAtomIndex(name_, ParserAtom::Atomize::Yes, &atomIndex_)) {
return false;
}
if (loc_.kind() == NameLocation::Kind::DynamicAnnexBVar) {
// Annex B vars always go on the nearest variable environment,
// even if lexical environments in between contain same-named
// bindings.
if (!bce_->emit1(JSOp::BindVar)) {
// [stack] ENV
return false;
}
} else {
if (!bce_->emitAtomOp(JSOp::BindName, atomIndex_)) {
// [stack] ENV
return false;
}
}
emittedBindOp_ = true;
break;
case NameLocation::Kind::Global:
if (!bce_->makeAtomIndex(name_, ParserAtom::Atomize::Yes, &atomIndex_)) {
return false;
}
MOZ_ASSERT(bce_->outermostScope().hasNonSyntacticScopeOnChain() ==
bce_->sc->hasNonSyntacticScope());
if (loc_.isLexical() && isInitialize()) {
// InitGLexical always gets the global lexical scope. It doesn't
// need a BindName/BindGName.
MOZ_ASSERT(bce_->innermostScope().is<GlobalScope>());
} else if (bce_->sc->hasNonSyntacticScope()) {
if (!bce_->emitAtomOp(JSOp::BindName, atomIndex_)) {
// [stack] ENV
return false;
}
emittedBindOp_ = true;
} else {
if (!bce_->emitAtomOp(JSOp::BindGName, atomIndex_)) {
// [stack] ENV
return false;
}
emittedBindOp_ = true;
}
break;
case NameLocation::Kind::Intrinsic:
break;
case NameLocation::Kind::NamedLambdaCallee:
break;
case NameLocation::Kind::ArgumentSlot:
break;
case NameLocation::Kind::FrameSlot:
break;
case NameLocation::Kind::DebugEnvironmentCoordinate:
break;
case NameLocation::Kind::EnvironmentCoordinate:
break;
}
// For compound assignments, first get the LHS value, then emit
// the RHS and the op.
if (isCompoundAssignment() || isIncDec()) {
if (loc_.kind() == NameLocation::Kind::Dynamic) {
// For dynamic accesses we need to emit GetBoundName instead of
// GetName for correctness: looking up @@unscopables on the
// environment chain (due to 'with' environments) must only happen
// once.
//
// GetBoundName uses the environment already pushed on the stack
// from the earlier BindName.
if (!bce_->emit1(JSOp::Dup)) {
// [stack] ENV ENV
return false;
}
if (!bce_->emitAtomOp(JSOp::GetBoundName, name_)) {
// [stack] ENV V
return false;
}
} else {
if (!emitGet()) {
// [stack] ENV? V
return false;
}
}
}
#ifdef DEBUG
state_ = State::Rhs;
#endif
return true;
}
#if defined(__clang__) && defined(XP_WIN) && \
(defined(_M_X64) || defined(__x86_64__))
__attribute__((__aligned__(32)))
#endif
bool NameOpEmitter::emitAssignment() {
MOZ_ASSERT(state_ == State::Rhs);
switch (loc_.kind()) {
case NameLocation::Kind::Dynamic:
case NameLocation::Kind::Import:
case NameLocation::Kind::DynamicAnnexBVar:
if (!bce_->emitAtomOp(bce_->strictifySetNameOp(JSOp::SetName),
atomIndex_)) {
return false;
}
break;
case NameLocation::Kind::Global: {
JSOp op;
if (emittedBindOp_) {
MOZ_ASSERT(bce_->outermostScope().hasNonSyntacticScopeOnChain() ==
bce_->sc->hasNonSyntacticScope());
if (bce_->sc->hasNonSyntacticScope()) {
op = bce_->strictifySetNameOp(JSOp::SetName);
} else {
op = bce_->strictifySetNameOp(JSOp::SetGName);
}
} else {
op = JSOp::InitGLexical;
}
if (!bce_->emitAtomOp(op, atomIndex_)) {
return false;
}
break;
}
case NameLocation::Kind::Intrinsic:
if (!bce_->emitAtomOp(JSOp::SetIntrinsic, name_)) {
return false;
}
break;
case NameLocation::Kind::NamedLambdaCallee:
// Assigning to the named lambda is a no-op in sloppy mode but
// throws in strict mode.
if (bce_->sc->strict()) {
if (!bce_->emitAtomOp(JSOp::ThrowSetConst, name_)) {
return false;
}
}
break;
case NameLocation::Kind::ArgumentSlot:
if (!bce_->emitArgOp(JSOp::SetArg, loc_.argumentSlot())) {
return false;
}
break;
case NameLocation::Kind::FrameSlot: {
JSOp op = JSOp::SetLocal;
// Lexicals, Synthetics and Private Methods have very similar handling
// around a variety of areas, including initialization.
if (loc_.isLexical() || loc_.isPrivateMethod() || loc_.isSynthetic()) {
if (isInitialize()) {
op = JSOp::InitLexical;
} else {
if (loc_.isConst()) {
op = JSOp::ThrowSetConst;
}
if (!bce_->emitTDZCheckIfNeeded(name_, loc_, ValueIsOnStack::No)) {
return false;
}
}
}
if (op == JSOp::ThrowSetConst) {
if (!bce_->emitAtomOp(op, name_)) {
return false;
}
} else {
if (!bce_->emitLocalOp(op, loc_.frameSlot())) {
return false;
}
}
if (op == JSOp::InitLexical) {
if (!bce_->innermostTDZCheckCache->noteTDZCheck(bce_, name_,
DontCheckTDZ)) {
return false;
}
}
break;
}
case NameLocation::Kind::EnvironmentCoordinate: {
JSOp op = JSOp::SetAliasedVar;
// Lexicals, Synthetics and Private Methods have very similar handling
// around a variety of areas, including initialization.
if (loc_.isLexical() || loc_.isPrivateMethod() || loc_.isSynthetic()) {
if (isInitialize()) {
op = JSOp::InitAliasedLexical;
} else {
if (loc_.isConst()) {
op = JSOp::ThrowSetConst;
}
if (!bce_->emitTDZCheckIfNeeded(name_, loc_, ValueIsOnStack::No)) {
return false;
}
}
}
if (loc_.bindingKind() == BindingKind::NamedLambdaCallee) {
// Assigning to the named lambda is a no-op in sloppy mode and throws
// in strict mode.
op = JSOp::ThrowSetConst;
if (bce_->sc->strict()) {
if (!bce_->emitAtomOp(op, name_)) {
return false;
}
}
} else {
if (op == JSOp::ThrowSetConst) {
if (!bce_->emitAtomOp(op, name_)) {
return false;
}
} else {
if (!bce_->emitEnvCoordOp(op, loc_.environmentCoordinate())) {
return false;
}
}
}
if (op == JSOp::InitAliasedLexical) {
if (!bce_->innermostTDZCheckCache->noteTDZCheck(bce_, name_,
DontCheckTDZ)) {
return false;
}
}
break;
}
case NameLocation::Kind::DebugEnvironmentCoordinate:
MOZ_CRASH("Shouldn't be assigning to a private brand");
break;
}
#ifdef DEBUG
state_ = State::Assignment;
#endif
return true;
}
bool NameOpEmitter::emitIncDec(ValueUsage valueUsage) {
MOZ_ASSERT(state_ == State::Start);
JSOp incOp = isInc() ? JSOp::Inc : JSOp::Dec;
if (!prepareForRhs()) {
// [stack] ENV? V
return false;
}
if (!bce_->emit1(JSOp::ToNumeric)) {
// [stack] ENV? N
return false;
}
if (isPostIncDec() && valueUsage == ValueUsage::WantValue) {
if (!bce_->emit1(JSOp::Dup)) {
// [stack] ENV? N N
return false;
}
}
if (!bce_->emit1(incOp)) {
// [stack] ENV? N? N+1
return false;
}
if (isPostIncDec() && emittedBindOp() &&
valueUsage == ValueUsage::WantValue) {
if (!bce_->emit2(JSOp::Pick, 2)) {
// [stack] N N+1 ENV
return false;
}
if (!bce_->emit1(JSOp::Swap)) {
// [stack] N ENV N+1
return false;
}
}
if (!emitAssignment()) {
// [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;
}