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Diffstat (limited to '')
-rw-r--r-- | js/src/frontend/PrivateOpEmitter.cpp | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/js/src/frontend/PrivateOpEmitter.cpp b/js/src/frontend/PrivateOpEmitter.cpp new file mode 100644 index 0000000000..9e617b209e --- /dev/null +++ b/js/src/frontend/PrivateOpEmitter.cpp @@ -0,0 +1,331 @@ +/* -*- 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/PrivateOpEmitter.h" + +#include "frontend/BytecodeEmitter.h" +#include "frontend/NameOpEmitter.h" +#include "vm/Opcodes.h" +#include "vm/ThrowMsgKind.h" // ThrowMsgKind + +using namespace js; +using namespace js::frontend; + +PrivateOpEmitter::PrivateOpEmitter(BytecodeEmitter* bce, Kind kind, + TaggedParserAtomIndex name) + : bce_(bce), kind_(kind), name_(name) { + MOZ_ASSERT(kind_ != Kind::Delete); +} + +bool PrivateOpEmitter::init() { + // Static analysis needs us to initialise this to something, so use Dynamic() + NameLocation loc = NameLocation::Dynamic(); + bce_->lookupPrivate(name_, loc, brandLoc_); + loc_ = mozilla::Some(loc); + return true; +} + +bool PrivateOpEmitter::emitLoad(TaggedParserAtomIndex name, + const NameLocation& loc) { + NameOpEmitter noe(bce_, name, loc, NameOpEmitter::Kind::Get); + return noe.emitGet(); +} + +bool PrivateOpEmitter::emitLoadPrivateBrand() { + return emitLoad(TaggedParserAtomIndex::WellKnown::dotPrivateBrand(), + *brandLoc_); +} + +bool PrivateOpEmitter::emitBrandCheck() { + MOZ_ASSERT(state_ == State::Reference); + + if (isBrandCheck()) { + // Emit a CheckPrivateField CheckRhs; note: The message is irrelvant here, + // it will never be thrown, so DoubleInit was chosen arbitrarily. + if (!bce_->emitCheckPrivateField(ThrowCondition::OnlyCheckRhs, + ThrowMsgKind::PrivateDoubleInit)) { + // [stack] OBJ KEY BBOOL + return false; + } + + return true; + } + + // [stack] OBJ KEY + if (isFieldInit()) { + if (!bce_->emitCheckPrivateField(ThrowCondition::ThrowHas, + ThrowMsgKind::PrivateDoubleInit)) { + // [stack] OBJ KEY false + return false; + } + } else { + bool assigning = + isSimpleAssignment() || isCompoundAssignment() || isIncDec(); + if (!bce_->emitCheckPrivateField(ThrowCondition::ThrowHasNot, + assigning + ? ThrowMsgKind::MissingPrivateOnSet + : ThrowMsgKind::MissingPrivateOnGet)) { + // [stack] OBJ KEY true + return false; + } + } + + return true; +} + +bool PrivateOpEmitter::emitReference() { + MOZ_ASSERT(state_ == State::Start); + + if (!init()) { + return false; + } + + if (brandLoc_) { + if (!emitLoadPrivateBrand()) { + // [stack] OBJ BRAND + return false; + } + } else { + if (!emitLoad(name_, loc_.ref())) { + // [stack] OBJ NAME + return false; + } + } +#ifdef DEBUG + state_ = State::Reference; +#endif + return true; +} + +bool PrivateOpEmitter::skipReference() { + MOZ_ASSERT(state_ == State::Start); + + if (!init()) { + return false; + } + +#ifdef DEBUG + state_ = State::Reference; +#endif + return true; +} + +bool PrivateOpEmitter::emitGet() { + MOZ_ASSERT(state_ == State::Reference); + + // [stack] OBJ NAME + + if (brandLoc_) { + // Note that the decision of what we leave on the stack depends on kind_, + // not loc_->bindingKind(). We can't emit code for a call just because this + // private member is a method. `obj.#method` is allowed without a call, + // just fetching the function object (it's useful in code like + // `obj.#method.bind(...)`). Even if the user says `obj.#method += 7`, we + // emit honest bytecode for the brand check, method load, and addition, and + // throw the error later. This preserves stack nuses/ndefs balance. + if (!emitBrandCheck()) { + // [stack] OBJ BRAND true + return false; + } + + if (isCompoundAssignment()) { + if (!bce_->emit1(JSOp::Pop)) { + // [stack] OBJ BRAND + return false; + } + } else if (isCall()) { + if (!bce_->emitPopN(2)) { + // [stack] OBJ + return false; + } + } else { + if (!bce_->emitPopN(3)) { + // [stack] + return false; + } + } + + if (!emitLoad(name_, loc_.ref())) { + // [stack] OBJ BRAND METHOD # if isCompoundAssignment + // [stack] OBJ METHOD # if call + // [stack] METHOD # otherwise + return false; + } + } else { + if (isCall()) { + if (!bce_->emitDupAt(1)) { + // [stack] OBJ NAME OBJ + return false; + } + if (!bce_->emit1(JSOp::Swap)) { + // [stack] OBJ OBJ NAME + return false; + } + } + // [stack] OBJ? OBJ NAME + if (!emitBrandCheck()) { + // [stack] OBJ? OBJ NAME true + return false; + } + if (!bce_->emit1(JSOp::Pop)) { + // [stack] OBJ? OBJ NAME + return false; + } + + if (isCompoundAssignment()) { + if (!bce_->emit1(JSOp::Dup2)) { + // [stack] OBJ NAME OBJ NAME + return false; + } + } + + if (!bce_->emitElemOpBase(JSOp::GetElem)) { + // [stack] OBJ NAME VALUE # if isCompoundAssignment + // [stack] OBJ METHOD # if Call + // [stack] VALUE # otherwise + return false; + } + } + + if (isCall()) { + if (!bce_->emit1(JSOp::Swap)) { + // [stack] METHOD OBJ + return false; + } + } + + // [stack] OBJ NAME VALUE # if isCompoundAssignment + // [stack] METHOD OBJ # if call + // [stack] VALUE # otherwise + +#ifdef DEBUG + state_ = State::Get; +#endif + return true; +} + +bool PrivateOpEmitter::emitGetForCallOrNew() { return emitGet(); } + +bool PrivateOpEmitter::emitAssignment() { + MOZ_ASSERT(isSimpleAssignment() || isFieldInit() || isCompoundAssignment()); + MOZ_ASSERT_IF(!isCompoundAssignment(), state_ == State::Reference); + MOZ_ASSERT_IF(isCompoundAssignment(), state_ == State::Get); + + // [stack] OBJ KEY RHS + + if (brandLoc_) { + if (!bce_->emit2(JSOp::ThrowMsg, + uint8_t(ThrowMsgKind::AssignToPrivateMethod))) { + return false; + } + + // Balance the expression stack. + if (!bce_->emitPopN(2)) { + // [stack] OBJ + return false; + } + } else { + // Emit a brand check. If this is compound assignment, emitGet() already + // emitted a check for this object and key. There's no point checking + // again--a private field can't be removed from an object. + if (!isCompoundAssignment()) { + if (!bce_->emitUnpickN(2)) { + // [stack] RHS OBJ KEY + return false; + } + if (!emitBrandCheck()) { + // [stack] RHS OBJ KEY BOOL + return false; + } + if (!bce_->emit1(JSOp::Pop)) { + // [stack] RHS OBJ KEY + return false; + } + if (!bce_->emitPickN(2)) { + // [stack] OBJ KEY RHS + return false; + } + } + + JSOp setOp = isFieldInit() ? JSOp::InitElem : JSOp::StrictSetElem; + if (!bce_->emitElemOpBase(setOp)) { + // [stack] RHS + return false; + } + } + +#ifdef DEBUG + state_ = State::Assignment; +#endif + return true; +} + +bool PrivateOpEmitter::emitIncDec(ValueUsage valueUsage) { + MOZ_ASSERT(state_ == State::Reference); + MOZ_ASSERT(isIncDec()); + // [stack] OBJ NAME + + if (!bce_->emitDupAt(1, 2)) { + // [stack] OBJ NAME OBJ NAME + return false; + } + + if (!emitGet()) { + // [stack] OBJ NAME VALUE + return false; + } + + MOZ_ASSERT(state_ == State::Get); + + JSOp incOp = isInc() ? JSOp::Inc : JSOp::Dec; + + if (!bce_->emit1(JSOp::ToNumeric)) { + // [stack] OBJ NAME N + return false; + } + if (isPostIncDec() && valueUsage == ValueUsage::WantValue) { + // [stack] OBJ NAME N + if (!bce_->emit1(JSOp::Dup)) { + // [stack] OBJ NAME N N + return false; + } + if (!bce_->emit2(JSOp::Unpick, 3)) { + // [stack] N OBJ NAME N + return false; + } + } + if (!bce_->emit1(incOp)) { + // [stack] N? OBJ NAME N+1 + return false; + } + + if (brandLoc_) { + if (!bce_->emit2(JSOp::ThrowMsg, + uint8_t(ThrowMsgKind::AssignToPrivateMethod))) { + return false; + } + + // Balance the expression stack. + if (!bce_->emitPopN(2)) { + // [stack] N? N+1 + return false; + } + } else { + if (!bce_->emitElemOpBase(JSOp::StrictSetElem)) { + // [stack] N? N+1 + return false; + } + } + + if (isPostIncDec() && valueUsage == ValueUsage::WantValue) { + if (!bce_->emit1(JSOp::Pop)) { + // [stack] N + return false; + } + } + + return true; +} |