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Diffstat (limited to 'js/src/frontend/Stencil.cpp')
| -rw-r--r-- | js/src/frontend/Stencil.cpp | 5592 |
1 files changed, 5592 insertions, 0 deletions
diff --git a/js/src/frontend/Stencil.cpp b/js/src/frontend/Stencil.cpp new file mode 100644 index 0000000000..7c6eba4c5a --- /dev/null +++ b/js/src/frontend/Stencil.cpp @@ -0,0 +1,5592 @@ +/* -*- 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/Stencil.h" + +#include "mozilla/AlreadyAddRefed.h" // already_AddRefed +#include "mozilla/Assertions.h" // MOZ_RELEASE_ASSERT +#include "mozilla/Maybe.h" // mozilla::Maybe +#include "mozilla/OperatorNewExtensions.h" // mozilla::KnownNotNull +#include "mozilla/PodOperations.h" // mozilla::PodCopy +#include "mozilla/RefPtr.h" // RefPtr +#include "mozilla/ScopeExit.h" // mozilla::ScopeExit +#include "mozilla/Sprintf.h" // SprintfLiteral + +#include <algorithm> // std::fill +#include <string.h> // strlen + +#include "ds/LifoAlloc.h" // LifoAlloc +#include "frontend/AbstractScopePtr.h" // ScopeIndex +#include "frontend/BytecodeCompiler.h" // CompileGlobalScriptToStencil, InstantiateStencils, CanLazilyParse, ParseModuleToStencil +#include "frontend/BytecodeSection.h" // EmitScriptThingsVector +#include "frontend/CompilationStencil.h" // CompilationStencil, CompilationState, ExtensibleCompilationStencil, CompilationGCOutput, CompilationStencilMerger +#include "frontend/FrontendContext.h" +#include "frontend/NameAnalysisTypes.h" // EnvironmentCoordinate +#include "frontend/ParserAtom.h" // ParserAtom, ParserAtomIndex, TaggedParserAtomIndex, ParserAtomsTable, Length{1,2,3}StaticParserString, InstantiateMarkedAtoms, InstantiateMarkedAtomsAsPermanent, GetWellKnownAtom +#include "frontend/ScopeBindingCache.h" // ScopeBindingCache +#include "frontend/SharedContext.h" +#include "frontend/StencilXdr.h" // XDRStencilEncoder, XDRStencilDecoder +#include "gc/AllocKind.h" // gc::AllocKind +#include "gc/Tracer.h" // TraceNullableRoot +#include "js/CallArgs.h" // JSNative +#include "js/CompileOptions.h" // JS::DecodeOptions, JS::ReadOnlyDecodeOptions +#include "js/experimental/JSStencil.h" // JS::Stencil +#include "js/GCAPI.h" // JS::AutoCheckCannotGC +#include "js/Printer.h" // js::Fprinter +#include "js/RealmOptions.h" // JS::RealmBehaviors +#include "js/RootingAPI.h" // Rooted +#include "js/Transcoding.h" // JS::TranscodeBuffer +#include "js/Utility.h" // js_malloc, js_calloc, js_free +#include "js/Value.h" // ObjectValue +#include "js/WasmModule.h" // JS::WasmModule +#include "vm/BigIntType.h" // ParseBigIntLiteral, BigIntLiteralIsZero +#include "vm/BindingKind.h" // BindingKind +#include "vm/EnvironmentObject.h" +#include "vm/GeneratorAndAsyncKind.h" // GeneratorKind, FunctionAsyncKind +#include "vm/JSContext.h" // JSContext +#include "vm/JSFunction.h" // JSFunction, GetFunctionPrototype, NewFunctionWithProto +#include "vm/JSObject.h" // JSObject, TenuredObject +#include "vm/JSONPrinter.h" // js::JSONPrinter +#include "vm/JSScript.h" // BaseScript, JSScript +#include "vm/Realm.h" // JS::Realm +#include "vm/RegExpObject.h" // js::RegExpObject +#include "vm/Scope.h" // Scope, *Scope, ScopeKind::*, ScopeKindString, ScopeIter, ScopeKindIsCatch, BindingIter, GetScopeDataTrailingNames, SizeOfParserScopeData +#include "vm/ScopeKind.h" // ScopeKind +#include "vm/SelfHosting.h" // SetClonedSelfHostedFunctionName +#include "vm/StaticStrings.h" +#include "vm/StencilEnums.h" // ImmutableScriptFlagsEnum +#include "vm/StringType.h" // JSAtom, js::CopyChars +#include "wasm/AsmJS.h" // InstantiateAsmJS + +#include "vm/EnvironmentObject-inl.h" // JSObject::enclosingEnvironment +#include "vm/JSFunction-inl.h" // JSFunction::create + +using namespace js; +using namespace js::frontend; + +// These 2 functions are used to write the same code with lambda using auto +// arguments. The auto argument type is set by the Variant.match function of the +// InputScope variant. Thus dispatching to either a Scope* or to a +// ScopeStencilRef. This function can then be used as a way to specialize the +// code within the lambda without duplicating the code. +// +// Identically, an InputName is constructed using the scope type and the +// matching binding name type. This way, functions which are called by this +// lambda can manipulate an InputName and do not have to be duplicated. +// +// for (InputScopeIter si(...); si; si++) { +// si.scope().match([](auto& scope) { +// for (auto bi = InputBindingIter(scope); bi; bi++) { +// InputName name(scope, bi.name()); +// } +// }); +// } +static js::BindingIter InputBindingIter(Scope* ptr) { + return js::BindingIter(ptr); +} + +static ParserBindingIter InputBindingIter(const ScopeStencilRef& ref) { + return ParserBindingIter(ref); +} + +static ParserBindingIter InputBindingIter(const FakeStencilGlobalScope&) { + MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("No bindings on empty global."); +} + +InputName InputScript::displayAtom() const { + return script_.match( + [](BaseScript* ptr) { + return InputName(ptr, ptr->function()->fullDisplayAtom()); + }, + [](const ScriptStencilRef& ref) { + return InputName(ref, ref.scriptData().functionAtom); + }); +} + +TaggedParserAtomIndex InputName::internInto(FrontendContext* fc, + ParserAtomsTable& parserAtoms, + CompilationAtomCache& atomCache) { + return variant_.match( + [&](JSAtom* ptr) -> TaggedParserAtomIndex { + return parserAtoms.internJSAtom(fc, atomCache, ptr); + }, + [&](NameStencilRef& ref) -> TaggedParserAtomIndex { + return parserAtoms.internExternalParserAtomIndex(fc, ref.context_, + ref.atomIndex_); + }); +} + +bool InputName::isEqualTo(FrontendContext* fc, ParserAtomsTable& parserAtoms, + CompilationAtomCache& atomCache, + TaggedParserAtomIndex other, + JSAtom** otherCached) const { + return variant_.match( + [&](const JSAtom* ptr) -> bool { + if (ptr->hash() != parserAtoms.hash(other)) { + return false; + } + + // JSAtom variant is used only on the main thread delazification, + // where JSContext is always available. + JSContext* cx = fc->maybeCurrentJSContext(); + MOZ_ASSERT(cx); + + if (!*otherCached) { + // TODO-Stencil: + // Here, we convert our name into a JSAtom*, and hard-crash on failure + // to allocate. This conversion should not be required as we should be + // able to iterate up snapshotted scope chains that use parser atoms. + // + // This will be fixed when the enclosing scopes are snapshotted. + // + // See bug 1690277. + AutoEnterOOMUnsafeRegion oomUnsafe; + *otherCached = parserAtoms.toJSAtom(cx, fc, other, atomCache); + if (!*otherCached) { + oomUnsafe.crash("InputName::isEqualTo"); + } + } else { + MOZ_ASSERT(atomCache.getExistingAtomAt(cx, other) == *otherCached); + } + return ptr == *otherCached; + }, + [&](const NameStencilRef& ref) -> bool { + return parserAtoms.isEqualToExternalParserAtomIndex(other, ref.context_, + ref.atomIndex_); + }); +} + +GenericAtom::GenericAtom(FrontendContext* fc, ParserAtomsTable& parserAtoms, + CompilationAtomCache& atomCache, + TaggedParserAtomIndex index) + : ref(EmitterName(fc, parserAtoms, atomCache, index)) { + hash = parserAtoms.hash(index); +} + +GenericAtom::GenericAtom(const CompilationStencil& context, + TaggedParserAtomIndex index) + : ref(StencilName{context, index}) { + if (index.isParserAtomIndex()) { + ParserAtom* atom = context.parserAtomData[index.toParserAtomIndex()]; + hash = atom->hash(); + } else { + hash = index.staticOrWellKnownHash(); + } +} + +GenericAtom::GenericAtom(ScopeStencilRef& scope, TaggedParserAtomIndex index) + : GenericAtom(scope.context_, index) {} + +BindingHasher<TaggedParserAtomIndex>::Lookup::Lookup(ScopeStencilRef& scope_ref, + const GenericAtom& other) + : keyStencil(scope_ref.context_), other(other) {} + +bool GenericAtom::operator==(const GenericAtom& other) const { + return ref.match( + [&other](const EmitterName& name) -> bool { + return other.ref.match( + [&name](const EmitterName& other) -> bool { + // We never have multiple Emitter context at the same time. + MOZ_ASSERT(name.fc == other.fc); + MOZ_ASSERT(&name.parserAtoms == &other.parserAtoms); + MOZ_ASSERT(&name.atomCache == &other.atomCache); + return name.index == other.index; + }, + [&name](const StencilName& other) -> bool { + return name.parserAtoms.isEqualToExternalParserAtomIndex( + name.index, other.stencil, other.index); + }, + [&name](JSAtom* other) -> bool { + // JSAtom variant is used only on the main thread delazification, + // where JSContext is always available. + JSContext* cx = name.fc->maybeCurrentJSContext(); + MOZ_ASSERT(cx); + AutoEnterOOMUnsafeRegion oomUnsafe; + JSAtom* namePtr = name.parserAtoms.toJSAtom( + cx, name.fc, name.index, name.atomCache); + if (!namePtr) { + oomUnsafe.crash("GenericAtom(EmitterName == JSAtom*)"); + } + return namePtr == other; + }); + }, + [&other](const StencilName& name) -> bool { + return other.ref.match( + [&name](const EmitterName& other) -> bool { + return other.parserAtoms.isEqualToExternalParserAtomIndex( + other.index, name.stencil, name.index); + }, + [&name](const StencilName& other) -> bool { + // Technically it is possible to have multiple stencils, but in + // this particular case let's assume we never encounter a case + // where we are comparing names from different stencils. + // + // The reason this assumption is safe today is that we are only + // using this in the context of a stencil-delazification, where + // the only StencilNames are coming from the CompilationStencil + // provided to CompilationInput::initFromStencil. + MOZ_ASSERT(&name.stencil == &other.stencil); + return name.index == other.index; + }, + [](JSAtom* other) -> bool { + MOZ_CRASH("Never used."); + return false; + }); + }, + [&other](JSAtom* name) -> bool { + return other.ref.match( + [&name](const EmitterName& other) -> bool { + // JSAtom variant is used only on the main thread delazification, + // where JSContext is always available. + JSContext* cx = other.fc->maybeCurrentJSContext(); + MOZ_ASSERT(cx); + AutoEnterOOMUnsafeRegion oomUnsafe; + JSAtom* otherPtr = other.parserAtoms.toJSAtom( + cx, other.fc, other.index, other.atomCache); + if (!otherPtr) { + oomUnsafe.crash("GenericAtom(JSAtom* == EmitterName)"); + } + return name == otherPtr; + }, + [](const StencilName& other) -> bool { + MOZ_CRASH("Never used."); + return false; + }, + [&name](JSAtom* other) -> bool { return name == other; }); + }); +} + +#ifdef DEBUG +template <typename SpanT, typename VecT> +void AssertBorrowingSpan(const SpanT& span, const VecT& vec) { + MOZ_ASSERT(span.size() == vec.length()); + MOZ_ASSERT(span.data() == vec.begin()); +} +#endif + +bool ScopeBindingCache::canCacheFor(Scope* ptr) { + MOZ_CRASH("Unexpected scope chain type: Scope*"); +} + +bool ScopeBindingCache::canCacheFor(ScopeStencilRef ref) { + MOZ_CRASH("Unexpected scope chain type: ScopeStencilRef"); +} + +bool ScopeBindingCache::canCacheFor(const FakeStencilGlobalScope& ref) { + MOZ_CRASH("Unexpected scope chain type: FakeStencilGlobalScope"); +} + +BindingMap<JSAtom*>* ScopeBindingCache::createCacheFor(Scope* ptr) { + MOZ_CRASH("Unexpected scope chain type: Scope*"); +} + +BindingMap<JSAtom*>* ScopeBindingCache::lookupScope(Scope* ptr, + CacheGeneration gen) { + MOZ_CRASH("Unexpected scope chain type: Scope*"); +} + +BindingMap<TaggedParserAtomIndex>* ScopeBindingCache::createCacheFor( + ScopeStencilRef ref) { + MOZ_CRASH("Unexpected scope chain type: ScopeStencilRef"); +} + +BindingMap<TaggedParserAtomIndex>* ScopeBindingCache::lookupScope( + ScopeStencilRef ref, CacheGeneration gen) { + MOZ_CRASH("Unexpected scope chain type: ScopeStencilRef"); +} + +BindingMap<TaggedParserAtomIndex>* ScopeBindingCache::createCacheFor( + const FakeStencilGlobalScope& ref) { + MOZ_CRASH("Unexpected scope chain type: FakeStencilGlobalScope"); +} + +BindingMap<TaggedParserAtomIndex>* ScopeBindingCache::lookupScope( + const FakeStencilGlobalScope& ref, CacheGeneration gen) { + MOZ_CRASH("Unexpected scope chain type: FakeStencilGlobalScope"); +} + +bool NoScopeBindingCache::canCacheFor(Scope* ptr) { return false; } + +bool NoScopeBindingCache::canCacheFor(ScopeStencilRef ref) { return false; } + +bool NoScopeBindingCache::canCacheFor(const FakeStencilGlobalScope& ref) { + return false; +} + +bool RuntimeScopeBindingCache::canCacheFor(Scope* ptr) { return true; } + +BindingMap<JSAtom*>* RuntimeScopeBindingCache::createCacheFor(Scope* ptr) { + BaseScopeData* dataPtr = ptr->rawData(); + BindingMap<JSAtom*> bindingCache; + if (!scopeMap.putNew(dataPtr, std::move(bindingCache))) { + return nullptr; + } + + return lookupScope(ptr, cacheGeneration); +} + +BindingMap<JSAtom*>* RuntimeScopeBindingCache::lookupScope( + Scope* ptr, CacheGeneration gen) { + MOZ_ASSERT(gen == cacheGeneration); + BaseScopeData* dataPtr = ptr->rawData(); + auto valuePtr = scopeMap.lookup(dataPtr); + if (!valuePtr) { + return nullptr; + } + return &valuePtr->value(); +} + +bool StencilScopeBindingCache::canCacheFor(ScopeStencilRef ref) { return true; } + +BindingMap<TaggedParserAtomIndex>* StencilScopeBindingCache::createCacheFor( + ScopeStencilRef ref) { +#ifdef DEBUG + AssertBorrowingSpan(ref.context_.scopeNames, merger_.getResult().scopeNames); +#endif + auto* dataPtr = ref.context_.scopeNames[ref.scopeIndex_]; + BindingMap<TaggedParserAtomIndex> bindingCache; + if (!scopeMap.putNew(dataPtr, std::move(bindingCache))) { + return nullptr; + } + + return lookupScope(ref, 1); +} + +BindingMap<TaggedParserAtomIndex>* StencilScopeBindingCache::lookupScope( + ScopeStencilRef ref, CacheGeneration gen) { +#ifdef DEBUG + AssertBorrowingSpan(ref.context_.scopeNames, merger_.getResult().scopeNames); +#endif + auto* dataPtr = ref.context_.scopeNames[ref.scopeIndex_]; + auto ptr = scopeMap.lookup(dataPtr); + if (!ptr) { + return nullptr; + } + return &ptr->value(); +} + +static AbstractBaseScopeData<TaggedParserAtomIndex> + moduleGlobalAbstractScopeData; + +bool StencilScopeBindingCache::canCacheFor(const FakeStencilGlobalScope& ref) { + return true; +} + +BindingMap<TaggedParserAtomIndex>* StencilScopeBindingCache::createCacheFor( + const FakeStencilGlobalScope& ref) { + auto* dataPtr = &moduleGlobalAbstractScopeData; + BindingMap<TaggedParserAtomIndex> bindingCache; + if (!scopeMap.putNew(dataPtr, std::move(bindingCache))) { + return nullptr; + } + + return lookupScope(ref, 1); +} + +BindingMap<TaggedParserAtomIndex>* StencilScopeBindingCache::lookupScope( + const FakeStencilGlobalScope& ref, CacheGeneration gen) { + auto* dataPtr = &moduleGlobalAbstractScopeData; + auto ptr = scopeMap.lookup(dataPtr); + if (!ptr) { + return nullptr; + } + return &ptr->value(); +} + +bool ScopeContext::init(FrontendContext* fc, CompilationInput& input, + ParserAtomsTable& parserAtoms, + ScopeBindingCache* scopeCache, InheritThis inheritThis, + JSObject* enclosingEnv) { + // Record the scopeCache to be used while looking up NameLocation bindings. + this->scopeCache = scopeCache; + scopeCacheGen = scopeCache->getCurrentGeneration(); + + InputScope maybeNonDefaultEnclosingScope( + input.maybeNonDefaultEnclosingScope()); + + // If this eval is in response to Debugger.Frame.eval, we may have an + // incomplete scope chain. In order to provide a better debugging experience, + // we inspect the (optional) environment chain to determine it's enclosing + // FunctionScope if there is one. If there is no such scope, we use the + // orignal scope provided. + // + // NOTE: This is used to compute the ThisBinding kind and to allow access to + // private fields and methods, while other contextual information only + // uses the actual scope passed to the compile. + auto effectiveScope = + determineEffectiveScope(maybeNonDefaultEnclosingScope, enclosingEnv); + + if (inheritThis == InheritThis::Yes) { + computeThisBinding(effectiveScope); + computeThisEnvironment(maybeNonDefaultEnclosingScope); + } + computeInScope(maybeNonDefaultEnclosingScope); + + cacheEnclosingScope(input.enclosingScope); + + if (input.target == CompilationInput::CompilationTarget::Eval) { + if (!cacheEnclosingScopeBindingForEval(fc, input, parserAtoms)) { + return false; + } + if (!cachePrivateFieldsForEval(fc, input, enclosingEnv, effectiveScope, + parserAtoms)) { + return false; + } + } + + return true; +} + +void ScopeContext::computeThisEnvironment(const InputScope& enclosingScope) { + uint32_t envCount = 0; + for (InputScopeIter si(enclosingScope); si; si++) { + if (si.kind() == ScopeKind::Function) { + // Arrow function inherit the "this" environment of the enclosing script, + // so continue ignore them. + if (!si.scope().isArrow()) { + allowNewTarget = true; + + if (si.scope().allowSuperProperty()) { + allowSuperProperty = true; + enclosingThisEnvironmentHops = envCount; + } + + if (si.scope().isClassConstructor()) { + memberInitializers = + si.scope().useMemberInitializers() + ? mozilla::Some(si.scope().getMemberInitializers()) + : mozilla::Some(MemberInitializers::Empty()); + MOZ_ASSERT(memberInitializers->valid); + } else { + if (si.scope().isSyntheticFunction()) { + allowArguments = false; + } + } + + if (si.scope().isDerivedClassConstructor()) { + allowSuperCall = true; + } + + // Found the effective "this" environment, so stop. + return; + } + } + + if (si.scope().hasEnvironment()) { + envCount++; + } + } +} + +void ScopeContext::computeThisBinding(const InputScope& scope) { + // Inspect the scope-chain. + for (InputScopeIter si(scope); si; si++) { + if (si.kind() == ScopeKind::Module) { + thisBinding = ThisBinding::Module; + return; + } + + if (si.kind() == ScopeKind::Function) { + // Arrow functions don't have their own `this` binding. + if (si.scope().isArrow()) { + continue; + } + + // Derived class constructors (and their nested arrow functions and evals) + // use ThisBinding::DerivedConstructor, which ensures TDZ checks happen + // when accessing |this|. + if (si.scope().isDerivedClassConstructor()) { + thisBinding = ThisBinding::DerivedConstructor; + } else { + thisBinding = ThisBinding::Function; + } + + return; + } + } + + thisBinding = ThisBinding::Global; +} + +void ScopeContext::computeInScope(const InputScope& enclosingScope) { + for (InputScopeIter si(enclosingScope); si; si++) { + if (si.kind() == ScopeKind::ClassBody) { + inClass = true; + } + + if (si.kind() == ScopeKind::With) { + inWith = true; + } + } +} + +void ScopeContext::cacheEnclosingScope(const InputScope& enclosingScope) { + if (enclosingScope.isNull()) { + return; + } + + enclosingScopeEnvironmentChainLength = + enclosingScope.environmentChainLength(); + enclosingScopeKind = enclosingScope.kind(); + + if (enclosingScopeKind == ScopeKind::Function) { + enclosingScopeIsArrow = enclosingScope.isArrow(); + } + + enclosingScopeHasEnvironment = enclosingScope.hasEnvironment(); + +#ifdef DEBUG + hasNonSyntacticScopeOnChain = + enclosingScope.hasOnChain(ScopeKind::NonSyntactic); + + // This computes a general answer for the query "does the enclosing scope + // have a function scope that needs a home object?", but it's only asserted + // if the parser parses eval body that contains `super` that needs a home + // object. + for (InputScopeIter si(enclosingScope); si; si++) { + if (si.kind() == ScopeKind::Function) { + if (si.scope().isArrow()) { + continue; + } + if (si.scope().allowSuperProperty() && si.scope().needsHomeObject()) { + hasFunctionNeedsHomeObjectOnChain = true; + } + break; + } + } +#endif + + // Pre-fill the scope cache by iterating over all the names. Stop iterating + // as soon as we find a scope which already has a filled scope cache. + AutoEnterOOMUnsafeRegion oomUnsafe; + for (InputScopeIter si(enclosingScope); si; si++) { + // If the current scope already exists, then there is no need to go deeper + // as the scope which are encoded after this one should already be present + // in the cache. + bool hasScopeCache = si.scope().match([&](auto& scope_ref) -> bool { + MOZ_ASSERT(scopeCache->canCacheFor(scope_ref)); + return scopeCache->lookupScope(scope_ref, scopeCacheGen); + }); + if (hasScopeCache) { + return; + } + + bool hasEnv = si.hasSyntacticEnvironment(); + auto setCacthAll = [&](NameLocation loc) { + return si.scope().match([&](auto& scope_ref) { + using BindingMapPtr = decltype(scopeCache->createCacheFor(scope_ref)); + BindingMapPtr bindingMapPtr = scopeCache->createCacheFor(scope_ref); + if (!bindingMapPtr) { + oomUnsafe.crash( + "ScopeContext::cacheEnclosingScope: scopeCache->createCacheFor"); + return; + } + + bindingMapPtr->catchAll.emplace(loc); + }); + }; + auto createEmpty = [&]() { + return si.scope().match([&](auto& scope_ref) { + using BindingMapPtr = decltype(scopeCache->createCacheFor(scope_ref)); + BindingMapPtr bindingMapPtr = scopeCache->createCacheFor(scope_ref); + if (!bindingMapPtr) { + oomUnsafe.crash( + "ScopeContext::cacheEnclosingScope: scopeCache->createCacheFor"); + return; + } + }); + }; + + switch (si.kind()) { + case ScopeKind::Function: + if (hasEnv) { + if (si.scope().funHasExtensibleScope()) { + setCacthAll(NameLocation::Dynamic()); + return; + } + + si.scope().match([&](auto& scope_ref) { + using BindingMapPtr = + decltype(scopeCache->createCacheFor(scope_ref)); + using Lookup = + typename std::remove_pointer_t<BindingMapPtr>::Lookup; + BindingMapPtr bindingMapPtr = scopeCache->createCacheFor(scope_ref); + if (!bindingMapPtr) { + oomUnsafe.crash( + "ScopeContext::cacheEnclosingScope: " + "scopeCache->createCacheFor"); + return; + } + + for (auto bi = InputBindingIter(scope_ref); bi; bi++) { + NameLocation loc = bi.nameLocation(); + if (loc.kind() != NameLocation::Kind::EnvironmentCoordinate) { + continue; + } + auto ctxFreeKey = bi.name(); + GenericAtom ctxKey(scope_ref, ctxFreeKey); + Lookup ctxLookup(scope_ref, ctxKey); + if (!bindingMapPtr->hashMap.put(ctxLookup, ctxFreeKey, loc)) { + oomUnsafe.crash( + "ScopeContext::cacheEnclosingScope: bindingMapPtr->put"); + return; + } + } + }); + } else { + createEmpty(); + } + break; + + case ScopeKind::StrictEval: + case ScopeKind::FunctionBodyVar: + case ScopeKind::Lexical: + case ScopeKind::NamedLambda: + case ScopeKind::StrictNamedLambda: + case ScopeKind::SimpleCatch: + case ScopeKind::Catch: + case ScopeKind::FunctionLexical: + case ScopeKind::ClassBody: + if (hasEnv) { + si.scope().match([&](auto& scope_ref) { + using BindingMapPtr = + decltype(scopeCache->createCacheFor(scope_ref)); + using Lookup = + typename std::remove_pointer_t<BindingMapPtr>::Lookup; + BindingMapPtr bindingMapPtr = scopeCache->createCacheFor(scope_ref); + if (!bindingMapPtr) { + oomUnsafe.crash( + "ScopeContext::cacheEnclosingScope: " + "scopeCache->createCacheFor"); + return; + } + + for (auto bi = InputBindingIter(scope_ref); bi; bi++) { + NameLocation loc = bi.nameLocation(); + if (loc.kind() != NameLocation::Kind::EnvironmentCoordinate) { + continue; + } + auto ctxFreeKey = bi.name(); + GenericAtom ctxKey(scope_ref, ctxFreeKey); + Lookup ctxLookup(scope_ref, ctxKey); + if (!bindingMapPtr->hashMap.putNew(ctxLookup, ctxFreeKey, loc)) { + oomUnsafe.crash( + "ScopeContext::cacheEnclosingScope: bindingMapPtr->put"); + return; + } + } + }); + } else { + createEmpty(); + } + break; + + case ScopeKind::Module: + // This case is used only when delazifying a function inside + // module. + // Initial compilation of module doesn't have enlcosing scope. + if (hasEnv) { + si.scope().match([&](auto& scope_ref) { + using BindingMapPtr = + decltype(scopeCache->createCacheFor(scope_ref)); + using Lookup = + typename std::remove_pointer_t<BindingMapPtr>::Lookup; + BindingMapPtr bindingMapPtr = scopeCache->createCacheFor(scope_ref); + if (!bindingMapPtr) { + oomUnsafe.crash( + "ScopeContext::cacheEnclosingScope: " + "scopeCache->createCacheFor"); + return; + } + + for (auto bi = InputBindingIter(scope_ref); bi; bi++) { + // Imports are on the environment but are indirect + // bindings and must be accessed dynamically instead of + // using an EnvironmentCoordinate. + NameLocation loc = bi.nameLocation(); + if (loc.kind() != NameLocation::Kind::EnvironmentCoordinate && + loc.kind() != NameLocation::Kind::Import) { + continue; + } + auto ctxFreeKey = bi.name(); + GenericAtom ctxKey(scope_ref, ctxFreeKey); + Lookup ctxLookup(scope_ref, ctxKey); + if (!bindingMapPtr->hashMap.putNew(ctxLookup, ctxFreeKey, loc)) { + oomUnsafe.crash( + "ScopeContext::cacheEnclosingScope: bindingMapPtr->put"); + return; + } + } + }); + } else { + createEmpty(); + } + break; + + case ScopeKind::Eval: + // As an optimization, if the eval doesn't have its own var + // environment and its immediate enclosing scope is a global + // scope, all accesses are global. + if (!hasEnv) { + ScopeKind kind = si.scope().enclosing().kind(); + if (kind == ScopeKind::Global || kind == ScopeKind::NonSyntactic) { + setCacthAll(NameLocation::Global(BindingKind::Var)); + return; + } + } + + setCacthAll(NameLocation::Dynamic()); + return; + + case ScopeKind::Global: + setCacthAll(NameLocation::Global(BindingKind::Var)); + return; + + case ScopeKind::With: + case ScopeKind::NonSyntactic: + setCacthAll(NameLocation::Dynamic()); + return; + + case ScopeKind::WasmInstance: + case ScopeKind::WasmFunction: + MOZ_CRASH("No direct eval inside wasm functions"); + } + } + + MOZ_CRASH("Malformed scope chain"); +} + +InputScope ScopeContext::determineEffectiveScope(InputScope& scope, + JSObject* environment) { + MOZ_ASSERT(effectiveScopeHops == 0); + // If the scope-chain is non-syntactic, we may still determine a more precise + // effective-scope to use instead. + if (environment && scope.hasOnChain(ScopeKind::NonSyntactic)) { + JSObject* env = environment; + while (env) { + // Look at target of any DebugEnvironmentProxy, but be sure to use + // enclosingEnvironment() of the proxy itself. + JSObject* unwrapped = env; + if (env->is<DebugEnvironmentProxy>()) { + unwrapped = &env->as<DebugEnvironmentProxy>().environment(); +#ifdef DEBUG + enclosingEnvironmentIsDebugProxy_ = true; +#endif + } + + if (unwrapped->is<CallObject>()) { + JSFunction* callee = &unwrapped->as<CallObject>().callee(); + return InputScope(callee->nonLazyScript()->bodyScope()); + } + + env = env->enclosingEnvironment(); + effectiveScopeHops++; + } + } + + return scope; +} + +static uint32_t DepthOfNearestVarScopeForDirectEval(const InputScope& scope) { + uint32_t depth = 0; + if (scope.isNull()) { + return depth; + } + for (InputScopeIter si(scope); si; si++) { + depth++; + switch (si.scope().kind()) { + case ScopeKind::Function: + case ScopeKind::FunctionBodyVar: + case ScopeKind::Global: + case ScopeKind::NonSyntactic: + return depth; + default: + break; + } + } + return depth; +} + +bool ScopeContext::cacheEnclosingScopeBindingForEval( + FrontendContext* fc, CompilationInput& input, + ParserAtomsTable& parserAtoms) { + enclosingLexicalBindingCache_.emplace(); + + uint32_t varScopeDepth = + DepthOfNearestVarScopeForDirectEval(input.enclosingScope); + uint32_t depth = 0; + for (InputScopeIter si(input.enclosingScope); si; si++) { + bool success = si.scope().match([&](auto& scope_ref) { + for (auto bi = InputBindingIter(scope_ref); bi; bi++) { + switch (bi.kind()) { + case BindingKind::Let: { + // Annex B.3.5 allows redeclaring simple (non-destructured) + // catch parameters with var declarations. + bool annexB35Allowance = si.kind() == ScopeKind::SimpleCatch; + if (!annexB35Allowance) { + auto kind = ScopeKindIsCatch(si.kind()) + ? EnclosingLexicalBindingKind::CatchParameter + : EnclosingLexicalBindingKind::Let; + InputName binding(scope_ref, bi.name()); + if (!addToEnclosingLexicalBindingCache( + fc, parserAtoms, input.atomCache, binding, kind)) { + return false; + } + } + break; + } + + case BindingKind::Const: { + InputName binding(scope_ref, bi.name()); + if (!addToEnclosingLexicalBindingCache( + fc, parserAtoms, input.atomCache, binding, + EnclosingLexicalBindingKind::Const)) { + return false; + } + break; + } + + case BindingKind::Synthetic: { + InputName binding(scope_ref, bi.name()); + if (!addToEnclosingLexicalBindingCache( + fc, parserAtoms, input.atomCache, binding, + EnclosingLexicalBindingKind::Synthetic)) { + return false; + } + break; + } + + case BindingKind::PrivateMethod: { + InputName binding(scope_ref, bi.name()); + if (!addToEnclosingLexicalBindingCache( + fc, parserAtoms, input.atomCache, binding, + EnclosingLexicalBindingKind::PrivateMethod)) { + return false; + } + break; + } + + case BindingKind::Import: + case BindingKind::FormalParameter: + case BindingKind::Var: + case BindingKind::NamedLambdaCallee: + break; + } + } + return true; + }); + if (!success) { + return false; + } + + if (++depth == varScopeDepth) { + break; + } + } + + return true; +} + +bool ScopeContext::addToEnclosingLexicalBindingCache( + FrontendContext* fc, ParserAtomsTable& parserAtoms, + CompilationAtomCache& atomCache, InputName& name, + EnclosingLexicalBindingKind kind) { + TaggedParserAtomIndex parserName = + name.internInto(fc, parserAtoms, atomCache); + if (!parserName) { + return false; + } + + // Same lexical binding can appear multiple times across scopes. + // + // enclosingLexicalBindingCache_ map is used for detecting conflicting + // `var` binding, and inner binding should be reported in the error. + // + // cacheEnclosingScopeBindingForEval iterates from inner scope, and + // inner-most binding is added to the map first. + // + // Do not overwrite the value with outer bindings. + auto p = enclosingLexicalBindingCache_->lookupForAdd(parserName); + if (!p) { + if (!enclosingLexicalBindingCache_->add(p, parserName, kind)) { + ReportOutOfMemory(fc); + return false; + } + } + + return true; +} + +static bool IsPrivateField(Scope*, JSAtom* atom) { + MOZ_ASSERT(atom->length() > 0); + + JS::AutoCheckCannotGC nogc; + if (atom->hasLatin1Chars()) { + return atom->latin1Chars(nogc)[0] == '#'; + } + + return atom->twoByteChars(nogc)[0] == '#'; +} + +static bool IsPrivateField(ScopeStencilRef& scope, TaggedParserAtomIndex atom) { + if (atom.isParserAtomIndex()) { + const CompilationStencil& context = scope.context_; + ParserAtom* parserAtom = context.parserAtomData[atom.toParserAtomIndex()]; + return parserAtom->isPrivateName(); + } + +#ifdef DEBUG + if (atom.isWellKnownAtomId()) { + const auto& info = GetWellKnownAtomInfo(atom.toWellKnownAtomId()); + // #constructor is a well-known term, but it is invalid private name. + MOZ_ASSERT(!(info.length > 1 && info.content[0] == '#')); + } else if (atom.isLength2StaticParserString()) { + char content[2]; + ParserAtomsTable::getLength2Content(atom.toLength2StaticParserString(), + content); + // # character is not part of the allowed character of static strings. + MOZ_ASSERT(content[0] != '#'); + } +#endif + + return false; +} + +static bool IsPrivateField(const FakeStencilGlobalScope&, + TaggedParserAtomIndex) { + MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("No private fields on empty global."); +} + +bool ScopeContext::cachePrivateFieldsForEval(FrontendContext* fc, + CompilationInput& input, + JSObject* enclosingEnvironment, + const InputScope& effectiveScope, + ParserAtomsTable& parserAtoms) { + effectiveScopePrivateFieldCache_.emplace(); + + // We compute an environment coordinate relative to the effective scope + // environment. In order to safely consume these environment coordinates, + // we re-map them to include the hops to get the to the effective scope: + // see EmitterScope::lookupPrivate + uint32_t hops = effectiveScopeHops; + for (InputScopeIter si(effectiveScope); si; si++) { + if (si.scope().kind() == ScopeKind::ClassBody) { + uint32_t slots = 0; + bool success = si.scope().match([&](auto& scope_ref) { + for (auto bi = InputBindingIter(scope_ref); bi; bi++) { + if (bi.kind() == BindingKind::PrivateMethod || + (bi.kind() == BindingKind::Synthetic && + IsPrivateField(scope_ref, bi.name()))) { + InputName binding(scope_ref, bi.name()); + auto parserName = + binding.internInto(fc, parserAtoms, input.atomCache); + if (!parserName) { + return false; + } + + NameLocation loc = NameLocation::DebugEnvironmentCoordinate( + bi.kind(), hops, slots); + + if (!effectiveScopePrivateFieldCache_->put(parserName, loc)) { + ReportOutOfMemory(fc); + return false; + } + } + slots++; + } + return true; + }); + if (!success) { + return false; + } + } + + // Hops is only consumed by GetAliasedDebugVar, which uses this to + // traverse the debug environment chain. See the [SMDOC] for Debug + // Environment Chain, which explains why we don't check for + // isEnvironment when computing hops here (basically, debug proxies + // pretend all scopes have environments, even if they were actually + // optimized out). + hops++; + } + + return true; +} + +#ifdef DEBUG +static bool NameIsOnEnvironment(FrontendContext* fc, + ParserAtomsTable& parserAtoms, + CompilationAtomCache& atomCache, + InputScope& scope, TaggedParserAtomIndex name) { + JSAtom* jsname = nullptr; + return scope.match([&](auto& scope_ref) { + if (std::is_same_v<decltype(scope_ref), FakeStencilGlobalScope&>) { + // This condition is added to handle the FakeStencilGlobalScope which is + // used to emulate the global object when delazifying while executing, and + // which is not provided by the Stencil. + return true; + } + for (auto bi = InputBindingIter(scope_ref); bi; bi++) { + // If found, the name must already be on the environment or an import, + // or else there is a bug in the closed-over name analysis in the + // Parser. + InputName binding(scope_ref, bi.name()); + if (binding.isEqualTo(fc, parserAtoms, atomCache, name, &jsname)) { + BindingLocation::Kind kind = bi.location().kind(); + + if (bi.hasArgumentSlot()) { + // The following is equivalent to + // functionScope.script()->functionAllowsParameterRedeclaration() + if (scope.hasMappedArgsObj()) { + // Check for duplicate positional formal parameters. + using InputBindingIter = decltype(bi); + for (InputBindingIter bi2(bi); bi2 && bi2.hasArgumentSlot(); + bi2++) { + InputName binding2(scope_ref, bi2.name()); + if (binding2.isEqualTo(fc, parserAtoms, atomCache, name, + &jsname)) { + kind = bi2.location().kind(); + } + } + } + } + + return kind == BindingLocation::Kind::Global || + kind == BindingLocation::Kind::Environment || + kind == BindingLocation::Kind::Import; + } + } + + // If not found, assume it's on the global or dynamically accessed. + return true; + }); +} +#endif + +NameLocation ScopeContext::searchInEnclosingScope(FrontendContext* fc, + CompilationInput& input, + ParserAtomsTable& parserAtoms, + TaggedParserAtomIndex name) { + MOZ_ASSERT(input.target == + CompilationInput::CompilationTarget::Delazification || + input.target == CompilationInput::CompilationTarget::Eval); + + MOZ_ASSERT(scopeCache); + if (scopeCacheGen != scopeCache->getCurrentGeneration()) { + return searchInEnclosingScopeNoCache(fc, input, parserAtoms, name); + } + +#ifdef DEBUG + // Catch assertion failures in the NoCache variant before looking at the + // cached content. + NameLocation expect = + searchInEnclosingScopeNoCache(fc, input, parserAtoms, name); +#endif + + NameLocation found = + searchInEnclosingScopeWithCache(fc, input, parserAtoms, name); + MOZ_ASSERT(expect == found); + return found; +} + +NameLocation ScopeContext::searchInEnclosingScopeWithCache( + FrontendContext* fc, CompilationInput& input, ParserAtomsTable& parserAtoms, + TaggedParserAtomIndex name) { + MOZ_ASSERT(input.target == + CompilationInput::CompilationTarget::Delazification || + input.target == CompilationInput::CompilationTarget::Eval); + + // Generic atom of the looked up name. + GenericAtom genName(fc, parserAtoms, input.atomCache, name); + mozilla::Maybe<NameLocation> found; + + // Number of enclosing scope we walked over. + uint8_t hops = 0; + + for (InputScopeIter si(input.enclosingScope); si; si++) { + MOZ_ASSERT(NameIsOnEnvironment(fc, parserAtoms, input.atomCache, si.scope(), + name)); + + // If the result happens to be in the cached content of the scope that we + // are iterating over, then return it. + si.scope().match([&](auto& scope_ref) { + using BindingMapPtr = + decltype(scopeCache->lookupScope(scope_ref, scopeCacheGen)); + BindingMapPtr bindingMapPtr = + scopeCache->lookupScope(scope_ref, scopeCacheGen); + MOZ_ASSERT(bindingMapPtr); + + auto& bindingMap = *bindingMapPtr; + if (bindingMap.catchAll.isSome()) { + found = bindingMap.catchAll; + return; + } + + // The scope_ref is given as argument to know where to lookup the key + // index of the hash table if the names have to be compared. + using Lookup = typename std::remove_pointer_t<BindingMapPtr>::Lookup; + Lookup ctxName(scope_ref, genName); + auto ptr = bindingMap.hashMap.lookup(ctxName); + if (!ptr) { + return; + } + + found.emplace(ptr->value()); + }); + + if (found.isSome()) { + // Cached entries do not store the number of hops, as it might be reused + // by multiple inner functions, which might different number of hops. + found = found.map([&hops](NameLocation loc) { + if (loc.kind() != NameLocation::Kind::EnvironmentCoordinate) { + return loc; + } + return loc.addHops(hops); + }); + return found.value(); + } + + bool hasEnv = si.hasSyntacticEnvironment(); + + if (hasEnv) { + MOZ_ASSERT(hops < ENVCOORD_HOPS_LIMIT - 1); + hops++; + } + } + + MOZ_CRASH("Malformed scope chain"); +} + +NameLocation ScopeContext::searchInEnclosingScopeNoCache( + FrontendContext* fc, CompilationInput& input, ParserAtomsTable& parserAtoms, + TaggedParserAtomIndex name) { + MOZ_ASSERT(input.target == + CompilationInput::CompilationTarget::Delazification || + input.target == CompilationInput::CompilationTarget::Eval); + + // Cached JSAtom equivalent of the TaggedParserAtomIndex `name` argument. + JSAtom* jsname = nullptr; + + // NameLocation which contains relative locations to access `name`. + mozilla::Maybe<NameLocation> result; + + // Number of enclosing scoep we walked over. + uint8_t hops = 0; + + for (InputScopeIter si(input.enclosingScope); si; si++) { + MOZ_ASSERT(NameIsOnEnvironment(fc, parserAtoms, input.atomCache, si.scope(), + name)); + + bool hasEnv = si.hasSyntacticEnvironment(); + switch (si.kind()) { + case ScopeKind::Function: + if (hasEnv) { + if (si.scope().funHasExtensibleScope()) { + return NameLocation::Dynamic(); + } + + si.scope().match([&](auto& scope_ref) { + for (auto bi = InputBindingIter(scope_ref); bi; bi++) { + InputName binding(scope_ref, bi.name()); + if (!binding.isEqualTo(fc, parserAtoms, input.atomCache, name, + &jsname)) { + continue; + } + + BindingLocation bindLoc = bi.location(); + // hasMappedArgsObj == script.functionAllowsParameterRedeclaration + if (bi.hasArgumentSlot() && si.scope().hasMappedArgsObj()) { + // Check for duplicate positional formal parameters. + using InputBindingIter = decltype(bi); + for (InputBindingIter bi2(bi); bi2 && bi2.hasArgumentSlot(); + bi2++) { + if (bi.name() == bi2.name()) { + bindLoc = bi2.location(); + } + } + } + + MOZ_ASSERT(bindLoc.kind() == BindingLocation::Kind::Environment); + result.emplace(NameLocation::EnvironmentCoordinate( + bi.kind(), hops, bindLoc.slot())); + return; + } + }); + } + break; + + case ScopeKind::StrictEval: + case ScopeKind::FunctionBodyVar: + case ScopeKind::Lexical: + case ScopeKind::NamedLambda: + case ScopeKind::StrictNamedLambda: + case ScopeKind::SimpleCatch: + case ScopeKind::Catch: + case ScopeKind::FunctionLexical: + case ScopeKind::ClassBody: + if (hasEnv) { + si.scope().match([&](auto& scope_ref) { + for (auto bi = InputBindingIter(scope_ref); bi; bi++) { + InputName binding(scope_ref, bi.name()); + if (!binding.isEqualTo(fc, parserAtoms, input.atomCache, name, + &jsname)) { + continue; + } + + // The name must already have been marked as closed + // over. If this assertion is hit, there is a bug in the + // name analysis. + BindingLocation bindLoc = bi.location(); + MOZ_ASSERT(bindLoc.kind() == BindingLocation::Kind::Environment); + result.emplace(NameLocation::EnvironmentCoordinate( + bi.kind(), hops, bindLoc.slot())); + return; + } + }); + } + break; + + case ScopeKind::Module: + // This case is used only when delazifying a function inside + // module. + // Initial compilation of module doesn't have enlcosing scope. + if (hasEnv) { + si.scope().match([&](auto& scope_ref) { + for (auto bi = InputBindingIter(scope_ref); bi; bi++) { + InputName binding(scope_ref, bi.name()); + if (!binding.isEqualTo(fc, parserAtoms, input.atomCache, name, + &jsname)) { + continue; + } + + BindingLocation bindLoc = bi.location(); + + // Imports are on the environment but are indirect + // bindings and must be accessed dynamically instead of + // using an EnvironmentCoordinate. + if (bindLoc.kind() == BindingLocation::Kind::Import) { + MOZ_ASSERT(si.kind() == ScopeKind::Module); + result.emplace(NameLocation::Import()); + return; + } + + MOZ_ASSERT(bindLoc.kind() == BindingLocation::Kind::Environment); + result.emplace(NameLocation::EnvironmentCoordinate( + bi.kind(), hops, bindLoc.slot())); + return; + } + }); + } + break; + + case ScopeKind::Eval: + // As an optimization, if the eval doesn't have its own var + // environment and its immediate enclosing scope is a global + // scope, all accesses are global. + if (!hasEnv) { + ScopeKind kind = si.scope().enclosing().kind(); + if (kind == ScopeKind::Global || kind == ScopeKind::NonSyntactic) { + return NameLocation::Global(BindingKind::Var); + } + } + return NameLocation::Dynamic(); + + case ScopeKind::Global: + return NameLocation::Global(BindingKind::Var); + + case ScopeKind::With: + case ScopeKind::NonSyntactic: + return NameLocation::Dynamic(); + + case ScopeKind::WasmInstance: + case ScopeKind::WasmFunction: + MOZ_CRASH("No direct eval inside wasm functions"); + } + + if (result.isSome()) { + return result.value(); + } + + if (hasEnv) { + MOZ_ASSERT(hops < ENVCOORD_HOPS_LIMIT - 1); + hops++; + } + } + + MOZ_CRASH("Malformed scope chain"); +} + +mozilla::Maybe<ScopeContext::EnclosingLexicalBindingKind> +ScopeContext::lookupLexicalBindingInEnclosingScope(TaggedParserAtomIndex name) { + auto p = enclosingLexicalBindingCache_->lookup(name); + if (!p) { + return mozilla::Nothing(); + } + + return mozilla::Some(p->value()); +} + +bool ScopeContext::effectiveScopePrivateFieldCacheHas( + TaggedParserAtomIndex name) { + return effectiveScopePrivateFieldCache_->has(name); +} + +mozilla::Maybe<NameLocation> ScopeContext::getPrivateFieldLocation( + TaggedParserAtomIndex name) { + // The locations returned by this method are only valid for + // traversing debug environments. + // + // See the comment in cachePrivateFieldsForEval + MOZ_ASSERT(enclosingEnvironmentIsDebugProxy_); + auto p = effectiveScopePrivateFieldCache_->lookup(name); + if (!p) { + return mozilla::Nothing(); + } + return mozilla::Some(p->value()); +} + +bool CompilationInput::initScriptSource(FrontendContext* fc) { + source = do_AddRef(fc->getAllocator()->new_<ScriptSource>()); + if (!source) { + return false; + } + + return source->initFromOptions(fc, options); +} + +bool CompilationInput::initForStandaloneFunctionInNonSyntacticScope( + FrontendContext* fc, Handle<Scope*> functionEnclosingScope) { + MOZ_ASSERT(!functionEnclosingScope->as<GlobalScope>().isSyntactic()); + + target = CompilationTarget::StandaloneFunctionInNonSyntacticScope; + if (!initScriptSource(fc)) { + return false; + } + enclosingScope = InputScope(functionEnclosingScope); + return true; +} + +FunctionSyntaxKind CompilationInput::functionSyntaxKind() const { + if (functionFlags().isClassConstructor()) { + if (functionFlags().hasBaseScript() && isDerivedClassConstructor()) { + return FunctionSyntaxKind::DerivedClassConstructor; + } + return FunctionSyntaxKind::ClassConstructor; + } + if (functionFlags().isMethod()) { + if (functionFlags().hasBaseScript() && isSyntheticFunction()) { + // return FunctionSyntaxKind::FieldInitializer; + MOZ_ASSERT_UNREACHABLE( + "Lazy parsing of class field initializers not supported (yet)"); + } + return FunctionSyntaxKind::Method; + } + if (functionFlags().isGetter()) { + return FunctionSyntaxKind::Getter; + } + if (functionFlags().isSetter()) { + return FunctionSyntaxKind::Setter; + } + if (functionFlags().isArrow()) { + return FunctionSyntaxKind::Arrow; + } + return FunctionSyntaxKind::Statement; +} + +bool CompilationInput::internExtraBindings(FrontendContext* fc, + ParserAtomsTable& parserAtoms) { + MOZ_ASSERT(hasExtraBindings()); + + for (auto& bindingInfo : *maybeExtraBindings_) { + if (bindingInfo.isShadowed) { + continue; + } + + const char* chars = bindingInfo.nameChars.get(); + auto index = parserAtoms.internUtf8( + fc, reinterpret_cast<const mozilla::Utf8Unit*>(chars), strlen(chars)); + if (!index) { + return false; + } + + bindingInfo.nameIndex = index; + } + + return true; +} + +void InputScope::trace(JSTracer* trc) { + using ScopePtr = Scope*; + if (scope_.is<ScopePtr>()) { + ScopePtr* ptrAddr = &scope_.as<ScopePtr>(); + TraceNullableRoot(trc, ptrAddr, "compilation-input-scope"); + } +} + +void InputScript::trace(JSTracer* trc) { + using ScriptPtr = BaseScript*; + if (script_.is<ScriptPtr>()) { + ScriptPtr* ptrAddr = &script_.as<ScriptPtr>(); + TraceNullableRoot(trc, ptrAddr, "compilation-input-lazy"); + } +} + +void CompilationInput::trace(JSTracer* trc) { + atomCache.trace(trc); + lazy_.trace(trc); + enclosingScope.trace(trc); +} + +bool CompilationSyntaxParseCache::init(FrontendContext* fc, LifoAlloc& alloc, + ParserAtomsTable& parseAtoms, + CompilationAtomCache& atomCache, + const InputScript& lazy) { + if (!copyFunctionInfo(fc, parseAtoms, atomCache, lazy)) { + return false; + } + bool success = lazy.raw().match([&](auto& ref) { + if (!copyScriptInfo(fc, alloc, parseAtoms, atomCache, ref)) { + return false; + } + if (!copyClosedOverBindings(fc, alloc, parseAtoms, atomCache, ref)) { + return false; + } + return true; + }); + if (!success) { + return false; + } +#ifdef DEBUG + isInitialized = true; +#endif + return true; +} + +bool CompilationSyntaxParseCache::copyFunctionInfo( + FrontendContext* fc, ParserAtomsTable& parseAtoms, + CompilationAtomCache& atomCache, const InputScript& lazy) { + InputName name = lazy.displayAtom(); + if (!name.isNull()) { + displayAtom_ = name.internInto(fc, parseAtoms, atomCache); + if (!displayAtom_) { + return false; + } + } + + funExtra_.immutableFlags = lazy.immutableFlags(); + funExtra_.extent = lazy.extent(); + if (funExtra_.useMemberInitializers()) { + funExtra_.setMemberInitializers(lazy.getMemberInitializers()); + } + + return true; +} + +bool CompilationSyntaxParseCache::copyScriptInfo( + FrontendContext* fc, LifoAlloc& alloc, ParserAtomsTable& parseAtoms, + CompilationAtomCache& atomCache, BaseScript* lazy) { + using GCThingsSpan = mozilla::Span<TaggedScriptThingIndex>; + using ScriptDataSpan = mozilla::Span<ScriptStencil>; + using ScriptExtraSpan = mozilla::Span<ScriptStencilExtra>; + cachedGCThings_ = GCThingsSpan(nullptr); + cachedScriptData_ = ScriptDataSpan(nullptr); + cachedScriptExtra_ = ScriptExtraSpan(nullptr); + + auto gcthings = lazy->gcthings(); + size_t length = gcthings.Length(); + if (length == 0) { + return true; + } + + // Reduce the length to the first element which is not a function. + for (size_t i = 0; i < length; i++) { + gc::Cell* cell = gcthings[i].asCell(); + if (!cell || !cell->is<JSObject>()) { + length = i; + break; + } + MOZ_ASSERT(cell->as<JSObject>()->is<JSFunction>()); + } + + TaggedScriptThingIndex* gcThingsData = + alloc.newArrayUninitialized<TaggedScriptThingIndex>(length); + ScriptStencil* scriptData = + alloc.newArrayUninitialized<ScriptStencil>(length); + ScriptStencilExtra* scriptExtra = + alloc.newArrayUninitialized<ScriptStencilExtra>(length); + if (!gcThingsData || !scriptData || !scriptExtra) { + ReportOutOfMemory(fc); + return false; + } + + for (size_t i = 0; i < length; i++) { + gc::Cell* cell = gcthings[i].asCell(); + JSFunction* fun = &cell->as<JSObject>()->as<JSFunction>(); + gcThingsData[i] = TaggedScriptThingIndex(ScriptIndex(i)); + new (mozilla::KnownNotNull, &scriptData[i]) ScriptStencil(); + ScriptStencil& data = scriptData[i]; + new (mozilla::KnownNotNull, &scriptExtra[i]) ScriptStencilExtra(); + ScriptStencilExtra& extra = scriptExtra[i]; + + if (fun->fullDisplayAtom()) { + TaggedParserAtomIndex displayAtom = + parseAtoms.internJSAtom(fc, atomCache, fun->fullDisplayAtom()); + if (!displayAtom) { + return false; + } + data.functionAtom = displayAtom; + } + data.functionFlags = fun->flags(); + + BaseScript* lazy = fun->baseScript(); + extra.immutableFlags = lazy->immutableFlags(); + extra.extent = lazy->extent(); + + // Info derived from parent compilation should not be set yet for our inner + // lazy functions. Instead that info will be updated when we finish our + // compilation. + MOZ_ASSERT(lazy->hasEnclosingScript()); + } + + cachedGCThings_ = GCThingsSpan(gcThingsData, length); + cachedScriptData_ = ScriptDataSpan(scriptData, length); + cachedScriptExtra_ = ScriptExtraSpan(scriptExtra, length); + return true; +} + +bool CompilationSyntaxParseCache::copyScriptInfo( + FrontendContext* fc, LifoAlloc& alloc, ParserAtomsTable& parseAtoms, + CompilationAtomCache& atomCache, const ScriptStencilRef& lazy) { + using GCThingsSpan = mozilla::Span<TaggedScriptThingIndex>; + using ScriptDataSpan = mozilla::Span<ScriptStencil>; + using ScriptExtraSpan = mozilla::Span<ScriptStencilExtra>; + cachedGCThings_ = GCThingsSpan(nullptr); + cachedScriptData_ = ScriptDataSpan(nullptr); + cachedScriptExtra_ = ScriptExtraSpan(nullptr); + + size_t offset = lazy.scriptData().gcThingsOffset.index; + size_t length = lazy.scriptData().gcThingsLength; + if (length == 0) { + return true; + } + + // Reduce the length to the first element which is not a function. + for (size_t i = offset; i < offset + length; i++) { + if (!lazy.context_.gcThingData[i].isFunction()) { + length = i - offset; + break; + } + } + + TaggedScriptThingIndex* gcThingsData = + alloc.newArrayUninitialized<TaggedScriptThingIndex>(length); + ScriptStencil* scriptData = + alloc.newArrayUninitialized<ScriptStencil>(length); + ScriptStencilExtra* scriptExtra = + alloc.newArrayUninitialized<ScriptStencilExtra>(length); + if (!gcThingsData || !scriptData || !scriptExtra) { + ReportOutOfMemory(fc); + return false; + } + + for (size_t i = 0; i < length; i++) { + ScriptStencilRef inner{lazy.context_, + lazy.context_.gcThingData[i + offset].toFunction()}; + gcThingsData[i] = TaggedScriptThingIndex(ScriptIndex(i)); + new (mozilla::KnownNotNull, &scriptData[i]) ScriptStencil(); + ScriptStencil& data = scriptData[i]; + ScriptStencilExtra& extra = scriptExtra[i]; + + InputName name{inner, inner.scriptData().functionAtom}; + if (!name.isNull()) { + auto displayAtom = name.internInto(fc, parseAtoms, atomCache); + if (!displayAtom) { + return false; + } + data.functionAtom = displayAtom; + } + data.functionFlags = inner.scriptData().functionFlags; + + extra = inner.scriptExtra(); + } + + cachedGCThings_ = GCThingsSpan(gcThingsData, length); + cachedScriptData_ = ScriptDataSpan(scriptData, length); + cachedScriptExtra_ = ScriptExtraSpan(scriptExtra, length); + return true; +} + +bool CompilationSyntaxParseCache::copyClosedOverBindings( + FrontendContext* fc, LifoAlloc& alloc, ParserAtomsTable& parseAtoms, + CompilationAtomCache& atomCache, BaseScript* lazy) { + using ClosedOverBindingsSpan = mozilla::Span<TaggedParserAtomIndex>; + closedOverBindings_ = ClosedOverBindingsSpan(nullptr); + + // The gcthings() array contains the inner function list followed by the + // closed-over bindings data. Skip the inner function list, as it is already + // cached in cachedGCThings_. See also: BaseScript::CreateLazy. + size_t start = cachedGCThings_.Length(); + auto gcthings = lazy->gcthings(); + size_t length = gcthings.Length(); + MOZ_ASSERT(start <= length); + if (length - start == 0) { + return true; + } + + TaggedParserAtomIndex* closedOverBindings = + alloc.newArrayUninitialized<TaggedParserAtomIndex>(length - start); + if (!closedOverBindings) { + ReportOutOfMemory(fc); + return false; + } + + for (size_t i = start; i < length; i++) { + gc::Cell* cell = gcthings[i].asCell(); + if (!cell) { + closedOverBindings[i - start] = TaggedParserAtomIndex::null(); + continue; + } + + MOZ_ASSERT(cell->as<JSString>()->isAtom()); + + auto name = static_cast<JSAtom*>(cell); + auto parserAtom = parseAtoms.internJSAtom(fc, atomCache, name); + if (!parserAtom) { + return false; + } + + closedOverBindings[i - start] = parserAtom; + } + + closedOverBindings_ = + ClosedOverBindingsSpan(closedOverBindings, length - start); + return true; +} + +bool CompilationSyntaxParseCache::copyClosedOverBindings( + FrontendContext* fc, LifoAlloc& alloc, ParserAtomsTable& parseAtoms, + CompilationAtomCache& atomCache, const ScriptStencilRef& lazy) { + using ClosedOverBindingsSpan = mozilla::Span<TaggedParserAtomIndex>; + closedOverBindings_ = ClosedOverBindingsSpan(nullptr); + + // The gcthings array contains the inner function list followed by the + // closed-over bindings data. Skip the inner function list, as it is already + // cached in cachedGCThings_. See also: BaseScript::CreateLazy. + size_t offset = lazy.scriptData().gcThingsOffset.index; + size_t length = lazy.scriptData().gcThingsLength; + size_t start = cachedGCThings_.Length(); + MOZ_ASSERT(start <= length); + if (length - start == 0) { + return true; + } + length -= start; + start += offset; + + // Atoms from the lazy.context (CompilationStencil) are not registered in the + // the parseAtoms table. Thus we create a new span which will contain all the + // interned atoms. + TaggedParserAtomIndex* closedOverBindings = + alloc.newArrayUninitialized<TaggedParserAtomIndex>(length); + if (!closedOverBindings) { + ReportOutOfMemory(fc); + return false; + } + + for (size_t i = 0; i < length; i++) { + auto gcThing = lazy.context_.gcThingData[i + start]; + if (gcThing.isNull()) { + closedOverBindings[i] = TaggedParserAtomIndex::null(); + continue; + } + + MOZ_ASSERT(gcThing.isAtom()); + InputName name(lazy, gcThing.toAtom()); + auto parserAtom = name.internInto(fc, parseAtoms, atomCache); + if (!parserAtom) { + return false; + } + + closedOverBindings[i] = parserAtom; + } + + closedOverBindings_ = ClosedOverBindingsSpan(closedOverBindings, length); + return true; +} + +template <typename T> +PreAllocateableGCArray<T>::~PreAllocateableGCArray() { + if (elems_) { + js_free(elems_); + elems_ = nullptr; + } +} + +template <typename T> +bool PreAllocateableGCArray<T>::allocate(size_t length) { + MOZ_ASSERT(empty()); + + length_ = length; + + if (isInline()) { + inlineElem_ = nullptr; + return true; + } + + elems_ = reinterpret_cast<T*>(js_calloc(sizeof(T) * length_)); + if (!elems_) { + return false; + } + + return true; +} + +template <typename T> +bool PreAllocateableGCArray<T>::allocateWith(T init, size_t length) { + MOZ_ASSERT(empty()); + + length_ = length; + + if (isInline()) { + inlineElem_ = init; + return true; + } + + elems_ = reinterpret_cast<T*>(js_malloc(sizeof(T) * length_)); + if (!elems_) { + return false; + } + + std::fill(elems_, elems_ + length_, init); + return true; +} + +template <typename T> +void PreAllocateableGCArray<T>::steal(Preallocated&& buffer) { + MOZ_ASSERT(empty()); + + length_ = buffer.length_; + buffer.length_ = 0; + + if (isInline()) { + inlineElem_ = nullptr; + return; + } + + elems_ = reinterpret_cast<T*>(buffer.elems_); + buffer.elems_ = nullptr; + +#ifdef DEBUG + for (size_t i = 0; i < length_; i++) { + MOZ_ASSERT(elems_[i] == nullptr); + } +#endif +} + +template <typename T> +void PreAllocateableGCArray<T>::trace(JSTracer* trc) { + if (empty()) { + return; + } + + if (isInline()) { + TraceNullableRoot(trc, &inlineElem_, "PreAllocateableGCArray::inlineElem_"); + return; + } + + for (size_t i = 0; i < length_; i++) { + TraceNullableRoot(trc, &elems_[i], "PreAllocateableGCArray::elems_"); + } +} + +template <typename T> +PreAllocateableGCArray<T>::Preallocated::~Preallocated() { + if (elems_) { + js_free(elems_); + elems_ = nullptr; + } +} + +template <typename T> +bool PreAllocateableGCArray<T>::Preallocated::allocate(size_t length) { + MOZ_ASSERT(empty()); + + length_ = length; + + if (isInline()) { + return true; + } + + elems_ = reinterpret_cast<uintptr_t*>(js_calloc(sizeof(uintptr_t) * length_)); + if (!elems_) { + return false; + } + + return true; +} + +template struct js::frontend::PreAllocateableGCArray<JSFunction*>; +template struct js::frontend::PreAllocateableGCArray<js::Scope*>; + +void CompilationAtomCache::trace(JSTracer* trc) { atoms_.trace(trc); } + +void CompilationGCOutput::trace(JSTracer* trc) { + TraceNullableRoot(trc, &script, "compilation-gc-output-script"); + TraceNullableRoot(trc, &module, "compilation-gc-output-module"); + TraceNullableRoot(trc, &sourceObject, "compilation-gc-output-source"); + functions.trace(trc); + scopes.trace(trc); +} + +RegExpObject* RegExpStencil::createRegExp( + JSContext* cx, const CompilationAtomCache& atomCache) const { + Rooted<JSAtom*> atom(cx, atomCache.getExistingAtomAt(cx, atom_)); + return RegExpObject::createSyntaxChecked(cx, atom, flags(), TenuredObject); +} + +RegExpObject* RegExpStencil::createRegExpAndEnsureAtom( + JSContext* cx, FrontendContext* fc, ParserAtomsTable& parserAtoms, + CompilationAtomCache& atomCache) const { + Rooted<JSAtom*> atom(cx, parserAtoms.toJSAtom(cx, fc, atom_, atomCache)); + if (!atom) { + return nullptr; + } + return RegExpObject::createSyntaxChecked(cx, atom, flags(), TenuredObject); +} + +AbstractScopePtr ScopeStencil::enclosing( + CompilationState& compilationState) const { + if (hasEnclosing()) { + return AbstractScopePtr(compilationState, enclosing()); + } + + return AbstractScopePtr::compilationEnclosingScope(compilationState); +} + +Scope* ScopeStencil::enclosingExistingScope( + const CompilationInput& input, const CompilationGCOutput& gcOutput) const { + if (hasEnclosing()) { + Scope* result = gcOutput.getScopeNoBaseIndex(enclosing()); + MOZ_ASSERT(result, "Scope must already exist to use this method"); + return result; + } + + // When creating a scope based on the input and a gc-output, we assume that + // the scope stencil that we are looking at has not been merged into another + // stencil, and thus that we still have the compilation input of the stencil. + // + // Otherwise, if this was in the case of an input generated from a Stencil + // instead of live-gc values, we would not know its associated gcOutput as it + // might not even have one yet. + return input.enclosingScope.variant().as<Scope*>(); +} + +Scope* ScopeStencil::createScope(JSContext* cx, CompilationInput& input, + CompilationGCOutput& gcOutput, + BaseParserScopeData* baseScopeData) const { + Rooted<Scope*> enclosingScope(cx, enclosingExistingScope(input, gcOutput)); + return createScope(cx, input.atomCache, enclosingScope, baseScopeData); +} + +Scope* ScopeStencil::createScope(JSContext* cx, CompilationAtomCache& atomCache, + Handle<Scope*> enclosingScope, + BaseParserScopeData* baseScopeData) const { + switch (kind()) { + case ScopeKind::Function: { + using ScopeType = FunctionScope; + MOZ_ASSERT(matchScopeKind<ScopeType>(kind())); + return createSpecificScope<ScopeType, CallObject>( + cx, atomCache, enclosingScope, baseScopeData); + } + case ScopeKind::Lexical: + case ScopeKind::SimpleCatch: + case ScopeKind::Catch: + case ScopeKind::NamedLambda: + case ScopeKind::StrictNamedLambda: + case ScopeKind::FunctionLexical: { + using ScopeType = LexicalScope; + MOZ_ASSERT(matchScopeKind<ScopeType>(kind())); + return createSpecificScope<ScopeType, BlockLexicalEnvironmentObject>( + cx, atomCache, enclosingScope, baseScopeData); + } + case ScopeKind::ClassBody: { + using ScopeType = ClassBodyScope; + MOZ_ASSERT(matchScopeKind<ScopeType>(kind())); + return createSpecificScope<ScopeType, BlockLexicalEnvironmentObject>( + cx, atomCache, enclosingScope, baseScopeData); + } + case ScopeKind::FunctionBodyVar: { + using ScopeType = VarScope; + MOZ_ASSERT(matchScopeKind<ScopeType>(kind())); + return createSpecificScope<ScopeType, VarEnvironmentObject>( + cx, atomCache, enclosingScope, baseScopeData); + } + case ScopeKind::Global: + case ScopeKind::NonSyntactic: { + using ScopeType = GlobalScope; + MOZ_ASSERT(matchScopeKind<ScopeType>(kind())); + return createSpecificScope<ScopeType, std::nullptr_t>( + cx, atomCache, enclosingScope, baseScopeData); + } + case ScopeKind::Eval: + case ScopeKind::StrictEval: { + using ScopeType = EvalScope; + MOZ_ASSERT(matchScopeKind<ScopeType>(kind())); + return createSpecificScope<ScopeType, VarEnvironmentObject>( + cx, atomCache, enclosingScope, baseScopeData); + } + case ScopeKind::Module: { + using ScopeType = ModuleScope; + MOZ_ASSERT(matchScopeKind<ScopeType>(kind())); + return createSpecificScope<ScopeType, ModuleEnvironmentObject>( + cx, atomCache, enclosingScope, baseScopeData); + } + case ScopeKind::With: { + using ScopeType = WithScope; + MOZ_ASSERT(matchScopeKind<ScopeType>(kind())); + return createSpecificScope<ScopeType, std::nullptr_t>( + cx, atomCache, enclosingScope, baseScopeData); + } + case ScopeKind::WasmFunction: + case ScopeKind::WasmInstance: { + // ScopeStencil does not support WASM + break; + } + } + MOZ_CRASH(); +} + +bool CompilationState::prepareSharedDataStorage(FrontendContext* fc) { + size_t allScriptCount = scriptData.length(); + size_t nonLazyScriptCount = nonLazyFunctionCount; + if (!scriptData[0].isFunction()) { + nonLazyScriptCount++; + } + return sharedData.prepareStorageFor(fc, nonLazyScriptCount, allScriptCount); +} + +static bool CreateLazyScript(JSContext* cx, + const CompilationAtomCache& atomCache, + const CompilationStencil& stencil, + CompilationGCOutput& gcOutput, + const ScriptStencil& script, + const ScriptStencilExtra& scriptExtra, + ScriptIndex scriptIndex, HandleFunction function) { + Rooted<ScriptSourceObject*> sourceObject(cx, gcOutput.sourceObject); + + size_t ngcthings = script.gcThingsLength; + + Rooted<BaseScript*> lazy( + cx, BaseScript::CreateRawLazy(cx, ngcthings, function, sourceObject, + scriptExtra.extent, + scriptExtra.immutableFlags)); + if (!lazy) { + return false; + } + + if (ngcthings) { + if (!EmitScriptThingsVector(cx, atomCache, stencil, gcOutput, + script.gcthings(stencil), + lazy->gcthingsForInit())) { + return false; + } + } + + if (scriptExtra.useMemberInitializers()) { + lazy->setMemberInitializers(scriptExtra.memberInitializers()); + } + + function->initScript(lazy); + + return true; +} + +// Parser-generated functions with the same prototype will share the same shape. +// By computing the correct values up front, we can save a lot of time in the +// Object creation code. For simplicity, we focus only on plain synchronous +// functions which are by far the most common. +// +// NOTE: Keep this in sync with `js::NewFunctionWithProto`. +static JSFunction* CreateFunctionFast(JSContext* cx, + CompilationAtomCache& atomCache, + Handle<SharedShape*> shape, + const ScriptStencil& script, + const ScriptStencilExtra& scriptExtra) { + MOZ_ASSERT( + !scriptExtra.immutableFlags.hasFlag(ImmutableScriptFlagsEnum::IsAsync)); + MOZ_ASSERT(!scriptExtra.immutableFlags.hasFlag( + ImmutableScriptFlagsEnum::IsGenerator)); + MOZ_ASSERT(!script.functionFlags.isAsmJSNative()); + + FunctionFlags flags = script.functionFlags; + gc::AllocKind allocKind = flags.isExtended() + ? gc::AllocKind::FUNCTION_EXTENDED + : gc::AllocKind::FUNCTION; + + JSFunction* fun = JSFunction::create(cx, allocKind, gc::Heap::Tenured, shape); + if (!fun) { + return nullptr; + } + + fun->setArgCount(scriptExtra.nargs); + fun->setFlags(flags); + + fun->initScript(nullptr); + fun->initEnvironment(nullptr); + + if (script.functionAtom) { + JSAtom* atom = atomCache.getExistingAtomAt(cx, script.functionAtom); + MOZ_ASSERT(atom); + fun->initAtom(atom); + } + +#ifdef DEBUG + fun->assertFunctionKindIntegrity(); +#endif + + return fun; +} + +static JSFunction* CreateFunction(JSContext* cx, + CompilationAtomCache& atomCache, + const CompilationStencil& stencil, + const ScriptStencil& script, + const ScriptStencilExtra& scriptExtra, + ScriptIndex functionIndex) { + GeneratorKind generatorKind = + scriptExtra.immutableFlags.hasFlag(ImmutableScriptFlagsEnum::IsGenerator) + ? GeneratorKind::Generator + : GeneratorKind::NotGenerator; + FunctionAsyncKind asyncKind = + scriptExtra.immutableFlags.hasFlag(ImmutableScriptFlagsEnum::IsAsync) + ? FunctionAsyncKind::AsyncFunction + : FunctionAsyncKind::SyncFunction; + + // Determine the new function's proto. This must be done for singleton + // functions. + RootedObject proto(cx); + if (!GetFunctionPrototype(cx, generatorKind, asyncKind, &proto)) { + return nullptr; + } + + gc::AllocKind allocKind = script.functionFlags.isExtended() + ? gc::AllocKind::FUNCTION_EXTENDED + : gc::AllocKind::FUNCTION; + bool isAsmJS = script.functionFlags.isAsmJSNative(); + + JSNative maybeNative = isAsmJS ? InstantiateAsmJS : nullptr; + + Rooted<JSAtom*> displayAtom(cx); + if (script.functionAtom) { + displayAtom.set(atomCache.getExistingAtomAt(cx, script.functionAtom)); + MOZ_ASSERT(displayAtom); + } + RootedFunction fun( + cx, NewFunctionWithProto(cx, maybeNative, scriptExtra.nargs, + script.functionFlags, nullptr, displayAtom, + proto, allocKind, TenuredObject)); + if (!fun) { + return nullptr; + } + + if (isAsmJS) { + RefPtr<const JS::WasmModule> asmJS = + stencil.asmJS->moduleMap.lookup(functionIndex)->value(); + + JSObject* moduleObj = asmJS->createObjectForAsmJS(cx); + if (!moduleObj) { + return nullptr; + } + + fun->setExtendedSlot(FunctionExtended::ASMJS_MODULE_SLOT, + ObjectValue(*moduleObj)); + } + + return fun; +} + +static bool InstantiateAtoms(JSContext* cx, FrontendContext* fc, + CompilationAtomCache& atomCache, + const CompilationStencil& stencil) { + return InstantiateMarkedAtoms(cx, fc, stencil.parserAtomData, atomCache); +} + +static bool InstantiateScriptSourceObject(JSContext* cx, + const JS::InstantiateOptions& options, + const CompilationStencil& stencil, + CompilationGCOutput& gcOutput) { + MOZ_ASSERT(stencil.source); + + gcOutput.sourceObject = ScriptSourceObject::create(cx, stencil.source.get()); + if (!gcOutput.sourceObject) { + return false; + } + + Rooted<ScriptSourceObject*> sourceObject(cx, gcOutput.sourceObject); + if (!ScriptSourceObject::initFromOptions(cx, sourceObject, options)) { + return false; + } + + return true; +} + +// Instantiate ModuleObject. Further initialization is done after the associated +// BaseScript is instantiated in InstantiateTopLevel. +static bool InstantiateModuleObject(JSContext* cx, FrontendContext* fc, + CompilationAtomCache& atomCache, + const CompilationStencil& stencil, + CompilationGCOutput& gcOutput) { + MOZ_ASSERT(stencil.isModule()); + + gcOutput.module = ModuleObject::create(cx); + if (!gcOutput.module) { + return false; + } + + Rooted<ModuleObject*> module(cx, gcOutput.module); + return stencil.moduleMetadata->initModule(cx, fc, atomCache, module); +} + +// Instantiate JSFunctions for each FunctionBox. +static bool InstantiateFunctions(JSContext* cx, FrontendContext* fc, + CompilationAtomCache& atomCache, + const CompilationStencil& stencil, + CompilationGCOutput& gcOutput) { + using ImmutableFlags = ImmutableScriptFlagsEnum; + + MOZ_ASSERT(gcOutput.functions.length() == stencil.scriptData.size()); + + // Most JSFunctions will be have the same Shape so we can compute it now to + // allow fast object creation. Generators / Async will use the slow path + // instead. + Rooted<SharedShape*> functionShape( + cx, GlobalObject::getFunctionShapeWithDefaultProto( + cx, /* extended = */ false)); + if (!functionShape) { + return false; + } + + Rooted<SharedShape*> extendedShape( + cx, GlobalObject::getFunctionShapeWithDefaultProto( + cx, /* extended = */ true)); + if (!extendedShape) { + return false; + } + + for (auto item : + CompilationStencil::functionScriptStencils(stencil, gcOutput)) { + const auto& scriptStencil = item.script; + const auto& scriptExtra = (*item.scriptExtra); + auto index = item.index; + + MOZ_ASSERT(!item.function); + + // Plain functions can use a fast path. + bool useFastPath = + !scriptExtra.immutableFlags.hasFlag(ImmutableFlags::IsAsync) && + !scriptExtra.immutableFlags.hasFlag(ImmutableFlags::IsGenerator) && + !scriptStencil.functionFlags.isAsmJSNative(); + + JSFunction* fun; + if (useFastPath) { + Handle<SharedShape*> shape = scriptStencil.functionFlags.isExtended() + ? extendedShape + : functionShape; + fun = + CreateFunctionFast(cx, atomCache, shape, scriptStencil, scriptExtra); + } else { + fun = CreateFunction(cx, atomCache, stencil, scriptStencil, scriptExtra, + index); + } + + if (!fun) { + return false; + } + + // Self-hosted functions may have a canonical name to use when instantiating + // into other realms. + if (scriptStencil.hasSelfHostedCanonicalName()) { + JSAtom* canonicalName = atomCache.getExistingAtomAt( + cx, scriptStencil.selfHostedCanonicalName()); + fun->setAtom(canonicalName); + } + + gcOutput.getFunctionNoBaseIndex(index) = fun; + } + + return true; +} + +// Instantiate Scope for each ScopeStencil. +// +// This should be called after InstantiateFunctions, given FunctionScope needs +// associated JSFunction pointer, and also should be called before +// InstantiateScriptStencils, given JSScript needs Scope pointer in gc things. +static bool InstantiateScopes(JSContext* cx, CompilationInput& input, + const CompilationStencil& stencil, + CompilationGCOutput& gcOutput) { + // While allocating Scope object from ScopeStencil, Scope object for the + // enclosing Scope should already be allocated. + // + // Enclosing scope of ScopeStencil can be either ScopeStencil or Scope* + // pointer. + // + // If the enclosing scope is ScopeStencil, it's guaranteed to be earlier + // element in stencil.scopeData, because enclosing_ field holds + // index into it, and newly created ScopeStencil is pushed back to the array. + // + // If the enclosing scope is Scope*, it's CompilationInput.enclosingScope. + + MOZ_ASSERT(stencil.scopeData.size() == stencil.scopeNames.size()); + size_t scopeCount = stencil.scopeData.size(); + for (size_t i = 0; i < scopeCount; i++) { + Scope* scope = stencil.scopeData[i].createScope(cx, input, gcOutput, + stencil.scopeNames[i]); + if (!scope) { + return false; + } + gcOutput.scopes[i] = scope; + } + + return true; +} + +// Instantiate js::BaseScripts from ScriptStencils for inner functions of the +// compilation. Note that standalone functions and functions being delazified +// are handled below with other top-levels. +static bool InstantiateScriptStencils(JSContext* cx, + CompilationAtomCache& atomCache, + const CompilationStencil& stencil, + CompilationGCOutput& gcOutput) { + MOZ_ASSERT(stencil.isInitialStencil()); + + Rooted<JSFunction*> fun(cx); + for (auto item : + CompilationStencil::functionScriptStencils(stencil, gcOutput)) { + auto& scriptStencil = item.script; + auto* scriptExtra = item.scriptExtra; + fun = item.function; + auto index = item.index; + if (scriptStencil.hasSharedData()) { + // If the function was not referenced by enclosing script's bytecode, we + // do not generate a BaseScript for it. For example, `(function(){});`. + // + // `wasEmittedByEnclosingScript` is false also for standalone + // functions. They are handled in InstantiateTopLevel. + if (!scriptStencil.wasEmittedByEnclosingScript()) { + continue; + } + + RootedScript script( + cx, JSScript::fromStencil(cx, atomCache, stencil, gcOutput, index)); + if (!script) { + return false; + } + + if (scriptStencil.allowRelazify()) { + MOZ_ASSERT(script->isRelazifiable()); + script->setAllowRelazify(); + } + } else if (scriptStencil.functionFlags.isAsmJSNative()) { + MOZ_ASSERT(fun->isAsmJSNative()); + } else { + MOZ_ASSERT(fun->isIncomplete()); + if (!CreateLazyScript(cx, atomCache, stencil, gcOutput, scriptStencil, + *scriptExtra, index, fun)) { + return false; + } + } + } + + return true; +} + +// Instantiate the Stencil for the top-level script of the compilation. This +// includes standalone functions and functions being delazified. +static bool InstantiateTopLevel(JSContext* cx, CompilationInput& input, + const CompilationStencil& stencil, + CompilationGCOutput& gcOutput) { + const ScriptStencil& scriptStencil = + stencil.scriptData[CompilationStencil::TopLevelIndex]; + + // Top-level asm.js does not generate a JSScript. + if (scriptStencil.functionFlags.isAsmJSNative()) { + return true; + } + + MOZ_ASSERT(scriptStencil.hasSharedData()); + MOZ_ASSERT(stencil.sharedData.get(CompilationStencil::TopLevelIndex)); + + if (!stencil.isInitialStencil()) { + MOZ_ASSERT(input.lazyOuterBaseScript()); + RootedScript script(cx, + JSScript::CastFromLazy(input.lazyOuterBaseScript())); + if (!JSScript::fullyInitFromStencil(cx, input.atomCache, stencil, gcOutput, + script, + CompilationStencil::TopLevelIndex)) { + return false; + } + + if (scriptStencil.allowRelazify()) { + MOZ_ASSERT(script->isRelazifiable()); + script->setAllowRelazify(); + } + + gcOutput.script = script; + return true; + } + + gcOutput.script = + JSScript::fromStencil(cx, input.atomCache, stencil, gcOutput, + CompilationStencil::TopLevelIndex); + if (!gcOutput.script) { + return false; + } + + if (scriptStencil.allowRelazify()) { + MOZ_ASSERT(gcOutput.script->isRelazifiable()); + gcOutput.script->setAllowRelazify(); + } + + const ScriptStencilExtra& scriptExtra = + stencil.scriptExtra[CompilationStencil::TopLevelIndex]; + + // Finish initializing the ModuleObject if needed. + if (scriptExtra.isModule()) { + RootedScript script(cx, gcOutput.script); + Rooted<ModuleObject*> module(cx, gcOutput.module); + + script->outermostScope()->as<ModuleScope>().initModule(module); + + module->initScriptSlots(script); + + if (!ModuleObject::createEnvironment(cx, module)) { + return false; + } + + if (!ModuleObject::Freeze(cx, module)) { + return false; + } + } + + return true; +} + +// When a function is first referenced by enclosing script's bytecode, we need +// to update it with information determined by the BytecodeEmitter. This applies +// to both initial and delazification parses. The functions being update may or +// may not have bytecode at this point. +static void UpdateEmittedInnerFunctions(JSContext* cx, + CompilationAtomCache& atomCache, + const CompilationStencil& stencil, + CompilationGCOutput& gcOutput) { + for (auto item : + CompilationStencil::functionScriptStencils(stencil, gcOutput)) { + auto& scriptStencil = item.script; + auto& fun = item.function; + if (!scriptStencil.wasEmittedByEnclosingScript()) { + continue; + } + + if (scriptStencil.functionFlags.isAsmJSNative() || + fun->baseScript()->hasBytecode()) { + // Non-lazy inner functions don't use the enclosingScope_ field. + MOZ_ASSERT(!scriptStencil.hasLazyFunctionEnclosingScopeIndex()); + } else { + // Apply updates from FunctionEmitter::emitLazy(). + BaseScript* script = fun->baseScript(); + + ScopeIndex index = scriptStencil.lazyFunctionEnclosingScopeIndex(); + Scope* scope = gcOutput.getScopeNoBaseIndex(index); + script->setEnclosingScope(scope); + + // Inferred and Guessed names are computed by BytecodeEmitter and so may + // need to be applied to existing JSFunctions during delazification. + if (fun->fullDisplayAtom() == nullptr) { + JSAtom* funcAtom = nullptr; + if (scriptStencil.functionFlags.hasInferredName() || + scriptStencil.functionFlags.hasGuessedAtom()) { + funcAtom = + atomCache.getExistingAtomAt(cx, scriptStencil.functionAtom); + MOZ_ASSERT(funcAtom); + } + if (scriptStencil.functionFlags.hasInferredName()) { + fun->setInferredName(funcAtom); + } + if (scriptStencil.functionFlags.hasGuessedAtom()) { + fun->setGuessedAtom(funcAtom); + } + } + } + } +} + +// During initial parse we must link lazy-functions-inside-lazy-functions to +// their enclosing script. +static void LinkEnclosingLazyScript(const CompilationStencil& stencil, + CompilationGCOutput& gcOutput) { + for (auto item : + CompilationStencil::functionScriptStencils(stencil, gcOutput)) { + auto& scriptStencil = item.script; + auto& fun = item.function; + if (!scriptStencil.functionFlags.hasBaseScript()) { + continue; + } + + if (!fun->baseScript()) { + continue; + } + + if (fun->baseScript()->hasBytecode()) { + continue; + } + + BaseScript* script = fun->baseScript(); + MOZ_ASSERT(!script->hasBytecode()); + + for (auto inner : script->gcthings()) { + if (!inner.is<JSObject>()) { + continue; + } + JSFunction* innerFun = &inner.as<JSObject>().as<JSFunction>(); + + MOZ_ASSERT(innerFun->hasBaseScript(), + "inner function should have base script"); + if (!innerFun->hasBaseScript()) { + continue; + } + + // Check for the case that the inner function has the base script flag, + // but still doesn't have the actual base script pointer. + // `baseScript` method asserts the pointer itself, so no extra MOZ_ASSERT + // here. + if (!innerFun->baseScript()) { + continue; + } + + innerFun->setEnclosingLazyScript(script); + } + } +} + +#ifdef DEBUG +// Some fields aren't used in delazification, given the target functions and +// scripts are already instantiated, but they still should match. +static void AssertDelazificationFieldsMatch(const CompilationStencil& stencil, + CompilationGCOutput& gcOutput) { + for (auto item : + CompilationStencil::functionScriptStencils(stencil, gcOutput)) { + auto& scriptStencil = item.script; + auto* scriptExtra = item.scriptExtra; + auto& fun = item.function; + + MOZ_ASSERT(scriptExtra == nullptr); + + // Names are updated by UpdateInnerFunctions. + constexpr uint16_t HAS_INFERRED_NAME = + uint16_t(FunctionFlags::Flags::HAS_INFERRED_NAME); + constexpr uint16_t HAS_GUESSED_ATOM = + uint16_t(FunctionFlags::Flags::HAS_GUESSED_ATOM); + constexpr uint16_t MUTABLE_FLAGS = + uint16_t(FunctionFlags::Flags::MUTABLE_FLAGS); + constexpr uint16_t acceptableDifferenceForFunction = + HAS_INFERRED_NAME | HAS_GUESSED_ATOM | MUTABLE_FLAGS; + + MOZ_ASSERT((fun->flags().toRaw() | acceptableDifferenceForFunction) == + (scriptStencil.functionFlags.toRaw() | + acceptableDifferenceForFunction)); + + // Delazification shouldn't delazify inner scripts. + MOZ_ASSERT_IF(item.index == CompilationStencil::TopLevelIndex, + scriptStencil.hasSharedData()); + MOZ_ASSERT_IF(item.index > CompilationStencil::TopLevelIndex, + !scriptStencil.hasSharedData()); + } +} +#endif // DEBUG + +// When delazifying, use the existing JSFunctions. The initial and delazifying +// parse are required to generate the same sequence of functions for lazy +// parsing to work at all. +static void FunctionsFromExistingLazy(CompilationInput& input, + CompilationGCOutput& gcOutput) { + MOZ_ASSERT(!gcOutput.functions[0]); + + size_t instantiatedFunIndex = 0; + gcOutput.functions[instantiatedFunIndex++] = input.function(); + + for (JS::GCCellPtr elem : input.lazyOuterBaseScript()->gcthings()) { + if (!elem.is<JSObject>()) { + continue; + } + JSFunction* fun = &elem.as<JSObject>().as<JSFunction>(); + gcOutput.functions[instantiatedFunIndex++] = fun; + } +} + +void CompilationStencil::borrowFromExtensibleCompilationStencil( + ExtensibleCompilationStencil& extensibleStencil) { + canLazilyParse = extensibleStencil.canLazilyParse; + functionKey = extensibleStencil.functionKey; + + // Borrow the vector content as span. + scriptData = extensibleStencil.scriptData; + scriptExtra = extensibleStencil.scriptExtra; + + gcThingData = extensibleStencil.gcThingData; + + scopeData = extensibleStencil.scopeData; + scopeNames = extensibleStencil.scopeNames; + + regExpData = extensibleStencil.regExpData; + bigIntData = extensibleStencil.bigIntData; + objLiteralData = extensibleStencil.objLiteralData; + + // Borrow the parser atoms as span. + parserAtomData = extensibleStencil.parserAtoms.entries_; + + // Borrow container. + sharedData.setBorrow(&extensibleStencil.sharedData); + + // Share ref-counted data. + source = extensibleStencil.source; + asmJS = extensibleStencil.asmJS; + moduleMetadata = extensibleStencil.moduleMetadata; +} + +#ifdef DEBUG +void CompilationStencil::assertBorrowingFromExtensibleCompilationStencil( + const ExtensibleCompilationStencil& extensibleStencil) const { + MOZ_ASSERT(canLazilyParse == extensibleStencil.canLazilyParse); + MOZ_ASSERT(functionKey == extensibleStencil.functionKey); + + AssertBorrowingSpan(scriptData, extensibleStencil.scriptData); + AssertBorrowingSpan(scriptExtra, extensibleStencil.scriptExtra); + + AssertBorrowingSpan(gcThingData, extensibleStencil.gcThingData); + + AssertBorrowingSpan(scopeData, extensibleStencil.scopeData); + AssertBorrowingSpan(scopeNames, extensibleStencil.scopeNames); + + AssertBorrowingSpan(regExpData, extensibleStencil.regExpData); + AssertBorrowingSpan(bigIntData, extensibleStencil.bigIntData); + AssertBorrowingSpan(objLiteralData, extensibleStencil.objLiteralData); + + AssertBorrowingSpan(parserAtomData, extensibleStencil.parserAtoms.entries_); + + MOZ_ASSERT(sharedData.isBorrow()); + MOZ_ASSERT(sharedData.asBorrow() == &extensibleStencil.sharedData); + + MOZ_ASSERT(source == extensibleStencil.source); + MOZ_ASSERT(asmJS == extensibleStencil.asmJS); + MOZ_ASSERT(moduleMetadata == extensibleStencil.moduleMetadata); +} +#endif + +CompilationStencil::CompilationStencil( + UniquePtr<ExtensibleCompilationStencil>&& extensibleStencil) + : alloc(LifoAllocChunkSize) { + ownedBorrowStencil = std::move(extensibleStencil); + + storageType = StorageType::OwnedExtensible; + + borrowFromExtensibleCompilationStencil(*ownedBorrowStencil); + +#ifdef DEBUG + assertNoExternalDependency(); +#endif +} + +/* static */ +bool CompilationStencil::instantiateStencils(JSContext* cx, + CompilationInput& input, + const CompilationStencil& stencil, + CompilationGCOutput& gcOutput) { + AutoReportFrontendContext fc(cx); + if (!prepareForInstantiate(&fc, input.atomCache, stencil, gcOutput)) { + return false; + } + + return instantiateStencilAfterPreparation(cx, input, stencil, gcOutput); +} + +/* static */ +bool CompilationStencil::instantiateStencilAfterPreparation( + JSContext* cx, CompilationInput& input, const CompilationStencil& stencil, + CompilationGCOutput& gcOutput) { + // Distinguish between the initial (possibly lazy) compile and any subsequent + // delazification compiles. Delazification will update existing GC things. + bool isInitialParse = stencil.isInitialStencil(); + MOZ_ASSERT(stencil.isInitialStencil() == input.isInitialStencil()); + + // Assert the consistency between the compile option and the target global. + MOZ_ASSERT_IF(cx->realm()->behaviors().discardSource(), + !stencil.canLazilyParse); + + CompilationAtomCache& atomCache = input.atomCache; + const JS::InstantiateOptions options(input.options); + + // Phase 1: Instantiate JSAtom/JSStrings. + AutoReportFrontendContext fc(cx); + if (!InstantiateAtoms(cx, &fc, atomCache, stencil)) { + return false; + } + + // Phase 2: Instantiate ScriptSourceObject, ModuleObject, JSFunctions. + if (isInitialParse) { + if (!InstantiateScriptSourceObject(cx, options, stencil, gcOutput)) { + return false; + } + + if (stencil.moduleMetadata) { + // The enclosing script of a module is always the global scope. Fetch the + // scope of the current global and update input data. + MOZ_ASSERT(input.enclosingScope.isNull()); + input.enclosingScope = InputScope(&cx->global()->emptyGlobalScope()); + MOZ_ASSERT(input.enclosingScope.environmentChainLength() == + ModuleScope::EnclosingEnvironmentChainLength); + + if (!InstantiateModuleObject(cx, &fc, atomCache, stencil, gcOutput)) { + return false; + } + } + + if (!InstantiateFunctions(cx, &fc, atomCache, stencil, gcOutput)) { + return false; + } + } else { + MOZ_ASSERT( + stencil.scriptData[CompilationStencil::TopLevelIndex].isFunction()); + + // FunctionKey is used when caching to map a delazification stencil to a + // specific lazy script. It is not used by instantiation, but we should + // ensure it is correctly defined. + MOZ_ASSERT(stencil.functionKey == input.extent().toFunctionKey()); + + FunctionsFromExistingLazy(input, gcOutput); + MOZ_ASSERT(gcOutput.functions.length() == stencil.scriptData.size()); + +#ifdef DEBUG + AssertDelazificationFieldsMatch(stencil, gcOutput); +#endif + } + + // Phase 3: Instantiate js::Scopes. + if (!InstantiateScopes(cx, input, stencil, gcOutput)) { + return false; + } + + // Phase 4: Instantiate (inner) BaseScripts. + if (isInitialParse) { + if (!InstantiateScriptStencils(cx, atomCache, stencil, gcOutput)) { + return false; + } + } + + // Phase 5: Finish top-level handling + if (!InstantiateTopLevel(cx, input, stencil, gcOutput)) { + return false; + } + + // !! Must be infallible from here forward !! + + // Phase 6: Update lazy scripts. + if (stencil.canLazilyParse) { + UpdateEmittedInnerFunctions(cx, atomCache, stencil, gcOutput); + + if (isInitialParse) { + LinkEnclosingLazyScript(stencil, gcOutput); + } + } + + return true; +} + +// The top-level self-hosted script is created and executed in each realm that +// needs it. While the stencil has a gcthings list for the various top-level +// functions, we use special machinery to create them on demand. So instead we +// use a placeholder JSFunction that should never be called. +static bool SelfHostedDummyFunction(JSContext* cx, unsigned argc, + JS::Value* vp) { + MOZ_CRASH("Self-hosting top-level should not use functions directly"); +} + +bool CompilationStencil::instantiateSelfHostedAtoms( + JSContext* cx, AtomSet& atomSet, CompilationAtomCache& atomCache) const { + MOZ_ASSERT(isInitialStencil()); + + // We must instantiate atoms during startup so they can be made permanent + // across multiple runtimes. + AutoReportFrontendContext fc(cx); + return InstantiateMarkedAtomsAsPermanent(cx, &fc, atomSet, parserAtomData, + atomCache); +} + +JSScript* CompilationStencil::instantiateSelfHostedTopLevelForRealm( + JSContext* cx, CompilationInput& input) { + MOZ_ASSERT(isInitialStencil()); + + Rooted<CompilationGCOutput> gcOutput(cx); + + gcOutput.get().sourceObject = SelfHostingScriptSourceObject(cx); + if (!gcOutput.get().sourceObject) { + return nullptr; + } + + // The top-level script has ScriptIndex references in its gcthings list, but + // we do not want to instantiate those functions here since they are instead + // created on demand from the stencil. Create a dummy function and populate + // the functions array of the CompilationGCOutput with references to it. + RootedFunction dummy( + cx, NewNativeFunction(cx, SelfHostedDummyFunction, 0, nullptr)); + if (!dummy) { + return nullptr; + } + + if (!gcOutput.get().functions.allocateWith(dummy, scriptData.size())) { + ReportOutOfMemory(cx); + return nullptr; + } + + if (!InstantiateTopLevel(cx, input, *this, gcOutput.get())) { + return nullptr; + } + + return gcOutput.get().script; +} + +JSFunction* CompilationStencil::instantiateSelfHostedLazyFunction( + JSContext* cx, CompilationAtomCache& atomCache, ScriptIndex index, + Handle<JSAtom*> name) { + GeneratorKind generatorKind = scriptExtra[index].immutableFlags.hasFlag( + ImmutableScriptFlagsEnum::IsGenerator) + ? GeneratorKind::Generator + : GeneratorKind::NotGenerator; + FunctionAsyncKind asyncKind = scriptExtra[index].immutableFlags.hasFlag( + ImmutableScriptFlagsEnum::IsAsync) + ? FunctionAsyncKind::AsyncFunction + : FunctionAsyncKind::SyncFunction; + + Rooted<JSAtom*> funName(cx); + if (scriptData[index].hasSelfHostedCanonicalName()) { + // SetCanonicalName was used to override the name. + funName = atomCache.getExistingAtomAt( + cx, scriptData[index].selfHostedCanonicalName()); + } else if (name) { + // Our caller has a name it wants to use. + funName = name; + } else { + MOZ_ASSERT(scriptData[index].functionAtom); + funName = atomCache.getExistingAtomAt(cx, scriptData[index].functionAtom); + } + + RootedObject proto(cx); + if (!GetFunctionPrototype(cx, generatorKind, asyncKind, &proto)) { + return nullptr; + } + + RootedObject env(cx, &cx->global()->lexicalEnvironment()); + + RootedFunction fun( + cx, + NewFunctionWithProto(cx, nullptr, scriptExtra[index].nargs, + scriptData[index].functionFlags, env, funName, proto, + gc::AllocKind::FUNCTION_EXTENDED, TenuredObject)); + if (!fun) { + return nullptr; + } + + fun->initSelfHostedLazyScript(&cx->runtime()->selfHostedLazyScript.ref()); + + JSAtom* selfHostedName = + atomCache.getExistingAtomAt(cx, scriptData[index].functionAtom); + SetClonedSelfHostedFunctionName(fun, selfHostedName->asPropertyName()); + + return fun; +} + +bool CompilationStencil::delazifySelfHostedFunction( + JSContext* cx, CompilationAtomCache& atomCache, ScriptIndexRange range, + HandleFunction fun) { + // Determine the equivalent ScopeIndex range by looking at the outermost scope + // of the scripts defining the range. Take special care if this is the last + // script in the list. + auto getOutermostScope = [this](ScriptIndex scriptIndex) -> ScopeIndex { + MOZ_ASSERT(scriptData[scriptIndex].hasSharedData()); + auto gcthings = scriptData[scriptIndex].gcthings(*this); + return gcthings[GCThingIndex::outermostScopeIndex()].toScope(); + }; + ScopeIndex scopeIndex = getOutermostScope(range.start); + ScopeIndex scopeLimit = (range.limit < scriptData.size()) + ? getOutermostScope(range.limit) + : ScopeIndex(scopeData.size()); + + // Prepare to instantiate by allocating the output arrays. We also set a base + // index to avoid allocations in most cases. + AutoReportFrontendContext fc(cx); + Rooted<CompilationGCOutput> gcOutput(cx); + if (!gcOutput.get().ensureAllocatedWithBaseIndex( + &fc, range.start, range.limit, scopeIndex, scopeLimit)) { + return false; + } + + // Phase 1: Instantiate JSAtoms. + // NOTE: The self-hosted atoms are all "permanent" and the + // CompilationAtomCache is already stored on the JSRuntime. + + // Phase 2: Instantiate ScriptSourceObject, ModuleObject, JSFunctions. + + // Get the corresponding ScriptSourceObject to use in current realm. + gcOutput.get().sourceObject = SelfHostingScriptSourceObject(cx); + if (!gcOutput.get().sourceObject) { + return false; + } + + size_t instantiatedFunIndex = 0; + + // Delazification target function. + gcOutput.get().functions[instantiatedFunIndex++] = fun; + + // Allocate inner functions. Self-hosted functions do not allocate these with + // the initial function. + for (size_t i = range.start + 1; i < range.limit; i++) { + JSFunction* innerFun = CreateFunction(cx, atomCache, *this, scriptData[i], + scriptExtra[i], ScriptIndex(i)); + if (!innerFun) { + return false; + } + gcOutput.get().functions[instantiatedFunIndex++] = innerFun; + } + + // Phase 3: Instantiate js::Scopes. + // NOTE: When the enclosing scope is not a stencil, directly use the + // `emptyGlobalScope` instead of reading from CompilationInput. This is + // a special case for self-hosted delazification that allows us to reuse + // the CompilationInput between different realms. + size_t instantiatedScopeIndex = 0; + for (size_t i = scopeIndex; i < scopeLimit; i++) { + ScopeStencil& data = scopeData[i]; + Rooted<Scope*> enclosingScope( + cx, data.hasEnclosing() ? gcOutput.get().getScope(data.enclosing()) + : &cx->global()->emptyGlobalScope()); + + js::Scope* scope = + data.createScope(cx, atomCache, enclosingScope, scopeNames[i]); + if (!scope) { + return false; + } + gcOutput.get().scopes[instantiatedScopeIndex++] = scope; + } + + // Phase 4: Instantiate (inner) BaseScripts. + ScriptIndex innerStart(range.start + 1); + for (size_t i = innerStart; i < range.limit; i++) { + if (!JSScript::fromStencil(cx, atomCache, *this, gcOutput.get(), + ScriptIndex(i))) { + return false; + } + } + + // Phase 5: Finish top-level handling + // NOTE: We do not have a `CompilationInput` handy here, so avoid using the + // `InstantiateTopLevel` helper and directly create the JSScript. Our + // caller also handles the `AllowRelazify` flag for us since self-hosted + // delazification is a special case. + if (!JSScript::fromStencil(cx, atomCache, *this, gcOutput.get(), + range.start)) { + return false; + } + + // Phase 6: Update lazy scripts. + // NOTE: Self-hosting is always fully parsed so there is nothing to do here. + + return true; +} + +/* static */ +bool CompilationStencil::prepareForInstantiate( + FrontendContext* fc, CompilationAtomCache& atomCache, + const CompilationStencil& stencil, CompilationGCOutput& gcOutput) { + // Allocate the `gcOutput` arrays. + if (!gcOutput.ensureAllocated(fc, stencil.scriptData.size(), + stencil.scopeData.size())) { + return false; + } + + return atomCache.allocate(fc, stencil.parserAtomData.size()); +} + +/* static */ +bool CompilationStencil::prepareForInstantiate( + FrontendContext* fc, const CompilationStencil& stencil, + PreallocatedCompilationGCOutput& gcOutput) { + return gcOutput.allocate(fc, stencil.scriptData.size(), + stencil.scopeData.size()); +} + +bool CompilationStencil::serializeStencils(JSContext* cx, + CompilationInput& input, + JS::TranscodeBuffer& buf, + bool* succeededOut) const { + if (succeededOut) { + *succeededOut = false; + } + AutoReportFrontendContext fc(cx); + XDRStencilEncoder encoder(&fc, buf); + + XDRResult res = encoder.codeStencil(*this); + if (res.isErr()) { + if (JS::IsTranscodeFailureResult(res.unwrapErr())) { + buf.clear(); + return true; + } + MOZ_ASSERT(res.unwrapErr() == JS::TranscodeResult::Throw); + + return false; + } + + if (succeededOut) { + *succeededOut = true; + } + return true; +} + +bool CompilationStencil::deserializeStencils( + FrontendContext* fc, const JS::ReadOnlyCompileOptions& compileOptions, + const JS::TranscodeRange& range, bool* succeededOut) { + if (succeededOut) { + *succeededOut = false; + } + MOZ_ASSERT(parserAtomData.empty()); + XDRStencilDecoder decoder(fc, range); + JS::DecodeOptions options(compileOptions); + + XDRResult res = decoder.codeStencil(options, *this); + if (res.isErr()) { + if (JS::IsTranscodeFailureResult(res.unwrapErr())) { + return true; + } + MOZ_ASSERT(res.unwrapErr() == JS::TranscodeResult::Throw); + + return false; + } + + if (succeededOut) { + *succeededOut = true; + } + return true; +} + +ExtensibleCompilationStencil::ExtensibleCompilationStencil(ScriptSource* source) + : alloc(CompilationStencil::LifoAllocChunkSize), + source(source), + parserAtoms(alloc) {} + +ExtensibleCompilationStencil::ExtensibleCompilationStencil( + CompilationInput& input) + : canLazilyParse(CanLazilyParse(input.options)), + alloc(CompilationStencil::LifoAllocChunkSize), + source(input.source), + parserAtoms(alloc) {} + +ExtensibleCompilationStencil::ExtensibleCompilationStencil( + const JS::ReadOnlyCompileOptions& options, RefPtr<ScriptSource> source) + : canLazilyParse(CanLazilyParse(options)), + alloc(CompilationStencil::LifoAllocChunkSize), + source(std::move(source)), + parserAtoms(alloc) {} + +CompilationState::CompilationState(FrontendContext* fc, + LifoAllocScope& parserAllocScope, + CompilationInput& input) + : ExtensibleCompilationStencil(input), + directives(input.options.forceStrictMode()), + usedNames(fc), + parserAllocScope(parserAllocScope), + input(input) {} + +BorrowingCompilationStencil::BorrowingCompilationStencil( + ExtensibleCompilationStencil& extensibleStencil) + : CompilationStencil(extensibleStencil.source) { + storageType = StorageType::Borrowed; + + borrowFromExtensibleCompilationStencil(extensibleStencil); +} + +SharedDataContainer::~SharedDataContainer() { + if (isEmpty()) { + // Nothing to do. + } else if (isSingle()) { + asSingle()->Release(); + } else if (isVector()) { + js_delete(asVector()); + } else if (isMap()) { + js_delete(asMap()); + } else { + MOZ_ASSERT(isBorrow()); + // Nothing to do. + } +} + +bool SharedDataContainer::initVector(FrontendContext* fc) { + MOZ_ASSERT(isEmpty()); + + auto* vec = js_new<SharedDataVector>(); + if (!vec) { + ReportOutOfMemory(fc); + return false; + } + data_ = uintptr_t(vec) | VectorTag; + return true; +} + +bool SharedDataContainer::initMap(FrontendContext* fc) { + MOZ_ASSERT(isEmpty()); + + auto* map = js_new<SharedDataMap>(); + if (!map) { + ReportOutOfMemory(fc); + return false; + } + data_ = uintptr_t(map) | MapTag; + return true; +} + +bool SharedDataContainer::prepareStorageFor(FrontendContext* fc, + size_t nonLazyScriptCount, + size_t allScriptCount) { + MOZ_ASSERT(isEmpty()); + + if (nonLazyScriptCount <= 1) { + MOZ_ASSERT(isSingle()); + return true; + } + + // If the ratio of scripts with bytecode is small, allocating the Vector + // storage with the number of all scripts isn't space-efficient. + // In that case use HashMap instead. + // + // In general, we expect either all scripts to contain bytecode (priviledge + // and self-hosted), or almost none to (eg standard lazy parsing output). + constexpr size_t thresholdRatio = 8; + bool useHashMap = nonLazyScriptCount < allScriptCount / thresholdRatio; + if (useHashMap) { + if (!initMap(fc)) { + return false; + } + if (!asMap()->reserve(nonLazyScriptCount)) { + ReportOutOfMemory(fc); + return false; + } + } else { + if (!initVector(fc)) { + return false; + } + if (!asVector()->resize(allScriptCount)) { + ReportOutOfMemory(fc); + return false; + } + } + + return true; +} + +bool SharedDataContainer::cloneFrom(FrontendContext* fc, + const SharedDataContainer& other) { + MOZ_ASSERT(isEmpty()); + + if (other.isBorrow()) { + return cloneFrom(fc, *other.asBorrow()); + } + + if (other.isSingle()) { + // As we clone, we add an extra reference. + RefPtr<SharedImmutableScriptData> ref(other.asSingle()); + setSingle(ref.forget()); + } else if (other.isVector()) { + if (!initVector(fc)) { + return false; + } + if (!asVector()->appendAll(*other.asVector())) { + ReportOutOfMemory(fc); + return false; + } + } else if (other.isMap()) { + if (!initMap(fc)) { + return false; + } + auto& otherMap = *other.asMap(); + if (!asMap()->reserve(otherMap.count())) { + ReportOutOfMemory(fc); + return false; + } + auto& map = *asMap(); + for (auto iter = otherMap.iter(); !iter.done(); iter.next()) { + auto& entry = iter.get(); + map.putNewInfallible(entry.key(), entry.value()); + } + } + return true; +} + +js::SharedImmutableScriptData* SharedDataContainer::get( + ScriptIndex index) const { + if (isSingle()) { + if (index == CompilationStencil::TopLevelIndex) { + return asSingle(); + } + return nullptr; + } + + if (isVector()) { + auto& vec = *asVector(); + if (index.index < vec.length()) { + return vec[index]; + } + return nullptr; + } + + if (isMap()) { + auto& map = *asMap(); + auto p = map.lookup(index); + if (p) { + return p->value(); + } + return nullptr; + } + + MOZ_ASSERT(isBorrow()); + return asBorrow()->get(index); +} + +bool SharedDataContainer::convertFromSingleToMap(FrontendContext* fc) { + MOZ_ASSERT(isSingle()); + + // Use a temporary container so that on OOM we do not break the stencil. + SharedDataContainer other; + if (!other.initMap(fc)) { + return false; + } + + if (!other.asMap()->putNew(CompilationStencil::TopLevelIndex, asSingle())) { + ReportOutOfMemory(fc); + return false; + } + + std::swap(data_, other.data_); + return true; +} + +bool SharedDataContainer::addAndShare(FrontendContext* fc, ScriptIndex index, + js::SharedImmutableScriptData* data) { + MOZ_ASSERT(!isBorrow()); + + if (isSingle()) { + MOZ_ASSERT(index == CompilationStencil::TopLevelIndex); + RefPtr<SharedImmutableScriptData> ref(data); + if (!SharedImmutableScriptData::shareScriptData(fc, ref)) { + return false; + } + setSingle(ref.forget()); + return true; + } + + if (isVector()) { + auto& vec = *asVector(); + // Resized by SharedDataContainer::prepareStorageFor. + vec[index] = data; + return SharedImmutableScriptData::shareScriptData(fc, vec[index]); + } + + MOZ_ASSERT(isMap()); + auto& map = *asMap(); + // Reserved by SharedDataContainer::prepareStorageFor. + map.putNewInfallible(index, data); + auto p = map.lookup(index); + MOZ_ASSERT(p); + return SharedImmutableScriptData::shareScriptData(fc, p->value()); +} + +bool SharedDataContainer::addExtraWithoutShare( + FrontendContext* fc, ScriptIndex index, + js::SharedImmutableScriptData* data) { + MOZ_ASSERT(!isEmpty()); + + if (isSingle()) { + if (!convertFromSingleToMap(fc)) { + return false; + } + } + + if (isVector()) { + // SharedDataContainer::prepareStorageFor allocates space for all scripts. + (*asVector())[index] = data; + return true; + } + + MOZ_ASSERT(isMap()); + // SharedDataContainer::prepareStorageFor doesn't allocate space for + // delazification, and this can fail. + if (!asMap()->putNew(index, data)) { + ReportOutOfMemory(fc); + return false; + } + return true; +} + +#ifdef DEBUG +void CompilationStencil::assertNoExternalDependency() const { + if (ownedBorrowStencil) { + ownedBorrowStencil->assertNoExternalDependency(); + + assertBorrowingFromExtensibleCompilationStencil(*ownedBorrowStencil); + return; + } + + MOZ_ASSERT_IF(!scriptData.empty(), alloc.contains(scriptData.data())); + MOZ_ASSERT_IF(!scriptExtra.empty(), alloc.contains(scriptExtra.data())); + + MOZ_ASSERT_IF(!scopeData.empty(), alloc.contains(scopeData.data())); + MOZ_ASSERT_IF(!scopeNames.empty(), alloc.contains(scopeNames.data())); + for (const auto* data : scopeNames) { + MOZ_ASSERT_IF(data, alloc.contains(data)); + } + + MOZ_ASSERT_IF(!regExpData.empty(), alloc.contains(regExpData.data())); + + MOZ_ASSERT_IF(!bigIntData.empty(), alloc.contains(bigIntData.data())); + for (const auto& data : bigIntData) { + MOZ_ASSERT(data.isContainedIn(alloc)); + } + + MOZ_ASSERT_IF(!objLiteralData.empty(), alloc.contains(objLiteralData.data())); + for (const auto& data : objLiteralData) { + MOZ_ASSERT(data.isContainedIn(alloc)); + } + + MOZ_ASSERT_IF(!parserAtomData.empty(), alloc.contains(parserAtomData.data())); + for (const auto* data : parserAtomData) { + MOZ_ASSERT_IF(data, alloc.contains(data)); + } + + MOZ_ASSERT(!sharedData.isBorrow()); +} + +void ExtensibleCompilationStencil::assertNoExternalDependency() const { + for (const auto& data : bigIntData) { + MOZ_ASSERT(data.isContainedIn(alloc)); + } + + for (const auto& data : objLiteralData) { + MOZ_ASSERT(data.isContainedIn(alloc)); + } + + for (const auto* data : scopeNames) { + MOZ_ASSERT_IF(data, alloc.contains(data)); + } + + for (const auto* data : parserAtoms.entries()) { + MOZ_ASSERT_IF(data, alloc.contains(data)); + } + + MOZ_ASSERT(!sharedData.isBorrow()); +} +#endif // DEBUG + +template <typename T, typename VectorT> +[[nodiscard]] bool CopySpanToVector(FrontendContext* fc, VectorT& vec, + mozilla::Span<T>& span) { + auto len = span.size(); + if (len == 0) { + return true; + } + + if (!vec.append(span.data(), len)) { + js::ReportOutOfMemory(fc); + return false; + } + return true; +} + +template <typename T, typename IntoSpanT, size_t Inline, typename AllocPolicy> +[[nodiscard]] bool CopyToVector(FrontendContext* fc, + mozilla::Vector<T, Inline, AllocPolicy>& vec, + const IntoSpanT& source) { + mozilla::Span<const T> span = source; + return CopySpanToVector(fc, vec, span); +} + +// Span and Vector do not share the same method names. +template <typename T, size_t Inline, typename AllocPolicy> +size_t GetLength(const mozilla::Vector<T, Inline, AllocPolicy>& vec) { + return vec.length(); +} +template <typename T> +size_t GetLength(const mozilla::Span<T>& span) { + return span.Length(); +} + +// Copy scope names from `src` into `alloc`, and returns the allocated data. +BaseParserScopeData* CopyScopeData(FrontendContext* fc, LifoAlloc& alloc, + ScopeKind kind, + const BaseParserScopeData* src) { + MOZ_ASSERT(kind != ScopeKind::With); + + size_t dataSize = SizeOfParserScopeData(kind, src->length); + + auto* dest = static_cast<BaseParserScopeData*>(alloc.alloc(dataSize)); + if (!dest) { + js::ReportOutOfMemory(fc); + return nullptr; + } + memcpy(dest, src, dataSize); + + return dest; +} + +template <typename Stencil> +bool ExtensibleCompilationStencil::cloneFromImpl(FrontendContext* fc, + const Stencil& other) { + MOZ_ASSERT(alloc.isEmpty()); + + canLazilyParse = other.canLazilyParse; + functionKey = other.functionKey; + + if (!CopyToVector(fc, scriptData, other.scriptData)) { + return false; + } + + if (!CopyToVector(fc, scriptExtra, other.scriptExtra)) { + return false; + } + + if (!CopyToVector(fc, gcThingData, other.gcThingData)) { + return false; + } + + size_t scopeSize = GetLength(other.scopeData); + if (!CopyToVector(fc, scopeData, other.scopeData)) { + return false; + } + if (!scopeNames.reserve(scopeSize)) { + js::ReportOutOfMemory(fc); + return false; + } + for (size_t i = 0; i < scopeSize; i++) { + if (other.scopeNames[i]) { + BaseParserScopeData* data = CopyScopeData( + fc, alloc, other.scopeData[i].kind(), other.scopeNames[i]); + if (!data) { + return false; + } + scopeNames.infallibleEmplaceBack(data); + } else { + scopeNames.infallibleEmplaceBack(nullptr); + } + } + + if (!CopyToVector(fc, regExpData, other.regExpData)) { + return false; + } + + // If CompilationStencil has external dependency, peform deep copy. + + size_t bigIntSize = GetLength(other.bigIntData); + if (!bigIntData.resize(bigIntSize)) { + js::ReportOutOfMemory(fc); + return false; + } + for (size_t i = 0; i < bigIntSize; i++) { + if (!bigIntData[i].init(fc, alloc, other.bigIntData[i].source())) { + return false; + } + } + + size_t objLiteralSize = GetLength(other.objLiteralData); + if (!objLiteralData.reserve(objLiteralSize)) { + js::ReportOutOfMemory(fc); + return false; + } + for (const auto& data : other.objLiteralData) { + size_t length = data.code().size(); + auto* code = alloc.newArrayUninitialized<uint8_t>(length); + if (!code) { + js::ReportOutOfMemory(fc); + return false; + } + memcpy(code, data.code().data(), length); + objLiteralData.infallibleEmplaceBack(code, length, data.kind(), + data.flags(), data.propertyCount()); + } + + // Regardless of whether CompilationStencil has external dependency or not, + // ParserAtoms should be interned, to populate internal HashMap. + for (const auto* entry : other.parserAtomsSpan()) { + if (!entry) { + if (!parserAtoms.addPlaceholder(fc)) { + return false; + } + continue; + } + + auto index = parserAtoms.internExternalParserAtom(fc, entry); + if (!index) { + return false; + } + } + + // We copy the stencil and increment the reference count of each + // SharedImmutableScriptData. + if (!sharedData.cloneFrom(fc, other.sharedData)) { + return false; + } + + // Note: moduleMetadata and asmJS are known after the first parse, and are + // not mutated by any delazifications later on. Thus we can safely increment + // the reference counter and keep these as-is. + moduleMetadata = other.moduleMetadata; + asmJS = other.asmJS; + +#ifdef DEBUG + assertNoExternalDependency(); +#endif + + return true; +} + +bool ExtensibleCompilationStencil::cloneFrom(FrontendContext* fc, + const CompilationStencil& other) { + return cloneFromImpl(fc, other); +} +bool ExtensibleCompilationStencil::cloneFrom( + FrontendContext* fc, const ExtensibleCompilationStencil& other) { + return cloneFromImpl(fc, other); +} + +bool ExtensibleCompilationStencil::steal(FrontendContext* fc, + RefPtr<CompilationStencil>&& other) { + MOZ_ASSERT(alloc.isEmpty()); + using StorageType = CompilationStencil::StorageType; + StorageType storageType = other->storageType; + if (other->refCount > 1) { + storageType = StorageType::Borrowed; + } + + if (storageType == StorageType::OwnedExtensible) { + auto& otherExtensible = other->ownedBorrowStencil; + + canLazilyParse = otherExtensible->canLazilyParse; + functionKey = otherExtensible->functionKey; + + alloc.steal(&otherExtensible->alloc); + + source = std::move(otherExtensible->source); + + scriptData = std::move(otherExtensible->scriptData); + scriptExtra = std::move(otherExtensible->scriptExtra); + gcThingData = std::move(otherExtensible->gcThingData); + scopeData = std::move(otherExtensible->scopeData); + scopeNames = std::move(otherExtensible->scopeNames); + regExpData = std::move(otherExtensible->regExpData); + bigIntData = std::move(otherExtensible->bigIntData); + objLiteralData = std::move(otherExtensible->objLiteralData); + + parserAtoms = std::move(otherExtensible->parserAtoms); + parserAtoms.fixupAlloc(alloc); + + sharedData = std::move(otherExtensible->sharedData); + moduleMetadata = std::move(otherExtensible->moduleMetadata); + asmJS = std::move(otherExtensible->asmJS); + +#ifdef DEBUG + assertNoExternalDependency(); +#endif + + return true; + } + + if (storageType == StorageType::Borrowed) { + return cloneFrom(fc, *other); + } + + MOZ_ASSERT(storageType == StorageType::Owned); + + canLazilyParse = other->canLazilyParse; + functionKey = other->functionKey; + +#ifdef DEBUG + other->assertNoExternalDependency(); + MOZ_ASSERT(other->refCount == 1); +#endif + + // If CompilationStencil has no external dependency, + // steal LifoAlloc and perform shallow copy. + alloc.steal(&other->alloc); + + if (!CopySpanToVector(fc, scriptData, other->scriptData)) { + return false; + } + + if (!CopySpanToVector(fc, scriptExtra, other->scriptExtra)) { + return false; + } + + if (!CopySpanToVector(fc, gcThingData, other->gcThingData)) { + return false; + } + + if (!CopySpanToVector(fc, scopeData, other->scopeData)) { + return false; + } + if (!CopySpanToVector(fc, scopeNames, other->scopeNames)) { + return false; + } + + if (!CopySpanToVector(fc, regExpData, other->regExpData)) { + return false; + } + + if (!CopySpanToVector(fc, bigIntData, other->bigIntData)) { + return false; + } + + if (!CopySpanToVector(fc, objLiteralData, other->objLiteralData)) { + return false; + } + + // Regardless of whether CompilationStencil has external dependency or not, + // ParserAtoms should be interned, to populate internal HashMap. + for (const auto* entry : other->parserAtomData) { + if (!entry) { + if (!parserAtoms.addPlaceholder(fc)) { + return false; + } + continue; + } + + auto index = parserAtoms.internExternalParserAtom(fc, entry); + if (!index) { + return false; + } + } + + sharedData = std::move(other->sharedData); + moduleMetadata = std::move(other->moduleMetadata); + asmJS = std::move(other->asmJS); + +#ifdef DEBUG + assertNoExternalDependency(); +#endif + + return true; +} + +bool CompilationStencil::isModule() const { + return scriptExtra[CompilationStencil::TopLevelIndex].isModule(); +} + +bool ExtensibleCompilationStencil::isModule() const { + return scriptExtra[CompilationStencil::TopLevelIndex].isModule(); +} + +mozilla::Span<TaggedScriptThingIndex> ScriptStencil::gcthings( + const CompilationStencil& stencil) const { + return stencil.gcThingData.Subspan(gcThingsOffset, gcThingsLength); +} + +bool BigIntStencil::init(FrontendContext* fc, LifoAlloc& alloc, + const mozilla::Span<const char16_t> buf) { +#ifdef DEBUG + // Assert we have no separators; if we have a separator then the algorithm + // used in BigInt::literalIsZero will be incorrect. + for (char16_t c : buf) { + MOZ_ASSERT(c != '_'); + } +#endif + size_t length = buf.size(); + char16_t* p = alloc.template newArrayUninitialized<char16_t>(length); + if (!p) { + ReportOutOfMemory(fc); + return false; + } + mozilla::PodCopy(p, buf.data(), length); + source_ = mozilla::Span(p, length); + return true; +} + +BigInt* BigIntStencil::createBigInt(JSContext* cx) const { + mozilla::Range<const char16_t> source(source_.data(), source_.size()); + return js::ParseBigIntLiteral(cx, source); +} + +bool BigIntStencil::isZero() const { + mozilla::Range<const char16_t> source(source_.data(), source_.size()); + return js::BigIntLiteralIsZero(source); +} + +#ifdef DEBUG +bool BigIntStencil::isContainedIn(const LifoAlloc& alloc) const { + return alloc.contains(source_.data()); +} +#endif + +#if defined(DEBUG) || defined(JS_JITSPEW) + +void frontend::DumpTaggedParserAtomIndex(js::JSONPrinter& json, + TaggedParserAtomIndex taggedIndex, + const CompilationStencil* stencil) { + if (taggedIndex.isParserAtomIndex()) { + json.property("tag", "AtomIndex"); + auto index = taggedIndex.toParserAtomIndex(); + if (stencil && stencil->parserAtomData[index]) { + GenericPrinter& out = json.beginStringProperty("atom"); + stencil->parserAtomData[index]->dumpCharsNoQuote(out); + json.endString(); + } else { + json.property("index", size_t(index)); + } + return; + } + + if (taggedIndex.isWellKnownAtomId()) { + json.property("tag", "WellKnown"); + auto index = taggedIndex.toWellKnownAtomId(); + switch (index) { + case WellKnownAtomId::empty_: + json.property("atom", ""); + break; + +# define CASE_(name, _) case WellKnownAtomId::name: + FOR_EACH_NONTINY_COMMON_PROPERTYNAME(CASE_) +# undef CASE_ + +# define CASE_(name, _) case WellKnownAtomId::name: + JS_FOR_EACH_PROTOTYPE(CASE_) +# undef CASE_ + +# define CASE_(name) case WellKnownAtomId::name: + JS_FOR_EACH_WELL_KNOWN_SYMBOL(CASE_) +# undef CASE_ + + { + GenericPrinter& out = json.beginStringProperty("atom"); + ParserAtomsTable::dumpCharsNoQuote(out, index); + json.endString(); + break; + } + + default: + // This includes tiny WellKnownAtomId atoms, which is invalid. + json.property("index", size_t(index)); + break; + } + return; + } + + if (taggedIndex.isLength1StaticParserString()) { + json.property("tag", "Length1Static"); + auto index = taggedIndex.toLength1StaticParserString(); + GenericPrinter& out = json.beginStringProperty("atom"); + ParserAtomsTable::dumpCharsNoQuote(out, index); + json.endString(); + return; + } + + if (taggedIndex.isLength2StaticParserString()) { + json.property("tag", "Length2Static"); + auto index = taggedIndex.toLength2StaticParserString(); + GenericPrinter& out = json.beginStringProperty("atom"); + ParserAtomsTable::dumpCharsNoQuote(out, index); + json.endString(); + return; + } + + if (taggedIndex.isLength3StaticParserString()) { + json.property("tag", "Length3Static"); + auto index = taggedIndex.toLength3StaticParserString(); + GenericPrinter& out = json.beginStringProperty("atom"); + ParserAtomsTable::dumpCharsNoQuote(out, index); + json.endString(); + return; + } + + MOZ_ASSERT(taggedIndex.isNull()); + json.property("tag", "null"); +} + +void frontend::DumpTaggedParserAtomIndexNoQuote( + GenericPrinter& out, TaggedParserAtomIndex taggedIndex, + const CompilationStencil* stencil) { + if (taggedIndex.isParserAtomIndex()) { + auto index = taggedIndex.toParserAtomIndex(); + if (stencil && stencil->parserAtomData[index]) { + stencil->parserAtomData[index]->dumpCharsNoQuote(out); + } else { + out.printf("AtomIndex#%zu", size_t(index)); + } + return; + } + + if (taggedIndex.isWellKnownAtomId()) { + auto index = taggedIndex.toWellKnownAtomId(); + switch (index) { + case WellKnownAtomId::empty_: + out.put("#<zero-length name>"); + break; + +# define CASE_(name, _) case WellKnownAtomId::name: + FOR_EACH_NONTINY_COMMON_PROPERTYNAME(CASE_) +# undef CASE_ + +# define CASE_(name, _) case WellKnownAtomId::name: + JS_FOR_EACH_PROTOTYPE(CASE_) +# undef CASE_ + +# define CASE_(name) case WellKnownAtomId::name: + JS_FOR_EACH_WELL_KNOWN_SYMBOL(CASE_) +# undef CASE_ + + { + ParserAtomsTable::dumpCharsNoQuote(out, index); + break; + } + + default: + // This includes tiny WellKnownAtomId atoms, which is invalid. + out.printf("WellKnown#%zu", size_t(index)); + break; + } + return; + } + + if (taggedIndex.isLength1StaticParserString()) { + auto index = taggedIndex.toLength1StaticParserString(); + ParserAtomsTable::dumpCharsNoQuote(out, index); + return; + } + + if (taggedIndex.isLength2StaticParserString()) { + auto index = taggedIndex.toLength2StaticParserString(); + ParserAtomsTable::dumpCharsNoQuote(out, index); + return; + } + + if (taggedIndex.isLength3StaticParserString()) { + auto index = taggedIndex.toLength3StaticParserString(); + ParserAtomsTable::dumpCharsNoQuote(out, index); + return; + } + + MOZ_ASSERT(taggedIndex.isNull()); + out.put("#<null name>"); +} + +void RegExpStencil::dump() const { + js::Fprinter out(stderr); + js::JSONPrinter json(out); + dump(json, nullptr); +} + +void RegExpStencil::dump(js::JSONPrinter& json, + const CompilationStencil* stencil) const { + json.beginObject(); + dumpFields(json, stencil); + json.endObject(); +} + +void RegExpStencil::dumpFields(js::JSONPrinter& json, + const CompilationStencil* stencil) const { + json.beginObjectProperty("pattern"); + DumpTaggedParserAtomIndex(json, atom_, stencil); + json.endObject(); + + GenericPrinter& out = json.beginStringProperty("flags"); + + if (flags().global()) { + out.put("g"); + } + if (flags().ignoreCase()) { + out.put("i"); + } + if (flags().multiline()) { + out.put("m"); + } + if (flags().dotAll()) { + out.put("s"); + } + if (flags().unicode()) { + out.put("u"); + } + if (flags().sticky()) { + out.put("y"); + } + + json.endStringProperty(); +} + +void BigIntStencil::dump() const { + js::Fprinter out(stderr); + js::JSONPrinter json(out); + dump(json); +} + +void BigIntStencil::dump(js::JSONPrinter& json) const { + GenericPrinter& out = json.beginString(); + dumpCharsNoQuote(out); + json.endString(); +} + +void BigIntStencil::dumpCharsNoQuote(GenericPrinter& out) const { + for (char16_t c : source_) { + out.putChar(char(c)); + } +} + +void ScopeStencil::dump() const { + js::Fprinter out(stderr); + js::JSONPrinter json(out); + dump(json, nullptr, nullptr); +} + +void ScopeStencil::dump(js::JSONPrinter& json, + const BaseParserScopeData* baseScopeData, + const CompilationStencil* stencil) const { + json.beginObject(); + dumpFields(json, baseScopeData, stencil); + json.endObject(); +} + +void ScopeStencil::dumpFields(js::JSONPrinter& json, + const BaseParserScopeData* baseScopeData, + const CompilationStencil* stencil) const { + json.property("kind", ScopeKindString(kind_)); + + if (hasEnclosing()) { + json.formatProperty("enclosing", "ScopeIndex(%zu)", size_t(enclosing())); + } + + json.property("firstFrameSlot", firstFrameSlot_); + + if (hasEnvironmentShape()) { + json.formatProperty("numEnvironmentSlots", "%zu", + size_t(numEnvironmentSlots_)); + } + + if (isFunction()) { + json.formatProperty("functionIndex", "ScriptIndex(%zu)", + size_t(functionIndex_)); + } + + json.beginListProperty("flags"); + if (flags_ & HasEnclosing) { + json.value("HasEnclosing"); + } + if (flags_ & HasEnvironmentShape) { + json.value("HasEnvironmentShape"); + } + if (flags_ & IsArrow) { + json.value("IsArrow"); + } + json.endList(); + + if (!baseScopeData) { + return; + } + + json.beginObjectProperty("data"); + + mozilla::Span<const ParserBindingName> trailingNames; + switch (kind_) { + case ScopeKind::Function: { + const auto* data = + static_cast<const FunctionScope::ParserData*>(baseScopeData); + json.property("nextFrameSlot", data->slotInfo.nextFrameSlot); + json.property("hasParameterExprs", data->slotInfo.hasParameterExprs()); + json.property("nonPositionalFormalStart", + data->slotInfo.nonPositionalFormalStart); + json.property("varStart", data->slotInfo.varStart); + + trailingNames = GetScopeDataTrailingNames(data); + break; + } + + case ScopeKind::FunctionBodyVar: { + const auto* data = + static_cast<const VarScope::ParserData*>(baseScopeData); + json.property("nextFrameSlot", data->slotInfo.nextFrameSlot); + + trailingNames = GetScopeDataTrailingNames(data); + break; + } + + case ScopeKind::Lexical: + case ScopeKind::SimpleCatch: + case ScopeKind::Catch: + case ScopeKind::NamedLambda: + case ScopeKind::StrictNamedLambda: + case ScopeKind::FunctionLexical: { + const auto* data = + static_cast<const LexicalScope::ParserData*>(baseScopeData); + json.property("nextFrameSlot", data->slotInfo.nextFrameSlot); + json.property("constStart", data->slotInfo.constStart); + + trailingNames = GetScopeDataTrailingNames(data); + break; + } + + case ScopeKind::ClassBody: { + const auto* data = + static_cast<const ClassBodyScope::ParserData*>(baseScopeData); + json.property("nextFrameSlot", data->slotInfo.nextFrameSlot); + json.property("privateMethodStart", data->slotInfo.privateMethodStart); + + trailingNames = GetScopeDataTrailingNames(data); + break; + } + + case ScopeKind::With: { + break; + } + + case ScopeKind::Eval: + case ScopeKind::StrictEval: { + const auto* data = + static_cast<const EvalScope::ParserData*>(baseScopeData); + json.property("nextFrameSlot", data->slotInfo.nextFrameSlot); + + trailingNames = GetScopeDataTrailingNames(data); + break; + } + + case ScopeKind::Global: + case ScopeKind::NonSyntactic: { + const auto* data = + static_cast<const GlobalScope::ParserData*>(baseScopeData); + json.property("letStart", data->slotInfo.letStart); + json.property("constStart", data->slotInfo.constStart); + + trailingNames = GetScopeDataTrailingNames(data); + break; + } + + case ScopeKind::Module: { + const auto* data = + static_cast<const ModuleScope::ParserData*>(baseScopeData); + json.property("nextFrameSlot", data->slotInfo.nextFrameSlot); + json.property("varStart", data->slotInfo.varStart); + json.property("letStart", data->slotInfo.letStart); + json.property("constStart", data->slotInfo.constStart); + + trailingNames = GetScopeDataTrailingNames(data); + break; + } + + case ScopeKind::WasmInstance: { + const auto* data = + static_cast<const WasmInstanceScope::ParserData*>(baseScopeData); + json.property("nextFrameSlot", data->slotInfo.nextFrameSlot); + json.property("globalsStart", data->slotInfo.globalsStart); + + trailingNames = GetScopeDataTrailingNames(data); + break; + } + + case ScopeKind::WasmFunction: { + const auto* data = + static_cast<const WasmFunctionScope::ParserData*>(baseScopeData); + json.property("nextFrameSlot", data->slotInfo.nextFrameSlot); + + trailingNames = GetScopeDataTrailingNames(data); + break; + } + + default: { + MOZ_CRASH("Unexpected ScopeKind"); + break; + } + } + + if (!trailingNames.empty()) { + char index[64]; + json.beginObjectProperty("trailingNames"); + for (size_t i = 0; i < trailingNames.size(); i++) { + const auto& name = trailingNames[i]; + SprintfLiteral(index, "%zu", i); + json.beginObjectProperty(index); + + json.boolProperty("closedOver", name.closedOver()); + + json.boolProperty("isTopLevelFunction", name.isTopLevelFunction()); + + json.beginObjectProperty("name"); + DumpTaggedParserAtomIndex(json, name.name(), stencil); + json.endObject(); + + json.endObject(); + } + json.endObject(); + } + + json.endObject(); +} + +static void DumpModuleRequestVectorItems( + js::JSONPrinter& json, const StencilModuleMetadata::RequestVector& requests, + const CompilationStencil* stencil) { + for (const auto& request : requests) { + json.beginObject(); + if (request.specifier) { + json.beginObjectProperty("specifier"); + DumpTaggedParserAtomIndex(json, request.specifier, stencil); + json.endObject(); + } + json.endObject(); + } +} + +static void DumpModuleEntryVectorItems( + js::JSONPrinter& json, const StencilModuleMetadata::EntryVector& entries, + const CompilationStencil* stencil) { + for (const auto& entry : entries) { + json.beginObject(); + if (entry.moduleRequest) { + json.property("moduleRequest", entry.moduleRequest.value()); + } + if (entry.localName) { + json.beginObjectProperty("localName"); + DumpTaggedParserAtomIndex(json, entry.localName, stencil); + json.endObject(); + } + if (entry.importName) { + json.beginObjectProperty("importName"); + DumpTaggedParserAtomIndex(json, entry.importName, stencil); + json.endObject(); + } + if (entry.exportName) { + json.beginObjectProperty("exportName"); + DumpTaggedParserAtomIndex(json, entry.exportName, stencil); + json.endObject(); + } + // TODO: Dump assertions. + json.endObject(); + } +} + +void StencilModuleMetadata::dump() const { + js::Fprinter out(stderr); + js::JSONPrinter json(out); + dump(json, nullptr); +} + +void StencilModuleMetadata::dump(js::JSONPrinter& json, + const CompilationStencil* stencil) const { + json.beginObject(); + dumpFields(json, stencil); + json.endObject(); +} + +void StencilModuleMetadata::dumpFields( + js::JSONPrinter& json, const CompilationStencil* stencil) const { + json.beginListProperty("moduleRequests"); + DumpModuleRequestVectorItems(json, moduleRequests, stencil); + json.endList(); + + json.beginListProperty("requestedModules"); + DumpModuleEntryVectorItems(json, requestedModules, stencil); + json.endList(); + + json.beginListProperty("importEntries"); + DumpModuleEntryVectorItems(json, importEntries, stencil); + json.endList(); + + json.beginListProperty("localExportEntries"); + DumpModuleEntryVectorItems(json, localExportEntries, stencil); + json.endList(); + + json.beginListProperty("indirectExportEntries"); + DumpModuleEntryVectorItems(json, indirectExportEntries, stencil); + json.endList(); + + json.beginListProperty("starExportEntries"); + DumpModuleEntryVectorItems(json, starExportEntries, stencil); + json.endList(); + + json.beginListProperty("functionDecls"); + for (const auto& index : functionDecls) { + json.value("ScriptIndex(%zu)", size_t(index)); + } + json.endList(); + + json.boolProperty("isAsync", isAsync); +} + +void js::DumpImmutableScriptFlags(js::JSONPrinter& json, + ImmutableScriptFlags immutableFlags) { + for (uint32_t i = 1; i; i = i << 1) { + if (uint32_t(immutableFlags) & i) { + switch (ImmutableScriptFlagsEnum(i)) { + case ImmutableScriptFlagsEnum::IsForEval: + json.value("IsForEval"); + break; + case ImmutableScriptFlagsEnum::IsModule: + json.value("IsModule"); + break; + case ImmutableScriptFlagsEnum::IsFunction: + json.value("IsFunction"); + break; + case ImmutableScriptFlagsEnum::SelfHosted: + json.value("SelfHosted"); + break; + case ImmutableScriptFlagsEnum::ForceStrict: + json.value("ForceStrict"); + break; + case ImmutableScriptFlagsEnum::HasNonSyntacticScope: + json.value("HasNonSyntacticScope"); + break; + case ImmutableScriptFlagsEnum::NoScriptRval: + json.value("NoScriptRval"); + break; + case ImmutableScriptFlagsEnum::TreatAsRunOnce: + json.value("TreatAsRunOnce"); + break; + case ImmutableScriptFlagsEnum::Strict: + json.value("Strict"); + break; + case ImmutableScriptFlagsEnum::HasModuleGoal: + json.value("HasModuleGoal"); + break; + case ImmutableScriptFlagsEnum::HasInnerFunctions: + json.value("HasInnerFunctions"); + break; + case ImmutableScriptFlagsEnum::HasDirectEval: + json.value("HasDirectEval"); + break; + case ImmutableScriptFlagsEnum::BindingsAccessedDynamically: + json.value("BindingsAccessedDynamically"); + break; + case ImmutableScriptFlagsEnum::HasCallSiteObj: + json.value("HasCallSiteObj"); + break; + case ImmutableScriptFlagsEnum::IsAsync: + json.value("IsAsync"); + break; + case ImmutableScriptFlagsEnum::IsGenerator: + json.value("IsGenerator"); + break; + case ImmutableScriptFlagsEnum::FunHasExtensibleScope: + json.value("FunHasExtensibleScope"); + break; + case ImmutableScriptFlagsEnum::FunctionHasThisBinding: + json.value("FunctionHasThisBinding"); + break; + case ImmutableScriptFlagsEnum::NeedsHomeObject: + json.value("NeedsHomeObject"); + break; + case ImmutableScriptFlagsEnum::IsDerivedClassConstructor: + json.value("IsDerivedClassConstructor"); + break; + case ImmutableScriptFlagsEnum::IsSyntheticFunction: + json.value("IsSyntheticFunction"); + break; + case ImmutableScriptFlagsEnum::UseMemberInitializers: + json.value("UseMemberInitializers"); + break; + case ImmutableScriptFlagsEnum::HasRest: + json.value("HasRest"); + break; + case ImmutableScriptFlagsEnum::NeedsFunctionEnvironmentObjects: + json.value("NeedsFunctionEnvironmentObjects"); + break; + case ImmutableScriptFlagsEnum::FunctionHasExtraBodyVarScope: + json.value("FunctionHasExtraBodyVarScope"); + break; + case ImmutableScriptFlagsEnum::ShouldDeclareArguments: + json.value("ShouldDeclareArguments"); + break; + case ImmutableScriptFlagsEnum::NeedsArgsObj: + json.value("NeedsArgsObj"); + break; + case ImmutableScriptFlagsEnum::HasMappedArgsObj: + json.value("HasMappedArgsObj"); + break; + case ImmutableScriptFlagsEnum::IsInlinableLargeFunction: + json.value("IsInlinableLargeFunction"); + break; + case ImmutableScriptFlagsEnum::FunctionHasNewTargetBinding: + json.value("FunctionHasNewTargetBinding"); + break; + case ImmutableScriptFlagsEnum::UsesArgumentsIntrinsics: + json.value("UsesArgumentsIntrinsics"); + break; + default: + json.value("Unknown(%x)", i); + break; + } + } + } +} + +void js::DumpFunctionFlagsItems(js::JSONPrinter& json, + FunctionFlags functionFlags) { + switch (functionFlags.kind()) { + case FunctionFlags::FunctionKind::NormalFunction: + json.value("NORMAL_KIND"); + break; + case FunctionFlags::FunctionKind::AsmJS: + json.value("ASMJS_KIND"); + break; + case FunctionFlags::FunctionKind::Wasm: + json.value("WASM_KIND"); + break; + case FunctionFlags::FunctionKind::Arrow: + json.value("ARROW_KIND"); + break; + case FunctionFlags::FunctionKind::Method: + json.value("METHOD_KIND"); + break; + case FunctionFlags::FunctionKind::ClassConstructor: + json.value("CLASSCONSTRUCTOR_KIND"); + break; + case FunctionFlags::FunctionKind::Getter: + json.value("GETTER_KIND"); + break; + case FunctionFlags::FunctionKind::Setter: + json.value("SETTER_KIND"); + break; + default: + json.value("Unknown(%x)", uint8_t(functionFlags.kind())); + break; + } + + static_assert(FunctionFlags::FUNCTION_KIND_MASK == 0x0007, + "FunctionKind should use the lowest 3 bits"); + for (uint16_t i = 1 << 3; i; i = i << 1) { + if (functionFlags.toRaw() & i) { + switch (FunctionFlags::Flags(i)) { + case FunctionFlags::Flags::EXTENDED: + json.value("EXTENDED"); + break; + case FunctionFlags::Flags::SELF_HOSTED: + json.value("SELF_HOSTED"); + break; + case FunctionFlags::Flags::BASESCRIPT: + json.value("BASESCRIPT"); + break; + case FunctionFlags::Flags::SELFHOSTLAZY: + json.value("SELFHOSTLAZY"); + break; + case FunctionFlags::Flags::CONSTRUCTOR: + json.value("CONSTRUCTOR"); + break; + case FunctionFlags::Flags::LAZY_ACCESSOR_NAME: + json.value("LAZY_ACCESSOR_NAME"); + break; + case FunctionFlags::Flags::LAMBDA: + json.value("LAMBDA"); + break; + case FunctionFlags::Flags::WASM_JIT_ENTRY: + json.value("WASM_JIT_ENTRY"); + break; + case FunctionFlags::Flags::HAS_INFERRED_NAME: + json.value("HAS_INFERRED_NAME"); + break; + case FunctionFlags::Flags::HAS_GUESSED_ATOM: + json.value("HAS_GUESSED_ATOM"); + break; + case FunctionFlags::Flags::RESOLVED_NAME: + json.value("RESOLVED_NAME"); + break; + case FunctionFlags::Flags::RESOLVED_LENGTH: + json.value("RESOLVED_LENGTH"); + break; + case FunctionFlags::Flags::GHOST_FUNCTION: + json.value("GHOST_FUNCTION"); + break; + default: + json.value("Unknown(%x)", i); + break; + } + } + } +} + +static void DumpScriptThing(js::JSONPrinter& json, + const CompilationStencil* stencil, + TaggedScriptThingIndex thing) { + switch (thing.tag()) { + case TaggedScriptThingIndex::Kind::ParserAtomIndex: + case TaggedScriptThingIndex::Kind::WellKnown: + json.beginObject(); + json.property("type", "Atom"); + DumpTaggedParserAtomIndex(json, thing.toAtom(), stencil); + json.endObject(); + break; + case TaggedScriptThingIndex::Kind::Null: + json.nullValue(); + break; + case TaggedScriptThingIndex::Kind::BigInt: + json.value("BigIntIndex(%zu)", size_t(thing.toBigInt())); + break; + case TaggedScriptThingIndex::Kind::ObjLiteral: + json.value("ObjLiteralIndex(%zu)", size_t(thing.toObjLiteral())); + break; + case TaggedScriptThingIndex::Kind::RegExp: + json.value("RegExpIndex(%zu)", size_t(thing.toRegExp())); + break; + case TaggedScriptThingIndex::Kind::Scope: + json.value("ScopeIndex(%zu)", size_t(thing.toScope())); + break; + case TaggedScriptThingIndex::Kind::Function: + json.value("ScriptIndex(%zu)", size_t(thing.toFunction())); + break; + case TaggedScriptThingIndex::Kind::EmptyGlobalScope: + json.value("EmptyGlobalScope"); + break; + } +} + +void ScriptStencil::dump() const { + js::Fprinter out(stderr); + js::JSONPrinter json(out); + dump(json, nullptr); +} + +void ScriptStencil::dump(js::JSONPrinter& json, + const CompilationStencil* stencil) const { + json.beginObject(); + dumpFields(json, stencil); + json.endObject(); +} + +void ScriptStencil::dumpFields(js::JSONPrinter& json, + const CompilationStencil* stencil) const { + json.formatProperty("gcThingsOffset", "CompilationGCThingIndex(%u)", + gcThingsOffset.index); + json.property("gcThingsLength", gcThingsLength); + + if (stencil) { + json.beginListProperty("gcThings"); + for (const auto& thing : gcthings(*stencil)) { + DumpScriptThing(json, stencil, thing); + } + json.endList(); + } + + json.beginListProperty("flags"); + if (flags_ & WasEmittedByEnclosingScriptFlag) { + json.value("WasEmittedByEnclosingScriptFlag"); + } + if (flags_ & AllowRelazifyFlag) { + json.value("AllowRelazifyFlag"); + } + if (flags_ & HasSharedDataFlag) { + json.value("HasSharedDataFlag"); + } + if (flags_ & HasLazyFunctionEnclosingScopeIndexFlag) { + json.value("HasLazyFunctionEnclosingScopeIndexFlag"); + } + json.endList(); + + if (isFunction()) { + json.beginObjectProperty("functionAtom"); + DumpTaggedParserAtomIndex(json, functionAtom, stencil); + json.endObject(); + + json.beginListProperty("functionFlags"); + DumpFunctionFlagsItems(json, functionFlags); + json.endList(); + + if (hasLazyFunctionEnclosingScopeIndex()) { + json.formatProperty("lazyFunctionEnclosingScopeIndex", "ScopeIndex(%zu)", + size_t(lazyFunctionEnclosingScopeIndex())); + } + + if (hasSelfHostedCanonicalName()) { + json.beginObjectProperty("selfHostCanonicalName"); + DumpTaggedParserAtomIndex(json, selfHostedCanonicalName(), stencil); + json.endObject(); + } + } +} + +void ScriptStencilExtra::dump() const { + js::Fprinter out(stderr); + js::JSONPrinter json(out); + dump(json); +} + +void ScriptStencilExtra::dump(js::JSONPrinter& json) const { + json.beginObject(); + dumpFields(json); + json.endObject(); +} + +void ScriptStencilExtra::dumpFields(js::JSONPrinter& json) const { + json.beginListProperty("immutableFlags"); + DumpImmutableScriptFlags(json, immutableFlags); + json.endList(); + + json.beginObjectProperty("extent"); + json.property("sourceStart", extent.sourceStart); + json.property("sourceEnd", extent.sourceEnd); + json.property("toStringStart", extent.toStringStart); + json.property("toStringEnd", extent.toStringEnd); + json.property("lineno", extent.lineno); + json.property("column", extent.column.oneOriginValue()); + json.endObject(); + + json.property("memberInitializers", memberInitializers_); + + json.property("nargs", nargs); +} + +void SharedDataContainer::dump() const { + js::Fprinter out(stderr); + js::JSONPrinter json(out); + dump(json); +} + +void SharedDataContainer::dump(js::JSONPrinter& json) const { + json.beginObject(); + dumpFields(json); + json.endObject(); +} + +void SharedDataContainer::dumpFields(js::JSONPrinter& json) const { + if (isEmpty()) { + json.nullProperty("ScriptIndex(0)"); + return; + } + + if (isSingle()) { + json.formatProperty("ScriptIndex(0)", "u8[%zu]", + asSingle()->immutableDataLength()); + return; + } + + if (isVector()) { + auto& vec = *asVector(); + + char index[64]; + for (size_t i = 0; i < vec.length(); i++) { + SprintfLiteral(index, "ScriptIndex(%zu)", i); + if (vec[i]) { + json.formatProperty(index, "u8[%zu]", vec[i]->immutableDataLength()); + } else { + json.nullProperty(index); + } + } + return; + } + + if (isMap()) { + auto& map = *asMap(); + + char index[64]; + for (auto iter = map.iter(); !iter.done(); iter.next()) { + SprintfLiteral(index, "ScriptIndex(%u)", iter.get().key().index); + json.formatProperty(index, "u8[%zu]", + iter.get().value()->immutableDataLength()); + } + return; + } + + MOZ_ASSERT(isBorrow()); + asBorrow()->dumpFields(json); +} + +struct DumpOptionsFields { + js::JSONPrinter& json; + + void operator()(const char* name, JS::AsmJSOption value) { + const char* valueStr = nullptr; + switch (value) { + case JS::AsmJSOption::Enabled: + valueStr = "JS::AsmJSOption::Enabled"; + break; + case JS::AsmJSOption::DisabledByAsmJSPref: + valueStr = "JS::AsmJSOption::DisabledByAsmJSPref"; + break; + case JS::AsmJSOption::DisabledByLinker: + valueStr = "JS::AsmJSOption::DisabledByLinker"; + break; + case JS::AsmJSOption::DisabledByNoWasmCompiler: + valueStr = "JS::AsmJSOption::DisabledByNoWasmCompiler"; + break; + case JS::AsmJSOption::DisabledByDebugger: + valueStr = "JS::AsmJSOption::DisabledByDebugger"; + break; + } + json.property(name, valueStr); + } + + void operator()(const char* name, JS::DelazificationOption value) { + const char* valueStr = nullptr; + switch (value) { +# define SelectValueStr_(Strategy) \ + case JS::DelazificationOption::Strategy: \ + valueStr = "JS::DelazificationOption::" #Strategy; \ + break; + + FOREACH_DELAZIFICATION_STRATEGY(SelectValueStr_) +# undef SelectValueStr_ + } + json.property(name, valueStr); + } + + void operator()(const char* name, char16_t* value) {} + + void operator()(const char* name, bool value) { json.property(name, value); } + + void operator()(const char* name, uint32_t value) { + json.property(name, value); + } + + void operator()(const char* name, uint64_t value) { + json.property(name, value); + } + + void operator()(const char* name, const char* value) { + if (value) { + json.property(name, value); + return; + } + json.nullProperty(name); + } + + void operator()(const char* name, JS::ConstUTF8CharsZ value) { + if (value) { + json.property(name, value.c_str()); + return; + } + json.nullProperty(name); + } +}; + +static void DumpOptionsFields(js::JSONPrinter& json, + const JS::ReadOnlyCompileOptions& options) { + struct DumpOptionsFields printer { + json + }; + options.dumpWith(printer); +} + +static void DumpInputScopeFields(js::JSONPrinter& json, + const InputScope& scope) { + json.property("kind", ScopeKindString(scope.kind())); + + InputScope enclosing = scope.enclosing(); + if (enclosing.isNull()) { + json.nullProperty("enclosing"); + } else { + json.beginObjectProperty("enclosing"); + DumpInputScopeFields(json, enclosing); + json.endObject(); + } +} + +static void DumpInputScriptFields(js::JSONPrinter& json, + const InputScript& script) { + json.beginObjectProperty("extent"); + { + SourceExtent extent = script.extent(); + json.property("sourceStart", extent.sourceStart); + json.property("sourceEnd", extent.sourceEnd); + json.property("toStringStart", extent.toStringStart); + json.property("toStringEnd", extent.toStringEnd); + json.property("lineno", extent.lineno); + json.property("column", extent.column.oneOriginValue()); + } + json.endObject(); + + json.beginListProperty("immutableFlags"); + DumpImmutableScriptFlags(json, script.immutableFlags()); + json.endList(); + + json.beginListProperty("functionFlags"); + DumpFunctionFlagsItems(json, script.functionFlags()); + json.endList(); + + json.property("hasPrivateScriptData", script.hasPrivateScriptData()); + + InputScope scope = script.enclosingScope(); + if (scope.isNull()) { + json.nullProperty("enclosingScope"); + } else { + json.beginObjectProperty("enclosingScope"); + DumpInputScopeFields(json, scope); + json.endObject(); + } + + if (script.useMemberInitializers()) { + json.property("memberInitializers", + script.getMemberInitializers().serialize()); + } +} + +void CompilationInput::dump() const { + js::Fprinter out(stderr); + js::JSONPrinter json(out); + dump(json); + out.put("\n"); +} + +void CompilationInput::dump(js::JSONPrinter& json) const { + json.beginObject(); + dumpFields(json); + json.endObject(); +} + +void CompilationInput::dumpFields(js::JSONPrinter& json) const { + const char* targetStr = nullptr; + switch (target) { + case CompilationTarget::Global: + targetStr = "CompilationTarget::Global"; + break; + case CompilationTarget::SelfHosting: + targetStr = "CompilationTarget::SelfHosting"; + break; + case CompilationTarget::StandaloneFunction: + targetStr = "CompilationTarget::StandaloneFunction"; + break; + case CompilationTarget::StandaloneFunctionInNonSyntacticScope: + targetStr = "CompilationTarget::StandaloneFunctionInNonSyntacticScope"; + break; + case CompilationTarget::Eval: + targetStr = "CompilationTarget::Eval"; + break; + case CompilationTarget::Module: + targetStr = "CompilationTarget::Module"; + break; + case CompilationTarget::Delazification: + targetStr = "CompilationTarget::Delazification"; + break; + } + json.property("target", targetStr); + + json.beginObjectProperty("options"); + DumpOptionsFields(json, options); + json.endObject(); + + if (lazy_.isNull()) { + json.nullProperty("lazy_"); + } else { + json.beginObjectProperty("lazy_"); + DumpInputScriptFields(json, lazy_); + json.endObject(); + } + + if (enclosingScope.isNull()) { + json.nullProperty("enclosingScope"); + } else { + json.beginObjectProperty("enclosingScope"); + DumpInputScopeFields(json, enclosingScope); + json.endObject(); + } + + // TODO: Support printing the atomCache and the source fields. +} + +void CompilationStencil::dump() const { + js::Fprinter out(stderr); + js::JSONPrinter json(out); + dump(json); + out.put("\n"); +} + +void CompilationStencil::dump(js::JSONPrinter& json) const { + json.beginObject(); + dumpFields(json); + json.endObject(); +} + +void CompilationStencil::dumpFields(js::JSONPrinter& json) const { + char index[64]; + + json.beginObjectProperty("scriptData"); + for (size_t i = 0; i < scriptData.size(); i++) { + SprintfLiteral(index, "ScriptIndex(%zu)", i); + json.beginObjectProperty(index); + scriptData[i].dumpFields(json, this); + json.endObject(); + } + json.endObject(); + + json.beginObjectProperty("scriptExtra"); + for (size_t i = 0; i < scriptExtra.size(); i++) { + SprintfLiteral(index, "ScriptIndex(%zu)", i); + json.beginObjectProperty(index); + scriptExtra[i].dumpFields(json); + json.endObject(); + } + json.endObject(); + + json.beginObjectProperty("scopeData"); + MOZ_ASSERT(scopeData.size() == scopeNames.size()); + for (size_t i = 0; i < scopeData.size(); i++) { + SprintfLiteral(index, "ScopeIndex(%zu)", i); + json.beginObjectProperty(index); + scopeData[i].dumpFields(json, scopeNames[i], this); + json.endObject(); + } + json.endObject(); + + json.beginObjectProperty("sharedData"); + sharedData.dumpFields(json); + json.endObject(); + + json.beginObjectProperty("regExpData"); + for (size_t i = 0; i < regExpData.size(); i++) { + SprintfLiteral(index, "RegExpIndex(%zu)", i); + json.beginObjectProperty(index); + regExpData[i].dumpFields(json, this); + json.endObject(); + } + json.endObject(); + + json.beginObjectProperty("bigIntData"); + for (size_t i = 0; i < bigIntData.size(); i++) { + SprintfLiteral(index, "BigIntIndex(%zu)", i); + GenericPrinter& out = json.beginStringProperty(index); + bigIntData[i].dumpCharsNoQuote(out); + json.endStringProperty(); + } + json.endObject(); + + json.beginObjectProperty("objLiteralData"); + for (size_t i = 0; i < objLiteralData.size(); i++) { + SprintfLiteral(index, "ObjLiteralIndex(%zu)", i); + json.beginObjectProperty(index); + objLiteralData[i].dumpFields(json, this); + json.endObject(); + } + json.endObject(); + + if (moduleMetadata) { + json.beginObjectProperty("moduleMetadata"); + moduleMetadata->dumpFields(json, this); + json.endObject(); + } + + json.beginObjectProperty("asmJS"); + if (asmJS) { + for (auto iter = asmJS->moduleMap.iter(); !iter.done(); iter.next()) { + SprintfLiteral(index, "ScriptIndex(%u)", iter.get().key().index); + json.formatProperty(index, "asm.js"); + } + } + json.endObject(); +} + +void CompilationStencil::dumpAtom(TaggedParserAtomIndex index) const { + js::Fprinter out(stderr); + js::JSONPrinter json(out); + json.beginObject(); + DumpTaggedParserAtomIndex(json, index, this); + json.endObject(); +} + +void ExtensibleCompilationStencil::dump() { + frontend::BorrowingCompilationStencil borrowingStencil(*this); + borrowingStencil.dump(); +} + +void ExtensibleCompilationStencil::dump(js::JSONPrinter& json) { + frontend::BorrowingCompilationStencil borrowingStencil(*this); + borrowingStencil.dump(json); +} + +void ExtensibleCompilationStencil::dumpFields(js::JSONPrinter& json) { + frontend::BorrowingCompilationStencil borrowingStencil(*this); + borrowingStencil.dumpFields(json); +} + +void ExtensibleCompilationStencil::dumpAtom(TaggedParserAtomIndex index) { + frontend::BorrowingCompilationStencil borrowingStencil(*this); + borrowingStencil.dumpAtom(index); +} + +#endif // defined(DEBUG) || defined(JS_JITSPEW) + +JSString* CompilationAtomCache::getExistingStringAt( + ParserAtomIndex index) const { + MOZ_RELEASE_ASSERT(atoms_.length() >= index); + return atoms_[index]; +} + +JSString* CompilationAtomCache::getExistingStringAt( + JSContext* cx, TaggedParserAtomIndex taggedIndex) const { + if (taggedIndex.isParserAtomIndex()) { + auto index = taggedIndex.toParserAtomIndex(); + return getExistingStringAt(index); + } + + if (taggedIndex.isWellKnownAtomId()) { + auto index = taggedIndex.toWellKnownAtomId(); + return GetWellKnownAtom(cx, index); + } + + if (taggedIndex.isLength1StaticParserString()) { + auto index = taggedIndex.toLength1StaticParserString(); + return cx->staticStrings().getUnit(char16_t(index)); + } + + if (taggedIndex.isLength2StaticParserString()) { + auto index = taggedIndex.toLength2StaticParserString(); + return cx->staticStrings().getLength2FromIndex(size_t(index)); + } + + MOZ_ASSERT(taggedIndex.isLength3StaticParserString()); + auto index = taggedIndex.toLength3StaticParserString(); + return cx->staticStrings().getUint(uint32_t(index)); +} + +JSString* CompilationAtomCache::getStringAt(ParserAtomIndex index) const { + if (size_t(index) >= atoms_.length()) { + return nullptr; + } + return atoms_[index]; +} + +JSAtom* CompilationAtomCache::getExistingAtomAt(ParserAtomIndex index) const { + return &getExistingStringAt(index)->asAtom(); +} + +JSAtom* CompilationAtomCache::getExistingAtomAt( + JSContext* cx, TaggedParserAtomIndex taggedIndex) const { + return &getExistingStringAt(cx, taggedIndex)->asAtom(); +} + +JSAtom* CompilationAtomCache::getAtomAt(ParserAtomIndex index) const { + if (size_t(index) >= atoms_.length()) { + return nullptr; + } + if (!atoms_[index]) { + return nullptr; + } + return &atoms_[index]->asAtom(); +} + +bool CompilationAtomCache::hasAtomAt(ParserAtomIndex index) const { + if (size_t(index) >= atoms_.length()) { + return false; + } + return !!atoms_[index]; +} + +bool CompilationAtomCache::setAtomAt(FrontendContext* fc, ParserAtomIndex index, + JSString* atom) { + if (size_t(index) < atoms_.length()) { + atoms_[index] = atom; + return true; + } + + if (!atoms_.resize(size_t(index) + 1)) { + ReportOutOfMemory(fc); + return false; + } + + atoms_[index] = atom; + return true; +} + +bool CompilationAtomCache::allocate(FrontendContext* fc, size_t length) { + MOZ_ASSERT(length >= atoms_.length()); + if (length == atoms_.length()) { + return true; + } + + if (!atoms_.resize(length)) { + ReportOutOfMemory(fc); + return false; + } + + return true; +} + +void CompilationAtomCache::stealBuffer(AtomCacheVector& atoms) { + atoms_ = std::move(atoms); + // Destroy elements, without unreserving. + atoms_.clear(); +} + +void CompilationAtomCache::releaseBuffer(AtomCacheVector& atoms) { + atoms = std::move(atoms_); +} + +bool CompilationState::allocateGCThingsUninitialized( + FrontendContext* fc, ScriptIndex scriptIndex, size_t length, + TaggedScriptThingIndex** cursor) { + MOZ_ASSERT(gcThingData.length() <= UINT32_MAX); + + auto gcThingsOffset = CompilationGCThingIndex(gcThingData.length()); + + if (length > INDEX_LIMIT) { + ReportAllocationOverflow(fc); + return false; + } + uint32_t gcThingsLength = length; + + if (!gcThingData.growByUninitialized(length)) { + js::ReportOutOfMemory(fc); + return false; + } + + if (gcThingData.length() > UINT32_MAX) { + ReportAllocationOverflow(fc); + return false; + } + + ScriptStencil& script = scriptData[scriptIndex]; + script.gcThingsOffset = gcThingsOffset; + script.gcThingsLength = gcThingsLength; + + *cursor = gcThingData.begin() + gcThingsOffset; + return true; +} + +bool CompilationState::appendScriptStencilAndData(FrontendContext* fc) { + if (!scriptData.emplaceBack()) { + js::ReportOutOfMemory(fc); + return false; + } + + if (isInitialStencil()) { + if (!scriptExtra.emplaceBack()) { + scriptData.popBack(); + MOZ_ASSERT(scriptData.length() == scriptExtra.length()); + + js::ReportOutOfMemory(fc); + return false; + } + } + + return true; +} + +bool CompilationState::appendGCThings( + FrontendContext* fc, ScriptIndex scriptIndex, + mozilla::Span<const TaggedScriptThingIndex> things) { + MOZ_ASSERT(gcThingData.length() <= UINT32_MAX); + + auto gcThingsOffset = CompilationGCThingIndex(gcThingData.length()); + + if (things.size() > INDEX_LIMIT) { + ReportAllocationOverflow(fc); + return false; + } + uint32_t gcThingsLength = uint32_t(things.size()); + + if (!gcThingData.append(things.data(), things.size())) { + js::ReportOutOfMemory(fc); + return false; + } + + if (gcThingData.length() > UINT32_MAX) { + ReportAllocationOverflow(fc); + return false; + } + + ScriptStencil& script = scriptData[scriptIndex]; + script.gcThingsOffset = gcThingsOffset; + script.gcThingsLength = gcThingsLength; + return true; +} + +CompilationState::CompilationStatePosition CompilationState::getPosition() { + return CompilationStatePosition{scriptData.length(), + asmJS ? asmJS->moduleMap.count() : 0}; +} + +void CompilationState::rewind( + const CompilationState::CompilationStatePosition& pos) { + if (asmJS && asmJS->moduleMap.count() != pos.asmJSCount) { + for (size_t i = pos.scriptDataLength; i < scriptData.length(); i++) { + asmJS->moduleMap.remove(ScriptIndex(i)); + } + MOZ_ASSERT(asmJS->moduleMap.count() == pos.asmJSCount); + } + // scriptExtra is empty for delazification. + if (scriptExtra.length()) { + MOZ_ASSERT(scriptExtra.length() == scriptData.length()); + scriptExtra.shrinkTo(pos.scriptDataLength); + } + scriptData.shrinkTo(pos.scriptDataLength); +} + +void CompilationState::markGhost( + const CompilationState::CompilationStatePosition& pos) { + for (size_t i = pos.scriptDataLength; i < scriptData.length(); i++) { + scriptData[i].setIsGhost(); + } +} + +bool CompilationStencilMerger::buildFunctionKeyToIndex(FrontendContext* fc) { + if (!functionKeyToInitialScriptIndex_.reserve(initial_->scriptExtra.length() - + 1)) { + ReportOutOfMemory(fc); + return false; + } + + for (size_t i = 1; i < initial_->scriptExtra.length(); i++) { + const auto& extra = initial_->scriptExtra[i]; + auto key = extra.extent.toFunctionKey(); + + // There can be multiple ScriptStencilExtra with same extent if + // the function is parsed multiple times because of rewind for + // arrow function, and in that case the last one's index should be used. + // Overwrite with the last one. + // + // Already reserved above, but OOMTest can hit failure mode in + // HashTable::add. + if (!functionKeyToInitialScriptIndex_.put(key, ScriptIndex(i))) { + ReportOutOfMemory(fc); + return false; + } + } + + return true; +} + +ScriptIndex CompilationStencilMerger::getInitialScriptIndexFor( + const CompilationStencil& delazification) const { + auto p = functionKeyToInitialScriptIndex_.lookup(delazification.functionKey); + MOZ_ASSERT(p); + return p->value(); +} + +bool CompilationStencilMerger::buildAtomIndexMap( + FrontendContext* fc, const CompilationStencil& delazification, + AtomIndexMap& atomIndexMap) { + uint32_t atomCount = delazification.parserAtomData.size(); + if (!atomIndexMap.reserve(atomCount)) { + ReportOutOfMemory(fc); + return false; + } + for (const auto& atom : delazification.parserAtomData) { + auto mappedIndex = initial_->parserAtoms.internExternalParserAtom(fc, atom); + if (!mappedIndex) { + return false; + } + atomIndexMap.infallibleAppend(mappedIndex); + } + return true; +} + +bool CompilationStencilMerger::setInitial( + FrontendContext* fc, UniquePtr<ExtensibleCompilationStencil>&& initial) { + MOZ_ASSERT(!initial_); + + initial_ = std::move(initial); + + return buildFunctionKeyToIndex(fc); +} + +template <typename GCThingIndexMapFunc, typename AtomIndexMapFunc, + typename ScopeIndexMapFunc> +static void MergeScriptStencil(ScriptStencil& dest, const ScriptStencil& src, + GCThingIndexMapFunc mapGCThingIndex, + AtomIndexMapFunc mapAtomIndex, + ScopeIndexMapFunc mapScopeIndex, + bool isTopLevel) { + // If this function was lazy, all inner functions should have been lazy. + MOZ_ASSERT(!dest.hasSharedData()); + + // If the inner lazy function is skipped, gcThingsLength is empty. + if (src.gcThingsLength) { + dest.gcThingsOffset = mapGCThingIndex(src.gcThingsOffset); + dest.gcThingsLength = src.gcThingsLength; + } + + if (src.functionAtom) { + dest.functionAtom = mapAtomIndex(src.functionAtom); + } + + if (!dest.hasLazyFunctionEnclosingScopeIndex() && + src.hasLazyFunctionEnclosingScopeIndex()) { + // Both enclosing function and this function were lazy, and + // now enclosing function is non-lazy and this function is still lazy. + dest.setLazyFunctionEnclosingScopeIndex( + mapScopeIndex(src.lazyFunctionEnclosingScopeIndex())); + } else if (dest.hasLazyFunctionEnclosingScopeIndex() && + !src.hasLazyFunctionEnclosingScopeIndex()) { + // The enclosing function was non-lazy and this function was lazy, and + // now this function is non-lazy. + dest.resetHasLazyFunctionEnclosingScopeIndexAfterStencilMerge(); + } else { + // The enclosing function is still lazy. + MOZ_ASSERT(!dest.hasLazyFunctionEnclosingScopeIndex()); + MOZ_ASSERT(!src.hasLazyFunctionEnclosingScopeIndex()); + } + +#ifdef DEBUG + uint16_t BASESCRIPT = uint16_t(FunctionFlags::Flags::BASESCRIPT); + uint16_t HAS_INFERRED_NAME = + uint16_t(FunctionFlags::Flags::HAS_INFERRED_NAME); + uint16_t HAS_GUESSED_ATOM = uint16_t(FunctionFlags::Flags::HAS_GUESSED_ATOM); + uint16_t acceptableDifferenceForLazy = HAS_INFERRED_NAME | HAS_GUESSED_ATOM; + uint16_t acceptableDifferenceForNonLazy = + BASESCRIPT | HAS_INFERRED_NAME | HAS_GUESSED_ATOM; + + MOZ_ASSERT_IF( + isTopLevel, + (dest.functionFlags.toRaw() | acceptableDifferenceForNonLazy) == + (src.functionFlags.toRaw() | acceptableDifferenceForNonLazy)); + + // NOTE: Currently we don't delazify inner functions. + MOZ_ASSERT_IF(!isTopLevel, + (dest.functionFlags.toRaw() | acceptableDifferenceForLazy) == + (src.functionFlags.toRaw() | acceptableDifferenceForLazy)); +#endif // DEBUG + dest.functionFlags = src.functionFlags; + + // Other flags. + + if (src.wasEmittedByEnclosingScript()) { + // NOTE: the top-level function of the delazification have + // src.wasEmittedByEnclosingScript() == false, and that shouldn't + // be copied. + dest.setWasEmittedByEnclosingScript(); + } + + if (src.allowRelazify()) { + dest.setAllowRelazify(); + } + + if (src.hasSharedData()) { + dest.setHasSharedData(); + } +} + +bool CompilationStencilMerger::addDelazification( + FrontendContext* fc, const CompilationStencil& delazification) { + MOZ_ASSERT(initial_); + + auto delazifiedFunctionIndex = getInitialScriptIndexFor(delazification); + auto& destFun = initial_->scriptData[delazifiedFunctionIndex]; + + if (destFun.hasSharedData()) { + // If the function was already non-lazy, it means the following happened: + // A. delazified twice within single incremental encoding + // 1. this function is lazily parsed + // 2. incremental encoding is started + // 3. this function is delazified, encoded, and merged + // 4. this function is relazified + // 5. this function is delazified, encoded, and merged + // + // B. delazified twice across decode + // 1. this function is lazily parsed + // 2. incremental encoding is started + // 3. this function is delazified, encoded, and merged + // 4. incremental encoding is finished + // 5. decoded + // 6. incremental encoding is started + // here, this function is non-lazy + // 7. this function is relazified + // 8. this function is delazified, encoded, and merged + // + // A can happen with public API. + // + // B cannot happen with public API, but can happen if incremental + // encoding at step B.6 is explicitly started by internal function. + // See Evaluate and StartIncrementalEncoding in js/src/shell/js.cpp. + return true; + } + + // If any failure happens, the initial stencil is left in the broken state. + // Immediately discard it. + auto failureCase = mozilla::MakeScopeExit([&] { initial_.reset(); }); + + mozilla::Maybe<ScopeIndex> functionEnclosingScope; + if (destFun.hasLazyFunctionEnclosingScopeIndex()) { + // lazyFunctionEnclosingScopeIndex_ can be Nothing if this is + // top-level function. + functionEnclosingScope = + mozilla::Some(destFun.lazyFunctionEnclosingScopeIndex()); + } + + // A map from ParserAtomIndex in delazification to TaggedParserAtomIndex + // in initial_. + AtomIndexMap atomIndexMap; + if (!buildAtomIndexMap(fc, delazification, atomIndexMap)) { + return false; + } + auto mapAtomIndex = [&](TaggedParserAtomIndex index) { + if (index.isParserAtomIndex()) { + return atomIndexMap[index.toParserAtomIndex()]; + } + + return index; + }; + + size_t gcThingOffset = initial_->gcThingData.length(); + size_t regExpOffset = initial_->regExpData.length(); + size_t bigIntOffset = initial_->bigIntData.length(); + size_t objLiteralOffset = initial_->objLiteralData.length(); + size_t scopeOffset = initial_->scopeData.length(); + + // Map delazification's ScriptIndex to initial's ScriptIndex. + // + // The lazy function's gcthings list stores inner function's ScriptIndex. + // The n-th gcthing holds the ScriptIndex of the (n+1)-th script in + // delazification. + // + // NOTE: Currently we don't delazify inner functions. + auto lazyFunctionGCThingsOffset = destFun.gcThingsOffset; + auto mapScriptIndex = [&](ScriptIndex index) { + if (index == CompilationStencil::TopLevelIndex) { + return delazifiedFunctionIndex; + } + + return initial_->gcThingData[lazyFunctionGCThingsOffset + index.index - 1] + .toFunction(); + }; + + // Map other delazification's indices into initial's indices. + auto mapGCThingIndex = [&](CompilationGCThingIndex offset) { + return CompilationGCThingIndex(gcThingOffset + offset.index); + }; + auto mapRegExpIndex = [&](RegExpIndex index) { + return RegExpIndex(regExpOffset + index.index); + }; + auto mapBigIntIndex = [&](BigIntIndex index) { + return BigIntIndex(bigIntOffset + index.index); + }; + auto mapObjLiteralIndex = [&](ObjLiteralIndex index) { + return ObjLiteralIndex(objLiteralOffset + index.index); + }; + auto mapScopeIndex = [&](ScopeIndex index) { + return ScopeIndex(scopeOffset + index.index); + }; + + // Append gcThingData, with mapping TaggedScriptThingIndex. + if (!initial_->gcThingData.append(delazification.gcThingData.data(), + delazification.gcThingData.size())) { + js::ReportOutOfMemory(fc); + return false; + } + for (size_t i = gcThingOffset; i < initial_->gcThingData.length(); i++) { + auto& index = initial_->gcThingData[i]; + if (index.isNull()) { + // Nothing to do. + } else if (index.isAtom()) { + index = TaggedScriptThingIndex(mapAtomIndex(index.toAtom())); + } else if (index.isBigInt()) { + index = TaggedScriptThingIndex(mapBigIntIndex(index.toBigInt())); + } else if (index.isObjLiteral()) { + index = TaggedScriptThingIndex(mapObjLiteralIndex(index.toObjLiteral())); + } else if (index.isRegExp()) { + index = TaggedScriptThingIndex(mapRegExpIndex(index.toRegExp())); + } else if (index.isScope()) { + index = TaggedScriptThingIndex(mapScopeIndex(index.toScope())); + } else if (index.isFunction()) { + index = TaggedScriptThingIndex(mapScriptIndex(index.toFunction())); + } else { + MOZ_ASSERT(index.isEmptyGlobalScope()); + // Nothing to do + } + } + + // Append regExpData, with mapping RegExpStencil.atom_. + if (!initial_->regExpData.append(delazification.regExpData.data(), + delazification.regExpData.size())) { + js::ReportOutOfMemory(fc); + return false; + } + for (size_t i = regExpOffset; i < initial_->regExpData.length(); i++) { + auto& data = initial_->regExpData[i]; + data.atom_ = mapAtomIndex(data.atom_); + } + + // Append bigIntData, with copying BigIntStencil.source_. + if (!initial_->bigIntData.reserve(bigIntOffset + + delazification.bigIntData.size())) { + js::ReportOutOfMemory(fc); + return false; + } + for (const auto& data : delazification.bigIntData) { + initial_->bigIntData.infallibleEmplaceBack(); + if (!initial_->bigIntData.back().init(fc, initial_->alloc, data.source())) { + return false; + } + } + + // Append objLiteralData, with copying ObjLiteralStencil.code_, and mapping + // TaggedParserAtomIndex in it. + if (!initial_->objLiteralData.reserve(objLiteralOffset + + delazification.objLiteralData.size())) { + js::ReportOutOfMemory(fc); + return false; + } + for (const auto& data : delazification.objLiteralData) { + size_t length = data.code().size(); + auto* code = initial_->alloc.newArrayUninitialized<uint8_t>(length); + if (!code) { + js::ReportOutOfMemory(fc); + return false; + } + memcpy(code, data.code().data(), length); + + ObjLiteralModifier modifier(mozilla::Span(code, length)); + modifier.mapAtom(mapAtomIndex); + + initial_->objLiteralData.infallibleEmplaceBack( + code, length, data.kind(), data.flags(), data.propertyCount()); + } + + // Append scopeData, with mapping indices in ScopeStencil fields. + // And append scopeNames, with copying the entire data, and mapping + // trailingNames. + if (!initial_->scopeData.reserve(scopeOffset + + delazification.scopeData.size())) { + js::ReportOutOfMemory(fc); + return false; + } + if (!initial_->scopeNames.reserve(scopeOffset + + delazification.scopeNames.size())) { + js::ReportOutOfMemory(fc); + return false; + } + for (size_t i = 0; i < delazification.scopeData.size(); i++) { + const auto& srcData = delazification.scopeData[i]; + const auto* srcNames = delazification.scopeNames[i]; + + mozilla::Maybe<ScriptIndex> functionIndex = mozilla::Nothing(); + if (srcData.isFunction()) { + // Inner functions should be in the same order as initial, beginning from + // the delazification's index. + functionIndex = mozilla::Some(mapScriptIndex(srcData.functionIndex())); + } + + BaseParserScopeData* destNames = nullptr; + if (srcNames) { + destNames = CopyScopeData(fc, initial_->alloc, srcData.kind(), srcNames); + if (!destNames) { + return false; + } + auto trailingNames = + GetParserScopeDataTrailingNames(srcData.kind(), destNames); + for (auto& name : trailingNames) { + if (name.name()) { + name.updateNameAfterStencilMerge(mapAtomIndex(name.name())); + } + } + } + + initial_->scopeData.infallibleEmplaceBack( + srcData.kind(), + srcData.hasEnclosing() + ? mozilla::Some(mapScopeIndex(srcData.enclosing())) + : functionEnclosingScope, + srcData.firstFrameSlot(), + srcData.hasEnvironmentShape() + ? mozilla::Some(srcData.numEnvironmentSlots()) + : mozilla::Nothing(), + functionIndex, srcData.isArrow()); + + initial_->scopeNames.infallibleEmplaceBack(destNames); + } + + // Add delazified function's shared data. + // + // NOTE: Currently we don't delazify inner functions. + if (!initial_->sharedData.addExtraWithoutShare( + fc, delazifiedFunctionIndex, + delazification.sharedData.get(CompilationStencil::TopLevelIndex))) { + return false; + } + + // Update scriptData, with mapping indices in ScriptStencil fields. + for (uint32_t i = 0; i < delazification.scriptData.size(); i++) { + auto destIndex = mapScriptIndex(ScriptIndex(i)); + MergeScriptStencil(initial_->scriptData[destIndex], + delazification.scriptData[i], mapGCThingIndex, + mapAtomIndex, mapScopeIndex, + i == CompilationStencil::TopLevelIndex); + } + + // WARNING: moduleMetadata and asmJS fields are known at script/module + // top-level parsing, any mutation made in this function should be reflected + // to ExtensibleCompilationStencil::steal and CompilationStencil::clone. + + // Function shouldn't be a module. + MOZ_ASSERT(!delazification.moduleMetadata); + + // asm.js shouldn't appear inside delazification, given asm.js forces + // full-parse. + MOZ_ASSERT(!delazification.asmJS); + + failureCase.release(); + return true; +} + +void JS::StencilAddRef(JS::Stencil* stencil) { stencil->refCount++; } +void JS::StencilRelease(JS::Stencil* stencil) { + MOZ_RELEASE_ASSERT(stencil->refCount > 0); + if (--stencil->refCount == 0) { + js_delete(stencil); + } +} + +template <typename CharT> +static already_AddRefed<JS::Stencil> CompileGlobalScriptToStencilImpl( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + JS::SourceText<CharT>& srcBuf) { + ScopeKind scopeKind = + options.nonSyntacticScope ? ScopeKind::NonSyntactic : ScopeKind::Global; + + AutoReportFrontendContext fc(cx); + NoScopeBindingCache scopeCache; + Rooted<CompilationInput> input(cx, CompilationInput(options)); + RefPtr<JS::Stencil> stencil = js::frontend::CompileGlobalScriptToStencil( + cx, &fc, cx->tempLifoAlloc(), input.get(), &scopeCache, srcBuf, + scopeKind); + if (!stencil) { + return nullptr; + } + + // Convert the UniquePtr to a RefPtr and increment the count (to 1). + return stencil.forget(); +} + +already_AddRefed<JS::Stencil> JS::CompileGlobalScriptToStencil( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + JS::SourceText<mozilla::Utf8Unit>& srcBuf) { + return CompileGlobalScriptToStencilImpl(cx, options, srcBuf); +} + +already_AddRefed<JS::Stencil> JS::CompileGlobalScriptToStencil( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + JS::SourceText<char16_t>& srcBuf) { + return CompileGlobalScriptToStencilImpl(cx, options, srcBuf); +} + +template <typename CharT> +static already_AddRefed<JS::Stencil> CompileModuleScriptToStencilImpl( + JSContext* cx, const JS::ReadOnlyCompileOptions& optionsInput, + JS::SourceText<CharT>& srcBuf) { + JS::CompileOptions options(cx, optionsInput); + options.setModule(); + + AutoReportFrontendContext fc(cx); + NoScopeBindingCache scopeCache; + Rooted<CompilationInput> input(cx, CompilationInput(options)); + RefPtr<JS::Stencil> stencil = js::frontend::ParseModuleToStencil( + cx, &fc, cx->tempLifoAlloc(), input.get(), &scopeCache, srcBuf); + if (!stencil) { + return nullptr; + } + + // Convert the UniquePtr to a RefPtr and increment the count (to 1). + return stencil.forget(); +} + +already_AddRefed<JS::Stencil> JS::CompileModuleScriptToStencil( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + JS::SourceText<mozilla::Utf8Unit>& srcBuf) { + return CompileModuleScriptToStencilImpl(cx, options, srcBuf); +} + +already_AddRefed<JS::Stencil> JS::CompileModuleScriptToStencil( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + JS::SourceText<char16_t>& srcBuf) { + return CompileModuleScriptToStencilImpl(cx, options, srcBuf); +} + +JS_PUBLIC_API JSScript* JS::InstantiateGlobalStencil( + JSContext* cx, const JS::InstantiateOptions& options, JS::Stencil* stencil, + JS::InstantiationStorage* storage) { + MOZ_ASSERT_IF(storage, storage->isValid()); + + CompileOptions compileOptions(cx); + options.copyTo(compileOptions); + Rooted<CompilationInput> input(cx, CompilationInput(compileOptions)); + Rooted<CompilationGCOutput> gcOutput(cx); + if (storage) { + gcOutput.get().steal(std::move(*storage->gcOutput_)); + } + + if (!InstantiateStencils(cx, input.get(), *stencil, gcOutput.get())) { + return nullptr; + } + return gcOutput.get().script; +} + +JS_PUBLIC_API bool JS::StencilIsBorrowed(Stencil* stencil) { + return stencil->storageType == CompilationStencil::StorageType::Borrowed; +} + +JS_PUBLIC_API JSObject* JS::InstantiateModuleStencil( + JSContext* cx, const JS::InstantiateOptions& options, JS::Stencil* stencil, + JS::InstantiationStorage* storage) { + MOZ_ASSERT_IF(storage, storage->isValid()); + + CompileOptions compileOptions(cx); + options.copyTo(compileOptions); + compileOptions.setModule(); + Rooted<CompilationInput> input(cx, CompilationInput(compileOptions)); + Rooted<CompilationGCOutput> gcOutput(cx); + if (storage) { + gcOutput.get().steal(std::move(*storage->gcOutput_)); + } + + if (!InstantiateStencils(cx, input.get(), *stencil, gcOutput.get())) { + return nullptr; + } + return gcOutput.get().module; +} + +JS::TranscodeResult JS::EncodeStencil(JSContext* cx, JS::Stencil* stencil, + TranscodeBuffer& buffer) { + AutoReportFrontendContext fc(cx); + XDRStencilEncoder encoder(&fc, buffer); + XDRResult res = encoder.codeStencil(*stencil); + if (res.isErr()) { + return res.unwrapErr(); + } + return TranscodeResult::Ok; +} + +JS::TranscodeResult JS::DecodeStencil(JSContext* cx, + const JS::ReadOnlyDecodeOptions& options, + const JS::TranscodeRange& range, + JS::Stencil** stencilOut) { + AutoReportFrontendContext fc(cx); + return JS::DecodeStencil(&fc, options, range, stencilOut); +} + +JS::TranscodeResult JS::DecodeStencil(JS::FrontendContext* fc, + const JS::ReadOnlyDecodeOptions& options, + const JS::TranscodeRange& range, + JS::Stencil** stencilOut) { + RefPtr<ScriptSource> source = fc->getAllocator()->new_<ScriptSource>(); + if (!source) { + return TranscodeResult::Throw; + } + RefPtr<JS::Stencil> stencil( + fc->getAllocator()->new_<CompilationStencil>(source)); + if (!stencil) { + return TranscodeResult::Throw; + } + XDRStencilDecoder decoder(fc, range); + XDRResult res = decoder.codeStencil(options, *stencil); + if (res.isErr()) { + return res.unwrapErr(); + } + *stencilOut = stencil.forget().take(); + return TranscodeResult::Ok; +} + +JS_PUBLIC_API size_t JS::SizeOfStencil(Stencil* stencil, + mozilla::MallocSizeOf mallocSizeOf) { + return stencil->sizeOfIncludingThis(mallocSizeOf); +} + +JS::InstantiationStorage::~InstantiationStorage() { + if (gcOutput_) { + js_delete(gcOutput_); + gcOutput_ = nullptr; + } +} |