/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- * vim: set ts=8 sts=4 et sw=4 tw=99: * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ /* * JS script operations. */ #include "jsscriptinlines.h" #include "mozilla/DebugOnly.h" #include "mozilla/MathAlgorithms.h" #include "mozilla/MemoryReporting.h" #include "mozilla/PodOperations.h" #include "mozilla/ScopeExit.h" #include "mozilla/Sprintf.h" #include "mozilla/Unused.h" #include "mozilla/Vector.h" #include <algorithm> #include <string.h> #include "jsapi.h" #include "jsatom.h" #include "jscntxt.h" #include "jsfun.h" #include "jsgc.h" #include "jsobj.h" #include "jsopcode.h" #include "jsprf.h" #include "jstypes.h" #include "jsutil.h" #include "jswrapper.h" #include "frontend/BytecodeCompiler.h" #include "frontend/BytecodeEmitter.h" #include "frontend/SharedContext.h" #include "gc/Marking.h" #include "jit/BaselineJIT.h" #include "jit/Ion.h" #include "jit/IonCode.h" #include "js/MemoryMetrics.h" #include "js/Utility.h" #include "vm/ArgumentsObject.h" #include "vm/Compression.h" #include "vm/Debugger.h" #include "vm/Opcodes.h" #include "vm/SelfHosting.h" #include "vm/Shape.h" #include "vm/SharedImmutableStringsCache.h" #include "vm/Xdr.h" #include "jsfuninlines.h" #include "jsobjinlines.h" #include "vm/EnvironmentObject-inl.h" #include "vm/NativeObject-inl.h" #include "vm/SharedImmutableStringsCache-inl.h" #include "vm/Stack-inl.h" using namespace js; using namespace js::gc; using namespace js::frontend; using mozilla::AsVariant; using mozilla::PodCopy; using mozilla::PodZero; using mozilla::RotateLeft; template<XDRMode mode> bool js::XDRScriptConst(XDRState<mode>* xdr, MutableHandleValue vp) { JSContext* cx = xdr->cx(); enum ConstTag { SCRIPT_INT, SCRIPT_DOUBLE, SCRIPT_ATOM, SCRIPT_TRUE, SCRIPT_FALSE, SCRIPT_NULL, SCRIPT_OBJECT, SCRIPT_VOID, SCRIPT_HOLE }; ConstTag tag; if (mode == XDR_ENCODE) { if (vp.isInt32()) { tag = SCRIPT_INT; } else if (vp.isDouble()) { tag = SCRIPT_DOUBLE; } else if (vp.isString()) { tag = SCRIPT_ATOM; } else if (vp.isTrue()) { tag = SCRIPT_TRUE; } else if (vp.isFalse()) { tag = SCRIPT_FALSE; } else if (vp.isNull()) { tag = SCRIPT_NULL; } else if (vp.isObject()) { tag = SCRIPT_OBJECT; } else if (vp.isMagic(JS_ELEMENTS_HOLE)) { tag = SCRIPT_HOLE; } else { MOZ_ASSERT(vp.isUndefined()); tag = SCRIPT_VOID; } } if (!xdr->codeEnum32(&tag)) return false; switch (tag) { case SCRIPT_INT: { uint32_t i; if (mode == XDR_ENCODE) i = uint32_t(vp.toInt32()); if (!xdr->codeUint32(&i)) return false; if (mode == XDR_DECODE) vp.set(Int32Value(int32_t(i))); break; } case SCRIPT_DOUBLE: { double d; if (mode == XDR_ENCODE) d = vp.toDouble(); if (!xdr->codeDouble(&d)) return false; if (mode == XDR_DECODE) vp.set(DoubleValue(d)); break; } case SCRIPT_ATOM: { RootedAtom atom(cx); if (mode == XDR_ENCODE) atom = &vp.toString()->asAtom(); if (!XDRAtom(xdr, &atom)) return false; if (mode == XDR_DECODE) vp.set(StringValue(atom)); break; } case SCRIPT_TRUE: if (mode == XDR_DECODE) vp.set(BooleanValue(true)); break; case SCRIPT_FALSE: if (mode == XDR_DECODE) vp.set(BooleanValue(false)); break; case SCRIPT_NULL: if (mode == XDR_DECODE) vp.set(NullValue()); break; case SCRIPT_OBJECT: { RootedObject obj(cx); if (mode == XDR_ENCODE) obj = &vp.toObject(); if (!XDRObjectLiteral(xdr, &obj)) return false; if (mode == XDR_DECODE) vp.setObject(*obj); break; } case SCRIPT_VOID: if (mode == XDR_DECODE) vp.set(UndefinedValue()); break; case SCRIPT_HOLE: if (mode == XDR_DECODE) vp.setMagic(JS_ELEMENTS_HOLE); break; default: // Fail in debug, but only soft-fail in release MOZ_ASSERT(false, "Bad XDR value kind"); return xdr->fail(JS::TranscodeResult_Failure_BadDecode); } return true; } template bool js::XDRScriptConst(XDRState<XDR_ENCODE>*, MutableHandleValue); template bool js::XDRScriptConst(XDRState<XDR_DECODE>*, MutableHandleValue); // Code LazyScript's closed over bindings. template<XDRMode mode> static bool XDRLazyClosedOverBindings(XDRState<mode>* xdr, MutableHandle<LazyScript*> lazy) { JSContext* cx = xdr->cx(); RootedAtom atom(cx); for (size_t i = 0; i < lazy->numClosedOverBindings(); i++) { uint8_t endOfScopeSentinel; if (mode == XDR_ENCODE) { atom = lazy->closedOverBindings()[i]; endOfScopeSentinel = !atom; } if (!xdr->codeUint8(&endOfScopeSentinel)) return false; if (endOfScopeSentinel) atom = nullptr; else if (!XDRAtom(xdr, &atom)) return false; if (mode == XDR_DECODE) lazy->closedOverBindings()[i] = atom; } return true; } // Code the missing part needed to re-create a LazyScript from a JSScript. template<XDRMode mode> static bool XDRRelazificationInfo(XDRState<mode>* xdr, HandleFunction fun, HandleScript script, HandleScope enclosingScope, MutableHandle<LazyScript*> lazy) { MOZ_ASSERT_IF(mode == XDR_ENCODE, script->isRelazifiable() && script->maybeLazyScript()); MOZ_ASSERT_IF(mode == XDR_ENCODE, !lazy->numInnerFunctions()); JSContext* cx = xdr->cx(); uint64_t packedFields; { uint32_t begin = script->sourceStart(); uint32_t end = script->sourceEnd(); uint32_t lineno = script->lineno(); uint32_t column = script->column(); if (mode == XDR_ENCODE) { packedFields = lazy->packedFields(); MOZ_ASSERT(begin == lazy->begin()); MOZ_ASSERT(end == lazy->end()); MOZ_ASSERT(lineno == lazy->lineno()); MOZ_ASSERT(column == lazy->column()); // We can assert we have no inner functions because we don't // relazify scripts with inner functions. See // JSFunction::createScriptForLazilyInterpretedFunction. MOZ_ASSERT(lazy->numInnerFunctions() == 0); } if (!xdr->codeUint64(&packedFields)) return false; if (mode == XDR_DECODE) { lazy.set(LazyScript::Create(cx, fun, script, enclosingScope, script, packedFields, begin, end, lineno, column)); // As opposed to XDRLazyScript, we need to restore the runtime bits // of the script, as we are trying to match the fact this function // has already been parsed and that it would need to be re-lazified. lazy->initRuntimeFields(packedFields); } } // Code binding names. if (!XDRLazyClosedOverBindings(xdr, lazy)) return false; // No need to do anything with inner functions, since we asserted we don't // have any. return true; } static inline uint32_t FindScopeIndex(JSScript* script, Scope& scope) { ScopeArray* scopes = script->scopes(); GCPtrScope* vector = scopes->vector; unsigned length = scopes->length; for (uint32_t i = 0; i < length; ++i) { if (vector[i] == &scope) return i; } MOZ_CRASH("Scope not found"); } enum XDRClassKind { CK_RegexpObject, CK_JSFunction, CK_JSObject }; template<XDRMode mode> bool js::XDRScript(XDRState<mode>* xdr, HandleScope scriptEnclosingScope, HandleScript enclosingScript, HandleFunction fun, MutableHandleScript scriptp) { /* NB: Keep this in sync with CopyScript. */ enum ScriptBits { NoScriptRval, Strict, ContainsDynamicNameAccess, FunHasExtensibleScope, FunHasAnyAliasedFormal, ArgumentsHasVarBinding, NeedsArgsObj, HasMappedArgsObj, FunctionHasThisBinding, FunctionHasExtraBodyVarScope, IsGeneratorExp, IsLegacyGenerator, IsStarGenerator, IsAsync, HasRest, OwnSource, ExplicitUseStrict, SelfHosted, HasSingleton, TreatAsRunOnce, HasLazyScript, HasNonSyntacticScope, HasInnerFunctions, NeedsHomeObject, IsDerivedClassConstructor, IsDefaultClassConstructor, }; uint32_t length, lineno, column, nfixed, nslots; uint32_t natoms, nsrcnotes, i; uint32_t nconsts, nobjects, nscopes, nregexps, ntrynotes, nscopenotes, nyieldoffsets; uint32_t prologueLength, version; uint32_t funLength = 0; uint32_t nTypeSets = 0; uint32_t scriptBits = 0; uint32_t bodyScopeIndex = 0; JSContext* cx = xdr->cx(); RootedScript script(cx); natoms = nsrcnotes = 0; nconsts = nobjects = nscopes = nregexps = ntrynotes = nscopenotes = nyieldoffsets = 0; if (mode == XDR_ENCODE) { script = scriptp.get(); MOZ_ASSERT_IF(enclosingScript, enclosingScript->compartment() == script->compartment()); MOZ_ASSERT(script->functionNonDelazifying() == fun); if (!fun && script->treatAsRunOnce()) { // This is a toplevel or eval script that's runOnce. We want to // make sure that we're not XDR-saving an object we emitted for // JSOP_OBJECT that then got modified. So throw if we're not // cloning in JSOP_OBJECT or if we ever didn't clone in it in the // past. JSCompartment* comp = cx->compartment(); if (!comp->creationOptions().cloneSingletons() || !comp->behaviors().getSingletonsAsTemplates()) { return xdr->fail(JS::TranscodeResult_Failure_RunOnceNotSupported); } } } if (mode == XDR_ENCODE) length = script->length(); if (!xdr->codeUint32(&length)) return false; if (mode == XDR_ENCODE) { prologueLength = script->mainOffset(); MOZ_ASSERT(script->getVersion() != JSVERSION_UNKNOWN); version = script->getVersion(); lineno = script->lineno(); column = script->column(); nfixed = script->nfixed(); nslots = script->nslots(); bodyScopeIndex = script->bodyScopeIndex(); natoms = script->natoms(); nsrcnotes = script->numNotes(); if (script->hasConsts()) nconsts = script->consts()->length; if (script->hasObjects()) nobjects = script->objects()->length; nscopes = script->scopes()->length; if (script->hasTrynotes()) ntrynotes = script->trynotes()->length; if (script->hasScopeNotes()) nscopenotes = script->scopeNotes()->length; if (script->hasYieldOffsets()) nyieldoffsets = script->yieldOffsets().length(); nTypeSets = script->nTypeSets(); funLength = script->funLength(); if (script->noScriptRval()) scriptBits |= (1 << NoScriptRval); if (script->strict()) scriptBits |= (1 << Strict); if (script->explicitUseStrict()) scriptBits |= (1 << ExplicitUseStrict); if (script->selfHosted()) scriptBits |= (1 << SelfHosted); if (script->bindingsAccessedDynamically()) scriptBits |= (1 << ContainsDynamicNameAccess); if (script->funHasExtensibleScope()) scriptBits |= (1 << FunHasExtensibleScope); if (script->funHasAnyAliasedFormal()) scriptBits |= (1 << FunHasAnyAliasedFormal); if (script->argumentsHasVarBinding()) scriptBits |= (1 << ArgumentsHasVarBinding); if (script->analyzedArgsUsage() && script->needsArgsObj()) scriptBits |= (1 << NeedsArgsObj); if (script->hasMappedArgsObj()) scriptBits |= (1 << HasMappedArgsObj); if (script->functionHasThisBinding()) scriptBits |= (1 << FunctionHasThisBinding); if (script->functionHasExtraBodyVarScope()) scriptBits |= (1 << FunctionHasExtraBodyVarScope); if (!enclosingScript || enclosingScript->scriptSource() != script->scriptSource()) scriptBits |= (1 << OwnSource); if (script->isGeneratorExp()) scriptBits |= (1 << IsGeneratorExp); if (script->isLegacyGenerator()) scriptBits |= (1 << IsLegacyGenerator); if (script->isStarGenerator()) scriptBits |= (1 << IsStarGenerator); if (script->asyncKind() == AsyncFunction) scriptBits |= (1 << IsAsync); if (script->hasRest()) scriptBits |= (1 << HasRest); if (script->hasSingletons()) scriptBits |= (1 << HasSingleton); if (script->treatAsRunOnce()) scriptBits |= (1 << TreatAsRunOnce); if (script->isRelazifiable()) scriptBits |= (1 << HasLazyScript); if (script->hasNonSyntacticScope()) scriptBits |= (1 << HasNonSyntacticScope); if (script->hasInnerFunctions()) scriptBits |= (1 << HasInnerFunctions); if (script->needsHomeObject()) scriptBits |= (1 << NeedsHomeObject); if (script->isDerivedClassConstructor()) scriptBits |= (1 << IsDerivedClassConstructor); if (script->isDefaultClassConstructor()) scriptBits |= (1 << IsDefaultClassConstructor); } if (!xdr->codeUint32(&prologueLength)) return false; if (!xdr->codeUint32(&version)) return false; // To fuse allocations, we need lengths of all embedded arrays early. if (!xdr->codeUint32(&natoms)) return false; if (!xdr->codeUint32(&nsrcnotes)) return false; if (!xdr->codeUint32(&nconsts)) return false; if (!xdr->codeUint32(&nobjects)) return false; if (!xdr->codeUint32(&nscopes)) return false; if (!xdr->codeUint32(&ntrynotes)) return false; if (!xdr->codeUint32(&nscopenotes)) return false; if (!xdr->codeUint32(&nyieldoffsets)) return false; if (!xdr->codeUint32(&nTypeSets)) return false; if (!xdr->codeUint32(&funLength)) return false; if (!xdr->codeUint32(&scriptBits)) return false; if (mode == XDR_DECODE) { JSVersion version_ = JSVersion(version); MOZ_ASSERT((version_ & VersionFlags::MASK) == unsigned(version_)); CompileOptions options(cx); options.setVersion(version_) .setNoScriptRval(!!(scriptBits & (1 << NoScriptRval))) .setSelfHostingMode(!!(scriptBits & (1 << SelfHosted))); RootedScriptSource sourceObject(cx); if (scriptBits & (1 << OwnSource)) { ScriptSource* ss = cx->new_<ScriptSource>(); if (!ss) return false; ScriptSourceHolder ssHolder(ss); /* * We use this CompileOptions only to initialize the * ScriptSourceObject. Most CompileOptions fields aren't used by * ScriptSourceObject, and those that are (element; elementAttributeName) * aren't preserved by XDR. So this can be simple. */ CompileOptions options(cx); ss->initFromOptions(cx, options); sourceObject = ScriptSourceObject::create(cx, ss); if (!sourceObject || !ScriptSourceObject::initFromOptions(cx, sourceObject, options)) return false; } else { MOZ_ASSERT(enclosingScript); // When decoding, all the scripts and the script source object // are in the same compartment, so the script's source object // should never be a cross-compartment wrapper. MOZ_ASSERT(enclosingScript->sourceObject()->is<ScriptSourceObject>()); sourceObject = &enclosingScript->sourceObject()->as<ScriptSourceObject>(); } script = JSScript::Create(cx, options, sourceObject, 0, 0); if (!script) return false; // Set the script in its function now so that inner scripts to be // decoded may iterate the static scope chain. if (fun) fun->initScript(script); } if (mode == XDR_DECODE) { if (!JSScript::partiallyInit(cx, script, nscopes, nconsts, nobjects, ntrynotes, nscopenotes, nyieldoffsets, nTypeSets)) { return false; } MOZ_ASSERT(!script->mainOffset()); script->mainOffset_ = prologueLength; script->funLength_ = funLength; scriptp.set(script); if (scriptBits & (1 << Strict)) script->strict_ = true; if (scriptBits & (1 << ExplicitUseStrict)) script->explicitUseStrict_ = true; if (scriptBits & (1 << ContainsDynamicNameAccess)) script->bindingsAccessedDynamically_ = true; if (scriptBits & (1 << FunHasExtensibleScope)) script->funHasExtensibleScope_ = true; if (scriptBits & (1 << FunHasAnyAliasedFormal)) script->funHasAnyAliasedFormal_ = true; if (scriptBits & (1 << ArgumentsHasVarBinding)) script->setArgumentsHasVarBinding(); if (scriptBits & (1 << NeedsArgsObj)) script->setNeedsArgsObj(true); if (scriptBits & (1 << HasMappedArgsObj)) script->hasMappedArgsObj_ = true; if (scriptBits & (1 << FunctionHasThisBinding)) script->functionHasThisBinding_ = true; if (scriptBits & (1 << FunctionHasExtraBodyVarScope)) script->functionHasExtraBodyVarScope_ = true; if (scriptBits & (1 << IsGeneratorExp)) script->isGeneratorExp_ = true; if (scriptBits & (1 << HasSingleton)) script->hasSingletons_ = true; if (scriptBits & (1 << TreatAsRunOnce)) script->treatAsRunOnce_ = true; if (scriptBits & (1 << HasNonSyntacticScope)) script->hasNonSyntacticScope_ = true; if (scriptBits & (1 << HasInnerFunctions)) script->hasInnerFunctions_ = true; if (scriptBits & (1 << NeedsHomeObject)) script->needsHomeObject_ = true; if (scriptBits & (1 << IsDerivedClassConstructor)) script->isDerivedClassConstructor_ = true; if (scriptBits & (1 << IsDefaultClassConstructor)) script->isDefaultClassConstructor_ = true; if (scriptBits & (1 << IsLegacyGenerator)) { MOZ_ASSERT(!(scriptBits & (1 << IsStarGenerator))); script->setGeneratorKind(LegacyGenerator); } else if (scriptBits & (1 << IsStarGenerator)) script->setGeneratorKind(StarGenerator); if (scriptBits & (1 << IsAsync)) script->setAsyncKind(AsyncFunction); if (scriptBits & (1 << HasRest)) script->setHasRest(); } JS_STATIC_ASSERT(sizeof(jsbytecode) == 1); JS_STATIC_ASSERT(sizeof(jssrcnote) == 1); if (scriptBits & (1 << OwnSource)) { if (!script->scriptSource()->performXDR<mode>(xdr)) return false; } if (!xdr->codeUint32(&script->sourceStart_)) return false; if (!xdr->codeUint32(&script->sourceEnd_)) return false; if (!xdr->codeUint32(&lineno) || !xdr->codeUint32(&column) || !xdr->codeUint32(&nfixed) || !xdr->codeUint32(&nslots)) { return false; } if (!xdr->codeUint32(&bodyScopeIndex)) return false; if (mode == XDR_DECODE) { script->lineno_ = lineno; script->column_ = column; script->nfixed_ = nfixed; script->nslots_ = nslots; script->bodyScopeIndex_ = bodyScopeIndex; } auto scriptDataGuard = mozilla::MakeScopeExit([&] { if (mode == XDR_DECODE) script->freeScriptData(); }); if (mode == XDR_DECODE) { if (!script->createScriptData(cx, length, nsrcnotes, natoms)) return false; } jsbytecode* code = script->code(); if (!xdr->codeBytes(code, length) || !xdr->codeBytes(code + length, nsrcnotes)) { return false; } for (i = 0; i != natoms; ++i) { if (mode == XDR_DECODE) { RootedAtom tmp(cx); if (!XDRAtom(xdr, &tmp)) return false; script->atoms()[i].init(tmp); } else { RootedAtom tmp(cx, script->atoms()[i]); if (!XDRAtom(xdr, &tmp)) return false; } } scriptDataGuard.release(); if (mode == XDR_DECODE) { if (!script->shareScriptData(cx)) return false; } if (nconsts) { GCPtrValue* vector = script->consts()->vector; RootedValue val(cx); for (i = 0; i != nconsts; ++i) { if (mode == XDR_ENCODE) val = vector[i]; if (!XDRScriptConst(xdr, &val)) return false; if (mode == XDR_DECODE) vector[i].init(val); } } { MOZ_ASSERT(nscopes != 0); GCPtrScope* vector = script->scopes()->vector; RootedScope scope(cx); RootedScope enclosing(cx); ScopeKind scopeKind; uint32_t enclosingScopeIndex = 0; for (i = 0; i != nscopes; ++i) { if (mode == XDR_ENCODE) { scope = vector[i]; scopeKind = scope->kind(); } else { scope = nullptr; } if (!xdr->codeEnum32(&scopeKind)) return false; if (mode == XDR_ENCODE) { if (i == 0) { enclosingScopeIndex = UINT32_MAX; } else { MOZ_ASSERT(scope->enclosing()); enclosingScopeIndex = FindScopeIndex(script, *scope->enclosing()); } } if (!xdr->codeUint32(&enclosingScopeIndex)) return false; if (mode == XDR_DECODE) { if (i == 0) { MOZ_ASSERT(enclosingScopeIndex == UINT32_MAX); enclosing = scriptEnclosingScope; } else { MOZ_ASSERT(enclosingScopeIndex < i); enclosing = vector[enclosingScopeIndex]; } } switch (scopeKind) { case ScopeKind::Function: MOZ_ASSERT(i == script->bodyScopeIndex()); if (!FunctionScope::XDR(xdr, fun, enclosing, &scope)) return false; break; case ScopeKind::FunctionBodyVar: case ScopeKind::ParameterExpressionVar: if (!VarScope::XDR(xdr, scopeKind, enclosing, &scope)) return false; break; case ScopeKind::Lexical: case ScopeKind::SimpleCatch: case ScopeKind::Catch: case ScopeKind::NamedLambda: case ScopeKind::StrictNamedLambda: if (!LexicalScope::XDR(xdr, scopeKind, enclosing, &scope)) return false; break; case ScopeKind::With: if (mode == XDR_DECODE) { scope = WithScope::create(cx, enclosing); if (!scope) return false; } break; case ScopeKind::Eval: case ScopeKind::StrictEval: if (!EvalScope::XDR(xdr, scopeKind, enclosing, &scope)) return false; break; case ScopeKind::Global: case ScopeKind::NonSyntactic: if (!GlobalScope::XDR(xdr, scopeKind, &scope)) return false; break; case ScopeKind::Module: MOZ_CRASH("NYI"); break; default: // Fail in debug, but only soft-fail in release MOZ_ASSERT(false, "Bad XDR scope kind"); return xdr->fail(JS::TranscodeResult_Failure_BadDecode); } if (mode == XDR_DECODE) vector[i].init(scope); } // Verify marker to detect data corruption after decoding scope data. A // mismatch here indicates we will almost certainly crash in release. if (!xdr->codeMarker(0xF81F7F5A)) return false; } /* * Here looping from 0-to-length to xdr objects is essential to ensure that * all references to enclosing blocks (via FindScopeIndex below) happen * after the enclosing block has been XDR'd. */ for (i = 0; i != nobjects; ++i) { GCPtrObject* objp = &script->objects()->vector[i]; XDRClassKind classk; if (mode == XDR_ENCODE) { JSObject* obj = *objp; if (obj->is<RegExpObject>()) classk = CK_RegexpObject; else if (obj->is<JSFunction>()) classk = CK_JSFunction; else if (obj->is<PlainObject>() || obj->is<ArrayObject>()) classk = CK_JSObject; else MOZ_CRASH("Cannot encode this class of object."); } if (!xdr->codeEnum32(&classk)) return false; switch (classk) { case CK_RegexpObject: { Rooted<RegExpObject*> regexp(cx); if (mode == XDR_ENCODE) regexp = &(*objp)->as<RegExpObject>(); if (!XDRScriptRegExpObject(xdr, ®exp)) return false; if (mode == XDR_DECODE) *objp = regexp; break; } case CK_JSFunction: { /* Code the nested function's enclosing scope. */ uint32_t funEnclosingScopeIndex = 0; RootedScope funEnclosingScope(cx); if (mode == XDR_ENCODE) { RootedFunction function(cx, &(*objp)->as<JSFunction>()); if (function->isInterpretedLazy()) { funEnclosingScope = function->lazyScript()->enclosingScope(); } else if (function->isInterpreted()) { funEnclosingScope = function->nonLazyScript()->enclosingScope(); } else { MOZ_ASSERT(function->isAsmJSNative()); return xdr->fail(JS::TranscodeResult_Failure_AsmJSNotSupported); } funEnclosingScopeIndex = FindScopeIndex(script, *funEnclosingScope); } if (!xdr->codeUint32(&funEnclosingScopeIndex)) return false; if (mode == XDR_DECODE) { MOZ_ASSERT(funEnclosingScopeIndex < script->scopes()->length); funEnclosingScope = script->scopes()->vector[funEnclosingScopeIndex]; } // Code nested function and script. RootedFunction tmp(cx); if (mode == XDR_ENCODE) tmp = &(*objp)->as<JSFunction>(); if (!XDRInterpretedFunction(xdr, funEnclosingScope, script, &tmp)) return false; *objp = tmp; break; } case CK_JSObject: { /* Code object literal. */ RootedObject tmp(cx, *objp); if (!XDRObjectLiteral(xdr, &tmp)) return false; *objp = tmp; break; } default: { // Fail in debug, but only soft-fail in release MOZ_ASSERT(false, "Bad XDR class kind"); return xdr->fail(JS::TranscodeResult_Failure_BadDecode); } } } // Verify marker to detect data corruption after decoding object data. A // mismatch here indicates we will almost certainly crash in release. if (!xdr->codeMarker(0x223DB179)) return false; if (ntrynotes != 0) { JSTryNote* tnfirst = script->trynotes()->vector; MOZ_ASSERT(script->trynotes()->length == ntrynotes); JSTryNote* tn = tnfirst + ntrynotes; do { --tn; if (!xdr->codeUint8(&tn->kind) || !xdr->codeUint32(&tn->stackDepth) || !xdr->codeUint32(&tn->start) || !xdr->codeUint32(&tn->length)) { return false; } } while (tn != tnfirst); } for (i = 0; i < nscopenotes; ++i) { ScopeNote* note = &script->scopeNotes()->vector[i]; if (!xdr->codeUint32(¬e->index) || !xdr->codeUint32(¬e->start) || !xdr->codeUint32(¬e->length) || !xdr->codeUint32(¬e->parent)) { return false; } } for (i = 0; i < nyieldoffsets; ++i) { uint32_t* offset = &script->yieldOffsets()[i]; if (!xdr->codeUint32(offset)) return false; } if (scriptBits & (1 << HasLazyScript)) { Rooted<LazyScript*> lazy(cx); if (mode == XDR_ENCODE) lazy = script->maybeLazyScript(); if (!XDRRelazificationInfo(xdr, fun, script, scriptEnclosingScope, &lazy)) return false; if (mode == XDR_DECODE) script->setLazyScript(lazy); } if (mode == XDR_DECODE) { scriptp.set(script); /* see BytecodeEmitter::tellDebuggerAboutCompiledScript */ if (!fun) Debugger::onNewScript(cx, script); } return true; } template bool js::XDRScript(XDRState<XDR_ENCODE>*, HandleScope, HandleScript, HandleFunction, MutableHandleScript); template bool js::XDRScript(XDRState<XDR_DECODE>*, HandleScope, HandleScript, HandleFunction, MutableHandleScript); template<XDRMode mode> bool js::XDRLazyScript(XDRState<mode>* xdr, HandleScope enclosingScope, HandleScript enclosingScript, HandleFunction fun, MutableHandle<LazyScript*> lazy) { JSContext* cx = xdr->cx(); { uint32_t begin; uint32_t end; uint32_t lineno; uint32_t column; uint64_t packedFields; if (mode == XDR_ENCODE) { // Note: it's possible the LazyScript has a non-null script_ pointer // to a JSScript. We don't encode it: we can just delazify the // lazy script. MOZ_ASSERT(fun == lazy->functionNonDelazifying()); begin = lazy->begin(); end = lazy->end(); lineno = lazy->lineno(); column = lazy->column(); packedFields = lazy->packedFields(); } if (!xdr->codeUint32(&begin) || !xdr->codeUint32(&end) || !xdr->codeUint32(&lineno) || !xdr->codeUint32(&column) || !xdr->codeUint64(&packedFields)) { return false; } if (mode == XDR_DECODE) { lazy.set(LazyScript::Create(cx, fun, nullptr, enclosingScope, enclosingScript, packedFields, begin, end, lineno, column)); if (!lazy) return false; fun->initLazyScript(lazy); } } // Code closed-over bindings. if (!XDRLazyClosedOverBindings(xdr, lazy)) return false; // Code inner functions. { RootedFunction func(cx); GCPtrFunction* innerFunctions = lazy->innerFunctions(); size_t numInnerFunctions = lazy->numInnerFunctions(); for (size_t i = 0; i < numInnerFunctions; i++) { if (mode == XDR_ENCODE) func = innerFunctions[i]; if (!XDRInterpretedFunction(xdr, nullptr, nullptr, &func)) return false; if (mode == XDR_DECODE) innerFunctions[i] = func; } } return true; } template bool js::XDRLazyScript(XDRState<XDR_ENCODE>*, HandleScope, HandleScript, HandleFunction, MutableHandle<LazyScript*>); template bool js::XDRLazyScript(XDRState<XDR_DECODE>*, HandleScope, HandleScript, HandleFunction, MutableHandle<LazyScript*>); void JSScript::setSourceObject(JSObject* object) { MOZ_ASSERT(compartment() == object->compartment()); sourceObject_ = object; } js::ScriptSourceObject& JSScript::scriptSourceUnwrap() const { return UncheckedUnwrap(sourceObject())->as<ScriptSourceObject>(); } js::ScriptSource* JSScript::scriptSource() const { return scriptSourceUnwrap().source(); } js::ScriptSource* JSScript::maybeForwardedScriptSource() const { return UncheckedUnwrap(MaybeForwarded(sourceObject()))->as<ScriptSourceObject>().source(); } bool JSScript::initScriptCounts(JSContext* cx) { MOZ_ASSERT(!hasScriptCounts()); // Record all pc which are the first instruction of a basic block. mozilla::Vector<jsbytecode*, 16, SystemAllocPolicy> jumpTargets; jsbytecode* mainPc = main(); jsbytecode* end = codeEnd(); for (jsbytecode* pc = code(); pc != end; pc = GetNextPc(pc)) { if (BytecodeIsJumpTarget(JSOp(*pc)) || pc == mainPc) { if (!jumpTargets.append(pc)) { ReportOutOfMemory(cx); return false; } } } // Initialize all PCCounts counters to 0. ScriptCounts::PCCountsVector base; if (!base.reserve(jumpTargets.length())) { ReportOutOfMemory(cx); return false; } for (size_t i = 0; i < jumpTargets.length(); i++) base.infallibleEmplaceBack(pcToOffset(jumpTargets[i])); // Create compartment's scriptCountsMap if necessary. ScriptCountsMap* map = compartment()->scriptCountsMap; if (!map) { map = cx->new_<ScriptCountsMap>(); if (!map) { ReportOutOfMemory(cx); return false; } if (!map->init()) { js_delete(map); ReportOutOfMemory(cx); return false; } compartment()->scriptCountsMap = map; } // Allocate the ScriptCounts. ScriptCounts* sc = cx->new_<ScriptCounts>(Move(base)); if (!sc) { ReportOutOfMemory(cx); return false; } auto guardScriptCounts = mozilla::MakeScopeExit([&] () { js_delete(sc); }); // Register the current ScriptCounts in the compartment's map. if (!map->putNew(this, sc)) { ReportOutOfMemory(cx); return false; } // safe to set this; we can't fail after this point. hasScriptCounts_ = true; guardScriptCounts.release(); // Enable interrupts in any interpreter frames running on this script. This // is used to let the interpreter increment the PCCounts, if present. for (ActivationIterator iter(cx->runtime()); !iter.done(); ++iter) { if (iter->isInterpreter()) iter->asInterpreter()->enableInterruptsIfRunning(this); } return true; } static inline ScriptCountsMap::Ptr GetScriptCountsMapEntry(JSScript* script) { MOZ_ASSERT(script->hasScriptCounts()); ScriptCountsMap* map = script->compartment()->scriptCountsMap; ScriptCountsMap::Ptr p = map->lookup(script); MOZ_ASSERT(p); return p; } ScriptCounts& JSScript::getScriptCounts() { ScriptCountsMap::Ptr p = GetScriptCountsMapEntry(this); return *p->value(); } js::PCCounts* ScriptCounts::maybeGetPCCounts(size_t offset) { PCCounts searched = PCCounts(offset); PCCounts* elem = std::lower_bound(pcCounts_.begin(), pcCounts_.end(), searched); if (elem == pcCounts_.end() || elem->pcOffset() != offset) return nullptr; return elem; } const js::PCCounts* ScriptCounts::maybeGetPCCounts(size_t offset) const { PCCounts searched = PCCounts(offset); const PCCounts* elem = std::lower_bound(pcCounts_.begin(), pcCounts_.end(), searched); if (elem == pcCounts_.end() || elem->pcOffset() != offset) return nullptr; return elem; } js::PCCounts* ScriptCounts::getImmediatePrecedingPCCounts(size_t offset) { PCCounts searched = PCCounts(offset); PCCounts* elem = std::lower_bound(pcCounts_.begin(), pcCounts_.end(), searched); if (elem == pcCounts_.end()) return &pcCounts_.back(); if (elem->pcOffset() == offset) return elem; if (elem != pcCounts_.begin()) return elem - 1; return nullptr; } const js::PCCounts* ScriptCounts::maybeGetThrowCounts(size_t offset) const { PCCounts searched = PCCounts(offset); const PCCounts* elem = std::lower_bound(throwCounts_.begin(), throwCounts_.end(), searched); if (elem == throwCounts_.end() || elem->pcOffset() != offset) return nullptr; return elem; } const js::PCCounts* ScriptCounts::getImmediatePrecedingThrowCounts(size_t offset) const { PCCounts searched = PCCounts(offset); const PCCounts* elem = std::lower_bound(throwCounts_.begin(), throwCounts_.end(), searched); if (elem == throwCounts_.end()) { if (throwCounts_.begin() == throwCounts_.end()) return nullptr; return &throwCounts_.back(); } if (elem->pcOffset() == offset) return elem; if (elem != throwCounts_.begin()) return elem - 1; return nullptr; } js::PCCounts* ScriptCounts::getThrowCounts(size_t offset) { PCCounts searched = PCCounts(offset); PCCounts* elem = std::lower_bound(throwCounts_.begin(), throwCounts_.end(), searched); if (elem == throwCounts_.end() || elem->pcOffset() != offset) elem = throwCounts_.insert(elem, searched); return elem; } void JSScript::setIonScript(JSRuntime* maybeRuntime, js::jit::IonScript* ionScript) { MOZ_ASSERT_IF(ionScript != ION_DISABLED_SCRIPT, !baselineScript()->hasPendingIonBuilder()); if (hasIonScript()) js::jit::IonScript::writeBarrierPre(zone(), ion); ion = ionScript; MOZ_ASSERT_IF(hasIonScript(), hasBaselineScript()); updateBaselineOrIonRaw(maybeRuntime); } js::PCCounts* JSScript::maybeGetPCCounts(jsbytecode* pc) { MOZ_ASSERT(containsPC(pc)); return getScriptCounts().maybeGetPCCounts(pcToOffset(pc)); } const js::PCCounts* JSScript::maybeGetThrowCounts(jsbytecode* pc) { MOZ_ASSERT(containsPC(pc)); return getScriptCounts().maybeGetThrowCounts(pcToOffset(pc)); } js::PCCounts* JSScript::getThrowCounts(jsbytecode* pc) { MOZ_ASSERT(containsPC(pc)); return getScriptCounts().getThrowCounts(pcToOffset(pc)); } uint64_t JSScript::getHitCount(jsbytecode* pc) { MOZ_ASSERT(containsPC(pc)); if (pc < main()) pc = main(); ScriptCounts& sc = getScriptCounts(); size_t targetOffset = pcToOffset(pc); const js::PCCounts* baseCount = sc.getImmediatePrecedingPCCounts(targetOffset); if (!baseCount) return 0; if (baseCount->pcOffset() == targetOffset) return baseCount->numExec(); MOZ_ASSERT(baseCount->pcOffset() < targetOffset); uint64_t count = baseCount->numExec(); do { const js::PCCounts* throwCount = sc.getImmediatePrecedingThrowCounts(targetOffset); if (!throwCount) return count; if (throwCount->pcOffset() <= baseCount->pcOffset()) return count; count -= throwCount->numExec(); targetOffset = throwCount->pcOffset() - 1; } while (true); } void JSScript::incHitCount(jsbytecode* pc) { MOZ_ASSERT(containsPC(pc)); if (pc < main()) pc = main(); ScriptCounts& sc = getScriptCounts(); js::PCCounts* baseCount = sc.getImmediatePrecedingPCCounts(pcToOffset(pc)); if (!baseCount) return; baseCount->numExec()++; } void JSScript::addIonCounts(jit::IonScriptCounts* ionCounts) { ScriptCounts& sc = getScriptCounts(); if (sc.ionCounts_) ionCounts->setPrevious(sc.ionCounts_); sc.ionCounts_ = ionCounts; } jit::IonScriptCounts* JSScript::getIonCounts() { return getScriptCounts().ionCounts_; } void JSScript::takeOverScriptCountsMapEntry(ScriptCounts* entryValue) { #ifdef DEBUG ScriptCountsMap::Ptr p = GetScriptCountsMapEntry(this); MOZ_ASSERT(entryValue == p->value()); #endif hasScriptCounts_ = false; } void JSScript::releaseScriptCounts(ScriptCounts* counts) { ScriptCountsMap::Ptr p = GetScriptCountsMapEntry(this); *counts = Move(*p->value()); js_delete(p->value()); compartment()->scriptCountsMap->remove(p); hasScriptCounts_ = false; } void JSScript::destroyScriptCounts(FreeOp* fop) { if (hasScriptCounts()) { ScriptCounts scriptCounts; releaseScriptCounts(&scriptCounts); } } void ScriptSourceObject::trace(JSTracer* trc, JSObject* obj) { ScriptSourceObject* sso = static_cast<ScriptSourceObject*>(obj); // Don't trip over the poison 'not yet initialized' values. if (!sso->getReservedSlot(INTRODUCTION_SCRIPT_SLOT).isMagic(JS_GENERIC_MAGIC)) { JSScript* script = sso->introductionScript(); if (script) { TraceManuallyBarrieredEdge(trc, &script, "ScriptSourceObject introductionScript"); sso->setReservedSlot(INTRODUCTION_SCRIPT_SLOT, PrivateValue(script)); } } } void ScriptSourceObject::finalize(FreeOp* fop, JSObject* obj) { MOZ_ASSERT(fop->onMainThread()); ScriptSourceObject* sso = &obj->as<ScriptSourceObject>(); // If code coverage is enabled, record the filename associated with this // source object. if (fop->runtime()->lcovOutput.isEnabled()) sso->compartment()->lcovOutput.collectSourceFile(sso->compartment(), sso); sso->source()->decref(); sso->setReservedSlot(SOURCE_SLOT, PrivateValue(nullptr)); } static const ClassOps ScriptSourceObjectClassOps = { nullptr, /* addProperty */ nullptr, /* delProperty */ nullptr, /* getProperty */ nullptr, /* setProperty */ nullptr, /* enumerate */ nullptr, /* resolve */ nullptr, /* mayResolve */ ScriptSourceObject::finalize, nullptr, /* call */ nullptr, /* hasInstance */ nullptr, /* construct */ ScriptSourceObject::trace }; const Class ScriptSourceObject::class_ = { "ScriptSource", JSCLASS_HAS_RESERVED_SLOTS(RESERVED_SLOTS) | JSCLASS_IS_ANONYMOUS | JSCLASS_FOREGROUND_FINALIZE, &ScriptSourceObjectClassOps }; ScriptSourceObject* ScriptSourceObject::create(ExclusiveContext* cx, ScriptSource* source) { RootedObject object(cx, NewObjectWithGivenProto(cx, &class_, nullptr)); if (!object) return nullptr; RootedScriptSource sourceObject(cx, &object->as<ScriptSourceObject>()); source->incref(); // The matching decref is in ScriptSourceObject::finalize. sourceObject->initReservedSlot(SOURCE_SLOT, PrivateValue(source)); // The remaining slots should eventually be populated by a call to // initFromOptions. Poison them until that point. sourceObject->initReservedSlot(ELEMENT_SLOT, MagicValue(JS_GENERIC_MAGIC)); sourceObject->initReservedSlot(ELEMENT_PROPERTY_SLOT, MagicValue(JS_GENERIC_MAGIC)); sourceObject->initReservedSlot(INTRODUCTION_SCRIPT_SLOT, MagicValue(JS_GENERIC_MAGIC)); return sourceObject; } /* static */ bool ScriptSourceObject::initFromOptions(JSContext* cx, HandleScriptSource source, const ReadOnlyCompileOptions& options) { releaseAssertSameCompartment(cx, source); MOZ_ASSERT(source->getReservedSlot(ELEMENT_SLOT).isMagic(JS_GENERIC_MAGIC)); MOZ_ASSERT(source->getReservedSlot(ELEMENT_PROPERTY_SLOT).isMagic(JS_GENERIC_MAGIC)); MOZ_ASSERT(source->getReservedSlot(INTRODUCTION_SCRIPT_SLOT).isMagic(JS_GENERIC_MAGIC)); RootedValue element(cx, ObjectOrNullValue(options.element())); if (!cx->compartment()->wrap(cx, &element)) return false; source->setReservedSlot(ELEMENT_SLOT, element); RootedValue elementAttributeName(cx); if (options.elementAttributeName()) elementAttributeName = StringValue(options.elementAttributeName()); else elementAttributeName = UndefinedValue(); if (!cx->compartment()->wrap(cx, &elementAttributeName)) return false; source->setReservedSlot(ELEMENT_PROPERTY_SLOT, elementAttributeName); // There is no equivalent of cross-compartment wrappers for scripts. If the // introduction script and ScriptSourceObject are in different compartments, // we would be creating a cross-compartment script reference, which is // forbidden. In that case, simply don't bother to retain the introduction // script. if (options.introductionScript() && options.introductionScript()->compartment() == cx->compartment()) { source->setReservedSlot(INTRODUCTION_SCRIPT_SLOT, PrivateValue(options.introductionScript())); } else { source->setReservedSlot(INTRODUCTION_SCRIPT_SLOT, UndefinedValue()); } return true; } /* static */ bool JSScript::loadSource(JSContext* cx, ScriptSource* ss, bool* worked) { MOZ_ASSERT(!ss->hasSourceData()); *worked = false; if (!cx->runtime()->sourceHook || !ss->sourceRetrievable()) return true; char16_t* src = nullptr; size_t length; if (!cx->runtime()->sourceHook->load(cx, ss->filename(), &src, &length)) return false; if (!src) return true; if (!ss->setSource(cx, mozilla::UniquePtr<char16_t[], JS::FreePolicy>(src), length)) return false; *worked = true; return true; } JSFlatString* JSScript::sourceData(JSContext* cx) { MOZ_ASSERT(scriptSource()->hasSourceData()); return scriptSource()->substring(cx, sourceStart(), sourceEnd()); } UncompressedSourceCache::AutoHoldEntry::AutoHoldEntry() : cache_(nullptr), sourceChunk_() { } void UncompressedSourceCache::AutoHoldEntry::holdEntry(UncompressedSourceCache* cache, const ScriptSourceChunk& sourceChunk) { // Initialise the holder for a specific cache and script source. This will // hold on to the cached source chars in the event that the cache is purged. MOZ_ASSERT(!cache_ && !sourceChunk_.valid() && !charsToFree_); cache_ = cache; sourceChunk_ = sourceChunk; } void UncompressedSourceCache::AutoHoldEntry::holdChars(UniqueTwoByteChars chars) { MOZ_ASSERT(!cache_ && !sourceChunk_.valid() && !charsToFree_); charsToFree_ = Move(chars); } void UncompressedSourceCache::AutoHoldEntry::deferDelete(UniqueTwoByteChars chars) { // Take ownership of source chars now the cache is being purged. Remove our // reference to the ScriptSource which might soon be destroyed. MOZ_ASSERT(cache_ && sourceChunk_.valid() && !charsToFree_); cache_ = nullptr; sourceChunk_ = ScriptSourceChunk(); charsToFree_ = Move(chars); } UncompressedSourceCache::AutoHoldEntry::~AutoHoldEntry() { if (cache_) { MOZ_ASSERT(sourceChunk_.valid()); cache_->releaseEntry(*this); } } void UncompressedSourceCache::holdEntry(AutoHoldEntry& holder, const ScriptSourceChunk& ssc) { MOZ_ASSERT(!holder_); holder.holdEntry(this, ssc); holder_ = &holder; } void UncompressedSourceCache::releaseEntry(AutoHoldEntry& holder) { MOZ_ASSERT(holder_ == &holder); holder_ = nullptr; } const char16_t* UncompressedSourceCache::lookup(const ScriptSourceChunk& ssc, AutoHoldEntry& holder) { MOZ_ASSERT(!holder_); if (!map_) return nullptr; if (Map::Ptr p = map_->lookup(ssc)) { holdEntry(holder, ssc); return p->value().get(); } return nullptr; } bool UncompressedSourceCache::put(const ScriptSourceChunk& ssc, UniqueTwoByteChars str, AutoHoldEntry& holder) { MOZ_ASSERT(!holder_); if (!map_) { UniquePtr<Map> map = MakeUnique<Map>(); if (!map || !map->init()) return false; map_ = Move(map); } if (!map_->put(ssc, Move(str))) return false; holdEntry(holder, ssc); return true; } void UncompressedSourceCache::purge() { if (!map_) return; for (Map::Range r = map_->all(); !r.empty(); r.popFront()) { if (holder_ && r.front().key() == holder_->sourceChunk()) { holder_->deferDelete(Move(r.front().value())); holder_ = nullptr; } } map_.reset(); } size_t UncompressedSourceCache::sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) { size_t n = 0; if (map_ && !map_->empty()) { n += map_->sizeOfIncludingThis(mallocSizeOf); for (Map::Range r = map_->all(); !r.empty(); r.popFront()) n += mallocSizeOf(r.front().value().get()); } return n; } const char16_t* ScriptSource::chunkChars(JSContext* cx, UncompressedSourceCache::AutoHoldEntry& holder, size_t chunk) { const Compressed& c = data.as<Compressed>(); ScriptSourceChunk ssc(this, chunk); if (const char16_t* decompressed = cx->caches.uncompressedSourceCache.lookup(ssc, holder)) return decompressed; size_t totalLengthInBytes = length() * sizeof(char16_t); size_t chunkBytes = Compressor::chunkSize(totalLengthInBytes, chunk); MOZ_ASSERT((chunkBytes % sizeof(char16_t)) == 0); const size_t lengthWithNull = (chunkBytes / sizeof(char16_t)) + 1; UniqueTwoByteChars decompressed(js_pod_malloc<char16_t>(lengthWithNull)); if (!decompressed) { JS_ReportOutOfMemory(cx); return nullptr; } if (!DecompressStringChunk((const unsigned char*) c.raw.chars(), chunk, reinterpret_cast<unsigned char*>(decompressed.get()), chunkBytes)) { JS_ReportOutOfMemory(cx); return nullptr; } decompressed[lengthWithNull - 1] = '\0'; const char16_t* ret = decompressed.get(); if (!cx->caches.uncompressedSourceCache.put(ssc, Move(decompressed), holder)) { JS_ReportOutOfMemory(cx); return nullptr; } return ret; } const char16_t* ScriptSource::chars(JSContext* cx, UncompressedSourceCache::AutoHoldEntry& holder, size_t begin, size_t len) { MOZ_ASSERT(begin + len <= length()); if (data.is<Uncompressed>()) { const char16_t* chars = data.as<Uncompressed>().string.chars(); if (!chars) return nullptr; return chars + begin; } if (data.is<Missing>()) MOZ_CRASH("ScriptSource::chars() on ScriptSource with SourceType = Missing"); MOZ_ASSERT(data.is<Compressed>()); // Determine which chunk(s) we are interested in, and the offsets within // these chunks. size_t firstChunk, lastChunk; size_t firstChunkOffset, lastChunkOffset; MOZ_ASSERT(len > 0); Compressor::toChunkOffset(begin * sizeof(char16_t), &firstChunk, &firstChunkOffset); Compressor::toChunkOffset((begin + len - 1) * sizeof(char16_t), &lastChunk, &lastChunkOffset); MOZ_ASSERT(firstChunkOffset % sizeof(char16_t) == 0); size_t firstChar = firstChunkOffset / sizeof(char16_t); if (firstChunk == lastChunk) { const char16_t* chars = chunkChars(cx, holder, firstChunk); if (!chars) return nullptr; return chars + firstChar; } // We need multiple chunks. Allocate a (null-terminated) buffer to hold // |len| chars and copy uncompressed chars from the chunks into it. We use // chunkChars() so we benefit from chunk caching by UncompressedSourceCache. MOZ_ASSERT(firstChunk < lastChunk); size_t lengthWithNull = len + 1; UniqueTwoByteChars decompressed(js_pod_malloc<char16_t>(lengthWithNull)); if (!decompressed) { JS_ReportOutOfMemory(cx); return nullptr; } size_t totalLengthInBytes = length() * sizeof(char16_t); char16_t* cursor = decompressed.get(); for (size_t i = firstChunk; i <= lastChunk; i++) { UncompressedSourceCache::AutoHoldEntry chunkHolder; const char16_t* chars = chunkChars(cx, chunkHolder, i); if (!chars) return nullptr; size_t numChars = Compressor::chunkSize(totalLengthInBytes, i) / sizeof(char16_t); if (i == firstChunk) { MOZ_ASSERT(firstChar < numChars); chars += firstChar; numChars -= firstChar; } else if (i == lastChunk) { size_t numCharsNew = lastChunkOffset / sizeof(char16_t) + 1; MOZ_ASSERT(numCharsNew <= numChars); numChars = numCharsNew; } mozilla::PodCopy(cursor, chars, numChars); cursor += numChars; } *cursor++ = '\0'; MOZ_ASSERT(size_t(cursor - decompressed.get()) == lengthWithNull); // Transfer ownership to |holder|. const char16_t* ret = decompressed.get(); holder.holdChars(Move(decompressed)); return ret; } JSFlatString* ScriptSource::substring(JSContext* cx, size_t start, size_t stop) { MOZ_ASSERT(start <= stop); size_t len = stop - start; UncompressedSourceCache::AutoHoldEntry holder; const char16_t* chars = this->chars(cx, holder, start, len); if (!chars) return nullptr; return NewStringCopyN<CanGC>(cx, chars, len); } JSFlatString* ScriptSource::substringDontDeflate(JSContext* cx, size_t start, size_t stop) { MOZ_ASSERT(start <= stop); size_t len = stop - start; UncompressedSourceCache::AutoHoldEntry holder; const char16_t* chars = this->chars(cx, holder, start, len); if (!chars) return nullptr; return NewStringCopyNDontDeflate<CanGC>(cx, chars, len); } JSFlatString* ScriptSource::functionBodyString(JSContext* cx) { MOZ_ASSERT(isFunctionBody()); size_t start = parameterListEnd_ + (sizeof(FunctionConstructorMedialSigils) - 1); size_t stop = length() - (sizeof(FunctionConstructorFinalBrace) - 1); return substring(cx, start, stop); } MOZ_MUST_USE bool ScriptSource::setSource(ExclusiveContext* cx, mozilla::UniquePtr<char16_t[], JS::FreePolicy>&& source, size_t length) { auto& cache = cx->zone()->runtimeFromAnyThread()->sharedImmutableStrings(); auto deduped = cache.getOrCreate(mozilla::Move(source), length); if (!deduped) { ReportOutOfMemory(cx); return false; } setSource(mozilla::Move(*deduped)); return true; } void ScriptSource::setSource(SharedImmutableTwoByteString&& string) { MOZ_ASSERT(data.is<Missing>()); data = SourceType(Uncompressed(mozilla::Move(string))); } MOZ_MUST_USE bool ScriptSource::setCompressedSource(ExclusiveContext* cx, mozilla::UniquePtr<char[], JS::FreePolicy>&& raw, size_t rawLength, size_t sourceLength) { MOZ_ASSERT(raw); auto& cache = cx->zone()->runtimeFromAnyThread()->sharedImmutableStrings(); auto deduped = cache.getOrCreate(mozilla::Move(raw), rawLength); if (!deduped) { ReportOutOfMemory(cx); return false; } setCompressedSource(mozilla::Move(*deduped), sourceLength); return true; } void ScriptSource::setCompressedSource(SharedImmutableString&& raw, size_t uncompressedLength) { MOZ_ASSERT(data.is<Missing>() || data.is<Uncompressed>()); MOZ_ASSERT_IF(data.is<Uncompressed>(), data.as<Uncompressed>().string.length() == uncompressedLength); data = SourceType(Compressed(mozilla::Move(raw), uncompressedLength)); } bool ScriptSource::setSourceCopy(ExclusiveContext* cx, SourceBufferHolder& srcBuf, SourceCompressionTask* task) { MOZ_ASSERT(!hasSourceData()); auto& cache = cx->zone()->runtimeFromAnyThread()->sharedImmutableStrings(); auto deduped = cache.getOrCreate(srcBuf.get(), srcBuf.length(), [&]() { return srcBuf.ownsChars() ? mozilla::UniquePtr<char16_t[], JS::FreePolicy>(srcBuf.take()) : DuplicateString(srcBuf.get(), srcBuf.length()); }); if (!deduped) { ReportOutOfMemory(cx); return false; } setSource(mozilla::Move(*deduped)); // There are several cases where source compression is not a good idea: // - If the script is tiny, then compression will save little or no space. // - If there is only one core, then compression will contend with JS // execution (which hurts benchmarketing). // - If the source contains a giant string, then parsing will finish much // faster than compression which increases latency (this case is handled // in Parser::stringLiteral). // // Lastly, since the parsing thread will eventually perform a blocking wait // on the compression task's thread, require that there are at least 2 // helper threads: // - If we are on a helper thread, there must be another helper thread to // execute our compression task. // - If we are on the main thread, there must be at least two helper // threads since at most one helper thread can be blocking on the main // thread (see HelperThreadState::canStartParseTask) which would cause a // deadlock if there wasn't a second helper thread that could make // progress on our compression task. bool canCompressOffThread = HelperThreadState().cpuCount > 1 && HelperThreadState().threadCount >= 2 && CanUseExtraThreads(); const size_t TINY_SCRIPT = 256; if (TINY_SCRIPT <= srcBuf.length() && canCompressOffThread) { task->ss = this; if (!StartOffThreadCompression(cx, task)) return false; } return true; } static MOZ_MUST_USE bool reallocUniquePtr(UniquePtr<char[], JS::FreePolicy>& unique, size_t size) { auto newPtr = static_cast<char*>(js_realloc(unique.get(), size)); if (!newPtr) return false; // Since the realloc succeeded, unique is now holding a freed pointer. mozilla::Unused << unique.release(); unique.reset(newPtr); return true; } SourceCompressionTask::ResultType SourceCompressionTask::work() { MOZ_ASSERT(ss->data.is<ScriptSource::Uncompressed>()); // Try to keep the maximum memory usage down by only allocating half the // size of the string, first. size_t inputBytes = ss->length() * sizeof(char16_t); size_t firstSize = inputBytes / 2; mozilla::UniquePtr<char[], JS::FreePolicy> compressed(js_pod_malloc<char>(firstSize)); if (!compressed) return OOM; const char16_t* chars = ss->data.as<ScriptSource::Uncompressed>().string.chars(); Compressor comp(reinterpret_cast<const unsigned char*>(chars), inputBytes); if (!comp.init()) return OOM; comp.setOutput(reinterpret_cast<unsigned char*>(compressed.get()), firstSize); bool cont = true; bool reallocated = false; while (cont) { if (abort_) return Aborted; switch (comp.compressMore()) { case Compressor::CONTINUE: break; case Compressor::MOREOUTPUT: { if (reallocated) { // The compressed string is longer than the original string. return Aborted; } // The compressed output is greater than half the size of the // original string. Reallocate to the full size. if (!reallocUniquePtr(compressed, inputBytes)) return OOM; comp.setOutput(reinterpret_cast<unsigned char*>(compressed.get()), inputBytes); reallocated = true; break; } case Compressor::DONE: cont = false; break; case Compressor::OOM: return OOM; } } size_t totalBytes = comp.totalBytesNeeded(); // Shrink the buffer to the size of the compressed data. if (!reallocUniquePtr(compressed, totalBytes)) return OOM; comp.finish(compressed.get(), totalBytes); auto& strings = cx->sharedImmutableStrings(); resultString = strings.getOrCreate(mozilla::Move(compressed), totalBytes); if (!resultString) return OOM; return Success; } void ScriptSource::addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf, JS::ScriptSourceInfo* info) const { info->misc += mallocSizeOf(this) + mallocSizeOf(filename_.get()) + mallocSizeOf(introducerFilename_.get()); info->numScripts++; } template<XDRMode mode> bool ScriptSource::performXDR(XDRState<mode>* xdr) { struct CompressedLengthMatcher { size_t match(Uncompressed&) { return 0; } size_t match(Compressed& c) { return c.raw.length(); } size_t match(Missing&) { MOZ_CRASH("Missing source data in ScriptSource::performXDR"); return 0; } }; struct RawDataMatcher { void* match(Uncompressed& u) { return (void*) u.string.chars(); } void* match(Compressed& c) { return (void*) c.raw.chars(); } void* match(Missing&) { MOZ_CRASH("Missing source data in ScriptSource::performXDR"); return nullptr; } }; uint8_t hasSource = hasSourceData(); if (!xdr->codeUint8(&hasSource)) return false; uint8_t retrievable = sourceRetrievable_; if (!xdr->codeUint8(&retrievable)) return false; sourceRetrievable_ = retrievable; if (hasSource && !sourceRetrievable_) { uint32_t len = 0; if (mode == XDR_ENCODE) len = length(); if (!xdr->codeUint32(&len)) return false; uint32_t compressedLength; if (mode == XDR_ENCODE) { CompressedLengthMatcher m; compressedLength = data.match(m); } if (!xdr->codeUint32(&compressedLength)) return false; size_t byteLen = compressedLength ? compressedLength : (len * sizeof(char16_t)); if (mode == XDR_DECODE) { uint8_t* p = xdr->cx()->template pod_malloc<uint8_t>(Max<size_t>(byteLen, 1)); if (!p || !xdr->codeBytes(p, byteLen)) { js_free(p); return false; } if (compressedLength) { mozilla::UniquePtr<char[], JS::FreePolicy> compressedSource( reinterpret_cast<char*>(p)); if (!setCompressedSource(xdr->cx(), mozilla::Move(compressedSource), byteLen, len)) return false; } else { mozilla::UniquePtr<char16_t[], JS::FreePolicy> source( reinterpret_cast<char16_t*>(p)); if (!setSource(xdr->cx(), mozilla::Move(source), len)) return false; } } else { RawDataMatcher rdm; void* p = data.match(rdm); if (!xdr->codeBytes(p, byteLen)) return false; } } uint8_t haveSourceMap = hasSourceMapURL(); if (!xdr->codeUint8(&haveSourceMap)) return false; if (haveSourceMap) { uint32_t sourceMapURLLen = (mode == XDR_DECODE) ? 0 : js_strlen(sourceMapURL_.get()); if (!xdr->codeUint32(&sourceMapURLLen)) return false; if (mode == XDR_DECODE) { sourceMapURL_ = xdr->cx()->template make_pod_array<char16_t>(sourceMapURLLen + 1); if (!sourceMapURL_) return false; } if (!xdr->codeChars(sourceMapURL_.get(), sourceMapURLLen)) { if (mode == XDR_DECODE) sourceMapURL_ = nullptr; return false; } sourceMapURL_[sourceMapURLLen] = '\0'; } uint8_t haveDisplayURL = hasDisplayURL(); if (!xdr->codeUint8(&haveDisplayURL)) return false; if (haveDisplayURL) { uint32_t displayURLLen = (mode == XDR_DECODE) ? 0 : js_strlen(displayURL_.get()); if (!xdr->codeUint32(&displayURLLen)) return false; if (mode == XDR_DECODE) { displayURL_ = xdr->cx()->template make_pod_array<char16_t>(displayURLLen + 1); if (!displayURL_) return false; } if (!xdr->codeChars(displayURL_.get(), displayURLLen)) { if (mode == XDR_DECODE) displayURL_ = nullptr; return false; } displayURL_[displayURLLen] = '\0'; } uint8_t haveFilename = !!filename_; if (!xdr->codeUint8(&haveFilename)) return false; if (haveFilename) { const char* fn = filename(); if (!xdr->codeCString(&fn)) return false; if (mode == XDR_DECODE && !setFilename(xdr->cx(), fn)) return false; } return true; } // Format and return a cx->zone()->pod_malloc'ed URL for a generated script like: // {filename} line {lineno} > {introducer} // For example: // foo.js line 7 > eval // indicating code compiled by the call to 'eval' on line 7 of foo.js. static char* FormatIntroducedFilename(ExclusiveContext* cx, const char* filename, unsigned lineno, const char* introducer) { // Compute the length of the string in advance, so we can allocate a // buffer of the right size on the first shot. // // (JS_smprintf would be perfect, as that allocates the result // dynamically as it formats the string, but it won't allocate from cx, // and wants us to use a special free function.) char linenoBuf[15]; size_t filenameLen = strlen(filename); size_t linenoLen = SprintfLiteral(linenoBuf, "%u", lineno); size_t introducerLen = strlen(introducer); size_t len = filenameLen + 6 /* == strlen(" line ") */ + linenoLen + 3 /* == strlen(" > ") */ + introducerLen + 1 /* \0 */; char* formatted = cx->zone()->pod_malloc<char>(len); if (!formatted) { ReportOutOfMemory(cx); return nullptr; } mozilla::DebugOnly<size_t> checkLen = snprintf(formatted, len, "%s line %s > %s", filename, linenoBuf, introducer); MOZ_ASSERT(checkLen == len - 1); return formatted; } bool ScriptSource::initFromOptions(ExclusiveContext* cx, const ReadOnlyCompileOptions& options, Maybe<uint32_t> parameterListEnd) { MOZ_ASSERT(!filename_); MOZ_ASSERT(!introducerFilename_); mutedErrors_ = options.mutedErrors(); introductionType_ = options.introductionType; setIntroductionOffset(options.introductionOffset); parameterListEnd_ = parameterListEnd.isSome() ? parameterListEnd.value() : 0; if (options.hasIntroductionInfo) { MOZ_ASSERT(options.introductionType != nullptr); const char* filename = options.filename() ? options.filename() : "<unknown>"; char* formatted = FormatIntroducedFilename(cx, filename, options.introductionLineno, options.introductionType); if (!formatted) return false; filename_.reset(formatted); } else if (options.filename()) { if (!setFilename(cx, options.filename())) return false; } if (options.introducerFilename()) { introducerFilename_ = DuplicateString(cx, options.introducerFilename()); if (!introducerFilename_) return false; } return true; } bool ScriptSource::setFilename(ExclusiveContext* cx, const char* filename) { MOZ_ASSERT(!filename_); filename_ = DuplicateString(cx, filename); return filename_ != nullptr; } bool ScriptSource::setDisplayURL(ExclusiveContext* cx, const char16_t* displayURL) { MOZ_ASSERT(displayURL); if (hasDisplayURL()) { // FIXME: filename_.get() should be UTF-8 (bug 987069). if (cx->isJSContext() && !JS_ReportErrorFlagsAndNumberLatin1(cx->asJSContext(), JSREPORT_WARNING, GetErrorMessage, nullptr, JSMSG_ALREADY_HAS_PRAGMA, filename_.get(), "//# sourceURL")) { return false; } } size_t len = js_strlen(displayURL) + 1; if (len == 1) return true; displayURL_ = DuplicateString(cx, displayURL); return displayURL_ != nullptr; } bool ScriptSource::setSourceMapURL(ExclusiveContext* cx, const char16_t* sourceMapURL) { MOZ_ASSERT(sourceMapURL); size_t len = js_strlen(sourceMapURL) + 1; if (len == 1) return true; sourceMapURL_ = DuplicateString(cx, sourceMapURL); return sourceMapURL_ != nullptr; } /* * Shared script data management. */ SharedScriptData* js::SharedScriptData::new_(ExclusiveContext* cx, uint32_t codeLength, uint32_t srcnotesLength, uint32_t natoms) { uint32_t dataLength = natoms * sizeof(GCPtrAtom) + codeLength + srcnotesLength; uint32_t allocLength = offsetof(SharedScriptData, data_) + dataLength; auto entry = reinterpret_cast<SharedScriptData*>(cx->zone()->pod_malloc<uint8_t>(allocLength)); if (!entry) { ReportOutOfMemory(cx); return nullptr; } entry->refCount_ = 0; entry->dataLength_ = dataLength; entry->natoms_ = natoms; entry->codeLength_ = codeLength; /* * Call constructors to initialize the storage that will be accessed as a * GCPtrAtom array via atoms(). */ GCPtrAtom* atoms = entry->atoms(); MOZ_ASSERT(reinterpret_cast<uintptr_t>(atoms) % sizeof(GCPtrAtom*) == 0); for (unsigned i = 0; i < natoms; ++i) new (&atoms[i]) GCPtrAtom(); return entry; } bool JSScript::createScriptData(ExclusiveContext* cx, uint32_t codeLength, uint32_t srcnotesLength, uint32_t natoms) { MOZ_ASSERT(!scriptData()); SharedScriptData* ssd = SharedScriptData::new_(cx, codeLength, srcnotesLength, natoms); if (!ssd) return false; setScriptData(ssd); return true; } void JSScript::freeScriptData() { MOZ_ASSERT(scriptData_->refCount() == 1); scriptData_->decRefCount(); scriptData_ = nullptr; } void JSScript::setScriptData(js::SharedScriptData* data) { MOZ_ASSERT(!scriptData_); scriptData_ = data; scriptData_->incRefCount(); } /* * Takes ownership of its *ssd parameter and either adds it into the runtime's * ScriptDataTable or frees it if a matching entry already exists. * * Sets the |code| and |atoms| fields on the given JSScript. */ bool JSScript::shareScriptData(ExclusiveContext* cx) { SharedScriptData* ssd = scriptData(); MOZ_ASSERT(ssd); MOZ_ASSERT(ssd->refCount() == 1); AutoLockForExclusiveAccess lock(cx); ScriptBytecodeHasher::Lookup l(ssd); ScriptDataTable::AddPtr p = cx->scriptDataTable(lock).lookupForAdd(l); if (p) { MOZ_ASSERT(ssd != *p); freeScriptData(); setScriptData(*p); } else { if (!cx->scriptDataTable(lock).add(p, ssd)) { freeScriptData(); ReportOutOfMemory(cx); return false; } // Being in the table counts as a reference on the script data. scriptData()->incRefCount(); } MOZ_ASSERT(scriptData()->refCount() >= 2); return true; } void js::SweepScriptData(JSRuntime* rt, AutoLockForExclusiveAccess& lock) { // Entries are removed from the table when their reference count is one, // i.e. when the only reference to them is from the table entry. ScriptDataTable& table = rt->scriptDataTable(lock); for (ScriptDataTable::Enum e(table); !e.empty(); e.popFront()) { SharedScriptData* scriptData = e.front(); if (scriptData->refCount() == 1) { scriptData->decRefCount(); e.removeFront(); } } } void js::FreeScriptData(JSRuntime* rt, AutoLockForExclusiveAccess& lock) { ScriptDataTable& table = rt->scriptDataTable(lock); if (!table.initialized()) return; // The table should be empty unless the embedding leaked GC things. MOZ_ASSERT_IF(rt->gc.shutdownCollectedEverything(), table.empty()); for (ScriptDataTable::Enum e(table); !e.empty(); e.popFront()) { #ifdef DEBUG SharedScriptData* scriptData = e.front(); fprintf(stderr, "ERROR: GC found live SharedScriptData %p with ref count %d at shutdown\n", scriptData, scriptData->refCount()); #endif js_free(e.front()); } table.clear(); } /* * JSScript::data and SharedScriptData::data have complex, * manually-controlled, memory layouts. * * JSScript::data begins with some optional array headers. They are optional * because they often aren't needed, i.e. the corresponding arrays often have * zero elements. Each header has a bit in JSScript::hasArrayBits that * indicates if it's present within |data|; from this the offset of each * present array header can be computed. Each header has an accessor function * in JSScript that encapsulates this offset computation. * * Array type Array elements Accessor * ---------- -------------- -------- * ConstArray Consts consts() * ObjectArray Objects objects() * ObjectArray Regexps regexps() * TryNoteArray Try notes trynotes() * ScopeNoteArray Scope notes scopeNotes() * * Then are the elements of several arrays. * - Most of these arrays have headers listed above (if present). For each of * these, the array pointer and the array length is stored in the header. * - The remaining arrays have pointers and lengths that are stored directly in * JSScript. This is because, unlike the others, they are nearly always * non-zero length and so the optional-header space optimization isn't * worthwhile. * * Array elements Pointed to by Length * -------------- ------------- ------ * Consts consts()->vector consts()->length * Objects objects()->vector objects()->length * Regexps regexps()->vector regexps()->length * Try notes trynotes()->vector trynotes()->length * Scope notes scopeNotes()->vector scopeNotes()->length * * IMPORTANT: This layout has two key properties. * - It ensures that everything has sufficient alignment; in particular, the * consts() elements need Value alignment. * - It ensures there are no gaps between elements, which saves space and makes * manual layout easy. In particular, in the second part, arrays with larger * elements precede arrays with smaller elements. * * SharedScriptData::data contains data that can be shared within a * runtime. These items' layout is manually controlled to make it easier to * manage both during (temporary) allocation and during matching against * existing entries in the runtime. As the jsbytecode has to come first to * enable lookup by bytecode identity, SharedScriptData::data, the atoms part * has to manually be aligned sufficiently by adding padding after the notes * part. * * Array elements Pointed to by Length * -------------- ------------- ------ * jsbytecode code length * jsscrnote notes() numNotes() * Atoms atoms natoms * * The following static assertions check JSScript::data's alignment properties. */ template<class T> constexpr bool KeepsValueAlignment() { return alignof(JS::Value) % alignof(T) == 0 && sizeof(T) % sizeof(JS::Value) == 0; } template<class T> constexpr bool HasValueAlignment() { return alignof(JS::Value) == alignof(T) && sizeof(T) == sizeof(JS::Value); } template<class T1, class T2> constexpr bool NoPaddingBetweenEntries() { return alignof(T1) % alignof(T2) == 0; } /* * These assertions ensure that there is no padding between the array headers, * and also that the consts() elements (which follow immediately afterward) are * Value-aligned. (There is an assumption that |data| itself is Value-aligned; * we check this below). */ JS_STATIC_ASSERT(KeepsValueAlignment<ConstArray>()); JS_STATIC_ASSERT(KeepsValueAlignment<ObjectArray>()); /* there are two of these */ JS_STATIC_ASSERT(KeepsValueAlignment<TryNoteArray>()); JS_STATIC_ASSERT(KeepsValueAlignment<ScopeNoteArray>()); /* These assertions ensure there is no padding required between array elements. */ JS_STATIC_ASSERT(HasValueAlignment<GCPtrValue>()); JS_STATIC_ASSERT((NoPaddingBetweenEntries<GCPtrValue, GCPtrObject>())); JS_STATIC_ASSERT((NoPaddingBetweenEntries<GCPtrObject, GCPtrObject>())); JS_STATIC_ASSERT((NoPaddingBetweenEntries<GCPtrObject, JSTryNote>())); JS_STATIC_ASSERT((NoPaddingBetweenEntries<JSTryNote, uint32_t>())); JS_STATIC_ASSERT((NoPaddingBetweenEntries<uint32_t, uint32_t>())); JS_STATIC_ASSERT((NoPaddingBetweenEntries<GCPtrValue, ScopeNote>())); JS_STATIC_ASSERT((NoPaddingBetweenEntries<ScopeNote, ScopeNote>())); JS_STATIC_ASSERT((NoPaddingBetweenEntries<JSTryNote, ScopeNote>())); JS_STATIC_ASSERT((NoPaddingBetweenEntries<GCPtrObject, ScopeNote>())); JS_STATIC_ASSERT((NoPaddingBetweenEntries<ScopeNote, uint32_t>())); static inline size_t ScriptDataSize(uint32_t nscopes, uint32_t nconsts, uint32_t nobjects, uint32_t ntrynotes, uint32_t nscopenotes, uint32_t nyieldoffsets) { size_t size = 0; MOZ_ASSERT(nscopes != 0); size += sizeof(ScopeArray) + nscopes * sizeof(Scope*); if (nconsts != 0) size += sizeof(ConstArray) + nconsts * sizeof(Value); if (nobjects != 0) size += sizeof(ObjectArray) + nobjects * sizeof(NativeObject*); if (ntrynotes != 0) size += sizeof(TryNoteArray) + ntrynotes * sizeof(JSTryNote); if (nscopenotes != 0) size += sizeof(ScopeNoteArray) + nscopenotes * sizeof(ScopeNote); if (nyieldoffsets != 0) size += sizeof(YieldOffsetArray) + nyieldoffsets * sizeof(uint32_t); return size; } void JSScript::initCompartment(ExclusiveContext* cx) { compartment_ = cx->compartment_; } /* static */ JSScript* JSScript::Create(ExclusiveContext* cx, const ReadOnlyCompileOptions& options, HandleObject sourceObject, uint32_t bufStart, uint32_t bufEnd) { MOZ_ASSERT(bufStart <= bufEnd); RootedScript script(cx, Allocate<JSScript>(cx)); if (!script) return nullptr; PodZero(script.get()); script->initCompartment(cx); script->selfHosted_ = options.selfHostingMode; script->noScriptRval_ = options.noScriptRval; script->treatAsRunOnce_ = options.isRunOnce; script->version = options.version; MOZ_ASSERT(script->getVersion() == options.version); // assert that no overflow occurred script->setSourceObject(sourceObject); script->sourceStart_ = bufStart; script->sourceEnd_ = bufEnd; return script; } static inline uint8_t* AllocScriptData(JS::Zone* zone, size_t size) { if (!size) return nullptr; uint8_t* data = zone->pod_calloc<uint8_t>(JS_ROUNDUP(size, sizeof(Value))); if (!data) return nullptr; MOZ_ASSERT(size_t(data) % sizeof(Value) == 0); return data; } /* static */ bool JSScript::partiallyInit(ExclusiveContext* cx, HandleScript script, uint32_t nscopes, uint32_t nconsts, uint32_t nobjects, uint32_t ntrynotes, uint32_t nscopenotes, uint32_t nyieldoffsets, uint32_t nTypeSets) { size_t size = ScriptDataSize(nscopes, nconsts, nobjects, ntrynotes, nscopenotes, nyieldoffsets); script->data = AllocScriptData(script->zone(), size); if (size && !script->data) { ReportOutOfMemory(cx); return false; } script->dataSize_ = size; MOZ_ASSERT(nTypeSets <= UINT16_MAX); script->nTypeSets_ = uint16_t(nTypeSets); uint8_t* cursor = script->data; // There must always be at least 1 scope, the body scope. MOZ_ASSERT(nscopes != 0); cursor += sizeof(ScopeArray); if (nconsts != 0) { script->setHasArray(CONSTS); cursor += sizeof(ConstArray); } if (nobjects != 0) { script->setHasArray(OBJECTS); cursor += sizeof(ObjectArray); } if (ntrynotes != 0) { script->setHasArray(TRYNOTES); cursor += sizeof(TryNoteArray); } if (nscopenotes != 0) { script->setHasArray(SCOPENOTES); cursor += sizeof(ScopeNoteArray); } YieldOffsetArray* yieldOffsets = nullptr; if (nyieldoffsets != 0) { yieldOffsets = reinterpret_cast<YieldOffsetArray*>(cursor); cursor += sizeof(YieldOffsetArray); } if (nconsts != 0) { MOZ_ASSERT(reinterpret_cast<uintptr_t>(cursor) % sizeof(JS::Value) == 0); script->consts()->length = nconsts; script->consts()->vector = (GCPtrValue*)cursor; cursor += nconsts * sizeof(script->consts()->vector[0]); } script->scopes()->length = nscopes; script->scopes()->vector = (GCPtrScope*)cursor; cursor += nscopes * sizeof(script->scopes()->vector[0]); if (nobjects != 0) { script->objects()->length = nobjects; script->objects()->vector = (GCPtrObject*)cursor; cursor += nobjects * sizeof(script->objects()->vector[0]); } if (ntrynotes != 0) { script->trynotes()->length = ntrynotes; script->trynotes()->vector = reinterpret_cast<JSTryNote*>(cursor); size_t vectorSize = ntrynotes * sizeof(script->trynotes()->vector[0]); #ifdef DEBUG memset(cursor, 0, vectorSize); #endif cursor += vectorSize; } if (nscopenotes != 0) { script->scopeNotes()->length = nscopenotes; script->scopeNotes()->vector = reinterpret_cast<ScopeNote*>(cursor); size_t vectorSize = nscopenotes * sizeof(script->scopeNotes()->vector[0]); #ifdef DEBUG memset(cursor, 0, vectorSize); #endif cursor += vectorSize; } if (nyieldoffsets != 0) { yieldOffsets->init(reinterpret_cast<uint32_t*>(cursor), nyieldoffsets); size_t vectorSize = nyieldoffsets * sizeof(script->yieldOffsets()[0]); #ifdef DEBUG memset(cursor, 0, vectorSize); #endif cursor += vectorSize; } MOZ_ASSERT(cursor == script->data + size); return true; } /* static */ bool JSScript::initFunctionPrototype(ExclusiveContext* cx, Handle<JSScript*> script, HandleFunction functionProto) { uint32_t numScopes = 1; uint32_t numConsts = 0; uint32_t numObjects = 0; uint32_t numTryNotes = 0; uint32_t numScopeNotes = 0; uint32_t numYieldOffsets = 0; uint32_t numTypeSets = 0; if (!partiallyInit(cx, script, numScopes, numConsts, numObjects, numTryNotes, numScopeNotes, numYieldOffsets, numTypeSets)) { return false; } RootedScope enclosing(cx, &cx->global()->emptyGlobalScope()); Scope* functionProtoScope = FunctionScope::create(cx, nullptr, false, false, functionProto, enclosing); if (!functionProtoScope) return false; script->scopes()->vector[0].init(functionProtoScope); uint32_t codeLength = 1; uint32_t srcNotesLength = 1; uint32_t numAtoms = 0; if (!script->createScriptData(cx, codeLength, srcNotesLength, numAtoms)) return false; jsbytecode* code = script->code(); code[0] = JSOP_RETRVAL; code[1] = SRC_NULL; return script->shareScriptData(cx); } static void InitAtomMap(frontend::AtomIndexMap& indices, GCPtrAtom* atoms) { for (AtomIndexMap::Range r = indices.all(); !r.empty(); r.popFront()) { JSAtom* atom = r.front().key(); uint32_t index = r.front().value(); MOZ_ASSERT(index < indices.count()); atoms[index].init(atom); } } /* static */ void JSScript::initFromFunctionBox(ExclusiveContext* cx, HandleScript script, frontend::FunctionBox* funbox) { JSFunction* fun = funbox->function(); if (fun->isInterpretedLazy()) fun->setUnlazifiedScript(script); else fun->setScript(script); script->funHasExtensibleScope_ = funbox->hasExtensibleScope(); script->needsHomeObject_ = funbox->needsHomeObject(); script->isDerivedClassConstructor_ = funbox->isDerivedClassConstructor(); if (funbox->argumentsHasLocalBinding()) { script->setArgumentsHasVarBinding(); if (funbox->definitelyNeedsArgsObj()) script->setNeedsArgsObj(true); } else { MOZ_ASSERT(!funbox->definitelyNeedsArgsObj()); } script->hasMappedArgsObj_ = funbox->hasMappedArgsObj(); script->functionHasThisBinding_ = funbox->hasThisBinding(); script->functionHasExtraBodyVarScope_ = funbox->hasExtraBodyVarScope(); script->funLength_ = funbox->length; script->isGeneratorExp_ = funbox->isGenexpLambda; script->setGeneratorKind(funbox->generatorKind()); script->setAsyncKind(funbox->asyncKind()); if (funbox->hasRest()) script->setHasRest(); PositionalFormalParameterIter fi(script); while (fi && !fi.closedOver()) fi++; script->funHasAnyAliasedFormal_ = !!fi; script->setHasInnerFunctions(funbox->hasInnerFunctions()); } /* static */ void JSScript::initFromModuleContext(ExclusiveContext* cx, HandleScript script, frontend::ModuleSharedContext* modulesc) { script->funHasExtensibleScope_ = false; script->needsHomeObject_ = false; script->isDerivedClassConstructor_ = false; script->funLength_ = 0; script->isGeneratorExp_ = false; script->setGeneratorKind(NotGenerator); // Since modules are only run once, mark the script so that initializers // created within it may be given more precise types. script->setTreatAsRunOnce(); MOZ_ASSERT(!script->hasRunOnce()); } /* static */ bool JSScript::fullyInitFromEmitter(ExclusiveContext* cx, HandleScript script, BytecodeEmitter* bce) { /* The counts of indexed things must be checked during code generation. */ MOZ_ASSERT(bce->atomIndices->count() <= INDEX_LIMIT); MOZ_ASSERT(bce->objectList.length <= INDEX_LIMIT); uint32_t mainLength = bce->offset(); uint32_t prologueLength = bce->prologueOffset(); uint32_t nsrcnotes; if (!bce->finishTakingSrcNotes(&nsrcnotes)) return false; uint32_t natoms = bce->atomIndices->count(); if (!partiallyInit(cx, script, bce->scopeList.length(), bce->constList.length(), bce->objectList.length, bce->tryNoteList.length(), bce->scopeNoteList.length(), bce->yieldOffsetList.length(), bce->typesetCount)) { return false; } MOZ_ASSERT(script->mainOffset() == 0); script->mainOffset_ = prologueLength; script->lineno_ = bce->firstLine; if (!script->createScriptData(cx, prologueLength + mainLength, nsrcnotes, natoms)) return false; jsbytecode* code = script->code(); PodCopy<jsbytecode>(code, bce->prologue.code.begin(), prologueLength); PodCopy<jsbytecode>(code + prologueLength, bce->main.code.begin(), mainLength); bce->copySrcNotes((jssrcnote*)(code + script->length()), nsrcnotes); InitAtomMap(*bce->atomIndices, script->atoms()); if (!script->shareScriptData(cx)) return false; if (bce->constList.length() != 0) bce->constList.finish(script->consts()); if (bce->objectList.length != 0) bce->objectList.finish(script->objects()); if (bce->scopeList.length() != 0) bce->scopeList.finish(script->scopes()); if (bce->tryNoteList.length() != 0) bce->tryNoteList.finish(script->trynotes()); if (bce->scopeNoteList.length() != 0) bce->scopeNoteList.finish(script->scopeNotes(), prologueLength); script->strict_ = bce->sc->strict(); script->explicitUseStrict_ = bce->sc->hasExplicitUseStrict(); script->bindingsAccessedDynamically_ = bce->sc->bindingsAccessedDynamically(); script->hasSingletons_ = bce->hasSingletons; uint64_t nslots = bce->maxFixedSlots + static_cast<uint64_t>(bce->maxStackDepth); if (nslots > UINT32_MAX) { bce->reportError(nullptr, JSMSG_NEED_DIET, js_script_str); return false; } script->nfixed_ = bce->maxFixedSlots; script->nslots_ = nslots; script->bodyScopeIndex_ = bce->bodyScopeIndex; script->hasNonSyntacticScope_ = bce->outermostScope()->hasOnChain(ScopeKind::NonSyntactic); if (bce->sc->isFunctionBox()) initFromFunctionBox(cx, script, bce->sc->asFunctionBox()); else if (bce->sc->isModuleContext()) initFromModuleContext(cx, script, bce->sc->asModuleContext()); // Copy yield offsets last, as the generator kind is set in // initFromFunctionBox. if (bce->yieldOffsetList.length() != 0) bce->yieldOffsetList.finish(script->yieldOffsets(), prologueLength); #ifdef DEBUG script->assertValidJumpTargets(); #endif return true; } #ifdef DEBUG void JSScript::assertValidJumpTargets() const { jsbytecode* end = codeEnd(); jsbytecode* mainEntry = main(); for (jsbytecode* pc = code(); pc != end; pc = GetNextPc(pc)) { // Check jump instructions' target. if (IsJumpOpcode(JSOp(*pc))) { jsbytecode* target = pc + GET_JUMP_OFFSET(pc); MOZ_ASSERT(mainEntry <= target && target < end); MOZ_ASSERT(BytecodeIsJumpTarget(JSOp(*target))); // Check fallthrough of conditional jump instructions. if (BytecodeFallsThrough(JSOp(*pc))) { jsbytecode* fallthrough = GetNextPc(pc); MOZ_ASSERT(mainEntry <= fallthrough && fallthrough < end); MOZ_ASSERT(BytecodeIsJumpTarget(JSOp(*fallthrough))); } } // Check table switch case labels. if (JSOp(*pc) == JSOP_TABLESWITCH) { jsbytecode* pc2 = pc; int32_t len = GET_JUMP_OFFSET(pc2); // Default target. MOZ_ASSERT(mainEntry <= pc + len && pc + len < end); MOZ_ASSERT(BytecodeIsJumpTarget(JSOp(*(pc + len)))); pc2 += JUMP_OFFSET_LEN; int32_t low = GET_JUMP_OFFSET(pc2); pc2 += JUMP_OFFSET_LEN; int32_t high = GET_JUMP_OFFSET(pc2); for (int i = 0; i < high - low + 1; i++) { pc2 += JUMP_OFFSET_LEN; int32_t off = (int32_t) GET_JUMP_OFFSET(pc2); // Case (i + low) MOZ_ASSERT_IF(off, mainEntry <= pc + off && pc + off < end); MOZ_ASSERT_IF(off, BytecodeIsJumpTarget(JSOp(*(pc + off)))); } } } // Check catch/finally blocks as jump targets. if (hasTrynotes()) { JSTryNote* tn = trynotes()->vector; JSTryNote* tnlimit = tn + trynotes()->length; for (; tn < tnlimit; tn++) { jsbytecode* tryStart = mainEntry + tn->start; jsbytecode* tryPc = tryStart - 1; if (tn->kind != JSTRY_CATCH && tn->kind != JSTRY_FINALLY) continue; MOZ_ASSERT(JSOp(*tryPc) == JSOP_TRY); jsbytecode* tryTarget = tryStart + tn->length; MOZ_ASSERT(mainEntry <= tryTarget && tryTarget < end); MOZ_ASSERT(BytecodeIsJumpTarget(JSOp(*tryTarget))); } } } #endif size_t JSScript::computedSizeOfData() const { return dataSize(); } size_t JSScript::sizeOfData(mozilla::MallocSizeOf mallocSizeOf) const { return mallocSizeOf(data); } size_t JSScript::sizeOfTypeScript(mozilla::MallocSizeOf mallocSizeOf) const { return types_->sizeOfIncludingThis(mallocSizeOf); } /* * Nb: srcnotes are variable-length. This function computes the number of * srcnote *slots*, which may be greater than the number of srcnotes. */ uint32_t JSScript::numNotes() { jssrcnote* sn; jssrcnote* notes_ = notes(); for (sn = notes_; !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn)) continue; return sn - notes_ + 1; /* +1 for the terminator */ } js::GlobalObject& JSScript::uninlinedGlobal() const { return global(); } void JSScript::finalize(FreeOp* fop) { // NOTE: this JSScript may be partially initialized at this point. E.g. we // may have created it and partially initialized it with // JSScript::Create(), but not yet finished initializing it with // fullyInitFromEmitter() or fullyInitTrivial(). // Collect code coverage information for this script and all its inner // scripts, and store the aggregated information on the compartment. if (fop->runtime()->lcovOutput.isEnabled()) compartment()->lcovOutput.collectCodeCoverageInfo(compartment(), sourceObject(), this); fop->runtime()->spsProfiler.onScriptFinalized(this); if (types_) types_->destroy(); jit::DestroyJitScripts(fop, this); destroyScriptCounts(fop); destroyDebugScript(fop); if (data) { JS_POISON(data, 0xdb, computedSizeOfData()); fop->free_(data); } if (scriptData_) scriptData_->decRefCount(); fop->runtime()->contextFromMainThread()->caches.lazyScriptCache.remove(this); // In most cases, our LazyScript's script pointer will reference this // script, and thus be nulled out by normal weakref processing. However, if // we unlazified the LazyScript during incremental sweeping, it will have a // completely different JSScript. MOZ_ASSERT_IF(lazyScript && !IsAboutToBeFinalizedUnbarriered(&lazyScript), !lazyScript->hasScript() || lazyScript->maybeScriptUnbarriered() != this); } static const uint32_t GSN_CACHE_THRESHOLD = 100; void GSNCache::purge() { code = nullptr; if (map.initialized()) map.finish(); } jssrcnote* js::GetSrcNote(GSNCache& cache, JSScript* script, jsbytecode* pc) { size_t target = pc - script->code(); if (target >= script->length()) return nullptr; if (cache.code == script->code()) { MOZ_ASSERT(cache.map.initialized()); GSNCache::Map::Ptr p = cache.map.lookup(pc); return p ? p->value() : nullptr; } size_t offset = 0; jssrcnote* result; for (jssrcnote* sn = script->notes(); ; sn = SN_NEXT(sn)) { if (SN_IS_TERMINATOR(sn)) { result = nullptr; break; } offset += SN_DELTA(sn); if (offset == target && SN_IS_GETTABLE(sn)) { result = sn; break; } } if (cache.code != script->code() && script->length() >= GSN_CACHE_THRESHOLD) { unsigned nsrcnotes = 0; for (jssrcnote* sn = script->notes(); !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn)) { if (SN_IS_GETTABLE(sn)) ++nsrcnotes; } if (cache.code) { MOZ_ASSERT(cache.map.initialized()); cache.map.finish(); cache.code = nullptr; } if (cache.map.init(nsrcnotes)) { pc = script->code(); for (jssrcnote* sn = script->notes(); !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn)) { pc += SN_DELTA(sn); if (SN_IS_GETTABLE(sn)) cache.map.putNewInfallible(pc, sn); } cache.code = script->code(); } } return result; } jssrcnote* js::GetSrcNote(JSContext* cx, JSScript* script, jsbytecode* pc) { return GetSrcNote(cx->caches.gsnCache, script, pc); } unsigned js::PCToLineNumber(unsigned startLine, jssrcnote* notes, jsbytecode* code, jsbytecode* pc, unsigned* columnp) { unsigned lineno = startLine; unsigned column = 0; /* * Walk through source notes accumulating their deltas, keeping track of * line-number notes, until we pass the note for pc's offset within * script->code. */ ptrdiff_t offset = 0; ptrdiff_t target = pc - code; for (jssrcnote* sn = notes; !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn)) { offset += SN_DELTA(sn); if (offset > target) break; SrcNoteType type = (SrcNoteType) SN_TYPE(sn); if (type == SRC_SETLINE) { lineno = unsigned(GetSrcNoteOffset(sn, 0)); column = 0; } else if (type == SRC_NEWLINE) { lineno++; column = 0; } else if (type == SRC_COLSPAN) { ptrdiff_t colspan = SN_OFFSET_TO_COLSPAN(GetSrcNoteOffset(sn, 0)); MOZ_ASSERT(ptrdiff_t(column) + colspan >= 0); column += colspan; } } if (columnp) *columnp = column; return lineno; } unsigned js::PCToLineNumber(JSScript* script, jsbytecode* pc, unsigned* columnp) { /* Cope with InterpreterFrame.pc value prior to entering Interpret. */ if (!pc) return 0; return PCToLineNumber(script->lineno(), script->notes(), script->code(), pc, columnp); } jsbytecode* js::LineNumberToPC(JSScript* script, unsigned target) { ptrdiff_t offset = 0; ptrdiff_t best = -1; unsigned lineno = script->lineno(); unsigned bestdiff = SN_MAX_OFFSET; for (jssrcnote* sn = script->notes(); !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn)) { /* * Exact-match only if offset is not in the prologue; otherwise use * nearest greater-or-equal line number match. */ if (lineno == target && offset >= ptrdiff_t(script->mainOffset())) goto out; if (lineno >= target) { unsigned diff = lineno - target; if (diff < bestdiff) { bestdiff = diff; best = offset; } } offset += SN_DELTA(sn); SrcNoteType type = (SrcNoteType) SN_TYPE(sn); if (type == SRC_SETLINE) { lineno = unsigned(GetSrcNoteOffset(sn, 0)); } else if (type == SRC_NEWLINE) { lineno++; } } if (best >= 0) offset = best; out: return script->offsetToPC(offset); } JS_FRIEND_API(unsigned) js::GetScriptLineExtent(JSScript* script) { unsigned lineno = script->lineno(); unsigned maxLineNo = lineno; for (jssrcnote* sn = script->notes(); !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn)) { SrcNoteType type = (SrcNoteType) SN_TYPE(sn); if (type == SRC_SETLINE) lineno = unsigned(GetSrcNoteOffset(sn, 0)); else if (type == SRC_NEWLINE) lineno++; if (maxLineNo < lineno) maxLineNo = lineno; } return 1 + maxLineNo - script->lineno(); } void js::DescribeScriptedCallerForCompilation(JSContext* cx, MutableHandleScript maybeScript, const char** file, unsigned* linenop, uint32_t* pcOffset, bool* mutedErrors, LineOption opt) { if (opt == CALLED_FROM_JSOP_EVAL) { jsbytecode* pc = nullptr; maybeScript.set(cx->currentScript(&pc)); static_assert(JSOP_SPREADEVAL_LENGTH == JSOP_STRICTSPREADEVAL_LENGTH, "next op after a spread must be at consistent offset"); static_assert(JSOP_EVAL_LENGTH == JSOP_STRICTEVAL_LENGTH, "next op after a direct eval must be at consistent offset"); MOZ_ASSERT(JSOp(*pc) == JSOP_EVAL || JSOp(*pc) == JSOP_STRICTEVAL || JSOp(*pc) == JSOP_SPREADEVAL || JSOp(*pc) == JSOP_STRICTSPREADEVAL); bool isSpread = JSOp(*pc) == JSOP_SPREADEVAL || JSOp(*pc) == JSOP_STRICTSPREADEVAL; jsbytecode* nextpc = pc + (isSpread ? JSOP_SPREADEVAL_LENGTH : JSOP_EVAL_LENGTH); MOZ_ASSERT(*nextpc == JSOP_LINENO); *file = maybeScript->filename(); *linenop = GET_UINT32(nextpc); *pcOffset = pc - maybeScript->code(); *mutedErrors = maybeScript->mutedErrors(); return; } NonBuiltinFrameIter iter(cx, cx->compartment()->principals()); if (iter.done()) { maybeScript.set(nullptr); *file = nullptr; *linenop = 0; *pcOffset = 0; *mutedErrors = false; return; } *file = iter.filename(); *linenop = iter.computeLine(); *mutedErrors = iter.mutedErrors(); // These values are only used for introducer fields which are debugging // information and can be safely left null for wasm frames. if (iter.hasScript()) { maybeScript.set(iter.script()); *pcOffset = iter.pc() - maybeScript->code(); } else { maybeScript.set(nullptr); *pcOffset = 0; } } template <class T> static inline T* Rebase(JSScript* dst, JSScript* src, T* srcp) { size_t off = reinterpret_cast<uint8_t*>(srcp) - src->data; return reinterpret_cast<T*>(dst->data + off); } static JSObject* CloneInnerInterpretedFunction(JSContext* cx, HandleScope enclosingScope, HandleFunction srcFun) { /* NB: Keep this in sync with XDRInterpretedFunction. */ RootedObject cloneProto(cx); if (srcFun->isStarGenerator()) { cloneProto = GlobalObject::getOrCreateStarGeneratorFunctionPrototype(cx, cx->global()); if (!cloneProto) return nullptr; } gc::AllocKind allocKind = srcFun->getAllocKind(); uint16_t flags = srcFun->flags(); if (srcFun->isSelfHostedBuiltin()) { // Functions in the self-hosting compartment are only extended in // debug mode. For top-level functions, FUNCTION_EXTENDED gets used by // the cloning algorithm. Do the same for inner functions here. allocKind = gc::AllocKind::FUNCTION_EXTENDED; flags |= JSFunction::Flags::EXTENDED; } RootedAtom atom(cx, srcFun->displayAtom()); RootedFunction clone(cx, NewFunctionWithProto(cx, nullptr, srcFun->nargs(), JSFunction::Flags(flags), nullptr, atom, cloneProto, allocKind, TenuredObject)); if (!clone) return nullptr; JSScript::AutoDelazify srcScript(cx, srcFun); if (!srcScript) return nullptr; JSScript* cloneScript = CloneScriptIntoFunction(cx, enclosingScope, clone, srcScript); if (!cloneScript) return nullptr; if (!JSFunction::setTypeForScriptedFunction(cx, clone)) return nullptr; return clone; } bool js::detail::CopyScript(JSContext* cx, HandleScript src, HandleScript dst, MutableHandle<GCVector<Scope*>> scopes) { if (src->treatAsRunOnce() && !src->functionNonDelazifying()) { JS_ReportErrorASCII(cx, "No cloning toplevel run-once scripts"); return false; } /* NB: Keep this in sync with XDRScript. */ /* Some embeddings are not careful to use ExposeObjectToActiveJS as needed. */ MOZ_ASSERT(!src->sourceObject()->asTenured().isMarked(gc::GRAY)); uint32_t nconsts = src->hasConsts() ? src->consts()->length : 0; uint32_t nobjects = src->hasObjects() ? src->objects()->length : 0; uint32_t nscopes = src->scopes()->length; uint32_t ntrynotes = src->hasTrynotes() ? src->trynotes()->length : 0; uint32_t nscopenotes = src->hasScopeNotes() ? src->scopeNotes()->length : 0; uint32_t nyieldoffsets = src->hasYieldOffsets() ? src->yieldOffsets().length() : 0; /* Script data */ size_t size = src->dataSize(); ScopedJSFreePtr<uint8_t> data(AllocScriptData(cx->zone(), size)); if (size && !data) { ReportOutOfMemory(cx); return false; } /* Scopes */ // The passed in scopes vector contains body scopes that needed to be // cloned especially, depending on whether the script is a function or // global scope. Starting at scopes.length() means we only deal with // intra-body scopes. { MOZ_ASSERT(nscopes != 0); MOZ_ASSERT(src->bodyScopeIndex() + 1 == scopes.length()); GCPtrScope* vector = src->scopes()->vector; RootedScope original(cx); RootedScope clone(cx); for (uint32_t i = scopes.length(); i < nscopes; i++) { original = vector[i]; clone = Scope::clone(cx, original, scopes[FindScopeIndex(src, *original->enclosing())]); if (!clone || !scopes.append(clone)) return false; } } /* Objects */ AutoObjectVector objects(cx); if (nobjects != 0) { GCPtrObject* vector = src->objects()->vector; RootedObject obj(cx); RootedObject clone(cx); for (unsigned i = 0; i < nobjects; i++) { obj = vector[i]; clone = nullptr; if (obj->is<RegExpObject>()) { clone = CloneScriptRegExpObject(cx, obj->as<RegExpObject>()); } else if (obj->is<JSFunction>()) { RootedFunction innerFun(cx, &obj->as<JSFunction>()); if (innerFun->isNative()) { if (cx->compartment() != innerFun->compartment()) { MOZ_ASSERT(innerFun->isAsmJSNative()); JS_ReportErrorASCII(cx, "AsmJS modules do not yet support cloning."); return false; } clone = innerFun; } else { if (innerFun->isInterpretedLazy()) { AutoCompartment ac(cx, innerFun); if (!innerFun->getOrCreateScript(cx)) return false; } Scope* enclosing = innerFun->nonLazyScript()->enclosingScope(); RootedScope enclosingClone(cx, scopes[FindScopeIndex(src, *enclosing)]); clone = CloneInnerInterpretedFunction(cx, enclosingClone, innerFun); } } else { clone = DeepCloneObjectLiteral(cx, obj, TenuredObject); } if (!clone || !objects.append(clone)) return false; } } /* This assignment must occur before all the Rebase calls. */ dst->data = data.forget(); dst->dataSize_ = size; MOZ_ASSERT(bool(dst->data) == bool(src->data)); if (dst->data) memcpy(dst->data, src->data, size); /* Script filenames, bytecodes and atoms are runtime-wide. */ dst->setScriptData(src->scriptData()); dst->lineno_ = src->lineno(); dst->mainOffset_ = src->mainOffset(); dst->nfixed_ = src->nfixed(); dst->nslots_ = src->nslots(); dst->bodyScopeIndex_ = src->bodyScopeIndex_; dst->funLength_ = src->funLength(); dst->nTypeSets_ = src->nTypeSets(); if (src->argumentsHasVarBinding()) { dst->setArgumentsHasVarBinding(); if (src->analyzedArgsUsage()) dst->setNeedsArgsObj(src->needsArgsObj()); } dst->hasMappedArgsObj_ = src->hasMappedArgsObj(); dst->functionHasThisBinding_ = src->functionHasThisBinding(); dst->functionHasExtraBodyVarScope_ = src->functionHasExtraBodyVarScope(); dst->cloneHasArray(src); dst->strict_ = src->strict(); dst->explicitUseStrict_ = src->explicitUseStrict(); dst->hasNonSyntacticScope_ = scopes[0]->hasOnChain(ScopeKind::NonSyntactic); dst->bindingsAccessedDynamically_ = src->bindingsAccessedDynamically(); dst->funHasExtensibleScope_ = src->funHasExtensibleScope(); dst->funHasAnyAliasedFormal_ = src->funHasAnyAliasedFormal(); dst->hasSingletons_ = src->hasSingletons(); dst->treatAsRunOnce_ = src->treatAsRunOnce(); dst->hasInnerFunctions_ = src->hasInnerFunctions(); dst->isGeneratorExp_ = src->isGeneratorExp(); dst->setGeneratorKind(src->generatorKind()); dst->isDerivedClassConstructor_ = src->isDerivedClassConstructor(); dst->needsHomeObject_ = src->needsHomeObject(); dst->isDefaultClassConstructor_ = src->isDefaultClassConstructor(); dst->isAsync_ = src->asyncKind() == AsyncFunction; dst->hasRest_ = src->hasRest_; if (nconsts != 0) { GCPtrValue* vector = Rebase<GCPtrValue>(dst, src, src->consts()->vector); dst->consts()->vector = vector; for (unsigned i = 0; i < nconsts; ++i) MOZ_ASSERT_IF(vector[i].isGCThing(), vector[i].toString()->isAtom()); } if (nobjects != 0) { GCPtrObject* vector = Rebase<GCPtrObject>(dst, src, src->objects()->vector); dst->objects()->vector = vector; for (unsigned i = 0; i < nobjects; ++i) vector[i].init(&objects[i]->as<NativeObject>()); } { GCPtrScope* vector = Rebase<GCPtrScope>(dst, src, src->scopes()->vector); dst->scopes()->vector = vector; for (uint32_t i = 0; i < nscopes; ++i) vector[i].init(scopes[i]); } if (ntrynotes != 0) dst->trynotes()->vector = Rebase<JSTryNote>(dst, src, src->trynotes()->vector); if (nscopenotes != 0) dst->scopeNotes()->vector = Rebase<ScopeNote>(dst, src, src->scopeNotes()->vector); if (nyieldoffsets != 0) dst->yieldOffsets().vector_ = Rebase<uint32_t>(dst, src, src->yieldOffsets().vector_); /* * Function delazification assumes that their script does not have a * non-syntactic global scope. We ensure that as follows: * * 1) Initial parsing only creates lazy functions if * !hasNonSyntacticScope. * 2) Cloning a lazy function into a non-global scope will always require * that its script be cloned. See comments in * CloneFunctionObjectUseSameScript. * 3) Cloning a script never sets a lazyScript on the clone, so the function * cannot be relazified. * * If you decide that lazy functions should be supported with a * non-syntactic global scope, make sure delazification can deal. */ MOZ_ASSERT_IF(dst->hasNonSyntacticScope(), !dst->maybeLazyScript()); MOZ_ASSERT_IF(dst->hasNonSyntacticScope(), !dst->isRelazifiable()); return true; } static JSScript* CreateEmptyScriptForClone(JSContext* cx, HandleScript src) { /* * Wrap the script source object as needed. Self-hosted scripts may be * in another runtime, so lazily create a new script source object to * use for them. */ RootedObject sourceObject(cx); if (cx->runtime()->isSelfHostingCompartment(src->compartment())) { if (!cx->compartment()->selfHostingScriptSource) { CompileOptions options(cx); FillSelfHostingCompileOptions(options); ScriptSourceObject* obj = frontend::CreateScriptSourceObject(cx, options); if (!obj) return nullptr; cx->compartment()->selfHostingScriptSource.set(obj); } sourceObject = cx->compartment()->selfHostingScriptSource; } else { sourceObject = src->sourceObject(); if (!cx->compartment()->wrap(cx, &sourceObject)) return nullptr; } CompileOptions options(cx); options.setMutedErrors(src->mutedErrors()) .setSelfHostingMode(src->selfHosted()) .setNoScriptRval(src->noScriptRval()) .setVersion(src->getVersion()); return JSScript::Create(cx, options, sourceObject, src->sourceStart(), src->sourceEnd()); } JSScript* js::CloneGlobalScript(JSContext* cx, ScopeKind scopeKind, HandleScript src) { MOZ_ASSERT(scopeKind == ScopeKind::Global || scopeKind == ScopeKind::NonSyntactic); RootedScript dst(cx, CreateEmptyScriptForClone(cx, src)); if (!dst) return nullptr; MOZ_ASSERT(src->bodyScopeIndex() == 0); Rooted<GCVector<Scope*>> scopes(cx, GCVector<Scope*>(cx)); Rooted<GlobalScope*> original(cx, &src->bodyScope()->as<GlobalScope>()); GlobalScope* clone = GlobalScope::clone(cx, original, scopeKind); if (!clone || !scopes.append(clone)) return nullptr; if (!detail::CopyScript(cx, src, dst, &scopes)) return nullptr; return dst; } JSScript* js::CloneScriptIntoFunction(JSContext* cx, HandleScope enclosingScope, HandleFunction fun, HandleScript src) { MOZ_ASSERT(fun->isInterpreted()); MOZ_ASSERT(!fun->hasScript() || fun->hasUncompiledScript()); RootedScript dst(cx, CreateEmptyScriptForClone(cx, src)); if (!dst) return nullptr; // Clone the non-intra-body scopes. Rooted<GCVector<Scope*>> scopes(cx, GCVector<Scope*>(cx)); RootedScope original(cx); RootedScope enclosingClone(cx); for (uint32_t i = 0; i <= src->bodyScopeIndex(); i++) { original = src->getScope(i); if (i == 0) { enclosingClone = enclosingScope; } else { MOZ_ASSERT(src->getScope(i - 1) == original->enclosing()); enclosingClone = scopes[i - 1]; } Scope* clone; if (original->is<FunctionScope>()) clone = FunctionScope::clone(cx, original.as<FunctionScope>(), fun, enclosingClone); else clone = Scope::clone(cx, original, enclosingClone); if (!clone || !scopes.append(clone)) return nullptr; } // Save flags in case we need to undo the early mutations. const int preservedFlags = fun->flags(); if (!detail::CopyScript(cx, src, dst, &scopes)) { fun->setFlags(preservedFlags); return nullptr; } // Finally set the script after all the fallible operations. if (fun->isInterpretedLazy()) fun->setUnlazifiedScript(dst); else fun->initScript(dst); return dst; } DebugScript* JSScript::debugScript() { MOZ_ASSERT(hasDebugScript_); DebugScriptMap* map = compartment()->debugScriptMap; MOZ_ASSERT(map); DebugScriptMap::Ptr p = map->lookup(this); MOZ_ASSERT(p); return p->value(); } DebugScript* JSScript::releaseDebugScript() { MOZ_ASSERT(hasDebugScript_); DebugScriptMap* map = compartment()->debugScriptMap; MOZ_ASSERT(map); DebugScriptMap::Ptr p = map->lookup(this); MOZ_ASSERT(p); DebugScript* debug = p->value(); map->remove(p); hasDebugScript_ = false; return debug; } void JSScript::destroyDebugScript(FreeOp* fop) { if (hasDebugScript_) { #ifdef DEBUG for (jsbytecode* pc = code(); pc < codeEnd(); pc++) { if (BreakpointSite* site = getBreakpointSite(pc)) { /* Breakpoints are swept before finalization. */ MOZ_ASSERT(site->firstBreakpoint() == nullptr); MOZ_ASSERT(getBreakpointSite(pc) == nullptr); } } #endif fop->free_(releaseDebugScript()); } } bool JSScript::ensureHasDebugScript(JSContext* cx) { if (hasDebugScript_) return true; size_t nbytes = offsetof(DebugScript, breakpoints) + length() * sizeof(BreakpointSite*); DebugScript* debug = (DebugScript*) zone()->pod_calloc<uint8_t>(nbytes); if (!debug) return false; /* Create compartment's debugScriptMap if necessary. */ DebugScriptMap* map = compartment()->debugScriptMap; if (!map) { map = cx->new_<DebugScriptMap>(); if (!map || !map->init()) { js_free(debug); js_delete(map); return false; } compartment()->debugScriptMap = map; } if (!map->putNew(this, debug)) { js_free(debug); return false; } hasDebugScript_ = true; // safe to set this; we can't fail after this point /* * Ensure that any Interpret() instances running on this script have * interrupts enabled. The interrupts must stay enabled until the * debug state is destroyed. */ for (ActivationIterator iter(cx->runtime()); !iter.done(); ++iter) { if (iter->isInterpreter()) iter->asInterpreter()->enableInterruptsIfRunning(this); } return true; } void JSScript::setNewStepMode(FreeOp* fop, uint32_t newValue) { DebugScript* debug = debugScript(); uint32_t prior = debug->stepMode; debug->stepMode = newValue; if (!prior != !newValue) { if (hasBaselineScript()) baseline->toggleDebugTraps(this, nullptr); if (!stepModeEnabled() && !debug->numSites) fop->free_(releaseDebugScript()); } } bool JSScript::incrementStepModeCount(JSContext* cx) { assertSameCompartment(cx, this); MOZ_ASSERT(cx->compartment()->isDebuggee()); if (!ensureHasDebugScript(cx)) return false; DebugScript* debug = debugScript(); uint32_t count = debug->stepMode; setNewStepMode(cx->runtime()->defaultFreeOp(), count + 1); return true; } void JSScript::decrementStepModeCount(FreeOp* fop) { DebugScript* debug = debugScript(); uint32_t count = debug->stepMode; MOZ_ASSERT(count > 0); setNewStepMode(fop, count - 1); } BreakpointSite* JSScript::getOrCreateBreakpointSite(JSContext* cx, jsbytecode* pc) { if (!ensureHasDebugScript(cx)) return nullptr; DebugScript* debug = debugScript(); BreakpointSite*& site = debug->breakpoints[pcToOffset(pc)]; if (!site) { site = cx->runtime()->new_<BreakpointSite>(this, pc); if (!site) { ReportOutOfMemory(cx); return nullptr; } debug->numSites++; } return site; } void JSScript::destroyBreakpointSite(FreeOp* fop, jsbytecode* pc) { DebugScript* debug = debugScript(); BreakpointSite*& site = debug->breakpoints[pcToOffset(pc)]; MOZ_ASSERT(site); fop->delete_(site); site = nullptr; if (--debug->numSites == 0 && !stepModeEnabled()) fop->free_(releaseDebugScript()); } void JSScript::clearBreakpointsIn(FreeOp* fop, js::Debugger* dbg, JSObject* handler) { if (!hasAnyBreakpointsOrStepMode()) return; for (jsbytecode* pc = code(); pc < codeEnd(); pc++) { BreakpointSite* site = getBreakpointSite(pc); if (site) { Breakpoint* nextbp; for (Breakpoint* bp = site->firstBreakpoint(); bp; bp = nextbp) { nextbp = bp->nextInSite(); if ((!dbg || bp->debugger == dbg) && (!handler || bp->getHandler() == handler)) bp->destroy(fop); } } } } bool JSScript::hasBreakpointsAt(jsbytecode* pc) { BreakpointSite* site = getBreakpointSite(pc); if (!site) return false; return site->enabledCount > 0; } void SharedScriptData::traceChildren(JSTracer* trc) { MOZ_ASSERT(refCount() != 0); for (uint32_t i = 0; i < natoms(); ++i) TraceNullableEdge(trc, &atoms()[i], "atom"); } void JSScript::traceChildren(JSTracer* trc) { // NOTE: this JSScript may be partially initialized at this point. E.g. we // may have created it and partially initialized it with // JSScript::Create(), but not yet finished initializing it with // fullyInitFromEmitter() or fullyInitTrivial(). MOZ_ASSERT_IF(trc->isMarkingTracer() && static_cast<GCMarker*>(trc)->shouldCheckCompartments(), zone()->isCollecting()); if (scriptData()) scriptData()->traceChildren(trc); if (ScopeArray* scopearray = scopes()) TraceRange(trc, scopearray->length, scopearray->vector, "scopes"); if (hasConsts()) { ConstArray* constarray = consts(); TraceRange(trc, constarray->length, constarray->vector, "consts"); } if (hasObjects()) { ObjectArray* objarray = objects(); TraceRange(trc, objarray->length, objarray->vector, "objects"); } MOZ_ASSERT_IF(sourceObject(), MaybeForwarded(sourceObject())->compartment() == compartment()); TraceNullableEdge(trc, &sourceObject_, "sourceObject"); if (maybeLazyScript()) TraceManuallyBarrieredEdge(trc, &lazyScript, "lazyScript"); if (trc->isMarkingTracer()) compartment()->mark(); jit::TraceJitScripts(trc, this); } void LazyScript::finalize(FreeOp* fop) { fop->free_(table_); } size_t JSScript::calculateLiveFixed(jsbytecode* pc) { size_t nlivefixed = numAlwaysLiveFixedSlots(); if (nfixed() != nlivefixed) { Scope* scope = lookupScope(pc); if (scope) scope = MaybeForwarded(scope); // Find the nearest LexicalScope in the same script. while (scope && scope->is<WithScope>()) { scope = scope->enclosing(); if (scope) scope = MaybeForwarded(scope); } if (scope) { if (scope->is<LexicalScope>()) nlivefixed = scope->as<LexicalScope>().nextFrameSlot(); else if (scope->is<VarScope>()) nlivefixed = scope->as<VarScope>().nextFrameSlot(); } } MOZ_ASSERT(nlivefixed <= nfixed()); MOZ_ASSERT(nlivefixed >= numAlwaysLiveFixedSlots()); return nlivefixed; } Scope* JSScript::lookupScope(jsbytecode* pc) { MOZ_ASSERT(containsPC(pc)); if (!hasScopeNotes()) return nullptr; size_t offset = pc - code(); ScopeNoteArray* notes = scopeNotes(); Scope* scope = nullptr; // Find the innermost block chain using a binary search. size_t bottom = 0; size_t top = notes->length; while (bottom < top) { size_t mid = bottom + (top - bottom) / 2; const ScopeNote* note = ¬es->vector[mid]; if (note->start <= offset) { // Block scopes are ordered in the list by their starting offset, and since // blocks form a tree ones earlier in the list may cover the pc even if // later blocks end before the pc. This only happens when the earlier block // is a parent of the later block, so we need to check parents of |mid| in // the searched range for coverage. size_t check = mid; while (check >= bottom) { const ScopeNote* checkNote = ¬es->vector[check]; MOZ_ASSERT(checkNote->start <= offset); if (offset < checkNote->start + checkNote->length) { // We found a matching block chain but there may be inner ones // at a higher block chain index than mid. Continue the binary search. if (checkNote->index == ScopeNote::NoScopeIndex) scope = nullptr; else scope = getScope(checkNote->index); break; } if (checkNote->parent == UINT32_MAX) break; check = checkNote->parent; } bottom = mid + 1; } else { top = mid; } } return scope; } Scope* JSScript::innermostScope(jsbytecode* pc) { if (Scope* scope = lookupScope(pc)) return scope; return bodyScope(); } void JSScript::setArgumentsHasVarBinding() { argsHasVarBinding_ = true; needsArgsAnalysis_ = true; } void JSScript::setNeedsArgsObj(bool needsArgsObj) { MOZ_ASSERT_IF(needsArgsObj, argumentsHasVarBinding()); needsArgsAnalysis_ = false; needsArgsObj_ = needsArgsObj; } void js::SetFrameArgumentsObject(JSContext* cx, AbstractFramePtr frame, HandleScript script, JSObject* argsobj) { /* * Replace any optimized arguments in the frame with an explicit arguments * object. Note that 'arguments' may have already been overwritten. */ Rooted<BindingIter> bi(cx, BindingIter(script)); while (bi && bi.name() != cx->names().arguments) bi++; if (!bi) return; if (bi.location().kind() == BindingLocation::Kind::Environment) { /* * Scan the script to find the slot in the call object that 'arguments' * is assigned to. */ jsbytecode* pc = script->code(); while (*pc != JSOP_ARGUMENTS) pc += GetBytecodeLength(pc); pc += JSOP_ARGUMENTS_LENGTH; MOZ_ASSERT(*pc == JSOP_SETALIASEDVAR); // Note that here and below, it is insufficient to only check for // JS_OPTIMIZED_ARGUMENTS, as Ion could have optimized out the // arguments slot. EnvironmentObject& env = frame.callObj().as<EnvironmentObject>(); if (IsOptimizedPlaceholderMagicValue(env.aliasedBinding(bi))) env.setAliasedBinding(cx, bi, ObjectValue(*argsobj)); } else { MOZ_ASSERT(bi.location().kind() == BindingLocation::Kind::Frame); uint32_t frameSlot = bi.location().slot(); if (IsOptimizedPlaceholderMagicValue(frame.unaliasedLocal(frameSlot))) frame.unaliasedLocal(frameSlot) = ObjectValue(*argsobj); } } /* static */ bool JSScript::argumentsOptimizationFailed(JSContext* cx, HandleScript script) { MOZ_ASSERT(script->functionNonDelazifying()); MOZ_ASSERT(script->analyzedArgsUsage()); MOZ_ASSERT(script->argumentsHasVarBinding()); /* * It is possible that the arguments optimization has already failed, * everything has been fixed up, but there was an outstanding magic value * on the stack that has just now flowed into an apply. In this case, there * is nothing to do; GuardFunApplySpeculation will patch in the real * argsobj. */ if (script->needsArgsObj()) return true; MOZ_ASSERT(!script->isGenerator()); script->needsArgsObj_ = true; /* * Since we can't invalidate baseline scripts, set a flag that's checked from * JIT code to indicate the arguments optimization failed and JSOP_ARGUMENTS * should create an arguments object next time. */ if (script->hasBaselineScript()) script->baselineScript()->setNeedsArgsObj(); /* * By design, the arguments optimization is only made when there are no * outstanding cases of MagicValue(JS_OPTIMIZED_ARGUMENTS) at any points * where the optimization could fail, other than an active invocation of * 'f.apply(x, arguments)'. Thus, there are no outstanding values of * MagicValue(JS_OPTIMIZED_ARGUMENTS) on the stack. However, there are * three things that need fixup: * - there may be any number of activations of this script that don't have * an argsObj that now need one. * - jit code compiled (and possible active on the stack) with the static * assumption of !script->needsArgsObj(); * - type inference data for the script assuming script->needsArgsObj */ for (AllScriptFramesIter i(cx); !i.done(); ++i) { /* * We cannot reliably create an arguments object for Ion activations of * this script. To maintain the invariant that "script->needsArgsObj * implies fp->hasArgsObj", the Ion bail mechanism will create an * arguments object right after restoring the BaselineFrame and before * entering Baseline code (in jit::FinishBailoutToBaseline). */ if (i.isIon()) continue; AbstractFramePtr frame = i.abstractFramePtr(); if (frame.isFunctionFrame() && frame.script() == script) { /* We crash on OOM since cleaning up here would be complicated. */ AutoEnterOOMUnsafeRegion oomUnsafe; ArgumentsObject* argsobj = ArgumentsObject::createExpected(cx, frame); if (!argsobj) oomUnsafe.crash("JSScript::argumentsOptimizationFailed"); SetFrameArgumentsObject(cx, frame, script, argsobj); } } return true; } bool JSScript::formalIsAliased(unsigned argSlot) { if (functionHasParameterExprs()) return false; for (PositionalFormalParameterIter fi(this); fi; fi++) { if (fi.argumentSlot() == argSlot) return fi.closedOver(); } MOZ_CRASH("Argument slot not found"); } bool JSScript::formalLivesInArgumentsObject(unsigned argSlot) { return argsObjAliasesFormals() && !formalIsAliased(argSlot); } LazyScript::LazyScript(JSFunction* fun, void* table, uint64_t packedFields, uint32_t begin, uint32_t end, uint32_t lineno, uint32_t column) : script_(nullptr), function_(fun), enclosingScope_(nullptr), sourceObject_(nullptr), table_(table), packedFields_(packedFields), begin_(begin), end_(end), lineno_(lineno), column_(column) { MOZ_ASSERT(begin <= end); } void LazyScript::initScript(JSScript* script) { MOZ_ASSERT(script); MOZ_ASSERT(!script_.unbarrieredGet()); script_.set(script); } void LazyScript::resetScript() { MOZ_ASSERT(script_.unbarrieredGet()); script_.set(nullptr); } void LazyScript::setEnclosingScopeAndSource(Scope* enclosingScope, ScriptSourceObject* sourceObject) { MOZ_ASSERT(function_->compartment() == sourceObject->compartment()); // This method may be called to update the enclosing scope. See comment // above the callsite in BytecodeEmitter::emitFunction. MOZ_ASSERT_IF(sourceObject_, sourceObject_ == sourceObject && enclosingScope_); MOZ_ASSERT_IF(!sourceObject_, !enclosingScope_); enclosingScope_ = enclosingScope; sourceObject_ = sourceObject; } ScriptSourceObject* LazyScript::sourceObject() const { return sourceObject_ ? &sourceObject_->as<ScriptSourceObject>() : nullptr; } ScriptSource* LazyScript::maybeForwardedScriptSource() const { return UncheckedUnwrap(MaybeForwarded(sourceObject()))->as<ScriptSourceObject>().source(); } /* static */ LazyScript* LazyScript::CreateRaw(ExclusiveContext* cx, HandleFunction fun, uint64_t packedFields, uint32_t begin, uint32_t end, uint32_t lineno, uint32_t column) { union { PackedView p; uint64_t packed; }; packed = packedFields; // Reset runtime flags to obtain a fresh LazyScript. p.hasBeenCloned = false; p.treatAsRunOnce = false; size_t bytes = (p.numClosedOverBindings * sizeof(JSAtom*)) + (p.numInnerFunctions * sizeof(GCPtrFunction)); ScopedJSFreePtr<uint8_t> table(bytes ? fun->zone()->pod_malloc<uint8_t>(bytes) : nullptr); if (bytes && !table) { ReportOutOfMemory(cx); return nullptr; } LazyScript* res = Allocate<LazyScript>(cx); if (!res) return nullptr; cx->compartment()->scheduleDelazificationForDebugger(); return new (res) LazyScript(fun, table.forget(), packed, begin, end, lineno, column); } /* static */ LazyScript* LazyScript::Create(ExclusiveContext* cx, HandleFunction fun, const frontend::AtomVector& closedOverBindings, Handle<GCVector<JSFunction*, 8>> innerFunctions, JSVersion version, uint32_t begin, uint32_t end, uint32_t lineno, uint32_t column) { union { PackedView p; uint64_t packedFields; }; p.version = version; p.shouldDeclareArguments = false; p.hasThisBinding = false; p.isAsync = false; p.hasRest = false; p.numClosedOverBindings = closedOverBindings.length(); p.numInnerFunctions = innerFunctions.length(); p.generatorKindBits = GeneratorKindAsBits(NotGenerator); p.strict = false; p.bindingsAccessedDynamically = false; p.hasDebuggerStatement = false; p.hasDirectEval = false; p.isLikelyConstructorWrapper = false; p.isDerivedClassConstructor = false; p.needsHomeObject = false; LazyScript* res = LazyScript::CreateRaw(cx, fun, packedFields, begin, end, lineno, column); if (!res) return nullptr; JSAtom** resClosedOverBindings = res->closedOverBindings(); for (size_t i = 0; i < res->numClosedOverBindings(); i++) resClosedOverBindings[i] = closedOverBindings[i]; GCPtrFunction* resInnerFunctions = res->innerFunctions(); for (size_t i = 0; i < res->numInnerFunctions(); i++) resInnerFunctions[i].init(innerFunctions[i]); MOZ_ASSERT_IF(res, res->version() == version); return res; } /* static */ LazyScript* LazyScript::Create(ExclusiveContext* cx, HandleFunction fun, HandleScript script, HandleScope enclosingScope, HandleScript enclosingScript, uint64_t packedFields, uint32_t begin, uint32_t end, uint32_t lineno, uint32_t column) { // Dummy atom which is not a valid property name. RootedAtom dummyAtom(cx, cx->names().comma); // Dummy function which is not a valid function as this is the one which is // holding this lazy script. HandleFunction dummyFun = fun; LazyScript* res = LazyScript::CreateRaw(cx, fun, packedFields, begin, end, lineno, column); if (!res) return nullptr; // Fill with dummies, to be GC-safe after the initialization of the free // variables and inner functions. size_t i, num; JSAtom** closedOverBindings = res->closedOverBindings(); for (i = 0, num = res->numClosedOverBindings(); i < num; i++) closedOverBindings[i] = dummyAtom; GCPtrFunction* functions = res->innerFunctions(); for (i = 0, num = res->numInnerFunctions(); i < num; i++) functions[i].init(dummyFun); // Set the enclosing scope and source object of the lazy function. These // values should only be non-null if we have a non-lazy enclosing script. // AddLazyFunctionsForCompartment relies on the source object being null // if we're nested inside another lazy function. MOZ_ASSERT(!!enclosingScript == !!enclosingScope); MOZ_ASSERT(!res->sourceObject()); MOZ_ASSERT(!res->enclosingScope()); if (enclosingScript) res->setEnclosingScopeAndSource(enclosingScope, &enclosingScript->scriptSourceUnwrap()); MOZ_ASSERT(!res->hasScript()); if (script) res->initScript(script); return res; } void LazyScript::initRuntimeFields(uint64_t packedFields) { union { PackedView p; uint64_t packed; }; packed = packedFields; p_.hasBeenCloned = p.hasBeenCloned; p_.treatAsRunOnce = p.treatAsRunOnce; } bool LazyScript::hasUncompiledEnclosingScript() const { // It can happen that we created lazy scripts while compiling an enclosing // script, but we errored out while compiling that script. When we iterate // over lazy script in a compartment, we might see lazy scripts that never // escaped to script and should be ignored. // // If the enclosing scope is a function with a null script or has a script // without code, it was not successfully compiled. if (!enclosingScope() || !enclosingScope()->is<FunctionScope>()) return false; JSFunction* fun = enclosingScope()->as<FunctionScope>().canonicalFunction(); return !fun->hasScript() || fun->hasUncompiledScript() || !fun->nonLazyScript()->code(); } void JSScript::updateBaselineOrIonRaw(JSRuntime* maybeRuntime) { if (hasBaselineScript() && baseline->hasPendingIonBuilder()) { MOZ_ASSERT(maybeRuntime); MOZ_ASSERT(!isIonCompilingOffThread()); baselineOrIonRaw = maybeRuntime->jitRuntime()->lazyLinkStub()->raw(); baselineOrIonSkipArgCheck = maybeRuntime->jitRuntime()->lazyLinkStub()->raw(); } else if (hasIonScript()) { baselineOrIonRaw = ion->method()->raw(); baselineOrIonSkipArgCheck = ion->method()->raw() + ion->getSkipArgCheckEntryOffset(); } else if (hasBaselineScript()) { baselineOrIonRaw = baseline->method()->raw(); baselineOrIonSkipArgCheck = baseline->method()->raw(); } else { baselineOrIonRaw = nullptr; baselineOrIonSkipArgCheck = nullptr; } } bool JSScript::hasLoops() { if (!hasTrynotes()) return false; JSTryNote* tn = trynotes()->vector; JSTryNote* tnlimit = tn + trynotes()->length; for (; tn < tnlimit; tn++) { if (tn->kind == JSTRY_FOR_IN || tn->kind == JSTRY_LOOP) return true; } return false; } bool JSScript::mayReadFrameArgsDirectly() { return argumentsHasVarBinding() || hasRest(); } static inline void LazyScriptHash(uint32_t lineno, uint32_t column, uint32_t begin, uint32_t end, HashNumber hashes[3]) { HashNumber hash = lineno; hash = RotateLeft(hash, 4) ^ column; hash = RotateLeft(hash, 4) ^ begin; hash = RotateLeft(hash, 4) ^ end; hashes[0] = hash; hashes[1] = RotateLeft(hashes[0], 4) ^ begin; hashes[2] = RotateLeft(hashes[1], 4) ^ end; } void LazyScriptHashPolicy::hash(const Lookup& lookup, HashNumber hashes[3]) { LazyScript* lazy = lookup.lazy; LazyScriptHash(lazy->lineno(), lazy->column(), lazy->begin(), lazy->end(), hashes); } void LazyScriptHashPolicy::hash(JSScript* script, HashNumber hashes[3]) { LazyScriptHash(script->lineno(), script->column(), script->sourceStart(), script->sourceEnd(), hashes); } bool LazyScriptHashPolicy::match(JSScript* script, const Lookup& lookup) { JSContext* cx = lookup.cx; LazyScript* lazy = lookup.lazy; // To be a match, the script and lazy script need to have the same line // and column and to be at the same position within their respective // source blobs, and to have the same source contents and version. // // While the surrounding code in the source may differ, this is // sufficient to ensure that compiling the lazy script will yield an // identical result to compiling the original script. // // Note that the filenames and origin principals of the lazy script and // original script can differ. If there is a match, these will be fixed // up in the resulting clone by the caller. if (script->lineno() != lazy->lineno() || script->column() != lazy->column() || script->getVersion() != lazy->version() || script->sourceStart() != lazy->begin() || script->sourceEnd() != lazy->end()) { return false; } UncompressedSourceCache::AutoHoldEntry holder; size_t scriptBegin = script->sourceStart(); size_t length = script->sourceEnd() - scriptBegin; const char16_t* scriptChars = script->scriptSource()->chars(cx, holder, scriptBegin, length); if (!scriptChars) return false; MOZ_ASSERT(scriptBegin == lazy->begin()); const char16_t* lazyChars = lazy->scriptSource()->chars(cx, holder, scriptBegin, length); if (!lazyChars) return false; return !memcmp(scriptChars, lazyChars, length); } void JSScript::AutoDelazify::holdScript(JS::HandleFunction fun) { if (fun) { if (fun->compartment()->isSelfHosting) { // The self-hosting compartment is shared across runtimes, so we // can't use JSAutoCompartment: it could cause races. Functions in // the self-hosting compartment will never be lazy, so we can safely // assume we don't have to delazify. script_ = fun->nonLazyScript(); } else { JSAutoCompartment ac(cx_, fun); script_ = fun->getOrCreateScript(cx_); if (script_) { oldDoNotRelazify_ = script_->doNotRelazify_; script_->setDoNotRelazify(true); } } } } void JSScript::AutoDelazify::dropScript() { // Don't touch script_ if it's in the self-hosting compartment, see the // comment in holdScript. if (script_ && !script_->compartment()->isSelfHosting) script_->setDoNotRelazify(oldDoNotRelazify_); script_ = nullptr; } JS::ubi::Node::Size JS::ubi::Concrete<JSScript>::size(mozilla::MallocSizeOf mallocSizeOf) const { Size size = Arena::thingSize(get().asTenured().getAllocKind()); size += get().sizeOfData(mallocSizeOf); size += get().sizeOfTypeScript(mallocSizeOf); size_t baselineSize = 0; size_t baselineStubsSize = 0; jit::AddSizeOfBaselineData(&get(), mallocSizeOf, &baselineSize, &baselineStubsSize); size += baselineSize; size += baselineStubsSize; size += jit::SizeOfIonData(&get(), mallocSizeOf); MOZ_ASSERT(size > 0); return size; } const char* JS::ubi::Concrete<JSScript>::scriptFilename() const { return get().filename(); } JS::ubi::Node::Size JS::ubi::Concrete<js::LazyScript>::size(mozilla::MallocSizeOf mallocSizeOf) const { Size size = js::gc::Arena::thingSize(get().asTenured().getAllocKind()); size += get().sizeOfExcludingThis(mallocSizeOf); return size; } const char* JS::ubi::Concrete<js::LazyScript>::scriptFilename() const { auto sourceObject = get().sourceObject(); if (!sourceObject) return nullptr; auto source = sourceObject->source(); if (!source) return nullptr; return source->filename(); }