/* -*- 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/. */ #ifndef vm_Interpreter_inl_h #define vm_Interpreter_inl_h #include "vm/Interpreter.h" #include "jscompartment.h" #include "jsnum.h" #include "jsstr.h" #include "jit/Ion.h" #include "vm/ArgumentsObject.h" #include "jsatominlines.h" #include "jsobjinlines.h" #include "vm/EnvironmentObject-inl.h" #include "vm/Stack-inl.h" #include "vm/String-inl.h" namespace js { /* * Every possible consumer of MagicValue(JS_OPTIMIZED_ARGUMENTS) (as determined * by ScriptAnalysis::needsArgsObj) must check for these magic values and, when * one is received, act as if the value were the function's ArgumentsObject. * Additionally, it is possible that, after 'arguments' was copied into a * temporary, the arguments object has been created a some other failed guard * that called JSScript::argumentsOptimizationFailed. In this case, it is * always valid (and necessary) to replace JS_OPTIMIZED_ARGUMENTS with the real * arguments object. */ static inline bool IsOptimizedArguments(AbstractFramePtr frame, MutableHandleValue vp) { if (vp.isMagic(JS_OPTIMIZED_ARGUMENTS) && frame.script()->needsArgsObj()) vp.setObject(frame.argsObj()); return vp.isMagic(JS_OPTIMIZED_ARGUMENTS); } /* * One optimized consumer of MagicValue(JS_OPTIMIZED_ARGUMENTS) is f.apply. * However, this speculation must be guarded before calling 'apply' in case it * is not the builtin Function.prototype.apply. */ static inline bool GuardFunApplyArgumentsOptimization(JSContext* cx, AbstractFramePtr frame, CallArgs& args) { if (args.length() == 2 && IsOptimizedArguments(frame, args[1])) { if (!IsNativeFunction(args.calleev(), js::fun_apply)) { RootedScript script(cx, frame.script()); if (!JSScript::argumentsOptimizationFailed(cx, script)) return false; args[1].setObject(frame.argsObj()); } } return true; } /* * Per ES6, lexical declarations may not be accessed in any fashion until they * are initialized (i.e., until the actual declaring statement is * executed). The various LEXICAL opcodes need to check if the slot is an * uninitialized let declaration, represented by the magic value * JS_UNINITIALIZED_LEXICAL. */ static inline bool IsUninitializedLexical(const Value& val) { // Use whyMagic here because JS_OPTIMIZED_ARGUMENTS could flow into here. return val.isMagic() && val.whyMagic() == JS_UNINITIALIZED_LEXICAL; } static inline bool IsUninitializedLexicalSlot(HandleObject obj, HandleShape shape) { MOZ_ASSERT(shape); if (obj->is()) return false; // We check for IsImplicitDenseOrTypedArrayElement even though the shape // is always a non-indexed property because proxy hooks may return a // "non-native property found" shape, which happens to be encoded in the // same way as the "dense element" shape. See MarkNonNativePropertyFound. if (IsImplicitDenseOrTypedArrayElement(shape) || !shape->hasSlot() || !shape->hasDefaultGetter() || !shape->hasDefaultSetter()) { return false; } MOZ_ASSERT(obj->as().containsPure(shape)); return IsUninitializedLexical(obj->as().getSlot(shape->slot())); } static inline void ReportUninitializedLexical(JSContext* cx, HandlePropertyName name) { ReportRuntimeLexicalError(cx, JSMSG_UNINITIALIZED_LEXICAL, name); } static inline void ReportUninitializedLexical(JSContext* cx, HandleScript script, jsbytecode* pc) { ReportRuntimeLexicalError(cx, JSMSG_UNINITIALIZED_LEXICAL, script, pc); } static inline bool CheckUninitializedLexical(JSContext* cx, PropertyName* name_, HandleValue val) { if (IsUninitializedLexical(val)) { RootedPropertyName name(cx, name_); ReportUninitializedLexical(cx, name); return false; } return true; } static inline bool CheckUninitializedLexical(JSContext* cx, HandleScript script, jsbytecode* pc, HandleValue val) { if (IsUninitializedLexical(val)) { ReportUninitializedLexical(cx, script, pc); return false; } return true; } static inline void ReportRuntimeConstAssignment(JSContext* cx, HandlePropertyName name) { ReportRuntimeLexicalError(cx, JSMSG_BAD_CONST_ASSIGN, name); } static inline void ReportRuntimeConstAssignment(JSContext* cx, HandleScript script, jsbytecode* pc) { ReportRuntimeLexicalError(cx, JSMSG_BAD_CONST_ASSIGN, script, pc); } inline bool GetLengthProperty(const Value& lval, MutableHandleValue vp) { /* Optimize length accesses on strings, arrays, and arguments. */ if (lval.isString()) { vp.setInt32(lval.toString()->length()); return true; } if (lval.isObject()) { JSObject* obj = &lval.toObject(); if (obj->is()) { vp.setNumber(obj->as().length()); return true; } if (obj->is()) { ArgumentsObject* argsobj = &obj->as(); if (!argsobj->hasOverriddenLength()) { uint32_t length = argsobj->initialLength(); MOZ_ASSERT(length < INT32_MAX); vp.setInt32(int32_t(length)); return true; } } } return false; } template inline bool FetchName(JSContext* cx, HandleObject obj, HandleObject obj2, HandlePropertyName name, HandleShape shape, MutableHandleValue vp) { if (!shape) { if (TypeOf) { vp.setUndefined(); return true; } return ReportIsNotDefined(cx, name); } /* Take the slow path if shape was not found in a native object. */ if (!obj->isNative() || !obj2->isNative()) { Rooted id(cx, NameToId(name)); if (!GetProperty(cx, obj, obj, id, vp)) return false; } else { RootedObject normalized(cx, obj); if (normalized->is() && !shape->hasDefaultGetter()) normalized = &normalized->as().object(); if (shape->isDataDescriptor() && shape->hasDefaultGetter()) { /* Fast path for Object instance properties. */ MOZ_ASSERT(shape->hasSlot()); vp.set(obj2->as().getSlot(shape->slot())); } else { if (!NativeGetExistingProperty(cx, normalized, obj2.as(), shape, vp)) return false; } } // We do our own explicit checking for |this| if (name == cx->names().dotThis) return true; // NAME operations are the slow paths already, so unconditionally check // for uninitialized lets. return CheckUninitializedLexical(cx, name, vp); } inline bool FetchNameNoGC(JSObject* pobj, Shape* shape, MutableHandleValue vp) { if (!shape || !pobj->isNative() || !shape->isDataDescriptor() || !shape->hasDefaultGetter()) return false; vp.set(pobj->as().getSlot(shape->slot())); return !IsUninitializedLexical(vp); } inline bool GetIntrinsicOperation(JSContext* cx, jsbytecode* pc, MutableHandleValue vp) { RootedPropertyName name(cx, cx->currentScript()->getName(pc)); return GlobalObject::getIntrinsicValue(cx, cx->global(), name, vp); } inline bool SetIntrinsicOperation(JSContext* cx, JSScript* script, jsbytecode* pc, HandleValue val) { RootedPropertyName name(cx, script->getName(pc)); return GlobalObject::setIntrinsicValue(cx, cx->global(), name, val); } inline void SetAliasedVarOperation(JSContext* cx, JSScript* script, jsbytecode* pc, EnvironmentObject& obj, EnvironmentCoordinate ec, const Value& val, MaybeCheckTDZ checkTDZ) { MOZ_ASSERT_IF(checkTDZ, !IsUninitializedLexical(obj.aliasedBinding(ec))); // Avoid computing the name if no type updates are needed, as this may be // expensive on scopes with large numbers of variables. PropertyName* name = obj.isSingleton() ? EnvironmentCoordinateName(cx->caches.envCoordinateNameCache, script, pc) : nullptr; obj.setAliasedBinding(cx, ec, name, val); } inline bool SetNameOperation(JSContext* cx, JSScript* script, jsbytecode* pc, HandleObject env, HandleValue val) { MOZ_ASSERT(*pc == JSOP_SETNAME || *pc == JSOP_STRICTSETNAME || *pc == JSOP_SETGNAME || *pc == JSOP_STRICTSETGNAME); MOZ_ASSERT_IF((*pc == JSOP_SETGNAME || *pc == JSOP_STRICTSETGNAME) && !script->hasNonSyntacticScope(), env == cx->global() || env == &cx->global()->lexicalEnvironment() || env->is()); bool strict = *pc == JSOP_STRICTSETNAME || *pc == JSOP_STRICTSETGNAME; RootedPropertyName name(cx, script->getName(pc)); // In strict mode, assigning to an undeclared global variable is an // error. To detect this, we call NativeSetProperty directly and pass // Unqualified. It stores the error, if any, in |result|. bool ok; ObjectOpResult result; RootedId id(cx, NameToId(name)); RootedValue receiver(cx, ObjectValue(*env)); if (env->isUnqualifiedVarObj()) { RootedNativeObject varobj(cx); if (env->is()) varobj = &env->as().environment().as(); else varobj = &env->as(); MOZ_ASSERT(!varobj->getOpsSetProperty()); ok = NativeSetProperty(cx, varobj, id, val, receiver, Unqualified, result); } else { ok = SetProperty(cx, env, id, val, receiver, result); } return ok && result.checkStrictErrorOrWarning(cx, env, id, strict); } inline bool DefLexicalOperation(JSContext* cx, Handle lexicalEnv, HandleObject varObj, HandlePropertyName name, unsigned attrs) { // Redeclaration checks should have already been done. MOZ_ASSERT(CheckLexicalNameConflict(cx, lexicalEnv, varObj, name)); RootedId id(cx, NameToId(name)); RootedValue uninitialized(cx, MagicValue(JS_UNINITIALIZED_LEXICAL)); return NativeDefineProperty(cx, lexicalEnv, id, uninitialized, nullptr, nullptr, attrs); } inline bool DefLexicalOperation(JSContext* cx, LexicalEnvironmentObject* lexicalEnvArg, JSObject* varObjArg, JSScript* script, jsbytecode* pc) { MOZ_ASSERT(*pc == JSOP_DEFLET || *pc == JSOP_DEFCONST); RootedPropertyName name(cx, script->getName(pc)); unsigned attrs = JSPROP_ENUMERATE | JSPROP_PERMANENT; if (*pc == JSOP_DEFCONST) attrs |= JSPROP_READONLY; Rooted lexicalEnv(cx, lexicalEnvArg); RootedObject varObj(cx, varObjArg); MOZ_ASSERT_IF(!script->hasNonSyntacticScope(), lexicalEnv == &cx->global()->lexicalEnvironment() && varObj == cx->global()); return DefLexicalOperation(cx, lexicalEnv, varObj, name, attrs); } inline void InitGlobalLexicalOperation(JSContext* cx, LexicalEnvironmentObject* lexicalEnvArg, JSScript* script, jsbytecode* pc, HandleValue value) { MOZ_ASSERT_IF(!script->hasNonSyntacticScope(), lexicalEnvArg == &cx->global()->lexicalEnvironment()); MOZ_ASSERT(*pc == JSOP_INITGLEXICAL); Rooted lexicalEnv(cx, lexicalEnvArg); RootedShape shape(cx, lexicalEnv->lookup(cx, script->getName(pc))); MOZ_ASSERT(shape); lexicalEnv->setSlotWithType(cx, shape, value); } inline bool InitPropertyOperation(JSContext* cx, JSOp op, HandleObject obj, HandleId id, HandleValue rhs) { MOZ_ASSERT(obj->is() || obj->is()); unsigned propAttrs = GetInitDataPropAttrs(op); return NativeDefineProperty(cx, obj.as(), id, rhs, nullptr, nullptr, propAttrs); } inline bool DefVarOperation(JSContext* cx, HandleObject varobj, HandlePropertyName dn, unsigned attrs) { MOZ_ASSERT(varobj->isQualifiedVarObj()); #ifdef DEBUG // Per spec, it is an error to redeclare a lexical binding. This should // have already been checked. if (JS_HasExtensibleLexicalEnvironment(varobj)) { Rooted lexicalEnv(cx); lexicalEnv = &JS_ExtensibleLexicalEnvironment(varobj)->as(); MOZ_ASSERT(CheckVarNameConflict(cx, lexicalEnv, dn)); } #endif RootedShape prop(cx); RootedObject obj2(cx); if (!LookupProperty(cx, varobj, dn, &obj2, &prop)) return false; /* Steps 8c, 8d. */ if (!prop || (obj2 != varobj && varobj->is())) { if (!DefineProperty(cx, varobj, dn, UndefinedHandleValue, nullptr, nullptr, attrs)) return false; } if (varobj->is()) { if (!varobj->compartment()->addToVarNames(cx, dn)) return false; } return true; } static MOZ_ALWAYS_INLINE bool NegOperation(JSContext* cx, HandleScript script, jsbytecode* pc, HandleValue val, MutableHandleValue res) { /* * When the operand is int jsval, INT32_FITS_IN_JSVAL(i) implies * INT32_FITS_IN_JSVAL(-i) unless i is 0 or INT32_MIN when the * results, -0.0 or INT32_MAX + 1, are double values. */ int32_t i; if (val.isInt32() && (i = val.toInt32()) != 0 && i != INT32_MIN) { res.setInt32(-i); } else { double d; if (!ToNumber(cx, val, &d)) return false; res.setNumber(-d); } return true; } static MOZ_ALWAYS_INLINE bool ToIdOperation(JSContext* cx, HandleScript script, jsbytecode* pc, HandleValue idval, MutableHandleValue res) { if (idval.isInt32()) { res.set(idval); return true; } RootedId id(cx); if (!ToPropertyKey(cx, idval, &id)) return false; res.set(IdToValue(id)); return true; } static MOZ_ALWAYS_INLINE bool GetObjectElementOperation(JSContext* cx, JSOp op, JS::HandleObject obj, JS::HandleObject receiver, HandleValue key, MutableHandleValue res) { MOZ_ASSERT(op == JSOP_GETELEM || op == JSOP_CALLELEM || op == JSOP_GETELEM_SUPER); MOZ_ASSERT_IF(op == JSOP_GETELEM || op == JSOP_CALLELEM, obj == receiver); do { uint32_t index; if (IsDefinitelyIndex(key, &index)) { if (GetElementNoGC(cx, obj, receiver, index, res.address())) break; if (!GetElement(cx, obj, receiver, index, res)) return false; break; } if (key.isString()) { JSString* str = key.toString(); JSAtom* name = str->isAtom() ? &str->asAtom() : AtomizeString(cx, str); if (!name) return false; if (name->isIndex(&index)) { if (GetElementNoGC(cx, obj, receiver, index, res.address())) break; } else { if (GetPropertyNoGC(cx, obj, receiver, name->asPropertyName(), res.address())) break; } } RootedId id(cx); if (!ToPropertyKey(cx, key, &id)) return false; if (!GetProperty(cx, obj, receiver, id, res)) return false; } while (false); assertSameCompartmentDebugOnly(cx, res); return true; } static MOZ_ALWAYS_INLINE bool GetPrimitiveElementOperation(JSContext* cx, JSOp op, JS::HandleValue receiver, HandleValue key, MutableHandleValue res) { MOZ_ASSERT(op == JSOP_GETELEM || op == JSOP_CALLELEM); // FIXME: Bug 1234324 We shouldn't be boxing here. RootedObject boxed(cx, ToObjectFromStack(cx, receiver)); if (!boxed) return false; do { uint32_t index; if (IsDefinitelyIndex(key, &index)) { if (GetElementNoGC(cx, boxed, receiver, index, res.address())) break; if (!GetElement(cx, boxed, receiver, index, res)) return false; break; } if (key.isString()) { JSString* str = key.toString(); JSAtom* name = str->isAtom() ? &str->asAtom() : AtomizeString(cx, str); if (!name) return false; if (name->isIndex(&index)) { if (GetElementNoGC(cx, boxed, receiver, index, res.address())) break; } else { if (GetPropertyNoGC(cx, boxed, receiver, name->asPropertyName(), res.address())) break; } } RootedId id(cx); if (!ToPropertyKey(cx, key, &id)) return false; if (!GetProperty(cx, boxed, receiver, id, res)) return false; } while (false); assertSameCompartmentDebugOnly(cx, res); return true; } static MOZ_ALWAYS_INLINE bool GetElemOptimizedArguments(JSContext* cx, AbstractFramePtr frame, MutableHandleValue lref, HandleValue rref, MutableHandleValue res, bool* done) { MOZ_ASSERT(!*done); if (IsOptimizedArguments(frame, lref)) { if (rref.isInt32()) { int32_t i = rref.toInt32(); if (i >= 0 && uint32_t(i) < frame.numActualArgs()) { res.set(frame.unaliasedActual(i)); *done = true; return true; } } RootedScript script(cx, frame.script()); if (!JSScript::argumentsOptimizationFailed(cx, script)) return false; lref.set(ObjectValue(frame.argsObj())); } return true; } static MOZ_ALWAYS_INLINE bool GetElementOperation(JSContext* cx, JSOp op, MutableHandleValue lref, HandleValue rref, MutableHandleValue res) { MOZ_ASSERT(op == JSOP_GETELEM || op == JSOP_CALLELEM); uint32_t index; if (lref.isString() && IsDefinitelyIndex(rref, &index)) { JSString* str = lref.toString(); if (index < str->length()) { str = cx->staticStrings().getUnitStringForElement(cx, str, index); if (!str) return false; res.setString(str); return true; } } if (lref.isPrimitive()) { RootedValue thisv(cx, lref); return GetPrimitiveElementOperation(cx, op, thisv, rref, res); } RootedObject thisv(cx, &lref.toObject()); return GetObjectElementOperation(cx, op, thisv, thisv, rref, res); } static MOZ_ALWAYS_INLINE JSString* TypeOfOperation(const Value& v, JSRuntime* rt) { JSType type = js::TypeOfValue(v); return TypeName(type, *rt->commonNames); } static inline JSString* TypeOfObjectOperation(JSObject* obj, JSRuntime* rt) { JSType type = js::TypeOfObject(obj); return TypeName(type, *rt->commonNames); } static MOZ_ALWAYS_INLINE bool InitElemOperation(JSContext* cx, jsbytecode* pc, HandleObject obj, HandleValue idval, HandleValue val) { MOZ_ASSERT(!val.isMagic(JS_ELEMENTS_HOLE)); MOZ_ASSERT(!obj->getClass()->getGetProperty()); MOZ_ASSERT(!obj->getClass()->getSetProperty()); RootedId id(cx); if (!ToPropertyKey(cx, idval, &id)) return false; unsigned flags = JSOp(*pc) == JSOP_INITHIDDENELEM ? 0 : JSPROP_ENUMERATE; return DefineProperty(cx, obj, id, val, nullptr, nullptr, flags); } static MOZ_ALWAYS_INLINE bool InitArrayElemOperation(JSContext* cx, jsbytecode* pc, HandleObject obj, uint32_t index, HandleValue val) { JSOp op = JSOp(*pc); MOZ_ASSERT(op == JSOP_INITELEM_ARRAY || op == JSOP_INITELEM_INC); MOZ_ASSERT(obj->is() || obj->is()); if (op == JSOP_INITELEM_INC && index == INT32_MAX) { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_SPREAD_TOO_LARGE); return false; } /* * If val is a hole, do not call DefineElement. * * Furthermore, if the current op is JSOP_INITELEM_INC, always call * SetLengthProperty even if it is not the last element initialiser, * because it may be followed by JSOP_SPREAD, which will not set the array * length if nothing is spread. * * Alternatively, if the current op is JSOP_INITELEM_ARRAY, the length will * have already been set by the earlier JSOP_NEWARRAY; JSOP_INITELEM_ARRAY * cannot follow JSOP_SPREAD. */ if (val.isMagic(JS_ELEMENTS_HOLE)) { if (op == JSOP_INITELEM_INC) { if (!SetLengthProperty(cx, obj, index + 1)) return false; } } else { if (!DefineElement(cx, obj, index, val, nullptr, nullptr, JSPROP_ENUMERATE)) return false; } return true; } static MOZ_ALWAYS_INLINE bool ProcessCallSiteObjOperation(JSContext* cx, RootedObject& cso, RootedObject& raw, RootedValue& rawValue) { bool extensible; if (!IsExtensible(cx, cso, &extensible)) return false; if (extensible) { JSAtom* name = cx->names().raw; if (!DefineProperty(cx, cso, name->asPropertyName(), rawValue, nullptr, nullptr, 0)) return false; if (!FreezeObject(cx, raw)) return false; if (!FreezeObject(cx, cso)) return false; } return true; } #define RELATIONAL_OP(OP) \ JS_BEGIN_MACRO \ /* Optimize for two int-tagged operands (typical loop control). */ \ if (lhs.isInt32() && rhs.isInt32()) { \ *res = lhs.toInt32() OP rhs.toInt32(); \ } else { \ if (!ToPrimitive(cx, JSTYPE_NUMBER, lhs)) \ return false; \ if (!ToPrimitive(cx, JSTYPE_NUMBER, rhs)) \ return false; \ if (lhs.isString() && rhs.isString()) { \ JSString* l = lhs.toString(); \ JSString* r = rhs.toString(); \ int32_t result; \ if (!CompareStrings(cx, l, r, &result)) \ return false; \ *res = result OP 0; \ } else { \ double l, r; \ if (!ToNumber(cx, lhs, &l) || !ToNumber(cx, rhs, &r)) \ return false; \ *res = (l OP r); \ } \ } \ return true; \ JS_END_MACRO static MOZ_ALWAYS_INLINE bool LessThanOperation(JSContext* cx, MutableHandleValue lhs, MutableHandleValue rhs, bool* res) { RELATIONAL_OP(<); } static MOZ_ALWAYS_INLINE bool LessThanOrEqualOperation(JSContext* cx, MutableHandleValue lhs, MutableHandleValue rhs, bool* res) { RELATIONAL_OP(<=); } static MOZ_ALWAYS_INLINE bool GreaterThanOperation(JSContext* cx, MutableHandleValue lhs, MutableHandleValue rhs, bool* res) { RELATIONAL_OP(>); } static MOZ_ALWAYS_INLINE bool GreaterThanOrEqualOperation(JSContext* cx, MutableHandleValue lhs, MutableHandleValue rhs, bool* res) { RELATIONAL_OP(>=); } static MOZ_ALWAYS_INLINE bool BitNot(JSContext* cx, HandleValue in, int* out) { int i; if (!ToInt32(cx, in, &i)) return false; *out = ~i; return true; } static MOZ_ALWAYS_INLINE bool BitXor(JSContext* cx, HandleValue lhs, HandleValue rhs, int* out) { int left, right; if (!ToInt32(cx, lhs, &left) || !ToInt32(cx, rhs, &right)) return false; *out = left ^ right; return true; } static MOZ_ALWAYS_INLINE bool BitOr(JSContext* cx, HandleValue lhs, HandleValue rhs, int* out) { int left, right; if (!ToInt32(cx, lhs, &left) || !ToInt32(cx, rhs, &right)) return false; *out = left | right; return true; } static MOZ_ALWAYS_INLINE bool BitAnd(JSContext* cx, HandleValue lhs, HandleValue rhs, int* out) { int left, right; if (!ToInt32(cx, lhs, &left) || !ToInt32(cx, rhs, &right)) return false; *out = left & right; return true; } static MOZ_ALWAYS_INLINE bool BitLsh(JSContext* cx, HandleValue lhs, HandleValue rhs, int* out) { int32_t left, right; if (!ToInt32(cx, lhs, &left) || !ToInt32(cx, rhs, &right)) return false; *out = uint32_t(left) << (right & 31); return true; } static MOZ_ALWAYS_INLINE bool BitRsh(JSContext* cx, HandleValue lhs, HandleValue rhs, int* out) { int32_t left, right; if (!ToInt32(cx, lhs, &left) || !ToInt32(cx, rhs, &right)) return false; *out = left >> (right & 31); return true; } static MOZ_ALWAYS_INLINE bool UrshOperation(JSContext* cx, HandleValue lhs, HandleValue rhs, MutableHandleValue out) { uint32_t left; int32_t right; if (!ToUint32(cx, lhs, &left) || !ToInt32(cx, rhs, &right)) return false; left >>= right & 31; out.setNumber(uint32_t(left)); return true; } template static MOZ_ALWAYS_INLINE bool SignExtendOperation(JSContext* cx, HandleValue in, int* out) { int32_t i; if (!ToInt32(cx, in, &i)) return false; *out = (T)i; return true; } #undef RELATIONAL_OP inline JSFunction* ReportIfNotFunction(JSContext* cx, HandleValue v, MaybeConstruct construct = NO_CONSTRUCT) { if (v.isObject() && v.toObject().is()) return &v.toObject().as(); ReportIsNotFunction(cx, v, -1, construct); return nullptr; } /* * FastCallGuard is used to optimize calls to JS functions from natives written * in C++, e.g. Array.prototype.map. If the callee is not Ion-compiled, this * will just call js::Call. If the callee has a valid IonScript, however, it * will enter Ion directly. */ class FastCallGuard { InvokeArgs args_; RootedFunction fun_; RootedScript script_; // Constructing a JitContext is pretty expensive due to the TLS access, // so only do this if we have to. bool useIon_; public: FastCallGuard(JSContext* cx, const Value& fval) : args_(cx) , fun_(cx) , script_(cx) , useIon_(jit::IsIonEnabled(cx)) { initFunction(fval); } void initFunction(const Value& fval) { if (fval.isObject() && fval.toObject().is()) { JSFunction* fun = &fval.toObject().as(); if (fun->isInterpreted()) fun_ = fun; } } InvokeArgs& args() { return args_; } bool call(JSContext* cx, HandleValue callee, HandleValue thisv, MutableHandleValue rval) { args_.CallArgs::setCallee(callee); args_.CallArgs::setThis(thisv); if (useIon_ && fun_) { if (!script_) { script_ = JSFunction::getOrCreateScript(cx, fun_); if (!script_) return false; } MOZ_ASSERT(fun_->nonLazyScript() == script_); jit::MethodStatus status = jit::CanEnterUsingFastInvoke(cx, script_, args_.length()); if (status == jit::Method_Error) return false; if (status == jit::Method_Compiled) { jit::JitExecStatus result = jit::FastInvoke(cx, fun_, args_); if (IsErrorStatus(result)) return false; MOZ_ASSERT(result == jit::JitExec_Ok); rval.set(args_.CallArgs::rval()); return true; } MOZ_ASSERT(status == jit::Method_Skipped); if (script_->canIonCompile()) { // This script is not yet hot. Since calling into Ion is much // faster here, bump the warm-up counter a bit to account for this. script_->incWarmUpCounter(5); } } if (!InternalCallOrConstruct(cx, args_, NO_CONSTRUCT)) return false; rval.set(args_.CallArgs::rval()); return true; } private: FastCallGuard(const FastCallGuard& other) = delete; void operator=(const FastCallGuard& other) = delete; }; } /* namespace js */ #endif /* vm_Interpreter_inl_h */