// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file // for details. All rights reserved. Use of this source code is governed by a // BSD-style license that can be found in the LICENSE file. #include "vm/class_finalizer.h" #include "vm/code_generator.h" #include "vm/flags.h" #include "vm/heap.h" #include "vm/isolate.h" #include "vm/longjump.h" #include "vm/object_store.h" #include "vm/symbols.h" namespace dart { DEFINE_FLAG(bool, error_on_bad_override, false, "Report error for bad overrides."); DEFINE_FLAG(bool, error_on_bad_type, false, "Report error for malformed types."); DEFINE_FLAG(bool, print_classes, false, "Prints details about loaded classes."); DEFINE_FLAG(bool, trace_class_finalization, false, "Trace class finalization."); DEFINE_FLAG(bool, trace_type_finalization, false, "Trace type finalization."); DECLARE_FLAG(bool, enable_type_checks); DECLARE_FLAG(bool, use_cha); bool ClassFinalizer::AllClassesFinalized() { ObjectStore* object_store = Isolate::Current()->object_store(); const GrowableObjectArray& classes = GrowableObjectArray::Handle(object_store->pending_classes()); return classes.Length() == 0; } // Removes optimized code once we load more classes, since --use_cha based // optimizations may have become invalid. // Only methods which owner classes where subclasses can be invalid. // TODO(srdjan): Be even more precise by recording the exact CHA optimization. static void RemoveOptimizedCode( const GrowableArray& added_subclass_to_cids) { ASSERT(FLAG_use_cha); if (added_subclass_to_cids.is_empty()) return; // Deoptimize all live frames. DeoptimizeIfOwner(added_subclass_to_cids); // Switch all functions' code to unoptimized. const ClassTable& class_table = *Isolate::Current()->class_table(); Class& cls = Class::Handle(); Array& array = Array::Handle(); Function& function = Function::Handle(); for (intptr_t i = 0; i < added_subclass_to_cids.length(); i++) { intptr_t cid = added_subclass_to_cids[i]; cls = class_table.At(cid); ASSERT(!cls.IsNull()); array = cls.functions(); const intptr_t num_functions = array.IsNull() ? 0 : array.Length(); for (intptr_t f = 0; f < num_functions; f++) { function ^= array.At(f); ASSERT(!function.IsNull()); if (function.HasOptimizedCode()) { function.SwitchToUnoptimizedCode(); } } } } void AddSuperType(const AbstractType& type, GrowableArray* finalized_super_classes) { ASSERT(type.HasResolvedTypeClass()); ASSERT(!type.IsDynamicType()); if (type.IsObjectType()) { return; } const Class& cls = Class::Handle(type.type_class()); ASSERT(cls.is_finalized()); const intptr_t cid = cls.id(); for (intptr_t i = 0; i < finalized_super_classes->length(); i++) { if ((*finalized_super_classes)[i] == cid) { // Already added. return; } } finalized_super_classes->Add(cid); const AbstractType& super_type = AbstractType::Handle(cls.super_type()); AddSuperType(super_type, finalized_super_classes); } // Use array instead of set since we expect very few subclassed classes // to occur. static void CollectFinalizedSuperClasses( const Class& cls_, GrowableArray* finalized_super_classes) { Class& cls = Class::Handle(cls_.raw()); AbstractType& super_type = Type::Handle(); super_type = cls.super_type(); if (!super_type.IsNull()) { if (!super_type.IsMalformed() && super_type.HasResolvedTypeClass()) { cls ^= super_type.type_class(); if (cls.is_finalized()) { AddSuperType(super_type, finalized_super_classes); } } } } // Processing ObjectStore::pending_classes_ occurs: // a) when bootstrap process completes (VerifyBootstrapClasses). // b) after the user classes are loaded (dart_api). bool ClassFinalizer::ProcessPendingClasses() { bool retval = true; Isolate* isolate = Isolate::Current(); ASSERT(isolate != NULL); HANDLESCOPE(isolate); ObjectStore* object_store = isolate->object_store(); const Error& error = Error::Handle(isolate, object_store->sticky_error()); if (!error.IsNull()) { return false; } if (AllClassesFinalized()) { return true; } LongJump* base = isolate->long_jump_base(); LongJump jump; isolate->set_long_jump_base(&jump); if (setjmp(*jump.Set()) == 0) { GrowableObjectArray& class_array = GrowableObjectArray::Handle(); class_array = object_store->pending_classes(); ASSERT(!class_array.IsNull()); Class& cls = Class::Handle(); // First resolve all superclasses. for (intptr_t i = 0; i < class_array.Length(); i++) { cls ^= class_array.At(i); GrowableArray visited_interfaces; ResolveSuperTypeAndInterfaces(cls, &visited_interfaces); } // Finalize all classes. for (intptr_t i = 0; i < class_array.Length(); i++) { cls ^= class_array.At(i); FinalizeTypesInClass(cls); } if (FLAG_print_classes) { for (intptr_t i = 0; i < class_array.Length(); i++) { cls ^= class_array.At(i); PrintClassInformation(cls); } } // Clear pending classes array. class_array = GrowableObjectArray::New(); object_store->set_pending_classes(class_array); VerifyImplicitFieldOffsets(); // Verification after an error may fail. } else { retval = false; } isolate->set_long_jump_base(base); return retval; } // Adds all interfaces of cls into 'collected'. Duplicate entries may occur. // No cycles are allowed. void ClassFinalizer::CollectInterfaces(const Class& cls, const GrowableObjectArray& collected) { const Array& interface_array = Array::Handle(cls.interfaces()); AbstractType& interface = AbstractType::Handle(); Class& interface_class = Class::Handle(); for (intptr_t i = 0; i < interface_array.Length(); i++) { interface ^= interface_array.At(i); interface_class = interface.type_class(); collected.Add(interface_class); CollectInterfaces(interface_class, collected); } } void ClassFinalizer::VerifyBootstrapClasses() { if (FLAG_trace_class_finalization) { OS::Print("VerifyBootstrapClasses START.\n"); } ObjectStore* object_store = Isolate::Current()->object_store(); Class& cls = Class::Handle(); #if defined(DEBUG) // Basic checking. cls = object_store->object_class(); ASSERT(Instance::InstanceSize() == cls.instance_size()); cls = object_store->integer_implementation_class(); ASSERT(Integer::InstanceSize() == cls.instance_size()); cls = object_store->smi_class(); ASSERT(Smi::InstanceSize() == cls.instance_size()); cls = object_store->mint_class(); ASSERT(Mint::InstanceSize() == cls.instance_size()); cls = object_store->bigint_class(); ASSERT(Bigint::InstanceSize() == cls.instance_size()); cls = object_store->one_byte_string_class(); ASSERT(OneByteString::InstanceSize() == cls.instance_size()); cls = object_store->two_byte_string_class(); ASSERT(TwoByteString::InstanceSize() == cls.instance_size()); cls = object_store->external_one_byte_string_class(); ASSERT(ExternalOneByteString::InstanceSize() == cls.instance_size()); cls = object_store->external_two_byte_string_class(); ASSERT(ExternalTwoByteString::InstanceSize() == cls.instance_size()); cls = object_store->double_class(); ASSERT(Double::InstanceSize() == cls.instance_size()); cls = object_store->bool_class(); ASSERT(Bool::InstanceSize() == cls.instance_size()); cls = object_store->array_class(); ASSERT(Array::InstanceSize() == cls.instance_size()); cls = object_store->immutable_array_class(); ASSERT(ImmutableArray::InstanceSize() == cls.instance_size()); cls = object_store->weak_property_class(); ASSERT(WeakProperty::InstanceSize() == cls.instance_size()); #endif // defined(DEBUG) // Remember the currently pending classes. const GrowableObjectArray& class_array = GrowableObjectArray::Handle(object_store->pending_classes()); for (intptr_t i = 0; i < class_array.Length(); i++) { // TODO(iposva): Add real checks. cls ^= class_array.At(i); if (cls.is_finalized() || cls.is_prefinalized()) { // Pre-finalized bootstrap classes must not define any fields. ASSERT(!cls.HasInstanceFields()); } } // Finalize type hierarchy for types that aren't pre-finalized // by Object::Init(). if (!ProcessPendingClasses()) { // TODO(srdjan): Exit like a real VM instead. const Error& err = Error::Handle(object_store->sticky_error()); OS::PrintErr("Could not verify bootstrap classes : %s\n", err.ToErrorCString()); OS::Exit(255); } if (FLAG_trace_class_finalization) { OS::Print("VerifyBootstrapClasses END.\n"); } Isolate::Current()->heap()->Verify(); } // Resolve unresolved_class in the library of cls, or return null. RawClass* ClassFinalizer::ResolveClass( const Class& cls, const UnresolvedClass& unresolved_class) { const String& class_name = String::Handle(unresolved_class.ident()); Library& lib = Library::Handle(); Class& resolved_class = Class::Handle(); if (unresolved_class.library_prefix() == LibraryPrefix::null()) { lib = cls.library(); ASSERT(!lib.IsNull()); resolved_class = lib.LookupClass(class_name); } else { LibraryPrefix& lib_prefix = LibraryPrefix::Handle(); lib_prefix = unresolved_class.library_prefix(); ASSERT(!lib_prefix.IsNull()); resolved_class = lib_prefix.LookupClass(class_name); } return resolved_class.raw(); } void ClassFinalizer::ResolveRedirectingFactory(const Class& cls, const Function& factory) { const Function& target = Function::Handle(factory.RedirectionTarget()); if (target.IsNull()) { Type& type = Type::Handle(factory.RedirectionType()); if (!type.IsMalformed()) { const GrowableObjectArray& visited_factories = GrowableObjectArray::Handle(GrowableObjectArray::New()); ResolveRedirectingFactoryTarget(cls, factory, visited_factories); } if (factory.is_const()) { type = factory.RedirectionType(); if (type.IsMalformedOrMalbounded()) { ReportError(Error::Handle(type.error())); } } } } void ClassFinalizer::ResolveRedirectingFactoryTarget( const Class& cls, const Function& factory, const GrowableObjectArray& visited_factories) { ASSERT(factory.IsRedirectingFactory()); // Check for redirection cycle. for (intptr_t i = 0; i < visited_factories.Length(); i++) { if (visited_factories.At(i) == factory.raw()) { // A redirection cycle is reported as a compile-time error. const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, factory.token_pos(), "factory '%s' illegally redirects to itself", String::Handle(factory.name()).ToCString()); } } visited_factories.Add(factory); // Check if target is already resolved. Type& type = Type::Handle(factory.RedirectionType()); Function& target = Function::Handle(factory.RedirectionTarget()); if (type.IsMalformedOrMalbounded()) { // Already resolved to a malformed or malbounded type. Will throw on usage. ASSERT(target.IsNull()); return; } if (!target.IsNull()) { // Already resolved. return; } // Target is not resolved yet. if (FLAG_trace_class_finalization) { OS::Print("Resolving redirecting factory: %s\n", String::Handle(factory.name()).ToCString()); } ResolveType(cls, type); type ^= FinalizeType(cls, type, kCanonicalize); factory.SetRedirectionType(type); if (type.IsMalformedOrMalbounded()) { ASSERT(factory.RedirectionTarget() == Function::null()); return; } ASSERT(!type.IsTypeParameter()); // Resolved in parser. if (type.IsDynamicType()) { // Replace the type with a malformed type and compile a throw when called. type = NewFinalizedMalformedType( Error::Handle(), // No previous error. Script::Handle(cls.script()), factory.token_pos(), "factory may not redirect to 'dynamic'"); factory.SetRedirectionType(type); ASSERT(factory.RedirectionTarget() == Function::null()); return; } const Class& target_class = Class::Handle(type.type_class()); String& target_class_name = String::Handle(target_class.Name()); String& target_name = String::Handle( String::Concat(target_class_name, Symbols::Dot())); const String& identifier = String::Handle(factory.RedirectionIdentifier()); if (!identifier.IsNull()) { target_name = String::Concat(target_name, identifier); } // Verify that the target constructor of the redirection exists. target = target_class.LookupConstructor(target_name); if (target.IsNull()) { target = target_class.LookupFactory(target_name); } if (target.IsNull()) { const String& user_visible_target_name = identifier.IsNull() ? target_class_name : target_name; // Replace the type with a malformed type and compile a throw when called. type = NewFinalizedMalformedType( Error::Handle(), // No previous error. Script::Handle(target_class.script()), factory.token_pos(), "class '%s' has no constructor or factory named '%s'", target_class_name.ToCString(), user_visible_target_name.ToCString()); factory.SetRedirectionType(type); ASSERT(factory.RedirectionTarget() == Function::null()); return; } if (FLAG_error_on_bad_override) { // Verify that the target is compatible with the redirecting factory. Error& error = Error::Handle(); if (!target.HasCompatibleParametersWith(factory, &error)) { const Script& script = Script::Handle(target_class.script()); type = NewFinalizedMalformedType( error, script, target.token_pos(), "constructor '%s' has incompatible parameters with " "redirecting factory '%s'", String::Handle(target.name()).ToCString(), String::Handle(factory.name()).ToCString()); factory.SetRedirectionType(type); ASSERT(factory.RedirectionTarget() == Function::null()); return; } } // Verify that the target is const if the redirecting factory is const. if (factory.is_const() && !target.is_const()) { const Script& script = Script::Handle(target_class.script()); ReportError(Error::Handle(), // No previous error. script, target.token_pos(), "constructor '%s' must be const as required by redirecting " "const factory '%s'", String::Handle(target.name()).ToCString(), String::Handle(factory.name()).ToCString()); } // Update redirection data with resolved target. factory.SetRedirectionTarget(target); // Not needed anymore. factory.SetRedirectionIdentifier(Object::null_string()); if (!target.IsRedirectingFactory()) { return; } // The target is itself a redirecting factory. Recursively resolve its own // target and update the current redirection data to point to the end target // of the redirection chain. ResolveRedirectingFactoryTarget(target_class, target, visited_factories); Type& target_type = Type::Handle(target.RedirectionType()); Function& target_target = Function::Handle(target.RedirectionTarget()); if (target_target.IsNull()) { ASSERT(target_type.IsMalformed()); } else { // If the target type refers to type parameters, substitute them with the // type arguments of the redirection type. if (!target_type.IsInstantiated()) { const AbstractTypeArguments& type_args = AbstractTypeArguments::Handle( type.arguments()); Error& bound_error = Error::Handle(); target_type ^= target_type.InstantiateFrom(type_args, &bound_error); if (bound_error.IsNull()) { target_type ^= FinalizeType(cls, target_type, kCanonicalize); } else { ASSERT(target_type.IsInstantiated() && type_args.IsInstantiated()); const Script& script = Script::Handle(target_class.script()); FinalizeMalformedType(bound_error, script, target_type, "cannot resolve redirecting factory"); target_target = Function::null(); } } } factory.SetRedirectionType(target_type); factory.SetRedirectionTarget(target_target); } void ClassFinalizer::ResolveType(const Class& cls, const AbstractType& type) { if (type.IsResolved() || type.IsFinalized()) { return; } if (FLAG_trace_type_finalization) { OS::Print("Resolve type '%s'\n", String::Handle(type.Name()).ToCString()); } // Resolve the type class. if (!type.HasResolvedTypeClass()) { // Type parameters are always resolved in the parser in the correct // non-static scope or factory scope. That resolution scope is unknown here. // Being able to resolve a type parameter from class cls here would indicate // that the type parameter appeared in a static scope. Leaving the type as // unresolved is the correct thing to do. // Lookup the type class. const UnresolvedClass& unresolved_class = UnresolvedClass::Handle(type.unresolved_class()); const Class& type_class = Class::Handle(ResolveClass(cls, unresolved_class)); // Replace unresolved class with resolved type class. const Type& parameterized_type = Type::Cast(type); if (type_class.IsNull()) { // The type class could not be resolved. The type is malformed. FinalizeMalformedType( Error::Handle(), // No previous error. Script::Handle(cls.script()), parameterized_type, "cannot resolve class '%s' from '%s'", String::Handle(unresolved_class.Name()).ToCString(), String::Handle(cls.Name()).ToCString()); return; } parameterized_type.set_type_class(type_class); } // Resolve type arguments, if any. const AbstractTypeArguments& arguments = AbstractTypeArguments::Handle(type.arguments()); if (!arguments.IsNull()) { const intptr_t num_arguments = arguments.Length(); AbstractType& type_argument = AbstractType::Handle(); for (intptr_t i = 0; i < num_arguments; i++) { type_argument = arguments.TypeAt(i); ResolveType(cls, type_argument); } } } void ClassFinalizer::FinalizeTypeParameters( const Class& cls, GrowableObjectArray* pending_types) { if (cls.IsMixinApplication()) { // Setup the type parameters of the mixin application and finalize the // mixin type. ApplyMixinType(cls, pending_types); } // The type parameter bounds are not finalized here. const TypeArguments& type_parameters = TypeArguments::Handle(cls.type_parameters()); if (!type_parameters.IsNull()) { TypeParameter& type_parameter = TypeParameter::Handle(); const intptr_t num_types = type_parameters.Length(); for (intptr_t i = 0; i < num_types; i++) { type_parameter ^= type_parameters.TypeAt(i); type_parameter ^= FinalizeType( cls, type_parameter, kFinalize, pending_types); type_parameters.SetTypeAt(i, type_parameter); } } } // Finalize the type argument vector 'arguments' of the type defined by the // class 'cls' parameterized with the type arguments 'cls_args'. // The vector 'cls_args' is already initialized as a subvector at the correct // position in the passed in 'arguments' vector. // The subvector 'cls_args' has length cls.NumTypeParameters() and starts at // offset cls.NumTypeArguments() - cls.NumTypeParameters() of the 'arguments' // vector. // The type argument vector of cls may overlap the type argument vector of its // super class. In case of an overlap, the overlapped type arguments of the // super class are already initialized. The still uninitialized ones have an // offset smaller than 'num_uninitialized_arguments'. // Example 1 (without overlap): // Declared: class C extends B { ... } // class B extends A { ... } // Input: C expressed as // cls = C, arguments = [dynamic, dynamic, String, double], // num_uninitialized_arguments = 2, // i.e. cls_args = [String, double], offset = 2, length = 2. // Output: arguments = [int, double, String, double] // Example 2 (with overlap): // Declared: class C extends B { ... } // class B extends A { ... } // Input: C expressed as // cls = C, arguments = [dynamic, String, double], // num_uninitialized_arguments = 1, // i.e. cls_args = [String, double], offset = 1, length = 2. // Output: arguments = [int, String, double] // // It is too early to canonicalize the type arguments of the vector, because // several type argument vectors may be mutually recursive and finalized at the // same time. Canonicalization happens when pending types are processed. void ClassFinalizer::FinalizeTypeArguments( const Class& cls, const AbstractTypeArguments& arguments, intptr_t num_uninitialized_arguments, Error* bound_error, GrowableObjectArray* pending_types) { ASSERT(arguments.Length() >= cls.NumTypeArguments()); if (!cls.is_type_finalized()) { FinalizeTypeParameters(cls, pending_types); ResolveUpperBounds(cls); } AbstractType& super_type = AbstractType::Handle(cls.super_type()); if (!super_type.IsNull()) { const Class& super_class = Class::Handle(super_type.type_class()); const intptr_t num_super_type_params = super_class.NumTypeParameters(); const intptr_t num_super_type_args = super_class.NumTypeArguments(); ASSERT(num_super_type_args == (cls.NumTypeArguments() - cls.NumOwnTypeArguments())); if (!super_type.IsFinalized() && !super_type.IsBeingFinalized()) { super_type ^= FinalizeType( cls, super_type, kFinalize, pending_types); cls.set_super_type(super_type); } AbstractTypeArguments& super_type_args = AbstractTypeArguments::Handle( super_type.arguments()); // Offset of super type's type parameters in cls' type argument vector. const intptr_t super_offset = num_super_type_args - num_super_type_params; AbstractType& super_type_arg = AbstractType::Handle(Type::DynamicType()); for (intptr_t i = super_offset; i < num_uninitialized_arguments; i++) { if (!super_type_args.IsNull()) { super_type_arg = super_type_args.TypeAt(i); if (!super_type_arg.IsFinalized()) { super_type_arg ^= FinalizeType( cls, super_type_arg, kFinalize, pending_types); super_type_args.SetTypeAt(i, super_type_arg); } if (!super_type_arg.IsInstantiated()) { Error& error = Error::Handle(); super_type_arg = super_type_arg.InstantiateFrom(arguments, &error); if (!error.IsNull()) { // InstantiateFrom does not report an error if the type is still // uninstantiated. Instead, it will return a new BoundedType so that // the check is postponed to run time. ASSERT(super_type_arg.IsInstantiated()); // Keep only the first bound error. if (bound_error->IsNull()) { *bound_error = error.raw(); } } } } arguments.SetTypeAt(i, super_type_arg); } FinalizeTypeArguments(super_class, arguments, super_offset, bound_error, pending_types); } } // Check the type argument vector 'arguments' against the corresponding bounds // of the type parameters of class 'cls' and, recursively, of its superclasses. // Replace a type argument that cannot be checked at compile time by a // BoundedType, thereby postponing the bound check to run time. // Return a bound error if a type argument is not within bound at compile time. void ClassFinalizer::CheckTypeArgumentBounds( const Class& cls, const AbstractTypeArguments& arguments, Error* bound_error) { if (!cls.is_type_finalized()) { FinalizeUpperBounds(cls); } // Note that when finalizing a type, we need to verify the bounds in both // production mode and checked mode, because the finalized type may be written // to a snapshot. It would be wrong to ignore bounds when generating the // snapshot in production mode and then use the unchecked type in checked mode // after reading it from the snapshot. // However, we do not immediately report a bound error, which would be wrong // in production mode, but simply postpone the bound checking to runtime. const intptr_t num_type_params = cls.NumTypeParameters(); const intptr_t offset = cls.NumTypeArguments() - num_type_params; AbstractType& type_arg = AbstractType::Handle(); AbstractType& cls_type_param = AbstractType::Handle(); AbstractType& declared_bound = AbstractType::Handle(); AbstractType& instantiated_bound = AbstractType::Handle(); const TypeArguments& cls_type_params = TypeArguments::Handle(cls.type_parameters()); ASSERT((cls_type_params.IsNull() && (num_type_params == 0)) || (cls_type_params.Length() == num_type_params)); // In case of overlapping type argument vectors, the same type argument may // get checked against different bounds. for (intptr_t i = 0; i < num_type_params; i++) { type_arg = arguments.TypeAt(offset + i); if (type_arg.IsDynamicType()) { continue; } ASSERT(type_arg.IsFinalized()); cls_type_param = cls_type_params.TypeAt(i); const TypeParameter& type_param = TypeParameter::Cast(cls_type_param); ASSERT(type_param.IsFinalized()); declared_bound = type_param.bound(); if (!declared_bound.IsObjectType() && !declared_bound.IsDynamicType()) { if (!declared_bound.IsFinalized() && !declared_bound.IsBeingFinalized()) { declared_bound = FinalizeType(cls, declared_bound, kCanonicalize); type_param.set_bound(declared_bound); } ASSERT(declared_bound.IsFinalized() || declared_bound.IsBeingFinalized()); Error& error = Error::Handle(); // Note that the bound may be malformed, in which case the bound check // will return an error and the bound check will be postponed to run time. if (declared_bound.IsInstantiated()) { instantiated_bound = declared_bound.raw(); } else { instantiated_bound = declared_bound.InstantiateFrom(arguments, &error); } if (!instantiated_bound.IsFinalized()) { // The bound refers to type parameters, creating a cycle; postpone // bound check to run time, when the bound will be finalized. // The bound may not necessarily be 'IsBeingFinalized' yet, as is the // case with a pair of type parameters of the same class referring to // each other via their bounds. type_arg = BoundedType::New(type_arg, instantiated_bound, type_param); arguments.SetTypeAt(offset + i, type_arg); continue; } // Shortcut the special case where we check a type parameter against its // declared upper bound. if (error.IsNull() && !(type_arg.Equals(type_param) && instantiated_bound.Equals(declared_bound))) { if (!type_param.CheckBound(type_arg, instantiated_bound, &error) && error.IsNull()) { // The bound cannot be checked at compile time; postpone to run time. type_arg = BoundedType::New(type_arg, instantiated_bound, type_param); arguments.SetTypeAt(offset + i, type_arg); } } if (!error.IsNull() && bound_error->IsNull()) { *bound_error = error.raw(); } } } AbstractType& super_type = AbstractType::Handle(cls.super_type()); if (!super_type.IsNull()) { const Class& super_class = Class::Handle(super_type.type_class()); CheckTypeArgumentBounds(super_class, arguments, bound_error); } } void ClassFinalizer::CheckTypeBounds(const Class& cls, const Type& type) { ASSERT(type.IsFinalized()); AbstractTypeArguments& arguments = AbstractTypeArguments::Handle(type.arguments()); if (arguments.IsNull()) { return; } Class& owner_class = Class::Handle(); Class& type_class = Class::Handle(type.type_class()); if (type_class.IsSignatureClass()) { const Function& signature_fun = Function::Handle(type_class.signature_function()); ASSERT(!signature_fun.is_static()); owner_class = signature_fun.Owner(); } else { owner_class = type_class.raw(); } Error& bound_error = Error::Handle(); CheckTypeArgumentBounds(owner_class, arguments, &bound_error); type.set_arguments(arguments); // If a bound error occurred, mark the type as malbounded. // The bound error will be ignored in production mode. if (!bound_error.IsNull()) { // No compile-time error during finalization. const String& type_name = String::Handle(type.UserVisibleName()); FinalizeMalboundedType(bound_error, Script::Handle(cls.script()), type, "type '%s' has an out of bound type argument", type_name.ToCString()); if (FLAG_trace_type_finalization) { OS::Print("Marking type '%s' as malbounded: %s\n", String::Handle(type.Name()).ToCString(), bound_error.ToCString()); } } } RawAbstractType* ClassFinalizer::FinalizeType( const Class& cls, const AbstractType& type, FinalizationKind finalization, GrowableObjectArray* pending_types) { // Only the 'root' type of the graph can be canonicalized, after all depending // types have been bound checked. ASSERT((pending_types == NULL) || (finalization < kCanonicalize)); if (type.IsFinalized()) { // Ensure type is canonical if canonicalization is requested, unless type is // malformed. if ((finalization >= kCanonicalize) && !type.IsMalformed()) { return type.Canonicalize(); } return type.raw(); } ASSERT(type.IsResolved()); ASSERT(finalization >= kFinalize); if (type.IsTypeRef()) { // The referenced type will be finalized later by the code that set the // is_being_finalized mark bit. return type.raw(); } if (type.IsBeingFinalized()) { if (FLAG_trace_type_finalization) { OS::Print("Creating TypeRef '%s' for class '%s'\n", String::Handle(type.Name()).ToCString(), cls.ToCString()); } return TypeRef::New(type); } if (FLAG_trace_type_finalization) { OS::Print("Finalizing type '%s' for class '%s'\n", String::Handle(type.Name()).ToCString(), cls.ToCString()); } if (type.IsTypeParameter()) { const TypeParameter& type_parameter = TypeParameter::Cast(type); const Class& parameterized_class = Class::Handle(type_parameter.parameterized_class()); ASSERT(!parameterized_class.IsNull()); // The index must reflect the position of this type parameter in the type // arguments vector of its parameterized class. The offset to add is the // number of type arguments in the super type, which is equal to the // difference in number of type arguments and type parameters of the // parameterized class. const intptr_t offset = parameterized_class.NumTypeArguments() - parameterized_class.NumTypeParameters(); // Calling NumTypeParameters() may finalize this type parameter if it // belongs to a mixin application class. if (!type_parameter.IsFinalized()) { type_parameter.set_index(type_parameter.index() + offset); type_parameter.set_is_finalized(); } else { ASSERT(cls.IsMixinApplication()); } if (FLAG_trace_type_finalization) { OS::Print("Done finalizing type parameter '%s' with index %" Pd "\n", String::Handle(type_parameter.name()).ToCString(), type_parameter.index()); } // We do not canonicalize type parameters. return type_parameter.raw(); } // At this point, we can only have a parameterized_type. const Type& parameterized_type = Type::Cast(type); // This type is the root type of the type graph if no pending types queue is // allocated yet. const bool is_root_type = (pending_types == NULL); GrowableObjectArray& types = GrowableObjectArray::Handle(); if (is_root_type) { types = GrowableObjectArray::New(); pending_types = &types; } // The type class does not need to be finalized in order to finalize the type, // however, it must at least be resolved (this was done as part of resolving // the type itself, a precondition to calling FinalizeType). // Also, the interfaces of the type class must be resolved and the type // parameters of the type class must be finalized. Class& type_class = Class::Handle(parameterized_type.type_class()); if (!type_class.is_type_finalized()) { FinalizeTypeParameters(type_class, pending_types); ResolveUpperBounds(type_class); } // The finalized type argument vector needs num_type_arguments types. const intptr_t num_type_arguments = type_class.NumTypeArguments(); // The type class has num_type_parameters type parameters. const intptr_t num_type_parameters = type_class.NumTypeParameters(); // Initialize the type argument vector. // Check the number of parsed type arguments, if any. // Specifying no type arguments indicates a raw type, which is not an error. // However, type parameter bounds are checked below, even for a raw type. AbstractTypeArguments& arguments = AbstractTypeArguments::Handle(parameterized_type.arguments()); if (!arguments.IsNull() && (arguments.Length() != num_type_parameters)) { // Wrong number of type arguments. The type is mapped to the raw type. if (FLAG_error_on_bad_type) { const Script& script = Script::Handle(cls.script()); const String& type_class_name = String::Handle(type_class.Name()); ReportError(Error::Handle(), // No previous error. script, parameterized_type.token_pos(), "wrong number of type arguments for class '%s'", type_class_name.ToCString()); } // Make the type raw and continue without reporting any error. // A static warning should have been reported. arguments = AbstractTypeArguments::null(); parameterized_type.set_arguments(arguments); } // The full type argument vector consists of the type arguments of the // super types of type_class, which are initialized from the parsed // type arguments, followed by the parsed type arguments. TypeArguments& full_arguments = TypeArguments::Handle(); Error& bound_error = Error::Handle(); if (num_type_arguments > 0) { // If no type arguments were parsed and if the super types do not prepend // type arguments to the vector, we can leave the vector as null. if (!arguments.IsNull() || (num_type_arguments > num_type_parameters)) { full_arguments = TypeArguments::New(num_type_arguments); // Copy the parsed type arguments at the correct offset in the full type // argument vector. const intptr_t offset = num_type_arguments - num_type_parameters; AbstractType& type_arg = AbstractType::Handle(Type::DynamicType()); // TODO(regis): Leave the temporary type argument values as null. for (intptr_t i = 0; i < offset; i++) { // Temporarily set the type arguments of the super classes to dynamic. full_arguments.SetTypeAt(i, type_arg); } for (intptr_t i = 0; i < num_type_parameters; i++) { // If no type parameters were provided, a raw type is desired, so we // create a vector of dynamic. if (!arguments.IsNull()) { type_arg = arguments.TypeAt(i); // The parsed type_arg may or may not be finalized. } full_arguments.SetTypeAt(offset + i, type_arg); } // Replace the compile-time argument vector (of length zero or // num_type_parameters) of this type being finalized with the still // unfinalized run-time argument vector (of length num_type_arguments). // This type being finalized may be recursively reached via bounds // checking, in which case type arguments of super classes will be seen // as dynamic. parameterized_type.set_arguments(full_arguments); // Mark type as being finalized in order to detect self reference. parameterized_type.set_is_being_finalized(); // Finalize the current type arguments of the type, which are still the // parsed type arguments. if (!arguments.IsNull()) { for (intptr_t i = 0; i < num_type_parameters; i++) { type_arg = full_arguments.TypeAt(offset + i); ASSERT(!type_arg.IsBeingFinalized()); type_arg = FinalizeType(cls, type_arg, kFinalize, pending_types); if (type_arg.IsMalformed()) { // Malformed type arguments are mapped to dynamic. type_arg = Type::DynamicType(); } full_arguments.SetTypeAt(offset + i, type_arg); } } // If the type class is a signature class, the full argument vector // must include the argument vector of the super type. // If the signature class is a function type alias, it is also the owner // of its signature function and no super type is involved. // If the signature class is canonical (not an alias), the owner of its // signature function may either be an alias or the enclosing class of a // local function, in which case the super type of the enclosing class is // also considered when filling up the argument vector. Class& owner_class = Class::Handle(); if (type_class.IsSignatureClass()) { const Function& signature_fun = Function::Handle(type_class.signature_function()); ASSERT(!signature_fun.is_static()); owner_class = signature_fun.Owner(); } else { owner_class = type_class.raw(); } if (offset > 0) { FinalizeTypeArguments(owner_class, full_arguments, offset, &bound_error, pending_types); } if (full_arguments.IsRaw(0, num_type_arguments)) { // The parameterized_type is raw. Set its argument vector to null, which // is more efficient in type tests. full_arguments = TypeArguments::null(); } else { // Postpone bound checking until after all types in the graph of // mutually recursive types are finalized. pending_types->Add(parameterized_type); } parameterized_type.set_arguments(full_arguments); } else { ASSERT(full_arguments.IsNull()); // Use null vector for raw type. } } // Self referencing types may get finalized indirectly. if (!parameterized_type.IsFinalized()) { ASSERT(full_arguments.IsNull() || !full_arguments.IsRaw(0, num_type_arguments)); // Mark the type as finalized. parameterized_type.SetIsFinalized(); } // If we are done finalizing a graph of mutually recursive types, check their // bounds. if (is_root_type) { Type& type = Type::Handle(); for (intptr_t i = 0; i < types.Length(); i++) { type ^= types.At(i); CheckTypeBounds(cls, type); } } // If the type class is a signature class, we are currently finalizing a // signature type, i.e. finalizing the result type and parameter types of the // signature function of this signature type. // We do this after marking this type as finalized in order to allow a // function type to refer to itself via its parameter types and result type. if (type_class.IsSignatureClass()) { // The class may be created while parsing a function body, after all // pending classes have already been finalized. FinalizeTypesInClass(type_class); } if (FLAG_trace_type_finalization) { OS::Print("Done finalizing type '%s' with %" Pd " type args: %s\n", String::Handle(parameterized_type.Name()).ToCString(), parameterized_type.arguments() == AbstractTypeArguments::null() ? 0 : num_type_arguments, parameterized_type.ToCString()); } if (finalization >= kCanonicalize) { return parameterized_type.Canonicalize(); } else { return parameterized_type.raw(); } } void ClassFinalizer::ResolveAndFinalizeSignature(const Class& cls, const Function& function) { // Resolve result type. AbstractType& type = AbstractType::Handle(function.result_type()); // It is not a compile time error if this name does not resolve to a class or // interface. ResolveType(cls, type); type = FinalizeType(cls, type, kCanonicalize); // The result type may be malformed or malbounded. function.set_result_type(type); // Resolve formal parameter types. const intptr_t num_parameters = function.NumParameters(); for (intptr_t i = 0; i < num_parameters; i++) { type = function.ParameterTypeAt(i); ResolveType(cls, type); type = FinalizeType(cls, type, kCanonicalize); // The parameter type may be malformed or malbounded. function.SetParameterTypeAt(i, type); } } // Check if an instance field, getter, or method of same name exists // in any super class. static RawClass* FindSuperOwnerOfInstanceMember(const Class& cls, const String& name, const String& getter_name) { Class& super_class = Class::Handle(); Function& function = Function::Handle(); Field& field = Field::Handle(); super_class = cls.SuperClass(); while (!super_class.IsNull()) { function = super_class.LookupFunction(name); if (!function.IsNull() && !function.is_static()) { return super_class.raw(); } function = super_class.LookupFunction(getter_name); if (!function.IsNull() && !function.is_static()) { return super_class.raw(); } field = super_class.LookupField(name); if (!field.IsNull() && !field.is_static()) { return super_class.raw(); } super_class = super_class.SuperClass(); } return Class::null(); } // Check if an instance method of same name exists in any super class. static RawClass* FindSuperOwnerOfFunction(const Class& cls, const String& name) { Class& super_class = Class::Handle(); Function& function = Function::Handle(); super_class = cls.SuperClass(); while (!super_class.IsNull()) { function = super_class.LookupFunction(name); if (!function.IsNull() && !function.is_static() && !function.IsMethodExtractor()) { return super_class.raw(); } super_class = super_class.SuperClass(); } return Class::null(); } // Resolve the upper bounds of the type parameters of class cls. void ClassFinalizer::ResolveUpperBounds(const Class& cls) { const intptr_t num_type_params = cls.NumTypeParameters(); TypeParameter& type_param = TypeParameter::Handle(); AbstractType& bound = AbstractType::Handle(); const AbstractTypeArguments& type_params = AbstractTypeArguments::Handle(cls.type_parameters()); ASSERT((type_params.IsNull() && (num_type_params == 0)) || (type_params.Length() == num_type_params)); // In a first pass, resolve all bounds. This guarantees that finalization // of mutually referencing bounds will not encounter an unresolved bound. for (intptr_t i = 0; i < num_type_params; i++) { type_param ^= type_params.TypeAt(i); bound = type_param.bound(); ResolveType(cls, bound); } } // Finalize the upper bounds of the type parameters of class cls. void ClassFinalizer::FinalizeUpperBounds(const Class& cls) { const intptr_t num_type_params = cls.NumTypeParameters(); TypeParameter& type_param = TypeParameter::Handle(); AbstractType& bound = AbstractType::Handle(); const AbstractTypeArguments& type_params = AbstractTypeArguments::Handle(cls.type_parameters()); ASSERT((type_params.IsNull() && (num_type_params == 0)) || (type_params.Length() == num_type_params)); for (intptr_t i = 0; i < num_type_params; i++) { type_param ^= type_params.TypeAt(i); bound = type_param.bound(); if (bound.IsFinalized() || bound.IsBeingFinalized()) { // A bound involved in F-bounded quantification may form a cycle. continue; } bound = FinalizeType(cls, bound, kCanonicalize); type_param.set_bound(bound); } } void ClassFinalizer::ResolveAndFinalizeMemberTypes(const Class& cls) { // Note that getters and setters are explicitly listed as such in the list of // functions of a class, so we do not need to consider fields as implicitly // generating getters and setters. // Most overriding conflicts are only static warnings, i.e. they are not // reported as compile-time errors by the vm. However, signature conflicts in // overrides can be reported if the flag --error_on_bad_override is specified. // Static warning examples are: // - a static getter 'v' conflicting with an inherited instance setter 'v='. // - a static setter 'v=' conflicting with an inherited instance member 'v'. // - an instance member 'v' conflicting with an accessible static member 'v' // or 'v=' of a super class (except that an instance method 'v' does not // conflict with an accessible static setter 'v=' of a super class). // The compile-time errors we report are: // - a static member 'v' conflicting with an inherited instance member 'v'. // - a static setter 'v=' conflicting with an inherited instance setter 'v='. // - an instance method conflicting with an inherited instance field or // instance getter. // - an instance field or instance getter conflicting with an inherited // instance method. // Resolve type of fields and check for conflicts in super classes. Array& array = Array::Handle(cls.fields()); Field& field = Field::Handle(); AbstractType& type = AbstractType::Handle(); String& name = String::Handle(); String& getter_name = String::Handle(); String& setter_name = String::Handle(); Class& super_class = Class::Handle(); const intptr_t num_fields = array.Length(); for (intptr_t i = 0; i < num_fields; i++) { field ^= array.At(i); type = field.type(); ResolveType(cls, type); type = FinalizeType(cls, type, kCanonicalize); field.set_type(type); name = field.name(); if (field.is_static()) { getter_name = Field::GetterSymbol(name); super_class = FindSuperOwnerOfInstanceMember(cls, name, getter_name); if (!super_class.IsNull()) { const String& class_name = String::Handle(cls.Name()); const String& super_class_name = String::Handle(super_class.Name()); const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, field.token_pos(), "static field '%s' of class '%s' conflicts with " "instance member '%s' of super class '%s'", name.ToCString(), class_name.ToCString(), name.ToCString(), super_class_name.ToCString()); } // An implicit setter is not generated for a static field, therefore, we // cannot rely on the code below handling the static setter case to report // a conflict with an instance setter. So we check explicitly here. setter_name = Field::SetterSymbol(name); super_class = FindSuperOwnerOfFunction(cls, setter_name); if (!super_class.IsNull()) { const String& class_name = String::Handle(cls.Name()); const String& super_class_name = String::Handle(super_class.Name()); const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, field.token_pos(), "static field '%s' of class '%s' conflicts with " "instance setter '%s=' of super class '%s'", name.ToCString(), class_name.ToCString(), name.ToCString(), super_class_name.ToCString()); } } else { // Instance field. Check whether the field overrides a method // (but not getter). super_class = FindSuperOwnerOfFunction(cls, name); if (!super_class.IsNull()) { const String& class_name = String::Handle(cls.Name()); const String& super_class_name = String::Handle(super_class.Name()); const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, field.token_pos(), "field '%s' of class '%s' conflicts with method '%s' " "of super class '%s'", name.ToCString(), class_name.ToCString(), name.ToCString(), super_class_name.ToCString()); } } if (field.is_static() && (field.is_const() || field.is_final()) && (field.value() != Object::null()) && (field.value() != Object::sentinel().raw())) { // The parser does not preset the value if the type is a type parameter or // is parameterized unless the value is null. Error& error = Error::Handle(); if (type.IsMalformedOrMalbounded()) { error = type.error(); } else { ASSERT(type.IsInstantiated()); } const Instance& const_value = Instance::Handle(field.value()); if (!error.IsNull() || (!type.IsDynamicType() && !const_value.IsInstanceOf(type, AbstractTypeArguments::Handle(), &error))) { if (FLAG_error_on_bad_type) { const AbstractType& const_value_type = AbstractType::Handle( const_value.GetType()); const String& const_value_type_name = String::Handle( const_value_type.UserVisibleName()); const String& type_name = String::Handle(type.UserVisibleName()); const Script& script = Script::Handle(cls.script()); ReportError(error, script, field.token_pos(), "error initializing static %s field '%s': " "type '%s' is not a subtype of type '%s'", field.is_const() ? "const" : "final", name.ToCString(), const_value_type_name.ToCString(), type_name.ToCString()); } else { // Do not report an error yet, even in checked mode, since the field // may not actually be used. // Also, we may be generating a snapshot in production mode that will // later be executed in checked mode, in which case an error needs to // be reported, should the field be accessed. // Therefore, we undo the optimization performed by the parser, i.e. // we create an implicit static final getter and reset the field value // to the sentinel value. const Function& getter = Function::Handle( Function::New(getter_name, RawFunction::kImplicitStaticFinalGetter, /* is_static = */ true, /* is_const = */ field.is_const(), /* is_abstract = */ false, /* is_external = */ false, /* is_native = */ false, cls, field.token_pos())); getter.set_result_type(type); cls.AddFunction(getter); field.set_value(Instance::Handle(Object::sentinel().raw())); // Create initializer function. if (!field.is_const()) { const Function& init_function = Function::ZoneHandle( Function::NewStaticInitializer(field)); cls.AddFunction(init_function); } } } } } // Collect interfaces, super interfaces, and super classes of this class. const GrowableObjectArray& interfaces = GrowableObjectArray::Handle(GrowableObjectArray::New()); CollectInterfaces(cls, interfaces); // Include superclasses in list of interfaces and super interfaces. super_class = cls.SuperClass(); while (!super_class.IsNull()) { interfaces.Add(super_class); CollectInterfaces(super_class, interfaces); super_class = super_class.SuperClass(); } // Resolve function signatures and check for conflicts in super classes and // interfaces. array = cls.functions(); Function& function = Function::Handle(); Function& overridden_function = Function::Handle(); const intptr_t num_functions = array.Length(); Error& error = Error::Handle(); for (intptr_t i = 0; i < num_functions; i++) { function ^= array.At(i); ResolveAndFinalizeSignature(cls, function); name = function.name(); if (FLAG_error_on_bad_override && // Report signature conflicts only. !function.is_static() && !function.IsConstructor()) { // A constructor cannot override anything. for (intptr_t i = 0; i < interfaces.Length(); i++) { super_class ^= interfaces.At(i); overridden_function = super_class.LookupDynamicFunction(name); if (!overridden_function.IsNull() && !function.HasCompatibleParametersWith(overridden_function, &error)) { const String& class_name = String::Handle(cls.Name()); const String& super_class_name = String::Handle(super_class.Name()); const Script& script = Script::Handle(cls.script()); ReportError(error, script, function.token_pos(), "class '%s' overrides method '%s' of super class '%s' " "with incompatible parameters", class_name.ToCString(), name.ToCString(), super_class_name.ToCString()); } } } if (function.IsSetterFunction() || function.IsImplicitSetterFunction()) { if (function.is_static()) { super_class = FindSuperOwnerOfFunction(cls, name); if (!super_class.IsNull()) { const String& class_name = String::Handle(cls.Name()); const String& super_class_name = String::Handle(super_class.Name()); const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, function.token_pos(), "static setter '%s=' of class '%s' conflicts with " "instance setter '%s=' of super class '%s'", name.ToCString(), class_name.ToCString(), name.ToCString(), super_class_name.ToCString()); } } continue; } if (function.IsGetterFunction() || function.IsImplicitGetterFunction()) { getter_name = name.raw(); name = Field::NameFromGetter(getter_name); } else { getter_name = Field::GetterSymbol(name); } if (function.is_static()) { super_class = FindSuperOwnerOfInstanceMember(cls, name, getter_name); if (!super_class.IsNull()) { const String& class_name = String::Handle(cls.Name()); const String& super_class_name = String::Handle(super_class.Name()); const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, function.token_pos(), "static %s '%s' of class '%s' conflicts with " "instance member '%s' of super class '%s'", (function.IsGetterFunction() || function.IsImplicitGetterFunction()) ? "getter" : "method", name.ToCString(), class_name.ToCString(), name.ToCString(), super_class_name.ToCString()); } // The function may be a still unresolved redirecting factory. Do not yet // try to resolve it in order to avoid cycles in class finalization. } else if (function.IsGetterFunction() || function.IsImplicitGetterFunction()) { super_class = FindSuperOwnerOfFunction(cls, name); if (!super_class.IsNull()) { const String& class_name = String::Handle(cls.Name()); const String& super_class_name = String::Handle(super_class.Name()); const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, function.token_pos(), "getter '%s' of class '%s' conflicts with " "method '%s' of super class '%s'", name.ToCString(), class_name.ToCString(), name.ToCString(), super_class_name.ToCString()); } } else if (!function.IsSetterFunction() && !function.IsImplicitSetterFunction()) { // A function cannot conflict with a setter, since they cannot // have the same name. Thus, we do not need to check setters. super_class = FindSuperOwnerOfFunction(cls, getter_name); if (!super_class.IsNull()) { const String& class_name = String::Handle(cls.Name()); const String& super_class_name = String::Handle(super_class.Name()); const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, function.token_pos(), "method '%s' of class '%s' conflicts with " "getter '%s' of super class '%s'", name.ToCString(), class_name.ToCString(), name.ToCString(), super_class_name.ToCString()); } } } } // Clone the type parameters of the super class and of the mixin class of this // mixin application class and use them as the type parameters of this mixin // application class. Set the type arguments of the super type, of the mixin // type (as well as of the interface type, which is identical to the mixin type) // to refer to the respective type parameters of the mixin application class. // In other words, decorate this mixin application class with type parameters // that forward to the super type and mixin type (and interface type). // Example: // class S { } // class M { } // class C extends S with M> { } // results in // class S&M extends S implements M { } // mixin == M // class C extends S&M> { } // CloneMixinAppTypeParameters decorates class S&M with type parameters T` and // T, and use them as type arguments in S and M. void ClassFinalizer::CloneMixinAppTypeParameters(const Class& mixin_app_class) { ASSERT(mixin_app_class.type_parameters() == AbstractTypeArguments::null()); const AbstractType& super_type = AbstractType::Handle( mixin_app_class.super_type()); ASSERT(super_type.IsResolved()); const Class& super_class = Class::Handle(super_type.type_class()); const intptr_t num_super_type_params = super_class.NumTypeParameters(); const Type& mixin_type = Type::Handle(mixin_app_class.mixin()); const Class& mixin_class = Class::Handle(mixin_type.type_class()); const intptr_t num_mixin_type_params = mixin_class.NumTypeParameters(); // The mixin class cannot be Object and this was checked earlier. ASSERT(!mixin_class.IsObjectClass()); // Add the mixin type to the interfaces that the mixin application // class implements. This is necessary so that type tests work. const Array& interfaces = Array::Handle(Array::New(1)); const Type& interface = Type::Handle(Type::New( mixin_class, Object::null_abstract_type_arguments(), // Set again below if generic. mixin_app_class.token_pos())); ASSERT(!interface.IsFinalized()); interfaces.SetAt(0, interface); ASSERT(mixin_app_class.interfaces() == Object::empty_array().raw()); mixin_app_class.set_interfaces(interfaces); // If both the super type and the mixin type are non generic, the mixin // application class is non generic as well and we can skip type parameter // cloning. if ((num_super_type_params + num_mixin_type_params) > 0) { // First, clone the super class type parameters. Rename them so that // there can be no name conflict between the parameters of the super // class and the mixin class. const TypeArguments& cloned_type_params = TypeArguments::Handle( TypeArguments::New(num_super_type_params + num_mixin_type_params)); TypeParameter& param = TypeParameter::Handle(); TypeParameter& cloned_param = TypeParameter::Handle(); String& param_name = String::Handle(); AbstractType& param_bound = AbstractType::Handle(); intptr_t cloned_index = 0; if (num_super_type_params > 0) { const TypeArguments& super_type_params = TypeArguments::Handle(super_class.type_parameters()); const TypeArguments& super_type_args = TypeArguments::Handle(TypeArguments::New(num_super_type_params)); for (intptr_t i = 0; i < num_super_type_params; i++) { param ^= super_type_params.TypeAt(i); param_name = param.name(); param_bound = param.bound(); // TODO(14453): handle type bounds. if (!param_bound.IsObjectType()) { const Script& script = Script::Handle(mixin_app_class.script()); ReportError(Error::Handle(), // No previous error. script, param.token_pos(), "type parameter '%s': type bounds not yet" " implemented for mixins\n", param_name.ToCString()); } param_name = String::Concat(param_name, Symbols::Backtick()); param_name = Symbols::New(param_name); cloned_param = TypeParameter::New(mixin_app_class, cloned_index, param_name, param_bound, param.token_pos()); cloned_type_params.SetTypeAt(cloned_index, cloned_param); // Change the type arguments of the super type to refer to the // cloned type parameters of the mixin application class. super_type_args.SetTypeAt(cloned_index, cloned_param); cloned_index++; } // TODO(14453): May need to handle BoundedType here. ASSERT(super_type.IsType()); Type::Cast(super_type).set_arguments(super_type_args); ASSERT(!super_type.IsFinalized()); } // Second, clone the type parameters of the mixin class. // We need to retain the parameter names of the mixin class // since the code that will be compiled in the context of the // mixin application class may refer to the type parameters // with that name. if (num_mixin_type_params > 0) { const TypeArguments& mixin_params = TypeArguments::Handle(mixin_class.type_parameters()); const TypeArguments& mixin_type_args = TypeArguments::Handle( TypeArguments::New(num_mixin_type_params)); // TODO(regis): Can we share interface type and mixin_type? const TypeArguments& interface_type_args = TypeArguments::Handle( TypeArguments::New(num_mixin_type_params)); for (intptr_t i = 0; i < num_mixin_type_params; i++) { param ^= mixin_params.TypeAt(i); param_name = param.name(); param_bound = param.bound(); // TODO(14453): handle type bounds. if (!param_bound.IsObjectType()) { const Script& script = Script::Handle(mixin_app_class.script()); ReportError(Error::Handle(), // No previous error. script, param.token_pos(), "type parameter '%s': type bounds not yet" " implemented for mixins\n", param_name.ToCString()); } cloned_param = TypeParameter::New(mixin_app_class, cloned_index, param_name, param_bound, param.token_pos()); cloned_type_params.SetTypeAt(cloned_index, cloned_param); interface_type_args.SetTypeAt(i, cloned_param); mixin_type_args.SetTypeAt(i, cloned_param); cloned_index++; } // Lastly, set the type arguments of the mixin type and of the single // interface type. ASSERT(!mixin_type.IsFinalized()); mixin_type.set_arguments(mixin_type_args); ASSERT(!interface.IsFinalized()); interface.set_arguments(interface_type_args); } mixin_app_class.set_type_parameters(cloned_type_params); } // If the mixin class is a mixin application alias class, we insert a new // synthesized mixin application class in the super chain of this mixin // application class. The new class will have the aliased mixin as actual // mixin. if (mixin_class.is_mixin_app_alias()) { ApplyMixinAppAlias(mixin_app_class); } } /* Support for mixin alias. Consider the following example: class I { } class J { } class S { } class M { } class A = Object with M> implements I; class C = S with A> implements J; Before the call to ApplyMixinAppAlias, the VM has already synthesized 2 mixin application classes Object&M and S&A: Object&M extends Object implements M { ... members of M applied here ... } A extends Object&M> implements I { } S&A extends S implements A { } C extends S&A> implements J { } In theory, class A should be an alias of Object&M instead of extending it. In practice, the additional class provides a hook for implemented interfaces (e.g. I) and for type argument substitution via the super type relation (e.g. type parameter T of Object&M is substituted with Map, U and V being the type parameters of the alias A). Similarly, class C should be an alias of S&A instead of extending it. Since A is used as a mixin, it must extend Object. The fact that it extends Object&M must be hidden so that no error is wrongly reported. Now, A does not have any members to be mixed into S&A, because A is an alias. The members to be mixed in are actually those of M, and they should appear in a scope where the type parameter T is visible. The class S&A declares the type parameters of A, i.e. U and V, but not T. Therefore, the call to ApplyMixinAppAlias inserts another synthesized class S&A` as the superclass of S&A. The class S&A` declares a type argument T: Instead of S&A extends S implements A { } We now have: S&A` extends S implements M { ... members of M applied here ... } S&A extends S&A`> implements A { } The main implementation difficulty resides in the fact that the type parameters U and V in the super type S&A`> of S&A must refer to the type parameters U and V of S&A. However, Map is copied from the super type Object&M> of A and, therefore, U and V refer to A. An instantiation step with a properly crafted instantiator vector takes care of the required type parameter substitution. The instantiator vector must end with the type parameters U and V of S&A. The offset of the first type parameter U of S&A must be at the finalized index of type parameter U of A. */ void ClassFinalizer::ApplyMixinAppAlias(const Class& mixin_app_class) { // If this mixin alias is aliasing another mixin alias, another class // will be inserted via recursion. No need to check here. // The mixin type may or may not be finalized yet. AbstractType& super_type = AbstractType::Handle(mixin_app_class.super_type()); const Type& mixin_type = Type::Handle(mixin_app_class.mixin()); const Class& mixin_class = Class::Handle(mixin_type.type_class()); ASSERT(mixin_class.is_mixin_app_alias()); const Class& aliased_mixin_app_class = Class::Handle( mixin_class.SuperClass()); const Type& aliased_mixin_type = Type::Handle( aliased_mixin_app_class.mixin()); // The name of the inserted mixin application class is the name of mixin // class name with a backtick added. String& inserted_class_name = String::Handle(mixin_app_class.Name()); inserted_class_name = String::Concat(inserted_class_name, Symbols::Backtick()); const Library& library = Library::Handle(mixin_app_class.library()); Class& inserted_class = Class::Handle( library.LookupLocalClass(inserted_class_name)); if (inserted_class.IsNull()) { inserted_class_name = Symbols::New(inserted_class_name); const Script& script = Script::Handle(mixin_app_class.script()); inserted_class = Class::New( inserted_class_name, script, mixin_app_class.token_pos()); inserted_class.set_is_synthesized_class(); library.AddClass(inserted_class); if (FLAG_trace_class_finalization) { OS::Print("Creating mixin application alias %s\n", inserted_class.ToCString()); } // The super type of the inserted class is identical to the super type of // this mixin application class, except that it must refer to the type // parameters of the inserted class rather than to those of the mixin // application class. // The type arguments of the super type will be set properly when calling // CloneMixinAppTypeParameters on the inserted class, as long as the super // type class is set properly. inserted_class.set_super_type(super_type); // Super class only is used. // The mixin type and interface type must also be set before calling // CloneMixinAppTypeParameters. // After FinalizeTypesInClass, they will refer to the type parameters of // the mixin class typedef. const Type& generic_mixin_type = Type::Handle( Type::New(Class::Handle(aliased_mixin_type.type_class()), Object::null_abstract_type_arguments(), aliased_mixin_type.token_pos())); inserted_class.set_mixin(generic_mixin_type); // The interface will be set in CloneMixinAppTypeParameters. } // Finalize the types and call CloneMixinAppTypeParameters. FinalizeTypesInClass(inserted_class); // The super type of this mixin application class must point to the // inserted class. The super type arguments are the concatenation of the // old super type arguments (propagating type arguments to the super class) // with new type arguments providing type arguments to the mixin. // The appended type arguments are those of the super type of the mixin // application alias that are forwarding to the aliased mixin type, except // that they must refer to the type parameters of the mixin application // class rather than to those of the mixin application alias class. // This type parameter substitution is performed by an instantiation step. // It is important that the type parameters of the mixin application class // are not finalized yet, because new type parameters may have been added // to the super class. Class& super_class = Class::Handle(super_type.type_class()); ASSERT(mixin_app_class.SuperClass() == super_class.raw()); while (super_class.IsMixinApplication()) { super_class = super_class.SuperClass(); } const intptr_t num_super_type_params = super_class.NumTypeParameters(); const intptr_t num_mixin_type_params = mixin_class.NumTypeParameters(); intptr_t offset = mixin_class.NumTypeArguments() - mixin_class.NumTypeParameters(); const TypeArguments& type_params = TypeArguments::Handle(mixin_app_class.type_parameters()); TypeArguments& instantiator = TypeArguments::Handle( TypeArguments::New(offset + num_mixin_type_params)); AbstractType& type = AbstractType::Handle(); for (intptr_t i = 0; i < num_mixin_type_params; i++) { type = type_params.TypeAt(num_super_type_params + i); instantiator.SetTypeAt(offset + i, type); } ASSERT(aliased_mixin_type.IsFinalized()); const Class& aliased_mixin_type_class = Class::Handle( aliased_mixin_type.type_class()); const intptr_t num_aliased_mixin_type_params = aliased_mixin_type_class.NumTypeParameters(); const intptr_t num_aliased_mixin_type_args = aliased_mixin_type_class.NumTypeArguments(); offset = num_aliased_mixin_type_args - num_aliased_mixin_type_params; ASSERT(inserted_class.NumTypeParameters() == (num_super_type_params + num_aliased_mixin_type_params)); // The aliased_mixin_type may be raw. const AbstractTypeArguments& mixin_class_super_type_args = AbstractTypeArguments::Handle( AbstractType::Handle(mixin_class.super_type()).arguments()); TypeArguments& new_mixin_type_args = TypeArguments::Handle(); if ((num_aliased_mixin_type_params > 0) && !mixin_class_super_type_args.IsNull()) { new_mixin_type_args = TypeArguments::New(num_aliased_mixin_type_params); for (intptr_t i = 0; i < num_aliased_mixin_type_params; i++) { type = mixin_class_super_type_args.TypeAt(offset + i); new_mixin_type_args.SetTypeAt(i, type); } } if (!new_mixin_type_args.IsNull() && !new_mixin_type_args.IsInstantiated()) { Error& bound_error = Error::Handle(); new_mixin_type_args ^= new_mixin_type_args.InstantiateFrom(instantiator, &bound_error); // TODO(14453): Handle bound error. ASSERT(bound_error.IsNull()); } TypeArguments& new_super_type_args = TypeArguments::Handle(); if ((num_super_type_params + num_aliased_mixin_type_params) > 0) { new_super_type_args = TypeArguments::New(num_super_type_params + num_aliased_mixin_type_params); for (intptr_t i = 0; i < num_super_type_params; i++) { type = type_params.TypeAt(i); new_super_type_args.SetTypeAt(i, type); } for (intptr_t i = 0; i < num_aliased_mixin_type_params; i++) { if (new_mixin_type_args.IsNull()) { type = Type::DynamicType(); } else { type = new_mixin_type_args.TypeAt(i); } new_super_type_args.SetTypeAt(num_super_type_params + i, type); } } super_type = Type::New(inserted_class, new_super_type_args, mixin_app_class.token_pos()); mixin_app_class.set_super_type(super_type); // Mark this mixin application class as being an alias. mixin_app_class.set_is_mixin_app_alias(); ASSERT(!mixin_app_class.is_type_finalized()); ASSERT(!mixin_app_class.is_mixin_type_applied()); if (FLAG_trace_class_finalization) { OS::Print("Inserting class %s to mixin application alias %s " "with super type '%s'\n", inserted_class.ToCString(), mixin_app_class.ToCString(), String::Handle(super_type.Name()).ToCString()); } } void ClassFinalizer::ApplyMixinType(const Class& mixin_app_class, GrowableObjectArray* pending_types) { if (mixin_app_class.is_mixin_type_applied()) { return; } Type& mixin_type = Type::Handle(mixin_app_class.mixin()); ASSERT(!mixin_type.IsNull()); ASSERT(mixin_type.HasResolvedTypeClass()); const Class& mixin_class = Class::Handle(mixin_type.type_class()); if (FLAG_trace_class_finalization) { OS::Print("Applying mixin type '%s' to %s at pos %" Pd "\n", String::Handle(mixin_type.Name()).ToCString(), mixin_app_class.ToCString(), mixin_app_class.token_pos()); } // Check for illegal self references. This has to be done before checking // that the super class of the mixin class is class Object. GrowableArray visited_mixins; if (!IsMixinCycleFree(mixin_class, &visited_mixins)) { const Script& script = Script::Handle(mixin_class.script()); const String& class_name = String::Handle(mixin_class.Name()); ReportError(Error::Handle(), // No previous error. script, mixin_class.token_pos(), "mixin class '%s' illegally refers to itself", class_name.ToCString()); } // Check that the super class of the mixin class is class Object. Class& mixin_super_class = Class::Handle(mixin_class.SuperClass()); // Skip over mixin application alias classes, which are implemented as // subclasses of the mixin application classes they name. if (!mixin_super_class.IsNull() && mixin_class.is_mixin_app_alias()) { while (mixin_super_class.is_mixin_app_alias()) { mixin_super_class = mixin_super_class.SuperClass(); } mixin_super_class = mixin_super_class.SuperClass(); } if (mixin_super_class.IsNull() || !mixin_super_class.IsObjectClass()) { const Script& script = Script::Handle(mixin_app_class.script()); const String& class_name = String::Handle(mixin_class.Name()); ReportError(Error::Handle(), // No previous error. script, mixin_app_class.token_pos(), "mixin class '%s' must extend class 'Object'", class_name.ToCString()); } // Copy type parameters to mixin application class. CloneMixinAppTypeParameters(mixin_app_class); // Verify that no restricted class is used as a mixin by checking the // interfaces of the mixin application class, which implements its mixin. GrowableArray visited_interfaces; ResolveSuperTypeAndInterfaces(mixin_app_class, &visited_interfaces); if (FLAG_trace_class_finalization) { OS::Print("Done applying mixin type '%s' to class '%s' %s extending '%s'\n", String::Handle(mixin_type.Name()).ToCString(), String::Handle(mixin_app_class.Name()).ToCString(), TypeArguments::Handle( mixin_app_class.type_parameters()).ToCString(), AbstractType::Handle(mixin_app_class.super_type()).ToCString()); } // Mark the application class as having been applied its mixin type in order // to avoid cycles while finalizing its mixin type. mixin_app_class.set_is_mixin_type_applied(); // Finalize the mixin type, which may have been changed in case // mixin_app_class is an alias. mixin_type = mixin_app_class.mixin(); ASSERT(!mixin_type.IsBeingFinalized()); mixin_type ^= FinalizeType(mixin_app_class, mixin_type, kFinalize, pending_types); // TODO(14453): Check for a malbounded mixin_type. mixin_app_class.set_mixin(mixin_type); } void ClassFinalizer::CreateForwardingConstructors( const Class& mixin_app, const GrowableObjectArray& cloned_funcs) { const String& mixin_name = String::Handle(mixin_app.Name()); const Class& super_class = Class::Handle(mixin_app.SuperClass()); const String& super_name = String::Handle(super_class.Name()); const Type& dynamic_type = Type::Handle(Type::DynamicType()); const Array& functions = Array::Handle(super_class.functions()); const intptr_t num_functions = functions.Length(); Function& func = Function::Handle(); for (intptr_t i = 0; i < num_functions; i++) { func ^= functions.At(i); if (func.IsConstructor()) { // Build constructor name from mixin application class name // and name of cloned super class constructor. const String& ctor_name = String::Handle(func.name()); String& clone_name = String::Handle( String::SubString(ctor_name, super_name.Length())); clone_name = String::Concat(mixin_name, clone_name); clone_name = Symbols::New(clone_name); if (FLAG_trace_class_finalization) { OS::Print("Cloning constructor '%s' as '%s'\n", ctor_name.ToCString(), clone_name.ToCString()); } const Function& clone = Function::Handle( Function::New(clone_name, func.kind(), func.is_static(), false, // Not const. false, // Not abstract. false, // Not external. false, // Not native. mixin_app, mixin_app.token_pos())); clone.set_num_fixed_parameters(func.num_fixed_parameters()); clone.SetNumOptionalParameters(func.NumOptionalParameters(), func.HasOptionalPositionalParameters()); clone.set_result_type(dynamic_type); const intptr_t num_parameters = func.NumParameters(); // The cloned ctor shares the parameter names array with the // original. const Array& parameter_names = Array::Handle(func.parameter_names()); ASSERT(parameter_names.Length() == num_parameters); clone.set_parameter_names(parameter_names); // The parameter types of the cloned constructor are 'dynamic'. clone.set_parameter_types(Array::Handle(Array::New(num_parameters))); for (intptr_t n = 0; n < num_parameters; n++) { clone.SetParameterTypeAt(n, dynamic_type); } cloned_funcs.Add(clone); } } } void ClassFinalizer::ApplyMixinMembers(const Class& cls) { Isolate* isolate = Isolate::Current(); const Type& mixin_type = Type::Handle(isolate, cls.mixin()); ASSERT(!mixin_type.IsNull()); ASSERT(mixin_type.HasResolvedTypeClass()); const Class& mixin_cls = Class::Handle(isolate, mixin_type.type_class()); mixin_cls.EnsureIsFinalized(isolate); // If the mixin is a mixin application alias class, there are no members to // apply here. A new synthesized class representing the aliased mixin // application class was inserted in the super chain of this mixin application // class. Members of the actual mixin class will be applied when visiting // the mixin application class referring to the actual mixin. ASSERT(!mixin_cls.is_mixin_app_alias() || Class::Handle(isolate, cls.SuperClass()).IsMixinApplication()); // A default constructor will be created for the mixin app alias class. if (FLAG_trace_class_finalization) { OS::Print("Applying mixin members of %s to %s at pos %" Pd "\n", mixin_cls.ToCString(), cls.ToCString(), cls.token_pos()); } const GrowableObjectArray& cloned_funcs = GrowableObjectArray::Handle(isolate, GrowableObjectArray::New()); CreateForwardingConstructors(cls, cloned_funcs); Array& functions = Array::Handle(isolate); Function& func = Function::Handle(isolate); // The parser creates the mixin application class with no functions. ASSERT((functions = cls.functions(), functions.Length() == 0)); // Now clone the functions from the mixin class. functions = mixin_cls.functions(); const intptr_t num_functions = functions.Length(); for (intptr_t i = 0; i < num_functions; i++) { func ^= functions.At(i); if (func.IsConstructor()) { // A mixin class must not have explicit constructors. if (!func.IsImplicitConstructor()) { const Script& script = Script::Handle(isolate, cls.script()); ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "mixin class '%s' must not have constructors\n", String::Handle(isolate, mixin_cls.Name()).ToCString()); } continue; // Skip the implicit constructor. } if (!func.is_static()) { func = func.Clone(cls); cloned_funcs.Add(func); } } functions = Array::MakeArray(cloned_funcs); cls.SetFunctions(functions); // Now clone the fields from the mixin class. There should be no // existing fields in the mixin application class. ASSERT(Array::Handle(cls.fields()).Length() == 0); Array& fields = Array::Handle(isolate, mixin_cls.fields()); Field& field = Field::Handle(isolate); const GrowableObjectArray& cloned_fields = GrowableObjectArray::Handle(isolate, GrowableObjectArray::New()); const intptr_t num_fields = fields.Length(); for (intptr_t i = 0; i < num_fields; i++) { field ^= fields.At(i); if (!field.is_static()) { field = field.Clone(cls); cloned_fields.Add(field); } } fields = Array::MakeArray(cloned_fields); cls.SetFields(fields); if (FLAG_trace_class_finalization) { OS::Print("Done applying mixin members of %s to %s\n", mixin_cls.ToCString(), cls.ToCString()); } } void ClassFinalizer::FinalizeTypesInClass(const Class& cls) { HANDLESCOPE(Isolate::Current()); if (cls.is_type_finalized()) { return; } if (FLAG_trace_class_finalization) { OS::Print("Finalize types in %s\n", cls.ToCString()); } if (!IsSuperCycleFree(cls)) { const String& name = String::Handle(cls.Name()); const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "class '%s' has a cycle in its superclass relationship", name.ToCString()); } // Finalize super class. Class& super_class = Class::Handle(cls.SuperClass()); if (!super_class.IsNull()) { FinalizeTypesInClass(super_class); } // Finalize type parameters before finalizing the super type. FinalizeTypeParameters(cls); // May change super type. super_class = cls.SuperClass(); ASSERT(super_class.IsNull() || super_class.is_type_finalized()); ResolveUpperBounds(cls); // Finalize super type. AbstractType& super_type = AbstractType::Handle(cls.super_type()); if (!super_type.IsNull()) { // In case of a bound error in the super type in production mode, the // finalized super type will be a BoundedType with a malformed bound. // It should not be a problem if the class is written to a snapshot and // later executed in checked mode. Note that the finalized type argument // vector of any type of the base class will contain a BoundedType for the // out of bound type argument. super_type = FinalizeType(cls, super_type, kCanonicalizeWellFormed); cls.set_super_type(super_type); } if (cls.IsSignatureClass()) { // Check for illegal self references. GrowableArray visited_aliases; if (!IsAliasCycleFree(cls, &visited_aliases)) { const String& name = String::Handle(cls.Name()); const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "typedef '%s' illegally refers to itself", name.ToCString()); } cls.set_is_type_finalized(); // The type parameters of signature classes may have bounds. FinalizeUpperBounds(cls); // Resolve and finalize the result and parameter types of the signature // function of this signature class. const Function& sig_function = Function::Handle(cls.signature_function()); ResolveAndFinalizeSignature(cls, sig_function); // Resolve and finalize the signature type of this signature class. const Type& sig_type = Type::Handle(cls.SignatureType()); FinalizeType(cls, sig_type, kCanonicalizeWellFormed); return; } // Finalize interface types (but not necessarily interface classes). Array& interface_types = Array::Handle(cls.interfaces()); AbstractType& interface_type = AbstractType::Handle(); AbstractType& seen_interf = AbstractType::Handle(); for (intptr_t i = 0; i < interface_types.Length(); i++) { interface_type ^= interface_types.At(i); interface_type = FinalizeType(cls, interface_type, kCanonicalizeWellFormed); interface_types.SetAt(i, interface_type); // Check whether the interface is duplicated. We need to wait with // this check until the super type and interface types are finalized, // so that we can use Type::Equals() for the test. ASSERT(interface_type.IsFinalized()); ASSERT(super_type.IsNull() || super_type.IsFinalized()); if (!super_type.IsNull() && interface_type.Equals(super_type)) { const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "super type '%s' may not be listed in " "implements clause of class '%s'", String::Handle(super_type.Name()).ToCString(), String::Handle(cls.Name()).ToCString()); } for (intptr_t j = 0; j < i; j++) { seen_interf ^= interface_types.At(j); if (interface_type.Equals(seen_interf)) { const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "interface '%s' appears twice in " "implements clause of class '%s'", String::Handle(interface_type.Name()).ToCString(), String::Handle(cls.Name()).ToCString()); } } } // Mark as type finalized before resolving type parameter upper bounds // in order to break cycles. cls.set_is_type_finalized(); // Finalize bounds even if running in production mode, so that a snapshot // contains them. FinalizeUpperBounds(cls); // Add this class to the direct subclasses of the superclass, unless the // superclass is Object. if (!super_type.IsNull() && !super_type.IsObjectType()) { ASSERT(!super_class.IsNull()); super_class.AddDirectSubclass(cls); } // A top level class is parsed eagerly so just finalize it. if (cls.IsTopLevel()) { FinalizeClass(cls); } else { // This class should not contain any fields or functions yet, because it has // not been compiled yet. Since 'ResolveAndFinalizeMemberTypes(cls)' has not // been called yet, unfinalized member types could choke the snapshotter. ASSERT(Array::Handle(cls.fields()).Length() == 0); ASSERT(Array::Handle(cls.functions()).Length() == 0); } } void ClassFinalizer::FinalizeClass(const Class& cls) { HANDLESCOPE(Isolate::Current()); if (cls.is_finalized()) { return; } if (FLAG_trace_class_finalization) { OS::Print("Finalize %s\n", cls.ToCString()); } if (cls.IsMixinApplication()) { // Copy instance methods and fields from the mixin class. // This has to happen before the check whether the methods of // the class conflict with inherited methods. ApplyMixinMembers(cls); } GrowableArray added_subclass_to_cids; CollectFinalizedSuperClasses(cls, &added_subclass_to_cids); // Ensure super class is finalized. const Class& super = Class::Handle(cls.SuperClass()); if (!super.IsNull()) { FinalizeClass(super); } // Mark as parsed and finalized. cls.Finalize(); // Mixin app alias classes may still lack their forwarding constructor. if (cls.is_mixin_app_alias() && (cls.functions() == Object::empty_array().raw())) { const GrowableObjectArray& cloned_funcs = GrowableObjectArray::Handle(GrowableObjectArray::New()); CreateForwardingConstructors(cls, cloned_funcs); const Array& functions = Array::Handle(Array::MakeArray(cloned_funcs)); cls.SetFunctions(functions); } // Every class should have at least a constructor, unless it is a top level // class or a signature class. ASSERT(cls.IsTopLevel() || cls.IsSignatureClass() || (Array::Handle(cls.functions()).Length() > 0)); // Resolve and finalize all member types. ResolveAndFinalizeMemberTypes(cls); // Run additional checks after all types are finalized. if (cls.is_const()) { CheckForLegalConstClass(cls); } if (FLAG_use_cha) { RemoveOptimizedCode(added_subclass_to_cids); } } bool ClassFinalizer::IsSuperCycleFree(const Class& cls) { Class& test1 = Class::Handle(cls.raw()); Class& test2 = Class::Handle(cls.SuperClass()); // A finalized class has been checked for cycles. // Using the hare and tortoise algorithm for locating cycles. while (!test1.is_type_finalized() && !test2.IsNull() && !test2.is_type_finalized()) { if (test1.raw() == test2.raw()) { // Found a cycle. return false; } test1 = test1.SuperClass(); test2 = test2.SuperClass(); if (!test2.IsNull()) { test2 = test2.SuperClass(); } } // No cycles. return true; } // Helper function called by IsAliasCycleFree. bool ClassFinalizer::IsTypeCycleFree( const Class& cls, const AbstractType& type, GrowableArray* visited) { ASSERT(visited != NULL); ResolveType(cls, type); if (type.IsType() && !type.IsMalformed()) { const Class& type_class = Class::Handle(type.type_class()); if (!type_class.is_type_finalized() && type_class.IsSignatureClass() && !IsAliasCycleFree(type_class, visited)) { return false; } const AbstractTypeArguments& type_args = AbstractTypeArguments::Handle( type.arguments()); if (!type_args.IsNull()) { AbstractType& type_arg = AbstractType::Handle(); for (intptr_t i = 0; i < type_args.Length(); i++) { type_arg = type_args.TypeAt(i); if (!IsTypeCycleFree(cls, type_arg, visited)) { return false; } } } } return true; } // Returns false if the function type alias illegally refers to itself. bool ClassFinalizer::IsAliasCycleFree(const Class& cls, GrowableArray* visited) { ASSERT(cls.IsSignatureClass()); ASSERT(!cls.is_type_finalized()); ASSERT(visited != NULL); const intptr_t cls_index = cls.id(); for (intptr_t i = 0; i < visited->length(); i++) { if ((*visited)[i] == cls_index) { // We have already visited alias 'cls'. We found a cycle. return false; } } // Visit the bounds, result type, and parameter types of this signature type. visited->Add(cls.id()); AbstractType& type = AbstractType::Handle(); // Check the bounds of this signature type. const intptr_t num_type_params = cls.NumTypeParameters(); TypeParameter& type_param = TypeParameter::Handle(); const AbstractTypeArguments& type_params = AbstractTypeArguments::Handle(cls.type_parameters()); ASSERT((type_params.IsNull() && (num_type_params == 0)) || (type_params.Length() == num_type_params)); for (intptr_t i = 0; i < num_type_params; i++) { type_param ^= type_params.TypeAt(i); type = type_param.bound(); if (!IsTypeCycleFree(cls, type, visited)) { return false; } } // Check the result type of the function of this signature type. const Function& function = Function::Handle(cls.signature_function()); type = function.result_type(); if (!IsTypeCycleFree(cls, type, visited)) { return false; } // Check the formal parameter types of the function of this signature type. const intptr_t num_parameters = function.NumParameters(); for (intptr_t i = 0; i < num_parameters; i++) { type = function.ParameterTypeAt(i); if (!IsTypeCycleFree(cls, type, visited)) { return false; } } visited->RemoveLast(); return true; } // Returns false if the mixin illegally refers to itself. bool ClassFinalizer::IsMixinCycleFree(const Class& cls, GrowableArray* visited) { ASSERT(visited != NULL); const intptr_t cls_index = cls.id(); for (intptr_t i = 0; i < visited->length(); i++) { if ((*visited)[i] == cls_index) { // We have already visited mixin 'cls'. We found a cycle. return false; } } // Visit the super chain of cls. visited->Add(cls.id()); Class& super_class = Class::Handle(cls.raw()); do { if (super_class.IsMixinApplication()) { const Type& mixin_type = Type::Handle(super_class.mixin()); ASSERT(!mixin_type.IsNull()); ASSERT(mixin_type.HasResolvedTypeClass()); const Class& mixin_class = Class::Handle(mixin_type.type_class()); if (!IsMixinCycleFree(mixin_class, visited)) { return false; } } super_class = super_class.SuperClass(); } while (!super_class.IsNull()); visited->RemoveLast(); return true; } void ClassFinalizer::CollectTypeArguments( const Class& cls, const Type& type, const GrowableObjectArray& collected_args) { ASSERT(type.HasResolvedTypeClass()); Class& type_class = Class::Handle(type.type_class()); AbstractTypeArguments& type_args = AbstractTypeArguments::Handle(type.arguments()); const intptr_t num_type_parameters = type_class.NumTypeParameters(); const intptr_t num_type_arguments = type_args.IsNull() ? 0 : type_args.Length(); AbstractType& arg = AbstractType::Handle(); if (num_type_arguments > 0) { if (num_type_arguments == num_type_parameters) { for (intptr_t i = 0; i < num_type_arguments; i++) { arg = type_args.TypeAt(i); arg = arg.CloneUnfinalized(); ASSERT(!arg.IsBeingFinalized()); collected_args.Add(arg); } return; } if (FLAG_error_on_bad_type) { const Script& script = Script::Handle(cls.script()); const String& type_class_name = String::Handle(type_class.Name()); ReportError(Error::Handle(), // No previous error. script, type.token_pos(), "wrong number of type arguments for class '%s'", type_class_name.ToCString()); } // Discard provided type arguments and treat type as raw. } // Fill arguments with type dynamic. for (intptr_t i = 0; i < num_type_parameters; i++) { arg = Type::DynamicType(); collected_args.Add(arg); } } RawType* ClassFinalizer::ResolveMixinAppType( const Class& cls, const MixinAppType& mixin_app_type) { // Lookup or create mixin application classes in the library of cls // and resolve super type and mixin types. const Library& library = Library::Handle(cls.library()); ASSERT(!library.IsNull()); const Script& script = Script::Handle(cls.script()); ASSERT(!script.IsNull()); const GrowableObjectArray& type_args = GrowableObjectArray::Handle(GrowableObjectArray::New()); AbstractType& mixin_super_type = AbstractType::Handle(mixin_app_type.super_type()); ResolveType(cls, mixin_super_type); ASSERT(mixin_super_type.HasResolvedTypeClass()); // TODO(14453): May need to handle BoundedType here. ASSERT(mixin_super_type.IsType()); CollectTypeArguments(cls, Type::Cast(mixin_super_type), type_args); AbstractType& mixin_type = AbstractType::Handle(); Type& generic_mixin_type = Type::Handle(); Class& mixin_type_class = Class::Handle(); Class& mixin_app_class = Class::Handle(); String& mixin_app_class_name = String::Handle(); String& mixin_type_class_name = String::Handle(); const intptr_t depth = mixin_app_type.Depth(); for (intptr_t i = 0; i < depth; i++) { mixin_type = mixin_app_type.MixinTypeAt(i); ASSERT(!mixin_type.IsNull()); ResolveType(cls, mixin_type); ASSERT(mixin_type.HasResolvedTypeClass()); ASSERT(mixin_type.IsType()); CollectTypeArguments(cls, Type::Cast(mixin_type), type_args); // The name of the mixin application class is a combination of // the super class name and mixin class name. mixin_app_class_name = mixin_super_type.ClassName(); mixin_app_class_name = String::Concat(mixin_app_class_name, Symbols::Ampersand()); mixin_type_class_name = mixin_type.ClassName(); mixin_app_class_name = String::Concat(mixin_app_class_name, mixin_type_class_name); mixin_app_class = library.LookupLocalClass(mixin_app_class_name); if (mixin_app_class.IsNull()) { mixin_app_class_name = Symbols::New(mixin_app_class_name); mixin_app_class = Class::New(mixin_app_class_name, script, mixin_type.token_pos()); mixin_app_class.set_super_type(mixin_super_type); mixin_type_class = mixin_type.type_class(); generic_mixin_type = Type::New(mixin_type_class, Object::null_abstract_type_arguments(), mixin_type.token_pos()); mixin_app_class.set_mixin(generic_mixin_type); mixin_app_class.set_is_synthesized_class(); library.AddClass(mixin_app_class); // No need to add the new class to pending_classes, since it will be // processed via the super_type chain of a pending class. if (FLAG_trace_class_finalization) { OS::Print("Creating mixin application %s\n", mixin_app_class.ToCString()); } } // This mixin application class becomes the type class of the super type of // the next mixin application class. It is however too early to provide the // correct super type arguments. We use the raw type for now. mixin_super_type = Type::New(mixin_app_class, Object::null_abstract_type_arguments(), mixin_type.token_pos()); } AbstractType& type_arg = AbstractType::Handle(); const TypeArguments& mixin_app_args = TypeArguments::Handle(TypeArguments::New(type_args.Length())); for (intptr_t i = 0; i < type_args.Length(); i++) { type_arg ^= type_args.At(i); mixin_app_args.SetTypeAt(i, type_arg); } if (FLAG_trace_class_finalization) { OS::Print("ResolveMixinAppType: mixin appl type args: %s\n", mixin_app_args.ToCString()); } // The mixin application class at depth k is a subclass of mixin application // class at depth k - 1. Build a new super type with the class at the highest // depth (the last one processed by the loop above) as the type class and the // collected type arguments from the super type and all mixin types. // This super type replaces the MixinAppType object in the class that extends // the mixin application. return Type::New(mixin_app_class, mixin_app_args, mixin_app_type.token_pos()); } // Recursively walks the graph of explicitly declared super type and // interfaces, resolving unresolved super types and interfaces. // Reports an error if there is an interface reference that cannot be // resolved, or if there is a cycle in the graph. We detect cycles by // remembering interfaces we've visited in each path through the // graph. If we visit an interface a second time on a given path, // we found a loop. void ClassFinalizer::ResolveSuperTypeAndInterfaces( const Class& cls, GrowableArray* visited) { ASSERT(visited != NULL); if (FLAG_trace_class_finalization) { OS::Print("Resolving super and interfaces: %s\n", cls.ToCString()); } const intptr_t cls_index = cls.id(); for (intptr_t i = 0; i < visited->length(); i++) { if ((*visited)[i] == cls_index) { // We have already visited class 'cls'. We found a cycle. const String& class_name = String::Handle(cls.Name()); const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "cyclic reference found for class '%s'", class_name.ToCString()); } } // If the class/interface has no explicit super class/interfaces // and is not a mixin application, we are done. AbstractType& super_type = AbstractType::Handle(cls.super_type()); Array& super_interfaces = Array::Handle(cls.interfaces()); if ((super_type.IsNull() || super_type.IsObjectType()) && (super_interfaces.Length() == 0)) { return; } if (super_type.IsMixinAppType()) { const MixinAppType& mixin_app_type = MixinAppType::Cast(super_type); super_type = ResolveMixinAppType(cls, mixin_app_type); cls.set_super_type(super_type); } // If cls belongs to core lib, restrictions about allowed interfaces // are lifted. const bool cls_belongs_to_core_lib = cls.library() == Library::CoreLibrary(); // Resolve and check the super type and interfaces of cls. visited->Add(cls_index); AbstractType& interface = AbstractType::Handle(); Class& interface_class = Class::Handle(); // Resolve super type. Failures lead to a longjmp. ResolveType(cls, super_type); if (super_type.IsMalformedOrMalbounded()) { ReportError(Error::Handle(super_type.error())); } if (super_type.IsDynamicType()) { const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "class '%s' may not extend 'dynamic'", String::Handle(cls.Name()).ToCString()); } interface_class = super_type.type_class(); if (interface_class.IsSignatureClass()) { const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "class '%s' may not extend function type alias '%s'", String::Handle(cls.Name()).ToCString(), String::Handle(super_type.UserVisibleName()).ToCString()); } // If cls belongs to core lib or to core lib's implementation, restrictions // about allowed interfaces are lifted. if (!cls_belongs_to_core_lib) { // Prevent extending core implementation classes. bool is_error = false; switch (interface_class.id()) { case kNumberCid: case kIntegerCid: // Class Integer, not int. case kSmiCid: case kMintCid: case kBigintCid: case kDoubleCid: // Class Double, not double. case kOneByteStringCid: case kTwoByteStringCid: case kExternalOneByteStringCid: case kExternalTwoByteStringCid: case kBoolCid: case kNullCid: case kArrayCid: case kImmutableArrayCid: case kGrowableObjectArrayCid: #define DO_NOT_EXTEND_TYPED_DATA_CLASSES(clazz) \ case kTypedData##clazz##Cid: \ case kTypedData##clazz##ViewCid: \ case kExternalTypedData##clazz##Cid: CLASS_LIST_TYPED_DATA(DO_NOT_EXTEND_TYPED_DATA_CLASSES) #undef DO_NOT_EXTEND_TYPED_DATA_CLASSES case kByteDataViewCid: case kWeakPropertyCid: is_error = true; break; default: { // Special case: classes for which we don't have a known class id. if (super_type.IsDoubleType() || super_type.IsIntType() || super_type.IsStringType()) { is_error = true; } break; } } if (is_error) { const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "'%s' is not allowed to extend '%s'", String::Handle(cls.Name()).ToCString(), String::Handle(interface_class.Name()).ToCString()); } } // Now resolve the super interfaces of the super type. ResolveSuperTypeAndInterfaces(interface_class, visited); // Resolve interfaces. Failures lead to a longjmp. for (intptr_t i = 0; i < super_interfaces.Length(); i++) { interface ^= super_interfaces.At(i); ResolveType(cls, interface); ASSERT(!interface.IsTypeParameter()); // Should be detected by parser. // A malbounded interface is only reported when involved in a type test. if (interface.IsMalformed()) { ReportError(Error::Handle(interface.error())); } if (interface.IsDynamicType()) { const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "'dynamic' may not be used as interface"); } interface_class = interface.type_class(); if (interface_class.IsSignatureClass()) { const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "function type alias '%s' may not be used as interface", String::Handle(interface_class.Name()).ToCString()); } // Verify that unless cls belongs to core lib, it cannot extend, implement, // or mixin any of Null, bool, num, int, double, String, dynamic. if (!cls_belongs_to_core_lib) { if (interface.IsBoolType() || interface.IsNullType() || interface.IsNumberType() || interface.IsIntType() || interface.IsDoubleType() || interface.IsStringType() || interface.IsDynamicType()) { const Script& script = Script::Handle(cls.script()); const String& interface_name = String::Handle(interface_class.Name()); if (cls.IsMixinApplication()) { ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "illegal mixin of '%s'", interface_name.ToCString()); } else { ReportError(Error::Handle(), // No previous error. script, cls.token_pos(), "'%s' is not allowed to extend or implement '%s'", String::Handle(cls.Name()).ToCString(), interface_name.ToCString()); } } } interface_class.set_is_implemented(); // Now resolve the super interfaces. ResolveSuperTypeAndInterfaces(interface_class, visited); } visited->RemoveLast(); } // A class is marked as constant if it has one constant constructor. // A constant class can only have final instance fields. // Note: we must check for cycles before checking for const properties. void ClassFinalizer::CheckForLegalConstClass(const Class& cls) { ASSERT(cls.is_const()); const Array& fields_array = Array::Handle(cls.fields()); intptr_t len = fields_array.Length(); Field& field = Field::Handle(); for (intptr_t i = 0; i < len; i++) { field ^= fields_array.At(i); if (!field.is_static() && !field.is_final()) { const String& class_name = String::Handle(cls.Name()); const String& field_name = String::Handle(field.name()); const Script& script = Script::Handle(cls.script()); ReportError(Error::Handle(), // No previous error. script, field.token_pos(), "const class '%s' has non-final field '%s'", class_name.ToCString(), field_name.ToCString()); } } } void ClassFinalizer::PrintClassInformation(const Class& cls) { HANDLESCOPE(Isolate::Current()); const String& class_name = String::Handle(cls.Name()); OS::Print("class '%s'", class_name.ToCString()); const Library& library = Library::Handle(cls.library()); if (!library.IsNull()) { OS::Print(" library '%s%s':\n", String::Handle(library.url()).ToCString(), String::Handle(library.private_key()).ToCString()); } else { OS::Print(" (null library):\n"); } const AbstractType& super_type = AbstractType::Handle(cls.super_type()); if (super_type.IsNull()) { OS::Print(" Super: NULL"); } else { const String& super_name = String::Handle(super_type.Name()); OS::Print(" Super: %s", super_name.ToCString()); } const Array& interfaces_array = Array::Handle(cls.interfaces()); if (interfaces_array.Length() > 0) { OS::Print("; interfaces: "); AbstractType& interface = AbstractType::Handle(); intptr_t len = interfaces_array.Length(); for (intptr_t i = 0; i < len; i++) { interface ^= interfaces_array.At(i); OS::Print(" %s ", interface.ToCString()); } } OS::Print("\n"); const Array& functions_array = Array::Handle(cls.functions()); Function& function = Function::Handle(); intptr_t len = functions_array.Length(); for (intptr_t i = 0; i < len; i++) { function ^= functions_array.At(i); OS::Print(" %s\n", function.ToCString()); } const Array& fields_array = Array::Handle(cls.fields()); Field& field = Field::Handle(); len = fields_array.Length(); for (intptr_t i = 0; i < len; i++) { field ^= fields_array.At(i); OS::Print(" %s\n", field.ToCString()); } } // Either report an error or mark the type as malformed. void ClassFinalizer::ReportMalformedType(const Error& prev_error, const Script& script, const Type& type, const char* format, va_list args) { LanguageError& error = LanguageError::Handle( LanguageError::NewFormattedV( prev_error, script, type.token_pos(), LanguageError::kMalformedType, Heap::kOld, format, args)); if (FLAG_error_on_bad_type) { ReportError(error); } type.set_error(error); // Make the type raw, since it may not be possible to // properly finalize its type arguments. type.set_type_class(Class::Handle(Object::dynamic_class())); type.set_arguments(Object::null_abstract_type_arguments()); if (!type.IsFinalized()) { type.SetIsFinalized(); // Do not canonicalize malformed types, since they may not be resolved. } else { // The only case where the malformed type was already finalized is when its // type arguments are not within bounds. In that case, we have a prev_error. ASSERT(!prev_error.IsNull()); } } RawType* ClassFinalizer::NewFinalizedMalformedType(const Error& prev_error, const Script& script, intptr_t type_pos, const char* format, ...) { va_list args; va_start(args, format); const UnresolvedClass& unresolved_class = UnresolvedClass::Handle( UnresolvedClass::New(LibraryPrefix::Handle(), Symbols::Empty(), type_pos)); const Type& type = Type::Handle( Type::New(unresolved_class, TypeArguments::Handle(), type_pos)); ReportMalformedType(prev_error, script, type, format, args); va_end(args); ASSERT(type.IsMalformed()); ASSERT(type.IsFinalized()); return type.raw(); } void ClassFinalizer::FinalizeMalformedType(const Error& prev_error, const Script& script, const Type& type, const char* format, ...) { va_list args; va_start(args, format); ReportMalformedType(prev_error, script, type, format, args); va_end(args); } void ClassFinalizer::FinalizeMalboundedType(const Error& prev_error, const Script& script, const Type& type, const char* format, ...) { va_list args; va_start(args, format); LanguageError& error = LanguageError::Handle( LanguageError::NewFormattedV( prev_error, script, type.token_pos(), LanguageError::kMalboundedType, Heap::kOld, format, args)); va_end(args); if (FLAG_error_on_bad_type) { ReportError(error); } type.set_error(error); if (!type.IsFinalized()) { type.SetIsFinalized(); // Do not canonicalize malbounded types. } } void ClassFinalizer::ReportError(const Error& error) { Isolate::Current()->long_jump_base()->Jump(1, error); UNREACHABLE(); } void ClassFinalizer::ReportError(const Error& prev_error, const Script& script, intptr_t token_pos, const char* format, ...) { va_list args; va_start(args, format); Error& error = Error::Handle( LanguageError::NewFormattedV( prev_error, script, token_pos, LanguageError::kError, Heap::kNew, format, args)); va_end(args); ReportError(error); } void ClassFinalizer::VerifyImplicitFieldOffsets() { #ifdef DEBUG Isolate* isolate = Isolate::Current(); const ClassTable& class_table = *(isolate->class_table()); Class& cls = Class::Handle(isolate); Array& fields_array = Array::Handle(isolate); Field& field = Field::Handle(isolate); String& name = String::Handle(isolate); String& expected_name = String::Handle(isolate); Error& error = Error::Handle(isolate); // First verify field offsets of all the TypedDataView classes. for (intptr_t cid = kTypedDataInt8ArrayViewCid; cid <= kTypedDataFloat32x4ArrayViewCid; cid++) { cls = class_table.At(cid); // Get the TypedDataView class. error = cls.EnsureIsFinalized(isolate); ASSERT(error.IsNull()); cls = cls.SuperClass(); // Get it's super class '_TypedListView'. fields_array ^= cls.fields(); ASSERT(fields_array.Length() == TypedDataView::NumberOfFields()); field ^= fields_array.At(0); ASSERT(field.Offset() == TypedDataView::data_offset()); name ^= field.name(); expected_name ^= String::New("_typedData"); ASSERT(String::EqualsIgnoringPrivateKey(name, expected_name)); field ^= fields_array.At(1); ASSERT(field.Offset() == TypedDataView::offset_in_bytes_offset()); name ^= field.name(); ASSERT(name.Equals("offsetInBytes")); field ^= fields_array.At(2); ASSERT(field.Offset() == TypedDataView::length_offset()); name ^= field.name(); ASSERT(name.Equals("length")); } // Now verify field offsets of '_ByteDataView' class. cls = class_table.At(kByteDataViewCid); error = cls.EnsureIsFinalized(isolate); ASSERT(error.IsNull()); fields_array ^= cls.fields(); ASSERT(fields_array.Length() == TypedDataView::NumberOfFields()); field ^= fields_array.At(0); ASSERT(field.Offset() == TypedDataView::data_offset()); name ^= field.name(); expected_name ^= String::New("_typedData"); ASSERT(String::EqualsIgnoringPrivateKey(name, expected_name)); field ^= fields_array.At(1); ASSERT(field.Offset() == TypedDataView::offset_in_bytes_offset()); name ^= field.name(); expected_name ^= String::New("_offset"); ASSERT(String::EqualsIgnoringPrivateKey(name, expected_name)); field ^= fields_array.At(2); ASSERT(field.Offset() == TypedDataView::length_offset()); name ^= field.name(); ASSERT(name.Equals("length")); #endif } } // namespace dart