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dart / sdk.git / 33da06f01a31e9e599fff49097b20f93fb45c3c9 / . / runtime / vm / class_finalizer.cc
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// 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/flags.h"
#include "vm/heap.h"
#include "vm/isolate.h"
#include "vm/longjump.h"
#include "vm/object_store.h"
#include "vm/parser.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<intptr_t>& added_subclasses_to_cids) {
ASSERT(FLAG_use_cha);
if (added_subclasses_to_cids.is_empty()) return;
// Deoptimize all live frames.
DeoptimizeIfOwner(added_subclasses_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_subclasses_to_cids.length(); i++) {
intptr_t cid = added_subclasses_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<intptr_t>* 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 GrowableObjectArray& pending_classes,
GrowableArray<intptr_t>* finalized_super_classes) {
Class& cls = Class::Handle();
AbstractType& super_type = Type::Handle();
for (intptr_t i = 0; i < pending_classes.Length(); i++) {
cls ^= pending_classes.At(i);
ASSERT(!cls.is_finalized());
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);
}
}
}
}
}
// Class finalization occurs:
// a) when bootstrap process completes (VerifyBootstrapClasses).
// b) after the user classes are loaded (dart_api).
bool ClassFinalizer::FinalizePendingClasses() {
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;
}
GrowableArray<intptr_t> added_subclasses_to_cids;
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());
// Collect superclasses that were already finalized before this run of
// finalization.
CollectFinalizedSuperClasses(class_array, &added_subclasses_to_cids);
Class& cls = Class::Handle();
// First resolve all superclasses.
for (intptr_t i = 0; i < class_array.Length(); i++) {
cls ^= class_array.At(i);
GrowableArray<intptr_t> 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);
if (FLAG_use_cha) {
RemoveOptimizedCode(added_subclasses_to_cids);
}
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 classes that aren't pre-finalized by Object::Init().
if (!FinalizePendingClasses()) {
// 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()) {
const Type& type = Type::Handle(factory.RedirectionType());
if (!type.IsMalformed()) {
const GrowableObjectArray& visited_factories =
GrowableObjectArray::Handle(GrowableObjectArray::New());
ResolveRedirectingFactoryTarget(cls, factory, visited_factories);
}
}
}
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.IsMalformed()) {
// Already resolved to a malformed 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, kCanonicalize);
type ^= FinalizeType(cls, type, kCanonicalize);
factory.SetRedirectionType(type);
if (type.IsMalformed()) {
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& malformed_error = Error::Handle();
target_type ^= target_type.InstantiateFrom(type_args, &malformed_error);
if (malformed_error.IsNull()) {
target_type ^= FinalizeType(cls, target_type, kCanonicalize);
} else {
const Script& script = Script::Handle(target_class.script());
FinalizeMalformedType(malformed_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,
FinalizationKind finalization) {
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()) {
if ((finalization == kCanonicalizeWellFormed) ||
FLAG_error_on_bad_type) {
// 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());
} else {
// Map the malformed type to dynamic and ignore type arguments.
parameterized_type.set_type_class(Class::Handle(
Object::dynamic_class()));
parameterized_type.set_arguments(
Object::null_abstract_type_arguments());
}
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, finalization);
}
}
}
void ClassFinalizer::FinalizeTypeParameters(const Class& cls) {
if (cls.IsMixinApplication()) {
// Setup the type parameters of the mixin application and finalize the
// mixin type.
ApplyMixinType(cls);
}
// 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,
kCanonicalizeWellFormed);
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.
// Example:
// Declared: class C<K, V> extends B<V> { ... }
// class B<T> extends A<int> { ... }
// Input: C<String, double> expressed as
// cls = C, arguments = [null, null, String, double],
// i.e. cls_args = [String, double], offset = 2, length = 2.
// Output: arguments = [int, double, String, double]
void ClassFinalizer::FinalizeTypeArguments(
const Class& cls,
const AbstractTypeArguments& arguments,
FinalizationKind finalization,
Error* bound_error) {
ASSERT(arguments.Length() >= cls.NumTypeArguments());
if (!cls.is_type_finalized()) {
FinalizeTypeParameters(cls);
ResolveUpperBounds(cls);
}
AbstractType& super_type = AbstractType::Handle(cls.super_type());
if (!super_type.IsNull()) {
const Class& super_class = Class::Handle(super_type.type_class());
AbstractTypeArguments& super_type_args = AbstractTypeArguments::Handle();
if (super_type.IsBeingFinalized()) {
// This type references itself via its type arguments. This is legal, but
// we must avoid endless recursion. We therefore map the innermost
// super type to dynamic.
// Note that a direct self-reference via the super class chain is illegal
// and reported as an error earlier.
// Such legal self-references occur with F-bounded quantification.
// Example 1: class Derived extends Base<Derived>.
// The type 'Derived' forms a cycle by pointing to itself via its
// flattened type argument vector: Derived[Base[Derived[Base[...]]]]
// We break the cycle as follows: Derived[Base[Derived[dynamic]]]
// Example 2: class Derived extends Base<Middle<Derived>> results in
// Derived[Base[Middle[Derived[dynamic]]]]
// Example 3: class Derived<T> extends Base<Derived<T>> results in
// Derived[Base[Derived[dynamic]], T].
ASSERT(super_type_args.IsNull()); // Same as a vector of dynamic.
} else {
super_type ^= FinalizeType(cls, super_type, finalization);
cls.set_super_type(super_type);
super_type_args = super_type.arguments();
}
const intptr_t num_super_type_params = super_class.NumTypeParameters();
const intptr_t offset = super_class.NumTypeArguments();
const intptr_t super_offset = offset - num_super_type_params;
ASSERT(offset == (cls.NumTypeArguments() - cls.NumTypeParameters()));
AbstractType& super_type_arg = AbstractType::Handle(Type::DynamicType());
for (intptr_t i = 0; i < num_super_type_params; i++) {
if (!super_type_args.IsNull()) {
super_type_arg = super_type_args.TypeAt(super_offset + i);
if (!super_type_arg.IsInstantiated()) {
Error& malformed_error = Error::Handle();
super_type_arg = super_type_arg.InstantiateFrom(arguments,
&malformed_error);
if (!malformed_error.IsNull()) {
if (!super_type_arg.IsInstantiated()) {
// CheckTypeArgumentBounds will insert a BoundedType.
} else if (bound_error->IsNull()) {
*bound_error = malformed_error.raw();
}
}
}
if (finalization >= kCanonicalize) {
super_type_arg = super_type_arg.Canonicalize();
}
}
arguments.SetTypeAt(super_offset + i, super_type_arg);
}
FinalizeTypeArguments(super_class, arguments, finalization, bound_error);
}
}
// 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));
for (intptr_t i = 0; i < num_type_params; i++) {
type_arg = arguments.TypeAt(offset + i);
if (type_arg.IsDynamicType()) {
continue;
}
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& malformed_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, &malformed_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;
}
// TODO(regis): We could simplify this code if we could differentiate
// between a failed bound check and a bound check that is undecidable at
// compile time.
// Shortcut the special case where we check a type parameter against its
// declared upper bound.
bool below_bound = true;
if (malformed_error.IsNull() &&
(!type_arg.Equals(type_param) ||
!instantiated_bound.Equals(declared_bound))) {
// Pass NULL to prevent expensive and unnecessary error formatting in
// the case the bound check is postponed to run time.
below_bound = type_param.CheckBound(type_arg, instantiated_bound, NULL);
}
if (!malformed_error.IsNull() || !below_bound) {
if (!type_arg.IsInstantiated() ||
!instantiated_bound.IsInstantiated()) {
type_arg = BoundedType::New(type_arg, instantiated_bound, type_param);
arguments.SetTypeAt(offset + i, type_arg);
} else if (bound_error->IsNull()) {
if (malformed_error.IsNull()) {
// Call CheckBound again to format error message.
type_param.CheckBound(type_arg,
instantiated_bound,
&malformed_error);
}
ASSERT(!malformed_error.IsNull());
*bound_error = malformed_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);
}
}
RawAbstractType* ClassFinalizer::FinalizeType(const Class& cls,
const AbstractType& type,
FinalizationKind finalization) {
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 (FLAG_trace_type_finalization) {
OS::Print("Finalize 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());
}
// 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);
// Types illegally referring to themselves should have been detected earlier.
ASSERT(!parameterized_type.IsBeingFinalized());
// Mark type as being finalized in order to detect illegal self reference.
parameterized_type.set_is_being_finalized();
// 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);
ResolveUpperBounds(type_class);
}
// Finalize the current type arguments of the type, which are still the
// parsed type arguments.
AbstractTypeArguments& arguments =
AbstractTypeArguments::Handle(parameterized_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);
type_argument = FinalizeType(cls, type_argument, finalization);
if (type_argument.IsMalformed()) {
// Malformed type arguments are mapped to dynamic.
type_argument = Type::DynamicType();
}
arguments.SetTypeAt(i, type_argument);
}
}
// 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.
if (!arguments.IsNull() && (arguments.Length() != num_type_parameters)) {
// Wrong number of type arguments. The type is malformed.
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 may be 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());
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);
}
ASSERT(type_arg.IsFinalized()); // Index of type parameter is adjusted.
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);
// 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.
if (type_class.IsSignatureClass()) {
const Function& signature_fun =
Function::Handle(type_class.signature_function());
ASSERT(!signature_fun.is_static());
const Class& sig_fun_owner = Class::Handle(signature_fun.Owner());
FinalizeTypeArguments(
sig_fun_owner, full_arguments, finalization, &bound_error);
CheckTypeArgumentBounds(sig_fun_owner, full_arguments, &bound_error);
} else {
FinalizeTypeArguments(
type_class, full_arguments, finalization, &bound_error);
CheckTypeArgumentBounds(type_class, full_arguments, &bound_error);
}
if (full_arguments.IsRaw(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 if (finalization >= kCanonicalize) {
// FinalizeTypeArguments can modify 'full_arguments',
// canonicalize afterwards.
full_arguments ^= full_arguments.Canonicalize();
}
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()) {
// Mark the type as finalized.
parameterized_type.SetIsFinalized();
}
// 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 a bound error occurred, return a BoundedType with a malformed bound.
// The malformed bound will be ignored in production mode.
if (!bound_error.IsNull()) {
// No compile-time error during finalization.
const String& parameterized_type_name = String::Handle(
parameterized_type.UserVisibleName());
const Type& malformed_bound = Type::Handle(
NewFinalizedMalformedType(bound_error,
Script::Handle(cls.script()),
parameterized_type.token_pos(),
"type '%s' has an out of bound type argument",
parameterized_type_name.ToCString()));
return BoundedType::New(parameterized_type,
malformed_bound,
TypeParameter::Handle());
}
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, kCanonicalize);
type = FinalizeType(cls, type, kCanonicalize);
// A malformed result type is mapped to dynamic.
ASSERT(!type.IsMalformed());
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, kCanonicalize);
type = FinalizeType(cls, type, kCanonicalize);
// A malformed parameter type is mapped to dynamic.
ASSERT(!type.IsMalformed());
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, kCanonicalize);
}
}
// 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, kCanonicalize);
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& malformed_error = Error::Handle();
if (type.IsMalformed()) {
malformed_error = type.malformed_error();
} else {
ASSERT(type.IsInstantiated());
}
const Instance& const_value = Instance::Handle(field.value());
if (!malformed_error.IsNull() ||
(!type.IsDynamicType() &&
!const_value.IsInstanceOf(type,
AbstractTypeArguments::Handle(),
&malformed_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(malformed_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,
cls,
field.token_pos()));
getter.set_result_type(type);
cls.AddFunction(getter);
field.set_value(Instance::Handle(Object::sentinel().raw()));
}
}
}
}
// 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());
}
}
}
}
// Copy the type parameters of the super and mixin classes to the
// mixin application class. Change type arguments of super type and of
// interfaces to refer to the respective type parameters of the mixin
// application class.
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);
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(hausner): 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(hausner): 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& 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(hausner): 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);
cloned_index++;
}
// Lastly, set the type arguments of the single interface type.
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 typedef 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_typedef()) {
ApplyMixinTypedef(mixin_app_class);
}
}
/* Support for mixin typedef.
Consider the following example:
class I<T> { }
class J<T> { }
class S<T> { }
class M<T> { }
typedef A<U, V> = Object with M<Map<U, V>> implements I<V>;
typedef C<T, K> = S<T> with A<T, List<K>> implements J<K>;
Before the call to ApplyMixinTypedef, the VM has already synthesized 2 mixin
application classes Object&M and S&A:
Object&M<T> extends Object implements M<T> { ... members of M applied here ... }
A<U, V> extends Object&M<Map<U, V>> implements I<V> { }
S&A<T`, U, V> extends S<T`> implements A<U, V> { }
C<T, K> extends S&A<T, T, List<K>> implements J<K> { }
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<V>) and for type argument substitution via the super type relation (e.g.
type parameter T of Object&M is substituted with Map<U, V>, U and V being the
type parameters of the typedef 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 a typedef.
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 ApplyMixinTypedef 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<T`, U, V> extends S<T`> implements A<U, V> { }
We now have:
S&A`<T`, T> extends S<T`> implements M<T> { ... members of M applied here ... }
S&A<T`, U, V> extends S&A`<T`, Map<U, V>> implements A<U, V> { }
The main implementation difficulty resides in the fact that the type parameters
U and V in the super type S&A`<T`, Map<U, V>> of S&A refer to the type
parameters U and V of S&A, not to U and V of A. An instantiation step with
a properly crafted instantiator vector takes care of the required type parameter
substitution.
*/
void ClassFinalizer::ApplyMixinTypedef(const Class& mixin_app_class) {
// If this mixin typedef is aliasing another mixin typedef, another class
// will be inserted via recursion. No need to check here.
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_typedef());
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());
inserted_class_name = Symbols::New(inserted_class_name);
const Script& script = Script::Handle(mixin_app_class.script());
const Library& library = Library::Handle(mixin_app_class.library());
const Class& inserted_class = Class::Handle(Class::New(
inserted_class_name, script, mixin_app_class.token_pos()));
inserted_class.set_library(library);
inserted_class.set_is_synthesized_class();
// 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.
AbstractType& super_type = AbstractType::Handle(mixin_app_class.super_type());
inserted_class.set_super_type(super_type); // Super class only is used.
// The mixin type must also be set before calling CloneMixinAppTypeParameters.
// It refers to the type parameters of the mixin class typedef.
inserted_class.set_mixin(aliased_mixin_type); // Mixin class only is used.
// 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 aliased mixin type, except
// that they must refer to the type parameters of the mixin application
// class rather than to those of the aliased mixin 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 = aliased_mixin_app_class.NumTypeArguments();
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& aliased_mixin_type_args =
AbstractTypeArguments::Handle(aliased_mixin_type.arguments());
TypeArguments& new_mixin_type_args = TypeArguments::Handle();
if ((num_aliased_mixin_type_params > 0) &&
!aliased_mixin_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 = aliased_mixin_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(regis): 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 a typedef.
mixin_app_class.set_is_mixin_typedef();
ASSERT(!mixin_app_class.is_type_finalized());
if (FLAG_trace_class_finalization) {
OS::Print("Inserting class %s to mixin typedef application %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) {
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<intptr_t> 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 typedef classes, which are aliases (but are
// implemented as subclasses) of the mixin application classes they name.
if (!mixin_super_class.IsNull() && mixin_class.is_mixin_typedef()) {
while (mixin_super_class.is_mixin_typedef()) {
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<intptr_t> 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 a typedef.
mixin_type = mixin_app_class.mixin();
ASSERT(!mixin_type.IsBeingFinalized());
mixin_type ^=
FinalizeType(mixin_app_class, mixin_type, kCanonicalizeWellFormed);
// TODO(regis): 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.
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 typedef 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_typedef() ||
Class::Handle(isolate, cls.SuperClass()).IsMixinApplication());
// A default constructor will be created for the typedef 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<intptr_t> 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);
}
// 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 typedef classes may still lack their forwarding constructor.
if (cls.is_mixin_typedef() &&
(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);
}
}
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::IsParameterTypeCycleFree(
const Class& cls,
const AbstractType& type,
GrowableArray<intptr_t>* visited) {
ASSERT(visited != NULL);
ResolveType(cls, type, kCanonicalize);
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 (!IsParameterTypeCycleFree(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<intptr_t>* 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 result type and parameter types of this signature type.
visited->Add(cls.id());
const Function& function = Function::Handle(cls.signature_function());
// Check class of result type.
AbstractType& type = AbstractType::Handle(function.result_type());
if (!IsParameterTypeCycleFree(cls, type, visited)) {
return false;
}
// Check classes of formal parameter types.
const intptr_t num_parameters = function.NumParameters();
for (intptr_t i = 0; i < num_parameters; i++) {
type = function.ParameterTypeAt(i);
if (!IsParameterTypeCycleFree(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<intptr_t>* 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) {
// Resolve super type and all mixin types.
const GrowableObjectArray& type_args =
GrowableObjectArray::Handle(GrowableObjectArray::New());
AbstractType& type = AbstractType::Handle(mixin_app.SuperType());
ResolveType(cls, type, kCanonicalizeWellFormed);
ASSERT(type.HasResolvedTypeClass());
// TODO(hausner): May need to handle BoundedType here.
ASSERT(type.IsType());
CollectTypeArguments(cls, Type::Cast(type), type_args);
Class& mixin_app_class = Class::Handle();
const intptr_t depth = mixin_app.Depth();
for (intptr_t i = 0; i < depth; i++) {
mixin_app_class = mixin_app.MixinAppAt(i);
type = mixin_app_class.mixin();
ASSERT(!type.IsNull());
ResolveType(cls, type, kCanonicalizeWellFormed);
ASSERT(type.HasResolvedTypeClass());
ASSERT(type.IsType());
CollectTypeArguments(cls, Type::Cast(type), type_args);
}
const TypeArguments& mixin_app_args =
TypeArguments::Handle(TypeArguments::New(type_args.Length()));
for (intptr_t i = 0; i < type_args.Length(); i++) {
type ^= type_args.At(i);
mixin_app_args.SetTypeAt(i, type);
}
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.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<intptr_t>* 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, kCanonicalizeWellFormed);
if (super_type.IsMalformed()) {
ReportError(Error::Handle(super_type.malformed_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, kCanonicalizeWellFormed);
ASSERT(!interface.IsTypeParameter()); // Should be detected by parser.
if (interface.IsMalformed()) {
ReportError(Error::Handle(interface.malformed_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();
if (prev_error.IsNull()) {
error ^= Parser::FormatError(
script, type.token_pos(), "Error", format, args);
} else {
error ^= Parser::FormatErrorWithAppend(
prev_error, script, type.token_pos(), "Error", format, args);
}
if (FLAG_error_on_bad_type) {
ReportError(error);
}
type.set_malformed_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::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();
if (prev_error.IsNull()) {
error ^= Parser::FormatError(script, token_pos, "Error", format, args);
} else {
error ^= Parser::FormatErrorWithAppend(
prev_error, script, token_pos, "Error", format, args);
}
va_end(args);
ReportError(error);
}
void ClassFinalizer::ReportError(const char* format, ...) {
va_list args;
va_start(args, format);
const Error& error = Error::Handle(
Parser::FormatError(Script::Handle(), -1, "Error", 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