Fix type checking of void type.

runtime/vm/object.cc

 // Copyright (c) 2012, 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/object.h"
 
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
 #include "vm/bootstrap.h"
@@ skipping 1764 matching lines @@
 // Type S is specified by this class parameterized with 'type_arguments', and
 // type T by class 'other' parameterized with 'other_type_arguments'.
 // This class and class 'other' do not need to be finalized, however, they must
 // be resolved as well as their interfaces.
 bool Class::TypeTest(
     TypeTestKind test_kind,
     const AbstractTypeArguments& type_arguments,
     const Class& other,
     const AbstractTypeArguments& other_type_arguments,
     Error* malformed_error) const {
+  ASSERT(!IsVoidClass());
   // Check for DynamicType.
   // Each occurrence of DynamicType in type T is interpreted as the Dynamic
   // type, a supertype of all types.
   if (other.IsDynamicClass()) {
     return true;
   }
   // In the case of a subtype test, each occurrence of DynamicType in type S is
   // interpreted as the bottom type, a subtype of all types.
   if (IsDynamicClass()) {
     return test_kind == kIsSubtypeOf;
@@ skipping 550 matching lines @@
 }
 
 
 RawAbstractType* AbstractType::Canonicalize() const {
   // AbstractType is an abstract class.
   UNREACHABLE();
   return NULL;
 }
 
 
+// TODO(regis): Investigate if we can safely map internal integer types (Smi,
+// Mint, and Bigint) to 'int' and internal String types (OneByteString, etc...)
+// to 'String' here. It may be too early. Also consider the upcoming type()
+// method.
 RawString* AbstractType::Name() const {
   // If the type is still being finalized, we may be reporting an error about
   // an illformed type, so proceed with caution.
   const AbstractTypeArguments& args =
       AbstractTypeArguments::Handle(arguments());
   const intptr_t num_args = args.IsNull() ? 0 : args.Length();
   String& class_name = String::Handle();
   intptr_t first_type_param_index;
   intptr_t num_type_params;  // Number of type parameters to print.
   if (HasResolvedTypeClass()) {
@@ skipping 5287 matching lines @@
   ASSERT(field_offset != Class::kNoTypeArguments);
   *FieldAddrAtOffset(field_offset) = value.raw();
 }
 
 
 bool Instance::IsInstanceOf(const AbstractType& other,
                             const AbstractTypeArguments& other_instantiator,
                             Error* malformed_error) const {
   ASSERT(other.IsFinalized());
   ASSERT(!other.IsDynamicType());
-  ASSERT(!other.IsVoidType());
   ASSERT(!other.IsMalformed());
   if (IsNull()) {
+    // The null instance can be returned from a void function.
+    if (other.IsVoidType()) {
+      return true;
+    }
+    // Otherwise, null is only an instance of Object and of Dynamic.
+    // It is not necessary to fully instantiate the other type for this test.
     Class& other_class = Class::Handle();
     if (other.IsTypeParameter()) {
       if (other_instantiator.IsNull()) {
         return true;  // Other type is uninstantiated, i.e. Dynamic.
       }
       const TypeParameter& other_type_param = TypeParameter::Cast(other);
       const AbstractType& instantiated_other = AbstractType::Handle(
           other_instantiator.TypeAt(other_type_param.index()));
       ASSERT(instantiated_other.IsInstantiated());
       other_class = instantiated_other.type_class();
     } else {
       other_class = other.type_class();
     }
     return other_class.IsObjectClass() || other_class.IsDynamicClass();
   }
+  if (other.IsVoidType()) {
+    return false;
+  }
   const Class& cls = Class::Handle(clazz());
   // We must not encounter Object::sentinel() or Object::transition_sentinel(),
   // both instances of class NullClass, but not instance Object::null().
   ASSERT(!cls.IsNullClass());
   AbstractTypeArguments& type_arguments = AbstractTypeArguments::Handle();
   const intptr_t num_type_arguments = cls.NumTypeArguments();
   if (num_type_arguments > 0) {
     type_arguments = GetTypeArguments();
     if (!type_arguments.IsNull() && !type_arguments.IsCanonical()) {
       type_arguments = type_arguments.Canonicalize();
@@ skipping 3097 matching lines @@
   const String& str = String::Handle(pattern());
   const char* format = "JSRegExp: pattern=%s flags=%s";
   intptr_t len = OS::SNPrint(NULL, 0, format, str.ToCString(), Flags());
   char* chars = reinterpret_cast<char*>(
       Isolate::Current()->current_zone()->Allocate(len + 1));
   OS::SNPrint(chars, (len + 1), format, str.ToCString(), Flags());
   return chars;
 }
 
 }  // namespace dart