Refactor resolution code in the vm to properly handle ambiguity errors.

runtime/vm/dart_entry_test.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 "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/object.h"
 #include "vm/resolver.h"
 #include "vm/symbols.h"
 #include "vm/unit_test.h"
 
 namespace dart {
 
 TEST_CASE(DartEntry) {
   const char* kScriptChars =
       "class A {\n"
       "  static foo() { return 42; }\n"
       "}\n";
   String& url = String::Handle(String::New("dart-test:DartEntry"));
   String& source = String::Handle(String::New(kScriptChars));
   Script& script = Script::Handle(Script::New(url,
                                               source,
                                               RawScript::kScriptTag));
   Library& lib = Library::Handle(Library::CoreLibrary());
   EXPECT_EQ(true, CompilerTest::TestCompileScript(lib, script));
   EXPECT(ClassFinalizer::FinalizePendingClasses());
+  String& ambiguity_error_msg = String::Handle();
   Class& cls = Class::Handle(
-      lib.LookupClass(String::Handle(Symbols::New("A"))));
-  EXPECT(!cls.IsNull());
+      lib.LookupClass(String::Handle(Symbols::New("A")), &ambiguity_error_msg));
+  EXPECT(!cls.IsNull());  // No ambiguity error expected.
   String& name = String::Handle(String::New("foo"));
   Function& function = Function::Handle(cls.LookupStaticFunction(name));
   EXPECT(!function.IsNull());
 
   EXPECT(CompilerTest::TestCompileFunction(function));
   EXPECT(function.HasCode());
   const Smi& retval = Smi::Handle(reinterpret_cast<RawSmi*>(
       DartEntry::InvokeFunction(function, Object::empty_array())));
   EXPECT_EQ(Smi::New(42), retval.raw());
 }
 
 
 TEST_CASE(InvokeStatic_CompileError) {
   const char* kScriptChars =
       "class A {\n"
       "  static foo() { return ++++; }\n"
       "}\n";
   String& url = String::Handle(String::New("dart-test:DartEntry"));
   String& source = String::Handle(String::New(kScriptChars));
   Script& script = Script::Handle(Script::New(url,
                                               source,
                                               RawScript::kScriptTag));
   Library& lib = Library::Handle(Library::CoreLibrary());
   EXPECT_EQ(true, CompilerTest::TestCompileScript(lib, script));
   EXPECT(ClassFinalizer::FinalizePendingClasses());
+  String& ambiguity_error_msg = String::Handle();
   Class& cls = Class::Handle(
-      lib.LookupClass(String::Handle(Symbols::New("A"))));
-  EXPECT(!cls.IsNull());
+      lib.LookupClass(String::Handle(Symbols::New("A")), &ambiguity_error_msg));
+  EXPECT(!cls.IsNull());  // No ambiguity error expected.
   String& name = String::Handle(String::New("foo"));
   Function& function = Function::Handle(cls.LookupStaticFunction(name));
   EXPECT(!function.IsNull());
   GrowableArray<const Object*> arguments;
   const Object& retval = Object::Handle(
       DartEntry::InvokeFunction(function, Object::empty_array()));
   EXPECT(retval.IsError());
   EXPECT_SUBSTRING("++++", Error::Cast(retval).ToErrorCString());
 }
 
 
 TEST_CASE(InvokeDynamic_CompileError) {
   const char* kScriptChars =
       "class A {\n"
       "  foo() { return ++++; }\n"
       "}\n";
   String& url = String::Handle(String::New("dart-test:DartEntry"));
   String& source = String::Handle(String::New(kScriptChars));
   Script& script = Script::Handle(Script::New(url,
                                               source,
                                               RawScript::kScriptTag));
   Library& lib = Library::Handle(Library::CoreLibrary());
   EXPECT_EQ(true, CompilerTest::TestCompileScript(lib, script));
   EXPECT(ClassFinalizer::FinalizePendingClasses());
+  String& ambiguity_error_msg = String::Handle();
   Class& cls = Class::Handle(
-      lib.LookupClass(String::Handle(Symbols::New("A"))));
-  EXPECT(!cls.IsNull());
+      lib.LookupClass(String::Handle(Symbols::New("A")), &ambiguity_error_msg));
+  EXPECT(!cls.IsNull());  // No ambiguity error expected.
 
   // Invoke the constructor.
   const Instance& instance = Instance::Handle(Instance::New(cls));
   const Array& constructor_arguments = Array::Handle(Array::New(2));
   constructor_arguments.SetAt(0, instance);
   constructor_arguments.SetAt(
       1, Smi::Handle(Smi::New(Function::kCtorPhaseAll)));
   String& constructor_name = String::Handle(Symbols::New("A."));
   Function& constructor =
     Function::Handle(cls.LookupConstructor(constructor_name));
   ASSERT(!constructor.IsNull());
   DartEntry::InvokeFunction(constructor, constructor_arguments);
 
   // Call foo.
   String& name = String::Handle(String::New("foo"));
   Function& function = Function::Handle(cls.LookupDynamicFunction(name));
   EXPECT(!function.IsNull());
   const Array& args = Array::Handle(Array::New(1));
   args.SetAt(0, instance);
   const Object& retval = Object::Handle(DartEntry::InvokeFunction(function,
                                                                   args));
   EXPECT(retval.IsError());
   EXPECT_SUBSTRING("++++", Error::Cast(retval).ToErrorCString());
 }
 
 }  // namespace dart