Fix VM implementation of CastError not to extend TypeError (issue 5280).

runtime/vm/exceptions.cc

 // Copyright (c) 2011, 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/exceptions.h"
 
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
 #include "vm/flags.h"
@@ skipping 478 matching lines @@
   const String& cls_name = String::Handle(Symbols::New(class_name));
   const Library& core_lib = Library::Handle(Library::CoreLibrary());
   // No ambiguity error expected: passing NULL.
   Class& cls = Class::Handle(core_lib.LookupClass(cls_name, NULL));
   ASSERT(!cls.IsNull());
   // There are no parameterized error types, so no need to set type arguments.
   return Instance::New(cls);
 }
 
 
-// Allocate, initialize, and throw a TypeError.
+// Allocate, initialize, and throw a TypeError or CastError.
 void Exceptions::CreateAndThrowTypeError(intptr_t location,
                                          const String& src_type_name,
                                          const String& dst_type_name,
                                          const String& dst_name,
                                          const String& malformed_error) {
-  const Array& args = Array::Handle(Array::New(8));
+  const Array& args = Array::Handle(Array::New(7));
 
   ExceptionType exception_type =
       dst_name.Equals(kCastErrorDstName) ? kCast : kType;
 
-  // Initialize argument 'failedAssertion'.
-  // Printing the src_obj value would be possible, but ToString() is expensive
-  // and not meaningful for all classes, so we just print '$expr instanceof...'.
-  // Users should look at TypeError.ToString(), which contains more useful
-  // information than AssertionError.failedAssertion.
-  String& failed_assertion = String::Handle(String::New("$expr instanceof "));
-  failed_assertion = String::Concat(failed_assertion, dst_type_name);
-  args.SetAt(0, failed_assertion);
-
-  // Initialize 'url', 'line', and 'column' arguments.
   DartFrameIterator iterator;
   const Script& script = Script::Handle(GetCallerScript(&iterator));
   intptr_t line, column;
   script.GetTokenLocation(location, &line, &column);
-  args.SetAt(1, String::Handle(script.url()));
-  args.SetAt(2, Smi::Handle(Smi::New(line)));
-  args.SetAt(3, Smi::Handle(Smi::New(column)));
+  // Initialize '_url', '_line', and '_column' arguments.
+  args.SetAt(0, String::Handle(script.url()));
+  args.SetAt(1, Smi::Handle(Smi::New(line)));
+  args.SetAt(2, Smi::Handle(Smi::New(column)));
 
-  // Initialize argument 'srcType'.
-  args.SetAt(4, src_type_name);
-  args.SetAt(5, dst_type_name);
-  args.SetAt(6, dst_name);
-  args.SetAt(7, malformed_error);
+  // Initialize '_srcType', '_dstType', '_dstName', and '_malformedError'.
+  args.SetAt(3, src_type_name);
+  args.SetAt(4, dst_type_name);
+  args.SetAt(5, dst_name);
+  args.SetAt(6, malformed_error);
 
   // Type errors in the core library may be difficult to diagnose.
   // Print type error information before throwing the error when debugging.
   if (FLAG_print_stacktrace_at_throw) {
     if (!malformed_error.IsNull()) {
       OS::Print("%s\n", malformed_error.ToCString());
     }
     intptr_t line, column;
     script.GetTokenLocation(location, &line, &column);
     OS::Print("'%s': Failed type check: line %"Pd" pos %"Pd": ",
               String::Handle(script.url()).ToCString(), line, column);
     if (!dst_name.IsNull() && (dst_name.Length() > 0)) {
       OS::Print("type '%s' is not a subtype of type '%s' of '%s'.\n",
                 src_type_name.ToCString(),
                 dst_type_name.ToCString(),
                 dst_name.ToCString());
     } else {
       OS::Print("malformed type used.\n");
     }
   }
-  // Throw TypeError instance.
+  // Throw TypeError or CastError instance.
   Exceptions::ThrowByType(exception_type, args);
   UNREACHABLE();
 }
 
 
 void Exceptions::Throw(const Instance& exception) {
   Isolate* isolate = Isolate::Current();
   isolate->debugger()->SignalExceptionThrown(exception);
   // Null object is a valid exception object.
   ThrowExceptionHelper(exception, Instance::Handle(isolate));
@@ skipping 74 matching lines @@
       library = Library::CoreLibrary();
       class_name = &Symbols::RangeError();
       break;
     case kArgument:
       library = Library::CoreLibrary();
       class_name = &Symbols::ArgumentError();
       break;
     case kNoSuchMethod:
       library = Library::CoreLibrary();
       class_name = &Symbols::NoSuchMethodError();
-      constructor_name = &String::Handle(Symbols::New("._withType"));
+      constructor_name = &Symbols::DotWithType();
       break;
     case kFormat:
       library = Library::CoreLibrary();
       class_name = &Symbols::FormatException();
       break;
     case kUnsupported:
       library = Library::CoreLibrary();
       class_name = &Symbols::UnsupportedError();
       break;
     case kInternalError:
@@ skipping 12 matching lines @@
       library = Library::IsolateLibrary();
       class_name = &Symbols::IsolateUnhandledException();
       break;
     case kJavascriptIntegerOverflowError:
       library = Library::CoreLibrary();
       class_name = &Symbols::JavascriptIntegerOverflowError();
       break;
     case kAssertion:
       library = Library::CoreLibrary();
       class_name = &Symbols::AssertionError();
+      constructor_name = &Symbols::DotCreate();
       break;
     case kCast:
       library = Library::CoreLibrary();
       class_name = &Symbols::CastError();
+      constructor_name = &Symbols::DotCreate();
       break;
     case kType:
       library = Library::CoreLibrary();
       class_name = &Symbols::TypeError();
+      constructor_name = &Symbols::DotCreate();
       break;
     case kFallThrough:
       library = Library::CoreLibrary();
       class_name = &Symbols::FallThroughError();
+      constructor_name = &Symbols::DotCreate();
       break;
     case kAbstractClassInstantiation:
       library = Library::CoreLibrary();
       class_name = &Symbols::AbstractClassInstantiationError();
+      constructor_name = &Symbols::DotCreate();
       break;
     case kMirroredUncaughtExceptionError:
       library = Library::MirrorsLibrary();
       class_name = &Symbols::MirroredUncaughtExceptionError();
       break;
     case kMirroredCompilationError:
       library = Library::MirrorsLibrary();
       class_name = &Symbols::MirroredCompilationError();
       break;
   }
 
   return DartLibraryCalls::InstanceCreate(library,
                                           *class_name,
                                           *constructor_name,
                                           arguments);
 }
 
 }  // namespace dart