Cleanup VM error handling.

runtime/vm/exceptions.cc

Index: runtime/vm/exceptions.cc
diff --git a/runtime/vm/exceptions.cc b/runtime/vm/exceptions.cc
index b1555642cbad814fcff2959b33a97a991c06c279..e8931539745861dd3a223f2bc5973e49a7b93546 100644
--- a/runtime/vm/exceptions.cc
+++ b/runtime/vm/exceptions.cc
@@ -413,17 +413,20 @@ void Exceptions::SetField(const Instance& instance,
 }
 
 
-// Initialize the fields 'url', 'line', and 'column' in the given instance
+// Set the fields 'url', 'line', and 'column' in the given instance
 // according to the given token location in the given script.
-void Exceptions::SetLocationFields(const Instance& instance,
-                                   const Class& cls,
-                                   const Script& script,
-                                   intptr_t location) {
-  SetField(instance, cls, "url", String::Handle(script.url()));
+//
+// Returns the number of items that have been added to the 'args' array.
+intptr_t Exceptions::SetLocationFields(const Array& args,
+                                       intptr_t index,
+                                       const Script& script,
+                                       intptr_t location) {
+  args.SetAt(index, String::Handle(script.url()));
   intptr_t line, column;
   script.GetTokenLocation(location, &line, &column);
-  SetField(instance, cls, "line", Smi::Handle(Smi::New(line)));
-  SetField(instance, cls, "column", Smi::Handle(Smi::New(column)));
+  args.SetAt(index + 1, Smi::Handle(Smi::New(line)));
+  args.SetAt(index + 2, Smi::Handle(Smi::New(column)));
+  return 3;
 }
 
 
@@ -433,48 +436,33 @@ void Exceptions::CreateAndThrowTypeError(intptr_t location,
                                          const String& dst_type_name,
                                          const String& dst_name,
                                          const String& malformed_error) {
-  // Allocate a new instance of TypeError or CastError.
-  Instance& type_error = Instance::Handle();
-  Class& cls = Class::Handle();
-  if (dst_name.Equals(kCastErrorDstName)) {
-    type_error = NewInstance("CastErrorImplementation");
-    cls = type_error.clazz();
-    cls = cls.SuperClass();
-  } else {
-    type_error = NewInstance("TypeErrorImplementation");
-    cls = type_error.clazz();
-  }
+  const Array& args = Array::Handle(Array::New(8));
 
-  // Initialize 'url', 'line', and 'column' fields.
-  DartFrameIterator iterator;
-  const Script& script = Script::Handle(GetCallerScript(&iterator));
-  // Location fields are defined in AssertionError, the superclass of TypeError.
-  const Class& assertion_error_class = Class::Handle(cls.SuperClass());
-  SetLocationFields(type_error, assertion_error_class, script, location);
+  ExceptionType exception_type =
+      dst_name.Equals(kCastErrorDstName) ? kCast : kType;
 
-  // Initialize field 'failedAssertion' in AssertionError superclass.
+  // 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);
-  SetField(type_error,
-           assertion_error_class,
-           "failedAssertion",
-           failed_assertion);
-
-  // Initialize field 'srcType'.
-  SetField(type_error, cls, "srcType", src_type_name);
+  intptr_t args_index = 0;
+  args.SetAt(args_index++, failed_assertion);
 
-  // Initialize field 'dstType'.
-  SetField(type_error, cls, "dstType", dst_type_name);
-
-  // Initialize field 'dstName'.
-  SetField(type_error, cls, "dstName", dst_name);
+  // Initialize 'url', 'line', and 'column' arguments.
+  DartFrameIterator iterator;
+  const Script& script = Script::Handle(GetCallerScript(&iterator));
+  args_index += SetLocationFields(args, args_index, script, location);
+  ASSERT(args_index == 4);
 
-  // Initialize field 'malformedError'.
-  SetField(type_error, cls, "malformedError", malformed_error);
+  // Initialize argument 'srcType'.
+  args.SetAt(args_index++, src_type_name);
+  args.SetAt(args_index++, dst_type_name);
+  args.SetAt(args_index++, dst_name);
+  args.SetAt(args_index++, malformed_error);
+  ASSERT(args_index == args.Length());

[siva, 2013/07/12 16:49:36]

ditto comment about using 0, 1, 2 etc. instead of args_index

[floitsch, 2013/07/12 17:12:36]

Done.

 
   // Type errors in the core library may be difficult to diagnose.
   // Print type error information before throwing the error when debugging.
@@ -496,7 +484,7 @@ void Exceptions::CreateAndThrowTypeError(intptr_t location,
     }
   }
   // Throw TypeError instance.
-  Exceptions::Throw(type_error);
+  Exceptions::ThrowByType(exception_type, args);
   UNREACHABLE();
 }
 
@@ -626,6 +614,26 @@ RawObject* Exceptions::Create(ExceptionType type, const Array& arguments) {
       library = Library::CoreLibrary();
       class_name = &Symbols::FiftyThreeBitOverflowError();
       break;
+    case kAssertion:
+      library = Library::CoreLibrary();
+      class_name = &Symbols::AssertionError();
+      break;
+    case kCast:
+      library = Library::CoreLibrary();
+      class_name = &Symbols::CastError();
+      break;
+    case kType:
+      library = Library::CoreLibrary();
+      class_name = &Symbols::TypeError();
+      break;
+    case kFallThrough:
+      library = Library::CoreLibrary();
+      class_name = &Symbols::FallThroughError();
+      break;
+    case kAbstractClassInstantiation:
+      library = Library::CoreLibrary();
+      class_name = &Symbols::AbstractClassInstantiationError();
+      break;
   }
 
   return DartLibraryCalls::ExceptionCreate(library,