Cleanup VM error handling.

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 395 matching lines @@
                           const Class& cls,
                           const char* field_name,
                           const Object& value) {
   const Field& field = Field::Handle(cls.LookupInstanceField(
       String::Handle(Symbols::New(field_name))));
   ASSERT(!field.IsNull());
   instance.SetField(field, value);
 }
 
 
-// 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;
 }
 
 
 // Allocate, initialize, and throw a TypeError.
 void Exceptions::CreateAndThrowTypeError(intptr_t location,
                                          const String& src_type_name,
                                          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);
+  intptr_t args_index = 0;
+  args.SetAt(args_index++, failed_assertion);
 
-  // Initialize field 'srcType'.
-  SetField(type_error, cls, "srcType", src_type_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 'dstType'.
-  SetField(type_error, cls, "dstType", dst_type_name);
-
-  // Initialize field 'dstName'.
-  SetField(type_error, cls, "dstName", dst_name);
-
-  // 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.
   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.
-  Exceptions::Throw(type_error);
+  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 109 matching lines @@
       class_name = &Symbols::IsolateSpawnException();
       break;
     case kIsolateUnhandledException:
       library = Library::IsolateLibrary();
       class_name = &Symbols::IsolateUnhandledException();
       break;
     case kFiftyThreeBitOverflowError:
       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,
                                            *class_name,
                                            *constructor_name,
                                            arguments);
 }
 
 }  // namespace dart