MalformedType used for all invalid type annotations.

sdk/lib/_internal/compiler/implementation/ssa/codegen.dart

 // 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.
 
 part of ssa;
 
 class SsaCodeGeneratorTask extends CompilerTask {
 
   final JavaScriptBackend backend;
 
@@ skipping 2062 matching lines @@
         backend.registerNonCallStaticUse(node);
         if (node.element.isFunction()) {
           world.registerInstantiatedClass(compiler.functionClass);
         }
       } else if (instr.target != node) {
         backend.registerNonCallStaticUse(node);
       }
     });
     Element element = node.element;
     world.registerStaticUse(element);
-    ClassElement cls = element.getEnclosingClass();    
+    ClassElement cls = element.getEnclosingClass();
     if (element.isGenerativeConstructor()
         || (element.isFactoryConstructor() && cls == compiler.listClass)) {
       world.registerInstantiatedClass(cls);
     }
     push(new js.VariableUse(backend.namer.isolateAccess(node.element)));
   }
 
   void visitLazyStatic(HLazyStatic node) {
     Element element = node.element;
     world.registerStaticUse(element);
@@ skipping 173 matching lines @@
     js.Expression functionTest = pop();
     checkObject(input, '===');
     js.Expression objectTest = pop();
     checkType(input, type);
     push(new js.Binary('||',
                        functionTest,
                        new js.Binary('&&', objectTest, pop())));
   }
 
   void checkType(HInstruction input, DartType type, {bool negative: false}) {
+    assert(invariant(input, !type.isMalformed,
+                     message: 'Attempt to check malformed type $type'));
     world.registerIsCheck(type);
     Element element = type.element;
     use(input);
     js.PropertyAccess field =
         new js.PropertyAccess.field(pop(), backend.namer.operatorIs(element));
     if (backend.emitter.nativeEmitter.requiresNativeIsCheck(element)) {
       push(new js.Call(field, <js.Expression>[]));
       if (negative) push(new js.Prefix('!', pop()));
     } else {
       // We always negate at least once so that the result is boolified.
@@ skipping 164 matching lines @@
           const SourceString("stringSuperTypeCast"),
       "listTypeCheck":
           const SourceString("listTypeCast"),
       "listSuperNativeTypeCheck":
           const SourceString("listSuperNativeTypeCast"),
       "listSuperTypeCheck":
           const SourceString("listSuperTypeCast"),
       "callTypeCheck":
           const SourceString("callTypeCast"),
       "propertyTypeCheck":
-          const SourceString("propertyTypeCast")
+          const SourceString("propertyTypeCast"),
+      "malformedTypeCheck":
+          const SourceString("malformedTypeCheck")

[ahe, 2012/11/30 15:44:07]

How about adding malformedTypeCast which gives a slightly different error
message.

[Johnni Winther, 2012/12/04 10:07:17]

Added a TODO.

     };
 
     if (node.isChecked) {
       DartType type = node.type.computeType(compiler);
       Element element = type.element;
       world.registerIsCheck(type);
 
       if (node.isArgumentTypeCheck) {
         if (element == compiler.intClass) {
           checkInt(node.checkedInput, '!==');
@@ skipping 20 matching lines @@
         helper = backend.getCheckedModeHelper(type);
         if (node.isCastTypeCheck) {
           helper = castNames[helper.stringValue];
         }
       }
       FunctionElement helperElement = compiler.findHelper(helper);
       world.registerStaticUse(helperElement);
       List<js.Expression> arguments = <js.Expression>[];
       use(node.checkedInput);
       arguments.add(pop());
-      if (helperElement.computeSignature(compiler).parameterCount != 1) {
+      int parameterCount =
+          helperElement.computeSignature(compiler).parameterCount;
+      if (parameterCount == 2) {

[ahe, 2012/11/30 15:44:07]

Could you document what is going on here?

[Johnni Winther, 2012/12/04 10:07:17]

Done.

+        assert(!type.isMalformed);
         String additionalArgument = backend.namer.operatorIs(element);
         arguments.add(new js.LiteralString("'$additionalArgument'"));
+      } else if (parameterCount == 3) {
+        assert(type.isMalformed);
+        String reasons = fetchReasonsFromMalformedType(type);
+        arguments.add(new js.LiteralString("'$type'"));
+        arguments.add(new js.LiteralString("'$reasons)}'"));

[ahe, 2012/11/30 15:44:07]

How about using writeJsonEscapedCharsOn from util.dart?

[Johnni Winther, 2012/12/04 10:07:17]

Added a TODO.

+      } else {
+        assert(!type.isMalformed);
       }
       String helperName = backend.namer.isolateAccess(helperElement);
       push(new js.Call(new js.VariableUse(helperName), arguments));
     } else {
       use(node.checkedInput);
     }
   }
 }
 
 class SsaOptimizedCodeGenerator extends SsaCodeGenerator {
@@ skipping 519 matching lines @@
   if (leftType.canBeNull() && rightType.canBeNull()) {
     if (left.isConstantNull() || right.isConstantNull() ||
         (leftType.isPrimitive() && leftType == rightType)) {
       return '==';
     }
     return null;
   } else {
     return '===';
   }
 }