Start work on a non-complete type inferrer. Currently only analyzes return types.

sdk/lib/_internal/compiler/implementation/ssa/builder.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;
 
 /**
  * A special element for the extra parameter taken by intercepted
  * methods. We need to override [Element.computeType] because our
  * optimizers may look at its declared type.
@@ skipping 278 matching lines @@
                   parameterElement)) {
             // The parameter will be a field in the box passed as the
             // last parameter. So no need to have it.
             return;
           }
         }
         HInstruction parameter = builder.addParameter(parameterElement);
         builder.parameters[parameterElement] = parameter;
         directLocals[parameterElement] = parameter;
         parameter.guaranteedType =
-            builder.mapInferredType(
-                typesTask.getGuaranteedTypeOfElement(parameterElement));
+            builder.getGuaranteedTypeOfElement(parameterElement);
       });
     }
 
     enterScope(node, element);
 
     // If the freeVariableMapping is not empty, then this function was a
     // nested closure that captures variables. Redirect the captured
     // variables to fields in the closure.
     closureData.freeVariableMapping.forEach((Element from, Element to) {
       redirectElement(from, to);
@@ skipping 3058 matching lines @@
         generateWrongArgumentCountError(node, element, node.arguments);
         return;
       }
 
       if (isIdenticalFunction) {
         pushWithPosition(new HIdentity(inputs[1], inputs[2]), node);
         return;
       }
 
       HInvokeStatic instruction = new HInvokeStatic(inputs, HType.UNKNOWN);
-      // TODO(ngeoffray): Only do this if knowing the return type is
-      // useful.
-      HType returnType =
-          builder.backend.optimisticReturnTypesWithRecompilationOnTypeChange(
-              currentElement, element);
+      HType returnType = getGuaranteedTypeOfElement(element);
+      if (returnType.isUnknown()) {
+        // TODO(ngeoffray): Only do this if knowing the return type is
+        // useful.
+        returnType =
+            builder.backend.optimisticReturnTypesWithRecompilationOnTypeChange(
+                currentElement, element);
+      }
       if (returnType != null) instruction.guaranteedType = returnType;
       pushWithPosition(instruction, node);
     } else {
       generateGetter(node, element);
       List<HInstruction> inputs = <HInstruction>[pop()];
       addDynamicSendArgumentsToList(node, inputs);
       Selector closureSelector = new Selector.callClosureFrom(selector);
       pushWithPosition(new HInvokeClosure(closureSelector, inputs), node);
     }
   }
@@ skipping 171 matching lines @@
                                           List<HInstruction> arguments) {
     Set<ClassElement> interceptedClasses = getInterceptedClassesOn(selector);
     List<HInstruction> inputs = <HInstruction>[];
     bool isIntercepted = interceptedClasses != null;
     if (isIntercepted) {
       assert(!interceptedClasses.isEmpty);
       inputs.add(invokeInterceptor(interceptedClasses, receiver, node));
     }
     inputs.add(receiver);
     inputs.addAll(arguments);
-    return new HInvokeDynamicMethod(selector, inputs, isIntercepted);
+    HInstruction invoke = new HInvokeDynamicMethod(
+        selector, inputs, isIntercepted);
+    HType returnType = mapInferredType(
+        compiler.typesTask.getGuaranteedTypeOfNode(work.element, node));
+    if (returnType != null) {
+      invoke.guaranteedType = returnType;
+    }
+    return invoke;
   }
 
   visitSendSet(SendSet node) {
     Element element = elements[node];
     if (!Elements.isUnresolved(element) && element.impliesType()) {
       Identifier selector = node.selector;
       generateThrowNoSuchMethod(node, selector.source.slowToString(),
                                 argumentNodes: node.arguments);
       return;
     }
@@ skipping 1063 matching lines @@
           cls.computeType(compiler), compiler);
     }
   }
 
   HType mapInferredType(ConcreteType concreteType) {
     if (concreteType == null) return HType.UNKNOWN;
     HType ssaType = HType.CONFLICTING;
     for (BaseType baseType in concreteType.baseTypes) {
       ssaType = ssaType.union(mapBaseType(baseType), compiler);
     }
-    assert(!ssaType.isConflicting());
+    if (ssaType.isConflicting()) return HType.UNKNOWN;
     return ssaType;
   }
 
+  HType getGuaranteedTypeOfElement(Element element) {
+    return mapInferredType(
+        compiler.typesTask.getGuaranteedTypeOfElement(element));
+  }
+
   // [type] is either an instance of [DartType] or special objects
   // like [native.SpecialType.JsObject], or [native.SpecialType.JsArray].
   HType mapNativeType(type) {
     if (type == native.SpecialType.JsObject) {
       return new HType.nonNullExactClass(
           compiler.objectClass.computeType(compiler), compiler);
     } else if (type == native.SpecialType.JsArray) {
       return HType.READABLE_ARRAY;
     } else {
       return new HType.nonNullSubclass(type, compiler);
@@ skipping 389 matching lines @@
           new HSubGraphBlockInformation(elseBranch.graph));
 
     HBasicBlock conditionStartBlock = conditionBranch.block;
     conditionStartBlock.setBlockFlow(info, joinBlock);
     SubGraph conditionGraph = conditionBranch.graph;
     HIf branch = conditionGraph.end.last;
     assert(branch is HIf);
     branch.blockInformation = conditionStartBlock.blockFlow;
   }
 }