Basic type inference skeleton

dart/lib/compiler/implementation/ssa/builder.dart

Index: dart/lib/compiler/implementation/ssa/builder.dart
diff --git a/dart/lib/compiler/implementation/ssa/builder.dart b/dart/lib/compiler/implementation/ssa/builder.dart
index a66dbaf7c2a4c7ff9fa48ead04383232ebeafb22..9ec35abf63a242c6d2ed1528a8e8896d3dabe96c 100644
--- a/dart/lib/compiler/implementation/ssa/builder.dart
+++ b/dart/lib/compiler/implementation/ssa/builder.dart
@@ -217,6 +217,8 @@ class LocalsHandler {
       : directLocals = new Map<Element, HInstruction>(),
         redirectionMapping = new Map<Element, Element>();
 
+  get typesTask() => builder.compiler.typesTask;
+
   /**
    * Creates a new [LocalsHandler] based on [other]. We only need to
    * copy the [directLocals], since the other fields can be shared
@@ -315,6 +317,8 @@ class LocalsHandler {
       builder.add(parameter);
       builder.parameters[element] = parameter;
       directLocals[element] = parameter;
+      parameter.guaranteedType =
+        builder.mapInferredType(typesTask.getGuaranteedTypeOfElement(element));
     });
 
     enterScope(node);
@@ -3291,6 +3295,17 @@ class SsaBuilder extends ResolvedVisitor implements Visitor {
     compiler.internalError('SsaBuilder.visitTypeVariable');
   }
 
+  HType mapInferredType(Element element) {
+    if (element === builder.compiler.boolClass) return HType.BOOLEAN;

[ngeoffray, 2012/08/16 12:53:10]

Should those be BOOLEAN_OR_NULL, ... ?

[ahe, 2012/08/16 17:26:54]

No. It has been inferred that it must be a bool. This is the "concrete" part of
concrete-type inference, and why it felt appropriate to use elements.

However, I think when Paul's changes land, we will probably switch to a cleaner
abstraction for concrete types.

See the discussion of concrete types vs abstract types in
http://labs.oracle.com/techrep/1996/smli_tr-96-52.pdf page 4.

+    if (element === builder.compiler.doubleClass) return HType.DOUBLE;
+    if (element === builder.compiler.intClass) return HType.INTEGER;
+    // TODO(ahe): How to map listClass to HType?

[ngeoffray, 2012/08/16 12:53:10]

new HBoundedPotentialPrimitiveArray(element.computeType(), canBeNull: true)

(or something)

[ahe, 2012/08/16 17:26:54]

It can't be null and it will be a primitive array.

+    if (element === builder.compiler.listClass) return HType.UNKNOWN;
+    if (element === builder.compiler.nullClass) return HType.NULL;
+    if (element === builder.compiler.stringClass) return HType.STRING;
+    return HType.UNKNOWN;
+  }
+
   /** HACK HACK HACK */
   void hackAroundPossiblyAbortingBody(Node statement, void body()) {
     visitCondition() {