Infer guaranteed types for static calls that are only called once.

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 6f72e0441d5bddb8822d44995fcd7cfd0299d721..7aba3c44accefc88a226b09e8344a2dba8bc4830 100644
--- a/dart/lib/compiler/implementation/ssa/builder.dart
+++ b/dart/lib/compiler/implementation/ssa/builder.dart
@@ -3299,8 +3299,7 @@ class SsaBuilder extends ResolvedVisitor implements Visitor {
     if (element === builder.compiler.boolClass) return HType.BOOLEAN;

[kasperl, 2012/08/08 12:36:47]

I'm a bit worried about how we deal with null here. I think the compiler assumes
that anything that has HType.INTEGER associated with it cannot be null, but I'm
pretty sure that is not the case everywhere we know something has the type
represented with the intClass element.

[ahe, 2012/08/08 12:40:04]

Right now, I use the intClass to mean the concrete type non-null SMI. I really
should have something like this:

new ConcreteType(compiler.intClass);

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

[ngeoffray, 2012/08/16 12:55:40]

Why?

[ahe, 2012/08/16 17:15:19]

What else would you use?

[ngeoffray, 2012/08/17 07:59:28]

HBoundedPotentialPrimitiveArray. A user-defined class that extends List will not
be a readable array. Maybe the assumption here is that it will always be a JS
array (because that's what READABLE_ARRAY is), but this deserves a comment.

[ahe, 2012/08/21 15:05:38]

It will always be a JS array. That is what concrete-type inference is about.

I assume we will get a better infrastructure for this, so we don't use elements
to represent concrete types.

     if (element === builder.compiler.nullClass) return HType.NULL;
     if (element === builder.compiler.stringClass) return HType.STRING;
     return HType.UNKNOWN;