RFC: Resolution based tree-shaking.

dart/lib/compiler/implementation/resolver.dart

Index: dart/lib/compiler/implementation/resolver.dart
diff --git a/dart/lib/compiler/implementation/resolver.dart b/dart/lib/compiler/implementation/resolver.dart
index 3be55cfe742a5e19e8b5fda3e9aa4fca53533f01..51111cf07df9b37a56d72d898ec23bafd9372c89 100644
--- a/dart/lib/compiler/implementation/resolver.dart
+++ b/dart/lib/compiler/implementation/resolver.dart
@@ -123,6 +123,8 @@ class ResolverTask extends CompilerTask {
       FunctionExpression tree = element.parseNode(compiler);
       if (isConstructor) {
         resolveConstructorImplementation(element, tree);
+        compiler.enqueuer.resolution.registerStaticUse(
+            element.defaultImplementation);
       }
       ResolverVisitor visitor = new ResolverVisitor(compiler, element);
       visitor.useElement(tree, element);
@@ -803,6 +805,18 @@ class ResolverVisitor extends CommonResolverVisitor<Element> {
 
   Element useElement(Node node, Element element) {
     if (element === null) return null;
+    ElementKind kind = element.kind;
+    if (element.isTopLevel() || element.isMember()) {
+      int allowed = ElementCategory.VARIABLE | ElementCategory.FUNCTION
+        | ElementCategory.FACTORY;
+      if ((element.kind.category & allowed) != 0 || element.isAccessor()) {
+        if (element.isInstanceMember()) {
+          compiler.enqueuer.resolution.registerDynamicInvocationOf(element);
+        } else {
+          compiler.enqueuer.resolution.registerStaticUse(element);
+        }
+      }
+    }
     return mapping[node] = element;
   }
 
@@ -1064,6 +1078,26 @@ class ResolverVisitor extends CommonResolverVisitor<Element> {
     // TODO(ngeoffray): Warn if target is null and the send is
     // unqualified.
     useElement(node, target);
+    if (target === null || target.isMember()) {
+      Identifier id = node.selector.asIdentifier();
+      if (id !== null) {
+        compiler.enqueuer.resolution.registerDynamicInvocation(
+            id.source,
+            mapping.getSelector(node));
+      }
+      // target = new Interceptors(compiler).getStaticInterceptor(
+      //     node.selector.asIdentifier().source,
+      //     node.argumentCount());
+    }
+    if (target !== null &&
+        target.kind !== ElementKind.VARIABLE &&
+        target.kind !== ElementKind.CLASS) {
+      if (target.isInstanceMember()) {
+        compiler.enqueuer.resolution.registerDynamicInvocationOf(target);
+      } else {
+        compiler.enqueuer.resolution.registerStaticUse(target);
+      }
+    }
     if (node.isPropertyAccess) return target;
   }
 
@@ -1168,6 +1202,7 @@ class ResolverVisitor extends CommonResolverVisitor<Element> {
       // parameters. We cannot do this rigth now because of the
       // List constructor.
     }
+    compiler.enqueuer.resolution.registerStaticUse(constructor);
     useElement(node.send, constructor);
     return null;
   }
@@ -1232,6 +1267,8 @@ class ResolverVisitor extends CommonResolverVisitor<Element> {
   }
 
   visitStringInterpolation(StringInterpolation node) {
+    compiler.enqueuer.resolution.registerStaticUse(compiler.findHelper(
+        const SourceString("S")));
     node.visitChildren(this);
   }