Handle metadata on nested function parameters.

sdk/lib/_internal/compiler/implementation/resolution/members.dart

Index: sdk/lib/_internal/compiler/implementation/resolution/members.dart
diff --git a/sdk/lib/_internal/compiler/implementation/resolution/members.dart b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
index bf1cf2267e9232baf26acf3007537b504545a1a5..c7e4611cf317e33eef8183fc9bc5d55879c4e439 100644
--- a/sdk/lib/_internal/compiler/implementation/resolution/members.dart
+++ b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
@@ -259,8 +259,11 @@ class ResolverTask extends CompilerTask {
     return measure(() {
       if (Elements.isErroneousElement(element)) return null;
 
-      for (MetadataAnnotation metadata in element.metadata) {
-        metadata.ensureResolved(compiler);
+      processMetadata([result]) {
+        for (MetadataAnnotation metadata in element.metadata) {
+          metadata.ensureResolved(compiler);
+        }
+        return result;
       }
 
       ElementKind kind = element.kind;
@@ -268,18 +271,19 @@ class ResolverTask extends CompilerTask {
           identical(kind, ElementKind.FUNCTION) ||
           identical(kind, ElementKind.GETTER) ||
           identical(kind, ElementKind.SETTER)) {
-        return resolveMethodElement(element);
+        return processMetadata(resolveMethodElement(element));
       }
 
-      if (identical(kind, ElementKind.FIELD)) return resolveField(element);
-
+      if (identical(kind, ElementKind.FIELD)) {
+        return processMetadata(resolveField(element));
+      }
       if (element.isClass) {
         ClassElement cls = element;
         cls.ensureResolved(compiler);
-        return null;
+        return processMetadata();
       } else if (element.isTypedef) {
         TypedefElement typdef = element;
-        return resolveTypedef(typdef);
+        return processMetadata(resolveTypedef(typdef));
       }
 
       compiler.unimplemented(element, "resolve($element)");
@@ -543,10 +547,15 @@ class ResolverTask extends CompilerTask {
     });
   }
 
+  /// Creates a [ResolverVisitor] for resolving an AST in context of [element].
+  /// If [useEnclosingScope] is `true` then the initial scope of the visitor
+  /// does not include inner scope of [element].
+  ///
   /// This method should only be used by this library (or tests of
   /// this library).
-  ResolverVisitor visitorFor(Element element) {
-    return new ResolverVisitor(compiler, element, _ensureTreeElements(element));
+  ResolverVisitor visitorFor(Element element, {bool useEnclosingScope: false}) {
+    return new ResolverVisitor(compiler, element,
+        _ensureTreeElements(element), useEnclosingScope: useEnclosingScope);
   }
 
   TreeElements resolveField(VariableElementX element) {
@@ -1185,20 +1194,18 @@ class ResolverTask extends CompilerTask {
       annotation.resolutionState = STATE_STARTED;
 
       Node node = annotation.parseNode(compiler);
-      // TODO(johnniwinther): Find the right analyzable element to hold the
-      // [TreeElements] for the annotation.
       Element annotatedElement = annotation.annotatedElement;
-      Element context = annotatedElement.enclosingElement;
-      if (context == null) {
-        context = annotatedElement;
-      }
-      ResolverVisitor visitor = visitorFor(context);
+      AnalyzableElement context = annotatedElement.analyzableElement;
+      assert(invariant(node, context != null,
+          message: "No context found for metadata annotation "
+                   "on $annotatedElement."));
+      ResolverVisitor visitor = visitorFor(context, useEnclosingScope: true);
       node.accept(visitor);
       annotation.value =
           constantCompiler.compileMetadata(annotation, node, visitor.mapping);
       // TODO(johnniwinther): Register the relation between the annotation
-      // and the annotated element instead. This will allow the backed to
-      // retrieve the backend constant and only registered metadata on the
+      // and the annotated element instead. This will allow the backend to
+      // retrieve the backend constant and only register metadata on the
       // elements for which it is needed. (Issue 17732).
       compiler.backend.registerMetadataConstant(
           annotation.value, visitor.mapping);
@@ -2003,7 +2010,8 @@ class ResolverVisitor extends MappingVisitor<Element> {
 
   ResolverVisitor(Compiler compiler,
                   Element element,
-                  TreeElementMapping mapping)
+                  TreeElementMapping mapping,
+                  {bool useEnclosingScope: false})
     : this.enclosingElement = element,
       // When the element is a field, we are actually resolving its
       // initial value, which should not have access to instance
@@ -2013,7 +2021,8 @@ class ResolverVisitor extends MappingVisitor<Element> {
       this.currentClass = element.isMember ? element.enclosingClass
                                              : null,
       this.statementScope = new StatementScope(),
-      scope = element.buildScope(),
+      scope = useEnclosingScope
+          ? Scope.buildEnclosingScope(element) : element.buildScope(),
       // The type annotations on a typedef do not imply type checks.
       // TODO(karlklose): clean this up (dartbug.com/8870).
       inCheckContext = compiler.enableTypeAssertions &&
@@ -4657,14 +4666,14 @@ Element lookupInScope(Compiler compiler, Node node,
   return Elements.unwrap(scope.lookup(name), compiler, node);
 }
 
-TreeElements _ensureTreeElements(AnalyzableElement element) {
+TreeElements _ensureTreeElements(AnalyzableElementX element) {
   if (element._treeElements == null) {
     element._treeElements = new TreeElementMapping(element);
   }
   return element._treeElements;
 }
 
-abstract class AnalyzableElement implements Element {
+abstract class AnalyzableElementX implements AnalyzableElement {
   TreeElements _treeElements;
 
   bool get hasTreeElements => _treeElements != null;