Implement part-of directive.

dart/lib/compiler/implementation/elements/elements.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.
 
 #library('elements');
 
 #import('dart:uri');
 
+// TODO(ahe): Rename prefix to 'api' when VM bug is fixed.
+#import('../../compiler.dart', prefix: 'api_e');
 #import('../tree/tree.dart');
 #import('../scanner/scannerlib.dart');
 #import('../leg.dart');  // TODO(karlklose): we only need type.
 #import('../universe/universe.dart');
 #import('../util/util.dart');
 
 const int STATE_NOT_STARTED = 0;
 const int STATE_STARTED = 1;
 const int STATE_DONE = 2;
 
@@ skipping 467 matching lines @@
       } else {
         field.setter = accessor;
       }
       addToScope(field, listener);
     }
   }
 }
 
 class CompilationUnitElement extends ContainerElement {
   final Script script;
+  PartOf partTag;
 
   CompilationUnitElement(Script script, LibraryElement library)
     : this.script = script,
       super(new SourceString(script.name),
             ElementKind.COMPILATION_UNIT,
             library) {
     library.addCompilationUnit(this);
   }
 
   void addMember(Element element, DiagnosticListener listener) {
     // Keep a list of top level members.
     super.addMember(element, listener);
     // Provide the member to the library to build scope.
     if (enclosingElement.isPatch) {
       getImplementationLibrary().addMember(element, listener);
     } else {
       getLibrary().addMember(element, listener);
     }
   }
+
+  void setPartOf(PartOf tag, DiagnosticListener listener) {
+    LibraryElement library = enclosingElement;
+    if (library.entryCompilationUnit == this) {
+      listener.reportMessage(
+          listener.spanFromNode(tag),
+          MessageKind.ILLEGAL_DIRECTIVE.error(),
+          api_e.Diagnostic.WARNING);
+      return;
+    }
+    if (!localMembers.isEmpty()) {
+      listener.reportMessage(
+          listener.spanFromNode(tag),
+          MessageKind.BEFORE_TOP_LEVEL.error(),
+          api_e.Diagnostic.ERROR);
+      return;
+    }
+    if (partTag != null) {
+      listener.reportMessage(
+          listener.spanFromNode(tag),
+          MessageKind.DUPLICATED_PART_OF.error(),
+          api_e.Diagnostic.WARNING);
+      return;
+    }
+    partTag = tag;
+    LibraryName libraryTag = getLibrary().libraryTag;
+    if (libraryTag != null) {

[Johnni Winther, 2012/10/09 07:43:36]

Isn't it also an error if the library does not have a libraryTag?

[ahe, 2012/10/09 07:48:09]

A script may have parts, but no library name:

scriptDefinition:
scriptTag? libraryName? libraryImport* partDirective* topLevelDefinition*

+      String expectedName = tag.name.toString();
+      String actualName = libraryTag.name.toString();
+      if (expectedName != actualName) {
+        listener.reportMessage(
+            listener.spanFromNode(tag.name),
+            MessageKind.LIBRARY_NAME_MISMATCH.error([expectedName]),
+            api_e.Diagnostic.WARNING);
+      }
+    }
+  }
 }
 
 class LibraryElement extends ScopeContainerElement {
   final Uri uri;
   CompilationUnitElement entryCompilationUnit;
   Link<CompilationUnitElement> compilationUnits =
       const EmptyLink<CompilationUnitElement>();
   Link<LibraryTag> tags = const EmptyLink<LibraryTag>();
   LibraryName libraryTag;
   bool canUseNative = false;
@@ skipping 1348 matching lines @@
 
   MetadataAnnotation ensureResolved(Compiler compiler) {
     if (resolutionState == STATE_NOT_STARTED) {
       compiler.resolver.resolveMetadataAnnotation(this);
     }
     return this;
   }
 
   String toString() => 'MetadataAnnotation($value, $resolutionState)';
 }