Implement part-of directive.

dart/lib/compiler/implementation/elements/elements.dart

Index: dart/lib/compiler/implementation/elements/elements.dart
diff --git a/dart/lib/compiler/implementation/elements/elements.dart b/dart/lib/compiler/implementation/elements/elements.dart
index 3dfee4956fba2b2051c86d758a4487239b3ca02a..71a7d0007dc859acdfd21e5800441658cf7d6755 100644
--- a/dart/lib/compiler/implementation/elements/elements.dart
+++ b/dart/lib/compiler/implementation/elements/elements.dart
@@ -6,6 +6,8 @@
 
 #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.
@@ -493,6 +495,7 @@ class ScopeContainerElement extends ContainerElement {
 
 class CompilationUnitElement extends ContainerElement {
   final Script script;
+  PartOf partTag;
 
   CompilationUnitElement(Script script, LibraryElement library)
     : this.script = script,
@@ -512,6 +515,43 @@ class CompilationUnitElement extends ContainerElement {
       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 {