Parameterize WorkItem.run.

dart/lib/compiler/implementation/scanner/scanner_task.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.
 
 class ScannerTask extends CompilerTask {
   ScannerTask(Compiler compiler) : super(compiler);
   String get name() => 'Scanner';
 
   void scan(CompilationUnitElement compilationUnit) {
     measure(() {
@@ skipping 73 matching lines @@
     }
     if (implicitlyImportCoreLibrary) {
       importLibrary(library, compiler.coreLibrary, null);
     }
   }
 
   void scanElements(CompilationUnitElement compilationUnit) {
     Script script = compilationUnit.script;
     Token tokens;
     try {
-      try {
-        tokens = new StringScanner(script.text).tokenize();
-      } catch (MalformedInputException ex) {
-        Token token;
-        var message;
-        if (ex.position is num) {
-          // TODO(ahe): Always use tokens in MalformedInputException.
-          token = new Token(EOF_INFO, ex.position);
-        } else {
-          token = ex.position;
-        }
-        compiler.cancel(ex.message, token: token);
+      tokens = new StringScanner(script.text).tokenize();
+    } catch (MalformedInputException ex) {
+      Token token;
+      var message;
+      if (ex.position is num) {
+        // TODO(ahe): Always use tokens in MalformedInputException.
+        token = new Token(EOF_INFO, ex.position);
+      } else {
+        token = ex.position;
       }
-      compiler.dietParser.dietParse(compilationUnit, tokens);
-    } catch (CompilerCancelledException ex) {
-      throw;
-    } catch (var ex) {
-      compiler.unhandledExceptionOnElement(compilationUnit);
-      throw;
+      compiler.cancel(ex.message, token: token);
     }
+    compiler.dietParser.dietParse(compilationUnit, tokens);
   }
 
   LibraryElement loadLibrary(Uri uri, Node node) {
     bool newLibrary = false;
     LibraryElement library =
       compiler.libraries.putIfAbsent(uri.toString(), () {
           newLibrary = true;
           Script script = compiler.readScript(uri, node);
           LibraryElement element = new LibraryElement(script);
           native.maybeEnableNative(compiler, element, uri);
           return element;
         });
     if (newLibrary) {
-      compiler.withCurrentElement(library, () => scan(library));
-      compiler.onLibraryLoaded(library, uri);
+      compiler.withCurrentElement(library, () {
+        scan(library);
+        compiler.onLibraryLoaded(library, uri);
+      });
     }
     return library;
   }
 
   void importLibrary(LibraryElement library, LibraryElement imported,
                      ScriptTag tag) {
     if (!imported.hasLibraryName()) {
       compiler.withCurrentElement(library, () {
         compiler.reportError(tag === null ? null : tag.argument,
                              'no #library tag found in ${imported.script.uri}');
@@ skipping 66 matching lines @@
   static final int RESOURCE = 4;
 
   /** Next state. */
   static final List<int> NEXT =
       const <int>[NO_TAG_SEEN,
                   IMPORT, // Only one library tag is allowed.
                   IMPORT,
                   SOURCE,
                   RESOURCE];
 }