Handle missing imports/exports/parts.

sdk/lib/_internal/compiler/implementation/apiimpl.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 leg_apiimpl;
 
 import 'dart:async';
 
 import '../compiler.dart' as api;
 import 'dart2jslib.dart' as leg;
@@ skipping 156 matching lines @@
                     node: node);
     }
     return fileReadingTask.measure(() {
       Uri resourceUri = translateUri(readableUri, node);
       String text = "";
       try {
         // TODO(ahe): We expect the future to be complete and call value
         // directly. In effect, we don't support truly asynchronous API.
         text = deprecatedFutureValue(provider(resourceUri));
       } catch (exception) {
-        if (node != null) {
-          cancel("$exception", node: node);
-        } else {
-          reportError(
-              null,
+        reportError(
+              node,
               leg.MessageKind.GENERIC, {'text': 'Error: $exception'});

[ahe, 2013/08/06 15:01:00]

Could you turn this into a non-generic message?

For example:

Error: Can't read "#{uri}" (#{exception})

[Johnni Winther, 2013/08/19 08:05:19]

Done.

-          throw new leg.CompilerCancelledException("$exception");
-        }
+        return null;
       }
       SourceFile sourceFile = new SourceFile(resourceUri.toString(), text);
       // We use [readableUri] as the URI for the script since need to preserve
       // the scheme in the script because [Script.uri] is used for resolving
       // relative URIs mentioned in the script. See the comment on
       // [LibraryLoader] for more details.
       return new leg.Script(readableUri, sourceFile);
     });
   }
 
@@ skipping 18 matching lines @@
       bool allowInternalLibraryAccess = false;
       if (importingLibrary != null) {
         if (importingLibrary.isPlatformLibrary || importingLibrary.isPatch) {
           allowInternalLibraryAccess = true;
         } else if (importingLibrary.canonicalUri.path.contains(
                        'dart/tests/compiler/dart2js_native')) {
           allowInternalLibraryAccess = true;
         }
       }
       if (!allowInternalLibraryAccess) {
-        if (node != null && importingLibrary != null) {
+        if (importingLibrary != null) {
           reportError(
               node,
-              leg.MessageKind.GENERIC,
-              {'text':
-                  'Error: Internal library $resolvedUri is not accessible from '
-                  '${importingLibrary.canonicalUri}.'});
+              leg.MessageKind.INTERNAL_LIBRARY_FROM,
+              {'resolvedUri': resolvedUri,
+               'importingUri': importingLibrary.canonicalUri});
         } else {
           reportError(
-              null,
-              leg.MessageKind.GENERIC,
-              {'text':
-                  'Error: Internal library $resolvedUri is not accessible.'});
+              node,
+              leg.MessageKind.INTERNAL_LIBRARY,
+              {'resolvedUri': resolvedUri});
         }
       }
     }
     if (path == null) {
-      if (node != null) {
-        reportFatalError(
-            node,
-            leg.MessageKind.GENERIC,
-            {'text': 'Error: Library not found ${resolvedUri}.'});
-      } else {
-        reportFatalError(
-            null,
-            leg.MessageKind.GENERIC,
-            {'text': 'Error: Library not found ${resolvedUri}.'});
-      }
+      reportError(node, leg.MessageKind.LIBRARY_NOT_FOUND, 
+                  {'resolvedUri': resolvedUri});
       return null;
     }
     if (resolvedUri.path == 'html' ||
         resolvedUri.path == 'io') {
       // TODO(ahe): Get rid of mockableLibraryUsed when test.dart
       // supports this use case better.
       mockableLibraryUsed = true;
     }
     return libraryRoot.resolve(path);
   }
@@ skipping 40 matching lines @@
       handler(translateUri(span.uri, null), span.begin, span.end,
               message, kind);
     }
   }
 
   bool get isMockCompilation {
     return mockableLibraryUsed
       && (options.indexOf('--allow-mock-compilation') != -1);
   }
 }