dart2js: add support for configuration-specific imports.

pkg/compiler/lib/src/patch_parser.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.
 
 /**
  * This library contains the infrastructure to parse and integrate patch files.
  *
  * Three types of elements can be patched: [LibraryElement], [ClassElement],
  * [FunctionElement]. Patches are introduced in patch libraries which are loaded
  * together with the corresponding origin library. Which libraries that are
@@ skipping 141 matching lines @@
     Parser;
 import 'scanner/scanner.dart' show
     Scanner;
 import 'script.dart';
 import 'tokens/token.dart' show
     StringToken,
     Token;
 
 class PatchParserTask extends CompilerTask {
   final String name = "Patching Parser";
+  final bool _enableConditionalDirectives;
 
-  PatchParserTask(Compiler compiler): super(compiler);
+  PatchParserTask(Compiler compiler, {bool enableConditionalDirectives})
+      : this._enableConditionalDirectives = enableConditionalDirectives,
+        super(compiler);
 
   /**
    * Scans a library patch file, applies the method patches and
    * injections to the library, and returns a list of class
    * patches.
    */
   Future patchLibrary(LibraryLoader loader,
                       Uri patchUri, LibraryElement originLibrary) {
     return compiler.readScript(originLibrary, patchUri)
         .then((Script script) {
@@ skipping 14 matching lines @@
   void scanLibraryElements(CompilationUnitElement compilationUnit) {
     measure(() {
       // TODO(johnniwinther): Test that parts and exports are handled correctly.
       Script script = compilationUnit.script;
       Token tokens = new Scanner(script.file).tokenize();
       Function idGenerator = compiler.getNextFreeClassId;
       Listener patchListener = new PatchElementListener(compiler,
                                                         compilationUnit,
                                                         idGenerator);
       try {
-        new PartialParser(patchListener).parseUnit(tokens);
+        new PartialParser(patchListener,
+            enableConditionalDirectives: _enableConditionalDirectives)
+            .parseUnit(tokens);
       } on ParserError catch (e) {
         // No need to recover from a parser error in platform libraries, user
         // will never see this if the libraries are tested correctly.
         reporter.internalError(
             compilationUnit, "Parser error in patch file: $e");
       }
     });
   }
 
   void parsePatchClassNode(PartialClassElement cls) {
     // Parse [PartialClassElement] using a "patch"-aware parser instead
     // of calling its [parseNode] method.
     if (cls.cachedNode != null) return;
 
     measure(() => reporter.withCurrentElement(cls, () {
       MemberListener listener = new PatchMemberListener(compiler, cls);
-      Parser parser = new PatchClassElementParser(listener);
+      Parser parser = new PatchClassElementParser(
+          listener, enableConditionalDirectives: _enableConditionalDirectives);
       try {
         Token token = parser.parseTopLevelDeclaration(cls.beginToken);
         assert(identical(token, cls.endToken.next));
       } on ParserError catch (e) {
         // No need to recover from a parser error in platform libraries, user
         // will never see this if the libraries are tested correctly.
         reporter.internalError(
             cls, "Parser error in patch file: $e");
       }
       cls.cachedNode = listener.popNode();
@@ skipping 31 matching lines @@
       enclosingClass.addMember(patch, reporter);
     }
   }
 }
 
 /**
  * Partial parser for patch files that also handles the members of class
  * declarations.
  */
 class PatchClassElementParser extends PartialParser {
-  PatchClassElementParser(Listener listener) : super(listener);
+  PatchClassElementParser(Listener listener, {bool enableConditionalDirectives})
+      : super(listener,
+          enableConditionalDirectives: enableConditionalDirectives);
 
   Token parseClassBody(Token token) => fullParseClassBody(token);
 }
 
 /**
  * Extension of [ElementListener] for parsing patch files.
  */
 class PatchElementListener extends ElementListener implements Listener {
   final Compiler compiler;
 
@@ skipping 410 matching lines @@
 
 class PatchVersion {
   final String tag;
 
   const PatchVersion(this.tag);
 
   bool isActive(String patchTag) => tag == null || tag == patchTag;
 
   String toString() => 'PatchVersion($tag)';
 }