Patches to support Dart VM patch files in dart2js.

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 124 matching lines @@
 import 'library_loader.dart' show LibraryLoader;
 import 'options.dart' show ParserOptions;
 import 'parser/listener.dart' show Listener, ParserError;
 import 'parser/element_listener.dart' show ElementListener;
 import 'parser/member_listener.dart' show MemberListener;
 import 'parser/partial_elements.dart' show PartialClassElement;
 import 'parser/partial_parser.dart' show PartialParser;
 import 'parser/parser.dart' show Parser;
 import 'scanner/scanner.dart' show Scanner;
 import 'script.dart';
-import 'tokens/token.dart' show StringToken, Token;
+import 'tokens/token.dart' show SymbolToken, StringToken, Token;
+
+import 'tokens/token_constants.dart' show EOF_TOKEN;
+
+import 'tokens/precedence_constants.dart' show AT_INFO;
+
+class PartialPatchParser extends PartialParser {
+  PartialPatchParser(Listener listener, ParserOptions options)
+      : super(listener, options);
+
+  Token parseMetadataStar(Token token, {bool forParameter: false}) {
+    listener.beginMetadataStar(token);
+    int count = 0;
+    while (token.kind != EOF_TOKEN) {
+      if (optional('@', token)) {
+        token = parseMetadata(token);
+        count++;
+      } else if (optional('patch', token)) {
+        token = parsePatchKeyword(token);
+      } else {
+        break;
+      }
+    }
+    listener.endMetadataStar(count, forParameter);
+    return token;
+  }
+
+  Token parsePatchKeyword(Token token) {
+    listener.beginMetadata(token);
+    Token start = new SymbolToken(AT_INFO, token.charOffset)..next = token;
+    assert(optional('patch', token));
+    token = parseIdentifier(token);
+    token = parseQualifiedRestOpt(token);
+    token = parseTypeArgumentsOpt(token);
+    Token period = null;
+    if (optional('.', token)) {
+      period = token;
+      token = parseIdentifier(token.next);
+    }
+    token = parseArgumentsOpt(token);
+    listener.endMetadata(start, period, token);
+    return token;
+  }
+}
 
 class PatchParserTask extends CompilerTask {
   final String name = "Patching Parser";
   final ParserOptions parserOptions;
 
   PatchParserTask(Compiler compiler, this.parserOptions) : 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(patchUri, originLibrary).then((Script script) {
       var patchLibrary = new LibraryElementX(script, null, originLibrary);
       return reporter.withCurrentElement(patchLibrary, () {
         loader.registerNewLibrary(patchLibrary);
         reporter.withCurrentElement(patchLibrary.entryCompilationUnit, () {
           // This patches the elements of the patch library into [library].
           // Injected elements are added directly under the compilation unit.
           // Patch elements are stored on the patched functions or classes.
           scanLibraryElements(patchLibrary.entryCompilationUnit);
         });
-        return loader.processLibraryTags(patchLibrary);
+        return loader.processLibraryTags(patchLibrary, isPatchLibrary: true);
       });
     });
   }
 
   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();
       Listener patchListener =
           new PatchElementListener(compiler, compilationUnit, compiler);
       try {
-        new PartialParser(patchListener, parserOptions).parseUnit(tokens);
+        new PartialPatchParser(patchListener, parserOptions).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, parserOptions);
           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();
           assert(listener.nodes.isEmpty);
         }));
   }
+
+  void scanUnit(CompilationUnitElement unit, {bool isPart: true}) {
+    // TODO(ahe): Implement this.
+    throw "not implemented";
+  }
 }
 
 class PatchMemberListener extends MemberListener {
   final Compiler compiler;
 
   PatchMemberListener(Compiler compiler, ClassElement enclosingClass)
       : this.compiler = compiler,
         super(compiler.parsing.getScannerOptionsFor(enclosingClass),
             compiler.reporter, enclosingClass);
 
   @override
   void addMember(Element patch) {
     addMetadata(patch);
 
     PatchVersion patchVersion = getPatchVersion(compiler, patch);
     if (patchVersion != null) {
       if (patchVersion.isActive(compiler.patchVersion)) {
         Element origin = enclosingClass.origin.localLookup(patch.name);
         patchElement(compiler, reporter, origin, patch);
         enclosingClass.addMember(patch, reporter);
       } else {
         // Skip this element.
       }
     } else {
-      if (Name.isPublicName(patch.name)) {
+      Element origin = enclosingClass.origin.localLookup(patch.name);
+      if (origin != null) {
+        patchElement(compiler, reporter, origin, patch);
+      } else if (Name.isPublicName(patch.name)) {
         reporter.reportErrorMessage(patch, MessageKind.INJECTED_PUBLIC_MEMBER);
       }
       enclosingClass.addMember(patch, reporter);
     }
   }
 }
 
 /**
  * Partial parser for patch files that also handles the members of class
  * declarations.
@@ skipping 26 matching lines @@
       if (patchVersion.isActive(compiler.patchVersion)) {
         LibraryElement originLibrary = compilationUnitElement.library;
         assert(originLibrary.isPatched);
         Element origin = originLibrary.localLookup(patch.name);
         patchElement(compiler, reporter, origin, patch);
         compilationUnitElement.addMember(patch, reporter);
       } else {
         // Skip this element.
       }
     } else {
-      if (Name.isPublicName(patch.name)) {
+      LibraryElement originLibrary = compilationUnitElement.library;
+      Element origin = originLibrary.localLookup(patch.name);
+      if (origin != null) {
+        patchElement(compiler, reporter, origin, patch);
+      } else if (Name.isPublicName(patch.name)) {
         reporter.reportErrorMessage(patch, MessageKind.INJECTED_PUBLIC_MEMBER);
       }
       compilationUnitElement.addMember(patch, reporter);
     }
   }
 }
 
 void patchElement(Compiler compiler, DiagnosticReporter reporter,
     Element origin, Element patch) {
   if (origin == null) {
@@ skipping 317 matching lines @@
 
 class PatchVersion {
   final String tag;
 
   const PatchVersion(this.tag);
 
   bool isActive(String patchTag) => tag == null || tag == patchTag;
 
   String toString() => 'PatchVersion($tag)';
 }