Add support for source maps in deferred libraries.

sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/emitter.dart

 // Copyright (c) 2014, 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.
 
 part of dart2js.js_emitter;
 
 
 class OldEmitter implements Emitter {
   final Compiler compiler;
   final CodeEmitterTask task;
@@ skipping 1275 matching lines @@
         [   constructorName, js.string(constructorName),
             constructorName,
             constructorName, js.string(constructorName),
             constructorName,
             constructorName
          ]));
 
     cspPrecompiledConstructorNamesFor(outputUnit).add(js('#', constructorName));
   }
 
-  /// Returns a name composed of the main output file name and [name].
+  /// Extracts the output name of the compiler's outputUri.
   String deferredPartFileName(OutputUnit outputUnit,
                               {bool addExtension: true}) {
     String outPath = compiler.outputUri != null
         ? compiler.outputUri.path
         : "out";
     String outName = outPath.substring(outPath.lastIndexOf('/') + 1);
     String extension = addExtension ? ".part.js" : "";
     if (outputUnit == compiler.deferredLoadTask.mainOutputUnit) {
       return "$outName$extension";
     } else {
@@ skipping 332 matching lines @@
     if (compiler.useContentSecurityPolicy) {
       mainBuffer.write(
           jsAst.prettyPrint(
               precompiledFunctionAst,
               compiler,
               monitor: compiler.dumpInfoTask,
               allowVariableMinification: false).getText());
     }
 
     String assembledCode = mainBuffer.getText();
-    String sourceMapTags = "";
     if (generateSourceMap) {
       outputSourceMap(assembledCode, mainBuffer, '',
           compiler.sourceMapUri, compiler.outputUri);
-      sourceMapTags =
-          generateSourceMapTag(compiler.sourceMapUri, compiler.outputUri);
+      mainBuffer.add(
+          generateSourceMapTag(compiler.sourceMapUri, compiler.outputUri));
+      assembledCode = mainBuffer.getText();
     }
-    mainBuffer.add(sourceMapTags);
-    assembledCode = mainBuffer.getText();
+
     compiler.outputProvider('', 'js')
         ..add(assembledCode)
         ..close();
     compiler.assembledCode = assembledCode;
 
     if (!compiler.useContentSecurityPolicy) {
       CodeBuffer cspBuffer = new CodeBuffer();
       cspBuffer.add(mainBuffer);
       cspBuffer.write("""
 {
@@ skipping 209 matching lines @@
         jsAst.FunctionDeclaration precompiledFunctionAst =
             buildCspPrecompiledFunctionFor(outputUnit);
 
         outputBuffer.write(
             jsAst.prettyPrint(
                 precompiledFunctionAst, compiler,
                 monitor: compiler.dumpInfoTask,
                 allowVariableMinification: false).getText());
       }
 
-      String code = outputBuffer.getText();
-
       // Make a unique hash of the code (before the sourcemaps are added)
       // This will be used to retrieve the initializing function from the global
       // variable.
-      String hash = hashOfString(code);
+      String hash = hashOfString(outputBuffer.getText());
+
+      outputBuffer.add('${deferredInitializers}["$hash"]$_=$_'
+                       '${deferredInitializers}.current$N');
+
+      if (generateSourceMap) {
+        String partName =
+            '${deferredPartFileName(outputUnit, addExtension: false)}.part';
+
+        String mapFileName = partName + ".js.map";
+        List<String> mapSegments = compiler.sourceMapUri.pathSegments.toList();
+        mapSegments[mapSegments.length - 1] = mapFileName;
+        Uri mapUri = compiler.sourceMapUri.replace(pathSegments: mapSegments);
+
+        String partFileName = partName + ".js";
+        List<String> partSegments = compiler.outputUri.pathSegments.toList();
+        partSegments[mapSegments.length - 1] = partFileName;
+        Uri partUri = compiler.outputUri.replace(pathSegments: partSegments);
+
+        outputSourceMap(outputBuffer.getText(), outputBuffer, partName,
+            mapUri, partUri);
+        outputBuffer.add(generateSourceMapTag(mapUri, partUri));
+      }
 
       outputBuffers[outputUnit] = outputBuffer;
       compiler.outputProvider(
           deferredPartFileName(outputUnit, addExtension: false), 'part.js')

[Johnni Winther, 2014/10/14 07:46:41]

Store `deferredPartFileName(...)` is local variable and use it here and in
[partName].

[floitsch, 2014/10/14 09:34:06]

Done.

-        ..add(code)
-        ..add('${deferredInitializers}["$hash"]$_=$_'
-                '${deferredInitializers}.current$N')
+        ..add(outputBuffer.getText())
         ..close();
 
       hunkHashes[outputUnit] = hash;
-      // TODO(johnniwinther): Support source maps for deferred code.
     }
     return hunkHashes;
   }
 
   String buildGeneratedBy() {
     var suffix = '';
     if (compiler.hasBuildId) suffix = ' version: ${compiler.buildId}';
     return '// Generated by dart2js, the Dart to JavaScript compiler$suffix.\n';
   }
 
@@ skipping 18 matching lines @@
     for (Element element in compiler.enqueuer.codegen.newlyEnqueuedElements) {
       if (element.isInstanceMember) {
         cachedClassBuilders.remove(element.enclosingClass);
 
         nativeEmitter.cachedBuilders.remove(element.enclosingClass);
 
       }
     }
   }
 }