Associate partial source map with each code block in Universe.generatedCode.

lib/compiler/implementation/dart2js.dart

Index: lib/compiler/implementation/dart2js.dart
diff --git a/lib/compiler/implementation/dart2js.dart b/lib/compiler/implementation/dart2js.dart
index a4ce8c0ad021f619be40926d78c1adb932a2968a..9f01d36374400e97c6523a989d15bb8422fb4eb4 100644
--- a/lib/compiler/implementation/dart2js.dart
+++ b/lib/compiler/implementation/dart2js.dart
@@ -242,7 +242,6 @@ void compile(List<String> argv) {
   if (code === null) {
     fail('Error: Compilation failed.');
   }
-  code = '$code\n//@ sourceMappingURL=${relativize(out, sourceMapOut)}';

[ahe, 2012/08/02 20:34:56]

Doesn't this mean that we ignore source maps?

[podivilov, 2012/08/21 12:29:35]

I think dart2js shouldn't inject sourceMappingURL comment into compiled code.
You may want to use X-SourceMap http header to link compiled code to source map.
And it is easier to append new sourceMappingURL comment than fixing existing one
in case the relative path changed or you want to use absolute paths for source
maps on your server.

[ahe, 2012/08/21 12:42:32]

How do we enable source maps by default without having a special HTTP server?

[podivilov, 2012/08/21 17:04:25]

Should we enable them by default? One can easily append the comment as a
deployment step if needed.

[ahe, 2012/08/22 09:39:43]

I think the default behavior should be to enable source maps by default. We can
later consider if there should be an option to not enable them.

   writeString(out, code);
   int jsBytesWritten = code.length;
   info('compiled $dartBytesRead bytes Dart -> $jsBytesWritten bytes JS '