From 5f0baaac73726e8f7151f62a2c6065ae16856a61 Mon Sep 17 00:00:00 2001
From: Tim Blasi <tjblasi@google.com>
Date: Wed, 20 Jan 2016 17:56:29 -0800
Subject: [PATCH] fix(dart/transform): Ensure template codegen is completed
 sync

Previously, template codegen was done asynchronously, which could result
in reflector state being overwritten and leading to compile errors.

Update the codegen to run synchronously to ensure this does not happen.

Closes #6603
---
 .../lib/src/transform/common/logging.dart     | 20 ++++++++++++++++++-
 .../template_compiler/generator.dart          |  4 +++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/modules_dart/transform/lib/src/transform/common/logging.dart b/modules_dart/transform/lib/src/transform/common/logging.dart
index 976af4f6b7..b4e681642a 100644
--- a/modules_dart/transform/lib/src/transform/common/logging.dart
+++ b/modules_dart/transform/lib/src/transform/common/logging.dart
@@ -22,13 +22,31 @@ Future logElapsedAsync(Future asyncOperation(),
   final timer = new Stopwatch()..start();
   final result = await asyncOperation();
   timer.stop();
+  _logElapsed(timer, operationName, assetId);
+  return result;
+}
+
+/// Writes a log entry at `LogLevel.FINE` granularity with the time taken by
+/// `operation`.
+///
+/// Returns the result of executing `operation`.
+dynamic logElapsedSync(dynamic operation(),
+    {String operationName: 'unknown', AssetId assetId}) {
+  final timer = new Stopwatch()..start();
+  final result = operation();
+  timer.stop();
+  _logElapsed(timer, operationName, assetId);
+  return result;
+}
+
+/// Logs the time since `timer` was started.
+void _logElapsed(Stopwatch timer, String operationName, AssetId assetId) {
   final buf =
       new StringBuffer('[$operationName] took ${timer.elapsedMilliseconds} ms');
   if (assetId != null) {
     buf.write(' on $assetId');
   }
   log.fine(buf.toString(), asset: assetId);
-  return result;
 }
 
 /// Prints logged messages to the console.
diff --git a/modules_dart/transform/lib/src/transform/template_compiler/generator.dart b/modules_dart/transform/lib/src/transform/template_compiler/generator.dart
index 89029e8f9d..dc680d907e 100644
--- a/modules_dart/transform/lib/src/transform/template_compiler/generator.dart
+++ b/modules_dart/transform/lib/src/transform/template_compiler/generator.dart
@@ -69,7 +69,9 @@ Future<Outputs> processTemplates(AssetReader reader, AssetId assetId,
 
   var savedReflectionCapabilities = reflector.reflectionCapabilities;
   reflector.reflectionCapabilities = const NullReflectionCapabilities();
-  final compiledTemplates = await logElapsedAsync(() async {
+  // Since we need global state to remain consistent here, make sure not to do
+  // any asynchronous operations here.
+  final compiledTemplates = logElapsedSync(() {
     return templateCompiler.compileTemplatesCodeGen(compileData);
   }, operationName: 'compileTemplatesCodegen', assetId: assetId);
   reflector.reflectionCapabilities = savedReflectionCapabilities;