Opt-in to generate code for compile-time error. Only supported for SSA.

pkg/compiler/lib/src/compiler.dart

Index: pkg/compiler/lib/src/compiler.dart
diff --git a/pkg/compiler/lib/src/compiler.dart b/pkg/compiler/lib/src/compiler.dart
index 2565f3097bc19f64cce6aff347f3b263e811fb29..93fc66a315304d01daa47bf774b8f0440ddb3f3b 100644
--- a/pkg/compiler/lib/src/compiler.dart
+++ b/pkg/compiler/lib/src/compiler.dart
@@ -302,8 +302,6 @@ abstract class Backend {
 
   List<CompilerTask> get tasks;
 
-  bool get canHandleCompilationFailed;
-
   void onResolutionComplete() {}
   void onTypeInferenceComplete() {}
 
@@ -314,9 +312,13 @@ abstract class Backend {
   bool classNeedsRti(ClassElement cls);
   bool methodNeedsRti(FunctionElement function);
 
-  /// Register deferred loading. Returns `true` if the backend supports deferred
+  /// Enable compilation of code with compile time errors. Returns `true` if
+  /// supported by the backend.
+  bool enableCodegenWithErrorsIfSupported(Spannable node);
+
+  /// Enable deferred loading. Returns `true` if the backend supports deferred
   /// loading.
-  bool registerDeferredLoading(Spannable node, Registry registry);
+  bool enableDeferredLoadingIfSupported(Spannable node, Registry registry);
 
   /// Called during codegen when [constant] has been used.
   void registerCompileTimeConstant(ConstantValue constant, Registry registry) {}
@@ -794,6 +796,9 @@ abstract class Compiler implements DiagnosticListener {
   /// Generate output even when there are compile-time errors.
   final bool generateCodeWithCompileTimeErrors;
 
+  /// The compiler is run from the build bot.
+  final bool testMode;
+
   bool disableInlining = false;
 
   List<Uri> librariesToAnalyzeWhenRun;
@@ -1053,6 +1058,7 @@ abstract class Compiler implements DiagnosticListener {
             this.allowNativeExtensions: false,
             this.enableNullAwareOperators: false,
             this.generateCodeWithCompileTimeErrors: false,
+            this.testMode: false,
             api.CompilerOutputProvider outputProvider,
             List<String> strips: const []})
       : this.disableTypeInferenceFlag =
@@ -1621,9 +1627,11 @@ abstract class Compiler implements DiagnosticListener {
       });
     }
 
-    // TODO(sigurdm): The dart backend should handle failed compilations.
-    if (compilationFailed && !backend.canHandleCompilationFailed) {
-      return;
+    if (compilationFailed){
+      if (!generateCodeWithCompileTimeErrors) return;
+      if (!backend.enableCodegenWithErrorsIfSupported(NO_LOCATION_SPANNABLE)) {
+        return;
+      }
     }
 
     if (analyzeOnly) {
@@ -2159,7 +2167,14 @@ abstract class Compiler implements DiagnosticListener {
   }
 
   EventSink<String> outputProvider(String name, String extension) {
-    if (compilationFailed) return new NullSink('$name.$extension');
+    if (compilationFailed) {
+      if (!generateCodeWithCompileTimeErrors || testMode) {
+        // Disable output in test mode: The build bot currently uses the time
+        // stamp of the generated file to determine whether the output is
+        // up-to-date.
+        return new NullSink('$name.$extension');
+      }
+    }
     return userOutputProvider(name, extension);
   }
 }