Various caches for incremental compilation.

dart/sdk/lib/_internal/compiler/implementation/compiler.dart

Index: dart/sdk/lib/_internal/compiler/implementation/compiler.dart
diff --git a/dart/sdk/lib/_internal/compiler/implementation/compiler.dart b/dart/sdk/lib/_internal/compiler/implementation/compiler.dart
index 4be232a54f3234ac1629f6096eeacd17ec39bd04..9f2f23a2dfe91942fbafea8662be87ecd52492aa 100644
--- a/dart/sdk/lib/_internal/compiler/implementation/compiler.dart
+++ b/dart/sdk/lib/_internal/compiler/implementation/compiler.dart
@@ -506,6 +506,8 @@ abstract class Compiler implements DiagnosticListener {
   String assembledCode;
   Types types;
 
+  final CacheStrategy cacheStrategy = new CacheStrategy();

[Johnni Winther, 2014/06/19 14:14:04]

Use a noop strategy when hasIncrementalSupport is false?

[ahe, 2014/06/19 14:33:26]

Done.

I've haven't actually created a no-op class, as that seemed excessive for what I
need right now :-)

+
   /**
    * Map from token to the first preceeding comment token.
    */
@@ -600,6 +602,10 @@ abstract class Compiler implements DiagnosticListener {
 
   final bool suppressWarnings;
 
+  /// If `true`, some values are cached for reuse in incremental compilation.
+  /// Incremental compilation is basically calling [run] more than once.
+  final bool hasIncrementalSupport;
+
   api.CompilerOutputProvider outputProvider;
 
   bool disableInlining = false;
@@ -839,6 +845,7 @@ abstract class Compiler implements DiagnosticListener {
             this.showPackageWarnings: false,
             this.useContentSecurityPolicy: false,
             this.suppressWarnings: false,
+            this.hasIncrementalSupport: false,
             outputProvider,
             List<String> strips: const []})
       : this.disableTypeInferenceFlag =