[cfe] Remember if finalizeExports was done

jensjoha · commit-bot@chromium.org · commit 801ad8b5214c · 2019-06-11T11:32:34.000Z
Before this CL, whenever a dill library builder was asked to compute the outline it would finalize its exports - even if it was already done. This is not really a problem (it mostly puts stuff into maps --- doing it again will just overwrite what's already there with the same thing again), but when having many dill library builders, and asking them to compute the outline again and again because we've added a few new ones (e.g. via kernel worker) it adds up to a lot of wasted time. This CL adds a boolean to the dill library builders to avoid re-doing this already done work. An internal benchmark via kernel worker of lots of outline calculations in worker mode with reuse and the incremental compiler (and lots of dill loaded dependencies) goes from ~149 seconds to ~143 seconds. Change-Id: I19cadbf64ff5e0ff117bad4df86c83832a1f28fa Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/105243 Commit-Queue: Jens Johansen <jensj@google.com> Reviewed-by: Kevin Millikin <kmillikin@google.com>
diff --git a/pkg/front_end/lib/src/fasta/dill/dill_library_builder.dart b/pkg/front_end/lib/src/fasta/dill/dill_library_builder.dart
@@ -62,6 +62,8 @@ class DillLibraryBuilder extends LibraryBuilder<KernelTypeBuilder, Library> {
   /// [../kernel/kernel_library_builder.dart].
   Map<String, String> unserializableExports;
 
+  bool exportsAlreadyFinalized = false;
+
   DillLibraryBuilder(this.library, this.loader)
       : super(library.fileUri, new Scope.top(), new Scope.top());
 
@@ -173,6 +175,8 @@ class DillLibraryBuilder extends LibraryBuilder<KernelTypeBuilder, Library> {
   }
 
   void finalizeExports() {
+    if (exportsAlreadyFinalized) return;
+    exportsAlreadyFinalized = true;
     unserializableExports?.forEach((String name, String messageText) {
       Declaration declaration;
       switch (name) {
