Debug garbage collector does not correctly remove cross-gen garbage

runtime/vm/heap.cc

Index: runtime/vm/heap.cc
diff --git a/runtime/vm/heap.cc b/runtime/vm/heap.cc
index 975d0d55c27a38cdea105418f05c13953f0103a2..634b75d31f71961cb0ed8e9b328e0823aa68e57f 100644
--- a/runtime/vm/heap.cc
+++ b/runtime/vm/heap.cc
@@ -364,6 +364,21 @@ void Heap::UpdateClassHeapStatsBeforeGC(Heap::Space space) {
 }
 #endif
 

[rmacnak, 2017/06/30 22:24:56]

Two lines between functions (clang-format doesn't handle everything).

[danunez, 2017/06/30 22:33:58]

Done.

+void Heap::EvacuateNewSpaceGarbage(Thread* thread, GCReason reason) {
+  ASSERT(reason == kFull);
+  if (BeginNewSpaceGC(thread)) {
+    RecordBeforeGC(kNew, kFull);
+    VMTagScope tagScope(thread, VMTag::kGCNewSpaceTagId);
+    TIMELINE_FUNCTION_GC_DURATION(thread, "CollectNewGeneration");

[rmacnak, 2017/06/30 22:24:56]

"EvacuateNewGeneration"

[danunez, 2017/06/30 22:33:58]

Done.

+    NOT_IN_PRODUCT(UpdateClassHeapStatsBeforeGC(kNew));
+    new_space_.Evacuate();
+    NOT_IN_PRODUCT(isolate()->class_table()->UpdatePromoted());
+    RecordAfterGC(kNew);
+    PrintStats();
+    NOT_IN_PRODUCT(PrintStatsToTimeline(&tds));
+    EndNewSpaceGC();
+  }
+}
 

[rmacnak, 2017/06/30 22:24:56]

Two lines

[danunez, 2017/06/30 22:33:58]

Done.

 void Heap::CollectNewSpaceGarbage(Thread* thread,
                                   ApiCallbacks api_callbacks,
@@ -444,7 +459,10 @@ void Heap::CollectGarbage(Space space) {
 
 void Heap::CollectAllGarbage() {
   Thread* thread = Thread::Current();
-  CollectNewSpaceGarbage(thread, kInvokeApiCallbacks, kFull);
+
+  // New space is evacuated so this GC will collect all dead objects
+  // kept alive by a cross-generational pointer.
+  EvacuateNewSpaceGarbage(thread, kFull);
   CollectOldSpaceGarbage(thread, kInvokeApiCallbacks, kFull);
 }