Add a verification step which iterates over the heap and verifies that all canonical objects are co…

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index c20def45467837153a63515762f8a6c5f22139bb..c0571f89a1fd78190003e60a566d0583835f2019 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -45,6 +45,7 @@
 #include "vm/timeline.h"
 #include "vm/timeline_analysis.h"
 #include "vm/timer.h"
+#include "vm/verifier.h"
 #include "vm/visitor.h"
 
 
@@ -1091,10 +1092,12 @@ void Isolate::ReportReloadError(const Error& error) {
 
 
 void Isolate::ReloadSources(bool test_mode) {
+  // TODO(asiva): Add verification of canonical objects.
   ASSERT(!IsReloading());
   has_attempted_reload_ = true;
   reload_context_ = new IsolateReloadContext(this, test_mode);
   reload_context_->StartReload();
+  // TODO(asiva): Add verification of canonical objects.
 }
 #endif  // !PRODUCT
 
@@ -1492,6 +1495,13 @@ static void ShutdownIsolate(uword parameter) {
     ASSERT(thread->isolate() == isolate);
     StackZone zone(thread);
     HandleScope handle_scope(thread);
+#if defined(DEBUG)
+    if (!isolate->HasAttemptedReload()) {
+      isolate->heap()->CollectAllGarbage();
+      VerifyCanonicalVisitor check_canonical(thread);
+      isolate->heap()->IterateObjects(&check_canonical);
+    }
+#endif  // DEBUG
     const Error& error = Error::Handle(thread->sticky_error());
     if (!error.IsNull() && !error.IsUnwindError()) {
       OS::PrintErr("in ShutdownIsolate: %s\n", error.ToErrorCString());