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..17b70cab151ec321037e42f92e3ebebddd537016 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 +1495,11 @@ static void ShutdownIsolate(uword parameter) {
     ASSERT(thread->isolate() == isolate);
     StackZone zone(thread);
     HandleScope handle_scope(thread);
+#if defined(DEBUG)
+    isolate->heap()->CollectAllGarbage();
+    VerifyCanonicalVisitor check_canonical(thread);

[Cutch, 2016/07/25 13:51:26]

Should this be:

#if defined(DEBUG)
if (!HasAttemptedReload()) {
  // TODO(asiva): Do this even if the isolate has been reloaded.
  isolate->heap()->CollectAllGarbage();
  VerifyCanonicalVisitor check_canonical(thread);
  isolate->heap()->IterateObjects(&check_canonical);
}
#endif

[siva, 2016/07/25 21:00:27]

Done for now, After fixing the issues I am seeing when reloading this can be
made unconditional.

+    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());