VM: [Kernel] Ensure we record [FieldLoadInstr]s in the ParsedFunction when using field guards

runtime/vm/kernel_to_il.cc

Index: runtime/vm/kernel_to_il.cc
diff --git a/runtime/vm/kernel_to_il.cc b/runtime/vm/kernel_to_il.cc
index 8e251bbee1a45bc62689bff6f61a552e9b305773..f6947f545cc7596b127944bd7a9fbe87d113898e 100644
--- a/runtime/vm/kernel_to_il.cc
+++ b/runtime/vm/kernel_to_il.cc
@@ -2455,6 +2455,13 @@ Fragment FlowGraphBuilder::LoadField(const dart::Field& field) {
   LoadFieldInstr* load = new (Z) LoadFieldInstr(
       Pop(), &MayCloneField(Z, field),
       AbstractType::ZoneHandle(Z, field.type()), TokenPosition::kNoSource);
+  if (field.guarded_cid() != kIllegalCid) {

[Vyacheslav Egorov (Google), 2017/02/17 10:24:31]

I wonder if we should make a factory function on LoadFieldInstr that creates
load fields and makes sure to add it to the list of guarded fields?

[kustermann, 2017/02/17 10:58:04]

We have a number of places with this code, so I'll go ahead and do that.

+    ASSERT(FLAG_use_field_guards);
+    if (!field.is_nullable() || (field.guarded_cid() == kNullCid)) {
+      load->set_result_cid(field.guarded_cid());
+    }
+    parsed_function_->AddToGuardedFields(&field);
+  }
   Push(load);
   return Fragment(load);
 }