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

runtime/vm/kernel_to_il.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <map>
 #include <set>
 #include <string>
 
 #include "vm/kernel_to_il.h"
 
@@ skipping 2437 matching lines @@
     ASSERT(field.IsZoneHandle());
     return field;
   }
 }
 
 
 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);
 }
 
 
 Fragment FlowGraphBuilder::LoadField(intptr_t offset, intptr_t class_id) {
   LoadFieldInstr* load = new (Z) LoadFieldInstr(
       Pop(), offset, AbstractType::ZoneHandle(Z), TokenPosition::kNoSource);
   load->set_result_cid(class_id);
   Push(load);
   return Fragment(load);
 }
 
 
 Fragment FlowGraphBuilder::LoadNativeField(MethodRecognizer::Kind kind,

[kustermann, 2017/02/17 09:59:12]

For LoadFields for context and native fields we don't need it, right?

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

No.

                                            intptr_t offset,
                                            const Type& type,
                                            intptr_t class_id,
                                            bool is_immutable) {
   LoadFieldInstr* load =
       new (Z) LoadFieldInstr(Pop(), offset, type, TokenPosition::kNoSource);
   load->set_recognized_kind(kind);
   load->set_result_cid(class_id);
   load->set_is_immutable(is_immutable);
   Push(load);
@@ skipping 3797 matching lines @@
     thread->clear_sticky_error();
     return error.raw();
   }
 }
 
 
 }  // namespace kernel
 }  // namespace dart
 
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)