Deletion barrier: Distinguish+verify field initialization in ia32 generated code.

runtime/vm/intermediate_language.h

 // Copyright (c) 2013, 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.
 
 #ifndef VM_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 3407 matching lines @@
  public:
   StoreInstanceFieldInstr(const Field& field,
                           Value* instance,
                           Value* value,
                           StoreBarrierType emit_store_barrier,
                           intptr_t token_pos)
       : field_(field),
         offset_in_bytes_(field.Offset()),
         emit_store_barrier_(emit_store_barrier),
         token_pos_(token_pos),
-        is_initialization_(false) {
+        is_potential_unboxed_initialization_(false),
+        is_object_reference_initialization_(false) {
     SetInputAt(kInstancePos, instance);
     SetInputAt(kValuePos, value);
   }
 
   StoreInstanceFieldInstr(intptr_t offset_in_bytes,
                           Value* instance,
                           Value* value,
                           StoreBarrierType emit_store_barrier,
                           intptr_t token_pos)
       : field_(Field::Handle()),
         offset_in_bytes_(offset_in_bytes),
         emit_store_barrier_(emit_store_barrier),
         token_pos_(token_pos),
-        is_initialization_(false) {
+        is_potential_unboxed_initialization_(false),
+        is_object_reference_initialization_(false) {
     SetInputAt(kInstancePos, instance);
     SetInputAt(kValuePos, value);
   }
 
   DECLARE_INSTRUCTION(StoreInstanceField)
 
-  void set_is_initialization(bool value) { is_initialization_ = value; }
+  void set_is_potential_unboxed_initialization(bool value) {
+    is_potential_unboxed_initialization_ = value;
+  }
+  void set_is_object_reference_initialization(bool value) {
+    is_object_reference_initialization_ = value;
+  }
 
   enum {
     kInstancePos = 0,
     kValuePos = 1
   };
 
   Value* instance() const { return inputs_[kInstancePos]; }
   Value* value() const { return inputs_[kValuePos]; }
-  bool is_initialization() const { return is_initialization_; }
+  bool is_potential_unboxed_initialization() const {
+    return is_potential_unboxed_initialization_;
+  }
+  bool is_object_reference_initialization() const {
+    return is_object_reference_initialization_;
+  }
   virtual intptr_t token_pos() const { return token_pos_; }
 
   const Field& field() const { return field_; }
   intptr_t offset_in_bytes() const { return offset_in_bytes_; }
 
   bool ShouldEmitStoreBarrier() const {
     return value()->NeedsStoreBuffer()
         && (emit_store_barrier_ == kEmitStoreBarrier);
   }
 
@@ skipping 24 matching lines @@
     const intptr_t cid = value()->Type()->ToNullableCid();
     // Write barrier is skipped for nullable and non-nullable smis.
     ASSERT(cid != kSmiCid);
     return (cid == kDynamicCid);
   }
 
   const Field& field_;
   intptr_t offset_in_bytes_;
   const StoreBarrierType emit_store_barrier_;
   const intptr_t token_pos_;
-  bool is_initialization_;  // Marks stores in the constructor.
+  // This may be the first store to an unboxed field.
+  bool is_potential_unboxed_initialization_;
+  // True if this store initializes an object reference field of an object that
+  // was allocated uninitialized; see AllocateUninitializedContext.
+  bool is_object_reference_initialization_;
 
   DISALLOW_COPY_AND_ASSIGN(StoreInstanceFieldInstr);
 };
 
 
 class GuardFieldInstr : public TemplateInstruction<1, NoThrow, Pure> {
  public:
   GuardFieldInstr(Value* value,
                   const Field& field,
                   intptr_t deopt_id)
@@ skipping 4501 matching lines @@
       Isolate* isolate, bool opt) const {                                     \
     UNIMPLEMENTED();                                                          \
     return NULL;                                                              \
   }                                                                           \
   void Name::EmitNativeCode(FlowGraphCompiler* compiler) { UNIMPLEMENTED(); }
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_