Keep original order of fields in Class.

The fields of a class are ordered alphabetically in the dex
file. Keep the same order in the field arrays so that we can
do binary search lookups by name. Those lookups will be
implemented in a subsequent change in libcore/.

Bug: 18211592

(cherry picked from commit bfa3ed0ad988e1da13626ddbaf6dcae0c58ea79e)

Change-Id: I8f979de62ffe37d1c7d5c721717d2f3501e7c9e6

1 files changed, 6 insertions, 4 deletions

diff --git a/compiler/image_writer.cc b/compiler/image_writer.cc
index cf2cddb896..b7283a4e19 100644
--- a/compiler/image_writer.cc
+++ b/compiler/image_writer.cc
@@ -484,13 +484,14 @@ void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass)
   }
   //
   size_t num_reference_fields = h_class->NumReferenceInstanceFields();
+  MemberOffset field_offset = h_class->GetFirstReferenceInstanceFieldOffset();
   for (size_t i = 0; i < num_reference_fields; ++i) {
-    mirror::ArtField* field = h_class->GetInstanceField(i);
-    MemberOffset field_offset = field->GetOffset();
     mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset);
     if (value != nullptr) {
       WalkFieldsInOrder(value);
     }
+    field_offset = MemberOffset(field_offset.Uint32Value() +
+                                sizeof(mirror::HeapReference<mirror::Object>));
   }
 }
 
@@ -507,13 +508,14 @@ void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) {
     // Walk static fields of a Class.
     if (h_obj->IsClass()) {
       size_t num_static_fields = klass->NumReferenceStaticFields();
+      MemberOffset field_offset = klass->GetFirstReferenceStaticFieldOffset();
       for (size_t i = 0; i < num_static_fields; ++i) {
-        mirror::ArtField* field = klass->GetStaticField(i);
-        MemberOffset field_offset = field->GetOffset();
         mirror::Object* value = h_obj->GetFieldObject<mirror::Object>(field_offset);
         if (value != nullptr) {
           WalkFieldsInOrder(value);
         }
+        field_offset = MemberOffset(field_offset.Uint32Value() +
+                                    sizeof(mirror::HeapReference<mirror::Object>));
       }
     } else if (h_obj->IsObjectArray()) {
       // Walk elements of an object array.