WIP

Author: byroot

object.c

@@ -322,61 +322,93 @@ rb_obj_singleton_class(VALUE obj)
     return rb_singleton_class(obj);
 }
 
+struct ivar_copy_value_args = {
+    VALUE dest;
+    VALUE src;
+};
+
+static int
+ivar_copy_value_i(ID key, VALUE _empty_val, st_data_t data)
+{
+    struct ivar_copy_value_args args = (struct ivar_copy_value_args*)data;
+
+    rb_ivar_set(args->dest, key, rb_ivar_get(args->src, key));
+    return ST_CONTINUE;
+}
+
 /*! \private */
 void
 rb_obj_copy_ivar(VALUE dest, VALUE obj)
 {
     RUBY_ASSERT(!RB_TYPE_P(obj, T_CLASS) && !RB_TYPE_P(obj, T_MODULE));
 
     RUBY_ASSERT(BUILTIN_TYPE(dest) == BUILTIN_TYPE(obj));
+
+    unsigned long src_num_ivs = rb_ivar_count(obj);
+    if (!src_num_ivs) {
+        return;
+    }
+
     rb_shape_t *src_shape = rb_shape_get_shape(obj);
 
-    if (rb_shape_obj_too_complex(obj)) {
+    if (rb_shape_too_complex_p(src_shape)) {
         // obj is TOO_COMPLEX so we can copy its iv_hash
         st_table *table = st_copy(ROBJECT_IV_HASH(obj));
+        if (rb_shape_has_object_id(src_shape)) {
+            st_data_t id = (st_data_t)internal_object_id;
+            st_delete(table, &id, NULL);
+        }
         rb_obj_init_too_complex(dest, table);
 
         return;
     }
 
-    uint32_t src_num_ivs = RBASIC_FIELDS_COUNT(obj);
     rb_shape_t *shape_to_set_on_dest = src_shape;
-    VALUE * src_buf;
-    VALUE * dest_buf;
-
-    if (!src_num_ivs) {
-        return;
-    }
-
-    src_buf = ROBJECT_IVPTR(obj);
-    dest_buf = ROBJECT_IVPTR(dest);
-
     rb_shape_t *initial_shape = rb_shape_get_shape(dest);
 
     if (initial_shape->heap_index != src_shape->heap_index || !rb_shape_canonical_p(src_shape)) {
         RUBY_ASSERT(initial_shape->type == SHAPE_T_OBJECT);
 
         shape_to_set_on_dest = rb_shape_rebuild_shape(initial_shape, src_shape);
         if (UNLIKELY(rb_shape_too_complex_p(shape_to_set_on_dest))) {
-            st_table * table = rb_st_init_numtable_with_size(src_num_ivs);
+            st_table *table = rb_st_init_numtable_with_size(src_num_ivs);
             rb_obj_copy_ivs_to_hash_table(obj, table);
             rb_obj_init_too_complex(dest, table);
 
             return;
         }
     }
 
-    RUBY_ASSERT(src_num_ivs <= shape_to_set_on_dest->capacity || rb_shape_too_complex_p(shape_to_set_on_dest));
+    VALUE *src_buf = ROBJECT_IVPTR(obj);
+    VALUE *dest_buf = ROBJECT_IVPTR(dest);
+
+    RUBY_ASSERT(src_num_ivs <= shape_to_set_on_dest->capacity);
     if (initial_shape->capacity < shape_to_set_on_dest->capacity) {
         rb_ensure_iv_list_size(dest, initial_shape->capacity, shape_to_set_on_dest->capacity);
         dest_buf = ROBJECT_IVPTR(dest);
     }
 
-    MEMCPY(dest_buf, src_buf, VALUE, src_num_ivs);
+    if (src_shape->next_field_index == shape_to_set_on_dest->next_field_index) {
+        // Happy path, we can just memcpy the ivptr content
+        MEMCPY(dest_buf, src_buf, VALUE, src_num_ivs);
 
-    // Fire write barriers
-    for (uint32_t i = 0; i < src_num_ivs; i++) {
-        RB_OBJ_WRITTEN(dest, Qundef, dest_buf[i]);
+        // Fire write barriers
+        for (uint32_t i = 0; i < src_num_ivs; i++) {
+            RB_OBJ_WRITTEN(dest, Qundef, dest_buf[i]);
+        }
+    }
+    else {
+        itr_data = {
+            .dest = dest,
+            .src_obj = obj,
+        }
+        VALUE args[2] = {dest, obj};
+        iterate_over_shapes_with_callback(shape_to_set_on_dest, ivar_copy_value, &itr_data);
+        // FIXME: this is a stub
+        
+        rb_ivar_foreach(obj, ivar_copy_i, (st_data_t)dest);
+        // The shape was rebuilt, we have to copy ivars one by one.
+        // rb_bug("Not implemented");
     }
 
     rb_shape_set_shape(dest, shape_to_set_on_dest);