Make special const and too complex shapes before T_OBJECT shapes

gc.c

@@ -8119,7 +8119,7 @@ gc_compact_move(rb_objspace_t *objspace, rb_heap_t *heap, rb_size_pool_t *size_p
     if (RB_TYPE_P(src, T_OBJECT)) {
         orig_shape = rb_shape_get_shape(src);
         if (dheap != heap && !rb_shape_obj_too_complex(src)) {
-            rb_shape_t *initial_shape = rb_shape_get_shape_by_id((shape_id_t)((dest_pool - size_pools) + SIZE_POOL_COUNT));
+            rb_shape_t *initial_shape = rb_shape_get_shape_by_id((shape_id_t)((dest_pool - size_pools) + FIRST_T_OBJECT_SHAPE_ID));
             new_shape = rb_shape_traverse_from_new_root(initial_shape, orig_shape);
 
             if (!new_shape) {

object.c

@@ -135,7 +135,7 @@ rb_class_allocate_instance(VALUE klass)
     RUBY_ASSERT(rb_shape_get_shape(obj)->type == SHAPE_ROOT);
 
     // Set the shape to the specific T_OBJECT shape.
-    ROBJECT_SET_SHAPE_ID(obj, (shape_id_t)(rb_gc_size_pool_id_for_size(size) + 1));
+    ROBJECT_SET_SHAPE_ID(obj, (shape_id_t)(rb_gc_size_pool_id_for_size(size) + FIRST_T_OBJECT_SHAPE_ID));
 
 #if RUBY_DEBUG
     RUBY_ASSERT(!rb_shape_obj_too_complex(obj));

shape.c

@@ -1256,18 +1256,6 @@ Init_default_shapes(void)
     GET_SHAPE_TREE()->root_shape = root;
     RUBY_ASSERT(rb_shape_id(GET_SHAPE_TREE()->root_shape) == ROOT_SHAPE_ID);
 
-    // Make shapes for T_OBJECT
-    size_t *sizes = rb_gc_size_pool_sizes();
-    for (int i = 0; sizes[i] > 0; i++) {
-        rb_shape_t *t_object_shape =
-            rb_shape_alloc_with_parent_id(0, INVALID_SHAPE_ID);
-        t_object_shape->type = SHAPE_T_OBJECT;
-        t_object_shape->capacity = (uint32_t)((sizes[i] - offsetof(struct RObject, as.ary)) / sizeof(VALUE));
-        t_object_shape->edges = rb_id_table_create(0);
-        t_object_shape->ancestor_index = LEAF;
-        RUBY_ASSERT(rb_shape_id(t_object_shape) == (shape_id_t)(i + 1));
-    }
-
     bool dont_care;
     // Special const shape
 #if RUBY_DEBUG
@@ -1323,6 +1311,7 @@ Init_shape(void)
     rb_define_const(rb_cShape, "SHAPE_FLAG_SHIFT", INT2NUM(SHAPE_FLAG_SHIFT));
     rb_define_const(rb_cShape, "SPECIAL_CONST_SHAPE_ID", INT2NUM(SPECIAL_CONST_SHAPE_ID));
     rb_define_const(rb_cShape, "OBJ_TOO_COMPLEX_SHAPE_ID", INT2NUM(OBJ_TOO_COMPLEX_SHAPE_ID));
+    rb_define_const(rb_cShape, "FIRST_T_OBJECT_SHAPE_ID", INT2NUM(FIRST_T_OBJECT_SHAPE_ID));
     rb_define_const(rb_cShape, "SHAPE_MAX_VARIATIONS", INT2NUM(SHAPE_MAX_VARIATIONS));
     rb_define_const(rb_cShape, "SIZEOF_RB_SHAPE_T", INT2NUM(sizeof(rb_shape_t)));
     rb_define_const(rb_cShape, "SIZEOF_REDBLACK_NODE_T", INT2NUM(sizeof(redblack_node_t)));

shape.h

@@ -35,8 +35,9 @@ typedef uint32_t redblack_id_t;
 # define INVALID_SHAPE_ID SHAPE_MASK
 # define ROOT_SHAPE_ID 0x0
 
-# define SPECIAL_CONST_SHAPE_ID (SIZE_POOL_COUNT + 1)
+# define SPECIAL_CONST_SHAPE_ID (ROOT_SHAPE_ID + 1)
 # define OBJ_TOO_COMPLEX_SHAPE_ID (SPECIAL_CONST_SHAPE_ID + 1)
+# define FIRST_T_OBJECT_SHAPE_ID (OBJ_TOO_COMPLEX_SHAPE_ID + 1)
 
 typedef struct redblack_node redblack_node_t;
 

test/ruby/test_shapes.rb

@@ -786,7 +786,7 @@ class TestShapes < Test::Unit::TestCase
   def test_remove_instance_variable_capacity_transition
     assert_separately([], "#{<<~"begin;"}\n#{<<~'end;'}")
     begin;
-      t_object_shape = RubyVM::Shape.find_by_id(1)
+      t_object_shape = RubyVM::Shape.find_by_id(RubyVM::Shape::FIRST_T_OBJECT_SHAPE_ID)
       assert_equal(RubyVM::Shape::SHAPE_T_OBJECT, t_object_shape.type)
 
       initial_capacity = t_object_shape.capacity