7 files changed, 191 insertions, 76 deletions
diff --git a/gc.c b/gc.c
index afa1ae94fe..7b7e31e9ca 100644
--- a/gc.c
+++ b/gc.c
@@ -666,9 +666,6 @@ typedef struct gc_function_map {
     void (*undefine_finalizer)(void *objspace_ptr, VALUE obj);
     void (*copy_finalizer)(void *objspace_ptr, VALUE dest, VALUE obj);
     void (*shutdown_call_finalizer)(void *objspace_ptr);
-    // Object ID
-    VALUE (*object_id)(void *objspace_ptr, VALUE obj);
-    VALUE (*object_id_to_ref)(void *objspace_ptr, VALUE object_id);
     // Forking
     void (*before_fork)(void *objspace_ptr);
     void (*after_fork)(void *objspace_ptr, rb_pid_t pid);
@@ -1892,16 +1889,35 @@ class_object_id(VALUE klass)
     return id;
 }
 
+static inline VALUE
+object_id_get(VALUE obj, shape_id_t shape_id)
+{
+    VALUE id;
+    if (rb_shape_too_complex_p(shape_id)) {
+        id = rb_obj_field_get(obj, ROOT_TOO_COMPLEX_WITH_OBJ_ID);
+    }
+    else {
+        id = rb_obj_field_get(obj, rb_shape_object_id(shape_id));
+    }
+
+#if RUBY_DEBUG
+    if (!(FIXNUM_P(id) || RB_TYPE_P(id, T_BIGNUM))) {
+        rb_p(obj);
+        rb_bug("Object's shape includes object_id, but it's missing %s", rb_obj_info(obj));
+    }
+#endif
+
+    return id;
+}
+
 static VALUE
 object_id0(VALUE obj)
 {
     VALUE id = Qfalse;
+    shape_id_t shape_id = RBASIC_SHAPE_ID(obj);
 
-    if (rb_shape_has_object_id(RBASIC_SHAPE_ID(obj))) {
-        shape_id_t object_id_shape_id = rb_shape_transition_object_id(obj);
-        id = rb_obj_field_get(obj, object_id_shape_id);
-        RUBY_ASSERT(id, "object_id missing");
-        return id;
+    if (rb_shape_has_object_id(shape_id)) {
+        return object_id_get(obj, shape_id);
     }
 
     // rb_shape_object_id_shape may lock if the current shape has
@@ -1910,6 +1926,10 @@ object_id0(VALUE obj)
 
     id = generate_next_object_id();
     rb_obj_field_set(obj, object_id_shape_id, id);
+
+    RUBY_ASSERT(RBASIC_SHAPE_ID(obj) == object_id_shape_id);
+    RUBY_ASSERT(rb_shape_obj_has_id(obj));
+
     if (RB_UNLIKELY(id2ref_tbl)) {
         st_insert(id2ref_tbl, (st_data_t)id, (st_data_t)obj);
     }
@@ -2016,30 +2036,47 @@ obj_free_object_id(VALUE obj)
         return;
     }
 
+#if RUBY_DEBUG
+    switch (BUILTIN_TYPE(obj)) {
+      case T_CLASS:
+      case T_MODULE:
+        break;
+      default:
+        if (rb_shape_obj_has_id(obj)) {
+            VALUE id = object_id_get(obj, RBASIC_SHAPE_ID(obj)); // Crash if missing
+            if (!(FIXNUM_P(id) || RB_TYPE_P(id, T_BIGNUM))) {
+                rb_p(obj);
+                rb_bug("Corrupted object_id");
+            }
+        }
+        break;
+    }
+#endif
+
     VALUE obj_id = 0;
     if (RB_UNLIKELY(id2ref_tbl)) {
         switch (BUILTIN_TYPE(obj)) {
           case T_CLASS:
           case T_MODULE:
-            if (RCLASS(obj)->object_id) {
-                obj_id = RCLASS(obj)->object_id;
-            }
+            obj_id = RCLASS(obj)->object_id;
             break;
-          default:
-            if (rb_shape_obj_has_id(obj)) {
-                obj_id = object_id(obj);
+          default: {
+            shape_id_t shape_id = RBASIC_SHAPE_ID(obj);
+            if (rb_shape_has_object_id(shape_id)) {
+                obj_id = object_id_get(obj, shape_id);
             }
             break;
+          }
         }
-    }
 
-    if (RB_UNLIKELY(obj_id)) {
-        RUBY_ASSERT(FIXNUM_P(obj_id) || RB_TYPE_P(obj, T_BIGNUM));
+        if (RB_UNLIKELY(obj_id)) {
+            RUBY_ASSERT(FIXNUM_P(obj_id) || RB_TYPE_P(obj_id, T_BIGNUM));
 
-        if (!st_delete(id2ref_tbl, (st_data_t *)&obj_id, NULL)) {
-            // If we're currently building the table then it's not a bug
-            if (id2ref_tbl_built) {
-                rb_bug("Object ID seen, but not in _id2ref table: object_id=%llu object=%s", NUM2ULL(obj_id), rb_obj_info(obj));
+            if (!st_delete(id2ref_tbl, (st_data_t *)&obj_id, NULL)) {
+                // If we're currently building the table then it's not a bug
+                if (id2ref_tbl_built) {
+                    rb_bug("Object ID seen, but not in _id2ref table: object_id=%llu object=%s", NUM2ULL(obj_id), rb_obj_info(obj));
+                }
             }
         }
     }
diff --git a/shape.c b/shape.c
index 9bbc82428b..766b6bfb23 100644
--- a/shape.c
+++ b/shape.c
@@ -424,12 +424,6 @@ rb_shape_depth(shape_id_t shape_id)
     return depth;
 }
 
-static inline rb_shape_t *
-obj_shape(VALUE obj)
-{
-    return RSHAPE(rb_obj_shape_id(obj));
-}
-
 static rb_shape_t *
 shape_alloc(void)
 {
@@ -461,7 +455,6 @@ rb_shape_alloc(ID edge_name, rb_shape_t *parent, enum shape_type type)
 {
     rb_shape_t *shape = rb_shape_alloc_with_parent_id(edge_name, raw_shape_id(parent));
     shape->type = (uint8_t)type;
-    shape->flags = parent->flags;
     shape->heap_index = parent->heap_index;
     shape->capacity = parent->capacity;
     shape->edges = 0;
@@ -510,8 +503,6 @@ rb_shape_alloc_new_child(ID id, rb_shape_t *shape, enum shape_type shape_type)
 
     switch (shape_type) {
       case SHAPE_OBJ_ID:
-        new_shape->flags |= SHAPE_FL_HAS_OBJECT_ID;
-        // fallthrough
       case SHAPE_IVAR:
         if (UNLIKELY(shape->next_field_index >= shape->capacity)) {
             RUBY_ASSERT(shape->next_field_index == shape->capacity);
@@ -711,6 +702,16 @@ remove_shape_recursive(rb_shape_t *shape, ID id, rb_shape_t **removed_shape)
     }
 }
 
+static inline shape_id_t
+transition_frozen(shape_id_t shape_id)
+{
+    if (rb_shape_has_object_id(shape_id)) {
+        return ROOT_TOO_COMPLEX_WITH_OBJ_ID | (shape_id & SHAPE_ID_FLAGS_MASK);
+    }
+    return ROOT_TOO_COMPLEX_SHAPE_ID | (shape_id & SHAPE_ID_FLAGS_MASK);
+}
+
+
 shape_id_t
 rb_shape_transition_remove_ivar(VALUE obj, ID id, shape_id_t *removed_shape_id)
 {
@@ -732,7 +733,7 @@ rb_shape_transition_remove_ivar(VALUE obj, ID id, shape_id_t *removed_shape_id)
     else if (removed_shape) {
         // We found the shape to remove, but couldn't create a new variation.
         // We must transition to TOO_COMPLEX.
-        return ROOT_TOO_COMPLEX_SHAPE_ID | (original_shape_id & SHAPE_ID_FLAGS_MASK);
+        return transition_frozen(original_shape_id);
     }
     return original_shape_id;
 }
@@ -749,41 +750,42 @@ rb_shape_transition_frozen(VALUE obj)
 shape_id_t
 rb_shape_transition_complex(VALUE obj)
 {
-    shape_id_t original_shape_id = RBASIC_SHAPE_ID(obj);
-    return ROOT_TOO_COMPLEX_SHAPE_ID | (original_shape_id & SHAPE_ID_FLAGS_MASK);
+    return transition_frozen(RBASIC_SHAPE_ID(obj));
 }
 
-static inline bool
-shape_has_object_id(rb_shape_t *shape)
+shape_id_t
+rb_shape_transition_object_id(VALUE obj)
 {
-    return shape->flags & SHAPE_FL_HAS_OBJECT_ID;
-}
+    shape_id_t original_shape_id = RBASIC_SHAPE_ID(obj);
 
-bool
-rb_shape_has_object_id(shape_id_t shape_id)
-{
-    return shape_has_object_id(RSHAPE(shape_id));
+    RUBY_ASSERT(!rb_shape_has_object_id(original_shape_id));
+
+    rb_shape_t *shape = NULL;
+    if (!rb_shape_too_complex_p(original_shape_id)) {
+        bool dont_care;
+        shape = get_next_shape_internal(RSHAPE(original_shape_id), ruby_internal_object_id, SHAPE_OBJ_ID, &dont_care, true);
+    }
+
+    if (!shape) {
+        shape = RSHAPE(ROOT_TOO_COMPLEX_WITH_OBJ_ID);
+    }
+    return shape_id(shape, original_shape_id) | SHAPE_ID_FL_HAS_OBJECT_ID;
 }
 
 shape_id_t
-rb_shape_transition_object_id(VALUE obj)
+rb_shape_object_id(shape_id_t original_shape_id)
 {
-    shape_id_t original_shape_id = RBASIC_SHAPE_ID(obj);
-
-    rb_shape_t* shape = RSHAPE(original_shape_id);
-    RUBY_ASSERT(shape);
+    RUBY_ASSERT(rb_shape_has_object_id(original_shape_id));
 
-    if (shape->flags & SHAPE_FL_HAS_OBJECT_ID) {
-        while (shape->type != SHAPE_OBJ_ID) {
-            shape = RSHAPE(shape->parent_id);
+    rb_shape_t *shape = RSHAPE(original_shape_id);
+    while (shape->type != SHAPE_OBJ_ID) {
+        if (UNLIKELY(shape->parent_id == INVALID_SHAPE_ID)) {
+            rb_bug("Missing object_id in shape tree");
         }
+        shape = RSHAPE(shape->parent_id);
     }
-    else {
-        bool dont_care;
-        shape = get_next_shape_internal(shape, ruby_internal_object_id, SHAPE_OBJ_ID, &dont_care, true);
-    }
-    RUBY_ASSERT(shape);
-    return shape_id(shape, original_shape_id);
+
+    return shape_id(shape, original_shape_id) | SHAPE_ID_FL_HAS_OBJECT_ID;
 }
 
 /*
@@ -892,17 +894,19 @@ shape_get_next(rb_shape_t *shape, VALUE obj, ID id, bool emit_warnings)
 shape_id_t
 rb_shape_transition_add_ivar(VALUE obj, ID id)
 {
-    RUBY_ASSERT(!shape_frozen_p(RBASIC_SHAPE_ID(obj)));
+    shape_id_t original_shape_id = RBASIC_SHAPE_ID(obj);
+    RUBY_ASSERT(!shape_frozen_p(original_shape_id));
 
-    return raw_shape_id(shape_get_next(obj_shape(obj), obj, id, true));
+    return shape_id(shape_get_next(RSHAPE(original_shape_id), obj, id, true), original_shape_id);
 }
 
 shape_id_t
 rb_shape_transition_add_ivar_no_warnings(VALUE obj, ID id)
 {
-    RUBY_ASSERT(!shape_frozen_p(RBASIC_SHAPE_ID(obj)));
+    shape_id_t original_shape_id = RBASIC_SHAPE_ID(obj);
+    RUBY_ASSERT(!shape_frozen_p(original_shape_id));
 
-    return raw_shape_id(shape_get_next(obj_shape(obj), obj, id, false));
+    return shape_id(shape_get_next(RSHAPE(original_shape_id), obj, id, false), original_shape_id);
 }
 
 // Same as rb_shape_get_iv_index, but uses a provided valid shape id and index
@@ -1180,7 +1184,40 @@ rb_shape_memsize(shape_id_t shape_id)
     return memsize;
 }
 
+#if RUBY_DEBUG
+bool
+rb_shape_verify_consistency(VALUE obj, shape_id_t shape_id)
+{
+    rb_shape_t *shape = RSHAPE(shape_id);
+
+    bool has_object_id = false;
+    while (shape->parent_id != INVALID_SHAPE_ID) {
+        if (shape->type == SHAPE_OBJ_ID) {
+            has_object_id = true;
+            break;
+        }
+        shape = RSHAPE(shape->parent_id);
+    }
+
+    if (rb_shape_has_object_id(shape_id)) {
+        if (!has_object_id) {
+            rb_p(obj);
+            rb_bug("shape_id claim having obj_id but doesn't shape_id=%u, obj=%s", shape_id, rb_obj_info(obj));
+        }
+    }
+    else {
+        if (has_object_id) {
+            rb_p(obj);
+            rb_bug("shape_id claim not having obj_id but it does shape_id=%u, obj=%s", shape_id, rb_obj_info(obj));
+        }
+    }
+
+    return true;
+}
+#endif
+
 #if SHAPE_DEBUG
+
 /*
  * Exposing Shape to Ruby via RubyVM.debug_shape
  */
@@ -1203,8 +1240,7 @@ static VALUE
 shape_has_object_id_p(VALUE self)
 {
     shape_id_t shape_id = NUM2INT(rb_struct_getmember(self, rb_intern("id")));
-    rb_shape_t *shape = RSHAPE(shape_id);
-    return RBOOL(shape_has_object_id(shape));
+    return RBOOL(rb_shape_has_object_id(shape_id));
 }
 
 static VALUE
@@ -1441,6 +1477,13 @@ Init_default_shapes(void)
     GET_SHAPE_TREE()->root_shape = root;
     RUBY_ASSERT(raw_shape_id(GET_SHAPE_TREE()->root_shape) == ROOT_SHAPE_ID);
 
+    rb_shape_t *root_with_obj_id = rb_shape_alloc_with_parent_id(0, ROOT_SHAPE_ID);
+    root_with_obj_id->type = SHAPE_OBJ_ID;
+    root_with_obj_id->edge_name = ruby_internal_object_id;
+    root_with_obj_id->next_field_index++;
+    root_with_obj_id->heap_index = 0;
+    RUBY_ASSERT(raw_shape_id(root_with_obj_id) == ROOT_SHAPE_WITH_OBJ_ID);
+
     // Make shapes for T_OBJECT
     size_t *sizes = rb_gc_heap_sizes();
     for (int i = 0; sizes[i] > 0; i++) {
@@ -1489,7 +1532,6 @@ Init_shape(void)
     rb_define_const(rb_cShape, "SHAPE_ID_NUM_BITS", INT2NUM(SHAPE_ID_NUM_BITS));
     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, "ROOT_TOO_COMPLEX_SHAPE_ID", INT2NUM(ROOT_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)));
diff --git a/shape.h b/shape.h
index 4fe84aa6a7..0c8bfbcc28 100644
--- a/shape.h
+++ b/shape.h
@@ -14,7 +14,9 @@ STATIC_ASSERT(shape_id_num_bits, SHAPE_ID_NUM_BITS == sizeof(shape_id_t) * CHAR_
 #define SHAPE_ID_OFFSET_MASK (SHAPE_BUFFER_SIZE - 1)
 #define SHAPE_ID_FLAGS_MASK (shape_id_t)(((1 << (SHAPE_ID_NUM_BITS - SHAPE_ID_OFFSET_NUM_BITS)) - 1) << SHAPE_ID_OFFSET_NUM_BITS)
 #define SHAPE_ID_FL_FROZEN (SHAPE_FL_FROZEN << SHAPE_ID_OFFSET_NUM_BITS)
+#define SHAPE_ID_FL_HAS_OBJECT_ID (SHAPE_FL_HAS_OBJECT_ID << SHAPE_ID_OFFSET_NUM_BITS)
 #define SHAPE_ID_FL_TOO_COMPLEX (SHAPE_FL_TOO_COMPLEX << SHAPE_ID_OFFSET_NUM_BITS)
+#define SHAPE_ID_FL_NON_CANONICAL_MASK (SHAPE_FL_NON_CANONICAL_MASK << SHAPE_ID_OFFSET_NUM_BITS)
 #define SHAPE_ID_READ_ONLY_MASK (~SHAPE_ID_FL_FROZEN)
 
 typedef uint32_t redblack_id_t;
@@ -28,10 +30,12 @@ typedef uint32_t redblack_id_t;
 #define INVALID_SHAPE_ID ((shape_id_t)-1)
 #define ATTR_INDEX_NOT_SET ((attr_index_t)-1)
 
-#define ROOT_SHAPE_ID               0x0
-#define ROOT_TOO_COMPLEX_SHAPE_ID   (ROOT_SHAPE_ID | SHAPE_ID_FL_TOO_COMPLEX)
-#define SPECIAL_CONST_SHAPE_ID      (ROOT_SHAPE_ID | SHAPE_ID_FL_FROZEN)
-#define FIRST_T_OBJECT_SHAPE_ID     0x1
+#define ROOT_SHAPE_ID                   0x0
+#define ROOT_SHAPE_WITH_OBJ_ID          0x1
+#define ROOT_TOO_COMPLEX_SHAPE_ID       (ROOT_SHAPE_ID | SHAPE_ID_FL_TOO_COMPLEX)
+#define ROOT_TOO_COMPLEX_WITH_OBJ_ID    (ROOT_SHAPE_WITH_OBJ_ID | SHAPE_ID_FL_TOO_COMPLEX | SHAPE_ID_FL_HAS_OBJECT_ID)
+#define SPECIAL_CONST_SHAPE_ID          (ROOT_SHAPE_ID | SHAPE_ID_FL_FROZEN)
+#define FIRST_T_OBJECT_SHAPE_ID         0x2
 
 extern ID ruby_internal_object_id;
 
@@ -46,7 +50,6 @@ struct rb_shape {
     attr_index_t capacity; // Total capacity of the object with this shape
     uint8_t type;
     uint8_t heap_index;
-    uint8_t flags;
 };
 
 typedef struct rb_shape rb_shape_t;
@@ -119,11 +122,16 @@ RBASIC_SHAPE_ID_FOR_READ(VALUE obj)
     return RBASIC_SHAPE_ID(obj) & SHAPE_ID_READ_ONLY_MASK;
 }
 
+#if RUBY_DEBUG
+bool rb_shape_verify_consistency(VALUE obj, shape_id_t shape_id);
+#endif
+
 static inline void
 RBASIC_SET_SHAPE_ID(VALUE obj, shape_id_t shape_id)
 {
     RUBY_ASSERT(!RB_SPECIAL_CONST_P(obj));
     RUBY_ASSERT(!RB_TYPE_P(obj, T_IMEMO));
+    RUBY_ASSERT(rb_shape_verify_consistency(obj, shape_id));
 #if RBASIC_SHAPE_ID_FIELD
     RBASIC(obj)->shape_id = (VALUE)shape_id;
 #else
@@ -142,7 +150,6 @@ RUBY_FUNC_EXPORTED shape_id_t rb_obj_shape_id(VALUE obj);
 shape_id_t rb_shape_get_next_iv_shape(shape_id_t shape_id, ID id);
 bool rb_shape_get_iv_index(shape_id_t shape_id, ID id, attr_index_t *value);
 bool rb_shape_get_iv_index_with_hint(shape_id_t shape_id, ID id, attr_index_t *value, shape_id_t *shape_id_hint);
-bool rb_shape_has_object_id(shape_id_t shape_id);
 
 shape_id_t rb_shape_transition_frozen(VALUE obj);
 shape_id_t rb_shape_transition_complex(VALUE obj);
@@ -150,6 +157,7 @@ shape_id_t rb_shape_transition_remove_ivar(VALUE obj, ID id, shape_id_t *removed
 shape_id_t rb_shape_transition_add_ivar(VALUE obj, ID id);
 shape_id_t rb_shape_transition_add_ivar_no_warnings(VALUE obj, ID id);
 shape_id_t rb_shape_transition_object_id(VALUE obj);
+shape_id_t rb_shape_object_id(shape_id_t original_shape_id);
 
 void rb_shape_free_all(void);
 
@@ -170,9 +178,15 @@ rb_shape_obj_too_complex_p(VALUE obj)
 }
 
 static inline bool
+rb_shape_has_object_id(shape_id_t shape_id)
+{
+    return shape_id & SHAPE_ID_FL_HAS_OBJECT_ID;
+}
+
+static inline bool
 rb_shape_canonical_p(shape_id_t shape_id)
 {
-    return !(shape_id & SHAPE_ID_FLAGS_MASK) && !RSHAPE(shape_id)->flags;
+    return !(shape_id & SHAPE_ID_FL_NON_CANONICAL_MASK);
 }
 
 static inline shape_id_t
diff --git a/test/ruby/test_shapes.rb b/test/ruby/test_shapes.rb
index a3b952da1c..25fb6f3bf7 100644
--- a/test/ruby/test_shapes.rb
+++ b/test/ruby/test_shapes.rb
@@ -651,6 +651,22 @@ class TestShapes < Test::Unit::TestCase
     end;
   end
 
+  def test_object_id_transition_too_complex
+    assert_separately([], "#{<<~"begin;"}\n#{<<~'end;'}")
+    begin;
+      class Hi; end
+      obj = Hi.new
+      obj.instance_variable_set(:@a, 1)
+      obj.instance_variable_set(:@b, 2)
+      old_id = obj.object_id
+
+      RubyVM::Shape.exhaust_shapes
+      obj.remove_instance_variable(:@a)
+
+      assert_equal old_id, obj.object_id
+    end;
+  end
+
   def test_too_complex_and_frozen_and_object_id
     assert_separately([], "#{<<~"begin;"}\n#{<<~'end;'}")
     begin;
@@ -676,7 +692,7 @@ class TestShapes < Test::Unit::TestCase
       assert_predicate frozen_shape, :shape_frozen?
       refute_predicate frozen_shape, :has_object_id?
 
-      tc.object_id
+      assert_equal tc.object_id, tc.object_id
 
       id_shape = RubyVM::Shape.of(tc)
       refute_equal frozen_shape.id, id_shape.id
diff --git a/variable.c b/variable.c
index 7c7f793073..288692ed4d 100644
--- a/variable.c
+++ b/variable.c
@@ -1343,6 +1343,13 @@ rb_obj_field_get(VALUE obj, shape_id_t target_shape_id)
         }
         VALUE value = Qundef;
         st_lookup(fields_hash, RSHAPE(target_shape_id)->edge_name, &value);
+
+#if RUBY_DEBUG
+        if (UNDEF_P(value)) {
+            rb_bug("Object's shape includes object_id, but it's missing %s", rb_obj_info(obj));
+        }
+#endif
+
         RUBY_ASSERT(!UNDEF_P(value));
         return value;
     }
@@ -1617,13 +1624,13 @@ obj_transition_too_complex(VALUE obj, st_table *table)
         if (!(RBASIC(obj)->flags & ROBJECT_EMBED)) {
             old_fields = ROBJECT_FIELDS(obj);
         }
-        rb_obj_set_shape_id(obj, shape_id);
+        RBASIC_SET_SHAPE_ID(obj, shape_id);
         ROBJECT_SET_FIELDS_HASH(obj, table);
         break;
       case T_CLASS:
       case T_MODULE:
         old_fields = RCLASS_PRIME_FIELDS(obj);
-        rb_obj_set_shape_id(obj, shape_id);
+        RBASIC_SET_SHAPE_ID(obj, shape_id);
         RCLASS_SET_FIELDS_HASH(obj, table);
         break;
       default:
@@ -1647,7 +1654,7 @@ obj_transition_too_complex(VALUE obj, st_table *table)
             fields_tbl->as.complex.table = table;
             st_insert(gen_ivs, (st_data_t)obj, (st_data_t)fields_tbl);
 
-            rb_obj_set_shape_id(obj, shape_id);
+            RBASIC_SET_SHAPE_ID(obj, shape_id);
         }
     }
 
@@ -1776,8 +1783,9 @@ general_field_set(VALUE obj, shape_id_t target_shape_id, VALUE val, void *data,
         }
 
         st_table *table = too_complex_table_func(obj, data);
+
         if (RSHAPE_LEN(target_shape_id) > RSHAPE_LEN(current_shape_id)) {
-            set_shape_id_func(obj, target_shape_id, data);
+            RBASIC_SET_SHAPE_ID(obj, target_shape_id);
         }
 
         st_insert(table, (st_data_t)RSHAPE_EDGE_NAME(target_shape_id), (st_data_t)val);
diff --git a/yjit/src/cruby_bindings.inc.rs b/yjit/src/cruby_bindings.inc.rs
index 15b6a1d765..558d675e5d 100644
--- a/yjit/src/cruby_bindings.inc.rs
+++ b/yjit/src/cruby_bindings.inc.rs
@@ -699,7 +699,6 @@ pub struct rb_shape {
     pub capacity: attr_index_t,
     pub type_: u8,
     pub heap_index: u8,
-    pub flags: u8,
 }
 pub type rb_shape_t = rb_shape;
 #[repr(C)]
diff --git a/zjit/src/cruby_bindings.inc.rs b/zjit/src/cruby_bindings.inc.rs
index a5569a3db0..8b73194509 100644
--- a/zjit/src/cruby_bindings.inc.rs
+++ b/zjit/src/cruby_bindings.inc.rs
@@ -407,7 +407,6 @@ pub struct rb_shape {
     pub capacity: attr_index_t,
     pub type_: u8,
     pub heap_index: u8,
-    pub flags: u8,
 }
 pub type rb_shape_t = rb_shape;
 #[repr(C)]