Add ST table to gen_ivtbl for complex shapes

On 32-bit systems, we must store the shape ID in the gen_ivtbl to not
lose the shape. If we directly store the ST table into the generic
ivar table, then we lose the shape. This makes it impossible to
determine the shape of the object and whether it is too complex or not.

1 files changed, 9 insertions, 2 deletions

diff --git a/variable.h b/variable.h
index 5c0366de32..12ada66108 100644
--- a/variable.h
+++ b/variable.h
@@ -16,8 +16,15 @@ struct gen_ivtbl {
 #if !SHAPE_IN_BASIC_FLAGS
     uint16_t shape_id;
 #endif
-    uint32_t numiv;
-    VALUE ivptr[FLEX_ARY_LEN];
+    union {
+        struct {
+            uint32_t numiv;
+            VALUE ivptr[1];
+        } shape;
+        struct {
+            st_table *table;
+        } complex;
+    } as;
 };
 
 int rb_ivar_generic_ivtbl_lookup(VALUE obj, struct gen_ivtbl **);