From f8ddcecbdf34b8d33ed4311b34d498d4ff380a3e Mon Sep 17 00:00:00 2001
From: Peter Zhu <peter@peterzhu.ca>
Date: Tue, 12 Dec 2023 10:45:59 -0500
Subject: [PATCH] [Bug #20061] Clear mark bits when rb_free_on_exit

When compiling with cppflags=-DRGENGC_CHECK_MODE, the following crashes:

```
$ RUBY_FREE_ON_EXIT=1 ./miniruby -e 0
-e: [BUG] obj_free: RVALUE_MARKED(0x0000000103570020 [3LM    ] T_CLASS (anon)) != FALSE
```

This commit clears the mark bits when rb_free_on_exit is enabled.
---
 gc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/gc.c b/gc.c
index a8a55377d8b445..59c9162a8947ec 100644
--- a/gc.c
+++ b/gc.c
@@ -4651,6 +4651,14 @@ rb_objspace_call_finalizer(rb_objspace_t *objspace)
     /* Abort incremental marking and lazy sweeping to speed up shutdown. */
     gc_abort(objspace);
 
+    if (rb_free_on_exit) {
+        for (int i = 0; i < SIZE_POOL_COUNT; i++) {
+            rb_size_pool_t *size_pool = &size_pools[i];
+            rb_heap_t *heap = SIZE_POOL_EDEN_HEAP(size_pool);
+            rgengc_mark_and_rememberset_clear(objspace, heap);
+        }
+    }
+
     /* prohibit GC because force T_DATA finalizers can break an object graph consistency */
     dont_gc_on();