From 1f4204a762b2ddcc2f235b1a2b6a10071ef90d3b Mon Sep 17 00:00:00 2001
From: "Urabe, Shyouhei" <shyouhei@ruby-lang.org>
Date: Tue, 23 Apr 2019 17:55:15 +0900
Subject: [PATCH] disable assertion when MSAN is active

These assertions check if a newly allocated object (which is marked
as an uninitialized memory region in MSAN) is in fact a T_NONE.

Thus they intentionally read uninitialized memory regions, which do
not interface well with MSAN.  Just disalbe them.
---
 gc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gc.c b/gc.c
index 82199bb47e..b4ad456b41 100644
--- a/gc.c
+++ b/gc.c
@@ -1891,8 +1891,10 @@ gc_event_hook_body(rb_execution_context_t *ec, rb_objspace_t *objspace, const rb
 static inline VALUE
 newobj_init(VALUE klass, VALUE flags, VALUE v1, VALUE v2, VALUE v3, int wb_protected, rb_objspace_t *objspace, VALUE obj)
 {
+#if !__has_feature(memory_sanitizer)
     assert(BUILTIN_TYPE(obj) == T_NONE);
     assert((flags & FL_WB_PROTECTED) == 0);
+#endif
 
     /* OBJSETUP */
     RBASIC(obj)->flags = flags;