From 545101040df050dcc412d714640c95f417194600 Mon Sep 17 00:00:00 2001
From: hyd-dev <yd-huang@outlook.com>
Date: Thu, 3 Jun 2021 21:26:11 +0800
Subject: [PATCH] Don't `unwrap()` in `in_std()`

---
 src/helpers.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/helpers.rs b/src/helpers.rs
index 7f99aa19970..a9cafd2a9e3 100644
--- a/src/helpers.rs
+++ b/src/helpers.rs
@@ -631,8 +631,10 @@ fn check_abi<'a>(&self, abi: Abi, exp_abi: Abi) -> InterpResult<'a, ()> {
 
     fn in_std(&self) -> bool {
         let this = self.eval_context_ref();
-        this.tcx.def_path(this.frame().instance.def_id()).krate
-            == this.tcx.def_path(this.tcx.lang_items().start_fn().unwrap()).krate
+        this.tcx.lang_items().start_fn().map_or(false, |start_fn| {
+            this.tcx.def_path(this.frame().instance.def_id()).krate
+                == this.tcx.def_path(start_fn).krate
+        })
     }
 }