From 1c22cb5e515548b22ccb260f4451edc119151584 Mon Sep 17 00:00:00 2001
From: Shawn Landden <shawn@git.icu>
Date: Mon, 4 Nov 2019 17:41:45 -0800
Subject: [PATCH] fix noreturn function that may return.

we do not want undefined behavior here in --release-fast
and --release-small modes
---
 lib/std/special/c.zig | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/std/special/c.zig b/lib/std/special/c.zig
index a9fd9857ff..473d2d4e33 100644
--- a/lib/std/special/c.zig
+++ b/lib/std/special/c.zig
@@ -82,9 +82,11 @@ pub fn panic(msg: []const u8, error_return_trace: ?*builtin.StackTrace) noreturn
     if (builtin.is_test) {
         @setCold(true);
         std.debug.panic("{}", msg);
-    } else {
-        unreachable;
     }
+    if (builtin.os != .freestanding) {
+        std.os.abort();
+    }
+    while (true) {}
 }
 
 export fn memset(dest: ?[*]u8, c: u8, n: usize) ?[*]u8 {