From e75abd343896967c1d26615c874331521bbe7e5a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Steinbrink?= <bsteinbr@gmail.com>
Date: Sat, 22 Aug 2015 17:07:37 +0200
Subject: [PATCH] Don't emit memcpy's for zero-sized types

---
 src/librustc_trans/trans/base.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/librustc_trans/trans/base.rs b/src/librustc_trans/trans/base.rs
index 6be2bb08464..78bbe0d4ebc 100644
--- a/src/librustc_trans/trans/base.rs
+++ b/src/librustc_trans/trans/base.rs
@@ -956,6 +956,11 @@ pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                              t: Ty<'tcx>) {
     let _icx = push_ctxt("memcpy_ty");
     let ccx = bcx.ccx();
+
+    if type_is_zero_size(ccx, t) {
+        return;
+    }
+
     if t.is_structural() {
         let llty = type_of::type_of(ccx, t);
         let llsz = llsize_of(ccx, llty);