From a8d5a4f2f40f8dd269d867f6739cb1a9cdf67914 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Tue, 27 Aug 2019 05:56:52 -0600
Subject: [PATCH] avoid unneed preprocessor redefinition

Limit a Mac-specific declaration that isn't needed anyway.

Related to #2797
---
 racket/src/racket/src/unwind/libunwind.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/racket/src/racket/src/unwind/libunwind.h b/racket/src/racket/src/unwind/libunwind.h
index 735f78307d..6932bf7932 100644
--- a/racket/src/racket/src/unwind/libunwind.h
+++ b/racket/src/racket/src/unwind/libunwind.h
@@ -57,7 +57,9 @@ extern "C" {
 
 #include <inttypes.h>
 #ifndef UNW_ARM
-# define _XOPEN_SOURCE /* needed for Mac OS X */
+# ifdef __APPLE__
+#  define _XOPEN_SOURCE
+# endif
 # define __USE_GNU
 # include <ucontext.h>
 # undef __USE_GNU