From 3ff1c95208c2a933d193f38cbd75dbc896a6776f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Sun, 20 Mar 2022 10:50:57 +0100
Subject: [PATCH] char32: only include stdc-predef.h if it is available

Use the (relatively new) macro __has_include() to check if
stdc-predef.h exists, and only include it if it does.

If stdc-predef.h does not exist, or if the compiler does not implement
__has_include(), stdc-predef.h is *not* included.
---
 char32.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/char32.c b/char32.c
index 71d2ae5..0ca029a 100644
--- a/char32.c
+++ b/char32.c
@@ -5,7 +5,12 @@
 #include <assert.h>
 
 #include <wchar.h>
-#include <stdc-predef.h>
+
+#if defined __has_include
+ #if __has_include (<stdc-predef.h>)
+   #include <stdc-predef.h>
+ #endif
+#endif
 
 #define LOG_MODULE "char32"
 #define LOG_ENABLE_DBG 0