From d3074235e24383e4ea4d80c13c3e74d6bda00b50 Mon Sep 17 00:00:00 2001
From: jsg <jsg@openbsd.org>
Date: Sat, 7 Dec 2019 03:09:41 +0000
Subject: [PATCH] build Mesa with _ISOC11_SOURCE for c11 visibility

autoconf function tests run without --std and have c11 visibility
timespec_get(3), a c11 function is found this way.

With gcc < 4.6 Mesa will build with --std=gnu99 with clang it will
build with --std=c99 and timespec_get() will no longer be visibile.
Further complicating things gcc 4.2 does not recognise --std=c11.

This was not noticed on linux as they build with _GNU_SOURCE which
among other things gives c11 visibility even with --std=c99.

discussed with millert@
---
 lib/mesa/configure.ac | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/mesa/configure.ac b/lib/mesa/configure.ac
index bb94f9da4..8e9f068cc 100644
--- a/lib/mesa/configure.ac
+++ b/lib/mesa/configure.ac
@@ -315,6 +315,9 @@ linux*|*-gnu*|gnu*|cygwin*)
 solaris*)
     DEFINES="$DEFINES -DSVR4"
     ;;
+openbsd*)
+    DEFINES="$DEFINES -D_ISOC11_SOURCE"
+    ;;
 esac
 
 AM_CONDITIONAL(HAVE_ANDROID, test "x$android" = xyes)