autotools: error out when building with mangling and glvnd

It's not a thing that can work, nor is a wise idea to attempt.

v2: Tweak error message (Dylan)

CC: <mesa-stable@lists.freedesktop.org>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Adam Jackson <ajax@redhat.com> (v1)

diff --git a/configure.ac b/configure.ac
index 6b1b8aca753f662f983387d07e0290acde7407f5..e2c48a455c26cf153fe1a20c73d22a990f22cdde 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1524,6 +1524,9 @@ AC_ARG_ENABLE([mangling],
   [enable_mangling=no]
 )
 if test "x${enable_mangling}" = "xyes" ; then
+  if test "x$enable_libglvnd" = xyes; then
+    AC_MSG_ERROR([Conflicting options --enable-mangling and --enable-libglvnd.])
+  fi
   DEFINES="${DEFINES} -DUSE_MGL_NAMESPACE"
   GL_LIB="Mangled${GL_LIB}"
   OSMESA_LIB="Mangled${OSMESA_LIB}"