configure.ac: append to existing MSVC compat flags
Currently we were overwriting the existing warning flags, instead of
adding new [as applicable].
v2: Add missing space before -Werror (Eric)
Fixes e4b2b69e828 ("configure: Add and use AX_CHECK_COMPILE_FLAG")
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Matt Turner <mattst88@gmail.com> (v1)
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
diff --git a/configure.ac b/configure.ac
index 59a111a..b6f2d45 100644
--- a/configure.ac
+++ b/configure.ac
@@ -309,11 +309,11 @@
# - non-Linux/Posix OpenGL portions needs to build on MSVC 2013 (which
# supports most of C99)
# - the rest has no compiler compiler restrictions
-AX_CHECK_COMPILE_FLAG([-Werror=pointer-arith], [MSVC2013_COMPAT_CFLAGS="-Werror=pointer-arith"])
-AX_CHECK_COMPILE_FLAG([-Werror=vla], [MSVC2013_COMPAT_CFLAGS="-Werror=vla"])
+AX_CHECK_COMPILE_FLAG([-Werror=pointer-arith], [MSVC2013_COMPAT_CFLAGS="$MSVC2013_COMPAT_CFLAGS -Werror=pointer-arith"])
+AX_CHECK_COMPILE_FLAG([-Werror=vla], [MSVC2013_COMPAT_CFLAGS="$MSVC2013_COMPAT_CFLAGS -Werror=vla"])
AC_LANG_PUSH([C++])
-AX_CHECK_COMPILE_FLAG([-Werror=pointer-arith], [MSVC2013_COMPAT_CXXFLAGS="-Werror=pointer-arith"])
-AX_CHECK_COMPILE_FLAG([-Werror=vla], [MSVC2013_COMPAT_CXXFLAGS="-Werror=vla"])
+AX_CHECK_COMPILE_FLAG([-Werror=pointer-arith], [MSVC2013_COMPAT_CXXFLAGS="$MSVC2013_COMPAT_CXXFLAGS -Werror=pointer-arith"])
+AX_CHECK_COMPILE_FLAG([-Werror=vla], [MSVC2013_COMPAT_CXXFLAGS="$MSVC2013_COMPAT_CXXFLAGS -Werror=vla"])
AC_LANG_POP([C++])
AC_SUBST([MSVC2013_COMPAT_CFLAGS])