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 59a111ae01ea55403962b9d5c7d93724eebb2567..b6f2d4595ef6a0055528248793a02f83f983d60d 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -309,11 +309,11 @@ AC_LANG_POP([C++])
 # - 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])