check cc flags viability before setting them
diff --git a/configure.ac b/configure.ac
index ec0ab34..e04f3a3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -28,31 +28,26 @@
[ --enable-Werror abort compilation after any C compiler warning],
enable_werror=$enableval, enable_werror=no)
if test x$enable_werror = xyes; then
- ADD_CFLAGS="-Werror -W -Wpointer-arith"
+ TESTSUITE_CFLAGS="-Werror -W -Wpointer-arith"
fi
-AC_SUBST(ADD_CFLAGS)
+AC_SUBST(TESTSUITE_CFLAGS)
-dnl Add these flags if we're using GCC.
-case "$GCC$enable_werror" in
- yesno)
- CFLAGS="$CFLAGS -Wall" # Enable only if not going to fail with -Werror
- ;;
-esac
-case "$GCC" in
- yes)
- CFLAGS="$CFLAGS -Wall"
- CFLAGS="$CFLAGS -Wshadow"
- CFLAGS="$CFLAGS -Wcast-qual"
- CFLAGS="$CFLAGS -Wchar-subscripts"
- CFLAGS="$CFLAGS -Wmissing-prototypes"
- CFLAGS="$CFLAGS -Wmissing-declarations"
- # There are legitimate uses for these features
- CFLAGS="$CFLAGS -Wno-error=cast-align"
- CFLAGS="$CFLAGS -Wno-error=visibility"
- CFLAGS="$CFLAGS -Wno-error=parentheses-equality"
- ;;
-esac
+AX_CHECK_COMPILE_FLAG([-Wall], [CFLAGS="$CFLAGS -Wall"])
+AX_CHECK_COMPILE_FLAG([-Wcast-qual], [CFLAGS="$CFLAGS -Wcast-qual"])
+AX_CHECK_COMPILE_FLAG([-Wchar-subscripts],
+ [CFLAGS="$CFLAGS -Wchar-subscripts"])
+AX_CHECK_COMPILE_FLAG([-Wmissing-prototypes],
+ [CFLAGS="$CFLAGS -Wmissing-prototypes"])
+AX_CHECK_COMPILE_FLAG([-Wmissing-declarations],
+ [CFLAGS="$CFLAGS -Wmissing-declarations"])
+dnl There are legitimate uses for these features, disable warnings/errors.
+AX_CHECK_COMPILE_FLAG([-Wno-error=cast-align],
+ [CFLAGS="$CFLAGS -Wno-error=cast-align"])
+AX_CHECK_COMPILE_FLAG([-Wno-error=visibility],
+ [CFLAGS="$CFLAGS -Wno-error=visibility"])
+AX_CHECK_COMPILE_FLAG([-Wno-error=parentheses-equality],
+ [CFLAGS="$CFLAGS -Wno-error=parentheses-equality"])
dnl Checks for header files.
AC_HEADER_STDC