On RHEL 6.2, gcc 4.4.6 complains: cc1: warning: command line option "-Wenum-compare" is valid for C++/ObjC++ but not for C which in turn breaks a -Werror build. Meanwhile, in Fedora 17, gcc 4.7.0, -Wenum-compare has been enhanced to also work on C, but at the same time, it is documented that -Wall now implicitly includes -Wenum-compare. Therefore, it is sufficient to remove explicit checks for this option, avoiding the warning from older gcc while still getting the compile-time safety from newer gcc. * m4/virt-compile-warnings.m4 (-Wenum-compare): Omit explicit check. --- Pushing under the build-breaker rule. m4/virt-compile-warnings.m4 | 2 ++ 1 file changed, 2 insertions(+) diff --git a/m4/virt-compile-warnings.m4 b/m4/virt-compile-warnings.m4 index c3ff962..d1173eb 100644 --- a/m4/virt-compile-warnings.m4 +++ b/m4/virt-compile-warnings.m4 @@ -57,6 +57,8 @@ AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[ dontwarn="$dontwarn -Wformat-nonliteral" # Gnulib's stat-time.h violates this dontwarn="$dontwarn -Waggregate-return" + # gcc 4.4.6 complains this is C++ only; gcc 4.7.0 implies this from -Wall + dontwarn="$dontwarn -Wenum-compare" # Gnulib uses '#pragma GCC diagnostic push' to silence some # warnings, but older gcc doesn't support this. -- 1.7.11.4