[libvirt] [PATCH v2 42/42] m4: enable the -Wswitch-default warning flag

Even if the compiler has validated that all enum constants have case statements in a switch, it is not safe to omit a default: case statement. When assigning a value to a variable / struct field that is defined with an enum type, nothing prevents an invalid value being assigned. So defensive code must assume existance of invalid values and thus all switches should have a default: case. This enables the -Wswitch-default compiler warning flag which will now enforce this requirement. Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- m4/virt-compile-warnings.m4 | 2 -- 1 file changed, 2 deletions(-) diff --git a/m4/virt-compile-warnings.m4 b/m4/virt-compile-warnings.m4 index fc185aef38..216a3ee0e9 100644 --- a/m4/virt-compile-warnings.m4 +++ b/m4/virt-compile-warnings.m4 @@ -45,8 +45,6 @@ AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[ dontwarn="$dontwarn -Wcast-qual" # We need to use long long in many places dontwarn="$dontwarn -Wlong-long" - # We allow manual list of all enum cases without default: - dontwarn="$dontwarn -Wswitch-default" # Not a problem since we don't use -fstrict-overflow dontwarn="$dontwarn -Wstrict-overflow" # Not a problem since we don't use -funsafe-loop-optimizations -- 2.14.3