As a general rule any time we switch() on something that is an enum, we
want to have a case for every enum constant. The -Wswitch warning will
report any switch where we've violated this rule, except if that switch
has a default case.
Unfortunately it is reasonable to want to list all enum constants *and*
also have a default case. To get a warning in that scenario requires
that we turn on -Wswitch-enum.
In a few cases where we explicitly don't want to list all enum cases, we
can discard the enum type checking by casting the value to a plain int.
Signed-off-by: Daniel P. Berrangé <berrange@xxxxxxxxxx>
---
m4/virt-compile-warnings.m4 | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/m4/virt-compile-warnings.m4 b/m4/virt-compile-warnings.m4
index 4b35a6f6b5..fc185aef38 100644
--- a/m4/virt-compile-warnings.m4
+++ b/m4/virt-compile-warnings.m4
@@ -47,8 +47,6 @@ AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[
dontwarn="$dontwarn -Wlong-long"
# We allow manual list of all enum cases without default:
dontwarn="$dontwarn -Wswitch-default"
- # We allow optional default: instead of listing all enum values
- dontwarn="$dontwarn -Wswitch-enum"
# Not a problem since we don't use -fstrict-overflow
dontwarn="$dontwarn -Wstrict-overflow"
# Not a problem since we don't use -funsafe-loop-optimizations
@@ -184,6 +182,11 @@ AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[
# that one off, so we need to manually enable this again
wantwarn="$wantwarn -Wjump-misses-init"
+ # GNULIB explicitly filters it out, preferring -Wswitch
+ # but that doesn't report missing enums if a default:
+ # is present.
+ wantwarn="$wantwarn -Wswitch-enum"
+
# GNULIB turns on -Wformat=2 which implies -Wformat-nonliteral,
# so we need to manually re-exclude it. Also, older gcc 4.2
# added an implied ATTRIBUTE_NONNULL on any parameter marked
--
2.14.3
--
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