https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77887
Bug ID: 77887
Summary: -Wimplicit-fallthrough fails to trigger in an unused
function template specialisation
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: marc.mutz at kdab dot com
Target Milestone: ---
I have a switch statement here that -Wimplicit-fallthrough fails to warn about:
template <>
inline void qt_memfill_template(quint16 *dest, quint16 value, int count)
{
if (count < 3) {
switch (count) {
case 2: *dest++ = value;
// fall through <------ absence is not detected
case 1: *dest = value;
}
return;
}
// ...
This specialisation ends up not being instantiated, but I'd expect a warning
from a full specialisation nonetheless.
Hmm. If I change from specialisation to overloading (ie. to a non-template),
the switch still doesn't trigger.
I thought the warning was generated by the front-end, but it seems it'd
generated by the backend instead, after dead code elimination...?
