Given:
int main(void)
{
enum foo { A, B, C, D} bar;
bar = D;
if(bar == A) {
;
} else if(bar == B) {
;
} else {
switch(bar) {
case C:
case D:
;
}
}
return 0;
}
barbeque/zarathustra:src: /usr/local/bin/gcc-4.1.0 -Wswitch-enum a.c
a.c: In function 'main':
a.c:10: warning: enumeration value 'A' not handled in switch
a.c:10: warning: enumeration value 'B' not handled in switch
A & B aren't valid targets for the switch statement by the time it's hit as
they have been handled by the if statements above.
Locally built gcc:
barbeque/zarathustra:src: /usr/local/bin/gcc-4.1.0 -v
Using built-in specs.
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-4.1.0/configure --prefix=/usr/local/stow/gcc-4.1.0
--enable-languages=c,c++,objc --infodir=/usr/local/stow/gcc-4.1.0/share/info
--mandir=/usr/local/stow/gcc-4.1.0/share/man --enable-shared --enable-threads
--enable-tls --program-suffix=-4.1.0 --enable-__cxa_atexit
--enable-version-specific-runtime-libs
--enable-targets=x86_64-unknown-linux-gnu --enable-bootstrap=lean
--disable-biarch --disable-multilib
Thread model: posix
gcc version 4.1.0
On Debian/stable from amd64.debian.net.
Also happens on gcc 3.3.5 from the Debian apt archives.
--
Summary: -Wswitch-enums doesn't detect impossible cases in
switch()
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: ramune+gcc at net-ronin dot org
GCC build triplet: x86_64-unknown-linux-gnu
GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27126
