The program to be attached produces the warning [ssp@dhcp-100-2-40 ~]$ gcc gb.c gb.c: In function ‘main’: gb.c:11: warning: ignoring return value of ‘foo’, declared with attribute warn_unused_result which is expected. However, it should also produce a warning for line 12, which is exactly the same except a dummy variable is declared. Using built-in specs. Target: i386-redhat-linux Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --enable-plugin --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre --enable-libgcj-multifile --enable-java-maintainer-mode --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib --with-cpu=generic --build=i386-redhat-linux Thread model: posix gcc version 4.3.2 20081105 (Red Hat 4.3.2-7) (GCC)
Created attachment 17654 [details] program
I think neither of these cases should be warned about since you are using it with a statement expression.
Why not? If not using the return value is a bug, then it's also a bug if it isn't used after being passed through a statement expression.
Confirmed.
Anyone looking at this? If not, I'd like to.
Dave is on it.