On Mon, 5 Feb 2024 at 13:16, Samuel Tardieu <s...@rfc1149.net> wrote: > > > Daniel P. Berrangé <berra...@redhat.com> writes: > > > $ gcc -Wall -Wuninitialized -o jump jump.c > > Note that many GCC warnings don't trigger if you don't enable > optimizations. In the case you exhibit, adding -O is enough to get > a sensible warning: > > $ gcc -Wall -O -o jump jump.c > jump.c: In function ‘main’: > jump.c:11:3: warning: ‘foo’ may be used uninitialized > [-Wmaybe-uninitialized] > 11 | free(foo); > | ^~~~~~~~~ > jump.c:8:9: note: ‘foo’ was declared here > 8 | char *foo = malloc(30); > | ^~~
llvm also prints a warning: jump.c:5:7: warning: variable 'foo' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] I confirmed that QEMU's current compiler flags enable these warnings so both gcc and llvm detect the issue that Daniel pointed out in QEMU code. Daniel: Does this address your concern about compiler warnings? Stefan
