https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87038
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
And for the goto case Clang says:
87038.c:2:13: warning: variable 'foo' is used uninitialized whenever 'if'
condition is true [-Wsometimes-uninitialized]
if (x == 0) goto lbl;
^~~~~~
87038.c:5:31: note: uninitialized use occurs here
printf("foo is %d\n", foo);
^~~
87038.c:2:9: note: remove the 'if' if its condition is always false
if (x == 0) goto lbl;
^~~~~~~~~~~~~~~~~~~~
87038.c:3:9: note: variable 'foo' is declared here
int foo = 3;
^
1 warning generated.
