https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104550
--- Comment #18 from qinzhao at gcc dot gnu.org --- One question here, for the following testing case: [opc@qinzhao-ol7u9 104550]$ cat t1.c struct vx_audio_level { int has_monitor_level : 1; }; void vx_set_monitor_level() { struct vx_audio_level info; __builtin_clear_padding (&info); } [opc@qinzhao-ol7u9 104550]$ sh t /home/opc/Install/latest/bin/gcc -O -Wuninitialized -Wall t1.c -S t1.c: In function ‘vx_set_monitor_level’: t1.c:7:2: warning: ‘info’ is used uninitialized [-Wuninitialized] 7 | __builtin_clear_padding (&info); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ t1.c:6:24: note: ‘info’ declared here 6 | struct vx_audio_level info; | ^~~~ We can see that the compiler emitted the exactly same warning as with -ftrivial-auto-var-init=pattern. my question is, is the "info" in __builtin_clear_padding(&info) a REAL use of "info"? is it correct to report the uninitialized use message for it?