https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115274
qinzhao at gcc dot gnu.org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |NEW --- Comment #14 from qinzhao at gcc dot gnu.org --- with my work-in-progress patch, for the creduced small testing case, I got the following diagnostic when adding -fdiagnostics-explain-harder: t_115274.c:4:25: warning: ‘strlen’ reading 1 or more bytes from a region of size 0 [-Wstringop-overread] 4 | int b(char *d) { return strlen(d); } | ^~~~~~~~~ ‘e’: events 1-2 4 | int b(char *d) { return strlen(d); } | ~~~~~~~~~ | | | (2) out of array bounds here ...... 8 | if (c == 0) | ^ | | | (1) when the condition is evaluated to true In function ‘e’: cc1: note: source object is likely at address zero Looks like a helpful diagnostic to the user.