https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71831
--- Comment #7 from Martin Sebor <msebor at gcc dot gnu.org> --- To elaborate on the use case: my immediate need for it is to detect at compile time possible buffer overflow in calls to sprintf (the -Wformat-length patch) without _FORTIFY_SOURCE that not all projects use and without optimization. The Linux kernel, for example, isn't affected by _FORTIFY_SOURCE because it defines its own sprintf et at.. Although itdoes obviously benefits from optimization, without _FORTIFY_SOURCE inserting calls to __builtin_object_size, the compute_builtin_object_size function fails just as it does without optimization. Another use case is to make -Warray-bounds usable without optimization (bug 67872). Yet another one is to improve the -Wplacement-new warning. It seems that any feature (warning or otherwise) in GCC that needs to compute the size of an indirectly referenced object could potentially benefit by using the same function instead of rolling its own. Beyond GCC itself, I think the feature will be generally more useful when funcational (in the unambiguous "constant" cases) without optimization.
