* Joseph Myers: > On Thu, 26 Jun 2025, Richard Biener wrote: > >> The following prototypes diagnostics for conversions to/from time_t >> where the source/destination does not have sufficient precision for it. >> I've lumped this into -Wconversion for the moment and didn't bother >> fixing up the testcase for !ilp32 or the -Wconversion diagnostics that >> happen. >> >> Would -Wtime-conversion (or -Wtime_t-conversion?) be an appropriate >> option? I'd enable it with -Wconversion. > > I think such a warning should be based on an attribute on the time_t type > that means "warn for implicit truncation of this type" (I'm less clear on > why warnings for implicit widening conversions *to* time_t are supposed to > be useful), rather than hardcoding it to be based on the time_t name. > It's hardly just time_t for which a warning about such implicit truncation > might be useful.
Ideally, we'd also warn about conversion to long, when long isn't actually uint64_t. This way, we can diagnose potential truncation during 64-bit builds. Thanks, Florian
