Paul Eggert wrote: > Compiling everything with -fwrapv is simple. It has > optimization drawbacks, but if that's the best we can do > now, then we'll probably do it. And once we do it, human > nature suggests that we will generally not bother with the > painstaking analysis needed to omit -fwrapv.
Certainly noone will try to analyze megabytes of source code in order to someday be able to omit -fwrapv from the CFLAGS. But if GCC would give a warning every time it does these optimizations which are OK according to C99 but break LIA-1 assumptions, it would be manageable. This way, programmers would have a chance to use 'unsigned int' instead of 'int' in those few places where it matters. Such a warning should be simple to implement: Everywhere you use the value of 'flag_wrapv' in a way that matters, give a warning. No? Bruno
