On Tue, Jul 13, 2010 at 12:52:48AM -0700, Chris Li wrote: > On Sat, Jul 10, 2010 at 2:07 AM, Josh Triplett <josh@xxxxxxxxxxxxxxxx> wrote: > > __builtin_unreachable has special semantics beyond just a function. > > This definition will suffice to allow compilation, but > > __builtin_unreachable should have the same effect in sparse that it does > > in GCC: mark the point (and the remainder of the basic block) as > > unreachable. Something like the mechanism used for handling noreturn > > would work here as well; declaring the function to have attribute > > noreturn would probably have almost the right semantics. > > > > The attribute noreturn will apply to the whole function. The function > NEVER returns. > __builtin_unreachable only apply to current basic block. e.g. some > error handling path like panic. The function can still return a value on the > normal path. It has different meaning than attribute noreturn. So I don't think > automatically give the function noreturn attribute is the right thing to do. No, I didn't mean that using __builtin_unreachable should mark the function calling it as noreturn. I meant that as an approximation to the right behavior, __builtin_unreachable *itself* could have attribute noreturn. - Josh Triplett -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
