Re: [PATCH 2/2] parser: define __builtin_unreachable

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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

- 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

[Index of Archives]     [Newbies FAQ]     [Kernel List]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Photo]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]     [Trinity Fuzzer Tool]

Powered by Linux