Re: [PATCH 3/5] compiler_attributes: Add overflow_behavior macros __ob_trap and __ob_wrap

Peter Zijlstra
2026-04-01T09:08:27Z

On Tue, Mar 31, 2026 at 12:52:10PM -0700, Kees Cook wrote:

> I think for this series, __ob_trap/__ob_wrap is what should be used.
>
> And for other folks, the background here is that we originally wanted
> to use macros for "__trap" and "__wrap", but the powerpc C compiler
> (both Clang and GCC) have a builtin macro named "__trap" already. So
> I switched to just using the Clang-native type qualifier. We can use
> the attribute style too, but there was a lot of confusion during the
> Clang development phases where people kept forgetting this was a type
> qualifier, not an attribute (i.e. the attribute is an internal alias
> for the qualifier, and the qualifier is a new type).

Since you mention qualifiers...

What is the result of __typeof_unqual__(int __ob_trap) ?