On Wed, 20 Mar 2019 10:26:17 -0700 Linus Torvalds <torva...@linux-foundation.org> wrote:
> On Wed, Mar 20, 2019 at 4:17 AM David Laight <david.lai...@aculab.com> wrote: > > > > > ______r = !!(cond); \ > > > > Is that (or maybe just the !!) needed any more?? > > It is, because the 'cond' expression might not be an int, it could be > a test for a pointer being non-NULL, or an u64 being non-zero, and not > having the "!!" would mean that you'd get a warning or drop bits when > assigning to 'int'. > > And you do need the new temporary variable to avoid double evaluation > the way that code is written. > > That said, I do think the code is really ugly. We could: > > - avoid the temporary by just simplifying things. > > - do the '!!' just once in the parent macro. > > - Steven has this crazy model of "more underscores are better". They > aren't. They don't help if things nest anyway, but what does help is > meaningful names. Both when things don't nest, and when looking at > generated asm files. > > - ,, and finally, what _is_ better is to chop things up so that they > are smaller and make each macro do only one thing > > So maybe do the patch something like the attached instead? Completely > untested, but it looks sane to me. > Linus, This patch works. Can I get your Signed-off-by for it? -- Steve
