Messages in this thread |  | | From | Masahiro Yamada <> | Date | Tue, 7 Jan 2020 15:28:33 +0900 | Subject | Re: [PATCH] treewide: remove redundent IS_ERR() before error code check |
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On Tue, Jan 7, 2020 at 2:15 PM Eric Biggers <ebiggers@kernel.org> wrote: > > On Mon, Jan 06, 2020 at 01:58:33PM +0900, Masahiro Yamada wrote: > > 'PTR_ERR(p) == -E*' is a stronger condition than IS_ERR(p). > > Hence, IS_ERR(p) is unneeded. > > > > The semantic patch that generates this commit is as follows: > > > > // <smpl> > > @@ > > expression ptr; > > constant error_code; > > @@ > > -IS_ERR(ptr) && (PTR_ERR(ptr) == - error_code) > > +PTR_ERR(ptr) == - error_code > > // </smpl> > > > > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> > > Any reason for not doing instead: > > ptr == ERR_PTR(-error_code) > > ?
Because there is no reason to change
PTR_ERR(ptr) == -error_code to ptr == ERR_PTR(-error_code)
if (PTR_ERR(ptr) == -error_code) style seems to be used more often.
But, I think it is just a matter of preference after all. Both work equally fine.
> To me it seems weird to use PTR_ERR() on non-error pointers. I even had to > double check that it returns a 'long' and not an 'int'. (If it returned an > 'int', it wouldn't work...) > > - Eric
-- Best Regards Masahiro Yamada
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