Re: [PATCH] docs: printk-formats: Stop encouraging use of unnecessary %h[xudi] and %hh[xudi]
From: Jonathan Corbet
Date: Sat Sep 14 2019 - 03:59:09 EST
On Fri, 06 Sep 2019 14:11:51 -0700
Joe Perches <joe@xxxxxxxxxxx> wrote:
> Standard integer promotion is already done and %hx and %hhx is useless
> so do not encourage the use of %hh[xudi] or %h[xudi].
> As Linus said in:
> Link: https://lore.kernel.org/lkml/CAHk-=wgoxnmsj8GEVFJSvTwdnWm8wVJthefNk2n6+4TC=20e0Q@xxxxxxxxxxxxxx/
> It's a pointless warning, making for more complex code, and
> making people remember esoteric printf format details that have no
> reason for existing.
> The "h" and "hh" things should never be used. The only reason for them
> being used if if you have an "int", but you want to print it out as a
> "char" (and honestly, that is a really bad reason, you'd be better off
> just using a proper cast to make the code more obvious).
> So if what you have a "char" (or unsigned char) you should always just
> print it out as an "int", knowing that the compiler already did the
> proper type conversion.
> Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
I took the liberty of removing "Link:" (but not the URL) from the commit
message. That wasn't a patch tag, there is no real reason to make it
look like one...