[PATCH 6/6] checkpatch.pl: Request if() instead #ifdef

[AKASHI Takahiro]

On Thu, Jun 04, 2020 at 07:39:35PM -0400, Tom Rini wrote:
> On Fri, May 22, 2020 at 04:32:40PM -0600, Simon Glass wrote:
> 
> > There is a lot of use of #ifdefs in U-Boot. In an effort reduce this,
> > suggest using the compile-time construct.
> > 
> > Signed-off-by: Simon Glass <sjg at chromium.org>
> 
> Applied to u-boot/master, thanks!

This check is simple, but IMHO, too simple.
It will generate false-positive, or pointless, warnings
for some common use cases. Say,

In an include header,
#ifdef CONFIG_xxx
extern int foo_data;
int foo(void);
#endif

Or in a C file (foo_common.c),
#ifdef CONFIG_xxx_a
int foo_a(void)
...
#endif
#ifdef CONFIG_xxx_b
int foo_b(void)
...
#endif

Or,

struct baa baa_list[] = {
#ifdef CONFIG_xxx
        data_xxx,
#endif
...

They are harmless and can be ignored, but also annoying.
Can you sophisticate this check?

In addition, if I want to stick to this rule, there can co-exist
an "old" style and "new" style of code in a single file.
(particularly tons of examples in UEFI subsystem)

How should we deal with this?

Thanks,
-Takahiro Akashi

> -- 
> Tom