[U-Boot] use of C99

Premi, Sanjeev
2009-04-08T21:26:26Z

> -----Original Message-----
> From: Timur Tabi [mailto:timur at freescale.com]
> Sent: Thursday, April 09, 2009 2:28 AM
> To: Premi, Sanjeev
> Cc: Jerry Van Baren; U-Boot-Users ML; Kumar Gala
> Subject: Re: [U-Boot] use of C99
>
> Premi, Sanjeev wrote:
>
> > One of the biggest problem is uncontrolled variable definitions that
> > gets even nasty when variables have same names with different types;
> > though under different set of #ifdefs. Quite possible for commonly
> > used variable names - i, ptr, tmp, etc.
>
> Then let's just say that if you're going to define a variable in the
> middle of a function, it can't have the same name as another
> variable in
> that function.
>
> > I feel, here, ifdefs provide a false sense of 'enclosure'
> with possibility
> > of frequent breaches - in code (while implementing) and in
> simple reading
> > (for understanding).
>
> Sorry, I don't understand what you're talking about. The #ifdefs are
> used to enable feature-specific code on platforms that have
> that feature.

I was referring to declaring variable within #ifdefs with belief that
use will be contained.

e.g.
#ifdef CONFIG_COOL_FEATURE
int i;
int* ptr ;
...
...
#endif

...
... 2 screenful down; in same function...
...

#ifdef CONFIG_HOT_FEATURE
u32 i;
void* ptr;
...
...
#endif

Maybe for sometime the usage seems contained. Until someone decides to have
both the COOL and HOT feature.

~sanjeev
>
> --
> Timur Tabi
> Linux kernel developer at Freescale
>
>