From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jerry Van Baren <gerald.vanbaren@ge.com>
Date: Wed, 08 Apr 2009 15:46:37 -0400
Subject: [U-Boot] use of C99
In-Reply-To: <20090408192832.8D48F8560EFB@gemini.denx.de>
References: <4A0B9AAA-4714-4C27-84A7-22FCE4D91DDA@freescale.com>
	<20090408192832.8D48F8560EFB@gemini.denx.de>
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To: u-boot@lists.denx.de

Hi Wolfgang,

Wolfgang Denk wrote:
> Dear Kumar Gala,
> 
> In message <4A0B9AAA-4714-4C27-84A7-22FCE4D91DDA@freescale.com> you wrote:
>> I was wondering if there was any reason we avoid C99 features in u- 
>> boot source.
>>
>> Specifically the ability to declare variables in the middle of  
>> functions.
> 
> One reason is that I consider such code extremely ugly and hard to
> read and understand.

ACK.  I don't expect to see variables spring into life in the middle of 
nowhere.

>> There are a slew of places that we have something like:
> ...
>> #ifdef CONFIG_COOL_FEATURE
>> 	u32 myvarrocks = foo * bar * bar;
>>
>> 	gd->neato = myvarrocks
>> #endif
> 
> It would be even better to avoid such #ifdef's, or at least the need
> for such special local variables.

Sometimes (often?) that is impossible.

> Best regards,
> 
> Wolfgang Denk

If I'm not confused, I've seen block-local u-boot variables, has the 
advantages of being more distinctive and limits the lifetime of the 
variable.

#ifdef CONFIG_COOL_FEATURE
	{
		u32 myvarrocks = foo * bar * bar;

		gd->neato = myvarrocks
	}
#endif

Is this an acceptable compromise?

Best regards,
gvb