Re: [PATCH] LLVMLinux: Remove warning about returning an uninitialized variable

From: "H. Peter Anvin" <hpa@zytor.com>
To: Behan Webster <behanw@converseincode.com>, arnd@arndb.de
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
	dwmw2@infradead.org, pageexec@freemail.hu,
	Mark Charlebois <charlebm@gmail.com>
Subject: Re: [PATCH] LLVMLinux: Remove warning about returning an uninitialized variable
Date: Mon, 31 Mar 2014 15:11:40 -0700	[thread overview]
Message-ID: <5339E81C.4010901@zytor.com> (raw)
In-Reply-To: <5339E7CB.2080001@converseincode.com>

On 03/31/2014 03:10 PM, Behan Webster wrote:
>>>
>>> diff --git a/include/asm-generic/cmpxchg-local.h
>>> b/include/asm-generic/cmpxchg-local.h
>>> index d8d4c89..4c41bb8 100644
>>> --- a/include/asm-generic/cmpxchg-local.h
>>> +++ b/include/asm-generic/cmpxchg-local.h
>>> @@ -41,6 +41,7 @@ static inline unsigned long
>>> __cmpxchg_local_generic(volatile void *ptr,
>>>           break;
>>>       default:
>>>           wrong_size_cmpxchg(ptr);
>>> +        prev = 0;
>>>       }
>>>       raw_local_irq_restore(flags);
>>>       return prev;
>>>
>> Shouldn't this be a build time assert (__compiletime_error())?
> I changed it to a __noreturn on wrong_size_cmpxchg thanks to James
> Bottomley.
> 
> Which would be better?
> 

__compiletime_error traps at compile time rather than link time, which
is what you want.

	-hpa