Messages in this thread |  | | | Date | Sat, 22 Nov 2008 09:39:35 +0000 | | From | Ralf Baechle <> | | Subject | Re: [PATCH] MIPS: Make BUG() __noreturn. |
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On Thu, Nov 20, 2008 at 05:26:36PM -0800, David Daney wrote: > From: David Daney <ddaney@caviumnetworks.com> > Date: Thu, 20 Nov 2008 17:26:36 -0800 > To: linux-mips <linux-mips@linux-mips.org> > CC: linux-kernel@vger.kernel.org > Subject: [PATCH] MIPS: Make BUG() __noreturn. > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > MIPS: Make BUG() __noreturn.
Please don't repeat the subject in the body of a patch email. Git takes the subject followed by the body upto the --- line as the log message so this is just duplication that will need to be manually deleted again.
> Often we do things like put BUG() in the default clause of a case > statement. Since it was not declared __noreturn, this could sometimes > lead to bogus compiler warnings that variables were used > uninitialized. > > There is a small problem in that we have to put a magic while(1); loop to > fool GCC into really thinking it is noreturn. This makes the new > BUG() function 3 instructions long instead of just 1, but I think it > is worth it as it is now unnecessary to do extra work to silence the > 'used uninitialized' warnings. > > I also re-wrote BUG_ON so that if it is given a constant condition, it > just does BUG() instead of loading a constant value in to a register > and testing it.
I don't like the endless loop in the BUG() macros but at this time it seems the best solution. Looking forward to __builtin_noreturn().
Patch applied,
Ralf
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