lkml.org 
[lkml]   [2008]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] MIPS: Make BUG() __noreturn.
    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


    \
     
     \ /
      Last update: 2008-11-22 10:43    [W:0.022 / U:94.432 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site