[LLVMdev] [llvm-commits] [PATCH] A "very verbose" mode for FileCheck

[Dmitri Gribenko]

On Wed, Jan 16, 2013 at 8:38 PM, Eli Bendersky <eliben at google.com> wrote:
> On Wed, Jan 16, 2013 at 10:32 AM, Dmitri Gribenko <gribozavr at gmail.com> wrote:
>> Hello,
>>
>> When someone breaks a FileCheck-based test on some buildbot, sometimes
>> it may not be obvious *why* did it fail.  If the failure can not be
>> reproduced locally, it can be very hard to fix.
>>
>> I propose adding a "very verbose" mode to FileCheck.  In this mode
>> FileCheck will dump the input file in case of failure.  This mode will
>> be enabled by an environment variable "FILECHECK_VERY_VERBOSE".  If we
>> chose a command line option, we would have to edit all FileCheck-based
>> tests to use %FileCheck.
>>
>> Attached is the proposed patch.  A patch for zorg will follow if this
>> is accepted.  Normal output for 'make check' is unchanged.
>>
>> I am not attached to the name "FILECHECK_VERY_VERBOSE", suggestions
>> for better names are welcome.
>>
>
> Could you describe a situation where this helps in more detail? It's
> quite easy to reproduce the input file to FileCheck locally.

Imagine a situation when you have opt | FileCheck.  And 'opt' produces
something weird only on a buildbot, while on your machine the output
is correct.

See, for example, this thread
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130114/162207.html

Dmitri

-- 
main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if
(j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/