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

[Dmitri Gribenko]

On Thu, Jan 17, 2013 at 1:23 AM, Evgeniy Stepanov
<eugeni.stepanov at gmail.com> wrote:
> On Thu, Jan 17, 2013 at 1:19 AM, Dmitri Gribenko <gribozavr at gmail.com> wrote:
>> On Wed, Jan 16, 2013 at 9:33 PM, Dmitri Gribenko <gribozavr at gmail.com> wrote:
>>> On Wed, Jan 16, 2013 at 9:24 PM, Chris Lattner <clattner at apple.com> wrote:
>>>>
>>>> On 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.
>>>>
>>>> I think that this idea is good, but I'd prefer it be implemented a different way:
>>>>
>>>>  - Filecheck should take a new flag -dump-input-on-error that causes it to... dump the input file on error.
>>>>  - Lit should be the thing that checks the environment (or perhaps add a new option to lit), and adds the flag to FileCheck invocations.
>>>>
>>>> I don't like it when the behavior of such a low-level tool like this changes based on environment variables.  It isn't discoverable in --help.  If for some reason, it is bad for lit to implicitly pass the option, I'd rather have a standard FILECHECK_COMMANDLINE environment variable, and have filecheck parse arbitrary options out of it using the cl::ParseEnvironmentOptions function.
>>>
>>> I agree that a command line option would be better.  But in that case
>>> all tests should be updated.  It is not an issue for me -- it is
>>> mostly mechanical.  So should I change tests to use %FileCheck?
>>
>> Here's a third attempt.
>>
>> The new behavior is as follows:
>>
>> 1. In case of errors we always dump output to a temporary file and print
>
> Does it mean we get one more file in /tmp every time a test fails, and
> it is not cleaned up automatically? I don't think this should happen
> in the "default" mode of the tool.

Well, yes.  David requested that and I agreed that it is a good idea.
Are you strongly opposed to it?

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>*/