[llvm-dev] [RFC] FileCheck: (dis)allowing unused prefixes

Fri Nov 6 07:00:11 PST 2020

On Fri, Nov 6, 2020 at 2:22 AM James Henderson <jh7370.2008 at my.bristol.ac.uk>
wrote:

> I think it would make more sense to add it at each individual call site.
> This ensures that all cases are fixed, rather than just one in a file. It
> also ensures that in the (hopefully unlikely) event that there are both
> intentional and unintentional use-cases within a file, each one gets
> checked.
>
> That would be better indeed, but may be trickier to automate - the
challenge, in my mind, comes from multi-line RUN statements, but maybe I'm
missing something / maybe there aren't that many. If folks have
suggestions, please don't hesitate to throw them my way!

Thanks!

> On Thu, 5 Nov 2020 at 20:29, Mircea Trofin via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Thanks!
>>
>> On Thu, Nov 5, 2020 at 11:50 AM Fāng-ruì Sòng <maskray at google.com> wrote:
>>
>>> On Thu, Nov 5, 2020 at 11:36 AM David Blaikie via llvm-dev
>>> <llvm-dev at lists.llvm.org> wrote:
>>> >
>>> >
>>> >
>>> > On Thu, Nov 5, 2020 at 10:46 AM Mircea Trofin <mtrofin at google.com>
>>> wrote:
>>> >>
>>> >>
>>> >>
>>> >> On Thu, Nov 5, 2020 at 10:40 AM David Blaikie <dblaikie at gmail.com>
>>> wrote:
>>> >>>
>>> >>>
>>> >>>
>>> >>> On Thu, Nov 5, 2020 at 7:30 AM Mircea Trofin via llvm-dev <
>>> llvm-dev at lists.llvm.org> wrote:
>>> >>>>
>>> >>>> There are currently 1350 owner-less failures in the spreadsheet.
>>> These seem to be the larger areas there.
>>> >>>>
>>> >>>> If you see an area you have ownership or expertise in, please sign
>>> up for fixing the tests by Monday, Nov. 9.
>>> >>>>
>>> >>>> Otherwise, I will "blanket-add" --allow-unused-prefixes=true to the
>>> remaining failing tests.
>>> >>>
>>> >>>
>>> >>> If/when you do that, probably worth adding a comment at each site to
>>> clarify that this was added automatically, not vetted/intentionally added
>>> by a human. Something like "// FIXME: Verify that unused prefixes are used
>>> intentionally" or the like.
>>> >>
>>> >> Ack. or, we can grep for -allow-unused-prefixes=true, wdyt?
>>> >
>>> >
>>> > Not sure I understand who/when <https://teams.googleplex.com/u/when>
>>> they would grep for that?
>>>
>>
>> AAh! Nevermind me :) forgot that there are reasonable cases using it.
>> Yes, it makes sense to add a FIXME, perhaps at the start of each file
>>
>>
>>> >
>>> > I was suggesting adding an explicit "this use of
>>> --allow-unused-prefixes=true hasn't been confirmed as intentional" so that
>>> the backwards compatibility cases can be distinguished from the intentional
>>> cases when someone is reading the test case, rather than puzzling over why
>>> this flag was added (which looks intentional) though the unused prefix may
>>> not make sense in that particular test. It'll make it easier in the future
>>> when someone does look at the test for them to not feel like they're being
>>> implicitly told "this use of unused prefixes is intentional" (by the
>>> presence of an explicit flag requesting such support) while staring at the
>>> test and not being able to see why someone would've done that intentionally.
>>>
>>> Directly CCing some folks who can fix or find people to fix some
>>> directories (*/AMDGPU, */X86, */OpenMP, */AArch64) on
>>>
>>> https://docs.google.com/spreadsheets/d/1o6q3XH1n3DDyyccnYZ_kVfhFbTDzC_S09e973_cwYuw/edit#gid=0
>>> After these big directories are cleaned up, the remaining tests should
>>> be manageable in amount.
>>>
>>> How to reproduce:
>>>
>>> sed -i '/allow-unused-prefixes/s/true/false/'
>>> llvm/utils/FileCheck/FileCheck.cpp
>>> git update-index --assume-unchanged llvm/utils/FileCheck/FileCheck.cpp
>>> ninja check-llvm   # or check-clang ...
>>>
>>>
>>>
>>>
>>> >>>
>>> >>>
>>> >>>>
>>> >>>>
>>> >>>>
>>> >>>> On Fri, Oct 30, 2020 at 12:48 PM Mircea Trofin <mtrofin at google.com>
>>> wrote:
>>> >>>>>
>>> >>>>> An update: as of 871d658c9ceb, the flag is now available, if folks
>>> need to use it.
>>> >>>>>
>>> >>>>> On Thu, Oct 29, 2020 at 10:28 AM Mircea Trofin <mtrofin at google.com>
>>> wrote:
>>> >>>>>>
>>> >>>>>> Hello all,
>>> >>>>>>
>>> >>>>>> TL;DR; if you used FileCheck --check-prefixes and you missed
>>> (misspelled, for instance) one of the prefixes in your test, FileCheck
>>> silently ignores that and the test passes.
>>> >>>>>>
>>> >>>>>> 1579 tests have this property.
>>> >>>>>>
>>> >>>>>>
>>> >>>>>> The details
>>> >>>>>> =========
>>> >>>>>> Please refer to https://reviews.llvm.org/D90281 and the
>>> discussion there for more details (make sure you open "older changes" for
>>> full context)
>>> >>>>>>
>>> >>>>>> The problem is covered by the TL;DR;.
>>> >>>>>>
>>> >>>>>> The proposal is to add an explicit flag to FileCheck,
>>> --allow-unused-prefixes, to indicate whether the current behavior is
>>> intended (for instance, jdoerfert contributed a scenario where that is the
>>> case).
>>> >>>>>>
>>> >>>>>> We want the default behavior to be 'strict', i.e.
>>> --allow-unused-prefixes=false. Doing that right now would lead to 1500 test
>>> failures.
>>> >>>>>>
>>> >>>>>> To get there (thanks, maskray, for suggestion), we propose we:
>>> >>>>>> * land D90281 where the flag is introduced, but is flipped to
>>> match today's behavior
>>> >>>>>> * employ a 'busy beavers' approach, where test maintainers patch
>>> their tests:
>>> >>>>>>   - either leveraging the flag, to explicitly indicate that
>>> unused prefixes is intended (i.e. add --allow-unused-patches=true); or
>>> >>>>>>   - fix the test (e.g. maybe there was a misspelling
>>> issue/omission/etc).
>>> >>>>>>
>>> >>>>>> A spreadsheet with the failing tests is available here [1].
>>> >>>>>>
>>> >>>>>> The request to the community members is to please sign up for
>>> their respective area in the spreadsheet, and then mark it completed when
>>> that's the case (yes/no in the respective column).
>>> >>>>>>
>>> >>>>>> When all the tests are fixed, we will then flip
>>> --allow-unused-prefixes to false by default.
>>> >>>>>>
>>> >>>>>> Meanwhile, please consider leveraging the flag explicitly when
>>> you author new tests that use --check-prefixes. That can be then cleaned up
>>> easily after we switch to the 'strict' behavior.
>>> >>>>>>
>>> >>>>>> Thanks!
>>> >>>>>>
>>> >>>>>> [1]
>>> https://docs.google.com/spreadsheets/d/1o6q3XH1n3DDyyccnYZ_kVfhFbTDzC_S09e973_cwYuw/edit?usp=sharing
>>> >>>>
>>> >>>> _______________________________________________
>>> >>>> LLVM Developers mailing list
>>> >>>> llvm-dev at lists.llvm.org
>>> >>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>> >
>>> > _______________________________________________
>>> > LLVM Developers mailing list
>>> > llvm-dev at lists.llvm.org
>>> > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>
>>>
>>>
>>> --
>>> 宋方睿
>>>
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