[cfe-dev] Paragraph numbers in C++ tests

[David Blaikie via cfe-dev]

On Tue, Apr 30, 2019 at 8:12 AM via cfe-dev <cfe-dev at lists.llvm.org> wrote:
>
>
>
> > -----Original Message-----
> > From: cfe-dev [mailto:cfe-dev-bounces at lists.llvm.org] On Behalf Of Bruno
> > Ricci via cfe-dev
> > Sent: Tuesday, April 30, 2019 10:34 AM
> > To: cfe-dev at lists.llvm.org
> > Subject: Re: [cfe-dev] Paragraph numbers in C++ tests
> >
> >
> >
> > On 29/04/2019 19:33, David Blaikie wrote:
> > > Even if they're updated to reflect current paragraph numbers, they'd
> > > still fall into disrepair in future standards & be hard to know which
> > > version they applied to. So I'd support adding C++ version numbers to
> > > them. At least on principle - but the reality/situations they're used
> > > in might make that awkward/problematic, I don't know.
> >
> > I was thinking about the naming of tests for sections of the C++ standard.
> > For example the tests for [namespace.udecl] are:
> >   p1.cpp
> >   p3.cpp
> >   p4.cpp
> >   p5-cxx0x.cpp
> >   p6-cxx11.cpp
> >   p7.cpp
> >   p8.cpp
> >   p8-cxx0x.cpp
> >   p10.cpp
> >   p11.cpp
> >   p12.cpp
> >   p13.cpp
> >   p15.cpp
> >   p18.cpp
> >
> > I think that naming the tests pn-cxxmm.cpp to mean, "paragraph pn of
> > cxxmm"
> > is reasonable, with the understanding that naming a test p3-cxx17.cpp does
> > not
> > mean that the corresponding rule is specific to C++17, just that it was
> > written
> > against C++17.
> >
> > Bruno
>
> The real issue is, "p3" in C++11 might be renumbered "p4" in C++14
> and "p5" in C++17 and ...  so what does "p3.cpp" actually test?
> You can't tell just from the name of the file because the name's
> meaning is context-sensitive.
>
> Intuitively I'd think "p3-cxx11.cpp" means "tests p3 as it existed in
> the C++11 standard" and whether that paragraph is still p3 in later
> editions is an exercise for the reader.

I think that^ is what Bruno was saying.

> I recommend, give up on naming tests after paragraph numbers, because
> they aren't actually meaningful.

Eh, I think there's merit to having tests by feature in the standard
and being able to inspect their coverage (yeah, that gets wonky when
paragraphs are renumbered - so you might have to update the numbering
- but the benefit of a correspondence between some part/version of the
standard even if you have to do some work remapping to a consistent
version.

> --paulr
>
> >
> > >
> > > On Mon, Apr 29, 2019 at 7:28 AM Bruno Ricci via cfe-dev
> > > <cfe-dev at lists.llvm.org> wrote:
> > >>
> > >> Hi,
> > >>
> > >> An annoying part of writing tests for C++ is that the paragraph numbers
> > are not
> > >> stable between versions of the standard. Is there an accepted way to
> > deal with
> > >> this issue ? I can imagine several ways to deal with this:
> > >>   - Rename the tests so that they match the latest standard/draft.
> > >>   - Add a suffix/prefix with the version for the paragraph number.
> > >>   - ... ?
> > >>
> > >> Bruno
> > >> _______________________________________________
> > >> cfe-dev mailing list
> > >> cfe-dev at lists.llvm.org
> > >> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
> > _______________________________________________
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