[llvm-dev] [RFC] Updating googletest to non-release tagged version

Fri Mar 16 02:41:15 PDT 2018

Thanks. The motivating example can be seen in this review:
https://reviews.llvm.org/D44382.

In that review, I am unit testing .debug_line parsing, specifically, the
behaviour when the parser is fed a malformed section. Most of the code
under test goes through some slight variations in the code path, depending
on a) the DWARF version (interesting cases are 3, 4 and 5), and b) whether
the DWARF is 32-bit DWARF or 64-bit DWARF. So I have two axes, with
multiple values on each. The end "symptoms" being tested aren't much
different in each case, so it makes sense to share the test code as much as
possible. Without Combine, I have to do the following:

INSTANTIATE_TEST_CASE_P(
    LineTableTestParams, DebugLineParameterisedFixture,
    Values(std::make_pair(2, DWARF32), std::make_pair(3, DWARF32),
           std::make_pair(4, DWARF32), std::make_pair(5, DWARF32),
           std::make_pair(2, DWARF64), std::make_pair(3, DWARF64),
           std::make_pair(4, DWARF64), std::make_pair(5, DWARF64)));

I realised whilst typing this out, that I don't need a distinction between
v2 and v3. However, there's still 6 different combinations, which I have to
explicitly list. Combine would, by my understanding, allow me to do
something like "Combine(Values(3, 4, 5), Values(DWARF32, DWARF64))".

As to why it doesn't work in 1.8, it's because LLVM has explicitly
overridden the GTEST_HAS_TR1_TUPLE define (see
utils\unittest\CMakeLists.txt and r316798). The short-story is that it's
because recent MSVC compilers (sorry, I guess I was too broad in my
original statement) have started issuing TR1 deprecation warnings, combined
with C++11 not being detected properly.

On 15 March 2018 at 18:31, Roman Lebedev <lebedev.ri at gmail.com> wrote:

> On Thu, Mar 15, 2018 at 9:09 PM, David Blaikie via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
> > +Chandler who might have some thoughts on this.
> >
> > Could you provide an example here of the motivation for the feature
> you're
> > missing? Might help motivate the discussion (and/or we'll end up
> nitpicking
> > how it could be done differently without that feature... - which is sort
> of
> > where I'm going with this. Combinatorial test case expansion does seem a
> bit
> > suspicious to me - I'd hope we could pick a few examples from the various
> > equivalence classes & that would suffice?)
> >
> > On Mon, Mar 12, 2018 at 9:01 AM James Henderson via llvm-dev
> > <llvm-dev at lists.llvm.org> wrote:
> >>
> >> Hi all,
> >>
> >> I'm currently writing some unit tests for some debug line error handling
> >> code I'm working on (see e.g. https://reviews.llvm.org/D44382), and I
> just
> >> ran into an annoying disabled feature in gtest, specifically the
> "Combine"
> >> feature for use in combinatorially generating parameterised tests. A
> FIXME
> >> comment in ProfileData\CoverageMappingTest.cpp suggests that I'm not
> the
> >> only one to have tried and discovered that they cannot use this
> feature. The
> >> problem is that the version of googletest (v 1.8.0, released in Aug
> 2016) in
> >> the LLVM tree requires TR1 tuple support for this feature, which is not
> >> really supported in recent compilers, and has been explicitly disabled
> in
> >> our googletest CMakeLists.txt, thus disabling "Combine".
> >>
> >> I did a bit of looking around, and v 1.8.0 is indeed the last officially
> >> tagged release of googletest. However, there has been a lot of
> development
> >> on the framework since that point, including a fix to enable use of
> Combine
> >> with std::tuple-supporting compilers. There have been a number of issue
> >> raised on the googletest issue tracker (see e.g.
> >> https://github.com/google/googletest/issues/1467 or
> >> https://github.com/google/googletest/issues/1079) asking about a 1.9.0
> >> release, and there has been zero response from anybody answering the
> query
> >> of when/if it will happen. In the meantime, the last release gets older
> and
> >> crustier...
> >>
> >> I'd therefore like to propose something that might be seen as slightly
> >> controversial: update to use ToT googletest (or at least some reasonably
> >> recent version of master), at least until a new release is created.
> >>
> >> Thoughts?
> This sounds strange.
>
> I've been using googletest-1.8.0 in my project, with fresh compilers
> (clang, gcc - https://godbolt.org/g/jg4tFG - tr1/tuple works)
> and not once did i have any issues with unavailability of Combine,
> even though i do use it.
>
> Debian sid:
> $ dpkg -S tr1/tuple
> libstdc++-7-dev:amd64: /usr/include/c++/7/tr1/tuple
> libstdc++-5-dev:amd64: /usr/include/c++/5/tr1/tuple
> libstdc++-6-dev:amd64: /usr/include/c++/6/tr1/tuple
>
> So "which is not really supported in recent compilers" part is at
> least too broad.
>
> Roman.
>
> >> James
> >> _______________________________________________
> >> LLVM Developers mailing list
> >> llvm-dev at lists.llvm.org
> >> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> >
> >
> > _______________________________________________
> > LLVM Developers mailing list
> > llvm-dev at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> >
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20180316/4224fcae/attachment.html>