[llvm-dev] [CMake] External File Dependencies for Unit Tests

[Zachary Turner via llvm-dev]

That said, why doesn't a lit test suffice for the OP's case of
creating an object file and doing something with it?

On Tue, Jun 25, 2019 at 11:20 AM Zachary Turner <zturner at roblox.com> wrote:
>
> I actually added support to our unit tests for external file
> dependencies a year or so ago.  Search for
> `add_llvm_unittest_with_input_files` in unittests/*.txt and that will
> give you an example usage.
>
> On Tue, Jun 25, 2019 at 2:40 AM Pavel Labath via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
> >
> > On 25/06/2019 11:24, James Henderson via llvm-dev wrote:
> > > Hi Alex,
> > >
> > >     Would you recommend that I do what is done in
> > >     unittest/ObjectYAML/MinidumpYAMLTest.cpp which just uses a string
> > >     inside the source file, or use an Inputs directory? Both are not
> > >     great, as you point out about using an Inputs directory
> > >
> > >
> > > I'd be inclined to go with the string in the source file approach. It
> > > keeps the whole test localised to one place, making it easier to
> > > understand what the test is actually testing.
> > >
> > >     Also, I'm not sure that I can create an object without invoking
> > >     yaml2obj itself, I can't seem to find a function to do this exposed
> > >     by libObjectYAML.
> > >
> > >
> > > It looks to me like you'd need to move big chunks of code out of the
> > > yaml2obj tool into the ObjectYAML library. The Minidump version was
> > > added quite recently, and took the approach of doing all the layout in
> > > the library, whereas for most other formats, the work is done in the
> > > executable layer. I think it would be perfectly reasonable to do this
> > > code moving, and would then allow you to use the library in your test
> > > setup, similar to how minidump works.
> >
> > [Disclaimer: I'm the person who added the minidump code.]
> >
> > I would very much like to see this happen. Lldb has some unit tests
> > which need to binary files to operate. The way that's handled right now
> > is by shelling out to yaml2obj from inside the unit test (so, not from
> > cmake). However, it would be infinitely better if we could just invoke a
> > library function to do this conversion for us.
> >
> >
> > >
> > >     If I do need to invoke yaml2obj, would you happen to know how to
> > >     tell CMake to build yaml2obj first, and also where would I find that
> > >     executable?
> > >
> > >
> > > I'm not a CMake expert by any means, but I think you would need to
> > > create a dependency on yaml2obj from the test target, then add a step in
> > > the test's CMakeLists.txt to run yaml2obj and generate your inputs. I'm
> > > still not convinced that it's the right way to go though.
> >
> > Running yaml2obj from the unit test like lldb does is probably a bit
> > better than doing it from cmake. You can search for ReadYAMLObjectFile
> > to see how it's done there. However, I wouldn't really recommend
> > emulating that... :)
> >
> > cheers,
> > pl
> >
> >
> > _______________________________________________
> > LLVM Developers mailing list
> > llvm-dev at lists.llvm.org
> > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev