RE: GDB/Fortran: Support for Assumed Rank Zero.

["Kempke, Nils-Christian via Gdb-patches" <gdb-patches@sourceware.org>]

> -----Original Message-----
> From: Gdb-patches <gdb-patches-bounces+nils-
> christian.kempke=intel.com@sourceware.org> On Behalf Of Potharla,
> Rupesh via Gdb-patches
> Sent: Wednesday, April 20, 2022 2:29 AM
> To: Kevin Buettner <kevinb@redhat.com>; Kevin Buettner via Gdb-patches
> <gdb-patches@sourceware.org>
> Cc: George, Jini Susan <JiniSusan.George@amd.com>; Parasuraman,
> Hariharan <Hariharan.Parasuraman@amd.com>; Sharma, Alok Kumar
> <AlokKumar.Sharma@amd.com>
> Subject: RE: GDB/Fortran: Support for Assumed Rank Zero.
> 
> [AMD Official Use Only]
> 
> 
> >On Mon, 18 Apr 2022 08:33:28 -0700
> >Kevin Buettner via Gdb-patches <gdb-patches@sourceware.org> wrote:
> >
> >> I'm also (still) wondering how to run the testsuite to use flang
> >> instead of gfortran since it'd be nice to test to see if the
> >> setup_xfail actually works.  I spent just enough time looking at it
> >> last week to convince myself that GDB's testing infrastructure
> >> currently lacks the mechanisms to do this.  However, I could be wrong,
> >> so if someone knows how it's done, I'd like to learn about it...
> >
> >It seems that the answer is to run the test as follows:
> >
> >make check TESTS="gdb.fortran/assumedrank.exp"
> >RUNTESTFLAGS="F90_FOR_TARGET=flang"
> >
> >(I thought that I had tried this last week.)
> >
> >When I run the above command on my Fedora 35 machine, I see:
> >
> ># of expected passes            500
> ># of unexpected failures        2503
> ># of unresolved testcases       500
> >
> But the command should only run assumedrank.exp testcase, looks like it ran
> all the tests under gdb.fortran.
> 
> gdb summary after running assumedrank.exp with flang:
> 
>                 === gdb Summary ===
> 
> # of expected passes            25
> # of expected failures          1
> 
> >So it seems that this test doesn't work very well with flang at the moment.
> >
> >That being the case, while I'm not against adding setup_xfail for clang, it
> >doesn't seem all that useful due to the dismal results when testing against
> >flang.
> >
> 
> 
>         if {$test_count == 1 && [test_compiler_info {clang-*}]} {
>            setup_xfail "*-*-*"
>            fail "compiler does not support rank 0"
>            continue
>         }
> 
> I think failing the testcase at the iteration entry and continuing to test next
> case is the best way to handle these dismal results.
> Please let me know your suggestions/comments on this.
> 
> Regards,
> Rupesh P

Please not a problem with this - if one wants to use a Fortran compiler other than
gfortran one always has to also supply the respective c-compiler in order for it to
get recognized properly. This is a shortcoming in the current compiler
identification - I'm actually working on a patch for that.

But running
   make check TESTS="gdb.fortran/assumedrank.exp" RUNTESTFLAGS="F90_FOR_TARGET=flang"
and looking at the log will show that the compiler identification actually identified
gcc and gfortran as the compiler used (it will still try to compile with flang but the identified
compiler in get_/test_compiler_info is gcc..). From my run in gdb.log:

   get_compiler_info: gcc-9-3-0
   UNTESTED: gdb.fortran/assumedrank.exp: compiler does not support assumed rank
   testcase /.../gdb/testsuite/gdb.fortran/assumedrank.exp completed in 0 seconds

                   === gdb Summary ===

   # of untested testcases         1

The correct command would probably be

   make check TESTS="gdb.fortran/assumedrank.exp" RUNTESTFLAGS="F90_FOR_TARGET=flang
      CC_FOR_TARGET=clang"

which leads to output like:

   Running .../testsuite/gdb.fortran/pointers.exp ...
   get_compiler_info: clang-10-0-0

Cheers,
Nils
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