[petsc-dev] Install location for MPIUNI mpi.h

[Jed Brown]

"Smith, Barry F." <bsmith at mcs.anl.gov> writes:

>> On Apr 25, 2018, at 2:31 PM, Jed Brown <jed at jedbrown.org> wrote:
>> 
>> "Smith, Barry F." <bsmith at mcs.anl.gov> writes:
>> 
>>>> On Apr 25, 2018, at 1:36 PM, Jed Brown <jed at jedbrown.org> wrote:
>>>> 
>>>> It is currently installed to include/petsc/mpiuni/mpi.h and petscsys.h
>>>> includes it as <mpi.h>, which means that users of MPIUNI need to put
>>>> -I/prefix/include/petsc/mpiuni in their command lines.  Matt and I agree
>>>> that this is bad.  We disagree on the solution.
>>>> 
>>>> He wants to install it to /prefix/include/mpi.h as though the user had
>>>> written --download-mpich.  This would conflict if a user later installs
>>>> a real MPI to that location.
>>> 
>>>  Jed,
>>> 
>>>   So you propose in petscsys.h ?
>>> 
>>> #if defined(PETSC_HAVE_MPIUNI)
>>> #include <petsc/mpiuni/mpi.h> 
>>> #else
>>> #include <mpi.h>
>>> #endif
>>> 
>>>  I don't have a problem with this.
>> 
>> Yes, and same installation layout as today.
>
>    Ok, this is far better than copying the mpiuni mpi.h file to a
>    public place (Matt's suggestion) and is a bit better than requiring
>    the extra -I flag (Satish's suggestion)

Is this okay for 'maint'?  It feels aggressive, but I'm having trouble
constructing a scenario in which it would break an existing installation
or existing code.