[mpich-discuss] Extensible Clang type annotation

[Dmitri Gribenko]

On Wed, Jan 2, 2013 at 8:02 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
> On Wed, Jan 2, 2013 at 11:51 AM, Dmitri Gribenko <gribozavr at gmail.com>
> wrote:
>>
>> [resending to the list, sorry for duplicates]
>>
>> On Wed, Jan 2, 2013 at 7:38 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
>> > Also, could there be a way (maybe in a future clang release) for me to
>> > get
>> > static type checking for my own types, such as __float128 or pair types
>> > like
>> > {long,long} (which are not in the MPI standard)? It can't truly be a
>> > static
>> > value because I have to create the type at run-time, but perhaps there
>> > could
>> > be a way to tell clang "I promise to set this type up like so."
>>
>> Sorry, I did not understand your requirements completely, but you can
>> annotate your own 'MPI_Datatype's (as I described in the previous
>> email).  Is that sufficient for your task?
>
>
> I can't annotate mine because they don't have a static value. (Unless there
> is a way that's not in the documentation.)
>
> I'm actually just setting
>
> MPI_Datatype MY_MPI_ENUM = MPI_INT;
>
> in a different compilation unit.

Sorry if what I wrote was unclear.  Here's a complete example:

$ cat t.cc
#include <mpi.h>

enum MyEnum { Foo };
MPI_Datatype MyEnumDatatype MPICH_ATTR_TYPE_TAG(MyEnum);

void foo(MyEnum e, int i) {
  MPI_Send(&e, 1, MyEnumDatatype, 0, 0, MPI_COMM_WORLD);
  MPI_Send(&i, 1, MyEnumDatatype, 0, 0, MPI_COMM_WORLD);
  MPI_Send(&e, 1, MPI_INT, 0, 0, MPI_COMM_WORLD);
}

$ clang -fsyntax-only -I mpich2-build/src/include/ t.cc
t.cc:8:12: warning: argument type 'int *' doesn't match specified
'MPI' type tag that requires 'MyEnum *' [-Wtype-safety]
  MPI_Send(&i, 1, MyEnumDatatype, 0, 0, MPI_COMM_WORLD);
           ^~     ~~~~~~~~~~~~~~
t.cc:9:12: warning: argument type 'MyEnum *' doesn't match specified
'MPI' type tag that requires 'int *' [-Wtype-safety]
  MPI_Send(&e, 1, MPI_INT, 0, 0, MPI_COMM_WORLD);
           ^~     ~~~~~~~
2 warnings generated.

Dmitri

-- 
main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if
(j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/