build: warning with gcc-11.2.0 for MPIC_Waitall

[thomasgillis]

I have been trying to compile mpich from the sources on perlmutter using gcc-11.2.0 and I get a few warnings in the collectives and the topo.

As pointed out by @raffenet this issue is similar to #5687 and the PR #5749

collectives:

CC       src/mpi/coll/allgather/lib_libmpi_la-allgather_intra_ring.lo
src/mpi/coll/allgather/allgather_intra_k_brucks.c: In function 'MPIR_Allgather_intra_k_brucks':
src/mpi/coll/allgather/allgather_intra_k_brucks.c:165:21: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  165 |         mpi_errno = MPIC_Waitall(num_reqs, reqs, MPI_STATUSES_IGNORE);
      |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allgather/allgather_intra_k_brucks.c:165:21: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allgather/allgather_intra_k_brucks.c:7:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~

  CC       src/mpi/coll/allreduce/lib_libmpi_la-allreduce_inter_reduce_exchange_bcast.lo
src/mpi/coll/allreduce/allreduce_intra_tree.c: In function 'MPIR_Allreduce_intra_tree':
src/mpi/coll/allreduce/allreduce_intra_tree.c:164:21: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  164 |         mpi_errno = MPIC_Waitall(num_reqs, reqs, MPI_STATUSES_IGNORE);
      |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_tree.c:164:21: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_tree.c:9:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
  CC       src/mpi/coll/alltoall/lib_libmpi_la-alltoall_allcomm_nb.lo
src/mpi/coll/allreduce/allreduce_intra_ring.c: In function 'MPIR_Allreduce_intra_ring':
src/mpi/coll/allreduce/allreduce_intra_ring.c:88:21: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
   88 |         mpi_errno = MPIC_Waitall(2, reqs, MPI_STATUSES_IGNORE);
      |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_ring.c:88:21: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_ring.c:10:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c: In function 'MPIR_Allreduce_intra_recexch':
src/mpi/coll/allreduce/allreduce_intra_recexch.c:161:25: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  161 |             mpi_errno = MPIC_Waitall(recv_nreq, recv_reqs, MPI_STATUSES_IGNORE);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c:161:25: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_recexch.c:8:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c:208:21: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  208 |         mpi_errno = MPIC_Waitall(send_nreq, send_reqs, MPI_STATUSES_IGNORE);
      |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c:208:21: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_recexch.c:8:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c:212:21: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  212 |         mpi_errno = MPIC_Waitall((k - 1), recv_reqs, MPI_STATUSES_IGNORE);
      |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c:212:21: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_recexch.c:8:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c:253:29: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  253 |                 mpi_errno = MPIC_Waitall(send_nreq, send_reqs, MPI_STATUSES_IGNORE);
      |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c:253:29: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_recexch.c:8:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c:256:29: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  256 |                 mpi_errno = MPIC_Waitall((k - 1), recv_reqs + (k - 1), MPI_STATUSES_IGNORE);
      |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c:256:29: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_recexch.c:8:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c:299:21: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  299 |         mpi_errno = MPIC_Waitall(i, send_reqs, MPI_STATUSES_IGNORE);
      |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_recexch.c:299:21: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_recexch.c:8:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c: In function 'MPIR_Allreduce_intra_k_reduce_scatter_allgather':
src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:182:29: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  182 |                 mpi_errno = MPIC_Waitall(num_rreq, recv_reqs, MPI_STATUSES_IGNORE);
      |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:182:29: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:8:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:233:25: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  233 |             mpi_errno = MPIC_Waitall((k - 1), recv_reqs, MPI_STATUSES_IGNORE);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:233:25: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:8:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:256:33: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  256 |                     mpi_errno = MPIC_Waitall((k - 1), recv_reqs + (k - 1), MPI_STATUSES_IGNORE);
      |                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:256:33: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:8:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:262:25: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  262 |             mpi_errno = MPIC_Waitall(num_sreq, send_reqs, MPI_STATUSES_IGNORE);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:262:25: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:8:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:282:25: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  282 |             mpi_errno = MPIC_Waitall(i, send_reqs, MPI_STATUSES_IGNORE);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:282:25: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/coll/allreduce/allreduce_intra_k_reduce_scatter_allgather.c:8:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~

topologies:

CC       src/mpi/topo/lib_libmpi_la-topoutil.lo
src/mpi/topo/dist_graph_create.c: In function 'MPIR_Dist_graph_create_impl':
src/mpi/topo/dist_graph_create.c:260:17: warning: 'MPIC_Waitall' accessing 20 bytes in a region of size 0 [-Wstringop-overflow=]
  260 |     mpi_errno = MPIC_Waitall(idx, reqs, MPI_STATUSES_IGNORE);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/mpi/topo/dist_graph_create.c:260:17: note: referencing argument 3 of type 'MPI_Status *'
In file included from ./src/include/mpiimpl.h:212,
                 from src/mpi/topo/dist_graph_create.c:6:
./src/include/mpir_coll.h:50:5: note: in a call to function 'MPIC_Waitall'
   50 | int MPIC_Waitall(int numreq, MPIR_Request * requests[], MPI_Status statuses[]);
      |     ^~~~~~~~~~~~

[hzhou]

Just need to declare MPIC_Watiall using status pointers rather as array.