Default Open MPI 4.0.0 does not provide functions deprecated in MPI-2.0

[bertwesarg]

Background information

What version of Open MPI are you using? (e.g., v1.10.3, v2.1.0, git branch name and hash, etc.)

Open MPI 4.0.0

Describe how Open MPI was installed (e.g., from a source/distribution tarball, from a git clone, from an operating system distribution package, etc.)

$ tar xf openmpi-4.0.0.tar.bz2
$ cd openmpi-4.0.0
$ mkdir _build
$ cd _build
$ ../configure --prefix=…

Please describe the system on which you are running

• Operating system/version: Ubuntu 18.04..1
• Computer hardware: ThinkPad X480s
• Network type: N.A

---

Details of the problem

libmpi.so.40.20.0 misses the following symbols, which are deprecated in MPI-2.0 (see Chapter 15, page 599 pp.)

• MPI_Keyval_create
• MPI_Keyval_free
• MPI_Attr_put
• MPI_Attr_get
• MPI_Attr_delete

$ nm ./ompi/.libs/libmpi.so.40.20.0 | grep '\(MPI_Keyval_create\|MPI_Keyval_free\|MPI_Attr_put\|MPI_Attr_get\|MPI_Attr_delete\)'
$

The worst part is, that there are prototypes in mpi.h:

cat >declcheck-depr-mpi-2.0.c <<EOF
#include <mpi.h>

void test()
{
    int ret = MPI_Keyval_create(NULL, NULL, NULL, NULL);
    ret = MPI_Keyval_free(NULL);
    ret = MPI_Attr_put(MPI_COMM_WORLD, 0, NULL);
    ret = MPI_Attr_get(MPI_COMM_WORLD, 0, NULL, NULL);
    ret = MPI_Attr_delete(MPI_COMM_WORLD, 0);
}
EOF
$ gcc -Iompi/include -c declcheck-depr-mpi-2.0.c

declcheck-depr-mpi-2.0.c: In function ‘test’:
declcheck-depr-mpi-2.0.c:5:5: warning: ‘MPI_Keyval_create’ is deprecated: MPI_Keyval_create was deprecated in MPI-2.0; use MPI_Comm_create_keyval instead. [-Wdeprecated-declarations]
     int ret = MPI_Keyval_create(NULL, NULL, NULL, NULL);
     ^~~
In file included from declcheck-depr-mpi-2.0.c:1:0:
ompi/include/mpi.h:2625:20: note: declared here
 OMPI_DECLSPEC  int MPI_Keyval_create(MPI_Copy_function *copy_fn,
                    ^~~~~~~~~~~~~~~~~
declcheck-depr-mpi-2.0.c:6:5: warning: ‘MPI_Keyval_free’ is deprecated: MPI_Keyval_free was deprecated in MPI-2.0; MPI_Comm_free_keyval instead. [-Wdeprecated-declarations]
     ret = MPI_Keyval_free(NULL);
     ^~~
In file included from declcheck-depr-mpi-2.0.c:1:0:
ompi/include/mpi.h:2633:20: note: declared here
 OMPI_DECLSPEC  int MPI_Keyval_free(int *keyval)
                    ^~~~~~~~~~~~~~~
declcheck-depr-mpi-2.0.c:7:5: warning: ‘MPI_Attr_put’ is deprecated: MPI_Attr_put was deprecated in MPI-2.0; use MPI_Comm_set_attr instead [-Wdeprecated-declarations]
     ret = MPI_Attr_put(MPI_COMM_WORLD, 0, NULL);
     ^~~
In file included from declcheck-depr-mpi-2.0.c:1:0:
ompi/include/mpi.h:2609:20: note: declared here
 OMPI_DECLSPEC  int MPI_Attr_put(MPI_Comm comm, int keyval, void *attribute_val)
                    ^~~~~~~~~~~~
declcheck-depr-mpi-2.0.c:8:5: warning: ‘MPI_Attr_get’ is deprecated: MPI_Attr_get was deprecated in MPI-2.0; use MPI_Comm_get_attr instead [-Wdeprecated-declarations]
     ret = MPI_Attr_get(MPI_COMM_WORLD, 0, NULL, NULL);
     ^~~
In file included from declcheck-depr-mpi-2.0.c:1:0:
ompi/include/mpi.h:2605:20: note: declared here
 OMPI_DECLSPEC  int MPI_Attr_get(MPI_Comm comm, int keyval, void *attribute_val, int *flag)
                    ^~~~~~~~~~~~
declcheck-depr-mpi-2.0.c:9:5: warning: ‘MPI_Attr_delete’ is deprecated: MPI_Attr_delete was deprecated in MPI-2.0; use MPI_Comm_delete_attr instead [-Wdeprecated-declarations]
     ret = MPI_Attr_delete(MPI_COMM_WORLD, 0);
     ^~~
In file included from declcheck-depr-mpi-2.0.c:1:0:
ompi/include/mpi.h:2601:20: note: declared here
 OMPI_DECLSPEC  int MPI_Attr_delete(MPI_Comm comm, int keyval)
                    ^~~~~~~~~~~~~~~

[bosilca]

The prototypes are there just so that the compiler can give you a nice warnings about the use of deprecated symbols.

[bertwesarg]

The prototypes are there just so that the compiler can give you a nice warnings about the use of deprecated symbols.

"deprecated" is not the same as "removed". So what do you want me to tell with your comment?

[bosilca]

Nothing more than these symbols should not be used. It's been years MPI libraries issue warnings about deprecated symbols, and still some software developers chose to ignore them. The warnings suggest what functions should be used instead, updating software packages should be easy.

[bertwesarg]

Sorry, you just explained "deprecated" to me. But what Open MPI did, was to "remove" these functions without removing the declaration.

[jsquyres]

Shoot. I know we intended to fix this before v4.0.0 went out the door -- and I see that #6018 was the attempt to do that. But it looks like #6018 fixed mpi.h, but did not fix Makefile.am. 😦

[jsquyres]

Actually, @hjelmn @bertwesarg, was #6118 enough? I.e., shouldn't all the .c files in ompi/mpi/c always be in the library? I.e., the --enable-mpi-compatibility flag should only affect whether declarations are in mpi.h, right?

[hjelmn]

#6118 was enough for master. Need one more for v4.0.x

[hjelmn]

Really hate that close and comment button.......