Cleanup PGI Compiler Warnings

[jjhursey]

Mentioned in this thread the PGI compiler is throwing some warnings around the atomics code on ppc64le:

"/tmp/ompi-src/opal/mca/pmix/pmix4x/openpmix/src/atomics/sys/powerpc/atomic.h",
          line 142: warning: "cc" clobber ignored
                            : "cc", "memory");
                              ^

"/tmp/ompi-src/opal/mca/pmix/pmix4x/openpmix/src/atomics/sys/powerpc/atomic.h",
          line 210: warning: "cc" clobber ignored
                            : "cc", "memory");
                              ^

"/tmp/ompi-src/opal/mca/pmix/pmix4x/openpmix/src/atomics/sys/powerpc/atomic.h",
          line 239: warning: "cc" clobber ignored
  PMIX_ATOMIC_POWERPC_DEFINE_ATOMIC_64(add, add)
  ^

"/tmp/ompi-src/opal/mca/pmix/pmix4x/openpmix/src/atomics/sys/powerpc/atomic.h",
          line 239: warning: variable "t" was set but never used
  PMIX_ATOMIC_POWERPC_DEFINE_ATOMIC_64(add, add)
  ^

We should sweep through and clean those up.

[jjhursey]

@awlauria Filed part of this for OpenPMIx in openpmix/openpmix#2042 (master branch). Thanks!

[jjhursey]

@awlauria you did a bunch of cleanup here. Do you think we can close this and just keep working on cleaning up the warnings as we can?

I still see a number of warnings, but I think it has gotten much better recently.

A few of the warnings I still see in PGI CI (note that some are outside the scope of OMPI):

This from hwloc

"/tmp/ompi-src/3rd-party/hwloc-2.4.0/include/private/misc.h", line 386:
          warning: enumerated type mixed with another type
        return HWLOC_OBJ_L1ICACHE + depth-1;

This from OpenPMIx

"/tmp/ompi-src/3rd-party/openpmix/src/atomics/sys/atomic_stdc.h", line 127:
          warning: ellipsis with no explicit parameters is nonstandard
  PMIX_ATOMIC_STDC_DEFINE_FETCH_OP(add, 32, int32_t, +)
  ^

This from PGI compiler itself

"/opt/nvidia/hpc_sdk/Linux_ppc64le/20.11/compilers/include-gcc49/_cplus_macros.
          h", line 20: warning: zero used for undefined preprocessing
          identifier "__cplusplus"
  #if __cplusplus >= 201103L
      ^

"/opt/nvidia/hpc_sdk/Linux_ppc64le/20.11/compilers/include/_cplus_preinclude.h"
          , line 42: warning: use of non-prototype function declarator
  extern void __builtin_pgi_va_start();

This from PRRTE:

"prte_mca_base_components_register.c", line 150: warning: enumerated type mixed
          with another type
                                                 0, PRTE_MCA_BASE_VAR_FLAG_DEFAULT_ONLY | PRTE_MCA_BASE_VAR_FLAG_INTERNAL,
                                                    ^

This from OPAL in OMPI

"../../opal/include/opal_stdatomic.h", line 38: warning: unrecognized
          preprocessing directive
  #warning C11 _Atomic type not fully supported. The C11 atomic support should have been disabled.
   ^

"../../opal/include/opal/sys/atomic_stdc.h", line 115: warning: ellipsis with
          no explicit parameters is nonstandard
  OPAL_ATOMIC_STDC_DEFINE_FETCH_OP(add, 32, int32_t, +)
  ^

[awlauria]

The MPI PR is still open and needs rebasing. I'll put some cycles in this week to try and get that in.

There were still some in PMIx and HWLOC/PRRTE, but most of those got cleaned up. I think OMPI is the main culprit now.