AztecOO, etc.: Trilinos configure support for implicit function declarations

[dridzal]

I've heard that recent clang versions (16+) report errors for what used to be warnings about implicit function declarations, which are necessary to compile packages like AztecOO. To my surprise, even clang12 on MacOS reports errors (with certain package configurations). At the moment, I'm using the configure line

-D CMAKE_C_FLAGS="-Wno-error=implicit-function-declaration" \

to get around this problem. Have there been discussions on this topic? A possible answer is to simply wait for the removal of the old solver stack.

[cgcgcg]

Do you know if other packages apart from AztecOO are affected by this?

[dridzal]

I'm not 100% sure if there are other packages with this issue. I don't think so. I've included all warnings I get below, and a list of all packages I built in this instance. I guess it would have to be a C package. I could investigate further, however if we don't need to support those packages for much longer, it may be best to use the above flag.

$ ls packages/
amesos         epetra         intrepid       minitensor     rtop           stratimikos    xpetra
amesos2        epetraext      intrepid2      ml             sacado         teuchos        zoltan
aztecoo        galeri         isorropia      muelu          seacas         thyra          zoltan2
belos          ifpack         kokkos         pamgen         shards         tpetra
common         ifpack2        kokkos-kernels rol            shylu          triutils

Warnings:

[713/2362] Building C object packages/aztecoo/src/CMakeFiles/aztecoo.dir/az_domain_decomp.c.o
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_domain_decomp.c:513:7: warning: implicit declaration of function 'az_fnroot_c' is invalid in C99 [-Wimplicit-function-declaration]
      AZ_FNROOT_F77(&root,bindx2,&(bindx2[N+1]),mask, &nlvl, 
      ^
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_aztec.h:611:42: note: expanded from macro 'AZ_FNROOT_F77'
#   define AZ_FNROOT_F77                 az_fnroot_c
                                         ^
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_domain_decomp.c:515:7: warning: implicit declaration of function 'az_rcm_c' is invalid in C99 [-Wimplicit-function-declaration]
      AZ_RCM_F77(&root,bindx2,&(bindx2[N+1]),mask,&((*ordering)[total]),
      ^
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_aztec.h:613:42: note: expanded from macro 'AZ_RCM_F77'
#   define AZ_RCM_F77                    az_rcm_c
                                         ^
2 warnings generated.
[725/2362] Building C object packages/aztecoo/src/CMakeFiles/aztecoo.dir/az_gmres.c.o
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_gmres.c:426:9: warning: implicit declaration of function 'az_dlaic1_c' is invalid in C99 [-Wimplicit-function-declaration]
        AZ_DLAIC1_F77(&ijob, &i, svbig, &big, vectmp, &vectmp[i], &sestpr, &ss, &cc);
        ^
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_aztec.h:631:24: note: expanded from macro 'AZ_DLAIC1_F77'
#define AZ_DLAIC1_F77  az_dlaic1_c
                       ^
1 warning generated.
[735/2362] Building C object packages/aztecoo/src/CMakeFiles/aztecoo.dir/az_gmres_condnum.c.o
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_gmres_condnum.c:422:9: warning: implicit declaration of function 'az_dlaic1_c' is invalid in C99 [-Wimplicit-function-declaration]
        AZ_DLAIC1_F77(&ijob, &i, svbig, &big, vectmp, &vectmp[i], &sestpr, &ss, &cc);
        ^
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_aztec.h:631:24: note: expanded from macro 'AZ_DLAIC1_F77'
#define AZ_DLAIC1_F77  az_dlaic1_c
                       ^
1 warning generated.
[739/2362] Building C object packages/aztecoo/src/CMakeFiles/aztecoo.dir/az_c_util.c.o
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_c_util.c:1148:9: warning: implicit declaration of function 'sswap_' is invalid in C99 [-Wimplicit-function-declaration]
        SSWAP_F77(n, &a[i__ + a_dim1], lda, &a[ip + a_dim1], lda);
        ^
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_c_util.c:58:19: note: expanded from macro 'SSWAP_F77'
#define SSWAP_F77 F77_BLAS_MANGLE(sswap,SSWAP)
                  ^
/Users/dridzal/development/Trilinos/build/fem-cubed/packages/aztecoo/src/AztecOO_config.h:5:38: note: expanded from macro 'F77_BLAS_MANGLE'
#  define F77_BLAS_MANGLE(name,NAME) name ## _
                                     ^
<scratch space>:10:1: note: expanded from here
sswap_
^
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_c_util.c:1157:9: warning: implicit declaration of function 'sswap_' is invalid in C99 [-Wimplicit-function-declaration]
        SSWAP_F77(n, &a[i__ + a_dim1], lda, &a[ip + a_dim1], lda);
        ^
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_c_util.c:58:19: note: expanded from macro 'SSWAP_F77'
#define SSWAP_F77 F77_BLAS_MANGLE(sswap,SSWAP)
                  ^
/Users/dridzal/development/Trilinos/build/fem-cubed/packages/aztecoo/src/AztecOO_config.h:5:38: note: expanded from macro 'F77_BLAS_MANGLE'
#  define F77_BLAS_MANGLE(name,NAME) name ## _
                                     ^
<scratch space>:11:1: note: expanded from here
sswap_
^
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_c_util.c:1167:9: warning: implicit declaration of function 'sswap_' is invalid in C99 [-Wimplicit-function-declaration]
        SSWAP_F77(n, &a[i__ + a_dim1], lda, &a[ip + a_dim1], lda);
        ^
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_c_util.c:58:19: note: expanded from macro 'SSWAP_F77'
#define SSWAP_F77 F77_BLAS_MANGLE(sswap,SSWAP)
                  ^
/Users/dridzal/development/Trilinos/build/fem-cubed/packages/aztecoo/src/AztecOO_config.h:5:38: note: expanded from macro 'F77_BLAS_MANGLE'
#  define F77_BLAS_MANGLE(name,NAME) name ## _
                                     ^
<scratch space>:12:1: note: expanded from here
sswap_
^
3 warnings generated.
[741/2362] Building C object packages/aztecoo/src/CMakeFiles/aztecoo.dir/az_scaling.c.o
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_scaling.c:552:11: warning: implicit declaration of function 'az_dlaswp_c' is invalid in C99 [-Wimplicit-function-declaration]
          AZ_DLASWP_F77( &ione, &(b[rpntr[iblk_row]]), &m1, &ione, &m1, &(ipiv[rpntr[iblk_row]]), &iminus_one );
          ^
/Users/dridzal/development/Trilinos/packages/aztecoo/src/az_aztec.h:630:24: note: expanded from macro 'AZ_DLASWP_F77'
#define AZ_DLASWP_F77  az_dlaswp_c
                       ^
1 warning generated.

[cgcgcg]

Ok. Sounds like we can just wait until we officially remove them. I don't think we have had many changes to AztecOO in the last couple of years.