[petsc-dev] ugliness due to missing lapack routines

[Barry Smith]

  PETSc is littered with 

  if (A->factortype == MAT_FACTOR_LU) {
#if defined(PETSC_MISSING_LAPACK_GETRS)
    SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"GETRS - Lapack routine is unavailable.");
#else
    PetscStackCall("LAPACKgetrs",LAPACKgetrs_("N",&m,&nrhs,mat->v,&mat->lda,mat->pivots,x,&m,&info));
    if (info) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"GETRS - Bad solve");
#endif
  } else if (A->factortype == MAT_FACTOR_CHOLESKY) {
#if defined(PETSC_MISSING_LAPACK_POTRS)
    SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"POTRS - Lapack routine is unavailable.");
#else
    PetscStackCall("LAPACKpotrs",LAPACKpotrs_("L",&m,&nrhs,mat->v,&mat->lda,x,&m,&info));
    if (info) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"POTRS Bad solve");
#endif


due to missing LAPACK routines.   I propose for each missing routine we provide a dummy routine that calls SETERRQ() with the PETSC_ERR_SUP error and returns a "special" error code in the info arg. This way we can have pretty (CPPless :-) code like

  if (A->factortype == MAT_FACTOR_LU) {
    PetscStackCall("LAPACKgetrs",LAPACKgetrs_("N",&m,&nrhs,mat->v,&mat->lda,mat->pivots,x,&m,&info));
    if (info) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"GETRS - Bad solve");
  } else if (A->factortype == MAT_FACTOR_CHOLESKY) {
    PetscStackCall("LAPACKpotrs",LAPACKpotrs_("L",&m,&nrhs,mat->v,&mat->lda,x,&m,&info));
    if (info) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"POTRS Bad solve");
  }

  Does anyone see a problem with doing this?

   Barry