Changed if-condition for PETSc version according to the suggestion by Nori

CMakeLists.txt

@@ -117,11 +117,7 @@ IF(OGS_USE_LIS)
 ENDIF()
 
 IF(OGS_USE_PETSC)
-    MESSAGE(STATUS "PETSc version is ${PETSC_VERSION}")
     ADD_DEFINITIONS(-DUSE_PETSC)
-    IF(PETSC_VERSION VERSION_GREATER 3.4)
-      ADD_DEFINITIONS(-DPETSC_V35)
-    ENDIF(PETSC_VERSION VERSION_GREATER 3.4) 
 ENDIF()
 
 IF(OGS_USE_EIGEN)

MathLib/LinAlg/PETSc/PETScLinearSolver.cpp

@@ -41,9 +41,9 @@ bool PETScLinearSolver::solve(const PETScVector &b, PETScVector &x)
     PetscMemoryGetCurrentUsage(&mem1);
 #endif
 
-#ifdef PETSC_V35
+#if (PETSC_VERSION_MAJOR == 3) && (PETSC_VERSION_MINOR > 4)
     KSPSetOperators(_solver, _A.getRawMatrix(), _A.getRawMatrix());
-#else 
+#else
     KSPSetOperators(_solver, _A.getRawMatrix(), _A.getRawMatrix(), DIFFERENT_NONZERO_PATTERN);
 #endif