On Feb 13, 2013, at 6:43 AM, Jed Brown <[email protected]> wrote:

On Thu, Feb 7, 2013 at 9:56 PM, Barry Smith <[email protected]> wrote: I have removed the use of PETSC_NULL from all PETSc C code. Please remember to just use NULL in PETSc source code in the future (or Karl's script will find you).

I see you changed to

#define PETSC_IGNORE NULL

but kept

#define PETSC_NULL 0

Should the second be updated to

#define PETSC_NULL NULL

because it is stricter about passing PETSC_NULL for an integer argument?

Yes, I was hesitant to change too much at once. It is fine to change and fine to add the damn deprecated message. Barry

Also, we could do something like this (properly guarded, of course):

__attribute__((deprecated)) PETSC_UNUSED PETSC_STATIC_INLINE void PETSC_NULL_IS_DEPRECATED_JUST_USE_NULL() {}; #define PETSC_NULL (PETSC_NULL_IS_DEPRECATED_JUST_USE_NULL(),NULL)

which can be used for any compiler that supports non-static statements in declarations (everything but Sun and MSVC?) and has __attribute__((deprecated)). This produces warnings like this under Clang

ex5.c:102:36: warning: 'PETSC_NULL_IS_DEPRECATED_JUST_USE_NULL' is deprecated [-Wdeprecated-declarations] ierr = PetscOptionsGetReal(PETSC_NULL,"-par",&user.param,NULL);CHKERRQ(ierr); ^ /home/jed/petsc/include/petscsys.h:387:31: note: expanded from macro 'PETSC_NULL' #define PETSC_NULL (PETSC_NULL_IS_DEPRECATED_JUST_USE_NULL(),NULL) ^ /home/jed/petsc/include/petscsys.h:385:33: note: 'PETSC_NULL_IS_DEPRECATED_JUST_USE_NULL' declared here PETSC_UNUSED static inline void PETSC_NULL_IS_DEPRECATED_JUST_USE_NULL() {}; ^ 1 warning generated.

and like this with GCC:

ex5.c: In function ‘main’: ex5.c:102:3: warning: ‘PETSC_NULL_IS_DEPRECATED_JUST_USE_NULL’ is deprecated (declared at /home/jed/petsc/include/petscsys.h:385) [-Wdeprecated-declarations]

We can make the error message cleaner (but more confusing) with

__attribute__((deprecated)) PETSC_UNUSED static inline void PETSC_NULL() {}; #define PETSC_NULL (PETSC_NULL(),NULL)

which produces:

ex5.c: In function ‘main’: ex5.c:102:3: warning: ‘PETSC_NULL’ is deprecated (declared at /home/jed/petsc/include/petscsys.h:385) [-Wdeprecated-declarations]

Any sense in this stuff?