On Feb 13, 2013, at 6:43 AM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
>
> On Thu, Feb 7, 2013 at 9:56 PM, Barry Smith <bsmith at mcs.anl.gov> 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?
