[petsc-dev] meaning of PETSC_USE_EXTERN_CXX?

[Barry Smith]

   Are we ready to move this "branch" back into petsc-dev?   (Aside from the visibility stuff which is not yet mainstream and won't affect users, I think it is ready to go).

    Barry

On Mar 6, 2013, at 12:10 AM, Jed Brown <jedbrown at mcs.anl.gov> wrote:

> 
> On Tue, Mar 5, 2013 at 11:57 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
> This is very nice, much better than before, no confusing macros and complicated #if conditions, simpler for the users to understand also.
> 
>   Does this mean we shouldn't/don't need to/should continue to mark functions used in a single file as static?
> 
> If we use --with-visibility, unadorned functions behave like PETSC_INTERN except that their names will be mangled for clanguage=C++. (The symbols aren't visible outside the library so that doesn't matter, except to language purists and possibly C++ exception propagation.) I would still prefer to use 'static' whenever possible because it makes it easier to determine how much code could depend on that function.
>  
>   I found a few problems so far
> 
>    0) Do these really need PETSC_EXTERN? Note that they are not declared PETSC_EXTERN when defined, only in snesimpl.h
> 
> PETSC_EXTERN PetscErrorCode SNESReset_VI(SNES);
> PETSC_EXTERN PetscErrorCode SNESDestroy_VI(SNES);
> PETSC_EXTERN PetscErrorCode SNESView_VI(SNES,PetscViewer);
> PETSC_EXTERN PetscErrorCode SNESSetFromOptions_VI(SNES);
> PETSC_EXTERN PetscErrorCode SNESSetUp_VI(SNES);
> PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESVIComputeVariableBoundsFunction)(SNES,Vec,Vec);
> PETSC_EXTERN PetscErrorCode SNESVISetComputeVariableBounds_VI(SNES,SNESVIComputeVariableBoundsFunction);
> PETSC_EXTERN PetscErrorCode SNESVISetVariableBounds_VI(SNES,Vec,Vec);
> PETSC_EXTERN PetscErrorCode SNESDefaultConverged_VI(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*);
> 
> They can all become PETSC_INTERN unless we have reason to support plugin authors or petscts calling those directly instead of using an interface.
> 
>