[petsc-dev] macro wrappers around functions to caste suck

[Barry Smith]

  The biggest mistake of C was CPP

   Hey, we can eliminate the currently needed (PetscObject) cast in a bunch of places with this horrible trick.

   This actually doesn't introduce any more macros, its the same number with more reasonable naming.

   Barry

On Apr 5, 2013, at 7:50 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:

> 
> On Fri, Apr 5, 2013 at 7:40 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
> (lldb) b PetscFunctionListAdd
> Breakpoint 4: no locations (pending).
> WARNING:  Unable to resolve breakpoint to any actual locations.
> (lldb) b PetscFunctionListAdd_Private
> Breakpoint 5: where = libpetsc.dylib`PetscFunctionListAdd_Private + 23 at reg.c:173, address = 0x000000010a1d3697
> 
> The solution to too many macros is always MOAR MACROS!
> 
> This is valid:
> 
> PETSC_EXTERN PetscErrorCode PetscFunctionListAdd(PetscFunctionList*,const char[],void (*)(void));
> #define PetscFunctionListAdd(list,name,fptr) PetscFunctionListAdd((list),(name),(PetscVoidFunction)(fptr))
> 
> 
> off in the implementation:
> 
> #undef PetscFunctionListAdd
> PETSC_EXTERN PetscErrorCode PetscFunctionListAdd(PetscFunctionList *fl,const char name[],void (*fnc)(void))
> {
>   ...
> }
> 
> 
> This would make the debugging thing work, at the expense of being slightly more confusing to the reader. But maybe comments would be enough to explain what's going on?