[petsc-dev] Fwd: SACUDA - Cannot compile

[Barry Smith]

  Satish,

    We already had this fight and this change lost. Making this change means that one can never build a VecType on the fly, so all VecType must be declared at compile time which defeats the entire purpose of PETSc.

   I don't understand why "const" is scoped differently for a macro than for the typedef." but it seems to me an annoying feature of C.

   Barry


On Oct 27, 2010, at 5:08 PM, Satish Balay wrote:

> On Wed, 27 Oct 2010, Barry Smith wrote:
> 
>> 
>> On Oct 27, 2010, at 4:48 PM, Jed Brown wrote:
>> 
>>> On Wed, Oct 27, 2010 at 17:45, Barry Smith <bsmith at mcs.anl.gov> wrote:
>>> hmm, is there any reason we can't/shouldn't use a typedef for our VecType (and its many friends)?
>>> 
>>> I think the issue is because "const" is scoped differently for a macro than for the typedef.
>>> 
>>> typedef char *Foo;
>>> 
>>> now "const Foo" means "char *const" instead of "const char *".
>> 
>>  Damn, damn, damn, damn,
> 
> -#define VecType char*
> +typedef const char* VecType;
> 
> -EXTERN PetscErrorCode PETSCVEC_DLLEXPORT VecGetType(Vec, const VecType *);
> +EXTERN PetscErrorCode PETSCVEC_DLLEXPORT VecGetType(Vec, VecType *);
> 
> The above type of change [i.e 'const VecType' to 'VecType'] gets
> src/vec/vec/interface sources compiled..
> 
> Satish