[Patch, Fortran] PR 46974: Handle C_(FUN)PTR variables in TRANSFER

[Steve Kargl]

On Sat, Dec 18, 2010 at 08:36:07PM +0100, Tobias Burnus wrote:
> The patch adds compile-time simplification support for C_PTR/C_FUNPTR 
> variables. Those are special beasts as they are derived types in Fortran 
> (gfc_expr/gfc_symbol) but for the middle end (tree) they are simple 
> (function) pointers.
> 
> The patch add special treatment to the <transfer bits> -> 
> C_(FUN)PTR-type conversion in target-memory.c - and it handles them 
> explicitly in assignment. I removed the bits about C_NULL_PTR which 
> seems to be dead code. I believe the function is never called for 
> C_NULL_PTR as the conversion to an c_intptr_t-like integer happens 
> earlier. Additionally, even if for C_NULL_PTR the code block would be 
> entered, there were a segfault as the component->backend_decl is NULL. 
> -- At least that's how I read gfc_get_derived_type.
> 
> Build and regtested on x86-64-linux.
> OK for the trunk?
> 
> Tobias
> 
> PS: I wrote in the PR that one should try to avoid the special handling 
> - obviously, I failed. However, the patch at least fixes the PR and 
> allows compile-time simplification.

OK.

Thanks for jumping in on the PR.  I think I was heading down the
wrong road.  In fact, it was becoming "a long and winding road"
(in honor of J. Lennon).

-- 
Steve