[Patch, fortran] PR25289 Cannot handle record numbers large than huge(0_4)

[FX Coudert]

> In libgfortran you can see that gfc_offset is defined in terms of off_t 
> and it is 64 bits there.  However, at the point of interest in 
> trans-io.c, off_t is int4 and not int8.
> 
> I found this out trying gfc_get_int_type (sizeof(off_t)) which fails 
> miserably and in -fdump-tree-original you can see that rec is assigned 
> (int4) n, with the int4 cast.
[...]
 > If I use gfc_get_int_type (sizeof(off64_t)) all appears to work fine.
 > Is it safe to assume off64_t is defined for all targets of interest?

You cannot do that kind of things anyhow, because the host off64_t 
(which will be used when the front-end is compiled) might not have the 
same size as the target off64_t (which will be used for the library). On 
that topic, you can e.g. read the thread that lead to 
http://gcc.gnu.org/ml/fortran/2005-12/msg00136.html According to Richard 
Henderson, that problem is solvable 
(http://gcc.gnu.org/ml/fortran/2005-12/msg00142.html), but I'm not sure 
if he's in possession of a constructive proof of existence ;-)

One possibility it to define a gfc_large_int to be integer(kind=8) if it 
exists, and integer(kind=4) otherwise (and do the same in the library).

FX