http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49509
Summary: cannot promote types for arguments passed by value
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: stev...@alum.mit.edu
Compile the following test program gfortran, which is a toy example of
iso_c_binding that calls malloc(3).
program bug
use, intrinsic :: iso_c_binding
implicit none
interface
type(C_PTR) function malloc(n) bind(C, name='malloc')
import
integer(C_SIZE_T), value :: n
end function malloc
end interface
integer, parameter :: n = 3
integer(C_SIZE_T) sz
type(C_PTR) p
p = malloc(n) ! compiler error, cannot promote argument passed by value
sz = n ! ... whereas assignment succeeds
p = malloc(sz)
end program bug
I obtain the following error:
promote.f03:15.13:
p = malloc(n) ! compiler error, cannot promote argument type
1
Error: Type mismatch in argument 'n' at (1); passed INTEGER(4) to INTEGER(8)
(Similarly with older versions of gcc.) Note that "n" is passed by value, so
my understanding is that this should act much like the assignment sz = n (which
succeeds): gfortran should automatically promote n to a size_t, like any other
assignment of a narrower type to a wider type.
Please consider applying the same type-promotion rules that are used for
assignments to passing arguments by value. (I don't have the Fortran 2003
standard handy, but it is hard to believe that the two situations should be
treated differently.)
