c_null_ptr missing inside iso_c_binding ?

[tilio]

I did:

program test
use, intrinsic :: iso_c_binding
implicit none

type(c_ptr) :: it
it=C_NULL_PTR

end program test

gives on compilation:

Undefined symbols:
"_iso_c_binding_mp_c_null_ptr_", referenced from:
_MAIN__ in ifortSi2yr6.o

on MAC OS 10.5.2 with ifort 10.1

[Steven_L_Intel1]

This is a known problem that is fixed in a future release. I think you can work around it with something like this:

module my_iso_c_binding
use, intrinsic :: iso_c_binding, dummy=>C_NULL_PTR
type(c_ptr) :: C_NULL_PTR
!DEC$ ATTRIBUTES EXTERN,ALIAS:"iso_c_binding_mp_c_null_ptr" :: C_NULL_PTR
end module my_iso_c_binding

program test
use my_iso_c_binding
implicit none

type(c_ptr) :: it
it=C_NULL_PTR

end program test

[tilio]

I copy pasted your code but it still doesn't compile:

Undefined symbols:
"iso_c_binding_mp_c_null_ptr", referenced from:
_MAIN__ in ifortFw4qcO.o
ld: symbol(s) not found

[Steven_L_Intel1]

Oops. Use this instead:

!DEC$ ATTRIBUTES EXTERN,ALIAS:"iso_c_binding_mp_c_null_ptr_" :: C_NULL_PTR

I never can keep the different name decorations straight. The problem is that we fixed a bug in the compiler that left off a leading underscore but missed updating the run-time library.