Missing only clause to use statement causing compilation errors #363

The recent v0.3.0 introduced a behavior change that caused compilation errors in our project.

To illustrate the issue, let me use a very simple Fortran module defining a module variable and a subroutine used to print a number:

module global

  implicit none

  integer :: number

contains

  subroutine print_number(number)
    integer, intent(in) :: number

    print*, number
  end subroutine print_number
end module global

The special thing here is that the module variable and subroutine argument have the same name, which is totally OK on the Fortran side because they have different scopes.

Now comes the difference. When generating the f90wrap_ interfaces, versions < 0.3.0 would use the only clause to only bring in the function being interfaced:

! Module global_ defined in file global.f90

subroutine f90wrap_global__print_number(number)
    use global, only: print_number
    implicit none
    
    integer, intent(in) :: number
    call print_number(number=number)
end subroutine f90wrap_global__print_number

[...]

The new 0.3.0 version doesn't use the only clause for some reason leading to the following:

! Module global_ defined in file global.f90

subroutine f90wrap_global__print_num(num)
    use global
    implicit none
    
    integer, intent(in) :: num
    call print_num(num=num)
end subroutine f90wrap_global__print_num

Because of the unrestricted use, we now have two variables with the same name in the same scope leading to a compilation error:

    7 |     integer, intent(in) :: number
      |                                 1
Error: Name ‘number’ at (1) is an ambiguous reference to ‘number’ from current program unit
f90wrap_global_3.0.f90:3:46:

    3 | subroutine f90wrap_global__print_number(number)
      |                                              1
Error: Symbol ‘number’ at (1) has no IMPLICIT type

I am currently looking into the f90wrap code to try debugging this problem. I already open the issue hoping that someone already has an answer :)