Symbols and FL_PARAMETER in "interface; subroutine" versus "contains; subroutine"

[Tobias Burnus <burnus at net-b dot de>]

Hi all,

when I implemented IMPORT I missed to check two cases, which promptly
don't work:
(as the example by Harald Anlauf in comment 0 in PR27546 actually
triggers this, this is really my fault)

a) "import :: items" in an interface which is part of a _module_
(otherwise importing of an derived type works, also for module-defined
derived types)

b) Import of constants used in kind expressions.

while for (a) I have a (hopefully correct) idea, I'd like to get some
pointers for (b) since I don't know at which routine of all the *.c
files to look.

Example for (b):
   integer, parameter :: dp = 4
   interface
     subroutine foo(a)
       import
       real(dp) :: a
     end subroutine foo
   end interface
end

The "import" only disables the check whether a symbol is in the
interface namespace or not
(in decl.c's variable_decl).

What I currently don't see is the difference between a subroutine in an
interface block and a subroutine in "contains" in the same  program. In
the latter case it works, in the former case it ends up in expr.c's
check_init_expr
  case EXPR_VARIABLE:
    if (e->symtree->n.sym->attr.flavor == FL_PARAMETER)
      {
        t = simplify_parameter_variable (e, 0);
        break;
      }
    gfc_error ("Parameter '%s' at %L has not been declared or is "
where it fails as FL_PARAMETER does not match, even though "dp" is a
parameter.

I somehow fail to see how this symbol gets propagated or, respectively,
where it gets resolved for subroutines (thus I can do the same for
"subroutine"s in interfaces).

Thanks for any pointer,

Tobias