Question

Is there a simple way to prevent Ada names from getting mangled when creating an Ada DLL?

Here is my .adb code

with Ada.Text_IO;
package body testDLL is
   procedure Print_Call is
   begin
      Ada.Text_IO.Put_Line("Hello World");
   end Print_Call;

   function Add_Nums(A,B : in Integer) return Integer is
   begin
      return A + B;
   end Add_Nums;

end testDLL;

my .ads

package testDLL is
   procedure Print_Call;
   pragma export (dll, Print_Call, "Print_Call");

   function Add_Nums(A,B : in Integer) return Integer;
   pragma export (dll, Add_Nums, "Add_Nums");
end testDLL;

my python

import ctypes

TestDLL = ctypes.WinDLL ("libTestDLL.dll")
Print_Call = getattr(TestDLL, "Print_Call@0")
Print_Call()

you can see that I have to add ‘@0’ to the end of my function name, but this seems to change when I move the same code to a different compiler. This is creating some problems for me. I need either a standard mangling format or a way to remove the mangling all together.

Answer 1

You can control the object name via the Link_Name and External_Name parameters of the pragma, writing it like so:

pragma Export (C, Print_Call, "Print_Call", "Print_Call");

Alternatively, if you’re using Ada2012 you can use aspects to specify these:

function Add_Nums(A,B : in Integer) return Integer
    with Export, Convention => Ada, Link_Name => "Add_Nums";

The following covers Ada’s interfacing pragmas:
http://www.ada-auth.org/standards/12rm/html/RM-J-15-5.html

This thread covers a little discussion revealing the differences of the two:
https://groups.google.com/forum/?fromgroups=#!searchin/comp.lang.ada/opengl/comp.lang.ada/6IVlMbtvrrU/mv3UUiDg5RwJ