Re: Building an encapsulated library that uses GNAT sockets under Windows

[Ahlan <ahlan.marriott@gmail.com>]

On Friday, 22 April 2016 10:23:31 UTC+2, Dmitry A. Kazakov  wrote:
> On 22/04/2016 09:58, ahlan@marriott.org wrote:
> > On Thursday, 21 April 2016 15:00:04 UTC+2, Dmitry A. Kazakov  wrote:
> >> It seems I finally found a way to build it. The solution is quite
> >> perplexing. I would be glad if anybody could shed some light on it.
> >>
> >> An encapsulated library requires that -lws2_32 -lwsock32 appeared *both*
> >> at the beginning and the end of the linker command line. Only then no
> >> "undefined reference" messages appear.
> >>
> >> For this build this program:
> >> --------------------------------------- gcc_wrapper.adb ---
> >> with Ada.Command_Line;  use Ada.Command_Line;
> >> with Ada.Exceptions;    use Ada.Exceptions;
> >> with Ada.Text_IO;       use Ada.Text_IO;
> >> with GNAT.OS_Lib;       use GNAT.OS_Lib;
> >>
> >> procedure GCC_Wrapper is
> >>      Prefix : String_List :=
> >>               (  new String'("-lwsock32"),
> >>                  new String'("-lws2_32")
> >>               );
> >>      Options : String_List (1..Argument_Count);
> >> begin
> >>      for No in 1..Argument_Count loop
> >>         Options (No) := new String'(Argument (No));
> >>      end loop;
> >>      declare
> >>         List : String_List := Prefix & Options & Prefix;
> >>      begin
> >>         Put ("gcc.exe");
> >>         for No in List'Range loop
> >>            Put (" " & List (No).all);
> >>         end loop;
> >>         New_Line;
> >>         Set_Exit_Status (Exit_Status (Spawn ("gcc.exe", List)));
> >>      end;
> >> exception
> >>      when Error : others =>
> >>         Put_Line
> >>         (  Standard_Error,
> >>            "Fault: " & Exception_Information (Error)
> >>         );
> >>         Set_Exit_Status (2);
> >> end GCC_Wrapper;
> >> --------------------------------------- gcc_wrapper.adb ---
> >>
> >> The project file must contain:
> >>
> >>      package Linker is
> >>         for Driver use "<absolute-path-to>/gcc_wrapper.exe";
> >>      end Linker;
> >>
> >> --
> >> Regards,
> >> Dmitry A. Kazakov
> >> http://www.dmitry-kazakov.de
> >
> > Dear Dmitry,
> >
> > Is this perhaps the solution to my question "Using Gnat.Sockets in a Windows DLL" that I posted on 8-Dec-2015?
> 
> Yes, I think it is the same problem you reported. BTW, I built gprbuild 
> from the latest Git sources. That did not fix the problem.
> 
> It looks really weird how GCC linker searches libraries under Windows. 
> Not to mention its abysmal performance. It takes literally an hour to 
> link an executable against 20-30 libraries.
> 
> -- 
> Regards,
> Dmitry A. Kazakov
> http://www.dmitry-kazakov.de

Dear Dmitry,
The problem is not in Gprbuild.exe but in libexe/gprbuild/gprlib.exe
Have you tried building Gprlib from the git sources? - that might be a more elegant solution.

MfG
Ahlan