ada dll and c++ work together easy guide

ada dll and c++ work together easy guide

[bubble]

dear all,

I just want to share some of my experience about MS visual C++ work with 
ada.
if possible,please modify it and put it in ada wiki.

before start,you should check your environment.
It is my work environment.

1. Ada GPL 2006 and GPS.
2. microsoft visual studio 2005


please follow the steps.
1. write your ada code and build dynamic library.
2. make a .lib file (for static linking)
3. work together
4. run your code.





step 1.   source code.

----------------------------- t.ads
with interfaces.c;
package t is

   package C renames interfaces.c;

   procedure test(a,b,z,d,e:c.int) ;
   pragma export (stdcall, test, "test");


end t;



--------------------------------t.adb

with ada.text_io;
with t.th;
package body t is
   procedure test(a,b,z,d,e:c.int) is
      myd : integer := 0;
   begin
      t.th.t.getToken (myd);
      ada.text_io.put_line(myd'img & " and e value is" & c.int'image(e));
   end;

end t;



------------------------------------th.ads
package t.th is


   task T is
      entry getToken (t : out integer);
   end;
private
d : integer := 0;

end t.th;




-------------------------------------th.adb

with ada.text_io;
package body t.th is
   task body T is
      use ada.text_io;

   begin

      loop
         select
            accept getToken (t : out integer) do
               t := d;
            end getToken;
         or
            terminate;
         end select;
         d := d + 1;
      end loop;

   end ;
end t.th;

-------------------------------------


and most important thing is your project file.
It make you more easy.



project Testdll is
   for Library_Name use "Te";
   for Library_Dir use "dll";
   for Library_Ali_Dir use "ali";
   for Library_Kind use "dynamic";
   for Languages use ("Ada");
   for Object_Dir use "obj";
   for Library_Interface use ("t");


   for Library_Auto_Init use "False";
   for Library_Src_Dir use "dll";
end Testdll;







of course, you can config all settings in your GPS IDE(almost).
be careful,the GPS can not do Library_Interface setting correctly.
after configure it , you should check the project file and modify it.
Library_Interface means which package contain export functions in DLL.

Library_Auto_Init is interesting and you must choose a correct setting in 
your project.

if choose True, it will call adaInit when library load. (which means 
elaboration appear in loading time automaticly )
if choose False, it will export init and finalize functions in DLL and you 
must call them by yourself.

if you export function like C/C++ "normal" function without any elaboration 
parts, you may set library_auto_init to True.


if your ada code not only work like C/C++ but also need Ada elaboration 
function.
you should initialize/finalize by yourself.

"DANGEROUS" DANGEROUS" DANGEROUS"DANGEROUS"DANGEROUS"

for example,
if you has library level task need to elaboration in load time and use 
implied linking and loading
it will "deadlock WAITING"  when DllMain call init code
It's unexpected behaviour that you don't want to.

DANGEROUS"DANGEROUS"DANGEROUS"DANGEROUS"DANGEROUS"


in some case , you may use LoadLibrary / GetProcAddress to work (Explicit 
loading).
It is not easy to management your code,especially you export many functions 
.




2. make a .lib file (for static linking)
you can use utilities dumpbin and lib to generate .lib file
(2.A)

     dumpbin/exports Te.dll > te.def,

the file file content is

Microsoft (R) COFF/PE Dumper Version 8.00.50727.42
Copyright (C) Microsoft Corporation.  All rights reserved.


Dump of file te.dll

File Type: DLL

  Section contains the following exports for Te.dll

    00000000 characteristics
    44E2ABD2 time date stamp Wed Aug 16 13:23:30 2006
        0.00 version
           1 ordinal base
          19 number of functions
          19 number of names

    ordinal hint RVA      name

          1    0 00001461 Tefinal
          2    1 000011A0 Teinit
          3    2 00005130 _CRT_MT
          4    3 000050E0 t_E
          5    4 000050D0 t__th_E
          6    5 0000155F t__th__P2sIP
          7    6 00007040 t__th___chain
          8    7 00001745 t__th___elabb
          9    8 0000156E t__th___elabs
         10    9 00007044 t__th___master
         11    A 000050D8 t__th__d
         12    B 00007048 t__th__t
         13    C 00006010 t__th__tT1
         14    D 000016B9 t__th__tTKB
         15    E 000050D1 t__th__tTKE
         16    F 00001490 t__th__tTKVIP
         17   10 000050D4 t__th__tTKZ
         18   11 00005000 temain_E
         19   12 0000178F test@20

  Summary

        1000 .bss
        1000 .data
        1000 .edata
        2000 .idata
        1000 .rdata
        1000 .reloc
       2E000 .stab
       E3000 .stabstr
        4000 .text


 (2.b)
remove all in Te.def but leave ...

EXPORTS
          Tefinal
          Teinit
          _CRT_MT
          t_E
          t___elabb
          t__th_E
          t__th__P2sIP
          t__th___elabb
          t__th__d
          t__th__tB
          t__th__tE
          t__th__tVIP
          t__th__tZ
          temain_E
          test@20


The Teinit and Tefinal is used to elaborate and terminate the Ada 
elaboration part after Te.dll loaded.
(the name does not call adainit/adafinalize but still the same function as 
adainit/adafinalize)


3. work together in MS VC++
 start visual stdio c++ project and add Te.lib to your linker setting.
 writing a Te.h header for Ada DLL
(the GPS should generate .lib and .h for you ^^; ).


extern "C" extern void _stdcall test(int a,int b,int c,int d,int e);
extern "C" extern void  Teinit();
extern "C" extern void  Tefinal();

and write a c/c++ test code to generate a .exe file

#include "stdafx.h"

#include "Te.h"
#include <iostream>
#include <windows.h>

int _tmain(int argc, _TCHAR* argv[])
{

 Teinit();  //start init
 for (int i = 0 ; i< 300 ;i++)
  test(0,0,0,0,i);

 Tefinal(); //end  init
 return 0;
}



4. run your code.

put .exe and .dll in the same directary and run the test

the loader will find dll follow the sequence
1. current directory
2. path variable
3. winodws directory


put the dll and exe in the same directary  is better

Re: ada dll and c++ work together easy guide

[Georg Bauhaus]

On Wed, 2006-08-16 at 16:58 +0800, bubble wrote:
> dear all,
> 
> I just want to share some of my experience about MS visual C++ work with 
> ada.
> if possible,please modify it and put it in ada wiki.

These are valuable hints. Please be sure to emphasize
that they are both GNAT-specific and also Windows-specific.
They probably will be version specific in addition.


-- Georg 

Re: ada dll and c++ work together easy guide

[Manuel Gomez]

bubble ha escrito:
> I just want to share some of my experience about MS visual C++ work with
> ada.
> if possible,please modify it and put it in ada wiki.
>

I have copied your text to the Ada Programming wiki and formated it in
the usual style for the book. You can do further editing in the wiki
itself if you want.

http://en.wikibooks.org/wiki/Ada_Programming/Platform/Windows/Visual_C%2B%2B_-_GNAT_interface