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Re: Lot of undefined symbols at link time, even with -l option on good libraries

I think you're right, it seems to be a problem with trailing underscore in function naming.
For example :

in /usr/lib/w32api/libkernel32.a we found :

   00000000 T _FormatMessageA@28
                    U __head_libkernel32_a
   00000000 I __imp__FormatMessageA@28

which is required by win32-winbase.o, result of the build of /usr/lib/gcc/win32ada/win32-winbase.adb
U _FormatMessageA
U _FormatMessageW
U _GlobalReAlloc
U _LocalReAlloc

The source code for this part is the following :
  pragma Import (Stdcall, Doit, "FormatMessageA");

I try change it with pragma Import (C, Doit, "_FormatMessageA"); or things like that with no success.

May be it's the trailing @28 after symbol name which cause error, but I cannot control it ( it's DLL calling convention parameter size ). Compiler/linker should usually add or remove trailing @nn if necessary.

To answer your general questions, I'am building a large Ada application ( 200 source files ), using W32 API, with Win2000 GNAT Compiler.

Larry Hall a écrit :

At 05:38 AM 9/21/2004, you wrote:

Using latest release of CygWin ( 1.5.11-1 ) I install the devel kit,

including gcc and gnat compilers. Then I build from src GCC and GNAT release 3.4.1 ( which include necessary patchs for my application ).
All my Ada application compile well with gnatmake command, but link failed with a lot of undefined symbols mainly issued from w32api and system libraries.

Undefined symbols are for example : FormatMessageA, GlobalReAlloc, CreateDialogParamA, WSAStartup, accept, select, ... about 100 undefined from system libraries.
Of course system libraries are included at link time with the appropriate -l option ( -lnetapi32 -lwsock32 -lshell32 -ladvapi32 -lwinmm -lodbc32 -lwin32ada -luser32 -lgdi32 -lcomdlg32 -laddr2line -lbfd -liberty )
I verify with NM command, symbols are right defined in the included libraries.

If someone have an idea ?

Sure. Follow the problem reporting guidelines given here:

Problem reports:

That will give those on the list interested in helping you out with this problem at least the basic information about your system and what you're doing.

My WAG is that you haven't declared these symbols properly so that the calling convention is wrong (__cdecl vs __stdcall) but I'd need to see a small example of your code, how you compile it, and what the errors
are to be sure. Then again, maybe this idea is enough for you to have an "AHA!" moment and fix the problem yourself. :-)

Larry Hall
RFK Partners, Inc. (508) 893-9779 - RFK Office
838 Washington Street (508) 893-9889 - FAX
Holliston, MA 01746

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