From: ismaelj AT hotmail DOT com (" Ismael  Jurado")
Subject: Another problem with DLL's
19 Mar 1997 13:35:40 -0800
Approved: cygnus DOT gnu-win32 AT cygnus DOT com
Distribution: cygnus
Message-ID: <199703191639.IAA11461.cygnus.gnu-win32@f14.hotmail.com>
Content-Type: text/plain
X-Originating-IP: [194.179.125.167]
Original-To: gnu-win32 AT cygnus DOT com
Original-Sender: owner-gnu-win32 AT cygnus DOT com

I've got a problem with DLL's...

Folowing the instruccions of the home page of Cygnus, everything works
OK when I link the DLL with my executable but... if you try to load the
library indirectly via LoadLibrary(), it returns an HRESULT of 0

Someone knows how to solve this or is just a bug?

Thanks, 
     ismaelj AT hotmail DOT com


code folows:
----------------------------------------------------------------------
mydll.h
----------------------------------------------------------------------
#include <windows.h>

typedef void (*foop)();
void foof();

----------------------------------------------------------------------
mydll.c
----------------------------------------------------------------------
#include "dll.h"

int WINAPI DllMain(HINSTANCE H, DWORD d, PVOID p) {
  return TRUE;
}

void WINAPI foof() {
  MessageBox(NULL, "Hello from the DLL", "DLL", MB_OK);
}
asm (".section .idata$3\n" ".long 0,0,0,0,0,0,0,0");

----------------------------------------------------------------------
mydll.def
----------------------------------------------------------------------
EXPORTS
foof
----------------------------------------------------------------------
main.c
----------------------------------------------------------------------
#include <stdio.h>
#include "dll.h"

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,PSTR
szCmdLine, int iCmdShow) {
  HANDLE dllh;
  foop foo;
  char buf[126];
  dllh=LoadLibrary("mydll.dll");
  if ((UINT)dllh <= HINSTANCE_ERROR){
    sprintf(buf,"Error loading DLL: %d", dllh);
    MessageBox(NULL, buf, "APP", MB_OK);
  }
  else {
   foo=(foop)GetProcAddress(dllh, "foof");
  if (foo==NULL)
      MessageBox(NULL, "foo== null", "APP", MB_OK);
    else
      foo();
  }
  if ((UINT)dllh > HINSTANCE_ERROR)
    FreeLibrary(dllh);
  return 0;
}
----------------------------------------------------------------------
Dll link process:
----------------------------------------------------------------------
gcc -c mydll.c
ld --dll --subsystem windows -e _DllMain AT 12 -o jnk \
   --base-file dll.base mydll.o -L%LIBRARY_PATH% -luser32
dlltool --dllname mydll.dll --base-file dll.base \
    --def mydll.def --output-lib mydll.a --output-exp mydll.exp
ld --dll --subsystem windows -e _DllMain AT 12 -o mydll.dll \
   mydll.exp mydll.o -L%LIBRARY_PATH% -luser32
rm jnk dll.base

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