Problems using a DLL created with GNU from Microsoft VC++

[Kenneth Sandberg (ERA)]

I am trying to use a DLL created with cygwin g++ from an application created with Microsoft Visual C++. The reason is that I have C-code (huge) that is created for GNU and would like to use it in an application that requires Microsoft Visual C++.

This is what I have done:
 - I started with the example described in http://sources.redhat.com/cygwin/building-reloc-dlls.txt .

 - I changed the main-file to load the DLL:
	// Main file to try linking with a DLL under GNUwin32
	#include <windows.h>
	#include <stdio.h>

	typedef int (*doit)(int);
	typedef int (*doittoo)(int);

	int
	main()
	{
	   HINSTANCE hinstLib;
	   doit      doitPROC;
	   doittoo   doittooPROC;
	   int       x;

	   printf("main3.c\n");

	   //--- LOAD LIB ---
	   hinstLib = LoadLibrary("fooB.dll");
	   if (hinstLib == NULL) {
	      printf("Error loading DLL!\n");
	      exit(0);
	      }

	   //--- LOCATE FUNCTIONS ---
	   doitPROC = (doit)GetProcAddress(hinstLib,"doit__Fi");
	   if (doitPROC == NULL) {
	      printf("Can't locate doit()!\n");
	      exit(0);
	      }
	   doittooPROC = (doittoo)GetProcAddress(hinstLib,"doittoo__Fi");
	   if (doittooPROC == NULL) {
	      printf("Can't locate doittoo()!\n");
	      exit(0);
	      }

	   x = (doitPROC)(5);
	   printf("doit(5) returns %d\n",x);

	   x = (doittooPROC)(5);
	   printf("doittoo(5) returns %d\n",x);

	}

 - Compiled the code above with g++ main3.c -o main3.exe.  This works fine! Same result as before.

 - Compiled the code with Microsoft Visual C++ (unchanged). It compiles OK but it doesn't work. The message "Unhandled exception in main3.exe (NTDLL.DLL): 0xC000005: Access Violation." shows up. The Call Stack looks like this:
	NTDLL! 77f6cde6()
	NTDLL! 77f67506()
	CYGWIN1! 6101edff()
	CYGWIN1! 61047a6e()
	CYGWIN1! 61077304()
	CYGWIN1! 610774bb()
	CYGWIN1! 61073560()
	CYGWIN1! 6106f684()
	FOOB! 1000102b()
	main() line 38 + 7 bytes
	mainCRTStartup() line 206 + 25 bytes
	KERNEL32! 77f1ba3c()

I am running cygwin (latest release, I made a fresh install this morning) with Windows NT 4. Any suggestions?

/ Kenneth Sandberg  (Kenneth.Sandberg@era.ericsson.se)



--
Want to unsubscribe from this list?
Send a message to cygwin-unsubscribe@sourceware.cygnus.com