CFront compilation problems

c.kestas

I'm new in C/front and I'm having trouble compiling the sample program (sample.c) that comes with the Navision CD. I have C/Front for Navision 4.00 and I try to compile with C++ (Visual Studio .NET).

I get many errors like the one that follows:

error C2664: 'stricmp' : cannot convert parameter 1 from 'DBL_U8 *' to 'const char *'
Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast

Any ideas?
Thanks

dick11

That code is (old) standard C. The compiler of VS is more strict today so it complains more often. You could decrease you compiler warning level.

I use C#: no problem, only a lot of work.

Search for dllimport in this forum. Also look in the cf.h file for the exact interface.

Neosky

I had exactly the same problem. And I like to use c++ so I was happy to find this post but pity finding not solution here, so I work out a solution as follows.

After coping the content of sample.c to sample.cpp and libload.c to libload.cpp and compilation of sample.cpp with Visual Studio .NET 2003 you get the following error:

C1083 Include_file can’t be loaded ‘cf/ch.h’
Solution: change

#include <cf/cf.h>

To

Extern "C" {
#include "cf.h"
}

The same applies to lipload.cpp.

Neosky wrote:

Added:If you don't do so you will get in the end a Linker error: 92 unsolved reference.

Next error C1004 says that the file ends unexpected just delete the last symbol in the cf.h

c.kestas wrote:

error C2664: 'stricmp' : cannot convert parameter 1 from 'DBL_U8 *' to 'const char *'
Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast

After a little search [1] [2] [3] I found that it is a convert problem.

typedef unsigned char DBL_U8;		
DBL_U8     *NDBCDriverName = (DBL_U8*)"ndbcn";

unsigned char *NDBCDriverName;

The Code above shows that NDBCDriverName is a pointer to ‘unsigned char’ but ‘stricmp’ is requires a pointer to 'const char', the almost the same applies to lines below here ‘SessionInit’ is waiting for a pointer to unsigned char. The Solution is a typecast:

//<<<Changed by Neosky>>>---[(const char*)]---{to convert unsigned char* to const char*}
  //<<<Changed by Neosky>>>---[(unsigned char*)]---{to convert const char* to unsigned char*}
  if (!stricmp((const char*)NDBCDriverName, "NDBCN"))
    SessionInit((unsigned char*)"cfront.dll");
  else if (!stricmp((const char*)NDBCDriverName, "NDBCS"))
    SessionInit((unsigned char*)"cfrontsql.dll");

The next error C2440 ‘=’:’void*’ can’t be converted to ‘’comes after compiling libload.cpp

hGlobalSession = malloc(sizeof(DLL));

This means the function malloc gives out a void value witch need to be converted by typecast to HDLLSESSION, HDLLSESSION is a static struct DLL* as shown:

_CRTIMP void * __cdecl malloc(size_t);

typedef struct DLL
{
  char               DLLName[20];
  DBL_S16            DLLLoaded;
  DBL_DLLHandleType* DLLHandle;
} DLL;
typedef struct DLL* HDLLSESSION;
static HDLLSESSION hGlobalSession = NULL;

So the solution is as follows:

//<<<Changed by ber_lst>>>---[(struct DLL*)]---{to convert void* to struct DLL* }
  hGlobalSession = (struct DLL*)malloc(sizeof(DLL));

The last error C2664 says ‘strcpy’ converting of parameter 2 from ‘DBL_U8*’ to ‘const char*’ is not possible.

strcpy(hGlobalSession->DLLName, DLLName);

DLLName is a DBL_U8 type and as such it is unsigned char, so that means a pointer to unsigned char can’t be converted to a pointer to const char.

char *  __cdecl strcpy(char *, const char *);

void SessionInit(DBL_U8* DLLName)
{
  //<<<Changed by ber_lst>>>---[(struct DLL*)]---{to convert void* to struct DLL* }
  hGlobalSession = (struct DLL*)malloc(sizeof(DLL));
  strcpy(hGlobalSession->DLLName, DLLName);
  hGlobalSession-&gt;DLLLoaded = 0;
  DBL_Init&#40;&#41;;
&#125;

The Solution:

//<<<Changed by ber_lst>>>---[(const char*)]---{to convert unsigned char* to struct const char*}
  strcpy(hGlobalSession->DLLName, (const char*)DLLName);

Finally copy all needed files as descript in readme.txt of c/front sample to the debug folder, compil the sample.exe and have fun. =D>