Function signature error

[miteshpandey]

Hello all,

I have the following code:

class TiffStream {

public:
    // ctor/dtor
    TiffStream();
    ~TiffStream();

public:
    enum SeekDir {
	    beg,
	    cur,
	    end,
    };

public:
    // factory methods
    TIFF* makeFileStream(std::iostream* str);
    TIFF* makeFileStream(std::ifstream* str);
    TIFF* makeFileStream(std::ofstream* str);

public:
    // tiff client methods
    static tsize_t read(thandle_t fd, tdata_t buf, tsize_t size);
    static tsize_t write(thandle_t fd, tdata_t buf, tsize_t size);
    static toff_t seek(thandle_t fd, toff_t offset, int origin);
    static toff_t size(thandle_t fd);
    static int close(thandle_t fd);
    static int map(thandle_t fd, tdata_t* phase, toff_t* psize);
    static void unmap(thandle_t fd, tdata_t base, tsize_t size);

    ..................
    ..................
};

TIFF*
TiffStream::makeFileStream(ifstream* str)
{
    m_inStream = str;
    m_outStream = NULL;
    m_ioStream = NULL;
    m_streamLength = getSize(m_this);

    m_tif =  TIFFClientOpen(m_name, 
                           "r",
			   m_this,
			   read,
			   write,
			   seek,
			   close,
			   size,
			   map,
			   unmap);
    return m_tif;
}

TIFF*
TiffStream::makeFileStream(ofstream* str)
{
	m_inStream = NULL;
        m_outStream = str;
	m_ioStream = NULL;
	m_streamLength = getSize(m_this);

	m_tif =  TIFFClientOpen(m_name, 
                           "w",
			   m_this,
			   read,
			   write,
			   seek,
			   close,
			   size,
			   map,
			   unmap);
    return m_tif;
}

TIFF*
TiffStream::makeFileStream(iostream* str)
{
    m_inStream = NULL;
    m_outStream = NULL;
    m_ioStream = str;
    m_streamLength = getSize(m_this);

    m_tif =  TIFFClientOpen(m_name, 
	                       "r+w",
	                       m_this,
			       read,
			       write,
			       seek,
			       close,
			       size,
			       map,
			       unmap);
    return m_tif;
}

The error generated is as below:

1>i:\de5.5_sdk_21_may_2008(2)\de5.5_sdk\deplugins\plugins\2d\tiffstream.cpp(45) : error C2664: 'TIFFClientOpen' : cannot convert parameter 10 from 'void (__cdecl *)(thandle_t,tdata_t,tsize_t)' to 'TIFFUnmapFileProc'
1>        None of the functions with this name in scope match the target type
1>i:\de5.5_sdk_21_may_2008(2)\de5.5_sdk\deplugins\plugins\2d\tiffstream.cpp(66) : error C2664: 'TIFFClientOpen' : cannot convert parameter 10 from 'void (__cdecl *)(thandle_t,tdata_t,tsize_t)' to 'TIFFUnmapFileProc'
1>        None of the functions with this name in scope match the target type
1>i:\de5.5_sdk_21_may_2008(2)\de5.5_sdk\deplugins\plugins\2d\tiffstream.cpp(87) : error C2664: 'TIFFClientOpen' : cannot convert parameter 10 from 'void (__cdecl *)(thandle_t,tdata_t,tsize_t)' to 'TIFFUnmapFileProc'
1>        None of the functions with this name in scope match the target type
1>Build log was saved at "file://I:\DE5.5_SDK_21_May_2008(2)\DE5.5_SDK\DE42\Temp\Win32\vc80\Debug\2d\BuildLog.htm"
1>2d - 3 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 1 up-to-date, 0 skipped ==========

#if defined(__cplusplus)
extern "C" {
#endif
typedef	void (*TIFFErrorHandler)(const char*, const char*, va_list);
typedef	tsize_t (*TIFFReadWriteProc)(thandle_t, tdata_t, tsize_t);
typedef	toff_t (*TIFFSeekProc)(thandle_t, toff_t, int);
typedef	int (*TIFFCloseProc)(thandle_t);
typedef	toff_t (*TIFFSizeProc)(thandle_t);
typedef	int (*TIFFMapFileProc)(thandle_t, tdata_t*, toff_t*);
typedef	void (*TIFFUnmapFileProc)(thandle_t, tdata_t, toff_t);
................
................
................

The following is the TIFFClientOpen function's signature

TIFF*
TIFFClientOpen(
	const char* name, const char* mode,
	thandle_t clientdata,
	TIFFReadWriteProc readproc,
	TIFFReadWriteProc writeproc,
	TIFFSeekProc seekproc,
	TIFFCloseProc closeproc,
	TIFFSizeProc sizeproc,
	TIFFMapFileProc mapproc,
	TIFFUnmapFileProc unmapproc
)

The error is generated for only the "unmap" function. Instead of a static class member function I used a free function. But still the error is there. Please help. I am stuck with this.

[ProgramArtist]

Hi,

I would explicitly mark the function as "__cdecl".
I'm not sure if this is the solution, but you can give it a try.

__cdecl (like expected in the error message) is usually not the standard calling function of MS VC++ (but this depends on the projects options).

In my experience this helped when giving call back functions...

If this is the case it will work for static members as well as for "free" functions.

With regards
Programartist
Ingo Bochmann

[Martin O]

You're passing a function pointer to this:

static void unmap(thandle_t fd, tdata_t base, tsize_t size);

but the expected signature is:

typedef	void (*TIFFUnmapFileProc)(thandle_t, tdata_t, toff_t);

[miteshpandey]

Thanks a lot Martin O . Dear God how could I have missed that?