incomplete struct

[FUSILIER]

Hi all,

I created C program under Visual C++.
Compilation was done without any mistake.

I try to compile it under LabWindows/CVI 6.0, and
I have one error:
"Type error in argument 3 to `LoadFromFile'; found 'pointer to pointer
to struct FileData' expected 'pointer to pointer to incomplete struct
FileData defined at ElementOperations.h:182'."

I don't understand what is "incomplete struct" ?

Here is the "wrong code", the error is on the argument pFileData:

struct FileData* pFileData = 0;
.....
resFunction = ElementOperations_LoadFromFile(pElementOperation,
szFCFilePath, &pFileData, &errorInfo);
***********************
***********************
Here the prototype of the function ElementOperations_LoadFromFile:
EXPORTIMPORTDEF HRESULT ElementOperations_Load
FromFile
(
struct MotFCElementOperations* pTheObject,
const char* szFileName,
struct MotFCFileData** returnVal,
struct MotSErrorInfo* pErrorInfo
);
***********************
***********************
And here the definition of the structure:
struct MotFCFileData
{
long lReserved;
};

Any help is welcome.

Thank you.
Sébastien FUSILIER

[LuisG]

Sébastien,

It looks like pFileData is of type struct FileData*. Shouldn't it be of type struct MotCFFileData* instead?

- luis

[FUSILIER]

Sorry I make a mistake,
here the good prototype:

EXPORTIMPORTDEF HRESULT ElementOperations_LoadFromFile
(
struct ElementOperations* pTheObject,
const char* szFileName,
struct FileData** returnVal,
struct ErrorInfo* pErrorInfo
);

and the good definition of the structure:

struct FileData
{
long lReserved;
};


Sebastien.

[LuisG]

Okay, I see the problem now. This is happening because your LoadFromFile declaration takes place before the full definition of struct FileData. Because of that, the function uses the "incomplete" version of the data type, whereas the pFileData parameter (because there is an actual variable involved) uses the fully resolved structure definition. Hence the mismatch during compilation.

You can fix it by moving the struct FileData definition above the function declaration.

- luis