Help with DllStructCreate / Calling C DLL functions

[tehhahn]

Hi everybody,

I'm dealing with C functions exported in a dynamic link library at the moment. For that, I've implemented a simple Stack in C. Im already able to call functions, so building the .dll file and accessing its functions is not a problem for me. The problem is the AutoIt function DllStructCreate. I do not know how to create nested structures in AutoIt. I have the following implemented in C:

stack.h

#ifndef STACK_H
#define STACK_H

typedef int stackDataType;

typedef struct stack {
    stackDataType vValue;
    struct stack *pNext;
} SStack;

#ifdef  __cplusplus
extern "C" {
#endif

#ifndef DLL_TEST
#define DLL_DECLARE __declspec(dllexport)
#endif

DLL_DECLARE void dll_check();
DLL_DECLARE stackDataType pop(SStack **head);
DLL_DECLARE void push(SStack **head, stackDataType vValue);

#ifdef  __cplusplus
}
#endif

#endif

stack.c (not really relevant)

#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include "stack.h"

void dll_check() { printf("Works"); }

stackDataType pop(SStack **head) {
    SStack *pTop = *head;
    stackDataType vValue = pTop->vValue;
    *head = pTop->pNext;
    free(pTop);
    return vValue;
}

void push(SStack **head, stackDataType vValue) {
    SStack *pNode = malloc( sizeof(SStack) );
    pNode->vValue = vValue;
    pNode->pNext = *head;
    *head = pNode;
}

And last, but not least the CppStack.au3:

expandcollapse popup

#include-once

Exit Main()

Func Main()
    Local Const $hDLL = _StackCpp_Startup()
    MsgBox(64, "_StackCpp_Startup", @error)

    _StackCpp_Check($hDLL)
    MsgBox(64, "_StackCpp_Check", @error)

    _StackCpp_Push($hDLL, 1)
    MsgBox(64, "_StackCpp_Push", @error)

    _StackCpp_Shutdown($hDLL)
EndFunc   ;==>Main

Func _StackCpp_Startup($sFile = Default)
    Local $h = 0
    If $sFile = Default Then $sFile = @ScriptDir & "\libCppStack.dll"
    $h = DllOpen($sFile)
    If $h = -1 Then Return SetError(1, 0, False)
    Return $h
EndFunc   ;==>_StackCpp_Startup

Func _StackCpp_Shutdown(ByRef Const $h)
    DllClose($h)
EndFunc   ;==>_StackCpp_Shutdown

;~ Works...
Func _StackCpp_Check(ByRef Const $h)
    DllCall($h, "none", "dll_check")
    If @error Then Return SetError(@error, 0, False)
    Return True
EndFunc   ;==>_StackCpp_Check

;~ Does not work since the DllCall call fails with a runtime error...
Func _StackCpp_Push(ByRef Const $h, Const $V)
    Local Const $SSTACK = DllStructCreate("int;int")
    DllCall($h, "none", "push", "ptr", DllStructGetPtr($SSTACK), "int", $V)
    If @error Then Return SetError(@error, 0, False)
    Return True
EndFunc   ;==>_StackCpp_Push

My problem is to deal with the following two lines, since the second datatype in the structure is the structure itself.

Local Const $SSTACK = DllStructCreate("int;int")
DllCall($h, "none", "push", "ptr", DllStructGetPtr($SSTACK), "int", $V)

Can somebody explain me, how to realize that nested structure in AutoIt? I've added the project (NetBeans IDE) to the appendix!

Thanks!

CppStack.zip

[trancexx]

You just have to change calling convention and all should work. If you want to do that from your script then it's:

DllCall($h, "none", "push:cdecl", "ptr", DllStructGetPtr($SSTACK), "int", $V)

Or before compiling (to use stdcall). In that case AutoIt script can stay the way it is now.