C / C++ / MFC

// IsOnStack.cpp : Defines the entry point for the console application.
//
 
#include "stdafx.h"
#include <iostream>
#include <windows.h>
using namespace std;
 
bool IsOnStack(const void *pData)
{
	DWORD StackBase;
	DWORD StackLimit;
	__asm 
	{
		MOV EAX, DWORD PTR FS:[0x04]
		MOV StackBase, EAX
		MOV EAX, DWORD PTR FS:[0x08]
		MOV StackLimit, EAX
	}
 
	DWORD Address = reinterpret_cast<DWORD>(pData);
 
	return (Address >= StackLimit) && (Address < StackBase);
}
 
const char* PrintStack(const void *pData)
{
	return IsOnStack(pData) ? ": Stack" : ": Not on Stack";
}
 
int main(int argc, char* argv[])
{
	const char *pString1 = "String1";
	cout << pString1 << PrintStack(pString1) << endl;
 
	char String2[] = "String2";
	cout << String2 << PrintStack(String2) << endl;
 
	return 0;
}

String1: Not on Stack
String2: Stack

MOV EAX, DWORD PTR FS:[0x04]
MOV StackBase, EAX
MOV EAX, DWORD PTR FS:[0x08]
MOV StackLimit, EAX

code_discuss wrote:

found that the address of gC is different in a.exe between in b.dll.
Is it strange?

Mark Salsbery
Microsoft MVP - Visual C++

LONG lImageWidth = 640;//TransparentSrcBitmap.GetWidth();
LONG lImageHeight = 480;//TransparentSrcBitmap.GetHeight();
WORD wBitsPerPixel = 32;
 
//LONG lBytesPerRow = (((lImageWidth * (long)wBitsPerPixel + 31L) & (~31L)) / 8L);
LONG lBytesPerRow = lImageWidth * 4;
 
BYTE* pBitmapBits;
 
BITMAPINFO bmi;
memset(&bmi, 0, sizeof(BITMAPINFO));
bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bmi.bmiHeader.biWidth = lImageWidth;
bmi.bmiHeader.biHeight = lImageHeight;
bmi.bmiHeader.biPlanes = 1;
bmi.bmiHeader.biBitCount = wBitsPerPixel;
bmi.bmiHeader.biCompression = BI_RGB;
bmi.bmiHeader.biSizeImage = lBytesPerRow * lImageHeight;
//bmi.bmiHeader.biXPelsPerMeter = 0;
//bmi.bmiHeader.biYPelsPerMeter = 0;
//bmi.bmiHeader.biClrUsed = 0;
//bmi.bmiHeader.biClrImportant = 0;

HDC hdc = ::CreateCompatibleDC(0);

HBITMAP hBitmap = ::CreateDIBSection(hdc, &bmi, DIB_RGB_COLORS, (void**)&pBitmapBits, NULL, 0);

if (hBitmap)
{   
    <font color="Green">// Clear the pixels in the DIBsection to a shade of blue, setting alpha channel to 50% blend</font>
    RGBQUAD *pCurPixel = (RGBQUAD *)pBitmapBits;
    int PixelCount = lImageWidth * lImageHeight;
    while (PixelCount > 0)
    {
        (*pCurPixel).rgbRed =      0x00;
        (*pCurPixel).rgbGreen =    0x00;
        (*pCurPixel).rgbBlue =     0xA0;
        (*pCurPixel).rgbReserved = 0x80; <font color="Green">// alpha channel value</font>
        pCurPixel++;
        PixelCount--;
    }

    HGDIOBJ hOldBitmap = ::SelectObject(hdc, hBitmap);

    HDC hClientDC = ::GetDC(*this);

    HPEN hPen = ::CreatePen(PS_SOLID, 10, RGB(255,0,128));
    HGDIOBJ hOldPen = ::SelectObject(hClientDC, hPen);
    ::MoveToEx(hClientDC, 0, 0, NULL);
    ::LineTo(hClientDC, 650, 490);
    ::SelectObject(hClientDC, hOldPen);
    ::DeleteObject(hPen);

    BLENDFUNCTION bf;
    bf.BlendOp = AC_SRC_OVER;
    bf.BlendFlags = 0;
    bf.SourceConstantAlpha = 0xFF;
    bf.AlphaFormat = AC_SRC_ALPHA;

    ::AlphaBlend(hClientDC, 0, 0, lImageWidth, lImageHeight,
                        hdc, 0, 0, lImageWidth, lImageHeight, bf);

    ::ReleaseDC(*this, hClientDC);
    ::SelectObject(hdc, hOldBitmap);
    ::DeleteObject(hBitmap);
}

::DeleteDC(hdc);

Mark Salsbery
Microsoft MVP - Visual C++