unsafe c# code causes heap corruption on 64 bit platform unless built for x86 platform.......

Question

Hi all,

I have a simple util that uses some unsafe code to get the file version information. when I compiled this as mixed platform (vs2008/.net 3.5) and deploy to 64 bit machine I get a heap corruption error. If I recompile as x86 then everything works....

This was suprising because of my understanding of the .NET Common Type System. My unsafe code uses a pointer to a short and a pointer to a byte. Arent these common types the same size on any platform becuase of the CTS? what am I missing here

using System;
using System.Reflection;
using System.Runtime.InteropServices;


public class Win32Imports
{
    [DllImport("version.dll")]
    public static extern bool GetFileVersionInfo(string sFileName,
          int handle, int size, byte[] infoBuffer);

    [DllImport("version.dll")]
    public static extern int GetFileVersionInfoSize(string sFileName,
          out int handle);

    // The third parameter - "out string pValue" - is automatically
    // marshaled from ANSI to Unicode:
    [DllImport("version.dll")]
    unsafe public static extern bool VerQueryValue(byte[] pBlock,
          string pSubBlock, out string pValue, out uint len);

    // This VerQueryValue overload is marked with 'unsafe' because 
    // it uses a short*:
    [DllImport("version.dll")]
    unsafe public static extern bool VerQueryValue(byte[] pBlock,
          string pSubBlock, out short* pValue, out uint len);
}

public class FileInformation
{
    // Main is marked with 'unsafe' because it uses pointers:
    unsafe public static string GetVersionInformation(string path)
    {

        // Figure out how much version info there is:
        int handle = 0;
        int size =
              Win32Imports.GetFileVersionInfoSize(path,
              out handle);
        if (size == 0) return "";

        byte[] buffer = new byte[size];
        if (!Win32Imports.GetFileVersionInfo(path, handle, size, buffer)) return "";

        // Get the locale info from the version info:
        short* subBlock = null;
        uint len = 0;           
        if (!Win32Imports.VerQueryValue(buffer, @"\VarFileInfo\Translation", out subBlock, out len)) return "";


        // Get the ProductVersion value for this program:
        string spv = @"\StringFileInfo\" + subBlock[0].ToString("X4") + subBlock[1].ToString("X4") + @"\ProductVersion";
        byte* pVersion = null;
        string versionInfo;
        if (!Win32Imports.VerQueryValue(buffer, spv, out versionInfo, out len)) return "";
        return versionInfo;

    }
}

Thanks Killer of All zombies and waiting for the zombie Apocolypse....... -Jonathan

Answer 1

Is there any reason you couldn't use the FileVersionInfo managed class for this? I suspect it works properly on both 32 bit and 64 bit platforms.

Answer 2

Perhaps since pointers are 64-bit in the platform, but you are using unsafe, this isn't transformed correctly? Also please show what your p/invoke imports look like.