VBByValStrMarshaler.cs

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using System.Runtime.InteropServices;
 
namespace System.StubHelpers;
 
internal static class VBByValStrMarshaler
{
    internal unsafe static IntPtr ConvertToNative(string strManaged, bool fBestFit, bool fThrowOnUnmappableChar, ref int cch)
    {
        if (strManaged == null)
        {
            return IntPtr.Zero;
        }
        cch = strManaged.Length;
        int cb = checked(4 + (cch + 1) * Marshal.SystemMaxDBCSCharSize);
        byte* ptr = (byte*)(void*)Marshal.AllocCoTaskMem(cb);
        int* ptr2 = (int*)ptr;
        ptr += 4;
        if (cch == 0)
        {
            *ptr = 0;
            *ptr2 = 0;
        }
        else
        {
            int cbLength;
            byte[] array = AnsiCharMarshaler.DoAnsiConversion(strManaged, fBestFit, fThrowOnUnmappableChar, out cbLength);
            Buffer.Memmove(ref *ptr, ref MemoryMarshal.GetArrayDataReference(array), (nuint)cbLength);
            ptr[cbLength] = 0;
            *ptr2 = cbLength;
        }
        return new IntPtr(ptr);
    }
 
    internal unsafe static string ConvertToManaged(IntPtr pNative, int cch)
    {
        if (IntPtr.Zero == pNative)
        {
            return null;
        }
        return new string((sbyte*)(void*)pNative, 0, cch);
    }
 
    internal static void ClearNative(IntPtr pNative)
    {
        if (IntPtr.Zero != pNative)
        {
            Marshal.FreeCoTaskMem((IntPtr)((long)pNative - 4));
        }
    }
}