private static IntPtr LoadSymbol(IntPtr handle, string symbolName, out string errorMsg)
{
errorMsg = null;
if (Platform.IsWindows)
{
// See http://stackoverflow.com/questions/10473310 for background on this.
if (Platform.Is64Bit)
{
return(Windows.GetProcAddress(handle, symbolName));
}
else
{
IntPtr candidate = Windows.GetProcAddress(handle, symbolName);
if (candidate != IntPtr.Zero)
{
return(candidate);
}
// Yes, we could potentially predict the size... but it's a lot simpler to just try
// all the candidates. Most functions have a suffix of @0, @4 or @8 so we won't be trying
// many options - and if it takes a little bit longer to fail if we've really got the wrong
// library, that's not a big problem. This is only called once per function in the native library.
symbolName = "_" + symbolName + "@";
for (int stackSize = 0; stackSize < 128; stackSize += 4)
{
candidate = Windows.GetProcAddress(handle, symbolName + stackSize);
if (candidate != IntPtr.Zero)
{
return(candidate);
}
}
// Fail.
return(IntPtr.Zero);
}
}
if (Platform.IsLinux)
{
if (Platform.IsMono)
{
var monoAddr = Mono.dlsym(handle, symbolName);
errorMsg = Marshal.PtrToStringAnsi(Mono.dlerror());
return(monoAddr);
}
if (Platform.IsNetCore)
{
var coreAddr = CoreClr.dlsym(handle, symbolName);
errorMsg = Marshal.PtrToStringAnsi(CoreClr.dlerror());
return(coreAddr);
}
var addr = Linux.dlsym(handle, symbolName);
errorMsg = Marshal.PtrToStringAnsi(Linux.dlerror());
return(addr);
}
if (Platform.IsMacOSX)
{
var addr = MacOsx.dlsym(handle, symbolName);
errorMsg = Marshal.PtrToStringAnsi(MacOsx.dlerror());
return(addr);
}
throw new InvalidOperationException("Unsupported platform.");
}
