Gendarme.Rules.Interoperability.MarshalBooleansInPInvokeDeclarationsRule(2.10)

MarshalBooleansInPInvokeDeclarationsRule

Assembly: Gendarme.Rules.Interoperability
Version: 2.10

Description

This rule warns the developer if a MarshalAs attribute has not been specified for boolean parameters of a P/Invoke method. The size of boolean types varies across language (e.g. the C++ bool type is four bytes on some platforms and one byte on others). By default the CLR will marshal System.Booleanas a 32 bit value (UnmanagedType.Bool ) like the Win32 API BOOLuses. But, for clarity, you should always specify the correct value.

Examples

Bad example:

// bad assuming the last parameter is a single byte being mapped to a bool
[DllImport ("liberty")]
private static extern bool Bad (bool b1, ref bool b2);

Good example:

[DllImport ("liberty")]
[return: MarshalAs (UnmanagedType.Bool)]
private static extern bool Good ([MarshalAs (UnmanagedType.Bool)] bool b1, [MarshalAs (UnmanagedType.U1)] ref bool b2);