// Call imp where args points to buffers containing the arguments and result
// is a buffer where the result will be written.
public static void Call(IntPtr cif, IntPtr imp, IntPtr result, PtrArray args)
{
IntPtr exception = IntPtr.Zero;
FfiCall(cif, imp, result, args.ToIntPtr(), ref exception);
if (exception != IntPtr.Zero)
CocoaException.Raise(exception);
}
// Use ffi_type*'s to create an ffi_cif*. Note that libffi will save the atypes
// pointer so we can't free it (and we can't use an IntPtr[] without explicity
// saving the array).
public static IntPtr AllocCif(IntPtr rtype, PtrArray atypes)
{
if (atypes[atypes.Length - 1] != IntPtr.Zero)
throw new ArgumentException("atypes should be null terminated");
IntPtr cif = AllocCif(atypes.Length - 1, rtype, atypes.ToIntPtr());
if (cif.ToInt32() == 1)
throw new ArgumentException("FFI_BAD_TYPEDEF");
else if (cif.ToInt32() == 2)
throw new ArgumentException("FFI_BAD_ABI");
return cif;
}
private static IntPtr DoAllocStructFfiType(string sname, string pencoding)
{
List<IntPtr> fieldTypes = new List<IntPtr>();
int index = 0;
while (index < pencoding.Length)
{
if (pencoding[index] == '{')
{
int i = pencoding.IndexOf('=', index);
int j = pencoding.IndexOf('}', index);
string sname2 = pencoding.Substring(index + 1, i - index - 1);
string pencoding2 = pencoding.Substring(i + 1, j - i - 1);
fieldTypes.Add(DoAllocStructFfiType(sname2, pencoding2));
index = j + 1;
}
else
{
char code = DoGetCode(pencoding[index++].ToString());
if (code == '\x0')
throw new InvalidCallException("Can only marshal structs whose fields are primitive types or structs with primitive types and " + sname + " isn't.");
fieldTypes.Add(GetFfiType(code));
}
}
fieldTypes.Add(IntPtr.Zero);
// Note that we don't free these, but that should be OK since
// there should only be a limited number of structs we marshal
// and it doesn't hurt to cache the ffi_type* anyway.
PtrArray ft = new PtrArray(fieldTypes.Count);
for (int i = 0; i < ft.Length; ++i)
ft[i] = fieldTypes[i];
IntPtr result = AllocStructFfiType( ft.ToIntPtr());
return result;
}