1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139

// Copyright (c) 2017-present PyO3 Project and Contributors

/// Stringify a dotted path.
#[macro_export]
macro_rules! dot_stringify {
    ($e:ident) => (
        stringify!($e)
    );
    ($e:ident. $($es:ident).+) => (
        concat!(stringify!($e), ".", dot_stringify!($($es).*))
    );
}

/// Defines rust type for exception defined in Python code.
///
/// # Syntax
/// `import_exception!(module, MyError)`
///
/// * `module` is the name of the containing module.
/// * `MyError` is the name of the new exception type.
///
/// # Example
/// ```
/// #![feature(const_fn, const_ptr_null_mut)]
///
/// #[macro_use] extern crate pyo3;
///
/// use pyo3::{Python, PyDict};
///
/// import_exception!(socket, gaierror);
///
/// fn main() {
///     let gil = Python::acquire_gil();
///     let py = gil.python();
///     let ctx = PyDict::new(py);
///
///     ctx.set_item("gaierror", py.get_type::<gaierror>()).unwrap();
///     py.run("import socket; assert gaierror is socket.gaierror", None, Some(ctx)).unwrap();
/// }
/// ```
macro_rules! import_exception {
    ($($module:ident).+ , $name: ident) => {
        #[allow(non_camel_case_types)]
        pub struct $name;

        impl ::std::convert::From<$name> for $crate::PyErr {
            fn from(_err: $name) -> $crate::PyErr {
                $crate::PyErr::new::<$name, _>(())
            }
        }

        impl<T> ::std::convert::Into<$crate::PyResult<T>> for $name {
            fn into(self) -> $crate::PyResult<T> {
                $crate::PyErr::new::<$name, _>(()).into()
            }
        }

        impl $name {
            #[cfg_attr(feature = "cargo-clippy", allow(new_ret_no_self))]
            pub fn new<T: $crate::ToPyObject + 'static>(args: T) -> $crate::PyErr
                where Self: $crate::typeob::PyTypeObject + Sized
            {
                $crate::PyErr::new::<Self, T>(args)
            }
            pub fn into<R, T: $crate::ToPyObject + 'static>(args: T) -> $crate::PyResult<R>
                where Self: $crate::typeob::PyTypeObject + Sized
            {
                $crate::PyErr::new::<Self, T>(args).into()
            }
        }

        impl $crate::typeob::PyTypeObject for $name {
            #[inline(always)]
            fn init_type() {}

            #[inline]
            fn type_object() -> $crate::Py<$crate::PyType> {
                use $crate::IntoPyPointer;
                static mut TYPE_OBJECT: *mut $crate::ffi::PyTypeObject = ::std::ptr::null_mut();

                unsafe {
                    if TYPE_OBJECT.is_null() {
                        let gil = $crate::Python::acquire_gil();
                        let py = gil.python();

                        let imp = py.import(dot_stringify!($($module).*))
                            .expect(concat!(
                                "Can not import module: ", dot_stringify!($($module).*)));
                        let cls = imp.get(stringify!($name))
                            .expect(concat!(
                                "Can not load exception class: {}.{}", dot_stringify!($($module).*),
                                ".", stringify!($name)));
                        TYPE_OBJECT = cls.into_ptr() as *mut $crate::ffi::PyTypeObject;
                    }

                    $crate::Py::from_borrowed_ptr(
                        TYPE_OBJECT as *const _ as *mut $crate::ffi::PyObject)
                }
            }
        }
    };
}

#[cfg(test)]
mod test {
    use {PyErr, Python};
    use objects::PyDict;

    import_exception!(socket, gaierror);
    import_exception!(email.errors, MessageError);

    #[test]
    fn test_check_exception() {
        let gil = Python::acquire_gil();
        let py = gil.python();

        let err: PyErr = gaierror.into();

        let d = PyDict::new(py);
        d.set_item("socket", py.import("socket").map_err(|e| e.print(py)).unwrap()).unwrap();
        d.set_item("exc", err).unwrap();

        py.run("assert isinstance(exc, socket.gaierror)", None, Some(d)).unwrap();
    }

    #[test]
    fn test_check_exception_nested() {
        let gil = Python::acquire_gil();
        let py = gil.python();

        let err: PyErr = MessageError.into();

        let d = PyDict::new(py);
        d.set_item("email", py.import("email").map_err(|e| e.print(py)).unwrap()).unwrap();
        d.set_item("exc", err).unwrap();

        py.run("assert isinstance(exc, email.errors.MessageError)", None, Some(d)).unwrap();
    }
}