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// Copyright (c) 2016 Daniel Grunwald
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
#![cfg_attr(feature="nightly", allow(incomplete_features))]
#![cfg_attr(feature="nightly", feature(
specialization, // for impl FromPyObject<'s> for Vec<...> (#31844)
))]
#![allow(
unused_imports, // because some imports are only necessary with python 2.x or 3.x
clippy::missing_safety_doc,
clippy::manual_strip,
clippy::match_like_matches_macro
)]
//! Rust bindings to the Python interpreter.
//!
//! # Ownership and Lifetimes
//! In Python, all objects are implicitly reference counted.
//! In rust, we will use the `PyObject` type to represent a reference to a Python object.
//!
//! The method `clone_ref()` (from trait `PyClone`) can be used to create additional
//! references to the same Python object.
//!
//! Because all Python objects potentially have multiple owners, the
//! concept of Rust mutability does not apply to Python objects.
//! As a result, this API will allow mutating Python objects even if they are not stored
//! in a mutable Rust variable.
//!
//! The Python interpreter uses a global interpreter lock (GIL)
//! to ensure thread-safety.
//! This API uses a zero-sized `struct Python<'p>` as a token to indicate
//! that a function can assume that the GIL is held.
//!
//! You obtain a `Python` instance by acquiring the GIL,
//! and have to pass it into all operations that call into the Python runtime.
//!
//! # Python 2.7
//! The library will use the python3 bindings by default. To use the python2 bindings
//! you must specific the `python27` feature explicitly in your `Cargo.toml`.
//!
//! ```ignore
//! [dependencies.cpython]
//! version = "*"
//! default-features = false
//! features = ["python27-sys"]
//! ```
//!
//! # Error Handling
//! The vast majority of operations in this library will return `PyResult<...>`.
//! This is an alias for the type `Result<..., PyErr>`.
//!
//! A `PyErr` represents a Python exception. Errors within the rust-cpython library are
//! also exposed as Python exceptions.
//!
//! # Example
//! ```
//! use cpython::{Python, PyDict, PyResult};
//!
//! fn main() {
//! let gil = Python::acquire_gil();
//! hello(gil.python()).unwrap();
//! }
//!
//! fn hello(py: Python) -> PyResult<()> {
//! let sys = py.import("sys")?;
//! let version: String = sys.get(py, "version")?.extract(py)?;
//!
//! let locals = PyDict::new(py);
//! locals.set_item(py, "os", py.import("os")?)?;
//! let user: String = py.eval("os.getenv('USER') or os.getenv('USERNAME')", None, Some(&locals))?.extract(py)?;
//!
//! println!("Hello {}, I'm Python {}", user, version);
//! Ok(())
//! }
//! ```
use std::{mem, ptr};
#[cfg(feature = "python27-sys")]
pub(crate) use python27_sys as ffi;
#[cfg(feature = "python3-sys")]
pub(crate) use python3_sys as ffi;
pub use ffi::Py_ssize_t;
pub use crate::conversion::{FromPyObject, RefFromPyObject, ToPyObject};
pub use crate::err::{PyErr, PyResult};
pub use crate::objectprotocol::{ObjectProtocol, NumberProtocol};
pub use crate::objects::*;
pub use crate::py_class::CompareOp;
pub use crate::python::{
PyClone, PyDrop, Python, PythonObject, PythonObjectDowncastError,
PythonObjectWithCheckedDowncast, PythonObjectWithTypeObject,
};
pub use crate::pythonrun::{prepare_freethreaded_python, GILGuard, GILProtected};
pub use crate::sharedref::{
PyLeakedRef, PyLeakedRefMut, PySharedRef, PySharedRefCell, UnsafePyLeaked,
};
#[cfg(feature = "python27-sys")]
#[allow(non_camel_case_types)]
pub type Py_hash_t = libc::c_long;
#[cfg(feature = "python3-sys")]
#[allow(non_camel_case_types)]
pub type Py_hash_t = ffi::Py_hash_t;
/// Constructs a `&'static CStr` literal.
macro_rules! cstr(
($s: tt) => (
// TODO: verify that $s is a string literal without nuls
unsafe {
std::ffi::CStr::from_ptr(concat!($s, "\0").as_ptr() as *const _)
}
);
);
// AST coercion macros (https://danielkeep.github.io/tlborm/book/blk-ast-coercion.html)
#[macro_export]
#[doc(hidden)]
macro_rules! py_coerce_expr {
($s:expr) => {
$s
};
}
#[macro_export]
#[doc(hidden)]
macro_rules! py_coerce_item {
($s:item) => {
$s
};
}
#[macro_export]
#[doc(hidden)]
macro_rules! py_replace_expr {
($_t:tt $sub:expr) => {
$sub
};
}
#[macro_export]
#[doc(hidden)]
macro_rules! py_impl_to_py_object_for_python_object {
($T: ty) => {
/// Identity conversion: allows using existing `PyObject` instances where
/// `T: ToPyObject` is expected.
impl $crate::ToPyObject for $T {
type ObjectType = $T;
#[inline]
fn to_py_object(&self, py: $crate::Python) -> $T {
$crate::PyClone::clone_ref(self, py)
}
#[inline]
fn into_py_object(self, _py: $crate::Python) -> $T {
self
}
#[inline]
fn with_borrowed_ptr<F, R>(&self, _py: $crate::Python, f: F) -> R
where
F: FnOnce(*mut $crate::_detail::ffi::PyObject) -> R,
{
f($crate::PythonObject::as_object(self).as_ptr())
}
}
};
}
#[macro_export]
#[doc(hidden)]
macro_rules! py_impl_from_py_object_for_python_object {
($T:ty) => {
impl<'s> $crate::FromPyObject<'s> for $T {
#[inline]
fn extract(py: $crate::Python, obj: &'s $crate::PyObject) -> $crate::PyResult<$T> {
use $crate::PyClone;
Ok(obj.clone_ref(py).cast_into::<$T>(py)?)
}
}
impl<'s> $crate::FromPyObject<'s> for &'s $T {
#[inline]
fn extract(py: $crate::Python, obj: &'s $crate::PyObject) -> $crate::PyResult<&'s $T> {
Ok(obj.cast_as::<$T>(py)?)
}
}
};
}
pub mod argparse;
pub mod buffer;
mod conversion;
mod err;
mod function;
mod objectprotocol;
mod objects;
mod python;
mod pythonrun;
//pub mod rustobject;
pub mod py_class;
mod sharedref;
#[cfg(feature = "serde-convert")]
pub mod serde;
/// Private re-exports for macros. Do not use.
#[doc(hidden)]
pub mod _detail {
pub mod ffi {
pub use crate::ffi::*;
}
pub mod libc {
pub use libc::{c_char, c_int, c_void};
}
pub use crate::err::{from_owned_ptr_or_panic, result_from_owned_ptr};
pub use crate::function::{
handle_callback, py_fn_impl, AbortOnDrop, PyObjectCallbackConverter,
PythonObjectCallbackConverter,
};
pub use paste;
pub use std::result::Result;
}
/// Expands to an `extern "C"` function that allows Python to load
/// the rust code as a Python extension module.
///
/// Macro syntax: `py_module_initializer!($name, |$py, $m| $body)`
///
/// 1. `name`: The module name as a Rust identifier.
/// 2. A lambda of type `Fn(Python, &PyModule) -> PyResult<()>`.
/// This function will be called when the module is imported, and is responsible
/// for adding the module's members.
///
/// For backwards compatibilty with older versions of rust-cpython,
/// two additional name identifiers (for py2 and py3 initializer names)
/// can be provided, but they will be ignored.
///
/// # Example
/// ```
/// use cpython::{Python, PyResult, PyObject, py_module_initializer, py_fn};
///
/// py_module_initializer!(hello, |py, m| {
/// m.add(py, "__doc__", "Module documentation string")?;
/// m.add(py, "run", py_fn!(py, run()))?;
/// Ok(())
/// });
///
/// fn run(py: Python) -> PyResult<PyObject> {
/// println!("Rust says: Hello Python!");
/// Ok(py.None())
/// }
/// # fn main() {}
/// ```
///
/// In your `Cargo.toml`, use the `extension-module` feature for the `cpython` dependency:
/// ```cargo
/// [dependencies.cpython]
/// version = "*"
/// features = ["extension-module"]
/// ```
/// The full example project can be found at:
/// https://github.com/dgrunwald/rust-cpython/tree/master/extensions/hello
///
/// Rust will compile the code into a file named `libhello.so`, but we have to
/// rename the file in order to use it with Python:
///
/// ```bash
/// cp ./target/debug/libhello.so ./hello.so
/// ```
/// (Note: on Mac OS you will have to rename `libhello.dynlib` to `hello.so`)
///
/// The extension module can then be imported into Python:
///
/// ```python
/// >>> import hello
/// >>> hello.run()
/// Rust says: Hello Python!
/// ```
///
#[macro_export]
#[cfg(feature = "python27-sys")]
macro_rules! py_module_initializer {
($name: ident, $( $_py2: ident, $_py3: ident, )? |$py_id: ident, $m_id: ident| $body: tt) => {
$crate::_detail::paste::item! {
#[no_mangle]
#[allow(non_snake_case)]
pub unsafe extern "C" fn [< init $name >]() {
// Nest init function so that $body isn't in unsafe context
fn init($py_id: $crate::Python, $m_id: &$crate::PyModule) -> $crate::PyResult<()> {
$body
}
let name = concat!(stringify!($name), "\0").as_ptr() as *const _;
$crate::py_module_initializer_impl(name, init)
}
}
};
}
#[doc(hidden)]
#[cfg(feature = "python27-sys")]
pub unsafe fn py_module_initializer_impl(
name: *const libc::c_char,
init: fn(Python, &PyModule) -> PyResult<()>,
) {
let guard = function::AbortOnDrop("py_module_initializer");
let py = Python::assume_gil_acquired();
ffi::PyEval_InitThreads();
let module = ffi::Py_InitModule(name, ptr::null_mut());
if module.is_null() {
mem::forget(guard);
return;
}
let module = match PyObject::from_borrowed_ptr(py, module).cast_into::<PyModule>(py) {
Ok(m) => m,
Err(e) => {
PyErr::from(e).restore(py);
mem::forget(guard);
return;
}
};
let ret = match init(py, &module) {
Ok(()) => (),
Err(e) => e.restore(py),
};
mem::forget(guard);
ret
}
#[macro_export]
#[cfg(feature = "python3-sys")]
macro_rules! py_module_initializer {
($name: ident, $( $_py2: ident, $_py3: ident, )? |$py_id: ident, $m_id: ident| $body: tt) => {
$crate::_detail::paste::item! {
#[no_mangle]
#[allow(non_snake_case)]
pub unsafe extern "C" fn [< PyInit_ $name >]() -> *mut $crate::_detail::ffi::PyObject {
// Nest init function so that $body isn't in unsafe context
fn init($py_id: $crate::Python, $m_id: &$crate::PyModule) -> $crate::PyResult<()> {
$body
}
static mut MODULE_DEF: $crate::_detail::ffi::PyModuleDef =
$crate::_detail::ffi::PyModuleDef_INIT;
// We can't convert &'static str to *const c_char within a static initializer,
// so we'll do it here in the module initialization:
MODULE_DEF.m_name = concat!(stringify!($name), "\0").as_ptr() as *const _;
$crate::py_module_initializer_impl(&mut MODULE_DEF, init)
}
}
};
}
#[doc(hidden)]
#[cfg(feature = "python3-sys")]
pub unsafe fn py_module_initializer_impl(
def: *mut ffi::PyModuleDef,
init: fn(Python, &PyModule) -> PyResult<()>,
) -> *mut ffi::PyObject {
let guard = function::AbortOnDrop("py_module_initializer");
let py = Python::assume_gil_acquired();
ffi::PyEval_InitThreads();
let module = ffi::PyModule_Create(def);
if module.is_null() {
mem::forget(guard);
return module;
}
let module = match PyObject::from_owned_ptr(py, module).cast_into::<PyModule>(py) {
Ok(m) => m,
Err(e) => {
PyErr::from(e).restore(py);
mem::forget(guard);
return ptr::null_mut();
}
};
let ret = match init(py, &module) {
Ok(()) => module.into_object().steal_ptr(),
Err(e) => {
e.restore(py);
ptr::null_mut()
}
};
mem::forget(guard);
ret
}
// Strip 'r#' prefix from stringified raw identifiers.
#[macro_export]
#[doc(hidden)]
macro_rules! strip_raw {
($s:expr) => {{
let s = $s;
if s.starts_with("r#") {
&s[2..]
} else {
s
}
}};
}