365 lines
12 KiB
Rust
365 lines
12 KiB
Rust
// Copyright (c) 2015 Daniel Grunwald
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy of this
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// software and associated documentation files (the "Software"), to deal in the Software
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// without restriction, including without limitation the rights to use, copy, modify, merge,
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// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
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// to whom the Software is furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in all copies or
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// substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
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// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
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// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
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// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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// DEALINGS IN THE SOFTWARE.
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#![cfg_attr(feature="nightly", feature(
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unsafe_no_drop_flag, filling_drop, // (#5016)
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// ^ These two are crucial so that `PyObject` is binary compatible with
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// `*mut ffi::PyObject`, which we use for efficient slice access and in
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// some other cases.
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const_fn, // for GILProtected::new (#24111)
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shared, // for std::ptr::Shared (#27730)
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//recover, // for converting panics to python exceptions (#27719)
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// -- TODO wait for stable release and promote recover code from cfg(nightly) (1.9?)
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// -- TODO remove <DUMMY> hack when it's no longer necessary on stable (1.9?)
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))]
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#![allow(unused_imports)] // because some imports are only necessary with python 2.x or 3.x
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//! Rust bindings to the Python interpreter.
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//!
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//! # Ownership and Lifetimes
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//! In Python, all objects are implicitly reference counted.
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//! In rust, we will use the `PyObject` type to represent a reference to a Python object.
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//!
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//! The method `clone_ref()` (from trait `PyClone`) can be used to create additional
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//! references to the same Python object.
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//!
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//! Because all Python objects potentially have multiple owners, the
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//! concept of Rust mutability does not apply to Python objects.
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//! As a result, this API will allow mutating Python objects even if they are not stored
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//! in a mutable Rust variable.
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//!
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//! The Python interpreter uses a global interpreter lock (GIL)
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//! to ensure thread-safety.
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//! This API uses a zero-sized `struct Python<'p>` as a token to indicate
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//! that a function can assume that the GIL is held.
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//!
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//! You obtain a `Python` instance by acquiring the GIL,
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//! and have to pass it into all operations that call into the Python runtime.
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//!
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//! # Error Handling
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//! The vast majority of operations in this library will return `PyResult<...>`.
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//! This is an alias for the type `Result<..., PyErr>`.
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//!
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//! A `PyErr` represents a Python exception. Errors within the rust-cpython library are
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//! also exposed as Python exceptions.
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//!
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//! # Example
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//! ```
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//! extern crate cpython;
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//!
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//! use cpython::{PythonObject, Python};
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//! use cpython::ObjectProtocol; //for call method
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//!
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//! fn main() {
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//! let gil = Python::acquire_gil();
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//! let py = gil.python(); // obtain `Python` token
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//!
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//! let sys = py.import("sys").unwrap();
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//! let version: String = sys.get(py, "version").unwrap().extract(py).unwrap();
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//!
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//! let os = py.import("os").unwrap();
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//! let getenv = os.get(py, "getenv").unwrap();
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//! let user: String = getenv.call(py, ("USER",), None).unwrap().extract(py).unwrap();
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//!
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//! println!("Hello {}, I'm Python {}", user, version);
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//! }
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//! ```
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extern crate libc;
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#[cfg(feature="python27-sys")]
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extern crate python27_sys as ffi;
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#[cfg(feature="python3-sys")]
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extern crate python3_sys as ffi;
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pub use ffi::Py_ssize_t;
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pub use err::{PyErr, PyResult};
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pub use objects::*;
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pub use python::{Python, PythonObject, PythonObjectWithCheckedDowncast, PythonObjectDowncastError, PythonObjectWithTypeObject, PyClone, PyDrop};
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pub use pythonrun::{GILGuard, GILProtected, prepare_freethreaded_python};
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pub use conversion::{FromPyObject, RefFromPyObject, ToPyObject};
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pub use py_class::{CompareOp};
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pub use objectprotocol::{ObjectProtocol};
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#[cfg(feature="python27-sys")]
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#[allow(non_camel_case_types)]
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pub type Py_hash_t = libc::c_long;
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#[cfg(feature="python3-sys")]
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#[allow(non_camel_case_types)]
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pub type Py_hash_t = ffi::Py_hash_t;
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use std::{ptr, mem};
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/// Constructs a `&'static CStr` literal.
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macro_rules! cstr(
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($s: tt) => (
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// TODO: verify that $s is a string literal without nuls
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unsafe {
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::std::ffi::CStr::from_ptr(concat!($s, "\0").as_ptr() as *const _)
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}
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);
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);
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// AST coercion macros (https://danielkeep.github.io/tlborm/book/blk-ast-coercion.html)
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#[macro_export] #[doc(hidden)]
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macro_rules! py_coerce_expr { ($s:expr) => {$s} }
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#[macro_export] #[doc(hidden)]
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macro_rules! py_coerce_item { ($s:item) => {$s} }
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#[macro_export] #[doc(hidden)]
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macro_rules! py_replace_expr {
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($_t:tt $sub:expr) => {$sub};
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}
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#[macro_export] #[doc(hidden)]
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macro_rules! py_impl_to_py_object_for_python_object {
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($T: ty) => (
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/// Identity conversion: allows using existing `PyObject` instances where
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/// `T: ToPyObject` is expected.
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impl $crate::ToPyObject for $T {
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type ObjectType = $T;
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#[inline]
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fn to_py_object(&self, py: $crate::Python) -> $T {
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$crate::PyClone::clone_ref(self, py)
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}
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#[inline]
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fn into_py_object(self, _py: $crate::Python) -> $T {
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self
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}
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#[inline]
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fn with_borrowed_ptr<F, R>(&self, _py: $crate::Python, f: F) -> R
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where F: FnOnce(*mut $crate::_detail::ffi::PyObject) -> R
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{
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f($crate::PythonObject::as_object(self).as_ptr())
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}
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}
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)
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}
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#[macro_export] #[doc(hidden)]
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macro_rules! py_impl_from_py_object_for_python_object {
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($T:ty) => {
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impl <'source> $crate::FromPyObject<'source> for $T {
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#[inline]
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fn extract(py: $crate::Python, obj: &'source $crate::PyObject) -> $crate::PyResult<$T> {
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use $crate::PyClone;
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Ok(try!(obj.clone_ref(py).cast_into::<$T>(py)))
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}
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}
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impl <'source> $crate::FromPyObject<'source> for &'source $T {
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#[inline]
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fn extract(py: $crate::Python, obj: &'source $crate::PyObject) -> $crate::PyResult<&'source $T> {
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Ok(try!(obj.cast_as::<$T>(py)))
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}
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}
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}
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}
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mod python;
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mod err;
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mod conversion;
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mod objects;
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mod objectprotocol;
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mod pythonrun;
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pub mod argparse;
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mod function;
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//pub mod rustobject;
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pub mod py_class;
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/// Private re-exports for macros. Do not use.
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#[doc(hidden)]
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pub mod _detail {
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pub mod ffi {
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pub use ::ffi::*;
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}
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pub mod libc {
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pub use ::libc::{c_char, c_void, c_int};
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}
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pub use err::{from_owned_ptr_or_panic, result_from_owned_ptr};
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pub use function::{handle_callback, py_fn_impl, AbortOnDrop,
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PyObjectCallbackConverter, PythonObjectCallbackConverter};
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}
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/// Expands to an `extern "C"` function that allows Python to load
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/// the rust code as a Python extension module.
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///
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/// Macro syntax: `py_module_initializer!($name, $py2_init, $py3_init, |$py, $m| $body)`
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///
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/// 1. `name`: The module name as a Rust identifier.
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/// 2. `py2_init`: "init" + $name. Necessary because macros can't use concat_idents!().
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/// 3. `py3_init`: "PyInit_" + $name. Necessary because macros can't use concat_idents!().
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/// 4. A lambda of type `Fn(Python, &PyModule) -> PyResult<()>`.
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/// This function will be called when the module is imported, and is responsible
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/// for adding the module's members.
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///
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/// # Example
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/// ```
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/// #![crate_type = "dylib"]
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/// #[macro_use] extern crate cpython;
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/// use cpython::{Python, PyResult, PyObject};
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///
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/// py_module_initializer!(example, initexample, PyInit_example, |py, m| {
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/// try!(m.add(py, "__doc__", "Module documentation string"));
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/// try!(m.add(py, "run", py_fn!(py, run())));
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/// Ok(())
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/// });
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///
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/// fn run(py: Python) -> PyResult<PyObject> {
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/// println!("Rust says: Hello Python!");
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/// Ok(py.None())
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/// }
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/// # fn main() {}
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/// ```
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/// The code must be compiled into a file `example.so`.
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///
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/// ```bash
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/// rustc example.rs -o example.so
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/// ```
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/// It can then be imported into Python:
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///
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/// ```python
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/// >>> import example
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/// >>> example.run()
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/// Rust says: Hello Python!
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/// ```
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///
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#[macro_export]
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#[cfg(feature="python27-sys")]
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macro_rules! py_module_initializer {
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($name: ident, $py2: ident, $py3: ident, |$py_id: ident, $m_id: ident| $body: expr) => {
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#[no_mangle]
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#[allow(non_snake_case)]
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pub unsafe extern "C" fn $py2() {
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// Nest init function so that $body isn't in unsafe context
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fn init($py_id: $crate::Python, $m_id: &$crate::PyModule) -> $crate::PyResult<()> {
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$body
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}
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let name = concat!(stringify!($name), "\0").as_ptr() as *const _;
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$crate::py_module_initializer_impl(name, init)
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}
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}
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}
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#[doc(hidden)]
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#[cfg(feature="python27-sys")]
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pub unsafe fn py_module_initializer_impl(
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name: *const libc::c_char,
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init: fn(Python, &PyModule) -> PyResult<()>
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) {
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let guard = function::AbortOnDrop("py_module_initializer");
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let py = Python::assume_gil_acquired();
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ffi::PyEval_InitThreads();
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let module = ffi::Py_InitModule(name, ptr::null_mut());
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if module.is_null() {
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mem::forget(guard);
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return;
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}
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let module = match PyObject::from_borrowed_ptr(py, module).cast_into::<PyModule>(py) {
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Ok(m) => m,
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Err(e) => {
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PyErr::from(e).restore(py);
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mem::forget(guard);
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return;
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}
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};
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let ret = match init(py, &module) {
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Ok(()) => (),
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Err(e) => e.restore(py)
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};
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mem::forget(guard);
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ret
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}
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#[macro_export]
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#[cfg(feature="python3-sys")]
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macro_rules! py_module_initializer {
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($name: ident, $py2: ident, $py3: ident, |$py_id: ident, $m_id: ident| $body: expr) => {
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#[no_mangle]
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#[allow(non_snake_case)]
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pub unsafe extern "C" fn $py3() -> *mut $crate::_detail::ffi::PyObject {
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// Nest init function so that $body isn't in unsafe context
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fn init($py_id: $crate::Python, $m_id: &$crate::PyModule) -> $crate::PyResult<()> {
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$body
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}
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static mut module_def: $crate::_detail::ffi::PyModuleDef = $crate::_detail::ffi::PyModuleDef {
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m_base: $crate::_detail::ffi::PyModuleDef_HEAD_INIT,
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m_name: 0 as *const _,
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m_doc: 0 as *const _,
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m_size: 0, // we don't use per-module state
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m_methods: 0 as *mut _,
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m_reload: None,
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m_traverse: None,
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m_clear: None,
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m_free: None
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};
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// We can't convert &'static str to *const c_char within a static initializer,
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// so we'll do it here in the module initialization:
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module_def.m_name = concat!(stringify!($name), "\0").as_ptr() as *const _;
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$crate::py_module_initializer_impl(&mut module_def, init)
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}
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}
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}
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#[doc(hidden)]
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#[cfg(feature="python3-sys")]
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pub unsafe fn py_module_initializer_impl(
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def: *mut ffi::PyModuleDef,
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init: fn(Python, &PyModule) -> PyResult<()>
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) -> *mut ffi::PyObject {
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let guard = function::AbortOnDrop("py_module_initializer");
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let py = Python::assume_gil_acquired();
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ffi::PyEval_InitThreads();
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let module = ffi::PyModule_Create(def);
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if module.is_null() {
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mem::forget(guard);
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return module;
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}
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let module = match PyObject::from_owned_ptr(py, module).cast_into::<PyModule>(py) {
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Ok(m) => m,
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Err(e) => {
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PyErr::from(e).restore(py);
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mem::forget(guard);
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return ptr::null_mut();
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}
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};
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let ret = match init(py, &module) {
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Ok(()) => module.into_object().steal_ptr(),
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Err(e) => {
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e.restore(py);
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ptr::null_mut()
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}
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};
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mem::forget(guard);
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ret
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}
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