Add context.h functions (PyContext_New, PyContext*)

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Added
 - Add argument names to `TypeError` messages generated by pymethod wrappers. [#1212](https://github.com/PyO3/pyo3/pull/1212)
 - Add `PyEval_SetProfile` and `PyEval_SetTrace` to FFI. [#1255](https://github.com/PyO3/pyo3/pull/1255)
+- Add context.h functions (`PyContext_New`, etc) to FFI. [#1259](https://github.com/PyO3/pyo3/pull/1259)
 
 ### Changed
 - Change `PyIterator` to be consistent with other native types: it is now used as `&PyIterator` instead of `PyIterator<'a>`. [#1176](https://github.com/PyO3/pyo3/pull/1176)

src/ffi/context.rs

@@ -0,0 +1,36 @@
+use crate::ffi::object::{PyObject, PyTypeObject, Py_TYPE};
+use std::os::raw::{c_char, c_int};
+
+extern "C" {
+    pub static mut PyContext_Type: PyTypeObject;
+    pub static mut PyContextVar_Type: PyTypeObject;
+    pub static mut PyContextToken_Type: PyTypeObject;
+    pub fn PyContext_New() -> *mut PyObject;
+    pub fn PyContext_Copy(ctx: *mut PyObject) -> *mut PyObject;
+    pub fn PyContext_CopyCurrent() -> *mut PyObject;
+    pub fn PyContext_Enter(ctx: *mut PyObject) -> c_int;
+    pub fn PyContext_Exit(ctx: *mut PyObject) -> c_int;
+    pub fn PyContextVar_New(name: *const c_char, def: *mut PyObject) -> *mut PyObject;
+    pub fn PyContextVar_Get(
+        var: *mut PyObject,
+        default_value: *mut PyObject,
+        value: *mut *mut PyObject,
+    ) -> c_int;
+    pub fn PyContextVar_Set(var: *mut PyObject, value: *mut PyObject) -> *mut PyObject;
+    pub fn PyContextVar_Reset(var: *mut PyObject, token: *mut PyObject) -> c_int;
+}
+
+#[inline]
+pub unsafe fn PyContext_CheckExact(op: *mut PyObject) -> c_int {
+    (Py_TYPE(op) == &mut PyContext_Type) as c_int
+}
+
+#[inline]
+pub unsafe fn PyContextVar_CheckExact(op: *mut PyObject) -> c_int {
+    (Py_TYPE(op) == &mut PyContextVar_Type) as c_int
+}
+
+#[inline]
+pub unsafe fn PyContextToken_CheckExact(op: *mut PyObject) -> c_int {
+    (Py_TYPE(op) == &mut PyContextToken_Type) as c_int
+}

src/ffi/mod.rs

@@ -11,6 +11,7 @@ pub use self::code::*;
 pub use self::codecs::*;
 pub use self::compile::*;
 pub use self::complexobject::*;
+pub use self::context::*;
 pub use self::datetime::*;
 pub use self::descrobject::*;
 pub use self::dictobject::*;
@@ -135,6 +136,13 @@ mod code {}
 mod code;
 
 mod compile; // TODO: incomplete
+
+#[cfg(all(Py_3_8, not(Py_LIMITED_API)))]
+mod context; // It's actually 3.7.1, but no cfg for patches.
+
+#[cfg(not(all(Py_3_8, not(Py_LIMITED_API))))]
+mod context {}
+
 mod eval; // TODO supports PEP-384 only; needs adjustment for Python 3.3 and 3.5
 
 // mod pyctype; TODO excluded by PEP-384