add regression test for PEP 587

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added the internal `IntoPyResult` trait to give better error messages when function return types do not implement `IntoPy`. [#2326](https://github.com/PyO3/pyo3/pull/2326)
 - Add `PyDictKeys`, `PyDictValues` and `PyDictItems` Rust types to represent `dict_keys`, `dict_values` and `dict_items` types. [#2358](https://github.com/PyO3/pyo3/pull/2358)
 - Add an experimental `generate-import-lib` feature to support auto-generating non-abi3 python import libraries for Windows targets. [#2364](https://github.com/PyO3/pyo3/pull/2364)
+- Add FFI definition `Py_ExitStatusException`. [#2374](https://github.com/PyO3/pyo3/pull/2374)
 
 ### Changed
 

Cargo.toml

@@ -49,6 +49,7 @@ send_wrapper = "0.5"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0.61"
 rayon = "1.0.2"
+widestring = "0.5.1"
 
 [build-dependencies]
 pyo3-build-config = { path = "pyo3-build-config", version = "0.16.4", features = ["resolve-config"] }

pyo3-ffi/src/cpython/pylifecycle.rs

@@ -23,7 +23,7 @@ extern "C" {
 
     pub fn Py_RunMain() -> c_int;
 
-    // skipped Py_ExitStatusException
+    pub fn Py_ExitStatusException(status: PyStatus) -> !;
 
     // skipped _Py_RestoreSignals
 

tests/test_pep_587.rs

@@ -0,0 +1,60 @@
+#![cfg(all(Py_3_8, not(any(PyPy, Py_LIMITED_API))))]
+
+use pyo3::ffi;
+
+#[cfg(Py_3_10)]
+use widestring::WideCString;
+
+#[test]
+fn test_default_interpreter() {
+    macro_rules! ensure {
+        ($py_call:expr) => {{
+            let status = $py_call;
+            unsafe {
+                if ffi::PyStatus_Exception(status) != 0 {
+                    ffi::Py_ExitStatusException(status);
+                }
+            }
+        }};
+    }
+
+    let mut preconfig = unsafe { std::mem::zeroed() };
+
+    unsafe { ffi::PyPreConfig_InitPythonConfig(&mut preconfig) };
+    preconfig.utf8_mode = 1;
+
+    ensure!(unsafe { ffi::Py_PreInitialize(&preconfig) });
+
+    let mut config = unsafe { std::mem::zeroed() };
+    unsafe { ffi::PyConfig_InitPythonConfig(&mut config) };
+
+    // Require manually calling _Py_InitializeMain to exercise more ffi code
+    config._init_main = 0;
+
+    #[cfg(Py_3_10)]
+    unsafe {
+        ffi::PyConfig_SetBytesString(
+            &mut config,
+            &mut config.program_name,
+            "some_test\0".as_ptr().cast(),
+        );
+    }
+
+    ensure!(unsafe { ffi::Py_InitializeFromConfig(&config) });
+
+    // The GIL is held.
+    assert_eq!(unsafe { ffi::PyGILState_Check() }, 1);
+
+    // Now proceed with the Python main initialization.
+    ensure!(unsafe { ffi::_Py_InitializeMain() });
+
+    // The GIL is held after finishing initialization.
+    assert_eq!(unsafe { ffi::PyGILState_Check() }, 1);
+
+    // Confirm program name set above was picked up correctly
+    #[cfg(Py_3_10)]
+    {
+        let program_name = unsafe { WideCString::from_ptr_str(ffi::Py_GetProgramName().cast()) };
+        assert_eq!(program_name.to_string().unwrap(), "some_test");
+    }
+}