Reguire GIL before constructing PyErr from Rust value

src/err.rs

@@ -16,6 +16,12 @@ use std::io;
 use std::os::raw::c_char;
 
 /// Represents a `PyErr` value
+///
+/// **CAUTION**
+///
+/// When you construct an instance of `PyErrValue`, we highly recommend to use `to_args` method.
+/// If you want to to construct `PyErrValue::ToArgs` directly, please do not forget calling
+/// `Python::acquire_gil`.
 pub enum PyErrValue {
     None,
     Value(PyObject),
@@ -23,6 +29,13 @@ pub enum PyErrValue {
     ToObject(Box<dyn ToPyObject>),
 }
 
+impl PyErrValue {
+    pub fn to_args<T: 'static + PyErrArguments>(value: T) -> Self {
+        let _ = Python::acquire_gil();
+        PyErrValue::ToArgs(Box::new(value))
+    }
+}
+
 /// Represents a Python exception that was raised.
 pub struct PyErr {
     /// The type of the exception. This should be either a `PyClass` or a `PyType`.
@@ -417,7 +430,7 @@ macro_rules! impl_to_pyerr {
 
         impl std::convert::From<$err> for PyErr {
             fn from(err: $err) -> PyErr {
-                PyErr::from_value::<$pyexc>(PyErrValue::ToArgs(Box::new(err)))
+                PyErr::from_value::<$pyexc>(PyErrValue::to_args(err))
             }
         }
     };
@@ -426,34 +439,35 @@ macro_rules! impl_to_pyerr {
 /// Create `OSError` from `io::Error`
 impl std::convert::From<io::Error> for PyErr {
     fn from(err: io::Error) -> PyErr {
+        macro_rules! err_value {
+            () => {
+                PyErrValue::to_args(err)
+            };
+        }
         match err.kind() {
             io::ErrorKind::BrokenPipe => {
-                PyErr::from_value::<exceptions::BrokenPipeError>(PyErrValue::ToArgs(Box::new(err)))
+                PyErr::from_value::<exceptions::BrokenPipeError>(err_value!())
+            }
+            io::ErrorKind::ConnectionRefused => {
+                PyErr::from_value::<exceptions::ConnectionRefusedError>(err_value!())
+            }
+            io::ErrorKind::ConnectionAborted => {
+                PyErr::from_value::<exceptions::ConnectionAbortedError>(err_value!())
             }
-            io::ErrorKind::ConnectionRefused => PyErr::from_value::<
-                exceptions::ConnectionRefusedError,
-            >(PyErrValue::ToArgs(Box::new(err))),
-            io::ErrorKind::ConnectionAborted => PyErr::from_value::<
-                exceptions::ConnectionAbortedError,
-            >(PyErrValue::ToArgs(Box::new(err))),
             io::ErrorKind::ConnectionReset => {
-                PyErr::from_value::<exceptions::ConnectionResetError>(PyErrValue::ToArgs(Box::new(
-                    err,
-                )))
+                PyErr::from_value::<exceptions::ConnectionResetError>(err_value!())
             }
             io::ErrorKind::Interrupted => {
-                PyErr::from_value::<exceptions::InterruptedError>(PyErrValue::ToArgs(Box::new(err)))
+                PyErr::from_value::<exceptions::InterruptedError>(err_value!())
+            }
+            io::ErrorKind::NotFound => {
+                PyErr::from_value::<exceptions::FileNotFoundError>(err_value!())
             }
-            io::ErrorKind::NotFound => PyErr::from_value::<exceptions::FileNotFoundError>(
-                PyErrValue::ToArgs(Box::new(err)),
-            ),
             io::ErrorKind::WouldBlock => {
-                PyErr::from_value::<exceptions::BlockingIOError>(PyErrValue::ToArgs(Box::new(err)))
+                PyErr::from_value::<exceptions::BlockingIOError>(err_value!())
             }
-            io::ErrorKind::TimedOut => {
-                PyErr::from_value::<exceptions::TimeoutError>(PyErrValue::ToArgs(Box::new(err)))
-            }
-            _ => PyErr::from_value::<exceptions::OSError>(PyErrValue::ToArgs(Box::new(err))),
+            io::ErrorKind::TimedOut => PyErr::from_value::<exceptions::TimeoutError>(err_value!()),
+            _ => PyErr::from_value::<exceptions::OSError>(err_value!()),
         }
     }
 }
@@ -466,7 +480,7 @@ impl PyErrArguments for io::Error {
 
 impl<W: 'static + Send + std::fmt::Debug> std::convert::From<std::io::IntoInnerError<W>> for PyErr {
     fn from(err: std::io::IntoInnerError<W>) -> PyErr {
-        PyErr::from_value::<exceptions::OSError>(PyErrValue::ToArgs(Box::new(err)))
+        PyErr::from_value::<exceptions::OSError>(PyErrValue::to_args(err))
     }
 }
 

tests/test_exceptions.rs

@@ -75,3 +75,18 @@ fn test_custom_error() {
         "#
     );
 }
+
+#[test]
+fn test_exception_nosegfault() {
+    use std::{net::TcpListener, panic};
+    fn io_err() -> PyResult<()> {
+        TcpListener::bind("no:address")?;
+        Ok(())
+    }
+    fn parse_int() -> PyResult<()> {
+        "@_@".parse::<i64>()?;
+        Ok(())
+    }
+    assert!(io_err().is_err());
+    assert!(parse_int().is_err());
+}