Add more c-api error functions (#7915)

bschoenmaeckers · web-flow · commit cea21f953dee · 2026-05-20T08:58:45.000+09:00
* Add more c-api error functions

* Return NULL when no cause is set
diff --git a/crates/capi/src/lib.rs b/crates/capi/src/lib.rs
@@ -17,6 +17,7 @@ pub mod pyerrors;
 pub mod pylifecycle;
 pub mod pystate;
 pub mod refcount;
+pub mod traceback;
 pub mod tupleobject;
 pub mod unicodeobject;
 mod util;
diff --git a/crates/capi/src/pyerrors.rs b/crates/capi/src/pyerrors.rs
@@ -1,5 +1,5 @@
-use crate::PyObject;
-use crate::pystate::with_vm;
+use crate::object::define_py_check;
+use crate::{PyObject, pystate::with_vm};
 use core::convert::Infallible;
 use core::ffi::{CStr, c_char, c_int};
 use core::ptr::NonNull;
@@ -96,6 +96,8 @@ define_exception_statics! {
     PyExc_EncodingWarning => encoding_warning,
 }
 
+define_py_check!(fn PyExceptionInstance_Check, exceptions.base_exception_type);
+
 #[unsafe(no_mangle)]
 pub extern "C" fn PyErr_Occurred() -> *mut PyObject {
     with_vm(|vm| {
@@ -191,6 +193,15 @@ pub unsafe extern "C" fn PyErr_WriteUnraisable(obj: *mut PyObject) {
     })
 }
 
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn PyExceptionClass_Check(obj: *mut PyObject) -> c_int {
+    with_vm(|vm| unsafe {
+        obj.as_ref()
+            .and_then(|obj| obj.downcast_ref::<PyType>())
+            .is_some_and(|ty| ty.is_subtype(vm.ctx.exceptions.base_exception_type))
+    })
+}
+
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn PyErr_NewException(
     name: *const c_char,
@@ -252,6 +263,42 @@ pub unsafe extern "C" fn PyErr_GivenExceptionMatches(
     })
 }
 
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn PyException_GetTraceback(exc: *mut PyObject) -> *mut PyObject {
+    with_vm(|vm| {
+        let exc = unsafe { &*exc }.try_downcast_ref::<PyBaseException>(vm)?;
+        let tb = exc
+            .__traceback__()
+            .map(|tb| tb.into_object().into_raw().as_ptr())
+            .unwrap_or_default();
+        Ok(tb)
+    })
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn PyException_GetCause(exc: *mut PyObject) -> *mut PyObject {
+    with_vm(|vm| {
+        let exc = unsafe { &*exc }.try_downcast_ref::<PyBaseException>(vm)?;
+        let cause = exc
+            .__cause__()
+            .map(|cause| cause.into_object().into_raw().as_ptr())
+            .unwrap_or_default();
+        Ok(cause)
+    })
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn PyException_GetContext(exc: *mut PyObject) -> *mut PyObject {
+    with_vm(|vm| {
+        let exc = unsafe { &*exc }.try_downcast_ref::<PyBaseException>(vm)?;
+        let context = exc
+            .__context__()
+            .map(|context| context.into_object().into_raw().as_ptr())
+            .unwrap_or_default();
+        Ok(context)
+    })
+}
+
 #[cfg(test)]
 mod tests {
     use pyo3::exceptions::PyTypeError;
diff --git a/crates/capi/src/traceback.rs b/crates/capi/src/traceback.rs
@@ -0,0 +1,24 @@
+use crate::PyObject;
+use crate::object::define_py_check;
+use crate::pystate::with_vm;
+use core::ffi::c_int;
+use rustpython_vm::function::{FuncArgs, KwArgs};
+
+define_py_check!(exact fn PyTraceBack_Check, types.traceback_type);
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn PyTraceBack_Print(tb: *mut PyObject, file: *mut PyObject) -> c_int {
+    with_vm(|vm| {
+        let tb = unsafe { &*tb };
+        let file = unsafe { &*file };
+        let tb_module = vm.import("traceback", 0)?;
+        let print_tb = tb_module.get_attr("print_tb", vm)?;
+
+        let kwargs: KwArgs = [("file".to_string(), file.to_owned())]
+            .into_iter()
+            .collect();
+        print_tb.call(FuncArgs::new(vec![tb.to_owned()], kwargs), vm)?;
+
+        Ok(())
+    })
+}
