From 117f60bed0f906fed843455b3dd77aa03303fe5f Mon Sep 17 00:00:00 2001
From: Alex Gaynor <alex.gaynor@gmail.com>
Date: Tue, 8 Sep 2020 08:59:22 -0400
Subject: [PATCH] Make PyType::name abi3 compatible

The implementation is more complex, because there's no equivalent to tp_name in the limited API
---
 guide/src/trait_bounds.md                |  8 ++++----
 pyo3-derive-backend/src/from_pyobject.rs |  2 +-
 src/err.rs                               | 11 +++++++----
 src/exceptions.rs                        |  6 +++---
 src/types/typeobject.rs                  |  6 ++----
 tests/test_methods.rs                    |  4 ++--
 6 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/guide/src/trait_bounds.md b/guide/src/trait_bounds.md
index e3aac085..8dde99e0 100644
--- a/guide/src/trait_bounds.md
+++ b/guide/src/trait_bounds.md
@@ -408,8 +408,8 @@ impl Model for UserModel {
                 .call_method("get_results", (), None)
                 .unwrap();
 
-            if py_result.get_type().name() != "list" {
-                panic!("Expected a list for the get_results() method signature, got {}", py_result.get_type().name());
+            if py_result.get_type().name().unwrap() != "list" {
+                panic!("Expected a list for the get_results() method signature, got {}", py_result.get_type().name().unwrap());
             }
             py_result.extract()
         })
@@ -536,8 +536,8 @@ impl Model for UserModel {
                 .call_method("get_results", (), None)
                 .unwrap();
 
-            if py_result.get_type().name() != "list" {
-                panic!("Expected a list for the get_results() method signature, got {}", py_result.get_type().name());
+            if py_result.get_type().name().unwrap() != "list" {
+                panic!("Expected a list for the get_results() method signature, got {}", py_result.get_type().name().unwrap());
             }
             py_result.extract()
         })
diff --git a/pyo3-derive-backend/src/from_pyobject.rs b/pyo3-derive-backend/src/from_pyobject.rs
index f7688e2b..c6dbd31a 100644
--- a/pyo3-derive-backend/src/from_pyobject.rs
+++ b/pyo3-derive-backend/src/from_pyobject.rs
@@ -72,7 +72,7 @@ impl<'a> Enum<'a> {
         };
         quote!(
             #(#var_extracts)*
-            let type_name = obj.get_type().name();
+            let type_name = obj.get_type().name()?;
             let from = obj
                 .repr()
                 .map(|s| format!("{} ({})", s.to_string_lossy(), type_name))
diff --git a/src/err.rs b/src/err.rs
index e1ade1ee..5fc10fef 100644
--- a/src/err.rs
+++ b/src/err.rs
@@ -478,10 +478,13 @@ impl<'a> std::fmt::Display for PyDowncastError<'a> {
         write!(
             f,
             "Can't convert {} to {}",
-            self.from
-                .repr()
-                .map(|s| s.to_string_lossy())
-                .unwrap_or_else(|_| self.from.get_type().name()),
+            self.from.repr().map(|s| s.to_string_lossy()).or_else(|_| {
+                self.from
+                    .get_type()
+                    .name()
+                    .map_err(|_| std::fmt::Error)
+                    .map(|s| s.into())
+            })?,
             self.to
         )
     }
diff --git a/src/exceptions.rs b/src/exceptions.rs
index be73c5d4..ca0412cc 100644
--- a/src/exceptions.rs
+++ b/src/exceptions.rs
@@ -38,8 +38,8 @@ macro_rules! impl_exception_boilerplate {
 
         impl std::fmt::Debug for $name {
             fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-                let type_name = self.get_type().name();
-                f.debug_struct(&*type_name)
+                let type_name = self.get_type().name().map_err(|_| std::fmt::Error)?;
+                f.debug_struct(type_name)
                     // TODO: print out actual fields!
                     .finish()
             }
@@ -47,7 +47,7 @@ macro_rules! impl_exception_boilerplate {
 
         impl std::fmt::Display for $name {
             fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-                let type_name = self.get_type().name();
+                let type_name = self.get_type().name().map_err(|_| std::fmt::Error)?;
                 write!(f, "{}", type_name)?;
                 if let Ok(s) = self.str() {
                     write!(f, ": {}", &s.to_string_lossy())
diff --git a/src/types/typeobject.rs b/src/types/typeobject.rs
index 7db9d6c3..30037a5c 100644
--- a/src/types/typeobject.rs
+++ b/src/types/typeobject.rs
@@ -6,8 +6,6 @@ use crate::err::{PyErr, PyResult};
 use crate::instance::PyNativeType;
 use crate::type_object::PyTypeObject;
 use crate::{ffi, AsPyPointer, PyAny, Python};
-use std::borrow::Cow;
-use std::ffi::CStr;
 
 /// Represents a reference to a Python `type object`.
 #[repr(transparent)]
@@ -39,8 +37,8 @@ impl PyType {
     }
 
     /// Gets the name of the `PyType`.
-    pub fn name(&self) -> Cow<str> {
-        unsafe { CStr::from_ptr((*self.as_type_ptr()).tp_name).to_string_lossy() }
+    pub fn name(&self) -> PyResult<&str> {
+        self.getattr("__qualname__")?.extract()
     }
 
     /// Checks whether `self` is subclass of type `T`.
diff --git a/tests/test_methods.rs b/tests/test_methods.rs
index 40db57ae..b6b8a7f8 100644
--- a/tests/test_methods.rs
+++ b/tests/test_methods.rs
@@ -76,7 +76,7 @@ impl ClassMethod {
     #[classmethod]
     /// Test class method.
     fn method(cls: &PyType) -> PyResult<String> {
-        Ok(format!("{}.method()!", cls.name()))
+        Ok(format!("{}.method()!", cls.name()?))
     }
 }
 
@@ -104,7 +104,7 @@ struct ClassMethodWithArgs {}
 impl ClassMethodWithArgs {
     #[classmethod]
     fn method(cls: &PyType, input: &PyString) -> PyResult<String> {
-        Ok(format!("{}.method({})", cls.name(), input))
+        Ok(format!("{}.method({})", cls.name()?, input))
     }
 }