Translate C++ std::bad_cast exception to Python TypeError

Cython/Compiler/ExprNodes.py

@@ -8228,6 +8228,8 @@ static void __Pyx_CppExn2PyErr() {
     PyErr_SetString(PyExc_ValueError, exn.what());
   } catch (const std::bad_alloc& exn) {
     PyErr_SetString(PyExc_MemoryError, exn.what());
+  } catch (const std::bad_cast& exn) {
+    PyErr_SetString(PyExc_TypeError, exn.what());
   } catch (const std::ios_base::failure& exn) {
     // Unfortunately, in standard C++ we have no way of distinguishing EOF
     // from other errors here; be careful with the exception mask

Cython/Compiler/Nodes.py

@@ -580,6 +580,7 @@ class CFuncDeclaratorNode(CDeclaratorNode):
             env.add_include_file('ios')         # for std::ios_base::failure
             env.add_include_file('new')         # for std::bad_alloc
             env.add_include_file('stdexcept')
+            env.add_include_file('typeinfo')    # for std::bad_cast
         if return_type.is_pyobject \
             and (self.exception_value or self.exception_check) \
             and self.exception_check != '+':

tests/run/cpp_exceptions.pyx

@@ -16,6 +16,7 @@ cdef extern from "cpp_exceptions_helper.h":
     cdef void raise_memory "raise_memory"() except +
     cdef void raise_overflow "raise_overflow"() except +
     cdef void raise_range_error "raise_range_error"() except +
+    cdef void raise_typeerror "raise_typeerror"() except +
     cdef void raise_underflow "raise_underflow"() except +
 
     cdef cppclass Foo:
@@ -65,6 +66,20 @@ def test_range_error():
     """
     raise_range_error()
 
+def test_typeerror():
+    """
+    >>> test_typeerror()
+    Traceback (most recent call last):
+    ...
+    TypeError
+    """
+    # Re-raise the exception without a description string because we can't
+    # rely on the implementation-defined value of what() in the doctest.
+    try:
+        raise_typeerror()
+    except TypeError:
+        raise TypeError
+
 def test_underflow():
     """
     >>> test_underflow()

tests/run/cpp_exceptions_helper.h

@@ -44,6 +44,16 @@ void raise_range_error() {
     throw std::range_error("range_error");
 }
 
+struct Base { virtual ~Base() {} };
+struct Derived : Base { void use() const { abort(); } };
+
+void raise_typeerror() {
+    Base foo;
+    Base &bar = foo;    // prevents "dynamic_cast can never succeed" warning
+    Derived &baz = dynamic_cast<Derived &>(bar);
+    baz.use();          // not reached; prevents "unused variable" warning
+}
+
 void raise_underflow() {
     throw std::underflow_error("underflow_error");
 }