bpo-36101: remove non-ascii characters in docstring (pythonGH-12018)

* remove non-ascii characters in docstring
* clinic.py emits a warning when docstring has non-ascii character

Modules/_curses_panel.c

@@ -412,12 +412,12 @@ _curses_panel.panel.set_userptr
     obj: object
     /
 
-Set the panel’s user pointer to obj.
+Set the panel's user pointer to obj.
 [clinic start generated code]*/
 
 static PyObject *
 _curses_panel_panel_set_userptr(PyCursesPanelObject *self, PyObject *obj)
-/*[clinic end generated code: output=6fb145b3af88cf4a input=2056be1cd148b05c]*/
+/*[clinic end generated code: output=6fb145b3af88cf4a input=d2c6a9dbefabbf39]*/
 {
     PyObject *oldobj;
     int rc;
@@ -587,12 +587,12 @@ _curses_panel.update_panels
 
 Updates the virtual screen after changes in the panel stack.
 
-This does not call curses.doupdate(), so you’ll have to do this yourself.
+This does not call curses.doupdate(), so you'll have to do this yourself.
 [clinic start generated code]*/
 
 static PyObject *
 _curses_panel_update_panels_impl(PyObject *module)
-/*[clinic end generated code: output=2f3b4c2e03d90ded input=a127069202b0a097]*/
+/*[clinic end generated code: output=2f3b4c2e03d90ded input=5299624c9a708621]*/
 {
     PyCursesInitialised;
     update_panels();

Python/context.c

@@ -592,12 +592,12 @@ _contextvars_Context_keys_impl(PyContext *self)
 /*[clinic input]
 _contextvars.Context.values
 
-Return a list of all variables’ values in the context object.
+Return a list of all variables' values in the context object.
 [clinic start generated code]*/
 
 static PyObject *
 _contextvars_Context_values_impl(PyContext *self)
-/*[clinic end generated code: output=d286dabfc8db6dde input=6c3d08639ba3bf67]*/
+/*[clinic end generated code: output=d286dabfc8db6dde input=ce8075d04a6ea526]*/
 {
     return _PyHamt_NewIterValues(self->ctx_vars);
 }

Tools/clinic/clinic.py

@@ -615,6 +615,9 @@ def render(self, clinic, signatures):
         return self.render_function(clinic, function)
 
     def docstring_for_c_string(self, f):
+        if re.search(r'[^\x00-\x7F]', f.docstring):
+            warn("Non-ascii character appear in docstring.")
+
         text, add, output = _text_accumulator()
         # turn docstring into a properly quoted C string
         for line in f.docstring.split('\n'):