gh-82312: Further improvement of error messages for generating AST nodes

This is a follow up of GH-17715.

* Use %T instead of _PyType_Name().
* Add the wrong type name we got for identifier and string.

Author: serhiy-storchaka

Lib/test/test_ast/test_ast.py

@@ -1098,10 +1098,17 @@ def test_required_field_messages(self):
         ):
             compile(expr_with_wrong_body, "<test>", "eval")
 
+        variable = ast.parse("test", mode="eval")
+        variable.body.id = b'test'
+        with self.assertRaisesRegex(TypeError,
+            "field 'id' was expecting a string object, got bytes"
+        ):
+            compile(variable, "<test>", "eval")
+
         constant = ast.parse("u'test'", mode="eval")
         constant.body.kind = 0xFF
-        with self.assertRaisesRegex(
-            TypeError, "field 'kind' was expecting a string or bytes object"
+        with self.assertRaisesRegex(TypeError,
+            "field 'kind' was expecting a string or bytes object, got int"
         ):
             compile(constant, "<test>", "eval")
 

Parser/asdl_c.py

@@ -554,8 +554,8 @@ def typeCheck(self, name):
         self.emit("return 1;", 2)
         self.emit("}", 1)
         self.emit("if (!isinstance && field != NULL) {", 1)
-        error = "field '%%s' was expecting node of type '%s', got '%%s'" % name
-        self.emit("PyErr_Format(PyExc_TypeError, \"%s\", field, _PyType_Name(Py_TYPE(obj)));" % error, 2, reflow=False)
+        error = "field '%%s' was expecting node of type '%s', got '%%T'" % name
+        self.emit("PyErr_Format(PyExc_TypeError, \"%s\", field, obj);" % error, 2, reflow=False)
         self.emit("return 1;", 2)
         self.emit("}", 1)
 
@@ -692,7 +692,7 @@ def visitField(self, field, name, sum=None, prod=None, depth=0):
             self.emit("Py_ssize_t i;", depth+1)
             self.emit("if (!PyList_Check(tmp)) {", depth+1)
             self.emit("PyErr_Format(PyExc_TypeError, \"%s field \\\"%s\\\" must "
-                      "be a list, not a %%.200s\", _PyType_Name(Py_TYPE(tmp)));" %
+                      "be a list, not a %%T\", tmp);" %
                       (name, field.name),
                       depth+2, reflow=False)
             self.emit("goto failed;", depth+2)
@@ -991,10 +991,9 @@ def visitModule(self, mod):
 
     res = 0; /* if no error occurs, this stays 0 to the end */
     if (numfields < PyTuple_GET_SIZE(args)) {
-        PyErr_Format(PyExc_TypeError, "%.400s constructor takes at most "
+        PyErr_Format(PyExc_TypeError, "%T constructor takes at most "
                      "%zd positional argument%s",
-                     _PyType_Name(Py_TYPE(self)),
-                     numfields, numfields == 1 ? "" : "s");
+                     self, numfields, numfields == 1 ? "" : "s");
         res = -1;
         goto cleanup;
     }
@@ -1748,7 +1747,7 @@ def visitModule(self, mod):
 static int obj2ast_identifier(struct ast_state *state, PyObject* obj, PyObject** out, const char* field, PyArena* arena)
 {
     if (!PyUnicode_CheckExact(obj) && obj != Py_None) {
-        PyErr_Format(PyExc_TypeError, "field '%s' was expecting a string object", field);
+        PyErr_Format(PyExc_TypeError, "field '%s' was expecting a string object, got %T", field, obj);
         return -1;
     }
     return obj2ast_object(state, obj, out, field, arena);
@@ -1757,7 +1756,7 @@ def visitModule(self, mod):
 static int obj2ast_string(struct ast_state *state, PyObject* obj, PyObject** out, const char* field, PyArena* arena)
 {
     if (!PyUnicode_CheckExact(obj) && !PyBytes_CheckExact(obj)) {
-        PyErr_Format(PyExc_TypeError, "field '%s' was expecting a string or bytes object", field);
+        PyErr_Format(PyExc_TypeError, "field '%s' was expecting a string or bytes object, got %T", field, obj);
         return -1;
     }
     return obj2ast_object(state, obj, out, field, arena);
@@ -2144,8 +2143,8 @@ class PartingShots(StaticVisitor):
         return -1;
     }
     if (!isinstance) {
-        PyErr_Format(PyExc_TypeError, "expected %s node, got %.400s",
-                     req_name[mode], _PyType_Name(Py_TYPE(ast)));
+        PyErr_Format(PyExc_TypeError, "expected %s node, got %T",
+                     req_name[mode], ast);
         return -1;
     }
     return 0;