bpo-40000: Improve error messages when validating invalid ast.Constant nodes (GH-19055)

isidentical · pablogsal · web-flow · commit 0ac59f93c0e3 · 2020-03-19T11:32:28.000Z
Co-authored-by: Pablo Galindo &lt;Pablogsal@gmail.com&gt;
diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
@@ -582,6 +582,15 @@ def test_invalid_identifier(self):
             compile(m, "<test>", "exec")
         self.assertIn("identifier must be of type str", str(cm.exception))
 
+    def test_invalid_constant(self):
+        for invalid_constant in int, (1, 2, int), frozenset((1, 2, int)):
+            e = ast.Expression(body=ast.Constant(invalid_constant))
+            ast.fix_missing_locations(e)
+            with self.assertRaisesRegex(
+                TypeError, "invalid type in Constant: type"
+            ):
+                compile(e, "<test>", "eval")
+
     def test_empty_yield_from(self):
         # Issue 16546: yield from value is not optional.
         empty_yield_from = ast.parse("def f():\n yield from g()")
diff --git a/Misc/NEWS.d/next/Library/2020-03-18-12-54-25.bpo-40000.FnsPZC.rst b/Misc/NEWS.d/next/Library/2020-03-18-12-54-25.bpo-40000.FnsPZC.rst
@@ -0,0 +1,2 @@
+Improved error messages for validation of ``ast.Constant`` nodes. Patch by
+Batuhan Taskaya.
diff --git a/Python/ast.c b/Python/ast.c
@@ -147,6 +147,11 @@ validate_constant(PyObject *value)
         return 1;
     }
 
+    if (!PyErr_Occurred()) {
+        PyErr_Format(PyExc_TypeError,
+                     "got an invalid type in Constant: %s",
+                     _PyType_Name(Py_TYPE(value)));
+    }
     return 0;
 }
 
@@ -261,9 +266,6 @@ validate_expr(expr_ty exp, expr_context_ty ctx)
             validate_keywords(exp->v.Call.keywords);
     case Constant_kind:
         if (!validate_constant(exp->v.Constant.value)) {
-            PyErr_Format(PyExc_TypeError,
-                         "got an invalid type in Constant: %s",
-                         _PyType_Name(Py_TYPE(exp->v.Constant.value)));
             return 0;
         }
         return 1;

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	+Improved error messages for validation of ``ast.Constant`` nodes. Patch by
	`2`	`+Batuhan Taskaya.`
Original file line number	Diff line number	Diff line change
`@@ -147,6 +147,11 @@ validate_constant(PyObject *value)`
`147`	`147`	`return 1;`
`148`	`148`	`}`
`149`	`149`
	`150`	`+ if (!PyErr_Occurred()) {`
	`151`	`+ PyErr_Format(PyExc_TypeError,`
	`152`	`+ "got an invalid type in Constant: %s",`
	`153`	`+ _PyType_Name(Py_TYPE(value)));`
	`154`	`+ }`
`150`	`155`	`return 0;`
`151`	`156`	`}`
`152`	`157`
`@@ -261,9 +266,6 @@ validate_expr(expr_ty exp, expr_context_ty ctx)`
`261`	`266`	`validate_keywords(exp->v.Call.keywords);`
`262`	`267`	`case Constant_kind:`
`263`	`268`	`if (!validate_constant(exp->v.Constant.value)) {`
`264`		`- PyErr_Format(PyExc_TypeError,`
`265`		`- "got an invalid type in Constant: %s",`
`266`		`- _PyType_Name(Py_TYPE(exp->v.Constant.value)));`
`267`	`269`	`return 0;`
`268`	`270`	`}`
`269`	`271`	`return 1;`