gh-87999: Change warning type for numeric literal followed by keyword (GH-91980)

The warning emitted by the Python parser for a numeric literal
immediately followed by keyword has been changed from deprecation
warning to syntax warning.

Author: serhiy-storchaka

Lib/test/test_grammar.py

@@ -104,6 +104,7 @@
 class TokenTests(unittest.TestCase):
 
     from test.support import check_syntax_error
+    from test.support.warnings_helper import check_syntax_warning
 
     def test_backslash(self):
         # Backslash means line continuation:
@@ -178,7 +179,7 @@ def test_floats(self):
     def test_float_exponent_tokenization(self):
         # See issue 21642.
         with warnings.catch_warnings():
-            warnings.simplefilter('ignore', DeprecationWarning)
+            warnings.simplefilter('ignore', SyntaxWarning)
             self.assertEqual(eval("1 if 1else 0"), 1)
             self.assertEqual(eval("1 if 0else 0"), 0)
         self.assertRaises(SyntaxError, eval, "0 if 1Else 0")
@@ -218,28 +219,36 @@ def check(test, error=False):
             with self.subTest(expr=test):
                 if error:
                     with warnings.catch_warnings(record=True) as w:
-                        with self.assertRaises(SyntaxError):
+                        with self.assertRaisesRegex(SyntaxError,
+                                    r'invalid \w+ literal'):
                             compile(test, "<testcase>", "eval")
                     self.assertEqual(w,  [])
                 else:
-                    with self.assertWarns(DeprecationWarning):
-                        compile(test, "<testcase>", "eval")
+                    self.check_syntax_warning(test,
+                            errtext=r'invalid \w+ literal')
 
         for num in "0xf", "0o7", "0b1", "9", "0", "1.", "1e3", "1j":
             compile(num, "<testcase>", "eval")
             check(f"{num}and x", error=(num == "0xf"))
             check(f"{num}or x", error=(num == "0"))
             check(f"{num}in x")
             check(f"{num}not in x")
-            with warnings.catch_warnings():
-                warnings.filterwarnings('ignore', '"is" with a literal',
-                                        SyntaxWarning)
-                check(f"{num}is x")
             check(f"{num}if x else y")
             check(f"x if {num}else y", error=(num == "0xf"))
             check(f"[{num}for x in ()]")
             check(f"{num}spam", error=True)
 
+            with warnings.catch_warnings():
+                warnings.filterwarnings('ignore', '"is" with a literal',
+                                        SyntaxWarning)
+                with self.assertWarnsRegex(SyntaxWarning,
+                            r'invalid \w+ literal'):
+                    compile(f"{num}is x", "<testcase>", "eval")
+                warnings.simplefilter('error', SyntaxWarning)
+                with self.assertRaisesRegex(SyntaxError,
+                            r'invalid \w+ literal'):
+                    compile(f"{num}is x", "<testcase>", "eval")
+
         check("[0x1ffor x in ()]")
         check("[0x1for x in ()]")
         check("[0xfor x in ()]")

Misc/NEWS.d/next/Core and Builtins/2022-04-27-10-36-43.gh-issue-87999.YSPHfO.rst

@@ -0,0 +1,3 @@
+The warning emitted by the Python parser for a numeric literal immediately
+followed by keyword has been changed from deprecation warning to syntax
+warning.

Parser/tokenizer.c

@@ -1139,7 +1139,7 @@ indenterror(struct tok_state *tok)
 }
 
 static int
-parser_warn(struct tok_state *tok, const char *format, ...)
+parser_warn(struct tok_state *tok, PyObject *category, const char *format, ...)
 {
     PyObject *errmsg;
     va_list vargs;
@@ -1154,9 +1154,9 @@ parser_warn(struct tok_state *tok, const char *format, ...)
         goto error;
     }
 
-    if (PyErr_WarnExplicitObject(PyExc_DeprecationWarning, errmsg, tok->filename,
+    if (PyErr_WarnExplicitObject(category, errmsg, tok->filename,
                                  tok->lineno, NULL, NULL) < 0) {
-        if (PyErr_ExceptionMatches(PyExc_DeprecationWarning)) {
+        if (PyErr_ExceptionMatches(category)) {
             /* Replace the DeprecationWarning exception with a SyntaxError
                to get a more accurate error report */
             PyErr_Clear();
@@ -1234,7 +1234,9 @@ verify_end_of_number(struct tok_state *tok, int c, const char *kind)
     }
     if (r) {
         tok_backup(tok, c);
-        if (parser_warn(tok, "invalid %s literal", kind)) {
+        if (parser_warn(tok, PyExc_SyntaxWarning,
+                "invalid %s literal", kind))
+        {
             return 0;
         }
         tok_nextc(tok);