bpo-40618: Disallow invalid targets in augassign and except clauses (GH-20083)
This commit fixes the new parser to disallow invalid targets in the
following scenarios:
- Augmented assignments must only accept a single target (Name,
Attribute or Subscript), but no tuples or lists.
- `except` clauses should only accept a single `Name` as a target.
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index 02ba8a8..e1a402e 100644
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -1279,7 +1279,7 @@
def test_try(self):
### try_stmt: 'try' ':' suite (except_clause ':' suite)+ ['else' ':' suite]
### | 'try' ':' suite 'finally' ':' suite
- ### except_clause: 'except' [expr ['as' expr]]
+ ### except_clause: 'except' [expr ['as' NAME]]
try:
1/0
except ZeroDivisionError:
@@ -1297,6 +1297,9 @@
except (EOFError, TypeError, ZeroDivisionError) as msg: pass
try: pass
finally: pass
+ with self.assertRaises(SyntaxError):
+ compile("try:\n pass\nexcept Exception as a.b:\n pass", "?", "exec")
+ compile("try:\n pass\nexcept Exception as a[b]:\n pass", "?", "exec")
def test_suite(self):
# simple_stmt | NEWLINE INDENT NEWLINE* (stmt NEWLINE*)+ DEDENT
diff --git a/Lib/test/test_peg_parser.py b/Lib/test/test_peg_parser.py
index df2d46d..71e0719 100644
--- a/Lib/test/test_peg_parser.py
+++ b/Lib/test/test_peg_parser.py
@@ -35,6 +35,9 @@
('attribute_simple', 'a.b'),
('attributes_subscript', 'a.b[0]'),
('augmented_assignment', 'x += 42'),
+ ('augmented_assignment_attribute', 'a.b.c += 42'),
+ ('augmented_assignment_paren', '(x) += 42'),
+ ('augmented_assignment_paren_subscript', '(x[0]) -= 42'),
('binop_add', '1 + 1'),
('binop_add_multiple', '1 + 1 + 1 + 1'),
('binop_all', '1 + 2 * 5 + 3 ** 2 - -3'),
@@ -547,6 +550,11 @@
with a as (x, y):
pass
'''),
+ ('with_list_target',
+ '''
+ with a as [x, y]:
+ pass
+ '''),
('yield', 'yield'),
('yield_expr', 'yield a'),
('yield_from', 'yield from a'),
@@ -560,6 +568,9 @@
("annotation_tuple", "(a,): int"),
("annotation_tuple_without_paren", "a,: int"),
("assignment_keyword", "a = if"),
+ ("augmented_assignment_list", "[a, b] += 1"),
+ ("augmented_assignment_tuple", "a, b += 1"),
+ ("augmented_assignment_tuple_paren", "(a, b) += (1, 2)"),
("comprehension_lambda", "(a for a in lambda: b)"),
("comprehension_else", "(a for a in b if c else d"),
("del_call", "del a()"),
@@ -589,6 +600,20 @@
a
"""),
("not_terminated_string", "a = 'example"),
+ ("try_except_attribute_target",
+ """
+ try:
+ pass
+ except Exception as a.b:
+ pass
+ """),
+ ("try_except_subscript_target",
+ """
+ try:
+ pass
+ except Exception as a[0]:
+ pass
+ """),
]
FAIL_SPECIALIZED_MESSAGE_CASES = [
diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py
index 06636ae..a3a1015 100644
--- a/Lib/test/test_syntax.py
+++ b/Lib/test/test_syntax.py
@@ -129,6 +129,18 @@
Traceback (most recent call last):
SyntaxError: cannot assign to conditional expression
+>>> a, b += 1, 2
+Traceback (most recent call last):
+SyntaxError: invalid syntax
+
+>>> (a, b) += 1, 2
+Traceback (most recent call last):
+SyntaxError: cannot assign to tuple
+
+>>> [a, b] += 1, 2
+Traceback (most recent call last):
+SyntaxError: cannot assign to list
+
From compiler_complex_args():
>>> def f(None=1):