Mirrors
/
cpython
mirror of https://github.com/python/cpython
3
0
Fork 0
Code Releases Activity
Browse Source

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>
pull/19983/head
Lysandros Nikolaou 6 years ago
committed by GitHub
parent
bcc3036095
commit
ce21cfca7b
No known key found for this signature in database GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 82 additions and 46 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 17
      Grammar/python.gram
  2. 5
      Lib/test/test_grammar.py
  3. 25
      Lib/test/test_peg_parser.py
  4. 12
      Lib/test/test_syntax.py
  5. 69
      Parser/pegen/parse.c

17
Grammar/python.gram
View File

@ -89,12 +89,12 @@ assignment[stmt_ty]:
"Variable annotation syntax is",
_Py_AnnAssign(CHECK(_PyPegen_set_expr_context(p, a, Store)), b, c, 1, EXTRA)
) }
| a=('(' b=inside_paren_ann_assign_target ')' { b }
| ann_assign_subscript_attribute_target) ':' b=expression c=['=' d=annotated_rhs { d }] {
| a=('(' b=single_target ')' { b }
| single_subscript_attribute_target) ':' b=expression c=['=' d=annotated_rhs { d }] {
CHECK_VERSION(6, "Variable annotations syntax is", _Py_AnnAssign(a, b, c, 0, EXTRA)) }
| a=(z=star_targets '=' { z })+ b=(yield_expr | star_expressions) tc=[TYPE_COMMENT] {
_Py_Assign(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) }
| a=target b=augassign c=(yield_expr | star_expressions) {
| a=single_target b=augassign c=(yield_expr | star_expressions) {
_Py_AugAssign(a, b->kind, c, EXTRA) }
| invalid_assignment
@ -185,7 +185,7 @@ try_stmt[stmt_ty]:
| 'try' ':' b=block f=finally_block { _Py_Try(b, NULL, NULL, f, EXTRA) }
| 'try' ':' b=block ex=except_block+ el=[else_block] f=[finally_block] { _Py_Try(b, ex, el, f, EXTRA) }
except_block[excepthandler_ty]:
| 'except' e=expression t=['as' z=target { z }] ':' b=block {
| 'except' e=expression t=['as' z=NAME { z }] ':' b=block {
_Py_ExceptHandler(e, (t) ? ((expr_ty) t)->v.Name.id : NULL, b, EXTRA) }
| 'except' ':' b=block { _Py_ExceptHandler(NULL, NULL, b, EXTRA) }
finally_block[asdl_seq*]: 'finally' ':' a=block { a }
@ -573,12 +573,11 @@ star_atom[expr_ty]:
| '(' a=[star_targets_seq] ')' { _Py_Tuple(a, Store, EXTRA) }
| '[' a=[star_targets_seq] ']' { _Py_List(a, Store, EXTRA) }
inside_paren_ann_assign_target[expr_ty]:
| ann_assign_subscript_attribute_target
single_target[expr_ty]:
| single_subscript_attribute_target
| a=NAME { _PyPegen_set_expr_context(p, a, Store) }
| '(' a=inside_paren_ann_assign_target ')' { a }
ann_assign_subscript_attribute_target[expr_ty]:
| '(' a=single_target ')' { a }
single_subscript_attribute_target[expr_ty]:
| a=t_primary '.' b=NAME !t_lookahead { _Py_Attribute(a, b->v.Name.id, Store, EXTRA) }
| a=t_primary '[' b=slices ']' !t_lookahead { _Py_Subscript(a, b, Store, EXTRA) }

5
Lib/test/test_grammar.py
View File

@ -1279,7 +1279,7 @@ class GrammarTests(unittest.TestCase):
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 @@ class GrammarTests(unittest.TestCase):
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

25
Lib/test/test_peg_parser.py
View File

@ -35,6 +35,9 @@ TEST_CASES = [
('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 @@ TEST_CASES = [
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 @@ FAIL_TEST_CASES = [
("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 @@ FAIL_TEST_CASES = [
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 = [

12
Lib/test/test_syntax.py
View File

@ -129,6 +129,18 @@ SyntaxError: cannot assign to __debug__
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):

69
Parser/pegen/parse.c
View File

@ -199,8 +199,8 @@ static KeywordToken *reserved_keywords[] = {
#define star_targets_seq_type 1128
#define star_target_type 1129
#define star_atom_type 1130
#define inside_paren_ann_assign_target_type 1131
#define ann_assign_subscript_attribute_target_type 1132
#define single_target_type 1131
#define single_subscript_attribute_target_type 1132
#define del_targets_type 1133
#define del_target_type 1134
#define del_t_atom_type 1135
@ -501,8 +501,8 @@ static expr_ty star_targets_rule(Parser *p);
static asdl_seq* star_targets_seq_rule(Parser *p);
static expr_ty star_target_rule(Parser *p);
static expr_ty star_atom_rule(Parser *p);
static expr_ty inside_paren_ann_assign_target_rule(Parser *p);
static expr_ty ann_assign_subscript_attribute_target_rule(Parser *p);
static expr_ty single_target_rule(Parser *p);
static expr_ty single_subscript_attribute_target_rule(Parser *p);
static asdl_seq* del_targets_rule(Parser *p);
static expr_ty del_target_rule(Parser *p);
static expr_ty del_t_atom_rule(Parser *p);
@ -1590,9 +1590,9 @@ compound_stmt_rule(Parser *p)
// assignment:
// | NAME ':' expression ['=' annotated_rhs]
// | ('(' inside_paren_ann_assign_target ')' | ann_assign_subscript_attribute_target) ':' expression ['=' annotated_rhs]
// | ('(' single_target ')' | single_subscript_attribute_target) ':' expression ['=' annotated_rhs]
// | ((star_targets '='))+ (yield_expr | star_expressions) TYPE_COMMENT?
// | target augassign (yield_expr | star_expressions)
// | single_target augassign (yield_expr | star_expressions)
// | invalid_assignment
static stmt_ty
assignment_rule(Parser *p)
@ -1642,13 +1642,13 @@ assignment_rule(Parser *p)
}
p->mark = _mark;
}
{ // ('(' inside_paren_ann_assign_target ')' | ann_assign_subscript_attribute_target) ':' expression ['=' annotated_rhs]
{ // ('(' single_target ')' | single_subscript_attribute_target) ':' expression ['=' annotated_rhs]
Token * _literal;
void *a;
expr_ty b;
void *c;
if (
(a = _tmp_20_rule(p)) // '(' inside_paren_ann_assign_target ')' | ann_assign_subscript_attribute_target
(a = _tmp_20_rule(p)) // '(' single_target ')' | single_subscript_attribute_target
&&
(_literal = _PyPegen_expect_token(p, 11)) // token=':'
&&
@ -1703,12 +1703,12 @@ assignment_rule(Parser *p)
}
p->mark = _mark;
}
{ // target augassign (yield_expr | star_expressions)
{ // single_target augassign (yield_expr | star_expressions)
expr_ty a;
AugOperator* b;
void *c;
if (
(a = target_rule(p)) // target
(a = single_target_rule(p)) // single_target
&&
(b = augassign_rule(p)) // augassign
&&
@ -3350,7 +3350,7 @@ try_stmt_rule(Parser *p)
return _res;
}
// except_block: 'except' expression ['as' target] ':' block | 'except' ':' block
// except_block: 'except' expression ['as' NAME] ':' block | 'except' ':' block
static excepthandler_ty
except_block_rule(Parser *p)
{
@ -3367,7 +3367,7 @@ except_block_rule(Parser *p)
UNUSED(_start_lineno); // Only used by EXTRA macro
int _start_col_offset = p->tokens[_mark]->col_offset;
UNUSED(_start_col_offset); // Only used by EXTRA macro
{ // 'except' expression ['as' target] ':' block
{ // 'except' expression ['as' NAME] ':' block
Token * _keyword;
Token * _literal;
asdl_seq* b;
@ -3378,7 +3378,7 @@ except_block_rule(Parser *p)
&&
(e = expression_rule(p)) // expression
&&
(t = _tmp_48_rule(p), 1) // ['as' target]
(t = _tmp_48_rule(p), 1) // ['as' NAME]
&&
(_literal = _PyPegen_expect_token(p, 11)) // token=':'
&&
@ -9605,25 +9605,22 @@ star_atom_rule(Parser *p)
return _res;
}
// inside_paren_ann_assign_target:
// | ann_assign_subscript_attribute_target
// | NAME
// | '(' inside_paren_ann_assign_target ')'
// single_target: single_subscript_attribute_target | NAME | '(' single_target ')'
static expr_ty
inside_paren_ann_assign_target_rule(Parser *p)
single_target_rule(Parser *p)
{
if (p->error_indicator) {
return NULL;
}
expr_ty _res = NULL;
int _mark = p->mark;
{ // ann_assign_subscript_attribute_target
expr_ty ann_assign_subscript_attribute_target_var;
{ // single_subscript_attribute_target
expr_ty single_subscript_attribute_target_var;
if (
(ann_assign_subscript_attribute_target_var = ann_assign_subscript_attribute_target_rule(p)) // ann_assign_subscript_attribute_target
(single_subscript_attribute_target_var = single_subscript_attribute_target_rule(p)) // single_subscript_attribute_target
)
{
_res = ann_assign_subscript_attribute_target_var;
_res = single_subscript_attribute_target_var;
goto done;
}
p->mark = _mark;
@ -9643,14 +9640,14 @@ inside_paren_ann_assign_target_rule(Parser *p)
}
p->mark = _mark;
}
{ // '(' inside_paren_ann_assign_target ')'
{ // '(' single_target ')'
Token * _literal;
Token * _literal_1;
expr_ty a;
if (
(_literal = _PyPegen_expect_token(p, 7)) // token='('
&&
(a = inside_paren_ann_assign_target_rule(p)) // inside_paren_ann_assign_target
(a = single_target_rule(p)) // single_target
&&
(_literal_1 = _PyPegen_expect_token(p, 8)) // token=')'
)
@ -9669,11 +9666,11 @@ inside_paren_ann_assign_target_rule(Parser *p)
return _res;
}
// ann_assign_subscript_attribute_target:
// single_subscript_attribute_target:
// | t_primary '.' NAME !t_lookahead
// | t_primary '[' slices ']' !t_lookahead
static expr_ty
ann_assign_subscript_attribute_target_rule(Parser *p)
single_subscript_attribute_target_rule(Parser *p)
{
if (p->error_indicator) {
return NULL;
@ -11907,7 +11904,7 @@ _tmp_19_rule(Parser *p)
return _res;
}
// _tmp_20: '(' inside_paren_ann_assign_target ')' | ann_assign_subscript_attribute_target
// _tmp_20: '(' single_target ')' | single_subscript_attribute_target
static void *
_tmp_20_rule(Parser *p)
{
@ -11916,14 +11913,14 @@ _tmp_20_rule(Parser *p)
}
void * _res = NULL;
int _mark = p->mark;
{ // '(' inside_paren_ann_assign_target ')'
{ // '(' single_target ')'
Token * _literal;
Token * _literal_1;
expr_ty b;
if (
(_literal = _PyPegen_expect_token(p, 7)) // token='('
&&
(b = inside_paren_ann_assign_target_rule(p)) // inside_paren_ann_assign_target
(b = single_target_rule(p)) // single_target
&&
(_literal_1 = _PyPegen_expect_token(p, 8)) // token=')'
)
@ -11937,13 +11934,13 @@ _tmp_20_rule(Parser *p)
}
p->mark = _mark;
}
{ // ann_assign_subscript_attribute_target
expr_ty ann_assign_subscript_attribute_target_var;
{ // single_subscript_attribute_target
expr_ty single_subscript_attribute_target_var;
if (
(ann_assign_subscript_attribute_target_var = ann_assign_subscript_attribute_target_rule(p)) // ann_assign_subscript_attribute_target
(single_subscript_attribute_target_var = single_subscript_attribute_target_rule(p)) // single_subscript_attribute_target
)
{
_res = ann_assign_subscript_attribute_target_var;
_res = single_subscript_attribute_target_var;
goto done;
}
p->mark = _mark;
@ -13073,7 +13070,7 @@ _loop1_47_rule(Parser *p)
return _seq;
}
// _tmp_48: 'as' target
// _tmp_48: 'as' NAME
static void *
_tmp_48_rule(Parser *p)
{
@ -13082,13 +13079,13 @@ _tmp_48_rule(Parser *p)
}
void * _res = NULL;
int _mark = p->mark;
{ // 'as' target
{ // 'as' NAME
Token * _keyword;
expr_ty z;
if (
(_keyword = _PyPegen_expect_token(p, 531)) // token='as'
&&
(z = target_rule(p)) // target
(z = _PyPegen_name_token(p)) // NAME
)
{
_res = z;

Write Preview
Loading…
Cancel
Save