File support-python-314.patch of Package python-pegen
From 30839512f752c69fcec5d63c23ae7b9e46c151a3 Mon Sep 17 00:00:00 2001
From: Alexander Sulfrian <alexander@sulfrian.net>
Date: Fri, 2 Jan 2026 16:31:24 +0100
Subject: [PATCH 1/5] Improve SyntaxError messages for pattern captures
python/cpython@23f159ae711d84177e8ce34cd9a6c8a762de64ac improved the
SyntaxError messages for invalid pattern targets. This adds support for the
more detailed messages in Python 3.14 and above.
---
data/python.gram | 7 +++++--
tests/python_parser/test_syntax_error_handling.py | 2 +-
2 files changed, 6 insertions(+), 3 deletions(-)
Index: pegen-0.3.0/data/python.gram
===================================================================
--- pegen-0.3.0.orig/data/python.gram
+++ pegen-0.3.0/data/python.gram
@@ -1047,13 +1047,29 @@ try_stmt[ast.Try]:
except_block[ast.ExceptHandler]:
| invalid_except_stmt_indent
+ | 'except' e=expressions ':' b=block {
+ PY_VERSION >= (3, 14);
+ ast.ExceptHandler(type=e, name=None, body=b, LOCATIONS) }
+ | 'except' e=expression 'as' t=NAME ':' b=block {
+ PY_VERSION >= (3, 14);
+ ast.ExceptHandler(type=e, name=t.string, body=b, LOCATIONS) }
| 'except' e=expression t=['as' z=NAME { z.string }] ':' b=block {
+ PY_VERSION < (3, 14);
ast.ExceptHandler(type=e, name=t, body=b, LOCATIONS) }
| 'except' ':' b=block { ast.ExceptHandler(type=None, name=None, body=b, LOCATIONS) }
| invalid_except_stmt
except_star_block[ast.ExceptHandler]:
| invalid_except_star_stmt_indent
+ | 'except' '*' e=expressions ':' b=block {
+ PY_VERSION >= (3, 14);
+ ast.ExceptHandler(type=e, name=None, body=b, LOCATIONS)
+ }
+ | 'except' '*' e=expression 'as' t=NAME ':' b=block {
+ PY_VERSION >= (3, 14);
+ ast.ExceptHandler(type=e, name=t.string, body=b, LOCATIONS)
+ }
| 'except' '*' e=expression t=['as' z=NAME { z.string }] ':' b=block {
+ PY_VERSION < (3, 14);
ast.ExceptHandler(type=e, name=t, body=b, LOCATIONS)
}
| invalid_except_stmt
@@ -2255,7 +2271,12 @@ invalid_try_stmt[NoReturn]:
)
}
invalid_except_stmt[None]:
+ | 'except' '*'? a=expression ',' expressions 'as' NAME ':' {
+ PY_VERSION >= (3, 14);
+ self.raise_syntax_error_starting_from("multiple exception types must be parenthesized when using 'as'", a)
+ }
| 'except' '*'? a=expression ',' expressions ['as' NAME ] ':' {
+ PY_VERSION < (3, 14);
self.raise_syntax_error_starting_from("multiple exception types must be parenthesized", a)
}
| a='except' '*'? expression ['as' NAME ] NEWLINE { self.raise_syntax_error("expected ':'") }
@@ -2314,8 +2335,11 @@ invalid_as_pattern[NoReturn]:
| or_pattern 'as' a="_" {
self.raise_syntax_error_known_location("cannot use '_' as a target", a)
}
- | or_pattern 'as' !NAME a=expression {
- self.raise_syntax_error_known_location("invalid pattern target", a)
+ | or_pattern 'as' a=expression {
+ self.raise_syntax_error_known_location(
+ f"cannot use {self.get_expr_name(a)} as pattern target", a)
+ if self.py_version >= (3, 14)
+ else self.raise_syntax_error_known_location("invalid pattern target", a)
}
invalid_class_pattern[NoReturn]:
| name_or_attr '(' a=invalid_class_argument_pattern {
Index: pegen-0.3.0/tests/python_parser/test_syntax_error_handling.py
===================================================================
--- pegen-0.3.0.orig/tests/python_parser/test_syntax_error_handling.py
+++ pegen-0.3.0/tests/python_parser/test_syntax_error_handling.py
@@ -976,26 +976,32 @@ def test_invalid_try_stmt(
sys.version_info < (3, 11), reason="Syntax unsupported before 3.11+"
),
),
- (
+ pytest.param(
"try:\n\tpass\nexcept ValueError, IndexError:",
SyntaxError,
"multiple exception types must be parenthesized",
(3, 8),
(3, 30),
+ marks=pytest.mark.skipif(
+ sys.version_info >= (3, 14), reason="PEP 758 allows unparenthesized except and except* blocks"
+ ),
),
- (
+ pytest.param(
"try:\n\tpass\nexcept ValueError, IndexError,:",
SyntaxError,
"multiple exception types must be parenthesized",
(3, 8),
(3, 31),
+ marks=pytest.mark.skipif(
+ sys.version_info >= (3, 14), reason="PEP 758 allows unparenthesized except and except* blocks"
+ ),
),
(
"try:\n\tpass\nexcept ValueError, IndexError, a=1:",
SyntaxError,
"invalid syntax",
- (3, 18),
- (3, 19),
+ (3, 33) if sys.version_info >= (3, 14) else (3, 18),
+ (3, 34) if sys.version_info >= (3, 14) else (3, 19),
),
(
"try:\n\tpass\nexcept Exception\npass",
@@ -1156,7 +1162,7 @@ def test_invalid_case_stmt(
(
"match a:\n\tcase 1 as 1+1:\n\t\tpass",
SyntaxError,
- "invalid pattern target",
+ "cannot use expression as pattern target" if sys.version_info >= (3, 14) else "invalid pattern target",
(2, 12),
(2, 15),
),
Index: pegen-0.3.0/src/pegen/python_generator.py
===================================================================
--- pegen-0.3.0.orig/src/pegen/python_generator.py
+++ pegen-0.3.0/src/pegen/python_generator.py
@@ -397,6 +397,7 @@ class PythonParserGenerator(ParserGenera
locations = False
unreachable = False
used = None
+ version_check = None
if action:
# Replace magic name in the action rule
if "LOCATIONS" in action:
@@ -405,6 +406,11 @@ class PythonParserGenerator(ParserGenera
if "UNREACHABLE" in action:
unreachable = True
action = action.replace("UNREACHABLE", self.unreachable_formatting)
+ if ";" in action:
+ parts = action.split(";", 1)
+ if parts[0].startswith("PY_VERSION"):
+ action = parts[1].lstrip()
+ version_check = parts[0].replace("PY_VERSION", "self.py_version")
# Extract the names actually used in the action.
used = self.usednamesvisitor.visit(ast.parse(action))
@@ -423,6 +429,11 @@ class PythonParserGenerator(ParserGenera
if has_invalid:
self.print("self.call_invalid_rules")
first = False
+ if version_check:
+ if not first:
+ self.print("and")
+ self.print(f"({version_check})")
+ first = False
for item in node.items:
if first:
first = False
Index: pegen-0.3.0/.github/workflows/test.yml
===================================================================
--- pegen-0.3.0.orig/.github/workflows/test.yml
+++ pegen-0.3.0/.github/workflows/test.yml
@@ -13,7 +13,7 @@ jobs:
runs-on: ubuntu-latest
strategy:
matrix:
- python-version: ['3.8','3.9','3.10', '3.11', '3.12', '3.13']
+ python-version: ['3.8','3.9','3.10', '3.11', '3.12', '3.13', '3.14']
steps:
- uses: actions/checkout@v4
- name: Get history and tags for SCM versioning to work
Index: pegen-0.3.0/pyproject.toml
===================================================================
--- pegen-0.3.0.orig/pyproject.toml
+++ pegen-0.3.0/pyproject.toml
@@ -24,6 +24,7 @@ classifiers = [
"Programming Language :: Python :: 3.11",
"Programming Language :: Python :: 3.12",
"Programming Language :: Python :: 3.13",
+ "Programming Language :: Python :: 3.14",
"Programming Language :: Python :: 3 :: Only",
]
keywords = ["parser", "CPython", "PEG", "pegen"]
