From c116c94ff119485761460f1033cdee425bed0310 Mon Sep 17 00:00:00 2001 From: Shantanu Date: Wed, 27 May 2020 13:30:38 -0700 Subject: [PATCH] bpo-40614: Respect feature version for f-string debug expressions (GH-20196) Co-authored-by: Lysandros Nikolaou Co-authored-by: Pablo Galindo --- Lib/test/test_ast.py | 5 +++++ .../next/Library/2020-05-18-22-41-02.bpo-40614.8j3kmq.rst | 1 + Parser/pegen/parse_string.c | 5 +++++ Python/ast.c | 6 ++++++ 4 files changed, 17 insertions(+) create mode 100644 Misc/NEWS.d/next/Library/2020-05-18-22-41-02.bpo-40614.8j3kmq.rst diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py index 3e9c8b55cdf..a3b366ec35d 100644 --- a/Lib/test/test_ast.py +++ b/Lib/test/test_ast.py @@ -663,6 +663,11 @@ class AST_Tests(unittest.TestCase): expressions[0] = f"expr = {ast.expr.__subclasses__()[0].__doc__}" self.assertCountEqual(ast.expr.__doc__.split("\n"), expressions) + def test_issue40614_feature_version(self): + ast.parse('f"{x=}"', feature_version=(3, 8)) + with self.assertRaises(SyntaxError): + ast.parse('f"{x=}"', feature_version=(3, 7)) + class ASTHelpers_Test(unittest.TestCase): maxDiff = None diff --git a/Misc/NEWS.d/next/Library/2020-05-18-22-41-02.bpo-40614.8j3kmq.rst b/Misc/NEWS.d/next/Library/2020-05-18-22-41-02.bpo-40614.8j3kmq.rst new file mode 100644 index 00000000000..238b98c14a3 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2020-05-18-22-41-02.bpo-40614.8j3kmq.rst @@ -0,0 +1 @@ +:func:`ast.parse` will not parse self documenting expressions in f-strings when passed ``feature_version`` is less than ``(3, 8)``. diff --git a/Parser/pegen/parse_string.c b/Parser/pegen/parse_string.c index a0ec698fa56..e24ecc58d3a 100644 --- a/Parser/pegen/parse_string.c +++ b/Parser/pegen/parse_string.c @@ -928,6 +928,11 @@ fstring_find_expr(Parser *p, const char **str, const char *end, int raw, int rec /* Check for =, which puts the text value of the expression in expr_text. */ if (**str == '=') { + if (p->feature_version < 8) { + RAISE_SYNTAX_ERROR("f-string: self documenting expressions are " + "only supported in Python 3.8 and greater"); + goto error; + } *str += 1; /* Skip over ASCII whitespace. No need to test for end of string diff --git a/Python/ast.c b/Python/ast.c index 2d20ca62aa8..c524b8e34e8 100644 --- a/Python/ast.c +++ b/Python/ast.c @@ -5069,6 +5069,12 @@ fstring_find_expr(const char **str, const char *end, int raw, int recurse_lvl, /* Check for =, which puts the text value of the expression in expr_text. */ if (**str == '=') { + if (c->c_feature_version < 8) { + ast_error(c, n, + "f-string: self documenting expressions are " + "only supported in Python 3.8 and greater"); + goto error; + } *str += 1; /* Skip over ASCII whitespace. No need to test for end of string