From 021bb87845e5727b370d6d05986d08f930bcc664 Mon Sep 17 00:00:00 2001 From: Zachary Ware Date: Fri, 24 Jan 2014 22:52:30 -0600 Subject: [PATCH] Issue #20381: Fix sanity checking on default arguments when c_default is also specified. --- Misc/NEWS | 5 +++++ Tools/clinic/clinic.py | 14 +++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/Misc/NEWS b/Misc/NEWS index a8cd06c07aa..a8e251a1e7b 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -141,6 +141,11 @@ Tests Tools/Demos ----------- + +- Issue #20381: Argument Clinic now sanity checks the default argument when + c_default is also specified, providing a nice failure message for + disallowed values. + - Issue #20189: Argument Clinic now ensures that parser functions for __new__ are always of type newfunc, the type of the tp_new slot. Similarly, parser functions for __init__ are now always of type initproc, diff --git a/Tools/clinic/clinic.py b/Tools/clinic/clinic.py index 8bf89777e79..d33abaed2a7 100755 --- a/Tools/clinic/clinic.py +++ b/Tools/clinic/clinic.py @@ -3279,11 +3279,11 @@ class DSLParser: fail("You can't specify py_default without specifying a default value!") else: default = default.strip() + bad = False ast_input = "x = {}".format(default) try: module = ast.parse(ast_input) - bad = False if 'c_default' not in kwargs: # we can only represent very simple data values in C. # detect whether default is okay, via a blacklist @@ -3317,8 +3317,16 @@ class DSLParser: bad = blacklist.bad else: # if they specify a c_default, we can be more lenient about the default value. - # but at least ensure that we can turn it into text and reconstitute it correctly. - bad = default != repr(eval(default)) + # but at least make an attempt at ensuring it's a valid expression. + try: + value = eval(default) + if value == unspecified: + fail("'unspecified' is not a legal default value!") + except NameError: + pass # probably a named constant + except Exception as e: + fail("Malformed expression given as default value\n" + "{!r} caused {!r}".format(default, e)) if bad: fail("Unsupported expression as default value: " + repr(default))