From a58eed9cca47c6548a231600e3e3379a273b0908 Mon Sep 17 00:00:00 2001 From: Mark Dickinson Date: Thu, 17 Jun 2010 12:37:17 +0000 Subject: [PATCH] Merged revisions 82043 via svnmerge from svn+ssh://pythondev@svn.python.org/python/branches/py3k ........ r82043 | mark.dickinson | 2010-06-17 13:33:22 +0100 (Thu, 17 Jun 2010) | 6 lines Issue #9011: Remove buggy and unnecessary ST->AST compilation code dealing with unary minus applied to a constant. The removed code was mutating the ST, causing a second compilation to fail. (The peephole optimizer already takes care of optimizing this case, so there's no lost optimization opportunity here.) ........ --- Lib/test/test_parser.py | 12 +++++++++++- Misc/NEWS | 5 +++++ Python/ast.c | 26 -------------------------- 3 files changed, 16 insertions(+), 27 deletions(-) diff --git a/Lib/test/test_parser.py b/Lib/test/test_parser.py index c7cc13fb84..e52be06686 100644 --- a/Lib/test/test_parser.py +++ b/Lib/test/test_parser.py @@ -479,8 +479,18 @@ class CompileTestCase(unittest.TestCase): st = parser.suite('a = "\\u1"') self.assertRaises(SyntaxError, parser.compilest, st) + def test_issue_9011(self): + # Issue 9011: compilation of an unary minus expression changed + # the meaning of the ST, so that a second compilation produced + # incorrect results. + st = parser.expr('-3') + code1 = parser.compilest(st) + self.assertEqual(eval(code1), -3) + code2 = parser.compilest(st) + self.assertEqual(eval(code2), -3) + class ParserStackLimitTestCase(unittest.TestCase): - """try to push the parser to/over it's limits. + """try to push the parser to/over its limits. see http://bugs.python.org/issue1881 for a discussion """ def _nested_expression(self, level): diff --git a/Misc/NEWS b/Misc/NEWS index ae0ca7e050..91c65a6507 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -12,6 +12,11 @@ What's New in Python 3.1.3? Core and Builtins ----------------- +- Issue #9011: Remove buggy and unnecessary (in 3.x) ST->AST + compilation code dealing with unary minus applied to a constant. + The removed code was mutating the ST, causing a second compilation + to fail. + - Issue #8941: decoding big endian UTF-32 data in UCS-2 builds could crash the interpreter with characters outside the Basic Multilingual Plane (higher than 0x10000). diff --git a/Python/ast.c b/Python/ast.c index b8cb56561f..ce9f21135a 100644 --- a/Python/ast.c +++ b/Python/ast.c @@ -1664,34 +1664,8 @@ ast_for_trailer(struct compiling *c, const node *n, expr_ty left_expr) static expr_ty ast_for_factor(struct compiling *c, const node *n) { - node *pfactor, *ppower, *patom, *pnum; expr_ty expression; - /* If the unary - operator is applied to a constant, don't generate - a UNARY_NEGATIVE opcode. Just store the approriate value as a - constant. The peephole optimizer already does something like - this but it doesn't handle the case where the constant is - (sys.maxint - 1). In that case, we want a PyIntObject, not a - PyLongObject. - */ - if (TYPE(CHILD(n, 0)) == MINUS - && NCH(n) == 2 - && TYPE((pfactor = CHILD(n, 1))) == factor - && NCH(pfactor) == 1 - && TYPE((ppower = CHILD(pfactor, 0))) == power - && NCH(ppower) == 1 - && TYPE((patom = CHILD(ppower, 0))) == atom - && TYPE((pnum = CHILD(patom, 0))) == NUMBER) { - char *s = PyObject_MALLOC(strlen(STR(pnum)) + 2); - if (s == NULL) - return NULL; - s[0] = '-'; - strcpy(s + 1, STR(pnum)); - PyObject_FREE(STR(pnum)); - STR(pnum) = s; - return ast_for_atom(c, patom); - } - expression = ast_for_expr(c, CHILD(n, 1)); if (!expression) return NULL; -- 2.40.0