From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22527 invoked by alias); 21 May 2013 16:24:02 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 22516 invoked by uid 89); 21 May 2013 16:24:02 -0000 X-Spam-SWARE-Status: No, score=-8.2 required=5.0 tests=AWL,BAYES_00,KHOP_THREADED,RCVD_IN_HOSTKARMA_W,RCVD_IN_HOSTKARMA_WL,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.1 Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.84/v0.84-167-ge50287c) with ESMTP; Tue, 21 May 2013 16:23:58 +0000 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r4LGNv5l012417 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 21 May 2013 12:23:57 -0400 Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r4LGNt9o031048; Tue, 21 May 2013 12:23:56 -0400 Message-ID: <519B9F9A.9070600@redhat.com> Date: Tue, 21 May 2013 16:24:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 MIME-Version: 1.0 To: Jan Kratochvil CC: Tom Tromey , gdb-patches@sourceware.org Subject: Re: [patch] Compilation regression with python-2.6 [Re: [PATCH 24/28] introduce gdb_pymodule_addobject] References: <87ehe638ww.fsf@fleche.redhat.com> <8761ziy43f.fsf@fleche.redhat.com> <20130521075803.GA404@host2.jankratochvil.net> <519B9B54.9090907@redhat.com> <20130521161400.GA2763@host2.jankratochvil.net> In-Reply-To: <20130521161400.GA2763@host2.jankratochvil.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-SW-Source: 2013-05/txt/msg00773.txt.bz2 On 05/21/2013 05:14 PM, Jan Kratochvil wrote: > On Tue, 21 May 2013 18:05:40 +0200, Pedro Alves wrote: >> How about we handle this in a central place with something like: > > Fine with me although there is also Py_INCREF and not sure if also others. Yeah. I guess we can handle those on an as needed basis. Here's a complete patch, with ChangeLog. I notice that py_decref could actually be using Py_XDECREF instead of doing the explicit 'if (py)' check. ---- Subject: Centralize workaround for Python 2.6's Py_DECREF. Wrap/redefine Py_DECREF ourselves, avoiding the need for uses to care about extra braces due to the fact that Python only started wrapping Py_DECREF in 'do {} while (0)' after 2.6. gdb/ 2013-05-21 Pedro Alves * python/py-utils.c (py_decref): Remove extra braces. (gdb_pymodule_addobject): Remove extra braces. * python-internal.h (gdb_Py_DECREF): New static inline function. (Py_DECREF): Redefine as calling gdb_Py_DECREF. --- gdb/python/py-utils.c | 11 ++--------- gdb/python/python-internal.h | 12 ++++++++++++ 2 files changed, 14 insertions(+), 9 deletions(-) diff --git a/gdb/python/py-utils.c b/gdb/python/py-utils.c index e78dee0..80bacf7 100644 --- a/gdb/python/py-utils.c +++ b/gdb/python/py-utils.c @@ -31,12 +31,8 @@ py_decref (void *p) { PyObject *py = p; - /* Note that we need the extra braces in this 'if' to avoid a - warning from gcc. */ if (py) - { - Py_DECREF (py); - } + Py_DECREF (py); } /* Return a new cleanup which will decrement the Python object's @@ -443,9 +439,6 @@ gdb_pymodule_addobject (PyObject *module, const char *name, PyObject *object) Py_INCREF (object); result = PyModule_AddObject (module, name, object); if (result < 0) - { - /* Python 2.6 did not wrap Py_DECREF in do { } while (0);. */ - Py_DECREF (object); - } + Py_DECREF (object); return result; } diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h index b01efa1..b5c34b6 100644 --- a/gdb/python/python-internal.h +++ b/gdb/python/python-internal.h @@ -169,6 +169,18 @@ typedef unsigned long gdb_py_ulongest; #endif /* HAVE_LONG_LONG */ +/* Python 2.6 did not wrap Py_DECREF in 'do {...} while (0)', leading + to 'suggest explicit braces to avoid ambiguous ‘else’' gcc errors. + Wrap it ourselves, so that callers don't need to care. */ + +static inline void +gdb_Py_DECREF (void *op) +{ + Py_DECREF (op); +} + +#undef Py_DECREF +#define Py_DECREF(op) gdb_Py_DECREF (op) /* In order to be able to parse symtab_and_line_to_sal_object function a real symtab_and_line structure is needed. */