From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from JPN01-OS0-obe.outbound.protection.outlook.com (mail-os0jpn01olkn2069.outbound.protection.outlook.com [40.92.98.69]) by sourceware.org (Postfix) with ESMTPS id E86A738582BE for ; Fri, 8 Jul 2022 13:47:48 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E86A738582BE ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=nlt/R1viuYW40F1b8QI5Y6s2PV6v822IrTH5ZUML6xHYVT1AnjUmvi7Dzz4vruDomIZ5nphJ3yh1gRwh7jy/F8WFdS96VtM5TaXCXANXtp41Wg+Kt8xK4ILX6U96KcIBPn8vlndTZJ+m5zQj+pwOyLAoe+4myd27BsxD+ccqqAfff7pgt1Wczmpjb40PpQnzJf5oDDvK1wsNVgbzWGQq9nLab9JfJvcI5BrYKXCX9gKeNa8bUd8LjXNxp+KHcL0c+U7Vd5ma/o8ib2Ct2dQigtRMtL2M2DU+XN4oIroXU4+8notPTC/zyWe27vGrP43bCryZiphBwQ41R2USrjYbSQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; 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On Wed, 2022-07-06 at 14:02 +0000, Metzger, Markus T wrote: > Hello Enze, >=20 > > > On a machine with gcc 12, I get this warning: > > >=20 > > > =C2=A0 CXX=C2=A0=C2=A0=C2=A0 nat/linux-btrace.o > > > In function =E2=80=98btrace_error linux_read_bts(btrace_data_bts*, > > > btrace_target_info*, btrace_read_type)=E2=80=99, > > > =C2=A0=C2=A0=C2=A0 inlined from =E2=80=98btrace_error linux_read_btra= ce(btrace_data*, > > > btrace_target_info*, btrace_read_type)=E2=80=99 at ../gdb/nat/linux- > > > btrace.c:935:29: > > > ../gdb/nat/linux-btrace.c:865:21: warning: =E2=80=98data_head=E2=80= =99 may be > > > used > > > uninitialized [-Wmaybe-uninitialized] > > > =C2=A0 865 |=C2=A0=C2=A0 pevent->last_head =3D data_head; > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 |=C2=A0=C2=A0 ~~~~~~~~~~~~~~~~~~^~~~~~= ~~~~~ >=20 > That's a false positive.=C2=A0 Since RETRIES > 0, the loop is executed at > least > once and DATA_HEAD is initialized. Yeah, that's my understanding as well. >=20 >=20 > > > diff --git a/gdb/nat/linux-btrace.c b/gdb/nat/linux-btrace.c > > > index b0d6dcd7cf1..c31fb5ffe43 100644 > > > --- a/gdb/nat/linux-btrace.c > > > +++ b/gdb/nat/linux-btrace.c > > > @@ -789,7 +789,7 @@ linux_read_bts (struct btrace_data_bts > > > *btrace, > > > =C2=A0=C2=A0 struct perf_event_buffer *pevent; > > > =C2=A0=C2=A0 const uint8_t *begin, *end, *start; > > > =C2=A0=C2=A0 size_t buffer_size, size; > > > -=C2=A0 __u64 data_head, data_tail; > > > +=C2=A0 __u64 data_head =3D 0, data_tail; > > > =C2=A0=C2=A0 unsigned int retries =3D 5; > > >=20 > > > =C2=A0=C2=A0 pevent =3D &tinfo->variant.bts.bts; >=20 > OK to pacify GCC.=C2=A0 Thanks for the patch.=C2=A0 LGTM. I'm checking this in now. Thanks, Enze >=20 > regards, > markus. > Intel Deutschland GmbH > Registered Address: Am Campeon 10, 85579 Neubiberg, Germany > Tel: +49 89 99 8853-0, www.intel.de=C2=A0 > Managing Directors: Christin Eisenschmid, Sharon Heck, Tiffany Doon > Silva=C2=A0=20 > Chairperson of the Supervisory Board: Nicole Lau > Registered Office: Munich > Commercial Register: Amtsgericht Muenchen HRB 186928