From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 9753E383E82C; Wed, 27 May 2020 10:05:10 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9753E383E82C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1590573910; bh=9e/5G+/ExWZmhU7L/363OAHzXeBg9017nV4gsnVss0s=; h=From:To:Subject:Date:From; b=P0BLY1C+1YbNnFUkkSW1HZPGX5o/qqs3i64QrHpsbkyR58wBdHs01C/dRTAT0hSk9 GC5THLGkMEZIAgPpJ8ehrp1NWXgEkYmUgsKfgYQdB1iVh1Bjx9K5MPbqfLPysIXl8w TnhjkWBgO/5yZxts4a61EN1KZZKtdR3xhNLUODpU= From: "yangyibiao at hust dot edu.cn" To: gcc-bugs@gcc.gnu.org Subject: [Bug debug/95360] New: inconsistent behaviors at -O0 Date: Wed, 27 May 2020 10:05:10 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: debug X-Bugzilla-Version: 10.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: yangyibiao at hust dot edu.cn X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 May 2020 10:05:10 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95360 Bug ID: 95360 Summary: inconsistent behaviors at -O0 Product: gcc Version: 10.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: debug Assignee: unassigned at gcc dot gnu.org Reporter: yangyibiao at hust dot edu.cn Target Milestone: --- $ gcc --version gcc (GCC) 10.0.1 20200419 (experimental) Copyright (C) 2020 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. $ gdb --version GNU gdb (GDB) 10.0.50.20200517-git Copyright (C) 2020 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. $ cat small.c unsigned int b,d; static int c[1][2] =3D {{0, 1}}; int main() { for (; d<1; d++) for (; b<1; b++) c[b][d+1] =3D 0; return 0; } $ gcc -O0 -g small.c $ gdb -q a.out Reading symbols from a.out... (gdb) b 5 Breakpoint 1 at 0x401106: file small.c, line 5. (gdb) r Starting program: /home/yibiao/Debugger/a.out=20 Breakpoint 1, main () at small.c:5 5 for (; d<1; d++) (gdb) stepi 0x0000000000401154 5 for (; d<1; d++) (gdb) stepi 0x000000000040115a 5 for (; d<1; d++) (gdb) stepi 0x000000000040115c 5 for (; d<1; d++) (gdb) stepi 0x000000000040113b 6 for (; b<1; b++) (gdb) stepi 0x0000000000401141 6 for (; b<1; b++) (gdb) stepi 0x0000000000401143 6 for (; b<1; b++) (gdb) stepi 7 c[b][d+1] =3D 0; (gdb) /***************************************************** As showed, Line 6 is hit first and then hit Line 7 with stepi. However, when using step, gdb is first hit Line 7 and then hit Line 6. This is an inconsistent behaviors between stepi and step *****************************************************/ $ gdb -q a.out Reading symbols from a.out... (gdb) b main Breakpoint 1 at 0x401106: file small.c, line 5. (gdb) r Starting program: /home/yibiao/Debugger/a.out=20 Breakpoint 1, main () at small.c:5 5 for (; d<1; d++) (gdb) step 7 c[b][d+1] =3D 0; (gdb)=20 6 for (; b<1; b++) (gdb)=20 Breakpoint 1, main () at small.c:6 6 for (; b<1; b++) (gdb)=