From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 23E7E3858430; Thu, 1 Dec 2022 07:44:03 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 23E7E3858430 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1669880643; bh=MyfPW+zSlhlfa//urIf3jJJHLJbDO/Tu3NZehfHu9xE=; h=From:To:Subject:Date:In-Reply-To:References:From; b=HCa5X4eGj1LzyPIHjhEwD5vf6EvW2ePTbEWZIu0dfcl6mECRFf+kjM2HPvjnNT02Y 3BzB1KwUOMYo8+Fl7j1OCkvObryyXpp2J6yQMf+MncKVLdLx4ffO+NDyswgllwl6+x CZSH1WuQnmxX5Xl1+ucnsb+6oh2F/f3BCweR1OuE= From: "egallager at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug c/107890] UB on integer overflow impacts code flow Date: Thu, 01 Dec 2022 07:44:02 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c X-Bugzilla-Version: 12.2.0 X-Bugzilla-Keywords: diagnostic X-Bugzilla-Severity: normal X-Bugzilla-Who: egallager at gcc dot gnu.org X-Bugzilla-Status: RESOLVED X-Bugzilla-Resolution: INVALID 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: cc keywords Message-ID: In-Reply-To: References: 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 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D107890 Eric Gallager changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |egallager at gcc dot gnu.o= rg Keywords| |diagnostic --- Comment #5 from Eric Gallager --- What I wonder is, why doesn't -Wstrict-overflow=3D5 catch this? That's supp= osed to be its strictest level, right? $ /usr/local/bin/gcc -Wall -Wextra -pedantic -Wstrict-overflow=3D5 -O2 1078= 90.c 107890.c: In function 'f': 107890.c:13:25: warning: comparison of integer expressions of different signedness: 'int32_t' {aka 'int'} and 'long unsigned int' [-Wsign-compare] 13 | if (i >=3D 0 && i < sizeof(tab)) { | ^ 107890.c: In function 'main': 107890.c:21:18: warning: unused parameter 'ac' [-Wunused-parameter] 21 | int main(int ac, char **av) | ~~~~^~ $=