From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id D2FDC3888832; Tue, 29 Mar 2022 20:17:24 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D2FDC3888832 From: "dmalcolm at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug analyzer/105103] New: RFE: detect bogus use of varargs in analyzer Date: Tue, 29 Mar 2022 20:17:24 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: analyzer X-Bugzilla-Version: 12.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: dmalcolm at gcc dot gnu.org X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: dmalcolm 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: Tue, 29 Mar 2022 20:17:24 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105103 Bug ID: 105103 Summary: RFE: detect bogus use of varargs in analyzer Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: analyzer Assignee: dmalcolm at gcc dot gnu.org Reporter: dmalcolm at gcc dot gnu.org Target Milestone: --- The analyzer doesn't yet have any handling for the types, macros, functions from : https://en.cppreference.com/w/c/variadic https://www.man7.org/linux/man-pages/man3/stdarg.3.html It would be nice to e.g. detect the various undefined behaviors listed in t= he above e.g.=20 "If ap is passed to a function that uses va_arg(ap,type), then the value of= ap is undefined after the return of that function." etc. We could also implement __builtin_va_start, __builtin_va_end, etc and have region_model unpack variadic args in interprocedural calls, effectively inlining the analysis.=