From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 5822B3858428; Sat, 16 Jul 2022 15:36:40 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5822B3858428 From: "dmalcolm at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug analyzer/106325] `analyzer-null-dereference` gets thrown on a parameter on a function marked with `__attribute__((nonnull))` Date: Sat, 16 Jul 2022 15:36:40 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: analyzer X-Bugzilla-Version: 12.1.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: dmalcolm at gcc dot gnu.org X-Bugzilla-Status: NEW 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: everconfirmed bug_status cf_reconfirmed_on 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 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: Sat, 16 Jul 2022 15:36:40 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D106325 David Malcolm changed: What |Removed |Added ---------------------------------------------------------------------------- Ever confirmed|0 |1 Status|UNCONFIRMED |NEW Last reconfirmed| |2022-07-16 --- Comment #3 from David Malcolm --- Thanks for filing this bug report. Near the start of the analysis, it sees: =E2=80=98arranger_object_unsplit=E2=80=99: event 1 | |../src/gui/backend/arranger_object.c:3021:1: | 3021 | arranger_object_unsplit ( | | ^~~~~~~~~~~~~~~~~~~~~~~ | | | | | (1) entry to =E2=80=98arranger_object_unsplit=E2=80=99 | =E2=80=98arranger_object_unsplit=E2=80=99: event 2 | |../src/gui/backend/arranger_object.c:3043:10: | 3043 | *obj =3D arranger_object_clone (r1); | | ^~~~~~~~~~~~~~~~~~~~~~~~~~ | | | | | (2) calling =E2=80=98arranger_object_clone=E2=80=99 f= rom =E2=80=98arranger_object_unsplit=E2=80=99 | +--> =E2=80=98arranger_object_clone=E2=80=99: events 3-6 | |../src/gui/backend/arranger_object.c:2568:1: | 2568 | arranger_object_clone (const ArrangerObject * self) | | ^~~~~~~~~~~~~~~~~~~~~ | | | | | (3) entry to =E2=80=98arranger_object_clone=E2=80=99 | 2569 | { | 2570 | g_return_val_if_fail (self, NULL); | | ~ ~~~~~~=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20 | | | |=20=20=20=20=20=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20 | | | | (5) ...to here=20=20=20= =20=20=20=20=20=20=20=20=20=20=20=20 (6) =E2=80=98r1=E2=80=99 is NULL | | (4) following =E2=80=98false=E2=80=99 branch = (when =E2=80=98self=E2=80=99 is NULL)... | <------+ ...and so within the g_return_val_if_fail in arranger_object_clone it consi= ders the case in which "self" (and thus the "r1" param passed to arranger_object_unsplit) is NULL. However, I see this declaration in the preprocessed code: __attribute__((nonnull(1, 2))) void arranger_object_unsplit ( ArrangerObject * r1, ArrangerObject * r2, ArrangerObject ** obj, _Bool fire_events); and hence the analyzer *ought* to be assuming that r1 and r2 are non-NULL, = and thus not consider the early-bailout case in that g_return_val_if_fail. Looks like a bug in the analyzer to me; marking as confirmed (reproduced on= gcc trunk).=