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From: "dmalcolm at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug analyzer/102692] -Wanalyzer-null-dereference false alarm with (!p || q || !p->next) Date: Fri, 07 Jan 2022 22:46:03 +0000 [thread overview] Message-ID: <bug-102692-4-p5TkWnIfmL@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-102692-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102692 David Malcolm <dmalcolm at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed| |2022-01-07 Ever confirmed|0 |1 Status|UNCONFIRMED |ASSIGNED --- Comment #2 from David Malcolm <dmalcolm at gcc dot gnu.org> --- Thanks for filing this. With trunk (for gcc 12) I see the false positive from comment #1, and also this false positive (new warning in gcc 12): ../../src/gcc/testsuite/gcc.dg/analyzer/pr102692.c:82:20: warning: use of uninitialized value ‘end’ [CWE-457] [-Wanalyzer-use-of-uninitialized-value] 82 | if (!tail || end < prev || !tail->next) /* { dg-bogus "use of uninitialized value 'end'" "uninit" } */ | ~~~~^~~~~~ ‘fix_overlays_before’: events 1-3 | | 75 | while (tail | | ~~~~ | 76 | && (tem = make_lisp_ptr (tail, 5), | | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | | | | | (1) following ‘false’ branch (when ‘tail’ is NULL)... | 77 | (end = marker_position (XOVERLAY (tem)->end)) >= pos)) | | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |...... | 82 | if (!tail || end < prev || !tail->next) /* { dg-bogus "use of uninitialized value 'end'" "uninit" } */ | | ~~~~~ ~~~~~~~~~~ | | | | | | | (3) use of uninitialized value ‘end’ here | | (2) ...to here | Am investigating.
next prev parent reply other threads:[~2022-01-07 22:46 UTC|newest] Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-10-11 21:47 [Bug analyzer/102692] New: " eggert at cs dot ucla.edu 2021-10-11 22:21 ` [Bug analyzer/102692] " eggert at cs dot ucla.edu 2022-01-07 22:46 ` dmalcolm at gcc dot gnu.org [this message] 2022-01-11 14:17 ` cvs-commit at gcc dot gnu.org 2022-02-11 17:40 ` dmalcolm at gcc dot gnu.org 2022-02-15 21:34 ` cvs-commit at gcc dot gnu.org 2022-02-15 21:39 ` dmalcolm at gcc dot gnu.org
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