From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id BCF7E385840B; Sun, 21 Jul 2024 14:35:24 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BCF7E385840B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1721572524; bh=uUbEPtI7n6mLmYpxpqhjmtGawyu55Q9Rmhh1RiyXUYc=; h=From:To:Subject:Date:In-Reply-To:References:From; b=pw/KN5/OQXZBMaenN1dggj2q/utqCyIUHAqHZCHp3I+Dv0YLTNYu7nf68Kb9JMZom uCxMejj6IurShI5dYE9LTIpq33jlA8pDFDt6s11A1gTEgVCKp3/F7BF6SBlhGevKB+ dzkOXn6tOdLgiRxshavpVSdYlygJ8EcR7ss5Jy+M= From: "unlvsur at live dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/115907] Libstdc++ and GCC itself should avoid glibc above 2.34 dependency Date: Sun, 21 Jul 2024 14:35:24 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libstdc++ X-Bugzilla-Version: unknown X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: unlvsur at live dot com 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: 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=3D115907 --- Comment #44 from cqwrteur --- (In reply to Andrew Pinski from comment #42) > (In reply to frankhb1989 from comment #41) > > I ran into exact the same trouble of C23 missing symbols on old systems= . In > > my case it is a custom build (with tailored source) of libfreeimage whi= ch > > has some calls to `sscanf` pulling the unwanted symbol references (to > > `__isoc23_sscanf@GLIBC_2.38`) into the library >=20 > That is not a glibc issue but rather you are thinking glibc will be forwa= rds > compatible; glibc is not and never can be; this is true for almost all OS > out there (Mac OS has a similar issue though they provide sysroots with a= ll > needed headers/libraries so it is slightly easier to handle rather than y= ou > need to go out and find one). It is definitely backwards compatiable. If = you > want to build a program that runs on older systems you 100% need to use t= he > earliest version of glibc to link (and use headers from) against rather t= han > the newest version. https://github.com/trcrsired/glibc/commit/4a724a45761fe27000247267d6ea02cb6= 4b17b3c#diff-e1c081599cb4df1d7224ee161959d04457b256c4b269e428baec5a6d34e630= d1 My patch just works perfectly. Don't know what's your opposition. I am not = even suggest an ABI lock down or something=