From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14645 invoked by alias); 7 Nov 2013 17:18:09 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 14616 invoked by uid 48); 7 Nov 2013 17:18:05 -0000 From: "ebotcazou at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug c/59039] Undocumented __builtin_longjmp/__builtin_setjmp Date: Thu, 07 Nov 2013 17:18:00 -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: 4.9.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: ebotcazou at gcc dot gnu.org X-Bugzilla-Status: NEW 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: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2013-11/txt/msg00649.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59039 --- Comment #12 from Eric Botcazou --- > %rdi holds the function parameter 'i'. But when __builtin_longjmp is > called, %rdi can have some random value. GCC doesn't save %rdi first. No, __builtin_longjmp doesn't touch %rdi at all. Don't worry too much, the SJLJ mechanism of the C++ and Ada compilers has been piggybacked on this for a couple of decades, this is quite robust.