From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31417 invoked by alias); 17 Feb 2015 04:46:51 -0000 Mailing-List: contact gdb-prs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-prs-owner@sourceware.org Received: (qmail 31351 invoked by uid 48); 17 Feb 2015 04:46:51 -0000 From: "tom.k.cook at gmail dot com" To: gdb-prs@sourceware.org Subject: [Bug fortran/17989] New: gdb hangs on some Fortran stack frames Date: Tue, 17 Feb 2015 05:46:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gdb X-Bugzilla-Component: fortran X-Bugzilla-Version: HEAD X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: tom.k.cook at gmail dot com X-Bugzilla-Status: NEW X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot 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 Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2015-q1/txt/msg00262.txt.bz2 https://sourceware.org/bugzilla/show_bug.cgi?id=17989 Bug ID: 17989 Summary: gdb hangs on some Fortran stack frames Product: gdb Version: HEAD Status: NEW Severity: normal Priority: P2 Component: fortran Assignee: unassigned at sourceware dot org Reporter: tom.k.cook at gmail dot com Overview: GDB hangs when trying to display some Fortran stack frames. Platform: Linux 3.13.0 x86_64 SMP (Ubuntu Trusty) Steps to reproduce: Unknown. Sorry! I'll give as much information as I can. The software being debugged is mixed Fortran/C++. The main method is in Fortran but the executable is linked using G++. The compiler is GCC 4.8 (for both Fortran and C++) but I have confirmed the bug when compiling with GCC 4.9. I have a fairly recent GCC HEAD (early January) build around and could try that if it might be useful. GDB hangs when attempting to display certain stack frames (eg. when a breakpoint is hit, or when 'finish' is used to move up a frame, or when 'bt' is used). 'info line' and 'list' still work in these situations. The problem always happens with Fortran stack frames, including when there are no C++ frames on the stack. The Fortran code is compiled with '-g -cpp -ffixed-line-length-none -ffree-line-length-none -fcoarray=single -fno-underscoring -fPIC'. The executable is linked with '-g', objects and libraries. When gdb hangs, it is consuming 100% CPU (ie one CPU core). The hang can be interrupted with Ctrl-C and the debugging session continued normally (so long as you don't want to display the call stack etc). I have checked that both GDB 7.7 (Ubuntu Trusty) and a fresh build from git latest today, using GCC-5.0 latest-as-of-early-January, display this problem. I have tried to reproduce the bug on a very simple Fortran/C++ project but have not been able to. Any suggestions on how to fix this, or on steps I might take to reliably reproduce it, will be gratefully received. I have a build of gdb latest-of-today and could debug gdb itself if this will be useful. Unfortunately the Fortran/C++ code being debugged when the problem occurs is commercial and can't be shared. -- You are receiving this mail because: You are on the CC list for the bug.