From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Jacobowitz To: Randolph Chung Cc: Andrew Cagney , gdb-patches@sources.redhat.com Subject: Re: [patch/rfa] Signal trampoline unwinder for hppa-hpux Date: Wed, 26 May 2004 13:20:00 -0000 Message-id: <20040526132043.GA7594@nevyn.them.org> References: <20040520041746.GW566@tausq.org> <40AE3F20.2030205@gnu.org> <20040522015808.GF7207@tausq.org> <20040523002931.GO7207@tausq.org> <40B23320.90201@gnu.org> <20040526053609.GV7207@tausq.org> X-SW-Source: 2004-05/msg00741.html On Tue, May 25, 2004 at 10:36:09PM -0700, Randolph Chung wrote: > > Yes, definitly. Having to do instruction examination should be > > considered a last resource. > > ok, this is checked in now too, but can someone please comment on this > bit: > > ================================================================ > Unfortunately this still fails a lot of the signal related testcases. > It is not because of a problem with the signal unwinder though: > > On HPUX-SOM, there is an export stub inserted into the call sequence in > some cases; the export stub is hit on the return path from indirect > function calls, and apparently on return from a signal handler. This > creates an extra frame in the backtrace, viz: > > (gdb) bt > #0 0x000029e4 in handle_USR1 (sig=0) > at ../../../gdb/gdb/testsuite/gdb.base/annota1.c:18 > #1 0x000029c8 in handle_USR1 () > at ../../../gdb/gdb/testsuite/gdb.base/annota1.c:17 > #2 > #3 main () at ../../../gdb/gdb/testsuite/gdb.base/annota1.c:40 > > Frame 1 comes from the export stub. Because of this, the pattern > matching in the backtrace test fails. I am not sure if this is a > problem with the test script or with the handling of export stubs -- am > I supposed to somehow supress the export stub from showing up in the > backtrace? (if so, how?) Right now, we don't have any mechanism to hide frames. I'm not sure whether it's a desirable feature or not. I've wanted it for C++ occasionally. I wonder if GDB should have a single knob to switch between "simplified" and more thorough/accurate display modes? Could any of the existing toggles be added to this? -- Daniel Jacobowitz