From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9790 invoked by alias); 20 Feb 2006 16:04:33 -0000 Received: (qmail 9781 invoked by uid 22791); 20 Feb 2006 16:04:32 -0000 X-Spam-Check-By: sourceware.org Received: from nevyn.them.org (HELO nevyn.them.org) (66.93.172.17) by sourceware.org (qpsmtpd/0.31.1) with ESMTP; Mon, 20 Feb 2006 16:04:31 +0000 Received: from drow by nevyn.them.org with local (Exim 4.54) id 1FBDWW-0004RE-Gd; Mon, 20 Feb 2006 11:04:28 -0500 Date: Mon, 20 Feb 2006 16:04:00 -0000 From: Daniel Jacobowitz To: Eli Zaretskii Cc: gdb-patches@sourceware.org Subject: Re: Prevent crashes using $arg0 Message-ID: <20060220160428.GD16058@nevyn.them.org> Mail-Followup-To: Eli Zaretskii , gdb-patches@sourceware.org References: <20060207193932.GA28960@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.8i X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2006-02/txt/msg00362.txt.bz2 On Tue, Feb 07, 2006 at 10:38:28PM +0200, Eli Zaretskii wrote: > Is it possible to have $arg0 behave outside user-defined functions as > any other convenience variable? That is, can we have this response > instead: > > (gdb) if 1 == 1 > >print $arg0 > >end > $1 = void > (gdb) > > ? If this is not too hard, it's cleaner, since it doesn't reserve the > names of these variables globally. Good idea. > [Time passes...] Actually, I'm quite sure we should behave like I > suggested, since we already do that without the if clause: > > (gdb) print $arg0 > $1 = void > (gdb) And let's test that too. Does this look better? Tested x86_64-pc-linux-gnu. -- Daniel Jacobowitz CodeSourcery 2006-02-20 Daniel Jacobowitz * cli/cli-script.c (insert_args): Handle NULL user_args. 2006-02-20 Daniel Jacobowitz * gdb.base/commands.exp (stray_arg0_test): New test. Index: cli/cli-script.c =================================================================== RCS file: /cvs/src/src/gdb/cli/cli-script.c,v retrieving revision 1.32 diff -u -p -r1.32 cli-script.c --- cli/cli-script.c 17 Dec 2005 22:40:17 -0000 1.32 +++ cli/cli-script.c 20 Feb 2006 16:00:50 -0000 @@ -1,8 +1,8 @@ /* GDB CLI command scripting. Copyright (c) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, - 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2005 Free - Software Foundation, Inc. + 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2006 + Free Software Foundation, Inc. This file is part of GDB. @@ -590,6 +590,11 @@ insert_args (char *line) char *p, *save_line, *new_line; unsigned len, i; + /* If we are not in a user-defined function, treat $argc, $arg0, et + cetera as normal convenience variables. */ + if (user_args == NULL) + return xstrdup (line); + /* First we need to know how much memory to allocate for the new line. */ save_line = line; len = 0; Index: testsuite/gdb.base/commands.exp =================================================================== RCS file: /cvs/src/src/gdb/testsuite/gdb.base/commands.exp,v retrieving revision 1.14 diff -u -p -r1.14 commands.exp --- testsuite/gdb.base/commands.exp 7 Mar 2005 21:36:16 -0000 1.14 +++ testsuite/gdb.base/commands.exp 20 Feb 2006 16:00:50 -0000 @@ -1,5 +1,5 @@ # Copyright 1988, 1990, 1991, 1992, 1994, 1995, 1997, 1998, 1999, 2000, -# 2001, 2002, 2003 Free Software Foundation, Inc. +# 2001, 2002, 2003, 2005, 2006 Free Software Foundation, Inc. # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by @@ -563,6 +563,26 @@ proc temporary_breakpoint_commands {} { timeout { fail "(timeout) run factorial until temporary breakpoint" } } } + +# Test that GDB can handle $arg0 outside of user functions without +# crashing. +proc stray_arg0_test { } { + gdb_test "print \$arg0" \ + "\\\$\[0-9\]* = void" \ + "stray_arg0_test #1" + + gdb_test "if 1 == 1\nprint \$arg0\nend" \ + "\\\$\[0-9\]* = void" \ + "stray_arg0_test #2" + + gdb_test "print \$arg0 = 1" \ + "\\\$\[0-9\]* = 1" \ + "stray_arg0_test #3" + + gdb_test "print \$arg0" \ + "\\\$\[0-9\]* = 1" \ + "stray_arg0_test #4" +} gdbvar_simple_if_test gdbvar_simple_while_test @@ -579,3 +599,4 @@ test_command_prompt_position deprecated_command_test bp_deleted_in_command_test temporary_breakpoint_commands +stray_arg0_test