From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9046 invoked by alias); 11 Apr 2002 20:55:50 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 9023 invoked from network); 11 Apr 2002 20:55:47 -0000 Received: from unknown (HELO cygnus.com) (205.180.230.5) by sources.redhat.com with SMTP; 11 Apr 2002 20:55:47 -0000 Received: from redhat.com (reddwarf.sfbay.redhat.com [172.16.24.50]) by runyon.cygnus.com (8.8.7-cygnus/8.8.7) with ESMTP id NAA01429; Thu, 11 Apr 2002 13:55:42 -0700 (PDT) Message-ID: <3CB5F583.8B2E6707@redhat.com> Date: Thu, 11 Apr 2002 13:55:00 -0000 From: Michael Snyder Organization: Red Hat, Inc. X-Accept-Language: en MIME-Version: 1.0 To: Don Howard CC: Hilfinger@cs.berkeley.edu, Daniel Jacobowitz , Andreas Schwab , gdb-patches@sources.redhat.com Subject: Re: [RFA] Avoid recursivly defined user functions. References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-SW-Source: 2002-04/txt/msg00431.txt.bz2 Don Howard wrote: > > On Tue, 9 Apr 2002, Don Howard wrote: > > > On Tue, 9 Apr 2002, Paul Hilfinger wrote: > > > > > > > > > How about something even simpler - track user command depth at runtime? > > > > Set an absurd limit, like 1024 deep, if we can handle that in a > > > > normal-sized stack limit. Then complain if we hit it at runtime. > > > > > > I completely agree with this. After all, if you were willing to > > > contemplate outlawing recursion altogether, you certainly won't LOSE > > > anything by Daniel's approach, and you gain everything you wanted in > > > the first place---to avoid crashing GDB. > > > > > > Paul > > > > > > > > > I like this approach, also. So do I. ;-) > > > > 2002-04-11 Don Howard > > * cli/cli-cmds.c (init_cli_cmds): Add new user settable value: > max_user_call_depth. > (init_cmd_lists): Initialize the new value; > * cli/cli-script.c (execute_user_command): Limit the call depth of > user defined commands. This avoids a core-dump when user commands > are infinitly recursive. > > Index: cli/cli-cmds.c > =================================================================== > RCS file: /cvs/src/src/gdb/cli/cli-cmds.c,v > retrieving revision 1.18 > diff -p -u -w -r1.18 cli-cmds.c > --- cli/cli-cmds.c 28 Mar 2002 01:35:56 -0000 1.18 > +++ cli/cli-cmds.c 11 Apr 2002 17:30:58 -0000 > @@ -80,6 +80,9 @@ static void shell_escape (char *, int); > > void apropos_command (char *, int); > > +/* Limit the call depth of user-defined commands */ > +int max_user_call_depth; > + > /* Define all cmd_list_elements. */ > > /* Chain containing all defined commands. */ > @@ -606,6 +609,8 @@ show_debug (char *args, int from_tty) > void > init_cmd_lists (void) > { > + max_user_call_depth = 1024; > + > cmdlist = NULL; > infolist = NULL; > enablelist = NULL; > @@ -823,4 +828,11 @@ With no arguments, run an inferior shell > Argument is the name of the user defined command.\n\ > With no argument, show definitions of all user defined commands.", &showlist); > add_com ("apropos", class_support, apropos_command, "Search for commands matching a REGEXP"); > + > + add_show_from_set ( > + add_set_cmd ("max_user_call_depth", no_class, var_integer, > + (char *) &max_user_call_depth, > + "Set the max call depth for user-defined commands.\n", > + &setlist), > + &showlist); > } > Index: cli/cli-script.c > =================================================================== > RCS file: /cvs/src/src/gdb/cli/cli-script.c,v > retrieving revision 1.11 > diff -p -u -w -r1.11 cli-script.c > --- cli/cli-script.c 17 Mar 2002 19:53:39 -0000 1.11 > +++ cli/cli-script.c 11 Apr 2002 17:30:59 -0000 > @@ -247,6 +247,15 @@ execute_cmd_post_hook (struct cmd_list_e > } > > /* Execute the command in CMD. */ > +void > +do_restore_user_call_depth (void * call_depth) > +{ > + int * depth = call_depth; > + /* We will be returning_to_top_level() at this point, so we want to > + reset our depth. */ > + (*depth) = 0; > +} > + > > void > execute_user_command (struct cmd_list_element *c, char *args) > @@ -254,6 +263,8 @@ execute_user_command (struct cmd_list_el > register struct command_line *cmdlines; > struct cleanup *old_chain; > enum command_control_type ret; > + static int user_call_depth = 0; > + extern int max_user_call_depth; > > old_chain = setup_user_args (args); > > @@ -262,6 +273,11 @@ execute_user_command (struct cmd_list_el > /* Null command */ > return; > > + if (user_call_depth++ > max_user_call_depth) > + error ("Max user call depth exceeded -- command aborted\n"); > + > + old_chain = make_cleanup (do_restore_user_call_depth, &user_call_depth); > + > /* Set the instream to 0, indicating execution of a > user-defined function. */ > old_chain = make_cleanup (do_restore_instream_cleanup, instream); > @@ -277,6 +293,8 @@ execute_user_command (struct cmd_list_el > cmdlines = cmdlines->next; > } > do_cleanups (old_chain); > + > + user_call_depth--; > } > > enum command_control_type > > -- > dhoward@redhat.com > gdb engineering