From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15060 invoked by alias); 25 Jul 2016 17:27:54 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 15040 invoked by uid 89); 25 Jul 2016 17:27:53 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=0.1 required=5.0 tests=AWL,BAYES_00,FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 spammy=Console, Paramjot, Oberoi, paramjot X-HELO: mail-wm0-f50.google.com Received: from mail-wm0-f50.google.com (HELO mail-wm0-f50.google.com) (74.125.82.50) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Mon, 25 Jul 2016 17:27:52 +0000 Received: by mail-wm0-f50.google.com with SMTP id o80so167238343wme.1 for ; Mon, 25 Jul 2016 10:27:51 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=Skq6qf01HVDNSpAZ6CDn9FuxeLRHIE6WIDL52SQlXSI=; b=D1gSfWmY2Y0/Cosj+NsndNNGyaZezw6JYIZDMPs8DPog106dqhhBMK7iwVXxZrJ0Av rpOgW9AJJuPtKS9zABRJIocQHaked77bnfmKD6/QhUPxHWNd6Q8T/vN8bzSEv1DY+Ro9 3Pa4tCs37MCQ7CWBBUPubKgoEp3i8LVcsH5BLyDBVCbJF+pZhzEZ4K1mHcJIWvMm2pER xEkj/h7O5oYQGNKSUim7l+IAPnKryH6HxXUtABJpdRL3SpfO2IaIpnsWxXPfD3Jbo+Gf RnHU3IGwBrKec5xPDAhV84CXk6ivRhX0bfgAZ8BtHn/Pl0Fh98fZKkaslXdG8bvVacJ7 4/7A== X-Gm-Message-State: AEkoousgSEbBXq8B5Sk4qA6RFCc+DZ4U+r54x+5r5tOaoHISioeHdDGYRPc2m09e2Rq97noplvzuvhSduAgW9Q== X-Received: by 10.194.58.112 with SMTP id p16mr16865721wjq.24.1469467669358; Mon, 25 Jul 2016 10:27:49 -0700 (PDT) MIME-Version: 1.0 Received: by 10.28.2.6 with HTTP; Mon, 25 Jul 2016 10:27:48 -0700 (PDT) In-Reply-To: References: From: dwk Date: Mon, 25 Jul 2016 17:27:00 -0000 Message-ID: Subject: Re: How to Read Program Architecture from GDB/MI? To: Paramjot Oberoi Cc: gdb@sourceware.org Content-Type: text/plain; charset=UTF-8 X-SW-Source: 2016-07/txt/msg00025.txt.bz2 This is a bug in gdb/cli/cli-setshow.c. The current code reads 647 /* FIXME: cagney/2005-02-10: Need to split this in half: code to 648 convert the value into a string (esentially the above); and 649 code to print the value out. For the latter there should be 650 MI and CLI specific versions. */ 651 652 if (ui_out_is_mi_like_p (uiout)) 653 ui_out_field_stream (uiout, "value", stb); 654 else 655 { 656 char *value = ui_file_xstrdup (stb, NULL); 657 658 make_cleanup (xfree, value); 659 if (c->show_value_func != NULL) 660 c->show_value_func (gdb_stdout, from_tty, c, value); 661 else 662 deprecated_show_value_hack (gdb_stdout, from_tty, c, value); 663 } The if statement is a special case for GDB/MI. It seems to prepare to generate a value but then never write anything. My guess is that this code was supposed to generate a nicely parsable version of the string. In the case of "-gdb-show architecture", there is a c->show_value_func (show_architecture) to call which prints "unfriendly" output. I tried playing with different code here but the simplest fix seems to be to disable the if statement entirely (add 0&& to its test). Then your "show architecture" command works correctly. (gdb) interpreter-exec mi "-gdb-show architecture" ~"The target architecture is set automatically (currently i386)\n" ^done (gdb) I don't know what cagney was worrying about when this split occurred, but given that it was in 2005 it may no longer be an issue. Perhaps try disabling the if statement as I suggested and see if other problems crop up. diff --git a/gdb/cli/cli-setshow.c b/gdb/cli/cli-setshow.c index eb17158..8d9b691 100644 --- a/gdb/cli/cli-setshow.c +++ b/gdb/cli/cli-setshow.c @@ -649,7 +649,7 @@ do_show_command (const char *arg, int from_tty, struct cmd_list_element *c) code to print the value out. For the latter there should be MI and CLI specific versions. */ - if (ui_out_is_mi_like_p (uiout)) + if (0 && ui_out_is_mi_like_p (uiout)) ui_out_field_stream (uiout, "value", stb); else { Cheers. ~~ dwk On Mon, Jul 25, 2016 at 1:30 AM, Paramjot Oberoi wrote: > Hi all, > > I am attempting to get the CPU architecture of the currently debugged > program via a GDB/MI command. I'm not sure what's I'm doing wrong: > > Console interpreter looks good: > (gdb) show architecture > The target architecture is set automatically (currently i386) > > MI interpreter succeeds without any data: > (gdb) interpreter-exec mi "-gdb-show architecture" > ^done > > If I set the arch to auto, then query with MI I get "auto" back...: > (gdb) set arch auto > The target architecture is set automatically (currently i386) > (gdb) interpreter-exec mi "-gdb-show architecture" > ^done,value="auto" > > Any advice on how I can query the architecture in GDB/MI mode? Thanks > in advance, I appreciate it.