From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8977 invoked by alias); 16 Feb 2011 16:49:43 -0000 Received: (qmail 8965 invoked by uid 22791); 16 Feb 2011 16:49:40 -0000 X-SWARE-Spam-Status: No, hits=-6.9 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 16 Feb 2011 16:49:35 +0000 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p1GGnSCr006942 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 16 Feb 2011 11:49:28 -0500 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p1GGnRdv032300; Wed, 16 Feb 2011 11:49:27 -0500 Received: from opsy.redhat.com (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id p1GGnQAK003224; Wed, 16 Feb 2011 11:49:27 -0500 Received: by opsy.redhat.com (Postfix, from userid 500) id 99FE3378C85; Wed, 16 Feb 2011 09:49:26 -0700 (MST) From: Tom Tromey To: Pedro Alves Cc: gdb-patches@sourceware.org, Jan Kratochvil Subject: Re: [unavailable values part 1, 16/17] don't merge almost but not quite adjacent memory ranges to collect References: <201102071435.20804.pedro@codesourcery.com> <20110214120116.GI2454@host1.dyn.jankratochvil.net> <201102161303.16592.pedro@codesourcery.com> Date: Wed, 16 Feb 2011 18:00:00 -0000 In-Reply-To: <201102161303.16592.pedro@codesourcery.com> (Pedro Alves's message of "Wed, 16 Feb 2011 13:03:16 +0000") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2011-02/txt/msg00372.txt.bz2 >>>>> "Pedro" == Pedro Alves writes: Pedro> While writting the test in the patch below I tripped Pedro> on an internal error: >> collect {int [4]}globalarr2 Pedro> ../../src/gdb/ax-gdb.c:2053: internal-error: gen_expr: OP_MEMVAL operand isn't an rvalue??? Pedro> A problem internal to GDB has been detected, Pedro> further debugging may prove unreliable. Pedro> ... bah. I think that code is just confused. Even the comment says so :-) Could you try the appended? I'm not totally sure about it; maybe for the axs_lvalue_memory case we should be calling gen_address_of. I can't really test it here, since newer versions of GCC confuse AX generation :-(. That is, I get this a lot when running collection.exp: DWARF operator DW_OP_call_frame_cfa cannot be translated to an agent expression This seems pretty important to fix. Tom diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c index 2908431..d1736e1 100644 --- a/gdb/ax-gdb.c +++ b/gdb/ax-gdb.c @@ -2044,14 +2044,13 @@ gen_expr (struct expression *exp, union exp_element **pc, (*pc) += 3; gen_expr (exp, pc, ax, value); - /* I'm not sure I understand UNOP_MEMVAL entirely. I think - it's just a hack for dealing with minsyms; you take some - integer constant, pretend it's the address of an lvalue of - the given type, and dereference it. */ - if (value->kind != axs_rvalue) - /* This would be weird. */ - internal_error (__FILE__, __LINE__, - _("gen_expr: OP_MEMVAL operand isn't an rvalue???")); + + /* If we have an axs_rvalue or an axs_lvalue_memory, then we + already have the right value on the stack. For + axs_lvalue_register, we must convert. */ + if (value->kind == axs_lvalue_register) + require_rvalue (ax, value); + value->type = type; value->kind = axs_lvalue_memory; }