From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29029 invoked by alias); 9 Mar 2009 22:33:49 -0000 Received: (qmail 29019 invoked by uid 22791); 9 Mar 2009 22:33:48 -0000 X-SWARE-Spam-Status: No, hits=-1.7 required=5.0 tests=AWL,BAYES_00,KAM_STOCKGEN X-Spam-Check-By: sourceware.org Received: from sibelius.xs4all.nl (HELO sibelius.xs4all.nl) (82.92.89.47) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 09 Mar 2009 22:33:41 +0000 Received: from brahms.sibelius.xs4all.nl (kettenis@localhost.sibelius.xs4all.nl [127.0.0.1]) by brahms.sibelius.xs4all.nl (8.14.3/8.14.3) with ESMTP id n29MXFEH009323; Mon, 9 Mar 2009 23:33:15 +0100 (CET) Received: (from kettenis@localhost) by brahms.sibelius.xs4all.nl (8.14.3/8.14.3/Submit) id n29MXEfG019900; Mon, 9 Mar 2009 23:33:14 +0100 (CET) Date: Mon, 09 Mar 2009 22:38:00 -0000 Message-Id: <200903092233.n29MXEfG019900@brahms.sibelius.xs4all.nl> From: Mark Kettenis To: jan.kratochvil@redhat.com CC: tromey@redhat.com, drow@false.org, gdb-patches@sourceware.org In-reply-to: <20090309015510.GA28986@host0.dyn.jankratochvil.net> (message from Jan Kratochvil on Mon, 9 Mar 2009 02:55:10 +0100) Subject: Re: [patch] Fix `return' of long/long-long results with no debuginfo References: <20090211205045.GB9762@caradoc.them.org> <200902112122.n1BLMf8q000100@brahms.sibelius.xs4all.nl> <20090211214646.GA22247@host0.dyn.jankratochvil.net> <200902112157.n1BLvplk011339@brahms.sibelius.xs4all.nl> <20090211220824.GA26040@host0.dyn.jankratochvil.net> <200902112237.n1BMbbOb006035@brahms.sibelius.xs4all.nl> <20090211225012.GA28683@host0.dyn.jankratochvil.net> <200903042129.n24LTUKa000770@brahms.sibelius.xs4all.nl> <20090309015510.GA28986@host0.dyn.jankratochvil.net> 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: 2009-03/txt/msg00134.txt.bz2 > Date: Mon, 9 Mar 2009 02:55:10 +0100 > From: Jan Kratochvil > > On Thu, 05 Mar 2009 01:15:08 +0100, Tom Tromey wrote: > > >>>>> "Mark" == Mark Kettenis writes: > > > > Mark> Do we have a way to figure out if such a cast is present in the > > Mark> expression passed as an argument to the return command? > > > > Yeah, it is not too hard. It just means having return_command call > > parse_expression directly, then look at the resulting expression. > > Attached, check-in approval requested. I think this is a reasonable compromise, and I think the implementation is ok. But I'd like the opinion of one of the other global maintainers (Daniel?, Joel?) before going this way. > gdb/ > 2009-03-09 Jan Kratochvil > > * stack.c (return_command ): New variables retval_expr > and old_chain. Inline parse_and_eval to initialize retval_expr. Check > RETVAL_EXPR for UNOP_CAST and set RETURN_TYPE to the RETURN_VALUE type > if RETURN_TYPE is NULL. > > gdb/testsuite/ > 2009-03-09 Jan Kratochvil > > * gdb.base/return-nodebug.exp, gdb.base/return-nodebug.S: New. > > --- gdb/stack.c 6 Mar 2009 18:51:05 -0000 1.186 > +++ gdb/stack.c 9 Mar 2009 01:52:55 -0000 > @@ -1796,18 +1796,26 @@ return_command (char *retval_exp, int fr > message. */ > if (retval_exp) > { > + struct expression *retval_expr = parse_expression (retval_exp); > + struct cleanup *old_chain = make_cleanup (xfree, retval_expr); > struct type *return_type = NULL; > > /* Compute the return value. Should the computation fail, this > call throws an error. */ > - return_value = parse_and_eval (retval_exp); > + return_value = evaluate_expression (retval_expr); > > /* Cast return value to the return type of the function. Should > the cast fail, this call throws an error. */ > if (thisfun != NULL) > return_type = TYPE_TARGET_TYPE (SYMBOL_TYPE (thisfun)); > if (return_type == NULL) > - return_type = builtin_type (get_frame_arch (thisframe))->builtin_int; > + { > + if (retval_expr->elts[0].opcode != UNOP_CAST) > + error (_("Selected stack frame (with no associated function) " > + "requires an explicit cast of the value to return")); > + return_type = value_type (return_value); > + } > + do_cleanups (old_chain); > CHECK_TYPEDEF (return_type); > return_value = value_cast (return_type, return_value); > > --- /dev/null 1 Jan 1970 00:00:00 -0000 > +++ gdb/testsuite/gdb.base/return-nodebug.c 9 Mar 2009 01:52:55 -0000 > @@ -0,0 +1,49 @@ > +/* This testcase is part of GDB, the GNU debugger. > + > + Copyright 2009 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 > + the Free Software Foundation; either version 3 of the License, or > + (at your option) any later version. > + > + This program is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + GNU General Public License for more details. > + > + You should have received a copy of the GNU General Public License > + along with this program. If not, see . */ > + > +#include > + > +static TYPE > +init (void) > +{ > + return 0; > +} > + > +static TYPE > +func (void) > +{ > + return 31; > +} > + > +static void > +marker (void) > +{ > +} > + > +int > +main (void) > +{ > + /* Preinitialize registers to 0 to avoid false PASS by leftover garbage. */ > + init (); > + > + printf ("result=" FORMAT "\n", CAST func ()); > + > + /* Cannot `next' with no debug info. */ > + marker (); > + > + return 0; > +} > --- /dev/null 1 Jan 1970 00:00:00 -0000 > +++ gdb/testsuite/gdb.base/return-nodebug.exp 9 Mar 2009 01:52:55 -0000 > @@ -0,0 +1,60 @@ > +# Copyright (C) 2009 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 > +# the Free Software Foundation; either version 3 of the License, or > +# (at your option) any later version. > +# > +# This program is distributed in the hope that it will be useful, > +# but WITHOUT ANY WARRANTY; without even the implied warranty of > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > +# GNU General Public License for more details. > +# > +# You should have received a copy of the GNU General Public License > +# along with this program. If not, see . > + > +proc do_test {type} { > + set typenospace [string map {{ } -} $type] > + > + global pf_prefix > + set old_prefix $pf_prefix > + lappend pf_prefix "$typenospace:" > + > + if {[runto "func"]} { > + # Test return from a function with no debug info (symbol; still it may > + # have a minimal-symbol) if it does not crash. > + > + gdb_test "return -1" \ > + "Selected stack frame \\(with no associated function\\) requires an explicit cast of the value to return" \ > + "return from function with no debug info without a cast" > + > + # Cast of the result to the proper width must be done explicitely. > + gdb_test "return ($type) -1" "#0 .* main \\(.*" \ > + "return from function with no debug info with a cast" \ > + "Make selected stack frame return now\\? \\(y or n\\) " "y" > + > + # And if it returned the full width of the result. > + gdb_test "adv marker" "\r\nresult=-1\r\n.* in marker \\(.*" \ > + "full width of the returned result" > + } > + > + set pf_prefix $old_prefix > +} > + > +foreach case {{{signed char} %d (int)} \ > + {{short} %d (int)} \ > + {{int} %d} \ > + {{long} %ld} \ > + {{long long} %lld}} { > + set type [lindex $case 0] > + set format [lindex $case 1] > + set cast [lindex $case 2] > + > + set typeesc [string map {{ } {\ }} $type] > + set typenospace [string map {{ } -} $type] > + > + if {[prepare_for_testing return-nodebug.exp "return-nodebug-$typenospace" "return-nodebug.c" \ > + [list "additional_flags=-DFORMAT=\"$format\" -DTYPE=$typeesc -DCAST=$cast"]] == 0} { > + do_test $type > + } > +} >