From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 103306 invoked by alias); 25 Jul 2018 14:22:33 -0000 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 Received: (qmail 103296 invoked by uid 89); 25 Jul 2018 14:22:32 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,KAM_SHORT,SPF_PASS autolearn=ham version=3.3.2 spammy=sk:DW_AT_a, sk:dw_at_a, gdb_test, 20180706 X-HELO: mx1.suse.de Received: from mx2.suse.de (HELO mx1.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 25 Jul 2018 14:22:30 +0000 Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 51A56AF45 for ; Wed, 25 Jul 2018 14:22:28 +0000 (UTC) Subject: [PING][PATCH][exp] Interpret size of vla with unknown size as References: <20180718132743.jitbu5pj4qilvsux@delia> To: gdb-patches@sourceware.org From: Tom de Vries X-Forwarded-Message-Id: <20180718132743.jitbu5pj4qilvsux@delia> Message-ID: <1822d1ff-9cc6-f4ec-d5fd-e223f0af6265@suse.de> Date: Wed, 25 Jul 2018 14:22:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180718132743.jitbu5pj4qilvsux@delia> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2018-07/txt/msg00690.txt.bz2 Hi, at -O3 -g -gstrict-dwarf, gcc generates for an optimized out vla 'a' a DW_TAG_variable with type DW_TAG_array_type containing one DW_TAG_subrange_type, but without DW_AT_upper_bound or DW_AT_count, which makes the upper bound value 'unknown': ... .uleb128 0x15 # (DIE (0x161) DW_TAG_variable) .long 0xec # DW_AT_abstract_origin .long 0x170 # DW_AT_type ... .uleb128 0xa # (DIE (0x170) DW_TAG_array_type) .long 0x110 # DW_AT_type .long 0x17f # DW_AT_sibling .uleb128 0x17 # (DIE (0x179) DW_TAG_subrange_type) .long 0xc6 # DW_AT_type .byte 0 # end of children of DIE 0x170 ... But gdb prints '0' for the size of 'a': ... /gdb ./vla-1.exe -batch -ex "b f1" -ex "run" -ex "p sizeof(a)" Breakpoint 1 at 0x4004c0: f1. (2 locations) Breakpoint 1, f1 (i=) at vla-1.c:18 18 } $1 = 0 ... while would be more appropriate. This patch fixes that in evaluate_subexp_for_sizeof. Build and reg-tested on x86_64-linux. OK for trunk? Thanks, - Tom [gdb/exp] Interpret size of vla with unknown size as 2018-07-06 Tom de Vries * eval.c (evaluate_subexp_for_sizeof): Interpret size of dynamic type with undefined upper bound as . * gdb.base/vla-optimized-out-o3.c: New test. * gdb.base/vla-optimized-out-o3.exp: New file. --- gdb/eval.c | 2 ++ gdb/testsuite/gdb.base/vla-optimized-out-o3.c | 34 +++++++++++++++++++++ gdb/testsuite/gdb.base/vla-optimized-out-o3.exp | 40 +++++++++++++++++++++++++ 3 files changed, 76 insertions(+) diff --git a/gdb/eval.c b/gdb/eval.c index 9db6e7c69d..0495a11bfd 100644 --- a/gdb/eval.c +++ b/gdb/eval.c @@ -3145,6 +3145,8 @@ evaluate_subexp_for_sizeof (struct expression *exp, int *pos, { val = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_NORMAL); type = value_type (val); + if (TYPE_HIGH_BOUND_UNDEFINED (TYPE_INDEX_TYPE (type))) + return allocate_optimized_out_value (size_type); } else (*pos) += 4; diff --git a/gdb/testsuite/gdb.base/vla-optimized-out-o3.c b/gdb/testsuite/gdb.base/vla-optimized-out-o3.c new file mode 100644 index 0000000000..799a1f7b10 --- /dev/null +++ b/gdb/testsuite/gdb.base/vla-optimized-out-o3.c @@ -0,0 +1,34 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2018 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 . */ + +int __attribute__((noinline)) +f1 (int i) +{ + char a[i + 1]; + a[0] = 5; + return a[0]; +} + +int +main (void) +{ + volatile int j; + int i = 5; + asm volatile ("" : "=r" (i) : "0" (i)); + j = f1 (i); + return 0; +} diff --git a/gdb/testsuite/gdb.base/vla-optimized-out-o3.exp b/gdb/testsuite/gdb.base/vla-optimized-out-o3.exp new file mode 100644 index 0000000000..bc435cc4aa --- /dev/null +++ b/gdb/testsuite/gdb.base/vla-optimized-out-o3.exp @@ -0,0 +1,40 @@ +# Copyright 2018 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 . + +# Check whether we can determine the size of an optimized-out vla. + +standard_testfile + +if { [prepare_for_testing "failed to prepare" $testfile $srcfile \ + {debug optimize=-O3 additional_flags=-gstrict-dwarf}] } { + return -1 +} + +proc vla_optimized_out { } { + if ![runto f1] { + fail "can't run to f1" + return + } + + gdb_test "p a" \ + { = } \ + "printed optimized out vla" + + gdb_test "p sizeof (a)" \ + { = } \ + "printed optimized out size of optimized out vla" +} + +vla_optimized_out