From patchwork Fri Apr 21 13:40:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tom Tromey X-Patchwork-Id: 68131 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id BDAC93857020 for ; Fri, 21 Apr 2023 13:41:00 +0000 (GMT) X-Original-To: gdb-patches@sourceware.org Delivered-To: gdb-patches@sourceware.org Received: from gproxy1-pub.mail.unifiedlayer.com (gproxy1-pub.mail.unifiedlayer.com [69.89.25.95]) by sourceware.org (Postfix) with ESMTPS id B58083858C83 for ; Fri, 21 Apr 2023 13:40:45 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org B58083858C83 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=tromey.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tromey.com Received: from cmgw11.mail.unifiedlayer.com (unknown [10.0.90.126]) by progateway3.mail.pro1.eigbox.com (Postfix) with ESMTP id F0BCF100417DD for ; Fri, 21 Apr 2023 13:40:28 +0000 (UTC) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with ESMTP id pr00pnve1CH3ypr00pWcfb; Fri, 21 Apr 2023 13:40:28 +0000 X-Authority-Reason: nr=8 X-Authority-Analysis: v=2.4 cv=XM719StE c=1 sm=1 tr=0 ts=6442924c a=ApxJNpeYhEAb1aAlGBBbmA==:117 a=ApxJNpeYhEAb1aAlGBBbmA==:17 a=dLZJa+xiwSxG16/P+YVxDGlgEgI=:19 a=dKHAf1wccvYA:10:nop_rcvd_month_year a=Qbun_eYptAEA:10:endurance_base64_authed_username_1 a=CCpqsmhAAAAA:8 a=mDV3o1hIAAAA:8 a=EG1crqb4tqOmzI0hE-AA:9 a=ul9cdbp4aOFLsgKbc677:22 a=_FVE-zBwftR9WsbkzFJk:22 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tromey.com; s=default; h=Content-Transfer-Encoding:MIME-Version:Message-Id:Date:Subject: Cc:To:From:Sender:Reply-To:Content-Type:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=xTjJ8whGLv4TVKsPHBRNnb4qyLzDDPoCSkCj+hvLmvM=; b=ZbvClJKVQZ0FJnlIK7yB+tENUv aXHM0ih8mkq+44fpRyaOzxRiL1Mp8S7Y6FNC3+L/7EaYo43T619H2thMMbm80t2Tung0Xl7Op7hHO wHsan8PXks/Rf7Vl/k5+ZBw0S; Received: from 71-211-191-82.hlrn.qwest.net ([71.211.191.82]:36866 helo=localhost.localdomain) by box5379.bluehost.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1ppr00-001AxD-P2; Fri, 21 Apr 2023 07:40:28 -0600 From: Tom Tromey To: gdb-patches@sourceware.org Cc: Tom Tromey Subject: [PATCH] Do not print when piece is optimized out Date: Fri, 21 Apr 2023 07:40:19 -0600 Message-Id: <20230421134019.1059830-1-tom@tromey.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - box5379.bluehost.com X-AntiAbuse: Original Domain - sourceware.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tromey.com X-BWhitelist: no X-Source-IP: 71.211.191.82 X-Source-L: No X-Exim-ID: 1ppr00-001AxD-P2 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 71-211-191-82.hlrn.qwest.net (localhost.localdomain) [71.211.191.82]:36866 X-Source-Auth: tom+tromey.com X-Email-Count: 1 X-Source-Cap: ZWx5bnJvYmk7ZWx5bnJvYmk7Ym94NTM3OS5ibHVlaG9zdC5jb20= X-Local-Domain: yes X-Spam-Status: No, score=-3025.9 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, GIT_PATCH_0, JMQ_SPF_NEUTRAL, KAM_SHORT, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gdb-patches-bounces+patchwork=sourceware.org@sourceware.org Sender: "Gdb-patches" A user reported a bug where printing a certain array of integer types would result in the nonsensical: (gdb) p l_126 $1 = {6639779683436459270, , , } I tracked this down to some issues in the DWARF expression code. First, check_pieced_synthetic_pointer did not account for the situation where a location expression does not describe all the bits of a value -- in this case it returned true, meaning there is a synthetic pointer, but in fact these bits are optimized out. (It turns out this incorrect output had already been erroneously tested for as well.) Next, rw_pieced_value did not mark these bits as optimized-out, either. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30296 --- gdb/dwarf2/expr.c | 19 +++-- .../gdb.dwarf2/opt-out-not-implptr.exp | 76 +++++++++++++++++++ gdb/testsuite/gdb.dwarf2/shortpiece.exp | 4 +- 3 files changed, 91 insertions(+), 8 deletions(-) create mode 100644 gdb/testsuite/gdb.dwarf2/opt-out-not-implptr.exp diff --git a/gdb/dwarf2/expr.c b/gdb/dwarf2/expr.c index 4aa4542d947..f12abd9599d 100644 --- a/gdb/dwarf2/expr.c +++ b/gdb/dwarf2/expr.c @@ -411,11 +411,11 @@ rw_pieced_value (value *v, value *from, bool check_optimized) break; case DWARF_VALUE_IMPLICIT_POINTER: - if (from != nullptr) - { - v->mark_bits_optimized_out (offset, this_size_bits); - break; - } + if (from != nullptr) + { + v->mark_bits_optimized_out (offset, this_size_bits); + break; + } /* These bits show up as zeros -- but do not cause the value to be considered optimized-out. */ @@ -435,6 +435,13 @@ rw_pieced_value (value *v, value *from, bool check_optimized) bits_to_skip = 0; } + if (offset < max_offset) + { + if (check_optimized) + return true; + v->mark_bits_optimized_out (offset, max_offset - offset); + } + return false; } @@ -493,7 +500,7 @@ check_pieced_synthetic_pointer (const value *value, LONGEST bit_offset, return false; } - return true; + return bit_length == 0; } /* An implementation of an lval_funcs method to indirect through a diff --git a/gdb/testsuite/gdb.dwarf2/opt-out-not-implptr.exp b/gdb/testsuite/gdb.dwarf2/opt-out-not-implptr.exp new file mode 100644 index 00000000000..949bc23492a --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/opt-out-not-implptr.exp @@ -0,0 +1,76 @@ +# Copyright 2023 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 . + +load_lib dwarf.exp + +require dwarf2_support + +standard_testfile main.c -dw.S + +set asm_file [standard_output_file $srcfile2] + +Dwarf::assemble $asm_file { + cu {} { + compile_unit {} { + declare_labels i64_type array + + i64_type: base_type { + {name "int64_t"} + {encoding @DW_ATE_signed} + {byte_size 8 DW_FORM_sdata} + } + + array: DW_TAG_array_type { + {DW_AT_name array_type} + {DW_AT_type :$i64_type} + } { + DW_TAG_subrange_type { + {DW_AT_type :$i64_type} + {DW_AT_lower_bound 0 DW_FORM_data1} + {DW_AT_upper_bound 3 DW_FORM_data1} + } + } + + DW_TAG_variable { + {name noptr} + {type :$array} + {location { + DW_OP_constu 6639779683436459270 + DW_OP_stack_value + DW_OP_piece 8 + } SPECIAL_expr} + } + } + } +} + +if {[build_executable ${testfile}.exp ${testfile} \ + [list $srcfile $asm_file] {nodebug}]} { + return -1 +} + +# We need --readnow because otherwise we never read in the CU we +# created above. +save_vars { GDBFLAGS } { + append set GDBFLAGS " -readnow" + clean_restart ${testfile} +} + +if {![runto_main]} { + return -1 +} + +gdb_test "print noptr" \ + " = \\{6639779683436459270, , , \\}" diff --git a/gdb/testsuite/gdb.dwarf2/shortpiece.exp b/gdb/testsuite/gdb.dwarf2/shortpiece.exp index dec219e95a8..82ea2c2eaa4 100644 --- a/gdb/testsuite/gdb.dwarf2/shortpiece.exp +++ b/gdb/testsuite/gdb.dwarf2/shortpiece.exp @@ -137,8 +137,8 @@ gdb_test "p s2" \ # value's content. # This test verifies that GDB can print a pieced value casted to a # different type. -gdb_test "p (int \[\]) s1" " = \\{1\\, 0\\}" -gdb_test "p (short \[\]) s1" " = \\{1\\, 0\\, 0\\, \\}" +gdb_test "p (int \[\]) s1" " = \\{1, \\}" +gdb_test "p (short \[\]) s1" " = \\{1, 0, 0, \\}" # Test for correct output if the size of the original object is not a # multiple of the array's element size.