From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id WryHDPIXe2DZOQAAWB0awg (envelope-from ) for ; Sat, 17 Apr 2021 13:16:34 -0400 Received: by simark.ca (Postfix, from userid 112) id 25D891F104; Sat, 17 Apr 2021 13:16:34 -0400 (EDT) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 2A48A1E813 for ; Sat, 17 Apr 2021 13:16:33 -0400 (EDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id C9CB33896C09; Sat, 17 Apr 2021 17:16:32 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C9CB33896C09 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1618679792; bh=+4brlZTbLBXKkUXIhybGwZu191DmPPuFIz4Df8K1Hls=; h=Date:To:Subject:References:In-Reply-To:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=rCUOvBpzwwI2QmaZKCBH/WutJxD68m8S/eBx3VQ+Q8UNbp+xpoyBa/xMJA8sUaARr mNsQb03oGazdUBnC9UGlwrAxhkVaRxhmy2DTsp4Vw9/8k8voh+PHzSiry0ymYOAUrE OmoPLZnbk8g4bYO2a/0yNGv2RZ7rlCnASRtyI3y8= Received: from lndn.lancelotsix.com (vps-42846194.vps.ovh.net [IPv6:2001:41d0:801:2000::2400]) by sourceware.org (Postfix) with ESMTPS id B78CF3896C03 for ; Sat, 17 Apr 2021 17:16:27 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org B78CF3896C03 Received: from Plymouth (unknown [IPv6:2a02:390:9086:0:3220:ba30:e6c6:f86c]) by lndn.lancelotsix.com (Postfix) with ESMTPSA id B95C481C09 for ; Sat, 17 Apr 2021 17:16:26 +0000 (UTC) Date: Sat, 17 Apr 2021 18:16:23 +0100 To: gdb-patches@sourceware.org Subject: Re: [PATCH v4] [PR gdb/27614] gdb-add-index fails on symlinks. Message-ID: <20210417171623.3pxtcz5vumenx7fu@Plymouth> References: <20210329205224.12859-1-lsix@lancelotsix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210329205224.12859-1-lsix@lancelotsix.com> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.11 (lndn.lancelotsix.com [0.0.0.0]); Sat, 17 Apr 2021 17:16:26 +0000 (UTC) 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: , From: Lancelot SIX via Gdb-patches Reply-To: Lancelot SIX Errors-To: gdb-patches-bounces@sourceware.org Sender: "Gdb-patches" Hi, Kindly pinging. Lancelot. On Mon, Mar 29, 2021 at 09:52:24PM +0100, Lancelot SIX wrote: > Since V3: > - Do net rely on GDB's maintenance commands to resolve > symlinks, revert to using readlink while maximizing portability. > > Since V2: > - Use GDB to follow symlink instead of readlink. Unlike > readlink, GDB is guaranteed to be available. > > Since V1: > - Replace '&>/dev/null' with '>/dev/null 2>&1' > > -- > > PR 27614 shows that gdb-add-index fails to generate the index when its > argument is a symlink. > > The following one liner illustrates the reported problem: > > $ echo 'int main(){}'|gcc -g -x c -;ln -s a.out symlink;gdb-add-index symlink > gdb-add-index: No index was created for symlink > gdb-add-index: [Was there no debuginfo? Was there already an index?] > $ ls -l > -rwxr-xr-x 1 25712 Mar 19 23:05 a.out* > -rw------- 1 8277 Mar 19 23:05 a.out.gdb-index > lrwxrwxrwx 1 5 Mar 19 23:05 symlink -> a.out* > > GDB generates the .gdb-index file with a name that matches the name of > the actual program (a.out.gdb-index here), not the symlink that > references it. The remaining of the script is looking for a file named > after the provided argument (would be 'symlink.gdb-index' in our > example). > > gdb/ChangeLog: > > PR gdb/27614 > * contrib/gdb-add-index.sh: Fix when called with a symlink as an > argument. > > gdb/testsuite/ChangeLog: > > PR gdb/27614 > * gdb.dwarf2/gdb-add-index-symlink.exp: New test. > --- > gdb/contrib/gdb-add-index.sh | 28 +++++++++++ > .../gdb.dwarf2/gdb-add-index-symlink.exp | 47 +++++++++++++++++++ > 2 files changed, 75 insertions(+) > create mode 100644 gdb/testsuite/gdb.dwarf2/gdb-add-index-symlink.exp > > diff --git a/gdb/contrib/gdb-add-index.sh b/gdb/contrib/gdb-add-index.sh > index 2ac3fddbf26..734110caa3b 100755 > --- a/gdb/contrib/gdb-add-index.sh > +++ b/gdb/contrib/gdb-add-index.sh > @@ -37,6 +37,34 @@ fi > > file="$1" > > +if test -L "$file"; then > + if ! command -v readlink >/dev/null 2>&1; then > + echo "$myname: 'readlink' missing. Failed to follow symlink $1." 1>&2 > + exit 1 > + fi > + > + # Count number of links followed in order to detect loops. > + count=0 > + while test -L "$file"; do > + target=$(readlink "$file") > + > + case "$target" in > + /*) > + file="$target" > + ;; > + *) > + file="$(dirname "$file")/$target" > + ;; > + esac > + > + count="$((count + 1))" > + if test "$count" -gt 10; then > + echo "$myname: Detected loop while following link $file" > + exit 1 > + fi > + done > +fi > + > if test ! -r "$file"; then > echo "$myname: unable to access: $file" 1>&2 > exit 1 > diff --git a/gdb/testsuite/gdb.dwarf2/gdb-add-index-symlink.exp b/gdb/testsuite/gdb.dwarf2/gdb-add-index-symlink.exp > new file mode 100644 > index 00000000000..eaeddec0250 > --- /dev/null > +++ b/gdb/testsuite/gdb.dwarf2/gdb-add-index-symlink.exp > @@ -0,0 +1,47 @@ > +# Copyright 2021 Free Software Foundation, Inc. > + > +# This program is free software; you can redistribute it and/or modify > +# it under the terms of the GNU General Public License as published by > +# the Free Software Foundation; either version 3 of the License, or > +# (at your option) any later version. > +# > +# This program is distributed in the hope that it will be useful, > +# but WITHOUT ANY WARRANTY; without even the implied warranty of > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > +# GNU General Public License for more details. > +# > +# You should have received a copy of the GNU General Public License > +# along with this program. If not, see . > + > +load_lib dwarf.exp > + > +# This test can only be run on targets which support DWARF-2. > +if {![dwarf2_support]} { > + return 0 > +} > + > +standard_testfile main.c > + > +if { [prepare_for_testing "failed to prepare" "${testfile}" \ > + [list ${srcfile}]] } { > + return -1 > +} > + > +set symlink [file dirname $binfile]/symlink > + > +if { ![file exists $symlink] } { > + file link -symbolic $symlink $binfile > +} > + > +if { [ensure_gdb_index $symlink] == -1 } { > + fail "Unable to call gdb-add-index with a symlink to a symfile" > + return -1 > +} > + > +# Ok, we have a copy of $binfile with an index. > +# Restart gdb and verify the index was used. > + > +clean_restart $symlink > +gdb_test "mt print objfiles ${testfile}" \ > + "(gdb_index|debug_names).*" \ > + "index used" > -- > 2.30.1 > -- Lancelot SIX