From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id MmWzLL6j91+/GQAAWB0awg (envelope-from ) for ; Thu, 07 Jan 2021 19:13:50 -0500 Received: by simark.ca (Postfix, from userid 112) id A8B7C1E965; Thu, 7 Jan 2021 19:13:50 -0500 (EST) 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 9EBC81E590 for ; Thu, 7 Jan 2021 19:13:49 -0500 (EST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id D8A7E386101C; Fri, 8 Jan 2021 00:13:48 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D8A7E386101C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1610064828; bh=S2/QKqy1zIMU4xsZVz5W2Utq3mTYtHRXJ9Sd9eDcm8E=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:Cc:From; b=Md7Stj2rmGNPzxHJEo9MDjIvyb0DH+vMC9qRynihyw4p7L77CR6Miw5AofBmxucxV bCoRtTmy0q9TDzgnXFlLX7XC+Rde6Hdgc4cEQ3cU5Yt8u4FIulYiZ6+rMGPMdgQa7w e8lOoQph3KDzXub4LkN9ZvYpbrMtodBJEIaBZ4AI= Received: from beryx.lancelotsix.com (beryx.lancelotsix.com [IPv6:2001:41d0:401:3000::1ab3]) by sourceware.org (Postfix) with ESMTPS id 398A7386101C for ; Fri, 8 Jan 2021 00:13:45 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 398A7386101C Received: from gwenhwyvar.lan (unknown [IPv6:2a02:390:8443:0:ac3f:305a:5a38:83cc]) by beryx.lancelotsix.com (Postfix) with ESMTPSA id F06AA2E070; Fri, 8 Jan 2021 01:13:43 +0100 (CET) To: gdb-patches@sourceware.org Subject: [PATCH] Improve gdb_tilde_expand logic Date: Fri, 8 Jan 2021 00:13:37 +0000 Message-Id: <20210108001337.29164-1-lsix@lancelotsix.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.11 (beryx.lancelotsix.com [0.0.0.0]); Fri, 08 Jan 2021 01:13:44 +0100 (CET) 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 Cc: Lancelot SIX Errors-To: gdb-patches-bounces@sourceware.org Sender: "Gdb-patches" Before this patch, gdb_tilde_expand would use glob(3) in order to expand tilde at the begining of a path. This implementation has limitation when expanding a tilde leading path to a non existing file since glob fails to expand. This patch proposes to use glob only to expand the tilde component of the path and leave the rest of the path unchanged. This patch is a followup to the following discution: https://sourceware.org/pipermail/gdb-patches/2021-January/174776.html Before: gdb_tilde_expand("~") -> "/home/lsix" gdb_tilde_expand("~/a/c/b") -> error() is called After the patch: gdb_tilde_expand("~") -> "/home/lsix" gdb_tilde_expand("~/a/c/b") -> "/home/lsix/a/c/b" Tested on x84_64 linux. I am unsure where to place unittests for this function. My copyright assignment is still pending, but should be signed soon. gdbsupport/ChangeLog: * gdb_tilde_expand.cc (gdb_tilde_expand): Improve implementation. (gdb_tilde_expand_up): Delegate logic to gdb_tilde_expand. * gdb_tilde_expand.h (gdb_tilde_expand): Update description. --- gdbsupport/gdb_tilde_expand.cc | 45 +++++++++++++++++++++++++--------- gdbsupport/gdb_tilde_expand.h | 3 +-- 2 files changed, 34 insertions(+), 14 deletions(-) diff --git a/gdbsupport/gdb_tilde_expand.cc b/gdbsupport/gdb_tilde_expand.cc index b31fc48446..d060e26f50 100644 --- a/gdbsupport/gdb_tilde_expand.cc +++ b/gdbsupport/gdb_tilde_expand.cc @@ -17,7 +17,9 @@ You should have received a copy of the GNU General Public License along with this program. If not, see . */ +#include #include "common-defs.h" +#include "filenames.h" #include "gdb_tilde_expand.h" #include @@ -71,14 +73,37 @@ private: std::string gdb_tilde_expand (const char *dir) { - gdb_glob glob (dir, GLOB_TILDE_CHECK, NULL); + if (dir[0] == '~') + { + /* This function uses glob in order to expand the ~. However, this + function will fail to expand if the actual dir we are looking + for does not exist. Given "~/does/not/exist", glob will fail. - gdb_assert (glob.pathc () > 0); - /* "glob" may return more than one match to the path provided by the - user, but we are only interested in the first match. */ - std::string expanded_dir = glob.pathv ()[0]; + In order to avoid such limitation, we only use + glob to expand "~" and keep "/does/not/exist" unchanged. - return expanded_dir; + Similarly, to expand ~gdb/might/not/exist, we only expand + "~gdb" using glob and leave "/might/not/exist" unchanged. */ + + const std::string d (dir); + + // Look for the first dir separator (if any) + const auto first_sep = + std::find_if (d.cbegin (), d.cend(), + [](const auto c) { return IS_DIR_SEPARATOR (c); }); + + // split d according to the first separator + const std::string to_expand (d.cbegin (), first_sep); + const std::string remainder (first_sep, d.cend ()); + + // Expand the first element + const gdb_glob glob (to_expand.c_str (), GLOB_TILDE_CHECK, nullptr); + gdb_assert (glob.pathc () == 1); + + return std::string (glob.pathv ()[0]) + remainder; + } + else + return std::string (dir); } /* See gdbsupport/gdb_tilde_expand.h. */ @@ -86,10 +111,6 @@ gdb_tilde_expand (const char *dir) gdb::unique_xmalloc_ptr gdb_tilde_expand_up (const char *dir) { - gdb_glob glob (dir, GLOB_TILDE_CHECK, NULL); - - gdb_assert (glob.pathc () > 0); - /* "glob" may return more than one match to the path provided by the - user, but we are only interested in the first match. */ - return make_unique_xstrdup (glob.pathv ()[0]); + auto const expanded = gdb_tilde_expand (dir); + return make_unique_xstrdup (expanded.c_str ()); } diff --git a/gdbsupport/gdb_tilde_expand.h b/gdbsupport/gdb_tilde_expand.h index e2d85cadad..a61f246329 100644 --- a/gdbsupport/gdb_tilde_expand.h +++ b/gdbsupport/gdb_tilde_expand.h @@ -20,8 +20,7 @@ #ifndef COMMON_GDB_TILDE_EXPAND_H #define COMMON_GDB_TILDE_EXPAND_H -/* Perform path expansion (i.e., tilde expansion) on DIR, and return - the full path. */ +/* Perform tilde expansion on DIR, and return the full path. */ extern std::string gdb_tilde_expand (const char *dir); /* Same as GDB_TILDE_EXPAND, but return the full path as a -- 2.29.2