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From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: git@vger.kernel.org
Cc: "Junio C Hamano" <gitster@pobox.com>, "Jeff King" <peff@peff.net>,
	"Jeffrey Walton" <noloader@gmail.com>,
	"Michał Kiedrowicz" <michal.kiedrowicz@gmail.com>,
	"J Smith" <dark.panda@gmail.com>,
	"Victor Leschuk" <vleschuk@gmail.com>,
	"Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>,
	"Fredrik Kuivinen" <frekui@gmail.com>,
	"Zoltán Herczeg" <hzmester@freemail.hu>,
	"Brandon Williams" <bmwill@google.com>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Subject: [PATCH v3 05/18] Makefile & configure: reword outdated comment about PCRE
Date: Thu, 20 Apr 2017 21:23:32 +0000	[thread overview]
Message-ID: <20170420212345.7408-6-avarab@gmail.com> (raw)
In-Reply-To: <20170420212345.7408-1-avarab@gmail.com>

Reword an outdated comment which suggests that only git-grep can use
PCRE.

This comment was added back when PCRE support was initially added in
commit 63e7e9d8b6 ("git-grep: Learn PCRE", 2011-05-09), and was true
at the time.

It hasn't been telling the full truth since git-log learned to use
PCRE with --grep in commit 727b6fc3ed ("log --grep: accept
--basic-regexp and --perl-regexp", 2012-10-03), and more importantly
is likely to get more inaccurate over time as more use is made of PCRE
in other areas.

Reword it to be more future-proof, and to more clearly explain that
this enables user-initiated runtime behavior.

Copy/pasting this so much in configure.ac is lame, these Makefile-like
flags aren't even used by autoconf, just the corresponding
--with[out]-* options. But copy/pasting the comments that make sense
for the Makefile to configure.ac where they make less sence is the
pattern everything else follows in that file. I'm not going to war
against that as part of this change, just following the existing
pattern.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 Makefile     |  6 ++++--
 configure.ac | 12 ++++++++----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index eb1a1a7cff..2e63b1cfcc 100644
--- a/Makefile
+++ b/Makefile
@@ -24,8 +24,10 @@ all::
 # Define NO_OPENSSL environment variable if you do not have OpenSSL.
 # This also implies BLK_SHA1.
 #
-# Define USE_LIBPCRE if you have and want to use libpcre. git-grep will be
-# able to use Perl-compatible regular expressions.
+# Define USE_LIBPCRE if you have and want to use libpcre. Various
+# commands such as log and grep offer runtime options to use
+# Perl-compatible regular expressions instead of standard or extended
+# POSIX regular expressions.
 #
 # Define LIBPCREDIR=/foo/bar if your libpcre header and library files are in
 # /foo/bar/include and /foo/bar/lib directories.
diff --git a/configure.ac b/configure.ac
index 128165529f..deeb968daa 100644
--- a/configure.ac
+++ b/configure.ac
@@ -250,8 +250,10 @@ AS_HELP_STRING([--with-openssl],[use OpenSSL library (default is YES)])
 AS_HELP_STRING([],              [ARG can be prefix for openssl library and headers]),
 GIT_PARSE_WITH([openssl]))
 
-# Define USE_LIBPCRE if you have and want to use libpcre. git-grep will be
-# able to use Perl-compatible regular expressions.
+# Define USE_LIBPCRE if you have and want to use libpcre. Various
+# commands such as log and grep offer runtime options to use
+# Perl-compatible regular expressions instead of standard or extended
+# POSIX regular expressions.
 #
 # Define LIBPCREDIR=/foo/bar if your libpcre header and library files are in
 # /foo/bar/include and /foo/bar/lib directories.
@@ -499,8 +501,10 @@ GIT_CONF_SUBST([NEEDS_SSL_WITH_CRYPTO])
 GIT_CONF_SUBST([NO_OPENSSL])
 
 #
-# Define USE_LIBPCRE if you have and want to use libpcre. git-grep will be
-# able to use Perl-compatible regular expressions.
+# Define USE_LIBPCRE if you have and want to use libpcre. Various
+# commands such as log and grep offer runtime options to use
+# Perl-compatible regular expressions instead of standard or extended
+# POSIX regular expressions.
 #
 
 if test -n "$USE_LIBPCRE"; then
-- 
2.11.0


  parent reply	other threads:[~2017-04-20 21:24 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-20 21:23 [PATCH v3 00/18] PCRE v1 improvements & PCRE v2 support Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 01/18] grep: amend submodule recursion test in preparation for rx engine testing Ævar Arnfjörð Bjarmason
2017-04-20 22:22   ` Brandon Williams
2017-04-20 21:23 ` [PATCH v3 02/18] grep: add tests for grep pattern types being passed to submodules Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 03/18] grep: submodule-related case statements should die if new fields are added Ævar Arnfjörð Bjarmason
2017-04-20 22:20   ` Brandon Williams
2017-04-20 22:27     ` Jeff King
2017-04-20 21:23 ` [PATCH v3 04/18] grep: remove redundant regflags assignment under PCRE Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` Ævar Arnfjörð Bjarmason [this message]
2017-04-20 21:23 ` [PATCH v3 06/18] grep: add a test for backreferences in PCRE patterns Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 07/18] log: add exhaustive tests for pattern style options & config Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 08/18] log: add -P as a synonym for --perl-regexp Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 09/18] grep & rev-list doc: stop promising libpcre " Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 10/18] grep: make grep.patternType=[pcre|pcre1] a synonym for "perl" Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 11/18] test-lib: rename the LIBPCRE prerequisite to PCRE Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 12/18] grep: change the internal PCRE macro names to be PCRE1 Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 13/18] grep: change the internal PCRE code & header " Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 14/18] perf: add a performance comparison test of grep -E and -P Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 15/18] grep: add support for the PCRE v1 JIT API Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 16/18] grep: add support for PCRE v2 Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 17/18] grep: remove support concurrent use of both PCRE v1 & v2 Ævar Arnfjörð Bjarmason
2017-04-20 21:23 ` [PATCH v3 18/18] Makefile & configure: make PCRE v2 the default PCRE implementation Ævar Arnfjörð Bjarmason

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