[PATCH v2 01/29] Makefile & configure: reword inaccurate comment about PCRE

From: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date: May 13, 2017, 23:14 UTC
Message-ID: <20170513231509.7834-2-avarab@gmail.com>
In-Reply-To: <20170513231509.7834-1-avarab@gmail.com>

Reword an outdated & inaccurate comment which suggests that only git-grep can use PCRE.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 sense 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 e35542e631..eedadb8056 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