From 0fe8b3c8116168e3b8b058df63ddedd45c3fcab0 Mon Sep 17 00:00:00 2001
From: =?utf8?q?J=C3=A1n=20Tomko?= <jtomko@redhat.com>
Date: Tue, 2 Aug 2016 15:41:13 +0200
Subject: [PATCH] maint.mk: expand the prohibit_doubled_word regex

This check has a static list of words that are checked for
repetitions.  Expand it before running the perl script to
avoid using expensive captures.  This decreases the cost
for libvirt from 1.66s to 0.66s.
* top/maint.mk (prohibit_doubled_word_expanded_): Define.
(sc_prohibit_doubled_word): Use it.
---
 ChangeLog    | 10 ++++++++++
 top/maint.mk |  7 ++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 8e8ba77718..7cfc6f73c9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2016-08-02  Ján Tomko  <jtomko@redhat.com>
+
+	maint.mk: expand the prohibit_doubled_word regex
+	This check has a static list of words that are checked for
+	repetitions.  Expand it before running the perl script to
+	avoid using expensive captures.  This decreases the cost
+	for libvirt from 1.66s to 0.66s.
+	* top/maint.mk (prohibit_doubled_word_expanded_): Define.
+	(sc_prohibit_doubled_word): Use it.
+
 2016-07-26  Ján Tomko  <jtomko@redhat.com>
 
 	useless-if-before-free: skip non-matching lines early
diff --git a/top/maint.mk b/top/maint.mk
index 9ca2bd3b32..868e10f004 100644
--- a/top/maint.mk
+++ b/top/maint.mk
@@ -962,8 +962,13 @@ perl_filename_lineno_text_ =						\
     -e '    print "$$ARGV:$$n:$$v\n";'					\
     -e '  }'
 
+prohibit_doubled_words_ = \
+    the then in an on if is it but for or at and do to
+# expand the regex before running the check to avoid using expensive captures
+prohibit_doubled_word_expanded_ = \
+    $(join $(prohibit_doubled_words_),$(addprefix \s+,$(prohibit_doubled_words_)))
 prohibit_doubled_word_RE_ ?= \
-  /\b(then?|[iao]n|i[fst]|but|f?or|at|and|[dt]o)\s+\1\b/gims
+    /\b(?:$(subst $(_sp),|,$(prohibit_doubled_word_expanded_)))\b/gims
 prohibit_doubled_word_ =						\
     -e 'while ($(prohibit_doubled_word_RE_))'				\
     $(perl_filename_lineno_text_)
-- 
2.39.5