From b979bceed1f14619df7b3331e1a7247dcbe87815 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Thu, 20 Mar 2014 19:01:21 -0700
Subject: [PATCH 6/6] Remove unused rules, and add a check for this.

* checktab.awk: Check for a Rule defined but never used.
* antarctica (NZAQ): Remove unused rule.
* NEWS: Document this.
---
 NEWS         |  5 +++++
 antarctica   | 12 ------------
 checktab.awk | 20 +++++++++++++++++---
 3 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/NEWS b/NEWS
index c33c214..4b53037 100644
--- a/NEWS
+++ b/NEWS
@@ -14,6 +14,11 @@ Unreleased, experimental changes
     per year for the forseeable future.  (Thanks to Andrew Main (Zefram).)
     Also, 'zic' avoids some unlikely failures due to integer overflow.
 
+  Changes affecting build procedure
+
+    'make check' now detects Rule lines defined but never used.
+    The NZAQ rules, an instance of this problem, have been removed.
+
   Changes affecting commentary and documentation
 
     Add a commented-out entry for Troll station, Antarctica.
diff --git a/antarctica b/antarctica
index 2e0806c..06da875 100644
--- a/antarctica
+++ b/antarctica
@@ -230,18 +230,6 @@ Zone Antarctica/Syowa	0	-	zzz	1957 Jan 29
 # year-round base
 # Scott Base, Ross Island, since 1957-01.
 # See Pacific/Auckland.
-#
-# These rules for New Zealand are stolen from the 'australasia' file.
-# Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
-Rule	NZAQ	1974	only	-	Nov	 3	2:00s	1:00	D
-Rule	NZAQ	1975	1988	-	Oct	lastSun	2:00s	1:00	D
-Rule	NZAQ	1989	only	-	Oct	 8	2:00s	1:00	D
-Rule	NZAQ	1990	2006	-	Oct	Sun>=1	2:00s	1:00	D
-Rule	NZAQ	1975	only	-	Feb	23	2:00s	0	S
-Rule	NZAQ	1976	1989	-	Mar	Sun>=1	2:00s	0	S
-Rule	NZAQ	1990	2007	-	Mar	Sun>=15	2:00s	0	S
-Rule	NZAQ	2007	max	-	Sep	lastSun	2:00s	1:00	D
-Rule	NZAQ	2008	max	-	Apr	Sun>=1	2:00s	0	S
 
 # Norway - territories
 # Bouvet (never inhabited)
diff --git a/checktab.awk b/checktab.awk
index fec4f62..d78ba73 100644
--- a/checktab.awk
+++ b/checktab.awk
@@ -115,10 +115,14 @@ BEGIN {
 	FS = " "
 }
 
+$1 ~ /^#/ { next }
+
 {
-	tz = ""
-	if ($1 == "Zone") tz = $2
-	if ($1 == "Link") {
+	tz = rules = ""
+	if ($1 == "Zone") {
+		tz = $2
+		ruleUsed[$4] = 1
+	} else if ($1 == "Link") {
 		# Ignore Link commands if source and destination basenames
 		# are identical, e.g. Europe/Istanbul versus Asia/Istanbul.
 		src = $2
@@ -126,6 +130,10 @@ BEGIN {
 		while ((i = index(src, "/"))) src = substr(src, i+1)
 		while ((i = index(dst, "/"))) dst = substr(dst, i+1)
 		if (src != dst) tz = $3
+	} else if ($1 == "Rule") {
+		ruleDefined[$2] = 1
+	} else {
+		ruleUsed[$2] = 1
 	}
 	if (tz && tz ~ /\//) {
 		if (!tztab[tz]) {
@@ -138,6 +146,12 @@ BEGIN {
 }
 
 END {
+	for (tz in ruleDefined) {
+		if (!ruleUsed[tz]) {
+			printf "%s: Rule never used\n", tz
+			status = 1
+		}
+	}
 	for (tz in tz2cc) {
 		if (!zoneSeen[tz]) {
 			printf "%s:%d: no Zone table for `%s'\n", \
-- 
1.8.5.3