# This script rebuilds the time zone files using files
# downloaded from the ICANN/IANA distribution.
-# Consult https://www.iana.org/time-zones for the latest versions.
+#
+# To prepare an update for a new Go release,
+# consult https://www.iana.org/time-zones for the latest versions,
+# update CODE and DATA below, and then run
+#
+# ./update.bash -commit
+#
+# That will prepare the files and create the commit.
+#
+# To review such a commit (as the reviewer), use:
+#
+# git codereview change NNNNNN # CL number
+# cd lib/time
+# ./update.bash
+#
+# If it prints "No updates needed.", then the generated files
+# in the CL match the update.bash in the CL.
# Versions to use.
-CODE=2022f
-DATA=2022f
+CODE=2022g
+DATA=2022g
set -e
+
+cd $(dirname $0)
rm -rf work
mkdir work
+go build -o work/mkzip mkzip.go # build now for correct paths in build errors
cd work
mkdir zoneinfo
-curl -L -O https://www.iana.org/time-zones/repository/releases/tzcode$CODE.tar.gz
-curl -L -O https://www.iana.org/time-zones/repository/releases/tzdata$DATA.tar.gz
+curl -sS -L -O https://www.iana.org/time-zones/repository/releases/tzcode$CODE.tar.gz
+curl -sS -L -O https://www.iana.org/time-zones/repository/releases/tzdata$DATA.tar.gz
tar xzf tzcode$CODE.tar.gz
tar xzf tzdata$DATA.tar.gz
-make CFLAGS=-DSTD_INSPIRED AWK=awk TZDIR=zoneinfo posix_only
+if ! make CFLAGS=-DSTD_INSPIRED AWK=awk TZDIR=zoneinfo posix_only >make.out 2>&1; then
+ cat make.out
+ exit 2
+fi
cd zoneinfo
-rm -f ../../zoneinfo.zip
-zip -0 -r ../../zoneinfo.zip *
+../mkzip ../../zoneinfo.zip
cd ../..
-
go generate time/tzdata
-echo
+files="update.bash zoneinfo.zip ../../src/time/tzdata/zipdata.go"
+modified=true
+if git diff --quiet $files; then
+ modified=false
+fi
+
if [ "$1" = "-work" ]; then
echo Left workspace behind in work/.
+ shift
else
rm -rf work
fi
-echo New time zone files in zoneinfo.zip.
+
+if ! $modified; then
+ echo No updates needed.
+ exit 0
+fi
+
+echo Updated for $CODE/$DATA: $files
+
+commitmsg="lib/time: update to $CODE/$DATA
+
+Commit generated by update.bash.
+
+For #22487.
+"
+
+if [ "$1" = "-commit" ]; then
+ echo "Creating commit. Run 'git reset HEAD^' to undo commit."
+ echo
+ git commit -m "$commitmsg" $files
+ echo
+ git log -n1 --stat
+ echo
+fi