CEF_Parser-update.sh wrapper fixes wild diffs from Parse::Yapp hash r…

…andomization

src/perl/prefvote/tools/CEF_Parser-update.pl

@@ -3,7 +3,9 @@
 # Copyright (c) 2023 by Ian Kluft
 # Open Source license: Apache License 2.0 https://www.apache.org/licenses/LICENSE-2.0
 #
-# Run this to update the generated parser code after modifications to the CEF grammar.
+# This updates the generated parser code after modifications to the CEF grammar.  Use the CEF_Parser-update.sh
+# wrapper script to run this. It sets environment variables so Perl will use the same hash keys each time and
+# generate consistent diffs on the generated code.
 use strict;
 use warnings;
 use utf8;

src/perl/prefvote/tools/CEF_Parser-update.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+# CEF_Parser-update.sh - shell warpper for CEF_Parser-update.pl to update CEF_Parser.pm with minimal diffs
+# Copyright (c) 2023 by Ian Kluft
+# Open Source license: Apache License 2.0 https://www.apache.org/licenses/LICENSE-2.0
+#
+# Run this to update the generated parser code after modifications to the CEF grammar.
+export PERL_HASH_SEED=0
+export PERL_PERTURB_KEYS="NO"
+readlink=$(which readlink)
+dirname=$(which dirname)
+if [ -n "$readlink" ] && [ -n "$dirname" ]
+then
+    # find location of the script because CEF_Parser-update.pl is in the same directory
+    canonical_script="$( $readlink -f -- "$0" )"
+    dir=$( $dirname -- "$canonical_script")
+else
+    # without readlink and dirname, we're at a disadvantage to determine the location of the script
+    # -> fall back to a requirement to run this script from the build root
+    dir="tools"
+fi
+
+# find the update script
+update_script="$dir/CEF_Parser-update.pl"
+if [ ! -f "$update_script" ]
+then
+    echo "update script not found at $update_script"
+    exit 1
+fi
+
+# run the update script
+perl "$update_script"