Introduce xxhash into third_party (#837)

third_party/xxhash/tests/unicode_lint.sh

@@ -0,0 +1,44 @@
+// clang-format off
+#!/bin/bash
+
+# `unicode_lint.sh' determines whether source files under ${dirs} directories
+# contain Unicode characters, and fails if any do.
+#
+# We don't recommend to call this script directly.
+# Instead of it, use `make lint-unicode` via root directory Makefile.
+
+# ${dirs} : target directories
+dirs=(./ ./cli ./tests ./tests/bench ./tests/collisions)
+
+SCRIPT_DIR="`dirname "${BASH_SOURCE[0]}"`"
+cd ${SCRIPT_DIR}/..
+
+echo "Ensure no unicode character is present in source files *.{c,h}"
+pass=true
+
+# Scan each directory in ${dirs} for Unicode in source (*.c, *.h) files
+i=0
+while [ $i -lt ${#dirs[@]} ]
+do
+  dir=${dirs[$i]}
+  echo dir=$dir
+  result=$(
+    find ${dir} -regex '.*\.\(c\|h\)$' -exec grep -P -n "[^\x00-\x7F]" {} \; -exec echo "{}: FAIL" \;
+  )
+  if [[ $result ]]; then
+    echo "$result"
+    pass=false
+  fi
+  i=`expr $i + 1`
+done
+
+
+# Result
+if [ "$pass" = true ]; then
+  echo "All tests successful: no unicode character detected"
+  echo "Result: PASS"
+  exit 0
+else
+  echo "Result: FAIL"
+  exit 1
+fi