uncrustify: add CI check

Co-authored-by: Kaspar Schleiser <kaspar@schleiser.de>

dist/tools/uncrustify/uncrustify.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+RIOTBASE=$(git rev-parse --show-toplevel)
+CURDIR=$(cd "$(dirname "$0")" && pwd)
+UNCRUSTIFY_CFG="$RIOTBASE"/uncrustify-riot.cfg
+
+WHITELIST=$CURDIR/whitelist.txt
+BLACKLIST=$CURDIR/blacklist.txt
+
+. "$RIOTBASE"/dist/tools/ci/changed_files.sh
+
+# only consider whitelisted stuff, then filter out blacklist
+# note: this also applies changed_files' default filter
+FILES=$(changed_files | grep -xf "$WHITELIST" | grep -xvf "$BLACKLIST")
+
+check () {
+    for F in $FILES
+    do
+        OUT="$(uncrustify -c "$UNCRUSTIFY_CFG" -f "$RIOTBASE/$F" --check 2> /dev/null)"
+        if [ "$OUT" ] ; then
+            echo "Please run 'dist/tools/uncrustify/uncrustify.sh'"
+            exit 1
+        fi
+    done
+    echo "All files are uncrustified!"
+}
+
+exec_uncrustify () {
+    if [ "$(git diff HEAD)" ] ; then
+        echo "Please commit all changes before running uncrustify.sh"
+        exit 1
+    fi
+    for F in $FILES
+    do
+        uncrustify -c "$UNCRUSTIFY_CFG" --no-backup "$RIOTBASE/$F"
+    done
+}
+
+if [ "$1" == "--check" ] ; then
+    check
+else
+    exec_uncrustify
+fi