Put clang-tidy into thin wrapper script

Otherwise we are not able to use the shell to dynamically get things

.github/scripts/clang-tidy-hook

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+# Thin wrapper around clang-tidy that we need to make sure that we can pass the
+# include directories for SIO to clang-tidy as it seems that it's not always
+# present in the compile database that is generated by CMake. This is mainly
+# necessary for template heavy header only parts that get included and for which
+# clang-tidy runs into a clang-diagnostic-error because it cannot find an SIO
+# header. We cannot do this in the pre-commit configuration because we cannot do
+# any shell expansion there.
+
+# Safe guard against environments where we do not have SIO available. The
+# clang-tidy checks will probably fail, but at least we are not getting problems
+# with passing garbage as extra arguments
+EXTRA_ARGS=""
+if which sio-dump > /dev/null 2>&1; then
+    EXTRA_ARGS="--extra-arg=-I$(realpath $(dirname $(which sio-dump))/../include)"
+fi
+
+clang-tidy -warnings-as-errors='*,-clang-diagnostic-deprecated-declarations' -p compile_commands.json $EXTRA_ARGS ${@}

.pre-commit-config.yaml

@@ -9,7 +9,7 @@ repos:
     hooks:
       - id: clang-tidy
         name: clang-tidy
-        entry: clang-tidy -warnings-as-errors='*,-clang-diagnostic-deprecated-declarations' -p compile_commands.json --extra-arg=-I$(realpath $(dirname $(which sio-dump))/../include)
+        entry: .github/scripts/clang-tidy-hook
         types: [c++]
         exclude: (tests/(datamodel|src|extra_code)/.*(h|cc)|podioVersion.in.h)
         language: system