Add clang-tidy pre-commit hook and fix clang-tidy warnings

- Add run_clang_tidy_hook.sh for pre-commit integration
  - Skips if clangd-21 not installed
  - Skips if compile_commands.json not found
  - Runs only on modified files
  - Fails on errors

- Fix clang-tidy warnings in exception tracking code:
  - Use anonymous namespace instead of static for tick_stack_
  - Add deleted move operations to TickStackGuard

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: facontidavide

.pre-commit-config.yaml

@@ -43,14 +43,15 @@ repos:
       - id: clang-format
         args: ['-fallback-style=none', '-i']
 
-  # C++ static analysis (installs clang-tidy automatically via pip)
-  # - repo: https://github.com/mxmlnrdr/clang_tidy_hook
-  #   rev: v0.3.1
-  #   hooks:
-  #     - id: clang-tidy
-  #       args:
-  #         - --config-file=.clang-tidy
-  #         - -p=build
+  # C++ static analysis via clangd-21 (skips if not installed)
+  - repo: local
+    hooks:
+      - id: clang-tidy
+        name: clang-tidy
+        entry: ./run_clang_tidy_hook.sh
+        language: script
+        files: \.(cpp|hpp|h)$
+        exclude: ^3rdparty/|^include/behaviortree_cpp/contrib/|^include/behaviortree_cpp/scripting/
 
   # Spell check
   - repo: https://github.com/codespell-project/codespell

run_clang_tidy_hook.sh

@@ -0,0 +1,57 @@
+#!/bin/bash
+# Pre-commit hook wrapper for clang-tidy.
+# - Skips if clangd-21 is not installed
+# - Skips if compile_commands.json not found
+# - Runs only on files passed as arguments (modified files)
+# - Fails if clang-tidy reports any errors
+
+script_dir=${0%/*}
+build_dir="${script_dir}/build"
+
+if ! command -v clangd-21 &> /dev/null; then
+  echo "Skipping clang-tidy: clangd-21 not installed"
+  exit 0
+fi
+
+if [ ! -f "${build_dir}/compile_commands.json" ]; then
+  echo "Skipping clang-tidy: compile_commands.json not found (run cmake first)"
+  exit 0
+fi
+
+if [ $# -eq 0 ]; then
+  echo "No files to check"
+  exit 0
+fi
+
+# Filter to only .cpp, .hpp, .h files and exclude 3rdparty/contrib/scripting
+files=()
+for f in "$@"; do
+  case "$f" in
+    3rdparty/*|*/contrib/*|*/scripting/*|*_WIN.cpp) continue ;;
+    *.cpp|*.hpp|*.h) files+=("$f") ;;
+  esac
+done
+
+if [ ${#files[@]} -eq 0 ]; then
+  exit 0
+fi
+
+echo "Running clang-tidy on ${#files[@]} file(s)..."
+
+failed=0
+for f in "${files[@]}"; do
+  echo "  Checking: $f"
+  output=$(clangd-21 \
+      --log=error \
+      --clang-tidy \
+      --compile-commands-dir="$build_dir" \
+      --check-locations=false \
+      --check="$f" 2>&1)
+  # Check for error lines (starts with E[)
+  if echo "$output" | grep -q "^E\["; then
+    echo "$output" | grep "^E\["
+    failed=1
+  fi
+done
+
+exit $failed

src/tree_node.cpp

@@ -20,10 +20,11 @@
 
 namespace BT
 {
-
+namespace
+{
 // Thread-local stack tracking the current tick hierarchy.
 // Used to build a backtrace when an exception is thrown during tick().
-static thread_local std::vector<const TreeNode*> tick_stack_;
+thread_local std::vector<const TreeNode*> tick_stack_;
 
 // RAII guard to push/pop nodes from the tick stack
 class TickStackGuard
@@ -39,6 +40,8 @@ class TickStackGuard
   }
   TickStackGuard(const TickStackGuard&) = delete;
   TickStackGuard& operator=(const TickStackGuard&) = delete;
+  TickStackGuard(TickStackGuard&&) = delete;
+  TickStackGuard& operator=(TickStackGuard&&) = delete;
 
   // Build a backtrace from the current tick stack
   static std::vector<TickBacktraceEntry> buildBacktrace()
@@ -52,6 +55,7 @@ class TickStackGuard
     return backtrace;
   }
 };
+}  // namespace
 
 struct TreeNode::PImpl
 {