From 0951ec69c60cadc7ea54f23f408d0c943f58c5c2 Mon Sep 17 00:00:00 2001
From: Toni Peter <mail@tonipeter.de>
Date: Fri, 17 Jan 2025 13:55:40 +0100
Subject: [PATCH] Run clang-format only over files changed in the PR

---
 .github/check-c-formatting.sh | 16 ++++++++++++++++
 .github/workflows/linting.yml |  4 +---
 2 files changed, 17 insertions(+), 3 deletions(-)
 create mode 100755 .github/check-c-formatting.sh

diff --git a/.github/check-c-formatting.sh b/.github/check-c-formatting.sh
new file mode 100755
index 000000000..1877ae9de
--- /dev/null
+++ b/.github/check-c-formatting.sh
@@ -0,0 +1,16 @@
+#!/usr/bin/env sh
+# I wanted to get the merge base using {{ github.base_ref }}, however this is only
+# available for the event that opens the PR or edits it, not on pushes to the branch.
+# Comparing to main should be an OK alternative, since it will - at worst - do more
+# autoformatting than it otherwise would.
+
+[ -z "$1" ] && merge_base=main || merge_base="$1"
+
+git fetch origin $merge_base:refs/remotes/origin/$merge_base
+
+(git diff --name-only "origin/$merge_base") | while read filename; do
+    extension="${filename##*.}"
+    if [ "$extension" = "c" ] || [ "$extension" = "h" ]; then
+        clang-format -i -style=file "$filename"
+    fi
+done
diff --git a/.github/workflows/linting.yml b/.github/workflows/linting.yml
index e0d357537..78d2cdd40 100644
--- a/.github/workflows/linting.yml
+++ b/.github/workflows/linting.yml
@@ -9,9 +9,7 @@ jobs:
       - name: Check out openvas-scanner
         uses: actions/checkout@v4
       - name: Formatting
-        run: |
-          clang-format -i -style=file {src,misc,nasl}/*.{c,h}
-          git diff --exit-code
+        run: sh .github/check-c-formatting.sh ${{ github.base_ref }}
   Rust:
     runs-on: ubuntu-latest
     defaults: