CI: Re-enable clang-format-check workflow

.githooks/pre-commit

@@ -0,0 +1,2 @@
+#!/bin/sh
+exec "$(git rev-parse --show-toplevel)/.github/scripts/clang-format-check.sh"

.github/scripts/clang-format-check.sh

@@ -0,0 +1,70 @@
+#!/bin/sh
+#
+# Rejects changed lines that are not clang-format clean. Shared by the
+# pre-commit hook and by CI so both judge identically.
+#
+#   clang-format-check.sh              staged changes (pre-commit)
+#   clang-format-check.sh <base-ref>   changes since <base-ref> (CI)
+#
+# Only the changed lines are checked, so this does not demand a reformat
+# of surrounding code that predates the style file.
+#
+# git-clang-format spawns a separate clang-format, defaulting to the
+# unversioned one on PATH, so the wrapper and the binary are both pinned
+# here. A mismatched pair fails outright.
+#
+# Bypass:
+#   git commit -n                 skips every hook
+#   SKIP_CLANG_FORMAT=1 git ...   skips just this check
+#
+
+[ -n "$SKIP_CLANG_FORMAT" ] && exit 0
+
+ver=${CLANG_FORMAT_VERSION:-18}
+bin="clang-format-$ver"
+wrapper="git-clang-format-$ver"
+
+top=$(git rev-parse --show-toplevel 2>/dev/null) || exit 0
+[ -f "$top/.clang-format" ] || exit 0
+
+# Skipping keeps a missing formatter from blocking commits. CI asserts the
+# binaries are present in a separate step, so it cannot skip silently.
+if ! command -v "$wrapper" >/dev/null 2>&1; then
+    echo "clang-format: $wrapper not found, skipping" >&2
+    exit 0
+fi
+
+# git-clang-format needs a commit to diff against, so the very first
+# commit in a repo cannot be checked.
+git rev-parse --verify --quiet HEAD >/dev/null || exit 0
+
+if [ -n "$1" ]; then
+    scope=$1
+else
+    scope=--staged
+fi
+
+out=$("$wrapper" --binary "$bin" --diff -q "$scope" 2>&1)
+ret=$?
+
+if [ $ret -eq 0 ]; then
+    exit 0
+fi
+
+if [ $ret -ne 1 ]; then
+    echo "$out" >&2
+    echo "clang-format: $wrapper failed (exit $ret)" >&2
+    exit $ret
+fi
+
+echo "$out"
+echo ""
+echo "ERROR: changed lines are not clang-format clean."
+echo ""
+# Not "&& git add -u": the wrapper exits 1 when it reformats something.
+echo "Fix with:"
+echo "    $wrapper --binary $bin $scope; git add -u"
+echo ""
+echo "Or bypass with:"
+echo "    SKIP_CLANG_FORMAT=1 git commit ..."
+exit 1

.github/workflows/clang-format-check.yml

@@ -13,7 +13,7 @@ permissions:
 
 jobs:
   clang-format-check:
-    name: Check PR formatting with clang-format-15
+    name: Check PR formatting with clang-format-18
     runs-on: ubuntu-latest
     timeout-minutes: 5
 
@@ -23,9 +23,15 @@ jobs:
       with:
         fetch-depth: 0  # Need full history to compare with main branch
 
-    - name: Install clang-format-15
+    - name: Verify clang-format-18
       run: |
-        sudo apt-get install -y clang-format-15
+        # 18 is preinstalled on ubuntu-latest. use it to avoid an update+install
+        command -v clang-format-18 >/dev/null || {
+          echo "clang-format-18 is missing from the runner image"; exit 1; }
+        command -v git-clang-format-18 >/dev/null || {
+          echo "git-clang-format-18 is missing from the runner image"; exit 1; }
+        clang-format-18 --version
+        clang-format --version || true
 
     - name: Fetch base branch
       env:
@@ -35,44 +41,8 @@ jobs:
 
     - name: Check formatting
       env:
-        BASE_SHA: ${{ github.event.pull_request.base.sha }}
         BASE_REF: ${{ github.event.pull_request.base.ref }}
       run: |
-        echo "Running git-clang-format-15 to check for formatting issues..."
         echo "Comparing against base branch: $BASE_REF"
-
-        # Create a temporary file for the diff and ensure cleanup
-        DIFF_FILE="$(mktemp)"
-        trap 'rm -f "$DIFF_FILE"' EXIT
-
-        # Run git-clang-format against the PR base commit and capture status safely under set -e
-        if git-clang-format-15 "$BASE_REF" > "$DIFF_FILE"; then
-          status=0
-        else
-          status=$?
-        fi
-
-        if [ "$status" -eq 0 ]; then
-          echo "✅ Code is properly formatted!"
-          exit 0
-        elif [ "$status" -eq 1 ]; then
-          echo "❌ Code formatting issues detected!"
-          echo ""
-          echo "The following changes would be made by clang-format-15:"
-          echo "=================================================="
-          cat "$DIFF_FILE"
-          echo "=================================================="
-          echo ""
-          echo "Please run the following command locally on your feature branch and commit the changes:"
-          echo "  git-clang-format-15 $BASE_REF"
-          exit 0
-          # TEMPORARY DISABLE DUE TO BUGS
-          #exit 1
-        else
-          echo "❌ git-clang-format-15 failed with exit code $status"
-          echo "Output (if any):"
-          cat "$DIFF_FILE"
-          exit 0
-          # TEMPORARY DISABLE DUE TO BUGS
-          #exit 1
-        fi
+        # Same script the pre-commit hook runs, so local and CI agree.
+        .github/scripts/clang-format-check.sh "$BASE_REF"

README.md

@@ -20,6 +20,13 @@ PKCS11 and AUTOSAR SHE.
 For a technical overview of wolfHSM and instructions on using wolfHSM in your application,
 please refer to the following resources.
 
+## Formatting
+
+Enable the pre-commit clang-format check, once per clone:
+
+    sudo apt-get install -y clang-format-18
+    git config core.hooksPath .githooks
+
 ## Resources
 
 - [wolfHSM Manual](https://www.wolfssl.com/documentation/manuals/wolfhsm/index.html)