chore(format): use clang-format 20

.github/workflows/clang-format.yml

@@ -8,15 +8,21 @@ on:
 jobs:
   format-check:
     runs-on: ubuntu-latest
+    env:
+      CLANG_FORMAT_VERSION: "20"
+      CLANG_FORMAT_PYPI_VERSION: "20.1.8"
+      CLANG_FORMAT_INSTALL_DIR: "clang-format-venv"
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Install clang-format 17
+      - name: Install clang-format 20
         run: |
-          sudo apt-get update
-          sudo apt-get install -y clang-format-17
-          sudo update-alternatives --install /usr/bin/clang-format clang-format /usr/bin/clang-format-17 100
+          python3 -m venv "${RUNNER_TEMP}/${CLANG_FORMAT_INSTALL_DIR}"
+          "${RUNNER_TEMP}/${CLANG_FORMAT_INSTALL_DIR}/bin/python" -m pip install --upgrade pip
+          "${RUNNER_TEMP}/${CLANG_FORMAT_INSTALL_DIR}/bin/python" -m pip install "clang-format==${CLANG_FORMAT_PYPI_VERSION}"
+          echo "CLANG_FORMAT=${RUNNER_TEMP}/${CLANG_FORMAT_INSTALL_DIR}/bin/clang-format" >> "${GITHUB_ENV}"
+          "${RUNNER_TEMP}/${CLANG_FORMAT_INSTALL_DIR}/bin/clang-format" --version
 
       - name: Run format-check
         run: ./scripts/format-check.sh

scripts/clang-format-common.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+
+CLANG_FORMAT_VERSION="${CLANG_FORMAT_VERSION:-20}"
+CLANG_FORMAT="${CLANG_FORMAT:-clang-format-${CLANG_FORMAT_VERSION}}"
+
+resolve_clang_format() {
+    if [[ ! "${CLANG_FORMAT_VERSION}" =~ ^[0-9]+$ ]]; then
+        echo "error: CLANG_FORMAT_VERSION must be a numeric major version." >&2
+        return 1
+    fi
+
+    local candidate=""
+    if command -v "${CLANG_FORMAT}" >/dev/null 2>&1; then
+        candidate="${CLANG_FORMAT}"
+    elif [ "${CLANG_FORMAT}" = "clang-format-${CLANG_FORMAT_VERSION}" ] && command -v clang-format >/dev/null 2>&1; then
+        candidate="clang-format"
+    else
+        echo "error: clang-format ${CLANG_FORMAT_VERSION}.x was not found." >&2
+        echo "Set CLANG_FORMAT to the clang-format binary to use." >&2
+        return 1
+    fi
+
+    local version_output
+    version_output="$("${candidate}" --version)"
+    if [[ ! "${version_output}" =~ (^|[[:space:]])version[[:space:]]+${CLANG_FORMAT_VERSION}\. ]]; then
+        echo "error: expected clang-format ${CLANG_FORMAT_VERSION}.x, got: ${version_output}" >&2
+        echo "Set CLANG_FORMAT_VERSION to override the required major version." >&2
+        return 1
+    fi
+
+    printf '%s\n' "${candidate}"
+}

scripts/format-check.sh

@@ -3,6 +3,9 @@ set -euo pipefail
 
 SCRIPT_DIR="$(cd -- "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 REPO_ROOT="$(cd -- "${SCRIPT_DIR}/.." && pwd)"
+source "${SCRIPT_DIR}/clang-format-common.sh"
+
+CLANG_FORMAT_BIN="$(resolve_clang_format)"
 
 files=()
 while IFS= read -r -d '' file; do
@@ -19,7 +22,7 @@ fi
 echo "Checking formatting on ${#files[@]} files..."
 failed=0
 for file in "${files[@]}"; do
-    if ! clang-format --dry-run --Werror "${file}"; then
+    if ! "${CLANG_FORMAT_BIN}" --dry-run --Werror "${file}"; then
         failed=1
     fi
 done

scripts/format.sh

@@ -3,6 +3,9 @@ set -euo pipefail
 
 SCRIPT_DIR="$(cd -- "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 REPO_ROOT="$(cd -- "${SCRIPT_DIR}/.." && pwd)"
+source "${SCRIPT_DIR}/clang-format-common.sh"
+
+CLANG_FORMAT_BIN="$(resolve_clang_format)"
 
 files=()
 while IFS= read -r -d '' file; do
@@ -16,5 +19,5 @@ if [ "${#files[@]}" -eq 0 ]; then
     exit 0
 fi
 
-echo "Formatting ${#files[@]} files with clang-format (style from ${REPO_ROOT}/.clang-format)..."
-clang-format -i "${files[@]}"
+echo "Formatting ${#files[@]} files with ${CLANG_FORMAT_BIN} (style from ${REPO_ROOT}/.clang-format)..."
+"${CLANG_FORMAT_BIN}" -i "${files[@]}"