build: add script to install clang

.github/workflows/CI.yml

@@ -156,6 +156,7 @@ jobs:
           path: artifacts
       - name: Install dependencies
         run: |
+          ./install-clang.sh 17
           .github/scripts/setup-self-hosted.sh
 
           sudo apt-get update

install-clang.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+set -e
+
+function install-clang-for-debian() {
+  local -r codename="$1"
+  local -r clang_version="$2"
+
+  if ! which sudo >/dev/null; then
+    apt-get update
+    apt-get install -y sudo
+  fi
+
+  sudo apt-get update
+  sudo apt-get install -y \
+    ca-certificates \
+    gnupg \
+    wget
+  wget -O- https://apt.llvm.org/llvm-snapshot.gpg.key | gpg --dearmor |
+    sudo tee /usr/share/keyrings/.llvm.gpg.tmp >/dev/null
+  sudo mv /usr/share/keyrings/.llvm.gpg.tmp /usr/share/keyrings/llvm.gpg
+  sudo tee /etc/apt/sources.list.d/llvm.list <<EOF
+deb [signed-by=/usr/share/keyrings/llvm.gpg] http://apt.llvm.org/${codename}/ llvm-toolchain-${codename}-${clang_version} main
+EOF
+
+  sudo apt-get update
+  sudo apt-get install -y "clang-${clang_version}" "libc++-${clang_version}-dev"
+}
+
+function main() {
+  local -r clang_version="$1"
+  source /etc/os-release
+  case "${ID}" in
+  debian | ubuntu)
+    install-clang-for-debian "${VERSION_CODENAME}" "${clang_version}"
+    ;;
+  *)
+    echo "unsupported os" >&2
+    exit 1
+    ;;
+  esac
+}
+
+main "$@"