diff --git a/.github/workflows/build-llvm.yaml b/.github/workflows/build-llvm.yaml
new file mode 100644
index 0000000..c3842b2
--- /dev/null
+++ b/.github/workflows/build-llvm.yaml
@@ -0,0 +1,55 @@
+name: "Build LLVM"
+
+on: [push]
+
+jobs:
+  build_llvm:
+    name: Build LLVM
+    strategy:
+      matrix:
+        # os: [ubuntu-20.04, macos-11, windows-2019]
+        os: [ubuntu-20.04]
+    runs-on: ${{ matrix.os }}
+    permissions:
+      contents: write # for creating releases
+    container:
+      # Intentionally old ubuntu version with old glibc.
+      image: ubuntu:18.04
+    steps:
+      - name: checkout
+        uses: actions/checkout@v3
+      - run: "apt update && apt install -y clang git wget build-essential python3"
+      - run: "wget https://github.com/Kitware/CMake/releases/download/v3.30.0-rc2/cmake-3.30.0-rc2-linux-x86_64.sh"
+      - run: "chmod +x cmake-*.sh"
+      - run: "./cmake-*.sh --skip-license --prefix=/usr"
+      - run: "cmake --version"
+      - run: "python3 --version"
+      - run: "./build-llvm-libs.sh"
+      - uses: actions/upload-artifact@v3
+        with:
+          name: llvm-static-libs
+          path: llvm-static-libs.tar.gz
+      - name: read version
+        id: read-version
+        run: |
+          echo ::set-output name=version::$(cat VERSION)
+        shell: bash
+      - name: create release
+        id: create-release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ steps.read-version.outputs.version }}
+          release_name: ${{ steps.read-version.outputs.version }}
+          draft: false
+          prerelease: true
+      - name: upload linux artifact
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        with:
+          upload_url: ${{ steps.create-release.outputs.upload_url }}
+          asset_path: ./llvm-static-libs.tar.gz
+          asset_name: llvm-static-linux-amd64.tar.gz
+          asset_content_type: application/gzip
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..567609b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+build/
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..0f355a5
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,63 @@
+cmake_minimum_required(VERSION 3.5)
+project(llvm-static)
+
+if(POLICY CMP0114)
+    cmake_policy(SET CMP0114 NEW)
+endif()
+
+# Avoid warning about DOWNLOAD_EXTRACT_TIMESTAMP in CMake 3.24:
+if(CMAKE_VERSION VERSION_GREATER_EQUAL "3.24.0")
+  cmake_policy(SET CMP0135 NEW)
+endif()
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+# set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+set(CMAKE_BUILD_TYPE Release)
+
+set(LLVM_LIBRARIES
+    clangTooling clangFormat clangToolingInclusions clangFrontend clangDriver clangParse clangSerialization clangSema clangAPINotes clangEdit clangAnalysis clangASTMatchers clangAST clangSupport clangToolingCore clangRewrite clangLex clangBasic
+    # Order as reported by llvm-config --libs --link-static
+    LLVMWindowsDriver LLVMOption LLVMFrontendOpenMP LLVMFrontendOffloading LLVMScalarOpts LLVMTransformUtils LLVMAnalysis LLVMProfileData LLVMDebugInfoDWARF LLVMObject LLVMTextAPI LLVMMCParser LLVMIRReader LLVMAsmParser LLVMMC LLVMBitReader LLVMCore LLVMRemarks LLVMBitstreamReader LLVMBinaryFormat LLVMTargetParser LLVMSupport LLVMDemangle)
+
+set(LLVM_PROJECT_TARGET external.llvm-project)
+set(LLVM_PROJECT_INSTALL_DIR ${CMAKE_CURRENT_BINARY_DIR}/${LLVM_PROJECT_TARGET})
+foreach(lib ${LLVM_LIBRARIES})
+    set(LIB_PATH ${LLVM_PROJECT_INSTALL_DIR}/lib/lib${lib})
+    list(APPEND LLVM_PROJECT_BUILD_BYPRODUCTS ${LIB_PATH})
+
+    add_library(${lib} STATIC IMPORTED)
+    set_property(TARGET ${lib} PROPERTY IMPORTED_LOCATION ${LIB_PATH})
+    add_dependencies(${lib} ${LLVM_PROJECT_TARGET})
+endforeach(lib)
+
+include(ExternalProject)
+ExternalProject_Add(${LLVM_PROJECT_TARGET}
+    PREFIX ${LLVM_PROJECT_TARGET}
+    GIT_REPOSITORY https://github.com/llvm/llvm-project.git
+    GIT_TAG llvmorg-18.1.5
+    GIT_SHALLOW ON
+    SOURCE_SUBDIR llvm
+    CMAKE_ARGS
+        -G${CMAKE_GENERATOR}
+        -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
+        -DCMAKE_INSTALL_PREFIX=<INSTALL_DIR>
+        -DCMAKE_C_COMPILER:FILEPATH=${CMAKE_C_COMPILER}
+        -DCMAKE_CXX_COMPILER:FILEPATH=${CMAKE_CXX_COMPILER}
+        -DCMAKE_C_COMPILER_LAUNCHER:FILEPATH=${CMAKE_C_COMPILER_LAUNCHER}
+        -DCMAKE_CXX_COMPILER_LAUNCHER:FILEPATH=${CMAKE_CXX_COMPILER_LAUNCHER}
+        -DCMAKE_CXX_STANDARD=${CMAKE_CXX_STANDARD}
+        -DCMAKE_POSITION_INDEPENDENT_CODE=${CMAKE_POSITION_INDEPENDENT_CODE}
+        -DLLVM_ENABLE_PROJECTS=clang
+        -DLLVM_ENABLE_RTTI=ON
+        -DLLVM_ENABLE_PIC=ON
+        -DLLVM_TARGETS_TO_BUILD=X86
+        -DLLVM_BUILD_TOOLS=OFF
+        -DLLVM_BUILD_TESTS=OFF
+        -DLLVM_ENABLE_TERMINFO=OFF
+        -DLLVM_ENABLE_ZLIB=OFF
+        -DLLVM_ENABLE_ZSTD=OFF
+        -DLLVM_ENABLE_LIBXML2=OFF
+    BUILD_COMMAND ${CMAKE_COMMAND} --build <BINARY_DIR> --target clangTooling -j16
+    BUILD_BYPRODUCTS ${LLVM_PROJECT_BUILD_BYPRODUCTS}
+)
diff --git a/VERSION b/VERSION
new file mode 100644
index 0000000..5f8e72c
--- /dev/null
+++ b/VERSION
@@ -0,0 +1 @@
+18.1.5
diff --git a/build-llvm-libs.sh b/build-llvm-libs.sh
new file mode 100755
index 0000000..dd698c5
--- /dev/null
+++ b/build-llvm-libs.sh
@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+BUILD_DIR="$SCRIPT_DIR/build"
+LLVM_BUILD_DIR="$BUILD_DIR/external.llvm-project"
+
+cd "$SCRIPT_DIR"
+mkdir -p build
+# cmake -B build .
+# cmake --build build
+
+
+echo "Mocked LLVM build"
+mkdir -p build/external.llvm-project/lib
+touch build/external.llvm-project/lib/libclangTooling.a
+mkdir -p build/external.llvm-project/include
+touch build/external.llvm-project/include/clang.h
+
+# Pack everything we need into a tar archive.
+# We only need the header files and all produced static libraries.
+cd $LLVM_BUILD_DIR
+tar -czvf "$SCRIPT_DIR/llvm-static-libs.tar.gz" include/ lib/*.a