action.yml

name: 'Builds LLVM for WebAssembly'
description: 'This action builds LLVM for WebAssembly targets via emscripten'
inputs:
  cache-hit:
    required: true

runs:
  using: composite
  steps:
    - name: Build LLVM/Cling on Unix systems if the cache is invalid (emscripten)
      if: ${{ inputs.cache-hit != 'true' && runner.os != 'Windows' }}
      shell: bash
      run: |
        ./emsdk/emsdk activate ${{ env.EMSDK_VER }}
        source ./emsdk/emsdk_env.sh

        cling_on=$(echo "${{ matrix.cling }}" | tr '[:lower:]' '[:upper:]')
        if [[ "${cling_on}" == "ON" ]]; then
          git clone https://github.com/root-project/cling.git
          (cd cling && git checkout tags/v${{ matrix.cling-version }} \
                    && git apply -v ../patches/llvm/cling1.2-LookupHelper.patch)
          git clone --depth=1 -b cling-llvm${{ matrix.clang-runtime }} https://github.com/root-project/llvm-project.git
        else
          git clone --depth=1 -b release/${{ matrix.clang-runtime }}.x https://github.com/llvm/llvm-project.git
        fi
        cd llvm-project

        # Native tblgen bootstrap (host-side llvm-tblgen + clang-tblgen).
        mkdir native_build
        (cd native_build && \
            cmake -DLLVM_ENABLE_PROJECTS=clang -DLLVM_TARGETS_TO_BUILD=host -DCMAKE_BUILD_TYPE=Release ../llvm/ && \
            cmake --build . --target llvm-tblgen clang-tblgen --parallel $(nproc --all))
        export NATIVE_DIR=$PWD/native_build/bin/

        # Apply repl-only emscripten patches; cling has its own patch flow above.
        if [[ "${cling_on}" != "ON" ]]; then
          rt='${{ matrix.clang-runtime }}'
          if [[ "$rt" =~ ^(19|20|21|22)$ ]]; then
            git apply -v ../patches/llvm/emscripten-clang${rt}-*.patch
            echo "Applied emscripten-clang${rt}-*.patch"
          fi
        fi

        common_flags=(
          -G Ninja
          -DCMAKE_BUILD_TYPE=Release
          -DLLVM_HOST_TRIPLE=wasm32-unknown-emscripten
          -DLLVM_TARGETS_TO_BUILD="${{ env.LLVM_TARGETS_TO_BUILD }}"
          -DLLVM_ENABLE_PROJECTS="${{ env.LLVM_ENABLE_PROJECTS }}"
          -DLLVM_NATIVE_TOOL_DIR="$NATIVE_DIR"
          -DLLVM_ENABLE_LIBEDIT=OFF
          -DLLVM_ENABLE_ZSTD=OFF
          -DLLVM_ENABLE_LIBXML2=OFF
          -DLLVM_ENABLE_LIBPFM=OFF
          -DLLVM_ENABLE_THREADS=OFF
          -DLLVM_INCLUDE_BENCHMARKS=OFF
          -DLLVM_INCLUDE_EXAMPLES=OFF
          -DLLVM_INCLUDE_TESTS=OFF
          -DLLVM_BUILD_TOOLS=OFF
          -DCLANG_BUILD_TOOLS=OFF
          -DCLANG_ENABLE_STATIC_ANALYZER=OFF
          -DCLANG_ENABLE_ARCMT=OFF
          -DCLANG_ENABLE_BOOTSTRAP=OFF
          -DCMAKE_CXX_FLAGS=-Dwait4=__syscall_wait4
          "-DCMAKE_C_FLAGS_RELEASE=-Oz -g0 -DNDEBUG"
          "-DCMAKE_CXX_FLAGS_RELEASE=-Oz -g0 -DNDEBUG"
          -DLLVM_ENABLE_LTO=Full
        )
        if [[ "${cling_on}" == "ON" ]]; then
          extra_flags=(-DLLVM_EXTERNAL_PROJECTS=cling -DLLVM_EXTERNAL_CLING_SOURCE_DIR=../../cling)
          targets=(clang cling lld gtest_main)
        else
          extra_flags=()
          targets=(libclang clangInterpreter clangStaticAnalyzerCore)
        fi

        mkdir build && cd build
        emcmake cmake "${common_flags[@]}" "${extra_flags[@]}" ../llvm
        EMCC_CFLAGS="-fwasm-exceptions" emmake ninja "${targets[@]}"
        cd ..

        # Trim source trees so the cache stays small. Cling rows additionally
        # need llvm/{utils} for runtime tablegen lookups.
        rm -rf $(find . -maxdepth 1 ! -name "build" ! -name "llvm" ! -name "clang" ! -name "." ! -name "native_build")
        keep=('!' -name include '!' -name lib '!' -name cmake '!' -name .)
        if [[ "${cling_on}" == "ON" ]]; then
          keep=('!' -name include '!' -name lib '!' -name cmake '!' -name utils '!' -name .)
        fi
        for d in llvm clang; do
          (cd "$d" && rm -rf $(find . -maxdepth 1 "${keep[@]}"))
        done


    - name: Build LLVM/Cling on Windows systems if the cache is invalid (emscripten)
      if: ${{ inputs.cache-hit != 'true' && runner.os == 'Windows' }}
      shell: powershell
      run: |
        .\emsdk\emsdk activate ${{ env.EMSDK_VER }}
        .\emsdk\emsdk_env.ps1
        $cling_on = "${{ matrix.cling }}" -imatch "On"
        if ( $cling_on ) {
          git clone https://github.com/root-project/cling.git
          Push-Location ./cling
          git checkout tags/v${{ matrix.cling-version }}
          git apply -v ../patches/llvm/cling1.2-LookupHelper.patch
          Pop-Location
          git clone --depth=1 -b cling-llvm${{ matrix.clang-runtime }} https://github.com/root-project/llvm-project.git
          $env:CLING_DIR = Join-Path $PWD.Path "cling"
          echo "CLING_DIR=$env:CLING_DIR"
        } else {
          git clone --depth=1 -b release/${{ matrix.clang-runtime }}.x https://github.com/llvm/llvm-project.git
        }

        cd llvm-project

        # Native tblgen bootstrap (host-side llvm-tblgen + clang-tblgen).
        mkdir native_build | Out-Null
        Push-Location native_build
        cmake -DLLVM_ENABLE_PROJECTS=clang -DLLVM_TARGETS_TO_BUILD=host -DCMAKE_BUILD_TYPE=Release -G Ninja ../llvm/
        cmake --build . --target llvm-tblgen clang-tblgen --parallel $(nproc --all)
        $env:NATIVE_DIR = Join-Path $PWD.Path "bin"
        Pop-Location

        # Apply repl-only emscripten patches; cling has its own patch flow above.
        if ( -not $cling_on ) {
          $rt = "${{ matrix.clang-runtime }}"
          if ( $rt -match "^(19|20|21|22)$" ) {
            Get-ChildItem -Path "..\patches\llvm" -Filter "emscripten-clang${rt}-*.patch" | ForEach-Object {
              git apply -v $_.FullName
            }
            echo "Applied emscripten-clang${rt}-*.patch"
          }
        }

        $common_flags = @(
          "-G", "Ninja"
          "-DCMAKE_BUILD_TYPE=Release"
          "-DLLVM_HOST_TRIPLE=wasm32-unknown-emscripten"
          "-DLLVM_TARGETS_TO_BUILD=${{ env.LLVM_TARGETS_TO_BUILD }}"
          "-DLLVM_ENABLE_PROJECTS=${{ env.LLVM_ENABLE_PROJECTS }}"
          "-DLLVM_NATIVE_TOOL_DIR=$env:NATIVE_DIR"
          "-DLLVM_ENABLE_LIBEDIT=OFF"
          "-DLLVM_ENABLE_ZSTD=OFF"
          "-DLLVM_ENABLE_LIBXML2=OFF"
          "-DLLVM_ENABLE_LIBPFM=OFF"
          "-DLLVM_ENABLE_THREADS=OFF"
          "-DLLVM_INCLUDE_BENCHMARKS=OFF"
          "-DLLVM_INCLUDE_EXAMPLES=OFF"
          "-DLLVM_INCLUDE_TESTS=OFF"
          "-DLLVM_BUILD_TOOLS=OFF"
          "-DCLANG_BUILD_TOOLS=OFF"
          "-DCLANG_ENABLE_STATIC_ANALYZER=OFF"
          "-DCLANG_ENABLE_ARCMT=OFF"
          "-DCLANG_ENABLE_BOOTSTRAP=OFF"
          "-DCMAKE_CXX_FLAGS=-Dwait4=__syscall_wait4"
          "-DCMAKE_C_FLAGS_RELEASE=-Oz -g0 -DNDEBUG"
          "-DCMAKE_CXX_FLAGS_RELEASE=-Oz -g0 -DNDEBUG"
          "-DLLVM_ENABLE_LTO=Full"
        )
        if ( $cling_on ) {
          $extra_flags = @("-DLLVM_EXTERNAL_PROJECTS=cling", "-DLLVM_EXTERNAL_CLING_SOURCE_DIR=../../cling")
          $targets = @("clang", "cling", "lld", "gtest_main")
        } else {
          $extra_flags = @()
          $targets = @("libclang", "clangInterpreter", "clangStaticAnalyzerCore")
        }

        mkdir build | Out-Null
        cd build
        emcmake cmake @common_flags @extra_flags ..\llvm
        $env:EMCC_CFLAGS = "-fwasm-exceptions"
        emmake ninja @targets
        $env:EMCC_CFLAGS = ""
        cd ..

        # Trim source trees so the cache stays small. Cling rows additionally
        # need llvm/{utils} for runtime tablegen lookups.
        rm -r -force $(find.exe . -maxdepth 1 ! -name "build" ! -name "llvm" ! -name "clang" ! -name "." ! -name "native_build")
        $keep = @("!", "-name", "include", "!", "-name", "lib", "!", "-name", "cmake", "!", "-name", ".")
        if ( $cling_on ) {
          $keep = @("!", "-name", "include", "!", "-name", "lib", "!", "-name", "cmake", "!", "-name", "utils", "!", "-name", ".")
        }
        foreach ($d in @("llvm", "clang")) {
          Push-Location $d
          rm -r -force $(find.exe . -maxdepth 1 @keep)
          Pop-Location
        }