name: Tail calling interpreter
on:
  pull_request:
    paths:
      - '.github/workflows/tail-call.yml'
      - 'Python/bytecodes.c'
      - 'Python/ceval.c'
      - 'Python/ceval_macros.h'
      - 'Python/generated_cases.c.h'
  push:
    paths:
      - '.github/workflows/tail-call.yml'
      - 'Python/bytecodes.c'
      - 'Python/ceval.c'
      - 'Python/ceval_macros.h'
      - 'Python/generated_cases.c.h'
  workflow_dispatch:

permissions:
  contents: read

concurrency:
  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
  cancel-in-progress: true

env:
  FORCE_COLOR: 1

jobs:
  tail-call:
    name: ${{ matrix.target }}
    runs-on: ${{ matrix.runner }}
    timeout-minutes: 90
    strategy:
      fail-fast: false
      matrix:
        target:
# Un-comment as we add support for more platforms for tail-calling interpreters.
#          - i686-pc-windows-msvc/msvc
          - x86_64-pc-windows-msvc/msvc
#          - aarch64-pc-windows-msvc/msvc
          - x86_64-apple-darwin/clang
          - aarch64-apple-darwin/clang
          - x86_64-unknown-linux-gnu/gcc
          - aarch64-unknown-linux-gnu/gcc
          - free-threading
        llvm:
          - 20
        include:
#          - target: i686-pc-windows-msvc/msvc
#            architecture: Win32
#            runner: windows-latest
          - target: x86_64-pc-windows-msvc/msvc
            architecture: x64
            runner: windows-latest
#          - target: aarch64-pc-windows-msvc/msvc
#            architecture: ARM64
#            runner: windows-latest
          - target: x86_64-apple-darwin/clang
            architecture: x86_64
            runner: macos-13
          - target: aarch64-apple-darwin/clang
            architecture: aarch64
            runner: macos-14
          - target: x86_64-unknown-linux-gnu/gcc
            architecture: x86_64
            runner: ubuntu-24.04
          - target: aarch64-unknown-linux-gnu/gcc
            architecture: aarch64
            runner: ubuntu-24.04-arm
          - target: free-threading
            architecture: x86_64
            runner: ubuntu-24.04
    steps:
      - uses: actions/checkout@v4
        with:
          persist-credentials: false
      - uses: actions/setup-python@v5
        with:
          python-version: '3.11'

      - name: Native Windows (debug)
        if: runner.os == 'Windows' && matrix.architecture != 'ARM64'
        shell: cmd
        run: |
          choco install llvm --allow-downgrade --no-progress --version ${{ matrix.llvm }}.1.0
          set PlatformToolset=clangcl
          set LLVMToolsVersion=${{ matrix.llvm }}.1.0
          set LLVMInstallDir=C:\Program Files\LLVM
          call ./PCbuild/build.bat --tail-call-interp -d -p ${{ matrix.architecture }}
          call ./PCbuild/rt.bat -d -p ${{ matrix.architecture }} -q --multiprocess 0 --timeout 4500 --verbose2 --verbose3

      # No tests (yet):
      - name: Emulated Windows (release)
        if: runner.os == 'Windows' && matrix.architecture == 'ARM64'
        shell: cmd
        run: |
          choco install llvm --allow-downgrade --no-progress --version ${{ matrix.llvm }}.1.0
          set PlatformToolset=clangcl
          set LLVMToolsVersion=${{ matrix.llvm }}.1.0
          set LLVMInstallDir=C:\Program Files\LLVM
          ./PCbuild/build.bat --tail-call-interp -p ${{ matrix.architecture }}

        # The `find` line is required as a result of https://github.com/actions/runner-images/issues/9966.
        # This is a bug in the macOS runner image where the pre-installed Python is installed in the same
        # directory as the Homebrew Python, which causes the build to fail for macos-13. This line removes
        # the symlink to the pre-installed Python so that the Homebrew Python is used instead.
        # Note: when a new LLVM is released, the homebrew installation directory changes, so the builds will fail.
        # We either need to upgrade LLVM or change the directory being pointed to.
      - name: Native macOS (release)
        if: runner.os == 'macOS'
        run: |
          brew update
          find /usr/local/bin -lname '*/Library/Frameworks/Python.framework/*' -delete
          brew install llvm@${{ matrix.llvm }}
          export SDKROOT="$(xcrun --show-sdk-path)"
          export PATH="/usr/local/opt/llvm/bin:$PATH"
          export PATH="/opt/homebrew/opt/llvm/bin:$PATH"
          CC=clang-20 ./configure --with-tail-call-interp
          make all --jobs 4
          ./python.exe -m test --multiprocess 0 --timeout 4500 --verbose2 --verbose3

      - name: Native Linux (debug)
        if: runner.os == 'Linux' && matrix.target != 'free-threading'
        run: |
          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ matrix.llvm }}
          export PATH="$(llvm-config-${{ matrix.llvm }} --bindir):$PATH"
          CC=clang-20 ./configure --with-tail-call-interp --with-pydebug
          make all --jobs 4
          ./python -m test --multiprocess 0 --timeout 4500 --verbose2 --verbose3

      - name: Native Linux with free-threading (release)
        if: matrix.target == 'free-threading'
        run: |
          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ matrix.llvm }}
          export PATH="$(llvm-config-${{ matrix.llvm }} --bindir):$PATH"
          CC=clang-20 ./configure --with-tail-call-interp --disable-gil
          make all --jobs 4
          ./python -m test --multiprocess 0 --timeout 4500 --verbose2 --verbose3