name: CI
on:
  push: { branches: [main] }
  pull_request:

concurrency:
  # Make sure that new pushes cancel running jobs
  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
  cancel-in-progress: true

env:
  CARGO_TERM_COLOR: always
  RUSTDOCFLAGS: -Dwarnings
  RUSTFLAGS: -Dwarnings
  RUST_BACKTRACE: full
  BENCHMARK_RUSTC: nightly-2025-12-01 # Pin the toolchain for reproducable results

jobs:
  # Determine which tests should be run based on changed files.
  calculate_vars:
    name: Calculate workflow variables
    runs-on: ubuntu-24.04
    timeout-minutes: 10
    env:
      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      PR_NUMBER: ${{ github.event.pull_request.number }}
    outputs:
      extensive_matrix: ${{ steps.script.outputs.extensive_matrix }}
      may_skip_libm_ci: ${{ steps.script.outputs.may_skip_libm_ci }}
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 500
      - name: Fetch pull request ref
        run: git fetch origin "$GITHUB_REF:$GITHUB_REF"
        if: github.event_name == 'pull_request'
      - run: |
          set -eo pipefail # Needed to actually fail the job if ci-util fails
          python3 ci/ci-util.py generate-matrix | tee "$GITHUB_OUTPUT"
        id: script

  test:
    name: Build and test
    timeout-minutes: 60
    strategy:
      fail-fast: false
      matrix:
        include:
        - target: aarch64-apple-darwin
          os: macos-15
        - target: aarch64-unknown-linux-gnu
          os: ubuntu-24.04-arm
        - target: aarch64-pc-windows-msvc
          os: windows-11-arm
        - target: arm-unknown-linux-gnueabi
          os: ubuntu-24.04
        - target: arm-unknown-linux-gnueabihf
          os: ubuntu-24.04
        - target: armv7-unknown-linux-gnueabihf
          os: ubuntu-24.04
        - target: i586-unknown-linux-gnu
          os: ubuntu-24.04
        - target: i686-unknown-linux-gnu
          os: ubuntu-24.04
        - target: loongarch64-unknown-linux-gnu
          os: ubuntu-24.04
        - target: powerpc-unknown-linux-gnu
          os: ubuntu-24.04
        - target: powerpc64-unknown-linux-gnu
          os: ubuntu-24.04
        - target: powerpc64le-unknown-linux-gnu
          os: ubuntu-24.04
        # - target: powerpc64le-unknown-linux-gnu
        #   os: ubuntu-24.04-ppc64le
        #   # FIXME(rust#151807): remove once PPC builds work again.
        #   channel: nightly-2026-01-23
        - target: riscv64gc-unknown-linux-gnu
          os: ubuntu-24.04
        # - target: s390x-unknown-linux-gnu
        #   os: ubuntu-24.04-s390x
        - target: thumbv6m-none-eabi
          os: ubuntu-24.04
        - target: thumbv7em-none-eabi
          os: ubuntu-24.04
        - target: thumbv7em-none-eabihf
          os: ubuntu-24.04
        - target: thumbv7m-none-eabi
          os: ubuntu-24.04
        - target: wasm32-unknown-unknown
          os: ubuntu-24.04
        - target: x86_64-unknown-linux-gnu
          os: ubuntu-24.04
        - target: x86_64-apple-darwin
          os: macos-15-intel
        - target: i686-pc-windows-msvc
          os: windows-2025
        - target: x86_64-pc-windows-msvc
          os: windows-2025
        - target: i686-pc-windows-gnu
          os: windows-2025
          channel: nightly-i686-gnu
        - target: x86_64-pc-windows-gnu
          os: windows-2025
          channel: nightly-x86_64-gnu
    runs-on: ${{ matrix.os }}
    needs: [calculate_vars]
    env:
      BUILD_ONLY: ${{ matrix.build_only }}
      MAY_SKIP_LIBM_CI: ${{ needs.calculate_vars.outputs.may_skip_libm_ci }}
    steps:
    - name: Print $HOME
      shell: bash
      run: |
        set -x
        echo "${HOME:-not found}"
        pwd
        printenv
    - name: Print runner information
      run: uname -a

    # Native ppc and s390x runners don't have rustup by default
    - name: Install rustup
      if: matrix.os == 'ubuntu-24.04-ppc64le' || matrix.os == 'ubuntu-24.04-s390x'
      run: sudo apt-get update && sudo apt-get install -y rustup

    - uses: actions/checkout@v4
    - name: Install Rust (rustup)
      shell: bash
      run: |
        channel="nightly"
        # Account for channels that have required components (MinGW)
        [ -n "${{ matrix.channel }}" ] && channel="${{ matrix.channel }}"
        rustup update "$channel" --no-self-update
        rustup default "$channel"
        rustup target add "${{ matrix.target }}"

    - uses: taiki-e/install-action@nextest

    - uses: Swatinem/rust-cache@v2
      with:
        key: ${{ matrix.target }}
    - name: Cache Docker layers
      uses: actions/cache@v4
      if: matrix.os == 'ubuntu-24.04'
      with:
        path: /tmp/.buildx-cache
        key: ${{ matrix.target }}-buildx-${{ github.sha }}
        restore-keys: ${{ matrix.target }}-buildx-
    # Configure buildx to use Docker layer caching
    - uses: docker/setup-buildx-action@v3
      if: matrix.os == 'ubuntu-24.04'

    - name: Cache compiler-rt
      id: cache-compiler-rt
      uses: actions/cache@v4
      with:
        path: compiler-rt
        key: ${{ runner.os }}-compiler-rt-${{ hashFiles('ci/download-compiler-rt.sh') }}
    - name: Download compiler-rt reference sources
      if: steps.cache-compiler-rt.outputs.cache-hit != 'true'
      run: ./ci/download-compiler-rt.sh
      shell: bash
    - run: echo "RUST_COMPILER_RT_ROOT=$(realpath ./compiler-rt)" >> "$GITHUB_ENV"
      shell: bash

    - name: Download musl source
      run: ./ci/update-musl.sh
      shell: bash

    - name: Verify API list
      if: matrix.os == 'ubuntu-24.04'
      run: python3 etc/update-api-list.py --check

    # Non-linux tests just use our raw script
    - name: Run locally
      if: matrix.os != 'ubuntu-24.04'
      shell: bash
      run: ./ci/run.sh ${{ matrix.target }}

    # Otherwise we use our docker containers to run builds
    - name: Run in Docker
      if: matrix.os == 'ubuntu-24.04'
      run: ./ci/run-docker.sh ${{ matrix.target }}

    - name: Print test logs if available
      if: always()
      run: if [ -f "target/test-log.txt" ]; then cat target/test-log.txt; fi
      shell: bash

    # Workaround to keep Docker cache smaller
    # https://github.com/docker/build-push-action/issues/252
    # https://github.com/moby/buildkit/issues/1896
    - name: Move Docker cache
      if: matrix.os == 'ubuntu-24.04'
      run: |
        rm -rf /tmp/.buildx-cache
        mv /tmp/.buildx-cache-new /tmp/.buildx-cache

  clippy:
    name: Clippy
    runs-on: ubuntu-24.04
    timeout-minutes: 10
    steps:
    - uses: actions/checkout@v4
    # Unlike rustfmt, stable clippy does not work on code with nightly features.
    - name: Install nightly `clippy`
      run: |
        rustup update nightly --no-self-update
        rustup default nightly
        rustup component add clippy
    - uses: Swatinem/rust-cache@v2
    - name: Download musl source
      run: ./ci/update-musl.sh
    - run: cargo clippy --workspace --all-targets

  build-custom:
    name: Build custom target
    runs-on: ubuntu-24.04
    timeout-minutes: 10
    steps:
    - uses: actions/checkout@v4
    - name: Install Rust
      run: |
        rustup update nightly --no-self-update
        rustup default nightly
        rustup component add rust-src
    - uses: Swatinem/rust-cache@v2
    - run: |
        # Ensure we can build with custom target.json files (these can interact
        # poorly with build scripts)
        cargo build -p compiler_builtins -p libm \
          --target etc/thumbv7em-none-eabi-renamed.json \
          -Zbuild-std=core \
          -Zjson-target-spec

  # FIXME: move this target to test job once https://github.com/rust-lang/rust/pull/150138 merged.
  build-thumbv6k:
    name: Build thumbv6k
    runs-on: ubuntu-24.04
    timeout-minutes: 10
    steps:
    - uses: actions/checkout@v4
    - name: Install Rust
      run: |
        rustup update nightly --no-self-update
        rustup default nightly
        rustup component add rust-src
    - uses: Swatinem/rust-cache@v2
    - run: |
        cargo build -p compiler_builtins -p libm \
          --target etc/thumbv6-none-eabi.json \
          -Zbuild-std=core \
          -Zjson-target-spec

  benchmarks:
    name: Benchmarks
    timeout-minutes: 20
    strategy:
      fail-fast: false
      matrix:
        include:
        - target: x86_64-unknown-linux-gnu
          os: ubuntu-24.04
        - target: aarch64-unknown-linux-gnu
          os: ubuntu-24.04-arm
    runs-on: ${{ matrix.os }}
    steps:
    - uses: actions/checkout@master
    - uses: taiki-e/install-action@cargo-binstall

    - name: Set up dependencies
      run: ./ci/install-bench-deps.sh
    - uses: Swatinem/rust-cache@v2
      with:
        key: ${{ matrix.target }}
    - name: Download musl source
      run: ./ci/update-musl.sh

    - name: Run icount benchmarks
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        PR_NUMBER: ${{ github.event.pull_request.number }}
      run: ./ci/bench-icount.sh ${{ matrix.target }}

    - name: Upload the benchmark baseline
      uses: actions/upload-artifact@v4
      with:
        name: ${{ env.BASELINE_NAME }}
        path: ${{ env.BASELINE_NAME }}.tar.xz

    - name: Run wall time benchmarks
      run: ./ci/bench-runtime.sh

    - name: Print test logs if available
      if: always()
      run: if [ -f "target/test-log.txt" ]; then cat target/test-log.txt; fi
      shell: bash

  miri:
    name: Miri
    runs-on: ubuntu-24.04
    timeout-minutes: 10
    steps:
    - uses: actions/checkout@v4
    - name: Install Rust (rustup)
      run: rustup update nightly --no-self-update && rustup default nightly
      shell: bash
    - run: rustup component add miri
    - run: cargo miri setup
    - uses: Swatinem/rust-cache@v2
    - run: ./ci/miri.sh

  msrv:
    name: Check libm MSRV
    runs-on: ubuntu-24.04
    timeout-minutes: 10
    env:
      RUSTFLAGS: # No need to check warnings on old MSRV, unset `-Dwarnings`
    steps:
    - uses: actions/checkout@master
    - name: Install Rust
      run: |
        msrv="$(perl -ne 'print if s/rust-version\s*=\s*"(.*)"/\1/g' libm/Cargo.toml)"
        echo "MSRV: $msrv"
        rustup update "$msrv" --no-self-update && rustup default "$msrv"
    - uses: Swatinem/rust-cache@v2
    - run: |
        # FIXME(msrv): Remove the workspace Cargo.toml so 1.63 cargo doesn't see
        # `edition = "2024"` and get spooked.
        rm Cargo.toml
        cargo build --manifest-path libm/Cargo.toml

  rustfmt:
    name: Rustfmt
    runs-on: ubuntu-24.04
    timeout-minutes: 10
    steps:
    - uses: actions/checkout@v4
    - name: Install nightly `rustfmt`
      run: rustup set profile minimal && rustup default nightly && rustup component add rustfmt
    - run: cargo fmt -- --check

  extensive:
    name: Extensive tests for ${{ matrix.ty }}
    needs:
      # Wait on `clippy` so we have some confidence that the crate will build
      - clippy
      - calculate_vars
    runs-on: ubuntu-24.04
    timeout-minutes: 240 # 4 hours
    strategy:
      matrix:
        # Use the output from `calculate_vars` to create the matrix
        # FIXME: it would be better to run all jobs (i.e. all types) but mark those that
        # didn't change as skipped, rather than completely excluding the job. However,
        # this is not currently possible https://github.com/actions/runner/issues/1985.
        include: ${{ fromJSON(needs.calculate_vars.outputs.extensive_matrix).extensive_matrix }}
    env:
      TO_TEST: ${{ matrix.to_test }}
    steps:
      - uses: actions/checkout@v4
      - name: Install Rust
        run: |
          rustup update nightly --no-self-update
          rustup default nightly
      - uses: Swatinem/rust-cache@v2
      - name: download musl source
        run: ./ci/update-musl.sh
      - name: Run extensive tests
        run: ./ci/run-extensive.sh
      - name: Print test logs if available
        run: if [ -f "target/test-log.txt" ]; then cat target/test-log.txt; fi
        shell: bash

  success:
    needs:
      - benchmarks
      - build-custom
      - build-thumbv6k
      - clippy
      - extensive
      - miri
      - msrv
      - rustfmt
      - test
    runs-on: ubuntu-24.04
    timeout-minutes: 10
    # GitHub branch protection is exceedingly silly and treats "jobs skipped because a dependency
    # failed" as success. So we have to do some contortions to ensure the job fails if any of its
    # dependencies fails.
    if: always() # make sure this is never "skipped"
    steps:
      # Manually check the status of all dependencies. `if: failure()` does not work.
      - name: check if any dependency failed
        run: jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'
