ci-linux-e2e.yml

name: ci-linux-e2e

# The e2e suite (tests/e2e/run_all.sh, ~18 min) split out of ci-linux.yml so it
# runs in PARALLEL with the build/unit/toolchain-matrix job instead of tacked on
# after it. Both workflows share the same cache lineage (mcpp sandbox + xlings +
# target/), so this job restores a warm build and the only added wall-clock vs.
# the inline version is one extra warm `mcpp build`. Net per-PR critical path
# drops from "build + … + e2e" to max(build+matrix, build+e2e).
#
# Paired workflows: ci-linux.yml (build + unit + toolchain matrix + integration),
# ci-macos.yml, ci-windows.yml.

on:
  push:
    branches: [ main ]
  pull_request:
    branches: [ main ]
  workflow_dispatch:

concurrency:
  group: ci-${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:
  e2e:
    name: e2e suite (linux x86_64, self-host)
    runs-on: ubuntu-24.04
    timeout-minutes: 45
    env:
      MCPP_HOME: /home/runner/.mcpp
      # NOTE: do NOT force MCPP_VERBOSE here. The e2e suite includes tests that
      # assert mcpp's DEFAULT (quiet) output — e.g. 48_build_error_output and
      # 53_namespaced_cache_label — which forced verbose would break. Verbose is
      # set only in the fresh-install workflows (cold bootstrap, no such asserts).
      # A specific test that needs verbose passes `--verbose` itself.
    steps:
      - uses: actions/checkout@v4

      # Same cache lineage as ci-linux.yml so this job lands on a warm
      # toolchain/sandbox instead of re-installing it. Both workflows read
      # (and may save) the same keys; actions/cache tolerates concurrent
      # "already exists" saves.
      - name: Cache mcpp sandbox
        uses: actions/cache@v4
        with:
          path: ~/.mcpp
          key: mcpp-sandbox-${{ runner.os }}-ci-${{ hashFiles('mcpp.toml', '.xlings.json') }}
          restore-keys: |
            mcpp-sandbox-${{ runner.os }}-ci-

      - name: Cache xlings
        uses: actions/cache@v4
        with:
          path: ~/.xlings
          key: xlings-${{ runner.os }}-v2-${{ hashFiles('.xlings.json') }}
          restore-keys: |
            xlings-${{ runner.os }}-v2-

      - name: Bootstrap mcpp via xlings
        env:
          XLINGS_NON_INTERACTIVE: '1'
          XLINGS_VERSION: '0.4.30'
        run: |
          tarball="xlings-${XLINGS_VERSION}-linux-x86_64.tar.gz"
          curl -fsSL -o "/tmp/${tarball}" \
            "https://github.com/d2learn/xlings/releases/download/v${XLINGS_VERSION}/${tarball}"
          tar -xzf "/tmp/${tarball}" -C /tmp
          "/tmp/xlings-${XLINGS_VERSION}-linux-x86_64/subos/default/bin/xlings" self install
          export PATH="$HOME/.xlings/subos/default/bin:$PATH"
          xlings --version
          xlings install mcpp -y
          MCPP="$HOME/.xlings/subos/default/bin/mcpp"
          test -x "$MCPP"
          "$MCPP" --version
          echo "MCPP=$MCPP" >> "$GITHUB_ENV"
          echo "XLINGS_BIN=$HOME/.xlings/subos/default/bin/xlings" >> "$GITHUB_ENV"

      - name: Cache target/ (build artifacts + BMIs)
        uses: actions/cache@v4
        with:
          path: target
          key: mcpp-target-${{ runner.os }}-${{ hashFiles('src/**', 'tests/**', 'mcpp.toml', 'mcpp.lock') }}
          restore-keys: |
            mcpp-target-${{ runner.os }}-

      - name: Configure mirror + Build mcpp from source (self-host)
        run: |
          export MCPP_VENDORED_XLINGS="$XLINGS_BIN"
          "$XLINGS_BIN" config --mirror GLOBAL 2>/dev/null || true
          "$MCPP" self config --mirror GLOBAL 2>/dev/null || true
          "$MCPP" build

      - name: E2E suite
        # Per-test 600s timeout lives in tests/e2e/run_all.sh and identifies
        # WHICH test hung; this caps the whole suite so a hang fails fast.
        timeout-minutes: 25
        run: |
          # Point the e2e runner at the freshly-built binary, not the
          # bootstrap one. Tests cd into mktemp -d, so $MCPP must be
          # absolute or the relative path breaks under the temp cwd.
          MCPP=$(realpath "$(find target -type f -name mcpp -printf '%T@ %p\n' | sort -rn | head -1 | cut -d' ' -f2)")
          test -x "$MCPP"
          export MCPP
          # Tests that set MCPP_HOME to a fresh tmpdir need an xlings to
          # bootstrap from; surface the xlings binary installed above.
          export MCPP_VENDORED_XLINGS="$XLINGS_BIN"
          test -x "$MCPP_VENDORED_XLINGS"
          # GitHub-hosted runners are outside CN; keep CI toolchain downloads on
          # the global mirror while mcpp's default remains CN for fresh local
          # sandboxes. E2E tests with their own MCPP_HOME read this variable.
          export MCPP_E2E_TOOLCHAIN_MIRROR=GLOBAL
          "$MCPP" self config --mirror "$MCPP_E2E_TOOLCHAIN_MIRROR"
          "$MCPP" self config
          # Pin the global default so test 28 (default-toolchain path) gets a
          # deterministic GNU answer instead of an auto-install pick.
          "$MCPP" toolchain default gcc@16.1.0
          # Warm musl once so fresh-home e2e tests inherit the payload.
          "$MCPP" toolchain install gcc 15.1.0-musl
          bash tests/e2e/run_all.sh

  # ──────────────────────────────────────────────────────────────────
  # Hermetic (no host toolchain): the ONLY environment class that
  # faithfully reproduces issue #195. Standard runners ship gcc +
  # libc6-dev, so a sandbox toolchain that leaks to the host's CRT
  # still links "green" there; this container has no compiler and no
  # host Scrt1.o, so any leak fails loudly. Builds PR code with the
  # bootstrap mcpp, then runs the llvm flow end-to-end.
  # ──────────────────────────────────────────────────────────────────
  hermetic:
    name: hermetic e2e (no host toolchain, container)
    runs-on: ubuntu-24.04
    container: debian:stable-slim
    timeout-minutes: 60
    env:
      XLINGS_NON_INTERACTIVE: '1'
    steps:
      - name: Install base utilities (NO compiler)
        run: |
          apt-get update -qq
          apt-get install -y -qq curl ca-certificates git xz-utils unzip
          # The whole point of this job: no host toolchain, no host CRT.
          ! command -v gcc
          ! command -v cc
          test ! -e /usr/lib/x86_64-linux-gnu/Scrt1.o
          test ! -e /usr/lib/gcc

      - uses: actions/checkout@v4

      # Payload cache (downloads only — the container still has no host
      # toolchain, which is the property under test).
      - name: Cache mcpp sandbox payloads
        uses: actions/cache@v4
        with:
          path: ~/.mcpp
          key: mcpp-hermetic-${{ hashFiles('mcpp.toml') }}
          restore-keys: |
            mcpp-hermetic-

      - name: Bootstrap xlings + released mcpp
        run: |
          curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh | bash -s v0.4.62
          export PATH="$HOME/.xlings/subos/current/bin:$PATH"
          xlings update
          xlings install mcpp -y -g
          MCPP_BOOT="$HOME/.xlings/subos/current/bin/mcpp"
          "$MCPP_BOOT" --version
          "$MCPP_BOOT" self config --mirror GLOBAL
          echo "MCPP_BOOT=$MCPP_BOOT" >> "$GITHUB_ENV"

      - name: Build PR mcpp from source (sandbox gcc only)
        run: |
          "$MCPP_BOOT" build
          MCPP=$(realpath "$(find target -type f -name mcpp -printf '%T@ %p\n' | sort -rn | head -1 | cut -d' ' -f2)")
          test -x "$MCPP"
          "$MCPP" --version
          echo "MCPP=$MCPP" >> "$GITHUB_ENV"

      - name: "issue #195 reproduction: manifest llvm toolchain, fresh"
        run: |
          cd "$(mktemp -d)"
          "$MCPP" new hello195
          cd hello195
          printf '\n[toolchain]\nlinux = "llvm@22.1.8"\n' >> mcpp.toml
          printf 'import std;\nint main() { std::println("hello {}", 195); return 0; }\n' > src/main.cpp
          "$MCPP" run

      - name: Hermetic llvm e2e subset
        run: |
          export PATH="$HOME/.xlings/subos/current/bin:$PATH"
          export MCPP
          bash tests/e2e/86_llvm_hermetic_link.sh
          bash tests/e2e/37_llvm_import_std.sh