# Github composite action to build a single-source-file test binary with an
# already-checked-out version of Rust's stdlib, that will be patched with a
# given revision of the backtrace crate.

name: Build with patched std
description: >
  Build a binary with a version of std that's had a specific revision of
  backtrace patched in.
inputs:
  backtrace-commit:
    description: The git commit of backtrace to patch in to std
    required: true
  main-rs:
    description: The (single) source code file to compile
    required: true
  rustc-dir:
    description: The root directory of the rustc repo
    required: true
outputs:
  test-binary-size:
    description: The size in bytes of the built test binary
    value: ${{ steps.measure.outputs.test-binary-size }}
runs:
  using: composite
  steps:
    - shell: bash
      id: measure
      env:
        RUSTC_FLAGS: -Copt-level=3 -Cstrip=symbols
        # This symlink is made by Build::new() in the bootstrap crate, using a
        # symlink on Linux and a junction on Windows, so it will exist on both
        # platforms.
        RUSTC_BUILD_DIR: build/host
        RUST_BACKTRACE: 1
      working-directory: ${{ inputs.rustc-dir }}
      run: |
        set -x
        rm -rf "$RUSTC_BUILD_DIR/stage0-std"

        (cd library/backtrace && git checkout ${{ inputs.backtrace-commit }})
        git add library/backtrace

        python3 x.py build library --stage 0

        TEMP_BUILD_OUTPUT=$(mktemp test-binary-XXXXXXXX)
        "$RUSTC_BUILD_DIR/stage0-sysroot/bin/rustc" $RUSTC_FLAGS "${{ inputs.main-rs }}" -o "$TEMP_BUILD_OUTPUT"
        BINARY_SIZE=$(stat -c '%s' "$TEMP_BUILD_OUTPUT")
        rm "$TEMP_BUILD_OUTPUT"

        echo "test-binary-size=$BINARY_SIZE" >> "$GITHUB_OUTPUT"