portage/tools/generate-stage2-prebuilts

#!/bin/bash
#
# Copyright 2023 The ChromiumOS Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# Copies the existing binpkgs out of the bazel root and generates a
# prebuilts.bazelrc that points to those packages. This allows us to avoid
# having to rebuild all packages when something primordial changes.
#
# Usage:
# $ generate-stage2-prebuilts [targets...]
#
# If `targets` is not specified a predefined list of targets will be used.

set -eu -o pipefail

join() {
  local IFS="$1"
  shift
  echo "$*"
}

: "${BINPKG_CACHE:=${HOME}/.cache/binpkgs}"

mkdir -p "${BINPKG_CACHE}"

declare -A BAZEL
while IFS=': ' read -r key value
do
    BAZEL["${key}"]="${value}"
done < <(bazel info)

WORKSPACE_ROOT="${BAZEL[workspace]}"

BAZEL_BIN="${BAZEL[bazel-bin]}"
PORTAGE_BIN="${BAZEL_BIN}/external/_main~portage~portage"

BAZEL_OUTPUT_BASE="${BAZEL[output_base]}"
BOARD_FILE="${BAZEL_OUTPUT_BASE}/external/_main~portage~portage_digest/board"


if [[ ! -v BOARD ]]; then
    if [[ ! -e "${BOARD_FILE}" ]]; then
        echo "Cannot determine BOARD, please run your build again" >&2
        exit 1
    fi

    BOARD="$(< "${BOARD_FILE}")"
    export BOARD
fi

PREBUILTS="${WORKSPACE_ROOT}/prebuilts.bazelrc"
exec 3> "${PREBUILTS}.tmp"

if [[ $# -ge 1 ]]; then
    IFS="+" declare -A TARGET_MAP=(
        ["prebuilts"]="$(join "+" "$@")"
    )
else
    declare -A TARGET_MAP=(
        ["prebuilts/stage2-sdk"]="@portage//internal/sdk/stage2"
        ["prebuilts/stage2-board-sdk"]="@portage//internal/sdk/stage2/target/board"
        ["prebuilts/stage2-${BOARD}"]="
            @portage//internal/packages/stage2/target/board/chromiumos/virtual/target-os-dev:1_package_set +
            @portage//internal/packages/stage2/target/board/chromiumos/virtual/target-os-factory-shim:1_package_set +
            @portage//internal/packages/stage2/target/board/chromiumos/virtual/target-os-factory:1_package_set +
            @portage//internal/packages/stage2/target/board/chromiumos/virtual/target-os-test:1_package_set +
            @portage//internal/packages/stage2/target/board/chromiumos/virtual/target-os:1_package_set
        "
    )
fi

echo "# Generated using BOARD='${BOARD}' $*" >&3

declare -A SRC_DEST_MAP

for KEY in "${!TARGET_MAP[@]}"
do
    TARGET="${TARGET_MAP["${KEY}"]}"

    readarray -t EBUILD_TARGETS < <(
        set -x
        bazel cquery --repo_env=_CACHE_BUST_DATE=none \
            --//bazel/portage:omit_ebuild_src \
            "kind(ebuild, deps(${TARGET}))" || kill "$$"
    )

    echo "common:${KEY} \\" >&3
    for TARGET in "${EBUILD_TARGETS[@]}"; do
        TARGET="${TARGET#@portage//}"
        TARGET="${TARGET% (*)}"
        TARGET_DIR="${TARGET%:*}"
        TARGET_NAME="$(basename "${TARGET_DIR}")"
        TARGET_VERSION="${TARGET#*:}"

        BINPKG_NAME="${TARGET_NAME}-${TARGET_VERSION}.tbz2"
        BINPKG_SRC="${PORTAGE_BIN}/${TARGET_DIR}/${BINPKG_NAME}"

        if [[ ! -f "${BINPKG_SRC}" ]]; then
            continue
        fi

        BINPKG_DEST_DIR="${BINPKG_CACHE}/${TARGET_DIR}"
        # Keep the target packages separated
        BINPKG_DEST_DIR="${BINPKG_DEST_DIR/target\/board/"target/${BOARD}"}"
        mkdir -p "${BINPKG_DEST_DIR}"
        BINPKG_DEST="${BINPKG_DEST_DIR}/${BINPKG_NAME}"

        SRC_DEST_MAP["${BINPKG_SRC}"]="${BINPKG_DEST}"

        echo "--@portage//${TARGET}_prebuilt=${BINPKG_DEST} \\" >&3
    done

    # Needed so we don't gobble up the next line
    echo "" >&3
done

echo "Copying packages to ${BINPKG_CACHE}" >&2
for SRC in "${!SRC_DEST_MAP[@]}"; do
    DEST="${SRC_DEST_MAP["${SRC}"]}"
    rsync --progress "${SRC}" "${DEST}" >&2
done

exec 3>&- #close fd 3.
mv "${PREBUILTS}.tmp" "${PREBUILTS}"

echo
echo "${PREBUILTS} was generated" >&2

if ! grep -q prebuilts.bazelrc "${WORKSPACE_ROOT}/workspace.bazelrc"; then
    echo "Adding prebuilts.bazelrc to workspace.bazelrc" >&2
    echo "try-import %workspace%/prebuilts.bazelrc" >>"${WORKSPACE_ROOT}/workspace.bazelrc"
fi

echo "You can now add any of the following to your \`bazel build\` command line:" >&2
for KEY in "${!TARGET_MAP[@]}"
do
    echo "  --config=${KEY}" >&2
done