scripts/lint_package.py

# Copyright 2022 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""This script emerges packages and retrieves their lints.

Currently support is provided for both general and differential linting of C++
with Clang Tidy and Rust with Cargo Clippy for all packages within platform2.
"""

import json
import sys
from typing import List, Text

from chromite.lib import build_target_lib
from chromite.lib import commandline
from chromite.lib import cros_build_lib
from chromite.lib import portage_util
from chromite.lib import terminal
from chromite.lib import workon_helper
from chromite.lib.parser import package_info
from chromite.service import toolchain
from chromite.utils import file_util


def parse_packages(
    build_target: build_target_lib.BuildTarget, packages: List[str]
) -> List[package_info.PackageInfo]:
    """Parse packages and insert the category if none is given.

    Args:
      build_target: build_target to find ebuild for
      packages: user input package names to parse

    Returns:
      A list of parsed PackageInfo objects
    """
    package_infos: List[package_info.PackageInfo] = []
    for package in packages:
        parsed = package_info.parse(package)
        if not parsed.category:
            # If a category is not specified, we can get it from the ebuild path.
            if build_target.is_host():
                ebuild_path = portage_util.FindEbuildForPackage(
                    package, build_target.root
                )
            else:
                ebuild_path = portage_util.FindEbuildForBoardPackage(
                    package, build_target.name, build_target.root
                )
            ebuild_data = portage_util.EBuild(ebuild_path)
            parsed = package_info.parse(ebuild_data.package)
        package_infos.append(parsed)
    return package_infos


def format_lint(lint: toolchain.LinterFinding) -> Text:
    """Formats a lint for human readable printing.

    Example output:
    [ClangTidy] In 'path/to/file.c' on line 36:
        Also in 'path/to/file.c' on line 40:
        Also in 'path/to/file.c' on lines 50-53:
      You did something bad, don't do it.

    Args:
      lint: A linter finding from the toolchain service.

    Returns:
      A correctly formatted string ready to be displayed to the user.
    """

    color = terminal.Color(True)
    lines = []
    linter_prefix = color.Color(
        terminal.Color.YELLOW,
        f"[{lint.linter}]",
        background_color=terminal.Color.BLACK,
    )
    for loc in lint.locations:
        if not lines:
            location_prefix = f"\n{linter_prefix} In"
        else:
            location_prefix = "   and in"
        if loc.line_start != loc.line_end:
            lines.append(
                f"{location_prefix} '{loc.filepath}' "
                f"lines {loc.line_start}-{loc.line_end}:"
            )
        else:
            lines.append(
                f"{location_prefix} '{loc.filepath}' line {loc.line_start}:"
            )
    message_lines = lint.message.split("\n")
    for line in message_lines:
        lines.append(f"  {line}")
    lines.append("")
    return "\n".join(lines)


def get_arg_parser() -> commandline.ArgumentParser:
    """Creates an argument parser for this script."""
    default_board = cros_build_lib.GetDefaultBoard()
    parser = commandline.ArgumentParser(description=__doc__)

    board_group = parser.add_mutually_exclusive_group(
        required=not default_board
    )
    board_group.add_argument(
        "-b",
        "--board",
        "--build-target",
        dest="board",
        default=default_board,
        help="The board to emerge packages for",
    )
    board_group.add_argument(
        "--host", action="store_true", help="emerge for host instead of board."
    )
    board_group.add_argument(
        "--fetch-only",
        action="store_true",
        help="Fetch lints from previous run without reseting or calling emerge.",
    )

    parser.add_argument(
        "--differential",
        action="store_true",
        help="only lint lines touched by the last commit",
    )
    parser.add_argument(
        "-o",
        "--output",
        default=sys.stdout,
        help="File to use instead of stdout.",
    )
    parser.add_argument(
        "--json", action="store_true", help="Output lints in JSON format."
    )
    parser.add_argument(
        "--no-clippy",
        dest="clippy",
        action="store_false",
        help="Disable cargo clippy linter.",
    )
    parser.add_argument(
        "--no-tidy",
        dest="tidy",
        action="store_false",
        help="Disable clang tidy linter.",
    )
    parser.add_argument(
        "--no-golint",
        dest="golint",
        action="store_false",
        help="Disable golint linter.",
    )
    parser.add_argument(
        "packages",
        nargs="*",
        help="package(s) to emerge and retrieve lints for",
    )
    return parser


def parse_args(argv: List[str]):
    """Parses arguments in argv and returns the options."""
    parser = get_arg_parser()
    opts = parser.parse_args(argv)
    opts.Freeze()

    # A package must be specified unless we are in fetch-only mode
    if not (opts.fetch_only or opts.packages):
        parser.error("Emerge requires specified package(s).")
    if opts.fetch_only and opts.packages:
        parser.error("Cannot specify packages for fetch-only mode.")

    return opts


def main(argv: List[str]) -> None:
    cros_build_lib.AssertInsideChroot()
    opts = parse_args(argv)

    if opts.host:
        # BuildTarget interprets None as host target
        build_target = build_target_lib.BuildTarget(None)
    else:
        build_target = build_target_lib.BuildTarget(opts.board)
    packages = parse_packages(build_target, opts.packages)
    package_atoms = [x.atom for x in packages]

    with workon_helper.WorkonScope(build_target, package_atoms):
        build_linter = toolchain.BuildLinter(
            packages, build_target.root, opts.differential
        )
        if opts.fetch_only:
            lints = build_linter.fetch_findings(
                use_clippy=opts.clippy,
                use_tidy=opts.tidy,
                use_golint=opts.golint,
            )
        else:
            lints = build_linter.emerge_with_linting(
                use_clippy=opts.clippy,
                use_tidy=opts.tidy,
                use_golint=opts.golint,
            )

    if opts.json:
        formatted_output = json.dumps([lint._asdict() for lint in lints])
    else:
        formatted_output = "\n".join(format_lint(lint) for lint in lints)

    with file_util.Open(opts.output, "w") as output_file:
        output_file.write(formatted_output)
        if not opts.json:
            output_file.write(f"\nFound {len(lints)} lints.")
        output_file.write("\n")