utils/bazel/tools/check_bazel_inputs.py

#!/usr/bin/env python3

# This file is licensed under the Apache License v2.0 with LLVM Exceptions.
# See https://llvm.org/LICENSE.txt for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

"""Checks that files in selected source subtrees are Bazel target inputs."""

import subprocess
import sys
from fnmatch import fnmatch
from pathlib import Path, PurePosixPath
from typing import Set

BAZEL_REPOSITORY = "@llvm-project"
SUBTREES = [
    # TODO: Add more directories as we support most of their files in bazel.
    # "libc",
    # "lldb",
    "lld",
]
IGNORED_GLOBS = [
    "*.md",
    "*.txt",
    "*.TXT",  # Both cases are used
    "*/.clang-format",
    "*/.clang-tidy",
    "*/.gitignore",
    "*/cmake/*",
    "*/CMakeLists.txt",
    "*/docs/*",
    "*/utils/*",
    "clang/www/*",
    "lld/test/Unit/lit.cfg.py",  # cmake shims
    "lld/test/Unit/lit.site.cfg.py.in",  # cmake shims
]


def source_files(project_root: Path) -> Set[str]:
    files = set()
    for subtree in SUBTREES:
        subtree_root = project_root / subtree
        if not subtree_root.is_dir():
            raise RuntimeError(f"source subtree does not exist: {subtree_root}")
        for path in subtree_root.rglob("*"):
            relative_path = path.relative_to(project_root)
            source_path = relative_path.as_posix()
            if path.is_file() and not any(
                fnmatch(source_path, glob) for glob in IGNORED_GLOBS
            ):
                files.add(source_path)
    return files


def label_to_source_path(label: str) -> str:
    repository, separator, remainder = label.partition("//")
    if not separator or repository != BAZEL_REPOSITORY:
        raise RuntimeError(f"unexpected Bazel label: {label}")

    package, separator, target = remainder.partition(":")
    if not separator:
        raise RuntimeError(f"unexpected Bazel label: {label}")
    return str(PurePosixPath(package, target))


def bazel_input_files(bazel_workspace: Path) -> Set[str]:
    target_patterns = " union ".join(
        f"{BAZEL_REPOSITORY}//{subtree}/..." for subtree in SUBTREES
    )
    query = (
        f'kind("source file", {BAZEL_REPOSITORY}//...:* '
        f"intersect deps({target_patterns}))"
    )
    result = subprocess.run(
        ["bazel", "query", "--output=label", query],
        cwd=bazel_workspace,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        text=True,
    )
    if result.returncode:
        sys.stderr.write(result.stderr)
        raise RuntimeError(f"bazel query failed with exit code {result.returncode}")

    return {label_to_source_path(label) for label in result.stdout.splitlines()}


def main() -> int:
    script = Path(__file__).resolve()
    bazel_workspace = script.parents[1]
    project_root = script.parents[3]

    try:
        files = source_files(project_root)
        orphaned = files - bazel_input_files(bazel_workspace)
    except (OSError, RuntimeError) as error:
        print(f"error: {error}", file=sys.stderr)
        return 2

    if orphaned:
        print("Files not used as inputs by any Bazel target:", file=sys.stderr)
        for path in sorted(orphaned):
            print(f"  {path}", file=sys.stderr)
        return 1

    subtree_word = "subtree" if len(SUBTREES) == 1 else "subtrees"
    print(f"All {len(files)} files in {len(SUBTREES)} {subtree_word} are Bazel inputs.")
    return 0


if __name__ == "__main__":
    sys.exit(main())