Function hash_input_files

ci/compile_pch.py:181–204

Hash the content of all input files to detect changes. Always includes each file path in the hash so that different sets of missing files produce distinct digests (avoiding false cache hits). Note: compiler args are NOT included in this hash. Meson/Ninja already tracks compiler fla

(files: list[Path])

def hash_input_files(files: list[Path]) -> str:
    """Hash the content of all input files to detect changes.

    Always includes each file path in the hash so that different sets of
    missing files produce distinct digests (avoiding false cache hits).

    Note: compiler args are NOT included in this hash. Meson/Ninja already
    tracks compiler flag changes via build.ninja regeneration. Including
    args here caused a mismatch between compile_pch.py (which has args)
    and invalidate_stale_pch (which doesn't), making the staleness check
    always delete freshly-built PCH files.
    """
    h = hashlib.sha256()
    for f in sorted(str(p) for p in files):
        p = Path(f)
        h.update(f.encode("utf-8"))  # Always include path in hash
        if p.exists():
            h.update(b"\x01")  # sentinel: file exists
            with open(p, "rb") as fh:
                for chunk in iter(lambda: fh.read(65536), b""):
                    h.update(chunk)
        else:
            h.update(b"\x00")  # sentinel: file missing
    return h.hexdigest()


def invalidate_stale_pch(pch_file: Path) -> None: