/**
 * Linux POSIX ACL absence check (SH-00084).
 *
 * Access ACLs change effective permissions independently of mode and group.
 * The guarded writers do not copy ACLs, so they require verified absence on
 * supported Linux/glibc. A default ACL initializes direct children at
 * creation, not existing descendants: query it only for directories where the
 * caller will create an object.
 *
 * Presence is queried only (size 0); no attribute value is read or copied.
 *
 * errno is thread-local and any later libc call on this thread, or a signal
 * handler that does not preserve it, can overwrite it. The probe therefore:
 * - resets errno before each query where the layer can write it,
 * - reads it as the very next step after the call, with nothing allocated in
 *   between (the call returns an immediate number, not a BigInt, and errno is
 *   read with bun:ffi's read.i32, which allocates nothing),
 * - re-queries a bounded number of times when the result is -1 with an errno
 *   other than the two "absent" answers, since a stray overwrite does not
 *   repeat while a genuine failure does. A persistent failure refuses.
 * A result other than -1 (the attribute exists, or an anomalous value) always
 * refuses at once and never depends on errno.
 */
/** ENODATA on the asm-generic errno table (Linux x86_64 and aarch64). */
export declare const LINUX_ENODATA = 61;
/** EOPNOTSUPP, which glibc also names ENOTSUP, on the asm-generic table. */
export declare const LINUX_EOPNOTSUPP = 95;
/** Queries per attribute before an unexplained failure refuses. */
export declare const LINUX_ACL_QUERY_ATTEMPTS = 4;
/**
 * Filesystems where an unsupported POSIX ACL attribute means the kernel
 * enforces no ACL at all (support compiled out, or mounted with noacl), so
 * mode and ownership are the whole access model. Network and FUSE filesystems
 * (NFSv4, SMB, 9p, FUSE and others) also answer EOPNOTSUPP while enforcing
 * their own ACLs or server-side access, so they stay unverified.
 */
export declare const LINUX_ACL_FREE_WHEN_UNSUPPORTED: ReadonlySet<bigint>;
/** The raw operations, separable so tests can drive every errno path. */
export interface LinuxAclProbe {
    /** process.arch of the running binary; only asm-generic errno tables are admitted. */
    readonly arch: string;
    /** Thread-local errno of the calling thread, or null when it cannot be located. */
    readonly errno: {
        get(): number;
        set?(value: number): void;
    } | null;
    /** fgetxattr(fd, name, NULL, 0): the attribute size, or -1. */
    fgetxattr(fd: number, attribute: string): number | bigint;
    /** fstatfs(fd).f_type, or null when fstatfs fails. */
    filesystemType(fd: number): bigint | null;
}
/** True only when every queried POSIX ACL attribute is verifiably absent. */
export declare function linuxAccessAclAbsent(probe: LinuxAclProbe, fd: number, creationParent: boolean): boolean;
/** Run with the glibc probe; any loading or ABI failure refuses (false). */
export declare function withGlibcAclProbe(use: (probe: LinuxAclProbe) => boolean): boolean;