feature-gate most Nix functions

Using features reduces build time and size for consumer crates.  By
default all features are enabled.

2 files changed, 17 insertions, 0 deletions

diff --git a/src/mount/bsd.rs b/src/mount/bsd.rs
index 627bfa5e..ba0c1a28 100644
--- a/src/mount/bsd.rs
+++ b/src/mount/bsd.rs
@@ -20,29 +20,36 @@ libc_bitflags!(
     pub struct MntFlags: c_int {
         /// ACL support enabled.
         #[cfg(any(target_os = "netbsd", target_os = "freebsd"))]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_ACLS;
         /// All I/O to the file system should be done asynchronously.
         MNT_ASYNC;
         /// dir should instead be a file system ID encoded as “FSID:val0:val1”.
         #[cfg(target_os = "freebsd")]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_BYFSID;
         /// Force a read-write mount even if the file system appears to be
         /// unclean.
         MNT_FORCE;
         /// GEOM journal support enabled.
         #[cfg(target_os = "freebsd")]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_GJOURNAL;
         /// MAC support for objects.
         #[cfg(any(target_os = "macos", target_os = "freebsd"))]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_MULTILABEL;
         /// Disable read clustering.
         #[cfg(any(target_os = "dragonfly", target_os = "freebsd"))]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_NOCLUSTERR;
         /// Disable write clustering.
         #[cfg(any(target_os = "dragonfly", target_os = "freebsd"))]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_NOCLUSTERW;
         /// Enable NFS version 4 ACLs.
         #[cfg(target_os = "freebsd")]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_NFS4ACLS;
         /// Do not update access times.
         MNT_NOATIME;
@@ -52,6 +59,7 @@ libc_bitflags!(
         MNT_NOSUID;
         /// Do not follow symlinks.
         #[cfg(any(target_os = "dragonfly", target_os = "freebsd"))]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_NOSYMFOLLOW;
         /// Mount read-only.
         MNT_RDONLY;
@@ -62,6 +70,7 @@ libc_bitflags!(
         ///
         /// See [mksnap_ffs(8)](https://www.freebsd.org/cgi/man.cgi?query=mksnap_ffs)
         #[cfg(any(target_os = "macos", target_os = "freebsd"))]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_SNAPSHOT;
         /// Using soft updates.
         #[cfg(any(
@@ -70,10 +79,12 @@ libc_bitflags!(
                 target_os = "netbsd",
                 target_os = "openbsd"
         ))]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_SOFTDEP;
         /// Directories with the SUID bit set chown new files to their own
         /// owner.
         #[cfg(any(target_os = "dragonfly", target_os = "freebsd"))]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_SUIDDIR;
         /// All I/O to the file system should be done synchronously.
         MNT_SYNCHRONOUS;
@@ -83,12 +94,14 @@ libc_bitflags!(
                 target_os = "freebsd",
                 target_os = "netbsd"
         ))]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_UNION;
         /// Indicates that the mount command is being applied to an already
         /// mounted file system.
         MNT_UPDATE;
         /// Check vnode use counts.
         #[cfg(target_os = "freebsd")]
+        #[cfg_attr(docsrs, doc(cfg(all())))]
         MNT_NONBUSY;
     }
 );
@@ -182,6 +195,7 @@ pub type NmountResult = std::result::Result<(), NmountError>;
 /// * [`nmount(2)`](https://www.freebsd.org/cgi/man.cgi?query=nmount)
 /// * [`nullfs(5)`](https://www.freebsd.org/cgi/man.cgi?query=nullfs)
 #[cfg(target_os = "freebsd")]
+#[cfg_attr(docsrs, doc(cfg(all())))]
 #[derive(Debug, Default)]
 pub struct Nmount<'a>{
     iov: Vec<IoVec<&'a [u8]>>,
@@ -189,6 +203,7 @@ pub struct Nmount<'a>{
 }
 
 #[cfg(target_os = "freebsd")]
+#[cfg_attr(docsrs, doc(cfg(all())))]
 impl<'a> Nmount<'a> {
     /// Add an opaque mount option.
     ///
diff --git a/src/mount/mod.rs b/src/mount/mod.rs
index 14bf2a96..e89c1a07 100644
--- a/src/mount/mod.rs
+++ b/src/mount/mod.rs
@@ -1,5 +1,6 @@
 //! Mount file systems
 #[cfg(any(target_os = "android", target_os = "linux"))]
+#[cfg_attr(docsrs, doc(cfg(all())))]
 mod linux;
 
 #[cfg(any(target_os = "android", target_os = "linux"))]
@@ -10,6 +11,7 @@ pub use self::linux::*;
           target_os = "macos",
           target_os = "netbsd",
           target_os = "openbsd"))]
+#[cfg_attr(docsrs, doc(cfg(all())))]
 mod bsd;
 
 #[cfg(any(target_os = "dragonfly",