process: fix raw_arg not showing up in docs (#5865)

Author: joriskleiber

tokio/src/macros/cfg.rs

@@ -25,6 +25,18 @@ macro_rules! cfg_windows {
     }
 }
 
+/// Enables unstable Windows-specific code.
+/// Use this macro instead of `cfg(windows)` to generate docs properly.
+macro_rules! cfg_unstable_windows {
+    ($($item:item)*) => {
+        $(
+            #[cfg(all(any(all(doc, docsrs), windows), tokio_unstable))]
+            #[cfg_attr(docsrs, doc(cfg(all(windows, tokio_unstable))))]
+            $item
+        )*
+    }
+}
+
 /// Enables enter::block_on.
 macro_rules! cfg_block_on {
     ($($item:item)*) => {

tokio/src/process/mod.rs

@@ -400,20 +400,21 @@ impl Command {
         self
     }
 
-    /// Append literal text to the command line without any quoting or escaping.
-    ///
-    /// This is useful for passing arguments to `cmd.exe /c`, which doesn't follow
-    /// `CommandLineToArgvW` escaping rules.
-    ///
-    /// **Note**: This is an [unstable API][unstable] but will be stabilised once
-    /// tokio's MSRV is sufficiently new. See [the documentation on
-    /// unstable features][unstable] for details about using unstable features.
-    #[cfg(windows)]
-    #[cfg(tokio_unstable)]
-    #[cfg_attr(docsrs, doc(cfg(all(windows, tokio_unstable))))]
-    pub fn raw_arg<S: AsRef<OsStr>>(&mut self, text_to_append_as_is: S) -> &mut Command {
-        self.std.raw_arg(text_to_append_as_is);
-        self
+    cfg_unstable_windows! {
+        /// Append literal text to the command line without any quoting or escaping.
+        ///
+        /// This is useful for passing arguments to `cmd.exe /c`, which doesn't follow
+        /// `CommandLineToArgvW` escaping rules.
+        ///
+        /// **Note**: This is an [unstable API][unstable] but will be stabilised once
+        /// tokio's MSRV is sufficiently new. See [the documentation on
+        /// unstable features][unstable] for details about using unstable features.
+        ///
+        /// [unstable]: crate#unstable-features
+        pub fn raw_arg<S: AsRef<OsStr>>(&mut self, text_to_append_as_is: S) -> &mut Command {
+            self.std.raw_arg(text_to_append_as_is);
+            self
+        }
     }
 
     /// Inserts or updates an environment variable mapping.