runtime: stabilize LocalRuntime (#7557)

tokio-macros/src/entry.rs

@@ -476,12 +476,7 @@ fn parse_knobs(mut input: ItemFn, is_test: bool, config: FinalConfig) -> TokenSt
         },
     };
 
-    let mut checks = vec![];
-    let mut errors = vec![];
-
     let build = if let RuntimeFlavor::Local = config.flavor {
-        checks.push(quote! { tokio_unstable });
-        errors.push("The local runtime flavor is only available when `tokio_unstable` is set.");
         quote_spanned! {last_stmt_start_span=> build_local(Default::default())}
     } else {
         quote_spanned! {last_stmt_start_span=> build()}
@@ -509,23 +504,10 @@ fn parse_knobs(mut input: ItemFn, is_test: bool, config: FinalConfig) -> TokenSt
         quote! {}
     };
 
-    let do_checks: TokenStream = checks
-        .iter()
-        .zip(&errors)
-        .map(|(check, error)| {
-            quote! {
-                #[cfg(not(#check))]
-                compile_error!(#error);
-            }
-        })
-        .collect();
-
     let body_ident = quote! { body };
     // This explicit `return` is intentional. See tokio-rs/tokio#4636
     let last_block = quote_spanned! {last_stmt_end_span=>
-        #do_checks
 
-        #[cfg(all(#(#checks),*))]
         #[allow(clippy::expect_used, clippy::diverging_sub_expression, clippy::needless_return, clippy::unwrap_in_result)]
         {
             #use_builder
@@ -537,10 +519,6 @@ fn parse_knobs(mut input: ItemFn, is_test: bool, config: FinalConfig) -> TokenSt
                 .block_on(#body_ident);
         }
 
-        #[cfg(not(all(#(#checks),*)))]
-        {
-            panic!("fell through checks")
-        }
     };
 
     let body = input.body();

tokio-macros/src/lib.rs

@@ -73,16 +73,11 @@ use proc_macro::TokenStream;
 ///
 /// ## Local
 ///
-/// [Unstable API][unstable] only.
-///
 /// To use the [local runtime], the macro can be configured using
 ///
 /// ```rust
-/// # #[cfg(tokio_unstable)]
 /// #[tokio::main(flavor = "local")]
 /// # async fn main() {}
-/// # #[cfg(not(tokio_unstable))]
-/// # fn main() {}
 /// ```
 ///
 /// # Function arguments
@@ -165,25 +160,19 @@ use proc_macro::TokenStream;
 ///
 /// ## Using the local runtime
 ///
-/// Available in the [unstable API][unstable] only.
-///
 /// The [local runtime] is similar to the current-thread runtime but
 /// supports [`task::spawn_local`](../tokio/task/fn.spawn_local.html).
 ///
 /// ```rust
-/// # #[cfg(tokio_unstable)]
 /// #[tokio::main(flavor = "local")]
 /// async fn main() {
 ///     println!("Hello world");
 /// }
-/// # #[cfg(not(tokio_unstable))]
-/// # fn main() {}
 /// ```
 ///
 /// Equivalent code not using `#[tokio::main]`
 ///
 /// ```rust
-/// # #[cfg(tokio_unstable)]
 /// fn main() {
 ///     tokio::runtime::Builder::new_current_thread()
 ///         .enable_all()
@@ -193,8 +182,6 @@ use proc_macro::TokenStream;
 ///             println!("Hello world");
 ///         })
 /// }
-/// # #[cfg(not(tokio_unstable))]
-/// # fn main() {}
 /// ```
 ///
 ///