Merge pull request #1033 from jackh726/issue-88862

Add benchmark for issue-88862

Author: Mark-Simulacrum

collector/benchmarks/README.md

@@ -89,6 +89,9 @@ programs.
   performance](https://github.com/rust-lang/rust/issues/46449) in the past.
 - **issue-58319**: A small program that caused [poor
   performance](https://github.com/rust-lang/rust/issues/58319) in the past.
+- **issue-88862**: A MCVE of a program that had a
+  [severe performance regression](https://github.com/rust-lang/rust/issues/88862)
+  when trying to normalize large opaque types with late-bound regions.
 - **many-assoc-items**: Contains a struct with many associated items, which
   caused [quadratic behavior](https://github.com/rust-lang/rust/issues/68957)
   in the past.

collector/benchmarks/issue-88862/Cargo.lock

@@ -0,0 +1,5 @@
+[package]
+name = "issue-88862"
+version = "0.1.0"
+edition = "2018"
+

collector/benchmarks/issue-88862/Cargo.toml

@@ -0,0 +1,196 @@
+#[derive(Debug)]
+struct Error;
+struct SharedPool {
+    a: PoolOptions,
+}
+
+struct PoolOptions;
+
+async fn check<'s: 'p, 'p>(
+    mut _conn: Floating<'s>,
+    _: &'p PoolOptions,
+) -> Result<(), DecrementSizeGuard<'s>> {
+    todo!()
+}
+
+impl SharedPool {
+    async fn acquire(&'_ self) -> Result<Floating<'_>, Error> {
+        async {
+            if let conn = todo!() {
+                if let d = check(conn, &self.a).await {}
+            }
+        }
+        .await;
+        todo!()
+    }
+}
+
+struct G;
+struct Floating<'s>(std::marker::PhantomData<dyn Fn(&'s ())>);
+impl<'s> Floating<'s> {
+    fn attach(self, e: &std::sync::Arc<SharedPool>) -> G { todo!() }
+}
+
+struct DecrementSizeGuard<'s>(std::marker::PhantomData<dyn Fn(&'s ())>);
+struct FooDb;
+impl FooDb {
+    fn acquire(&self) -> impl std::future::Future<Output = Result<G, Error>> + 'static {
+        let _shared: std::sync::Arc<SharedPool> = todo!();
+        async move { _shared.acquire().await.map(|conn| conn.attach(&_shared)) }
+    }
+
+    async fn nested(&self) -> Result<Option<String>, ()> {
+        (async move {
+            match async move {
+                async move {
+                    (
+                        async move {
+                            match async move {
+                                let db = FooDb;
+                                let mut _conn = db.acquire().await.unwrap();
+                                Ok::<_, ()>(String::default())
+                            }
+                            .await
+                            {
+                                Ok(x) => Ok(x),
+                                Err0 => todo!(),
+                            }
+                        },
+                        todo!(),
+                    )
+                        .0
+                        .await
+                }
+                .await
+                .map(Some)
+            }
+            .await
+            {
+                Ok(x) => Ok(x),
+                Err(e) => Err(e),
+            }
+        },)
+            .0
+            .await
+    }
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error + 'static>> {
+    factory(Factory::handle(route));
+    todo!()
+}
+
+fn factory<X, Req>(factory: X) -> BoxServiceFactory<Req>
+where X: ServiceFactory<Req> + 'static {
+    BoxServiceFactory(Box::new(FactoryWrapper(factory)))
+}
+
+
+async fn route(database: FooDb) -> Result<(), Error> {
+    database.nested().await;
+    todo!()
+}
+
+struct Factory<I, T, R> {
+    _hnd: I,
+    j: std::marker::PhantomData<(T, R)>,
+}
+
+impl<I, T, R> Factory<I, T, R> {
+    fn handle(_: I) -> Self { todo!() }
+}
+
+struct K;
+struct L;
+impl<I, T, R> ServiceFactory<K> for Factory<I, T, R>
+where
+    I: N<T, R>,
+    R: std::future::Future,
+    R::Output: Responder,
+{
+    type Future = std::future::Ready<Result<Self, ()>>;
+    type Service = Self;
+
+    fn new_service(&self, _: ()) -> Self::Future { todo!() }
+}
+
+impl<I, T, R> Service<K> for Factory<I, T, R> {
+    type Error = Error;
+    type Future = std::future::Ready<Result<L, Error>>;
+
+    fn poll(&self, _: &mut core::task::Context) -> core::task::Poll<Result<(), Error>> { todo!() }
+
+    fn call(&self, m: K) -> Self::Future { todo!() }
+}
+
+trait Responder {}
+
+impl<T, R> Responder for Result<T, R> {}
+
+trait N<T, R>: 'static
+where
+    R: std::future::Future,
+    R::Output: Responder, {
+    fn call(&self, param: T) -> R;
+}
+
+
+type BoxFuture<T> = std::pin::Pin<Box<dyn std::future::Future<Output = T>>>;
+
+struct BoxServiceFactory<Req>(
+    Box<
+        dyn ServiceFactory<
+            Req,
+            Service = Box<dyn Service<Req, Error = (), Future = BoxFuture<Result<(), ()>>>>,
+            Future = BoxFuture<
+                Result<Box<dyn Service<Req, Error = (), Future = BoxFuture<Result<(), ()>>>>, ()>,
+            >,
+        >,
+    >,
+);
+
+trait ServiceFactory<Req> {
+    type Service: Service<Req>;
+    type Future;
+    fn new_service(&self, _: ()) -> Self::Future;
+}
+
+trait Service<Req> {
+    type Error;
+    type Future;
+    fn poll(&self, ctx: &mut std::task::Context) -> std::task::Poll<Result<(), Self::Error>>;
+    fn call(&self, req: Req) -> Self::Future;
+}
+
+impl<S, Req> Service<Req> for Box<S>
+where S: Service<Req> + ?Sized
+{
+    type Error = S::Error;
+    type Future = S::Future;
+
+    fn poll(&self, _: &mut std::task::Context) -> std::task::Poll<Result<(), S::Error>> { todo!() }
+
+    fn call(&self, _: Req) -> S::Future { todo!() }
+}
+
+impl<SF, Req> ServiceFactory<Req> for FactoryWrapper<SF>
+where
+    SF: ServiceFactory<Req>,
+    SF: 'static,
+{
+    type Future = BoxFuture<Result<Self::Service, ()>>;
+    type Service = Box<dyn Service<Req, Error = (), Future = BoxFuture<Result<(), ()>>>>;
+
+    fn new_service(&self, _: ()) -> Self::Future { todo!() }
+}
+
+impl<Func, A, Res> N<(A,), Res> for Func
+where
+    Func: Fn(A) -> Res + 'static,
+    Res: std::future::Future,
+    Res::Output: Responder,
+{
+    fn call(&self, _: (A,)) -> Res { todo!() }
+}
+
+struct FactoryWrapper<T>(T);