From 196b8c40f90d97f0a81356602069d8d5f09d3206 Mon Sep 17 00:00:00 2001
From: Chris Denton <christophersdenton@gmail.com>
Date: Wed, 6 Jul 2022 16:36:52 +0100
Subject: [PATCH 01/21] Use `rtabort!` instead of `process::abort`

---
 library/std/src/sys/windows/handle.rs | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/library/std/src/sys/windows/handle.rs b/library/std/src/sys/windows/handle.rs
index ef9a8bd690031..6f38e4e828a9f 100644
--- a/library/std/src/sys/windows/handle.rs
+++ b/library/std/src/sys/windows/handle.rs
@@ -252,10 +252,7 @@ impl Handle {
             // If the operation has not completed then abort the process.
             // Doing otherwise means that the buffer and stack may be written to
             // after this function returns.
-            c::STATUS_PENDING => {
-                eprintln!("I/O error: operation failed to complete synchronously");
-                crate::process::abort();
-            }
+            c::STATUS_PENDING => rtabort!("I/O error: operation failed to complete synchronously"),
 
             // Return `Ok(0)` when there's nothing more to read.
             c::STATUS_END_OF_FILE => Ok(0),
@@ -298,9 +295,7 @@ impl Handle {
             // If the operation has not completed then abort the process.
             // Doing otherwise means that the buffer may be read and the stack
             // written to after this function returns.
-            c::STATUS_PENDING => {
-                rtabort!("I/O error: operation failed to complete synchronously");
-            }
+            c::STATUS_PENDING => rtabort!("I/O error: operation failed to complete synchronously"),
 
             // Success!
             status if c::nt_success(status) => Ok(io_status.Information),

From e59e58064c9ed33abd8b740c928a82b0eba4bde5 Mon Sep 17 00:00:00 2001
From: Chris Denton <christophersdenton@gmail.com>
Date: Wed, 6 Jul 2022 16:38:35 +0100
Subject: [PATCH 02/21] Windows: Fallback for overlapped I/O

Try waiting on the file handle once. If that fails then give up.
---
 library/std/src/sys/windows/c.rs      | 14 +++++++++++++-
 library/std/src/sys/windows/handle.rs | 13 +++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/library/std/src/sys/windows/c.rs b/library/std/src/sys/windows/c.rs
index 5f14edaf067c0..b92aa420177f3 100644
--- a/library/std/src/sys/windows/c.rs
+++ b/library/std/src/sys/windows/c.rs
@@ -325,7 +325,9 @@ union IO_STATUS_BLOCK_union {
 }
 impl Default for IO_STATUS_BLOCK_union {
     fn default() -> Self {
-        Self { Pointer: ptr::null_mut() }
+        let mut this = Self { Pointer: ptr::null_mut() };
+        this.Status = STATUS_PENDING;
+        this
     }
 }
 #[repr(C)]
@@ -334,6 +336,16 @@ pub struct IO_STATUS_BLOCK {
     u: IO_STATUS_BLOCK_union,
     pub Information: usize,
 }
+impl IO_STATUS_BLOCK {
+    pub fn status(&self) -> NTSTATUS {
+        // SAFETY: If `self.u.Status` was set then this is obviously safe.
+        // If `self.u.Pointer` was set then this is the equivalent to converting
+        // the pointer to an integer, which is also safe.
+        // Currently the only safe way to construct `IO_STATUS_BLOCK` outside of
+        // this module is to call the `default` method, which sets the `Status`.
+        unsafe { self.u.Status }
+    }
+}
 
 pub type LPOVERLAPPED_COMPLETION_ROUTINE = unsafe extern "system" fn(
     dwErrorCode: DWORD,
diff --git a/library/std/src/sys/windows/handle.rs b/library/std/src/sys/windows/handle.rs
index 6f38e4e828a9f..dd84d505cb322 100644
--- a/library/std/src/sys/windows/handle.rs
+++ b/library/std/src/sys/windows/handle.rs
@@ -248,6 +248,13 @@ impl Handle {
             offset.map(|n| n as _).as_ref(),
             None,
         );
+
+        let status = if status == c::STATUS_PENDING {
+            c::WaitForSingleObject(self.as_raw_handle(), c::INFINITE);
+            io_status.status()
+        } else {
+            status
+        };
         match status {
             // If the operation has not completed then abort the process.
             // Doing otherwise means that the buffer and stack may be written to
@@ -291,6 +298,12 @@ impl Handle {
                 None,
             )
         };
+        let status = if status == c::STATUS_PENDING {
+            unsafe { c::WaitForSingleObject(self.as_raw_handle(), c::INFINITE) };
+            io_status.status()
+        } else {
+            status
+        };
         match status {
             // If the operation has not completed then abort the process.
             // Doing otherwise means that the buffer may be read and the stack

From af3cc8e79c0d0e9731a5cf12f18e2dc709a24f89 Mon Sep 17 00:00:00 2001
From: Chris Denton <christophersdenton@gmail.com>
Date: Wed, 6 Jul 2022 16:39:06 +0100
Subject: [PATCH 03/21] Tests for unsound Windows file methods

---
 library/std/src/sys/windows/handle.rs         |  3 +
 library/std/src/sys/windows/handle/tests.rs   | 22 ++++++
 .../issues-81357-unsound-file-methods.rs      | 76 +++++++++++++++++++
 3 files changed, 101 insertions(+)
 create mode 100644 library/std/src/sys/windows/handle/tests.rs
 create mode 100644 src/test/ui-fulldeps/issues-81357-unsound-file-methods.rs

diff --git a/library/std/src/sys/windows/handle.rs b/library/std/src/sys/windows/handle.rs
index dd84d505cb322..6398c4456331c 100644
--- a/library/std/src/sys/windows/handle.rs
+++ b/library/std/src/sys/windows/handle.rs
@@ -1,5 +1,8 @@
 #![unstable(issue = "none", feature = "windows_handle")]
 
+#[cfg(test)]
+mod tests;
+
 use crate::cmp;
 use crate::io::{self, ErrorKind, IoSlice, IoSliceMut, Read, ReadBuf};
 use crate::mem;
diff --git a/library/std/src/sys/windows/handle/tests.rs b/library/std/src/sys/windows/handle/tests.rs
new file mode 100644
index 0000000000000..d836dae4c305b
--- /dev/null
+++ b/library/std/src/sys/windows/handle/tests.rs
@@ -0,0 +1,22 @@
+use crate::sys::pipe::{anon_pipe, Pipes};
+use crate::{thread, time};
+
+/// Test the synchronous fallback for overlapped I/O.
+#[test]
+fn overlapped_handle_fallback() {
+    // Create some pipes. `ours` will be asynchronous.
+    let Pipes { ours, theirs } = anon_pipe(true, false).unwrap();
+
+    let async_readable = ours.into_handle();
+    let sync_writeable = theirs.into_handle();
+
+    thread::scope(|_| {
+        thread::sleep(time::Duration::from_millis(100));
+        sync_writeable.write(b"hello world!").unwrap();
+    });
+
+    // The pipe buffer starts empty so reading won't complete synchronously unless
+    // our fallback path works.
+    let mut buffer = [0u8; 1024];
+    async_readable.read(&mut buffer).unwrap();
+}
diff --git a/src/test/ui-fulldeps/issues-81357-unsound-file-methods.rs b/src/test/ui-fulldeps/issues-81357-unsound-file-methods.rs
new file mode 100644
index 0000000000000..94b5798a0e7d2
--- /dev/null
+++ b/src/test/ui-fulldeps/issues-81357-unsound-file-methods.rs
@@ -0,0 +1,76 @@
+// run-fail
+// only-windows
+
+fn main() {
+    use std::fs;
+    use std::io::prelude::*;
+    use std::os::windows::prelude::*;
+    use std::ptr;
+    use std::sync::Arc;
+    use std::thread;
+    use std::time::Duration;
+
+    const FILE_FLAG_OVERLAPPED: u32 = 0x40000000;
+
+    fn create_pipe_server(path: &str) -> fs::File {
+        let mut path0 = path.as_bytes().to_owned();
+        path0.push(0);
+        extern "system" {
+            fn CreateNamedPipeA(
+                lpName: *const u8,
+                dwOpenMode: u32,
+                dwPipeMode: u32,
+                nMaxInstances: u32,
+                nOutBufferSize: u32,
+                nInBufferSize: u32,
+                nDefaultTimeOut: u32,
+                lpSecurityAttributes: *mut u8,
+            ) -> RawHandle;
+        }
+
+        unsafe {
+            let h = CreateNamedPipeA(path0.as_ptr(), 3, 0, 1, 0, 0, 0, ptr::null_mut());
+            assert_ne!(h as isize, -1);
+            fs::File::from_raw_handle(h)
+        }
+    }
+
+    let path = "\\\\.\\pipe\\repro";
+    let mut server = create_pipe_server(path);
+
+    let client = Arc::new(
+        fs::OpenOptions::new().custom_flags(FILE_FLAG_OVERLAPPED).read(true).open(path).unwrap(),
+    );
+
+    let spawn_read = |is_first: bool| {
+        thread::spawn({
+            let f = client.clone();
+            move || {
+                let mut buf = [0xcc; 1];
+                let mut f = f.as_ref();
+                f.read(&mut buf).unwrap();
+                if is_first {
+                    assert_ne!(buf[0], 0xcc);
+                } else {
+                    let b = buf[0]; // capture buf[0]
+                    thread::sleep(Duration::from_millis(200));
+
+                    // In this test, success is indicated by failing.
+                    if buf[0] == b {
+                        panic!("Success!");
+                    }
+                }
+            }
+        })
+    };
+
+    let t1 = spawn_read(true);
+    thread::sleep(Duration::from_millis(20));
+    let t2 = spawn_read(false);
+    thread::sleep(Duration::from_millis(100));
+    let _ = server.write(b"x");
+    thread::sleep(Duration::from_millis(100));
+    let _ = server.write(b"y");
+    let _ = t1.join();
+    let _ = t2.join();
+}

From f5edcc2256bfa25a8fd5ae45a2f5243b07c4572e Mon Sep 17 00:00:00 2001
From: Chris Denton <christophersdenton@gmail.com>
Date: Wed, 6 Jul 2022 18:47:44 +0100
Subject: [PATCH 04/21] Fix ui-fulldep test

---
 ...s.rs => issue-81357-unsound-file-methods.rs} | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)
 rename src/test/ui-fulldeps/{issues-81357-unsound-file-methods.rs => issue-81357-unsound-file-methods.rs} (83%)

diff --git a/src/test/ui-fulldeps/issues-81357-unsound-file-methods.rs b/src/test/ui-fulldeps/issue-81357-unsound-file-methods.rs
similarity index 83%
rename from src/test/ui-fulldeps/issues-81357-unsound-file-methods.rs
rename to src/test/ui-fulldeps/issue-81357-unsound-file-methods.rs
index 94b5798a0e7d2..fdf1150f8d25a 100644
--- a/src/test/ui-fulldeps/issues-81357-unsound-file-methods.rs
+++ b/src/test/ui-fulldeps/issue-81357-unsound-file-methods.rs
@@ -55,10 +55,9 @@ fn main() {
                     let b = buf[0]; // capture buf[0]
                     thread::sleep(Duration::from_millis(200));
 
-                    // In this test, success is indicated by failing.
-                    if buf[0] == b {
-                        panic!("Success!");
-                    }
+                    // Check the buffer hasn't been written to after read.
+                    dbg!(buf[0], b);
+                    assert_eq!(buf[0], b);
                 }
             }
         })
@@ -71,6 +70,12 @@ fn main() {
     let _ = server.write(b"x");
     thread::sleep(Duration::from_millis(100));
     let _ = server.write(b"y");
-    let _ = t1.join();
-    let _ = t2.join();
+
+    // This is run fail because we need to test for the `abort`.
+    // That failing to run is the success case.
+    if t1.join().is_err() || t2.join().is_err() {
+        return;
+    } else {
+        panic!("success");
+    }
 }

From d8d064e7a863ac5b5af3397e82e801f091b51a4b Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Wed, 29 Jun 2022 14:25:44 +0000
Subject: [PATCH 05/21] pessimistically treat all function items as containing
 an opaque type

---
 compiler/rustc_middle/src/ty/flags.rs          |  5 +++++
 .../issue-53398-cyclic-types.rs                |  2 +-
 .../issue-53398-cyclic-types.stderr            |  4 +---
 .../ui/type-alias-impl-trait/issue-98604.rs    | 13 +++++++++++++
 .../type-alias-impl-trait/issue-98604.stderr   | 18 ++++++++++++++++++
 .../ui/type-alias-impl-trait/issue-98608.rs    |  9 +++++++++
 .../type-alias-impl-trait/issue-98608.stderr   | 16 ++++++++++++++++
 7 files changed, 63 insertions(+), 4 deletions(-)
 create mode 100644 src/test/ui/type-alias-impl-trait/issue-98604.rs
 create mode 100644 src/test/ui/type-alias-impl-trait/issue-98604.stderr
 create mode 100644 src/test/ui/type-alias-impl-trait/issue-98608.rs
 create mode 100644 src/test/ui/type-alias-impl-trait/issue-98608.stderr

diff --git a/compiler/rustc_middle/src/ty/flags.rs b/compiler/rustc_middle/src/ty/flags.rs
index 7a3d615862cba..63b1352e66b80 100644
--- a/compiler/rustc_middle/src/ty/flags.rs
+++ b/compiler/rustc_middle/src/ty/flags.rs
@@ -207,6 +207,11 @@ impl FlagComputation {
 
             &ty::FnDef(_, substs) => {
                 self.add_substs(substs);
+                // HACK(#98608, oli-obk): Function items with opaque types in their signature will
+                // end up not having the HAS_TY_OPAQUE flag set, causing `evaluate_obligation` to
+                // optimistically assume the function item matches any signature. See documentation
+                // on `HAS_FREE_LOCAL_NAMES` for details.
+                self.add_flags(TypeFlags::HAS_TY_OPAQUE);
             }
 
             &ty::FnPtr(fn_sig) => self.bound_computation(fn_sig, |computation, fn_sig| {
diff --git a/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.rs b/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.rs
index 6c838f410036a..4bc0f9d920087 100644
--- a/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.rs
+++ b/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.rs
@@ -3,7 +3,7 @@
 type Foo = impl Fn() -> Foo;
 
 fn foo() -> Foo {
-    foo //~ ERROR: overflow evaluating the requirement `fn() -> Foo {foo}: Sized`
+    foo //~ ERROR: overflow evaluating the requirement `<fn() -> Foo {foo} as FnOnce<()>>::Output == fn() -> Foo {foo}`
 }
 
 fn main() {}
diff --git a/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.stderr b/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.stderr
index a9c2c18630c01..f69514b7808f5 100644
--- a/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.stderr
+++ b/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.stderr
@@ -1,10 +1,8 @@
-error[E0275]: overflow evaluating the requirement `fn() -> Foo {foo}: Sized`
+error[E0275]: overflow evaluating the requirement `<fn() -> Foo {foo} as FnOnce<()>>::Output == fn() -> Foo {foo}`
   --> $DIR/issue-53398-cyclic-types.rs:6:5
    |
 LL |     foo
    |     ^^^
-   |
-   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_53398_cyclic_types`)
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/type-alias-impl-trait/issue-98604.rs b/src/test/ui/type-alias-impl-trait/issue-98604.rs
new file mode 100644
index 0000000000000..a4fd8a82a04fd
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/issue-98604.rs
@@ -0,0 +1,13 @@
+// edition:2018
+
+type AsyncFnPtr = Box<
+    dyn Fn() -> std::pin::Pin<Box<dyn std::future::Future<Output = ()>>>,
+>;
+
+async fn test() {}
+
+#[allow(unused_must_use)]
+fn main() {
+    Box::new(test) as AsyncFnPtr;
+    //~^ ERROR type mismatch
+}
diff --git a/src/test/ui/type-alias-impl-trait/issue-98604.stderr b/src/test/ui/type-alias-impl-trait/issue-98604.stderr
new file mode 100644
index 0000000000000..f04d1b4d7877e
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/issue-98604.stderr
@@ -0,0 +1,18 @@
+error[E0271]: type mismatch resolving `<fn() -> impl Future<Output = ()> {test} as FnOnce<()>>::Output == Pin<Box<(dyn Future<Output = ()> + 'static)>>`
+  --> $DIR/issue-98604.rs:11:5
+   |
+LL |     Box::new(test) as AsyncFnPtr;
+   |     ^^^^^^^^^^^^^^ expected struct `Pin`, found opaque type
+   |
+note: while checking the return type of the `async fn`
+  --> $DIR/issue-98604.rs:7:17
+   |
+LL | async fn test() {}
+   |                 ^ checked the `Output` of this `async fn`, found opaque type
+   = note:   expected struct `Pin<Box<(dyn Future<Output = ()> + 'static)>>`
+           found opaque type `impl Future<Output = ()>`
+   = note: required for the cast from `fn() -> impl Future<Output = ()> {test}` to the object type `dyn Fn() -> Pin<Box<(dyn Future<Output = ()> + 'static)>>`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0271`.
diff --git a/src/test/ui/type-alias-impl-trait/issue-98608.rs b/src/test/ui/type-alias-impl-trait/issue-98608.rs
new file mode 100644
index 0000000000000..d75762a8b62f0
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/issue-98608.rs
@@ -0,0 +1,9 @@
+fn hi() -> impl Sized { std::ptr::null::<u8>() }
+
+fn main() {
+    let b: Box<dyn Fn() -> Box<u8>> = Box::new(hi);
+    //~^ ERROR type mismatch resolving `<fn() -> impl Sized {hi} as FnOnce<()>>::Output == Box<u8>`
+    let boxed = b();
+    let null = *boxed;
+    println!("{null:?}");
+}
diff --git a/src/test/ui/type-alias-impl-trait/issue-98608.stderr b/src/test/ui/type-alias-impl-trait/issue-98608.stderr
new file mode 100644
index 0000000000000..8f3ec7d9d1616
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/issue-98608.stderr
@@ -0,0 +1,16 @@
+error[E0271]: type mismatch resolving `<fn() -> impl Sized {hi} as FnOnce<()>>::Output == Box<u8>`
+  --> $DIR/issue-98608.rs:4:39
+   |
+LL | fn hi() -> impl Sized { std::ptr::null::<u8>() }
+   |            ---------- the found opaque type
+...
+LL |     let b: Box<dyn Fn() -> Box<u8>> = Box::new(hi);
+   |                                       ^^^^^^^^^^^^ expected struct `Box`, found opaque type
+   |
+   = note:   expected struct `Box<u8>`
+           found opaque type `impl Sized`
+   = note: required for the cast from `fn() -> impl Sized {hi}` to the object type `dyn Fn() -> Box<u8>`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0271`.

From 34a200304c2bf1cc75e6bc1d986827bf7eb18cf3 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Thu, 30 Jun 2022 13:24:35 +0000
Subject: [PATCH 06/21] use a method instead of manually doing what its body
 does

---
 compiler/rustc_infer/src/traits/project.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_infer/src/traits/project.rs b/compiler/rustc_infer/src/traits/project.rs
index b84ed3dc68937..18469208731c8 100644
--- a/compiler/rustc_infer/src/traits/project.rs
+++ b/compiler/rustc_infer/src/traits/project.rs
@@ -203,7 +203,7 @@ impl<'tcx> ProjectionCache<'_, 'tcx> {
             Some(&ProjectionCacheEntry::NormalizedTy { ref ty, complete: _ }) => {
                 info!("ProjectionCacheEntry::complete({:?}) - completing {:?}", key, ty);
                 let mut ty = ty.clone();
-                if result == EvaluationResult::EvaluatedToOk {
+                if result.must_apply_considering_regions() {
                     ty.obligations = vec![];
                 }
                 map.insert(key, ProjectionCacheEntry::NormalizedTy { ty, complete: Some(result) });

From 7e543bb165fe5c8f0f34d70aace232d6e9856321 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Thu, 30 Jun 2022 14:23:31 +0000
Subject: [PATCH 07/21] Make `evaluate_obligation` not succeed unconditionally
 if it registered new hidden types for opaque types

---
 compiler/rustc_infer/src/infer/mod.rs          |  4 ++++
 compiler/rustc_infer/src/infer/undo_log.rs     |  4 ++++
 compiler/rustc_middle/src/traits/select.rs     | 18 ++++++++++++++----
 compiler/rustc_middle/src/ty/flags.rs          |  5 -----
 .../src/traits/error_reporting/suggestions.rs  |  1 +
 .../src/traits/select/mod.rs                   |  4 ++++
 .../issue-53398-cyclic-types.rs                |  2 +-
 .../issue-53398-cyclic-types.stderr            |  4 +++-
 8 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index c9121f7d348ce..989cc551a82f7 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -929,6 +929,10 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             .region_constraints_added_in_snapshot(&snapshot.undo_snapshot)
     }
 
+    pub fn opaque_types_added_in_snapshot(&self, snapshot: &CombinedSnapshot<'a, 'tcx>) -> bool {
+        self.inner.borrow().undo_log.opaque_types_in_snapshot(&snapshot.undo_snapshot)
+    }
+
     pub fn add_given(&self, sub: ty::Region<'tcx>, sup: ty::RegionVid) {
         self.inner.borrow_mut().unwrap_region_constraints().add_given(sub, sup);
     }
diff --git a/compiler/rustc_infer/src/infer/undo_log.rs b/compiler/rustc_infer/src/infer/undo_log.rs
index 1b696f21cbcf4..74a26ebc39f81 100644
--- a/compiler/rustc_infer/src/infer/undo_log.rs
+++ b/compiler/rustc_infer/src/infer/undo_log.rs
@@ -185,6 +185,10 @@ impl<'tcx> InferCtxtUndoLogs<'tcx> {
         })
     }
 
+    pub(crate) fn opaque_types_in_snapshot(&self, s: &Snapshot<'tcx>) -> bool {
+        self.logs[s.undo_len..].iter().any(|log| matches!(log, UndoLog::OpaqueTypes(..)))
+    }
+
     pub(crate) fn region_constraints(
         &self,
     ) -> impl Iterator<Item = &'_ region_constraints::UndoLog<'tcx>> + Clone {
diff --git a/compiler/rustc_middle/src/traits/select.rs b/compiler/rustc_middle/src/traits/select.rs
index ffa70cddbd59c..025059fcbcfb8 100644
--- a/compiler/rustc_middle/src/traits/select.rs
+++ b/compiler/rustc_middle/src/traits/select.rs
@@ -174,6 +174,10 @@ pub enum SelectionCandidate<'tcx> {
 pub enum EvaluationResult {
     /// Evaluation successful.
     EvaluatedToOk,
+    /// Evaluation successful, but need to rerun because opaque types got
+    /// hidden types assigned without it being known whether the opaque types
+    /// are within their defining scope
+    EvaluatedToOkModuloOpaqueTypes,
     /// Evaluation successful, but there were unevaluated region obligations.
     EvaluatedToOkModuloRegions,
     /// Evaluation is known to be ambiguous -- it *might* hold for some
@@ -252,9 +256,11 @@ impl EvaluationResult {
 
     pub fn may_apply(self) -> bool {
         match self {
-            EvaluatedToOk | EvaluatedToOkModuloRegions | EvaluatedToAmbig | EvaluatedToUnknown => {
-                true
-            }
+            EvaluatedToOkModuloOpaqueTypes
+            | EvaluatedToOk
+            | EvaluatedToOkModuloRegions
+            | EvaluatedToAmbig
+            | EvaluatedToUnknown => true,
 
             EvaluatedToErr | EvaluatedToRecur => false,
         }
@@ -264,7 +270,11 @@ impl EvaluationResult {
         match self {
             EvaluatedToUnknown | EvaluatedToRecur => true,
 
-            EvaluatedToOk | EvaluatedToOkModuloRegions | EvaluatedToAmbig | EvaluatedToErr => false,
+            EvaluatedToOkModuloOpaqueTypes
+            | EvaluatedToOk
+            | EvaluatedToOkModuloRegions
+            | EvaluatedToAmbig
+            | EvaluatedToErr => false,
         }
     }
 }
diff --git a/compiler/rustc_middle/src/ty/flags.rs b/compiler/rustc_middle/src/ty/flags.rs
index 63b1352e66b80..7a3d615862cba 100644
--- a/compiler/rustc_middle/src/ty/flags.rs
+++ b/compiler/rustc_middle/src/ty/flags.rs
@@ -207,11 +207,6 @@ impl FlagComputation {
 
             &ty::FnDef(_, substs) => {
                 self.add_substs(substs);
-                // HACK(#98608, oli-obk): Function items with opaque types in their signature will
-                // end up not having the HAS_TY_OPAQUE flag set, causing `evaluate_obligation` to
-                // optimistically assume the function item matches any signature. See documentation
-                // on `HAS_FREE_LOCAL_NAMES` for details.
-                self.add_flags(TypeFlags::HAS_TY_OPAQUE);
             }
 
             &ty::FnPtr(fn_sig) => self.bound_computation(fn_sig, |computation, fn_sig| {
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index d20ba99ebc9b5..60cb5914dada8 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -761,6 +761,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
             Ok(
                 EvaluationResult::EvaluatedToOk
                 | EvaluationResult::EvaluatedToOkModuloRegions
+                | EvaluationResult::EvaluatedToOkModuloOpaqueTypes
                 | EvaluationResult::EvaluatedToAmbig,
             ) => {}
             _ => return false,
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 1c9f83f8f3408..ed4877638bff6 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -388,6 +388,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 Err(_) => return Ok(EvaluatedToErr),
             }
 
+            if self.infcx.opaque_types_added_in_snapshot(snapshot) {
+                return Ok(result.max(EvaluatedToOkModuloOpaqueTypes));
+            }
+
             match self.infcx.region_constraints_added_in_snapshot(snapshot) {
                 None => Ok(result),
                 Some(_) => Ok(result.max(EvaluatedToOkModuloRegions)),
diff --git a/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.rs b/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.rs
index 4bc0f9d920087..6c838f410036a 100644
--- a/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.rs
+++ b/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.rs
@@ -3,7 +3,7 @@
 type Foo = impl Fn() -> Foo;
 
 fn foo() -> Foo {
-    foo //~ ERROR: overflow evaluating the requirement `<fn() -> Foo {foo} as FnOnce<()>>::Output == fn() -> Foo {foo}`
+    foo //~ ERROR: overflow evaluating the requirement `fn() -> Foo {foo}: Sized`
 }
 
 fn main() {}
diff --git a/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.stderr b/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.stderr
index f69514b7808f5..a9c2c18630c01 100644
--- a/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.stderr
+++ b/src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.stderr
@@ -1,8 +1,10 @@
-error[E0275]: overflow evaluating the requirement `<fn() -> Foo {foo} as FnOnce<()>>::Output == fn() -> Foo {foo}`
+error[E0275]: overflow evaluating the requirement `fn() -> Foo {foo}: Sized`
   --> $DIR/issue-53398-cyclic-types.rs:6:5
    |
 LL |     foo
    |     ^^^
+   |
+   = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_53398_cyclic_types`)
 
 error: aborting due to previous error
 

From 838f779c7559f9cbe5841b5eb1a71ce305db1243 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Fri, 1 Jul 2022 13:19:27 +0000
Subject: [PATCH 08/21] Remove type flag based opaque type workaround

---
 compiler/rustc_type_ir/src/lib.rs             |   8 --
 src/test/ui/impl-trait/auto-trait-leak.rs     |   1 -
 src/test/ui/impl-trait/auto-trait-leak.stderr | 112 +++---------------
 .../auto-trait-leakage3.rs                    |   1 -
 .../auto-trait-leakage3.stderr                |  27 +----
 .../type-alias-impl-trait/inference-cycle.rs  |   1 -
 .../inference-cycle.stderr                    |  27 +----
 .../ui/type-alias-impl-trait/reveal_local.rs  |   1 -
 .../type-alias-impl-trait/reveal_local.stderr |  33 +-----
 9 files changed, 30 insertions(+), 181 deletions(-)

diff --git a/compiler/rustc_type_ir/src/lib.rs b/compiler/rustc_type_ir/src/lib.rs
index c63e9c31d535c..a46729f229e23 100644
--- a/compiler/rustc_type_ir/src/lib.rs
+++ b/compiler/rustc_type_ir/src/lib.rs
@@ -61,14 +61,6 @@ bitflags! {
                                           | TypeFlags::HAS_CT_INFER.bits
                                           | TypeFlags::HAS_TY_PLACEHOLDER.bits
                                           | TypeFlags::HAS_CT_PLACEHOLDER.bits
-                                          // The `evaluate_obligation` query does not return further
-                                          // obligations. If it evaluates an obligation with an opaque
-                                          // type, that opaque type may get compared to another type,
-                                          // constraining it. We would lose this information.
-                                          // FIXME: differentiate between crate-local opaque types
-                                          // and opaque types from other crates, as only opaque types
-                                          // from the local crate can possibly be a local name
-                                          | TypeFlags::HAS_TY_OPAQUE.bits
                                           // We consider 'freshened' types and constants
                                           // to depend on a particular fn.
                                           // The freshening process throws away information,
diff --git a/src/test/ui/impl-trait/auto-trait-leak.rs b/src/test/ui/impl-trait/auto-trait-leak.rs
index d2452abab0254..c2fbbf94fd666 100644
--- a/src/test/ui/impl-trait/auto-trait-leak.rs
+++ b/src/test/ui/impl-trait/auto-trait-leak.rs
@@ -11,7 +11,6 @@ fn main() {
 // return type, which can't depend on the obligation.
 fn cycle1() -> impl Clone {
     //~^ ERROR cycle detected
-    //~| ERROR cycle detected
     send(cycle2().clone());
 
     Rc::new(Cell::new(5))
diff --git a/src/test/ui/impl-trait/auto-trait-leak.stderr b/src/test/ui/impl-trait/auto-trait-leak.stderr
index 14db864f1c28a..634ff14869eb4 100644
--- a/src/test/ui/impl-trait/auto-trait-leak.stderr
+++ b/src/test/ui/impl-trait/auto-trait-leak.stderr
@@ -30,129 +30,47 @@ note: ...which requires building MIR for `cycle1`...
 LL | fn cycle1() -> impl Clone {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 note: ...which requires type-checking `cycle1`...
-  --> $DIR/auto-trait-leak.rs:12:1
-   |
-LL | fn cycle1() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires computing type of `cycle2::{opaque#0}`...
-  --> $DIR/auto-trait-leak.rs:20:16
-   |
-LL | fn cycle2() -> impl Clone {
-   |                ^^^^^^^^^^
-note: ...which requires borrow-checking `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
-   |
-LL | fn cycle2() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires processing `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
-   |
-LL | fn cycle2() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires processing MIR for `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
-   |
-LL | fn cycle2() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires unsafety-checking `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
-   |
-LL | fn cycle2() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires building MIR for `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
-   |
-LL | fn cycle2() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires type-checking `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
-   |
-LL | fn cycle2() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-   = note: ...which again requires computing type of `cycle1::{opaque#0}`, completing the cycle
-note: cycle used when checking item types in top-level module
-  --> $DIR/auto-trait-leak.rs:1:1
-   |
-LL | / use std::cell::Cell;
-LL | | use std::rc::Rc;
-LL | |
-LL | | fn send<T: Send>(_: T) {}
-...  |
-LL | |     Rc::new(String::from("foo"))
-LL | | }
-   | |_^
-
-error[E0391]: cycle detected when computing type of `cycle1::{opaque#0}`
-  --> $DIR/auto-trait-leak.rs:12:16
+  --> $DIR/auto-trait-leak.rs:14:5
    |
-LL | fn cycle1() -> impl Clone {
-   |                ^^^^^^^^^^
-   |
-note: ...which requires borrow-checking `cycle1`...
-  --> $DIR/auto-trait-leak.rs:12:1
-   |
-LL | fn cycle1() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires processing `cycle1`...
-  --> $DIR/auto-trait-leak.rs:12:1
-   |
-LL | fn cycle1() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires processing MIR for `cycle1`...
-  --> $DIR/auto-trait-leak.rs:12:1
-   |
-LL | fn cycle1() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires unsafety-checking `cycle1`...
-  --> $DIR/auto-trait-leak.rs:12:1
-   |
-LL | fn cycle1() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires building MIR for `cycle1`...
-  --> $DIR/auto-trait-leak.rs:12:1
-   |
-LL | fn cycle1() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires type-checking `cycle1`...
-  --> $DIR/auto-trait-leak.rs:12:1
-   |
-LL | fn cycle1() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     send(cycle2().clone());
+   |     ^^^^
+   = note: ...which requires evaluating trait selection obligation `impl core::clone::Clone: core::marker::Send`...
 note: ...which requires computing type of `cycle2::{opaque#0}`...
-  --> $DIR/auto-trait-leak.rs:20:16
+  --> $DIR/auto-trait-leak.rs:19:16
    |
 LL | fn cycle2() -> impl Clone {
    |                ^^^^^^^^^^
 note: ...which requires borrow-checking `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
+  --> $DIR/auto-trait-leak.rs:19:1
    |
 LL | fn cycle2() -> impl Clone {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 note: ...which requires processing `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
+  --> $DIR/auto-trait-leak.rs:19:1
    |
 LL | fn cycle2() -> impl Clone {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 note: ...which requires processing MIR for `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
+  --> $DIR/auto-trait-leak.rs:19:1
    |
 LL | fn cycle2() -> impl Clone {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 note: ...which requires unsafety-checking `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
+  --> $DIR/auto-trait-leak.rs:19:1
    |
 LL | fn cycle2() -> impl Clone {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 note: ...which requires building MIR for `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
+  --> $DIR/auto-trait-leak.rs:19:1
    |
 LL | fn cycle2() -> impl Clone {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 note: ...which requires type-checking `cycle2`...
-  --> $DIR/auto-trait-leak.rs:20:1
+  --> $DIR/auto-trait-leak.rs:20:5
    |
-LL | fn cycle2() -> impl Clone {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     send(cycle1().clone());
+   |     ^^^^
+   = note: ...which requires evaluating trait selection obligation `impl core::clone::Clone: core::marker::Send`...
    = note: ...which again requires computing type of `cycle1::{opaque#0}`, completing the cycle
 note: cycle used when checking item types in top-level module
   --> $DIR/auto-trait-leak.rs:1:1
@@ -166,6 +84,6 @@ LL | |     Rc::new(String::from("foo"))
 LL | | }
    | |_^
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0391`.
diff --git a/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.rs b/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.rs
index b456b1445e784..5fb7a9473d3df 100644
--- a/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.rs
+++ b/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.rs
@@ -6,7 +6,6 @@
 mod m {
     type Foo = impl std::fmt::Debug;
     //~^ ERROR: cycle detected when computing type of `m::Foo::{opaque#0}` [E0391]
-    //~| ERROR: cycle detected when computing type of `m::Foo::{opaque#0}` [E0391]
 
     pub fn foo() -> Foo {
         22_u32
diff --git a/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr b/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
index 4c44875b4a548..1e9a45aac79e9 100644
--- a/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
+++ b/src/test/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
@@ -5,10 +5,11 @@ LL |     type Foo = impl std::fmt::Debug;
    |                ^^^^^^^^^^^^^^^^^^^^
    |
 note: ...which requires type-checking `m::bar`...
-  --> $DIR/auto-trait-leakage3.rs:15:5
+  --> $DIR/auto-trait-leakage3.rs:15:9
    |
-LL |     pub fn bar() {
-   |     ^^^^^^^^^^^^
+LL |         is_send(foo());
+   |         ^^^^^^^
+   = note: ...which requires evaluating trait selection obligation `m::Foo: core::marker::Send`...
    = note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
 note: cycle used when checking item types in module `m`
   --> $DIR/auto-trait-leakage3.rs:6:1
@@ -16,24 +17,6 @@ note: cycle used when checking item types in module `m`
 LL | mod m {
    | ^^^^^
 
-error[E0391]: cycle detected when computing type of `m::Foo::{opaque#0}`
-  --> $DIR/auto-trait-leakage3.rs:7:16
-   |
-LL |     type Foo = impl std::fmt::Debug;
-   |                ^^^^^^^^^^^^^^^^^^^^
-   |
-note: ...which requires type-checking `m::bar`...
-  --> $DIR/auto-trait-leakage3.rs:15:5
-   |
-LL |     pub fn bar() {
-   |     ^^^^^^^^^^^^
-   = note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
-note: cycle used when checking item types in module `m`
-  --> $DIR/auto-trait-leakage3.rs:6:1
-   |
-LL | mod m {
-   | ^^^^^
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0391`.
diff --git a/src/test/ui/type-alias-impl-trait/inference-cycle.rs b/src/test/ui/type-alias-impl-trait/inference-cycle.rs
index 608572978a351..79caddf791320 100644
--- a/src/test/ui/type-alias-impl-trait/inference-cycle.rs
+++ b/src/test/ui/type-alias-impl-trait/inference-cycle.rs
@@ -4,7 +4,6 @@
 mod m {
     type Foo = impl std::fmt::Debug;
     //~^ ERROR cycle detected
-    //~| ERROR cycle detected
 
     // Cycle: error today, but it'd be nice if it eventually worked
 
diff --git a/src/test/ui/type-alias-impl-trait/inference-cycle.stderr b/src/test/ui/type-alias-impl-trait/inference-cycle.stderr
index 3ed86fae8a18d..b9d646b927a6f 100644
--- a/src/test/ui/type-alias-impl-trait/inference-cycle.stderr
+++ b/src/test/ui/type-alias-impl-trait/inference-cycle.stderr
@@ -5,10 +5,11 @@ LL |     type Foo = impl std::fmt::Debug;
    |                ^^^^^^^^^^^^^^^^^^^^
    |
 note: ...which requires type-checking `m::bar`...
-  --> $DIR/inference-cycle.rs:15:5
+  --> $DIR/inference-cycle.rs:15:9
    |
-LL |     pub fn bar() {
-   |     ^^^^^^^^^^^^
+LL |         is_send(foo()); // Today: error
+   |         ^^^^^^^
+   = note: ...which requires evaluating trait selection obligation `m::Foo: core::marker::Send`...
    = note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
 note: cycle used when checking item types in module `m`
   --> $DIR/inference-cycle.rs:4:1
@@ -16,24 +17,6 @@ note: cycle used when checking item types in module `m`
 LL | mod m {
    | ^^^^^
 
-error[E0391]: cycle detected when computing type of `m::Foo::{opaque#0}`
-  --> $DIR/inference-cycle.rs:5:16
-   |
-LL |     type Foo = impl std::fmt::Debug;
-   |                ^^^^^^^^^^^^^^^^^^^^
-   |
-note: ...which requires type-checking `m::bar`...
-  --> $DIR/inference-cycle.rs:15:5
-   |
-LL |     pub fn bar() {
-   |     ^^^^^^^^^^^^
-   = note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
-note: cycle used when checking item types in module `m`
-  --> $DIR/inference-cycle.rs:4:1
-   |
-LL | mod m {
-   | ^^^^^
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0391`.
diff --git a/src/test/ui/type-alias-impl-trait/reveal_local.rs b/src/test/ui/type-alias-impl-trait/reveal_local.rs
index 145186baa1faa..7ecb553530106 100644
--- a/src/test/ui/type-alias-impl-trait/reveal_local.rs
+++ b/src/test/ui/type-alias-impl-trait/reveal_local.rs
@@ -4,7 +4,6 @@ use std::fmt::Debug;
 
 type Foo = impl Debug;
 //~^ ERROR cycle detected
-//~| ERROR cycle detected
 
 fn is_send<T: Send>() { }
 
diff --git a/src/test/ui/type-alias-impl-trait/reveal_local.stderr b/src/test/ui/type-alias-impl-trait/reveal_local.stderr
index 5d48dd5b2bf73..27fded3332921 100644
--- a/src/test/ui/type-alias-impl-trait/reveal_local.stderr
+++ b/src/test/ui/type-alias-impl-trait/reveal_local.stderr
@@ -5,10 +5,11 @@ LL | type Foo = impl Debug;
    |            ^^^^^^^^^^
    |
 note: ...which requires type-checking `not_good`...
-  --> $DIR/reveal_local.rs:11:1
+  --> $DIR/reveal_local.rs:13:5
    |
-LL | fn not_good() {
-   | ^^^^^^^^^^^^^
+LL |     is_send::<Foo>();
+   |     ^^^^^^^^^^^^^^
+   = note: ...which requires evaluating trait selection obligation `Foo: core::marker::Send`...
    = note: ...which again requires computing type of `Foo::{opaque#0}`, completing the cycle
 note: cycle used when checking item types in top-level module
   --> $DIR/reveal_local.rs:1:1
@@ -22,30 +23,6 @@ LL | |
 LL | | fn main() {}
    | |____________^
 
-error[E0391]: cycle detected when computing type of `Foo::{opaque#0}`
-  --> $DIR/reveal_local.rs:5:12
-   |
-LL | type Foo = impl Debug;
-   |            ^^^^^^^^^^
-   |
-note: ...which requires type-checking `not_gooder`...
-  --> $DIR/reveal_local.rs:17:1
-   |
-LL | fn not_gooder() {
-   | ^^^^^^^^^^^^^^^
-   = note: ...which again requires computing type of `Foo::{opaque#0}`, completing the cycle
-note: cycle used when checking item types in top-level module
-  --> $DIR/reveal_local.rs:1:1
-   |
-LL | / #![feature(type_alias_impl_trait)]
-LL | |
-LL | | use std::fmt::Debug;
-LL | |
-...  |
-LL | |
-LL | | fn main() {}
-   | |____________^
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0391`.

From 7371ad990d0b62a2a073cc49291a223cd199fa41 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Thu, 7 Jul 2022 08:10:50 +0000
Subject: [PATCH 09/21] not knowing about opaque types is worse than not
 knowing about regions, make sure we don't accidentally mark something as
 ok-modulo-regions if there are opaque types involved

---
 compiler/rustc_middle/src/traits/select.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_middle/src/traits/select.rs b/compiler/rustc_middle/src/traits/select.rs
index 025059fcbcfb8..854dd215a37c0 100644
--- a/compiler/rustc_middle/src/traits/select.rs
+++ b/compiler/rustc_middle/src/traits/select.rs
@@ -174,12 +174,12 @@ pub enum SelectionCandidate<'tcx> {
 pub enum EvaluationResult {
     /// Evaluation successful.
     EvaluatedToOk,
+    /// Evaluation successful, but there were unevaluated region obligations.
+    EvaluatedToOkModuloRegions,
     /// Evaluation successful, but need to rerun because opaque types got
     /// hidden types assigned without it being known whether the opaque types
     /// are within their defining scope
     EvaluatedToOkModuloOpaqueTypes,
-    /// Evaluation successful, but there were unevaluated region obligations.
-    EvaluatedToOkModuloRegions,
     /// Evaluation is known to be ambiguous -- it *might* hold for some
     /// assignment of inference variables, but it might not.
     ///

From 781cbf6b708c2fc2129e0c173941f557d5b840d8 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Fri, 8 Jul 2022 13:59:44 +0000
Subject: [PATCH 10/21] Only register hidden types for opaque types from the
 current crate, nothing else would work anyway.

---
 compiler/rustc_infer/src/infer/opaque_types.rs | 2 +-
 compiler/rustc_middle/src/ty/mod.rs            | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_infer/src/infer/opaque_types.rs b/compiler/rustc_infer/src/infer/opaque_types.rs
index 92c0ed84057a6..3b9b6f7a2af99 100644
--- a/compiler/rustc_infer/src/infer/opaque_types.rs
+++ b/compiler/rustc_infer/src/infer/opaque_types.rs
@@ -99,7 +99,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         }
         let (a, b) = if a_is_expected { (a, b) } else { (b, a) };
         let process = |a: Ty<'tcx>, b: Ty<'tcx>| match *a.kind() {
-            ty::Opaque(def_id, substs) => {
+            ty::Opaque(def_id, substs) if def_id.is_local() => {
                 let origin = if self.defining_use_anchor.is_some() {
                     // Check that this is `impl Trait` type is
                     // declared by `parent_def_id` -- i.e., one whose
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 1c552591b117c..a254979162e83 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -1065,6 +1065,7 @@ impl<'tcx> InstantiatedPredicates<'tcx> {
     Lift
 )]
 pub struct OpaqueTypeKey<'tcx> {
+    // FIXME(oli-obk): make this a LocalDefId
     pub def_id: DefId,
     pub substs: SubstsRef<'tcx>,
 }

From f3b0cb5c5d851d423409cf040cad21624ce55908 Mon Sep 17 00:00:00 2001
From: Raoul Strackx <raoul.strackx@fortanix.com>
Date: Tue, 29 Mar 2022 15:31:42 +0200
Subject: [PATCH 11/21] Unify copying data from enclave to userspace

---
 library/std/src/sys/sgx/abi/usercalls/alloc.rs | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/library/std/src/sys/sgx/abi/usercalls/alloc.rs b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
index 3792a3820a534..9a64b7e4b150c 100644
--- a/library/std/src/sys/sgx/abi/usercalls/alloc.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
@@ -225,13 +225,9 @@ where
     /// Copies `val` into freshly allocated space in user memory.
     pub fn new_from_enclave(val: &T) -> Self {
         unsafe {
-            let ret = Self::new_uninit_bytes(mem::size_of_val(val));
-            ptr::copy(
-                val as *const T as *const u8,
-                ret.0.as_ptr() as *mut u8,
-                mem::size_of_val(val),
-            );
-            ret
+            let mut user = Self::new_uninit_bytes(mem::size_of_val(val));
+            user.copy_from_enclave(val);
+            user
         }
     }
 

From b5d842f65c74a475a0490cc0888a57033c648572 Mon Sep 17 00:00:00 2001
From: Raoul Strackx <raoul.strackx@fortanix.com>
Date: Mon, 28 Mar 2022 14:34:16 +0200
Subject: [PATCH 12/21] Mitigate MMIO stale data vulnerabilities

Intel Security Advisory: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00615.html
---
 .../std/src/sys/sgx/abi/usercalls/alloc.rs    | 100 +++++++++++++++++-
 1 file changed, 98 insertions(+), 2 deletions(-)

diff --git a/library/std/src/sys/sgx/abi/usercalls/alloc.rs b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
index 9a64b7e4b150c..b37e9b257edb4 100644
--- a/library/std/src/sys/sgx/abi/usercalls/alloc.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
@@ -1,13 +1,15 @@
 #![allow(unused)]
 
+use crate::arch::asm;
 use crate::cell::UnsafeCell;
+use crate::convert::TryInto;
 use crate::mem;
 use crate::ops::{CoerceUnsized, Deref, DerefMut, Index, IndexMut};
 use crate::ptr::{self, NonNull};
 use crate::slice;
 use crate::slice::SliceIndex;
 
-use super::super::mem::is_user_range;
+use super::super::mem::{is_enclave_range, is_user_range};
 use fortanix_sgx_abi::*;
 
 /// A type that can be safely read from or written to userspace.
@@ -300,6 +302,100 @@ where
     }
 }
 
+/// Copies `len` bytes of data from enclave pointer `src` to userspace `dst`
+///
+/// This function mitigates stale data vulnerabilities
+/// https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00615.html
+///
+/// # Panics
+/// This function panics if:
+///
+/// * The `src` pointer is null
+/// * The `dst` pointer is null
+/// * The `src` memory range is not in enclave memory
+/// * The `dst` memory range is not in user memory
+unsafe fn copy_to_userspace(src: *const u8, dst: *mut u8, len: usize) {
+    unsafe fn copy_bytewise_to_userspace(src: *const u8, dst: *mut u8, len: usize) {
+        unsafe {
+            let seg_sel: u16 = 0;
+            for off in 0..len {
+                asm!("
+                    mov %ds, ({seg_sel})
+                    verw ({seg_sel})
+                    movb {val}, ({dst})
+                    mfence
+                    lfence
+                     ",
+                    val = in(reg_byte) *src.offset(off as isize),
+                    dst = in(reg) dst.offset(off as isize),
+                    seg_sel = in(reg) &seg_sel,
+                    options(nostack, att_syntax)
+                );
+            }
+        }
+    }
+
+    unsafe fn copy_aligned_quadwords_to_userspace(src: *const u8, dst: *mut u8, len: usize) {
+        unsafe {
+            asm!(
+                "rep movsq (%rsi), (%rdi)",
+                inout("rcx") len / 8 => _,
+                inout("rdi") dst => _,
+                inout("rsi") src => _,
+                options(att_syntax, nostack, preserves_flags)
+            );
+        }
+    }
+    assert!(!src.is_null());
+    assert!(!dst.is_null());
+    assert!(is_enclave_range(src, len));
+    assert!(is_user_range(dst, len));
+    assert!(len < isize::MAX as usize);
+    assert!(!(src as usize).overflowing_add(len).1);
+    assert!(!(dst as usize).overflowing_add(len).1);
+
+    if len < 8 {
+        // Can't align on 8 byte boundary: copy safely byte per byte
+        unsafe {
+            copy_bytewise_to_userspace(src, dst, len);
+        }
+    } else if len % 8 == 0 && dst as usize % 8 == 0 {
+        // Copying 8-byte aligned quadwords: copy quad word per quad word
+        unsafe {
+            copy_aligned_quadwords_to_userspace(src, dst, len);
+        }
+    } else {
+        // Split copies into three parts:
+        //   +--------+
+        //   | small0 | Chunk smaller than 8 bytes
+        //   +--------+
+        //   |   big  | Chunk 8-byte aligned, and size a multiple of 8 bytes
+        //   +--------+
+        //   | small1 | Chunk smaller than 8 bytes
+        //   +--------+
+
+        unsafe {
+            // Copy small0
+            let small0_size = (8 - dst as usize % 8) as u8;
+            let small0_src = src;
+            let small0_dst = dst;
+            copy_bytewise_to_userspace(small0_src as _, small0_dst, small0_size as _);
+
+            // Copy big
+            let small1_size = ((len - small0_size as usize) % 8) as u8;
+            let big_size = len - small0_size as usize - small1_size as usize;
+            let big_src = src.offset(small0_size as _);
+            let big_dst = dst.offset(small0_size as _);
+            copy_aligned_quadwords_to_userspace(big_src as _, big_dst, big_size);
+
+            // Copy small1
+            let small1_src = src.offset(big_size as isize + small0_size as isize);
+            let small1_dst = dst.offset(big_size as isize + small0_size as isize);
+            copy_bytewise_to_userspace(small1_src, small1_dst, small1_size as _);
+        }
+    }
+}
+
 #[unstable(feature = "sgx_platform", issue = "56975")]
 impl<T: ?Sized> UserRef<T>
 where
@@ -348,7 +444,7 @@ where
     pub fn copy_from_enclave(&mut self, val: &T) {
         unsafe {
             assert_eq!(mem::size_of_val(val), mem::size_of_val(&*self.0.get()));
-            ptr::copy(
+            copy_to_userspace(
                 val as *const T as *const u8,
                 self.0.get() as *mut T as *mut u8,
                 mem::size_of_val(val),

From 36e6ca7d110267d98d82aca6648acf45fdafbaf2 Mon Sep 17 00:00:00 2001
From: Raoul Strackx <raoul.strackx@fortanix.com>
Date: Wed, 23 Mar 2022 10:03:00 +0100
Subject: [PATCH 13/21] Ensure userspace allocation is 8-byte aligned

---
 library/std/src/sys/sgx/abi/usercalls/alloc.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/library/std/src/sys/sgx/abi/usercalls/alloc.rs b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
index b37e9b257edb4..4c1f279857f9c 100644
--- a/library/std/src/sys/sgx/abi/usercalls/alloc.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
@@ -2,6 +2,7 @@
 
 use crate::arch::asm;
 use crate::cell::UnsafeCell;
+use crate::cmp;
 use crate::convert::TryInto;
 use crate::mem;
 use crate::ops::{CoerceUnsized, Deref, DerefMut, Index, IndexMut};
@@ -212,7 +213,9 @@ where
         unsafe {
             // Mustn't call alloc with size 0.
             let ptr = if size > 0 {
-                rtunwrap!(Ok, super::alloc(size, T::align_of())) as _
+                // `copy_to_userspace` is more efficient when data is 8-byte aligned
+                let alignment = cmp::max(T::align_of(), 8);
+                rtunwrap!(Ok, super::alloc(size, alignment)) as _
             } else {
                 T::align_of() as _ // dangling pointer ok for size 0
             };

From c1e8e4dbb4a7542f7617b5442179269ec843405e Mon Sep 17 00:00:00 2001
From: Raoul Strackx <raoul.strackx@fortanix.com>
Date: Tue, 22 Mar 2022 17:34:44 +0100
Subject: [PATCH 14/21] Test `copy_to_userspace` function

---
 .../std/src/sys/sgx/abi/usercalls/alloc.rs    |  2 +-
 library/std/src/sys/sgx/abi/usercalls/mod.rs  |  2 ++
 .../std/src/sys/sgx/abi/usercalls/tests.rs    | 30 +++++++++++++++++++
 3 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 library/std/src/sys/sgx/abi/usercalls/tests.rs

diff --git a/library/std/src/sys/sgx/abi/usercalls/alloc.rs b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
index 4c1f279857f9c..4ac27e85f8ba8 100644
--- a/library/std/src/sys/sgx/abi/usercalls/alloc.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
@@ -317,7 +317,7 @@ where
 /// * The `dst` pointer is null
 /// * The `src` memory range is not in enclave memory
 /// * The `dst` memory range is not in user memory
-unsafe fn copy_to_userspace(src: *const u8, dst: *mut u8, len: usize) {
+pub(crate) unsafe fn copy_to_userspace(src: *const u8, dst: *mut u8, len: usize) {
     unsafe fn copy_bytewise_to_userspace(src: *const u8, dst: *mut u8, len: usize) {
         unsafe {
             let seg_sel: u16 = 0;
diff --git a/library/std/src/sys/sgx/abi/usercalls/mod.rs b/library/std/src/sys/sgx/abi/usercalls/mod.rs
index 2f99abba77667..79d1db5e1c50d 100644
--- a/library/std/src/sys/sgx/abi/usercalls/mod.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/mod.rs
@@ -6,6 +6,8 @@ use crate::time::{Duration, Instant};
 pub(crate) mod alloc;
 #[macro_use]
 pub(crate) mod raw;
+#[cfg(test)]
+mod tests;
 
 use self::raw::*;
 
diff --git a/library/std/src/sys/sgx/abi/usercalls/tests.rs b/library/std/src/sys/sgx/abi/usercalls/tests.rs
new file mode 100644
index 0000000000000..cbf7d7d54f7a2
--- /dev/null
+++ b/library/std/src/sys/sgx/abi/usercalls/tests.rs
@@ -0,0 +1,30 @@
+use super::alloc::copy_to_userspace;
+use super::alloc::User;
+
+#[test]
+fn test_copy_function() {
+    let mut src = [0u8; 100];
+    let mut dst = User::<[u8]>::uninitialized(100);
+
+    for i in 0..src.len() {
+        src[i] = i as _;
+    }
+
+    for size in 0..48 {
+        // For all possible alignment
+        for offset in 0..8 {
+            // overwrite complete dst
+            dst.copy_from_enclave(&[0u8; 100]);
+
+            // Copy src[0..size] to dst + offset
+            unsafe { copy_to_userspace(src.as_ptr(), dst.as_mut_ptr().offset(offset), size) };
+
+            // Verify copy
+            for byte in 0..size {
+                unsafe {
+                    assert_eq!(*dst.as_ptr().offset(offset + byte as isize), src[byte as usize]);
+                }
+            }
+        }
+    }
+}

From f835f9cfda1f30bb3ccb104a26f8ed6354effc43 Mon Sep 17 00:00:00 2001
From: Raoul Strackx <raoul.strackx@fortanix.com>
Date: Wed, 22 Jun 2022 13:47:32 +0200
Subject: [PATCH 15/21] Address reviewer comments

---
 library/std/src/sys/sgx/abi/usercalls/alloc.rs | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/library/std/src/sys/sgx/abi/usercalls/alloc.rs b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
index 4ac27e85f8ba8..ea24fedd0eb3d 100644
--- a/library/std/src/sys/sgx/abi/usercalls/alloc.rs
+++ b/library/std/src/sys/sgx/abi/usercalls/alloc.rs
@@ -307,8 +307,9 @@ where
 
 /// Copies `len` bytes of data from enclave pointer `src` to userspace `dst`
 ///
-/// This function mitigates stale data vulnerabilities
-/// https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00615.html
+/// This function mitigates stale data vulnerabilities by ensuring all writes to untrusted memory are either:
+///  - preceded by the VERW instruction and followed by the MFENCE; LFENCE instruction sequence
+///  - or are in multiples of 8 bytes, aligned to an 8-byte boundary
 ///
 /// # Panics
 /// This function panics if:
@@ -317,10 +318,14 @@ where
 /// * The `dst` pointer is null
 /// * The `src` memory range is not in enclave memory
 /// * The `dst` memory range is not in user memory
+///
+/// # References
+///  - https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00615.html
+///  - https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/processor-mmio-stale-data-vulnerabilities.html#inpage-nav-3-2-2
 pub(crate) unsafe fn copy_to_userspace(src: *const u8, dst: *mut u8, len: usize) {
     unsafe fn copy_bytewise_to_userspace(src: *const u8, dst: *mut u8, len: usize) {
         unsafe {
-            let seg_sel: u16 = 0;
+            let mut seg_sel: u16 = 0;
             for off in 0..len {
                 asm!("
                     mov %ds, ({seg_sel})
@@ -328,10 +333,10 @@ pub(crate) unsafe fn copy_to_userspace(src: *const u8, dst: *mut u8, len: usize)
                     movb {val}, ({dst})
                     mfence
                     lfence
-                     ",
+                    ",
                     val = in(reg_byte) *src.offset(off as isize),
                     dst = in(reg) dst.offset(off as isize),
-                    seg_sel = in(reg) &seg_sel,
+                    seg_sel = in(reg) &mut seg_sel,
                     options(nostack, att_syntax)
                 );
             }

From d8c7a157e677cae4af99132e5ef039ef5d50a330 Mon Sep 17 00:00:00 2001
From: Camille GILLOT <gillot.camille@gmail.com>
Date: Tue, 5 Jul 2022 21:54:38 +0200
Subject: [PATCH 16/21] Return a FxIndexSet in is_late_bound query.

This return value is iterated upon by borrowck, hence the need to preserve
a deterministic iteration order.
---
 compiler/rustc_middle/src/arena.rs                   | 1 +
 compiler/rustc_middle/src/middle/resolve_lifetime.rs | 4 ++--
 compiler/rustc_middle/src/query/mod.rs               | 2 +-
 compiler/rustc_middle/src/ty/query.rs                | 2 +-
 compiler/rustc_resolve/src/late/lifetimes.rs         | 4 ++--
 5 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/compiler/rustc_middle/src/arena.rs b/compiler/rustc_middle/src/arena.rs
index 7c90cbb9092b8..c1ec5d68a7b6b 100644
--- a/compiler/rustc_middle/src/arena.rs
+++ b/compiler/rustc_middle/src/arena.rs
@@ -85,6 +85,7 @@ macro_rules! arena_types {
             [] attribute: rustc_ast::Attribute,
             [] name_set: rustc_data_structures::fx::FxHashSet<rustc_span::symbol::Symbol>,
             [] hir_id_set: rustc_hir::HirIdSet,
+            [] late_bound_lifetimes: rustc_data_structures::fx::FxIndexSet<rustc_hir::def_id::LocalDefId>,
 
             // Interned types
             [] tys: rustc_data_structures::intern::WithStableHash<rustc_middle::ty::TyS<'tcx>>,
diff --git a/compiler/rustc_middle/src/middle/resolve_lifetime.rs b/compiler/rustc_middle/src/middle/resolve_lifetime.rs
index 70586cefaeee1..11ce6313147d4 100644
--- a/compiler/rustc_middle/src/middle/resolve_lifetime.rs
+++ b/compiler/rustc_middle/src/middle/resolve_lifetime.rs
@@ -2,7 +2,7 @@
 
 use crate::ty;
 
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::{FxHashMap, FxIndexSet};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::ItemLocalId;
 use rustc_macros::HashStable;
@@ -64,7 +64,7 @@ pub struct ResolveLifetimes {
     /// Set of lifetime def ids that are late-bound; a region can
     /// be late-bound if (a) it does NOT appear in a where-clause and
     /// (b) it DOES appear in the arguments.
-    pub late_bound: FxHashMap<LocalDefId, FxHashSet<LocalDefId>>,
+    pub late_bound: FxHashMap<LocalDefId, FxIndexSet<LocalDefId>>,
 
     pub late_bound_vars: FxHashMap<LocalDefId, FxHashMap<ItemLocalId, Vec<ty::BoundVariableKind>>>,
 }
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 6d7ec247d0452..a23ff302a40aa 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -1537,7 +1537,7 @@ rustc_queries! {
         Option<&'tcx FxHashMap<ItemLocalId, Region>> {
         desc { "looking up a named region" }
     }
-    query is_late_bound_map(_: LocalDefId) -> Option<(LocalDefId, &'tcx FxHashSet<LocalDefId>)> {
+    query is_late_bound_map(_: LocalDefId) -> Option<(LocalDefId, &'tcx FxIndexSet<LocalDefId>)> {
         desc { "testing if a region is late bound" }
     }
     /// For a given item (like a struct), gets the default lifetimes to be used
diff --git a/compiler/rustc_middle/src/ty/query.rs b/compiler/rustc_middle/src/ty/query.rs
index fb937ded65af1..1bb49a59ba47b 100644
--- a/compiler/rustc_middle/src/ty/query.rs
+++ b/compiler/rustc_middle/src/ty/query.rs
@@ -36,7 +36,7 @@ use crate::ty::{self, AdtSizedConstraint, CrateInherentImpls, ParamEnvAnd, Ty, T
 use rustc_ast as ast;
 use rustc_ast::expand::allocator::AllocatorKind;
 use rustc_attr as attr;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_data_structures::steal::Steal;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::Lrc;
diff --git a/compiler/rustc_resolve/src/late/lifetimes.rs b/compiler/rustc_resolve/src/late/lifetimes.rs
index ff75e4eae3568..7f7c8ec53aa1b 100644
--- a/compiler/rustc_resolve/src/late/lifetimes.rs
+++ b/compiler/rustc_resolve/src/late/lifetimes.rs
@@ -8,7 +8,7 @@
 
 use crate::late::diagnostics::{ForLifetimeSpanType, MissingLifetimeSpot};
 use rustc_ast::walk_list;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_errors::{struct_span_err, Applicability, Diagnostic};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
@@ -540,7 +540,7 @@ fn item_for(tcx: TyCtxt<'_>, local_def_id: LocalDefId) -> LocalDefId {
 fn is_late_bound_map<'tcx>(
     tcx: TyCtxt<'tcx>,
     def_id: LocalDefId,
-) -> Option<(LocalDefId, &'tcx FxHashSet<LocalDefId>)> {
+) -> Option<(LocalDefId, &'tcx FxIndexSet<LocalDefId>)> {
     match tcx.def_kind(def_id) {
         DefKind::AnonConst | DefKind::InlineConst => {
             let mut def_id = tcx.local_parent(def_id);

From 5a4723abe4077e70c47dc788979f7bb2876679fd Mon Sep 17 00:00:00 2001
From: Camille GILLOT <gillot.camille@gmail.com>
Date: Wed, 6 Jul 2022 10:56:35 +0200
Subject: [PATCH 17/21] Add regression test.

---
 src/test/incremental/async-lifetimes.rs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 src/test/incremental/async-lifetimes.rs

diff --git a/src/test/incremental/async-lifetimes.rs b/src/test/incremental/async-lifetimes.rs
new file mode 100644
index 0000000000000..b97725d3b6a7d
--- /dev/null
+++ b/src/test/incremental/async-lifetimes.rs
@@ -0,0 +1,17 @@
+// revisions: rpass1 rpass2
+// edition:2021
+
+#![allow(unused)]
+
+struct Foo;
+
+impl Foo {
+    async fn f(&self, _: &&()) -> &() {
+        &()
+    }
+}
+
+#[cfg(rpass2)]
+enum Bar {}
+
+fn main() {}

From f1aa6522abfdd9d39f5a86f48fce2d89e7dd6325 Mon Sep 17 00:00:00 2001
From: Michael Woerister <michaelwoerister@users.noreply.github.com>
Date: Wed, 6 Jul 2022 11:32:55 +0200
Subject: [PATCH 18/21] Add link to issue for
 src/test/incremental/async-lifetimes.rs

---
 src/test/incremental/async-lifetimes.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/test/incremental/async-lifetimes.rs b/src/test/incremental/async-lifetimes.rs
index b97725d3b6a7d..90a0b93b99a13 100644
--- a/src/test/incremental/async-lifetimes.rs
+++ b/src/test/incremental/async-lifetimes.rs
@@ -1,6 +1,8 @@
 // revisions: rpass1 rpass2
 // edition:2021
 
+// See https://github.com/rust-lang/rust/issues/98890
+
 #![allow(unused)]
 
 struct Foo;

From 94ed9c9790de180c67c7e3fadef39975b7fda632 Mon Sep 17 00:00:00 2001
From: Camille GILLOT <gillot.camille@gmail.com>
Date: Thu, 14 Jul 2022 00:32:01 +0200
Subject: [PATCH 19/21] Sort query output.

---
 compiler/rustc_resolve/src/late/lifetimes.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/compiler/rustc_resolve/src/late/lifetimes.rs b/compiler/rustc_resolve/src/late/lifetimes.rs
index 7f7c8ec53aa1b..9b4184840bd27 100644
--- a/compiler/rustc_resolve/src/late/lifetimes.rs
+++ b/compiler/rustc_resolve/src/late/lifetimes.rs
@@ -482,6 +482,11 @@ fn convert_named_region_map(tcx: TyCtxt<'_>, named_region_map: NamedRegionMap) -
         let def_id = tcx.hir().local_def_id(hir_id);
         map.insert(def_id);
     }
+    for (_, late_bound) in &mut rl.late_bound {
+        late_bound.sort_by(|&a, &b| {
+            tcx.def_path_hash(a.to_def_id()).cmp(&tcx.def_path_hash(b.to_def_id()))
+        });
+    }
     for (hir_id, v) in named_region_map.late_bound_vars {
         let map = rl.late_bound_vars.entry(hir_id.owner).or_default();
         map.insert(hir_id.local_id, v);

From 650421c07156415e270b6456b0194c9094edd639 Mon Sep 17 00:00:00 2001
From: Mark Rousskov <mark.simulacrum@gmail.com>
Date: Fri, 15 Jul 2022 17:51:06 -0400
Subject: [PATCH 20/21] Release 1.62.1

---
 RELEASES.md | 18 ++++++++++++++++++
 src/version |  2 +-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/RELEASES.md b/RELEASES.md
index 3d88891ad215c..fa82077e65bb3 100644
--- a/RELEASES.md
+++ b/RELEASES.md
@@ -1,3 +1,21 @@
+Version 1.62.1 (2022-07-19)
+==========================
+
+Rust 1.62.1 addresses a few recent regressions in the compiler and standard
+library, and also mitigates a CPU vulnerability on Intel SGX.
+
+* [The compiler fixed unsound function coercions involving `impl Trait` return types.][98608]
+* [The compiler fixed an incremental compilation bug with `async fn` lifetimes.][98890]
+* [Windows added a fallback for overlapped I/O in synchronous reads and writes.][98950]
+* [The `x86_64-fortanix-unknown-sgx` target added a mitigation for the
+  MMIO stale data vulnerability][98126], advisory [INTEL-SA-00615].
+
+[98608]: https://github.com/rust-lang/rust/issues/98608
+[98890]: https://github.com/rust-lang/rust/issues/98890
+[98950]: https://github.com/rust-lang/rust/pull/98950
+[98126]: https://github.com/rust-lang/rust/pull/98126
+[INTEL-SA-00615]: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00615.html
+
 Version 1.62.0 (2022-06-30)
 ==========================
 
diff --git a/src/version b/src/version
index 76d0536205683..b77a81dcb12a8 100644
--- a/src/version
+++ b/src/version
@@ -1 +1 @@
-1.62.0
+1.62.1

From 647922f9d8a6f1fa639ab206e60a76d43cc9d3dd Mon Sep 17 00:00:00 2001
From: Mark Rousskov <mark.simulacrum@gmail.com>
Date: Sat, 9 Jul 2022 18:16:53 -0400
Subject: [PATCH 21/21] Fix tests after beta backport

---
 src/test/ui/type-alias-impl-trait/issue-98604.stderr | 2 +-
 src/test/ui/type-alias-impl-trait/issue-98608.stderr | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/test/ui/type-alias-impl-trait/issue-98604.stderr b/src/test/ui/type-alias-impl-trait/issue-98604.stderr
index f04d1b4d7877e..ad3982760c39c 100644
--- a/src/test/ui/type-alias-impl-trait/issue-98604.stderr
+++ b/src/test/ui/type-alias-impl-trait/issue-98604.stderr
@@ -11,7 +11,7 @@ LL | async fn test() {}
    |                 ^ checked the `Output` of this `async fn`, found opaque type
    = note:   expected struct `Pin<Box<(dyn Future<Output = ()> + 'static)>>`
            found opaque type `impl Future<Output = ()>`
-   = note: required for the cast from `fn() -> impl Future<Output = ()> {test}` to the object type `dyn Fn() -> Pin<Box<(dyn Future<Output = ()> + 'static)>>`
+   = note: required for the cast to the object type `dyn Fn() -> Pin<Box<(dyn Future<Output = ()> + 'static)>>`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/type-alias-impl-trait/issue-98608.stderr b/src/test/ui/type-alias-impl-trait/issue-98608.stderr
index 8f3ec7d9d1616..6773b01112d87 100644
--- a/src/test/ui/type-alias-impl-trait/issue-98608.stderr
+++ b/src/test/ui/type-alias-impl-trait/issue-98608.stderr
@@ -9,7 +9,7 @@ LL |     let b: Box<dyn Fn() -> Box<u8>> = Box::new(hi);
    |
    = note:   expected struct `Box<u8>`
            found opaque type `impl Sized`
-   = note: required for the cast from `fn() -> impl Sized {hi}` to the object type `dyn Fn() -> Box<u8>`
+   = note: required for the cast to the object type `dyn Fn() -> Box<u8>`
 
 error: aborting due to previous error