Auto merge of #61527 - pietroalbini:rollup-vhxyqlk, r=pietroalbini

Rollup of 5 pull requests

Successful merges:

 - #61069 (Make MIR drop terminators borrow the dropped location)
 - #61453 (Remove unneeded feature attr from atomic integers doctests)
 - #61488 (Fix NLL typeck ICEs)
 - #61500 (Fix regression 61475)
 - #61523 (Hide gen_future API from documentation)

Failed merges:

r? @ghost

src/libcore/sync/atomic.rs

@@ -1899,7 +1899,7 @@ atomic_int! {
     stable(feature = "integer_atomics_stable", since = "1.34.0"),
     unstable(feature = "integer_atomics", issue = "32976"),
     "i8", "../../../std/primitive.i8.html",
-    "#![feature(integer_atomics)]\n\n",
+    "",
     atomic_min, atomic_max,
     1,
     "AtomicI8::new(0)",
@@ -1915,7 +1915,7 @@ atomic_int! {
     stable(feature = "integer_atomics_stable", since = "1.34.0"),
     unstable(feature = "integer_atomics", issue = "32976"),
     "u8", "../../../std/primitive.u8.html",
-    "#![feature(integer_atomics)]\n\n",
+    "",
     atomic_umin, atomic_umax,
     1,
     "AtomicU8::new(0)",
@@ -1931,7 +1931,7 @@ atomic_int! {
     stable(feature = "integer_atomics_stable", since = "1.34.0"),
     unstable(feature = "integer_atomics", issue = "32976"),
     "i16", "../../../std/primitive.i16.html",
-    "#![feature(integer_atomics)]\n\n",
+    "",
     atomic_min, atomic_max,
     2,
     "AtomicI16::new(0)",
@@ -1947,7 +1947,7 @@ atomic_int! {
     stable(feature = "integer_atomics_stable", since = "1.34.0"),
     unstable(feature = "integer_atomics", issue = "32976"),
     "u16", "../../../std/primitive.u16.html",
-    "#![feature(integer_atomics)]\n\n",
+    "",
     atomic_umin, atomic_umax,
     2,
     "AtomicU16::new(0)",
@@ -1963,7 +1963,7 @@ atomic_int! {
     stable(feature = "integer_atomics_stable", since = "1.34.0"),
     unstable(feature = "integer_atomics", issue = "32976"),
     "i32", "../../../std/primitive.i32.html",
-    "#![feature(integer_atomics)]\n\n",
+    "",
     atomic_min, atomic_max,
     4,
     "AtomicI32::new(0)",
@@ -1979,7 +1979,7 @@ atomic_int! {
     stable(feature = "integer_atomics_stable", since = "1.34.0"),
     unstable(feature = "integer_atomics", issue = "32976"),
     "u32", "../../../std/primitive.u32.html",
-    "#![feature(integer_atomics)]\n\n",
+    "",
     atomic_umin, atomic_umax,
     4,
     "AtomicU32::new(0)",
@@ -1995,7 +1995,7 @@ atomic_int! {
     stable(feature = "integer_atomics_stable", since = "1.34.0"),
     unstable(feature = "integer_atomics", issue = "32976"),
     "i64", "../../../std/primitive.i64.html",
-    "#![feature(integer_atomics)]\n\n",
+    "",
     atomic_min, atomic_max,
     8,
     "AtomicI64::new(0)",
@@ -2011,7 +2011,7 @@ atomic_int! {
     stable(feature = "integer_atomics_stable", since = "1.34.0"),
     unstable(feature = "integer_atomics", issue = "32976"),
     "u64", "../../../std/primitive.u64.html",
-    "#![feature(integer_atomics)]\n\n",
+    "",
     atomic_umin, atomic_umax,
     8,
     "AtomicU64::new(0)",

src/librustc/infer/canonical/canonicalizer.rs

@@ -115,13 +115,17 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> {
 
     /// A hacky variant of `canonicalize_query` that does not
     /// canonicalize `'static`. Unfortunately, the existing leak
-    /// check treaks `'static` differently in some cases (see also
+    /// check treats `'static` differently in some cases (see also
     /// #33684), so if we are performing an operation that may need to
     /// prove "leak-check" related things, we leave `'static`
     /// alone.
+    ///
+    /// `'static` is also special cased when winnowing candidates when
+    /// selecting implementation candidates, so we also have to leave `'static`
+    /// alone for queries that do selection.
     //
-    // FIXME(#48536): once we have universes, we can remove this and just use
-    // `canonicalize_query`.
+    // FIXME(#48536): once the above issues are resolved, we can remove this
+    // and just use `canonicalize_query`.
     pub fn canonicalize_hr_query_hack<V>(
         &self,
         value: &V,

src/librustc/traits/query/normalize.rs

@@ -145,7 +145,9 @@ impl<'cx, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for QueryNormalizer<'cx, 'gcx, 'tcx
                 let gcx = self.infcx.tcx.global_tcx();
 
                 let mut orig_values = OriginalQueryValues::default();
-                let c_data = self.infcx.canonicalize_query(
+                // HACK(matthewjasper) `'static` is special-cased in selection,
+                // so we cannot canonicalize it.
+                let c_data = self.infcx.canonicalize_hr_query_hack(
                     &self.param_env.and(*data), &mut orig_values);
                 debug!("QueryNormalizer: c_data = {:#?}", c_data);
                 debug!("QueryNormalizer: orig_values = {:#?}", orig_values);

src/librustc_mir/borrow_check/nll/type_check/free_region_relations.rs

@@ -334,6 +334,13 @@ impl UniversalRegionRelationsBuilder<'cx, 'gcx, 'tcx> {
 
             match outlives_bound {
                 OutlivesBound::RegionSubRegion(r1, r2) => {
+                    // `where Type:` is lowered to `where Type: 'empty` so that
+                    // we check `Type` is well formed, but there's no use for
+                    // this bound here.
+                    if let ty::ReEmpty = r1 {
+                        return;
+                    }
+
                     // The bound says that `r1 <= r2`; we store `r2: r1`.
                     let r1 = self.universal_regions.to_region_vid(r1);
                     let r2 = self.universal_regions.to_region_vid(r2);

src/librustc_mir/dataflow/impls/borrowed_locals.rs

@@ -56,9 +56,20 @@ impl<'a, 'tcx> BitDenotation<'tcx> for HaveBeenBorrowedLocals<'a, 'tcx> {
     fn terminator_effect(&self,
                          sets: &mut BlockSets<'_, Local>,
                          loc: Location) {
+        let terminator = self.mir[loc.block].terminator();
         BorrowedLocalsVisitor {
             sets,
-        }.visit_terminator(self.mir[loc.block].terminator(), loc);
+        }.visit_terminator(terminator, loc);
+        match &terminator.kind {
+            // Drop terminators borrows the location
+            TerminatorKind::Drop { location, .. } |
+            TerminatorKind::DropAndReplace { location, .. } => {
+                if let Some(local) = find_local(location) {
+                    sets.gen(local);
+                }
+            }
+            _ => (),
+        }
     }
 
     fn propagate_call_return(

src/libstd/future.rs

@@ -16,12 +16,14 @@ pub use core::future::*;
 ///
 /// This function returns a `GenFuture` underneath, but hides it in `impl Trait` to give
 /// better error messages (`impl Future` rather than `GenFuture<[closure.....]>`).
+#[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
 pub fn from_generator<T: Generator<Yield = ()>>(x: T) -> impl Future<Output = T::Return> {
     GenFuture(x)
 }
 
 /// A wrapper around generators used to implement `Future` for `async`/`await` code.
+#[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
 struct GenFuture<T: Generator<Yield = ()>>(T);
@@ -30,6 +32,7 @@ struct GenFuture<T: Generator<Yield = ()>>(T);
 // self-referential borrows in the underlying generator.
 impl<T: Generator<Yield = ()>> !Unpin for GenFuture<T> {}
 
+#[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
 impl<T: Generator<Yield = ()>> Future for GenFuture<T> {
     type Output = T::Return;
@@ -57,6 +60,7 @@ impl Drop for SetOnDrop {
     }
 }
 
+#[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
 /// Sets the thread-local task context used by async/await futures.
 pub fn set_task_context<F, R>(cx: &mut Context<'_>, f: F) -> R
@@ -74,6 +78,7 @@ where
     f()
 }
 
+#[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
 /// Retrieves the thread-local task context used by async/await futures.
 ///
@@ -105,6 +110,7 @@ where
     unsafe { f(cx_ptr.as_mut()) }
 }
 
+#[doc(hidden)]
 #[unstable(feature = "gen_future", issue = "50547")]
 /// Polls a future in the current thread-local task waker.
 pub fn poll_with_tls_context<F>(f: Pin<&mut F>) -> Poll<F::Output>

src/libsyntax/parse/parser.rs

@@ -628,10 +628,10 @@ impl<'a> Parser<'a> {
             }
             _ => {
                 Err(if self.prev_token_kind == PrevTokenKind::DocComment {
-                        self.span_fatal_err(self.prev_span, Error::UselessDocComment)
-                    } else {
-                        self.expected_ident_found()
-                    })
+                    self.span_fatal_err(self.prev_span, Error::UselessDocComment)
+                } else {
+                    self.expected_ident_found()
+                })
             }
         }
     }
@@ -1657,8 +1657,8 @@ impl<'a> Parser<'a> {
             path = self.parse_path(PathStyle::Type)?;
             path_span = path_lo.to(self.prev_span);
         } else {
-            path = ast::Path { segments: Vec::new(), span: DUMMY_SP };
             path_span = self.span.to(self.span);
+            path = ast::Path { segments: Vec::new(), span: path_span };
         }
 
         // See doc comment for `unmatched_angle_bracket_count`.
@@ -2844,7 +2844,11 @@ impl<'a> Parser<'a> {
             // want to keep their span info to improve diagnostics in these cases in a later stage.
             (true, Some(AssocOp::Multiply)) | // `{ 42 } *foo = bar;` or `{ 42 } * 3`
             (true, Some(AssocOp::Subtract)) | // `{ 42 } -5`
-            (true, Some(AssocOp::Add)) => { // `{ 42 } + 42
+            (true, Some(AssocOp::LAnd)) | // `{ 42 } &&x` (#61475)
+            (true, Some(AssocOp::Add)) // `{ 42 } + 42
+            // If the next token is a keyword, then the tokens above *are* unambiguously incorrect:
+            // `if x { a } else { b } && if y { c } else { d }`
+            if !self.look_ahead(1, |t| t.is_reserved_ident()) => {
                 // These cases are ambiguous and can't be identified in the parser alone
                 let sp = self.sess.source_map().start_point(self.span);
                 self.sess.ambiguous_block_expr_parse.borrow_mut().insert(sp, lhs.span);
@@ -5298,7 +5302,7 @@ impl<'a> Parser<'a> {
         let mut where_clause = WhereClause {
             id: ast::DUMMY_NODE_ID,
             predicates: Vec::new(),
-            span: DUMMY_SP,
+            span: self.prev_span.to(self.prev_span),
         };
 
         if !self.eat_keyword(kw::Where) {

src/test/ui/consts/min_const_fn/min_const_fn_libstd.rs

@@ -1,5 +1,3 @@
-#![feature(integer_atomics)]
-
 // compile-pass
 
 use std::cell::UnsafeCell;

src/test/ui/issues/issue-61475.rs

@@ -0,0 +1,15 @@
+// run-pass
+#![allow(dead_code)]
+
+enum E {
+    A, B
+}
+
+fn main() {
+    match &&E::A {
+        &&E::A => {
+        }
+        &&E::B => {
+        }
+    };
+}

src/test/ui/nll/empty-type-predicate.rs

@@ -0,0 +1,11 @@
+// Regression test for #61315
+//
+// `dyn T:` is lowered to `dyn T: ReEmpty` - check that we don't ICE in NLL for
+// the unexpected region.
+
+// compile-pass
+
+trait T {}
+fn f() where dyn T: {}
+
+fn main() {}

src/test/ui/nll/issue-61311-normalize.rs

@@ -0,0 +1,34 @@
+// Regression test for #61311
+// We would ICE after failing to normalize `Self::Proj` in the `impl` below.
+
+// compile-pass
+
+pub struct Unit;
+trait Obj {}
+
+trait Bound {}
+impl Bound for Unit {}
+
+pub trait HasProj {
+    type Proj;
+}
+
+impl<T> HasProj for T {
+    type Proj = Unit;
+}
+
+trait HasProjFn {
+    type Proj;
+    fn the_fn(_: Self::Proj);
+}
+
+impl HasProjFn for Unit
+where
+    Box<dyn Obj + 'static>: HasProj,
+    <Box<dyn Obj + 'static> as HasProj>::Proj: Bound,
+{
+    type Proj = Unit;
+    fn the_fn(_: Self::Proj) {}
+}
+
+fn main() {}

src/test/ui/nll/issue-61320-normalize.rs

@@ -0,0 +1,160 @@
+// Regression test for #61320
+// This is the same issue as #61311, just a larger test case.
+
+// compile-pass
+
+pub struct AndThen<A, B, F>
+where
+    A: Future,
+    B: IntoFuture,
+{
+    state: (A, B::Future, F),
+}
+
+pub struct FutureResult<T, E> {
+    inner: Option<Result<T, E>>,
+}
+
+impl<T, E> Future for FutureResult<T, E> {
+    type Item = T;
+    type Error = E;
+
+    fn poll(&mut self) -> Poll<T, E> {
+        unimplemented!()
+    }
+}
+
+pub type Poll<T, E> = Result<T, E>;
+
+impl<A, B, F> Future for AndThen<A, B, F>
+where
+    A: Future,
+    B: IntoFuture<Error = A::Error>,
+    F: FnOnce(A::Item) -> B,
+{
+    type Item = B::Item;
+    type Error = B::Error;
+
+    fn poll(&mut self) -> Poll<B::Item, B::Error> {
+        unimplemented!()
+    }
+}
+
+pub trait Future {
+    type Item;
+
+    type Error;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error>;
+
+    fn and_then<F, B>(self, f: F) -> AndThen<Self, B, F>
+    where
+        F: FnOnce(Self::Item) -> B,
+        B: IntoFuture<Error = Self::Error>,
+        Self: Sized,
+    {
+        unimplemented!()
+    }
+}
+
+pub trait IntoFuture {
+    /// The future that this type can be converted into.
+    type Future: Future<Item = Self::Item, Error = Self::Error>;
+
+    /// The item that the future may resolve with.
+    type Item;
+    /// The error that the future may resolve with.
+    type Error;
+
+    /// Consumes this object and produces a future.
+    fn into_future(self) -> Self::Future;
+}
+
+impl<F: Future> IntoFuture for F {
+    type Future = F;
+    type Item = F::Item;
+    type Error = F::Error;
+
+    fn into_future(self) -> F {
+        self
+    }
+}
+
+impl<F: ?Sized + Future> Future for ::std::boxed::Box<F> {
+    type Item = F::Item;
+    type Error = F::Error;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        (**self).poll()
+    }
+}
+
+impl<T, E> IntoFuture for Result<T, E> {
+    type Future = FutureResult<T, E>;
+    type Item = T;
+    type Error = E;
+
+    fn into_future(self) -> FutureResult<T, E> {
+        unimplemented!()
+    }
+}
+
+struct Request<T>(T);
+
+trait RequestContext {}
+impl<T> RequestContext for T {}
+struct NoContext;
+impl AsRef<NoContext> for NoContext {
+    fn as_ref(&self) -> &Self {
+        &NoContext
+    }
+}
+
+type BoxedError = Box<dyn std::error::Error + Send + Sync>;
+type DefaultFuture<T, E> = Box<dyn Future<Item = T, Error = E> + Send>;
+
+trait Guard: Sized {
+    type Result: IntoFuture<Item = Self, Error = BoxedError>;
+    fn from_request(request: &Request<()>) -> Self::Result;
+}
+
+trait FromRequest: Sized {
+    type Context;
+    type Future: Future<Item = Self, Error = BoxedError> + Send;
+    fn from_request(request: Request<()>) -> Self::Future;
+}
+
+struct MyGuard;
+impl Guard for MyGuard {
+    type Result = Result<Self, BoxedError>;
+    fn from_request(_request: &Request<()>) -> Self::Result {
+        Ok(MyGuard)
+    }
+}
+
+struct Generic<I> {
+    _inner: I,
+}
+
+impl<I> FromRequest for Generic<I>
+where
+    MyGuard: Guard,
+    <MyGuard as Guard>::Result: IntoFuture<Item = MyGuard, Error = BoxedError>,
+    <<MyGuard as Guard>::Result as IntoFuture>::Future: Send,
+    I: FromRequest<Context = NoContext>,
+{
+    type Future = DefaultFuture<Self, BoxedError>;
+    type Context = NoContext;
+    fn from_request(headers: Request<()>) -> DefaultFuture<Self, BoxedError> {
+        let _future = <MyGuard as Guard>::from_request(&headers)
+            .into_future()
+            .and_then(move |_| {
+                <I as FromRequest>::from_request(headers)
+                    .into_future()
+                    .and_then(move |fld_inner| Ok(Generic { _inner: fld_inner }).into_future())
+            });
+        panic!();
+    }
+}
+
+fn main() {}