Rollup of 5 pull requests

src/bootstrap/builder.rs

@@ -1099,6 +1099,13 @@ impl<'a> Builder<'a> {
 
             if self.config.deny_warnings {
                 rustflags.arg("-Dwarnings");
+
+                // FIXME(#58633) hide "unused attribute" errors in incremental
+                // builds of the standard library, as the underlying checks are
+                // not yet properly integrated with incremental recompilation.
+                if mode == Mode::Std && compiler.stage == 0 && self.config.incremental {
+                    rustflags.arg("-Aunused-attributes");
+                }
             }
         }
 

src/librustc_mir/interpret/machine.rs

@@ -254,6 +254,14 @@ pub trait Machine<'mir, 'tcx>: Sized {
         kind: Option<MemoryKind<Self::MemoryKind>>,
     ) -> (Cow<'b, Allocation<Self::PointerTag, Self::AllocExtra>>, Self::PointerTag);
 
+    /// Called to notify the machine before a deallocation occurs.
+    fn before_deallocation(
+        _memory_extra: &mut Self::MemoryExtra,
+        _id: AllocId,
+    ) -> InterpResult<'tcx> {
+        Ok(())
+    }
+
     /// Return the "base" tag for the given *global* allocation: the one that is used for direct
     /// accesses to this static/const/fn allocation. If `id` is not a global allocation,
     /// this will return an unusable tag (i.e., accesses will be UB)!

src/librustc_mir/interpret/memory.rs

@@ -254,6 +254,8 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
             );
         }
 
+        M::before_deallocation(&mut self.extra, ptr.alloc_id)?;
+
         let (alloc_kind, mut alloc) = match self.alloc_map.remove(&ptr.alloc_id) {
             Some(alloc) => alloc,
             None => {

src/librustc_mir/transform/generator.rs

@@ -721,15 +721,18 @@ fn compute_layout<'tcx>(
         _ => bug!(),
     };
 
+    let param_env = tcx.param_env(source.def_id());
+
     for (local, decl) in body.local_decls.iter_enumerated() {
         // Ignore locals which are internal or not live
         if !live_locals.contains(local) || decl.internal {
             continue;
         }
+        let decl_ty = tcx.normalize_erasing_regions(param_env, decl.ty);
 
         // Sanity check that typeck knows about the type of locals which are
         // live across a suspension point
-        if !allowed.contains(&decl.ty) && !allowed_upvars.contains(&decl.ty) {
+        if !allowed.contains(&decl_ty) && !allowed_upvars.contains(&decl_ty) {
             span_bug!(
                 body.span,
                 "Broken MIR: generator contains type {} in MIR, \

src/librustc_typeck/check/cast.rs

@@ -536,7 +536,10 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                 match self.expr_ty.kind {
                     ty::FnDef(..) => {
                         // Attempt a coercion to a fn pointer type.
-                        let f = self.expr_ty.fn_sig(fcx.tcx);
+                        let f = fcx.normalize_associated_types_in(
+                            self.expr.span,
+                            &self.expr_ty.fn_sig(fcx.tcx),
+                        );
                         let res = fcx.try_coerce(
                             self.expr,
                             self.expr_ty,

src/test/ui/binding/issue-53114-borrow-checks.rs

@@ -0,0 +1,84 @@
+// Issue #53114: NLL's borrow check had some deviations from the old borrow
+// checker, and both had some deviations from our ideal state. This test
+// captures the behavior of how `_` bindings are handled with respect to how we
+// flag expressions that are meant to request unsafe blocks.
+#![allow(irrefutable_let_patterns)]
+struct M;
+
+fn let_wild_gets_moved_expr() {
+    let m = M;
+    drop(m);
+    let _ = m; // accepted, and want it to continue to be
+
+    let mm = (M, M); // variation on above with `_` in substructure
+    let (_x, _) = mm;
+    let (_, _y) = mm;
+    let (_, _) = mm;
+}
+
+fn match_moved_expr_to_wild() {
+    let m = M;
+    drop(m);
+    match m { _ => { } } // #53114: should eventually be accepted too
+    //~^ ERROR [E0382]
+
+    let mm = (M, M); // variation on above with `_` in substructure
+    match mm { (_x, _) => { } }
+    match mm { (_, _y) => { } }
+    //~^ ERROR [E0382]
+    match mm { (_, _) => { } }
+    //~^ ERROR [E0382]
+}
+
+fn if_let_moved_expr_to_wild() {
+    let m = M;
+    drop(m);
+    if let _ = m { } // #53114: should eventually be accepted too
+    //~^ ERROR [E0382]
+
+    let mm = (M, M); // variation on above with `_` in substructure
+    if let (_x, _) = mm { }
+    if let (_, _y) = mm { }
+    //~^ ERROR [E0382]
+    if let (_, _) = mm { }
+    //~^ ERROR [E0382]
+}
+
+fn let_wild_gets_borrowed_expr() {
+    let mut m = M;
+    let r = &mut m;
+    let _ = m; // accepted, and want it to continue to be
+    // let _x = m; // (compare with this error.)
+    drop(r);
+
+    let mut mm = (M, M); // variation on above with `_` in substructure
+    let (r1, r2) = (&mut mm.0, &mut mm.1);
+    let (_, _) = mm;
+    drop((r1, r2));
+}
+
+fn match_borrowed_expr_to_wild() {
+    let mut m = M;
+    let r = &mut m;
+    match m { _ => {} } ; // accepted, and want it to continue to be
+    drop(r);
+
+    let mut mm = (M, M); // variation on above with `_` in substructure
+    let (r1, r2) = (&mut mm.0, &mut mm.1);
+    match mm { (_, _) => { } }
+    drop((r1, r2));
+}
+
+fn if_let_borrowed_expr_to_wild() {
+    let mut m = M;
+    let r = &mut m;
+    if let _ = m { } // accepted, and want it to continue to be
+    drop(r);
+
+    let mut mm = (M, M); // variation on above with `_` in substructure
+    let (r1, r2) = (&mut mm.0, &mut mm.1);
+    if let (_, _) = mm { }
+    drop((r1, r2));
+}
+
+fn main() { }

src/test/ui/binding/issue-53114-borrow-checks.stderr

@@ -0,0 +1,65 @@
+error[E0382]: use of moved value: `m`
+  --> $DIR/issue-53114-borrow-checks.rs:22:11
+   |
+LL |     let m = M;
+   |         - move occurs because `m` has type `M`, which does not implement the `Copy` trait
+LL |     drop(m);
+   |          - value moved here
+LL |     match m { _ => { } } // #53114: should eventually be accepted too
+   |           ^ value used here after move
+
+error[E0382]: use of moved value: `mm`
+  --> $DIR/issue-53114-borrow-checks.rs:27:11
+   |
+LL |     match mm { (_x, _) => { } }
+   |                 -- value moved here
+LL |     match mm { (_, _y) => { } }
+   |           ^^ value used here after partial move
+   |
+   = note: move occurs because `mm.0` has type `M`, which does not implement the `Copy` trait
+
+error[E0382]: use of moved value: `mm`
+  --> $DIR/issue-53114-borrow-checks.rs:29:11
+   |
+LL |     match mm { (_, _y) => { } }
+   |                    -- value moved here
+LL |
+LL |     match mm { (_, _) => { } }
+   |           ^^ value used here after partial move
+   |
+   = note: move occurs because `mm.1` has type `M`, which does not implement the `Copy` trait
+
+error[E0382]: use of moved value: `m`
+  --> $DIR/issue-53114-borrow-checks.rs:36:16
+   |
+LL |     let m = M;
+   |         - move occurs because `m` has type `M`, which does not implement the `Copy` trait
+LL |     drop(m);
+   |          - value moved here
+LL |     if let _ = m { } // #53114: should eventually be accepted too
+   |                ^ value used here after move
+
+error[E0382]: use of moved value: `mm`
+  --> $DIR/issue-53114-borrow-checks.rs:41:22
+   |
+LL |     if let (_x, _) = mm { }
+   |             -- value moved here
+LL |     if let (_, _y) = mm { }
+   |                      ^^ value used here after partial move
+   |
+   = note: move occurs because `mm.0` has type `M`, which does not implement the `Copy` trait
+
+error[E0382]: use of moved value: `mm`
+  --> $DIR/issue-53114-borrow-checks.rs:43:21
+   |
+LL |     if let (_, _y) = mm { }
+   |                -- value moved here
+LL |
+LL |     if let (_, _) = mm { }
+   |                     ^^ value used here after partial move
+   |
+   = note: move occurs because `mm.1` has type `M`, which does not implement the `Copy` trait
+
+error: aborting due to 6 previous errors
+
+For more information about this error, try `rustc --explain E0382`.

src/test/ui/binding/issue-53114-safety-checks.rs

@@ -0,0 +1,51 @@
+// Issue #53114: NLL's borrow check had some deviations from the old borrow
+// checker, and both had some deviations from our ideal state. This test
+// captures the behavior of how `_` bindings are handled with respect to how we
+// flag expressions that are meant to request unsafe blocks.
+
+#![feature(untagged_unions)]
+
+struct I(i64);
+struct F(f64);
+
+union U { a: I, b: F }
+
+#[repr(packed)]
+struct P {
+    a: &'static i8,
+    b: &'static u32,
+}
+
+fn let_wild_gets_unsafe_field() {
+    let u1 = U { a: I(0) };
+    let u2 = U { a: I(1) };
+    let p = P { a: &2, b: &3 };
+    let _ = &p.b;  //~ WARN    E0133
+    //~^  WARN will become a hard error
+    let _ = u1.a;  // #53114: should eventually signal error as well
+    let _ = &u2.a; //~ ERROR  [E0133]
+
+    // variation on above with `_` in substructure
+    let (_,) = (&p.b,);  //~ WARN     E0133
+    //~^  WARN will become a hard error
+    let (_,) = (u1.a,);  //~ ERROR   [E0133]
+    let (_,) = (&u2.a,); //~ ERROR   [E0133]
+}
+
+fn match_unsafe_field_to_wild() {
+    let u1 = U { a: I(0) };
+    let u2 = U { a: I(1) };
+    let p = P { a: &2, b: &3 };
+    match &p.b  { _ => { } } //~ WARN     E0133
+    //~^  WARN will become a hard error
+    match u1.a  { _ => { } } //~ ERROR   [E0133]
+    match &u2.a { _ => { } } //~ ERROR   [E0133]
+
+    // variation on above with `_` in substructure
+    match (&p.b,)  { (_,) => { } } //~ WARN     E0133
+    //~^  WARN will become a hard error
+    match (u1.a,)  { (_,) => { } } //~ ERROR   [E0133]
+    match (&u2.a,) { (_,) => { } } //~ ERROR   [E0133]
+}
+
+fn main() { }

src/test/ui/binding/issue-53114-safety-checks.stderr

@@ -0,0 +1,100 @@
+warning: borrow of packed field is unsafe and requires unsafe function or block (error E0133)
+  --> $DIR/issue-53114-safety-checks.rs:23:13
+   |
+LL |     let _ = &p.b;
+   |             ^^^^
+   |
+   = note: `#[warn(safe_packed_borrows)]` on by default
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #46043 <https://github.com/rust-lang/rust/issues/46043>
+   = note: fields of packed structs might be misaligned: dereferencing a misaligned pointer or even just creating a misaligned reference is undefined behavior
+
+error[E0133]: access to union field is unsafe and requires unsafe function or block
+  --> $DIR/issue-53114-safety-checks.rs:26:13
+   |
+LL |     let _ = &u2.a;
+   |             ^^^^^ access to union field
+   |
+   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior
+
+warning: borrow of packed field is unsafe and requires unsafe function or block (error E0133)
+  --> $DIR/issue-53114-safety-checks.rs:29:17
+   |
+LL |     let (_,) = (&p.b,);
+   |                 ^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #46043 <https://github.com/rust-lang/rust/issues/46043>
+   = note: fields of packed structs might be misaligned: dereferencing a misaligned pointer or even just creating a misaligned reference is undefined behavior
+
+error[E0133]: access to union field is unsafe and requires unsafe function or block
+  --> $DIR/issue-53114-safety-checks.rs:31:17
+   |
+LL |     let (_,) = (u1.a,);
+   |                 ^^^^ access to union field
+   |
+   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior
+
+error[E0133]: access to union field is unsafe and requires unsafe function or block
+  --> $DIR/issue-53114-safety-checks.rs:32:17
+   |
+LL |     let (_,) = (&u2.a,);
+   |                 ^^^^^ access to union field
+   |
+   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior
+
+warning: borrow of packed field is unsafe and requires unsafe function or block (error E0133)
+  --> $DIR/issue-53114-safety-checks.rs:39:11
+   |
+LL |     match &p.b  { _ => { } }
+   |           ^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #46043 <https://github.com/rust-lang/rust/issues/46043>
+   = note: fields of packed structs might be misaligned: dereferencing a misaligned pointer or even just creating a misaligned reference is undefined behavior
+
+error[E0133]: access to union field is unsafe and requires unsafe function or block
+  --> $DIR/issue-53114-safety-checks.rs:41:11
+   |
+LL |     match u1.a  { _ => { } }
+   |           ^^^^ access to union field
+   |
+   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior
+
+error[E0133]: access to union field is unsafe and requires unsafe function or block
+  --> $DIR/issue-53114-safety-checks.rs:42:11
+   |
+LL |     match &u2.a { _ => { } }
+   |           ^^^^^ access to union field
+   |
+   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior
+
+warning: borrow of packed field is unsafe and requires unsafe function or block (error E0133)
+  --> $DIR/issue-53114-safety-checks.rs:45:12
+   |
+LL |     match (&p.b,)  { (_,) => { } }
+   |            ^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #46043 <https://github.com/rust-lang/rust/issues/46043>
+   = note: fields of packed structs might be misaligned: dereferencing a misaligned pointer or even just creating a misaligned reference is undefined behavior
+
+error[E0133]: access to union field is unsafe and requires unsafe function or block
+  --> $DIR/issue-53114-safety-checks.rs:47:12
+   |
+LL |     match (u1.a,)  { (_,) => { } }
+   |            ^^^^ access to union field
+   |
+   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior
+
+error[E0133]: access to union field is unsafe and requires unsafe function or block
+  --> $DIR/issue-53114-safety-checks.rs:48:12
+   |
+LL |     match (&u2.a,) { (_,) => { } }
+   |            ^^^^^ access to union field
+   |
+   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior
+
+error: aborting due to 7 previous errors
+
+For more information about this error, try `rustc --explain E0133`.

src/test/ui/issues/issue-54094.rs

@@ -0,0 +1,14 @@
+// check-pass
+trait Zoo {
+    type X;
+}
+
+impl Zoo for u16 {
+    type X = usize;
+}
+
+fn foo(abc: <u16 as Zoo>::X) {}
+
+fn main() {
+    let x: *const u8 = foo as _;
+}

src/test/ui/repeat_count_const_in_async_fn.rs

@@ -0,0 +1,10 @@
+// check-pass
+// edition:2018
+// compile-flags: --crate-type=lib
+
+pub async fn test() {
+    const C: usize = 4;
+    foo(&mut [0u8; C]).await;
+}
+
+async fn foo(_: &mut [u8]) {}