Auto merge of #89903 - matthiaskrgr:rollup-s0c69xl, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #86011 (move implicit `Sized` predicate to end of list)
 - #89821 (Add a strange test for `unsafe_code` lint.)
 - #89859 (add dedicated error variant for writing the discriminant of an uninhabited enum variant)
 - #89870 (Suggest Box::pin when Pin::new is used instead)
 - #89880 (Use non-checking TLS relocation in aarch64 asm! sym test.)
 - #89885 (add long explanation for E0183)
 - #89894 (Remove unused dependencies from rustc_const_eval)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Cargo.lock

@@ -3736,8 +3736,6 @@ dependencies = [
 name = "rustc_const_eval"
 version = "0.0.0"
 dependencies = [
- "either",
- "gsgdt",
  "rustc_apfloat",
  "rustc_ast",
  "rustc_attr",

compiler/rustc_const_eval/Cargo.toml

@@ -7,8 +7,6 @@ edition = "2021"
 doctest = false
 
 [dependencies]
-either = "1.5.0"
-gsgdt = "0.1.2"
 tracing = "0.1"
 rustc_apfloat = { path = "../rustc_apfloat" }
 rustc_ast = { path = "../rustc_ast" }

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -618,6 +618,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     }
 
     /// Read discriminant, return the runtime value as well as the variant index.
+    /// Can also legally be called on non-enums (e.g. through the discriminant_value intrinsic)!
     pub fn read_discriminant(
         &self,
         op: &OpTy<'tcx, M::PointerTag>,

compiler/rustc_const_eval/src/interpret/place.rs

@@ -988,10 +988,23 @@ where
         variant_index: VariantIdx,
         dest: &PlaceTy<'tcx, M::PointerTag>,
     ) -> InterpResult<'tcx> {
+        // This must be an enum or generator.
+        match dest.layout.ty.kind() {
+            ty::Adt(adt, _) => assert!(adt.is_enum()),
+            ty::Generator(..) => {}
+            _ => span_bug!(
+                self.cur_span(),
+                "write_discriminant called on non-variant-type (neither enum nor generator)"
+            ),
+        }
         // Layout computation excludes uninhabited variants from consideration
         // therefore there's no way to represent those variants in the given layout.
+        // Essentially, uninhabited variants do not have a tag that corresponds to their
+        // discriminant, so we cannot do anything here.
+        // When evaluating we will always error before even getting here, but ConstProp 'executes'
+        // dead code, so we cannot ICE here.
         if dest.layout.for_variant(self, variant_index).abi.is_uninhabited() {
-            throw_ub!(Unreachable);
+            throw_ub!(UninhabitedEnumVariantWritten)
         }
 
         match dest.layout.variants {

compiler/rustc_error_codes/src/error_codes.rs

@@ -92,6 +92,7 @@ E0164: include_str!("./error_codes/E0164.md"),
 E0165: include_str!("./error_codes/E0165.md"),
 E0170: include_str!("./error_codes/E0170.md"),
 E0178: include_str!("./error_codes/E0178.md"),
+E0183: include_str!("./error_codes/E0183.md"),
 E0184: include_str!("./error_codes/E0184.md"),
 E0185: include_str!("./error_codes/E0185.md"),
 E0186: include_str!("./error_codes/E0186.md"),
@@ -513,7 +514,6 @@ E0785: include_str!("./error_codes/E0785.md"),
 //  E0173, // manual implementations of unboxed closure traits are experimental
 //  E0174,
 //  E0182, // merged into E0229
-    E0183,
 //  E0187, // cannot infer the kind of the closure
 //  E0188, // can not cast an immutable reference to a mutable pointer
 //  E0189, // deprecated: can only cast a boxed pointer to a boxed object

compiler/rustc_error_codes/src/error_codes/E0183.md

@@ -0,0 +1,39 @@
+Manual implemetation of a `Fn*` trait.
+
+Erroneous code example:
+
+```compile_fail,E0183
+struct MyClosure {
+    foo: i32
+}
+
+impl FnOnce<()> for MyClosure {  // error
+    type Output = ();
+    extern "rust-call" fn call_once(self, args: ()) -> Self::Output {
+        println!("{}", self.foo);
+    }
+}
+```
+
+Manually implementing `Fn`, `FnMut` or `FnOnce` is unstable
+and requires `#![feature(fn_traits, unboxed_closures)]`.
+
+```
+#![feature(fn_traits, unboxed_closures)]
+
+struct MyClosure {
+    foo: i32
+}
+
+impl FnOnce<()> for MyClosure {  // ok!
+    type Output = ();
+    extern "rust-call" fn call_once(self, args: ()) -> Self::Output {
+        println!("{}", self.foo);
+    }
+}
+```
+
+The argumements must be a tuple representing the argument list.
+For more info, see the [tracking issue][iss29625]:
+
+[iss29625]: https://github.com/rust-lang/rust/issues/29625

compiler/rustc_middle/src/mir/interpret/error.rs

@@ -287,6 +287,8 @@ pub enum UndefinedBehaviorInfo<'tcx> {
         target_size: u64,
         data_size: u64,
     },
+    /// A discriminant of an uninhabited enum variant is written.
+    UninhabitedEnumVariantWritten,
 }
 
 impl fmt::Display for UndefinedBehaviorInfo<'_> {
@@ -391,6 +393,9 @@ impl fmt::Display for UndefinedBehaviorInfo<'_> {
                 "scalar size mismatch: expected {} bytes but got {} bytes instead",
                 target_size, data_size
             ),
+            UninhabitedEnumVariantWritten => {
+                write!(f, "writing discriminant of an uninhabited enum")
+            }
         }
     }
 }

compiler/rustc_typeck/src/bounds.rs

@@ -64,16 +64,16 @@ impl<'tcx> Bounds<'tcx> {
             })
         });
 
-        sized_predicate
-            .into_iter()
-            .chain(self.region_bounds.iter().map(|&(region_bound, span)| {
+        self.region_bounds
+            .iter()
+            .map(|&(region_bound, span)| {
                 (
                     region_bound
                         .map_bound(|region_bound| ty::OutlivesPredicate(param_ty, region_bound))
                         .to_predicate(tcx),
                     span,
                 )
-            }))
+            })
             .chain(self.trait_bounds.iter().map(|&(bound_trait_ref, span, constness)| {
                 let predicate = bound_trait_ref.with_constness(constness).to_predicate(tcx);
                 (predicate, span)
@@ -83,6 +83,7 @@ impl<'tcx> Bounds<'tcx> {
                     .iter()
                     .map(|&(projection, span)| (projection.to_predicate(tcx), span)),
             )
+            .chain(sized_predicate.into_iter())
             .collect()
     }
 }

compiler/rustc_typeck/src/check/fn_ctxt/suggestions.rs

@@ -8,11 +8,11 @@ use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind};
 use rustc_hir::lang_items::LangItem;
-use rustc_hir::{Expr, ExprKind, ItemKind, Node, Stmt, StmtKind};
+use rustc_hir::{Expr, ExprKind, ItemKind, Node, Path, QPath, Stmt, StmtKind, TyKind};
 use rustc_infer::infer;
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::{self, Binder, Ty};
-use rustc_span::symbol::kw;
+use rustc_span::symbol::{kw, sym};
 
 use std::iter;
 
@@ -350,6 +350,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     /// When encountering an `impl Future` where `BoxFuture` is expected, suggest `Box::pin`.
+    #[instrument(skip(self, err))]
     pub(in super::super) fn suggest_calling_boxed_future_when_appropriate(
         &self,
         err: &mut DiagnosticBuilder<'_>,
@@ -368,41 +369,70 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         if pin_did.is_none() || self.tcx.lang_items().owned_box().is_none() {
             return false;
         }
-        match expected.kind() {
-            ty::Adt(def, _) if Some(def.did) == pin_did => (),
-            _ => return false,
-        }
         let box_found = self.tcx.mk_box(found);
         let pin_box_found = self.tcx.mk_lang_item(box_found, LangItem::Pin).unwrap();
         let pin_found = self.tcx.mk_lang_item(found, LangItem::Pin).unwrap();
-        if self.can_coerce(pin_box_found, expected) {
-            debug!("can coerce {:?} to {:?}, suggesting Box::pin", pin_box_found, expected);
-            match found.kind() {
-                ty::Adt(def, _) if def.is_box() => {
-                    err.help("use `Box::pin`");
-                }
-                _ => {
-                    err.multipart_suggestion(
-                        "you need to pin and box this expression",
-                        vec![
-                            (expr.span.shrink_to_lo(), "Box::pin(".to_string()),
-                            (expr.span.shrink_to_hi(), ")".to_string()),
-                        ],
-                        Applicability::MaybeIncorrect,
-                    );
-                }
-            }
-            true
-        } else if self.can_coerce(pin_found, expected) {
-            match found.kind() {
-                ty::Adt(def, _) if def.is_box() => {
-                    err.help("use `Box::pin`");
+        match expected.kind() {
+            ty::Adt(def, _) if Some(def.did) == pin_did => {
+                if self.can_coerce(pin_box_found, expected) {
+                    debug!("can coerce {:?} to {:?}, suggesting Box::pin", pin_box_found, expected);
+                    match found.kind() {
+                        ty::Adt(def, _) if def.is_box() => {
+                            err.help("use `Box::pin`");
+                        }
+                        _ => {
+                            err.multipart_suggestion(
+                                "you need to pin and box this expression",
+                                vec![
+                                    (expr.span.shrink_to_lo(), "Box::pin(".to_string()),
+                                    (expr.span.shrink_to_hi(), ")".to_string()),
+                                ],
+                                Applicability::MaybeIncorrect,
+                            );
+                        }
+                    }
                     true
+                } else if self.can_coerce(pin_found, expected) {
+                    match found.kind() {
+                        ty::Adt(def, _) if def.is_box() => {
+                            err.help("use `Box::pin`");
+                            true
+                        }
+                        _ => false,
+                    }
+                } else {
+                    false
                 }
-                _ => false,
             }
-        } else {
-            false
+            ty::Adt(def, _) if def.is_box() && self.can_coerce(box_found, expected) => {
+                // Check if the parent expression is a call to Pin::new.  If it
+                // is and we were expecting a Box, ergo Pin<Box<expected>>, we
+                // can suggest Box::pin.
+                let parent = self.tcx.hir().get_parent_node(expr.hir_id);
+                let fn_name = match self.tcx.hir().find(parent) {
+                    Some(Node::Expr(Expr { kind: ExprKind::Call(fn_name, _), .. })) => fn_name,
+                    _ => return false,
+                };
+                match fn_name.kind {
+                    ExprKind::Path(QPath::TypeRelative(
+                        hir::Ty {
+                            kind: TyKind::Path(QPath::Resolved(_, Path { res: recv_ty, .. })),
+                            ..
+                        },
+                        method,
+                    )) if Some(recv_ty.def_id()) == pin_did && method.ident.name == sym::new => {
+                        err.span_suggestion(
+                            fn_name.span,
+                            "use `Box::pin` to pin and box this expression",
+                            "Box::pin".to_string(),
+                            Applicability::MachineApplicable,
+                        );
+                        true
+                    }
+                    _ => false,
+                }
+            }
+            _ => false,
         }
     }
 

src/test/ui/asm/aarch64/sym.rs

@@ -55,7 +55,7 @@ macro_rules! static_tls_addr {
                 // Add the top 12 bits of the symbol's offset
                 "add {out}, {out}, :tprel_hi12:{sym}",
                 // And the bottom 12 bits
-                "add {out}, {out}, :tprel_lo12:{sym}",
+                "add {out}, {out}, :tprel_lo12_nc:{sym}",
                 out = out(reg) result,
                 sym = sym $s
             );

src/test/ui/derives/derives-span-Hash-enum-struct-variant.stderr

@@ -11,7 +11,7 @@ note: required by a bound in `std::hash::Hash::hash`
   --> $SRC_DIR/core/src/hash/mod.rs:LL:COL
    |
 LL |     fn hash<H: Hasher>(&self, state: &mut H);
-   |             ^ required by this bound in `std::hash::Hash::hash`
+   |                ^^^^^^ required by this bound in `std::hash::Hash::hash`
    = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error

src/test/ui/derives/derives-span-Hash-enum.stderr

@@ -11,7 +11,7 @@ note: required by a bound in `std::hash::Hash::hash`
   --> $SRC_DIR/core/src/hash/mod.rs:LL:COL
    |
 LL |     fn hash<H: Hasher>(&self, state: &mut H);
-   |             ^ required by this bound in `std::hash::Hash::hash`
+   |                ^^^^^^ required by this bound in `std::hash::Hash::hash`
    = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error

src/test/ui/derives/derives-span-Hash-struct.stderr

@@ -11,7 +11,7 @@ note: required by a bound in `std::hash::Hash::hash`
   --> $SRC_DIR/core/src/hash/mod.rs:LL:COL
    |
 LL |     fn hash<H: Hasher>(&self, state: &mut H);
-   |             ^ required by this bound in `std::hash::Hash::hash`
+   |                ^^^^^^ required by this bound in `std::hash::Hash::hash`
    = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error

src/test/ui/derives/derives-span-Hash-tuple-struct.stderr

@@ -11,7 +11,7 @@ note: required by a bound in `std::hash::Hash::hash`
   --> $SRC_DIR/core/src/hash/mod.rs:LL:COL
    |
 LL |     fn hash<H: Hasher>(&self, state: &mut H);
-   |             ^ required by this bound in `std::hash::Hash::hash`
+   |                ^^^^^^ required by this bound in `std::hash::Hash::hash`
    = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error

src/test/ui/feature-gates/feature-gate-unboxed-closures-manual-impls.stderr

@@ -101,5 +101,5 @@ LL | impl FnOnce<()> for Baz {
 
 error: aborting due to 12 previous errors
 
-Some errors have detailed explanations: E0229, E0658.
-For more information about an error, try `rustc --explain E0229`.
+Some errors have detailed explanations: E0183, E0229, E0658.
+For more information about an error, try `rustc --explain E0183`.

src/test/ui/feature-gates/feature-gate-unboxed-closures.stderr

@@ -26,4 +26,5 @@ LL | impl FnOnce<(u32, u32)> for Test {
 
 error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0658`.
+Some errors have detailed explanations: E0183, E0658.
+For more information about an error, try `rustc --explain E0183`.

src/test/ui/generic-associated-types/issue-74816.stderr

@@ -1,19 +1,3 @@
-error[E0277]: the trait bound `Self: Trait1` is not satisfied
-  --> $DIR/issue-74816.rs:9:5
-   |
-LL |     type Associated: Trait1 = Self;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Trait1` is not implemented for `Self`
-   |
-note: required by a bound in `Trait2::Associated`
-  --> $DIR/issue-74816.rs:9:22
-   |
-LL |     type Associated: Trait1 = Self;
-   |                      ^^^^^^ required by this bound in `Trait2::Associated`
-help: consider further restricting `Self`
-   |
-LL | trait Trait2: Trait1 {
-   |             ++++++++
-
 error[E0277]: the size for values of type `Self` cannot be known at compilation time
   --> $DIR/issue-74816.rs:9:5
    |
@@ -30,6 +14,22 @@ help: consider further restricting `Self`
 LL | trait Trait2: Sized {
    |             +++++++
 
+error[E0277]: the trait bound `Self: Trait1` is not satisfied
+  --> $DIR/issue-74816.rs:9:5
+   |
+LL |     type Associated: Trait1 = Self;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Trait1` is not implemented for `Self`
+   |
+note: required by a bound in `Trait2::Associated`
+  --> $DIR/issue-74816.rs:9:22
+   |
+LL |     type Associated: Trait1 = Self;
+   |                      ^^^^^^ required by this bound in `Trait2::Associated`
+help: consider further restricting `Self`
+   |
+LL | trait Trait2: Trait1 {
+   |             ++++++++
+
 error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0277`.

src/test/ui/generic-associated-types/issue-86483.stderr

@@ -20,13 +20,13 @@ LL |     for<'a> T: 'a,
    |                ^^
 
 error[E0311]: the parameter type `T` may not live long enough
-  --> $DIR/issue-86483.rs:9:5
+  --> $DIR/issue-86483.rs:9:19
    |
 LL | pub trait IceIce<T>
    |                  - help: consider adding an explicit lifetime bound...: `T: 'a`
 ...
 LL |     type Ice<'v>: IntoIterator<Item = &'v T>;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds...
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds...
    |
 note: ...that is required by this bound
   --> $DIR/issue-86483.rs:7:16

src/test/ui/generics/issue-61631-default-type-param-can-reference-self-in-trait.stderr

@@ -6,10 +6,10 @@ LL | impl Tsized for () {}
    |
    = help: the trait `Sized` is not implemented for `[()]`
 note: required by a bound in `Tsized`
-  --> $DIR/issue-61631-default-type-param-can-reference-self-in-trait.rs:17:14
+  --> $DIR/issue-61631-default-type-param-can-reference-self-in-trait.rs:17:17
    |
 LL | trait Tsized<P: Sized = [Self]> {}
-   |              ^ required by this bound in `Tsized`
+   |                 ^^^^^ required by this bound in `Tsized`
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-16966.stderr

@@ -1,11 +1,21 @@
-error[E0282]: type annotations needed
+error[E0283]: type annotations needed
   --> $DIR/issue-16966.rs:2:5
    |
 LL |     panic!(std::default::Default::default());
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type for type parameter `M` declared on the function `begin_panic`
    |
+   = note: cannot satisfy `_: Any`
+note: required by a bound in `begin_panic`
+  --> $SRC_DIR/std/src/panicking.rs:LL:COL
+   |
+LL | pub fn begin_panic<M: Any + Send>(msg: M) -> ! {
+   |                       ^^^ required by this bound in `begin_panic`
    = note: this error originates in the macro `$crate::panic::panic_2015` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider specifying the type argument in the function call
+   |
+LL |         $crate::rt::begin_panic::<M>($msg)
+   |                                +++++
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0282`.
+For more information about this error, try `rustc --explain E0283`.

src/test/ui/issues/issue-21160.stderr

@@ -10,7 +10,7 @@ note: required by a bound in `std::hash::Hash::hash`
   --> $SRC_DIR/core/src/hash/mod.rs:LL:COL
    |
 LL |     fn hash<H: Hasher>(&self, state: &mut H);
-   |             ^ required by this bound in `std::hash::Hash::hash`
+   |                ^^^^^^ required by this bound in `std::hash::Hash::hash`
    = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to previous error

src/test/ui/issues/issue-23122-2.stderr

@@ -1,4 +1,4 @@
-error[E0275]: overflow evaluating the requirement `<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<T as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next: Sized`
+error[E0275]: overflow evaluating the requirement `<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<T as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next: Next`
   --> $DIR/issue-23122-2.rs:9:17
    |
 LL |     type Next = <GetNext<T::Next> as Next>::Next;

src/test/ui/issues/issue-54954.stderr

@@ -12,10 +12,10 @@ LL | const ARR_LEN: usize = Tt::const_val::<[i8; 123]>();
    |
    = note: cannot satisfy `_: Tt`
 note: required by a bound in `Tt::const_val`
-  --> $DIR/issue-54954.rs:5:24
+  --> $DIR/issue-54954.rs:5:27
    |
 LL |     const fn const_val<T: Sized>() -> usize {
-   |                        ^ required by this bound in `Tt::const_val`
+   |                           ^^^^^ required by this bound in `Tt::const_val`
 
 error: aborting due to 2 previous errors
 

src/test/ui/lint/unsafe_code/auxiliary/forge_unsafe_block.rs

@@ -0,0 +1,16 @@
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+
+use proc_macro::{Delimiter, Group, Ident, Span, TokenStream, TokenTree};
+
+#[proc_macro]
+pub fn forge_unsafe_block(input: TokenStream) -> TokenStream {
+    let mut output = TokenStream::new();
+    output.extend(Some(TokenTree::from(Ident::new("unsafe", Span::call_site()))));
+    output.extend(Some(TokenTree::from(Group::new(Delimiter::Brace, input))));
+    output
+}

src/test/ui/lint/unsafe_code/forge_unsafe_block.rs

@@ -0,0 +1,16 @@
+// check-pass
+// aux-build:forge_unsafe_block.rs
+
+#[macro_use]
+extern crate forge_unsafe_block;
+
+unsafe fn foo() {}
+
+#[forbid(unsafe_code)]
+fn main() {
+    // `forbid` doesn't work for non-user-provided unsafe blocks.
+    // see `UnsafeCode::check_expr`.
+    forge_unsafe_block! {
+        foo();
+    }
+}

src/test/ui/rfc-2632-const-trait-impl/trait-where-clause.stderr

@@ -20,11 +20,11 @@ error[E0277]: the trait bound `T: Bar` is not satisfied
 LL |     T::c::<T>();
    |     ^^^^^^^^^ the trait `Bar` is not implemented for `T`
    |
-note: required by `Foo::c`
-  --> $DIR/trait-where-clause.rs:9:5
+note: required by a bound in `Foo::c`
+  --> $DIR/trait-where-clause.rs:9:10
    |
 LL |     fn c<T: ~const Bar>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |          ^ required by this bound in `Foo::c`
 help: consider further restricting this bound
    |
 LL | const fn test1<T: ~const Foo + Bar + Bar>() {
@@ -52,11 +52,11 @@ error[E0277]: the trait bound `T: Bar` is not satisfied
 LL |     T::c::<T>();
    |     ^^^^^^^^^ the trait `Bar` is not implemented for `T`
    |
-note: required by `Foo::c`
-  --> $DIR/trait-where-clause.rs:9:5
+note: required by a bound in `Foo::c`
+  --> $DIR/trait-where-clause.rs:9:10
    |
 LL |     fn c<T: ~const Bar>();
-   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |          ^ required by this bound in `Foo::c`
 help: consider further restricting this bound
    |
 LL | fn test3<T: Foo + Bar>() {

src/test/ui/suggestions/expected-boxed-future-isnt-pinned.rs

@@ -15,9 +15,6 @@ fn bar<F: Future<Output=i32> + Send + 'static>(x: F) -> BoxFuture<'static, i32>
     Box::new(x) //~ ERROR mismatched types
 }
 
-// This case is still subpar:
-// `Pin::new(x)`: store this in the heap by calling `Box::new`: `Box::new(x)`
-// Should suggest changing the code from `Pin::new` to `Box::pin`.
 fn baz<F: Future<Output=i32> + Send + 'static>(x: F) -> BoxFuture<'static, i32> {
     Pin::new(x) //~ ERROR mismatched types
     //~^ ERROR E0277

src/test/ui/suggestions/expected-boxed-future-isnt-pinned.stderr

@@ -27,23 +27,20 @@ LL |     Box::new(x)
    = help: use `Box::pin`
 
 error[E0308]: mismatched types
-  --> $DIR/expected-boxed-future-isnt-pinned.rs:22:14
+  --> $DIR/expected-boxed-future-isnt-pinned.rs:19:14
    |
 LL | fn baz<F: Future<Output=i32> + Send + 'static>(x: F) -> BoxFuture<'static, i32> {
    |        - this type parameter
 LL |     Pin::new(x)
-   |              ^ expected struct `Box`, found type parameter `F`
+   |     -------- ^ expected struct `Box`, found type parameter `F`
+   |     |
+   |     help: use `Box::pin` to pin and box this expression: `Box::pin`
    |
    = note:      expected struct `Box<dyn Future<Output = i32> + Send>`
            found type parameter `F`
-   = note: for more on the distinction between the stack and the heap, read https://doc.rust-lang.org/book/ch15-01-box.html, https://doc.rust-lang.org/rust-by-example/std/box.html, and https://doc.rust-lang.org/std/boxed/index.html
-help: store this in the heap by calling `Box::new`
-   |
-LL |     Pin::new(Box::new(x))
-   |              +++++++++ +
 
 error[E0277]: `dyn Future<Output = i32> + Send` cannot be unpinned
-  --> $DIR/expected-boxed-future-isnt-pinned.rs:22:5
+  --> $DIR/expected-boxed-future-isnt-pinned.rs:19:5
    |
 LL |     Pin::new(x)
    |     ^^^^^^^^ the trait `Unpin` is not implemented for `dyn Future<Output = i32> + Send`
@@ -56,7 +53,7 @@ LL |     pub const fn new(pointer: P) -> Pin<P> {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0277]: `dyn Future<Output = i32> + Send` cannot be unpinned
-  --> $DIR/expected-boxed-future-isnt-pinned.rs:27:5
+  --> $DIR/expected-boxed-future-isnt-pinned.rs:24:5
    |
 LL |     Pin::new(Box::new(x))
    |     ^^^^^^^^ the trait `Unpin` is not implemented for `dyn Future<Output = i32> + Send`
@@ -69,7 +66,7 @@ LL |     pub const fn new(pointer: P) -> Pin<P> {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
-  --> $DIR/expected-boxed-future-isnt-pinned.rs:31:5
+  --> $DIR/expected-boxed-future-isnt-pinned.rs:28:5
    |
 LL |   fn zap() -> BoxFuture<'static, i32> {
    |               ----------------------- expected `Pin<Box<(dyn Future<Output = i32> + Send + 'static)>>` because of return type

src/test/ui/suggestions/issue-84973-blacklist.stderr

@@ -49,10 +49,10 @@ LL |     f_sized(*ref_cl);
    |
    = help: the trait `Sized` is not implemented for `dyn Fn()`
 note: required by a bound in `f_sized`
-  --> $DIR/issue-84973-blacklist.rs:9:12
+  --> $DIR/issue-84973-blacklist.rs:9:15
    |
 LL | fn f_sized<T: Sized>(t: T) {}
-   |            ^ required by this bound in `f_sized`
+   |               ^^^^^ required by this bound in `f_sized`
 
 error[E0277]: `Rc<{integer}>` cannot be sent between threads safely
   --> $DIR/issue-84973-blacklist.rs:27:12

src/test/ui/suggestions/slice-issue-87994.stderr

@@ -1,23 +1,3 @@
-error[E0277]: the size for values of type `[i32]` cannot be known at compilation time
-  --> $DIR/slice-issue-87994.rs:3:12
-   |
-LL |   for _ in v[1..] {
-   |            ^^^^^^ expected an implementor of trait `IntoIterator`
-   |
-   = note: the trait bound `[i32]: IntoIterator` is not satisfied
-   = note: required because of the requirements on the impl of `IntoIterator` for `[i32]`
-note: required by `into_iter`
-  --> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
-   |
-LL |     fn into_iter(self) -> Self::IntoIter;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-help: consider borrowing here
-   |
-LL |   for _ in &v[1..] {
-   |            +
-LL |   for _ in &mut v[1..] {
-   |            ++++
-
 error[E0277]: `[i32]` is not an iterator
   --> $DIR/slice-issue-87994.rs:3:12
    |
@@ -38,7 +18,27 @@ LL |   for _ in &v[1..] {
 LL |   for _ in &mut v[1..] {
    |            ++++
 
-error[E0277]: the size for values of type `[K]` cannot be known at compilation time
+error[E0277]: the size for values of type `[i32]` cannot be known at compilation time
+  --> $DIR/slice-issue-87994.rs:3:12
+   |
+LL |   for _ in v[1..] {
+   |            ^^^^^^ expected an implementor of trait `IntoIterator`
+   |
+   = note: the trait bound `[i32]: IntoIterator` is not satisfied
+   = note: required because of the requirements on the impl of `IntoIterator` for `[i32]`
+note: required by `into_iter`
+  --> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
+   |
+LL |     fn into_iter(self) -> Self::IntoIter;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: consider borrowing here
+   |
+LL |   for _ in &v[1..] {
+   |            +
+LL |   for _ in &mut v[1..] {
+   |            ++++
+
+error[E0277]: `[K]` is not an iterator
   --> $DIR/slice-issue-87994.rs:11:13
    |
 LL |   for i2 in v2[1..] {
@@ -58,7 +58,7 @@ LL |   for i2 in &v2[1..] {
 LL |   for i2 in &mut v2[1..] {
    |             ++++
 
-error[E0277]: `[K]` is not an iterator
+error[E0277]: the size for values of type `[K]` cannot be known at compilation time
   --> $DIR/slice-issue-87994.rs:11:13
    |
 LL |   for i2 in v2[1..] {

src/test/ui/type-alias-impl-trait/generic_duplicate_param_use9.rs

@@ -5,7 +5,7 @@ use std::fmt::Debug;
 fn main() {}
 
 type Two<A, B> = impl Debug;
-//~^ ERROR the trait bound `A: Foo` is not satisfied in `(A, B, <A as Foo>::Bar)`
+//~^ ERROR the trait bound `A: Foo` is not satisfied
 //~| ERROR `A` doesn't implement `Debug`
 //~| ERROR `B` doesn't implement `Debug`
 

src/test/ui/type-alias-impl-trait/generic_duplicate_param_use9.stderr

@@ -10,18 +10,6 @@ note: previous use here
 LL | fn two<T: Debug + Foo, U: Debug>(t: T, u: U) -> Two<T, U> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: the trait bound `A: Foo` is not satisfied in `(A, B, <A as Foo>::Bar)`
-  --> $DIR/generic_duplicate_param_use9.rs:7:18
-   |
-LL | type Two<A, B> = impl Debug;
-   |                  ^^^^^^^^^^ within `(A, B, <A as Foo>::Bar)`, the trait `Foo` is not implemented for `A`
-   |
-   = note: required because it appears within the type `(A, B, <A as Foo>::Bar)`
-help: consider restricting type parameter `A`
-   |
-LL | type Two<A: Foo, B> = impl Debug;
-   |           +++++
-
 error[E0277]: `A` doesn't implement `Debug`
   --> $DIR/generic_duplicate_param_use9.rs:7:18
    |
@@ -46,6 +34,18 @@ help: consider restricting type parameter `B`
 LL | type Two<A, B: std::fmt::Debug> = impl Debug;
    |              +++++++++++++++++
 
+error[E0277]: the trait bound `A: Foo` is not satisfied
+  --> $DIR/generic_duplicate_param_use9.rs:7:18
+   |
+LL | type Two<A, B> = impl Debug;
+   |                  ^^^^^^^^^^ the trait `Foo` is not implemented for `A`
+   |
+   = note: required because of the requirements on the impl of `Debug` for `(A, B, <A as Foo>::Bar)`
+help: consider restricting type parameter `A`
+   |
+LL | type Two<A: Foo, B> = impl Debug;
+   |           +++++
+
 error: aborting due to 4 previous errors
 
 For more information about this error, try `rustc --explain E0277`.

src/test/ui/unique-object-noncopyable.stderr

@@ -19,10 +19,10 @@ LL | | >(Unique<T>, A);
    | |________________- doesn't satisfy `Box<dyn Foo>: Clone`
    |
    = note: the following trait bounds were not satisfied:
-           `dyn Foo: Sized`
-           which is required by `Box<dyn Foo>: Clone`
            `dyn Foo: Clone`
            which is required by `Box<dyn Foo>: Clone`
+           `dyn Foo: Sized`
+           which is required by `Box<dyn Foo>: Clone`
 
 error: aborting due to previous error
 

src/test/ui/unsized/unsized-bare-typaram.stderr

@@ -7,10 +7,10 @@ LL | fn foo<T: ?Sized>() { bar::<T>() }
    |        this type parameter needs to be `std::marker::Sized`
    |
 note: required by a bound in `bar`
-  --> $DIR/unsized-bare-typaram.rs:1:8
+  --> $DIR/unsized-bare-typaram.rs:1:11
    |
 LL | fn bar<T: Sized>() { }
-   |        ^ required by this bound in `bar`
+   |           ^^^^^ required by this bound in `bar`
 help: consider removing the `?Sized` bound to make the type parameter `Sized`
    |
 LL - fn foo<T: ?Sized>() { bar::<T>() }

src/test/ui/unsized/unsized-struct.stderr

@@ -38,10 +38,10 @@ note: required because it appears within the type `Bar<T>`
 LL | struct Bar<T: ?Sized> { data: T }
    |        ^^^
 note: required by a bound in `is_sized`
-  --> $DIR/unsized-struct.rs:1:13
+  --> $DIR/unsized-struct.rs:1:15
    |
 LL | fn is_sized<T:Sized>() { }
-   |             ^ required by this bound in `is_sized`
+   |               ^^^^^ required by this bound in `is_sized`
 help: consider removing the `?Sized` bound to make the type parameter `Sized`
    |
 LL - fn bar2<T: ?Sized>() { is_sized::<Bar<T>>() }