Avoid sorting predicates by DefId

compiler/rustc_builtin_macros/src/lib.rs

@@ -11,6 +11,7 @@
 #![feature(or_patterns)]
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_quote)]
+#![recursion_limit = "256"]
 
 extern crate proc_macro;
 

compiler/rustc_parse/src/lib.rs

@@ -6,6 +6,7 @@
 #![feature(or_patterns)]
 #![feature(box_syntax)]
 #![feature(box_patterns)]
+#![recursion_limit = "256"]
 
 use rustc_ast as ast;
 use rustc_ast::token::{self, Nonterminal};

compiler/rustc_session/src/lib.rs

@@ -1,6 +1,7 @@
 #![feature(crate_visibility_modifier)]
 #![feature(once_cell)]
 #![feature(or_patterns)]
+#![recursion_limit = "256"]
 
 #[macro_use]
 extern crate bitflags;

compiler/rustc_typeck/src/astconv/mod.rs

@@ -942,7 +942,6 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         let mut bounds = Bounds::default();
 
         self.add_bounds(param_ty, ast_bounds, &mut bounds);
-        bounds.trait_bounds.sort_by_key(|(t, _, _)| t.def_id());
 
         bounds.implicitly_sized = if let SizedByDefault::Yes = sized_by_default {
             if !self.is_unsized(ast_bounds, span) { Some(span) } else { None }
@@ -1318,8 +1317,10 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
 
         // De-duplicate auto traits so that, e.g., `dyn Trait + Send + Send` is the same as
         // `dyn Trait + Send`.
-        auto_traits.sort_by_key(|i| i.trait_ref().def_id());
-        auto_traits.dedup_by_key(|i| i.trait_ref().def_id());
+        // We remove duplicates by inserting into a `FxHashSet` to avoid re-ordering
+        // the bounds
+        let mut duplicates = FxHashSet::default();
+        auto_traits.retain(|i| duplicates.insert(i.trait_ref().def_id()));
         debug!("regular_traits: {:?}", regular_traits);
         debug!("auto_traits: {:?}", auto_traits);
 

src/test/incremental/issue-82920-predicate-order-miscompile.rs

@@ -0,0 +1,31 @@
+// revisions: rpass1 rpass2
+
+trait MyTrait: One + Two {}
+impl<T> One for T {
+    fn method_one(&self) -> usize {
+        1
+    }
+}
+impl<T> Two for T {
+    fn method_two(&self) -> usize {
+        2
+    }
+}
+impl<T: One + Two> MyTrait for T {}
+
+fn main() {
+    let a: &dyn MyTrait = &true;
+    assert_eq!(a.method_one(), 1);
+    assert_eq!(a.method_two(), 2);
+}
+
+// Re-order traits 'One' and 'Two' between compilation
+// sessions
+
+#[cfg(rpass1)]
+trait One { fn method_one(&self) -> usize; }
+
+trait Two { fn method_two(&self) -> usize; }
+
+#[cfg(rpass2)]
+trait One { fn method_one(&self) -> usize; }

src/test/rustdoc/inline_cross/impl_trait.rs

@@ -18,7 +18,7 @@ pub use impl_trait_aux::func2;
 
 // @has impl_trait/fn.func3.html
 // @has - '//pre[@class="rust fn"]' "func3("
-// @has - '//pre[@class="rust fn"]' "_x: impl Clone + Iterator<Item = impl Iterator<Item = u8>>)"
+// @has - '//pre[@class="rust fn"]' "_x: impl Iterator<Item = impl Iterator<Item = u8>> + Clone)"
 // @!has - '//pre[@class="rust fn"]' 'where'
 pub use impl_trait_aux::func3;
 

src/test/rustdoc/unit-return.rs

@@ -10,8 +10,8 @@ pub fn f0<F: FnMut(u8) + Clone>(f: F) {}
 // @has 'foo/fn.f1.html' '//*[@class="rust fn"]' 'F: FnMut(u16) + Clone'
 pub fn f1<F: FnMut(u16) -> () + Clone>(f: F) {}
 
-// @has 'foo/fn.f2.html' '//*[@class="rust fn"]' 'F: Clone + FnMut(u32)'
+// @has 'foo/fn.f2.html' '//*[@class="rust fn"]' 'F: FnMut(u32) + Clone'
 pub use unit_return::f2;
 
-// @has 'foo/fn.f3.html' '//*[@class="rust fn"]' 'F: Clone + FnMut(u64)'
+// @has 'foo/fn.f3.html' '//*[@class="rust fn"]' 'F: FnMut(u64) + Clone'
 pub use unit_return::f3;

src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.stderr

@@ -1,15 +1,3 @@
-error[E0277]: `<<Self as Case1>::C as Iterator>::Item` is not an iterator
-  --> $DIR/bad-bounds-on-assoc-in-trait.rs:27:5
-   |
-LL |     type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `<<Self as Case1>::C as Iterator>::Item` is not an iterator
-   |
-   = help: the trait `Iterator` is not implemented for `<<Self as Case1>::C as Iterator>::Item`
-help: consider further restricting the associated type
-   |
-LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Iterator {
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error[E0277]: `<<Self as Case1>::C as Iterator>::Item` cannot be sent between threads safely
   --> $DIR/bad-bounds-on-assoc-in-trait.rs:27:36
    |
@@ -27,6 +15,23 @@ help: consider further restricting the associated type
 LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Send {
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+error[E0277]: `<<Self as Case1>::C as Iterator>::Item` is not an iterator
+  --> $DIR/bad-bounds-on-assoc-in-trait.rs:27:43
+   |
+LL |     type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
+   |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `<<Self as Case1>::C as Iterator>::Item` is not an iterator
+   | 
+  ::: $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
+   |
+LL | pub trait Iterator {
+   | ------------------ required by this bound in `Iterator`
+   |
+   = help: the trait `Iterator` is not implemented for `<<Self as Case1>::C as Iterator>::Item`
+help: consider further restricting the associated type
+   |
+LL | trait Case1 where <<Self as Case1>::C as Iterator>::Item: Iterator {
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 error[E0277]: `<<Self as Case1>::C as Iterator>::Item` cannot be shared between threads safely
   --> $DIR/bad-bounds-on-assoc-in-trait.rs:27:93
    |

src/test/ui/associated-types/associated-type-projection-from-multiple-supertraits.stderr

@@ -20,12 +20,12 @@ LL | fn dent<C:BoxCar>(c: C, color: C::Color) {
    |
 help: use fully qualified syntax to disambiguate
    |
-LL | fn dent<C:BoxCar>(c: C, color: <C as Box>::Color) {
-   |                                ^^^^^^^^^^^^^^^^^
-help: use fully qualified syntax to disambiguate
-   |
 LL | fn dent<C:BoxCar>(c: C, color: <C as Vehicle>::Color) {
    |                                ^^^^^^^^^^^^^^^^^^^^^
+help: use fully qualified syntax to disambiguate
+   |
+LL | fn dent<C:BoxCar>(c: C, color: <C as Box>::Color) {
+   |                                ^^^^^^^^^^^^^^^^^
 
 error[E0222]: ambiguous associated type `Color` in bounds of `BoxCar`
   --> $DIR/associated-type-projection-from-multiple-supertraits.rs:23:37
@@ -42,8 +42,8 @@ LL | fn dent_object<COLOR>(c: dyn BoxCar<Color=COLOR>) {
    = help: consider introducing a new type parameter `T` and adding `where` constraints:
                where
                    T: BoxCar,
-                   T: Box::Color = COLOR,
-                   T: Vehicle::Color = COLOR
+                   T: Vehicle::Color = COLOR,
+                   T: Box::Color = COLOR
 
 error[E0191]: the value of the associated types `Color` (from trait `Box`), `Color` (from trait `Vehicle`) must be specified
   --> $DIR/associated-type-projection-from-multiple-supertraits.rs:23:30
@@ -73,12 +73,12 @@ LL | fn paint<C:BoxCar>(c: C, d: C::Color) {
    |
 help: use fully qualified syntax to disambiguate
    |
-LL | fn paint<C:BoxCar>(c: C, d: <C as Box>::Color) {
-   |                             ^^^^^^^^^^^^^^^^^
-help: use fully qualified syntax to disambiguate
-   |
 LL | fn paint<C:BoxCar>(c: C, d: <C as Vehicle>::Color) {
    |                             ^^^^^^^^^^^^^^^^^^^^^
+help: use fully qualified syntax to disambiguate
+   |
+LL | fn paint<C:BoxCar>(c: C, d: <C as Box>::Color) {
+   |                             ^^^^^^^^^^^^^^^^^
 
 error[E0191]: the value of the associated types `Color` (from trait `Box`), `Color` (from trait `Vehicle`) must be specified
   --> $DIR/associated-type-projection-from-multiple-supertraits.rs:32:32

src/test/ui/associated-types/defaults-unsound-62211-1.stderr

@@ -13,20 +13,6 @@ help: consider further restricting `Self`
 LL | trait UncheckedCopy: Sized + std::fmt::Display {
    |                            ^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: the trait bound `Self: Deref` is not satisfied
-  --> $DIR/defaults-unsound-62211-1.rs:20:5
-   |
-LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
-   |     ^^^^^^^^^^^^^^^^^^^^-------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |     |                   |
-   |     |                   required by this bound in `UncheckedCopy::Output`
-   |     the trait `Deref` is not implemented for `Self`
-   |
-help: consider further restricting `Self`
-   |
-LL | trait UncheckedCopy: Sized + Deref {
-   |                            ^^^^^^^
-
 error[E0277]: cannot add-assign `&'static str` to `Self`
   --> $DIR/defaults-unsound-62211-1.rs:20:5
    |
@@ -41,6 +27,20 @@ help: consider further restricting `Self`
 LL | trait UncheckedCopy: Sized + AddAssign<&'static str> {
    |                            ^^^^^^^^^^^^^^^^^^^^^^^^^
 
+error[E0277]: the trait bound `Self: Deref` is not satisfied
+  --> $DIR/defaults-unsound-62211-1.rs:20:5
+   |
+LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
+   |     ^^^^^^^^^^^^^^^^^^^^-------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     |                   |
+   |     |                   required by this bound in `UncheckedCopy::Output`
+   |     the trait `Deref` is not implemented for `Self`
+   |
+help: consider further restricting `Self`
+   |
+LL | trait UncheckedCopy: Sized + Deref {
+   |                            ^^^^^^^
+
 error[E0277]: the trait bound `Self: Copy` is not satisfied
   --> $DIR/defaults-unsound-62211-1.rs:20:5
    |

src/test/ui/associated-types/defaults-unsound-62211-2.stderr

@@ -13,20 +13,6 @@ help: consider further restricting `Self`
 LL | trait UncheckedCopy: Sized + std::fmt::Display {
    |                            ^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: the trait bound `Self: Deref` is not satisfied
-  --> $DIR/defaults-unsound-62211-2.rs:20:5
-   |
-LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
-   |     ^^^^^^^^^^^^^^^^^^^^-------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |     |                   |
-   |     |                   required by this bound in `UncheckedCopy::Output`
-   |     the trait `Deref` is not implemented for `Self`
-   |
-help: consider further restricting `Self`
-   |
-LL | trait UncheckedCopy: Sized + Deref {
-   |                            ^^^^^^^
-
 error[E0277]: cannot add-assign `&'static str` to `Self`
   --> $DIR/defaults-unsound-62211-2.rs:20:5
    |
@@ -41,6 +27,20 @@ help: consider further restricting `Self`
 LL | trait UncheckedCopy: Sized + AddAssign<&'static str> {
    |                            ^^^^^^^^^^^^^^^^^^^^^^^^^
 
+error[E0277]: the trait bound `Self: Deref` is not satisfied
+  --> $DIR/defaults-unsound-62211-2.rs:20:5
+   |
+LL |     type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
+   |     ^^^^^^^^^^^^^^^^^^^^-------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     |                   |
+   |     |                   required by this bound in `UncheckedCopy::Output`
+   |     the trait `Deref` is not implemented for `Self`
+   |
+help: consider further restricting `Self`
+   |
+LL | trait UncheckedCopy: Sized + Deref {
+   |                            ^^^^^^^
+
 error[E0277]: the trait bound `Self: Copy` is not satisfied
   --> $DIR/defaults-unsound-62211-2.rs:20:5
    |

src/test/ui/issues/issue-40827.stderr

@@ -1,27 +1,27 @@
-error[E0277]: `Rc<Foo>` cannot be sent between threads safely
+error[E0277]: `Rc<Foo>` cannot be shared between threads safely
   --> $DIR/issue-40827.rs:14:5
    |
 LL | fn f<T: Send>(_: T) {}
    |         ---- required by this bound in `f`
 ...
 LL |     f(Foo(Arc::new(Bar::B(None))));
-   |     ^ `Rc<Foo>` cannot be sent between threads safely
+   |     ^ `Rc<Foo>` cannot be shared between threads safely
    |
-   = help: within `Bar`, the trait `Send` is not implemented for `Rc<Foo>`
+   = help: within `Bar`, the trait `Sync` is not implemented for `Rc<Foo>`
    = note: required because it appears within the type `Bar`
    = note: required because of the requirements on the impl of `Send` for `Arc<Bar>`
    = note: required because it appears within the type `Foo`
 
-error[E0277]: `Rc<Foo>` cannot be shared between threads safely
+error[E0277]: `Rc<Foo>` cannot be sent between threads safely
   --> $DIR/issue-40827.rs:14:5
    |
 LL | fn f<T: Send>(_: T) {}
    |         ---- required by this bound in `f`
 ...
 LL |     f(Foo(Arc::new(Bar::B(None))));
-   |     ^ `Rc<Foo>` cannot be shared between threads safely
+   |     ^ `Rc<Foo>` cannot be sent between threads safely
    |
-   = help: within `Bar`, the trait `Sync` is not implemented for `Rc<Foo>`
+   = help: within `Bar`, the trait `Send` is not implemented for `Rc<Foo>`
    = note: required because it appears within the type `Bar`
    = note: required because of the requirements on the impl of `Send` for `Arc<Bar>`
    = note: required because it appears within the type `Foo`

src/test/ui/suggestions/missing-trait-bounds-for-method-call.stderr

@@ -8,10 +8,10 @@ LL |         self.foo();
    |              ^^^ method cannot be called on `&Foo<T>` due to unsatisfied trait bounds
    |
    = note: the following trait bounds were not satisfied:
-           `T: Bar`
-           which is required by `Foo<T>: Bar`
            `T: Default`
            which is required by `Foo<T>: Bar`
+           `T: Bar`
+           which is required by `Foo<T>: Bar`
 help: consider restricting the type parameters to satisfy the trait bounds
    |
 LL | struct Foo<T> where T: Bar, T: Default {

src/test/ui/traits/inductive-overflow/simultaneous.stderr

@@ -1,4 +1,4 @@
-error[E0275]: overflow evaluating the requirement `{integer}: Tweedledum`
+error[E0275]: overflow evaluating the requirement `{integer}: Tweedledee`
   --> $DIR/simultaneous.rs:18:5
    |
 LL | fn is_ee<T: Combo>(t: T) {