add links to query documentation for E0391

compiler/rustc_error_codes/src/error_codes/E0391.md

@@ -14,3 +14,6 @@ trait SecondTrait : FirstTrait {
 
 The previous example contains a circular dependency between two traits:
 `FirstTrait` depends on `SecondTrait` which itself depends on `FirstTrait`.
+
+See https://rustc-dev-guide.rust-lang.org/overview.html#queries and
+https://rustc-dev-guide.rust-lang.org/query.html for more information.

compiler/rustc_query_system/messages.ftl

@@ -1,4 +1,5 @@
 query_system_cycle = cycle detected when {$stack_bottom}
+    .note = see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 query_system_cycle_recursive_trait_alias = trait aliases cannot be recursive
 

compiler/rustc_query_system/src/error.rs

@@ -57,6 +57,8 @@ pub struct Cycle {
     pub alias: Option<Alias>,
     #[subdiagnostic]
     pub cycle_usage: Option<CycleUsage>,
+    #[note]
+    pub note_span: (),
 }
 
 #[derive(Diagnostic)]

compiler/rustc_query_system/src/query/job.rs

@@ -607,6 +607,7 @@ pub(crate) fn report_cycle<'a, D: DepKind>(
         alias,
         cycle_usage: cycle_usage,
         stack_count,
+        note_span: (),
     };
 
     cycle_diag.into_diagnostic(&sess.parse_sess.span_diagnostic)

src/tools/miri/tests/fail/layout_cycle.stderr

@@ -2,6 +2,7 @@ error[E0391]: cycle detected when computing layout of `S<S<()>>`
    |
    = note: ...which requires computing layout of `<S<()> as Tr>::I`...
    = note: ...which again requires computing layout of `S<S<()>>`, completing the cycle
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: post-monomorphization error: a cycle occurred during layout computation
   --> RUSTLIB/core/src/mem/mod.rs:LL:CC

tests/rustdoc-ui/issue-110629-private-type-cycle-dyn.stderr

@@ -19,6 +19,7 @@ LL | | fn bar<'a, 'b>(i: &'a i32) -> Bar<'a, 'b> {
 LL | |     assert!(bar(&meh) == bar(&muh));
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/associated-consts/defaults-cyclic-fail.stderr

@@ -15,6 +15,7 @@ note: cycle used when const-evaluating + checking `main::promoted[1]`
    |
 LL |     assert_eq!(<() as Tr>::A, 0);
    |                ^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr

@@ -26,6 +26,7 @@ LL |     const BAR: u32 = IMPL_REF_BAR;
    |     ^^^^^^^^^^^^^^
    = note: ...which again requires elaborating drops for `<impl at $DIR/issue-24949-assoc-const-static-recursion-impl.rs:11:1: 11:19>::BAR`, completing the cycle
    = note: cycle used when running analysis passes on this crate
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr

@@ -26,6 +26,7 @@ LL |     const BAR: u32 = DEFAULT_REF_BAR;
    |     ^^^^^^^^^^^^^^
    = note: ...which again requires elaborating drops for `FooDefault::BAR`, completing the cycle
    = note: cycle used when running analysis passes on this crate
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr

@@ -26,6 +26,7 @@ LL |     const BAR: u32 = TRAIT_REF_BAR;
    |     ^^^^^^^^^^^^^^
    = note: ...which again requires elaborating drops for `<impl at $DIR/issue-24949-assoc-const-static-recursion-trait.rs:11:1: 11:28>::BAR`, completing the cycle
    = note: cycle used when running analysis passes on this crate
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-adt.stderr

@@ -37,6 +37,7 @@ LL | |
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-where-predicate.stderr

@@ -31,6 +31,7 @@ LL | | // FIXME(inherent_associated_types): This shouldn't lead to a cycle error
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/associated-type-bounds/ambiguous-associated-type2.rs

@@ -7,4 +7,6 @@ trait Bar<T> {
 trait Baz: Foo + Bar<Self::Item> {}
 //~^ ERROR cycle detected when computing the super traits of `Baz` with associated type name `Item` [E0391]
 
+
+
 fn main() {}

tests/ui/associated-type-bounds/ambiguous-associated-type2.stderr

@@ -10,6 +10,7 @@ note: cycle used when computing the super predicates of `Baz`
    |
 LL | trait Baz: Foo + Bar<Self::Item> {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/associated-types/issue-20825.stderr

@@ -10,6 +10,7 @@ note: cycle used when computing the super predicates of `Processor`
    |
 LL | pub trait Processor: Subscriber<Input = Self::Input> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/coherence/coherence-inherited-assoc-ty-cycle-err.stderr

@@ -20,6 +20,7 @@ note: cycle used when coherence checking all impls of trait `Trait`
    |
 LL | trait Trait<T> { type Assoc; }
    | ^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error; 1 warning emitted
 

tests/ui/const-generics/generic_const_exprs/closures.stderr

@@ -20,6 +20,7 @@ note: cycle used when checking that `test` is well-formed
    |
 LL | fn test<const N: usize>() -> [u8; N + (|| 42)()] {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/const-generics/issues/issue-83765.stderr

@@ -15,6 +15,7 @@ note: cycle used when computing candidate for `<LazyUpdim<'_, T, { T::DIM }, DIM
    |
 LL | trait TensorDimension {
    | ^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/consts/const-size_of-cycle.stderr

@@ -23,6 +23,7 @@ note: cycle used when checking that `Foo` is well-formed
    |
 LL | struct Foo {
    | ^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/consts/issue-103790.stderr

@@ -34,6 +34,7 @@ note: cycle used when computing type of `S`
    |
 LL | struct S<const S: (), const S: S = { S }>;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error[E0391]: cycle detected when computing type of `S`
   --> $DIR/issue-103790.rs:4:1
@@ -58,6 +59,7 @@ LL | | struct S<const S: (), const S: S = { S }>;
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to 4 previous errors
 

tests/ui/consts/issue-36163.stderr

@@ -15,6 +15,7 @@ note: cycle used when simplifying constant for the type system `Foo::B::{constan
    |
 LL |     B = A,
    |         ^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/consts/issue-44415.stderr

@@ -23,6 +23,7 @@ note: cycle used when checking that `Foo` is well-formed
    |
 LL | struct Foo {
    | ^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/consts/recursive-zst-static.default.stderr

@@ -19,6 +19,7 @@ LL | | fn main() {
 LL | |     FOO
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/consts/recursive-zst-static.unleash.stderr

@@ -19,6 +19,7 @@ LL | | fn main() {
 LL | |     FOO
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/consts/write-to-static-mut-in-static.stderr

@@ -27,6 +27,7 @@ LL | |
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to 2 previous errors
 

tests/ui/cycle-trait/cycle-trait-default-type-trait.stderr

@@ -14,6 +14,7 @@ LL | | }
 LL | |
 LL | | fn main() { }
    | |_____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/cycle-trait/cycle-trait-supertrait-direct.stderr

@@ -12,6 +12,7 @@ LL | / trait Chromosome: Chromosome {
 LL | |
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/cycle-trait/cycle-trait-supertrait-indirect.stderr

@@ -15,6 +15,7 @@ note: cycle used when computing the super predicates of `A`
    |
 LL | trait A: B {
    |          ^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/cycle-trait/issue-12511.stderr

@@ -17,6 +17,7 @@ LL | / trait T1 : T2 {
 LL | |
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/dyn-star/param-env-region-infer.next.stderr

@@ -23,6 +23,7 @@ LL | | use std::fmt::Debug;
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/impl-trait/auto-trait-leak.stderr

@@ -33,6 +33,7 @@ LL | | fn send<T: Send>(_: T) {}
 LL | |     Rc::new(String::from("foo"))
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error[E0391]: cycle detected when computing type of `cycle1::{opaque#0}`
   --> $DIR/auto-trait-leak.rs:11:16
@@ -68,6 +69,7 @@ LL | | fn send<T: Send>(_: T) {}
 LL | |     Rc::new(String::from("foo"))
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: cannot check whether the hidden type of opaque type satisfies auto traits
   --> $DIR/auto-trait-leak.rs:21:10

tests/ui/infinite/infinite-trait-alias-recursion.stderr

@@ -21,6 +21,7 @@ note: cycle used when collecting item types in top-level module
    |
 LL | trait T1 = T2;
    | ^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/infinite/infinite-type-alias-mutual-recursion.stderr

@@ -28,6 +28,7 @@ LL | | type X3 = X1;
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/infinite/infinite-vec-type-recursion.stderr

@@ -16,6 +16,7 @@ LL | |
 LL | |
 LL | | fn main() { let b: X = Vec::new(); }
    | |____________________________________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/issues/issue-17252.stderr

@@ -10,6 +10,7 @@ note: cycle used when const-evaluating + checking `main::{constant#0}`
    |
 LL |     let _x: [u8; FOO]; // caused stack overflow prior to fix
    |                  ^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/issues/issue-20772.stderr

@@ -10,6 +10,7 @@ note: cycle used when computing the super predicates of `T`
    |
 LL | trait T : Iterator<Item=Self::Item>
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/issues/issue-21177.stderr

@@ -10,6 +10,7 @@ note: cycle used when computing explicit predicates of `foo`
    |
 LL | fn foo<T: Trait<A = T::B>>() { }
    |                     ^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/issues/issue-23302-1.stderr

@@ -10,6 +10,7 @@ note: cycle used when simplifying constant for the type system `X::A::{constant#
    |
 LL |     A = X::A as isize,
    |         ^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/issues/issue-23302-2.stderr

@@ -10,6 +10,7 @@ note: cycle used when simplifying constant for the type system `Y::A::{constant#
    |
 LL |     A = Y::B as isize,
    |         ^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/issues/issue-23302-3.stderr

@@ -15,6 +15,7 @@ note: cycle used when simplifying constant for the type system `A`
    |
 LL | const A: i32 = B;
    | ^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/issues/issue-34373.stderr

@@ -21,6 +21,7 @@ LL | |     fn foo(_: T) {}
 LL | | fn main() {
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/recursion/issue-26548-recursion-via-normalize.rs

@@ -1,4 +1,5 @@
 //~ ERROR cycle detected when computing layout of `core::option::Option<S>`
+//~| NOTE see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 //~| NOTE ...which requires computing layout of `S`...
 //~| NOTE ...which requires computing layout of `core::option::Option<<S as Mirror>::It>`...
 //~| NOTE ...which again requires computing layout of `core::option::Option<S>`, completing the cycle

tests/ui/recursion/issue-26548-recursion-via-normalize.stderr

@@ -4,6 +4,7 @@ error[E0391]: cycle detected when computing layout of `core::option::Option<S>`
    = note: ...which requires computing layout of `core::option::Option<<S as Mirror>::It>`...
    = note: ...which again requires computing layout of `core::option::Option<S>`, completing the cycle
    = note: cycle used when computing layout of `core::option::Option<<S as Mirror>::It>`
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/recursion/recursive-static-definition.stderr

@@ -18,6 +18,7 @@ LL | |
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/resolve/resolve-self-in-impl.stderr

@@ -56,6 +56,7 @@ LL | | trait Tr<T = u8> {
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to 6 previous errors
 

tests/ui/sized/recursive-type-2.stderr

@@ -7,6 +7,7 @@ note: cycle used when elaborating drops for `main`
    |
 LL | fn main() {
    | ^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/traits/trait-upcasting/cyclic-trait-resolution.stderr

@@ -10,6 +10,7 @@ note: cycle used when collecting item types in top-level module
    |
 LL | trait A: B + A {}
    | ^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 

tests/ui/type-alias-enum-variants/self-in-enum-definition.stderr

@@ -67,6 +67,7 @@ LL | |     V2 = Self::V1 as u8 + 1,    // OK; See #50072.
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error