Add better default spans for the Ty impl of QueryKey

compiler/rustc_middle/src/query/keys.rs

@@ -5,6 +5,7 @@ use std::fmt::Debug;
 use std::hash::Hash;
 
 use rustc_ast::tokenstream::TokenStream;
+use rustc_data_structures::sso::SsoHashSet;
 use rustc_data_structures::stable_hasher::HashStable;
 use rustc_hir::def_id::{CrateNum, DefId, LOCAL_CRATE, LocalDefId, LocalModDefId};
 use rustc_hir::hir_id::OwnerId;
@@ -257,8 +258,8 @@ impl<'tcx> QueryKey for GenericArg<'tcx> {
 }
 
 impl<'tcx> QueryKey for Ty<'tcx> {
-    fn default_span(&self, _: TyCtxt<'_>) -> Span {
-        DUMMY_SP
+    fn default_span(&self, tcx: TyCtxt<'_>) -> Span {
+        def_id_of_type(*self).map(|def_id| tcx.def_span(def_id)).unwrap_or(DUMMY_SP)
     }
 }
 
@@ -361,3 +362,58 @@ impl<'tcx> QueryKey for (ty::Instance<'tcx>, CollectionMode) {
         self.0.default_span(tcx)
     }
 }
+
+/// Gets a `DefId` associated with a type
+///
+/// Visited set is needed to avoid full iteration over
+/// deeply nested tuples that have no DefId.
+fn def_id_of_type_cached<'a>(ty: Ty<'a>, visited: &mut SsoHashSet<Ty<'a>>) -> Option<DefId> {
+    match *ty.kind() {
+        ty::Adt(adt_def, _) => Some(adt_def.did()),
+
+        ty::Dynamic(data, ..) => data.principal_def_id(),
+
+        ty::Pat(subty, _) | ty::Array(subty, _) | ty::Slice(subty) => {
+            def_id_of_type_cached(subty, visited)
+        }
+
+        ty::RawPtr(ty, _) => def_id_of_type_cached(ty, visited),
+
+        ty::Ref(_, ty, _) => def_id_of_type_cached(ty, visited),
+
+        ty::Tuple(tys) => tys.iter().find_map(|ty| {
+            if visited.insert(ty) {
+                return def_id_of_type_cached(ty, visited);
+            }
+            return None;
+        }),
+
+        ty::FnDef(def_id, _)
+        | ty::Closure(def_id, _)
+        | ty::CoroutineClosure(def_id, _)
+        | ty::Coroutine(def_id, _)
+        | ty::CoroutineWitness(def_id, _)
+        | ty::Foreign(def_id) => Some(def_id),
+
+        ty::Alias(_, ty) => Some(ty.def_id),
+
+        ty::Bool
+        | ty::Char
+        | ty::Int(_)
+        | ty::Uint(_)
+        | ty::Str
+        | ty::FnPtr(..)
+        | ty::UnsafeBinder(_)
+        | ty::Placeholder(..)
+        | ty::Param(_)
+        | ty::Infer(_)
+        | ty::Bound(..)
+        | ty::Error(_)
+        | ty::Never
+        | ty::Float(_) => None,
+    }
+}
+
+fn def_id_of_type(ty: Ty<'_>) -> Option<DefId> {
+    def_id_of_type_cached(ty, &mut SsoHashSet::new())
+}

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

@@ -10,7 +10,11 @@ note: ...which requires simplifying constant for the type system `core::mem::Siz
   --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
 note: ...which requires const-evaluating + checking `core::mem::SizedTypeProperties::SIZE`...
   --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
-   = note: ...which requires computing layout of `Foo`...
+note: ...which requires computing layout of `Foo`...
+  --> $DIR/const-size_of-cycle.rs:1:1
+   |
+LL | struct Foo {
+   | ^^^^^^^^^^
    = note: ...which requires computing layout of `[u8; std::mem::size_of::<Foo>()]`...
 note: ...which requires normalizing `[u8; std::mem::size_of::<Foo>()]`...
   --> $DIR/const-size_of-cycle.rs:2:17

tests/ui/consts/issue-44415.stderr

@@ -9,7 +9,11 @@ note: ...which requires const-evaluating + checking `Foo::bytes::{constant#0}`..
    |
 LL |     bytes: [u8; unsafe { intrinsics::size_of::<Foo>() }],
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   = note: ...which requires computing layout of `Foo`...
+note: ...which requires computing layout of `Foo`...
+  --> $DIR/issue-44415.rs:5:1
+   |
+LL | struct Foo {
+   | ^^^^^^^^^^
    = note: ...which requires computing layout of `[u8; unsafe { intrinsics::size_of::<Foo>() }]`...
 note: ...which requires normalizing `[u8; unsafe { intrinsics::size_of::<Foo>() }]`...
   --> $DIR/issue-44415.rs:6:17

tests/ui/layout/layout-cycle.rs

@@ -1,11 +1,11 @@
 //@ build-fail
-//~^ ERROR: cycle detected when computing layout of
 
 // Issue #111176 -- ensure that we do not emit ICE on layout cycles
 
 use std::mem;
 
 pub struct S<T: Tr> {
+    //~^ ERROR: cycle detected when computing layout of
     pub f: <T as Tr>::I,
 }
 

tests/ui/layout/layout-cycle.stderr

@@ -1,6 +1,14 @@
 error[E0391]: cycle detected when computing layout of `S<S<()>>`
+  --> $DIR/layout-cycle.rs:7:1
    |
-   = note: ...which requires computing layout of `<S<()> as Tr>::I`...
+LL | pub struct S<T: Tr> {
+   | ^^^^^^^^^^^^^^^^^^^
+   |
+note: ...which requires computing layout of `<S<()> as Tr>::I`...
+  --> $DIR/layout-cycle.rs:13:5
+   |
+LL |     type I: Tr;
+   |     ^^^^^^^^^^
    = note: ...which again requires computing layout of `S<S<()>>`, completing the cycle
 note: cycle used when const-evaluating + checking `core::mem::SizedTypeProperties::SIZE`
   --> $SRC_DIR/core/src/mem/mod.rs:LL:COL

tests/ui/layout/post-mono-layout-cycle.rs

@@ -1,5 +1,4 @@
 //@ build-fail
-//~^ ERROR cycle detected when computing layout of `Wrapper<()>`
 
 trait Trait {
     type Assoc;
@@ -10,6 +9,7 @@ impl Trait for () {
 }
 
 struct Wrapper<T: Trait> {
+    //~^ ERROR cycle detected when computing layout of `Wrapper<()>`
     _x: <T as Trait>::Assoc,
 }
 

tests/ui/layout/post-mono-layout-cycle.stderr

@@ -1,8 +1,17 @@
 error[E0391]: cycle detected when computing layout of `Wrapper<()>`
+  --> $DIR/post-mono-layout-cycle.rs:11:1
    |
-   = note: ...which requires computing layout of `<() as Trait>::Assoc`...
+LL | struct Wrapper<T: Trait> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: ...which requires computing layout of `<() as Trait>::Assoc`...
+  --> $DIR/post-mono-layout-cycle.rs:4:5
+   |
+LL |     type Assoc;
+   |     ^^^^^^^^^^
    = note: ...which again requires computing layout of `Wrapper<()>`, completing the cycle
-   = note: cycle used when computing layout of `core::option::Option<Wrapper<()>>`
+note: cycle used when computing layout of `core::option::Option<Wrapper<()>>`
+  --> $SRC_DIR/core/src/option.rs:LL:COL
    = 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 1 previous error

tests/ui/pattern/non-structural-match-types-cycle-err.stderr

@@ -14,8 +14,13 @@ note: ...which requires const-evaluating + checking `<impl at $DIR/non-structura
    |
 LL |     const NONE: Option<T> = None;
    |     ^^^^^^^^^^^^^^^^^^^^^
-   = note: ...which requires computing layout of `core::option::Option<{async block@$DIR/non-structural-match-types-cycle-err.rs:18:16: 18:21}>`...
-   = note: ...which requires computing layout of `{async block@$DIR/non-structural-match-types-cycle-err.rs:18:16: 18:21}`...
+note: ...which requires computing layout of `core::option::Option<{async block@$DIR/non-structural-match-types-cycle-err.rs:18:16: 18:21}>`...
+  --> $SRC_DIR/core/src/option.rs:LL:COL
+note: ...which requires computing layout of `{async block@$DIR/non-structural-match-types-cycle-err.rs:18:16: 18:21}`...
+  --> $DIR/non-structural-match-types-cycle-err.rs:18:16
+   |
+LL |     match Some(async {}) {
+   |                ^^^^^
 note: ...which requires optimizing MIR for `defines::{closure#0}`...
   --> $DIR/non-structural-match-types-cycle-err.rs:18:16
    |

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

@@ -1,9 +1,8 @@
-//~ 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
-//~| NOTE cycle used when computing layout of `core::option::Option<<S as Mirror>::It>`
+//~? 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 `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>`
 
 trait Mirror {
     type It: ?Sized;
@@ -12,6 +11,7 @@ impl<T: ?Sized> Mirror for T {
     type It = Self;
 }
 struct S(Option<<S as Mirror>::It>);
+//~^ NOTE ...which requires computing layout of `S`...
 
 fn main() {
     let _s = S(None);

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

@@ -1,9 +1,16 @@
 error[E0391]: cycle detected when computing layout of `core::option::Option<S>`
+  --> $SRC_DIR/core/src/option.rs:LL:COL
    |
-   = note: ...which requires computing layout of `S`...
-   = note: ...which requires computing layout of `core::option::Option<<S as Mirror>::It>`...
+note: ...which requires computing layout of `S`...
+  --> $DIR/issue-26548-recursion-via-normalize.rs:13:1
+   |
+LL | struct S(Option<<S as Mirror>::It>);
+   | ^^^^^^^^
+note: ...which requires computing layout of `core::option::Option<<S as Mirror>::It>`...
+  --> $SRC_DIR/core/src/option.rs:LL:COL
    = 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: cycle used when computing layout of `core::option::Option<<S as Mirror>::It>`
+  --> $SRC_DIR/core/src/option.rs:LL:COL
    = 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 1 previous error

tests/ui/sized/recursive-type-binding.rs

@@ -1,12 +1,14 @@
 //@ build-fail
-//~^ ERROR cycle detected when computing layout of `Foo<()>`
 
-trait A { type Assoc: ?Sized; }
+trait A {
+    type Assoc: ?Sized;
+}
 
 impl A for () {
     type Assoc = Foo<()>;
 }
 struct Foo<T: A>(T::Assoc);
+//~^ ERROR cycle detected when computing layout of `Foo<()>`
 
 fn main() {
     let x: Foo<()>;

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

@@ -1,9 +1,17 @@
 error[E0391]: cycle detected when computing layout of `Foo<()>`
+  --> $DIR/recursive-type-binding.rs:10:1
    |
-   = note: ...which requires computing layout of `<() as A>::Assoc`...
+LL | struct Foo<T: A>(T::Assoc);
+   | ^^^^^^^^^^^^^^^^
+   |
+note: ...which requires computing layout of `<() as A>::Assoc`...
+  --> $DIR/recursive-type-binding.rs:4:5
+   |
+LL |     type Assoc: ?Sized;
+   |     ^^^^^^^^^^^^^^^^^^
    = note: ...which again requires computing layout of `Foo<()>`, completing the cycle
 note: cycle used when elaborating drops for `main`
-  --> $DIR/recursive-type-binding.rs:11:1
+  --> $DIR/recursive-type-binding.rs:13:1
    |
 LL | fn main() {
    | ^^^^^^^^^

tests/ui/sized/recursive-type-coercion-from-never.rs

@@ -1,15 +1,17 @@
 //@ build-fail
-//~^ ERROR cycle detected when computing layout of `Foo<()>`
 
 // Regression test for a stack overflow: https://github.com/rust-lang/rust/issues/113197
 
-trait A { type Assoc; }
+trait A {
+    type Assoc;
+}
 
 impl A for () {
     type Assoc = Foo<()>;
 }
 
 struct Foo<T: A>(T::Assoc);
+//~^ ERROR cycle detected when computing layout of `Foo<()>`
 
 fn main() {
     Foo::<()>(todo!());

tests/ui/sized/recursive-type-coercion-from-never.stderr

@@ -1,9 +1,17 @@
 error[E0391]: cycle detected when computing layout of `Foo<()>`
+  --> $DIR/recursive-type-coercion-from-never.rs:13:1
    |
-   = note: ...which requires computing layout of `<() as A>::Assoc`...
+LL | struct Foo<T: A>(T::Assoc);
+   | ^^^^^^^^^^^^^^^^
+   |
+note: ...which requires computing layout of `<() as A>::Assoc`...
+  --> $DIR/recursive-type-coercion-from-never.rs:6:5
+   |
+LL |     type Assoc;
+   |     ^^^^^^^^^^
    = note: ...which again requires computing layout of `Foo<()>`, completing the cycle
 note: cycle used when elaborating drops for `main`
-  --> $DIR/recursive-type-coercion-from-never.rs:14:1
+  --> $DIR/recursive-type-coercion-from-never.rs:16:1
    |
 LL | fn main() {
    | ^^^^^^^^^

tests/ui/sized/stack-overflow-trait-infer-98842.rs

@@ -2,11 +2,11 @@
 // issue: rust-lang/rust#98842
 //@ check-fail
 //@ edition:2021
-//~^^^^ ERROR cycle detected when computing layout of `Foo`
 
 // If the inner `Foo` is named through an associated type,
 // the "infinite size" error does not occur.
 struct Foo(<&'static Foo as ::core::ops::Deref>::Target);
+//~^ ERROR cycle detected when computing layout of `Foo`
 // But Rust will be unable to know whether `Foo` is sized or not,
 // and it will infinitely recurse somewhere trying to figure out the
 // size of this pointer (is my guess):

tests/ui/sized/stack-overflow-trait-infer-98842.stderr

@@ -1,6 +1,11 @@
 error[E0391]: cycle detected when computing layout of `Foo`
+  --> $DIR/stack-overflow-trait-infer-98842.rs:8:1
    |
-   = note: ...which requires computing layout of `<&'static Foo as core::ops::deref::Deref>::Target`...
+LL | struct Foo(<&'static Foo as ::core::ops::Deref>::Target);
+   | ^^^^^^^^^^
+   |
+note: ...which requires computing layout of `<&'static Foo as core::ops::deref::Deref>::Target`...
+  --> $SRC_DIR/core/src/ops/deref.rs:LL:COL
    = note: ...which again requires computing layout of `Foo`, completing the cycle
 note: cycle used when const-evaluating + checking `_`
   --> $DIR/stack-overflow-trait-infer-98842.rs:13:1

tests/ui/traits/solver-cycles/129541-recursive-enum-and-array-impl.current.stderr

@@ -1,8 +1,20 @@
 error[E0391]: cycle detected when computing layout of `<[Hello] as Normalize>::Assoc`
+  --> $DIR/129541-recursive-enum-and-array-impl.rs:8:5
    |
-   = note: ...which requires computing layout of `Hello`...
+LL |     type Assoc;
+   |     ^^^^^^^^^^
+   |
+note: ...which requires computing layout of `Hello`...
+  --> $DIR/129541-recursive-enum-and-array-impl.rs:21:1
+   |
+LL | enum Hello {
+   | ^^^^^^^^^^
    = note: ...which again requires computing layout of `<[Hello] as Normalize>::Assoc`, completing the cycle
-   = note: cycle used when computing layout of `Hello`
+note: cycle used when computing layout of `Hello`
+  --> $DIR/129541-recursive-enum-and-array-impl.rs:21:1
+   |
+LL | enum Hello {
+   | ^^^^^^^^^^
    = 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 1 previous error

tests/ui/traits/solver-cycles/129541-recursive-enum-and-array-impl.next.stderr

@@ -1,8 +1,20 @@
 error[E0391]: cycle detected when computing layout of `<[Hello] as Normalize>::Assoc`
+  --> $DIR/129541-recursive-enum-and-array-impl.rs:8:5
    |
-   = note: ...which requires computing layout of `Hello`...
+LL |     type Assoc;
+   |     ^^^^^^^^^^
+   |
+note: ...which requires computing layout of `Hello`...
+  --> $DIR/129541-recursive-enum-and-array-impl.rs:21:1
+   |
+LL | enum Hello {
+   | ^^^^^^^^^^
    = note: ...which again requires computing layout of `<[Hello] as Normalize>::Assoc`, completing the cycle
-   = note: cycle used when computing layout of `Hello`
+note: cycle used when computing layout of `Hello`
+  --> $DIR/129541-recursive-enum-and-array-impl.rs:21:1
+   |
+LL | enum Hello {
+   | ^^^^^^^^^^
    = 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 1 previous error

tests/ui/traits/solver-cycles/129541-recursive-enum-and-array-impl.rs

@@ -1,13 +1,12 @@
 // Regression test for #129541
-//~^ ERROR cycle detected when computing layout of `<[Hello] as Normalize>::Assoc` [E0391]
-
 //@ revisions: current next
 //@ ignore-compare-mode-next-solver (explicit revisions)
 //@[next] compile-flags: -Znext-solver
 
 trait Bound {}
 trait Normalize {
     type Assoc;
+    //~^ ERROR cycle detected when computing layout of `<[Hello] as Normalize>::Assoc` [E0391]
 }
 
 impl<T: Bound> Normalize for T {