Auto merge of #145395 - lcnr:review-coroutine-witness, r=petrochenkov

[BETA] Revert "Remove the witness type from coroutine args"

fixes rust-lang/rust#145151 and rust-lang/rust#145288

we do not revert on nightly as its instead fixed by rust-lang/rust#145194 and rust-lang/rust#145338.

See the discussion in https://rust-lang.zulipchat.com/#narrow/channel/238009-t-compiler.2Fmeetings/topic/.5Bweekly.5D.202025-08-14/near/534490313

10 files changed, 74 insertions, 10 deletions

diff --git a/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir b/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir
index 9bff257e063..109a41d1ef9 100644
--- a/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir
+++ b/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir
@@ -9,6 +9,10 @@
                     std::future::ResumeTy,
                     (),
                     (),
+                    CoroutineWitness(
+                        DefId(0:5 ~ async_await[ccf8]::a::{closure#0}),
+                        [],
+                    ),
                     (),
                 ],
             ),
@@ -26,6 +30,10 @@
                     std::future::ResumeTy,
                     (),
                     (),
+                    CoroutineWitness(
+                        DefId(0:5 ~ async_await[ccf8]::a::{closure#0}),
+                        [],
+                    ),
                     (),
                 ],
             ),
diff --git a/tests/ui/async-await/async-closures/def-path.stderr b/tests/ui/async-await/async-closures/def-path.stderr
index a507fa69760..58a5b0b79c4 100644
--- a/tests/ui/async-await/async-closures/def-path.stderr
+++ b/tests/ui/async-await/async-closures/def-path.stderr
@@ -5,11 +5,11 @@ LL |     let x = async || {};
    |                      -- the expected `async` closure body
 LL |
 LL |     let () = x();
-   |         ^^   --- this expression has type `{static main::{closure#0}::{closure#0}<?15t> upvar_tys=?14t resume_ty=ResumeTy yield_ty=() return_ty=()}`
+   |         ^^   --- this expression has type `{static main::{closure#0}::{closure#0}<?16t> upvar_tys=?15t resume_ty=ResumeTy yield_ty=() return_ty=() witness={main::{closure#0}::{closure#0}}}`
    |         |
    |         expected `async` closure body, found `()`
    |
-   = note: expected `async` closure body `{static main::{closure#0}::{closure#0}<?15t> upvar_tys=?14t resume_ty=ResumeTy yield_ty=() return_ty=()}`
+   = note: expected `async` closure body `{static main::{closure#0}::{closure#0}<?16t> upvar_tys=?15t resume_ty=ResumeTy yield_ty=() return_ty=() witness={main::{closure#0}::{closure#0}}}`
                          found unit type `()`
 
 error: aborting due to 1 previous error
diff --git a/tests/ui/async-await/higher-ranked-auto-trait-6.no_assumptions.stderr b/tests/ui/async-await/higher-ranked-auto-trait-6.no_assumptions.stderr
index d1c88101618..d1f2d9a0753 100644
--- a/tests/ui/async-await/higher-ranked-auto-trait-6.no_assumptions.stderr
+++ b/tests/ui/async-await/higher-ranked-auto-trait-6.no_assumptions.stderr
@@ -21,6 +21,30 @@ LL |     Box::new(async { new(|| async { f().await }).await })
    = help: consider pinning your async block and casting it to a trait object
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
-error: aborting due to 2 previous errors
+error[E0308]: mismatched types
+  --> $DIR/higher-ranked-auto-trait-6.rs:16:5
+   |
+LL |     Box::new(async { new(|| async { f().await }).await })
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other
+   |
+   = note: expected `async` block `{async block@$DIR/higher-ranked-auto-trait-6.rs:16:29: 16:34}`
+              found `async` block `{async block@$DIR/higher-ranked-auto-trait-6.rs:16:29: 16:34}`
+   = note: no two async blocks, even if identical, have the same type
+   = help: consider pinning your async block and casting it to a trait object
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+error[E0308]: mismatched types
+  --> $DIR/higher-ranked-auto-trait-6.rs:16:5
+   |
+LL |     Box::new(async { new(|| async { f().await }).await })
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other
+   |
+   = note: expected `async` block `{async block@$DIR/higher-ranked-auto-trait-6.rs:16:29: 16:34}`
+              found `async` block `{async block@$DIR/higher-ranked-auto-trait-6.rs:16:29: 16:34}`
+   = note: no two async blocks, even if identical, have the same type
+   = help: consider pinning your async block and casting it to a trait object
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+error: aborting due to 4 previous errors
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/async-await/recursive-async-auto-trait-overflow.rs b/tests/ui/async-await/recursive-async-auto-trait-overflow.rs
new file mode 100644
index 00000000000..716600ce472
--- /dev/null
+++ b/tests/ui/async-await/recursive-async-auto-trait-overflow.rs
@@ -0,0 +1,14 @@
+// Regression test for <https://github.com/rust-lang/rust/issues/145151>.
+
+//@ edition: 2024
+//@ check-pass
+
+async fn process<'a>() {
+    Box::pin(process()).await;
+}
+
+fn require_send(_: impl Send) {}
+
+fn main() {
+    require_send(process());
+}
diff --git a/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr b/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr
index 11b78e3bcf8..8877d45ddda 100644
--- a/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr
+++ b/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr
@@ -9,7 +9,7 @@ LL | |         drop(a);
 LL | |     });
    | |______^ coroutine is not `Sync`
    |
-   = help: within `{main::{closure#0} upvar_tys=() resume_ty=() yield_ty=() return_ty=()}`, the trait `Sync` is not implemented for `NotSync`
+   = help: within `{main::{closure#0} upvar_tys=() resume_ty=() yield_ty=() return_ty=() witness={main::{closure#0}}}`, the trait `Sync` is not implemented for `NotSync`
 note: coroutine is not `Sync` as this value is used across a yield
   --> $DIR/coroutine-print-verbose-2.rs:20:9
    |
@@ -34,7 +34,7 @@ LL | |         drop(a);
 LL | |     });
    | |______^ coroutine is not `Send`
    |
-   = help: within `{main::{closure#1} upvar_tys=() resume_ty=() yield_ty=() return_ty=()}`, the trait `Send` is not implemented for `NotSend`
+   = help: within `{main::{closure#1} upvar_tys=() resume_ty=() yield_ty=() return_ty=() witness={main::{closure#1}}}`, the trait `Send` is not implemented for `NotSend`
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/coroutine-print-verbose-2.rs:27:9
    |
diff --git a/tests/ui/coroutine/print/coroutine-print-verbose-3.stderr b/tests/ui/coroutine/print/coroutine-print-verbose-3.stderr
index 135e8175793..4a1e5b078a8 100644
--- a/tests/ui/coroutine/print/coroutine-print-verbose-3.stderr
+++ b/tests/ui/coroutine/print/coroutine-print-verbose-3.stderr
@@ -11,7 +11,7 @@ LL | |     };
    | |_____^ expected `()`, found coroutine
    |
    = note: expected unit type `()`
-              found coroutine `{main::{closure#0} upvar_tys=?4t resume_ty=() yield_ty=i32 return_ty=&'?1 str}`
+              found coroutine `{main::{closure#0} upvar_tys=?4t resume_ty=() yield_ty=i32 return_ty=&'?1 str witness={main::{closure#0}}}`
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/impl-trait/issues/issue-55872-2.rs b/tests/ui/impl-trait/issues/issue-55872-2.rs
index aea00dd9e3d..a3b2225126a 100644
--- a/tests/ui/impl-trait/issues/issue-55872-2.rs
+++ b/tests/ui/impl-trait/issues/issue-55872-2.rs
@@ -12,6 +12,7 @@ impl<S> Bar for S {
     type E = impl std::marker::Send;
     fn foo<T>() -> Self::E {
         //~^ ERROR type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+        //~| ERROR type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
         async {}
     }
 }
diff --git a/tests/ui/impl-trait/issues/issue-55872-2.stderr b/tests/ui/impl-trait/issues/issue-55872-2.stderr
index 91c2ecdc8a4..51a7dd00ade 100644
--- a/tests/ui/impl-trait/issues/issue-55872-2.stderr
+++ b/tests/ui/impl-trait/issues/issue-55872-2.stderr
@@ -4,5 +4,13 @@ error: type parameter `T` is part of concrete type but not used in parameter lis
 LL |     fn foo<T>() -> Self::E {
    |                    ^^^^^^^
 
-error: aborting due to 1 previous error
+error: type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+  --> $DIR/issue-55872-2.rs:13:20
+   |
+LL |     fn foo<T>() -> Self::E {
+   |                    ^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+error: aborting due to 2 previous errors
 
diff --git a/tests/ui/impl-trait/issues/issue-55872-3.rs b/tests/ui/impl-trait/issues/issue-55872-3.rs
index 698e7f36234..763b4b9fd32 100644
--- a/tests/ui/impl-trait/issues/issue-55872-3.rs
+++ b/tests/ui/impl-trait/issues/issue-55872-3.rs
@@ -14,6 +14,7 @@ impl<S> Bar for S {
     fn foo<T>() -> Self::E {
         //~^ ERROR : Copy` is not satisfied [E0277]
         //~| ERROR type parameter `T` is part of concrete type
+        //~| ERROR type parameter `T` is part of concrete type
         async {}
     }
 }
diff --git a/tests/ui/impl-trait/issues/issue-55872-3.stderr b/tests/ui/impl-trait/issues/issue-55872-3.stderr
index 5124c46baeb..b7711e47468 100644
--- a/tests/ui/impl-trait/issues/issue-55872-3.stderr
+++ b/tests/ui/impl-trait/issues/issue-55872-3.stderr
@@ -4,12 +4,20 @@ error: type parameter `T` is part of concrete type but not used in parameter lis
 LL |     fn foo<T>() -> Self::E {
    |                    ^^^^^^^
 
-error[E0277]: the trait bound `{async block@$DIR/issue-55872-3.rs:17:9: 17:14}: Copy` is not satisfied
+error: type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+  --> $DIR/issue-55872-3.rs:14:20
+   |
+LL |     fn foo<T>() -> Self::E {
+   |                    ^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+error[E0277]: the trait bound `{async block@$DIR/issue-55872-3.rs:18:9: 18:14}: Copy` is not satisfied
   --> $DIR/issue-55872-3.rs:14:20
    |
 LL |     fn foo<T>() -> Self::E {
-   |                    ^^^^^^^ the trait `Copy` is not implemented for `{async block@$DIR/issue-55872-3.rs:17:9: 17:14}`
+   |                    ^^^^^^^ the trait `Copy` is not implemented for `{async block@$DIR/issue-55872-3.rs:18:9: 18:14}`
 
-error: aborting due to 2 previous errors
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0277`.