register opaques that reference errors

aliemjay · aliemjay · commit 0dc006b3a890 · 2024-03-20T17:30:19.000Z
diff --git a/compiler/rustc_infer/src/infer/opaque_types/mod.rs b/compiler/rustc_infer/src/infer/opaque_types/mod.rs
@@ -94,9 +94,6 @@ impl<'tcx> InferCtxt<'tcx> {
         cause: &ObligationCause<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
     ) -> InferResult<'tcx, ()> {
-        if a.references_error() || b.references_error() {
-            return Ok(InferOk { value: (), obligations: vec![] });
-        }
         let process = |a: Ty<'tcx>, b: Ty<'tcx>| match *a.kind() {
             ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) if def_id.is_local() => {
                 let def_id = def_id.expect_local();
diff --git a/tests/ui/const-generics/generic_const_exprs/issue-109141.rs b/tests/ui/const-generics/generic_const_exprs/issue-109141.rs
@@ -4,6 +4,7 @@
 impl EntriesBuffer {
     fn a(&self) -> impl Iterator {
         self.0.iter_mut() //~ ERROR: cannot borrow `*self.0` as mutable, as it is behind a `&` reference
+                          //~| ERROR captures lifetime that does not appear in bounds
     }
 }
 
diff --git a/tests/ui/const-generics/generic_const_exprs/issue-109141.stderr b/tests/ui/const-generics/generic_const_exprs/issue-109141.stderr
@@ -1,5 +1,5 @@
 error[E0425]: cannot find value `HashesEntryLEN` in this scope
-  --> $DIR/issue-109141.rs:10:32
+  --> $DIR/issue-109141.rs:11:32
    |
 LL | struct EntriesBuffer(Box<[[u8; HashesEntryLEN]; 5]>);
    |                                ^^^^^^^^^^^^^^ not found in this scope
@@ -20,7 +20,22 @@ help: consider changing this to be a mutable reference
 LL |     fn a(&mut self) -> impl Iterator {
    |          ~~~~~~~~~
 
-error: aborting due to 2 previous errors
+error[E0700]: hidden type for `impl Iterator` captures lifetime that does not appear in bounds
+  --> $DIR/issue-109141.rs:6:9
+   |
+LL |     fn a(&self) -> impl Iterator {
+   |          -----     ------------- opaque type defined here
+   |          |
+   |          hidden type `std::slice::IterMut<'_, [u8; {const error}]>` captures the anonymous lifetime defined here
+LL |         self.0.iter_mut()
+   |         ^^^^^^^^^^^^^^^^^
+   |
+help: to declare that `impl Iterator` captures `'_`, you can add an explicit `'_` lifetime bound
+   |
+LL |     fn a(&self) -> impl Iterator + '_ {
+   |                                  ++++
+
+error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0425, E0596.
+Some errors have detailed explanations: E0425, E0596, E0700.
 For more information about an error, try `rustc --explain E0425`.
diff --git a/tests/ui/impl-trait/nested-rpit-hrtb.rs b/tests/ui/impl-trait/nested-rpit-hrtb.rs
@@ -31,6 +31,7 @@ fn one_hrtb_trait_param() -> impl for<'a> Foo<'a, Assoc = impl Qux<'a>> {}
 
 fn one_hrtb_outlives_uses() -> impl for<'a> Bar<'a, Assoc = impl Sized + 'a> {}
 //~^ ERROR `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait`
+//~| ERROR implementation of `Bar` is not general enough
 
 fn one_hrtb_trait_param_uses() -> impl for<'a> Bar<'a, Assoc = impl Qux<'a>> {}
 //~^ ERROR `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait`
@@ -43,7 +44,7 @@ fn one_hrtb_mention_fn_outlives<'b>() -> impl for<'a> Foo<'a, Assoc = impl Sized
 
 // This should resolve.
 fn one_hrtb_mention_fn_trait_param_uses<'b>() -> impl for<'a> Bar<'a, Assoc = impl Qux<'b>> {}
-//~^ ERROR: the trait bound `for<'a> &'a (): Qux<'b>` is not satisfied
+//~^ ERROR type annotations needed: cannot satisfy `for<'a> &'a (): Qux<'b>`
 
 // This should resolve.
 fn one_hrtb_mention_fn_outlives_uses<'b>() -> impl for<'a> Bar<'a, Assoc = impl Sized + 'b> {}
diff --git a/tests/ui/impl-trait/nested-rpit-hrtb.stderr b/tests/ui/impl-trait/nested-rpit-hrtb.stderr
@@ -1,5 +1,5 @@
 error[E0261]: use of undeclared lifetime name `'b`
-  --> $DIR/nested-rpit-hrtb.rs:56:77
+  --> $DIR/nested-rpit-hrtb.rs:57:77
    |
 LL | fn two_htrb_outlives() -> impl for<'a> Foo<'a, Assoc = impl for<'b> Sized + 'b> {}
    |                                                                             ^^ undeclared lifetime
@@ -15,7 +15,7 @@ LL | fn two_htrb_outlives<'b>() -> impl for<'a> Foo<'a, Assoc = impl for<'b> Siz
    |                     ++++
 
 error[E0261]: use of undeclared lifetime name `'b`
-  --> $DIR/nested-rpit-hrtb.rs:64:82
+  --> $DIR/nested-rpit-hrtb.rs:65:82
    |
 LL | fn two_htrb_outlives_uses() -> impl for<'a> Bar<'a, Assoc = impl for<'b> Sized + 'b> {}
    |                                                                                  ^^ undeclared lifetime
@@ -65,29 +65,39 @@ note: lifetime declared here
 LL | fn one_hrtb_outlives_uses() -> impl for<'a> Bar<'a, Assoc = impl Sized + 'a> {}
    |                                         ^^
 
+error: implementation of `Bar` is not general enough
+  --> $DIR/nested-rpit-hrtb.rs:32:78
+   |
+LL | fn one_hrtb_outlives_uses() -> impl for<'a> Bar<'a, Assoc = impl Sized + 'a> {}
+   |                                                                              ^^ implementation of `Bar` is not general enough
+   |
+   = note: `()` must implement `Bar<'a>`
+   = note: ...but it actually implements `Bar<'0>`, for some specific lifetime `'0`
+
 error[E0657]: `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait`
-  --> $DIR/nested-rpit-hrtb.rs:35:73
+  --> $DIR/nested-rpit-hrtb.rs:36:73
    |
 LL | fn one_hrtb_trait_param_uses() -> impl for<'a> Bar<'a, Assoc = impl Qux<'a>> {}
    |                                                                         ^^
    |
 note: lifetime declared here
-  --> $DIR/nested-rpit-hrtb.rs:35:44
+  --> $DIR/nested-rpit-hrtb.rs:36:44
    |
 LL | fn one_hrtb_trait_param_uses() -> impl for<'a> Bar<'a, Assoc = impl Qux<'a>> {}
    |                                            ^^
 
-error[E0277]: the trait bound `for<'a> &'a (): Qux<'b>` is not satisfied
-  --> $DIR/nested-rpit-hrtb.rs:45:79
+error[E0283]: type annotations needed: cannot satisfy `for<'a> &'a (): Qux<'b>`
+  --> $DIR/nested-rpit-hrtb.rs:46:79
    |
 LL | fn one_hrtb_mention_fn_trait_param_uses<'b>() -> impl for<'a> Bar<'a, Assoc = impl Qux<'b>> {}
-   |                                                                               ^^^^^^^^^^^^ the trait `for<'a> Qux<'b>` is not implemented for `&'a ()`
+   |                                                                               ^^^^^^^^^^^^
    |
+   = note: cannot satisfy `for<'a> &'a (): Qux<'b>`
    = help: the trait `Qux<'_>` is implemented for `()`
    = help: for that trait implementation, expected `()`, found `&'a ()`
 
 error: implementation of `Bar` is not general enough
-  --> $DIR/nested-rpit-hrtb.rs:49:93
+  --> $DIR/nested-rpit-hrtb.rs:50:93
    |
 LL | fn one_hrtb_mention_fn_outlives_uses<'b>() -> impl for<'a> Bar<'a, Assoc = impl Sized + 'b> {}
    |                                                                                             ^^ implementation of `Bar` is not general enough
@@ -96,7 +106,7 @@ LL | fn one_hrtb_mention_fn_outlives_uses<'b>() -> impl for<'a> Bar<'a, Assoc =
    = note: ...but it actually implements `Bar<'0>`, for some specific lifetime `'0`
 
 error[E0277]: the trait bound `for<'a, 'b> &'a (): Qux<'b>` is not satisfied
-  --> $DIR/nested-rpit-hrtb.rs:60:64
+  --> $DIR/nested-rpit-hrtb.rs:61:64
    |
 LL | fn two_htrb_trait_param_uses() -> impl for<'a> Bar<'a, Assoc = impl for<'b> Qux<'b>> {}
    |                                                                ^^^^^^^^^^^^^^^^^^^^ the trait `for<'a, 'b> Qux<'b>` is not implemented for `&'a ()`
@@ -105,15 +115,15 @@ LL | fn two_htrb_trait_param_uses() -> impl for<'a> Bar<'a, Assoc = impl for<'b>
    = help: for that trait implementation, expected `()`, found `&'a ()`
 
 error: implementation of `Bar` is not general enough
-  --> $DIR/nested-rpit-hrtb.rs:64:86
+  --> $DIR/nested-rpit-hrtb.rs:65:86
    |
 LL | fn two_htrb_outlives_uses() -> impl for<'a> Bar<'a, Assoc = impl for<'b> Sized + 'b> {}
    |                                                                                      ^^ implementation of `Bar` is not general enough
    |
    = note: `()` must implement `Bar<'a>`
    = note: ...but it actually implements `Bar<'0>`, for some specific lifetime `'0`
 
-error: aborting due to 10 previous errors
+error: aborting due to 11 previous errors
 
-Some errors have detailed explanations: E0261, E0277, E0657.
+Some errors have detailed explanations: E0261, E0277, E0283, E0657.
 For more information about an error, try `rustc --explain E0261`.
diff --git a/tests/ui/type-alias-impl-trait/escaping-bound-var.rs b/tests/ui/type-alias-impl-trait/escaping-bound-var.rs
@@ -8,7 +8,6 @@ trait Test<'a> {}
 
 pub type Foo = impl for<'a> Trait<'a, Assoc = impl Test<'a>>;
 //~^ ERROR `impl Trait` cannot capture higher-ranked lifetime from outer `impl Trait`
-//~| ERROR unconstrained opaque type
 
 impl Trait<'_> for () {
     type Assoc = ();
diff --git a/tests/ui/type-alias-impl-trait/escaping-bound-var.stderr b/tests/ui/type-alias-impl-trait/escaping-bound-var.stderr
@@ -10,14 +10,6 @@ note: lifetime declared here
 LL | pub type Foo = impl for<'a> Trait<'a, Assoc = impl Test<'a>>;
    |                         ^^
 
-error: unconstrained opaque type
-  --> $DIR/escaping-bound-var.rs:9:47
-   |
-LL | pub type Foo = impl for<'a> Trait<'a, Assoc = impl Test<'a>>;
-   |                                               ^^^^^^^^^^^^^
-   |
-   = note: `Foo` must be used in combination with a concrete type within the same module
-
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0657`.

Original file line number	Diff line number	Diff line change
`@@ -4,6 +4,7 @@`
`4`	`4`	`impl EntriesBuffer {`
`5`	`5`	`fn a(&self) -> impl Iterator {`
`6`	`6`	self.0.iter_mut() //~ ERROR: cannot borrow `*self.0` as mutable, as it is behind a `&` reference
	`7`	`+ //~\| ERROR captures lifetime that does not appear in bounds`
`7`	`8`	`}`
`8`	`9`	`}`
`9`	`10`