Do not skip "type annotation needed"/Sized error

Author: estebank

compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs

@@ -1503,11 +1503,8 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
                 // avoid inundating the user with unnecessary errors, but we now
                 // check upstream for type errors and don't add the obligations to
                 // begin with in those cases.
-                if self.tcx.lang_items().sized_trait() == Some(data.trait_ref.def_id) {
-                    self.emit_inference_failure_err(body_id, span, subst, ErrorCode::E0282, &[])
-                        .delay_as_bug();
-                    return;
-                }
+                let is_sized = self.tcx.lang_items().sized_trait() == Some(data.trait_ref.def_id);
+
                 // Try to find possible types that would satisfy the bounds in the type param to
                 // give an appropriate turbofish suggestion.
                 let turbofish_suggestions =
@@ -1516,11 +1513,12 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
                     body_id,
                     span,
                     subst,
-                    ErrorCode::E0283,
+                    if is_sized { ErrorCode::E0282 } else { ErrorCode::E0283 },
                     &turbofish_suggestions,
                 );
-                err.note(&format!("cannot satisfy `{}`", predicate));
-
+                if !is_sized {
+                    err.note(&format!("cannot satisfy `{}`", predicate));
+                }
                 if let ObligationCauseCode::ItemObligation(def_id) = obligation.cause.code {
                     self.suggest_fully_qualified_path(
                         &mut err,
@@ -1600,6 +1598,10 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
                         }
                     }
                 }
+                if is_sized {
+                    err.emit();
+                    return;
+                }
                 err
             }
 

src/test/ui/async-await/issues/issue-65159.rs

@@ -5,6 +5,7 @@
 async fn copy() -> Result<()> //~ ERROR wrong number of type arguments
 {
     Ok(())
+    //~^ ERROR type annotations needed
 }
 
 fn main() { }

src/test/ui/async-await/issues/issue-65159.stderr

@@ -4,6 +4,13 @@ error[E0107]: wrong number of type arguments: expected 2, found 1
 LL | async fn copy() -> Result<()>
    |                    ^^^^^^^^^^ expected 2 type arguments
 
-error: aborting due to previous error
+error[E0282]: type annotations needed
+  --> $DIR/issue-65159.rs:7:5
+   |
+LL |     Ok(())
+   |     ^^ cannot infer type for type parameter `E` declared on the enum `Result`
+
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0107`.
+Some errors have detailed explanations: E0107, E0282.
+For more information about an error, try `rustc --explain E0107`.

src/test/ui/closures/issue-52437.rs

@@ -1,5 +1,6 @@
 fn main() {
     [(); &(&'static: loop { |x| {}; }) as *const _ as usize]
     //~^ ERROR: invalid label name `'static`
+    //~| ERROR: type annotations needed
     //~| ERROR mismatched types
 }

src/test/ui/closures/issue-52437.stderr

@@ -4,6 +4,12 @@ error: invalid label name `'static`
 LL |     [(); &(&'static: loop { |x| {}; }) as *const _ as usize]
    |             ^^^^^^^
 
+error[E0282]: type annotations needed
+  --> $DIR/issue-52437.rs:2:30
+   |
+LL |     [(); &(&'static: loop { |x| {}; }) as *const _ as usize]
+   |                              ^ consider giving this closure parameter a type
+
 error[E0308]: mismatched types
   --> $DIR/issue-52437.rs:2:5
    |
@@ -12,6 +18,7 @@ LL | fn main() {
 LL |     [(); &(&'static: loop { |x| {}; }) as *const _ as usize]
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found array `[(); _]`
 
-error: aborting due to 2 previous errors
+error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0308`.
+Some errors have detailed explanations: E0282, E0308.
+For more information about an error, try `rustc --explain E0282`.

src/test/ui/consts/issue-52432.rs

@@ -3,6 +3,7 @@
 fn main() {
     [(); &(static |x| {}) as *const _ as usize];
     //~^ ERROR: closures cannot be static
+    //~| ERROR: type annotations needed
     [(); &(static || {}) as *const _ as usize];
     //~^ ERROR: closures cannot be static
     //~| ERROR evaluation of constant value failed

src/test/ui/consts/issue-52432.stderr

@@ -5,18 +5,24 @@ LL |     [(); &(static |x| {}) as *const _ as usize];
    |            ^^^^^^^^^^
 
 error[E0697]: closures cannot be static
-  --> $DIR/issue-52432.rs:6:12
+  --> $DIR/issue-52432.rs:7:12
    |
 LL |     [(); &(static || {}) as *const _ as usize];
    |            ^^^^^^^^^
 
+error[E0282]: type annotations needed
+  --> $DIR/issue-52432.rs:4:20
+   |
+LL |     [(); &(static |x| {}) as *const _ as usize];
+   |                    ^ consider giving this closure parameter a type
+
 error[E0080]: evaluation of constant value failed
-  --> $DIR/issue-52432.rs:6:10
+  --> $DIR/issue-52432.rs:7:10
    |
 LL |     [(); &(static || {}) as *const _ as usize];
    |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ "pointer-to-integer cast" needs an rfc before being allowed inside constants
 
-error: aborting due to 3 previous errors
+error: aborting due to 4 previous errors
 
-Some errors have detailed explanations: E0080, E0697.
+Some errors have detailed explanations: E0080, E0282, E0697.
 For more information about an error, try `rustc --explain E0080`.

src/test/ui/consts/issue-64662.rs

@@ -1,6 +1,6 @@
 enum Foo {
     A = foo(), //~ ERROR: type annotations needed
-    B = foo(), // We don't emit an error here, but if the one above is fixed, we will.
+    B = foo(), //~ ERROR: type annotations needed
 }
 
 const fn foo<T>() -> isize {

src/test/ui/consts/issue-64662.stderr

@@ -3,7 +3,23 @@ error[E0282]: type annotations needed
    |
 LL |     A = foo(),
    |         ^^^ cannot infer type for type parameter `T` declared on the function `foo`
+   |
+help: consider specifying the type argument in the function call
+   |
+LL |     A = foo::<T>(),
+   |            ^^^^^
+
+error[E0282]: type annotations needed
+  --> $DIR/issue-64662.rs:3:9
+   |
+LL |     B = foo(),
+   |         ^^^ cannot infer type for type parameter `T` declared on the function `foo`
+   |
+help: consider specifying the type argument in the function call
+   |
+LL |     B = foo::<T>(),
+   |            ^^^^^
 
-error: aborting due to previous error
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0282`.

src/test/ui/error-codes/E0401.stderr

@@ -32,22 +32,18 @@ LL |         fn helper(sel: &Self) -> u8 {
    |                         use of generic parameter from outer function
    |                         use a type here instead
 
-error[E0283]: type annotations needed
+error[E0282]: type annotations needed
   --> $DIR/E0401.rs:11:5
    |
-LL |     fn bfnr<U, V: Baz<U>, W: Fn()>(y: T) {
-   |                   ------ required by this bound in `bfnr`
-...
 LL |     bfnr(x);
-   |     ^^^^ cannot infer type for type parameter `V` declared on the function `bfnr`
+   |     ^^^^ cannot infer type for type parameter `U` declared on the function `bfnr`
    |
-   = note: cannot satisfy `_: Baz<_>`
 help: consider specifying the type arguments in the function call
    |
 LL |     bfnr::<U, V, W>(x);
    |         ^^^^^^^^^^^
 
 error: aborting due to 4 previous errors
 
-Some errors have detailed explanations: E0283, E0401.
-For more information about an error, try `rustc --explain E0283`.
+Some errors have detailed explanations: E0282, E0401.
+For more information about an error, try `rustc --explain E0282`.