Remove a bunch of has_errors checks that have no meaningful or the wrong effect

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

@@ -448,8 +448,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                         // FIXME(effects)
                         let predicate_is_const = false;
 
-                        if let Some(guar) = self.dcx().has_errors()
-                            && trait_predicate.references_error()
+                        if let Err(guar) = trait_predicate.error_reported()
                         {
                             return guar;
                         }
@@ -2625,9 +2624,6 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 if let Some(e) = self.tainted_by_errors() {
                     return e;
                 }
-                if let Some(e) = self.dcx().has_errors() {
-                    return e;
-                }
 
                 self.emit_inference_failure_err(
                     obligation.cause.body_id,
@@ -2645,10 +2641,6 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 if let Some(e) = self.tainted_by_errors() {
                     return e;
                 }
-                if let Some(e) = self.dcx().has_errors() {
-                    // no need to overload user in such cases
-                    return e;
-                }
                 let SubtypePredicate { a_is_expected: _, a, b } = data;
                 // both must be type variables, or the other would've been instantiated
                 assert!(a.is_ty_var() && b.is_ty_var());
@@ -2728,10 +2720,6 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 if let Some(e) = self.tainted_by_errors() {
                     return e;
                 }
-                if let Some(e) = self.dcx().has_errors() {
-                    // no need to overload user in such cases
-                    return e;
-                }
                 struct_span_code_err!(
                     self.dcx(),
                     span,

tests/ui/closures/issue-78720.rs

@@ -1,6 +1,7 @@
 fn server() -> impl {
 //~^ ERROR at least one trait must be specified
     ().map2(|| "")
+    //~^ ERROR type annotations needed
 }
 
 trait FilterBase2 {

tests/ui/closures/issue-78720.stderr

@@ -5,7 +5,7 @@ LL | fn server() -> impl {
    |                ^^^^
 
 error[E0412]: cannot find type `F` in this scope
-  --> $DIR/issue-78720.rs:13:12
+  --> $DIR/issue-78720.rs:14:12
    |
 LL |     _func: F,
    |            ^
@@ -22,8 +22,14 @@ help: you might be missing a type parameter
 LL | struct Map2<Segment2, F> {
    |                     +++
 
+error[E0282]: type annotations needed
+  --> $DIR/issue-78720.rs:3:5
+   |
+LL |     ().map2(|| "")
+   |     ^^^^^^^^^^^^^^ cannot infer type
+
 error[E0308]: mismatched types
-  --> $DIR/issue-78720.rs:7:39
+  --> $DIR/issue-78720.rs:8:39
    |
 LL |     fn map2<F>(self, f: F) -> Map2<F> {}
    |                                       ^^ expected `Map2<F>`, found `()`
@@ -32,7 +38,7 @@ LL |     fn map2<F>(self, f: F) -> Map2<F> {}
            found unit type `()`
 
 error[E0277]: the size for values of type `Self` cannot be known at compilation time
-  --> $DIR/issue-78720.rs:7:16
+  --> $DIR/issue-78720.rs:8:16
    |
 LL |     fn map2<F>(self, f: F) -> Map2<F> {}
    |                ^^^^ doesn't have a size known at compile-time
@@ -47,7 +53,7 @@ help: function arguments must have a statically known size, borrowed types alway
 LL |     fn map2<F>(&self, f: F) -> Map2<F> {}
    |                +
 
-error: aborting due to 4 previous errors
+error: aborting due to 5 previous errors
 
-Some errors have detailed explanations: E0277, E0308, E0412.
+Some errors have detailed explanations: E0277, E0282, E0308, E0412.
 For more information about an error, try `rustc --explain E0277`.

tests/ui/const-generics/defaults/rp_impl_trait_fail.rs

@@ -25,6 +25,6 @@ fn owo() -> impl Traitor {
 
 fn main() {
     rawr();
-    uwu();
+    uwu(); //~ ERROR: type annotations needed
     owo();
 }

tests/ui/const-generics/defaults/rp_impl_trait_fail.stderr

@@ -31,6 +31,18 @@ LL |     1_u64
    |
    = help: the trait `Traitor<1, 2>` is implemented for `u64`
 
-error: aborting due to 3 previous errors
+error[E0282]: type annotations needed
+  --> $DIR/rp_impl_trait_fail.rs:28:5
+   |
+LL |     uwu();
+   |     ^^^ cannot infer the value of the const parameter `N` declared on the function `uwu`
+   |
+help: consider specifying the generic argument
+   |
+LL |     uwu::<N>();
+   |        +++++
+
+error: aborting due to 4 previous errors
 
-For more information about this error, try `rustc --explain E0277`.
+Some errors have detailed explanations: E0277, E0282.
+For more information about an error, try `rustc --explain E0277`.

tests/ui/const-generics/generic_const_exprs/issue-62504.full.stderr

@@ -15,6 +15,18 @@ LL |         ArrayHolder([0; Self::SIZE])
    |
    = help: try adding a `where` bound using this expression: `where [(); Self::SIZE]:`
 
-error: aborting due to 2 previous errors
+error[E0282]: type annotations needed for `ArrayHolder<X>`
+  --> $DIR/issue-62504.rs:26:9
+   |
+LL |     let mut array = ArrayHolder::new();
+   |         ^^^^^^^^^
+   |
+help: consider giving `array` an explicit type, where the value of const parameter `X` is specified
+   |
+LL |     let mut array: ArrayHolder<X> = ArrayHolder::new();
+   |                  ++++++++++++++++
+
+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`.

tests/ui/const-generics/generic_const_exprs/issue-62504.min.stderr

@@ -22,6 +22,18 @@ note: tuple struct defined here
 LL | struct ArrayHolder<const X: usize>([u32; X]);
    |        ^^^^^^^^^^^
 
-error: aborting due to 2 previous errors
+error[E0282]: type annotations needed for `ArrayHolder<X>`
+  --> $DIR/issue-62504.rs:26:9
+   |
+LL |     let mut array = ArrayHolder::new();
+   |         ^^^^^^^^^
+   |
+help: consider giving `array` an explicit type, where the value of const parameter `X` is specified
+   |
+LL |     let mut array: ArrayHolder<X> = ArrayHolder::new();
+   |                  ++++++++++++++++
+
+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`.

tests/ui/const-generics/generic_const_exprs/issue-62504.rs

@@ -24,4 +24,5 @@ impl<const X: usize> ArrayHolder<X> {
 
 fn main() {
     let mut array = ArrayHolder::new();
+    //~^ ERROR: type annotations needed
 }

tests/ui/consts/issue-104609.rs

@@ -5,6 +5,7 @@ fn foo() {
 
 unsafe fn bar() {
     std::mem::transmute::<_, *mut _>(1_u8);
+    //~^ ERROR: type annotations needed
 }
 
 fn main() {}

tests/ui/consts/issue-104609.stderr

@@ -4,6 +4,13 @@ error[E0425]: cannot find value `oops` in this scope
 LL |     oops;
    |     ^^^^ not found in this scope
 
-error: aborting due to 1 previous error
+error[E0282]: type annotations needed
+  --> $DIR/issue-104609.rs:7:5
+   |
+LL |     std::mem::transmute::<_, *mut _>(1_u8);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type of the type parameter `Dst` declared on the function `transmute`
+
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0425`.
+Some errors have detailed explanations: E0282, E0425.
+For more information about an error, try `rustc --explain E0282`.

tests/ui/generic-const-items/parameter-defaults.stderr

@@ -8,7 +8,7 @@ error[E0282]: type annotations needed for `Option<T>`
   --> $DIR/parameter-defaults.rs:13:9
    |
 LL |     let _ = NONE;
-   |         ^
+   |         ^   ---- type must be known at this point
    |
 help: consider giving this pattern a type, where the type for type parameter `T` is specified
    |

tests/ui/inference/need_type_info/type-alias.rs

@@ -15,7 +15,7 @@ fn direct_alias() {
 
 type IndirectAlias<T> = Ty<Box<T>>;
 fn indirect_alias() {
-    IndirectAlias::new();
+    IndirectAlias::new(); //~ ERROR: type annotations needed
     // FIXME: This should also emit an error.
     //
     // Added it separately as `type-alias-indirect.rs`

tests/ui/inference/need_type_info/type-alias.stderr

@@ -4,12 +4,18 @@ error[E0282]: type annotations needed
 LL |     DirectAlias::new()
    |     ^^^^^^^^^^^^^^^^^^ cannot infer type for type parameter `T`
 
+error[E0282]: type annotations needed
+  --> $DIR/type-alias.rs:18:5
+   |
+LL |     IndirectAlias::new();
+   |     ^^^^^^^^^^^^^ cannot infer type for type parameter `T` declared on the type alias `IndirectAlias`
+
 error[E0282]: type annotations needed
   --> $DIR/type-alias.rs:32:5
    |
 LL |     DirectButWithDefaultAlias::new();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type for type parameter `T`
 
-error: aborting due to 2 previous errors
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0282`.

tests/ui/parser/issues/issue-89574.rs

@@ -1,4 +1,6 @@
 fn main() {
     const EMPTY_ARRAY = [];
     //~^ missing type for `const` item
+    //~| ERROR type annotations needed
+    //~| ERROR type annotations needed
 }

tests/ui/parser/issues/issue-89574.stderr

@@ -1,8 +1,23 @@
+error[E0282]: type annotations needed
+  --> $DIR/issue-89574.rs:2:25
+   |
+LL |     const EMPTY_ARRAY = [];
+   |                         ^^ cannot infer type
+
 error: missing type for `const` item
   --> $DIR/issue-89574.rs:2:22
    |
 LL |     const EMPTY_ARRAY = [];
    |                      ^ help: provide a type for the item: `: <type>`
 
-error: aborting due to 1 previous error
+error[E0282]: type annotations needed
+  --> $DIR/issue-89574.rs:2:25
+   |
+LL |     const EMPTY_ARRAY = [];
+   |                         ^^ cannot infer type
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+error: aborting due to 3 previous errors
 
+For more information about this error, try `rustc --explain E0282`.

tests/ui/parser/missing-closing-angle-bracket-eq-constraint.stderr

@@ -41,7 +41,7 @@ error[E0282]: type annotations needed for `Vec<_>`
   --> $DIR/missing-closing-angle-bracket-eq-constraint.rs:7:7
    |
 LL |   let v : Vec<(u32,_) = vec![];
-   |       ^
+   |       ^                 ------ type must be known at this point
    |
 help: consider giving `v` an explicit type, where the placeholders `_` are specified
    |
@@ -52,7 +52,7 @@ error[E0282]: type annotations needed for `Vec<_>`
   --> $DIR/missing-closing-angle-bracket-eq-constraint.rs:18:7
    |
 LL |   let v : Vec<'a = vec![];
-   |       ^
+   |       ^            ------ type must be known at this point
    |
 help: consider giving `v` an explicit type, where the placeholders `_` are specified
    |

tests/ui/traits/next-solver/specialization-transmute.rs

@@ -14,6 +14,7 @@ impl<T> Default for T {
     default type Id = T; //~ ERROR type annotations needed
     // This will be fixed by #111994
     fn intu(&self) -> &Self::Id {
+        //~^ ERROR type annotations needed
         self
     }
 }

tests/ui/traits/next-solver/specialization-transmute.stderr

@@ -10,12 +10,19 @@ LL | #![feature(specialization)]
 
 error: cannot normalize `<T as Default>::Id`
 
+error[E0284]: type annotations needed: cannot satisfy `<T as Default>::Id == _`
+  --> $DIR/specialization-transmute.rs:16:23
+   |
+LL |     fn intu(&self) -> &Self::Id {
+   |                       ^^^^^^^^^ cannot satisfy `<T as Default>::Id == _`
+
 error[E0282]: type annotations needed
   --> $DIR/specialization-transmute.rs:14:23
    |
 LL |     default type Id = T;
    |                       ^ cannot infer type for associated type `<T as Default>::Id`
 
-error: aborting due to 2 previous errors; 1 warning emitted
+error: aborting due to 3 previous errors; 1 warning emitted
 
-For more information about this error, try `rustc --explain E0282`.
+Some errors have detailed explanations: E0282, E0284.
+For more information about an error, try `rustc --explain E0282`.

tests/ui/typeck/issue-104510-ice.rs

@@ -6,7 +6,7 @@ struct W<T: ?Sized>(Oops);
 
 unsafe fn test() {
     let j = W(());
-    let pointer = &j as *const _;
+    let pointer = &j as *const _; //~ ERROR type annotations needed
     core::arch::asm!(
         "nop",
         in("eax") pointer,

tests/ui/typeck/issue-104510-ice.stderr

@@ -4,6 +4,18 @@ error[E0412]: cannot find type `Oops` in this scope
 LL | struct W<T: ?Sized>(Oops);
    |                     ^^^^ not found in this scope
 
-error: aborting due to 1 previous error
+error[E0282]: type annotations needed for `*const W<T>`
+  --> $DIR/issue-104510-ice.rs:9:9
+   |
+LL |     let pointer = &j as *const _;
+   |         ^^^^^^^
+   |
+help: consider giving `pointer` an explicit type, where the type for type parameter `T` is specified
+   |
+LL |     let pointer: *const W<T> = &j as *const _;
+   |                +++++++++++++
+
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0412`.
+Some errors have detailed explanations: E0282, E0412.
+For more information about an error, try `rustc --explain E0282`.