Make note_source_of_type_mismatch_constraint simpler

Author: compiler-errors

compiler/rustc_hir_typeck/src/demand.rs

@@ -807,24 +807,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 full_call_span,
                 format!("arguments to this {} are incorrect", call_name),
             );
-            if let (Some(callee_ty), hir::ExprKind::MethodCall(_, rcvr, _, _)) =
-                (callee_ty, &call_expr.kind)
-            {
-                // Type that would have accepted this argument if it hadn't been inferred earlier.
-                // FIXME: We leave an inference variable for now, but it'd be nice to get a more
-                // specific type to increase the accuracy of the diagnostic.
-                let expected = self.infcx.next_ty_var(TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::MiscVariable,
-                    span: full_call_span,
-                });
-                self.point_at_expr_source_of_inferred_type(
-                    &mut err,
-                    rcvr,
-                    expected,
-                    callee_ty,
-                    provided_arg_span,
-                );
-            }
+
+            // TODO: We would like to point out when the rcvr was constrained
+            // such that the arg mismatch occurs.
+
             // Call out where the function is defined
             self.label_fn_like(
                 &mut err,

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -67,9 +67,6 @@ LL |             x == 5
 error[E0308]: mismatched types
   --> $DIR/assignment-in-if.rs:44:18
    |
-LL |     if y = (Foo { foo: x }) {
-   |                        - here the type of `x` is inferred to be `usize`
-...
 LL |     if x == x && x = x && x == x {
    |        ------    ^ expected `bool`, found `usize`
    |        |
@@ -78,9 +75,6 @@ LL |     if x == x && x = x && x == x {
 error[E0308]: mismatched types
   --> $DIR/assignment-in-if.rs:44:22
    |
-LL |     if y = (Foo { foo: x }) {
-   |                        - here the type of `x` is inferred to be `usize`
-...
 LL |     if x == x && x = x && x == x {
    |                      ^ expected `bool`, found `usize`
 
@@ -98,9 +92,6 @@ LL |     if x == x && x == x && x == x {
 error[E0308]: mismatched types
   --> $DIR/assignment-in-if.rs:51:28
    |
-LL |     if y = (Foo { foo: x }) {
-   |                        - here the type of `x` is inferred to be `usize`
-...
 LL |     if x == x && x == x && x = x {
    |        ----------------    ^ expected `bool`, found `usize`
    |        |

tests/ui/type/type-check/assignment-in-if.stderr

@@ -2,7 +2,6 @@
 fn main() {
     let mut v = Vec::new();
     v.push(0i32);
-    //~^ NOTE this is of type `i32`, which causes `v` to be inferred as `Vec<i32>`
     v.push(0);
     v.push(1i32); //~ ERROR mismatched types
     //~^ NOTE expected `i32`, found `u32`

tests/ui/type/type-check/point-at-inference-3.fixed

@@ -2,7 +2,6 @@
 fn main() {
     let mut v = Vec::new();
     v.push(0i32);
-    //~^ NOTE this is of type `i32`, which causes `v` to be inferred as `Vec<i32>`
     v.push(0);
     v.push(1u32); //~ ERROR mismatched types
     //~^ NOTE expected `i32`, found `u32`

tests/ui/type/type-check/point-at-inference-3.rs

@@ -1,9 +1,6 @@
 error[E0308]: mismatched types
-  --> $DIR/point-at-inference-3.rs:7:12
+  --> $DIR/point-at-inference-3.rs:6:12
    |
-LL |     v.push(0i32);
-   |            ---- this is of type `i32`, which causes `v` to be inferred as `Vec<i32>`
-...
 LL |     v.push(1u32);
    |       ---- ^^^^ expected `i32`, found `u32`
    |       |

tests/ui/type/type-check/point-at-inference-3.stderr

@@ -11,6 +11,7 @@ fn main() {
     let s = S(None);
     s.infer(0i32);
     //~^ ERROR this method takes 2 arguments but 1 argument was supplied
+    //~| NOTE here the type of `s` is inferred to be `S<i32, _>`
     //~| NOTE an argument is missing
     //~| HELP provide the argument
     let t: S<u32, _> = s;

tests/ui/type/type-check/point-at-inference-4.rs

@@ -15,8 +15,11 @@ LL |     s.infer(0i32, /* b */);
    |            ~~~~~~~~~~~~~~~
 
 error[E0308]: mismatched types
-  --> $DIR/point-at-inference-4.rs:16:24
+  --> $DIR/point-at-inference-4.rs:17:24
    |
+LL |     s.infer(0i32);
+   |     - here the type of `s` is inferred to be `S<i32, _>`
+...
 LL |     let t: S<u32, _> = s;
    |            ---------   ^ expected `S<u32, _>`, found `S<i32, _>`
    |            |

tests/ui/type/type-check/point-at-inference-4.stderr

@@ -6,7 +6,7 @@ fn main() {
     let mut foo = vec![];
     baz(&foo);
     for i in &v {
-        foo.push(*i);
+        foo.push(i);
     }
     baz(&foo);
     bar(foo); //~ ERROR E0308

tests/ui/type/type-check/point-at-inference.fixed

@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/point-at-inference.rs:12:9
    |
 LL |         foo.push(i);
-   |                  - this is of type `&{integer}`, which causes `foo` to be inferred as `Vec<&{integer}>`
+   |         --- here the type of `foo` is inferred to be `Vec<&{integer}>`
 ...
 LL |     bar(foo);
    |     --- ^^^ expected `Vec<i32>`, found `Vec<&{integer}>`
@@ -16,10 +16,6 @@ note: function defined here
    |
 LL | fn bar(_: Vec<i32>) {}
    |    ^^^ -----------
-help: consider dereferencing the borrow
-   |
-LL |         foo.push(*i);
-   |                  +
 
 error: aborting due to previous error