Avoid extra path trimming in method not found error

Method errors have an extra check that force trim paths whenever the
normal string is longer than 10 characters, which can be quite unhelpful
when multiple items have the same name (for example an `Error`).

A user reported this force trimming as being quite unhelpful when they
had a method error where the precise path of the `Error` mattered.

The code uses `tcx.short_string` already to get the normal path, which
tries to be clever around trimming paths if necessary, so there is no
reason for this extra force trimming.

Author: Noratrieb

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -599,7 +599,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let tcx = self.tcx;
         let rcvr_ty = self.resolve_vars_if_possible(rcvr_ty);
         let mut ty_file = None;
-        let (mut ty_str, short_ty_str) =
+        let (ty_str, short_ty_str) =
             if trait_missing_method && let ty::Dynamic(predicates, _, _) = rcvr_ty.kind() {
                 (predicates.to_string(), with_forced_trimmed_paths!(predicates.to_string()))
             } else {
@@ -738,10 +738,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             err.span_label(within_macro_span, "due to this macro variable");
         }
 
-        if short_ty_str.len() < ty_str.len() && ty_str.len() > 10 {
-            ty_str = short_ty_str;
-        }
-
         if rcvr_ty.references_error() {
             err.downgrade_to_delayed_bug();
         }

tests/run-make/crate-loading/multiple-dep-versions.stderr

@@ -39,7 +39,7 @@ error[E0599]: no method named `foo` found for struct `dep_2_reexport::Type` in t
   --> replaced
    |
 LL |     Type.foo();
-   |          ^^^ method not found in `Type`
+   |          ^^^ method not found in `dep_2_reexport::Type`
    |
 note: there are multiple different versions of crate `dependency` in the dependency graph
   --> replaced
@@ -63,7 +63,7 @@ error[E0599]: no function or associated item named `bar` found for struct `dep_2
   --> replaced
    |
 LL |     Type::bar();
-   |           ^^^ function or associated item not found in `Type`
+   |           ^^^ function or associated item not found in `dep_2_reexport::Type`
    |
 note: there are multiple different versions of crate `dependency` in the dependency graph
   --> replaced

tests/ui/associated-types/issue-43924.stderr

@@ -14,7 +14,7 @@ error[E0599]: no function or associated item named `default` found for trait obj
   --> $DIR/issue-43924.rs:14:39
    |
 LL |     assert_eq!(<() as Foo<u32>>::Out::default().to_string(), "false");
-   |                                       ^^^^^^^ function or associated item not found in `dyn ToString`
+   |                                       ^^^^^^^ function or associated item not found in `(dyn ToString + 'static)`
 
 error: aborting due to 2 previous errors
 

tests/ui/attributes/rustc_confusables.stderr

@@ -42,13 +42,13 @@ error[E0599]: no method named `foo` found for struct `rustc_confusables_across_c
   --> $DIR/rustc_confusables.rs:15:7
    |
 LL |     x.foo();
-   |       ^^^ method not found in `BTreeSet`
+   |       ^^^ method not found in `rustc_confusables_across_crate::BTreeSet`
 
 error[E0599]: no method named `push` found for struct `rustc_confusables_across_crate::BTreeSet` in the current scope
   --> $DIR/rustc_confusables.rs:17:7
    |
 LL |     x.push();
-   |       ^^^^ method not found in `BTreeSet`
+   |       ^^^^ method not found in `rustc_confusables_across_crate::BTreeSet`
    |
 help: you might have meant to use `insert`
    |
@@ -60,7 +60,7 @@ error[E0599]: no method named `test` found for struct `rustc_confusables_across_
   --> $DIR/rustc_confusables.rs:20:7
    |
 LL |     x.test();
-   |       ^^^^ method not found in `BTreeSet`
+   |       ^^^^ method not found in `rustc_confusables_across_crate::BTreeSet`
 
 error[E0599]: no method named `pulled` found for struct `rustc_confusables_across_crate::BTreeSet` in the current scope
   --> $DIR/rustc_confusables.rs:22:7

tests/ui/empty/empty-struct-braces-expr.stderr

@@ -121,7 +121,7 @@ error[E0599]: no variant or associated item named `Empty3` found for enum `empty
   --> $DIR/empty-struct-braces-expr.rs:25:19
    |
 LL |     let xe3 = XE::Empty3;
-   |                   ^^^^^^ variant or associated item not found in `XE`
+   |                   ^^^^^^ variant or associated item not found in `empty_struct::XE`
    |
 help: there is a variant with a similar name
    |
@@ -132,7 +132,7 @@ error[E0599]: no variant or associated item named `Empty3` found for enum `empty
   --> $DIR/empty-struct-braces-expr.rs:26:19
    |
 LL |     let xe3 = XE::Empty3();
-   |                   ^^^^^^ variant or associated item not found in `XE`
+   |                   ^^^^^^ variant or associated item not found in `empty_struct::XE`
    |
 help: there is a variant with a similar name
    |

tests/ui/error-emitter/multiline-removal-suggestion.svg

@@ -8,7 +8,7 @@ error[E0599]: no method named `bar` found for struct `Arc<{closure@$DIR/fn-help-
   --> $DIR/fn-help-with-err.rs:19:10
    |
 LL |     arc2.bar();
-   |          ^^^ method not found in `Arc<{closure@fn-help-with-err.rs:18:36}>`
+   |          ^^^ method not found in `Arc<{closure@$DIR/fn-help-with-err.rs:18:36: 18:38}>`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `Bar` defines an item `bar`, perhaps you need to implement it

tests/ui/functions-closures/fn-help-with-err.stderr

@@ -1,4 +1,4 @@
-error[E0599]: the method `filterx` exists for struct `Map<Repeat, {closure@hrtb-doesnt-borrow-self-1.rs:113:27}>`, but its trait bounds were not satisfied
+error[E0599]: the method `filterx` exists for struct `Map<Repeat, {closure@$DIR/hrtb-doesnt-borrow-self-1.rs:113:27: 113:34}>`, but its trait bounds were not satisfied
   --> $DIR/hrtb-doesnt-borrow-self-1.rs:114:22
    |
 LL | pub struct Map<S, F> {

tests/ui/higher-ranked/trait-bounds/hrtb-doesnt-borrow-self-1.stderr

@@ -1,4 +1,4 @@
-error[E0599]: the method `countx` exists for struct `Filter<Map<Repeat, fn(&u64) -> &u64 {identity::<u64>}>, {closure@hrtb-doesnt-borrow-self-2.rs:109:30}>`, but its trait bounds were not satisfied
+error[E0599]: the method `countx` exists for struct `Filter<Map<Repeat, for<'a> fn(&'a u64) -> &'a u64 {identity::<u64>}>, {closure@$DIR/hrtb-doesnt-borrow-self-2.rs:109:30: 109:37}>`, but its trait bounds were not satisfied
   --> $DIR/hrtb-doesnt-borrow-self-2.rs:110:24
    |
 LL | pub struct Filter<S, F> {

tests/ui/higher-ranked/trait-bounds/hrtb-doesnt-borrow-self-2.stderr

@@ -173,7 +173,7 @@ error[E0599]: no method named `method2` found for struct `no_method_suggested_tr
   --> $DIR/no-method-suggested-traits.rs:52:37
    |
 LL |     no_method_suggested_traits::Foo.method2();
-   |                                     ^^^^^^^ method not found in `Foo`
+   |                                     ^^^^^^^ method not found in `no_method_suggested_traits::Foo`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `foo::Bar` defines an item `method2`, perhaps you need to implement it
@@ -186,7 +186,7 @@ error[E0599]: no method named `method2` found for struct `Rc<&mut Box<&no_method
   --> $DIR/no-method-suggested-traits.rs:54:71
    |
 LL |     std::rc::Rc::new(&mut Box::new(&no_method_suggested_traits::Foo)).method2();
-   |                                                                       ^^^^^^^ method not found in `Rc<&mut Box<&Foo>>`
+   |                                                                       ^^^^^^^ method not found in `Rc<&mut Box<&no_method_suggested_traits::Foo>>`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `foo::Bar` defines an item `method2`, perhaps you need to implement it
@@ -199,7 +199,7 @@ error[E0599]: no method named `method2` found for enum `no_method_suggested_trai
   --> $DIR/no-method-suggested-traits.rs:56:40
    |
 LL |     no_method_suggested_traits::Bar::X.method2();
-   |                                        ^^^^^^^ method not found in `Bar`
+   |                                        ^^^^^^^ method not found in `no_method_suggested_traits::Bar`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `foo::Bar` defines an item `method2`, perhaps you need to implement it
@@ -212,7 +212,7 @@ error[E0599]: no method named `method2` found for struct `Rc<&mut Box<&no_method
   --> $DIR/no-method-suggested-traits.rs:58:74
    |
 LL |     std::rc::Rc::new(&mut Box::new(&no_method_suggested_traits::Bar::X)).method2();
-   |                                                                          ^^^^^^^ method not found in `Rc<&mut Box<&Bar>>`
+   |                                                                          ^^^^^^^ method not found in `Rc<&mut Box<&no_method_suggested_traits::Bar>>`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `foo::Bar` defines an item `method2`, perhaps you need to implement it
@@ -283,25 +283,25 @@ error[E0599]: no method named `method3` found for struct `no_method_suggested_tr
   --> $DIR/no-method-suggested-traits.rs:73:37
    |
 LL |     no_method_suggested_traits::Foo.method3();
-   |                                     ^^^^^^^ method not found in `Foo`
+   |                                     ^^^^^^^ method not found in `no_method_suggested_traits::Foo`
 
 error[E0599]: no method named `method3` found for struct `Rc<&mut Box<&no_method_suggested_traits::Foo>>` in the current scope
   --> $DIR/no-method-suggested-traits.rs:74:71
    |
 LL |     std::rc::Rc::new(&mut Box::new(&no_method_suggested_traits::Foo)).method3();
-   |                                                                       ^^^^^^^ method not found in `Rc<&mut Box<&Foo>>`
+   |                                                                       ^^^^^^^ method not found in `Rc<&mut Box<&no_method_suggested_traits::Foo>>`
 
 error[E0599]: no method named `method3` found for enum `no_method_suggested_traits::Bar` in the current scope
   --> $DIR/no-method-suggested-traits.rs:76:40
    |
 LL |     no_method_suggested_traits::Bar::X.method3();
-   |                                        ^^^^^^^ method not found in `Bar`
+   |                                        ^^^^^^^ method not found in `no_method_suggested_traits::Bar`
 
 error[E0599]: no method named `method3` found for struct `Rc<&mut Box<&no_method_suggested_traits::Bar>>` in the current scope
   --> $DIR/no-method-suggested-traits.rs:77:74
    |
 LL |     std::rc::Rc::new(&mut Box::new(&no_method_suggested_traits::Bar::X)).method3();
-   |                                                                          ^^^^^^^ method not found in `Rc<&mut Box<&Bar>>`
+   |                                                                          ^^^^^^^ method not found in `Rc<&mut Box<&no_method_suggested_traits::Bar>>`
 
 error: aborting due to 24 previous errors