rust-lang · bors · Jan 28, 2021 · Sep 26, 2020
diff --git a/compiler/rustc_errors/src/diagnostic_builder.rs b/compiler/rustc_errors/src/diagnostic_builder.rs
@@ -74,19 +74,18 @@ macro_rules! forward {
         });
     };
 
-    // Forward pattern for &mut self -> &mut Self, with S: Into<MultiSpan>
-    // type parameter. No obvious way to make this more generic.
+    // Forward pattern for &mut self -> &mut Self, with generic parameters.
     (
         $(#[$attrs:meta])*
-        pub fn $n:ident<S: Into<MultiSpan>>(
+        pub fn $n:ident<$($generic:ident: $bound:path),*>(
             &mut self,
             $($name:ident: $ty:ty),*
             $(,)?
         ) -> &mut Self
     ) => {
         $(#[$attrs])*
         forward_inner_docs!(concat!("See [`Diagnostic::", stringify!($n), "()`].") =>
-        pub fn $n<S: Into<MultiSpan>>(&mut self, $($name: $ty),*) -> &mut Self {
+        pub fn $n<$($generic: $bound),*>(&mut self, $($name: $ty),*) -> &mut Self {
             self.0.diagnostic.$n($($name),*);
             self
         });
@@ -398,6 +397,7 @@ impl<'a> DiagnosticBuilder<'a> {
         self
     }
 
+    forward!(pub fn set_primary_message<M: Into<String>>(&mut self, msg: M) -> &mut Self);
     forward!(pub fn set_span<S: Into<MultiSpan>>(&mut self, sp: S) -> &mut Self);
     forward!(pub fn code(&mut self, s: DiagnosticId) -> &mut Self);
 

diff --git a/compiler/rustc_typeck/src/check/method/suggest.rs b/compiler/rustc_typeck/src/check/method/suggest.rs
@@ -446,6 +446,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
                 }
 
+                let mut label_span_not_found = || {
+                    if unsatisfied_predicates.is_empty() {
+                        err.span_label(span, format!("{item_kind} not found in `{ty_str}`"));
+                    } else {
+                        err.span_label(span, format!("{item_kind} cannot be called on `{ty_str}` due to unsatisfied trait bounds"));
+                    }
+                    self.tcx.sess.trait_methods_not_found.borrow_mut().insert(orig_span);
+                };
+
                 // If the method name is the name of a field with a function or closure type,
                 // give a helping note that it has to be called as `(x.f)(...)`.
                 if let SelfSource::MethodCall(expr) = source {
@@ -501,12 +510,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         let field_kind = if is_accessible { "field" } else { "private field" };
                         err.span_label(item_name.span, format!("{}, not a method", field_kind));
                     } else if lev_candidate.is_none() && static_sources.is_empty() {
-                        err.span_label(span, format!("{} not found in `{}`", item_kind, ty_str));
-                        self.tcx.sess.trait_methods_not_found.borrow_mut().insert(orig_span);
+                        label_span_not_found();
                     }
                 } else {
-                    err.span_label(span, format!("{} not found in `{}`", item_kind, ty_str));
-                    self.tcx.sess.trait_methods_not_found.borrow_mut().insert(orig_span);
+                    label_span_not_found();
                 }
 
                 if self.is_fn_ty(&rcvr_ty, span) {
@@ -721,10 +728,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             .map(|(_, path)| path)
                             .collect::<Vec<_>>()
                             .join("\n");
+                        let actual_prefix = actual.prefix_string();
+                        err.set_primary_message(&format!(
+                            "the {item_kind} `{item_name}` exists for {actual_prefix} `{ty_str}`, but its trait bounds were not satisfied"
+                        ));
                         err.note(&format!(
-                            "the method `{}` exists but the following trait bounds were not \
-                             satisfied:\n{}",
-                            item_name, bound_list
+                            "the following trait bounds were not satisfied:\n{bound_list}"
                         ));
                     }
                 }
@@ -742,7 +751,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     );
                 }
 
-                if actual.is_enum() {
+                // Don't emit a suggestion if we found an actual method
+                // that had unsatisfied trait bounds
+                if unsatisfied_predicates.is_empty() && actual.is_enum() {
                     let adt_def = actual.ty_adt_def().expect("enum is not an ADT");
                     if let Some(suggestion) = lev_distance::find_best_match_for_name(
                         &adt_def.variants.iter().map(|s| s.ident.name).collect::<Vec<_>>(),
@@ -778,17 +789,21 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         err.span_label(span, msg);
                     }
                 } else if let Some(lev_candidate) = lev_candidate {
-                    let def_kind = lev_candidate.kind.as_def_kind();
-                    err.span_suggestion(
-                        span,
-                        &format!(
-                            "there is {} {} with a similar name",
-                            def_kind.article(),
-                            def_kind.descr(lev_candidate.def_id),
-                        ),
-                        lev_candidate.ident.to_string(),
-                        Applicability::MaybeIncorrect,
-                    );
+                    // Don't emit a suggestion if we found an actual method
+                    // that had unsatisfied trait bounds
+                    if unsatisfied_predicates.is_empty() {
+                        let def_kind = lev_candidate.kind.as_def_kind();
+                        err.span_suggestion(
+                            span,
+                            &format!(
+                                "there is {} {} with a similar name",
+                                def_kind.article(),
+                                def_kind.descr(lev_candidate.def_id),
+                            ),
+                            lev_candidate.ident.to_string(),
+                            Applicability::MaybeIncorrect,
+                        );
+                    }
                 }
 
                 return Some(err);

diff --git a/compiler/rustc_typeck/src/lib.rs b/compiler/rustc_typeck/src/lib.rs
@@ -60,6 +60,7 @@ This API is completely unstable and subject to change.
 #![feature(bool_to_option)]
 #![feature(box_syntax)]
 #![feature(crate_visibility_modifier)]
+#![feature(format_args_capture)]
 #![feature(in_band_lifetimes)]
 #![feature(is_sorted)]
 #![feature(nll)]

diff --git a/src/test/ui/associated-types/hr-associated-type-bound-2.rs b/src/test/ui/associated-types/hr-associated-type-bound-2.rs
@@ -17,5 +17,5 @@ where
 
 fn main() {
     1u32.f("abc");
-    //~^ ERROR no method named `f` found for type `u32` in the current scope
+    //~^ ERROR the method
 }
diff --git a/src/test/ui/associated-types/hr-associated-type-bound-2.stderr b/src/test/ui/associated-types/hr-associated-type-bound-2.stderr
@@ -1,10 +1,10 @@
-error[E0599]: no method named `f` found for type `u32` in the current scope
+error[E0599]: the method `f` exists for type `u32`, but its trait bounds were not satisfied
   --> $DIR/hr-associated-type-bound-2.rs:19:10
    |
 LL |     1u32.f("abc");
-   |          ^ method not found in `u32`
+   |          ^ method cannot be called on `u32` due to unsatisfied trait bounds
    |
-   = note: the method `f` exists but the following trait bounds were not satisfied:
+   = note: the following trait bounds were not satisfied:
            `<u32 as X<'b>>::U: Clone`
            which is required by `u32: X`
 

diff --git a/src/test/ui/derives/derive-assoc-type-not-impl.stderr b/src/test/ui/derives/derive-assoc-type-not-impl.stderr
@@ -1,4 +1,4 @@
-error[E0599]: no method named `clone` found for struct `Bar<NotClone>` in the current scope
+error[E0599]: the method `clone` exists for struct `Bar<NotClone>`, but its trait bounds were not satisfied
   --> $DIR/derive-assoc-type-not-impl.rs:18:30
    |
 LL | struct Bar<T: Foo> {
@@ -11,7 +11,7 @@ LL | struct NotClone;
    | ---------------- doesn't satisfy `NotClone: Clone`
 ...
 LL |     Bar::<NotClone> { x: 1 }.clone();
-   |                              ^^^^^ method not found in `Bar<NotClone>`
+   |                              ^^^^^ method cannot be called on `Bar<NotClone>` due to unsatisfied trait bounds
    | 
   ::: $SRC_DIR/core/src/clone.rs:LL:COL
    |
@@ -21,7 +21,7 @@ LL |     fn clone(&self) -> Self;
    |        the method is available for `Arc<Bar<NotClone>>` here
    |        the method is available for `Rc<Bar<NotClone>>` here
    |
-   = note: the method `clone` exists but the following trait bounds were not satisfied:
+   = note: the following trait bounds were not satisfied:
            `NotClone: Clone`
            which is required by `Bar<NotClone>: Clone`
    = help: items from traits can only be used if the trait is implemented and in scope

diff --git a/src/test/ui/hrtb/issue-30786.migrate.stderr b/src/test/ui/hrtb/issue-30786.migrate.stderr
@@ -1,4 +1,4 @@
-error[E0599]: no method named `filterx` found for struct `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>` in the current scope
+error[E0599]: the method `filterx` exists for struct `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>`, but its trait bounds were not satisfied
   --> $DIR/issue-30786.rs:128:22
    |
 LL | pub struct Map<S, F> {
@@ -8,17 +8,17 @@ LL | pub struct Map<S, F> {
    | doesn't satisfy `_: StreamExt`
 ...
 LL |     let filter = map.filterx(|x: &_| true);
-   |                      ^^^^^^^ method not found in `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>`
+   |                      ^^^^^^^ method cannot be called on `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>` due to unsatisfied trait bounds
    |
-   = note: the method `filterx` exists but the following trait bounds were not satisfied:
+   = note: the following trait bounds were not satisfied:
            `&'a mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
            which is required by `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
            `&'a mut &Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
            which is required by `&Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
            `&'a mut &mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
            which is required by `&mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
 
-error[E0599]: no method named `countx` found for struct `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>` in the current scope
+error[E0599]: the method `countx` exists for struct `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>`, but its trait bounds were not satisfied
   --> $DIR/issue-30786.rs:141:24
    |
 LL | pub struct Filter<S, F> {
@@ -28,9 +28,9 @@ LL | pub struct Filter<S, F> {
    | doesn't satisfy `_: StreamExt`
 ...
 LL |     let count = filter.countx();
-   |                        ^^^^^^ method not found in `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>`
+   |                        ^^^^^^ method cannot be called on `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>` due to unsatisfied trait bounds
    |
-   = note: the method `countx` exists but the following trait bounds were not satisfied:
+   = note: the following trait bounds were not satisfied:
            `&'a mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
            which is required by `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: StreamExt`
            `&'a mut &Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`

diff --git a/src/test/ui/hrtb/issue-30786.nll.stderr b/src/test/ui/hrtb/issue-30786.nll.stderr
@@ -1,4 +1,4 @@
-error[E0599]: no method named `filterx` found for struct `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>` in the current scope
+error[E0599]: the method `filterx` exists for struct `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>`, but its trait bounds were not satisfied
   --> $DIR/issue-30786.rs:128:22
    |
 LL | pub struct Map<S, F> {
@@ -8,17 +8,17 @@ LL | pub struct Map<S, F> {
    | doesn't satisfy `_: StreamExt`
 ...
 LL |     let filter = map.filterx(|x: &_| true);
-   |                      ^^^^^^^ method not found in `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>`
+   |                      ^^^^^^^ method cannot be called on `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>` due to unsatisfied trait bounds
    |
-   = note: the method `filterx` exists but the following trait bounds were not satisfied:
+   = note: the following trait bounds were not satisfied:
            `&'a mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
            which is required by `Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
            `&'a mut &Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
            which is required by `&Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
            `&'a mut &mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: Stream`
            which is required by `&mut Map<Repeat, [closure@$DIR/issue-30786.rs:127:27: 127:36]>: StreamExt`
 
-error[E0599]: no method named `countx` found for struct `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>` in the current scope
+error[E0599]: the method `countx` exists for struct `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>`, but its trait bounds were not satisfied
   --> $DIR/issue-30786.rs:141:24
    |
 LL | pub struct Filter<S, F> {
@@ -28,9 +28,9 @@ LL | pub struct Filter<S, F> {
    | doesn't satisfy `_: StreamExt`
 ...
 LL |     let count = filter.countx();
-   |                        ^^^^^^ method not found in `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>`
+   |                        ^^^^^^ method cannot be called on `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>` due to unsatisfied trait bounds
    |
-   = note: the method `countx` exists but the following trait bounds were not satisfied:
+   = note: the following trait bounds were not satisfied:
            `&'a mut Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`
            which is required by `Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: StreamExt`
            `&'a mut &Filter<Map<Repeat, for<'r> fn(&'r u64) -> &'r u64 {identity::<u64>}>, [closure@$DIR/issue-30786.rs:140:30: 140:42]>: Stream`

diff --git a/src/test/ui/hrtb/issue-30786.rs b/src/test/ui/hrtb/issue-30786.rs
@@ -126,8 +126,8 @@ fn variant1() {
     // guess.
     let map = source.mapx(|x: &_| x);
     let filter = map.filterx(|x: &_| true);
-    //[migrate]~^ ERROR no method named `filterx`
-    //[nll]~^^ ERROR no method named `filterx`
+    //[migrate]~^ ERROR the method
+    //[nll]~^^ ERROR the method
 }
 
 fn variant2() {
@@ -139,8 +139,8 @@ fn variant2() {
     let map = source.mapx(identity);
     let filter = map.filterx(|x: &_| true);
     let count = filter.countx();
-    //[migrate]~^ ERROR no method named `countx`
-    //[nll]~^^ ERROR no method named `countx`
+    //[migrate]~^ ERROR the method
+    //[nll]~^^ ERROR the method
 }
 
 fn main() {}
diff --git a/src/test/ui/issues/issue-21596.stderr b/src/test/ui/issues/issue-21596.stderr
@@ -1,12 +1,12 @@
-error[E0599]: no method named `to_string` found for raw pointer `*const u8` in the current scope
+error[E0599]: the method `to_string` exists for raw pointer `*const u8`, but its trait bounds were not satisfied
   --> $DIR/issue-21596.rs:4:22
    |
 LL |     println!("{}", z.to_string());
-   |                      ^^^^^^^^^ method not found in `*const u8`
+   |                      ^^^^^^^^^ method cannot be called on `*const u8` due to unsatisfied trait bounds
    |
    = note: try using `<*const T>::as_ref()` to get a reference to the type behind the pointer: https://doc.rust-lang.org/std/primitive.pointer.html#method.as_ref
    = note: using `<*const T>::as_ref()` on a pointer which is unaligned or points to invalid or uninitialized memory is undefined behavior
-   = note: the method `to_string` exists but the following trait bounds were not satisfied:
+   = note: the following trait bounds were not satisfied:
            `*const u8: std::fmt::Display`
            which is required by `*const u8: ToString`
 

diff --git a/src/test/ui/issues/issue-31173.rs b/src/test/ui/issues/issue-31173.rs
@@ -11,7 +11,7 @@ pub fn get_tok(it: &mut IntoIter<u8>) {
         //~^ ERROR type mismatch resolving
         //~| expected type `u8`
         //~| found reference `&_`
-        .collect(); //~ ERROR no method named `collect`
+        .collect(); //~ ERROR the method
 }
 
 fn main() {}
diff --git a/src/test/ui/issues/issue-31173.stderr b/src/test/ui/issues/issue-31173.stderr
@@ -7,11 +7,11 @@ LL |         .cloned()
    = note:   expected type `u8`
            found reference `&_`
 
-error[E0599]: no method named `collect` found for struct `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 9:6]>>` in the current scope
+error[E0599]: the method `collect` exists for struct `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 9:6]>>`, but its trait bounds were not satisfied
   --> $DIR/issue-31173.rs:14:10
    |
 LL |         .collect();
-   |          ^^^^^^^ method not found in `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 9:6]>>`
+   |          ^^^^^^^ method cannot be called on `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 9:6]>>` due to unsatisfied trait bounds
    | 
   ::: $SRC_DIR/core/src/iter/adapters/cloned.rs:LL:COL
    |
@@ -23,7 +23,7 @@ LL | pub struct Cloned<I> {
 LL | pub struct TakeWhile<I, P> {
    | -------------------------- doesn't satisfy `<_ as Iterator>::Item = &_`
    |
-   = note: the method `collect` exists but the following trait bounds were not satisfied:
+   = note: the following trait bounds were not satisfied:
            `<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 9:6]> as Iterator>::Item = &_`
            which is required by `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 9:6]>>: Iterator`
            `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 9:6]>>: Iterator`

diff --git a/src/test/ui/issues/issue-35677.rs b/src/test/ui/issues/issue-35677.rs
@@ -2,7 +2,7 @@ use std::collections::HashSet;
 
 fn is_subset<T>(this: &HashSet<T>, other: &HashSet<T>) -> bool {
     this.is_subset(other)
-    //~^ ERROR no method named
+    //~^ ERROR the method
 }
 
 fn main() {}
diff --git a/src/test/ui/issues/issue-35677.stderr b/src/test/ui/issues/issue-35677.stderr
@@ -1,10 +1,10 @@
-error[E0599]: no method named `is_subset` found for reference `&HashSet<T>` in the current scope
+error[E0599]: the method `is_subset` exists for reference `&HashSet<T>`, but its trait bounds were not satisfied
   --> $DIR/issue-35677.rs:4:10
    |
 LL |     this.is_subset(other)
-   |          ^^^^^^^^^ method not found in `&HashSet<T>`
+   |          ^^^^^^^^^ method cannot be called on `&HashSet<T>` due to unsatisfied trait bounds
    |
-   = note: the method `is_subset` exists but the following trait bounds were not satisfied:
+   = note: the following trait bounds were not satisfied:
            `T: Eq`
            `T: Hash`
 

diff --git a/src/test/ui/issues/issue-50264-inner-deref-trait/option-as_deref.rs b/src/test/ui/issues/issue-50264-inner-deref-trait/option-as_deref.rs
@@ -1,4 +1,4 @@
 fn main() {
     let _result = &Some(42).as_deref();
-//~^ ERROR no method named `as_deref` found for enum `Option<{integer}>`
+//~^ ERROR the method
 }
diff --git a/src/test/ui/issues/issue-50264-inner-deref-trait/option-as_deref.stderr b/src/test/ui/issues/issue-50264-inner-deref-trait/option-as_deref.stderr
@@ -1,10 +1,10 @@
-error[E0599]: no method named `as_deref` found for enum `Option<{integer}>` in the current scope
+error[E0599]: the method `as_deref` exists for enum `Option<{integer}>`, but its trait bounds were not satisfied
   --> $DIR/option-as_deref.rs:2:29
    |
 LL |     let _result = &Some(42).as_deref();
-   |                             ^^^^^^^^ help: there is an associated function with a similar name: `as_ref`
+   |                             ^^^^^^^^
    |
-   = note: the method `as_deref` exists but the following trait bounds were not satisfied:
+   = note: the following trait bounds were not satisfied:
            `{integer}: Deref`
            `<{integer} as Deref>::Target = _`
 

diff --git a/src/test/ui/issues/issue-50264-inner-deref-trait/option-as_deref_mut.rs b/src/test/ui/issues/issue-50264-inner-deref-trait/option-as_deref_mut.rs
@@ -1,4 +1,4 @@
 fn main() {
     let _result = &mut Some(42).as_deref_mut();
-//~^ ERROR no method named `as_deref_mut` found for enum `Option<{integer}>`
+//~^ ERROR the method
 }