Separate suggestion in a help and a note

Author: estebank

src/librustc_typeck/check/method/suggest.rs

@@ -315,8 +315,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             let mut candidates = valid_out_of_scope_traits;
             candidates.sort();
             candidates.dedup();
-            let mut msg = format!("items from traits can only be used if the trait is in scope; \
-                                   the following {traits_are} implemented but not in scope, \
+            err.help("items from traits can only be used if the trait is in scope");
+            let mut msg = format!("the following {traits_are} implemented but not in scope, \
                                    perhaps add a `use` for {one_of_them}:",
                               traits_are = if candidates.len() == 1 {
                                   "trait is"
@@ -338,7 +338,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             if candidates.len() > limit {
                 msg.push_str(&format!("\nand {} others", candidates.len() - limit));
             }
-            err.help(&msg[..]);
+            err.note(&msg[..]);
 
             return;
         }
@@ -369,8 +369,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             // FIXME #21673 this help message could be tuned to the case
             // of a type parameter: suggest adding a trait bound rather
             // than implementing.
-            let mut msg = format!("items from traits can only be used if the trait is implemented \
-                                   and in scope; the following {traits_define} an item `{name}`, \
+            err.help("items from traits can only be used if the trait is implemented and in scope");
+            let mut msg = format!("the following {traits_define} an item `{name}`, \
                                    perhaps you need to implement {one_of_them}:",
                                   traits_define = if candidates.len() == 1 {
                                       "trait defines"
@@ -389,7 +389,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                                       i + 1,
                                       self.tcx.item_path_str(trait_info.def_id)));
             }
-            err.help(&msg[..]);
+            err.note(&msg[..]);
         }
     }
 

src/test/compile-fail/method-call-err-msg.rs

@@ -33,5 +33,6 @@ fn main() {
     y.zero()
      .take()    //~ ERROR no method named `take` found for type `Foo` in the current scope
      //~^ NOTE the method `take` exists but the following trait bounds were not satisfied
+     //~| NOTE the following traits define an item `take`, perhaps you need to implement one of them
      .one(0);
 }

src/test/ui/impl-trait/issue-21659-show-relevant-trait-impls-3.stderr

@@ -4,7 +4,8 @@ error[E0599]: no method named `foo` found for type `Bar` in the current scope
 30 |     f1.foo(1usize);
    |        ^^^
    |
-   = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `foo`, perhaps you need to implement it:
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following trait defines an item `foo`, perhaps you need to implement it:
            candidate #1: `Foo`
 
 error: aborting due to previous error(s)

src/test/ui/impl-trait/method-suggestion-no-duplication.stderr

@@ -4,7 +4,8 @@ error[E0599]: no method named `is_empty` found for type `Foo` in the current sco
 19 |     foo(|s| s.is_empty());
    |               ^^^^^^^^
    |
-   = help: items from traits can only be used if the trait is implemented and in scope; the following traits define an item `is_empty`, perhaps you need to implement one of them:
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following traits define an item `is_empty`, perhaps you need to implement one of them:
            candidate #1: `std::iter::ExactSizeIterator`
            candidate #2: `core::slice::SliceExt`
            candidate #3: `core::str::StrExt`

src/test/ui/impl-trait/no-method-suggested-traits.stderr

@@ -4,7 +4,8 @@ error[E0599]: no method named `method` found for type `u32` in the current scope
 33 |     1u32.method();
    |          ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope; the following traits are implemented but not in scope, perhaps add a `use` for one of them:
+   = help: items from traits can only be used if the trait is in scope
+   = note: the following traits are implemented but not in scope, perhaps add a `use` for one of them:
            candidate #1: `use foo::Bar;`
            candidate #2: `use no_method_suggested_traits::foo::PubPub;`
 
@@ -14,7 +15,8 @@ error[E0599]: no method named `method` found for type `std::rc::Rc<&mut std::box
 38 |     std::rc::Rc::new(&mut Box::new(&1u32)).method();
    |                                            ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope; the following traits are implemented but not in scope, perhaps add a `use` for one of them:
+   = help: items from traits can only be used if the trait is in scope
+   = note: the following traits are implemented but not in scope, perhaps add a `use` for one of them:
            candidate #1: `use foo::Bar;`
            candidate #2: `use no_method_suggested_traits::foo::PubPub;`
 
@@ -24,7 +26,8 @@ error[E0599]: no method named `method` found for type `char` in the current scop
 44 |     'a'.method();
    |         ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope; the following trait is implemented but not in scope, perhaps add a `use` for it:
+   = help: items from traits can only be used if the trait is in scope
+   = note: the following trait is implemented but not in scope, perhaps add a `use` for it:
            candidate #1: `use foo::Bar;`
 
 error[E0599]: no method named `method` found for type `std::rc::Rc<&mut std::boxed::Box<&char>>` in the current scope
@@ -33,7 +36,8 @@ error[E0599]: no method named `method` found for type `std::rc::Rc<&mut std::box
 48 |     std::rc::Rc::new(&mut Box::new(&'a')).method();
    |                                           ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope; the following trait is implemented but not in scope, perhaps add a `use` for it:
+   = help: items from traits can only be used if the trait is in scope
+   = note: the following trait is implemented but not in scope, perhaps add a `use` for it:
            candidate #1: `use foo::Bar;`
 
 error[E0599]: no method named `method` found for type `i32` in the current scope
@@ -42,7 +46,8 @@ error[E0599]: no method named `method` found for type `i32` in the current scope
 53 |     1i32.method();
    |          ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope; the following trait is implemented but not in scope, perhaps add a `use` for it:
+   = help: items from traits can only be used if the trait is in scope
+   = note: the following trait is implemented but not in scope, perhaps add a `use` for it:
            candidate #1: `use no_method_suggested_traits::foo::PubPub;`
 
 error[E0599]: no method named `method` found for type `std::rc::Rc<&mut std::boxed::Box<&i32>>` in the current scope
@@ -51,7 +56,8 @@ error[E0599]: no method named `method` found for type `std::rc::Rc<&mut std::box
 57 |     std::rc::Rc::new(&mut Box::new(&1i32)).method();
    |                                            ^^^^^^
    |
-   = help: items from traits can only be used if the trait is in scope; the following trait is implemented but not in scope, perhaps add a `use` for it:
+   = help: items from traits can only be used if the trait is in scope
+   = note: the following trait is implemented but not in scope, perhaps add a `use` for it:
            candidate #1: `use no_method_suggested_traits::foo::PubPub;`
 
 error[E0599]: no method named `method` found for type `Foo` in the current scope
@@ -60,7 +66,8 @@ error[E0599]: no method named `method` found for type `Foo` in the current scope
 62 |     Foo.method();
    |         ^^^^^^
    |
-   = help: items from traits can only be used if the trait is implemented and in scope; the following traits define an item `method`, perhaps you need to implement one of them:
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following traits define an item `method`, perhaps you need to implement one of them:
            candidate #1: `foo::Bar`
            candidate #2: `no_method_suggested_traits::foo::PubPub`
            candidate #3: `no_method_suggested_traits::bar::PubPriv`
@@ -74,7 +81,8 @@ error[E0599]: no method named `method` found for type `std::rc::Rc<&mut std::box
 71 |     std::rc::Rc::new(&mut Box::new(&Foo)).method();
    |                                           ^^^^^^
    |
-   = help: items from traits can only be used if the trait is implemented and in scope; the following traits define an item `method`, perhaps you need to implement one of them:
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following traits define an item `method`, perhaps you need to implement one of them:
            candidate #1: `foo::Bar`
            candidate #2: `no_method_suggested_traits::foo::PubPub`
            candidate #3: `no_method_suggested_traits::bar::PubPriv`
@@ -88,7 +96,8 @@ error[E0599]: no method named `method2` found for type `u64` in the current scop
 81 |     1u64.method2();
    |          ^^^^^^^
    |
-   = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `method2`, perhaps you need to implement it:
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following trait defines an item `method2`, perhaps you need to implement it:
            candidate #1: `foo::Bar`
 
 error[E0599]: no method named `method2` found for type `std::rc::Rc<&mut std::boxed::Box<&u64>>` in the current scope
@@ -97,7 +106,8 @@ error[E0599]: no method named `method2` found for type `std::rc::Rc<&mut std::bo
 85 |     std::rc::Rc::new(&mut Box::new(&1u64)).method2();
    |                                            ^^^^^^^
    |
-   = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `method2`, perhaps you need to implement it:
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following trait defines an item `method2`, perhaps you need to implement it:
            candidate #1: `foo::Bar`
 
 error[E0599]: no method named `method2` found for type `no_method_suggested_traits::Foo` in the current scope
@@ -106,7 +116,8 @@ error[E0599]: no method named `method2` found for type `no_method_suggested_trai
 90 |     no_method_suggested_traits::Foo.method2();
    |                                     ^^^^^^^
    |
-   = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `method2`, perhaps you need to implement it:
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following trait defines an item `method2`, perhaps you need to implement it:
            candidate #1: `foo::Bar`
 
 error[E0599]: no method named `method2` found for type `std::rc::Rc<&mut std::boxed::Box<&no_method_suggested_traits::Foo>>` in the current scope
@@ -115,7 +126,8 @@ error[E0599]: no method named `method2` found for type `std::rc::Rc<&mut std::bo
 94 |     std::rc::Rc::new(&mut Box::new(&no_method_suggested_traits::Foo)).method2();
    |                                                                       ^^^^^^^
    |
-   = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `method2`, perhaps you need to implement it:
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following trait defines an item `method2`, perhaps you need to implement it:
            candidate #1: `foo::Bar`
 
 error[E0599]: no method named `method2` found for type `no_method_suggested_traits::Bar` in the current scope
@@ -124,7 +136,8 @@ error[E0599]: no method named `method2` found for type `no_method_suggested_trai
 98 |     no_method_suggested_traits::Bar::X.method2();
    |                                        ^^^^^^^
    |
-   = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `method2`, perhaps you need to implement it:
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following trait defines an item `method2`, perhaps you need to implement it:
            candidate #1: `foo::Bar`
 
 error[E0599]: no method named `method2` found for type `std::rc::Rc<&mut std::boxed::Box<&no_method_suggested_traits::Bar>>` in the current scope
@@ -133,7 +146,8 @@ error[E0599]: no method named `method2` found for type `std::rc::Rc<&mut std::bo
 102 |     std::rc::Rc::new(&mut Box::new(&no_method_suggested_traits::Bar::X)).method2();
     |                                                                          ^^^^^^^
     |
-    = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `method2`, perhaps you need to implement it:
+    = help: items from traits can only be used if the trait is implemented and in scope
+    = note: the following trait defines an item `method2`, perhaps you need to implement it:
             candidate #1: `foo::Bar`
 
 error[E0599]: no method named `method3` found for type `Foo` in the current scope
@@ -142,7 +156,8 @@ error[E0599]: no method named `method3` found for type `Foo` in the current scop
 107 |     Foo.method3();
     |         ^^^^^^^
     |
-    = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `method3`, perhaps you need to implement it:
+    = help: items from traits can only be used if the trait is implemented and in scope
+    = note: the following trait defines an item `method3`, perhaps you need to implement it:
             candidate #1: `no_method_suggested_traits::foo::PubPub`
 
 error[E0599]: no method named `method3` found for type `std::rc::Rc<&mut std::boxed::Box<&Foo>>` in the current scope
@@ -151,7 +166,8 @@ error[E0599]: no method named `method3` found for type `std::rc::Rc<&mut std::bo
 111 |     std::rc::Rc::new(&mut Box::new(&Foo)).method3();
     |                                           ^^^^^^^
     |
-    = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `method3`, perhaps you need to implement it:
+    = help: items from traits can only be used if the trait is implemented and in scope
+    = note: the following trait defines an item `method3`, perhaps you need to implement it:
             candidate #1: `no_method_suggested_traits::foo::PubPub`
 
 error[E0599]: no method named `method3` found for type `Bar` in the current scope
@@ -160,7 +176,8 @@ error[E0599]: no method named `method3` found for type `Bar` in the current scop
 115 |     Bar::X.method3();
     |            ^^^^^^^
     |
-    = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `method3`, perhaps you need to implement it:
+    = help: items from traits can only be used if the trait is implemented and in scope
+    = note: the following trait defines an item `method3`, perhaps you need to implement it:
             candidate #1: `no_method_suggested_traits::foo::PubPub`
 
 error[E0599]: no method named `method3` found for type `std::rc::Rc<&mut std::boxed::Box<&Bar>>` in the current scope
@@ -169,7 +186,8 @@ error[E0599]: no method named `method3` found for type `std::rc::Rc<&mut std::bo
 119 |     std::rc::Rc::new(&mut Box::new(&Bar::X)).method3();
     |                                              ^^^^^^^
     |
-    = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `method3`, perhaps you need to implement it:
+    = help: items from traits can only be used if the trait is implemented and in scope
+    = note: the following trait defines an item `method3`, perhaps you need to implement it:
             candidate #1: `no_method_suggested_traits::foo::PubPub`
 
 error[E0599]: no method named `method3` found for type `usize` in the current scope

src/test/ui/span/issue-7575.stderr

@@ -23,7 +23,8 @@ note: candidate #3 is defined in the trait `UnusedTrait`
 29 |     fn f9(usize) -> usize; //~ NOTE candidate
    |     ^^^^^^^^^^^^^^^^^^^^^^
    = help: to disambiguate the method call, write `UnusedTrait::f9(u, 342)` instead
-   = help: items from traits can only be used if the trait is implemented and in scope; the following traits define an item `f9`, perhaps you need to implement one of them:
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following traits define an item `f9`, perhaps you need to implement one of them:
            candidate #1: `CtxtFn`
            candidate #2: `OtherTrait`
            candidate #3: `UnusedTrait`
@@ -58,7 +59,8 @@ note: candidate #1 is defined in the trait `ManyImplTrait`
 59 | |     }
    | |_____^
    = help: to disambiguate the method call, write `ManyImplTrait::is_str(t)` instead
-   = help: items from traits can only be used if the trait is implemented and in scope; the following trait defines an item `is_str`, perhaps you need to implement it:
+   = help: items from traits can only be used if the trait is implemented and in scope
+   = note: the following trait defines an item `is_str`, perhaps you need to implement it:
            candidate #1: `ManyImplTrait`
 
 error: aborting due to previous error(s)