Rebase and address comments

Author: oli-obk

src/librustc_errors/emitter.rs

@@ -43,7 +43,7 @@ impl Emitter for EmitterWriter {
                sugg.msg.split_whitespace().count() < 10 &&
                // don't display multiline suggestions as labels
                sugg.substitutes[0].find('\n').is_none() {
-                let msg = format!("{} `{}`", sugg.msg, sugg.substitutes[0]);
+                let msg = format!("help: {} `{}`", sugg.msg, sugg.substitutes[0]);
                 primary_span.push_span_label(sugg.msp.primary_spans()[0], msg);
             } else {
                 children.push(SubDiagnostic {

src/librustc_typeck/check/op.rs

@@ -245,7 +245,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                         if let Some(missing_trait) = missing_trait {
                             if missing_trait == "std::ops::Add" &&
                                 self.check_str_addition(expr, lhs_expr, lhs_ty,
-                                                         rhs_expr, rhs_ty_var, &mut err) {
+                                                        rhs_ty, &mut err) {
                                 // This has nothing here because it means we did string
                                 // concatenation (e.g. "Hello " + "World!"). This means
                                 // we don't want the note in the else clause to be emitted
@@ -269,7 +269,6 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                           expr: &'gcx hir::Expr,
                           lhs_expr: &'gcx hir::Expr,
                           lhs_ty: Ty<'tcx>,
-                          rhs_expr: &'gcx hir::Expr,
                           rhs_ty: Ty<'tcx>,
                           mut err: &mut errors::DiagnosticBuilder) -> bool {
         // If this function returns true it means a note was printed, so we don't need

src/test/ui/did_you_mean/E0178.stderr

@@ -2,19 +2,19 @@ error[E0178]: expected a path on the left-hand side of `+`, not `&'a Foo`
   --> $DIR/E0178.rs:14:8
    |
 14 |     w: &'a Foo + Copy,
-   |        ^^^^^^^^^^^^^^ try adding parentheses: `&'a (Foo + Copy)`
+   |        ^^^^^^^^^^^^^^ help: try adding parentheses: `&'a (Foo + Copy)`
 
 error[E0178]: expected a path on the left-hand side of `+`, not `&'a Foo`
   --> $DIR/E0178.rs:15:8
    |
 15 |     x: &'a Foo + 'a,
-   |        ^^^^^^^^^^^^ try adding parentheses: `&'a (Foo + 'a)`
+   |        ^^^^^^^^^^^^ help: try adding parentheses: `&'a (Foo + 'a)`
 
 error[E0178]: expected a path on the left-hand side of `+`, not `&'a mut Foo`
   --> $DIR/E0178.rs:16:8
    |
 16 |     y: &'a mut Foo + 'a,
-   |        ^^^^^^^^^^^^^^^^ try adding parentheses: `&'a mut (Foo + 'a)`
+   |        ^^^^^^^^^^^^^^^^ help: try adding parentheses: `&'a mut (Foo + 'a)`
 
 error[E0178]: expected a path on the left-hand side of `+`, not `fn() -> Foo`
   --> $DIR/E0178.rs:17:8

src/test/ui/did_you_mean/trait-object-reference-without-parens-suggestion.stderr

@@ -2,13 +2,13 @@ error[E0178]: expected a path on the left-hand side of `+`, not `&Copy`
   --> $DIR/trait-object-reference-without-parens-suggestion.rs:12:12
    |
 12 |     let _: &Copy + 'static;
-   |            ^^^^^^^^^^^^^^^ try adding parentheses: `&(Copy + 'static)`
+   |            ^^^^^^^^^^^^^^^ help: try adding parentheses: `&(Copy + 'static)`
 
 error[E0178]: expected a path on the left-hand side of `+`, not `&'static Copy`
   --> $DIR/trait-object-reference-without-parens-suggestion.rs:13:12
    |
 13 |     let _: &'static Copy + 'static;
-   |            ^^^^^^^^^^^^^^^^^^^^^^^ try adding parentheses: `&'static (Copy + 'static)`
+   |            ^^^^^^^^^^^^^^^^^^^^^^^ help: try adding parentheses: `&'static (Copy + 'static)`
 
 error[E0038]: the trait `std::marker::Copy` cannot be made into an object
   --> $DIR/trait-object-reference-without-parens-suggestion.rs:12:12

src/test/ui/pub/pub-restricted.stderr

@@ -2,7 +2,7 @@ error: incorrect visibility restriction
   --> $DIR/pub-restricted.rs:15:6
    |
 15 | pub (a) fn afn() {}
-   |      ^ make this visible only to module `a` with `in`: `in a`
+   |      ^ help: make this visible only to module `a` with `in`: `in a`
    |
    = help: some possible visibility restrictions are:
            `pub(crate)`: visible only on the current crate
@@ -13,7 +13,7 @@ error: incorrect visibility restriction
   --> $DIR/pub-restricted.rs:16:6
    |
 16 | pub (b) fn bfn() {}
-   |      ^ make this visible only to module `b` with `in`: `in b`
+   |      ^ help: make this visible only to module `b` with `in`: `in b`
    |
    = help: some possible visibility restrictions are:
            `pub(crate)`: visible only on the current crate
@@ -24,7 +24,7 @@ error: incorrect visibility restriction
   --> $DIR/pub-restricted.rs:32:14
    |
 32 |         pub (a) invalid: usize,
-   |              ^ make this visible only to module `a` with `in`: `in a`
+   |              ^ help: make this visible only to module `a` with `in`: `in a`
    |
    = help: some possible visibility restrictions are:
            `pub(crate)`: visible only on the current crate
@@ -35,7 +35,7 @@ error: incorrect visibility restriction
   --> $DIR/pub-restricted.rs:41:6
    |
 41 | pub (xyz) fn xyz() {}
-   |      ^^^ make this visible only to module `xyz` with `in`: `in xyz`
+   |      ^^^ help: make this visible only to module `xyz` with `in`: `in xyz`
    |
    = help: some possible visibility restrictions are:
            `pub(crate)`: visible only on the current crate

src/test/ui/span/suggestion-non-ascii.stderr

@@ -2,7 +2,7 @@ error: cannot index a value of type `({integer},)`
   --> $DIR/suggestion-non-ascii.rs:14:21
    |
 14 |     println!("☃{}", tup[0]);
-   |                     ^^^^^^ to access tuple elements, use `tup.0`
+   |                     ^^^^^^ help: to access tuple elements, use `tup.0`
 
 error: aborting due to previous error
 

src/test/ui/suggestions/tuple-float-index.stderr

@@ -2,10 +2,10 @@ error: unexpected token: `1.1`
   --> $DIR/tuple-float-index.rs:14:17
    |
 14 |     (1, (2, 3)).1.1;
-   |                 ^^^ unexpected token
-   |
-help: try parenthesizing the first index
-   |     ((1, (2, 3)).1).1;
+   |     ------------^^^
+   |     |           |
+   |     |           unexpected token
+   |     help: try parenthesizing the first index `((1, (2, 3)).1).1`
 
 error: aborting due to previous error