Add more detailed suggestion

Author: VirrageS

src/doc/rustc-guide

@@ -719,8 +719,8 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             // These items live in both the type and value namespaces.
             ItemKind::Struct(ref vdata, _) => {
                 // Define a name in the type namespace.
-                let item_def_id = self.r.definitions.local_def_id(item.id);
-                let res = Res::Def(DefKind::Struct, item_def_id);
+                let def_id = self.r.definitions.local_def_id(item.id);
+                let res = Res::Def(DefKind::Struct, def_id);
                 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
 
                 // Record field names for error reporting.
@@ -757,12 +757,12 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             }
 
             ItemKind::Union(ref vdata, _) => {
-                let item_def_id = self.r.definitions.local_def_id(item.id);
-                let res = Res::Def(DefKind::Union, item_def_id);
+                let def_id = self.r.definitions.local_def_id(item.id);
+                let res = Res::Def(DefKind::Union, def_id);
                 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
 
                 // Record field names for error reporting.
-                self.insert_field_names_local(item_def_id, vdata);
+                self.insert_field_names_local(def_id, vdata);
             }
 
             ItemKind::Impl(.., ref impl_items) => {

src/librustc_resolve/build_reduced_graph.rs

@@ -259,14 +259,14 @@ impl<'a> LateResolutionVisitor<'a, '_> {
             if let PathSource::Expr(parent) = source {
                 match &parent.map(|p| &p.kind) {
                     Some(ExprKind::Call(_, args)) if args.len() > 0 => {
-                        let mut expr_kind = &args.first().unwrap().kind;
+                        let mut expr_kind = &args[0].kind;
                         loop {
                             match expr_kind {
                                 ExprKind::Path(_, arg_name) if arg_name.segments.len() == 1 => {
                                     has_self_arg = arg_name.segments[0].ident.name == kw::SelfLower;
                                     break;
                                 },
-                                ExprKind::AddrOf(_, _, expr) => { expr_kind = &expr.kind; }
+                                ExprKind::AddrOf(_, _, expr) => expr_kind = &expr.kind,
                                 _ => break,
                             }
                         }
@@ -278,7 +278,7 @@ impl<'a> LateResolutionVisitor<'a, '_> {
             if has_self_arg {
                 err.span_suggestion(
                     span,
-                    &"try calling method instead of passing `self` as parameter",
+                    &format!("try calling `{}` as a method", ident),
                     format!("self.{}", path_str),
                     Applicability::MachineApplicable,
                 );

src/librustc_resolve/late/diagnostics.rs

@@ -4,12 +4,15 @@ impl Foo {
     fn foo(&self) {
         bar(self);
         //~^ ERROR cannot find function `bar` in this scope
-        //~| HELP try calling method instead of passing `self` as parameter
+        //~| HELP try calling `bar` as a method
 
+        bar(&&self, 102);
+        //~^ ERROR cannot find function `bar` in this scope
+        //~| HELP try calling `bar` as a method
 
-        bar(&self);
+        bar(&mut self, 102, &"str");
         //~^ ERROR cannot find function `bar` in this scope
-        //~| HELP try calling method instead of passing `self` as parameter
+        //~| HELP try calling `bar` as a method
 
         bar();
         //~^ ERROR cannot find function `bar` in this scope

src/test/ui/self/suggest-self-2.rs

@@ -2,27 +2,33 @@ error[E0425]: cannot find function `bar` in this scope
   --> $DIR/suggest-self-2.rs:5:9
    |
 LL |         bar(self);
-   |         ^^^ help: try calling method instead of passing `self` as parameter: `self.bar`
+   |         ^^^ help: try calling `bar` as a method: `self.bar`
 
 error[E0425]: cannot find function `bar` in this scope
-  --> $DIR/suggest-self-2.rs:10:9
+  --> $DIR/suggest-self-2.rs:9:9
    |
-LL |         bar(&self);
-   |         ^^^ help: try calling method instead of passing `self` as parameter: `self.bar`
+LL |         bar(&&self, 102);
+   |         ^^^ help: try calling `bar` as a method: `self.bar`
 
 error[E0425]: cannot find function `bar` in this scope
-  --> $DIR/suggest-self-2.rs:14:9
+  --> $DIR/suggest-self-2.rs:13:9
+   |
+LL |         bar(&mut self, 102, &"str");
+   |         ^^^ help: try calling `bar` as a method: `self.bar`
+
+error[E0425]: cannot find function `bar` in this scope
+  --> $DIR/suggest-self-2.rs:17:9
    |
 LL |         bar();
    |         ^^^ not found in this scope
 
 error[E0599]: no method named `bar` found for type `&Foo` in the current scope
-  --> $DIR/suggest-self-2.rs:17:14
+  --> $DIR/suggest-self-2.rs:20:14
    |
 LL |         self.bar();
    |              ^^^ method not found in `&Foo`
 
-error: aborting due to 4 previous errors
+error: aborting due to 5 previous errors
 
 Some errors have detailed explanations: E0425, E0599.
 For more information about an error, try `rustc --explain E0425`.