Add primary span label

Author: estebank

src/librustc_typeck/check/method/suggest.rs

@@ -297,7 +297,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                     tcx.sess.diagnostic().struct_dummy()
                 };
 
-                if let Some(def) =  actual.ty_adt_def() {
+                if let Some(def) = actual.ty_adt_def() {
                     if let Some(full_sp) = tcx.hir.span_if_local(def.did) {
                         let def_sp = tcx.sess.codemap().def_span(full_sp);
                         err.span_label(def_sp, format!("{} `{}` not found {}",
@@ -380,6 +380,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 if !static_sources.is_empty() {
                     err.note("found the following associated functions; to be used as methods, \
                               functions must have a `self` parameter");
+                    err.span_label(span, "this is an associated function, not a method");
                 }
                 if static_sources.len() == 1 {
                     if let Some(expr) = rcvr_expr {

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

@@ -2,7 +2,7 @@ error[E0599]: no method named `f9` found for type `usize` in the current scope
   --> $DIR/issue-7575.rs:74:18
    |
 LL |     u.f8(42) + u.f9(342) + m.fff(42)
-   |                  ^^
+   |                  ^^ this is an associated function, not a method
    |
    = note: found the following associated functions; to be used as methods, functions must have a `self` parameter
 note: candidate #1 is defined in the trait `CtxtFn`
@@ -37,7 +37,8 @@ LL | struct Myisize(isize);
 ...
 LL |     u.f8(42) + u.f9(342) + m.fff(42)
    |                            --^^^
-   |                            |
+   |                            | |
+   |                            | this is an associated function, not a method
    |                            help: use associated function syntax intead: `Myisize::fff`
    |
    = note: found the following associated functions; to be used as methods, functions must have a `self` parameter
@@ -51,7 +52,7 @@ error[E0599]: no method named `is_str` found for type `T` in the current scope
   --> $DIR/issue-7575.rs:82:7
    |
 LL |     t.is_str()
-   |       ^^^^^^
+   |       ^^^^^^ this is an associated function, not a method
    |
    = note: found the following associated functions; to be used as methods, functions must have a `self` parameter
 note: the candidate is defined in the trait `ManyImplTrait`