Auto merge of #29109 - nxnfufunezn:master, r=Manishearth

Fixes : #19668 

r? @Manishearth

Author: bors

src/librustc/lint/context.rs

@@ -435,6 +435,28 @@ pub trait LintContext: Sized {
         self.lookup_and_emit(lint, Some(span), msg);
     }
 
+    /// Emit a lint and note at the appropriate level, for a particular span.
+    fn span_lint_note(&self, lint: &'static Lint, span: Span, msg: &str,
+                      note_span: Span, note: &str) {
+        self.span_lint(lint, span, msg);
+        if self.current_level(lint) != Level::Allow {
+            if note_span == span {
+                self.sess().fileline_note(note_span, note)
+            } else {
+                self.sess().span_note(note_span, note)
+            }
+        }
+    }
+
+    /// Emit a lint and help at the appropriate level, for a particular span.
+    fn span_lint_help(&self, lint: &'static Lint, span: Span,
+                      msg: &str, help: &str) {
+        self.span_lint(lint, span, msg);
+        if self.current_level(lint) != Level::Allow {
+            self.sess().span_help(span, help)
+        }
+    }
+
     /// Emit a lint at the appropriate level, with no associated span.
     fn lint(&self, lint: &'static Lint, msg: &str) {
         self.lookup_and_emit(lint, None, msg);

src/librustc_lint/builtin.rs

@@ -1236,15 +1236,12 @@ impl LateLintPass for DropWithReprExtern {
                                                                      codemap::DUMMY_SP);
                         let self_defn_span = ctx.tcx.map.def_id_span(self_type_did,
                                                                      codemap::DUMMY_SP);
-                        ctx.span_lint(DROP_WITH_REPR_EXTERN,
-                                      drop_impl_span,
-                                      "implementing Drop adds hidden state to types, \
-                                       possibly conflicting with `#[repr(C)]`");
-                        // FIXME #19668: could be span_lint_note instead of manual guard.
-                        if ctx.current_level(DROP_WITH_REPR_EXTERN) != Level::Allow {
-                            ctx.sess().span_note(self_defn_span,
-                                               "the `#[repr(C)]` attribute is attached here");
-                        }
+                        ctx.span_lint_note(DROP_WITH_REPR_EXTERN,
+                                           drop_impl_span,
+                                           "implementing Drop adds hidden state to types, \
+                                            possibly conflicting with `#[repr(C)]`",
+                                            self_defn_span,
+                                            "the `#[repr(C)]` attribute is attached here");
                     }
                 }
                 _ => {}