1 files changed, 8 insertions, 4 deletions
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 4b8817529e3..54dcced5ba9 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -76,10 +76,14 @@ bool Sema::CanUseDecl(NamedDecl *D) {
 
 static void DiagnoseUnusedOfDecl(Sema &S, NamedDecl *D, SourceLocation Loc) {
   // Warn if this is used but marked unused.
-  if (D->hasAttr<UnusedAttr>()) {
-    const Decl *DC = cast_or_null<Decl>(S.getCurObjCLexicalContext());
-    if (DC && !DC->hasAttr<UnusedAttr>())
-      S.Diag(Loc, diag::warn_used_but_marked_unused) << D->getDeclName();
+  if (const auto *A = D->getAttr<UnusedAttr>()) {
+    // [[maybe_unused]] should not diagnose uses, but __attribute__((unused))
+    // should diagnose them.
+    if (A->getSemanticSpelling() != UnusedAttr::CXX11_maybe_unused) {
+      const Decl *DC = cast_or_null<Decl>(S.getCurObjCLexicalContext());
+      if (DC && !DC->hasAttr<UnusedAttr>())
+        S.Diag(Loc, diag::warn_used_but_marked_unused) << D->getDeclName();
+    }
   }
 }