Index: clang/lib/Format/UnwrappedLineParser.cpp
===================================================================
--- clang/lib/Format/UnwrappedLineParser.cpp
+++ clang/lib/Format/UnwrappedLineParser.cpp
@@ -2401,10 +2401,14 @@
   // it is often token-pasted.
   while (FormatTok->isOneOf(tok::identifier, tok::coloncolon, tok::hashhash,
                             tok::kw___attribute, tok::kw___declspec,
-                            tok::kw_alignas) ||
+                            tok::kw_alignas, tok::l_square) ||
          ((Style.Language == FormatStyle::LK_Java ||
            Style.Language == FormatStyle::LK_JavaScript) &&
           FormatTok->isOneOf(tok::period, tok::comma))) {
+
+    if (FormatTok->is(tok::l_square)) {
+      parseSquare();
+    }
     if (Style.Language == FormatStyle::LK_JavaScript &&
         FormatTok->isOneOf(Keywords.kw_extends, Keywords.kw_implements)) {
       // JavaScript/TypeScript supports inline object types in
Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -7636,6 +7636,10 @@
   verifyFormat("void f() [[deprecated(\"so sorry\")]];");
   verifyFormat("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n"
                "    [[unused]] aaaaaaaaaaaaaaaaaaaaaaa(int i);");
+  verifyFormat("[[nodiscard]] bool f() { return false; }");
+  verifyFormat("class [[nodiscard]] f {\npublic:\n  f() {}\n}");
+  verifyFormat("class [[deprecated(\"so sorry\")]] f {\npublic:\n  f() {}\n}");
+  verifyFormat("class [[gnu::unused]] f {\npublic:\n  f() {}\n}");
 
   // Make sure we do not mistake attributes for array subscripts.
   verifyFormat("int a() {}\n"