clang-format: Support enum type template arguments.

Before:
  template <enum E> class A { public : E *f(); };

After:
  template <enum E> class A {
  public:
    E *f();
  };

llvm-svn: 268878

clang/lib/Format/UnwrappedLineParser.cpp

@@ -902,6 +902,7 @@ void UnwrappedLineParser::parseStructuralElement() {
     break;
   }
   do {
+    const FormatToken *Previous = getPreviousToken();
     switch (FormatTok->Tok.getKind()) {
     case tok::at:
       nextToken();
@@ -909,6 +910,12 @@ void UnwrappedLineParser::parseStructuralElement() {
         parseBracedList();
       break;
     case tok::kw_enum:
+      // Ignore if this is part of "template <enum ...".
+      if (Previous && Previous->is(tok::less)) {
+        nextToken();
+        break;
+      }
+
       // parseEnum falls through and does not yet add an unwrapped line as an
       // enum definition can start a structural element.
       if (!parseEnum())

clang/unittests/Format/FormatTest.cpp

@@ -5381,6 +5381,10 @@ TEST_F(FormatTest, WrapsTemplateDeclarations) {
   verifyFormat("template <typename T> // T can be A, B or C.\n"
                "struct C {};",
                AlwaysBreak);
+  verifyFormat("template <enum E> class A {\n"
+               "public:\n"
+               "  E *f();\n"
+               "};");
 }
 
 TEST_F(FormatTest, WrapsAtNestedNameSpecifiers) {