[clang] [clang] require template arg list after template kw (PR #80801)

[Aaron Ballman via cfe-commits]

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@@ -2995,13 +2996,23 @@ bool Parser::ParseUnqualifiedId(CXXScopeSpec &SS, ParsedType ObjectType,
           SS, ObjectType, ObjectHadErrors,
           TemplateKWLoc ? *TemplateKWLoc : SourceLocation(), Id, IdLoc,
           EnteringContext, Result, TemplateSpecified);
-    else if (TemplateSpecified &&
-             Actions.ActOnTemplateName(
-                 getCurScope(), SS, *TemplateKWLoc, Result, ObjectType,
-                 EnteringContext, Template,
-                 /*AllowInjectedClassName*/ true) == TNK_Non_template)
-      return true;
 
+    if (TemplateSpecified) {
+      TemplateNameKind TNK =
+          Actions.ActOnTemplateName(getCurScope(), SS, *TemplateKWLoc, Result,
+                                    ObjectType, EnteringContext, Template,
+                                    /*AllowInjectedClassName*/ true);
+      if (TNK == TNK_Non_template)
+        return true;
+
+      // C++ [template.names]p6
+      // A name prefixed by the keyword template shall be followed by a template
+      // argument list or refer to a class template or an alias template.
+      if ((TNK == TNK_Function_template || TNK == TNK_Dependent_template_name ||
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AaronBallman wrote:

I think it's reasonable to handle in a follow-up, thanks!

https://github.com/llvm/llvm-project/pull/80801