From: Douglas Gregor <dgregor@apple.com>
Date: Thu, 21 Oct 2010 17:26:49 +0000 (+0000)
Subject: Diagnose the declaration of template template parameters that
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=369ea27b56b89379023366ff1b8ab362b5709e4e;p=clang

Diagnose the declaration of template template parameters that
themselves have no template parameters. This is actually a restriction
due to the grammar of template template parameters, but we choose to
diagnose it in Sema to provide better recovery.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@117032 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 87d2a9f81f..17a585896b 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1386,6 +1386,8 @@ def err_template_parameter_default_template_member : Error<
   "class template">;
 def err_template_parameter_default_friend_template : Error<
   "default template argument not permitted on a friend template">;
+def err_template_template_parm_no_parms : Error<
+  "template template parameter must have its own template parameters">;
 
 def err_template_variable : Error<"variable %0 declared as a template">;
 def err_template_variable_noparams : Error<
diff --git a/lib/Parse/ParseTemplate.cpp b/lib/Parse/ParseTemplate.cpp
index 8142cd226b..c472972e5c 100644
--- a/lib/Parse/ParseTemplate.cpp
+++ b/lib/Parse/ParseTemplate.cpp
@@ -540,7 +540,7 @@ Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
   TemplateParamsTy *ParamList =
     Actions.ActOnTemplateParameterList(Depth, SourceLocation(),
                                        TemplateLoc, LAngleLoc,
-                                       &TemplateParams[0],
+                                       TemplateParams.data(),
                                        TemplateParams.size(),
                                        RAngleLoc);
 
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index cd67955a22..95b2223658 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -666,7 +666,7 @@ Decl *Sema::ActOnTemplateTemplateParameter(Scope* S,
     TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
                                      NameLoc.isInvalid()? TmpLoc : NameLoc, 
                                      Depth, Position, Name,
-                                     (TemplateParameterList*)Params);
+                                     Params);
 
   // If the template template parameter has a name, then link the identifier 
   // into the scope and lookup mechanisms.
@@ -694,6 +694,11 @@ Decl *Sema::ActOnTemplateTemplateParameter(Scope* S,
     Param->setDefaultArgument(DefaultArg, false);
   }
   
+  if (Params->size() == 0) {
+    Diag(Param->getLocation(), diag::err_template_template_parm_no_parms)
+      << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc());
+    Param->setInvalidDecl();
+  }
   return Param;
 }
 
diff --git a/test/CXX/temp/temp.param/p1.cpp b/test/CXX/temp/temp.param/p1.cpp
index 676bffe31d..edc99733f0 100644
--- a/test/CXX/temp/temp.param/p1.cpp
+++ b/test/CXX/temp/temp.param/p1.cpp
@@ -1,4 +1,6 @@
 // Suppress 'no run line' failure.
-// RUN: echo ok
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+template<template<> class C> class D; // expected-error{{template template parameter must have its own template parameters}}
+
 
-// Paragraph 1 is descriptive, and therefore requires no tests.