diff --git a/include/clang/AST/CommentCommandTraits.h b/include/clang/AST/CommentCommandTraits.h
index 360a54b..0dfeea0 100644
--- a/include/clang/AST/CommentCommandTraits.h
+++ b/include/clang/AST/CommentCommandTraits.h
@@ -101,8 +101,15 @@
   /// \endcode
   unsigned IsDeclarationCommand : 1;
   
-  /// \brief True if verbatim-like line command is a function declaraton.
+  /// \brief True if verbatim-like line command is a function declaration.
   unsigned IsFunctionDeclarationCommand : 1;
+
+  /// \brief True if block command is further describing a container API; such
+  /// as @coclass, @classdesign, etc.
+  unsigned IsContainerDetailCommand : 1;
+  
+  /// \brief True if block command is a container API; such as @interface.
+  unsigned IsContainerDeclarationCommand : 1;
   
   /// \brief True if this command is unknown.  This \c CommandInfo object was
   /// created during parsing.
diff --git a/include/clang/AST/CommentCommands.td b/include/clang/AST/CommentCommands.td
index f3d9baa..ed5927c 100644
--- a/include/clang/AST/CommentCommands.td
+++ b/include/clang/AST/CommentCommands.td
@@ -25,6 +25,8 @@
   bit IsVerbatimLineCommand = 0;
   bit IsDeclarationCommand = 0;
   bit IsFunctionDeclarationCommand = 0;
+  bit IsContainerDetailCommand = 0;
+  bit IsContainerDeclarationCommand = 0;
 }
 
 class InlineCommand<string name> : Command<name> {
@@ -66,6 +68,12 @@
   let IsFunctionDeclarationCommand = 1;
 }
 
+class ContainerDeclarationVerbatimLineCommand<string name> :
+      VerbatimLineCommand<name> {
+  let IsDeclarationCommand = 1;
+  let IsContainerDeclarationCommand = 1;
+}
+
 //===----------------------------------------------------------------------===//
 // InlineCommand
 //===----------------------------------------------------------------------===//
@@ -181,9 +189,11 @@
 def Var       : DeclarationVerbatimLineCommand<"var">;
 
 // HeaderDoc commands.
-def Class     : DeclarationVerbatimLineCommand<"class">;
-def Interface : DeclarationVerbatimLineCommand<"interface">;
-def Protocol  : DeclarationVerbatimLineCommand<"protocol">;
+def Class     : ContainerDeclarationVerbatimLineCommand<"class">;
+def Interface : ContainerDeclarationVerbatimLineCommand<"interface">;
+def Protocol  : ContainerDeclarationVerbatimLineCommand<"protocol">;
+def Struct    : ContainerDeclarationVerbatimLineCommand<"struct">;
+def Union     : ContainerDeclarationVerbatimLineCommand<"union">;
 def Category  : DeclarationVerbatimLineCommand<"category">;
 def Template  : DeclarationVerbatimLineCommand<"template">;
 def Function  : FunctionDeclarationVerbatimLineCommand<"function">;
@@ -191,7 +201,38 @@
 def Callback  : FunctionDeclarationVerbatimLineCommand<"callback">;
 def Const     : DeclarationVerbatimLineCommand<"const">;
 def Constant  : DeclarationVerbatimLineCommand<"constant">;
-def Struct    : DeclarationVerbatimLineCommand<"struct">;
-def Union     : DeclarationVerbatimLineCommand<"union">;
 def Enum      : DeclarationVerbatimLineCommand<"enum">;
 
+def ClassDesign   : BlockCommand<"classdesign"> {
+  let IsContainerDetailCommand = 1; 
+}
+def CoClass       : BlockCommand<"coclass"> {
+ let IsContainerDetailCommand = 1; 
+}
+def Dependency    : BlockCommand<"dependency"> {
+ let IsContainerDetailCommand = 1; 
+}
+def Helper        : BlockCommand<"helper"> {
+ let IsContainerDetailCommand = 1; 
+}
+def HelperClass   : BlockCommand<"helperclass"> {
+ let IsContainerDetailCommand = 1; 
+}
+def Helps         : BlockCommand<"helps"> {
+ let IsContainerDetailCommand = 1; 
+}
+def InstanceSize  : BlockCommand<"instancesize"> {
+ let IsContainerDetailCommand = 1; 
+}
+def Ownership     : BlockCommand<"ownership"> {
+ let IsContainerDetailCommand = 1; 
+}
+def Performance   : BlockCommand<"performance"> {
+ let IsContainerDetailCommand = 1; 
+}
+def Security      : BlockCommand<"security"> {
+ let IsContainerDetailCommand = 1; 
+}
+def SuperClass    : BlockCommand<"superclass"> {
+ let IsContainerDetailCommand = 1; 
+}
diff --git a/include/clang/AST/CommentSema.h b/include/clang/AST/CommentSema.h
index 1d8112f..8294a81 100644
--- a/include/clang/AST/CommentSema.h
+++ b/include/clang/AST/CommentSema.h
@@ -200,6 +200,10 @@
   void checkDeprecatedCommand(const BlockCommandComment *Comment);
   
   void checkFunctionDeclVerbatimLine(const BlockCommandComment *Comment);
+  
+  void checkContainerDeclVerbatimLine(const BlockCommandComment *Comment);
+  
+  void checkContainerDecl(const BlockCommandComment *Comment);
 
   /// Resolve parameter names to parameter indexes in function declaration.
   /// Emit diagnostics about unknown parametrs.
@@ -211,6 +215,11 @@
   bool isObjCMethodDecl();
   bool isObjCPropertyDecl();
   bool isTemplateOrSpecialization();
+  bool isContainerDecl();
+  bool isClassStructDecl();
+  bool isUnionDecl();
+  bool isObjCInterfaceDecl();
+  bool isObjCProtocolDecl();
 
   ArrayRef<const ParmVarDecl *> getParamVars();
 
diff --git a/include/clang/Basic/DiagnosticCommentKinds.td b/include/clang/Basic/DiagnosticCommentKinds.td
index c87a0a7..7682b85 100644
--- a/include/clang/Basic/DiagnosticCommentKinds.td
+++ b/include/clang/Basic/DiagnosticCommentKinds.td
@@ -79,6 +79,18 @@
   "%select{a function|an Objective-C method|a pointer to function}2 declaration">,
   InGroup<Documentation>, DefaultIgnore;
   
+def warn_doc_api_container_decl_mismatch : Warning<
+  "'%select{\\|@}0%select{class|interface|protocol|struct|union}1' "
+  "command should not be used in a comment attached to a "
+  "non-%select{class|interface|protocol|struct|union}2 declaration">,
+  InGroup<Documentation>, DefaultIgnore;
+  
+def warn_doc_container_decl_mismatch : Warning<
+  "'%select{\\|@}0%select{classdesign|coclass|dependency|helper"
+  "|helperclass|helps|instancesize|ownership|performance|security|superclass}1' "
+  "command should not be used in a comment attached to a non-container declaration">,
+  InGroup<Documentation>, DefaultIgnore;
+  
 def warn_doc_param_duplicate : Warning<
   "parameter '%0' is already documented">,
   InGroup<Documentation>, DefaultIgnore;
diff --git a/lib/AST/CommentSema.cpp b/lib/AST/CommentSema.cpp
index 68a9ebb..0ca6fb1 100644
--- a/lib/AST/CommentSema.cpp
+++ b/lib/AST/CommentSema.cpp
@@ -52,8 +52,11 @@
                                       SourceLocation LocEnd,
                                       unsigned CommandID,
                                       CommandMarkerKind CommandMarker) {
-  return new (Allocator) BlockCommandComment(LocBegin, LocEnd, CommandID,
-                                             CommandMarker);
+  BlockCommandComment *BC = new (Allocator) BlockCommandComment(LocBegin, LocEnd,
+                                                                CommandID,
+                                                                CommandMarker);
+  checkContainerDecl(BC);
+  return BC;
 }
 
 void Sema::actOnBlockCommandArgs(BlockCommandComment *Command,
@@ -105,6 +108,52 @@
     << (DiagSelect-1) << (DiagSelect-1)
     << Comment->getSourceRange();
 }
+  
+void Sema::checkContainerDeclVerbatimLine(const BlockCommandComment *Comment) {
+  const CommandInfo *Info = Traits.getCommandInfo(Comment->getCommandID());
+  if (!Info->IsContainerDeclarationCommand)
+    return;
+  StringRef Name = Info->Name;
+  unsigned DiagSelect = llvm::StringSwitch<unsigned>(Name)
+  .Case("class", !isClassStructDecl() ? 1 : 0)
+  .Case("interface", !isObjCInterfaceDecl() ? 2 : 0)
+  .Case("protocol", !isObjCProtocolDecl() ? 3 : 0)
+  .Case("struct", !isClassStructDecl() ? 4 : 0)
+  .Case("union", !isUnionDecl() ? 5 : 0)
+  .Default(0);
+  
+  if (DiagSelect)
+    Diag(Comment->getLocation(), diag::warn_doc_api_container_decl_mismatch)
+    << Comment->getCommandMarker()
+    << (DiagSelect-1) << (DiagSelect-1)
+    << Comment->getSourceRange();
+}
+
+void Sema::checkContainerDecl(const BlockCommandComment *Comment) {
+  const CommandInfo *Info = Traits.getCommandInfo(Comment->getCommandID());
+  if (!Info->IsContainerDetailCommand || isContainerDecl())
+    return;
+  StringRef Name = Info->Name;
+  unsigned DiagSelect = llvm::StringSwitch<unsigned>(Name)
+  .Case("classdesign", 1)
+  .Case("coclass", 2)
+  .Case("dependency", 3)
+  .Case("helper", 4)
+  .Case("helperclass", 5)
+  .Case("helps", 6)
+  .Case("instancesize", 7)
+  .Case("ownership", 8)
+  .Case("performance", 9)
+  .Case("security", 10)
+  .Case("superclass", 11)
+  .Default(0);
+  
+  if (DiagSelect)
+    Diag(Comment->getLocation(), diag::warn_doc_container_decl_mismatch)
+    << Comment->getCommandMarker()
+    << (DiagSelect-1)
+    << Comment->getSourceRange();
+}
 
 void Sema::actOnParamCommandDirectionArg(ParamCommandComment *Command,
                                          SourceLocation ArgLocBegin,
@@ -362,6 +411,7 @@
                               TextBegin,
                               Text);
   checkFunctionDeclVerbatimLine(VL);
+  checkContainerDeclVerbatimLine(VL);
   return VL;
 }
 
@@ -735,6 +785,54 @@
   return ThisDeclInfo->getTemplateKind() != DeclInfo::NotTemplate;
 }
 
+bool Sema::isContainerDecl() {
+  if (!ThisDeclInfo)
+    return false;
+  if (!ThisDeclInfo->IsFilled)
+    inspectThisDecl();
+  return isUnionDecl() || isClassStructDecl() 
+         || isObjCInterfaceDecl() || isObjCProtocolDecl();
+}
+
+bool Sema::isUnionDecl() {
+  if (!ThisDeclInfo)
+    return false;
+  if (!ThisDeclInfo->IsFilled)
+    inspectThisDecl();
+  if (const RecordDecl *RD =
+        dyn_cast_or_null<RecordDecl>(ThisDeclInfo->CurrentDecl))
+    return RD->isUnion();
+  return false;
+}
+  
+bool Sema::isClassStructDecl() {
+  if (!ThisDeclInfo)
+    return false;
+  if (!ThisDeclInfo->IsFilled)
+    inspectThisDecl();
+  return ThisDeclInfo->CurrentDecl &&
+         isa<RecordDecl>(ThisDeclInfo->CurrentDecl) &&
+         !isUnionDecl();
+}
+
+bool Sema::isObjCInterfaceDecl() {
+  if (!ThisDeclInfo)
+    return false;
+  if (!ThisDeclInfo->IsFilled)
+    inspectThisDecl();
+  return ThisDeclInfo->CurrentDecl &&
+         isa<ObjCInterfaceDecl>(ThisDeclInfo->CurrentDecl);
+}
+  
+bool Sema::isObjCProtocolDecl() {
+  if (!ThisDeclInfo)
+    return false;
+  if (!ThisDeclInfo->IsFilled)
+    inspectThisDecl();
+  return ThisDeclInfo->CurrentDecl &&
+         isa<ObjCProtocolDecl>(ThisDeclInfo->CurrentDecl);
+}
+  
 ArrayRef<const ParmVarDecl *> Sema::getParamVars() {
   if (!ThisDeclInfo->IsFilled)
     inspectThisDecl();
diff --git a/test/Sema/warn-documentation.cpp b/test/Sema/warn-documentation.cpp
index 32e43a7..0132ef2 100644
--- a/test/Sema/warn-documentation.cpp
+++ b/test/Sema/warn-documentation.cpp
@@ -922,3 +922,31 @@
 // expected-warning@+1 {{empty paragraph passed to '@param' command}}
 ///@param x@param y
 int test_nocrash13(int x, int y);
+
+// rdar://12379114
+// expected-warning@+2 {{'@union' command should not be used in a comment attached to a non-union declaration}}
+/*!
+   @union U This is new 
+*/
+struct U { int iS; };
+
+/*!
+  @union U1
+*/
+union U1 {int i; };
+
+// expected-warning@+2 {{'@struct' command should not be used in a comment attached to a non-struct declaration}}
+/*!
+ @struct S2
+*/
+union S2 {};
+
+/*!
+  @class C1
+*/
+class C1;
+
+/*!
+  @struct S3;
+*/
+class S3;
diff --git a/test/Sema/warn-documentation.m b/test/Sema/warn-documentation.m
index 5150955..98c4993 100644
--- a/test/Sema/warn-documentation.m
+++ b/test/Sema/warn-documentation.m
@@ -105,3 +105,55 @@
 typedef id ID;
 - (unsigned) Base64EncodeEx : (ID)Arg;
 @end
+
+// rdar://12379114
+// expected-warning@+5 {{'@interface' command should not be used in a comment attached to a non-interface declaration}} 
+// expected-warning@+5 {{'@classdesign' command should not be used in a comment attached to a non-container declaration}}
+// expected-warning@+5 {{'@coclass' command should not be used in a comment attached to a non-container declaration}} 
+@interface NSObject @end
+/*!
+@interface IOCommandGate
+@classdesign Multiple paragraphs go here.
+@coclass myCoClass 
+*/
+
+typedef id OBJ;
+@interface IOCommandGate : NSObject {
+  OBJ iv;
+}
+@end
+
+// expected-warning@+2 {{'@protocol' command should not be used in a comment attached to a non-protocol declaration}}
+/*!
+@protocol PROTO
+*/
+struct S;
+
+/*!
+  @interface NSArray This is an array
+*/
+@class NSArray;
+@interface NSArray @end
+
+/*!
+@interface NSMutableArray 
+@super NSArray
+*/
+@interface NSMutableArray : NSArray @end
+
+/*!
+  @protocol MyProto
+*/
+@protocol MyProto @end
+
+// expected-warning@+2 {{'@protocol' command should not be used in a comment attached to a non-protocol declaration}}
+/*!
+ @protocol MyProto
+*/
+@interface INTF <MyProto> @end
+
+// expected-warning@+2 {{'@struct' command should not be used in a comment attached to a non-struct declaration}}
+/*!
+  @struct S1 THIS IS IT
+*/
+@interface S1 @end
diff --git a/utils/TableGen/ClangCommentCommandInfoEmitter.cpp b/utils/TableGen/ClangCommentCommandInfoEmitter.cpp
index b0bf752..f90cef3 100644
--- a/utils/TableGen/ClangCommentCommandInfoEmitter.cpp
+++ b/utils/TableGen/ClangCommentCommandInfoEmitter.cpp
@@ -48,6 +48,8 @@
        << Tag.getValueAsBit("IsVerbatimLineCommand") << ", "
        << Tag.getValueAsBit("IsDeclarationCommand") << ", "
        << Tag.getValueAsBit("IsFunctionDeclarationCommand") << ", "
+       << Tag.getValueAsBit("IsContainerDetailCommand") << ", "
+       << Tag.getValueAsBit("IsContainerDeclarationCommand") << ", "
        << /* IsUnknownCommand = */ "0"
        << " }";
     if (i + 1 != e)