Index: include/clang/AST/CommentCommandTraits.h
===================================================================
--- include/clang/AST/CommentCommandTraits.h	(revision 174067)
+++ include/clang/AST/CommentCommandTraits.h	(working copy)
@@ -96,6 +96,9 @@
   ///   \fn void f(int a);
   /// \endcode
   unsigned IsDeclarationCommand : 1;
+  
+  /// \brief True if this is a \headerfile documentation
+  unsigned IsHeaderfileCommand : 1;
 
   /// \brief True if this command is unknown.  This \c CommandInfo object was
   /// created during parsing.
Index: include/clang/AST/CommentCommands.td
===================================================================
--- include/clang/AST/CommentCommands.td	(revision 174067)
+++ include/clang/AST/CommentCommands.td	(working copy)
@@ -19,6 +19,7 @@
   bit IsVerbatimBlockEndCommand = 0;
   bit IsVerbatimLineCommand = 0;
   bit IsDeclarationCommand = 0;
+  bit IsHeaderfileCommand = 0;
 }
 
 class InlineCommand<string name> : Command<name> {
@@ -72,6 +73,7 @@
 
 // Doxygen
 def Tparam : BlockCommand<"tparam"> { let IsTParamCommand = 1; }
+def Headerfile : BlockCommand<"headerfile"> { let IsHeaderfileCommand = 1; }
 
 // HeaderDoc
 def Templatefield : BlockCommand<"templatefield"> { let IsTParamCommand = 1; }
Index: include/clang/AST/CommentSema.h
===================================================================
--- include/clang/AST/CommentSema.h	(revision 174067)
+++ include/clang/AST/CommentSema.h	(working copy)
@@ -60,6 +60,9 @@
 
   /// AST node for the \\returns command and its aliases.
   const BlockCommandComment *ReturnsCommand;
+  
+  /// AST node for the \\headerfile command.
+  const BlockCommandComment *HeaderfileCommand;
 
   DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) {
     return Diags.Report(Loc, DiagID);
Index: lib/AST/CommentSema.cpp
===================================================================
--- lib/AST/CommentSema.cpp	(revision 174067)
+++ lib/AST/CommentSema.cpp	(working copy)
@@ -29,7 +29,8 @@
            DiagnosticsEngine &Diags, CommandTraits &Traits,
            const Preprocessor *PP) :
     Allocator(Allocator), SourceMgr(SourceMgr), Diags(Diags), Traits(Traits),
-    PP(PP), ThisDeclInfo(NULL), BriefCommand(NULL), ReturnsCommand(NULL) {
+    PP(PP), ThisDeclInfo(NULL), BriefCommand(NULL), ReturnsCommand(NULL),
+    HeaderfileCommand(NULL){
 }
 
 void Sema::setDecl(const Decl *D) {
@@ -485,6 +486,12 @@
       return;
     }
     PrevCommand = ReturnsCommand;
+  } else if (Info->IsHeaderfileCommand) {
+    if (!HeaderfileCommand) {
+      HeaderfileCommand = Command;
+      return;
+    }
+    PrevCommand = HeaderfileCommand;
   } else {
     // We don't want to check this command for duplicates.
     return;
Index: test/Index/headerfile-comment-to-html.m
===================================================================
--- test/Index/headerfile-comment-to-html.m	(revision 0)
+++ test/Index/headerfile-comment-to-html.m	(working copy)
@@ -0,0 +1,81 @@
+// RUN: rm -rf %t
+// RUN: mkdir %t
+// RUN: c-index-test -test-load-source all -comments-xml-schema=%S/../../bindings/xml/comment-xml-schema.rng %s > %t/out
+// RUN: FileCheck %s < %t/out
+// rdar://13067629
+
+// Ensure that XML we generate is not invalid.
+// RUN: FileCheck %s -check-prefix=WRONG < %t/out
+// WRONG-NOT: CommentXMLInvalid
+
+// rdar://12397511
+
+/*!
+     \headerfile Device.h <Foundation/Device.h>
+
+      A Device represents a remote or local computer or device with which the Developer Tools can interact.  Each Device supports blah blah blah from doing blah blah blah.
+*/
+@interface Device
+@end
+// CHECK: headerfile-comment-to-html.m:[[@LINE-2]]:12: ObjCInterfaceDecl=Device:{{.*}} FullCommentAsXML=[<Other file="{{[^"]+}}headerfile-comment-to-html.m" line="[[@LINE-2]]" column="12"><Name>Device</Name><USR>c:objc(cs)Device</USR><Declaration>@interface Device\n@end</Declaration><Abstract><Para> Device.h &lt;Foundation/Device.h&gt;</Para><Para>      A Device represents a remote or local computer or device with which the Developer Tools can interact.  Each Device supports blah blah blah from doing blah blah blah.</Para></Abstract></Other>] CommentXMLValid
+// CHECK-NEXT:  CommentAST=[
+// CHECK-NEXT:    (CXComment_FullComment
+// CHECK-NEXT:       (CXComment_Paragraph IsWhitespace
+// CHECK-NEXT:         (CXComment_Text Text=[     ] IsWhitespace))
+// CHECK-NEXT:       (CXComment_BlockCommand CommandName=[headerfile]
+// CHECK-NEXT:         (CXComment_Paragraph
+// CHECK-NEXT:           (CXComment_Text Text=[ Device.h ])
+// CHECK-NEXT:           (CXComment_Text Text=[<Foundation])
+// CHECK-NEXT:           (CXComment_Text Text=[/Device.h>])))
+// CHECK-NEXT:       (CXComment_Paragraph
+// CHECK-NEXT:         (CXComment_Text Text=[      A Device represents a remote or local computer or device with which the Developer Tools can interact.  Each Device supports blah blah blah from doing blah blah blah.])))]
+
+/*!
+    \headerfile Sensor.h "Sensor.h"
+
+    \brief This is Sensor on the Device.
+    Its purpose is not to Sense Device's heat.
+*/
+
+@interface Sensor
+@end
+// CHECK: headerfile-comment-to-html.m:[[@LINE-2]]:12: ObjCInterfaceDecl=Sensor:{{.*}} FullCommentAsXML=[<Other file="{{[^"]+}}headerfile-comment-to-html.m" line="[[@LINE-2]]" column="12"><Name>Sensor</Name><USR>c:objc(cs)Sensor</USR><Declaration>@interface Sensor\n@end</Declaration><Abstract><Para> Sensor.h &quot;Sensor.h&quot;</Para><Para> This is Sensor on the Device.    Its purpose is not to Sense Device&apos;s heat.</Para></Abstract></Other>] CommentXMLValid
+// CHECK-NEXT:  CommentAST=[
+// CHECK-NEXT:    (CXComment_FullComment
+// CHECK-NEXT:       (CXComment_Paragraph IsWhitespace
+// CHECK-NEXT:         (CXComment_Text Text=[    ] IsWhitespace))
+// CHECK-NEXT:       (CXComment_BlockCommand CommandName=[headerfile]
+// CHECK-NEXT:         (CXComment_Paragraph
+// CHECK-NEXT:           (CXComment_Text Text=[ Sensor.h "Sensor.h"])))
+// CHECK-NEXT:       (CXComment_Paragraph IsWhitespace
+// CHECK-NEXT:         (CXComment_Text Text=[    ] IsWhitespace))
+// CHECK-NEXT:       (CXComment_BlockCommand CommandName=[brief]
+// CHECK-NEXT:         (CXComment_Paragraph
+// CHECK-NEXT:           (CXComment_Text Text=[ This is Sensor on the Device.] HasTrailingNewline)
+// CHECK-NEXT:           (CXComment_Text Text=[    Its purpose is not to Sense Device's heat.]))))]
+
+/*!
+    \brief Test that headerfile can come after brief.
+    \headerfile VTDevice.h <VTFoundation/VTDevice.h>
+
+    More property decription goes here.
+*/
+@interface VTDevice : Device
+@end
+// CHECK: headerfile-comment-to-html.m:[[@LINE-2]]:12: ObjCInterfaceDecl=VTDevice:{{.*}} FullCommentAsXML=[<Other file="{{[^"]+}}headerfile-comment-to-html.m" line="[[@LINE-2]]" column="12"><Name>VTDevice</Name><USR>c:objc(cs)VTDevice</USR><Declaration>@interface VTDevice : Device\n@end</Declaration><Abstract><Para> VTDevice.h &lt;VTFoundation/VTDevice.h&gt;</Para><Para> Test that headerfile can come after brief.    </Para></Abstract><Discussion><Para>    More property decription goes here.</Para></Discussion></Other>] CommentXMLValid
+// CHECK-NEXT:  CommentAST=[
+// CHECK-NEXT:    (CXComment_FullComment
+// CHECK-NEXT:       (CXComment_Paragraph IsWhitespace
+// CHECK-NEXT:         (CXComment_Text Text=[    ] IsWhitespace))
+// CHECK-NEXT:       (CXComment_BlockCommand CommandName=[brief]
+// CHECK-NEXT:         (CXComment_Paragraph
+// CHECK-NEXT:           (CXComment_Text Text=[ Test that headerfile can come after brief.] HasTrailingNewline)
+// CHECK-NEXT:           (CXComment_Text Text=[    ] IsWhitespace)))
+// CHECK-NEXT:       (CXComment_BlockCommand CommandName=[headerfile]
+// CHECK-NEXT:         (CXComment_Paragraph
+// CHECK-NEXT:           (CXComment_Text Text=[ VTDevice.h ])
+// CHECK-NEXT:           (CXComment_Text Text=[<VTFoundation])
+// CHECK-NEXT:           (CXComment_Text Text=[/VTDevice.h>])))
+// CHECK-NEXT:       (CXComment_Paragraph
+// CHECK-NEXT:         (CXComment_Text Text=[    More property decription goes here.])))]
+
Index: tools/libclang/CXComment.cpp
===================================================================
--- tools/libclang/CXComment.cpp	(revision 174067)
+++ tools/libclang/CXComment.cpp	(working copy)
@@ -411,6 +411,7 @@
                    const CommandTraits &Traits);
 
   const BlockContentComment *Brief;
+  const BlockContentComment *Headerfile;
   const ParagraphComment *FirstParagraph;
   const BlockCommandComment *Returns;
   SmallVector<const ParamCommandComment *, 8> Params;
@@ -420,7 +421,7 @@
 
 FullCommentParts::FullCommentParts(const FullComment *C,
                                    const CommandTraits &Traits) :
-    Brief(NULL), FirstParagraph(NULL), Returns(NULL) {
+    Brief(NULL), Headerfile(NULL), FirstParagraph(NULL), Returns(NULL) {
   for (Comment::child_iterator I = C->child_begin(), E = C->child_end();
        I != E; ++I) {
     const Comment *Child = *I;
@@ -448,6 +449,10 @@
         Brief = BCC;
         break;
       }
+      if (!Headerfile && Info->IsHeaderfileCommand) {
+        Headerfile = BCC;
+        break;
+      }
       if (!Returns && Info->IsReturnsCommand) {
         Returns = BCC;
         break;
@@ -750,6 +755,8 @@
   FullCommentParts Parts(C, Traits);
 
   bool FirstParagraphIsBrief = false;
+  if (Parts.Headerfile)
+    visit(Parts.Headerfile);
   if (Parts.Brief)
     visit(Parts.Brief);
   else if (Parts.FirstParagraph) {
@@ -1217,15 +1224,19 @@
   bool FirstParagraphIsBrief = false;
   if (Parts.Brief) {
     Result << "<Abstract>";
+    if (Parts.Headerfile)
+      visit(Parts.Headerfile);
     visit(Parts.Brief);
     Result << "</Abstract>";
   } else if (Parts.FirstParagraph) {
     Result << "<Abstract>";
+    if (Parts.Headerfile)
+      visit(Parts.Headerfile);
     visit(Parts.FirstParagraph);
     Result << "</Abstract>";
     FirstParagraphIsBrief = true;
   }
-
+  
   if (Parts.TParams.size() != 0) {
     Result << "<TemplateParameters>";
     for (unsigned i = 0, e = Parts.TParams.size(); i != e; ++i)
Index: utils/TableGen/ClangCommentCommandInfoEmitter.cpp
===================================================================
--- utils/TableGen/ClangCommentCommandInfoEmitter.cpp	(revision 174067)
+++ utils/TableGen/ClangCommentCommandInfoEmitter.cpp	(working copy)
@@ -46,6 +46,7 @@
        << Tag.getValueAsBit("IsVerbatimBlockEndCommand") << ", "
        << Tag.getValueAsBit("IsVerbatimLineCommand") << ", "
        << Tag.getValueAsBit("IsDeclarationCommand") << ", "
+       << Tag.getValueAsBit("IsHeaderfileCommand") << ", "
        << /* IsUnknownCommand = */ "0"
        << " }";
     if (i + 1 != e)