This is the libclang patch providing minimal API to

use clang's formatter. Currently, formatter is used 
to format declaration tags for xml comments. Since formatter
is in flux and its change will break several of the clang comment
tests, only a single tests is formatted using this facility.
Doug has reviewed and approved it for check-in. 


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@170467 91177308-0d34-0410-b5e6-96231b3b80d8

11 files changed, 277 insertions, 27 deletions

diff --git a/lib/AST/DeclPrinter.cpp b/lib/AST/DeclPrinter.cpp
index 5cef00f187..34c69059c4 100644
--- a/lib/AST/DeclPrinter.cpp
+++ b/lib/AST/DeclPrinter.cpp
@@ -915,6 +915,8 @@ void DeclPrinter::VisitObjCMethodDecl(ObjCMethodDecl *OMD) {
     OMD->getBody()->printPretty(Out, 0, Policy);
     Out << '\n';
   }
+  else
+    Out << ';';
 }
 
 void DeclPrinter::VisitObjCImplementationDecl(ObjCImplementationDecl *OID) {
@@ -1093,7 +1095,7 @@ void DeclPrinter::VisitObjCPropertyDecl(ObjCPropertyDecl *PDecl) {
     (void) first; // Silence dead store warning due to idiomatic code.
     Out << " )";
   }
-  Out << ' ' << PDecl->getType().getAsString(Policy) << ' ' << *PDecl;
+  Out << ' ' << PDecl->getType().getAsString(Policy) << ' ' << *PDecl << ';';
 }
 
 void DeclPrinter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *PID) {
diff --git a/test/Index/comment-objc-decls.m b/test/Index/comment-objc-decls.m
index 2894ee88f5..d037e05db2 100644
--- a/test/Index/comment-objc-decls.m
+++ b/test/Index/comment-objc-decls.m
@@ -31,9 +31,9 @@
 + ClassMethodMyProto;
 @end
 // CHECK: <Declaration>@protocol MyProto\n@end</Declaration>
-// CHECK: <Declaration>- (unsigned int) MethodMyProto:(id)anObject inRange:(unsigned int)range</Declaration>
-// CHECK: <Declaration>@optional\n@property ( readwrite,copy,atomic ) id PropertyMyProto</Declaration>
-// CHECK: <Declaration>+ (id) ClassMethodMyProto</Declaration>
+// CHECK: <Declaration>- (unsigned int) MethodMyProto:(id)anObject inRange:(unsigned int)range;</Declaration>
+// CHECK: <Declaration>@optional\n@property ( readwrite,copy,atomic ) id PropertyMyProto;</Declaration>
+// CHECK: <Declaration>+ (id) ClassMethodMyProto;</Declaration>
 
 /**
  * \brief NSObject is the root class.
@@ -75,9 +75,9 @@
 @end
 // CHECK: <Declaration>@interface MyClass : NSObject&lt;MyProto&gt; {\n    id IvarMyClass;\n}\n@end</Declaration>
 // CHECK: <Declaration>id IvarMyClass</Declaration>
-// CHECK: <Declaration>- (id) MethodMyClass</Declaration>
-// CHECK: <Declaration>+ (id) ClassMethodMyClass</Declaration>
-// CHECK: <Declaration>@property ( readwrite,copy,atomic ) id PropertyMyClass</Declaration
+// CHECK: <Declaration>- (id) MethodMyClass;</Declaration>
+// CHECK: <Declaration>+ (id) ClassMethodMyClass;</Declaration>
+// CHECK: <Declaration>@property ( readwrite,copy,atomic ) id PropertyMyClass;</Declaration
 
 /**
  * \brief - This is class extension of MyClass
@@ -109,10 +109,10 @@
 @property (copy) id PropertyMyClassCategory;
 @end
 // CHECK: <Declaration>@interface MyClass(Category)\n@end</Declaration>
-// CHECK: <Declaration>- (void) MethodMyClassCategory</Declaration>
-// CHECK: <Declaration>@property ( readwrite,copy,atomic ) id PropertyMyClassCategory</Declaration>
-// CHECK: <Declaration>- (id) PropertyMyClassCategory</Declaration>
-// CHECK: <Declaration>- (void) setPropertyMyClassCategory:(id)arg</Declaration>
+// CHECK: <Declaration>- (void) MethodMyClassCategory;</Declaration>
+// CHECK: <Declaration>@property ( readwrite,copy,atomic ) id PropertyMyClassCategory;</Declaration>
+// CHECK: <Declaration>- (id) PropertyMyClassCategory;</Declaration>
+// CHECK: <Declaration>- (void) setPropertyMyClassCategory:(id)arg;</Declaration>
 
 /// @implementation's
 
@@ -141,8 +141,8 @@
 @end
 // CHECK: <Declaration>@implementation MyClass{\n    id IvarPrivateToMyClassImpl;\n    id _PropertyMyClass;\n}\n@end</Declaration>
 // CHECK: <Declaration>id IvarPrivateToMyClassImpl</Declaration>
-// CHECK: <Declaration>- (id) MethodMyClass</Declaration>
-// CHECK: <Declaration>+ (id) ClassMethodMyClass</Declaration>
+// CHECK: <Declaration>- (id) MethodMyClass;</Declaration>
+// CHECK: <Declaration>+ (id) ClassMethodMyClass;</Declaration>
 
 /**
  * \brief MyClass (Category) is implementation of private to MyClass.
@@ -163,9 +163,9 @@
 - (void) setPropertyMyClassCategory : (id) arg {}
 @end
 // CHECK: <Declaration>@implementation MyClass(Category)\n@end</Declaration>
-// CHECK: <Declaration>- (void) MethodMyClassCategory</Declaration>
-// CHECK: <Declaration>- (id) PropertyMyClassCategory</Declaration>
-// CHECK: <Declaration>- (void) setPropertyMyClassCategory:(id)arg</Declaration>
+// CHECK: <Declaration>- (void) MethodMyClassCategory;</Declaration>
+// CHECK: <Declaration>- (id) PropertyMyClassCategory;</Declaration>
+// CHECK: <Declaration>- (void) setPropertyMyClassCategory:(id)arg;</Declaration>
 
 /**
  * \brief NSObject implementation
diff --git a/test/Index/format-comment-cdecls.c b/test/Index/format-comment-cdecls.c
new file mode 100644
index 0000000000..989ce5c022
--- /dev/null
+++ b/test/Index/format-comment-cdecls.c
@@ -0,0 +1,100 @@
+// RUN: rm -rf %t
+// RUN: mkdir %t
+// RUN: env LIBCLANG_ACTIVATE_FORMAT=1 \
+// RUN: c-index-test -test-load-source all -comments-xml-schema=%S/../../bindings/xml/comment-xml-schema.rng -target x86_64-apple-darwin10 %s \ 
+// RUN: | FileCheck %s 
+
+/**
+ * \brief Aaa.
+*/
+int global_function();
+// CHECK: <Declaration>int global_function()</Declaration>
+
+/**
+ * \param x1 Aaa.
+*/
+extern void external_function(int x1);
+// CHECK: <Declaration>extern void external_function(int x1)</Declaration>
+
+/**
+ * \brief global variable;
+*/
+int global_variable;
+// CHECK: <Declaration>int global_variable</Declaration>
+
+/**
+ * \brief local variable;
+*/
+static int static_variable;
+// CHECK: <Declaration>static int static_variable</Declaration>
+
+/**
+ * \brief external variable
+*/
+extern int external_variable;
+// CHECK: <Declaration>extern int external_variable</Declaration>
+
+int global_function() {
+  /**
+   * \brief a local variable
+  */
+  int local = 10;
+  return local;
+}
+// CHECK: <Declaration>int global_function()</Declaration>
+// CHECK: <Declaration>int local = 10</Declaration>
+
+/**
+ * \brief initialized decl.
+*/
+int initialized_global = 100;
+// CHECK: <Declaration>int initialized_global = 100</Declaration>
+
+/**
+ * \brief typedef example
+*/
+typedef int INT_T;
+// CHECK: <Declaration>typedef int INT_T</Declaration>
+
+/**
+ * \brief aggregate type example
+*/
+struct S {
+/**
+ * \brief iS1;
+*/
+  int iS1;
+/**
+ * \brief dS1;
+*/
+  double dS1;
+};
+// CHECK: <Declaration>struct S {\n}</Declaration>
+// CHECK: <Declaration>int iS1</Declaration>
+// CHECK: <Declaration>double dS1</Declaration>
+
+/**
+ * \brief enum e;
+*/
+enum e {
+  One,
+/**
+ * \brief Two;
+*/
+  Two,
+  Three
+};
+// CHECK: <Declaration>enum e {\n}</Declaration>
+// CHECK: <Declaration>Two</Declaration>
+
+/**
+ *\brief block declaration
+*/
+int (^Block) (int i, int j);
+// CHECK: <Declaration>int (^Block)(int, int)</Declaration>
+
+/**
+ *\brief block declaration
+*/
+int (^Block1) (int i, int j) = ^(int i, int j) { return i + j; };
+// CHECK: <Declaration>int (^ Block1) (int, int) = ^ (int i, int j) {\n}</Declaration>
diff --git a/test/Index/overriding-method-comments.mm b/test/Index/overriding-method-comments.mm
index 1641e85ef5..899b31d801 100644
--- a/test/Index/overriding-method-comments.mm
+++ b/test/Index/overriding-method-comments.mm
@@ -19,7 +19,7 @@
 - (void)METH:(id)AAA;
 @end
 
-// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}overriding-method-comments.mm" line="[[@LINE-3]]" column="1"><Name>METH:</Name><USR>c:objc(cs)Root(im)METH:</USR><Declaration>- (void) METH:(id)AAA</Declaration><Parameters><Parameter><Name>AAA</Name><Index>0</Index><Direction isExplicit="1">in</Direction><Discussion><Para> ZZZ </Para></Discussion></Parameter></Parameters></Function>]
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}overriding-method-comments.mm" line="[[@LINE-3]]" column="1"><Name>METH:</Name><USR>c:objc(cs)Root(im)METH:</USR><Declaration>- (void) METH:(id)AAA;</Declaration><Parameters><Parameter><Name>AAA</Name><Index>0</Index><Direction isExplicit="1">in</Direction><Discussion><Para> ZZZ </Para></Discussion></Parameter></Parameters></Function>]
 
 @interface Sub : Root
 @end
@@ -28,13 +28,13 @@
 - (void)METH:(id)BBB;
 @end
 
-// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}overriding-method-comments.mm" line="[[@LINE-3]]" column="1"><Name>METH:</Name><USR>c:objc(cs)Root(im)METH:</USR><Declaration>- (void) METH:(id)BBB</Declaration><Parameters><Parameter><Name>BBB</Name><Index>0</Index><Direction isExplicit="1">in</Direction><Discussion><Para> ZZZ </Para></Discussion></Parameter></Parameters></Function>]
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}overriding-method-comments.mm" line="[[@LINE-3]]" column="1"><Name>METH:</Name><USR>c:objc(cs)Root(im)METH:</USR><Declaration>- (void) METH:(id)BBB;</Declaration><Parameters><Parameter><Name>BBB</Name><Index>0</Index><Direction isExplicit="1">in</Direction><Discussion><Para> ZZZ </Para></Discussion></Parameter></Parameters></Function>]
 
 @implementation Sub(CAT)
 - (void)METH:(id)III {}
 @end
 
-// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}overriding-method-comments.mm" line="[[@LINE-3]]" column="1"><Name>METH:</Name><USR>c:objc(cs)Root(im)METH:</USR><Declaration>- (void) METH:(id)III</Declaration><Parameters><Parameter><Name>III</Name><Index>0</Index><Direction isExplicit="1">in</Direction><Discussion><Para> ZZZ </Para></Discussion></Parameter></Parameters></Function>]
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}overriding-method-comments.mm" line="[[@LINE-3]]" column="1"><Name>METH:</Name><USR>c:objc(cs)Root(im)METH:</USR><Declaration>- (void) METH:(id)III;</Declaration><Parameters><Parameter><Name>III</Name><Index>0</Index><Direction isExplicit="1">in</Direction><Discussion><Para> ZZZ </Para></Discussion></Parameter></Parameters></Function>]
 
 @interface Redec : Root
 @end
@@ -48,13 +48,13 @@
 - (void)EXT_METH:(id)AAA : (double)BBB : (int)CCC;
 @end
 
-// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}overriding-method-comments.mm" line="[[@LINE-3]]" column="1"><Name>EXT_METH:::</Name><USR>c:objc(cs)Redec(im)EXT_METH:::</USR><Declaration>- (void) EXT_METH:(id)AAA :(double)BBB :(int)CCC</Declaration><Parameters><Parameter><Name>AAA</Name><Index>0</Index><Direction isExplicit="1">in</Direction><Discussion><Para> input value </Para></Discussion></Parameter><Parameter><Name>BBB</Name><Index>1</Index><Direction isExplicit="1">in</Direction><Discussion><Para> 2nd input value is double </Para></Discussion></Parameter><Parameter><Name>CCC</Name><Index>2</Index><Direction isExplicit="1">out</Direction><Discussion><Para> output value is int </Para></Discussion></Parameter></Parameters></Function>]
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}overriding-method-comments.mm" line="[[@LINE-3]]" column="1"><Name>EXT_METH:::</Name><USR>c:objc(cs)Redec(im)EXT_METH:::</USR><Declaration>- (void) EXT_METH:(id)AAA :(double)BBB :(int)CCC;</Declaration><Parameters><Parameter><Name>AAA</Name><Index>0</Index><Direction isExplicit="1">in</Direction><Discussion><Para> input value </Para></Discussion></Parameter><Parameter><Name>BBB</Name><Index>1</Index><Direction isExplicit="1">in</Direction><Discussion><Para> 2nd input value is double </Para></Discussion></Parameter><Parameter><Name>CCC</Name><Index>2</Index><Direction isExplicit="1">out</Direction><Discussion><Para> output value is int </Para></Discussion></Parameter></Parameters></Function>]
 
 @implementation Redec
 - (void)EXT_METH:(id)PPP : (double)QQQ : (int)RRR {}
 @end
 
-// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}overriding-method-comments.mm" line="[[@LINE-3]]" column="1"><Name>EXT_METH:::</Name><USR>c:objc(cs)Redec(im)EXT_METH:::</USR><Declaration>- (void) EXT_METH:(id)PPP :(double)QQQ :(int)RRR</Declaration><Parameters><Parameter><Name>PPP</Name><Index>0</Index><Direction isExplicit="1">in</Direction><Discussion><Para> input value </Para></Discussion></Parameter><Parameter><Name>QQQ</Name><Index>1</Index><Direction isExplicit="1">in</Direction><Discussion><Para> 2nd input value is double </Para></Discussion></Parameter><Parameter><Name>RRR</Name><Index>2</Index><Direction isExplicit="1">out</Direction><Discussion><Para> output value is int </Para></Discussion></Parameter></Parameters></Function>]
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}overriding-method-comments.mm" line="[[@LINE-3]]" column="1"><Name>EXT_METH:::</Name><USR>c:objc(cs)Redec(im)EXT_METH:::</USR><Declaration>- (void) EXT_METH:(id)PPP :(double)QQQ :(int)RRR;</Declaration><Parameters><Parameter><Name>PPP</Name><Index>0</Index><Direction isExplicit="1">in</Direction><Discussion><Para> input value </Para></Discussion></Parameter><Parameter><Name>QQQ</Name><Index>1</Index><Direction isExplicit="1">in</Direction><Discussion><Para> 2nd input value is double </Para></Discussion></Parameter><Parameter><Name>RRR</Name><Index>2</Index><Direction isExplicit="1">out</Direction><Discussion><Para> output value is int </Para></Discussion></Parameter></Parameters></Function>]
 
 struct Base {
   /// \brief Does something.
diff --git a/tools/libclang/CIndex.cpp b/tools/libclang/CIndex.cpp
index 3532abd363..177b3a6d51 100644
--- a/tools/libclang/CIndex.cpp
+++ b/tools/libclang/CIndex.cpp
@@ -21,6 +21,7 @@
 #include "CXTranslationUnit.h"
 #include "CXType.h"
 #include "CursorVisitor.h"
+#include "SimpleFormatContext.h"
 #include "clang/AST/StmtVisitor.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/Version.h"
@@ -61,6 +62,8 @@ CXTranslationUnit cxtu::MakeCXTranslationUnit(CIndexer *CIdx, ASTUnit *TU) {
   D->StringPool = createCXStringPool();
   D->Diagnostics = 0;
   D->OverridenCursorsPool = createOverridenCXCursorsPool();
+  D->FormatContext = 0;
+  D->FormatInMemoryUniqueId = 0;
   return D;
 }
 
@@ -2779,6 +2782,7 @@ void clang_disposeTranslationUnit(CXTranslationUnit CTUnit) {
     disposeCXStringPool(CTUnit->StringPool);
     delete static_cast<CXDiagnosticSetImpl *>(CTUnit->Diagnostics);
     disposeOverridenCXCursorsPool(CTUnit->OverridenCursorsPool);
+    delete static_cast<SimpleFormatContext*>(CTUnit->FormatContext);
     delete CTUnit;
   }
 }
diff --git a/tools/libclang/CMakeLists.txt b/tools/libclang/CMakeLists.txt
index 1426c42b46..69480db4fe 100644
--- a/tools/libclang/CMakeLists.txt
+++ b/tools/libclang/CMakeLists.txt
@@ -38,6 +38,7 @@ set(SOURCES
   Indexing.cpp
   IndexingContext.cpp
   IndexingContext.h
+  SimpleFormatContext.h
   ../../include/clang-c/Index.h
   )
 
@@ -54,6 +55,7 @@ set(LIBRARIES
   clangLex
   clangTooling
   clangBasic
+  clangFormat
   )
 
 set(GENERATED_HEADERS
diff --git a/tools/libclang/CXComment.cpp b/tools/libclang/CXComment.cpp
index 8c8fe74bba..070b8b8207 100644
--- a/tools/libclang/CXComment.cpp
+++ b/tools/libclang/CXComment.cpp
@@ -15,13 +15,17 @@
 #include "CXComment.h"
 #include "CXCursor.h"
 #include "CXString.h"
+#include "SimpleFormatContext.h"
 #include "clang/AST/CommentCommandTraits.h"
 #include "clang/AST/CommentVisitor.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/PrettyPrinter.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
+#include "clang/Format/Format.h"
+#include "clang/Lex/Lexer.h"
 #include <climits>
 
 using namespace clang;
@@ -856,8 +860,12 @@ public:
   CommentASTToXMLConverter(const FullComment *FC,
                            SmallVectorImpl<char> &Str,
                            const CommandTraits &Traits,
-                           const SourceManager &SM) :
-      FC(FC), Result(Str), Traits(Traits), SM(SM) { }
+                           const SourceManager &SM,
+                           SimpleFormatContext &RTC,
+                           unsigned FUID) :
+      FC(FC), Result(Str), Traits(Traits), SM(SM),
+      FormatRewriterContext(RTC),
+      FormatInMemoryUniqueId(FUID) { }
 
   // Inline content.
   void visitTextComment(const TextComment *C);
@@ -878,6 +886,10 @@ public:
 
   // Helpers.
   void appendToResultWithXMLEscaping(StringRef S);
+    
+  unsigned getFormatInMemoryUniqueId() { return FormatInMemoryUniqueId; }
+  SimpleFormatContext &getFormatRewriterContext()
+    { return FormatRewriterContext; }
 
 private:
   const FullComment *FC;
@@ -887,6 +899,8 @@ private:
 
   const CommandTraits &Traits;
   const SourceManager &SM;
+  SimpleFormatContext &FormatRewriterContext;
+  unsigned FormatInMemoryUniqueId;
 };
 
 void getSourceTextOfDeclaration(const DeclInfo *ThisDecl,
@@ -900,6 +914,43 @@ void getSourceTextOfDeclaration(const DeclInfo *ThisDecl,
   ThisDecl->CurrentDecl->print(OS, PPolicy,
                                /*Indentation*/0, /*PrintInstantiation*/true);
 }
+  
+void formatTextOfDeclaration(CommentASTToXMLConverter *C,
+                             const DeclInfo *DI,
+                             SmallString<128> &Declaration) {
+  // FIXME. This conditional is TEMPORARY. We don't want to break multiple
+  // large tests each time Format.cpp changes. This condition will
+  // go away and formatting will happen for all declarations.
+  if (getenv("LIBCLANG_ACTIVATE_FORMAT")) {
+    SimpleFormatContext &FormatRewriterContext =
+      C->getFormatRewriterContext();
+    // FIXME. formatting API expects null terminated input string.
+    // There might be more efficient way of doing this.
+    std::string StringDecl = Declaration.str();
+    
+    // Formatter specific code.
+    // Form a unique in memory buffer name.
+    llvm::SmallString<128> filename;
+    filename += "xmldecl";
+    filename += llvm::utostr(C->getFormatInMemoryUniqueId());
+    filename += ".xd";
+    FileID ID = FormatRewriterContext.createInMemoryFile(filename, StringDecl);
+    SourceLocation Start =
+      FormatRewriterContext.Sources.getLocForStartOfFile(ID).getLocWithOffset(0);
+    unsigned Length = Declaration.size();
+    
+    std::vector<CharSourceRange>
+      Ranges(1, CharSourceRange::getCharRange(Start, Start.getLocWithOffset(Length)));
+    ASTContext &Context = DI->CurrentDecl->getASTContext();
+    const LangOptions &LangOpts = Context.getLangOpts();
+    Lexer Lex(ID, FormatRewriterContext.Sources.getBuffer(ID),
+              FormatRewriterContext.Sources, LangOpts);
+    tooling::Replacements Replace =
+      reformat(format::getLLVMStyle(), Lex, FormatRewriterContext.Sources, Ranges);
+    applyAllReplacements(Replace, FormatRewriterContext.Rewrite);
+    Declaration = FormatRewriterContext.getRewrittenText(ID);
+  }
+}
 
 } // end unnamed namespace
 
@@ -1165,7 +1216,9 @@ void CommentASTToXMLConverter::visitFullComment(const FullComment *C) {
     Result << "<Declaration>";
     SmallString<128> Declaration;
     getSourceTextOfDeclaration(DI, Declaration);
+    formatTextOfDeclaration(this, DI, Declaration);
     appendToResultWithXMLEscaping(Declaration);
+    
     Result << "</Declaration>";
   }
 
@@ -1320,12 +1373,25 @@ CXString clang_FullComment_getAsXML(CXComment CXC) {
   const FullComment *FC = getASTNodeAs<FullComment>(CXC);
   if (!FC)
     return createCXString((const char *) 0);
-
+  ASTContext &Context = FC->getDeclInfo()->CurrentDecl->getASTContext();
   CXTranslationUnit TU = CXC.TranslationUnit;
   SourceManager &SM = static_cast<ASTUnit *>(TU->TUData)->getSourceManager();
+  
+  SimpleFormatContext *SFC =
+    static_cast<SimpleFormatContext*>(TU->FormatContext);
+  if (!SFC) {
+    SFC = new SimpleFormatContext(Context.getLangOpts());
+    TU->FormatContext = SFC;
+  }
+  else if ((TU->FormatInMemoryUniqueId % 10) == 0) {
+    delete SFC;
+    SFC = new SimpleFormatContext(Context.getLangOpts());
+    TU->FormatContext = SFC;
+  }
 
   SmallString<1024> XML;
-  CommentASTToXMLConverter Converter(FC, XML, getCommandTraits(CXC), SM);
+  CommentASTToXMLConverter Converter(FC, XML, getCommandTraits(CXC), SM,
+                                     *SFC, TU->FormatInMemoryUniqueId++);
   Converter.visit(FC);
   return createCXString(XML.str(), /* DupString = */ true);
 }
diff --git a/tools/libclang/CXTranslationUnit.h b/tools/libclang/CXTranslationUnit.h
index 37789aafb9..1c713bf2d6 100644
--- a/tools/libclang/CXTranslationUnit.h
+++ b/tools/libclang/CXTranslationUnit.h
@@ -21,6 +21,8 @@ struct CXTranslationUnitImpl {
   void *StringPool;
   void *Diagnostics;
   void *OverridenCursorsPool;
+  void *FormatContext;
+  unsigned FormatInMemoryUniqueId;
 };
 }
 
diff --git a/tools/libclang/Makefile b/tools/libclang/Makefile
index 93f63cf86c..01223e0116 100644
--- a/tools/libclang/Makefile
+++ b/tools/libclang/Makefile
@@ -21,7 +21,8 @@ USEDLIBS = clangARCMigrate.a clangRewriteCore.a clangRewriteFrontend.a \
 	   clangFrontend.a clangDriver.a \
 	   clangSerialization.a \
 	   clangParse.a clangSema.a clangEdit.a clangAnalysis.a \
-	   clangAST.a clangLex.a clangTooling.a clangBasic.a
+	   clangAST.a clangLex.a clangTooling.a clangBasic.a \
+	   clangFormat.a 
 
 include $(CLANG_LEVEL)/Makefile
 
diff --git a/tools/libclang/SimpleFormatContext.h b/tools/libclang/SimpleFormatContext.h
new file mode 100644
index 0000000000..f322e63d06
--- /dev/null
+++ b/tools/libclang/SimpleFormatContext.h
@@ -0,0 +1,73 @@
+//===--- SimpleFormatContext.h ----------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines a utility class for Rewriter related tests.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_SIMPLE_FORM_CONTEXT_H
+#define LLVM_CLANG_SIMPLE_FORM_CONTEXT_H
+
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/DiagnosticOptions.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Rewrite/Core/Rewriter.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace clang {
+
+/// \brief A small class to be used by libclang clients to format
+/// a declaration string in memory. This object is instantiated once
+/// and used each time a formatting is needed.
+class SimpleFormatContext {
+ public:
+  SimpleFormatContext(LangOptions Options)
+      : DiagOpts(new DiagnosticOptions()),
+        Diagnostics(new DiagnosticsEngine(new DiagnosticIDs, 
+                                          DiagOpts.getPtr())),
+        Files((FileSystemOptions())),
+        Sources(*Diagnostics, Files),
+        Rewrite(Sources, Options) {
+    Diagnostics->setClient(new IgnoringDiagConsumer, true);
+  }
+
+  ~SimpleFormatContext() { }
+
+  FileID createInMemoryFile(StringRef Name, StringRef Content) {
+    const llvm::MemoryBuffer *Source =
+      llvm::MemoryBuffer::getMemBuffer(Content);
+    const FileEntry *Entry =
+      Files.getVirtualFile(Name, Source->getBufferSize(), 0);
+    Sources.overrideFileContents(Entry, Source, true);
+    assert(Entry != NULL);
+    return Sources.createFileID(Entry, SourceLocation(), SrcMgr::C_User);
+  }
+
+  std::string getRewrittenText(FileID ID) {
+    std::string Result;
+    llvm::raw_string_ostream OS(Result);
+    Rewrite.getEditBuffer(ID).write(OS);
+    OS.flush();
+    return Result;
+  }
+
+  llvm::IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts;
+  llvm::IntrusiveRefCntPtr<DiagnosticsEngine> Diagnostics;
+  FileManager Files;
+  SourceManager Sources;
+  Rewriter Rewrite;
+};
+
+} // end namespace clang
+
+#endif
diff --git a/unittests/AST/DeclPrinterTest.cpp b/unittests/AST/DeclPrinterTest.cpp
index 844b9a49e1..e9fc6fdea3 100644
--- a/unittests/AST/DeclPrinterTest.cpp
+++ b/unittests/AST/DeclPrinterTest.cpp
@@ -1234,6 +1234,6 @@ TEST(DeclPrinter, TestObjCMethod1) {
     "@end\n",
     namedDecl(hasName("A:inRange:"),
               hasDescendant(namedDecl(hasName("printThis")))).bind("id"),
-    "- (int) A:(id)anObject inRange:(long)range"));
+    "- (int) A:(id)anObject inRange:(long)range;"));
 }