Index: include/clang/Format/Format.h
===================================================================
--- include/clang/Format/Format.h
+++ include/clang/Format/Format.h
@@ -326,6 +326,10 @@
   /// a zero-length name is assumed.
   bool Cpp11BracedListStyle;
 
+  /// \brief Analyze the formatted file for the most used line ending. (``\r\n``
+  /// or ``\n``) ``UseCRLF`` is then used only as fallback.
+  bool DeriveLineEnding;
+
   /// \brief If ``true``, analyze the formatted file for the most common
   /// alignment of ``&`` and ``*``. ``PointerAlignment`` is then used only as
   /// fallback.
@@ -605,6 +609,9 @@
     UT_Always
   };
 
+  /// \brief Use ``\r\n`` instead of ``\n`` for line breaks.
+  bool UseCRLF;
+
   /// \brief The way to use tab characters in the resulting file.
   UseTabStyle UseTab;
 
@@ -661,6 +668,7 @@
                R.ConstructorInitializerIndentWidth &&
            ContinuationIndentWidth == R.ContinuationIndentWidth &&
            Cpp11BracedListStyle == R.Cpp11BracedListStyle &&
+           DeriveLineEnding == R.DeriveLineEnding &&
            DerivePointerAlignment == R.DerivePointerAlignment &&
            DisableFormat == R.DisableFormat &&
            ExperimentalAutoDetectBinPacking ==
@@ -698,7 +706,7 @@
            SpacesInParentheses == R.SpacesInParentheses &&
            SpacesInSquareBrackets == R.SpacesInSquareBrackets &&
            Standard == R.Standard && TabWidth == R.TabWidth &&
-           UseTab == R.UseTab &&
+           UseTab == R.UseTab && UseCRLF == R.UseCRLF &&
            JavaScriptQuotes == R.JavaScriptQuotes;
   }
 };
Index: lib/Format/Format.cpp
===================================================================
--- lib/Format/Format.cpp
+++ lib/Format/Format.cpp
@@ -294,6 +294,7 @@
                    Style.ConstructorInitializerIndentWidth);
     IO.mapOptional("ContinuationIndentWidth", Style.ContinuationIndentWidth);
     IO.mapOptional("Cpp11BracedListStyle", Style.Cpp11BracedListStyle);
+    IO.mapOptional("DeriveLineEnding", Style.DeriveLineEnding);
     IO.mapOptional("DerivePointerAlignment", Style.DerivePointerAlignment);
     IO.mapOptional("DisableFormat", Style.DisableFormat);
     IO.mapOptional("ExperimentalAutoDetectBinPacking",
@@ -343,6 +344,7 @@
     IO.mapOptional("SpacesInSquareBrackets", Style.SpacesInSquareBrackets);
     IO.mapOptional("Standard", Style.Standard);
     IO.mapOptional("TabWidth", Style.TabWidth);
+    IO.mapOptional("UseCRLF", Style.UseCRLF);
     IO.mapOptional("UseTab", Style.UseTab);
     IO.mapOptional("JavaScriptQuotes", Style.JavaScriptQuotes);
   }
@@ -510,6 +512,7 @@
   LLVMStyle.ConstructorInitializerIndentWidth = 4;
   LLVMStyle.ContinuationIndentWidth = 4;
   LLVMStyle.Cpp11BracedListStyle = true;
+  LLVMStyle.DeriveLineEnding = true;
   LLVMStyle.DerivePointerAlignment = false;
   LLVMStyle.ExperimentalAutoDetectBinPacking = false;
   LLVMStyle.ForEachMacros.push_back("foreach");
@@ -532,6 +535,7 @@
   LLVMStyle.PointerAlignment = FormatStyle::PAS_Right;
   LLVMStyle.SpacesBeforeTrailingComments = 1;
   LLVMStyle.Standard = FormatStyle::LS_Cpp11;
+  LLVMStyle.UseCRLF = false;
   LLVMStyle.UseTab = FormatStyle::UT_Never;
   LLVMStyle.JavaScriptQuotes = FormatStyle::JSQS_Leave;
   LLVMStyle.ReflowComments = true;
@@ -1448,8 +1452,11 @@
   Formatter(const FormatStyle &Style, SourceManager &SourceMgr, FileID ID,
             ArrayRef<CharSourceRange> Ranges)
       : Style(Style), ID(ID), SourceMgr(SourceMgr),
-        Whitespaces(SourceMgr, Style,
-                    inputUsesCRLF(SourceMgr.getBufferData(ID))),
+        Whitespaces(
+            SourceMgr, Style,
+            Style.DeriveLineEnding
+                ? inputUsesCRLF(SourceMgr.getBufferData(ID), Style.UseCRLF)
+                : Style.UseCRLF),
         Ranges(Ranges.begin(), Ranges.end()), UnwrappedLines(1),
         Encoding(encoding::detectEncoding(SourceMgr.getBufferData(ID))) {
     DEBUG(llvm::dbgs() << "File encoding: "
@@ -1733,8 +1740,10 @@
     return false;
   }
 
-  static bool inputUsesCRLF(StringRef Text) {
-    return Text.count('\r') * 2 > Text.count('\n');
+  static bool inputUsesCRLF(StringRef Text, bool DefaultToCRLF) {
+    size_t LF = Text.count('\n');
+    size_t CR = Text.count('\r') * 2;
+    return LF == CR ? DefaultToCRLF : CR > LF;
   }
 
   bool
Index: unittests/Format/FormatTest.cpp
===================================================================
--- unittests/Format/FormatTest.cpp
+++ unittests/Format/FormatTest.cpp
@@ -9908,6 +9908,7 @@
   CHECK_PARSE_BOOL(BreakConstructorInitializersBeforeComma);
   CHECK_PARSE_BOOL(BreakStringLiterals);
   CHECK_PARSE_BOOL(ConstructorInitializerAllOnOneLineOrOnePerLine);
+  CHECK_PARSE_BOOL(DeriveLineEnding);
   CHECK_PARSE_BOOL(DerivePointerAlignment);
   CHECK_PARSE_BOOL_FIELD(DerivePointerAlignment, "DerivePointerBinding");
   CHECK_PARSE_BOOL(DisableFormat);
@@ -9927,6 +9928,7 @@
   CHECK_PARSE_BOOL(SpacesInCStyleCastParentheses);
   CHECK_PARSE_BOOL(SpaceAfterCStyleCast);
   CHECK_PARSE_BOOL(SpaceBeforeAssignmentOperators);
+  CHECK_PARSE_BOOL(UseCRLF);
 
   CHECK_PARSE_NESTED_BOOL(BraceWrapping, AfterClass);
   CHECK_PARSE_NESTED_BOOL(BraceWrapping, AfterControlStatement);
@@ -11003,6 +11005,94 @@
                    "should not introduce\r\n"
                    "an extra carriage return\r\n"
                    "*/\r\n"));
+
+  FormatStyle style = getLLVMStyle();
+
+  style.DeriveLineEnding = true;
+  style.UseCRLF = false;
+  EXPECT_EQ("union FooBarBazQux {\n"
+            "  int foo;\n"
+            "  int bar;\n"
+            "  int baz;\n"
+            "};",
+            format("union FooBarBazQux {\r\n"
+                   "  int foo;\n"
+                   "  int bar;\r\n"
+                   "  int baz;\n"
+                   "};",
+                   style));
+  style.UseCRLF = true;
+  EXPECT_EQ("union FooBarBazQux {\r\n"
+            "  int foo;\r\n"
+            "  int bar;\r\n"
+            "  int baz;\r\n"
+            "};",
+            format("union FooBarBazQux {\r\n"
+                   "  int foo;\n"
+                   "  int bar;\r\n"
+                   "  int baz;\n"
+                   "};",
+                   style));
+
+  style.DeriveLineEnding = false;
+  style.UseCRLF = false;
+  EXPECT_EQ("union FooBarBazQux {\n"
+            "  int foo;\n"
+            "  int bar;\n"
+            "  int baz;\n"
+            "  int qux;\n"
+            "};",
+            format("union FooBarBazQux {\r\n"
+                   "  int foo;\n"
+                   "  int bar;\r\n"
+                   "  int baz;\n"
+                   "  int qux;\r\n"
+                   "};",
+                   style));
+  style.UseCRLF = true;
+  EXPECT_EQ("union FooBarBazQux {\r\n"
+            "  int foo;\r\n"
+            "  int bar;\r\n"
+            "  int baz;\r\n"
+            "  int qux;\r\n"
+            "};",
+            format("union FooBarBazQux {\r\n"
+                   "  int foo;\n"
+                   "  int bar;\r\n"
+                   "  int baz;\n"
+                   "  int qux;\n"
+                   "};",
+                   style));
+
+  style.DeriveLineEnding = true;
+  style.UseCRLF = false;
+  EXPECT_EQ("union FooBarBazQux {\r\n"
+            "  int foo;\r\n"
+            "  int bar;\r\n"
+            "  int baz;\r\n"
+            "  int qux;\r\n"
+            "};",
+            format("union FooBarBazQux {\r\n"
+                   "  int foo;\n"
+                   "  int bar;\r\n"
+                   "  int baz;\n"
+                   "  int qux;\r\n"
+                   "};",
+                   style));
+  style.UseCRLF = true;
+  EXPECT_EQ("union FooBarBazQux {\n"
+            "  int foo;\n"
+            "  int bar;\n"
+            "  int baz;\n"
+            "  int qux;\n"
+            "};",
+            format("union FooBarBazQux {\r\n"
+                   "  int foo;\n"
+                   "  int bar;\r\n"
+                   "  int baz;\n"
+                   "  int qux;\n"
+                   "};",
+                   style));
 }
 
 TEST_F(FormatTest, MunchSemicolonAfterBlocks) {