diff --git a/clang/include/clang/Format/Format.h b/clang/include/clang/Format/Format.h
--- a/clang/include/clang/Format/Format.h
+++ b/clang/include/clang/Format/Format.h
@@ -1217,6 +1217,10 @@
   /// \endcode
   bool Cpp11BracedListStyle;
 
+  /// \brief Analyze the formatted file for the most used line ending (``\r\n``
+  /// or ``\n``). ``UseCRLF`` is only used as a fallback if none can be derived.
+  bool DeriveLineEnding;
+
   /// If ``true``, analyze the formatted file for the most common
   /// alignment of ``&`` and ``*``.
   /// Pointer and reference alignment styles are going to be updated according
@@ -2032,6 +2036,10 @@
     UT_Always
   };
 
+  /// \brief Use ``\r\n`` instead of ``\n`` for line breaks.
+  /// Also used as fallback if ``DeriveLineEnding`` is true.
+  bool UseCRLF;
+
   /// The way to use tab characters in the resulting file.
   UseTabStyle UseTab;
 
@@ -2079,6 +2087,7 @@
                R.ConstructorInitializerIndentWidth &&
            ContinuationIndentWidth == R.ContinuationIndentWidth &&
            Cpp11BracedListStyle == R.Cpp11BracedListStyle &&
+           DeriveLineEnding == R.DeriveLineEnding &&
            DerivePointerAlignment == R.DerivePointerAlignment &&
            DisableFormat == R.DisableFormat &&
            ExperimentalAutoDetectBinPacking ==
@@ -2143,6 +2152,7 @@
            SpacesInSquareBrackets == R.SpacesInSquareBrackets &&
            Standard == R.Standard && TabWidth == R.TabWidth &&
            StatementMacros == R.StatementMacros && UseTab == R.UseTab &&
+           UseCRLF == R.UseCRLF &&
            TypenameMacros == R.TypenameMacros;
   }
 
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -467,6 +467,7 @@
                    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",
@@ -546,6 +547,7 @@
     IO.mapOptional("StatementMacros", Style.StatementMacros);
     IO.mapOptional("TabWidth", Style.TabWidth);
     IO.mapOptional("TypenameMacros", Style.TypenameMacros);
+    IO.mapOptional("UseCRLF", Style.UseCRLF);
     IO.mapOptional("UseTab", Style.UseTab);
   }
 };
@@ -762,6 +764,7 @@
   LLVMStyle.ConstructorInitializerIndentWidth = 4;
   LLVMStyle.ContinuationIndentWidth = 4;
   LLVMStyle.Cpp11BracedListStyle = true;
+  LLVMStyle.DeriveLineEnding = true;
   LLVMStyle.DerivePointerAlignment = false;
   LLVMStyle.ExperimentalAutoDetectBinPacking = false;
   LLVMStyle.FixNamespaceComments = true;
@@ -792,6 +795,7 @@
   LLVMStyle.PointerAlignment = FormatStyle::PAS_Right;
   LLVMStyle.SpacesBeforeTrailingComments = 1;
   LLVMStyle.Standard = FormatStyle::LS_Latest;
+  LLVMStyle.UseCRLF = false;
   LLVMStyle.UseTab = FormatStyle::UT_Never;
   LLVMStyle.ReflowComments = true;
   LLVMStyle.SpacesInParentheses = false;
@@ -1350,7 +1354,10 @@
 
     WhitespaceManager Whitespaces(
         Env.getSourceManager(), Style,
-        inputUsesCRLF(Env.getSourceManager().getBufferData(Env.getFileID())));
+        Style.DeriveLineEnding ?
+          inputUsesCRLF(Env.getSourceManager().getBufferData(Env.getFileID()),
+                        Style.UseCRLF) :
+          Style.UseCRLF);
     ContinuationIndenter Indenter(Style, Tokens.getKeywords(),
                                   Env.getSourceManager(), Whitespaces, Encoding,
                                   BinPackInconclusiveFunctions);
@@ -1371,8 +1378,10 @@
   }
 
 private:
-  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
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -12500,6 +12500,7 @@
   CHECK_PARSE_BOOL(BreakStringLiterals);
   CHECK_PARSE_BOOL(CompactNamespaces);
   CHECK_PARSE_BOOL(ConstructorInitializerAllOnOneLineOrOnePerLine);
+  CHECK_PARSE_BOOL(DeriveLineEnding);
   CHECK_PARSE_BOOL(DerivePointerAlignment);
   CHECK_PARSE_BOOL_FIELD(DerivePointerAlignment, "DerivePointerBinding");
   CHECK_PARSE_BOOL(DisableFormat);
@@ -12528,6 +12529,7 @@
   CHECK_PARSE_BOOL(SpaceBeforeCtorInitializerColon);
   CHECK_PARSE_BOOL(SpaceBeforeInheritanceColon);
   CHECK_PARSE_BOOL(SpaceBeforeRangeBasedForLoopColon);
+  CHECK_PARSE_BOOL(UseCRLF);
 
   CHECK_PARSE_NESTED_BOOL(BraceWrapping, AfterCaseLabel);
   CHECK_PARSE_NESTED_BOOL(BraceWrapping, AfterClass);
@@ -14056,6 +14058,94 @@
             format("/*\r\n"
                    "    \r\r\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) {