Index: lib/Format/Format.cpp
===================================================================
--- lib/Format/Format.cpp
+++ lib/Format/Format.cpp
@@ -2001,6 +2001,7 @@
   LangOpts.ObjC2 = 1;
   LangOpts.MicrosoftExt = 1;    // To get kw___try, kw___finally.
   LangOpts.DeclSpecKeyword = 1; // To get __declspec.
+  LangOpts.CoroutinesTS = Style.isCpp();
   return LangOpts;
 }
 
Index: lib/Format/TokenAnnotator.cpp
===================================================================
--- lib/Format/TokenAnnotator.cpp
+++ lib/Format/TokenAnnotator.cpp
@@ -609,6 +609,8 @@
         if (CurrentToken && CurrentToken->is(Keywords.kw_await))
           next();
       }
+      if (CurrentToken && CurrentToken->is(tok::kw_co_await))
+          next();
       Contexts.back().ColonIsForRangeExpr = true;
       next();
       if (!parseParens())
@@ -2245,6 +2247,11 @@
   if (Right.is(tok::l_paren)) {
     if (Left.is(tok::r_paren) && Left.is(TT_AttributeParen))
       return true;
+    if (Left.is(tok::kw_co_await) && Left.Previous &&
+        Left.Previous->is(tok::kw_operator))
+      return false;
+    if (Left.isOneOf(tok::kw_co_await, tok::kw_co_yield, tok::kw_co_return))
+      return true;
     return Line.Type == LT_ObjCDecl || Left.is(tok::semi) ||
            (Style.SpaceBeforeParens != FormatStyle::SBPO_Never &&
             (Left.isOneOf(tok::kw_if, tok::pp_elif, tok::kw_for, tok::kw_while,
@@ -2292,6 +2299,18 @@
   if (Style.isCpp()) {
     if (Left.is(tok::kw_operator))
       return Right.is(tok::coloncolon);
+    // for await ( ...
+    if (Right.is(tok::l_paren) && Left.is(tok::kw_co_await) &&
+        Left.Previous && Left.Previous->is(tok::kw_for))
+      return true;
+    if (Right.is(tok::l_paren) && Left.is(tok::kw_co_await) &&
+        Left.Previous && Left.Previous->is(tok::kw_operator))
+      return false;
+    if (Right.is(tok::star) && Left.is(tok::kw_co_yield))
+      return false;
+    if (Right.isOneOf(tok::l_brace, tok::l_square) &&
+        Left.isOneOf(tok::kw_co_yield, tok::kw_co_await))
+      return true;
   } else if (Style.Language == FormatStyle::LK_Proto ||
              Style.Language == FormatStyle::LK_TextProto) {
     if (Right.is(tok::period) &&
Index: lib/Format/UnwrappedLineParser.cpp
===================================================================
--- lib/Format/UnwrappedLineParser.cpp
+++ lib/Format/UnwrappedLineParser.cpp
@@ -1700,6 +1700,8 @@
   if (Style.Language == FormatStyle::LK_JavaScript &&
       FormatTok->is(Keywords.kw_await))
     nextToken();
+  if (Style.isCpp() && FormatTok->is(tok::kw_co_await))
+    nextToken();
   if (FormatTok->Tok.is(tok::l_paren))
     parseParens();
   if (FormatTok->Tok.is(tok::l_brace)) {
Index: unittests/Format/FormatTest.cpp
===================================================================
--- unittests/Format/FormatTest.cpp
+++ unittests/Format/FormatTest.cpp
@@ -11085,6 +11085,40 @@
   EXPECT_EQ("auto c = u8'a';", format("auto c = u8'a';"));
 }
 
+TEST_F(FormatTest, CoawaitForRangeCpp11) {
+  EXPECT_EQ("for co_await (auto x : range())\n  ;",
+            format("for co_await(auto x : range());"));
+}
+
+TEST_F(FormatTest, Coawait) {
+  EXPECT_EQ("int x = co_await foo();",
+            format("int x = co_await foo();"));
+  EXPECT_EQ("int x = (co_await foo());",
+            format("int x = (co_await foo());"));
+  EXPECT_EQ("co_await (42);",
+            format("co_await(42);"));
+  EXPECT_EQ("void operator co_await(int);",
+            format("void operator co_await (int);"));
+}
+
+TEST_F(FormatTest, Coyield) {
+  EXPECT_EQ("int x = co_yield foo();",
+            format("int x = co_yield foo();"));
+  EXPECT_EQ("int x = (co_yield foo());",
+            format("int x = (co_yield foo());"));
+  EXPECT_EQ("co_yield (42);",
+            format("co_yield(42);"));
+}
+
+TEST_F(FormatTest, Coreturn) {
+  EXPECT_EQ("int x = co_return foo();",
+            format("int x = co_return foo();"));
+  EXPECT_EQ("int x = (co_return foo());",
+            format("int x = (co_return foo());"));
+  EXPECT_EQ("co_return (42);",
+            format("co_return(42);"));
+}
+
 } // end namespace
 } // end namespace format
 } // end namespace clang