Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -543,6 +543,8 @@
 -----------------------
 - Clang now permits specifying ``--config=`` multiple times, to load multiple
   configuration files.
+- Clang now deprecates the ``-fcoroutines-ts`` flag and the flag will be
+  removed in LLVM17. Please use C++20 Coroutines instead.
 
 Removed Compiler Flags
 -------------------------
Index: clang/include/clang/Basic/DiagnosticDriverKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -627,6 +627,11 @@
   "command line to use the libc++ standard library instead">,
   InGroup<DiagGroup<"stdlibcxx-not-found">>;
 
+def warn_deperecated_fcoroutines_ts_flag : Warning<
+  "the \"-fcoroutines-ts\" flag is deprecated and it will be removed in LLVM17; "
+  "use C++20 Coroutines instead">,
+  InGroup<DeprecatedExperimentalCoroutine>;
+
 def err_drv_cannot_mix_options : Error<"cannot specify '%1' along with '%0'">;
 
 def err_drv_invalid_object_mode : Error<
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -6449,6 +6449,7 @@
   if (Args.hasFlag(options::OPT_fcoroutines_ts, options::OPT_fno_coroutines_ts,
                    false) &&
       types::isCXX(InputType)) {
+    D.Diag(diag::warn_deperecated_fcoroutines_ts_flag);
     CmdArgs.push_back("-fcoroutines-ts");
   }
 
Index: clang/test/Driver/coroutines.cpp
===================================================================
--- clang/test/Driver/coroutines.cpp
+++ clang/test/Driver/coroutines.cpp
@@ -5,5 +5,6 @@
 
 // RUN: %clang -fcoroutines-ts -### %s 2>&1 | FileCheck -check-prefix=CHECK-HAS-CORO  %s
 // RUN: %clang -fno-coroutines-ts -fcoroutines-ts -### %s 2>&1 | FileCheck -check-prefix=CHECK-HAS-CORO %s
+// CHECK-HAS-CORO: the "-fcoroutines-ts" flag is deprecated and it will be removed in LLVM17; use C++20 Coroutines instead
 // CHECK-HAS-CORO: -fcoroutines-ts