Index: include/clang/Basic/LangOptions.def
===================================================================
--- include/clang/Basic/LangOptions.def
+++ include/clang/Basic/LangOptions.def
@@ -85,6 +85,7 @@
 LANGOPT(C17               , 1, 0, "C17")
 LANGOPT(MSVCCompat        , 1, 0, "Microsoft Visual C++ full compatibility mode")
 LANGOPT(MicrosoftExt      , 1, 0, "Microsoft C++ extensions")
+BENIGN_LANGOPT(MicrosoftPragmaRegion, 1, 0, "region pragma support")
 LANGOPT(AsmBlocks         , 1, 0, "Microsoft inline asm blocks")
 LANGOPT(Borland           , 1, 0, "Borland extensions")
 LANGOPT(CPlusPlus         , 1, 0, "C++")
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -2160,6 +2160,7 @@
 
   Opts.MSVCCompat = Args.hasArg(OPT_fms_compatibility);
   Opts.MicrosoftExt = Opts.MSVCCompat || Args.hasArg(OPT_fms_extensions);
+  Opts.MicrosoftPragmaRegion = Opts.MicrosoftExt || T.isPS4();
   Opts.AsmBlocks = Args.hasArg(OPT_fasm_blocks) || Opts.MicrosoftExt;
   Opts.MSCompatibilityVersion = 0;
   if (const Arg *A = Args.getLastArg(OPT_fms_compatibility_version)) {
Index: lib/Lex/Pragma.cpp
===================================================================
--- lib/Lex/Pragma.cpp
+++ lib/Lex/Pragma.cpp
@@ -1781,6 +1781,10 @@
   if (LangOpts.MicrosoftExt) {
     AddPragmaHandler(new PragmaWarningHandler());
     AddPragmaHandler(new PragmaIncludeAliasHandler());
+  }
+
+  // Region support.
+  if (LangOpts.MicrosoftPragmaRegion) {
     AddPragmaHandler(new PragmaRegionHandler("region"));
     AddPragmaHandler(new PragmaRegionHandler("endregion"));
   }
Index: test/Frontend/region-pragmas.c
===================================================================
--- test/Frontend/region-pragmas.c
+++ test/Frontend/region-pragmas.c
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -triple x86_64-scei-ps4 -Wall -verify %s
+// RUN: %clang_cc1 -fms-compatibility -Wall -verify %s
+// RUN: %clang_cc1 -Wall -Wno-unknown-pragmas -verify %s
+// expected-no-diagnostics
+
+#pragma region foo
+#pragma endregion foo