Index: cfe/trunk/CMakeLists.txt
===================================================================
--- cfe/trunk/CMakeLists.txt
+++ cfe/trunk/CMakeLists.txt
@@ -212,6 +212,12 @@
 set(ENABLE_X86_RELAX_RELOCATIONS OFF CACHE BOOL
     "enable x86 relax relocations by default")
 
+# TODO: verify the values against LangStandards.def?
+set(CLANG_DEFAULT_STD_C "" CACHE STRING
+  "Default standard to use for C/ObjC code (IDENT from LangStandards.def, empty for platform default)")
+set(CLANG_DEFAULT_STD_CXX "" CACHE STRING
+  "Default standard to use for C++/ObjC++ code (IDENT from LangStandards.def, empty for platform default)")
+
 set(CLANG_DEFAULT_LINKER "" CACHE STRING
   "Default linker to use (linker name or absolute path, empty for platform default)")
 
Index: cfe/trunk/include/clang/Config/config.h.cmake
===================================================================
--- cfe/trunk/include/clang/Config/config.h.cmake
+++ cfe/trunk/include/clang/Config/config.h.cmake
@@ -11,6 +11,12 @@
 /* Default linker to use. */
 #define CLANG_DEFAULT_LINKER "${CLANG_DEFAULT_LINKER}"
 
+/* Default C/ObjC standard to use. */
+#cmakedefine CLANG_DEFAULT_STD_C LangStandard::lang_${CLANG_DEFAULT_STD_C}
+
+/* Default C++/ObjC++ standard to use. */
+#cmakedefine CLANG_DEFAULT_STD_CXX LangStandard::lang_${CLANG_DEFAULT_STD_CXX}
+
 /* Default C++ stdlib to use. */
 #define CLANG_DEFAULT_CXX_STDLIB "${CLANG_DEFAULT_CXX_STDLIB}"
 
Index: cfe/trunk/lib/Frontend/CompilerInvocation.cpp
===================================================================
--- cfe/trunk/lib/Frontend/CompilerInvocation.cpp
+++ cfe/trunk/lib/Frontend/CompilerInvocation.cpp
@@ -1809,18 +1809,30 @@
       break;
     case InputKind::Asm:
     case InputKind::C:
+#if defined(CLANG_DEFAULT_STD_C)
+      LangStd = CLANG_DEFAULT_STD_C;
+#else
       // The PS4 uses C99 as the default C standard.
       if (T.isPS4())
         LangStd = LangStandard::lang_gnu99;
       else
         LangStd = LangStandard::lang_gnu11;
+#endif
       break;
     case InputKind::ObjC:
+#if defined(CLANG_DEFAULT_STD_C)
+      LangStd = CLANG_DEFAULT_STD_C;
+#else
       LangStd = LangStandard::lang_gnu11;
+#endif
       break;
     case InputKind::CXX:
     case InputKind::ObjCXX:
+#if defined(CLANG_DEFAULT_STD_CXX)
+      LangStd = CLANG_DEFAULT_STD_CXX;
+#else
       LangStd = LangStandard::lang_gnucxx14;
+#endif
       break;
     case InputKind::RenderScript:
       LangStd = LangStandard::lang_c99;