Index: clang/include/clang/Basic/OpenCLExtensions.def
===================================================================
--- clang/include/clang/Basic/OpenCLExtensions.def
+++ clang/include/clang/Basic/OpenCLExtensions.def
@@ -58,7 +58,6 @@
 OPENCLEXT_INTERNAL(cles_khr_int64, 110, ~0U)
 
 // OpenCL 1.2.
-OPENCLEXT_INTERNAL(cl_khr_depth_images, 120, ~0U)
 OPENCLEXT_INTERNAL(cl_khr_gl_msaa_sharing, 120, ~0U)
 
 // OpenCL 2.0.
Index: clang/include/clang/Basic/TargetInfo.h
===================================================================
--- clang/include/clang/Basic/TargetInfo.h
+++ clang/include/clang/Basic/TargetInfo.h
@@ -829,6 +829,9 @@
   virtual void getTargetDefines(const LangOptions &Opts,
                                 MacroBuilder &Builder) const = 0;
 
+  /// Appends the \#define for supported extensions.
+  virtual void getOpenCLExtensionDefines(const LangOptions &Opts,
+                                MacroBuilder &Builder) const;
 
   /// Return information about target-specific builtins for
   /// the current primary target, and info about which builtins are non-portable
Index: clang/lib/Basic/Targets.cpp
===================================================================
--- clang/lib/Basic/Targets.cpp
+++ clang/lib/Basic/Targets.cpp
@@ -705,3 +705,21 @@
 
   return Target.release();
 }
+
+void TargetInfo::getOpenCLExtensionDefines(const LangOptions &Opts,
+                                           MacroBuilder &Builder) const {
+  // Add macros for extension that this target supports.
+  auto defineExtMacro = [&](llvm::StringRef Ext) {
+    if (getSupportedOpenCLOpts().isSupported(Ext, Opts))
+      Builder.defineMacro(Ext);
+  };
+
+#define OPENCLEXT(Ext) defineExtMacro(#Ext);
+#include "clang/Basic/OpenCLExtensions.def"
+
+  // Here we could define macros that are available unconditionally.
+  // Ideally only extensions that are implemented in the frontend or
+  // macros that can't be added in the implicit headers should be
+  // added here.
+  Builder.defineMacro("__opencl_c_int64");
+}
Index: clang/lib/Frontend/InitPreprocessor.cpp
===================================================================
--- clang/lib/Frontend/InitPreprocessor.cpp
+++ clang/lib/Frontend/InitPreprocessor.cpp
@@ -1111,10 +1111,8 @@
 
   // OpenCL definitions.
   if (LangOpts.OpenCL) {
-#define OPENCLEXT(Ext)                                                         \
-  if (TI.getSupportedOpenCLOpts().isSupported(#Ext, LangOpts))                 \
-    Builder.defineMacro(#Ext);
-#include "clang/Basic/OpenCLExtensions.def"
+    // Add OpenCL #defines for supported extensions. 
+    TI.getOpenCLExtensionDefines(LangOpts, Builder);
 
     if (TI.getTriple().isSPIR())
       Builder.defineMacro("__IMAGE_SUPPORT__");
Index: clang/lib/Headers/opencl-c.h
===================================================================
--- clang/lib/Headers/opencl-c.h
+++ clang/lib/Headers/opencl-c.h
@@ -11,7 +11,8 @@
 
 #include "opencl-c-base.h"
 
-#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ == CL_VERSION_2_0) || \
+    (__OPENCL_C_VERSION__ >= CL_VERSION_1_2 && defined(__SPIR__) && !defined(__undef_cl_khr_depth_images))
 #ifndef cl_khr_depth_images
 #define cl_khr_depth_images
 #endif //cl_khr_depth_images
Index: clang/test/Headers/opencl-c-header.cl
===================================================================
--- clang/test/Headers/opencl-c-header.cl
+++ clang/test/Headers/opencl-c-header.cl
@@ -95,3 +95,16 @@
 #pragma OPENCL EXTENSION cl_intel_planar_yuv : enable
 
 // CHECK-MOD: Reading modules
+
+// Check predefined extension macros
+
+#if defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ == 200 || \
+     (__OPENCL_C_VERSION__ >= 120 && defined(__SPIR__) && !defined(__undef_cl_khr_depth_images)) 
+#ifndef cl_khr_depth_images
+#error "Missing cl_khr_depth_images define"
+#endif
+#else
+#ifdef cl_khr_depth_images
+#error "Incorrect cl_khr_depth_images define"
+#endif
+#endif
Index: clang/test/SemaOpenCL/extension-version.cl
===================================================================
--- clang/test/SemaOpenCL/extension-version.cl
+++ clang/test/SemaOpenCL/extension-version.cl
@@ -9,11 +9,11 @@
 // RUN: %clang_cc1 -x cl -cl-std=CL2.0 %s -verify -triple spir-unknown-unknown -Wpedantic-core-features -DTEST_CORE_FEATURES
 // RUN: %clang_cc1 -x cl -cl-std=clc++ %s -verify -triple spir-unknown-unknown -Wpedantic-core-features -DTEST_CORE_FEATURES
 
-#if (defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ >= 200) && !defined(TEST_CORE_FEATURES)
-// expected-no-diagnostics
+// Extensions in all versions
+#ifndef __opencl_c_int64
+#error "Missing __opencl_c_int64 predefined macro"
 #endif
 
-// Extensions in all versions
 #ifndef cl_clang_storage_class_specifiers
 #error "Missing cl_clang_storage_class_specifiers define"
 #endif
@@ -167,17 +167,14 @@
 #endif
 #pragma OPENCL EXTENSION cl_amd_media_ops2 : enable
 
-#if (defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ >= 120)
-#ifndef cl_khr_depth_images
-#error "Missing cl_khr_depth_images define"
-#endif
-#else
-#ifdef cl_khr_depth_images
-#error "Incorrect cl_khr_depth_images define"
-#endif
-// expected-warning@+2{{unsupported OpenCL extension 'cl_khr_depth_images' - ignoring}}
-#endif
+// FIXME: This pragma is meaningless and it doesn't add any functionality.
+// However we will probably need to keep it for backward compatibility.
+// In which case there is no need to guard its use by any version or a target
+// setting as it does absolutely nothing anyway.
+// The warning diagnostic should change however to something like -
+// - pragma has no effect.
 #pragma OPENCL EXTENSION cl_khr_depth_images : enable
+// expected-warning@-1{{unknown OpenCL extension 'cl_khr_depth_images' - ignoring}}
 
 #if (defined(__OPENCL_CPP_VERSION__) || __OPENCL_C_VERSION__ >= 120)
 #ifndef cl_intel_subgroups