Merge topic 'clang-gnulike-support'

74829f01b1 Help: Add notes for topic 'clang-gnulike-support'
19669abe1d Tests: handle string escaping differences with NMake+clang
a2a90f41e3 Tests: require C++14 for the Tutorial
4819ff9647 Tests: fix failures with gnu mode clang on windows
26af0b25e7 cmake: use correct stack size with gnu mode clang on windows
d44c0db0b2 clang: setup correct configuration in gnu mode
b7d5ef23e9 cmGlobalNinjaGenerator: use gnu compatible paths with clang in gnu mode
3d0210d8dc binutils: add the llvm-* variants to the tool lists.
...

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Francesco Bertolaccini <francesco@bertolaccini.dev>
Acked-by: Stanislav Ershov <digital.stream.of.mind@gmail.com>
Acked-by: Saleem Abdulrasool <compnerd@compnerd.org>
Merge-request: !2992

39 files changed, 265 insertions, 102 deletions

diff --git a/CompileFlags.cmake b/CompileFlags.cmake
index c8a039a848..c231ede5a5 100644
--- a/CompileFlags.cmake
+++ b/CompileFlags.cmake
@@ -21,6 +21,12 @@ if(MSVC)
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -stack:10000000")
 endif()
 
+if(CMAKE_CXX_COMPILER_ID STREQUAL Clang
+   AND "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC"
+   AND "x${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}" STREQUAL "xGNU")
+  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Xlinker -stack:20000000")
+endif()
+
 #silence duplicate symbol warnings on AIX
 if(CMAKE_SYSTEM_NAME MATCHES "AIX")
   if(NOT CMAKE_COMPILER_IS_GNUCXX)
diff --git a/Help/release/dev/clang-gnulike-support.rst b/Help/release/dev/clang-gnulike-support.rst
new file mode 100644
index 0000000000..87715d7908
--- /dev/null
+++ b/Help/release/dev/clang-gnulike-support.rst
@@ -0,0 +1,5 @@
+clang-gnulike-support
+---------------------
+
+* The ``Clang`` compiler variant on Windows that targets the MSVC ABI
+  but has a GNU-like command line is now supported.
diff --git a/Modules/CMakeCCompiler.cmake.in b/Modules/CMakeCCompiler.cmake.in
index f473b0d1c8..9b8d423a6b 100644
--- a/Modules/CMakeCCompiler.cmake.in
+++ b/Modules/CMakeCCompiler.cmake.in
@@ -12,6 +12,7 @@ set(CMAKE_C11_COMPILE_FEATURES "@CMAKE_C11_COMPILE_FEATURES@")
 
 set(CMAKE_C_PLATFORM_ID "@CMAKE_C_PLATFORM_ID@")
 set(CMAKE_C_SIMULATE_ID "@CMAKE_C_SIMULATE_ID@")
+set(CMAKE_C_COMPILER_FRONTEND_VARIANT "@CMAKE_C_COMPILER_FRONTEND_VARIANT@")
 set(CMAKE_C_SIMULATE_VERSION "@CMAKE_C_SIMULATE_VERSION@")
 @_SET_CMAKE_C_COMPILER_ARCHITECTURE_ID@
 @SET_MSVC_C_ARCHITECTURE_ID@
diff --git a/Modules/CMakeCXXCompiler.cmake.in b/Modules/CMakeCXXCompiler.cmake.in
index a1be02b5cc..e7f0e70745 100644
--- a/Modules/CMakeCXXCompiler.cmake.in
+++ b/Modules/CMakeCXXCompiler.cmake.in
@@ -14,6 +14,7 @@ set(CMAKE_CXX20_COMPILE_FEATURES "@CMAKE_CXX20_COMPILE_FEATURES@")
 
 set(CMAKE_CXX_PLATFORM_ID "@CMAKE_CXX_PLATFORM_ID@")
 set(CMAKE_CXX_SIMULATE_ID "@CMAKE_CXX_SIMULATE_ID@")
+set(CMAKE_CXX_COMPILER_FRONTEND_VARIANT "@CMAKE_CXX_COMPILER_FRONTEND_VARIANT@")
 set(CMAKE_CXX_SIMULATE_VERSION "@CMAKE_CXX_SIMULATE_VERSION@")
 @_SET_CMAKE_CXX_COMPILER_ARCHITECTURE_ID@
 @SET_MSVC_CXX_ARCHITECTURE_ID@
diff --git a/Modules/CMakeDetermineCCompiler.cmake b/Modules/CMakeDetermineCCompiler.cmake
index 495d7e8dab..8be781a087 100644
--- a/Modules/CMakeDetermineCCompiler.cmake
+++ b/Modules/CMakeDetermineCCompiler.cmake
@@ -114,7 +114,6 @@ if(NOT CMAKE_C_COMPILER_ID_RUN)
 
   include(${CMAKE_ROOT}/Modules/CMakeDetermineCompilerId.cmake)
   CMAKE_DETERMINE_COMPILER_ID(C CFLAGS CMakeCCompilerId.c)
-  CMAKE_DIAGNOSE_UNSUPPORTED_CLANG(C CC)
 
   # Set old compiler and platform id variables.
   if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
diff --git a/Modules/CMakeDetermineCXXCompiler.cmake b/Modules/CMakeDetermineCXXCompiler.cmake
index afcd956c4b..00ef5b9f8a 100644
--- a/Modules/CMakeDetermineCXXCompiler.cmake
+++ b/Modules/CMakeDetermineCXXCompiler.cmake
@@ -109,7 +109,6 @@ if(NOT CMAKE_CXX_COMPILER_ID_RUN)
 
   include(${CMAKE_ROOT}/Modules/CMakeDetermineCompilerId.cmake)
   CMAKE_DETERMINE_COMPILER_ID(CXX CXXFLAGS CMakeCXXCompilerId.cpp)
-  CMAKE_DIAGNOSE_UNSUPPORTED_CLANG(CXX CXX)
 
   # Set old compiler and platform id variables.
   if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
diff --git a/Modules/CMakeDetermineCompilerId.cmake b/Modules/CMakeDetermineCompilerId.cmake
index c7e568569d..6083358b39 100644
--- a/Modules/CMakeDetermineCompilerId.cmake
+++ b/Modules/CMakeDetermineCompilerId.cmake
@@ -136,6 +136,31 @@ function(CMAKE_DETERMINE_COMPILER_ID lang flagvar src)
     set(CMAKE_${lang}_CL_SHOWINCLUDES_PREFIX "")
   endif()
 
+  set(_variant "")
+  if("x${CMAKE_${lang}_COMPILER_ID}" STREQUAL "xClang")
+    if(CMAKE_HOST_WIN32 AND "x${CMAKE_${lang}_SIMULATE_ID}" STREQUAL "xMSVC")
+      if(CMAKE_GENERATOR MATCHES "Visual Studio")
+        set(CMAKE_${lang}_COMPILER_FRONTEND_VARIANT "MSVC")
+      else()
+        # Test whether an MSVC-like command-line option works.
+        execute_process(COMMAND "${CMAKE_${lang}_COMPILER}" -?
+          RESULT_VARIABLE _clang_result
+          OUTPUT_VARIABLE _clang_stdout
+          ERROR_VARIABLE _clang_stderr)
+        if(_clang_result EQUAL 0)
+          set(CMAKE_${lang}_COMPILER_FRONTEND_VARIANT "MSVC")
+        else()
+          set(CMAKE_${lang}_COMPILER_FRONTEND_VARIANT "GNU")
+        endif()
+      endif()
+      set(_variant " with ${CMAKE_${lang}_COMPILER_FRONTEND_VARIANT}-like command-line")
+    else()
+      set(CMAKE_${lang}_COMPILER_FRONTEND_VARIANT "GNU")
+    endif()
+  else()
+    set(CMAKE_${lang}_COMPILER_FRONTEND_VARIANT "")
+  endif()
+
   # Display the final identification result.
   if(CMAKE_${lang}_COMPILER_ID)
     if(CMAKE_${lang}_COMPILER_VERSION)
@@ -149,9 +174,10 @@ function(CMAKE_DETERMINE_COMPILER_ID lang flagvar src)
       set(_archid "")
     endif()
     message(STATUS "The ${lang} compiler identification is "
-      "${CMAKE_${lang}_COMPILER_ID}${_archid}${_version}")
+      "${CMAKE_${lang}_COMPILER_ID}${_archid}${_version}${_variant}")
     unset(_archid)
     unset(_version)
+    unset(_variant)
   else()
     message(STATUS "The ${lang} compiler identification is unknown")
   endif()
@@ -163,6 +189,7 @@ function(CMAKE_DETERMINE_COMPILER_ID lang flagvar src)
     PARENT_SCOPE)
   set(CMAKE_${lang}_XCODE_ARCHS "${CMAKE_${lang}_XCODE_ARCHS}" PARENT_SCOPE)
   set(CMAKE_${lang}_CL_SHOWINCLUDES_PREFIX "${CMAKE_${lang}_CL_SHOWINCLUDES_PREFIX}" PARENT_SCOPE)
+  set(CMAKE_${lang}_COMPILER_FRONTEND_VARIANT "${CMAKE_${lang}_COMPILER_FRONTEND_VARIANT}" PARENT_SCOPE)
   set(CMAKE_${lang}_COMPILER_VERSION "${CMAKE_${lang}_COMPILER_VERSION}" PARENT_SCOPE)
   set(CMAKE_${lang}_COMPILER_VERSION_INTERNAL "${CMAKE_${lang}_COMPILER_VERSION_INTERNAL}" PARENT_SCOPE)
   set(CMAKE_${lang}_COMPILER_WRAPPER "${CMAKE_${lang}_COMPILER_WRAPPER}" PARENT_SCOPE)
@@ -864,38 +891,3 @@ function(CMAKE_DETERMINE_MSVC_SHOWINCLUDES_PREFIX lang userflags)
     set(CMAKE_${lang}_CL_SHOWINCLUDES_PREFIX "" PARENT_SCOPE)
   endif()
 endfunction()
-
-function(CMAKE_DIAGNOSE_UNSUPPORTED_CLANG lang envvar)
-  if(NOT CMAKE_HOST_WIN32 OR CMAKE_GENERATOR MATCHES "Visual Studio" OR
-      NOT "${CMAKE_${lang}_COMPILER_ID};${CMAKE_${lang}_SIMULATE_ID}" STREQUAL "Clang;MSVC")
-    return()
-  endif()
-
-  # Test whether an MSVC-like command-line option works.
-  execute_process(COMMAND "${CMAKE_${lang}_COMPILER}" -?
-    RESULT_VARIABLE _clang_result
-    OUTPUT_VARIABLE _clang_stdout
-    ERROR_VARIABLE _clang_stderr)
-  if(_clang_result EQUAL 0)
-    return()
-  endif()
-
-  # Help the user configure the environment to use the MSVC-like Clang.
-  string(CONCAT _msg
-    "The Clang compiler tool\n"
-    "  \"${CMAKE_${lang}_COMPILER}\"\n"
-    "targets the MSVC ABI but has a GNU-like command-line interface.  "
-    "This is not supported.  "
-    "Use 'clang-cl' instead, e.g. by setting '${envvar}=clang-cl' in the environment."
-    )
-  execute_process(COMMAND rc -help
-    RESULT_VARIABLE _rc_result
-    OUTPUT_VARIABLE _rc_stdout
-    ERROR_VARIABLE _rc_stderr)
-  if(NOT _rc_result EQUAL 0)
-    string(APPEND _msg "  "
-      "Furthermore, use the MSVC command-line environment."
-      )
-  endif()
-  message(FATAL_ERROR "${_msg}")
-endfunction()
diff --git a/Modules/CMakeFindBinUtils.cmake b/Modules/CMakeFindBinUtils.cmake
index 35f75c938d..0e84116400 100644
--- a/Modules/CMakeFindBinUtils.cmake
+++ b/Modules/CMakeFindBinUtils.cmake
@@ -60,7 +60,9 @@ __resolve_tool_path(CMAKE_MT     "${_CMAKE_TOOLCHAIN_LOCATION}" "Default Manifes
 set(_CMAKE_TOOL_VARS "")
 
 # if it's the MS C/CXX compiler, search for link
-if("x${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_SIMULATE_ID}" STREQUAL "xMSVC"
+if(("x${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_SIMULATE_ID}" STREQUAL "xMSVC" AND
+   ("x${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC"
+    OR NOT "x${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_ID}" STREQUAL "xClang"))
    OR "x${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_ID}" STREQUAL "xMSVC"
    OR (CMAKE_HOST_WIN32 AND "x${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_ID}" STREQUAL "xPGI")
    OR (CMAKE_HOST_WIN32 AND "x${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_ID}" STREQUAL "xNVIDIA")
@@ -80,17 +82,26 @@ else()
   if(CMAKE_CXX_COMPILER_EXTERNAL_TOOLCHAIN)
     set(_CMAKE_TOOLCHAIN_LOCATION ${_CMAKE_TOOLCHAIN_LOCATION} ${CMAKE_CXX_COMPILER_EXTERNAL_TOOLCHAIN}/bin)
   endif()
-  find_program(CMAKE_AR NAMES ${_CMAKE_TOOLCHAIN_PREFIX}ar${_CMAKE_TOOLCHAIN_SUFFIX} HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
 
-  find_program(CMAKE_RANLIB NAMES ${_CMAKE_TOOLCHAIN_PREFIX}ranlib HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
+  if("${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_ID}" STREQUAL Clang)
+    set(LLVM_OBJDUMP "llvm-objdump")
+    set(LLVM_LLD "ld.lld")
+    set(LLVM_RANLIB "llvm-ranlib")
+    set(LLVM_AR "llvm-ar")
+  endif()
+
+  find_program(CMAKE_AR NAMES ${_CMAKE_TOOLCHAIN_PREFIX}ar${_CMAKE_TOOLCHAIN_SUFFIX} ${LLVM_AR} HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
+
+  find_program(CMAKE_RANLIB NAMES ${_CMAKE_TOOLCHAIN_PREFIX}ranlib ${LLVM_RANLIB} HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
   if(NOT CMAKE_RANLIB)
     set(CMAKE_RANLIB : CACHE INTERNAL "noop for ranlib")
   endif()
 
+
   find_program(CMAKE_STRIP NAMES ${_CMAKE_TOOLCHAIN_PREFIX}strip${_CMAKE_TOOLCHAIN_SUFFIX} HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
-  find_program(CMAKE_LINKER NAMES ${_CMAKE_TOOLCHAIN_PREFIX}ld HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
+  find_program(CMAKE_LINKER NAMES ${_CMAKE_TOOLCHAIN_PREFIX}ld ${LLVM_LLD} HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
   find_program(CMAKE_NM NAMES ${_CMAKE_TOOLCHAIN_PREFIX}nm HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
-  find_program(CMAKE_OBJDUMP NAMES ${_CMAKE_TOOLCHAIN_PREFIX}objdump HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
+  find_program(CMAKE_OBJDUMP NAMES ${_CMAKE_TOOLCHAIN_PREFIX}objdump ${LLVM_OBJDUMP} HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
   find_program(CMAKE_OBJCOPY NAMES ${_CMAKE_TOOLCHAIN_PREFIX}objcopy HINTS ${_CMAKE_TOOLCHAIN_LOCATION})
 
   list(APPEND _CMAKE_TOOL_VARS CMAKE_AR CMAKE_RANLIB CMAKE_STRIP CMAKE_LINKER CMAKE_NM CMAKE_OBJDUMP CMAKE_OBJCOPY)
diff --git a/Modules/Compiler/Clang-CXX.cmake b/Modules/Compiler/Clang-CXX.cmake
index c116078be0..17f391746f 100644
--- a/Modules/Compiler/Clang-CXX.cmake
+++ b/Modules/Compiler/Clang-CXX.cmake
@@ -1,7 +1,7 @@
 include(Compiler/Clang)
 __compiler_clang(CXX)
 
-if(NOT "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC")
+if("x${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}" STREQUAL "xGNU")
   set(CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY_INLINES_HIDDEN "-fvisibility-inlines-hidden")
 endif()
 
@@ -10,7 +10,8 @@ if(APPLE AND NOT appleClangPolicy STREQUAL NEW)
   return()
 endif()
 
-if(NOT "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC")
+
+if("x${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}" STREQUAL "xGNU")
   if(NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 2.1)
     set(CMAKE_CXX98_STANDARD_COMPILE_OPTION "-std=c++98")
     set(CMAKE_CXX98_EXTENSION_COMPILE_OPTION "-std=gnu++98")
@@ -56,6 +57,14 @@ if(NOT "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC")
 
   unset(_clang_version_std17)
 
+  if("x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC")
+    # This clang++ is missing some features because of MSVC compatibility.
+    unset(CMAKE_CXX11_STANDARD__HAS_FULL_SUPPORT)
+    unset(CMAKE_CXX14_STANDARD__HAS_FULL_SUPPORT)
+    unset(CMAKE_CXX17_STANDARD__HAS_FULL_SUPPORT)
+    unset(CMAKE_CXX20_STANDARD__HAS_FULL_SUPPORT)
+  endif()
+
   __compiler_check_default_language_standard(CXX 2.1 98)
 elseif(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 3.9
     AND CMAKE_CXX_SIMULATE_VERSION VERSION_GREATER_EQUAL 19.0)
diff --git a/Modules/Platform/Windows-Clang.cmake b/Modules/Platform/Windows-Clang.cmake
index 007ae530d2..b317da6505 100644
--- a/Modules/Platform/Windows-Clang.cmake
+++ b/Modules/Platform/Windows-Clang.cmake
@@ -8,13 +8,120 @@ if(__WINDOWS_CLANG)
 endif()
 set(__WINDOWS_CLANG 1)
 
+macro(__windows_compiler_clang_gnu lang)
+  set(CMAKE_LIBRARY_PATH_FLAG "-L")
+  set(CMAKE_LINK_LIBRARY_FLAG "-l")
+
+  set(CMAKE_IMPORT_LIBRARY_PREFIX "")
+  set(CMAKE_SHARED_LIBRARY_PREFIX "")
+  set(CMAKE_SHARED_MODULE_PREFIX  "")
+  set(CMAKE_STATIC_LIBRARY_PREFIX "")
+  set(CMAKE_EXECUTABLE_SUFFIX     ".exe")
+  set(CMAKE_IMPORT_LIBRARY_SUFFIX ".lib")
+  set(CMAKE_SHARED_LIBRARY_SUFFIX ".dll")
+  set(CMAKE_SHARED_MODULE_SUFFIX  ".dll")
+  set(CMAKE_STATIC_LIBRARY_SUFFIX ".lib")
+  set(CMAKE_DEPFILE_FLAGS_${lang} "-MD -MT <OBJECT> -MF <DEPFILE>")
+
+  set(CMAKE_FIND_LIBRARY_PREFIXES "lib" "")
+  set(CMAKE_FIND_LIBRARY_SUFFIXES ".dll" ".dll.a" ".a" ".lib")
+  set(CMAKE_SUPPORT_WINDOWS_EXPORT_ALL_SYMBOLS 1)
+  set (CMAKE_LINK_DEF_FILE_FLAG "-Xlinker /DEF:")
+
+  if("${CMAKE_${lang}_SIMULATE_VERSION}" MATCHES "^([0-9]+)\\.([0-9]+)")
+    math(EXPR MSVC_VERSION "${CMAKE_MATCH_1}*100 + ${CMAKE_MATCH_2}")
+  endif()
+
+  # No -fPIC on Windows
+  set(CMAKE_${lang}_COMPILE_OPTIONS_PIC "")
+  set(CMAKE_${lang}_COMPILE_OPTIONS_PIE "")
+  set(_CMAKE_${lang}_PIE_MAY_BE_SUPPORTED_BY_LINKER NO)
+  set(CMAKE_${lang}_LINK_OPTIONS_PIE "")
+  set(CMAKE_${lang}_LINK_OPTIONS_NO_PIE "")
+  set(CMAKE_SHARED_LIBRARY_${lang}_FLAGS "")
+
+  set(CMAKE_${lang}_USE_RESPONSE_FILE_FOR_OBJECTS 1)
+  set(CMAKE_${lang}_USE_RESPONSE_FILE_FOR_LIBRARIES 1)
+  set(CMAKE_${lang}_USE_RESPONSE_FILE_FOR_INCLUDES 1)
+
+  # Create archiving rules to support large object file lists for static libraries.
+  set(CMAKE_${lang}_ARCHIVE_CREATE "<CMAKE_AR> qc <TARGET> <LINK_FLAGS> <OBJECTS>")
+  set(CMAKE_${lang}_ARCHIVE_APPEND "<CMAKE_AR> q  <TARGET> <LINK_FLAGS> <OBJECTS>")
+  set(CMAKE_${lang}_ARCHIVE_FINISH "<CMAKE_RANLIB> <TARGET>")
+  set(CMAKE_${lang}_CREATE_SHARED_LIBRARY
+    "<CMAKE_${lang}_COMPILER> -nostartfiles -nostdlib <CMAKE_SHARED_LIBRARY_${lang}_FLAGS> <LANGUAGE_COMPILE_FLAGS> <LINK_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS> -o <TARGET> ${CMAKE_GNULD_IMAGE_VERSION} -Xlinker /implib:<TARGET_IMPLIB> -Xlinker /pdb:<TARGET_PDB> -Xlinker /version:<TARGET_VERSION_MAJOR>.<TARGET_VERSION_MINOR> <OBJECTS> <LINK_LIBRARIES>")
+  set(CMAKE_${lang}_CREATE_SHARED_MODULE ${CMAKE_${lang}_CREATE_SHARED_LIBRARY})
+  set(CMAKE_${lang}_LINK_EXECUTABLE
+    "<CMAKE_${lang}_COMPILER> -nostartfiles -nostdlib <FLAGS> <CMAKE_${lang}_LINK_FLAGS> <LINK_FLAGS> <OBJECTS>  -o <TARGET> -Xlinker /implib:<TARGET_IMPLIB> -Xlinker /pdb:<TARGET_PDB> -Xlinker /version:<TARGET_VERSION_MAJOR>.<TARGET_VERSION_MINOR> ${CMAKE_GNULD_IMAGE_VERSION} <LINK_LIBRARIES>")
+
+  set(CMAKE_${lang}_COMPILE_OPTIONS_MSVC_RUNTIME_LIBRARY_MultiThreaded         -Xclang -flto-visibility-public-std -D_MT -Xclang --dependent-lib=libcmt)
+  set(CMAKE_${lang}_COMPILE_OPTIONS_MSVC_RUNTIME_LIBRARY_MultiThreadedDLL      -D_DLL -D_MT -Xclang --dependent-lib=msvcrt)
+  set(CMAKE_${lang}_COMPILE_OPTIONS_MSVC_RUNTIME_LIBRARY_MultiThreadedDebug    -D_DEBUG -Xclang -flto-visibility-public-std -D_MT -Xclang --dependent-lib=libcmtd)
+  set(CMAKE_${lang}_COMPILE_OPTIONS_MSVC_RUNTIME_LIBRARY_MultiThreadedDebugDLL -D_DEBUG -D_DLL -D_MT -Xclang --dependent-lib=msvcrtd)
+
+  if(CMAKE_MSVC_RUNTIME_LIBRARY_DEFAULT)
+    set(__ADDED_FLAGS "")
+    set(__ADDED_FLAGS_DEBUG "")
+  else()
+    set(__ADDED_FLAGS_DEBUG "-D_DEBUG -D_DLL -D_MT -Xclang --dependent-lib=msvcrtd")
+    set(__ADDED_FLAGS "-D_DLL -D_MT -Xclang --dependent-lib=msvcrt")
+  endif()
+
+  string(APPEND CMAKE_${lang}_FLAGS_DEBUG_INIT " -g -Xclang -gcodeview -O0 ${__ADDED_FLAGS_DEBUG}")
+  string(APPEND CMAKE_${lang}_FLAGS_MINSIZEREL_INIT " -Os -DNDEBUG ${__ADDED_FLAGS}")
+  string(APPEND CMAKE_${lang}_FLAGS_RELEASE_INIT " -O3 -DNDEBUG ${__ADDED_FLAGS}")
+  string(APPEND CMAKE_${lang}_FLAGS_RELWITHDEBINFO_INIT " -O2 -g -DNDEBUG -Xclang -gcodeview ${__ADDED_FLAGS}")
+  set(CMAKE_INCLUDE_SYSTEM_FLAG_${lang} "-isystem ")
+
+  unset(__ADDED_FLAGS)
+  unset(__ADDED_FLAGS_DEBUG)
+  string(TOLOWER "${CMAKE_BUILD_TYPE}" BUILD_TYPE_LOWER)
+  set(CMAKE_${lang}_STANDARD_LIBRARIES_INIT "-lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32 -loldnames")
+
+  enable_language(RC)
+endmacro()
+
 if("x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC"
     OR "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC")
-  include(Platform/Windows-MSVC)
-  macro(__windows_compiler_clang lang)
-    set(_COMPILE_${lang} "${_COMPILE_${lang}_MSVC}")
-    __windows_compiler_msvc(${lang})
-  endmacro()
+
+  if ( DEFINED CMAKE_C_COMPILER_ID AND DEFINED CMAKE_CXX_COMPILER_ID
+       AND NOT "x${CMAKE_C_COMPILER_ID}" STREQUAL "x${CMAKE_CXX_COMPILER_ID}")
+    message(FATAL_ERROR "The current configuration mixes Clang and MSVC or "
+            "some other CL compatible compiler tool. This is not supported. "
+            "Use either clang or MSVC as both C and C++ compilers.")
+  endif()
+
+  if ( DEFINED CMAKE_C_COMPILER_FRONTEND_VARIANT AND DEFINED CMAKE_CXX_COMPILER_FRONTEND_VARIANT
+       AND NOT "x${CMAKE_C_COMPILER_FRONTEND_VARIANT}" STREQUAL "x${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}")
+    message(FATAL_ERROR "The current configuration uses the Clang compiler "
+            "tool with mixed frontend variants, both the GNU and in MSVC CL "
+            "like variants. This is not supported. Use either clang/clang++ "
+            "or clang-cl as both C and C++ compilers.")
+  endif()
+
+  if ( "x${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC" OR "x${CMAKE_C_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC" )
+    include(Platform/Windows-MSVC)
+
+    macro(__windows_compiler_clang lang)
+      set(_COMPILE_${lang} "${_COMPILE_${lang}_MSVC}")
+      __windows_compiler_msvc(${lang})
+    endmacro()
+  else()
+    cmake_policy(GET CMP0091 __WINDOWS_CLANG_CMP0091)
+    if(__WINDOWS_CLANG_CMP0091 STREQUAL "NEW")
+      set(CMAKE_MSVC_RUNTIME_LIBRARY_DEFAULT "MultiThreaded$<$<CONFIG:Debug>:Debug>DLL")
+    else()
+      set(CMAKE_MSVC_RUNTIME_LIBRARY_DEFAULT "")
+    endif()
+    unset(__WINDOWS_CLANG_CMP0091)
+
+    set(CMAKE_BUILD_TYPE_INIT Debug)
+
+    macro(__windows_compiler_clang lang)
+      __windows_compiler_clang_gnu(${lang})
+    endmacro()
+  endif()
+
 else()
   include(Platform/Windows-GNU)
   macro(__windows_compiler_clang lang)
diff --git a/Source/cmGlobalNinjaGenerator.cxx b/Source/cmGlobalNinjaGenerator.cxx
index ea65a77bef..61dea80e7a 100644
--- a/Source/cmGlobalNinjaGenerator.cxx
+++ b/Source/cmGlobalNinjaGenerator.cxx
@@ -639,13 +639,20 @@ void cmGlobalNinjaGenerator::EnableLanguage(
     this->ResolveLanguageCompiler(l, mf, optional);
   }
 #ifdef _WIN32
-  if ((mf->GetSafeDefinition("CMAKE_C_SIMULATE_ID") != "MSVC") &&
-      (mf->GetSafeDefinition("CMAKE_CXX_SIMULATE_ID") != "MSVC") &&
-      (mf->IsOn("CMAKE_COMPILER_IS_MINGW") ||
-       (mf->GetSafeDefinition("CMAKE_C_COMPILER_ID") == "GNU") ||
-       (mf->GetSafeDefinition("CMAKE_CXX_COMPILER_ID") == "GNU") ||
-       (mf->GetSafeDefinition("CMAKE_C_COMPILER_ID") == "Clang") ||
-       (mf->GetSafeDefinition("CMAKE_CXX_COMPILER_ID") == "Clang"))) {
+  const bool clangGnuMode =
+    ((mf->GetSafeDefinition("CMAKE_C_COMPILER_ID") == "Clang") &&
+     (mf->GetSafeDefinition("CMAKE_C_COMPILER_FRONTEND_VARIANT") == "GNU")) ||
+    ((mf->GetSafeDefinition("CMAKE_CXX_COMPILER_ID") == "Clang") &&
+     (mf->GetSafeDefinition("CMAKE_CXX_COMPILER_FRONTEND_VARIANT") == "GNU"));
+
+  if (clangGnuMode ||
+      ((mf->GetSafeDefinition("CMAKE_C_SIMULATE_ID") != "MSVC") &&
+       (mf->GetSafeDefinition("CMAKE_CXX_SIMULATE_ID") != "MSVC") &&
+       (mf->IsOn("CMAKE_COMPILER_IS_MINGW") ||
+        (mf->GetSafeDefinition("CMAKE_C_COMPILER_ID") == "GNU") ||
+        (mf->GetSafeDefinition("CMAKE_CXX_COMPILER_ID") == "GNU") ||
+        (mf->GetSafeDefinition("CMAKE_C_COMPILER_ID") == "Clang") ||
+        (mf->GetSafeDefinition("CMAKE_CXX_COMPILER_ID") == "Clang")))) {
     this->UsingGCCOnWindows = true;
   }
 #endif
diff --git a/Tests/AliasTarget/CMakeLists.txt b/Tests/AliasTarget/CMakeLists.txt
index fc70135988..6271988101 100644
--- a/Tests/AliasTarget/CMakeLists.txt
+++ b/Tests/AliasTarget/CMakeLists.txt
@@ -7,7 +7,7 @@ set(CMAKE_CXX_STANDARD 98)
 # Clang/C2 in C++98 mode cannot properly handle some of MSVC headers
 if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
     CMAKE_CXX_SIMULATE_ID STREQUAL "MSVC")
-  set(CMAKE_CXX_STANDARD 11)
+  set(CMAKE_CXX_STANDARD 14)
 endif()
 
 add_library(foo SHARED empty.cpp)
diff --git a/Tests/COnly/CMakeLists.txt b/Tests/COnly/CMakeLists.txt
index b3cc43813b..3037f13cb6 100644
--- a/Tests/COnly/CMakeLists.txt
+++ b/Tests/COnly/CMakeLists.txt
@@ -7,7 +7,7 @@ add_library(testc1 STATIC libc1.c)
 add_library(testc2 SHARED libc2.c)
 add_executable (COnly conly.c foo.c foo.h)
 target_link_libraries(COnly testc1 testc2)
-if(MSVC_VERSION)
+if(MSVC_VERSION AND NOT CMAKE_C_COMPILER_ID STREQUAL Clang OR "x${CMAKE_C_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC")
   set_target_properties(COnly PROPERTIES
     LINK_FLAGS " /NODEFAULTLIB:\"libcdg.lib\" /NODEFAULTLIB:\"libcmtg.lib\" /NODEFAULTLIB:\"foomsvcrt.lib\" /NODEFAULTLIB:\"libbar.lib\" /NODEFAULTLIB:\"libfooba.lib\"")
 endif()
diff --git a/Tests/CompileOptions/CMakeLists.txt b/Tests/CompileOptions/CMakeLists.txt
index 18896bfe73..1433462ba7 100644
--- a/Tests/CompileOptions/CMakeLists.txt
+++ b/Tests/CompileOptions/CMakeLists.txt
@@ -43,7 +43,7 @@ else()
     )
 endif()
 
-if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang|Borland|Embarcadero")
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang|Borland|Embarcadero" AND NOT "${CMAKE_GENERATOR}" MATCHES "NMake Makefiles")
   set_property(TARGET CompileOptions APPEND PROPERTY COMPILE_OPTIONS
     "-DTEST_OCTOTHORPE=\"#\""
     )
diff --git a/Tests/Complex/CMakeLists.txt b/Tests/Complex/CMakeLists.txt
index 2e41754425..fef83f668a 100644
--- a/Tests/Complex/CMakeLists.txt
+++ b/Tests/Complex/CMakeLists.txt
@@ -446,6 +446,11 @@ if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
   set(CMAKE_CXX_STANDARD 11)
 endif()
 
+if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
+    CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "GNU")
+  set(CMAKE_CXX_STANDARD 14)
+endif()
+
 #
 # Create the libs and the main exe
 #
diff --git a/Tests/ComplexOneConfig/CMakeLists.txt b/Tests/ComplexOneConfig/CMakeLists.txt
index 628cd4ec3f..77baa4c320 100644
--- a/Tests/ComplexOneConfig/CMakeLists.txt
+++ b/Tests/ComplexOneConfig/CMakeLists.txt
@@ -403,6 +403,11 @@ if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
   set(CMAKE_CXX_STANDARD 11)
 endif()
 
+if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
+    CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "GNU")
+  set(CMAKE_CXX_STANDARD 14)
+endif()
+
 #
 # Create the libs and the main exe
 #
diff --git a/Tests/EnforceConfig.cmake.in b/Tests/EnforceConfig.cmake.in
index f84d18071c..b7587aa47d 100644
--- a/Tests/EnforceConfig.cmake.in
+++ b/Tests/EnforceConfig.cmake.in
@@ -18,7 +18,12 @@ if(NOT CTEST_CONFIGURATION_TYPE)
     endif()
   endforeach()
   if(NOT CTEST_CONFIGURATION_TYPE)
-    set(CTEST_CONFIGURATION_TYPE NoConfig)
+    if("@CMAKE_C_COMPILER_ID@;@CMAKE_C_SIMULATE_ID@;@CMAKE_C_COMPILER_FRONTEND_VARIANT@" STREQUAL "Clang;MSVC;GNU")
+      # A valid configuration is required for this compiler in tests that do not set CMP0091 to NEW.
+      set(CTEST_CONFIGURATION_TYPE Debug)
+    else()
+      set(CTEST_CONFIGURATION_TYPE NoConfig)
+    endif()
   endif()
   message("Guessing configuration ${CTEST_CONFIGURATION_TYPE}")
 endif()
diff --git a/Tests/Module/WriteCompilerDetectionHeader/CMakeLists.txt b/Tests/Module/WriteCompilerDetectionHeader/CMakeLists.txt
index cffef5a0b9..b30928d789 100644
--- a/Tests/Module/WriteCompilerDetectionHeader/CMakeLists.txt
+++ b/Tests/Module/WriteCompilerDetectionHeader/CMakeLists.txt
@@ -133,7 +133,9 @@ endif()
 
 # for msvc the compiler version determines which c++11 features are available.
 if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC"
-    OR (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC"))
+    OR (CMAKE_CXX_COMPILER_ID STREQUAL "Clang"
+    AND "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC"
+    AND "x${CMAKE_CXX_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC" ))
   if(";${CMAKE_CXX_COMPILE_FEATURES};" MATCHES ";cxx_delegating_constructors;")
     list(APPEND true_defs EXPECTED_COMPILER_CXX_DELEGATING_CONSTRUCTORS)
     list(APPEND true_defs EXPECTED_COMPILER_CXX_VARIADIC_TEMPLATES)
diff --git a/Tests/Plugin/CMakeLists.txt b/Tests/Plugin/CMakeLists.txt
index 8e8fa0759b..c4540db1e5 100644
--- a/Tests/Plugin/CMakeLists.txt
+++ b/Tests/Plugin/CMakeLists.txt
@@ -5,6 +5,17 @@ project(Plugin)
 # We need proper C++98 support from the compiler
 set(CMAKE_CXX_STANDARD 98)
 
+# Clang/C2 in C++98 mode cannot properly handle some of MSVC headers
+if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
+    CMAKE_CXX_SIMULATE_ID STREQUAL "MSVC")
+  set(CMAKE_CXX_STANDARD 11)
+endif()
+
+if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
+    CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "GNU")
+  set(CMAKE_CXX_STANDARD 14)
+endif()
+
 # Test per-target output directory properties.
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${Plugin_BINARY_DIR}/bin)
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${Plugin_BINARY_DIR}/lib/plugin)
@@ -29,12 +40,6 @@ include_directories(
   ${Plugin_SOURCE_DIR}/include
   )
 
-# Clang/C2 in C++98 mode cannot properly handle some of MSVC headers
-if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
-    CMAKE_CXX_SIMULATE_ID STREQUAL "MSVC")
-  set(CMAKE_CXX_STANDARD 11)
-endif()
-
 # Create an executable that exports an API for use by plugins.
 add_executable(example_exe src/example_exe.cxx)
 set_target_properties(example_exe PROPERTIES
diff --git a/Tests/Preprocess/CMakeLists.txt b/Tests/Preprocess/CMakeLists.txt
index 8c2cdc9e77..588af03204 100644
--- a/Tests/Preprocess/CMakeLists.txt
+++ b/Tests/Preprocess/CMakeLists.txt
@@ -28,6 +28,11 @@ endif()
 if("${CMAKE_GENERATOR}" MATCHES "Visual Studio")
   set(PP_VS 1)
 endif()
+if(CMAKE_C_COMPILER_ID STREQUAL "Clang" AND
+   "x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC" AND
+   "x${CMAKE_C_COMPILER_FRONTEND_VARIANT}" STREQUAL "xGNU")
+   set(CLANG_GNULIKE_WINDOWS 1)
+endif()
 
 # Some tests below check the PP_* variables set above.  They are meant
 # to test the case that the build tool is at fault.  Other tests below
@@ -53,7 +58,7 @@ endif()
 
 string(APPEND STRING_EXTRA " ")
 
-if(NOT PP_BORLAND AND NOT PP_WATCOM)
+if(NOT PP_BORLAND AND NOT PP_WATCOM AND NOT CLANG_GNULIKE_WINDOWS)
   # Borland, WMake: multiple spaces
   # The make tool seems to remove extra whitespace from inside
   # quoted strings when passing to the compiler.  It does not have
@@ -70,14 +75,14 @@ if(NOT PP_VS)
   string(APPEND STRING_EXTRA ",")
 endif()
 
-if(NOT PP_MINGW)
+if(NOT PP_MINGW AND NOT CLANG_GNULIKE_WINDOWS)
   # MinGW: &
   # When inside -D"FOO=\"a & b\"" MinGW make wants -D"FOO=\"a "&" b\""
   # but it does not like quoted ampersand elsewhere.
   string(APPEND STRING_EXTRA "&")
 endif()
 
-if(NOT PP_MINGW)
+if(NOT PP_MINGW AND NOT CLANG_GNULIKE_WINDOWS)
   # MinGW: |
   # When inside -D"FOO=\"a | b\"" MinGW make wants -D"FOO=\"a "|" b\""
   # but it does not like quoted pipe elsewhere.
@@ -100,7 +105,8 @@ endif()
 
 set(EXPR_OP1 "/")
 if((NOT MSVC OR PP_NMAKE) AND
-   NOT CMAKE_C_COMPILER_ID STREQUAL "Intel")
+   NOT CMAKE_C_COMPILER_ID STREQUAL "Intel" AND
+   NOT CLANG_GNULIKE_WINDOWS)
   # MSVC cl, Intel icl: %
   # When the cl compiler is invoked from the command line then % must
   # be written %% (to distinguish from %ENV% syntax).  However cl does
diff --git a/Tests/Preprocess/preprocess.c b/Tests/Preprocess/preprocess.c
index 2913f937a2..958c77ebcb 100644
--- a/Tests/Preprocess/preprocess.c
+++ b/Tests/Preprocess/preprocess.c
@@ -10,7 +10,8 @@ int check_defines_C(void)
 {
   int result = 1;
   if (strcmp(FILE_STRING, STRING_VALUE) != 0) {
-    fprintf(stderr, "FILE_STRING has wrong value in C [%s]\n", FILE_STRING);
+    fprintf(stderr, "FILE_STRING has wrong value in C [%s] vs [%s]\n",
+            FILE_STRING, STRING_VALUE);
     result = 0;
   }
   if (strcmp(TARGET_STRING, STRING_VALUE) != 0) {
diff --git a/Tests/RunCMake/GenerateExportHeader/GEH.cmake b/Tests/RunCMake/GenerateExportHeader/GEH.cmake
index ae9a84c43d..b3f1c7f53a 100644
--- a/Tests/RunCMake/GenerateExportHeader/GEH.cmake
+++ b/Tests/RunCMake/GenerateExportHeader/GEH.cmake
@@ -51,6 +51,11 @@ if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
   set(CMAKE_CXX_STANDARD 11)
 endif()
 
+if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND
+    CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "GNU")
+  set(CMAKE_CXX_STANDARD 14)
+endif()
+
 add_subdirectory(lib_shared_and_static)
 
 if(CMAKE_SYSTEM_NAME MATCHES "AIX" AND CMAKE_CXX_COMPILER_ID STREQUAL "GNU"
diff --git a/Tests/RunCMake/Ninja/greeting.c b/Tests/RunCMake/Ninja/greeting.c
index ba3e55beb0..1124d14c0f 100644
--- a/Tests/RunCMake/Ninja/greeting.c
+++ b/Tests/RunCMake/Ninja/greeting.c
@@ -6,4 +6,5 @@ __declspec(dllexport)
   void greeting(void)
 {
   printf("Hello world!\n");
+  fflush(stdout);
 }
diff --git a/Tests/RunCMake/Ninja/greeting2.c b/Tests/RunCMake/Ninja/greeting2.c
index c6ed87daa0..cc8409c117 100644
--- a/Tests/RunCMake/Ninja/greeting2.c
+++ b/Tests/RunCMake/Ninja/greeting2.c
@@ -3,4 +3,5 @@
 void greeting2(void)
 {
   printf("Hello world 2!\n");
+  fflush(stdout);
 }
diff --git a/Tests/RunCMake/try_compile/LinkOptions.cmake b/Tests/RunCMake/try_compile/LinkOptions.cmake
index 488cab1c70..7fae35ca9f 100644
--- a/Tests/RunCMake/try_compile/LinkOptions.cmake
+++ b/Tests/RunCMake/try_compile/LinkOptions.cmake
@@ -5,7 +5,9 @@ cmake_policy(SET CMP0054 NEW)
 
 set (lib_name "${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_STATIC_LIBRARY_PREFIX}lib${CMAKE_STATIC_LIBRARY_SUFFIX}")
 if (CMAKE_SYSTEM_NAME STREQUAL "Windows")
-  if (RunCMake_C_COMPILER_ID STREQUAL "MSVC" OR "x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC")
+  if (RunCMake_C_COMPILER_ID STREQUAL "MSVC"
+      OR ("x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC" AND
+          NOT CMAKE_C_COMPILER_ID STREQUAL "Clang" OR "x${CMAKE_C_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC"))
     if (CMAKE_SIZEOF_VOID_P EQUAL 4)
       set (undef_flag /INCLUDE:_func)
     else()
diff --git a/Tests/RunCMake/try_run/LinkOptions.cmake b/Tests/RunCMake/try_run/LinkOptions.cmake
index 9939a42828..b9a87f3ca1 100644
--- a/Tests/RunCMake/try_run/LinkOptions.cmake
+++ b/Tests/RunCMake/try_run/LinkOptions.cmake
@@ -5,7 +5,9 @@ cmake_policy(SET CMP0054 NEW)
 
 set (lib_name "${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_STATIC_LIBRARY_PREFIX}lib${CMAKE_STATIC_LIBRARY_SUFFIX}")
 if (CMAKE_SYSTEM_NAME STREQUAL "Windows")
-  if (RunCMake_C_COMPILER_ID STREQUAL "MSVC" OR "x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC")
+  if (RunCMake_C_COMPILER_ID STREQUAL "MSVC"
+      OR ("x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC" AND
+          NOT CMAKE_C_COMPILER_ID STREQUAL "Clang" OR "x${CMAKE_C_COMPILER_FRONTEND_VARIANT}" STREQUAL "xMSVC"))
     if (CMAKE_SIZEOF_VOID_P EQUAL 4)
       set (undef_flag /INCLUDE:_func)
     else()
diff --git a/Tests/Tutorial/Complete/CMakeLists.txt b/Tests/Tutorial/Complete/CMakeLists.txt
index 9658e65365..1c97545e47 100644
--- a/Tests/Tutorial/Complete/CMakeLists.txt
+++ b/Tests/Tutorial/Complete/CMakeLists.txt
@@ -7,8 +7,7 @@ set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}")
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}")
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}")
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_CXX_STANDARD 14)
 
 option(BUILD_SHARED_LIBS "Build using shared libraries" ON)
 
diff --git a/Tests/Tutorial/Consumer/CMakeLists.txt b/Tests/Tutorial/Consumer/CMakeLists.txt
index 4033b4da83..50979177e1 100644
--- a/Tests/Tutorial/Consumer/CMakeLists.txt
+++ b/Tests/Tutorial/Consumer/CMakeLists.txt
@@ -1,8 +1,7 @@
 cmake_minimum_required(VERSION 3.3)
 
 if(NOT DEFINED CMAKE_CXX_STANDARD)
-  set(CMAKE_CXX_STANDARD 11)
-  set(CMAKE_CXX_STANDARD_REQUIRED True)
+  set(CMAKE_CXX_STANDARD 14)
 endif()
 
 
diff --git a/Tests/Tutorial/Step10/CMakeLists.txt b/Tests/Tutorial/Step10/CMakeLists.txt
index b1d46c4b9d..79aadd5d64 100644
--- a/Tests/Tutorial/Step10/CMakeLists.txt
+++ b/Tests/Tutorial/Step10/CMakeLists.txt
@@ -7,8 +7,7 @@ set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}")
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}")
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}")
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_CXX_STANDARD 14)
 
 option(BUILD_SHARED_LIBS "Build using shared libraries" ON)
 
diff --git a/Tests/Tutorial/Step11/CMakeLists.txt b/Tests/Tutorial/Step11/CMakeLists.txt
index b1d46c4b9d..79aadd5d64 100644
--- a/Tests/Tutorial/Step11/CMakeLists.txt
+++ b/Tests/Tutorial/Step11/CMakeLists.txt
@@ -7,8 +7,7 @@ set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}")
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}")
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${PROJECT_BINARY_DIR}")
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_CXX_STANDARD 14)
 
 option(BUILD_SHARED_LIBS "Build using shared libraries" ON)
 
diff --git a/Tests/Tutorial/Step2/CMakeLists.txt b/Tests/Tutorial/Step2/CMakeLists.txt
index 48afaa327f..8e50e7c20d 100644
--- a/Tests/Tutorial/Step2/CMakeLists.txt
+++ b/Tests/Tutorial/Step2/CMakeLists.txt
@@ -1,9 +1,7 @@
 cmake_minimum_required(VERSION 3.3)
 project(Tutorial)
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
-
+set(CMAKE_CXX_STANDARD 14)
 # the version number.
 set(Tutorial_VERSION_MAJOR 1)
 set(Tutorial_VERSION_MINOR 0)
diff --git a/Tests/Tutorial/Step2/directions.txt b/Tests/Tutorial/Step2/directions.txt
index bb6662c7e6..48de7a2f16 100644
--- a/Tests/Tutorial/Step2/directions.txt
+++ b/Tests/Tutorial/Step2/directions.txt
@@ -44,8 +44,7 @@ the following:
   cmake_minimum_required(VERSION 3.3)
   project(Tutorial)
 
-  set(CMAKE_CXX_STANDARD 11)
-  set(CMAKE_CXX_STANDARD_REQUIRED True)
+  set(CMAKE_CXX_STANDARD 14)
 
   # the version number.
   set(Tutorial_VERSION_MAJOR 1)
diff --git a/Tests/Tutorial/Step3/CMakeLists.txt b/Tests/Tutorial/Step3/CMakeLists.txt
index f904ea7486..baa0a44407 100644
--- a/Tests/Tutorial/Step3/CMakeLists.txt
+++ b/Tests/Tutorial/Step3/CMakeLists.txt
@@ -1,8 +1,7 @@
 cmake_minimum_required(VERSION 3.3)
 project(Tutorial)
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_CXX_STANDARD 14)
 
 # should we use our own math functions
 option(USE_MYMATH "Use tutorial provided math implementation" ON)
diff --git a/Tests/Tutorial/Step4/CMakeLists.txt b/Tests/Tutorial/Step4/CMakeLists.txt
index 34eab55581..9ce60b91c8 100644
--- a/Tests/Tutorial/Step4/CMakeLists.txt
+++ b/Tests/Tutorial/Step4/CMakeLists.txt
@@ -1,8 +1,7 @@
 cmake_minimum_required(VERSION 3.3)
 project(Tutorial)
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_CXX_STANDARD 14)
 
 # should we use our own math functions
 option(USE_MYMATH "Use tutorial provided math implementation" ON)
diff --git a/Tests/Tutorial/Step5/CMakeLists.txt b/Tests/Tutorial/Step5/CMakeLists.txt
index 63e5410564..828b9fc974 100644
--- a/Tests/Tutorial/Step5/CMakeLists.txt
+++ b/Tests/Tutorial/Step5/CMakeLists.txt
@@ -1,8 +1,7 @@
 cmake_minimum_required(VERSION 3.3)
 project(Tutorial)
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_CXX_STANDARD 14)
 
 # should we use our own math functions
 option(USE_MYMATH "Use tutorial provided math implementation" ON)
diff --git a/Tests/Tutorial/Step6/CMakeLists.txt b/Tests/Tutorial/Step6/CMakeLists.txt
index 503a312905..a78b0ff767 100644
--- a/Tests/Tutorial/Step6/CMakeLists.txt
+++ b/Tests/Tutorial/Step6/CMakeLists.txt
@@ -1,8 +1,7 @@
 cmake_minimum_required(VERSION 3.3)
 project(Tutorial)
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_CXX_STANDARD 14)
 
 # the version number.
 set(Tutorial_VERSION_MAJOR 1)
diff --git a/Tests/Tutorial/Step7/CMakeLists.txt b/Tests/Tutorial/Step7/CMakeLists.txt
index f2d3839b70..33aa0396cc 100644
--- a/Tests/Tutorial/Step7/CMakeLists.txt
+++ b/Tests/Tutorial/Step7/CMakeLists.txt
@@ -1,8 +1,7 @@
 cmake_minimum_required(VERSION 3.3)
 project(Tutorial)
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_CXX_STANDARD 14)
 
 # the version number.
 set(Tutorial_VERSION_MAJOR 1)
diff --git a/Tests/Tutorial/Step8/CMakeLists.txt b/Tests/Tutorial/Step8/CMakeLists.txt
index c66bf96e34..03dc7c0f6e 100644
--- a/Tests/Tutorial/Step8/CMakeLists.txt
+++ b/Tests/Tutorial/Step8/CMakeLists.txt
@@ -1,8 +1,7 @@
 cmake_minimum_required(VERSION 3.3)
 project(Tutorial)
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_CXX_STANDARD 14)
 
 # the version number.
 set(Tutorial_VERSION_MAJOR 1)
diff --git a/Tests/Tutorial/Step9/CMakeLists.txt b/Tests/Tutorial/Step9/CMakeLists.txt
index 309d513ff8..4981fe20fd 100644
--- a/Tests/Tutorial/Step9/CMakeLists.txt
+++ b/Tests/Tutorial/Step9/CMakeLists.txt
@@ -1,8 +1,7 @@
 cmake_minimum_required(VERSION 3.3)
 project(Tutorial)
 
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_CXX_STANDARD 14)
 
 # the version number.
 set(Tutorial_VERSION_MAJOR 1)