Merge topic 'clangcl-fixes'

091afa7342 Tests: Teach tests when to treat clang-cl as MSVC
006768903c Work around clang-cl breakage on make_unique/std::forward
d625dfcdf9 Avoid compiling CMake itself as C++17 with Clang's MSVC ABI

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !2573

10 files changed, 26 insertions, 11 deletions

diff --git a/Source/Checks/cm_cxx17_check.cpp b/Source/Checks/cm_cxx17_check.cpp
index 4e89184..2de10d6 100644
--- a/Source/Checks/cm_cxx17_check.cpp
+++ b/Source/Checks/cm_cxx17_check.cpp
@@ -2,8 +2,21 @@
 #include <memory>
 #include <unordered_map>
 
+#ifdef _MSC_VER
+#  include <comdef.h>
+#endif
+
 int main()
 {
   std::unique_ptr<int> u(new int(0));
+
+#ifdef _MSC_VER
+  // clang-cl has problems instantiating this constructor in C++17 mode
+  //  error: indirection requires pointer operand ('const _GUID' invalid)
+  //      return *_IID;
+  IUnknownPtr ptr{};
+  IDispatchPtr disp(ptr);
+#endif
+
   return *u;
 }
diff --git a/Source/cmExportFileGenerator.cxx b/Source/cmExportFileGenerator.cxx
index c8f743a..a12e0c4 100644
--- a/Source/cmExportFileGenerator.cxx
+++ b/Source/cmExportFileGenerator.cxx
@@ -70,8 +70,9 @@ bool cmExportFileGenerator::GenerateImportFile()
   std::unique_ptr<cmsys::ofstream> foutPtr;
   if (this->AppendMode) {
     // Open for append.
+    auto openmodeApp = std::ios::app;
     foutPtr = cm::make_unique<cmsys::ofstream>(this->MainImportFile.c_str(),
-                                               std::ios::app);
+                                               openmodeApp);
   } else {
     // Generate atomically and with copy-if-different.
     std::unique_ptr<cmGeneratedFileStream> ap(
diff --git a/Source/cmExportLibraryDependenciesCommand.cxx b/Source/cmExportLibraryDependenciesCommand.cxx
index b4b2962..e542e50 100644
--- a/Source/cmExportLibraryDependenciesCommand.cxx
+++ b/Source/cmExportLibraryDependenciesCommand.cxx
@@ -50,8 +50,9 @@ void cmExportLibraryDependenciesCommand::ConstFinalPass() const
   // Use copy-if-different if not appending.
   std::unique_ptr<cmsys::ofstream> foutPtr;
   if (this->Append) {
+    const auto openmodeApp = std::ios::app;
     foutPtr =
-      cm::make_unique<cmsys::ofstream>(this->Filename.c_str(), std::ios::app);
+      cm::make_unique<cmsys::ofstream>(this->Filename.c_str(), openmodeApp);
   } else {
     std::unique_ptr<cmGeneratedFileStream> ap(
       new cmGeneratedFileStream(this->Filename, true));
diff --git a/Tests/CMakeLists.txt b/Tests/CMakeLists.txt
index e8e5a2c..40e53a2 100644
--- a/Tests/CMakeLists.txt
+++ b/Tests/CMakeLists.txt
@@ -459,7 +459,7 @@ if(BUILD_TESTING)
     set(runCxxDialectTest 1)
   endif()
   if(CMAKE_CXX_COMPILER_ID STREQUAL Clang
-        AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.4)
+        AND NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.4 AND NOT "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC")
     if(NOT APPLE OR POLICY CMP0025)
       set(runCxxDialectTest 1)
     endif()
diff --git a/Tests/CMakeOnly/CheckCXXCompilerFlag/CMakeLists.txt b/Tests/CMakeOnly/CheckCXXCompilerFlag/CMakeLists.txt
index 9be69f1..1f9d3ac 100644
--- a/Tests/CMakeOnly/CheckCXXCompilerFlag/CMakeLists.txt
+++ b/Tests/CMakeOnly/CheckCXXCompilerFlag/CMakeLists.txt
@@ -57,7 +57,7 @@ else()
   message("Unhandled Platform")
 endif()
 
-if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang" AND NOT "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC")
   check_cxx_compiler_flag("-x c++" HAVE_X_CXX)
   if(NOT HAVE_X_CXX)
     message(FATAL_ERROR "${CMAKE_CXX_COMPILER_ID} compiler flag '-x c++' check failed")
diff --git a/Tests/ExportImport/Import/A/CMakeLists.txt b/Tests/ExportImport/Import/A/CMakeLists.txt
index 811fff3..b5df961 100644
--- a/Tests/ExportImport/Import/A/CMakeLists.txt
+++ b/Tests/ExportImport/Import/A/CMakeLists.txt
@@ -407,7 +407,7 @@ endforeach()
 unset(_configs)
 
 if (((CMAKE_C_COMPILER_ID STREQUAL GNU AND CMAKE_C_COMPILER_VERSION VERSION_GREATER 4.4)
-    OR CMAKE_C_COMPILER_ID STREQUAL Clang)
+    OR (CMAKE_C_COMPILER_ID STREQUAL Clang AND NOT "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC"))
     AND (CMAKE_GENERATOR STREQUAL "Unix Makefiles" OR CMAKE_GENERATOR STREQUAL "Ninja"))
   include(CheckCXXCompilerFlag)
   check_cxx_compiler_flag(-Wunused-variable run_sys_includes_test)
diff --git a/Tests/IncludeDirectories/CMakeLists.txt b/Tests/IncludeDirectories/CMakeLists.txt
index b7b8320..761c405 100644
--- a/Tests/IncludeDirectories/CMakeLists.txt
+++ b/Tests/IncludeDirectories/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required (VERSION 2.6)
 project(IncludeDirectories)
 
 if (((CMAKE_C_COMPILER_ID STREQUAL GNU AND CMAKE_C_COMPILER_VERSION VERSION_GREATER 4.4)
-    OR CMAKE_C_COMPILER_ID STREQUAL Clang OR CMAKE_C_COMPILER_ID STREQUAL AppleClang)
+    OR (CMAKE_C_COMPILER_ID STREQUAL Clang AND NOT "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC") OR CMAKE_C_COMPILER_ID STREQUAL AppleClang)
     AND (CMAKE_GENERATOR STREQUAL "Unix Makefiles"
       OR CMAKE_GENERATOR STREQUAL "Ninja"
       OR (CMAKE_GENERATOR STREQUAL "Xcode" AND NOT XCODE_VERSION VERSION_LESS 6.0)))
diff --git a/Tests/Module/WriteCompilerDetectionHeader/CMakeLists.txt b/Tests/Module/WriteCompilerDetectionHeader/CMakeLists.txt
index 45bb229..616092d 100644
--- a/Tests/Module/WriteCompilerDetectionHeader/CMakeLists.txt
+++ b/Tests/Module/WriteCompilerDetectionHeader/CMakeLists.txt
@@ -61,7 +61,7 @@ if (C_expected_features)
   string(REGEX REPLACE "^[0-9]+\\.[0-9]+\\.([0-9]+).*" "\\1" COMPILER_VERSION_PATCH "${CMAKE_C_COMPILER_VERSION}")
 
   if (CMAKE_C_COMPILER_ID STREQUAL "GNU"
-      OR CMAKE_C_COMPILER_ID STREQUAL "Clang"
+      OR (CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC")
       OR CMAKE_C_COMPILER_ID STREQUAL "AppleClang"
       OR CMAKE_C_COMPILER_ID STREQUAL "Intel")
     add_executable(WriteCompilerDetectionHeader_C11 main.c)
@@ -118,7 +118,7 @@ string(REGEX REPLACE "^[0-9]+\\.([0-9]+)\\.[0-9]+.*" "\\1" COMPILER_VERSION_MINO
 string(REGEX REPLACE "^[0-9]+\\.[0-9]+\\.([0-9]+).*" "\\1" COMPILER_VERSION_PATCH "${CMAKE_CXX_COMPILER_VERSION}")
 
 if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU"
-    OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang"
+    OR (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND NOT "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC")
     OR CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang"
     OR CMAKE_CXX_COMPILER_ID STREQUAL "SunPro"
     OR CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
@@ -128,7 +128,7 @@ if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU"
 endif()
 
 # for msvc the compiler version determines which c++11 features are available.
-if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" OR "x${CMAKE_CXX_SIMULATE_ID}" STREQUAL "xMSVC")
   if(";${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/RunCMake/try_compile/LinkOptions.cmake b/Tests/RunCMake/try_compile/LinkOptions.cmake
index 9b246c4..488cab1 100644
--- a/Tests/RunCMake/try_compile/LinkOptions.cmake
+++ b/Tests/RunCMake/try_compile/LinkOptions.cmake
@@ -5,7 +5,7 @@ cmake_policy(SET CMP0054 NEW)
 
 set (lib_name "${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_STATIC_LIBRARY_PREFIX}lib${CMAKE_STATIC_LIBRARY_SUFFIX}")
 if (CMAKE_SYSTEM_NAME STREQUAL "Windows")
-  if (RunCMake_C_COMPILER_ID STREQUAL "MSVC")
+  if (RunCMake_C_COMPILER_ID STREQUAL "MSVC" OR "x${CMAKE_C_SIMULATE_ID}" 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 17af2f7..9939a42 100644
--- a/Tests/RunCMake/try_run/LinkOptions.cmake
+++ b/Tests/RunCMake/try_run/LinkOptions.cmake
@@ -5,7 +5,7 @@ cmake_policy(SET CMP0054 NEW)
 
 set (lib_name "${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_STATIC_LIBRARY_PREFIX}lib${CMAKE_STATIC_LIBRARY_SUFFIX}")
 if (CMAKE_SYSTEM_NAME STREQUAL "Windows")
-  if (RunCMake_C_COMPILER_ID STREQUAL "MSVC")
+  if (RunCMake_C_COMPILER_ID STREQUAL "MSVC" OR "x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC")
     if (CMAKE_SIZEOF_VOID_P EQUAL 4)
       set (undef_flag /INCLUDE:_func)
     else()