Tests: Only really run MFC test if we can build MFC apps (#11213)

Avoid problems on "undetected" VS Express build environments.

Tests/CMakeLists.txt

@@ -1244,6 +1244,56 @@ ${CMake_BINARY_DIR}/bin/cmake -DVERSION=master -P ${CMake_SOURCE_DIR}/Utilities/
           set(CTEST_RUN_MFC OFF)
         endif()
       endif()
+
+      # Last resort, after quick checks are done. Do a try_compile, and avoid
+      # the MFC test if the simplest possible MFC app cannot be compiled.
+      if(CTEST_RUN_MFC AND NOT DEFINED HAVE_MFC)
+        configure_file(
+          ${CMAKE_CURRENT_SOURCE_DIR}/MFC/try_compile/CMakeLists.txt
+          ${CMAKE_CURRENT_BINARY_DIR}/MFC/try_compile/CMakeLists.txt
+          COPYONLY
+          )
+        configure_file(
+          ${CMAKE_CURRENT_SOURCE_DIR}/MFC/mfc1/stdafx.cpp
+          ${CMAKE_CURRENT_BINARY_DIR}/MFC/try_compile/stdafx.cpp
+          COPYONLY
+          )
+        configure_file(
+          ${CMAKE_CURRENT_SOURCE_DIR}/MFC/mfc1/stdafx.h
+          ${CMAKE_CURRENT_BINARY_DIR}/MFC/try_compile/stdafx.h
+          COPYONLY
+          )
+
+        message(STATUS "Looking for MFC")
+
+        try_compile(HAVE_MFC
+          ${CMAKE_CURRENT_BINARY_DIR}/MFC/try_compile/build
+          ${CMAKE_CURRENT_BINARY_DIR}/MFC/try_compile
+          try_compile_mfc
+          OUTPUT_VARIABLE HAVE_MFC_OUTPUT)
+
+        if(HAVE_MFC)
+          message(STATUS "Looking for MFC - found")
+          set(HAVE_MFC 1 CACHE INTERNAL "Have MFC")
+          file(APPEND
+            ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+            "Determining if MFC exists passed with the following output:\n"
+            "${HAVE_MFC_OUTPUT}\n\n")
+        else()
+          message(STATUS "Looking for MFC - not found")
+          set(HAVE_MFC "" CACHE INTERNAL "Have MFC")
+          file(APPEND
+            ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+            "Determining if MFC exists failed with the following output:\n"
+            "${HAVE_MFC_OUTPUT}\n\n")
+        endif()
+      endif()
+
+      if(CTEST_RUN_MFC AND NOT HAVE_MFC)
+        message(STATUS
+          "cannot compile simplest ever MFC app, avoiding MFC test")
+        set(CTEST_RUN_MFC OFF)
+      endif()
     endif()
   endif()
 

Tests/MFC/try_compile/CMakeLists.txt

@@ -0,0 +1,15 @@
+cmake_minimum_required(VERSION 2.8)
+project(try_compile_mfc)
+
+set(files
+  stdafx.cpp
+  stdafx.h
+)
+
+set(CMAKE_MFC_FLAG "2")
+
+# VS generators add this automatically based on the CMAKE_MFC_FLAG value,
+# but generators matching "Make" require:
+add_definitions(-D_AFXDLL)
+
+add_executable(simplest_possible_mfc_exe WIN32 ${files})