Introduces gtest_force_shared_crt option for CMake build scripts.

CMakeLists.txt

@@ -12,6 +12,13 @@
 # make it prominent in the GUI.
 option(BUILD_SHARED_LIBS "Build shared libraries (DLLs)." OFF)
 
+# When other libraries are using a shared version of runtime libraries,
+# Google Test also has to use one.
+option(
+  gtest_force_shared_crt
+  "Use shared (DLL) run-time lib even when Google Test is built as static lib."
+  OFF)
+
 option(gtest_build_tests "Build all of gtest's own tests." OFF)
 
 option(gtest_build_samples "Build gtest's sample programs." OFF)

cmake/internal_utils.cmake

@@ -15,7 +15,7 @@ macro(fix_default_settings)
     foreach (flag_var
              CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_RELEASE
              CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELWITHDEBINFO)
-      if (NOT BUILD_SHARED_LIBS)
+      if (NOT BUILD_SHARED_LIBS AND NOT gtest_force_shared_crt)
         # When Google Test is built as a shared library, it should also use
         # shared runtime libraries.  Otherwise, it may end up with multiple
         # copies of runtime library data in different modules, resulting in