move gtest-specific check into gtest/CMakeLists.txt

test/CMakeLists.txt

@@ -8,13 +8,6 @@ target_link_libraries(test-main gtest)
 
 include(CheckCXXCompilerFlag)
 
-# Workaround GTest bug https://github.com/google/googletest/issues/705.
-check_cxx_compiler_flag(
-  -fno-delete-null-pointer-checks HAVE_FNO_DELETE_NULL_POINTER_CHECKS)
-if (HAVE_FNO_DELETE_NULL_POINTER_CHECKS)
-  target_compile_options(test-main PUBLIC -fno-delete-null-pointer-checks)
-endif ()
-
 # Use less strict pedantic flags for the tests because GMock doesn't compile
 # cleanly with -pedantic and -std=c++98.
 if (CMAKE_COMPILER_IS_GNUCXX OR (CMAKE_CXX_COMPILER_ID MATCHES "Clang"))

test/gtest/CMakeLists.txt

@@ -17,6 +17,13 @@ else ()
   target_compile_definitions(gtest PUBLIC GTEST_HAS_PTHREAD=0)
 endif ()
 
+# Workaround GTest bug https://github.com/google/googletest/issues/705.
+check_cxx_compiler_flag(
+  -fno-delete-null-pointer-checks HAVE_FNO_DELETE_NULL_POINTER_CHECKS)
+if (HAVE_FNO_DELETE_NULL_POINTER_CHECKS)
+  target_compile_options(gtest PUBLIC -fno-delete-null-pointer-checks)
+endif ()
+
 if (MSVC)
   # Disable MSVC warnings of _CRT_INSECURE_DEPRECATE functions.
   target_compile_definitions(gtest PRIVATE _CRT_SECURE_NO_WARNINGS)