Fix the linking of various tests against GMock

Summary: A define was needed to be able to link when built against a shared-library version of gmock and gtest.

Reviewed By: yfeldblum

Differential Revision: D5100409

fbshipit-source-id: 9a4c9df20f682a25edde642c451476b2d1e1ae22

CMake/FindGMock.cmake

 #
 # Find libgmock
 #
+#  LIBGMOCK_DEFINES     - List of defines when using libgmock.
 #  LIBGMOCK_INCLUDE_DIR - where to find gmock/gmock.h, etc.
 #  LIBGMOCK_LIBRARY     - List of libraries when using libgmock.
 #  LIBGMOCK_FOUND       - True if libgmock found.
@@ -15,9 +16,14 @@ FIND_PATH(LIBGMOCK_INCLUDE_DIR gmock/gmock.h)
 
 FIND_LIBRARY(LIBGMOCK_LIBRARY gmock_main)
 
+# There isn't currently an easy way to determine if a library was compiled as
+# a shared library on Windows, so just assume we've been built against a shared
+# build of gmock for now.
+SET(LIBGMOCK_DEFINES "GTEST_LINKED_AS_SHARED_LIBRARY=1" CACHE STRING "")
+
 # handle the QUIETLY and REQUIRED arguments and set LIBGMOCK_FOUND to TRUE if
 # all listed variables are TRUE
 INCLUDE(FindPackageHandleStandardArgs)
-FIND_PACKAGE_HANDLE_STANDARD_ARGS(LIBGMOCK DEFAULT_MSG LIBGMOCK_LIBRARY LIBGMOCK_INCLUDE_DIR)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(LIBGMOCK DEFAULT_MSG LIBGMOCK_DEFINES LIBGMOCK_LIBRARY LIBGMOCK_INCLUDE_DIR)
 
-MARK_AS_ADVANCED(LIBGMOCK_LIBRARY LIBGMOCK_INCLUDE_DIR)
+MARK_AS_ADVANCED(LIBGMOCK_DEFINES LIBGMOCK_LIBRARY LIBGMOCK_INCLUDE_DIR)

CMakeLists.txt

@@ -263,6 +263,10 @@ if (BUILD_TESTS)
     ${FOLLY_DIR}/io/async/test/UndelayedDestruction.h
     ${FOLLY_DIR}/io/async/test/Util.h
   )
+  target_compile_definitions(folly_test_support
+    PUBLIC
+      ${LIBGMOCK_DEFINES}
+  )
   target_include_directories(folly_test_support
     PUBLIC
       ${LIBGMOCK_INCLUDE_DIR}