moved to generator expressions for cmake debug flags

cmake_modules/TokuSetupCompiler.cmake

@@ -23,9 +23,9 @@ if (NOT CMAKE_SYSTEM_NAME STREQUAL FreeBSD)
 endif ()
 
 ## add TOKU_PTHREAD_DEBUG for debug builds
-set_property(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS_DEBUG TOKU_PTHREAD_DEBUG=1)
-set_property(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS_DRD TOKU_PTHREAD_DEBUG=1)
-set_property(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS_DRD _FORTIFY_SOURCE=2)
+set_property(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS
+  $<$<OR:$<CONFIG:DEBUG>,$<CONFIG:DRD>>:TOKU_PTHREAD_DEBUG=1>
+  $<$<CONFIG:DRD>:_FORTIFY_SOURCE=2>)
 
 ## coverage
 option(USE_GCOV "Use gcov for test coverage." OFF)