Use -dead_strip linker flag instead of --gc-sections on OS X.

toolchain/generic.cmake

@@ -13,8 +13,11 @@ set(SIZE                size)
 set(CMAKE_C_FLAGS   "-std=gnu99 -fdata-sections -ffunction-sections" CACHE INTERNAL "c compiler flags")
 set(CMAKE_CXX_FLAGS "-fdata-sections -ffunction-sections" CACHE INTERNAL "cxx compiler flags")
 set(CMAKE_ASM_FLAGS "" CACHE INTERNAL "asm compiler flags")
-set(CMAKE_EXE_LINKER_FLAGS "-Wl,--gc-sections" CACHE INTERNAL "exe link flags")
-
+if (APPLE)
+    set(CMAKE_EXE_LINKER_FLAGS "-dead_strip" CACHE INTERNAL "exe link flags")
+else (APPLE)
+    set(CMAKE_EXE_LINKER_FLAGS "-Wl,--gc-sections" CACHE INTERNAL "exe link flags")
+endif (APPLE)
 
 SET(CMAKE_C_FLAGS_DEBUG "-O0 -g -ggdb3" CACHE INTERNAL "c debug compiler flags")
 SET(CMAKE_CXX_FLAGS_DEBUG "-O0 -g -ggdb3" CACHE INTERNAL "cxx debug compiler flags")
@@ -22,4 +25,4 @@ SET(CMAKE_ASM_FLAGS_DEBUG "-g -ggdb3" CACHE INTERNAL "asm debug compiler flags")
 
 SET(CMAKE_C_FLAGS_RELEASE "-O2" CACHE INTERNAL "c release compiler flags")
 SET(CMAKE_CXX_FLAGS_RELEASE "-O2" CACHE INTERNAL "cxx release compiler flags")
-SET(CMAKE_ASM_FLAGS_RELEASE "" CACHE INTERNAL "asm release compiler flags")
+SET(CMAKE_ASM_FLAGS_RELEASE "" CACHE INTERNAL "asm release compiler flags")