20 #ifndef __JackCompilerDeps_POSIX__    21 #define __JackCompilerDeps_POSIX__    23 #include "JackConstants.h"    27     #define MEM_ALIGN(x,y) x __attribute__((aligned(y)))    28     #define LIB_EXPORT __attribute__((visibility("default")))    33             #define SERVER_EXPORT __attribute__((visibility("default")))    36         #define SERVER_EXPORT __attribute__((visibility("hidden")))    40     #define MEM_ALIGN(x,y) x