#include <string.h>/* config.h must not be in quotes: * https://gcc.gnu.org/onlinedocs/cpp/Search-Path.html */#include <config.h>#ifdef SHOULD_BE_UNDEF#error"FAIL!"#endifintmain(void) {#ifndef BE_TRUEreturn1;#elsereturnstrcmp(MESSAGE,"mystring");#endif}