#include <stdio.h> int main(){    /* must not affect how #pragma ppop_macro works */    #define pop_macro foobar1     /* must not affect how #pragma push_macro works */    #define push_macro foobar2     #undef abort    #define abort "111"    printf("abort = %s\n", abort);     #pragma push_macro("abort")    #undef abort    #define abort "222"    printf("abort = %s\n", abort);     #pragma push_macro("abort")    #undef abort    #define abort "333"    printf("abort = %s\n", abort);     #pragma pop_macro("abort")    printf("abort = %s\n", abort);     #pragma pop_macro("abort")    printf("abort = %s\n", abort);}