(root)/
gcc-13.2.0/
gcc/
testsuite/
gcc.dg/
cpp/
warn-undef.c
       1  // { dg-do preprocess }
       2  // { dg-options "-std=gnu99 -fdiagnostics-show-option -Wundef" }
       3  
       4  #if x  // { dg-warning "\"x\" is not defined, evaluates to 0 .-Wundef." }
       5  #endif