gcc/testsuite/gcc.dg/cpp/warn-comments-2.c

   1 // { dg-do preprocess }
   2 // { dg-options "-std=gnu99 -fdiagnostics-show-option -Werror=comments" }
   3
   4 /* /* */  // { dg-error "\"\.\*\" within comment .-Wcomments." }
   5
   6 // \
   7           // { dg-error "multi-line comment .-Wcomments." "multi-line" { target *-*-* } 6 }