array-2.c

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

/* { dg-do compile } */
/* { dg-options "" } */

/* Verify that we can't do things to get ourselves in trouble
   with GCC's initialized flexible array member extension.  */

struct f { int w; int x[]; };
struct g { struct f f; };
struct g g1 = { { 0, { } } };
struct g g2 = { { 0, { 1 } } }; /* { dg-error "(nested context)|(near initialization)" "nested" } */

struct h { int x[0]; int y; };
struct h h1 = { { 0 }, 1 }; /* { dg-error "(excess elements)|(near initialization)" "before end" } */