--- /dev/null
+/* testing the correct usage of flexible array members in unions
+ and alone in structures. */
+/* { dg-do run} */
+/* { dg-options "-Wpedantic" } */
+
+union with_fam_1 {
+ int a;
+ int b[]; /* { dg-warning "flexible array member in union is a GCC extension" } */
+};
+
+union with_fam_2 {
+ char a;
+ int b[]; /* { dg-warning "flexible array member in union is a GCC extension" } */
+};
+
+union with_fam_3 {
+ char a[]; /* { dg-warning "flexible array member in union is a GCC extension" } */
+ /* { dg-warning "in an otherwise empty" "" { target c++ } .-1 } */
+ int b[]; /* { dg-warning "flexible array member in union is a GCC extension" } */
+};
+
+struct only_fam {
+ int b[];
+ /* { dg-warning "in a struct with no named members" "" { target c } .-1 } */
+ /* { dg-warning "in an otherwise empty" "" { target c++ } .-2 } */
+ /* { dg-warning "forbids flexible array member" "" { target c++ } .-3 } */
+};
+
+struct only_fam_2 {
+ unsigned int : 2;
+ unsigned int : 3;
+ int b[];
+ /* { dg-warning "in a struct with no named members" "" { target c } .-1 } */
+ /* { dg-warning "in an otherwise empty" "" { target c++ } .-2 } */
+ /* { dg-warning "forbids flexible array member" "" { target c++ } .-3 } */
+};
+
+int main ()
+{
+ if (sizeof (union with_fam_1) != sizeof (int))
+ __builtin_abort ();
+ if (sizeof (union with_fam_2) != __alignof__ (int))
+ __builtin_abort ();
+ if (sizeof (union with_fam_3) != 0)
+ __builtin_abort ();
+ if (sizeof (struct only_fam) != 0)
+ __builtin_abort ();
+ if (sizeof (struct only_fam_2) != sizeof (int))
+ __builtin_abort ();
+ return 0;
+}
+
--- /dev/null
+/* testing the correct usage of flexible array members in unions
+ and alone in structures: initialization */
+/* { dg-do run} */
+/* { dg-options "-O2" } */
+
+union with_fam_1 {
+ int a;
+ int b[];
+} with_fam_1_v = {.b = {1, 2, 3, 4}};
+
+union with_fam_2 {
+ int a;
+ char b[];
+} with_fam_2_v = {.a = 0x1f2f3f4f};
+
+union with_fam_3 {
+ char a[];
+ int b[];
+} with_fam_3_v = {.b = {0x1f2f3f4f, 0x5f6f7f7f}};
+
+struct only_fam {
+ int b[];
+} only_fam_v = {{7, 11}};
+
+struct only_fam_2 {
+ unsigned int : 2;
+ unsigned int : 3;
+ int b[];
+} only_fam_2_v = {{7, 11}};
+
+int main ()
+{
+ if (with_fam_1_v.b[3] != 4
+ || with_fam_1_v.b[0] != 1)
+ __builtin_abort ();
+ if (with_fam_2_v.b[3] != 0x1f
+ || with_fam_2_v.b[0] != 0x4f)
+ __builtin_abort ();
+ if (with_fam_3_v.a[0] != 0x4f
+ || with_fam_3_v.a[7] != 0x5f)
+ __builtin_abort ();
+ if (only_fam_v.b[0] != 7
+ || only_fam_v.b[1] != 11)
+ __builtin_abort ();
+ if (only_fam_2_v.b[0] != 7
+ || only_fam_2_v.b[1] != 11)
+ __builtin_abort ();
+
+ return 0;
+}
+
--- /dev/null
+/* testing the correct usage of flexible array members in unions
+ and alone in structures. */
+/* { dg-do compile } */
+/* { dg-options "-pedantic-errors" } */
+
+union with_fam_1 {
+ int a;
+ int b[]; /* { dg-error "flexible array member in union is a GCC extension" } */
+};
+
+union with_fam_2 {
+ char a;
+ int b[]; /* { dg-error "flexible array member in union is a GCC extension" } */
+};
+
+union with_fam_3 {
+ char a[]; /* { dg-error "flexible array member in union is a GCC extension" } */
+ /* { dg-error "in an otherwise empty" "" { target c++ } .-1 } */
+ int b[]; /* { dg-error "flexible array member in union is a GCC extension" } */
+};
+
+struct only_fam {
+ int b[];
+ /* { dg-error "in a struct with no named members" "" { target c } .-1 } */
+ /* { dg-error "in an otherwise empty" "" { target c++ } .-2 } */
+ /* { dg-error "forbids flexible array member" "" { target c++ } .-3 } */
+};
+
+struct only_fam_2 {
+ unsigned int : 2;
+ unsigned int : 3;
+ int b[];
+ /* { dg-error "in a struct with no named members" "" { target c } .-1 } */
+ /* { dg-error "in an otherwise empty" "" { target c++ } .-2 } */
+ /* { dg-error "forbids flexible array member" "" { target c++ } .-3 } */
+};