PR c++/88565 - enhance -Warray-bounds for C++ trailing class member arrays

gcc/testsuite/ChangeLog:

	* g++.dg/warn/Warray-bounds-9.C: New test.

From-SVN: r277758

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2019-11-03  Martin Sebor  <msebor@redhat.com>
+
+	PR c++/88565
+	* g++.dg/warn/Warray-bounds-9.C: New test.
+
 2019-11-02  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	* g++.dg/conversion/ptrmem9.C: Check location.

gcc/testsuite/g++.dg/warn/Warray-bounds-9.C

@@ -0,0 +1,81 @@
+/* PR c++/88565 - enhance -Warray-bounds for C++ trailing class member arrays
+   { dg-do compile }
+   { dg-options "-O2 -Wall" } */
+
+struct S0
+{
+  S0 ();
+
+  int f ();
+
+  int a[0];
+};
+
+int S0::f ()
+{
+  // The following is not diagnosed but should be in a class with a ctor.
+  return a[0];      // { dg-warning "\\\[-Warray-bounds" "pr88565" { xfail *-*-* } }
+}
+
+
+struct S1
+{
+  S1 ();
+
+  int f ();
+
+  int a[1];
+};
+
+int S1::f ()
+{
+  // The following is only diagnosed with -Warray-bounds=2 but should
+  // be even at level 1 in a call with a ctor.
+  return a[1];      // { dg-warning "\\\[-Warray-bounds" "pr88565" { xfail *-*-* } }
+}
+
+
+struct S2
+{
+  S2 ();
+
+  int f ();
+
+  int a[2];
+};
+
+int S2::f ()
+{
+  return a[2];      // { dg-warning "\\\[-Warray-bounds" }
+}
+
+
+struct S3
+{
+  S3 ();
+
+  int f ();
+
+  int a[3];
+};
+
+int S3::f ()
+{
+  return a[3];      // { dg-warning "\\\[-Warray-bounds" }
+}
+
+
+struct Sx
+{
+  Sx ();
+
+  int f ();
+
+  int n, a[];
+};
+
+int Sx::f ()
+{
+  // The following is not diagnosed but should be in a class with a ctor.
+  return a[0];      // { dg-warning "\\\[-Warray-bounds" "pr88565" { xfail *-*-* } }
+}