re PR c++/85061 (ICE with __builtin_offsetof applied to static member)

	PR c++/85061
	* c-common.c (fold_offsetof_1) <case COMPOUND_EXPR>: Assert that
	get_base_address of the second operand is a VAR_P, rather than the
	operand itself, and use gcc_checking_assert instead of gcc_assert.

	* g++.dg/ext/builtin-offsetof3.C: New test.

From-SVN: r258902

gcc/c-family/ChangeLog

+2018-03-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/85061
+	* c-common.c (fold_offsetof_1) <case COMPOUND_EXPR>: Assert that
+	get_base_address of the second operand is a VAR_P, rather than the
+	operand itself, and use gcc_checking_assert instead of gcc_assert.
+
 2018-03-23  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/85045

gcc/c-family/c-common.c

@@ -6272,7 +6272,7 @@ fold_offsetof_1 (tree expr, enum tree_code ctx)
     case COMPOUND_EXPR:
       /* Handle static members of volatile structs.  */
       t = TREE_OPERAND (expr, 1);
-      gcc_assert (VAR_P (t));
+      gcc_checking_assert (VAR_P (get_base_address (t)));
       return fold_offsetof_1 (t);
 
     default:

gcc/testsuite/ChangeLog

 2018-03-27  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/85061
+	* g++.dg/ext/builtin-offsetof3.C: New test.
+
 	PR c++/85076
 	* g++.dg/cpp1y/pr85076.C: New test.
 

gcc/testsuite/g++.dg/ext/builtin-offsetof3.C

+// PR c++/85061
+// { dg-do compile }
+
+struct B { int a, b; };
+struct A
+{
+  static int x[2];
+  static int y;
+  static B z;
+};
+
+int i = __builtin_offsetof (volatile A, x[0]);	// { dg-error "cannot apply 'offsetof' to static data member 'A::x'" }
+int j = __builtin_offsetof (volatile A, y);	// { dg-error "cannot apply 'offsetof' to static data member 'A::y'" }
+int k = __builtin_offsetof (volatile A, z.a);	// { dg-error "cannot apply 'offsetof' to a non constant address" }