re PR c++/87398 (g++ ICE on valid code: tree check: expected record_type or…

re PR c++/87398 (g++ ICE on valid code: tree check: expected record_type or union_type or qual_union_type, have array_type in cxx_eval_constant_expression, at cp/constexpr.c:4820)

	PR c++/87398
	* constexpr.c (cxx_eval_constant_expression) <case OBJ_TYPE_REF>: Only
	look through COMPONENT_REFs with DECL_FIELD_IS_BASE FIELD_DECLs.

	* g++.dg/other/pr87398.C: New test.
	* g++.dg/cpp2a/constexpr-virtual10.C: New test.
	* g++.dg/cpp2a/constexpr-virtual11.C: New test.

From-SVN: r264580

gcc/cp/ChangeLog

+2018-09-25  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/87398
+	* constexpr.c (cxx_eval_constant_expression) <case OBJ_TYPE_REF>: Only
+	look through COMPONENT_REFs with DECL_FIELD_IS_BASE FIELD_DECLs.
+
 2018-09-25  Martin Liska  <mliska@suse.cz>
 
 	* name-lookup.c (namespace_scope_ht_size): Remove

gcc/cp/constexpr.c

@@ -4812,7 +4812,8 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t,
 	    return t;
 	  }
 	obj = TREE_OPERAND (obj, 0);
-	while (handled_component_p (obj))
+	while (TREE_CODE (obj) == COMPONENT_REF
+	       && DECL_FIELD_IS_BASE (TREE_OPERAND (obj, 1)))
 	  obj = TREE_OPERAND (obj, 0);
 	tree objtype = TREE_TYPE (obj);
 	/* Find the function decl in the virtual functions list.  TOKEN is

gcc/testsuite/ChangeLog

+2018-09-25  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/87398
+	* g++.dg/other/pr87398.C: New test.
+	* g++.dg/cpp2a/constexpr-virtual10.C: New test.
+	* g++.dg/cpp2a/constexpr-virtual11.C: New test.
+
 2018-09-25  Martin Jambor  <mjambor@suse.cz>
 
 	PR testsuite/87339

gcc/testsuite/g++.dg/cpp2a/constexpr-virtual10.C

+// P1064R0
+// { dg-do compile }
+// { dg-options "-std=c++2a" }
+
+struct X
+{
+  constexpr virtual int f() const { return 1; };
+};
+
+struct Y : public X
+{
+  constexpr virtual int f() const { return 2; };
+};
+
+constexpr X a[2][1][3];
+constexpr Y b[3][12];
+static_assert (a[1][0][1].f() == 1);
+static_assert (b[2][11].f() == 2);

gcc/testsuite/g++.dg/cpp2a/constexpr-virtual11.C

+// P1064R0
+// { dg-do compile }
+// { dg-options "-std=c++2a" }
+
+struct A
+{
+  constexpr virtual int f () const { return 1; }
+};
+
+struct B : public A
+{
+  constexpr virtual int f () const { return 2; }
+};
+
+struct C
+{
+  A a;
+  B b;
+};
+
+constexpr C c;
+constexpr const A &d = c.a;
+constexpr const A &e = c.b;
+constexpr const B &f = c.b;
+static_assert (c.a.f () == 1 && c.b.f () == 2);
+static_assert (d.f () == 1 && e.f () == 2 && f.f () == 2);

gcc/testsuite/g++.dg/other/pr87398.C

+// PR c++/87398
+// { dg-do compile }
+
+struct A { virtual int foo (); };
+
+int
+bar (int x)
+{
+  A e[5][2];
+  int f = e[4][x].foo ();
+  return f;
+}