From 69deaf149a531fe55c058b87609f9f1c56ab6fc6 Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Tue, 25 Sep 2018 18:40:57 +0200
Subject: [PATCH] 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                              |  6 +++++
 gcc/cp/constexpr.c                            |  3 ++-
 gcc/testsuite/ChangeLog                       |  7 +++++
 .../g++.dg/cpp2a/constexpr-virtual10.C        | 18 +++++++++++++
 .../g++.dg/cpp2a/constexpr-virtual11.C        | 26 +++++++++++++++++++
 gcc/testsuite/g++.dg/other/pr87398.C          | 12 +++++++++
 6 files changed, 71 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp2a/constexpr-virtual10.C
 create mode 100644 gcc/testsuite/g++.dg/cpp2a/constexpr-virtual11.C
 create mode 100644 gcc/testsuite/g++.dg/other/pr87398.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 9ce845d20ac..672626c27d9 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+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
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index 08d00e859d8..403edda8c47 100644
--- a/gcc/cp/constexpr.c
+++ b/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
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 24bf238e0f6..68f1c3d9a2b 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+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
diff --git a/gcc/testsuite/g++.dg/cpp2a/constexpr-virtual10.C b/gcc/testsuite/g++.dg/cpp2a/constexpr-virtual10.C
new file mode 100644
index 00000000000..dd96bef1810
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/constexpr-virtual10.C
@@ -0,0 +1,18 @@
+// 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);
diff --git a/gcc/testsuite/g++.dg/cpp2a/constexpr-virtual11.C b/gcc/testsuite/g++.dg/cpp2a/constexpr-virtual11.C
new file mode 100644
index 00000000000..f7b46d3098f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/constexpr-virtual11.C
@@ -0,0 +1,26 @@
+// 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);
diff --git a/gcc/testsuite/g++.dg/other/pr87398.C b/gcc/testsuite/g++.dg/other/pr87398.C
new file mode 100644
index 00000000000..00a2cd3f1c7
--- /dev/null
+++ b/gcc/testsuite/g++.dg/other/pr87398.C
@@ -0,0 +1,12 @@
+// 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;
+}
-- 
2.30.2