From cd09079cfd50d289cbb05eadb728a0713f6bae8a Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Fri, 15 Jan 2021 11:42:00 -0500
Subject: [PATCH] c++: Fix list-init of array of no-copy type [PR63707]

build_vec_init_elt models initialization from some arbitrary object of the
type, i.e. copy, but in the case of list-initialization we don't do a copy
from the elements, we initialize them directly.

gcc/cp/ChangeLog:

	PR c++/63707
	* tree.c (build_vec_init_expr): Don't call build_vec_init_elt
	if we got a CONSTRUCTOR.

gcc/testsuite/ChangeLog:

	PR c++/63707
	* g++.dg/cpp0x/initlist-array13.C: New test.
---
 gcc/cp/tree.c                                 | 10 +++++++++-
 gcc/testsuite/g++.dg/cpp0x/initlist-array13.C | 16 ++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/initlist-array13.C

diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index 3a9a86de34a0..290e73bad837 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -787,7 +787,15 @@ build_vec_init_expr (tree type, tree init, tsubst_flags_t complain)
 {
   tree slot;
   bool value_init = false;
-  tree elt_init = build_vec_init_elt (type, init, complain);
+  tree elt_init;
+  if (init && TREE_CODE (init) == CONSTRUCTOR)
+    {
+      gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (init));
+      /* We built any needed constructor calls in digest_init.  */
+      elt_init = init;
+    }
+  else
+    elt_init = build_vec_init_elt (type, init, complain);
 
   if (init == void_type_node)
     {
diff --git a/gcc/testsuite/g++.dg/cpp0x/initlist-array13.C b/gcc/testsuite/g++.dg/cpp0x/initlist-array13.C
new file mode 100644
index 000000000000..92fe97164cd3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/initlist-array13.C
@@ -0,0 +1,16 @@
+// PR c++/63707
+// { dg-do compile { target c++11 } }
+
+struct Child
+{
+  Child (int);
+  ~Child ();
+  Child (const Child &) = delete;
+};
+
+struct Parent
+{
+  Parent () : children {{5}, {7}} {}
+
+  Child children[2];
+};
-- 
GitLab