From 9d7b3aa647c400c15c773eda0e9a682a4ac2a547 Mon Sep 17 00:00:00 2001
From: jakub <jakub@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 5 Jan 2017 21:13:09 +0000
Subject: [PATCH] 	PR c++/78931 	* decl.c (cp_finish_decomp): Remove
 probe variable, if tt is 	REFERENCE_REF_P, set tt to its operand.

	* g++.dg/cpp1z/decomp19.C: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@244113 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/cp/ChangeLog                      |  4 ++++
 gcc/cp/decl.c                         |  7 +++----
 gcc/testsuite/ChangeLog               |  3 +++
 gcc/testsuite/g++.dg/cpp1z/decomp19.C | 13 +++++++++++++
 4 files changed, 23 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp1z/decomp19.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 5bc7d5217686..1d87845a882b 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2017-01-05  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/78931
+	* decl.c (cp_finish_decomp): Remove probe variable, if tt is
+	REFERENCE_REF_P, set tt to its operand.
+
 	PR c++/78890
 	* class.c (check_field_decls): Diagnose REFERENCE_TYPE fields in
 	unions even for C++11 and later.
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 26c11e261054..75baf94b2d96 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7593,10 +7593,9 @@ cp_finish_decomp (tree decl, tree first, unsigned int count)
 	else
 	  {
 	    tree tt = finish_non_static_data_member (field, t, NULL_TREE);
-	    tree probe = tt;
-	    if (REFERENCE_REF_P (probe))
-	      probe = TREE_OPERAND (probe, 0);
-	    TREE_TYPE (v[i]) = TREE_TYPE (probe);
+	    if (REFERENCE_REF_P (tt))
+	      tt = TREE_OPERAND (tt, 0);
+	    TREE_TYPE (v[i]) = TREE_TYPE (tt);
 	    layout_decl (v[i], 0);
 	    SET_DECL_VALUE_EXPR (v[i], tt);
 	    DECL_HAS_VALUE_EXPR_P (v[i]) = 1;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c992d7139219..cd205bd7dd4f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2017-01-05  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/78931
+	* g++.dg/cpp1z/decomp19.C: New test.
+
 	PR c++/78890
 	* g++.dg/init/ref14.C: Expect error even in C++11 and later.
 	* g++.dg/init/union1.C: Likewise.
diff --git a/gcc/testsuite/g++.dg/cpp1z/decomp19.C b/gcc/testsuite/g++.dg/cpp1z/decomp19.C
new file mode 100644
index 000000000000..e392e658e27a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/decomp19.C
@@ -0,0 +1,13 @@
+// PR c++/78931
+// { dg-do run { target c++11 } }
+// { dg-options "" }
+
+int
+main ()
+{
+  int x = 99;
+  struct S { int &x; };
+  S s{x};
+  auto [p] = s;		// { dg-warning "decomposition declaration only available with" "" { target c++14_down } }
+  return p - 99;
+}
-- 
2.11.4.GIT