4 files changed, 40 insertions, 0 deletions
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index bf6ce97..503d8b4 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2018-07-31  Tom de Vries  <tdevries@suse.de>
+
+	PR debug/86687
+	* optimize.c (update_cloned_parm): Copy DECL_BY_REFERENCE.
+
 2018-07-31  Jakub Jelinek  <jakub@redhat.com>
 
 	P1008R1 - prohibit aggregates with user-declared constructors
diff --git a/gcc/cp/optimize.c b/gcc/cp/optimize.c
index 0e9b84e..3923a5f 100644
--- a/gcc/cp/optimize.c
+++ b/gcc/cp/optimize.c
@@ -46,6 +46,8 @@ update_cloned_parm (tree parm, tree cloned_parm, bool first)
   /* We may have taken its address.  */
   TREE_ADDRESSABLE (cloned_parm) = TREE_ADDRESSABLE (parm);
 
+  DECL_BY_REFERENCE (cloned_parm) = DECL_BY_REFERENCE (parm);
+
   /* The definition might have different constness.  */
   TREE_READONLY (cloned_parm) = TREE_READONLY (parm);
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 90fb9c1..2cc6973 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-07-31  Tom de Vries  <tdevries@suse.de>
+
+	PR debug/86687
+	* g++.dg/guality/pr86687.C: New test.
+
 2018-07-31  Jakub Jelinek  <jakub@redhat.com>
 
 	P1008R1 - prohibit aggregates with user-declared constructors
diff --git a/gcc/testsuite/g++.dg/guality/pr86687.C b/gcc/testsuite/g++.dg/guality/pr86687.C
new file mode 100644
index 0000000..140a6fc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/guality/pr86687.C
@@ -0,0 +1,28 @@
+// PR debug/86687
+// { dg-do run }
+// { dg-options "-g" }
+
+class string {
+public:
+  string (int p) { this->p = p ; }
+  string (const string &s) { this->p = s.p; }
+
+  int p;
+};
+
+class foo {
+public:
+  foo (string dir_hint) {
+    p = dir_hint.p; // { dg-final { gdb-test . "dir_hint.p" 3 } }
+  }
+
+  int p;
+};
+
+int
+main (void)
+{
+  string s = 3;
+  foo bar(s);
+  return !(bar.p == 3);
+}