From e3a661b45e8d9baf96bef773e214f4c41581bc22 Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Fri, 15 Dec 2017 20:41:45 +0100
Subject: [PATCH] re PR c++/83217 (Compiler segfault: structured binding by
 reference to a templated type via a pointer)

	PR c++/83217
	* decl.c (cp_finish_decomp): If decl's type is REFERENCE_TYPE,
	call complete_type (TREE_TYPE (type)).

	* g++.dg/cpp1z/decomp33.C: New test.

From-SVN: r255702
---
 gcc/cp/ChangeLog                      |  4 ++++
 gcc/cp/decl.c                         |  4 +++-
 gcc/testsuite/ChangeLog               |  3 +++
 gcc/testsuite/g++.dg/cpp1z/decomp33.C | 21 +++++++++++++++++++++
 4 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp1z/decomp33.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 25d7f58ea58..1108aeb890c 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2017-12-15  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/83217
+	* decl.c (cp_finish_decomp): If decl's type is REFERENCE_TYPE,
+	call complete_type (TREE_TYPE (type)).
+
 	* tree.c (cxx_attribute_table, std_attribute_table): Swap
 	affects_type_identity and handler fields, adjust comments.
 
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 63a7b92b3bc..5df16bb21bf 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7404,7 +7404,9 @@ cp_finish_decomp (tree decl, tree first, unsigned int count)
   if (TREE_CODE (type) == REFERENCE_TYPE)
     {
       dexp = convert_from_reference (dexp);
-      type = TREE_TYPE (type);
+      type = complete_type (TREE_TYPE (type));
+      if (type == error_mark_node)
+	goto error_out;
     }
 
   tree eltype = NULL_TREE;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3d037b53d9d..cd208ff1a7f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2017-12-15  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/83217
+	* g++.dg/cpp1z/decomp33.C: New test.
+
 	PR tree-optimization/80631
 	* gcc.target/i386/avx2-pr80631.c: New test.
 
diff --git a/gcc/testsuite/g++.dg/cpp1z/decomp33.C b/gcc/testsuite/g++.dg/cpp1z/decomp33.C
new file mode 100644
index 00000000000..6429108dd7c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/decomp33.C
@@ -0,0 +1,21 @@
+// PR c++/83217
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+template <typename T>
+struct S
+{
+  T a;
+};
+
+void
+foo (S<int> *b)
+{
+  auto & [c] = *b;	// { dg-warning "structured bindings only available with" "" { target c++14_down } }
+}
+
+void
+bar (S<char> *d)
+{
+  auto [e] = *d;	// { dg-warning "structured bindings only available with" "" { target c++14_down } }
+}
-- 
2.30.2