re PR c++/83217 (Compiler segfault: structured binding by reference to a…

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

 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.
 

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;

gcc/testsuite/ChangeLog

 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.
 

gcc/testsuite/g++.dg/cpp1z/decomp33.C

+// 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 } }
+}