Fix PR c++/70590 (error: location references block not in block tree)

gcc/cp/ChangeLog:

	PR c++/70590
	PR c++/70452
	* constexpr.c (cxx_eval_outermost_expression): Call unshare_expr
	on the result if it's not a CONSTRUCTOR.

gcc/testsuite/ChangeLog:

	PR c++/70590
	PR c++/70452
	* g++.dg/pr70590.C: New test.
	* g++.dg/pr70590-2.C: New test.

From-SVN: r234837

gcc/cp/ChangeLog

+2016-04-08  Patrick Palka  <ppalka@gcc.gnu.org>
+
+	PR c++/70590
+	PR c++/70452
+	* constexpr.c (cxx_eval_outermost_expression): Call unshare_expr
+	on the result if it's not a CONSTRUCTOR.
+
 2016-04-07  Patrick Palka  <ppalka@gcc.gnu.org>
 
 	PR c++/70452

gcc/cp/constexpr.c

@@ -4164,6 +4164,12 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant,
   if (!non_constant_p && overflow_p)
     non_constant_p = true;
 
+  /* Unshare the result unless it's a CONSTRUCTOR in which case it's already
+     unshared.  */
+  bool should_unshare = true;
+  if (r == t || TREE_CODE (r) == CONSTRUCTOR)
+    should_unshare = false;
+
   if (non_constant_p && !allow_non_constant)
     return error_mark_node;
   else if (non_constant_p && TREE_CONSTANT (r))
@@ -4180,6 +4186,9 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant,
   else if (non_constant_p || r == t)
     return t;
 
+  if (should_unshare)
+    r = unshare_expr (r);
+
   if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r)))
     {
       if (TREE_CODE (t) == TARGET_EXPR

gcc/testsuite/ChangeLog

+2016-04-08  Patrick Palka  <ppalka@gcc.gnu.org>
+
+	PR c++/70590
+	PR c++/70452
+	* g++.dg/pr70590.C: New test.
+	* g++.dg/pr70590-2.C: New test.
+
 2016-04-08  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/70593

gcc/testsuite/g++.dg/pr70590-2.C

+// PR c++/70590
+// { dg-do compile { target c++11 } }
+// { dg-options "-O2" }
+
+int a;
+
+constexpr int *foo = &a;
+
+void blah (int *);
+
+int
+bar ()
+{
+  blah (foo);
+}
+
+int
+baz ()
+{
+  blah (foo);
+}

gcc/testsuite/g++.dg/pr70590.C

+// PR c++/70590
+// { dg-do compile { target c++11 } }
+// { dg-options "-O2" }
+
+int a;
+
+constexpr int *
+foo ()
+{
+  return &a;
+}
+
+void blah (int *);
+
+int
+bar ()
+{
+  blah (foo ());
+}
+
+int
+baz ()
+{
+  blah (foo ());
+}