From 102ce8a663b0e28174632073ce277e80bec5b1a8 Mon Sep 17 00:00:00 2001
From: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed, 23 Mar 2016 18:23:04 +0000
Subject: [PATCH] 	PR c++/70344

	* constexpr.c (cxx_eval_call_expression): Catch invalid recursion.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@234434 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/cp/ChangeLog                                |  5 +++++
 gcc/cp/constexpr.c                              | 15 +++++++++++++++
 .../g++.dg/cpp0x/constexpr-recursion2.C         | 17 +++++++++++++++++
 3 files changed, 37 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-recursion2.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index d36168957ca6..01fc2bd76574 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2016-03-23  Jason Merrill  <jason@redhat.com>
+
+	PR c++/70344
+	* constexpr.c (cxx_eval_call_expression): Catch invalid recursion.
+
 2016-03-23  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/69884
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index 7b136330b3f2..d71e488d5e09 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -1239,6 +1239,21 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
       return t;
     }
 
+  if (fun == current_function_decl)
+    {
+      /* A call to the current function, i.e.
+	 constexpr int f (int i) {
+	   constexpr int j = f(i-1);
+	   return j;
+	 }
+	 This would be OK without the constexpr on the declaration of j.  */
+      if (!ctx->quiet)
+	error_at (loc, "%qD called in a constant expression before its "
+		  "definition is complete", fun);
+      *non_constant_p = true;
+      return t;
+    }
+
   constexpr_ctx new_ctx = *ctx;
   if (DECL_CONSTRUCTOR_P (fun) && !ctx->object
       && TREE_CODE (t) == AGGR_INIT_EXPR)
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-recursion2.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-recursion2.C
new file mode 100644
index 000000000000..978b998afebc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-recursion2.C
@@ -0,0 +1,17 @@
+// PR c++/70344
+// { dg-do compile { target c++11 } }
+
+struct Z
+{
+  Z () = default;
+  Z (Z const &) = default;
+  constexpr Z (Z &&) {}
+};
+
+constexpr int
+fn (Z v)
+{
+  return fn (v);
+}
+
+auto t = fn (Z ());
-- 
2.47.3