re PR c++/70344 (ICE on invalid code at -O1 and above on x86_64-linux-gnu in…

re PR c++/70344 (ICE on invalid code at -O1 and above on x86_64-linux-gnu in record_reference, at cgraphbuild.c:64)

	PR c++/70344

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

From-SVN: r234434

gcc/cp/ChangeLog

+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

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)

gcc/testsuite/g++.dg/cpp0x/constexpr-recursion2.C

+// 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 ());