re PR c++/63940 (C++ constexpr errors on AIX)

	PR c++/63940
	* constexpr.c (cxx_eval_binary_expression): Don't assume the
	expression was already folded.
	(cxx_eval_unary_expression): Likewise.

From-SVN: r217738

gcc/cp/ChangeLog

+2014-11-18  Jason Merrill  <jason@redhat.com>
+
+	PR c++/63940
+	* constexpr.c (cxx_eval_binary_expression): Don't assume the
+	expression was already folded.
+	(cxx_eval_unary_expression): Likewise.
+
 2014-11-18  Marc Glisse  <marc.glisse@inria.fr>
 
 	PR libstdc++/43622

gcc/cp/constexpr.c

@@ -1461,9 +1461,17 @@ cxx_eval_unary_expression (const constexpr_ctx *ctx, tree t,
 					   addr, non_constant_p, overflow_p,
 					   NULL);
   VERIFY_CONSTANT (arg);
+  location_t loc = EXPR_LOCATION (t);
+  enum tree_code code = TREE_CODE (t);
+  tree type = TREE_TYPE (t);
+  r = fold_unary_loc (loc, code, type, arg);
+  if (r == NULL_TREE)
+    {
       if (arg == orig_arg)
-    return t;
-  r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), arg);
+	r = t;
+      else
+	r = build1_loc (loc, code, type, arg);
+    }
   VERIFY_CONSTANT (r);
   return r;
 }
@@ -1488,9 +1496,18 @@ cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t,
 				      allow_non_constant, addr,
 				      non_constant_p, overflow_p, NULL);
   VERIFY_CONSTANT (rhs);
+
+  location_t loc = EXPR_LOCATION (t);
+  enum tree_code code = TREE_CODE (t);
+  tree type = TREE_TYPE (t);
+  r = fold_binary_loc (loc, code, type, lhs, rhs);
+  if (r == NULL_TREE)
+    {
       if (lhs == orig_lhs && rhs == orig_rhs)
-    return t;
-  r = fold_build2 (TREE_CODE (t), TREE_TYPE (t), lhs, rhs);
+	r = t;
+      else
+	r = build2_loc (loc, code, type, lhs, rhs);
+    }
   VERIFY_CONSTANT (r);
   return r;
 }