From e16e4d0602e88c0282f07ba3e15b08f2c812ba8c Mon Sep 17 00:00:00 2001
From: Thierry Martinez <Thierry.Martinez@inria.fr>
Date: Sat, 23 May 2020 15:44:36 +0200
Subject: [PATCH] Define Pconst_string_patt

Suggested by Gabriel Scherer.
https://github.com/ocaml-ppx/ppx_deriving/pull/222#discussion_r429545180
---
 src/api/ppx_deriving.cppo.ml | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/api/ppx_deriving.cppo.ml b/src/api/ppx_deriving.cppo.ml
index 1d2259fd..20f9d238 100644
--- a/src/api/ppx_deriving.cppo.ml
+++ b/src/api/ppx_deriving.cppo.ml
@@ -27,6 +27,12 @@
 #define Rinherit_patt(typ) {prf_desc = Rinherit(typ); _}
 #endif
 
+#if OCAML_VERSION < (4, 11, 0)
+#define Pconst_string_patt(s, loc) Pconst_string(s, loc)
+#else
+#define Pconst_string_patt(s, loc) Pconst_string(s, loc, _)
+#endif
+
 open Longident
 open Location
 open Asttypes
@@ -152,12 +158,7 @@ type constant =
 
 let string_of_constant_opt (constant : constant) : string option =
   match constant with
-  #if OCAML_VERSION >= (4, 11, 0)
-  | Pconst_string (s, _, _) ->
-  #else
-  | Pconst_string (s, _) ->
-  #endif
-      Some s
+  | Pconst_string_patt (s, _) -> Some s
   | _ -> None
 
 let string_of_expression_opt (e : Parsetree.expression) : string option =