From 50b0afa269c221577e78e3dc9ed6095be5d5a4b3 Mon Sep 17 00:00:00 2001
From: Vincent Laporte <Vincent.Laporte@gmail.com>
Date: Wed, 4 Apr 2018 15:09:04 +0000
Subject: [PATCH] ocamlPackages.optcomp: fix build with OCaml 4.06

---
 pkgs/development/ocaml-modules/optcomp/META   | 12 ++++++++++
 .../ocaml-modules/optcomp/default.nix         | 24 ++++++++++++++++++-
 2 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 pkgs/development/ocaml-modules/optcomp/META

diff --git a/pkgs/development/ocaml-modules/optcomp/META b/pkgs/development/ocaml-modules/optcomp/META
new file mode 100644
index 000000000000..8a942288f752
--- /dev/null
+++ b/pkgs/development/ocaml-modules/optcomp/META
@@ -0,0 +1,12 @@
+# OASIS_START
+# DO NOT EDIT (digest: ec844fa3189acb2a866b89a69d111ba4)
+version = "1.6"
+description = "Optional compilation with cpp-like directives"
+requires = "camlp4"
+archive(syntax, preprocessor) = "optcomp.cma"
+archive(syntax, toploop) = "optcomp.cma"
+archive(syntax, preprocessor, native) = "optcomp.cmxa"
+archive(syntax, preprocessor, native, plugin) = "optcomp.cmxs"
+exists_if = "optcomp.cma"
+# OASIS_STOP
+
diff --git a/pkgs/development/ocaml-modules/optcomp/default.nix b/pkgs/development/ocaml-modules/optcomp/default.nix
index 8953373954a5..5b5661377471 100644
--- a/pkgs/development/ocaml-modules/optcomp/default.nix
+++ b/pkgs/development/ocaml-modules/optcomp/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, ocaml, findlib, ocamlbuild, camlp4 }:
+{ stdenv, fetchurl, fetchpatch, ocaml, findlib, ocamlbuild, camlp4 }:
 
 stdenv.mkDerivation {
   name = "ocaml-optcomp-1.6";
@@ -6,11 +6,33 @@ stdenv.mkDerivation {
     url = https://github.com/diml/optcomp/archive/1.6.tar.gz;
     sha256 = "0hhhb2gisah1h22zlg5iszbgqxdd7x85cwd57bd4mfkx9l7dh8jh";
   };
+
+  patches =
+    let inherit (stdenv.lib) optional versionAtLeast; in
+    optional (versionAtLeast ocaml.version "4.02") (fetchpatch {
+      url = "https://github.com/diml/optcomp/commit/b7f809360c9794b383a4bc0492f6df381276b429.patch";
+      sha256 = "1n095lk94jq1rwi0l24g2wbgms7249wdd31n0ji895dr6755s93y";
+    })
+  ;
   
   createFindlibDestdir = true;
 
   buildInputs = [ ocaml findlib ocamlbuild camlp4 ];
 
+  configurePhase = ''
+    cp ${./META} META
+  '';
+
+  buildPhase = ''
+    ocamlbuild src/optcomp.cmxs src/optcomp.cma src/optcomp_o.native src/optcomp_r.native
+  '';
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp _build/src/optcomp_o.native $out/bin/optcomp-o
+    cp _build/src/optcomp_r.native $out/bin/optcomp-r
+    ocamlfind install optcomp META _build/src/optcomp.{a,cma,cmxa,cmxs} _build/src/pa_optcomp.{cmi,cmx,mli}
+  '';
 
   meta =  {
     homepage = https://github.com/diml/optcomp;