From 7efd5abe4888d6270acd4b2cf6b736d24438cd0f Mon Sep 17 00:00:00 2001
From: Daiderd Jordan <daiderd@gmail.com>
Date: Sun, 29 Oct 2017 01:47:46 +0200
Subject: [PATCH] python-cffi: fix clang build

---
 pkgs/development/python-modules/cffi/clang.patch | 13 +++++++++++++
 pkgs/development/python-modules/cffi/default.nix |  6 ++++--
 2 files changed, 17 insertions(+), 2 deletions(-)
 create mode 100644 pkgs/development/python-modules/cffi/clang.patch

diff --git a/pkgs/development/python-modules/cffi/clang.patch b/pkgs/development/python-modules/cffi/clang.patch
new file mode 100644
index 000000000000..27674edb58b4
--- /dev/null
+++ b/pkgs/development/python-modules/cffi/clang.patch
@@ -0,0 +1,13 @@
+diff --git a/testing/cffi1/test_recompiler.py b/testing/cffi1/test_recompiler.py
+index a3277b0..0d6e2c3 100644
+--- a/testing/cffi1/test_recompiler.py
++++ b/testing/cffi1/test_recompiler.py
+@@ -2270,7 +2270,7 @@ def test_char16_char32_type(no_cpp=False):
+         char32_t foo_4bytes(char32_t);
+     """)
+     lib = verify(ffi, "test_char16_char32_type" + no_cpp * "_nocpp", """
+-    #if !defined(__cplusplus) || __cplusplus < 201103L
++    #if !defined(__cplusplus)
+     typedef uint_least16_t char16_t;
+     typedef uint_least32_t char32_t;
+     #endif
diff --git a/pkgs/development/python-modules/cffi/default.nix b/pkgs/development/python-modules/cffi/default.nix
index 5c99e77af56b..3389a6fd7054 100644
--- a/pkgs/development/python-modules/cffi/default.nix
+++ b/pkgs/development/python-modules/cffi/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, buildPythonPackage, isPyPy, fetchPypi, libffi, pycparser, pytest }:
+{ stdenv, buildPythonPackage, isPy27, isPyPy, fetchPypi, libffi, pycparser, pytest }:
 
 if isPyPy then null else buildPythonPackage rec {
   pname = "cffi";
@@ -10,13 +10,15 @@ if isPyPy then null else buildPythonPackage rec {
     sha256 = "ab87dd91c0c4073758d07334c1e5f712ce8fe48f007b86f8238773963ee700a6";
   };
 
+  patches = stdenv.lib.optional isPy27 ./clang.patch;
+
   outputs = [ "out" "dev" ];
 
   propagatedBuildInputs = [ libffi pycparser ];
   buildInputs = [ pytest ];
 
   # The tests use -Werror but with python3.6 clang detects some unreachable code.
-  NIX_CFLAGS_COMPILE = stdenv.lib.optional stdenv.cc.isClang "-Wno-unreachable-code";
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionals stdenv.cc.isClang [ "-Wno-unused-command-line-argument" "-Wno-unreachable-code" ];
 
   checkPhase = ''
     py.test