python310Packages.cffi: patch closures to work on M1 machines

pkgs/development/python-modules/cffi/darwin-use-libffi-closures.diff

@@ -0,0 +1,21 @@
+diff -r bac92fcfe4d7 c/_cffi_backend.c
+--- a/c/_cffi_backend.c	Mon Jul 18 15:58:34 2022 +0200
++++ b/c/_cffi_backend.c	Sat Aug 20 12:38:31 2022 -0700
+@@ -96,7 +96,7 @@
+ # define CFFI_CHECK_FFI_PREP_CIF_VAR 0
+ # define CFFI_CHECK_FFI_PREP_CIF_VAR_MAYBE 0
+
+-#elif defined(__APPLE__) && defined(FFI_AVAILABLE_APPLE)
++#elif defined(__APPLE__)
+
+ # define CFFI_CHECK_FFI_CLOSURE_ALLOC __builtin_available(macos 10.15, ios 13, watchos 6, tvos 13, *)
+ # define CFFI_CHECK_FFI_CLOSURE_ALLOC_MAYBE 1
+@@ -6413,7 +6413,7 @@
+     else
+ #endif
+     {
+-#if defined(__APPLE__) && defined(FFI_AVAILABLE_APPLE) && !FFI_LEGACY_CLOSURE_API
++#if defined(__APPLE__) && !FFI_LEGACY_CLOSURE_API
+         PyErr_Format(PyExc_SystemError, "ffi_prep_closure_loc() is missing");
+         goto error;
+ #else

pkgs/development/python-modules/cffi/default.nix

@@ -1,5 +1,12 @@
-{ lib, stdenv, buildPythonPackage, isPyPy, fetchPypi, pytestCheckHook,
-  libffi, pkg-config, pycparser
+{ lib
+, stdenv
+, buildPythonPackage
+, isPyPy
+, fetchPypi
+, pytestCheckHook
+, libffi
+, pkg-config
+, pycparser
 }:
 
 if isPyPy then null else buildPythonPackage rec {
@@ -11,6 +18,20 @@ if isPyPy then null else buildPythonPackage rec {
     sha256 = "sha256-1AC/uaN7E1ElPLQCZxzqfom97MKU6AFqcH9tHYrJNPk=";
   };
 
+  patches = [
+    #
+    # Trusts the libffi library inside of nixpkgs on Apple devices.
+    #
+    # Based on some analysis I did:
+    #
+    #   https://groups.google.com/g/python-cffi/c/xU0Usa8dvhk
+    #
+    # I believe that libffi already contains the code from Apple's fork that is
+    # deemed safe to trust in cffi.
+    #
+    ./darwin-use-libffi-closures.diff
+  ];
+
   buildInputs = [ libffi ];
 
   nativeBuildInputs = [ pkg-config ];
@@ -29,9 +50,7 @@ if isPyPy then null else buildPythonPackage rec {
   NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang
     "-Wno-unused-command-line-argument -Wno-unreachable-code -Wno-c++11-narrowing";
 
-  # Lots of tests fail on aarch64-darwin due to "Cannot allocate write+execute memory":
-  # * https://cffi.readthedocs.io/en/latest/using.html#callbacks
-  doCheck = !stdenv.hostPlatform.isMusl && !(stdenv.isDarwin && stdenv.isAarch64);
+  doCheck = !stdenv.hostPlatform.isMusl;
 
   checkInputs = [ pytestCheckHook ];
 

pkgs/development/python2-modules/cffi/default.nix

@@ -0,0 +1,45 @@
+{ lib, stdenv, cffi }:
+
+if cffi == null then null else cffi.overridePythonAttrs {
+  disabledTests = lib.optionals stdenv.isDarwin [
+    # cannot load library 'c'
+    "test_FILE"
+    "test_FILE_object"
+    "test_FILE_only_for_FILE_arg"
+    "test_load_and_call_function"
+    "test_load_library"
+
+    # cannot load library 'dl'
+    "test_dlopen_handle"
+
+    # cannot load library 'm'
+    "test_dir_on_dlopen_lib"
+    "test_dlclose"
+    "test_dlopen"
+    "test_dlopen_constant"
+    "test_dlopen_flags"
+    "test_function_typedef"
+    "test_line_continuation_in_defines"
+    "test_missing_function"
+    "test_remove_comments"
+    "test_remove_line_continuation_comments"
+    "test_simple"
+    "test_sin"
+    "test_sinf"
+    "test_stdcall_only_on_windows"
+    "test_wraps_from_stdlib"
+
+    # MemoryError
+    "test_callback_as_function_argument"
+    "test_callback_crash"
+    "test_callback_decorator"
+    "test_callback_large_struct"
+    "test_callback_returning_void"
+    "test_cast_functionptr_and_int"
+    "test_function_pointer"
+    "test_functionptr_intptr_return"
+    "test_functionptr_simple"
+    "test_functionptr_void_return"
+    "test_functionptr_voidptr_return"
+  ];
+}

pkgs/top-level/python2-packages.nix

@@ -15,6 +15,8 @@ with self; with super; {
 
   certifi = callPackage ../development/python2-modules/certifi { };
 
+  cffi = callPackage ../development/python2-modules/cffi { inherit cffi; };
+
   chardet = callPackage ../development/python2-modules/chardet { };
 
   cheetah = callPackage ../development/python2-modules/cheetah { };