Revert "python312Packages.cffi: remove unnecessary Darwin patch" (#37…

…1545)

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

@@ -0,0 +1,29 @@
+diff --git a/src/c/_cffi_backend.c b/src/c/_cffi_backend.c
+index 537271f..9c3bf94 100644
+--- a/src/c/_cffi_backend.c
++++ b/src/c/_cffi_backend.c
+@@ -103,11 +103,11 @@
+ # 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 1
+ # define CFFI_CHECK_FFI_CLOSURE_ALLOC_MAYBE 1
+-# define CFFI_CHECK_FFI_PREP_CLOSURE_LOC __builtin_available(macos 10.15, ios 13, watchos 6, tvos 13, *)
++# define CFFI_CHECK_FFI_PREP_CLOSURE_LOC 1
+ # define CFFI_CHECK_FFI_PREP_CLOSURE_LOC_MAYBE 1
+-# define CFFI_CHECK_FFI_PREP_CIF_VAR __builtin_available(macos 10.15, ios 13, watchos 6, tvos 13, *)
++# define CFFI_CHECK_FFI_PREP_CIF_VAR 1
+ # define CFFI_CHECK_FFI_PREP_CIF_VAR_MAYBE 1
+@@ -6422,7 +6422,7 @@ static PyObject *b_callback(PyObject *self, PyObject *args)
+     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

@@ -24,6 +24,20 @@ else
       hash = "sha256-HDnGAWwyvEjdVFYZUOvWg24WcPKuRhKPZ89J54nFKCQ=";
     };
 
+    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
+    ];
+
     nativeBuildInputs = [ pkg-config ];
 
     build-system = [ setuptools ];