From 340c3f68329b191bef56ad0eafa6b0a8c9fac85c Mon Sep 17 00:00:00 2001
From: Emily <vcs@emily.moe>
Date: Mon, 6 Jan 2025 20:20:32 +0000
Subject: [PATCH] Revert "python312Packages.cffi: remove unnecessary Darwin
 patch"
MIME-Version: 1.0
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Fix the build on `aarch64-darwin`. Need to figure out why either
`!defined(FFI_AVAILABLE_APPLE)` or the `__builtin_available` checks
are failing, but that’s a next cycle problem.

This reverts commit eff89e3bd808ba8949356d0f4a4a61ac93cba81c.
---
 .../cffi/darwin-use-libffi-closures.diff      | 29 +++++++++++++++++++
 .../python-modules/cffi/default.nix           | 14 +++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 pkgs/development/python-modules/cffi/darwin-use-libffi-closures.diff

diff --git a/pkgs/development/python-modules/cffi/darwin-use-libffi-closures.diff b/pkgs/development/python-modules/cffi/darwin-use-libffi-closures.diff
new file mode 100644
index 000000000000..4ef51274aa28
--- /dev/null
+++ b/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
diff --git a/pkgs/development/python-modules/cffi/default.nix b/pkgs/development/python-modules/cffi/default.nix
index 7ce279008bdb..6597dd4749d0 100644
--- a/pkgs/development/python-modules/cffi/default.nix
+++ b/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 ];