From 52688fea7c8a7f2af2baef9abebe66feb040e726 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marco=20K=C3=B6pcke?= <marco.koepcke@tudock.de>
Date: Wed, 26 Jun 2024 10:20:04 +0200
Subject: [PATCH] pythonPackages.cffi: include patch to fix clang error

Fixes null-pointer-subtraction
---
 .../avoid-null-pointer-subtraction-error.diff | 14 +++++++
 .../clang-pointer-substraction-warning.diff   | 11 ------
 .../python-modules/cffi/default.nix           | 38 ++++++++-----------
 3 files changed, 30 insertions(+), 33 deletions(-)
 create mode 100644 pkgs/development/python-modules/cffi/avoid-null-pointer-subtraction-error.diff
 delete mode 100644 pkgs/development/python-modules/cffi/clang-pointer-substraction-warning.diff

diff --git a/pkgs/development/python-modules/cffi/avoid-null-pointer-subtraction-error.diff b/pkgs/development/python-modules/cffi/avoid-null-pointer-subtraction-error.diff
new file mode 100644
index 0000000000000..e4bddc407f6ec
--- /dev/null
+++ b/pkgs/development/python-modules/cffi/avoid-null-pointer-subtraction-error.diff
@@ -0,0 +1,14 @@
+diff --git a/src/cffi/recompiler.py b/src/cffi/recompiler.py
+index 4167bc05..ac6c163e 100644
+--- a/src/cffi/recompiler.py
++++ b/src/cffi/recompiler.py
+@@ -953,7 +953,7 @@ def _struct_ctx(self, tp, cname, approxname, named_ptr=None):
+                 if cname is None or fbitsize >= 0:
+                     offset = '(size_t)-1'
+                 elif named_ptr is not None:
+-                    offset = '((char *)&((%s)0)->%s) - (char *)0' % (
++                    offset = '((char *)&((%s)4096)->%s) - (char *)4096' % (
+                         named_ptr.name, fldname)
+                 else:
+                     offset = 'offsetof(%s, %s)' % (tp.get_c_name(''), fldname)
+ Login with GitHub
diff --git a/pkgs/development/python-modules/cffi/clang-pointer-substraction-warning.diff b/pkgs/development/python-modules/cffi/clang-pointer-substraction-warning.diff
deleted file mode 100644
index 75b2677e380e7..0000000000000
--- a/pkgs/development/python-modules/cffi/clang-pointer-substraction-warning.diff
+++ /dev/null
@@ -1,11 +0,0 @@
-diff -r c649a735cf82 testing/support.py
---- a/testing/support.py	Thu Feb 23 05:42:01 2023 +0100
-+++ b/testing/support.py	Sat May 20 21:46:56 2023 -0400
-@@ -112,6 +112,7 @@
-                               '-Wno-unreachable-code']
-         # special things for clang
-         extra_compile_args.append('-Qunused-arguments')
-+        extra_compile_args.append('-Wno-null-pointer-subtraction')
-     else:
-         # assume a standard gcc
-         extra_compile_args = ['-Werror', '-Wall', '-Wextra', '-Wconversion',
diff --git a/pkgs/development/python-modules/cffi/default.nix b/pkgs/development/python-modules/cffi/default.nix
index 7d03ab82c7bca..c87adddd437ce 100644
--- a/pkgs/development/python-modules/cffi/default.nix
+++ b/pkgs/development/python-modules/cffi/default.nix
@@ -11,7 +11,6 @@
   pycparser,
   pythonAtLeast,
 }:
-
 if isPyPy then
   null
 else
@@ -25,27 +24,22 @@ else
       hash = "sha256-vLPvQ+WGZbvaL7GYaY/K5ndkg+DEpjGqVkeAbCXgLMA=";
     };
 
-    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
-      ]
-      ++ lib.optionals (stdenv.cc.isClang && lib.versionAtLeast (lib.getVersion stdenv.cc) "13") [
-        # -Wnull-pointer-subtraction is enabled with -Wextra. Suppress it to allow the following tests
-        # to run and pass when cffi is built with newer versions of clang:
-        # - testing/cffi1/test_verify1.py::test_enum_usage
-        # - testing/cffi1/test_verify1.py::test_named_pointer_as_argument
-        ./clang-pointer-substraction-warning.diff
-      ];
+    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
+      # https://github.com/python-cffi/cffi/commit/39bdab23615a83c1001ed822f974ae52020201ba
+      # Needed on newer Clang versions.
+      ./avoid-null-pointer-subtraction-error.diff
+    ];
 
     postPatch = lib.optionalString stdenv.isDarwin ''
       # Remove setup.py impurities