1 files changed, 133 insertions, 0 deletions
diff --git a/main/python3/bpo-30353.patch b/main/python3/bpo-30353.patch
new file mode 100644
index 0000000000..28fc93eef0
--- /dev/null
+++ b/main/python3/bpo-30353.patch
@@ -0,0 +1,133 @@
+https://github.com/python/cpython/commit/9ba3aa4d02a110d1a1ea464a8aff3be7dd9c63c3.patch
+
+From 9ba3aa4d02a110d1a1ea464a8aff3be7dd9c63c3 Mon Sep 17 00:00:00 2001
+From: Erik Bray <erik.m.bray@gmail.com>
+Date: Wed, 7 Jun 2017 18:42:24 +0100
+Subject: [PATCH] bpo-30353: Fix pass by value for structs on 64-bit
+ Cygwin/MinGW (GH-1559)
+
+---
+ Lib/ctypes/test/test_as_parameter.py |  4 ++++
+ Lib/ctypes/test/test_structures.py   | 22 ++++++++++++++++++++++
+ Modules/_ctypes/_ctypes_test.c       | 18 ++++++++++++++++++
+ Modules/_ctypes/callproc.c           | 23 +++++++++++++++++++++--
+ 4 files changed, 65 insertions(+), 2 deletions(-)
+
+diff --git a/Lib/ctypes/test/test_as_parameter.py b/Lib/ctypes/test/test_as_parameter.py
+index 2a3484bec01..a2640575a07 100644
+--- a/Lib/ctypes/test/test_as_parameter.py
++++ b/Lib/ctypes/test/test_as_parameter.py
+@@ -169,6 +169,10 @@ class S2H(Structure):
+         s2h = dll.ret_2h_func(self.wrap(inp))
+         self.assertEqual((s2h.x, s2h.y), (99*2, 88*3))
+ 
++        # Test also that the original struct was unmodified (i.e. was passed by
++        # value)
++        self.assertEqual((inp.x, inp.y), (99, 88))
++
+     def test_struct_return_8H(self):
+         class S8I(Structure):
+             _fields_ = [("a", c_int),
+diff --git a/Lib/ctypes/test/test_structures.py b/Lib/ctypes/test/test_structures.py
+index 2e778fb1b43..d90c71144c9 100644
+--- a/Lib/ctypes/test/test_structures.py
++++ b/Lib/ctypes/test/test_structures.py
+@@ -417,6 +417,28 @@ class X(Structure):
+         self.assertEqual(s.second, 0xcafebabe)
+         self.assertEqual(s.third, 0x0bad1dea)
+ 
++    def test_pass_by_value_in_register(self):
++        class X(Structure):
++            _fields_ = [
++                ('first', c_uint),
++                ('second', c_uint)
++            ]
++
++        s = X()
++        s.first = 0xdeadbeef
++        s.second = 0xcafebabe
++        dll = CDLL(_ctypes_test.__file__)
++        func = dll._testfunc_reg_struct_update_value
++        func.argtypes = (X,)
++        func.restype = None
++        func(s)
++        self.assertEqual(s.first, 0xdeadbeef)
++        self.assertEqual(s.second, 0xcafebabe)
++        got = X.in_dll(dll, "last_tfrsuv_arg")
++        self.assertEqual(s.first, got.first)
++        self.assertEqual(s.second, got.second)
++
++
+ class PointerMemberTestCase(unittest.TestCase):
+ 
+     def test(self):
+diff --git a/Modules/_ctypes/_ctypes_test.c b/Modules/_ctypes/_ctypes_test.c
+index fe0015c8013..2255e573393 100644
+--- a/Modules/_ctypes/_ctypes_test.c
++++ b/Modules/_ctypes/_ctypes_test.c
+@@ -57,6 +57,24 @@ _testfunc_large_struct_update_value(Test in)
+     ((volatile Test *)&in)->third = 0x0badf00d;
+ }
+ 
++typedef struct {
++    unsigned int first;
++    unsigned int second;
++} TestReg;
++
++
++EXPORT(TestReg) last_tfrsuv_arg;
++
++
++EXPORT(void)
++_testfunc_reg_struct_update_value(TestReg in)
++{
++    last_tfrsuv_arg = in;
++    ((volatile TestReg *)&in)->first = 0x0badf00d;
++    ((volatile TestReg *)&in)->second = 0x0badf00d;
++}
++
++
+ EXPORT(void)testfunc_array(int values[4])
+ {
+     printf("testfunc_array %d %d %d %d\n",
+diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
+index 0b6faf96c68..5439b939dc4 100644
+--- a/Modules/_ctypes/callproc.c
++++ b/Modules/_ctypes/callproc.c
+@@ -1039,6 +1039,13 @@ GetComError(HRESULT errcode, GUID *riid, IUnknown *pIunk)
+ }
+ #endif
+ 
++#if (defined(__x86_64__) && (defined(__MINGW64__) || defined(__CYGWIN__))) || \
++    defined(__aarch64__)
++#define CTYPES_PASS_BY_REF_HACK
++#define POW2(x) (((x & ~(x - 1)) == x) ? x : 0)
++#define IS_PASS_BY_REF(x) (x > 8 || !POW2(x))
++#endif
++
+ /*
+  * Requirements, must be ensured by the caller:
+  * - argtuple is tuple of arguments
+@@ -1136,8 +1143,20 @@ PyObject *_ctypes_callproc(PPROC pProc,
+     }
+     for (i = 0; i < argcount; ++i) {
+         atypes[i] = args[i].ffi_type;
+-        if (atypes[i]->type == FFI_TYPE_STRUCT
+-            )
++#ifdef CTYPES_PASS_BY_REF_HACK
++        size_t size = atypes[i]->size;
++        if (IS_PASS_BY_REF(size)) {
++            void *tmp = alloca(size);
++            if (atypes[i]->type == FFI_TYPE_STRUCT)
++                memcpy(tmp, args[i].value.p, size);
++            else
++                memcpy(tmp, (void*)&args[i].value, size);
++
++            avalues[i] = tmp;
++        }
++        else
++#endif
++        if (atypes[i]->type == FFI_TYPE_STRUCT)
+             avalues[i] = (void *)args[i].value.p;
+         else
+             avalues[i] = (void *)&args[i].value;