[Python-checkins] bpo-16865: Support arrays >=2GB in ctypes. (GH-3006)

[Miss Islington (bot)]

https://github.com/python/cpython/commit/2ce72e243fbc0e4f07f1191b20be548bfa5cbe11
commit: 2ce72e243fbc0e4f07f1191b20be548bfa5cbe11
branch: 3.7
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: GitHub <noreply at github.com>
date: 2018-05-14T22:40:27-07:00
summary:

bpo-16865: Support arrays >=2GB in ctypes. (GH-3006)

(cherry picked from commit 735abadd5bd91db4a9e6f4311969b0afacca0a1a)

Co-authored-by: Segev Finer <segev208 at gmail.com>

files:
A Misc/NEWS.d/next/Library/2017-09-29-16-40-38.bpo-16865.l-f6I_.rst
M Lib/ctypes/test/test_arrays.py
M Modules/_ctypes/_ctypes.c

diff --git a/Lib/ctypes/test/test_arrays.py b/Lib/ctypes/test/test_arrays.py
index 4ed566b48e67..6e562cfd24e6 100644
--- a/Lib/ctypes/test/test_arrays.py
+++ b/Lib/ctypes/test/test_arrays.py
@@ -1,4 +1,6 @@
 import unittest
+from test.support import bigmemtest, _2G
+import sys
 from ctypes import *
 
 from ctypes.test import need_symbol
@@ -181,5 +183,10 @@ class T(Array):
                 _type_ = c_int
                 _length_ = 1.87
 
+    @unittest.skipUnless(sys.maxsize > 2**32, 'requires 64bit platform')
+    @bigmemtest(size=_2G, memuse=1, dry_run=False)
+    def test_large_array(self, size):
+        c_char * size
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/Misc/NEWS.d/next/Library/2017-09-29-16-40-38.bpo-16865.l-f6I_.rst b/Misc/NEWS.d/next/Library/2017-09-29-16-40-38.bpo-16865.l-f6I_.rst
new file mode 100644
index 000000000000..afaff736bf1c
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2017-09-29-16-40-38.bpo-16865.l-f6I_.rst
@@ -0,0 +1 @@
+Support arrays >=2GiB in :mod:`ctypes`.  Patch by Segev Finer.
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index 93e8d8d42330..66bce151eb70 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -1390,8 +1390,7 @@ PyCArrayType_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     StgDictObject *stgdict;
     StgDictObject *itemdict;
     PyObject *length_attr, *type_attr;
-    long length;
-    int overflow;
+    Py_ssize_t length;
     Py_ssize_t itemsize, itemalign;
 
     /* create the new instance (which is a class,
@@ -1413,14 +1412,15 @@ PyCArrayType_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
         Py_XDECREF(length_attr);
         goto error;
     }
-    length = PyLong_AsLongAndOverflow(length_attr, &overflow);
-    if (overflow) {
-        PyErr_SetString(PyExc_OverflowError,
-                        "The '_length_' attribute is too large");
-        Py_DECREF(length_attr);
+    length = PyLong_AsSsize_t(length_attr);
+    Py_DECREF(length_attr);
+    if (length == -1 && PyErr_Occurred()) {
+        if (PyErr_ExceptionMatches(PyExc_OverflowError)) {
+            PyErr_SetString(PyExc_OverflowError,
+                            "The '_length_' attribute is too large");
+        }
         goto error;
     }
-    Py_DECREF(length_attr);
 
     type_attr = PyObject_GetAttrString((PyObject *)result, "_type_");
     if (!type_attr) {