explicit test of unaligned pointer reads/writes

1 files changed, 21 insertions, 0 deletions

diff --git a/c/test_c.py b/c/test_c.py
index fa24676..95ca812 100644
--- a/c/test_c.py
+++ b/c/test_c.py
@@ -4496,3 +4496,24 @@ def test_type_available_with_correct_names():
         tp = getattr(_cffi_backend, name)
         assert isinstance(tp, type)
         assert (tp.__module__, tp.__name__) == ('_cffi_backend', name)
+
+def test_unaligned_types():
+    BByteArray = new_array_type(
+        new_pointer_type(new_primitive_type("unsigned char")), None)
+    pbuf = newp(BByteArray, 40)
+    buf = buffer(pbuf)
+    #
+    for name in ['short', 'int', 'long', 'long long', 'float', 'double',
+                 'float _Complex', 'double _Complex']:
+        p = new_primitive_type(name)
+        if name.endswith(' _Complex'):
+            num = cast(p, 1.23 - 4.56j)
+        else:
+            num = cast(p, 0x0123456789abcdef)
+        size = sizeof(p)
+        buf[0:40] = b"\x00" * 40
+        pbuf1 = cast(new_pointer_type(p), pbuf + 1)
+        pbuf1[0] = num
+        assert pbuf1[0] == num
+        assert buf[0] == '\x00'
+        assert buf[1 + size] == '\x00'