Message287831
| Author |
Igor Kudrin |
| Recipients |
Igor Kudrin, christian.heimes, doko, mark.dickinson, meador.inge, paul.moore, steve.dower, tim.golden, vinay.sajip, zach.ware |
| Date |
2017年02月15日.09:48:33 |
| SpamBayes Score |
-1.0 |
| Marked as misclassified |
Yes |
| Message-id |
<1487152114.39.0.2484958241.issue29565@psf.upfronthosting.co.za> |
| In-reply-to |
| Content |
It looks like resolving https://bugs.python.org/issue20160 didn't fix all the issues. When a large struct is used as a parameter, a reference to the object itself is passed to the function, not a reference to a temporary copy, as it is required in https://msdn.microsoft.com/en-us/library/zthk2dkh.aspx.
Here is the reproduction sample:
=== Sample.c: ===
typedef struct
{
int v[3];
} Data;
__declspec(dllexport) void Cripple(Data data)
{
data.v[0] = 0;
}
=== Sample.py ===
from ctypes import *
class Data(Structure):
_fields_ = [("v", c_int * 3)]
lib = cdll.LoadLibrary('Sample.dll')
getattr(lib, 'Cripple').argtypes = [Data]
data = Data()
data.v[0] = 42
lib.Cripple(data)
assert data.v[0] == 42
print "OK"
=== repro.cmd ===
call "%VS140COMNTOOLS%/../../VC/vcvarsall.bat" x86_amd64
cl /LD Sample.c
python Sample.py |
|