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-rw-r--r--Lib/ctypes/__init__.py72
-rw-r--r--Lib/ctypes/test/test_errno.py76
-rw-r--r--Misc/NEWS3
-rw-r--r--Modules/_ctypes/_ctypes.c4
-rw-r--r--Modules/_ctypes/callbacks.c42
-rw-r--r--Modules/_ctypes/callproc.c154
-rw-r--r--Modules/_ctypes/ctypes.h6
7 files changed, 330 insertions, 27 deletions
diff --git a/Lib/ctypes/__init__.py b/Lib/ctypes/__init__.py
index 41d39dc..d3e11dc 100644
--- a/Lib/ctypes/__init__.py
+++ b/Lib/ctypes/__init__.py
@@ -33,7 +33,9 @@ if _os.name == "posix" and _sys.platform == "darwin":
DEFAULT_MODE = RTLD_GLOBAL
from _ctypes import FUNCFLAG_CDECL as _FUNCFLAG_CDECL, \
- FUNCFLAG_PYTHONAPI as _FUNCFLAG_PYTHONAPI
+ FUNCFLAG_PYTHONAPI as _FUNCFLAG_PYTHONAPI, \
+ FUNCFLAG_USE_ERRNO as _FUNCFLAG_USE_ERRNO, \
+ FUNCFLAG_USE_LASTERROR as _FUNCFLAG_USE_LASTERROR
"""
WINOLEAPI -> HRESULT
@@ -73,8 +75,9 @@ def c_buffer(init, size=None):
return create_string_buffer(init, size)
_c_functype_cache = {}
-def CFUNCTYPE(restype, *argtypes):
- """CFUNCTYPE(restype, *argtypes) -> function prototype.
+def CFUNCTYPE(restype, *argtypes, **kw):
+ """CFUNCTYPE(restype, *argtypes,
+ use_errno=False, use_last_error=False) -> function prototype.
restype: the result type
argtypes: a sequence specifying the argument types
@@ -88,14 +91,21 @@ def CFUNCTYPE(restype, *argtypes):
prototype((ordinal number, dll object)[, paramflags]) -> foreign function exported by ordinal
prototype((function name, dll object)[, paramflags]) -> foreign function exported by name
"""
+ flags = _FUNCFLAG_CDECL
+ if kw.pop("use_errno", False):
+ flags |= _FUNCFLAG_USE_ERRNO
+ if kw.pop("use_last_error", False):
+ flags |= _FUNCFLAG_USE_LASTERROR
+ if kw:
+ raise ValueError("unexpected keyword argument(s) %s" % kw.keys())
try:
- return _c_functype_cache[(restype, argtypes)]
+ return _c_functype_cache[(restype, argtypes, flags)]
except KeyError:
class CFunctionType(_CFuncPtr):
_argtypes_ = argtypes
_restype_ = restype
- _flags_ = _FUNCFLAG_CDECL
- _c_functype_cache[(restype, argtypes)] = CFunctionType
+ _flags_ = flags
+ _c_functype_cache[(restype, argtypes, flags)] = CFunctionType
return CFunctionType
if _os.name in ("nt", "ce"):
@@ -106,16 +116,23 @@ if _os.name in ("nt", "ce"):
_FUNCFLAG_STDCALL = _FUNCFLAG_CDECL
_win_functype_cache = {}
- def WINFUNCTYPE(restype, *argtypes):
+ def WINFUNCTYPE(restype, *argtypes, **kw):
# docstring set later (very similar to CFUNCTYPE.__doc__)
+ flags = _FUNCFLAG_STDCALL
+ if kw.pop("use_errno", False):
+ flags |= _FUNCFLAG_USE_ERRNO
+ if kw.pop("use_last_error", False):
+ flags |= _FUNCFLAG_USE_LASTERROR
+ if kw:
+ raise ValueError("unexpected keyword argument(s) %s" % kw.keys())
try:
- return _win_functype_cache[(restype, argtypes)]
+ return _win_functype_cache[(restype, argtypes, flags)]
except KeyError:
class WinFunctionType(_CFuncPtr):
_argtypes_ = argtypes
_restype_ = restype
- _flags_ = _FUNCFLAG_STDCALL
- _win_functype_cache[(restype, argtypes)] = WinFunctionType
+ _flags_ = flags
+ _win_functype_cache[(restype, argtypes, flags)] = WinFunctionType
return WinFunctionType
if WINFUNCTYPE.__doc__:
WINFUNCTYPE.__doc__ = CFUNCTYPE.__doc__.replace("CFUNCTYPE", "WINFUNCTYPE")
@@ -124,6 +141,7 @@ elif _os.name == "posix":
from _ctypes import dlopen as _dlopen
from _ctypes import sizeof, byref, addressof, alignment, resize
+from _ctypes import get_errno, set_errno
from _ctypes import _SimpleCData
def _check_size(typ, typecode=None):
@@ -313,12 +331,24 @@ class CDLL(object):
Calling the functions releases the Python GIL during the call and
reacquires it afterwards.
"""
- class _FuncPtr(_CFuncPtr):
- _flags_ = _FUNCFLAG_CDECL
- _restype_ = c_int # default, can be overridden in instances
+ _func_flags_ = _FUNCFLAG_CDECL
+ _func_restype_ = c_int
- def __init__(self, name, mode=DEFAULT_MODE, handle=None):
+ def __init__(self, name, mode=DEFAULT_MODE, handle=None,
+ use_errno=False,
+ use_last_error=False):
self._name = name
+ flags = self._func_flags_
+ if use_errno:
+ flags |= _FUNCFLAG_USE_ERRNO
+ if use_last_error:
+ flags |= _FUNCFLAG_USE_LASTERROR
+
+ class _FuncPtr(_CFuncPtr):
+ _flags_ = flags
+ _restype_ = self._func_restype_
+ self._FuncPtr = _FuncPtr
+
if handle is None:
self._handle = _dlopen(self._name, mode)
else:
@@ -348,9 +378,7 @@ class PyDLL(CDLL):
access Python API functions. The GIL is not released, and
Python exceptions are handled correctly.
"""
- class _FuncPtr(_CFuncPtr):
- _flags_ = _FUNCFLAG_CDECL | _FUNCFLAG_PYTHONAPI
- _restype_ = c_int # default, can be overridden in instances
+ _func_flags_ = _FUNCFLAG_CDECL | _FUNCFLAG_PYTHONAPI
if _os.name in ("nt", "ce"):
@@ -358,9 +386,7 @@ if _os.name in ("nt", "ce"):
"""This class represents a dll exporting functions using the
Windows stdcall calling convention.
"""
- class _FuncPtr(_CFuncPtr):
- _flags_ = _FUNCFLAG_STDCALL
- _restype_ = c_int # default, can be overridden in instances
+ _func_flags_ = _FUNCFLAG_STDCALL
# XXX Hm, what about HRESULT as normal parameter?
# Mustn't it derive from c_long then?
@@ -384,9 +410,8 @@ if _os.name in ("nt", "ce"):
HRESULT error values are automatically raised as WindowsError
exceptions.
"""
- class _FuncPtr(_CFuncPtr):
- _flags_ = _FUNCFLAG_STDCALL
- _restype_ = HRESULT
+ _func_flags_ = _FUNCFLAG_STDCALL
+ _func_restype_ = HRESULT
class LibraryLoader(object):
def __init__(self, dlltype):
@@ -424,6 +449,7 @@ if _os.name in ("nt", "ce"):
GetLastError = windll.kernel32.GetLastError
else:
GetLastError = windll.coredll.GetLastError
+ from _ctypes import get_last_error, set_last_error
def WinError(code=None, descr=None):
if code is None:
diff --git a/Lib/ctypes/test/test_errno.py b/Lib/ctypes/test/test_errno.py
new file mode 100644
index 0000000..ce1cfad
--- /dev/null
+++ b/Lib/ctypes/test/test_errno.py
@@ -0,0 +1,76 @@
+import unittest, os, errno
+from ctypes import *
+from ctypes.util import find_library
+import threading
+
+class Test(unittest.TestCase):
+ def test_open(self):
+ libc_name = find_library("c")
+ if libc_name is not None:
+ libc = CDLL(libc_name, use_errno=True)
+ if os.name == "nt":
+ libc_open = libc._open
+ else:
+ libc_open = libc.open
+
+ libc_open.argtypes = c_char_p, c_int
+
+ self.failUnlessEqual(libc_open("", 0), -1)
+ self.failUnlessEqual(get_errno(), errno.ENOENT)
+
+ self.failUnlessEqual(set_errno(32), errno.ENOENT)
+ self.failUnlessEqual(get_errno(), 32)
+
+
+ def _worker():
+ set_errno(0)
+
+ libc = CDLL(libc_name, use_errno=False)
+ if os.name == "nt":
+ libc_open = libc._open
+ else:
+ libc_open = libc.open
+ libc_open.argtypes = c_char_p, c_int
+ self.failUnlessEqual(libc_open("", 0), -1)
+ self.failUnlessEqual(get_errno(), 0)
+
+ t = threading.Thread(target=_worker)
+ t.start()
+ t.join()
+
+ self.failUnlessEqual(get_errno(), 32)
+ set_errno(0)
+
+ if os.name == "nt":
+
+ def test_GetLastError(self):
+ dll = WinDLL("kernel32", use_last_error=True)
+ GetModuleHandle = dll.GetModuleHandleA
+ GetModuleHandle.argtypes = [c_wchar_p]
+
+ self.failUnlessEqual(0, GetModuleHandle("foo"))
+ self.failUnlessEqual(get_last_error(), 126)
+
+ self.failUnlessEqual(set_last_error(32), 126)
+ self.failUnlessEqual(get_last_error(), 32)
+
+ def _worker():
+ set_last_error(0)
+
+ dll = WinDLL("kernel32", use_last_error=False)
+ GetModuleHandle = dll.GetModuleHandleW
+ GetModuleHandle.argtypes = [c_wchar_p]
+ GetModuleHandle("bar")
+
+ self.failUnlessEqual(get_last_error(), 0)
+
+ t = threading.Thread(target=_worker)
+ t.start()
+ t.join()
+
+ self.failUnlessEqual(get_last_error(), 32)
+
+ set_last_error(0)
+
+if __name__ == "__main__":
+ unittest.main()
diff --git a/Misc/NEWS b/Misc/NEWS
index 9083bbc..c0f25cc 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -72,6 +72,9 @@ Extension Modules
Library
-------
+- Issue #1798: Add ctypes calling convention that allows safe access
+ to errno.
+
- Issue #2404: ctypes objects support the new pep3118 buffer interface
- Patch #2125: Add GetInteger and GetString methods for
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index 30e981a..34ec9f2 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -3412,7 +3412,7 @@ CFuncPtr_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
thunk = AllocFunctionCallback(callable,
dict->argtypes,
dict->restype,
- dict->flags & FUNCFLAG_CDECL);
+ dict->flags);
if (!thunk)
return NULL;
@@ -5535,6 +5535,8 @@ init_ctypes(void)
PyModule_AddObject(m, "FUNCFLAG_STDCALL", PyInt_FromLong(FUNCFLAG_STDCALL));
#endif
PyModule_AddObject(m, "FUNCFLAG_CDECL", PyInt_FromLong(FUNCFLAG_CDECL));
+ PyModule_AddObject(m, "FUNCFLAG_USE_ERRNO", PyInt_FromLong(FUNCFLAG_USE_ERRNO));
+ PyModule_AddObject(m, "FUNCFLAG_USE_LASTERROR", PyInt_FromLong(FUNCFLAG_USE_LASTERROR));
PyModule_AddObject(m, "FUNCFLAG_PYTHONAPI", PyInt_FromLong(FUNCFLAG_PYTHONAPI));
PyModule_AddStringConstant(m, "__version__", "1.1.0");
diff --git a/Modules/_ctypes/callbacks.c b/Modules/_ctypes/callbacks.c
index b78c528..aa02154 100644
--- a/Modules/_ctypes/callbacks.c
+++ b/Modules/_ctypes/callbacks.c
@@ -189,12 +189,15 @@ static void _CallPythonObject(void *mem,
SETFUNC setfunc,
PyObject *callable,
PyObject *converters,
+ int flags,
void **pArgs)
{
Py_ssize_t i;
PyObject *result;
PyObject *arglist = NULL;
Py_ssize_t nArgs;
+ PyObject *error_object = NULL;
+ int *space;
#ifdef WITH_THREAD
PyGILState_STATE state = PyGILState_Ensure();
#endif
@@ -271,8 +274,41 @@ static void _CallPythonObject(void *mem,
#define CHECK(what, x) \
if (x == NULL) _AddTraceback(what, "_ctypes/callbacks.c", __LINE__ - 1), PyErr_Print()
+ if (flags & (FUNCFLAG_USE_ERRNO | FUNCFLAG_USE_LASTERROR)) {
+ error_object = get_error_object(&space);
+ if (error_object == NULL)
+ goto Done;
+ if (flags & FUNCFLAG_USE_ERRNO) {
+ int temp = space[0];
+ space[0] = errno;
+ errno = temp;
+ }
+#ifdef MS_WIN32
+ if (flags & FUNCFLAG_USE_LASTERROR) {
+ int temp = space[1];
+ space[1] = GetLastError();
+ SetLastError(temp);
+ }
+#endif
+ }
+
result = PyObject_CallObject(callable, arglist);
CHECK("'calling callback function'", result);
+
+#ifdef MS_WIN32
+ if (flags & FUNCFLAG_USE_LASTERROR) {
+ int temp = space[1];
+ space[1] = GetLastError();
+ SetLastError(temp);
+ }
+#endif
+ if (flags & FUNCFLAG_USE_ERRNO) {
+ int temp = space[0];
+ space[0] = errno;
+ errno = temp;
+ }
+ Py_XDECREF(error_object);
+
if ((restype != &ffi_type_void) && result) {
PyObject *keep;
assert(setfunc);
@@ -322,6 +358,7 @@ static void closure_fcn(ffi_cif *cif,
p->setfunc,
p->callable,
p->converters,
+ p->flags,
args);
}
@@ -351,7 +388,7 @@ static CThunkObject* CThunkObject_new(Py_ssize_t nArgs)
CThunkObject *AllocFunctionCallback(PyObject *callable,
PyObject *converters,
PyObject *restype,
- int is_cdecl)
+ int flags)
{
int result;
CThunkObject *p;
@@ -371,6 +408,7 @@ CThunkObject *AllocFunctionCallback(PyObject *callable,
goto error;
}
+ p->flags = flags;
for (i = 0; i < nArgs; ++i) {
PyObject *cnv = PySequence_GetItem(converters, i);
if (cnv == NULL)
@@ -398,7 +436,7 @@ CThunkObject *AllocFunctionCallback(PyObject *callable,
cc = FFI_DEFAULT_ABI;
#if defined(MS_WIN32) && !defined(_WIN32_WCE) && !defined(MS_WIN64)
- if (is_cdecl == 0)
+ if ((flags & FUNCFLAG_CDECL) == 0)
cc = FFI_STDCALL;
#endif
result = ffi_prep_cif(&p->cif, cc,
diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
index 0520176..89a4d68 100644
--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -83,7 +83,129 @@
#define DONT_USE_SEH
#endif
+/*
+ ctypes maintains thread-local storage that has space for two error numbers:
+ private copies of the system 'errno' value and, on Windows, the system error code
+ accessed by the GetLastError() and SetLastError() api functions.
+
+ Foreign functions created with CDLL(..., use_errno=True), when called, swap
+ the system 'errno' value with the private copy just before the actual
+ function call, and swapped again immediately afterwards. The 'use_errno'
+ parameter defaults to False, in this case 'ctypes_errno' is not touched.
+
+ On Windows, foreign functions created with CDLL(..., use_last_error=True) or
+ WinDLL(..., use_last_error=True) swap the system LastError value with the
+ ctypes private copy.
+
+ The values are also swapped immeditately before and after ctypes callback
+ functions are called, if the callbacks are constructed using the new
+ optional use_errno parameter set to True: CFUNCTYPE(..., use_errno=TRUE) or
+ WINFUNCTYPE(..., use_errno=True).
+
+ New ctypes functions are provided to access the ctypes private copies from
+ Python:
+
+ - ctypes.set_errno(value) and ctypes.set_last_error(value) store 'value' in
+ the private copy and returns the previous value.
+
+ - ctypes.get_errno() and ctypes.get_last_error() returns the current ctypes
+ private copies value.
+*/
+
+/*
+ This function creates and returns a thread-local Python object that has
+ space to store two integer error numbers; once created the Python object is
+ kept alive in the thread state dictionary as long as the thread itself.
+*/
+PyObject *
+get_error_object(int **pspace)
+{
+ PyObject *dict = PyThreadState_GetDict();
+ PyObject *errobj;
+ if (dict == 0) {
+ PyErr_SetString(PyExc_RuntimeError,
+ "cannot get thread state");
+ return NULL;
+ }
+ errobj = PyDict_GetItemString(dict, "ctypes.error_object");
+ if (errobj)
+ Py_INCREF(errobj);
+ else {
+ void *space = PyMem_Malloc(sizeof(int) * 2);
+ if (space == NULL)
+ return NULL;
+ memset(space, 0, sizeof(int) * 2);
+ errobj = PyCObject_FromVoidPtr(space, PyMem_Free);
+ if (errobj == NULL)
+ return NULL;
+ if (-1 == PyDict_SetItemString(dict, "ctypes.error_object",
+ errobj)) {
+ Py_DECREF(errobj);
+ return NULL;
+ }
+ }
+ *pspace = (int *)PyCObject_AsVoidPtr(errobj);
+ return errobj;
+}
+
+static PyObject *
+get_error_internal(PyObject *self, PyObject *args, int index)
+{
+ int *space;
+ PyObject *errobj = get_error_object(&space);
+ PyObject *result;
+
+ if (errobj == NULL)
+ return NULL;
+ result = PyInt_FromLong(space[index]);
+ Py_DECREF(errobj);
+ return result;
+}
+
+static PyObject *
+set_error_internal(PyObject *self, PyObject *args, int index)
+{
+ int new_errno, old_errno;
+ PyObject *errobj;
+ int *space;
+
+ if (!PyArg_ParseTuple(args, "i", &new_errno))
+ return NULL;
+ errobj = get_error_object(&space);
+ if (errobj == NULL)
+ return NULL;
+ old_errno = space[index];
+ space[index] = new_errno;
+ Py_DECREF(errobj);
+ return PyInt_FromLong(old_errno);
+}
+
+static PyObject *
+get_errno(PyObject *self, PyObject *args)
+{
+ return get_error_internal(self, args, 0);
+}
+
+static PyObject *
+set_errno(PyObject *self, PyObject *args)
+{
+ return set_error_internal(self, args, 0);
+}
+
#ifdef MS_WIN32
+
+static PyObject *
+get_last_error(PyObject *self, PyObject *args)
+{
+ return get_error_internal(self, args, 1);
+}
+
+static PyObject *
+set_last_error(PyObject *self, PyObject *args)
+{
+ return set_error_internal(self, args, 1);
+}
+
PyObject *ComError;
static TCHAR *FormatError(DWORD code)
@@ -625,6 +747,8 @@ static int _call_function_pointer(int flags,
#ifdef WITH_THREAD
PyThreadState *_save = NULL; /* For Py_BLOCK_THREADS and Py_UNBLOCK_THREADS */
#endif
+ PyObject *error_object = NULL;
+ int *space;
ffi_cif cif;
int cc;
#ifdef MS_WIN32
@@ -656,11 +780,26 @@ static int _call_function_pointer(int flags,
return -1;
}
+ if (flags & (FUNCFLAG_USE_ERRNO | FUNCFLAG_USE_LASTERROR)) {
+ error_object = get_error_object(&space);
+ if (error_object == NULL)
+ return -1;
+ }
#ifdef WITH_THREAD
if ((flags & FUNCFLAG_PYTHONAPI) == 0)
Py_UNBLOCK_THREADS
#endif
+ if (flags & FUNCFLAG_USE_ERRNO) {
+ int temp = space[0];
+ space[0] = errno;
+ errno = temp;
+ }
#ifdef MS_WIN32
+ if (flags & FUNCFLAG_USE_LASTERROR) {
+ int temp = space[1];
+ space[1] = GetLastError();
+ SetLastError(temp);
+ }
#ifndef DONT_USE_SEH
__try {
#endif
@@ -675,7 +814,18 @@ static int _call_function_pointer(int flags,
;
}
#endif
+ if (flags & FUNCFLAG_USE_LASTERROR) {
+ int temp = space[1];
+ space[1] = GetLastError();
+ SetLastError(temp);
+ }
#endif
+ if (flags & FUNCFLAG_USE_ERRNO) {
+ int temp = space[0];
+ space[0] = errno;
+ errno = temp;
+ }
+ Py_XDECREF(error_object);
#ifdef WITH_THREAD
if ((flags & FUNCFLAG_PYTHONAPI) == 0)
Py_BLOCK_THREADS
@@ -1692,6 +1842,8 @@ buffer_info(PyObject *self, PyObject *arg)
}
PyMethodDef module_methods[] = {
+ {"get_errno", get_errno, METH_NOARGS},
+ {"set_errno", set_errno, METH_VARARGS},
{"POINTER", POINTER, METH_O },
{"pointer", pointer, METH_O },
{"_unpickle", unpickle, METH_VARARGS },
@@ -1702,6 +1854,8 @@ PyMethodDef module_methods[] = {
{"set_conversion_mode", set_conversion_mode, METH_VARARGS, set_conversion_mode_doc},
#endif
#ifdef MS_WIN32
+ {"get_last_error", get_last_error, METH_NOARGS},
+ {"set_last_error", set_last_error, METH_VARARGS},
{"CopyComPointer", copy_com_pointer, METH_VARARGS, copy_com_pointer_doc},
{"FormatError", format_error, METH_VARARGS, format_error_doc},
{"LoadLibrary", load_library, METH_VARARGS, load_library_doc},
diff --git a/Modules/_ctypes/ctypes.h b/Modules/_ctypes/ctypes.h
index d068ea5..96db12f 100644
--- a/Modules/_ctypes/ctypes.h
+++ b/Modules/_ctypes/ctypes.h
@@ -87,6 +87,7 @@ typedef struct {
PyObject_VAR_HEAD
ffi_closure *pcl; /* the C callable */
ffi_cif cif;
+ int flags;
PyObject *converters;
PyObject *callable;
PyObject *restype;
@@ -185,7 +186,7 @@ extern PyMethodDef module_methods[];
extern CThunkObject *AllocFunctionCallback(PyObject *callable,
PyObject *converters,
PyObject *restype,
- int stdcall);
+ int flags);
/* a table entry describing a predefined ctypes type */
struct fielddesc {
char code;
@@ -311,6 +312,8 @@ PyObject *_CallProc(PPROC pProc,
#define FUNCFLAG_CDECL 0x1
#define FUNCFLAG_HRESULT 0x2
#define FUNCFLAG_PYTHONAPI 0x4
+#define FUNCFLAG_USE_ERRNO 0x8
+#define FUNCFLAG_USE_LASTERROR 0x10
#define TYPEFLAG_ISPOINTER 0x100
#define TYPEFLAG_HASPOINTER 0x200
@@ -429,6 +432,7 @@ extern char *alloc_format_string(const char *prefix, const char *suffix);
extern int IsSimpleSubType(PyObject *obj);
extern PyObject *_pointer_type_cache;
+PyObject *get_error_object(int **pspace);
#ifdef MS_WIN32
extern PyObject *ComError;
generated by cgit v0.12 at 2025-09-27 19:05:26 (GMT)