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Copy pathcallproc.c
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1827 lines (1643 loc) · 52.7 KB
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/*
* History: First version dated from 3/97, derived from my SCMLIB version
* for win16.
*/
/*
* Related Work:
* - calldll http://www.nightmare.com/software.html
* - libffi http://sourceware.cygnus.com/libffi/
* - ffcall http://clisp.cons.org/~haible/packages-ffcall.html
* and, of course, Don Beaudry's MESS package, but this is more ctypes
* related.
*/
/*
How are functions called, and how are parameters converted to C ?
1. _ctypes.c::PyCFuncPtr_call receives an argument tuple 'inargs' and a
keyword dictionary 'kwds'.
2. After several checks, _build_callargs() is called which returns another
tuple 'callargs'. This may be the same tuple as 'inargs', a slice of
'inargs', or a completely fresh tuple, depending on several things (is it a
COM method?, are 'paramflags' available?).
3. _build_callargs also calculates bitarrays containing indexes into
the callargs tuple, specifying how to build the return value(s) of
the function.
4. _ctypes_callproc is then called with the 'callargs' tuple. _ctypes_callproc first
allocates two arrays. The first is an array of 'struct argument' items, the
second array has 'void *' entries.
5. If 'converters' are present (converters is a sequence of argtypes'
from_param methods), for each item in 'callargs' converter is called and the
result passed to ConvParam. If 'converters' are not present, each argument
is directly passed to ConvParm.
6. For each arg, ConvParam stores the contained C data (or a pointer to it,
for structures) into the 'struct argument' array.
7. Finally, a loop fills the 'void *' array so that each item points to the
data contained in or pointed to by the 'struct argument' array.
8. The 'void *' argument array is what _call_function_pointer
expects. _call_function_pointer then has very little to do - only some
libffi specific stuff, then it calls ffi_call.
So, there are 4 data structures holding processed arguments:
- the inargs tuple (in PyCFuncPtr_call)
- the callargs tuple (in PyCFuncPtr_call)
- the 'struct arguments' array
- the 'void *' array
*/
#include "Python.h"
#include "structmember.h"
#ifdef MS_WIN32
#include <windows.h>
#include <tchar.h>
#else
#include "ctypes_dlfcn.h"
#endif
#ifdef MS_WIN32
#include <malloc.h>
#endif
#include <ffi.h>
#include "ctypes.h"
#ifdef HAVE_ALLOCA_H
/* AIX needs alloca.h for alloca() */
#include <alloca.h>
#endif
#if defined(_DEBUG) || defined(__MINGW32__)
/* Don't use structured exception handling on Windows if this is defined.
MingW, AFAIK, doesn't support it.
*/
#define DONT_USE_SEH
#endif
#define CTYPES_CAPSULE_NAME_PYMEM "_ctypes pymem"
static void pymem_destructor(PyObject *ptr)
{
void *p = PyCapsule_GetPointer(ptr, CTYPES_CAPSULE_NAME_PYMEM);
if (p) {
PyMem_Free(p);
}
}
/*
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 *
_ctypes_get_errobj(int **pspace)
{
PyObject *dict = PyThreadState_GetDict();
PyObject *errobj;
static PyObject *error_object_name;
if (dict == NULL) {
PyErr_SetString(PyExc_RuntimeError,
"cannot get thread state");
return NULL;
}
if (error_object_name == NULL) {
error_object_name = PyUnicode_InternFromString("ctypes.error_object");
if (error_object_name == NULL)
return NULL;
}
errobj = PyDict_GetItemRef(dict, error_object_name);
if (errobj) {
if (!PyCapsule_IsValid(errobj, CTYPES_CAPSULE_NAME_PYMEM)) {
Py_DECREF(errobj);
PyErr_SetString(PyExc_RuntimeError,
"ctypes.error_object is an invalid capsule");
return NULL;
}
}
else {
void *space = PyMem_Malloc(sizeof(int) * 2);
if (space == NULL)
return NULL;
memset(space, 0, sizeof(int) * 2);
errobj = PyCapsule_New(space, CTYPES_CAPSULE_NAME_PYMEM, pymem_destructor);
if (errobj == NULL) {
PyMem_Free(space);
return NULL;
}
if (-1 == PyDict_SetItem(dict, error_object_name,
errobj)) {
Py_DECREF(errobj);
return NULL;
}
}
*pspace = (int *)PyCapsule_GetPointer(errobj, CTYPES_CAPSULE_NAME_PYMEM);
return errobj;
}
static PyObject *
get_error_internal(PyObject *self, PyObject *args, int index)
{
int *space;
PyObject *errobj = _ctypes_get_errobj(&space);
PyObject *result;
if (errobj == NULL)
return NULL;
result = PyLong_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 = _ctypes_get_errobj(&space);
if (errobj == NULL)
return NULL;
old_errno = space[index];
space[index] = new_errno;
Py_DECREF(errobj);
return PyLong_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 WCHAR *FormatError(DWORD code)
{
WCHAR *lpMsgBuf;
DWORD n;
n = FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
NULL,
code,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), /* Default language */
(LPWSTR) &lpMsgBuf,
0,
NULL);
if (n) {
while (iswspace(lpMsgBuf[n-1]))
--n;
lpMsgBuf[n] = L'\0'; /* rstrip() */
}
return lpMsgBuf;
}
#ifndef DONT_USE_SEH
static void SetException(DWORD code, EXCEPTION_RECORD *pr)
{
/* The 'code' is a normal win32 error code so it could be handled by
PyErr_SetFromWindowsErr(). However, for some errors, we have additional
information not included in the error code. We handle those here and
delegate all others to the generic function. */
switch (code) {
case EXCEPTION_ACCESS_VIOLATION:
/* The thread attempted to read from or write
to a virtual address for which it does not
have the appropriate access. */
if (pr->ExceptionInformation[0] == 0)
PyErr_Format(PyExc_OSError,
"exception: access violation reading %p",
pr->ExceptionInformation[1]);
else
PyErr_Format(PyExc_OSError,
"exception: access violation writing %p",
pr->ExceptionInformation[1]);
break;
case EXCEPTION_BREAKPOINT:
/* A breakpoint was encountered. */
PyErr_SetString(PyExc_OSError,
"exception: breakpoint encountered");
break;
case EXCEPTION_DATATYPE_MISALIGNMENT:
/* The thread attempted to read or write data that is
misaligned on hardware that does not provide
alignment. For example, 16-bit values must be
aligned on 2-byte boundaries, 32-bit values on
4-byte boundaries, and so on. */
PyErr_SetString(PyExc_OSError,
"exception: datatype misalignment");
break;
case EXCEPTION_SINGLE_STEP:
/* A trace trap or other single-instruction mechanism
signaled that one instruction has been executed. */
PyErr_SetString(PyExc_OSError,
"exception: single step");
break;
case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
/* The thread attempted to access an array element
that is out of bounds, and the underlying hardware
supports bounds checking. */
PyErr_SetString(PyExc_OSError,
"exception: array bounds exceeded");
break;
case EXCEPTION_FLT_DENORMAL_OPERAND:
/* One of the operands in a floating-point operation
is denormal. A denormal value is one that is too
small to represent as a standard floating-point
value. */
PyErr_SetString(PyExc_OSError,
"exception: floating-point operand denormal");
break;
case EXCEPTION_FLT_DIVIDE_BY_ZERO:
/* The thread attempted to divide a floating-point
value by a floating-point divisor of zero. */
PyErr_SetString(PyExc_OSError,
"exception: float divide by zero");
break;
case EXCEPTION_FLT_INEXACT_RESULT:
/* The result of a floating-point operation cannot be
represented exactly as a decimal fraction. */
PyErr_SetString(PyExc_OSError,
"exception: float inexact");
break;
case EXCEPTION_FLT_INVALID_OPERATION:
/* This exception represents any floating-point
exception not included in this list. */
PyErr_SetString(PyExc_OSError,
"exception: float invalid operation");
break;
case EXCEPTION_FLT_OVERFLOW:
/* The exponent of a floating-point operation is
greater than the magnitude allowed by the
corresponding type. */
PyErr_SetString(PyExc_OSError,
"exception: float overflow");
break;
case EXCEPTION_FLT_STACK_CHECK:
/* The stack overflowed or underflowed as the result
of a floating-point operation. */
PyErr_SetString(PyExc_OSError,
"exception: stack over/underflow");
break;
case EXCEPTION_STACK_OVERFLOW:
/* The stack overflowed or underflowed as the result
of a floating-point operation. */
PyErr_SetString(PyExc_OSError,
"exception: stack overflow");
break;
case EXCEPTION_FLT_UNDERFLOW:
/* The exponent of a floating-point operation is less
than the magnitude allowed by the corresponding
type. */
PyErr_SetString(PyExc_OSError,
"exception: float underflow");
break;
case EXCEPTION_INT_DIVIDE_BY_ZERO:
/* The thread attempted to divide an integer value by
an integer divisor of zero. */
PyErr_SetString(PyExc_OSError,
"exception: integer divide by zero");
break;
case EXCEPTION_INT_OVERFLOW:
/* The result of an integer operation caused a carry
out of the most significant bit of the result. */
PyErr_SetString(PyExc_OSError,
"exception: integer overflow");
break;
case EXCEPTION_PRIV_INSTRUCTION:
/* The thread attempted to execute an instruction
whose operation is not allowed in the current
machine mode. */
PyErr_SetString(PyExc_OSError,
"exception: privileged instruction");
break;
case EXCEPTION_NONCONTINUABLE_EXCEPTION:
/* The thread attempted to continue execution after a
noncontinuable exception occurred. */
PyErr_SetString(PyExc_OSError,
"exception: nocontinuable");
break;
default:
PyErr_SetFromWindowsErr(code);
break;
}
}
static DWORD HandleException(EXCEPTION_POINTERS *ptrs,
DWORD *pdw, EXCEPTION_RECORD *record)
{
*pdw = ptrs->ExceptionRecord->ExceptionCode;
*record = *ptrs->ExceptionRecord;
/* We don't want to catch breakpoint exceptions, they are used to attach
* a debugger to the process.
*/
if (*pdw == EXCEPTION_BREAKPOINT)
return EXCEPTION_CONTINUE_SEARCH;
return EXCEPTION_EXECUTE_HANDLER;
}
#endif
static PyObject *
check_hresult(PyObject *self, PyObject *args)
{
HRESULT hr;
if (!PyArg_ParseTuple(args, "i", &hr))
return NULL;
if (FAILED(hr))
return PyErr_SetFromWindowsErr(hr);
return PyLong_FromLong(hr);
}
#endif
/**************************************************************/
PyCArgObject *
PyCArgObject_new(void)
{
PyCArgObject *p;
p = PyObject_New(PyCArgObject, &PyCArg_Type);
if (p == NULL)
return NULL;
p->pffi_type = NULL;
p->tag = '\0';
p->obj = NULL;
memset(&p->value, 0, sizeof(p->value));
return p;
}
static void
PyCArg_dealloc(PyCArgObject *self)
{
Py_XDECREF(self->obj);
PyObject_Del(self);
}
static PyObject *
PyCArg_repr(PyCArgObject *self)
{
char buffer[256];
switch(self->tag) {
case 'b':
case 'B':
sprintf(buffer, "<cparam '%c' (%d)>",
self->tag, self->value.b);
break;
case 'h':
case 'H':
sprintf(buffer, "<cparam '%c' (%d)>",
self->tag, self->value.h);
break;
case 'i':
case 'I':
sprintf(buffer, "<cparam '%c' (%d)>",
self->tag, self->value.i);
break;
case 'l':
case 'L':
sprintf(buffer, "<cparam '%c' (%ld)>",
self->tag, self->value.l);
break;
case 'q':
case 'Q':
sprintf(buffer,
#ifdef MS_WIN32
"<cparam '%c' (%I64d)>",
#else
"<cparam '%c' (%qd)>",
#endif
self->tag, self->value.q);
break;
case 'd':
sprintf(buffer, "<cparam '%c' (%f)>",
self->tag, self->value.d);
break;
case 'f':
sprintf(buffer, "<cparam '%c' (%f)>",
self->tag, self->value.f);
break;
case 'c':
sprintf(buffer, "<cparam '%c' (%c)>",
self->tag, self->value.c);
break;
/* Hm, are these 'z' and 'Z' codes useful at all?
Shouldn't they be replaced by the functionality of c_string
and c_wstring ?
*/
case 'z':
case 'Z':
case 'P':
sprintf(buffer, "<cparam '%c' (%p)>",
self->tag, self->value.p);
break;
default:
sprintf(buffer, "<cparam '%c' at %p>",
self->tag, self);
break;
}
return PyUnicode_FromString(buffer);
}
static PyMemberDef PyCArgType_members[] = {
{ "_obj", T_OBJECT,
offsetof(PyCArgObject, obj), READONLY,
"the wrapped object" },
{ NULL },
};
PyTypeObject PyCArg_Type = {
PyVarObject_HEAD_INIT(NULL, 0)
"CArgObject",
sizeof(PyCArgObject),
0,
(destructor)PyCArg_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_reserved */
(reprfunc)PyCArg_repr, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT, /* tp_flags */
0, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
0, /* tp_methods */
PyCArgType_members, /* tp_members */
};
/****************************************************************/
/*
* Convert a PyObject * into a parameter suitable to pass to an
* C function call.
*
* 1. Python integers are converted to C int and passed by value.
* Py_None is converted to a C NULL pointer.
*
* 2. 3-tuples are expected to have a format character in the first
* item, which must be 'i', 'f', 'd', 'q', or 'P'.
* The second item will have to be an integer, float, double, long long
* or integer (denoting an address void *), will be converted to the
* corresponding C data type and passed by value.
*
* 3. Other Python objects are tested for an '_as_parameter_' attribute.
* The value of this attribute must be an integer which will be passed
* by value, or a 2-tuple or 3-tuple which will be used according
* to point 2 above. The third item (if any), is ignored. It is normally
* used to keep the object alive where this parameter refers to.
* XXX This convention is dangerous - you can construct arbitrary tuples
* in Python and pass them. Would it be safer to use a custom container
* datatype instead of a tuple?
*
* 4. Other Python objects cannot be passed as parameters - an exception is raised.
*
* 5. ConvParam will store the converted result in a struct containing format
* and value.
*/
union result {
char c;
char b;
short h;
int i;
long l;
long long q;
long double D;
double d;
float f;
void *p;
};
struct argument {
ffi_type *ffi_type;
PyObject *keep;
union result value;
};
/*
* Convert a single Python object into a PyCArgObject and return it.
*/
static int ConvParam(PyObject *obj, Py_ssize_t index, struct argument *pa)
{
StgDictObject *dict;
pa->keep = NULL; /* so we cannot forget it later */
dict = PyObject_stgdict(obj);
if (dict) {
PyCArgObject *carg;
assert(dict->paramfunc);
/* If it has an stgdict, it is a CDataObject */
carg = dict->paramfunc((CDataObject *)obj);
if (carg == NULL)
return -1;
pa->ffi_type = carg->pffi_type;
memcpy(&pa->value, &carg->value, sizeof(pa->value));
pa->keep = (PyObject *)carg;
return 0;
}
if (PyCArg_CheckExact(obj)) {
PyCArgObject *carg = (PyCArgObject *)obj;
pa->ffi_type = carg->pffi_type;
Py_INCREF(obj);
pa->keep = obj;
memcpy(&pa->value, &carg->value, sizeof(pa->value));
return 0;
}
/* check for None, integer, string or unicode and use directly if successful */
if (obj == Py_None) {
pa->ffi_type = &ffi_type_pointer;
pa->value.p = NULL;
return 0;
}
if (PyLong_Check(obj)) {
pa->ffi_type = &ffi_type_sint;
pa->value.i = (long)PyLong_AsUnsignedLong(obj);
if (pa->value.i == -1 && PyErr_Occurred()) {
PyErr_Clear();
pa->value.i = PyLong_AsLong(obj);
if (pa->value.i == -1 && PyErr_Occurred()) {
PyErr_SetString(PyExc_OverflowError,
"int too long to convert");
return -1;
}
}
return 0;
}
if (PyBytes_Check(obj)) {
pa->ffi_type = &ffi_type_pointer;
pa->value.p = PyBytes_AsString(obj);
Py_INCREF(obj);
pa->keep = obj;
return 0;
}
#ifdef CTYPES_UNICODE
if (PyUnicode_Check(obj)) {
pa->ffi_type = &ffi_type_pointer;
pa->value.p = PyUnicode_AsWideCharString(obj, NULL);
if (pa->value.p == NULL)
return -1;
pa->keep = PyCapsule_New(pa->value.p, CTYPES_CAPSULE_NAME_PYMEM, pymem_destructor);
if (!pa->keep) {
PyMem_Free(pa->value.p);
return -1;
}
return 0;
}
#endif
{
PyObject *arg;
arg = PyObject_GetAttrString(obj, "_as_parameter_");
/* Which types should we exactly allow here?
integers are required for using Python classes
as parameters (they have to expose the '_as_parameter_'
attribute)
*/
if (arg) {
int result;
result = ConvParam(arg, index, pa);
Py_DECREF(arg);
return result;
}
PyErr_Format(PyExc_TypeError,
"Don't know how to convert parameter %d",
Py_SAFE_DOWNCAST(index, Py_ssize_t, int));
return -1;
}
}
ffi_type *_ctypes_get_ffi_type(PyObject *obj)
{
StgDictObject *dict;
if (obj == NULL)
return &ffi_type_sint;
dict = PyType_stgdict(obj);
if (dict == NULL)
return &ffi_type_sint;
#if defined(MS_WIN32) && !defined(_WIN32_WCE)
/* This little trick works correctly with MSVC.
It returns small structures in registers
*/
if (dict->ffi_type_pointer.type == FFI_TYPE_STRUCT) {
if (dict->ffi_type_pointer.size <= 4)
return &ffi_type_sint32;
else if (dict->ffi_type_pointer.size <= 8)
return &ffi_type_sint64;
}
#endif
return &dict->ffi_type_pointer;
}
/*
* libffi uses:
*
* ffi_status ffi_prep_cif(ffi_cif *cif, ffi_abi abi,
* unsigned int nargs,
* ffi_type *rtype,
* ffi_type **atypes);
*
* and then
*
* void ffi_call(ffi_cif *cif, void *fn, void *rvalue, void **avalues);
*/
static int _call_function_pointer(int flags,
PPROC pProc,
void **avalues,
ffi_type **atypes,
ffi_type *restype,
void *resmem,
int argcount)
{
PyThreadState *_save = NULL; /* For Py_BLOCK_THREADS and Py_UNBLOCK_THREADS */
PyObject *error_object = NULL;
int *space;
ffi_cif cif;
int cc;
#ifdef MS_WIN32
int delta;
#ifndef DONT_USE_SEH
DWORD dwExceptionCode = 0;
EXCEPTION_RECORD record;
#endif
#endif
/* XXX check before here */
if (restype == NULL) {
PyErr_SetString(PyExc_RuntimeError,
"No ffi_type for result");
return -1;
}
cc = FFI_DEFAULT_ABI;
#if defined(MS_WIN32) && !defined(MS_WIN64) && !defined(_WIN32_WCE)
if ((flags & FUNCFLAG_CDECL) == 0)
cc = FFI_STDCALL;
#endif
if (FFI_OK != ffi_prep_cif(&cif,
cc,
argcount,
restype,
atypes)) {
PyErr_SetString(PyExc_RuntimeError,
"ffi_prep_cif failed");
return -1;
}
if (flags & (FUNCFLAG_USE_ERRNO | FUNCFLAG_USE_LASTERROR)) {
error_object = _ctypes_get_errobj(&space);
if (error_object == NULL)
return -1;
}
if ((flags & FUNCFLAG_PYTHONAPI) == 0)
Py_UNBLOCK_THREADS
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
delta =
#endif
ffi_call(&cif, (void *)pProc, resmem, avalues);
#ifdef MS_WIN32
#ifndef DONT_USE_SEH
}
__except (HandleException(GetExceptionInformation(),
&dwExceptionCode, &record)) {
;
}
#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;
}
if ((flags & FUNCFLAG_PYTHONAPI) == 0)
Py_BLOCK_THREADS
Py_XDECREF(error_object);
#ifdef MS_WIN32
#ifndef DONT_USE_SEH
if (dwExceptionCode) {
SetException(dwExceptionCode, &record);
return -1;
}
#endif
#ifdef MS_WIN64
if (delta != 0) {
PyErr_Format(PyExc_RuntimeError,
"ffi_call failed with code %d",
delta);
return -1;
}
#else
if (delta < 0) {
if (flags & FUNCFLAG_CDECL)
PyErr_Format(PyExc_ValueError,
"Procedure called with not enough "
"arguments (%d bytes missing) "
"or wrong calling convention",
-delta);
else
PyErr_Format(PyExc_ValueError,
"Procedure probably called with not enough "
"arguments (%d bytes missing)",
-delta);
return -1;
} else if (delta > 0) {
PyErr_Format(PyExc_ValueError,
"Procedure probably called with too many "
"arguments (%d bytes in excess)",
delta);
return -1;
}
#endif
#endif
if ((flags & FUNCFLAG_PYTHONAPI) && PyErr_Occurred())
return -1;
return 0;
}
/*
* Convert the C value in result into a Python object, depending on restype.
*
* - If restype is NULL, return a Python integer.
* - If restype is None, return None.
* - If restype is a simple ctypes type (c_int, c_void_p), call the type's getfunc,
* pass the result to checker and return the result.
* - If restype is another ctypes type, return an instance of that.
* - Otherwise, call restype and return the result.
*/
static PyObject *GetResult(PyObject *restype, void *result, PyObject *checker)
{
StgDictObject *dict;
PyObject *retval, *v;
if (restype == NULL)
return PyLong_FromLong(*(int *)result);
if (restype == Py_None) {
Py_RETURN_NONE;
}
dict = PyType_stgdict(restype);
if (dict == NULL)
return PyObject_CallFunction(restype, "i", *(int *)result);
if (dict->getfunc && !_ctypes_simple_instance(restype)) {
retval = dict->getfunc(result, dict->size);
/* If restype is py_object (detected by comparing getfunc with
O_get), we have to call Py_DECREF because O_get has already
called Py_INCREF.
*/
if (dict->getfunc == _ctypes_get_fielddesc("O")->getfunc) {
Py_DECREF(retval);
}
} else
retval = PyCData_FromBaseObj(restype, NULL, 0, result);
if (!checker || !retval)
return retval;
v = PyObject_CallFunctionObjArgs(checker, retval, NULL);
if (v == NULL)
_PyTraceback_Add("GetResult", "_ctypes/callproc.c", __LINE__-2);
Py_DECREF(retval);
return v;
}
/*
* Raise a new exception 'exc_class', adding additional text to the original
* exception string.
*/
void _ctypes_extend_error(PyObject *exc_class, const char *fmt, ...)
{
va_list vargs;
PyObject *tp, *v, *tb, *s, *cls_str, *msg_str;
va_start(vargs, fmt);
s = PyUnicode_FromFormatV(fmt, vargs);
va_end(vargs);
if (!s)
return;
PyErr_Fetch(&tp, &v, &tb);
PyErr_NormalizeException(&tp, &v, &tb);
cls_str = PyObject_Str(tp);
if (cls_str) {
PyUnicode_AppendAndDel(&s, cls_str);
PyUnicode_AppendAndDel(&s, PyUnicode_FromString(": "));
if (s == NULL)
goto error;
} else
PyErr_Clear();
msg_str = PyObject_Str(v);
if (msg_str)
PyUnicode_AppendAndDel(&s, msg_str);
else {
PyErr_Clear();
PyUnicode_AppendAndDel(&s, PyUnicode_FromString("???"));
}
if (s == NULL)
goto error;
PyErr_SetObject(exc_class, s);
error:
Py_XDECREF(tp);
Py_XDECREF(v);
Py_XDECREF(tb);
Py_XDECREF(s);
}
#ifdef MS_WIN32
static PyObject *
GetComError(HRESULT errcode, GUID *riid, IUnknown *pIunk)
{
HRESULT hr;
ISupportErrorInfo *psei = NULL;
IErrorInfo *pei = NULL;
BSTR descr=NULL, helpfile=NULL, source=NULL;
GUID guid;
DWORD helpcontext=0;
LPOLESTR progid;
PyObject *obj;
LPOLESTR text;
/* We absolutely have to release the GIL during COM method calls,
otherwise we may get a deadlock!
*/
Py_BEGIN_ALLOW_THREADS
hr = pIunk->lpVtbl->QueryInterface(pIunk, &IID_ISupportErrorInfo, (void **)&psei);
if (FAILED(hr))
goto failed;
hr = psei->lpVtbl->InterfaceSupportsErrorInfo(psei, riid);
psei->lpVtbl->Release(psei);
if (FAILED(hr))
goto failed;
hr = GetErrorInfo(0, &pei);
if (hr != S_OK)
goto failed;
pei->lpVtbl->GetDescription(pei, &descr);
pei->lpVtbl->GetGUID(pei, &guid);
pei->lpVtbl->GetHelpContext(pei, &helpcontext);
pei->lpVtbl->GetHelpFile(pei, &helpfile);
pei->lpVtbl->GetSource(pei, &source);
pei->lpVtbl->Release(pei);
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