/* * 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 #include #else #include "ctypes_dlfcn.h" #endif #ifdef MS_WIN32 #include #endif #include #include "ctypes.h" #ifdef HAVE_ALLOCA_H /* AIX needs alloca.h for alloca() */ #include #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 == 0) { 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_GetItem(dict, error_object_name); if (errobj) { if (!PyCapsule_IsValid(errobj, CTYPES_CAPSULE_NAME_PYMEM)) { PyErr_SetString(PyExc_RuntimeError, "ctypes.error_object is an invalid capsule"); return NULL; } Py_INCREF(errobj); } 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, "", self->tag, self->value.b); break; case 'h': case 'H': sprintf(buffer, "", self->tag, self->value.h); break; case 'i': case 'I': sprintf(buffer, "", self->tag, self->value.i); break; case 'l': case 'L': sprintf(buffer, "", self->tag, self->value.l); break; case 'q': case 'Q': sprintf(buffer, #ifdef MS_WIN32 "", #else "", #endif self->tag, self->value.q); break; case 'd': sprintf(buffer, "", self->tag, self->value.d); break; case 'f': sprintf(buffer, "", self->tag, self->value.f); break; case 'c': sprintf(buffer, "", 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, "", self->tag, self->value.p); break; default: sprintf(buffer, "", 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) { #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 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; } #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 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; } #ifdef WITH_THREAD if ((flags & FUNCFLAG_PYTHONAPI) == 0) Py_BLOCK_THREADS #endif 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! */ #ifdef WITH_THREAD Py_BEGIN_ALLOW_THREADS #endif 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); failed: #ifdef WITH_THREAD Py_END_ALLOW_THREADS #endif progid = NULL; ProgIDFromCLSID(&guid, &progid); text = FormatError(errcode); obj = Py_BuildValue( "iu(uuuiu)", errcode, text, descr, source, helpfile, helpcontext, progid); if (obj) { PyErr_SetObject(ComError, obj); Py_DECREF(obj); } LocalFree(text); if (descr) SysFreeString(descr); if (helpfile) SysFreeString(helpfile); if (source) SysFreeString(source); return NULL; } #endif /* * Requirements, must be ensured by the caller: * - argtuple is tuple of arguments * - argtypes is either NULL, or a tuple of the same size as argtuple * * - XXX various requirements for restype, not yet collected */ PyObject *_ctypes_callproc(PPROC pProc, PyObject *argtuple, #ifdef MS_WIN32 IUnknown *pIunk, GUID *iid, #endif int flags, PyObject *argtypes, /* misleading name: This is a tuple of methods, not types: the .from_param class methods of the types */ PyObject *restype, PyObject *checker) { Py_ssize_t i, n, argcount, argtype_count; void *resbuf; struct argument *args, *pa; ffi_type **atypes; ffi_type *rtype; void **avalues; PyObject *retval = NULL; n = argcount = PyTuple_GET_SIZE(argtuple); #ifdef MS_WIN32 /* an optional COM object this pointer */ if (pIunk) ++argcount; #endif args = (struct argument *)alloca(sizeof(struct argument) * argcount); if (!args) { PyErr_NoMemory(); return NULL; } memset(args, 0, sizeof(struct argument) * argcount); argtype_count = argtypes ? PyTuple_GET_SIZE(argtypes) : 0; #ifdef MS_WIN32 if (pIunk) { args[0].ffi_type = &ffi_type_pointer; args[0].value.p = pIunk; pa = &args[1]; } else #endif pa = &args[0]; /* Convert the arguments */ for (i = 0; i < n; ++i, ++pa) { PyObject *converter; PyObject *arg; int err; arg = PyTuple_GET_ITEM(argtuple, i); /* borrowed ref */ /* For cdecl functions, we allow more actual arguments than the length of the argtypes tuple. This is checked in _ctypes::PyCFuncPtr_Call */ if (argtypes && argtype_count > i) { PyObject *v; converter = PyTuple_GET_ITEM(argtypes, i); v = PyObject_CallFunctionObjArgs(converter, arg, NULL); if (v == NULL) { _ctypes_extend_error(PyExc_ArgError, "argument %d: ", i+1); goto cleanup; } err = ConvParam(v, i+1, pa); Py_DECREF(v); if (-1 == err) { _ctypes_extend_error(PyExc_ArgError, "argument %d: ", i+1); goto cleanup; } } else { err = ConvParam(arg, i+1, pa); if (-1 == err) { _ctypes_extend_error(PyExc_ArgError, "argument %d: ", i+1); goto cleanup; /* leaking ? */ } } } rtype = _ctypes_get_ffi_type(restype); resbuf = alloca(max(rtype->size, sizeof(ffi_arg))); avalues = (void **)alloca(sizeof(void *) * argcount); atypes = (ffi_type **)alloca(sizeof(ffi_type *) * argcount); if (!resbuf || !avalues || !atypes) { PyErr_NoMemory(); goto cleanup; } for (i = 0; i < argcount; ++i) { atypes[i] = args[i].ffi_type; if (atypes[i]->type == FFI_TYPE_STRUCT ) avalues[i] = (void *)args[i].value.p; else avalues[i] = (void *)&args[i].value; } if (-1 == _call_function_pointer(flags, pProc, avalues, atypes, rtype, resbuf, Py_SAFE_DOWNCAST(argcount, Py_ssize_t, int))) goto cleanup; #ifdef WORDS_BIGENDIAN /* libffi returns the result in a buffer with sizeof(ffi_arg). This causes problems on big endian machines, since the result buffer address cannot simply be used as result pointer, instead we must adjust the pointer value: */ /* XXX I should find out and clarify why this is needed at all, especially why adjusting for ffi_type_float must be avoided on 64-bit platforms. */ if (rtype->type != FFI_TYPE_FLOAT && rtype->type != FFI_TYPE_STRUCT && rtype->size < sizeof(ffi_arg)) resbuf = (char *)resbuf + sizeof(ffi_arg) - rtype->size; #endif #ifdef MS_WIN32 if (iid && pIunk) { if (*(int *)resbuf & 0x80000000) retval = GetComError(*(HRESULT *)resbuf, iid, pIunk); else retval = PyLong_FromLong(*(int *)resbuf); } else if (flags & FUNCFLAG_HRESULT) { if (*(int *)resbuf & 0x80000000) retval = PyErr_SetFromWindowsErr(*(int *)resbuf); else retval = PyLong_FromLong(*(int *)resbuf); } else #endif retval = GetResult(restype, resbuf, checker); cleanup: for (i = 0; i < argcount; ++i) Py_XDECREF(args[i].keep); return retval; } static int _parse_voidp(PyObject *obj, void **address) { *address = PyLong_AsVoidPtr(obj); if (*address == NULL) return 0; return 1; } #ifdef MS_WIN32 static const char format_error_doc[] = "FormatError([integer]) -> string\n\ \n\ Convert a win32 error code into a string. If the error code is not\n\ given, the return value of a call to GetLastError() is used.\n"; static PyObject *format_error(PyObject *self, PyObject *args) { PyObject *result; wchar_t *lpMsgBuf; DWORD code = 0; if (!PyArg_ParseTuple(args, "|i:FormatError", &code)) return NULL; if (code == 0) code = GetLastError(); lpMsgBuf = FormatError(code); if (lpMsgBuf) { result = PyUnicode_FromWideChar(lpMsgBuf, wcslen(lpMsgBuf)); LocalFree(lpMsgBuf); } else { result = PyUnicode_FromString(""); } return result; } static const char load_library_doc[] = "LoadLibrary(name) -> handle\n\ \n\ Load an executable (usually a DLL), and return a handle to it.\n\ The handle may be used to locate exported functions in this\n\ module.\n"; static PyObject *load_library(PyObject *self, PyObject *args) { WCHAR *name; PyObject *nameobj; PyObject *ignored; HMODULE hMod; if (!PyArg_ParseTuple(args, "O|O:LoadLibrary", &nameobj, &ignored)) return NULL; name = PyUnicode_AsUnicode(nameobj); if (!name) return NULL; hMod = LoadLibraryW(name); if (!hMod) return PyErr_SetFromWindowsErr(GetLastError()); #ifdef _WIN64 return PyLong_FromVoidPtr(hMod); #else return Py_BuildValue("i", hMod); #endif } static const char free_library_doc[] = "FreeLibrary(handle) -> void\n\ \n\ Free the handle of an executable previously loaded by LoadLibrary.\n"; static PyObject *free_library(PyObject *self, PyObject *args) { void *hMod; if (!PyArg_ParseTuple(args, "O&:FreeLibrary", &_parse_voidp, &hMod)) return NULL; if (!FreeLibrary((HMODULE)hMod)) return PyErr_SetFromWindowsErr(GetLastError()); Py_RETURN_NONE; } static const char copy_com_pointer_doc[] = "CopyComPointer(src, dst) -> HRESULT value\n"; static PyObject * copy_com_pointer(PyObject *self, PyObject *args) { PyObject *p1, *p2, *r = NULL; struct argument a, b; IUnknown *src, **pdst; if (!PyArg_ParseTuple(args, "OO:CopyComPointer", &p1, &p2)) return NULL; a.keep = b.keep = NULL; if (-1 == ConvParam(p1, 0, &a) || -1 == ConvParam(p2, 1, &b)) goto done; src = (IUnknown *)a.value.p; pdst = (IUnknown **)b.value.p; if (pdst == NULL) r = PyLong_FromLong(E_POINTER); else { if (src) src->lpVtbl->AddRef(src); *pdst = src; r = PyLong_FromLong(S_OK); } done: Py_XDECREF(a.keep); Py_XDECREF(b.keep); return r; } #else static PyObject *py_dl_open(PyObject *self, PyObject *args) { PyObject *name, *name2; char *name_str; void * handle; #if HAVE_DECL_RTLD_LOCAL int mode = RTLD_NOW | RTLD_LOCAL; #else /* cygwin doesn't define RTLD_LOCAL */ int mode = RTLD_NOW; #endif if (!PyArg_ParseTuple(args, "O|i:dlopen", &name, &mode)) return NULL; mode |= RTLD_NOW; if (name != Py_None) { if (PyUnicode_FSConverter(name, &name2) == 0) return NULL; if (PyBytes_Check(name2)) name_str = PyBytes_AS_STRING(name2); else name_str = PyByteArray_AS_STRING(name2); } else { name_str = NULL; name2 = NULL; } handle = ctypes_dlopen(name_str, mode); Py_XDECREF(name2); if (!handle) { char *errmsg = ctypes_dlerror(); if (!errmsg) errmsg = "dlopen() error"; PyErr_SetString(PyExc_OSError, errmsg); return NULL; } return PyLong_FromVoidPtr(handle); } static PyObject *py_dl_close(PyObject *self, PyObject *args) { void *handle; if (!PyArg_ParseTuple(args, "O&:dlclose", &_parse_voidp, &handle)) return NULL; if (dlclose(handle)) { PyErr_SetString(PyExc_OSError, ctypes_dlerror()); return NULL; } Py_RETURN_NONE; } static PyObject *py_dl_sym(PyObject *self, PyObject *args) { char *name; void *handle; void *ptr; if (!PyArg_ParseTuple(args, "O&s:dlsym", &_parse_voidp, &handle, &name)) return NULL; ptr = ctypes_dlsym((void*)handle, name); if (!ptr) { PyErr_SetString(PyExc_OSError, ctypes_dlerror()); return NULL; } return PyLong_FromVoidPtr(ptr); } #endif /* * Only for debugging so far: So that we can call CFunction instances * * XXX Needs to accept more arguments: flags, argtypes, restype */ static PyObject * call_function(PyObject *self, PyObject *args) { void *func; PyObject *arguments; PyObject *result; if (!PyArg_ParseTuple(args, "O&O!", &_parse_voidp, &func, &PyTuple_Type, &arguments)) return NULL; result = _ctypes_callproc((PPROC)func, arguments, #ifdef MS_WIN32 NULL, NULL, #endif 0, /* flags */ NULL, /* self->argtypes */ NULL, /* self->restype */ NULL); /* checker */ return result; } /* * Only for debugging so far: So that we can call CFunction instances * * XXX Needs to accept more arguments: flags, argtypes, restype */ static PyObject * call_cdeclfunction(PyObject *self, PyObject *args) { void *func; PyObject *arguments; PyObject *result; if (!PyArg_ParseTuple(args, "O&O!", &_parse_voidp, &func, &PyTuple_Type, &arguments)) return NULL; result = _ctypes_callproc((PPROC)func, arguments, #ifdef MS_WIN32 NULL, NULL, #endif FUNCFLAG_CDECL, /* flags */ NULL, /* self->argtypes */ NULL, /* self->restype */ NULL); /* checker */ return result; } /***************************************************************** * functions */ static const char sizeof_doc[] = "sizeof(C type) -> integer\n" "sizeof(C instance) -> integer\n" "Return the size in bytes of a C instance"; static PyObject * sizeof_func(PyObject *self, PyObject *obj) { StgDictObject *dict; dict = PyType_stgdict(obj); if (dict) return PyLong_FromSsize_t(dict->size); if (CDataObject_Check(obj)) return PyLong_FromSsize_t(((CDataObject *)obj)->b_size); PyErr_SetString(PyExc_TypeError, "this type has no size"); return NULL; } static const char alignment_doc[] = "alignment(C type) -> integer\n" "alignment(C instance) -> integer\n" "Return the alignment requirements of a C instance"; static PyObject * align_func(PyObject *self, PyObject *obj) { StgDictObject *dict; dict = PyType_stgdict(obj); if (dict) return PyLong_FromSsize_t(dict->align); dict = PyObject_stgdict(obj); if (dict) return PyLong_FromSsize_t(dict->align); PyErr_SetString(PyExc_TypeError, "no alignment info"); return NULL; } static const char byref_doc[] = "byref(C instance[, offset=0]) -> byref-object\n" "Return a pointer lookalike to a C instance, only usable\n" "as function argument"; /* * We must return something which can be converted to a parameter, * but still has a reference to self. */ static PyObject * byref(PyObject *self, PyObject *args) { PyCArgObject *parg; PyObject *obj; PyObject *pyoffset = NULL; Py_ssize_t offset = 0; if (!PyArg_UnpackTuple(args, "byref", 1, 2, &obj, &pyoffset)) return NULL; if (pyoffset) { offset = PyNumber_AsSsize_t(pyoffset, NULL); if (offset == -1 && PyErr_Occurred()) return NULL; } if (!CDataObject_Check(obj)) { PyErr_Format(PyExc_TypeError, "byref() argument must be a ctypes instance, not '%s'", Py_TYPE(obj)->tp_name); return NULL; } parg = PyCArgObject_new(); if (parg == NULL) return NULL; parg->tag = 'P'; parg->pffi_type = &ffi_type_pointer; Py_INCREF(obj); parg->obj = obj; parg->value.p = (char *)((CDataObject *)obj)->b_ptr + offset; return (PyObject *)parg; } static const char addressof_doc[] = "addressof(C instance) -> integer\n" "Return the address of the C instance internal buffer"; static PyObject * addressof(PyObject *self, PyObject *obj) { if (CDataObject_Check(obj)) return PyLong_FromVoidPtr(((CDataObject *)obj)->b_ptr); PyErr_SetString(PyExc_TypeError, "invalid type"); return NULL; } static int converter(PyObject *obj, void **address) { *address = PyLong_AsVoidPtr(obj); return *address != NULL; } static PyObject * My_PyObj_FromPtr(PyObject *self, PyObject *args) { PyObject *ob; if (!PyArg_ParseTuple(args, "O&:PyObj_FromPtr", converter, &ob)) return NULL; Py_INCREF(ob); return ob; } static PyObject * My_Py_INCREF(PyObject *self, PyObject *arg) { Py_INCREF(arg); /* that's what this function is for */ Py_INCREF(arg); /* that for returning it */ return arg; } static PyObject * My_Py_DECREF(PyObject *self, PyObject *arg) { Py_DECREF(arg); /* that's what this function is for */ Py_INCREF(arg); /* that's for returning it */ return arg; } static PyObject * resize(PyObject *self, PyObject *args) { CDataObject *obj; StgDictObject *dict; Py_ssize_t size; if (!PyArg_ParseTuple(args, "On:resize", &obj, &size)) return NULL; dict = PyObject_stgdict((PyObject *)obj); if (dict == NULL) { PyErr_SetString(PyExc_TypeError, "excepted ctypes instance"); return NULL; } if (size < dict->size) { PyErr_Format(PyExc_ValueError, "minimum size is %zd", dict->size); return NULL; } if (obj->b_needsfree == 0) { PyErr_Format(PyExc_ValueError, "Memory cannot be resized because this object doesn't own it"); return NULL; } if ((size_t)size <= sizeof(obj->b_value)) { /* internal default buffer is large enough */ obj->b_size = size; goto done; } if (!_CDataObject_HasExternalBuffer(obj)) { /* We are currently using the objects default buffer, but it isn't large enough any more. */ void *ptr = PyMem_Malloc(size); if (ptr == NULL) return PyErr_NoMemory(); memset(ptr, 0, size); memmove(ptr, obj->b_ptr, obj->b_size); obj->b_ptr = ptr; obj->b_size = size; } else { void * ptr = PyMem_Realloc(obj->b_ptr, size); if (ptr == NULL) return PyErr_NoMemory(); obj->b_ptr = ptr; obj->b_size = size; } done: Py_RETURN_NONE; } static PyObject * unpickle(PyObject *self, PyObject *args) { PyObject *typ, *state, *meth, *obj, *result; _Py_IDENTIFIER(__new__); _Py_IDENTIFIER(__setstate__); if (!PyArg_ParseTuple(args, "OO!", &typ, &PyTuple_Type, &state)) return NULL; obj = _PyObject_CallMethodIdObjArgs(typ, &PyId___new__, typ, NULL); if (obj == NULL) return NULL; meth = _PyObject_GetAttrId(obj, &PyId___setstate__); if (meth == NULL) { goto error; } result = PyObject_Call(meth, state, NULL); Py_DECREF(meth); if (result == NULL) { goto error; } Py_DECREF(result); return obj; error: Py_DECREF(obj); return NULL; } static PyObject * POINTER(PyObject *self, PyObject *cls) { PyObject *result; PyTypeObject *typ; PyObject *key; char *buf; result = PyDict_GetItem(_ctypes_ptrtype_cache, cls); if (result) { Py_INCREF(result); return result; } if (PyUnicode_CheckExact(cls)) { const char *name = PyUnicode_AsUTF8(cls); if (name == NULL) return NULL; buf = PyMem_Malloc(strlen(name) + 3 + 1); if (buf == NULL) return PyErr_NoMemory(); sprintf(buf, "LP_%s", name); result = PyObject_CallFunction((PyObject *)Py_TYPE(&PyCPointer_Type), "s(O){}", buf, &PyCPointer_Type); PyMem_Free(buf); if (result == NULL) return result; key = PyLong_FromVoidPtr(result); if (key == NULL) { Py_DECREF(result); return NULL; } } else if (PyType_Check(cls)) { typ = (PyTypeObject *)cls; buf = PyMem_Malloc(strlen(typ->tp_name) + 3 + 1); if (buf == NULL) return PyErr_NoMemory(); sprintf(buf, "LP_%s", typ->tp_name); result = PyObject_CallFunction((PyObject *)Py_TYPE(&PyCPointer_Type), "s(O){sO}", buf, &PyCPointer_Type, "_type_", cls); PyMem_Free(buf); if (result == NULL) return result; Py_INCREF(cls); key = cls; } else { PyErr_SetString(PyExc_TypeError, "must be a ctypes type"); return NULL; } if (-1 == PyDict_SetItem(_ctypes_ptrtype_cache, key, result)) { Py_DECREF(result); Py_DECREF(key); return NULL; } Py_DECREF(key); return result; } static PyObject * pointer(PyObject *self, PyObject *arg) { PyObject *result; PyObject *typ; typ = PyDict_GetItem(_ctypes_ptrtype_cache, (PyObject *)Py_TYPE(arg)); if (typ) return PyObject_CallFunctionObjArgs(typ, arg, NULL); typ = POINTER(NULL, (PyObject *)Py_TYPE(arg)); if (typ == NULL) return NULL; result = PyObject_CallFunctionObjArgs(typ, arg, NULL); Py_DECREF(typ); return result; } static PyObject * buffer_info(PyObject *self, PyObject *arg) { StgDictObject *dict = PyType_stgdict(arg); PyObject *shape; Py_ssize_t i; if (dict == NULL) dict = PyObject_stgdict(arg); if (dict == NULL) { PyErr_SetString(PyExc_TypeError, "not a ctypes type or object"); return NULL; } shape = PyTuple_New(dict->ndim); if (shape == NULL) return NULL; for (i = 0; i < (int)dict->ndim; ++i) PyTuple_SET_ITEM(shape, i, PyLong_FromSsize_t(dict->shape[i])); if (PyErr_Occurred()) { Py_DECREF(shape); return NULL; } return Py_BuildValue("siN", dict->format, dict->ndim, shape); } PyMethodDef _ctypes_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 }, {"buffer_info", buffer_info, METH_O, "Return buffer interface information"}, {"resize", resize, METH_VARARGS, "Resize the memory buffer of a ctypes instance"}, #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}, {"FreeLibrary", free_library, METH_VARARGS, free_library_doc}, {"_check_HRESULT", check_hresult, METH_VARARGS}, #else {"dlopen", py_dl_open, METH_VARARGS, "dlopen(name, flag={RTLD_GLOBAL|RTLD_LOCAL}) open a shared library"}, {"dlclose", py_dl_close, METH_VARARGS, "dlclose a library"}, {"dlsym", py_dl_sym, METH_VARARGS, "find symbol in shared library"}, #endif {"alignment", align_func, METH_O, alignment_doc}, {"sizeof", sizeof_func, METH_O, sizeof_doc}, {"byref", byref, METH_VARARGS, byref_doc}, {"addressof", addressof, METH_O, addressof_doc}, {"call_function", call_function, METH_VARARGS }, {"call_cdeclfunction", call_cdeclfunction, METH_VARARGS }, {"PyObj_FromPtr", My_PyObj_FromPtr, METH_VARARGS }, {"Py_INCREF", My_Py_INCREF, METH_O }, {"Py_DECREF", My_Py_DECREF, METH_O }, {NULL, NULL} /* Sentinel */ }; /* Local Variables: compile-command: "cd .. && python setup.py -q build -g && python setup.py -q build install --home ~" End: */