errors.c

python s60 1.4.5版本的源代码

/* Portions Copyright (c) 2005 Nokia Corporation */

/* Error handling */

#include "Python.h"

#ifdef macintosh
extern char *PyMac_StrError(int);
#undef strerror
#define strerror PyMac_StrError
#endif /* macintosh */

#ifndef __STDC__
#ifndef MS_WINDOWS
extern char *strerror(int);
#endif
#endif

#ifdef MS_WIN32
#include "windows.h"
#include "winbase.h"
#endif

#include <ctype.h>

DL_EXPORT(void)
PyErr_Restore(PyObject *type, PyObject *value, PyObject *traceback)
{
	PyThreadState *tstate = PyThreadState_GET();
	PyObject *oldtype, *oldvalue, *oldtraceback;

	if (traceback != NULL && !PyTraceBack_Check(traceback)) {
		/* XXX Should never happen -- fatal error instead? */
		Py_DECREF(traceback);
		traceback = NULL;
	}

	/* Save these in locals to safeguard against recursive
	   invocation through Py_XDECREF */
	oldtype = tstate->curexc_type;
	oldvalue = tstate->curexc_value;
	oldtraceback = tstate->curexc_traceback;

	tstate->curexc_type = type;
	tstate->curexc_value = value;
	tstate->curexc_traceback = traceback;

	Py_XDECREF(oldtype);
	Py_XDECREF(oldvalue);
	Py_XDECREF(oldtraceback);
}

DL_EXPORT(void)
PyErr_SetObject(PyObject *exception, PyObject *value)
{
	Py_XINCREF(exception);
	Py_XINCREF(value);
	PyErr_Restore(exception, value, (PyObject *)NULL);
}

DL_EXPORT(void)
PyErr_SetNone(PyObject *exception)
{
	PyErr_SetObject(exception, (PyObject *)NULL);
}

DL_EXPORT(void)
PyErr_SetString(PyObject *exception, const char *string)
{
	PyObject *value = PyString_FromString(string);
	PyErr_SetObject(exception, value);
	Py_XDECREF(value);
}


DL_EXPORT(PyObject *)
PyErr_Occurred(void)
{
	PyThreadState *tstate = PyThreadState_GET();

	return tstate->curexc_type;
}


DL_EXPORT(int)
PyErr_GivenExceptionMatches(PyObject *err, PyObject *exc)
{
	if (err == NULL || exc == NULL) {
		/* maybe caused by "import exceptions" that failed early on */
		return 0;
	}
	if (PyTuple_Check(exc)) {
		int i, n;
		n = PyTuple_Size(exc);
		for (i = 0; i < n; i++) {
			/* Test recursively */
		     if (PyErr_GivenExceptionMatches(
			     err, PyTuple_GET_ITEM(exc, i)))
		     {
			     return 1;
		     }
		}
		return 0;
	}
	/* err might be an instance, so check its class. */
	if (PyInstance_Check(err))
		err = (PyObject*)((PyInstanceObject*)err)->in_class;

	if (PyClass_Check(err) && PyClass_Check(exc))
		return PyClass_IsSubclass(err, exc);

	return err == exc;
}


DL_EXPORT(int)
PyErr_ExceptionMatches(PyObject *exc)
{
	return PyErr_GivenExceptionMatches(PyErr_Occurred(), exc);
}


/* Used in many places to normalize a raised exception, including in
   eval_code2(), do_raise(), and PyErr_Print()
*/
DL_EXPORT(void)
PyErr_NormalizeException(PyObject **exc, PyObject **val, PyObject **tb)
{
	PyObject *type = *exc;
	PyObject *value = *val;
	PyObject *inclass = NULL;
	PyObject *initial_tb = NULL;

	if (type == NULL) {
		/* This is a bug.  Should never happen.  Don't dump core. */
		PyErr_SetString(PyExc_SystemError,
			"PyErr_NormalizeException() called without exception");
	}

	/* If PyErr_SetNone() was used, the value will have been actually
	   set to NULL.
	*/
	if (!value) {
		value = Py_None;
		Py_INCREF(value);
	}

	if (PyInstance_Check(value))
		inclass = (PyObject*)((PyInstanceObject*)value)->in_class;

	/* Normalize the exception so that if the type is a class, the
	   value will be an instance.
	*/
	if (PyClass_Check(type)) {
		/* if the value was not an instance, or is not an instance
		   whose class is (or is derived from) type, then use the
		   value as an argument to instantiation of the type
		   class.
		*/
		if (!inclass || !PyClass_IsSubclass(inclass, type)) {
			PyObject *args, *res;

			if (value == Py_None)
				args = Py_BuildValue("()");
			else if (PyTuple_Check(value)) {
				Py_INCREF(value);
				args = value;
			}
			else
				args = Py_BuildValue("(O)", value);

			if (args == NULL)
				goto finally;
			res = PyEval_CallObject(type, args);
			Py_DECREF(args);
			if (res == NULL)
				goto finally;
			Py_DECREF(value);
			value = res;
		}
		/* if the class of the instance doesn't exactly match the
		   class of the type, believe the instance
		*/
		else if (inclass != type) {
 			Py_DECREF(type);
			type = inclass;
			Py_INCREF(type);
		}
	}
	*exc = type;
	*val = value;
	return;
finally:
	Py_DECREF(type);
	Py_DECREF(value);
	/* If the new exception doesn't set a traceback and the old
	   exception had a traceback, use the old traceback for the
	   new exception.  It's better than nothing.
	*/
	initial_tb = *tb;
	PyErr_Fetch(exc, val, tb);
	if (initial_tb != NULL) {
		if (*tb == NULL)
			*tb = initial_tb;
		else
			Py_DECREF(initial_tb);
	}
	/* normalize recursively */
	PyErr_NormalizeException(exc, val, tb);
}


DL_EXPORT(void)
PyErr_Fetch(PyObject **p_type, PyObject **p_value, PyObject **p_traceback)
{
	PyThreadState *tstate = PyThreadState_Get();

	*p_type = tstate->curexc_type;
	*p_value = tstate->curexc_value;
	*p_traceback = tstate->curexc_traceback;

	tstate->curexc_type = NULL;
	tstate->curexc_value = NULL;
	tstate->curexc_traceback = NULL;
}

DL_EXPORT(void)
PyErr_Clear(void)
{
	PyErr_Restore(NULL, NULL, NULL);
}

/* Convenience functions to set a type error exception and return 0 */

DL_EXPORT(int)
PyErr_BadArgument(void)
{
	PyErr_SetString(PyExc_TypeError,
			"bad argument type for built-in operation");
	return 0;
}

DL_EXPORT(PyObject *)
PyErr_NoMemory(void)
{
	if (PyErr_ExceptionMatches(PyExc_MemoryError))
		/* already current */
		return NULL;

	/* raise the pre-allocated instance if it still exists */
	if (PyExc_MemoryErrorInst)
		PyErr_SetObject(PyExc_MemoryError, PyExc_MemoryErrorInst);
	else
		/* this will probably fail since there's no memory and hee,
		   hee, we have to instantiate this class
		*/
		PyErr_SetNone(PyExc_MemoryError);

	return NULL;
}

DL_EXPORT(PyObject *)
PyErr_SetFromErrnoWithFilename(PyObject *exc, char *filename)
{
	PyObject *v;
	char *s;
	int i = errno;
#ifdef MS_WIN32
	char *s_buf = NULL;
#endif
#ifdef EINTR
	if (i == EINTR && PyErr_CheckSignals())
		return NULL;
#endif
	if (i == 0)
		s = "Error"; /* Sometimes errno didn't get set */
	else
#ifndef MS_WIN32
		s = strerror(i);
#else
	{
		/* Note that the Win32 errors do not lineup with the
		   errno error.  So if the error is in the MSVC error
		   table, we use it, otherwise we assume it really _is_ 
		   a Win32 error code
		*/
		if (i > 0 && i < _sys_nerr) {
			s = _sys_errlist[i];
		}
		else {
			int len = FormatMessage(
				FORMAT_MESSAGE_ALLOCATE_BUFFER |
				FORMAT_MESSAGE_FROM_SYSTEM |
				FORMAT_MESSAGE_IGNORE_INSERTS,
				NULL,	/* no message source */
				i,
				MAKELANGID(LANG_NEUTRAL,
					   SUBLANG_DEFAULT),
				           /* Default language */
				(LPTSTR) &s_buf,
				0,	/* size not used */
				NULL);	/* no args */
			s = s_buf;
			/* remove trailing cr/lf and dots */
			while (len > 0 && (s[len-1] <= ' ' || s[len-1] == '.'))
				s[--len] = '\0';
		}
	}
#endif
	if (filename != NULL)
		v = Py_BuildValue("(iss)", i, s, filename);
	else
		v = Py_BuildValue("(is)", i, s);
	if (v != NULL) {
		PyErr_SetObject(exc, v);
		Py_DECREF(v);
	}
#ifdef MS_WIN32
	LocalFree(s_buf);
#endif
	return NULL;
}


DL_EXPORT(PyObject *)
PyErr_SetFromErrno(PyObject *exc)
{
	return PyErr_SetFromErrnoWithFilename(exc, NULL);
}

#ifdef MS_WINDOWS 
/* Windows specific error code handling */
PyObject *PyErr_SetFromWindowsErrWithFilename(
	int ierr,