Python/errors.c - platform/external/python/cpython3 - Gitiles


 /* Error handling */

 #include "Python.h"

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

 #ifdef MS_WINDOWS
 #include <windows.h>
 #include <winbase.h>
 #endif

 #include <ctype.h>

 #ifdef __cplusplus
 extern "C" {
 #endif


 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? */
         /* Well, it could be None. */
         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);
 }

 void
 PyErr_SetObject(PyObject *exception, PyObject *value)
 {
     PyThreadState *tstate = PyThreadState_GET();
     PyObject *exc_value;
     PyObject *tb = NULL;

     if (exception != NULL &&
         !PyExceptionClass_Check(exception)) {
         PyErr_Format(PyExc_SystemError,
                      "exception %R not a BaseException subclass",
                      exception);
         return;
     }
     Py_XINCREF(value);
     exc_value = tstate->exc_value;
     if (exc_value != NULL && exc_value != Py_None) {
         /* Implicit exception chaining */
         Py_INCREF(exc_value);
         if (value == NULL || !PyExceptionInstance_Check(value)) {
             /* We must normalize the value right now */
             PyObject *args, *fixed_value;
             if (value == NULL || value == Py_None)
                 args = PyTuple_New(0);
             else if (PyTuple_Check(value)) {
                 Py_INCREF(value);
                 args = value;
             }
             else
                 args = PyTuple_Pack(1, value);
             fixed_value = args ?
                 PyEval_CallObject(exception, args) : NULL;
             Py_XDECREF(args);
             Py_XDECREF(value);
             if (fixed_value == NULL)
                 return;
             value = fixed_value;
         }
         /* Avoid reference cycles through the context chain.
            This is O(chain length) but context chains are
            usually very short. Sensitive readers may try
            to inline the call to PyException_GetContext. */
         if (exc_value != value) {
             PyObject *o = exc_value, *context;
             while ((context = PyException_GetContext(o))) {
                 Py_DECREF(context);
                 if (context == value) {
                     PyException_SetContext(o, NULL);
                     break;
                 }
                 o = context;
             }
             PyException_SetContext(value, exc_value);
         } else {
             Py_DECREF(exc_value);
         }
     }
     if (value != NULL && PyExceptionInstance_Check(value))
         tb = PyException_GetTraceback(value);
     Py_XINCREF(exception);
     PyErr_Restore(exception, value, tb);
 }

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

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


 PyObject *
 PyErr_Occurred(void)
 {
     /* If there is no thread state, PyThreadState_GET calls
        Py_FatalError, which calls PyErr_Occurred.  To avoid the
        resulting infinite loop, we inline PyThreadState_GET here and
        treat no thread as no error. */
     PyThreadState *tstate =
         ((PyThreadState*)_Py_atomic_load_relaxed(&_PyThreadState_Current));

     return tstate == NULL ? NULL : tstate->curexc_type;
 }


 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)) {
         Py_ssize_t 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 (PyExceptionInstance_Check(err))
         err = PyExceptionInstance_Class(err);

     if (PyExceptionClass_Check(err) && PyExceptionClass_Check(exc)) {
         int res = 0;
         PyObject *exception, *value, *tb;
         PyErr_Fetch(&exception, &value, &tb);
         /* PyObject_IsSubclass() can recurse and therefore is
            not safe (see test_bad_getattr in test.pickletester). */
         res = PyType_IsSubtype((PyTypeObject *)err, (PyTypeObject *)exc);
         /* This function must not fail, so print the error here */
         if (res == -1) {
             PyErr_WriteUnraisable(err);
             res = 0;
         }
         PyErr_Restore(exception, value, tb);
         return res;
     }

     return err == exc;
 }


 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()

    XXX: should PyErr_NormalizeException() also call
             PyException_SetTraceback() with the resulting value and tb?
 */
 void
 PyErr_NormalizeException(PyObject **exc, PyObject **val, PyObject **tb)
 {
     PyObject *type = *exc;
     PyObject *value = *val;
     PyObject *inclass = NULL;
     PyObject *initial_tb = NULL;
     PyThreadState *tstate = NULL;

     if (type == NULL) {
         /* There was no exception, so nothing to do. */
         return;
     }

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

     if (PyExceptionInstance_Check(value))
         inclass = PyExceptionInstance_Class(value);

     /* Normalize the exception so that if the type is a class, the
        value will be an instance.
     */
     if (PyExceptionClass_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 || !PyObject_IsSubclass(inclass, type)) {
             PyObject *args, *res;

             if (value == Py_None)
                 args = PyTuple_New(0);
             else if (PyTuple_Check(value)) {
                 Py_INCREF(value);
                 args = value;
             }
             else
                 args = PyTuple_Pack(1, 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 */
     tstate = PyThreadState_GET();
     if (++tstate->recursion_depth > Py_GetRecursionLimit()) {
         --tstate->recursion_depth;
         /* throw away the old exception... */
         Py_DECREF(*exc);
         Py_DECREF(*val);
         /* ... and use the recursion error instead */
         *exc = PyExc_RuntimeError;
         *val = PyExc_RecursionErrorInst;
         Py_INCREF(*exc);
         Py_INCREF(*val);
         /* just keeping the old traceback */
         return;
     }
     PyErr_NormalizeException(exc, val, tb);
     --tstate->recursion_depth;
 }


 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;
 }

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

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

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

 PyObject *
 PyErr_NoMemory(void)
 {
     PyErr_SetNone(PyExc_MemoryError);
     return NULL;
 }

 PyObject *
 PyErr_SetFromErrnoWithFilenameObject(PyObject *exc, PyObject *filenameObject)
 {
     PyObject *message;
     PyObject *v;
     int i = errno;
 #ifndef MS_WINDOWS
     char *s;
 #else
     WCHAR *s_buf = NULL;
 #endif /* Unix/Windows */

 #ifdef EINTR
     if (i == EINTR && PyErr_CheckSignals())
         return NULL;
 #endif

 #ifndef MS_WINDOWS
     if (i == 0)
         s = "Error"; /* Sometimes errno didn't get set */
     else
         s = strerror(i);
     message = PyUnicode_DecodeUTF8(s, strlen(s), "ignore");
 #else
     if (i == 0)
         message = PyUnicode_FromString("Error"); /* Sometimes errno didn't get set */
     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) {
             message = PyUnicode_FromString(_sys_errlist[i]);
         }
         else {
             int len = FormatMessageW(
                 FORMAT_MESSAGE_ALLOCATE_BUFFER |
                 FORMAT_MESSAGE_FROM_SYSTEM |
                 FORMAT_MESSAGE_IGNORE_INSERTS,
                 NULL,                   /* no message source */
                 i,
                 MAKELANGID(LANG_NEUTRAL,
                            SUBLANG_DEFAULT),
                            /* Default language */
                 (LPWSTR) &s_buf,
                 0,                      /* size not used */
                 NULL);                  /* no args */
             if (len==0) {
                 /* Only ever seen this in out-of-mem
                    situations */
                 s_buf = NULL;
                 message = PyUnicode_FromFormat("Windows Error 0x%X", i);
             } else {
                 /* remove trailing cr/lf and dots */
                 while (len > 0 && (s_buf[len-1] <= L' ' || s_buf[len-1] == L'.'))
                     s_buf[--len] = L'\0';
                 message = PyUnicode_FromUnicode(s_buf, len);
             }
         }
     }
 #endif /* Unix/Windows */

     if (message == NULL)
     {
 #ifdef MS_WINDOWS
         LocalFree(s_buf);
 #endif
         return NULL;
     }

     if (filenameObject != NULL)
         v = Py_BuildValue("(iOO)", i, message, filenameObject);
     else
         v = Py_BuildValue("(iO)", i, message);
     Py_DECREF(message);

     if (v != NULL) {
         PyErr_SetObject(exc, v);
         Py_DECREF(v);
     }
 #ifdef MS_WINDOWS
     LocalFree(s_buf);
 #endif
     return NULL;
 }


 PyObject *
 PyErr_SetFromErrnoWithFilename(PyObject *exc, const char *filename)
 {
     PyObject *name = filename ? PyUnicode_DecodeFSDefault(filename) : NULL;
     PyObject *result = PyErr_SetFromErrnoWithFilenameObject(exc, name);
     Py_XDECREF(name);
     return result;
 }

 #ifdef MS_WINDOWS
 PyObject *
 PyErr_SetFromErrnoWithUnicodeFilename(PyObject *exc, const Py_UNICODE *filename)
 {
     PyObject *name = filename ?
                      PyUnicode_FromUnicode(filename, wcslen(filename)) :
              NULL;
     PyObject *result = PyErr_SetFromErrnoWithFilenameObject(exc, name);
     Py_XDECREF(name);
     return result;
 }
 #endif /* MS_WINDOWS */

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

 #ifdef MS_WINDOWS
 /* Windows specific error code handling */
 PyObject *PyErr_SetExcFromWindowsErrWithFilenameObject(
     PyObject *exc,
     int ierr,
     PyObject *filenameObject)
 {
     int len;
     WCHAR *s_buf = NULL; /* Free via LocalFree */
     PyObject *message;
     PyObject *v;
     DWORD err = (DWORD)ierr;
     if (err==0) err = GetLastError();
     len = FormatMessageW(
         /* Error API error */
         FORMAT_MESSAGE_ALLOCATE_BUFFER |
         FORMAT_MESSAGE_FROM_SYSTEM |
         FORMAT_MESSAGE_IGNORE_INSERTS,
         NULL,           /* no message source */
         err,
         MAKELANGID(LANG_NEUTRAL,
         SUBLANG_DEFAULT), /* Default language */
         (LPWSTR) &s_buf,
         0,              /* size not used */
         NULL);          /* no args */
     if (len==0) {
         /* Only seen this in out of mem situations */
         message = PyUnicode_FromFormat("Windows Error 0x%X", err);
         s_buf = NULL;
     } else {
         /* remove trailing cr/lf and dots */
         while (len > 0 && (s_buf[len-1] <= L' ' || s_buf[len-1] == L'.'))
             s_buf[--len] = L'\0';
         message = PyUnicode_FromUnicode(s_buf, len);
     }

     if (message == NULL)
     {
         LocalFree(s_buf);
         return NULL;
     }

     if (filenameObject != NULL)
         v = Py_BuildValue("(iOO)", err, message, filenameObject);
     else
         v = Py_BuildValue("(iO)", err, message);
     Py_DECREF(message);

     if (v != NULL) {
         PyErr_SetObject(exc, v);
         Py_DECREF(v);
     }
     LocalFree(s_buf);
     return NULL;
 }

 PyObject *PyErr_SetExcFromWindowsErrWithFilename(
     PyObject *exc,
     int ierr,
     const char *filename)
 {
     PyObject *name = filename ? PyUnicode_DecodeFSDefault(filename) : NULL;
     PyObject *ret = PyErr_SetExcFromWindowsErrWithFilenameObject(exc,
                                                                  ierr,
                                                                  name);
     Py_XDECREF(name);
     return ret;
 }

 PyObject *PyErr_SetExcFromWindowsErrWithUnicodeFilename(
     PyObject *exc,
     int ierr,
     const Py_UNICODE *filename)
 {
     PyObject *name = filename ?
                      PyUnicode_FromUnicode(filename, wcslen(filename)) :
              NULL;
     PyObject *ret = PyErr_SetExcFromWindowsErrWithFilenameObject(exc,
                                                                  ierr,
                                                                  name);
     Py_XDECREF(name);
     return ret;
 }

 PyObject *PyErr_SetExcFromWindowsErr(PyObject *exc, int ierr)
 {
     return PyErr_SetExcFromWindowsErrWithFilename(exc, ierr, NULL);
 }

 PyObject *PyErr_SetFromWindowsErr(int ierr)
 {
     return PyErr_SetExcFromWindowsErrWithFilename(PyExc_WindowsError,
                                                   ierr, NULL);
 }
 PyObject *PyErr_SetFromWindowsErrWithFilename(
     int ierr,
     const char *filename)
 {
     PyObject *name = filename ? PyUnicode_DecodeFSDefault(filename) : NULL;
     PyObject *result = PyErr_SetExcFromWindowsErrWithFilenameObject(
                                                   PyExc_WindowsError,
                                                   ierr, name);
     Py_XDECREF(name);
     return result;
 }

 PyObject *PyErr_SetFromWindowsErrWithUnicodeFilename(
     int ierr,
     const Py_UNICODE *filename)
 {
     PyObject *name = filename ?
                      PyUnicode_FromUnicode(filename, wcslen(filename)) :
              NULL;
     PyObject *result = PyErr_SetExcFromWindowsErrWithFilenameObject(
                                                   PyExc_WindowsError,
                                                   ierr, name);
     Py_XDECREF(name);
     return result;
 }
 #endif /* MS_WINDOWS */

 void
 _PyErr_BadInternalCall(const char *filename, int lineno)
 {
     PyErr_Format(PyExc_SystemError,
                  "%s:%d: bad argument to internal function",
                  filename, lineno);
 }

 /* Remove the preprocessor macro for PyErr_BadInternalCall() so that we can
    export the entry point for existing object code: */
 #undef PyErr_BadInternalCall
 void
 PyErr_BadInternalCall(void)
 {
     PyErr_Format(PyExc_SystemError,
                  "bad argument to internal function");
 }
 #define PyErr_BadInternalCall() _PyErr_BadInternalCall(__FILE__, __LINE__)


 PyObject *
 PyErr_Format(PyObject *exception, const char *format, ...)
 {
     va_list vargs;
     PyObject* string;

 #ifdef HAVE_STDARG_PROTOTYPES
     va_start(vargs, format);
 #else
     va_start(vargs);
 #endif

     string = PyUnicode_FromFormatV(format, vargs);
     PyErr_SetObject(exception, string);
     Py_XDECREF(string);
     va_end(vargs);
     return NULL;
 }


 PyObject *
 PyErr_NewException(const char *name, PyObject *base, PyObject *dict)
 {
     const char *dot;
     PyObject *modulename = NULL;
     PyObject *classname = NULL;
     PyObject *mydict = NULL;
     PyObject *bases = NULL;
     PyObject *result = NULL;
     dot = strrchr(name, '.');
     if (dot == NULL) {
         PyErr_SetString(PyExc_SystemError,
             "PyErr_NewException: name must be module.class");
         return NULL;
     }
     if (base == NULL)
         base = PyExc_Exception;
     if (dict == NULL) {
         dict = mydict = PyDict_New();
         if (dict == NULL)
             goto failure;
     }
     if (PyDict_GetItemString(dict, "__module__") == NULL) {
         modulename = PyUnicode_FromStringAndSize(name,
                                              (Py_ssize_t)(dot-name));
         if (modulename == NULL)
             goto failure;
         if (PyDict_SetItemString(dict, "__module__", modulename) != 0)
             goto failure;
     }
     if (PyTuple_Check(base)) {
         bases = base;
         /* INCREF as we create a new ref in the else branch */
         Py_INCREF(bases);
     } else {
         bases = PyTuple_Pack(1, base);
         if (bases == NULL)
             goto failure;
     }
     /* Create a real new-style class. */
     result = PyObject_CallFunction((PyObject *)&PyType_Type, "sOO",
                                    dot+1, bases, dict);
   failure:
     Py_XDECREF(bases);
     Py_XDECREF(mydict);
     Py_XDECREF(classname);
     Py_XDECREF(modulename);
     return result;
 }


 /* Create an exception with docstring */
 PyObject *
 PyErr_NewExceptionWithDoc(const char *name, const char *doc,
                           PyObject *base, PyObject *dict)
 {
     int result;
     PyObject *ret = NULL;
     PyObject *mydict = NULL; /* points to the dict only if we create it */
     PyObject *docobj;

     if (dict == NULL) {
         dict = mydict = PyDict_New();
         if (dict == NULL) {
             return NULL;
         }
     }

     if (doc != NULL) {
         docobj = PyUnicode_FromString(doc);
         if (docobj == NULL)
             goto failure;
         result = PyDict_SetItemString(dict, "__doc__", docobj);
         Py_DECREF(docobj);
         if (result < 0)
             goto failure;
     }

     ret = PyErr_NewException(name, base, dict);
   failure:
     Py_XDECREF(mydict);
     return ret;
 }


 /* Call when an exception has occurred but there is no way for Python
    to handle it.  Examples: exception in __del__ or during GC. */
 void
 PyErr_WriteUnraisable(PyObject *obj)
 {
     PyObject *f, *t, *v, *tb;
     PyErr_Fetch(&t, &v, &tb);
     f = PySys_GetObject("stderr");
     if (f != NULL && f != Py_None) {
         PyFile_WriteString("Exception ", f);
         if (t) {
             PyObject* moduleName;
             char* className;
             assert(PyExceptionClass_Check(t));
             className = PyExceptionClass_Name(t);
             if (className != NULL) {
                 char *dot = strrchr(className, '.');
                 if (dot != NULL)
                     className = dot+1;
             }

             moduleName = PyObject_GetAttrString(t, "__module__");
             if (moduleName == NULL)
                 PyFile_WriteString("<unknown>", f);
             else {
                 char* modstr = _PyUnicode_AsString(moduleName);
                 if (modstr &&
                     strcmp(modstr, "builtins") != 0)
                 {
                     PyFile_WriteString(modstr, f);
                     PyFile_WriteString(".", f);
                 }
             }
             if (className == NULL)
                 PyFile_WriteString("<unknown>", f);
             else
                 PyFile_WriteString(className, f);
             if (v && v != Py_None) {
                 PyFile_WriteString(": ", f);
                 PyFile_WriteObject(v, f, 0);
             }
             Py_XDECREF(moduleName);
         }
         if (obj) {
             PyFile_WriteString(" in ", f);
             PyFile_WriteObject(obj, f, 0);
         }
         PyFile_WriteString(" ignored\n", f);
         PyErr_Clear(); /* Just in case */
     }
     Py_XDECREF(t);
     Py_XDECREF(v);
     Py_XDECREF(tb);
 }

 extern PyObject *PyModule_GetWarningsModule(void);


 void
 PyErr_SyntaxLocation(const char *filename, int lineno) {
     PyErr_SyntaxLocationEx(filename, lineno, -1);
 }


 /* Set file and line information for the current exception.
    If the exception is not a SyntaxError, also sets additional attributes
    to make printing of exceptions believe it is a syntax error. */

 void
 PyErr_SyntaxLocationEx(const char *filename, int lineno, int col_offset)
 {
     PyObject *exc, *v, *tb, *tmp;

     /* add attributes for the line number and filename for the error */
     PyErr_Fetch(&exc, &v, &tb);
     PyErr_NormalizeException(&exc, &v, &tb);
     /* XXX check that it is, indeed, a syntax error. It might not
      * be, though. */
     tmp = PyLong_FromLong(lineno);
     if (tmp == NULL)
         PyErr_Clear();
     else {
         if (PyObject_SetAttrString(v, "lineno", tmp))
             PyErr_Clear();
         Py_DECREF(tmp);
     }
     if (col_offset >= 0) {
         tmp = PyLong_FromLong(col_offset);
         if (tmp == NULL)
             PyErr_Clear();
         else {
             if (PyObject_SetAttrString(v, "offset", tmp))
                 PyErr_Clear();
             Py_DECREF(tmp);
         }
     }
     if (filename != NULL) {
         tmp = PyUnicode_DecodeFSDefault(filename);
         if (tmp == NULL)
             PyErr_Clear();
         else {
             if (PyObject_SetAttrString(v, "filename", tmp))
                 PyErr_Clear();
             Py_DECREF(tmp);
         }

         tmp = PyErr_ProgramText(filename, lineno);
         if (tmp) {
             if (PyObject_SetAttrString(v, "text", tmp))
                 PyErr_Clear();
             Py_DECREF(tmp);
         }
     }
     if (PyObject_SetAttrString(v, "offset", Py_None)) {
         PyErr_Clear();
     }
     if (exc != PyExc_SyntaxError) {
         if (!PyObject_HasAttrString(v, "msg")) {
             tmp = PyObject_Str(v);
             if (tmp) {
                 if (PyObject_SetAttrString(v, "msg", tmp))
                     PyErr_Clear();
                 Py_DECREF(tmp);
             } else {
                 PyErr_Clear();
             }
         }
         if (!PyObject_HasAttrString(v, "print_file_and_line")) {
             if (PyObject_SetAttrString(v, "print_file_and_line",
                                        Py_None))
                 PyErr_Clear();
         }
     }
     PyErr_Restore(exc, v, tb);
 }

 /* Attempt to load the line of text that the exception refers to.  If it
    fails, it will return NULL but will not set an exception.

    XXX The functionality of this function is quite similar to the
    functionality in tb_displayline() in traceback.c. */

 PyObject *
 PyErr_ProgramText(const char *filename, int lineno)
 {
     FILE *fp;
     int i;
     char linebuf[1000];

     if (filename == NULL || *filename == '\0' || lineno <= 0)
         return NULL;
     fp = fopen(filename, "r" PY_STDIOTEXTMODE);
     if (fp == NULL)
         return NULL;
     for (i = 0; i < lineno; i++) {
         char *pLastChar = &linebuf[sizeof(linebuf) - 2];
         do {
             *pLastChar = '\0';
             if (Py_UniversalNewlineFgets(linebuf, sizeof linebuf,
                                          fp, NULL) == NULL)
                 break;
             /* fgets read *something*; if it didn't get as
                far as pLastChar, it must have found a newline
                or hit the end of the file; if pLastChar is \n,
                it obviously found a newline; else we haven't
                yet seen a newline, so must continue */
         } while (*pLastChar != '\0' && *pLastChar != '\n');
     }
     fclose(fp);
     if (i == lineno) {
         char *p = linebuf;
         PyObject *res;
         while (*p == ' ' || *p == '\t' || *p == '\014')
             p++;
         res = PyUnicode_FromString(p);
         if (res == NULL)
             PyErr_Clear();
         return res;
     }
     return NULL;
 }

 #ifdef __cplusplus
 }
 #endif

	/* Error handling */

	#include "Python.h"

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

	#ifdef MS_WINDOWS
	#include <windows.h>
	#include <winbase.h>
	#endif

	#include <ctype.h>

	#ifdef __cplusplus
	extern "C" {
	#endif


	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? */
	/* Well, it could be None. */
	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);
	}

	void
	PyErr_SetObject(PyObject exception, PyObject value)
	{
	PyThreadState *tstate = PyThreadState_GET();
	PyObject *exc_value;
	PyObject *tb = NULL;

	if (exception != NULL &&
	!PyExceptionClass_Check(exception)) {
	PyErr_Format(PyExc_SystemError,
	"exception %R not a BaseException subclass",
	exception);
	return;
	}
	Py_XINCREF(value);
	exc_value = tstate->exc_value;
	if (exc_value != NULL && exc_value != Py_None) {
	/* Implicit exception chaining */
	Py_INCREF(exc_value);
	if (value == NULL \|\| !PyExceptionInstance_Check(value)) {
	/* We must normalize the value right now */
	PyObject args, fixed_value;
	if (value == NULL \|\| value == Py_None)
	args = PyTuple_New(0);
	else if (PyTuple_Check(value)) {
	Py_INCREF(value);
	args = value;
	}
	else
	args = PyTuple_Pack(1, value);
	fixed_value = args ?
	PyEval_CallObject(exception, args) : NULL;
	Py_XDECREF(args);
	Py_XDECREF(value);
	if (fixed_value == NULL)
	return;
	value = fixed_value;
	}
	/* Avoid reference cycles through the context chain.
	This is O(chain length) but context chains are
	usually very short. Sensitive readers may try
	to inline the call to PyException_GetContext. */
	if (exc_value != value) {
	PyObject o = exc_value, context;
	while ((context = PyException_GetContext(o))) {
	Py_DECREF(context);
	if (context == value) {
	PyException_SetContext(o, NULL);
	break;
	}
	o = context;
	}
	PyException_SetContext(value, exc_value);
	} else {
	Py_DECREF(exc_value);
	}
	}
	if (value != NULL && PyExceptionInstance_Check(value))
	tb = PyException_GetTraceback(value);
	Py_XINCREF(exception);
	PyErr_Restore(exception, value, tb);
	}

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

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


	PyObject *
	PyErr_Occurred(void)
	{
	/* If there is no thread state, PyThreadState_GET calls
	Py_FatalError, which calls PyErr_Occurred. To avoid the
	resulting infinite loop, we inline PyThreadState_GET here and
	treat no thread as no error. */
	PyThreadState *tstate =
	((PyThreadState*)_Py_atomic_load_relaxed(&_PyThreadState_Current));

	return tstate == NULL ? NULL : tstate->curexc_type;
	}


	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)) {
	Py_ssize_t 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 (PyExceptionInstance_Check(err))
	err = PyExceptionInstance_Class(err);

	if (PyExceptionClass_Check(err) && PyExceptionClass_Check(exc)) {
	int res = 0;
	PyObject exception, value, *tb;
	PyErr_Fetch(&exception, &value, &tb);
	/* PyObject_IsSubclass() can recurse and therefore is
	not safe (see test_bad_getattr in test.pickletester). */
	res = PyType_IsSubtype((PyTypeObject )err, (PyTypeObject )exc);
	/* This function must not fail, so print the error here */
	if (res == -1) {
	PyErr_WriteUnraisable(err);
	res = 0;
	}
	PyErr_Restore(exception, value, tb);
	return res;
	}

	return err == exc;
	}


	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()

	XXX: should PyErr_NormalizeException() also call
	PyException_SetTraceback() with the resulting value and tb?
	*/
	void
	PyErr_NormalizeException(PyObject exc, PyObject val, PyObject **tb)
	{
	PyObject type = exc;
	PyObject value = val;
	PyObject *inclass = NULL;
	PyObject *initial_tb = NULL;
	PyThreadState *tstate = NULL;

	if (type == NULL) {
	/* There was no exception, so nothing to do. */
	return;
	}

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

	if (PyExceptionInstance_Check(value))
	inclass = PyExceptionInstance_Class(value);

	/* Normalize the exception so that if the type is a class, the
	value will be an instance.
	*/
	if (PyExceptionClass_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 \|\| !PyObject_IsSubclass(inclass, type)) {
	PyObject args, res;

	if (value == Py_None)
	args = PyTuple_New(0);
	else if (PyTuple_Check(value)) {
	Py_INCREF(value);
	args = value;
	}
	else
	args = PyTuple_Pack(1, 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 */
	tstate = PyThreadState_GET();
	if (++tstate->recursion_depth > Py_GetRecursionLimit()) {
	--tstate->recursion_depth;
	/* throw away the old exception... */
	Py_DECREF(*exc);
	Py_DECREF(*val);
	/* ... and use the recursion error instead */
	*exc = PyExc_RuntimeError;
	*val = PyExc_RecursionErrorInst;
	Py_INCREF(*exc);
	Py_INCREF(*val);
	/* just keeping the old traceback */
	return;
	}
	PyErr_NormalizeException(exc, val, tb);
	--tstate->recursion_depth;
	}


	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;
	}

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

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

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

	PyObject *
	PyErr_NoMemory(void)
	{
	PyErr_SetNone(PyExc_MemoryError);
	return NULL;
	}

	PyObject *
	PyErr_SetFromErrnoWithFilenameObject(PyObject exc, PyObject filenameObject)
	{
	PyObject *message;
	PyObject *v;
	int i = errno;
	#ifndef MS_WINDOWS
	char *s;
	#else
	WCHAR *s_buf = NULL;
	#endif /* Unix/Windows */

	#ifdef EINTR
	if (i == EINTR && PyErr_CheckSignals())
	return NULL;
	#endif

	#ifndef MS_WINDOWS
	if (i == 0)
	s = "Error"; /* Sometimes errno didn't get set */
	else
	s = strerror(i);
	message = PyUnicode_DecodeUTF8(s, strlen(s), "ignore");
	#else
	if (i == 0)
	message = PyUnicode_FromString("Error"); /* Sometimes errno didn't get set */
	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) {
	message = PyUnicode_FromString(_sys_errlist[i]);
	}
	else {
	int len = FormatMessageW(
	FORMAT_MESSAGE_ALLOCATE_BUFFER \|
	FORMAT_MESSAGE_FROM_SYSTEM \|
	FORMAT_MESSAGE_IGNORE_INSERTS,
	NULL, /* no message source */
	i,
	MAKELANGID(LANG_NEUTRAL,
	SUBLANG_DEFAULT),
	/* Default language */
	(LPWSTR) &s_buf,
	0, /* size not used */
	NULL); /* no args */
	if (len==0) {
	/* Only ever seen this in out-of-mem
	situations */
	s_buf = NULL;
	message = PyUnicode_FromFormat("Windows Error 0x%X", i);
	} else {
	/* remove trailing cr/lf and dots */
	while (len > 0 && (s_buf[len-1] <= L' ' \|\| s_buf[len-1] == L'.'))
	s_buf[--len] = L'\0';
	message = PyUnicode_FromUnicode(s_buf, len);
	}
	}
	}
	#endif /* Unix/Windows */

	if (message == NULL)
	{
	#ifdef MS_WINDOWS
	LocalFree(s_buf);
	#endif
	return NULL;
	}

	if (filenameObject != NULL)
	v = Py_BuildValue("(iOO)", i, message, filenameObject);
	else
	v = Py_BuildValue("(iO)", i, message);
	Py_DECREF(message);

	if (v != NULL) {
	PyErr_SetObject(exc, v);
	Py_DECREF(v);
	}
	#ifdef MS_WINDOWS
	LocalFree(s_buf);
	#endif
	return NULL;
	}


	PyObject *
	PyErr_SetFromErrnoWithFilename(PyObject exc, const char filename)
	{
	PyObject *name = filename ? PyUnicode_DecodeFSDefault(filename) : NULL;
	PyObject *result = PyErr_SetFromErrnoWithFilenameObject(exc, name);
	Py_XDECREF(name);
	return result;
	}

	#ifdef MS_WINDOWS
	PyObject *
	PyErr_SetFromErrnoWithUnicodeFilename(PyObject exc, const Py_UNICODE filename)
	{
	PyObject *name = filename ?
	PyUnicode_FromUnicode(filename, wcslen(filename)) :
	NULL;
	PyObject *result = PyErr_SetFromErrnoWithFilenameObject(exc, name);
	Py_XDECREF(name);
	return result;
	}
	#endif /* MS_WINDOWS */

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

	#ifdef MS_WINDOWS
	/* Windows specific error code handling */
	PyObject *PyErr_SetExcFromWindowsErrWithFilenameObject(
	PyObject *exc,
	int ierr,
	PyObject *filenameObject)
	{
	int len;
	WCHAR s_buf = NULL; / Free via LocalFree */
	PyObject *message;
	PyObject *v;
	DWORD err = (DWORD)ierr;
	if (err==0) err = GetLastError();
	len = FormatMessageW(
	/* Error API error */
	FORMAT_MESSAGE_ALLOCATE_BUFFER \|
	FORMAT_MESSAGE_FROM_SYSTEM \|
	FORMAT_MESSAGE_IGNORE_INSERTS,
	NULL, /* no message source */
	err,
	MAKELANGID(LANG_NEUTRAL,
	SUBLANG_DEFAULT), /* Default language */
	(LPWSTR) &s_buf,
	0, /* size not used */
	NULL); /* no args */
	if (len==0) {
	/* Only seen this in out of mem situations */
	message = PyUnicode_FromFormat("Windows Error 0x%X", err);
	s_buf = NULL;
	} else {
	/* remove trailing cr/lf and dots */
	while (len > 0 && (s_buf[len-1] <= L' ' \|\| s_buf[len-1] == L'.'))
	s_buf[--len] = L'\0';
	message = PyUnicode_FromUnicode(s_buf, len);
	}

	if (message == NULL)
	{
	LocalFree(s_buf);
	return NULL;
	}

	if (filenameObject != NULL)
	v = Py_BuildValue("(iOO)", err, message, filenameObject);
	else
	v = Py_BuildValue("(iO)", err, message);
	Py_DECREF(message);

	if (v != NULL) {
	PyErr_SetObject(exc, v);
	Py_DECREF(v);
	}
	LocalFree(s_buf);
	return NULL;
	}

	PyObject *PyErr_SetExcFromWindowsErrWithFilename(
	PyObject *exc,
	int ierr,
	const char *filename)
	{
	PyObject *name = filename ? PyUnicode_DecodeFSDefault(filename) : NULL;
	PyObject *ret = PyErr_SetExcFromWindowsErrWithFilenameObject(exc,
	ierr,
	name);
	Py_XDECREF(name);
	return ret;
	}

	PyObject *PyErr_SetExcFromWindowsErrWithUnicodeFilename(
	PyObject *exc,
	int ierr,
	const Py_UNICODE *filename)
	{
	PyObject *name = filename ?
	PyUnicode_FromUnicode(filename, wcslen(filename)) :
	NULL;
	PyObject *ret = PyErr_SetExcFromWindowsErrWithFilenameObject(exc,
	ierr,
	name);
	Py_XDECREF(name);
	return ret;
	}

	PyObject PyErr_SetExcFromWindowsErr(PyObject exc, int ierr)
	{
	return PyErr_SetExcFromWindowsErrWithFilename(exc, ierr, NULL);
	}

	PyObject *PyErr_SetFromWindowsErr(int ierr)
	{
	return PyErr_SetExcFromWindowsErrWithFilename(PyExc_WindowsError,
	ierr, NULL);
	}
	PyObject *PyErr_SetFromWindowsErrWithFilename(
	int ierr,
	const char *filename)
	{
	PyObject *name = filename ? PyUnicode_DecodeFSDefault(filename) : NULL;
	PyObject *result = PyErr_SetExcFromWindowsErrWithFilenameObject(
	PyExc_WindowsError,
	ierr, name);
	Py_XDECREF(name);
	return result;
	}

	PyObject *PyErr_SetFromWindowsErrWithUnicodeFilename(
	int ierr,
	const Py_UNICODE *filename)
	{
	PyObject *name = filename ?
	PyUnicode_FromUnicode(filename, wcslen(filename)) :
	NULL;
	PyObject *result = PyErr_SetExcFromWindowsErrWithFilenameObject(
	PyExc_WindowsError,
	ierr, name);
	Py_XDECREF(name);
	return result;
	}
	#endif /* MS_WINDOWS */

	void
	_PyErr_BadInternalCall(const char *filename, int lineno)
	{
	PyErr_Format(PyExc_SystemError,
	"%s:%d: bad argument to internal function",
	filename, lineno);
	}

	/* Remove the preprocessor macro for PyErr_BadInternalCall() so that we can
	export the entry point for existing object code: */
	#undef PyErr_BadInternalCall
	void
	PyErr_BadInternalCall(void)
	{
	PyErr_Format(PyExc_SystemError,
	"bad argument to internal function");
	}
	#define PyErr_BadInternalCall() _PyErr_BadInternalCall(__FILE__, __LINE__)



	PyObject *
	PyErr_Format(PyObject exception, const char format, ...)
	{
	va_list vargs;
	PyObject* string;

	#ifdef HAVE_STDARG_PROTOTYPES
	va_start(vargs, format);
	#else
	va_start(vargs);
	#endif

	string = PyUnicode_FromFormatV(format, vargs);
	PyErr_SetObject(exception, string);
	Py_XDECREF(string);
	va_end(vargs);
	return NULL;
	}



	PyObject *
	PyErr_NewException(const char name, PyObject base, PyObject *dict)
	{
	const char *dot;
	PyObject *modulename = NULL;
	PyObject *classname = NULL;
	PyObject *mydict = NULL;
	PyObject *bases = NULL;
	PyObject *result = NULL;
	dot = strrchr(name, '.');
	if (dot == NULL) {
	PyErr_SetString(PyExc_SystemError,
	"PyErr_NewException: name must be module.class");
	return NULL;
	}
	if (base == NULL)
	base = PyExc_Exception;
	if (dict == NULL) {
	dict = mydict = PyDict_New();
	if (dict == NULL)
	goto failure;
	}
	if (PyDict_GetItemString(dict, "__module__") == NULL) {
	modulename = PyUnicode_FromStringAndSize(name,
	(Py_ssize_t)(dot-name));
	if (modulename == NULL)
	goto failure;
	if (PyDict_SetItemString(dict, "__module__", modulename) != 0)
	goto failure;
	}
	if (PyTuple_Check(base)) {
	bases = base;
	/* INCREF as we create a new ref in the else branch */
	Py_INCREF(bases);
	} else {
	bases = PyTuple_Pack(1, base);
	if (bases == NULL)
	goto failure;
	}
	/* Create a real new-style class. */
	result = PyObject_CallFunction((PyObject *)&PyType_Type, "sOO",
	dot+1, bases, dict);
	failure:
	Py_XDECREF(bases);
	Py_XDECREF(mydict);
	Py_XDECREF(classname);
	Py_XDECREF(modulename);
	return result;
	}


	/* Create an exception with docstring */
	PyObject *
	PyErr_NewExceptionWithDoc(const char name, const char doc,
	PyObject base, PyObject dict)
	{
	int result;
	PyObject *ret = NULL;
	PyObject mydict = NULL; / points to the dict only if we create it */
	PyObject *docobj;

	if (dict == NULL) {
	dict = mydict = PyDict_New();
	if (dict == NULL) {
	return NULL;
	}
	}

	if (doc != NULL) {
	docobj = PyUnicode_FromString(doc);
	if (docobj == NULL)
	goto failure;
	result = PyDict_SetItemString(dict, "__doc__", docobj);
	Py_DECREF(docobj);
	if (result < 0)
	goto failure;
	}

	ret = PyErr_NewException(name, base, dict);
	failure:
	Py_XDECREF(mydict);
	return ret;
	}


	/* Call when an exception has occurred but there is no way for Python
	to handle it. Examples: exception in __del__ or during GC. */
	void
	PyErr_WriteUnraisable(PyObject *obj)
	{
	PyObject f, t, v, tb;
	PyErr_Fetch(&t, &v, &tb);
	f = PySys_GetObject("stderr");
	if (f != NULL && f != Py_None) {
	PyFile_WriteString("Exception ", f);
	if (t) {
	PyObject* moduleName;
	char* className;
	assert(PyExceptionClass_Check(t));
	className = PyExceptionClass_Name(t);
	if (className != NULL) {
	char *dot = strrchr(className, '.');
	if (dot != NULL)
	className = dot+1;
	}

	moduleName = PyObject_GetAttrString(t, "__module__");
	if (moduleName == NULL)
	PyFile_WriteString("<unknown>", f);
	else {
	char* modstr = _PyUnicode_AsString(moduleName);
	if (modstr &&
	strcmp(modstr, "builtins") != 0)
	{
	PyFile_WriteString(modstr, f);
	PyFile_WriteString(".", f);
	}
	}
	if (className == NULL)
	PyFile_WriteString("<unknown>", f);
	else
	PyFile_WriteString(className, f);
	if (v && v != Py_None) {
	PyFile_WriteString(": ", f);
	PyFile_WriteObject(v, f, 0);
	}
	Py_XDECREF(moduleName);
	}
	if (obj) {
	PyFile_WriteString(" in ", f);
	PyFile_WriteObject(obj, f, 0);
	}
	PyFile_WriteString(" ignored\n", f);
	PyErr_Clear(); /* Just in case */
	}
	Py_XDECREF(t);
	Py_XDECREF(v);
	Py_XDECREF(tb);
	}

	extern PyObject *PyModule_GetWarningsModule(void);


	void
	PyErr_SyntaxLocation(const char *filename, int lineno) {
	PyErr_SyntaxLocationEx(filename, lineno, -1);
	}


	/* Set file and line information for the current exception.
	If the exception is not a SyntaxError, also sets additional attributes
	to make printing of exceptions believe it is a syntax error. */

	void
	PyErr_SyntaxLocationEx(const char *filename, int lineno, int col_offset)
	{
	PyObject exc, v, tb, tmp;

	/* add attributes for the line number and filename for the error */
	PyErr_Fetch(&exc, &v, &tb);
	PyErr_NormalizeException(&exc, &v, &tb);
	/* XXX check that it is, indeed, a syntax error. It might not
	* be, though. */
	tmp = PyLong_FromLong(lineno);
	if (tmp == NULL)
	PyErr_Clear();
	else {
	if (PyObject_SetAttrString(v, "lineno", tmp))
	PyErr_Clear();
	Py_DECREF(tmp);
	}
	if (col_offset >= 0) {
	tmp = PyLong_FromLong(col_offset);
	if (tmp == NULL)
	PyErr_Clear();
	else {
	if (PyObject_SetAttrString(v, "offset", tmp))
	PyErr_Clear();
	Py_DECREF(tmp);
	}
	}
	if (filename != NULL) {
	tmp = PyUnicode_DecodeFSDefault(filename);
	if (tmp == NULL)
	PyErr_Clear();
	else {
	if (PyObject_SetAttrString(v, "filename", tmp))
	PyErr_Clear();
	Py_DECREF(tmp);
	}

	tmp = PyErr_ProgramText(filename, lineno);
	if (tmp) {
	if (PyObject_SetAttrString(v, "text", tmp))
	PyErr_Clear();
	Py_DECREF(tmp);
	}
	}
	if (PyObject_SetAttrString(v, "offset", Py_None)) {
	PyErr_Clear();
	}
	if (exc != PyExc_SyntaxError) {
	if (!PyObject_HasAttrString(v, "msg")) {
	tmp = PyObject_Str(v);
	if (tmp) {
	if (PyObject_SetAttrString(v, "msg", tmp))
	PyErr_Clear();
	Py_DECREF(tmp);
	} else {
	PyErr_Clear();
	}
	}
	if (!PyObject_HasAttrString(v, "print_file_and_line")) {
	if (PyObject_SetAttrString(v, "print_file_and_line",
	Py_None))
	PyErr_Clear();
	}
	}
	PyErr_Restore(exc, v, tb);
	}

	/* Attempt to load the line of text that the exception refers to. If it
	fails, it will return NULL but will not set an exception.

	XXX The functionality of this function is quite similar to the
	functionality in tb_displayline() in traceback.c. */

	PyObject *
	PyErr_ProgramText(const char *filename, int lineno)
	{
	FILE *fp;
	int i;
	char linebuf[1000];

	if (filename == NULL \|\| *filename == '\0' \|\| lineno <= 0)
	return NULL;
	fp = fopen(filename, "r" PY_STDIOTEXTMODE);
	if (fp == NULL)
	return NULL;
	for (i = 0; i < lineno; i++) {
	char *pLastChar = &linebuf[sizeof(linebuf) - 2];
	do {
	*pLastChar = '\0';
	if (Py_UniversalNewlineFgets(linebuf, sizeof linebuf,
	fp, NULL) == NULL)
	break;
	/* fgets read something; if it didn't get as
	far as pLastChar, it must have found a newline
	or hit the end of the file; if pLastChar is \n,
	it obviously found a newline; else we haven't
	yet seen a newline, so must continue */
	} while (pLastChar != '\0' && pLastChar != '\n');
	}
	fclose(fp);
	if (i == lineno) {
	char *p = linebuf;
	PyObject *res;
	while (p == ' ' \|\| p == '\t' \|\| *p == '\014')
	p++;
	res = PyUnicode_FromString(p);
	if (res == NULL)
	PyErr_Clear();
	return res;
	}
	return NULL;
	}

	#ifdef __cplusplus
	}
	#endif