/* Error handling */

#include "Python.h"

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

#ifdef MS_WINDOWS
#include 
#include 
#endif

#include 

#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);
}

void
PyErr_GetExcInfo(PyObject **p_type, PyObject **p_value, PyObject **p_traceback)
{
    PyThreadState *tstate = PyThreadState_GET();

    *p_type = tstate->exc_type;
    *p_value = tstate->exc_value;
    *p_traceback = tstate->exc_traceback;

    Py_XINCREF(*p_type);
    Py_XINCREF(*p_value);
    Py_XINCREF(*p_traceback);
}

void
PyErr_SetExcInfo(PyObject *p_type, PyObject *p_value, PyObject *p_traceback)
{
    PyObject *oldtype, *oldvalue, *oldtraceback;
    PyThreadState *tstate = PyThreadState_GET();

    oldtype = tstate->exc_type;
    oldvalue = tstate->exc_value;
    oldtraceback = tstate->exc_traceback;

    tstate->exc_type = p_type;
    tstate->exc_value = p_value;
    tstate->exc_traceback = p_traceback;

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

/* 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, *args;
    int i = errno;
#ifdef MS_WINDOWS
    WCHAR *s_buf = NULL;
#endif /* Unix/Windows */

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

#ifndef MS_WINDOWS
    if (i != 0) {
        char *s = strerror(i);
        message = PyUnicode_DecodeLocale(s, "surrogateescape");
    }
    else {
        /* Sometimes errno didn't get set */
        message = PyUnicode_FromString("Error");
    }
#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]  0 && (s_buf[len-1] = 0) {
        tmp = PyLong_FromLong(col_offset);
        if (tmp == NULL)
            PyErr_Clear();
        else {
            if (_PyObject_SetAttrId(v, &PyId_offset, tmp))
                PyErr_Clear();
            Py_DECREF(tmp);
        }
    }
    if (filename != NULL) {
        tmp = PyUnicode_DecodeFSDefault(filename);
        if (tmp == NULL)
            PyErr_Clear();
        else {
            if (_PyObject_SetAttrId(v, &PyId_filename, tmp))
                PyErr_Clear();
            Py_DECREF(tmp);
        }

        tmp = PyErr_ProgramText(filename, lineno);
        if (tmp) {
            if (_PyObject_SetAttrId(v, &PyId_text, tmp))
                PyErr_Clear();
            Py_DECREF(tmp);
        }
    }
    if (_PyObject_SetAttrId(v, &PyId_offset, Py_None)) {
        PyErr_Clear();
    }
    if (exc != PyExc_SyntaxError) {
        if (!_PyObject_HasAttrId(v, &PyId_msg)) {
            tmp = PyObject_Str(v);
            if (tmp) {
                if (_PyObject_SetAttrId(v, &PyId_msg, tmp))
                    PyErr_Clear();
                Py_DECREF(tmp);
            } else {
                PyErr_Clear();
            }
        }
        if (!_PyObject_HasAttrId(v, &PyId_print_file_and_line)) {
            if (_PyObject_SetAttrId(v, &PyId_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