/* Traceback implementation */

#include "Python.h"

#include "code.h"

#include "frameobject.h"

#include "structmember.h"

#include "osdefs.h"

#include "traceback.h"

#ifdef HAVE_FCNTL_H

#include <fcntl.h>

#endif

#define OFF(x) offsetof(PyTracebackObject, x)

/* Method from Parser/tokenizer.c */

extern char * PyTokenizer_FindEncoding(int);

static PyObject *

tb_dir(PyTracebackObject *self)

{

return Py_BuildValue("[ssss]", "tb_frame", "tb_next",

"tb_lasti", "tb_lineno");

}

static PyMethodDef tb_methods[] = {

{"__dir__", (PyCFunction)tb_dir, METH_NOARGS},

{NULL, NULL, 0, NULL},

};

static PyMemberDef tb_memberlist[] = {

{"tb_next", T_OBJECT, OFF(tb_next), READONLY},

{"tb_frame", T_OBJECT, OFF(tb_frame), READONLY},

{"tb_lasti", T_INT, OFF(tb_lasti), READONLY},

{"tb_lineno", T_INT, OFF(tb_lineno), READONLY},

{NULL} /* Sentinel */

};

static void

tb_dealloc(PyTracebackObject *tb)

{

PyObject_GC_UnTrack(tb);

Py_TRASHCAN_SAFE_BEGIN(tb)

Py_XDECREF(tb->tb_next);

Py_XDECREF(tb->tb_frame);

PyObject_GC_Del(tb);

Py_TRASHCAN_SAFE_END(tb)

}

static int

tb_traverse(PyTracebackObject *tb, visitproc visit, void *arg)

{

Py_VISIT(tb->tb_next);

Py_VISIT(tb->tb_frame);

return 0;

}

static void

tb_clear(PyTracebackObject *tb)

{

Py_CLEAR(tb->tb_next);

Py_CLEAR(tb->tb_frame);

}

PyTypeObject PyTraceBack_Type = {

PyVarObject_HEAD_INIT(&PyType_Type, 0)

"traceback",

sizeof(PyTracebackObject),

0,

(destructor)tb_dealloc, /*tp_dealloc*/

0, /*tp_print*/

0, /*tp_getattr*/

0, /*tp_setattr*/

0, /*tp_reserved*/

0, /*tp_repr*/

0, /*tp_as_number*/

0, /*tp_as_sequence*/

0, /*tp_as_mapping*/

0, /* tp_hash */

0, /* tp_call */

0, /* tp_str */

PyObject_GenericGetAttr, /* tp_getattro */

0, /* tp_setattro */

0, /* tp_as_buffer */

Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */

0, /* tp_doc */

(traverseproc)tb_traverse, /* tp_traverse */

(inquiry)tb_clear, /* tp_clear */

0, /* tp_richcompare */

0, /* tp_weaklistoffset */

0, /* tp_iter */

0, /* tp_iternext */

tb_methods, /* tp_methods */

tb_memberlist, /* tp_members */

0, /* tp_getset */

0, /* tp_base */

0, /* tp_dict */

};

static PyTracebackObject *

newtracebackobject(PyTracebackObject *next, PyFrameObject *frame)

{

PyTracebackObject *tb;

if ((next != NULL && !PyTraceBack_Check(next)) ||

frame == NULL || !PyFrame_Check(frame)) {

PyErr_BadInternalCall();

return NULL;

}

tb = PyObject_GC_New(PyTracebackObject, &PyTraceBack_Type);

if (tb != NULL) {

Py_XINCREF(next);

tb->tb_next = next;

Py_XINCREF(frame);

tb->tb_frame = frame;

tb->tb_lasti = frame->f_lasti;

tb->tb_lineno = PyFrame_GetLineNumber(frame);

PyObject_GC_Track(tb);

}

return tb;

}

int

PyTraceBack_Here(PyFrameObject *frame)

{

PyThreadState *tstate = PyThreadState_GET();

PyTracebackObject *oldtb = (PyTracebackObject *) tstate->curexc_traceback;

PyTracebackObject *tb = newtracebackobject(oldtb, frame);

if (tb == NULL)

return -1;

tstate->curexc_traceback = (PyObject *)tb;

Py_XDECREF(oldtb);

return 0;

}

static int

_Py_FindSourceFile(const char* filename, char* namebuf, size_t namelen, int open_flags)

{

int i;

int fd = -1;

PyObject *v;

Py_ssize_t _npath;

int npath;

size_t taillen;

PyObject *syspath;

const char* path;

const char* tail;

Py_ssize_t len;

/* Search tail of filename in sys.path before giving up */

tail = strrchr(filename, SEP);

if (tail == NULL)

tail = filename;

else

tail++;

taillen = strlen(tail);

syspath = PySys_GetObject("path");

if (syspath == NULL || !PyList_Check(syspath))

return -1;

_npath = PyList_Size(syspath);

npath = Py_SAFE_DOWNCAST(_npath, Py_ssize_t, int);

for (i = 0; i < npath; i++) {

v = PyList_GetItem(syspath, i);

if (v == NULL) {

PyErr_Clear();

break;

}

if (!PyUnicode_Check(v))

continue;

path = _PyUnicode_AsStringAndSize(v, &len);

if (len + 1 + (Py_ssize_t)taillen >= (Py_ssize_t)namelen - 1)

continue; /* Too long */

strcpy(namebuf, path);

if (strlen(namebuf) != len)

continue; /* v contains '\0' */

if (len > 0 && namebuf[len-1] != SEP)

namebuf[len++] = SEP;

strcpy(namebuf+len, tail);

Py_BEGIN_ALLOW_THREADS

fd = open(namebuf, open_flags);

Py_END_ALLOW_THREADS

if (0 <= fd) {

return fd;

}

}

return -1;

}

int

_Py_DisplaySourceLine(PyObject *f, const char *filename, int lineno, int indent)

{

int err = 0;

int fd;

int i;

char *found_encoding;

char *encoding;

PyObject *fob = NULL;

PyObject *lineobj = NULL;

#ifdef O_BINARY

const int open_flags = O_RDONLY | O_BINARY; /* necessary for Windows */

#else

const int open_flags = O_RDONLY;

#endif

char buf[MAXPATHLEN+1];

Py_UNICODE *u, *p;

Py_ssize_t len;

/* open the file */

if (filename == NULL)

return 0;

Py_BEGIN_ALLOW_THREADS

fd = open(filename, open_flags);

Py_END_ALLOW_THREADS

if (fd < 0) {

fd = _Py_FindSourceFile(filename, buf, sizeof(buf), open_flags);

if (fd < 0)

return 0;

filename = buf;

}

/* use the right encoding to decode the file as unicode */

found_encoding = PyTokenizer_FindEncoding(fd);

encoding = (found_encoding != NULL) ? found_encoding :

(char*)PyUnicode_GetDefaultEncoding();

lseek(fd, 0, 0); /* Reset position */

fob = PyFile_FromFd(fd, (char*)filename, "r", -1, (char*)encoding,

NULL, NULL, 1);

PyMem_FREE(found_encoding);

if (fob == NULL) {

PyErr_Clear();

close(fd);

return 0;

}

/* get the line number lineno */

for (i = 0; i < lineno; i++) {

Py_XDECREF(lineobj);

lineobj = PyFile_GetLine(fob, -1);

if (!lineobj) {

err = -1;

break;

}

}

Py_DECREF(fob);

if (!lineobj || !PyUnicode_Check(lineobj)) {

Py_XDECREF(lineobj);

return err;

}

/* remove the indentation of the line */

u = PyUnicode_AS_UNICODE(lineobj);

len = PyUnicode_GET_SIZE(lineobj);

for (p=u; *p == ' ' || *p == '\t' || *p == '\014'; p++)

len--;

if (u != p) {

PyObject *truncated;

truncated = PyUnicode_FromUnicode(p, len);

if (truncated) {

Py_DECREF(lineobj);

lineobj = truncated;

} else {

PyErr_Clear();

}

}

/* Write some spaces before the line */

strcpy(buf, " ");

assert (strlen(buf) == 10);

while (indent > 0) {

if(indent < 10)

buf[indent] = '\0';

err = PyFile_WriteString(buf, f);

if (err != 0)

break;

indent -= 10;

}

/* finally display the line */

if (err == 0)

err = PyFile_WriteObject(lineobj, f, Py_PRINT_RAW);

Py_DECREF(lineobj);

if (err == 0)

err = PyFile_WriteString("\n", f);

return err;

}

static int

tb_displayline(PyObject *f, const char *filename, int lineno, const char *name)

{

int err = 0;

char linebuf[2000];

if (filename == NULL || name == NULL)

return -1;

/* This is needed by Emacs' compile command */

#define FMT " File \"%.500s\", line %d, in %.500s\n"

PyOS_snprintf(linebuf, sizeof(linebuf), FMT, filename, lineno, name);

err = PyFile_WriteString(linebuf, f);

if (err != 0)

return err;

return _Py_DisplaySourceLine(f, filename, lineno, 4);

}

static int

tb_printinternal(PyTracebackObject *tb, PyObject *f, long limit)

{

int err = 0;

long depth = 0;

PyTracebackObject *tb1 = tb;

while (tb1 != NULL) {

depth++;

tb1 = tb1->tb_next;

}

while (tb != NULL && err == 0) {

if (depth <= limit) {

err = tb_displayline(f,

_PyUnicode_AsString(

tb->tb_frame->f_code->co_filename),

tb->tb_lineno,

_PyUnicode_AsString(tb->tb_frame->f_code->co_name));

}

depth--;

tb = tb->tb_next;

if (err == 0)

err = PyErr_CheckSignals();

}

return err;

}

#define PyTraceBack_LIMIT 1000

int

PyTraceBack_Print(PyObject *v, PyObject *f)

{

int err;

PyObject *limitv;

long limit = PyTraceBack_LIMIT;

if (v == NULL)

return 0;

if (!PyTraceBack_Check(v)) {

PyErr_BadInternalCall();

return -1;

}

limitv = PySys_GetObject("tracebacklimit");

if (limitv) {

PyObject *exc_type, *exc_value, *exc_tb;

PyErr_Fetch(&exc_type, &exc_value, &exc_tb);

limit = PyLong_AsLong(limitv);

if (limit == -1 && PyErr_Occurred()) {

if (PyErr_ExceptionMatches(PyExc_OverflowError)) {

limit = PyTraceBack_LIMIT;

}

else {

Py_XDECREF(exc_type);

Py_XDECREF(exc_value);

Py_XDECREF(exc_tb);

return 0;

}

}

else if (limit <= 0) {

limit = PyTraceBack_LIMIT;

}

PyErr_Restore(exc_type, exc_value, exc_tb);

}

err = PyFile_WriteString("Traceback (most recent call last):\n", f);

if (!err)

err = tb_printinternal((PyTracebackObject *)v, f, limit);

return err;

}