cpython/Python/traceback.c

375 lines
8.3 KiB
C

/* 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 = PyCode_Addr2Line(frame->f_code,
frame->f_lasti);
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;
}