intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 951 insertions, 0 deletions

diff --git a/contrib/tools/python3/src/Python/traceback.c b/contrib/tools/python3/src/Python/traceback.c
new file mode 100644
index 0000000000..23d0e38e73
--- /dev/null
+++ b/contrib/tools/python3/src/Python/traceback.c
@@ -0,0 +1,951 @@
+
+/* Traceback implementation */
+
+#include "Python.h"
+
+#include "code.h"
+#include "frameobject.h"          // PyFrame_GetBack()
+#include "structmember.h"         // PyMemberDef
+#include "osdefs.h"               // SEP
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#define OFF(x) offsetof(PyTracebackObject, x)
+
+#define PUTS(fd, str) _Py_write_noraise(fd, str, (int)strlen(str))
+#define MAX_STRING_LENGTH 500
+#define MAX_FRAME_DEPTH 100
+#define MAX_NTHREADS 100
+
+/* Function from Parser/tokenizer.c */
+extern char * PyTokenizer_FindEncodingFilename(int, PyObject *);
+
+_Py_IDENTIFIER(TextIOWrapper);
+_Py_IDENTIFIER(close);
+_Py_IDENTIFIER(open);
+_Py_IDENTIFIER(path);
+
+/*[clinic input]
+class TracebackType "PyTracebackObject *" "&PyTraceback_Type"
+[clinic start generated code]*/
+/*[clinic end generated code: output=da39a3ee5e6b4b0d input=928fa06c10151120]*/
+
+#include "clinic/traceback.c.h"
+
+static PyObject *
+tb_create_raw(PyTracebackObject *next, PyFrameObject *frame, int lasti,
+              int lineno)
+{
+    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 = lasti;
+        tb->tb_lineno = lineno;
+        PyObject_GC_Track(tb);
+    }
+    return (PyObject *)tb;
+}
+
+/*[clinic input]
+@classmethod
+TracebackType.__new__ as tb_new
+
+  tb_next: object
+  tb_frame: object(type='PyFrameObject *', subclass_of='&PyFrame_Type')
+  tb_lasti: int
+  tb_lineno: int
+
+Create a new traceback object.
+[clinic start generated code]*/
+
+static PyObject *
+tb_new_impl(PyTypeObject *type, PyObject *tb_next, PyFrameObject *tb_frame,
+            int tb_lasti, int tb_lineno)
+/*[clinic end generated code: output=fa077debd72d861a input=01cbe8ec8783fca7]*/
+{
+    if (tb_next == Py_None) {
+        tb_next = NULL;
+    } else if (!PyTraceBack_Check(tb_next)) {
+        return PyErr_Format(PyExc_TypeError,
+                            "expected traceback object or None, got '%s'",
+                            Py_TYPE(tb_next)->tp_name);
+    }
+
+    return tb_create_raw((PyTracebackObject *)tb_next, tb_frame, tb_lasti,
+                         tb_lineno);
+}
+
+static PyObject *
+tb_dir(PyTracebackObject *self, PyObject *Py_UNUSED(ignored))
+{
+    return Py_BuildValue("[ssss]", "tb_frame", "tb_next",
+                                   "tb_lasti", "tb_lineno");
+}
+
+static PyObject *
+tb_next_get(PyTracebackObject *self, void *Py_UNUSED(_))
+{
+    PyObject* ret = (PyObject*)self->tb_next;
+    if (!ret) {
+        ret = Py_None;
+    }
+    Py_INCREF(ret);
+    return ret;
+}
+
+static int
+tb_next_set(PyTracebackObject *self, PyObject *new_next, void *Py_UNUSED(_))
+{
+    if (!new_next) {
+        PyErr_Format(PyExc_TypeError, "can't delete tb_next attribute");
+        return -1;
+    }
+
+    /* We accept None or a traceback object, and map None -> NULL (inverse of
+       tb_next_get) */
+    if (new_next == Py_None) {
+        new_next = NULL;
+    } else if (!PyTraceBack_Check(new_next)) {
+        PyErr_Format(PyExc_TypeError,
+                     "expected traceback object, got '%s'",
+                     Py_TYPE(new_next)->tp_name);
+        return -1;
+    }
+
+    /* Check for loops */
+    PyTracebackObject *cursor = (PyTracebackObject *)new_next;
+    while (cursor) {
+        if (cursor == self) {
+            PyErr_Format(PyExc_ValueError, "traceback loop detected");
+            return -1;
+        }
+        cursor = cursor->tb_next;
+    }
+
+    PyObject *old_next = (PyObject*)self->tb_next;
+    Py_XINCREF(new_next);
+    self->tb_next = (PyTracebackObject *)new_next;
+    Py_XDECREF(old_next);
+
+    return 0;
+}
+
+
+static PyMethodDef tb_methods[] = {
+   {"__dir__", (PyCFunction)tb_dir, METH_NOARGS},
+   {NULL, NULL, 0, NULL},
+};
+
+static PyMemberDef tb_memberlist[] = {
+    {"tb_frame",        T_OBJECT,       OFF(tb_frame),  READONLY|READ_RESTRICTED},
+    {"tb_lasti",        T_INT,          OFF(tb_lasti),  READONLY},
+    {"tb_lineno",       T_INT,          OFF(tb_lineno), READONLY},
+    {NULL}      /* Sentinel */
+};
+
+static PyGetSetDef tb_getsetters[] = {
+    {"tb_next", (getter)tb_next_get, (setter)tb_next_set, NULL, NULL},
+    {NULL}      /* Sentinel */
+};
+
+static void
+tb_dealloc(PyTracebackObject *tb)
+{
+    PyObject_GC_UnTrack(tb);
+    Py_TRASHCAN_BEGIN(tb, tb_dealloc)
+    Py_XDECREF(tb->tb_next);
+    Py_XDECREF(tb->tb_frame);
+    PyObject_GC_Del(tb);
+    Py_TRASHCAN_END
+}
+
+static int
+tb_traverse(PyTracebackObject *tb, visitproc visit, void *arg)
+{
+    Py_VISIT(tb->tb_next);
+    Py_VISIT(tb->tb_frame);
+    return 0;
+}
+
+static int
+tb_clear(PyTracebackObject *tb)
+{
+    Py_CLEAR(tb->tb_next);
+    Py_CLEAR(tb->tb_frame);
+    return 0;
+}
+
+PyTypeObject PyTraceBack_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    "traceback",
+    sizeof(PyTracebackObject),
+    0,
+    (destructor)tb_dealloc, /*tp_dealloc*/
+    0,                  /*tp_vectorcall_offset*/
+    0,    /*tp_getattr*/
+    0,                  /*tp_setattr*/
+    0,                  /*tp_as_async*/
+    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 */
+    tb_new__doc__,                              /* 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 */
+    tb_getsetters,                              /* tp_getset */
+    0,                                          /* tp_base */
+    0,                                          /* tp_dict */
+    0,                                          /* tp_descr_get */
+    0,                                          /* tp_descr_set */
+    0,                                          /* tp_dictoffset */
+    0,                                          /* tp_init */
+    0,                                          /* tp_alloc */
+    tb_new,                                     /* tp_new */
+};
+
+
+PyObject*
+_PyTraceBack_FromFrame(PyObject *tb_next, PyFrameObject *frame)
+{
+    assert(tb_next == NULL || PyTraceBack_Check(tb_next));
+    assert(frame != NULL);
+
+    return tb_create_raw((PyTracebackObject *)tb_next, frame, frame->f_lasti,
+                         PyFrame_GetLineNumber(frame));
+}
+
+
+int
+PyTraceBack_Here(PyFrameObject *frame)
+{
+    PyObject *exc, *val, *tb, *newtb;
+    PyErr_Fetch(&exc, &val, &tb);
+    newtb = _PyTraceBack_FromFrame(tb, frame);
+    if (newtb == NULL) {
+        _PyErr_ChainExceptions(exc, val, tb);
+        return -1;
+    }
+    PyErr_Restore(exc, val, newtb);
+    Py_XDECREF(tb);
+    return 0;
+}
+
+/* Insert a frame into the traceback for (funcname, filename, lineno). */
+void _PyTraceback_Add(const char *funcname, const char *filename, int lineno)
+{
+    PyObject *globals;
+    PyCodeObject *code;
+    PyFrameObject *frame;
+    PyObject *exc, *val, *tb;
+
+    /* Save and clear the current exception. Python functions must not be
+       called with an exception set. Calling Python functions happens when
+       the codec of the filesystem encoding is implemented in pure Python. */
+    PyErr_Fetch(&exc, &val, &tb);
+
+    globals = PyDict_New();
+    if (!globals)
+        goto error;
+    code = PyCode_NewEmpty(filename, funcname, lineno);
+    if (!code) {
+        Py_DECREF(globals);
+        goto error;
+    }
+    frame = PyFrame_New(PyThreadState_Get(), code, globals, NULL);
+    Py_DECREF(globals);
+    Py_DECREF(code);
+    if (!frame)
+        goto error;
+    frame->f_lineno = lineno;
+
+    PyErr_Restore(exc, val, tb);
+    PyTraceBack_Here(frame);
+    Py_DECREF(frame);
+    return;
+
+error:
+    _PyErr_ChainExceptions(exc, val, tb);
+}
+
+static PyObject *
+_Py_FindSourceFile(PyObject *filename, char* namebuf, size_t namelen, PyObject *io)
+{
+    Py_ssize_t i;
+    PyObject *binary;
+    PyObject *v;
+    Py_ssize_t npath;
+    size_t taillen;
+    PyObject *syspath;
+    PyObject *path;
+    const char* tail;
+    PyObject *filebytes;
+    const char* filepath;
+    Py_ssize_t len;
+    PyObject* result;
+
+    filebytes = PyUnicode_EncodeFSDefault(filename);
+    if (filebytes == NULL) {
+        PyErr_Clear();
+        return NULL;
+    }
+    filepath = PyBytes_AS_STRING(filebytes);
+
+    /* Search tail of filename in sys.path before giving up */
+    tail = strrchr(filepath, SEP);
+    if (tail == NULL)
+        tail = filepath;
+    else
+        tail++;
+    taillen = strlen(tail);
+
+    syspath = _PySys_GetObjectId(&PyId_path);
+    if (syspath == NULL || !PyList_Check(syspath))
+        goto error;
+    npath = PyList_Size(syspath);
+
+    for (i = 0; i < npath; i++) {
+        v = PyList_GetItem(syspath, i);
+        if (v == NULL) {
+            PyErr_Clear();
+            break;
+        }
+        if (!PyUnicode_Check(v))
+            continue;
+        path = PyUnicode_EncodeFSDefault(v);
+        if (path == NULL) {
+            PyErr_Clear();
+            continue;
+        }
+        len = PyBytes_GET_SIZE(path);
+        if (len + 1 + (Py_ssize_t)taillen >= (Py_ssize_t)namelen - 1) {
+            Py_DECREF(path);
+            continue; /* Too long */
+        }
+        strcpy(namebuf, PyBytes_AS_STRING(path));
+        Py_DECREF(path);
+        if (strlen(namebuf) != (size_t)len)
+            continue; /* v contains '\0' */
+        if (len > 0 && namebuf[len-1] != SEP)
+            namebuf[len++] = SEP;
+        strcpy(namebuf+len, tail);
+
+        binary = _PyObject_CallMethodId(io, &PyId_open, "ss", namebuf, "rb");
+        if (binary != NULL) {
+            result = binary;
+            goto finally;
+        }
+        PyErr_Clear();
+    }
+    goto error;
+
+error:
+    result = NULL;
+finally:
+    Py_DECREF(filebytes);
+    return result;
+}
+
+int
+_Py_DisplaySourceLine(PyObject *f, PyObject *filename, int lineno, int indent)
+{
+    int err = 0;
+    int fd;
+    int i;
+    char *found_encoding;
+    const char *encoding;
+    PyObject *io;
+    PyObject *binary;
+    PyObject *fob = NULL;
+    PyObject *lineobj = NULL;
+    PyObject *res;
+    char buf[MAXPATHLEN+1];
+    int kind;
+    const void *data;
+
+    /* open the file */
+    if (filename == NULL)
+        return 0;
+
+    io = PyImport_ImportModuleNoBlock("io");
+    if (io == NULL)
+        return -1;
+    binary = _PyObject_CallMethodId(io, &PyId_open, "Os", filename, "rb");
+
+    if (binary == NULL) {
+        PyErr_Clear();
+
+        binary = _Py_FindSourceFile(filename, buf, sizeof(buf), io);
+        if (binary == NULL) {
+            Py_DECREF(io);
+            return -1;
+        }
+    }
+
+    /* use the right encoding to decode the file as unicode */
+    fd = PyObject_AsFileDescriptor(binary);
+    if (fd < 0) {
+        Py_DECREF(io);
+        Py_DECREF(binary);
+        return 0;
+    }
+    found_encoding = PyTokenizer_FindEncodingFilename(fd, filename);
+    if (found_encoding == NULL)
+        PyErr_Clear();
+    encoding = (found_encoding != NULL) ? found_encoding : "utf-8";
+    /* Reset position */
+    if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
+        Py_DECREF(io);
+        Py_DECREF(binary);
+        PyMem_FREE(found_encoding);
+        return 0;
+    }
+    fob = _PyObject_CallMethodId(io, &PyId_TextIOWrapper, "Os", binary, encoding);
+    Py_DECREF(io);
+    PyMem_FREE(found_encoding);
+
+    if (fob == NULL) {
+        PyErr_Clear();
+
+        res = _PyObject_CallMethodIdNoArgs(binary, &PyId_close);
+        Py_DECREF(binary);
+        if (res)
+            Py_DECREF(res);
+        else
+            PyErr_Clear();
+        return 0;
+    }
+    Py_DECREF(binary);
+
+    /* get the line number lineno */
+    for (i = 0; i < lineno; i++) {
+        Py_XDECREF(lineobj);
+        lineobj = PyFile_GetLine(fob, -1);
+        if (!lineobj) {
+            PyErr_Clear();
+            err = -1;
+            break;
+        }
+    }
+    res = _PyObject_CallMethodIdNoArgs(fob, &PyId_close);
+    if (res)
+        Py_DECREF(res);
+    else
+        PyErr_Clear();
+    Py_DECREF(fob);
+    if (!lineobj || !PyUnicode_Check(lineobj)) {
+        Py_XDECREF(lineobj);
+        return err;
+    }
+
+    /* remove the indentation of the line */
+    kind = PyUnicode_KIND(lineobj);
+    data = PyUnicode_DATA(lineobj);
+    for (i=0; i < PyUnicode_GET_LENGTH(lineobj); i++) {
+        Py_UCS4 ch = PyUnicode_READ(kind, data, i);
+        if (ch != ' ' && ch != '\t' && ch != '\014')
+            break;
+    }
+    if (i) {
+        PyObject *truncated;
+        truncated = PyUnicode_Substring(lineobj, i, PyUnicode_GET_LENGTH(lineobj));
+        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, PyObject *filename, int lineno, PyObject *name)
+{
+    int err;
+    PyObject *line;
+
+    if (filename == NULL || name == NULL)
+        return -1;
+    line = PyUnicode_FromFormat("  File \"%U\", line %d, in %U\n",
+                                filename, lineno, name);
+    if (line == NULL)
+        return -1;
+    err = PyFile_WriteObject(line, f, Py_PRINT_RAW);
+    Py_DECREF(line);
+    if (err != 0)
+        return err;
+    /* ignore errors since we can't report them, can we? */
+    if (_Py_DisplaySourceLine(f, filename, lineno, 4))
+        PyErr_Clear();
+    return err;
+}
+
+static const int TB_RECURSIVE_CUTOFF = 3; // Also hardcoded in traceback.py.
+
+static int
+tb_print_line_repeated(PyObject *f, long cnt)
+{
+    cnt -= TB_RECURSIVE_CUTOFF;
+    PyObject *line = PyUnicode_FromFormat(
+        (cnt > 1)
+          ? "  [Previous line repeated %ld more times]\n"
+          : "  [Previous line repeated %ld more time]\n",
+        cnt);
+    if (line == NULL) {
+        return -1;
+    }
+    int err = PyFile_WriteObject(line, f, Py_PRINT_RAW);
+    Py_DECREF(line);
+    return err;
+}
+
+static int
+tb_printinternal(PyTracebackObject *tb, PyObject *f, long limit)
+{
+    int err = 0;
+    Py_ssize_t depth = 0;
+    PyObject *last_file = NULL;
+    int last_line = -1;
+    PyObject *last_name = NULL;
+    long cnt = 0;
+    PyTracebackObject *tb1 = tb;
+    while (tb1 != NULL) {
+        depth++;
+        tb1 = tb1->tb_next;
+    }
+    while (tb != NULL && depth > limit) {
+        depth--;
+        tb = tb->tb_next;
+    }
+    while (tb != NULL && err == 0) {
+        PyCodeObject *code = PyFrame_GetCode(tb->tb_frame);
+        if (last_file == NULL ||
+            code->co_filename != last_file ||
+            last_line == -1 || tb->tb_lineno != last_line ||
+            last_name == NULL || code->co_name != last_name) {
+            if (cnt > TB_RECURSIVE_CUTOFF) {
+                err = tb_print_line_repeated(f, cnt);
+            }
+            last_file = code->co_filename;
+            last_line = tb->tb_lineno;
+            last_name = code->co_name;
+            cnt = 0;
+        }
+        cnt++;
+        if (err == 0 && cnt <= TB_RECURSIVE_CUTOFF) {
+            err = tb_displayline(f, code->co_filename, tb->tb_lineno,
+                                 code->co_name);
+            if (err == 0) {
+                err = PyErr_CheckSignals();
+            }
+        }
+        Py_DECREF(code);
+        tb = tb->tb_next;
+    }
+    if (err == 0 && cnt > TB_RECURSIVE_CUTOFF) {
+        err = tb_print_line_repeated(f, cnt);
+    }
+    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 && PyLong_Check(limitv)) {
+        int overflow;
+        limit = PyLong_AsLongAndOverflow(limitv, &overflow);
+        if (overflow > 0) {
+            limit = LONG_MAX;
+        }
+        else if (limit <= 0) {
+            return 0;
+        }
+    }
+    err = PyFile_WriteString("Traceback (most recent call last):\n", f);
+    if (!err)
+        err = tb_printinternal((PyTracebackObject *)v, f, limit);
+    return err;
+}
+
+/* Format an integer in range [0; 0xffffffff] to decimal and write it
+   into the file fd.
+
+   This function is signal safe. */
+
+void
+_Py_DumpDecimal(int fd, unsigned long value)
+{
+    /* maximum number of characters required for output of %lld or %p.
+       We need at most ceil(log10(256)*SIZEOF_LONG_LONG) digits,
+       plus 1 for the null byte.  53/22 is an upper bound for log10(256). */
+    char buffer[1 + (sizeof(unsigned long)*53-1) / 22 + 1];
+    char *ptr, *end;
+
+    end = &buffer[Py_ARRAY_LENGTH(buffer) - 1];
+    ptr = end;
+    *ptr = '\0';
+    do {
+        --ptr;
+        assert(ptr >= buffer);
+        *ptr = '0' + (value % 10);
+        value /= 10;
+    } while (value);
+
+    _Py_write_noraise(fd, ptr, end - ptr);
+}
+
+/* Format an integer in range [0; 0xffffffff] to hexadecimal of 'width' digits,
+   and write it into the file fd.
+
+   This function is signal safe. */
+
+void
+_Py_DumpHexadecimal(int fd, unsigned long value, Py_ssize_t width)
+{
+    char buffer[sizeof(unsigned long) * 2 + 1], *ptr, *end;
+    const Py_ssize_t size = Py_ARRAY_LENGTH(buffer) - 1;
+
+    if (width > size)
+        width = size;
+    /* it's ok if width is negative */
+
+    end = &buffer[size];
+    ptr = end;
+    *ptr = '\0';
+    do {
+        --ptr;
+        assert(ptr >= buffer);
+        *ptr = Py_hexdigits[value & 15];
+        value >>= 4;
+    } while ((end - ptr) < width || value);
+
+    _Py_write_noraise(fd, ptr, end - ptr);
+}
+
+void
+_Py_DumpASCII(int fd, PyObject *text)
+{
+    PyASCIIObject *ascii = (PyASCIIObject *)text;
+    Py_ssize_t i, size;
+    int truncated;
+    int kind;
+    void *data = NULL;
+    wchar_t *wstr = NULL;
+    Py_UCS4 ch;
+
+    if (!PyUnicode_Check(text))
+        return;
+
+    size = ascii->length;
+    kind = ascii->state.kind;
+    if (kind == PyUnicode_WCHAR_KIND) {
+        wstr = ((PyASCIIObject *)text)->wstr;
+        if (wstr == NULL)
+            return;
+        size = ((PyCompactUnicodeObject *)text)->wstr_length;
+    }
+    else if (ascii->state.compact) {
+        if (ascii->state.ascii)
+            data = ((PyASCIIObject*)text) + 1;
+        else
+            data = ((PyCompactUnicodeObject*)text) + 1;
+    }
+    else {
+        data = ((PyUnicodeObject *)text)->data.any;
+        if (data == NULL)
+            return;
+    }
+
+    if (MAX_STRING_LENGTH < size) {
+        size = MAX_STRING_LENGTH;
+        truncated = 1;
+    }
+    else {
+        truncated = 0;
+    }
+
+    // Is an ASCII string?
+    if (ascii->state.ascii) {
+        assert(kind == PyUnicode_1BYTE_KIND);
+        char *str = data;
+
+        int need_escape = 0;
+        for (i=0; i < size; i++) {
+            ch = str[i];
+            if (!(' ' <= ch && ch <= 126)) {
+                need_escape = 1;
+                break;
+            }
+        }
+        if (!need_escape) {
+            // The string can be written with a single write() syscall
+            _Py_write_noraise(fd, str, size);
+            goto done;
+        }
+    }
+
+    for (i=0; i < size; i++) {
+        if (kind != PyUnicode_WCHAR_KIND)
+            ch = PyUnicode_READ(kind, data, i);
+        else
+            ch = wstr[i];
+        if (' ' <= ch && ch <= 126) {
+            /* printable ASCII character */
+            char c = (char)ch;
+            _Py_write_noraise(fd, &c, 1);
+        }
+        else if (ch <= 0xff) {
+            PUTS(fd, "\\x");
+            _Py_DumpHexadecimal(fd, ch, 2);
+        }
+        else if (ch <= 0xffff) {
+            PUTS(fd, "\\u");
+            _Py_DumpHexadecimal(fd, ch, 4);
+        }
+        else {
+            PUTS(fd, "\\U");
+            _Py_DumpHexadecimal(fd, ch, 8);
+        }
+    }
+
+done:
+    if (truncated) {
+        PUTS(fd, "...");
+    }
+}
+
+/* Write a frame into the file fd: "File "xxx", line xxx in xxx".
+
+   This function is signal safe. */
+
+static void
+dump_frame(int fd, PyFrameObject *frame)
+{
+    PyCodeObject *code = PyFrame_GetCode(frame);
+    PUTS(fd, "  File ");
+    if (code->co_filename != NULL
+        && PyUnicode_Check(code->co_filename))
+    {
+        PUTS(fd, "\"");
+        _Py_DumpASCII(fd, code->co_filename);
+        PUTS(fd, "\"");
+    } else {
+        PUTS(fd, "???");
+    }
+
+    /* PyFrame_GetLineNumber() was introduced in Python 2.7.0 and 3.2.0 */
+    int lineno = PyCode_Addr2Line(code, frame->f_lasti);
+    PUTS(fd, ", line ");
+    if (lineno >= 0) {
+        _Py_DumpDecimal(fd, (unsigned long)lineno);
+    }
+    else {
+        PUTS(fd, "???");
+    }
+    PUTS(fd, " in ");
+
+    if (code->co_name != NULL
+       && PyUnicode_Check(code->co_name)) {
+        _Py_DumpASCII(fd, code->co_name);
+    }
+    else {
+        PUTS(fd, "???");
+    }
+
+    PUTS(fd, "\n");
+    Py_DECREF(code);
+}
+
+static void
+dump_traceback(int fd, PyThreadState *tstate, int write_header)
+{
+    PyFrameObject *frame;
+    unsigned int depth;
+
+    if (write_header) {
+        PUTS(fd, "Stack (most recent call first):\n");
+    }
+
+    // Use a borrowed reference. Avoid Py_INCREF/Py_DECREF, since this function
+    // can be called in a signal handler by the faulthandler module which must
+    // not modify Python objects.
+    frame = tstate->frame;
+    if (frame == NULL) {
+        PUTS(fd, "<no Python frame>\n");
+        return;
+    }
+
+    depth = 0;
+    while (1) {
+        if (MAX_FRAME_DEPTH <= depth) {
+            PUTS(fd, "  ...\n");
+            break;
+        }
+        if (!PyFrame_Check(frame)) {
+            break;
+        }
+        dump_frame(fd, frame);
+        PyFrameObject *back = frame->f_back;
+
+        if (back == NULL) {
+            break;
+        }
+        frame = back;
+        depth++;
+    }
+}
+
+/* Dump the traceback of a Python thread into fd. Use write() to write the
+   traceback and retry if write() is interrupted by a signal (failed with
+   EINTR), but don't call the Python signal handler.
+
+   The caller is responsible to call PyErr_CheckSignals() to call Python signal
+   handlers if signals were received. */
+void
+_Py_DumpTraceback(int fd, PyThreadState *tstate)
+{
+    dump_traceback(fd, tstate, 1);
+}
+
+/* Write the thread identifier into the file 'fd': "Current thread 0xHHHH:\" if
+   is_current is true, "Thread 0xHHHH:\n" otherwise.
+
+   This function is signal safe. */
+
+static void
+write_thread_id(int fd, PyThreadState *tstate, int is_current)
+{
+    if (is_current)
+        PUTS(fd, "Current thread 0x");
+    else
+        PUTS(fd, "Thread 0x");
+    _Py_DumpHexadecimal(fd,
+                        tstate->thread_id,
+                        sizeof(unsigned long) * 2);
+    PUTS(fd, " (most recent call first):\n");
+}
+
+/* Dump the traceback of all Python threads into fd. Use write() to write the
+   traceback and retry if write() is interrupted by a signal (failed with
+   EINTR), but don't call the Python signal handler.
+
+   The caller is responsible to call PyErr_CheckSignals() to call Python signal
+   handlers if signals were received. */
+const char*
+_Py_DumpTracebackThreads(int fd, PyInterpreterState *interp,
+                         PyThreadState *current_tstate)
+{
+    PyThreadState *tstate;
+    unsigned int nthreads;
+
+    if (current_tstate == NULL) {
+        /* _Py_DumpTracebackThreads() is called from signal handlers by
+           faulthandler.
+
+           SIGSEGV, SIGFPE, SIGABRT, SIGBUS and SIGILL are synchronous signals
+           and are thus delivered to the thread that caused the fault. Get the
+           Python thread state of the current thread.
+
+           PyThreadState_Get() doesn't give the state of the thread that caused
+           the fault if the thread released the GIL, and so
+           _PyThreadState_GET() cannot be used. Read the thread specific
+           storage (TSS) instead: call PyGILState_GetThisThreadState(). */
+        current_tstate = PyGILState_GetThisThreadState();
+    }
+
+    if (interp == NULL) {
+        if (current_tstate == NULL) {
+            interp = _PyGILState_GetInterpreterStateUnsafe();
+            if (interp == NULL) {
+                /* We need the interpreter state to get Python threads */
+                return "unable to get the interpreter state";
+            }
+        }
+        else {
+            interp = current_tstate->interp;
+        }
+    }
+    assert(interp != NULL);
+
+    /* Get the current interpreter from the current thread */
+    tstate = PyInterpreterState_ThreadHead(interp);
+    if (tstate == NULL)
+        return "unable to get the thread head state";
+
+    /* Dump the traceback of each thread */
+    tstate = PyInterpreterState_ThreadHead(interp);
+    nthreads = 0;
+    _Py_BEGIN_SUPPRESS_IPH
+    do
+    {
+        if (nthreads != 0)
+            PUTS(fd, "\n");
+        if (nthreads >= MAX_NTHREADS) {
+            PUTS(fd, "...\n");
+            break;
+        }
+        write_thread_id(fd, tstate, tstate == current_tstate);
+        dump_traceback(fd, tstate, 0);
+        tstate = PyThreadState_Next(tstate);
+        nthreads++;
+    } while (tstate != NULL);
+    _Py_END_SUPPRESS_IPH
+
+    return NULL;
+}
+