Modules/_io/_iomodule.c

   1 /*
   2     An implementation of the new I/O lib as defined by PEP 3116 - "New I/O"
   3
   4     Classes defined here: UnsupportedOperation, BlockingIOError.
   5     Functions defined here: open().
   6
   7     Mostly written by Amaury Forgeot d'Arc
   8 */
   9
  10 #define PY_SSIZE_T_CLEAN
  11 #include "Python.h"
  12 #include "structmember.h"
  13 #include "_iomodule.h"
  14
  15 #ifdef HAVE_SYS_TYPES_H
  16 #include <sys/types.h>
  17 #endif /* HAVE_SYS_TYPES_H */
  18
  19 #ifdef HAVE_SYS_STAT_H
  20 #include <sys/stat.h>
  21 #endif /* HAVE_SYS_STAT_H */
  22
  23
  24 /* Various interned strings */
  25
  26 PyObject *_PyIO_str_close;
  27 PyObject *_PyIO_str_closed;
  28 PyObject *_PyIO_str_decode;
  29 PyObject *_PyIO_str_encode;
  30 PyObject *_PyIO_str_fileno;
  31 PyObject *_PyIO_str_flush;
  32 PyObject *_PyIO_str_getstate;
  33 PyObject *_PyIO_str_isatty;
  34 PyObject *_PyIO_str_newlines;
  35 PyObject *_PyIO_str_nl;
  36 PyObject *_PyIO_str_read;
  37 PyObject *_PyIO_str_read1;
  38 PyObject *_PyIO_str_readable;
  39 PyObject *_PyIO_str_readinto;
  40 PyObject *_PyIO_str_readline;
  41 PyObject *_PyIO_str_reset;
  42 PyObject *_PyIO_str_seek;
  43 PyObject *_PyIO_str_seekable;
  44 PyObject *_PyIO_str_setstate;
  45 PyObject *_PyIO_str_tell;
  46 PyObject *_PyIO_str_truncate;
  47 PyObject *_PyIO_str_writable;
  48 PyObject *_PyIO_str_write;
  49
  50 PyObject *_PyIO_empty_str;
  51 PyObject *_PyIO_empty_bytes;
  52 PyObject *_PyIO_zero;
  53
  54 \f
  55 PyDoc_STRVAR(module_doc,
  56 "The io module provides the Python interfaces to stream handling. The\n"
  57 "builtin open function is defined in this module.\n"
  58 "\n"
  59 "At the top of the I/O hierarchy is the abstract base class IOBase. It\n"
  60 "defines the basic interface to a stream. Note, however, that there is no\n"
  61 "seperation between reading and writing to streams; implementations are\n"
  62 "allowed to throw an IOError if they do not support a given operation.\n"
  63 "\n"
  64 "Extending IOBase is RawIOBase which deals simply with the reading and\n"
  65 "writing of raw bytes to a stream. FileIO subclasses RawIOBase to provide\n"
  66 "an interface to OS files.\n"
  67 "\n"
  68 "BufferedIOBase deals with buffering on a raw byte stream (RawIOBase). Its\n"
  69 "subclasses, BufferedWriter, BufferedReader, and BufferedRWPair buffer\n"
  70 "streams that are readable, writable, and both respectively.\n"
  71 "BufferedRandom provides a buffered interface to random access\n"
  72 "streams. BytesIO is a simple stream of in-memory bytes.\n"
  73 "\n"
  74 "Another IOBase subclass, TextIOBase, deals with the encoding and decoding\n"
  75 "of streams into text. TextIOWrapper, which extends it, is a buffered text\n"
  76 "interface to a buffered raw stream (`BufferedIOBase`). Finally, StringIO\n"
  77 "is a in-memory stream for text.\n"
  78 "\n"
  79 "Argument names are not part of the specification, and only the arguments\n"
  80 "of open() are intended to be used as keyword arguments.\n"
  81 "\n"
  82 "data:\n"
  83 "\n"
  84 "DEFAULT_BUFFER_SIZE\n"
  85 "\n"
  86 "   An int containing the default buffer size used by the module's buffered\n"
  87 "   I/O classes. open() uses the file's blksize (as obtained by os.stat) if\n"
  88 "   possible.\n"
  89     );
  90 \f
  91
  92 /*
  93  * BlockingIOError extends IOError
  94  */
  95
  96 static int
  97 blockingioerror_init(PyBlockingIOErrorObject *self, PyObject *args,
  98                      PyObject *kwds)
  99 {
 100     PyObject *myerrno = NULL, *strerror = NULL;
 101     PyObject *baseargs = NULL;
 102     Py_ssize_t written = 0;
 103
 104     assert(PyTuple_Check(args));
 105
 106     self->written = 0;
 107     if (!PyArg_ParseTuple(args, "OO|n:BlockingIOError",
 108                           &myerrno, &strerror, &written))
 109         return -1;
 110
 111     baseargs = PyTuple_Pack(2, myerrno, strerror);
 112     if (baseargs == NULL)
 113         return -1;
 114     /* This will take care of initializing of myerrno and strerror members */
 115     if (((PyTypeObject *)PyExc_IOError)->tp_init(
 116                 (PyObject *)self, baseargs, kwds) == -1) {
 117         Py_DECREF(baseargs);
 118         return -1;
 119     }
 120     Py_DECREF(baseargs);
 121
 122     self->written = written;
 123     return 0;
 124 }
 125
 126 static PyMemberDef blockingioerror_members[] = {
 127     {"characters_written", T_PYSSIZET, offsetof(PyBlockingIOErrorObject, written), 0},
 128     {NULL}  /* Sentinel */
 129 };
 130
 131 static PyTypeObject _PyExc_BlockingIOError = {
 132     PyVarObject_HEAD_INIT(NULL, 0)
 133     "BlockingIOError", /*tp_name*/
 134     sizeof(PyBlockingIOErrorObject), /*tp_basicsize*/
 135     0,                          /*tp_itemsize*/
 136     0,                          /*tp_dealloc*/
 137     0,                          /*tp_print*/
 138     0,                          /*tp_getattr*/
 139     0,                          /*tp_setattr*/
 140     0,                          /*tp_compare */
 141     0,                          /*tp_repr*/
 142     0,                          /*tp_as_number*/
 143     0,                          /*tp_as_sequence*/
 144     0,                          /*tp_as_mapping*/
 145     0,                          /*tp_hash */
 146     0,                          /*tp_call*/
 147     0,                          /*tp_str*/
 148     0,                          /*tp_getattro*/
 149     0,                          /*tp_setattro*/
 150     0,                          /*tp_as_buffer*/
 151     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
 152     PyDoc_STR("Exception raised when I/O would block "
 153               "on a non-blocking I/O stream"), /* tp_doc */
 154     0,                          /* tp_traverse */
 155     0,                          /* tp_clear */
 156     0,                          /* tp_richcompare */
 157     0,                          /* tp_weaklistoffset */
 158     0,                          /* tp_iter */
 159     0,                          /* tp_iternext */
 160     0,                          /* tp_methods */
 161     blockingioerror_members,    /* tp_members */
 162     0,                          /* tp_getset */
 163     0,                          /* tp_base */
 164     0,                          /* tp_dict */
 165     0,                          /* tp_descr_get */
 166     0,                          /* tp_descr_set */
 167     0,                          /* tp_dictoffset */
 168     (initproc)blockingioerror_init, /* tp_init */
 169     0,                          /* tp_alloc */
 170     0,                          /* tp_new */
 171 };
 172 PyObject *PyExc_BlockingIOError = (PyObject *)&_PyExc_BlockingIOError;
 173 \f
 174
 175 /*
 176  * The main open() function
 177  */
 178 PyDoc_STRVAR(open_doc,
 179 "Open file and return a stream.  Raise IOError upon failure.\n"
 180 "\n"
 181 "file is either a text or byte string giving the name (and the path\n"
 182 "if the file isn't in the current working directory) of the file to\n"
 183 "be opened or an integer file descriptor of the file to be\n"
 184 "wrapped. (If a file descriptor is given, it is closed when the\n"
 185 "returned I/O object is closed, unless closefd is set to False.)\n"
 186 "\n"
 187 "mode is an optional string that specifies the mode in which the file\n"
 188 "is opened. It defaults to 'r' which means open for reading in text\n"
 189 "mode.  Other common values are 'w' for writing (truncating the file if\n"
 190 "it already exists), and 'a' for appending (which on some Unix systems,\n"
 191 "means that all writes append to the end of the file regardless of the\n"
 192 "current seek position). In text mode, if encoding is not specified the\n"
 193 "encoding used is platform dependent. (For reading and writing raw\n"
 194 "bytes use binary mode and leave encoding unspecified.) The available\n"
 195 "modes are:\n"
 196 "\n"
 197 "========= ===============================================================\n"
 198 "Character Meaning\n"
 199 "--------- ---------------------------------------------------------------\n"
 200 "'r'       open for reading (default)\n"
 201 "'w'       open for writing, truncating the file first\n"
 202 "'a'       open for writing, appending to the end of the file if it exists\n"
 203 "'b'       binary mode\n"
 204 "'t'       text mode (default)\n"
 205 "'+'       open a disk file for updating (reading and writing)\n"
 206 "'U'       universal newline mode (for backwards compatibility; unneeded\n"
 207 "          for new code)\n"
 208 "========= ===============================================================\n"
 209 "\n"
 210 "The default mode is 'rt' (open for reading text). For binary random\n"
 211 "access, the mode 'w+b' opens and truncates the file to 0 bytes, while\n"
 212 "'r+b' opens the file without truncation.\n"
 213 "\n"
 214 "Python distinguishes between files opened in binary and text modes,\n"
 215 "even when the underlying operating system doesn't. Files opened in\n"
 216 "binary mode (appending 'b' to the mode argument) return contents as\n"
 217 "bytes objects without any decoding. In text mode (the default, or when\n"
 218 "'t' is appended to the mode argument), the contents of the file are\n"
 219 "returned as strings, the bytes having been first decoded using a\n"
 220 "platform-dependent encoding or using the specified encoding if given.\n"
 221 "\n"
 222 "buffering is an optional integer used to set the buffering policy. By\n"
 223 "default full buffering is on. Pass 0 to switch buffering off (only\n"
 224 "allowed in binary mode), 1 to set line buffering, and an integer > 1\n"
 225 "for full buffering.\n"
 226 "\n"
 227 "encoding is the name of the encoding used to decode or encode the\n"
 228 "file. This should only be used in text mode. The default encoding is\n"
 229 "platform dependent, but any encoding supported by Python can be\n"
 230 "passed.  See the codecs module for the list of supported encodings.\n"
 231 "\n"
 232 "errors is an optional string that specifies how encoding errors are to\n"
 233 "be handled---this argument should not be used in binary mode. Pass\n"
 234 "'strict' to raise a ValueError exception if there is an encoding error\n"
 235 "(the default of None has the same effect), or pass 'ignore' to ignore\n"
 236 "errors. (Note that ignoring encoding errors can lead to data loss.)\n"
 237 "See the documentation for codecs.register for a list of the permitted\n"
 238 "encoding error strings.\n"
 239 "\n"
 240 "newline controls how universal newlines works (it only applies to text\n"
 241 "mode). It can be None, '', '\\n', '\\r', and '\\r\\n'.  It works as\n"
 242 "follows:\n"
 243 "\n"
 244 "* On input, if newline is None, universal newlines mode is\n"
 245 "  enabled. Lines in the input can end in '\\n', '\\r', or '\\r\\n', and\n"
 246 "  these are translated into '\\n' before being returned to the\n"
 247 "  caller. If it is '', universal newline mode is enabled, but line\n"
 248 "  endings are returned to the caller untranslated. If it has any of\n"
 249 "  the other legal values, input lines are only terminated by the given\n"
 250 "  string, and the line ending is returned to the caller untranslated.\n"
 251 "\n"
 252 "* On output, if newline is None, any '\\n' characters written are\n"
 253 "  translated to the system default line separator, os.linesep. If\n"
 254 "  newline is '', no translation takes place. If newline is any of the\n"
 255 "  other legal values, any '\\n' characters written are translated to\n"
 256 "  the given string.\n"
 257 "\n"
 258 "If closefd is False, the underlying file descriptor will be kept open\n"
 259 "when the file is closed. This does not work when a file name is given\n"
 260 "and must be True in that case.\n"
 261 "\n"
 262 "open() returns a file object whose type depends on the mode, and\n"
 263 "through which the standard file operations such as reading and writing\n"
 264 "are performed. When open() is used to open a file in a text mode ('w',\n"
 265 "'r', 'wt', 'rt', etc.), it returns a TextIOWrapper. When used to open\n"
 266 "a file in a binary mode, the returned class varies: in read binary\n"
 267 "mode, it returns a BufferedReader; in write binary and append binary\n"
 268 "modes, it returns a BufferedWriter, and in read/write mode, it returns\n"
 269 "a BufferedRandom.\n"
 270 "\n"
 271 "It is also possible to use a string or bytearray as a file for both\n"
 272 "reading and writing. For strings StringIO can be used like a file\n"
 273 "opened in a text mode, and for bytes a BytesIO can be used like a file\n"
 274 "opened in a binary mode.\n"
 275     );
 276
 277 static PyObject *
 278 io_open(PyObject *self, PyObject *args, PyObject *kwds)
 279 {
 280     char *kwlist[] = {"file", "mode", "buffering",
 281                       "encoding", "errors", "newline",
 282                       "closefd", NULL};
 283     PyObject *file;
 284     char *mode = "r";
 285     int buffering = -1, closefd = 1;
 286     char *encoding = NULL, *errors = NULL, *newline = NULL;
 287     unsigned i;
 288
 289     int reading = 0, writing = 0, appending = 0, updating = 0;
 290     int text = 0, binary = 0, universal = 0;
 291
 292     char rawmode[5], *m;
 293     int line_buffering, isatty;
 294
 295     PyObject *raw, *modeobj = NULL, *buffer = NULL, *wrapper = NULL;
 296
 297     if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|sizzzi:open", kwlist,
 298                                      &file, &mode, &buffering,
 299                                      &encoding, &errors, &newline,
 300                                      &closefd)) {
 301         return NULL;
 302     }
 303
 304     if (!PyUnicode_Check(file) &&
 305         !PyBytes_Check(file) &&
 306         !PyNumber_Check(file)) {
 307         PyObject *repr = PyObject_Repr(file);
 308         if (repr != NULL) {
 309             PyErr_Format(PyExc_TypeError, "invalid file: %s",
 310                          PyString_AS_STRING(repr));
 311             Py_DECREF(repr);
 312         }
 313         return NULL;
 314     }
 315
 316     /* Decode mode */
 317     for (i = 0; i < strlen(mode); i++) {
 318         char c = mode[i];
 319
 320         switch (c) {
 321         case 'r':
 322             reading = 1;
 323             break;
 324         case 'w':
 325             writing = 1;
 326             break;
 327         case 'a':
 328             appending = 1;
 329             break;
 330         case '+':
 331             updating = 1;
 332             break;
 333         case 't':
 334             text = 1;
 335             break;
 336         case 'b':
 337             binary = 1;
 338             break;
 339         case 'U':
 340             universal = 1;
 341             reading = 1;
 342             break;
 343         default:
 344             goto invalid_mode;
 345         }
 346
 347         /* c must not be duplicated */
 348         if (strchr(mode+i+1, c)) {
 349           invalid_mode:
 350             PyErr_Format(PyExc_ValueError, "invalid mode: '%s'", mode);
 351             return NULL;
 352         }
 353
 354     }
 355
 356     m = rawmode;
 357     if (reading)   *(m++) = 'r';
 358     if (writing)   *(m++) = 'w';
 359     if (appending) *(m++) = 'a';
 360     if (updating)  *(m++) = '+';
 361     *m = '\0';
 362
 363     /* Parameters validation */
 364     if (universal) {
 365         if (writing || appending) {
 366             PyErr_SetString(PyExc_ValueError,
 367                             "can't use U and writing mode at once");
 368             return NULL;
 369         }
 370         reading = 1;
 371     }
 372
 373     if (text && binary) {
 374         PyErr_SetString(PyExc_ValueError,
 375                         "can't have text and binary mode at once");
 376         return NULL;
 377     }
 378
 379     if (reading + writing + appending > 1) {
 380         PyErr_SetString(PyExc_ValueError,
 381                         "must have exactly one of read/write/append mode");
 382         return NULL;
 383     }
 384
 385     if (binary && encoding != NULL) {
 386         PyErr_SetString(PyExc_ValueError,
 387                         "binary mode doesn't take an encoding argument");
 388         return NULL;
 389     }
 390
 391     if (binary && errors != NULL) {
 392         PyErr_SetString(PyExc_ValueError,
 393                         "binary mode doesn't take an errors argument");
 394         return NULL;
 395     }
 396
 397     if (binary && newline != NULL) {
 398         PyErr_SetString(PyExc_ValueError,
 399                         "binary mode doesn't take a newline argument");
 400         return NULL;
 401     }
 402
 403     /* Create the Raw file stream */
 404     raw = PyObject_CallFunction((PyObject *)&PyFileIO_Type,
 405                                 "Osi", file, rawmode, closefd);
 406     if (raw == NULL)
 407         return NULL;
 408
 409     modeobj = PyUnicode_FromString(mode);
 410     if (modeobj == NULL)
 411         goto error;
 412
 413     /* buffering */
 414     {
 415         PyObject *res = PyObject_CallMethod(raw, "isatty", NULL);
 416         if (res == NULL)
 417             goto error;
 418         isatty = PyLong_AsLong(res);
 419         Py_DECREF(res);
 420         if (isatty == -1 && PyErr_Occurred())
 421             goto error;
 422     }
 423
 424     if (buffering == 1 || (buffering < 0 && isatty)) {
 425         buffering = -1;
 426         line_buffering = 1;
 427     }
 428     else
 429         line_buffering = 0;
 430
 431     if (buffering < 0) {
 432         buffering = DEFAULT_BUFFER_SIZE;
 433 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
 434         {
 435             struct stat st;
 436             long fileno;
 437             PyObject *res = PyObject_CallMethod(raw, "fileno", NULL);
 438             if (res == NULL)
 439                 goto error;
 440
 441             fileno = PyInt_AsLong(res);
 442             Py_DECREF(res);
 443             if (fileno == -1 && PyErr_Occurred())
 444                 goto error;
 445
 446             if (fstat(fileno, &st) >= 0)
 447                 buffering = st.st_blksize;
 448         }
 449 #endif
 450     }
 451     if (buffering < 0) {
 452         PyErr_SetString(PyExc_ValueError,
 453                         "invalid buffering size");
 454         goto error;
 455     }
 456
 457     /* if not buffering, returns the raw file object */
 458     if (buffering == 0) {
 459         if (!binary) {
 460             PyErr_SetString(PyExc_ValueError,
 461                             "can't have unbuffered text I/O");
 462             goto error;
 463         }
 464
 465         Py_DECREF(modeobj);
 466         return raw;
 467     }
 468
 469     /* wraps into a buffered file */
 470     {
 471         PyObject *Buffered_class;
 472
 473         if (updating)
 474             Buffered_class = (PyObject *)&PyBufferedRandom_Type;
 475         else if (writing || appending)
 476             Buffered_class = (PyObject *)&PyBufferedWriter_Type;
 477         else if (reading)
 478             Buffered_class = (PyObject *)&PyBufferedReader_Type;
 479         else {
 480             PyErr_Format(PyExc_ValueError,
 481                          "unknown mode: '%s'", mode);
 482             goto error;
 483         }
 484
 485         buffer = PyObject_CallFunction(Buffered_class, "Oi", raw, buffering);
 486     }
 487     Py_CLEAR(raw);
 488     if (buffer == NULL)
 489         goto error;
 490
 491
 492     /* if binary, returns the buffered file */
 493     if (binary) {
 494         Py_DECREF(modeobj);
 495         return buffer;
 496     }
 497
 498     /* wraps into a TextIOWrapper */
 499     wrapper = PyObject_CallFunction((PyObject *)&PyTextIOWrapper_Type,
 500                                     "Osssi",
 501                                     buffer,
 502                                     encoding, errors, newline,
 503                                     line_buffering);
 504     Py_CLEAR(buffer);
 505     if (wrapper == NULL)
 506         goto error;
 507
 508     if (PyObject_SetAttrString(wrapper, "mode", modeobj) < 0)
 509         goto error;
 510     Py_DECREF(modeobj);
 511     return wrapper;
 512
 513   error:
 514     Py_XDECREF(raw);
 515     Py_XDECREF(modeobj);
 516     Py_XDECREF(buffer);
 517     Py_XDECREF(wrapper);
 518     return NULL;
 519 }
 520 \f
 521 /*
 522  * Private helpers for the io module.
 523  */
 524
 525 Py_off_t
 526 PyNumber_AsOff_t(PyObject *item, PyObject *err)
 527 {
 528     Py_off_t result;
 529     PyObject *runerr;
 530     PyObject *value = PyNumber_Index(item);
 531     if (value == NULL)
 532         return -1;
 533
 534     if (PyInt_Check(value)) {
 535         /* We assume a long always fits in a Py_off_t... */
 536         result = (Py_off_t) PyInt_AS_LONG(value);
 537         goto finish;
 538     }
 539
 540     /* We're done if PyLong_AsSsize_t() returns without error. */
 541     result = PyLong_AsOff_t(value);
 542     if (result != -1 || !(runerr = PyErr_Occurred()))
 543         goto finish;
 544
 545     /* Error handling code -- only manage OverflowError differently */
 546     if (!PyErr_GivenExceptionMatches(runerr, PyExc_OverflowError))
 547         goto finish;
 548
 549     PyErr_Clear();
 550     /* If no error-handling desired then the default clipping
 551        is sufficient.
 552      */
 553     if (!err) {
 554         assert(PyLong_Check(value));
 555         /* Whether or not it is less than or equal to
 556            zero is determined by the sign of ob_size
 557         */
 558         if (_PyLong_Sign(value) < 0)
 559             result = PY_OFF_T_MIN;
 560         else
 561             result = PY_OFF_T_MAX;
 562     }
 563     else {
 564         /* Otherwise replace the error with caller's error object. */
 565         PyErr_Format(err,
 566                      "cannot fit '%.200s' into an offset-sized integer",
 567                      item->ob_type->tp_name);
 568     }
 569
 570  finish:
 571     Py_DECREF(value);
 572     return result;
 573 }
 574
 575
 576 /*
 577  * Module definition
 578  */
 579
 580 PyObject *_PyIO_os_module = NULL;
 581 PyObject *_PyIO_locale_module = NULL;
 582 PyObject *_PyIO_unsupported_operation = NULL;
 583
 584 static PyMethodDef module_methods[] = {
 585     {"open", (PyCFunction)io_open, METH_VARARGS|METH_KEYWORDS, open_doc},
 586     {NULL, NULL}
 587 };
 588
 589 PyMODINIT_FUNC
 590 init_io(void)
 591 {
 592     PyObject *m = Py_InitModule4("_io", module_methods,
 593                                  module_doc, NULL, PYTHON_API_VERSION);
 594     if (m == NULL)
 595         return;
 596
 597     /* put os in the module state */
 598     _PyIO_os_module = PyImport_ImportModule("os");
 599     if (_PyIO_os_module == NULL)
 600         goto fail;
 601
 602 #define ADD_TYPE(type, name) \
 603     if (PyType_Ready(type) < 0) \
 604         goto fail; \
 605     Py_INCREF(type); \
 606     if (PyModule_AddObject(m, name, (PyObject *)type) < 0) {  \
 607         Py_DECREF(type); \
 608         goto fail; \
 609     }
 610
 611     /* DEFAULT_BUFFER_SIZE */
 612     if (PyModule_AddIntMacro(m, DEFAULT_BUFFER_SIZE) < 0)
 613         goto fail;
 614
 615     /* UnsupportedOperation inherits from ValueError and IOError */
 616     _PyIO_unsupported_operation = PyObject_CallFunction(
 617         (PyObject *)&PyType_Type, "s(OO){}",
 618         "UnsupportedOperation", PyExc_ValueError, PyExc_IOError);
 619     if (_PyIO_unsupported_operation == NULL)
 620         goto fail;
 621     Py_INCREF(_PyIO_unsupported_operation);
 622     if (PyModule_AddObject(m, "UnsupportedOperation",
 623                            _PyIO_unsupported_operation) < 0)
 624         goto fail;
 625
 626     /* BlockingIOError */
 627     _PyExc_BlockingIOError.tp_base = (PyTypeObject *) PyExc_IOError;
 628     ADD_TYPE(&_PyExc_BlockingIOError, "BlockingIOError");
 629
 630     /* Concrete base types of the IO ABCs.
 631        (the ABCs themselves are declared through inheritance in io.py)
 632     */
 633     ADD_TYPE(&PyIOBase_Type, "_IOBase");
 634     ADD_TYPE(&PyRawIOBase_Type, "_RawIOBase");
 635     ADD_TYPE(&PyBufferedIOBase_Type, "_BufferedIOBase");
 636     ADD_TYPE(&PyTextIOBase_Type, "_TextIOBase");
 637
 638     /* Implementation of concrete IO objects. */
 639     /* FileIO */
 640     PyFileIO_Type.tp_base = &PyRawIOBase_Type;
 641     ADD_TYPE(&PyFileIO_Type, "FileIO");
 642
 643     /* BytesIO */
 644     PyBytesIO_Type.tp_base = &PyBufferedIOBase_Type;
 645     ADD_TYPE(&PyBytesIO_Type, "BytesIO");
 646
 647     /* StringIO */
 648     PyStringIO_Type.tp_base = &PyTextIOBase_Type;
 649     ADD_TYPE(&PyStringIO_Type, "StringIO");
 650
 651     /* BufferedReader */
 652     PyBufferedReader_Type.tp_base = &PyBufferedIOBase_Type;
 653     ADD_TYPE(&PyBufferedReader_Type, "BufferedReader");
 654
 655     /* BufferedWriter */
 656     PyBufferedWriter_Type.tp_base = &PyBufferedIOBase_Type;
 657     ADD_TYPE(&PyBufferedWriter_Type, "BufferedWriter");
 658
 659     /* BufferedRWPair */
 660     PyBufferedRWPair_Type.tp_base = &PyBufferedIOBase_Type;
 661     ADD_TYPE(&PyBufferedRWPair_Type, "BufferedRWPair");
 662
 663     /* BufferedRandom */
 664     PyBufferedRandom_Type.tp_base = &PyBufferedIOBase_Type;
 665     ADD_TYPE(&PyBufferedRandom_Type, "BufferedRandom");
 666
 667     /* TextIOWrapper */
 668     PyTextIOWrapper_Type.tp_base = &PyTextIOBase_Type;
 669     ADD_TYPE(&PyTextIOWrapper_Type, "TextIOWrapper");
 670
 671     /* IncrementalNewlineDecoder */
 672     ADD_TYPE(&PyIncrementalNewlineDecoder_Type, "IncrementalNewlineDecoder");
 673
 674     /* Interned strings */
 675     if (!(_PyIO_str_close = PyString_InternFromString("close")))
 676         goto fail;
 677     if (!(_PyIO_str_closed = PyString_InternFromString("closed")))
 678         goto fail;
 679     if (!(_PyIO_str_decode = PyString_InternFromString("decode")))
 680         goto fail;
 681     if (!(_PyIO_str_encode = PyString_InternFromString("encode")))
 682         goto fail;
 683     if (!(_PyIO_str_fileno = PyString_InternFromString("fileno")))
 684         goto fail;
 685     if (!(_PyIO_str_flush = PyString_InternFromString("flush")))
 686         goto fail;
 687     if (!(_PyIO_str_getstate = PyString_InternFromString("getstate")))
 688         goto fail;
 689     if (!(_PyIO_str_isatty = PyString_InternFromString("isatty")))
 690         goto fail;
 691     if (!(_PyIO_str_newlines = PyString_InternFromString("newlines")))
 692         goto fail;
 693     if (!(_PyIO_str_nl = PyString_InternFromString("\n")))
 694         goto fail;
 695     if (!(_PyIO_str_read = PyString_InternFromString("read")))
 696         goto fail;
 697     if (!(_PyIO_str_read1 = PyString_InternFromString("read1")))
 698         goto fail;
 699     if (!(_PyIO_str_readable = PyString_InternFromString("readable")))
 700         goto fail;
 701     if (!(_PyIO_str_readinto = PyString_InternFromString("readinto")))
 702         goto fail;
 703     if (!(_PyIO_str_readline = PyString_InternFromString("readline")))
 704         goto fail;
 705     if (!(_PyIO_str_reset = PyString_InternFromString("reset")))
 706         goto fail;
 707     if (!(_PyIO_str_seek = PyString_InternFromString("seek")))
 708         goto fail;
 709     if (!(_PyIO_str_seekable = PyString_InternFromString("seekable")))
 710         goto fail;
 711     if (!(_PyIO_str_setstate = PyString_InternFromString("setstate")))
 712         goto fail;
 713     if (!(_PyIO_str_tell = PyString_InternFromString("tell")))
 714         goto fail;
 715     if (!(_PyIO_str_truncate = PyString_InternFromString("truncate")))
 716         goto fail;
 717     if (!(_PyIO_str_write = PyString_InternFromString("write")))
 718         goto fail;
 719     if (!(_PyIO_str_writable = PyString_InternFromString("writable")))
 720         goto fail;
 721
 722     if (!(_PyIO_empty_str = PyUnicode_FromStringAndSize(NULL, 0)))
 723         goto fail;
 724     if (!(_PyIO_empty_bytes = PyBytes_FromStringAndSize(NULL, 0)))
 725         goto fail;
 726     if (!(_PyIO_zero = PyLong_FromLong(0L)))
 727         goto fail;
 728
 729     return;
 730
 731   fail:
 732     Py_CLEAR(_PyIO_os_module);
 733     Py_CLEAR(_PyIO_unsupported_operation);
 734     Py_DECREF(m);
 735 }