summaryrefslogtreecommitdiffstats
path: root/Objects/fileobject.c
blob: ab67cd23cef3b3e98ceab7a308cb50e968e8dd8f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
/* File object implementation (what's left of it -- see io.py) */

#define PY_SSIZE_T_CLEAN
#include "Python.h"
#include "pycore_call.h"          // _PyObject_CallNoArgs()
#include "pycore_runtime.h"       // _PyRuntime

#if defined(HAVE_GETC_UNLOCKED) && !defined(_Py_MEMORY_SANITIZER)
/* clang MemorySanitizer doesn't yet understand getc_unlocked. */
#define GETC(f) getc_unlocked(f)
#define FLOCKFILE(f) flockfile(f)
#define FUNLOCKFILE(f) funlockfile(f)
#else
#define GETC(f) getc(f)
#define FLOCKFILE(f)
#define FUNLOCKFILE(f)
#endif

/* Newline flags */
#define NEWLINE_UNKNOWN 0       /* No newline seen, yet */
#define NEWLINE_CR 1            /* \r newline seen */
#define NEWLINE_LF 2            /* \n newline seen */
#define NEWLINE_CRLF 4          /* \r\n newline seen */

#ifdef __cplusplus
extern "C" {
#endif

/* External C interface */

PyObject *
PyFile_FromFd(int fd, const char *name, const char *mode, int buffering, const char *encoding,
              const char *errors, const char *newline, int closefd)
{
    PyObject *open, *stream;

    /* import _io in case we are being used to open io.py */
    open = _PyImport_GetModuleAttrString("_io", "open");
    if (open == NULL)
        return NULL;
    stream = PyObject_CallFunction(open, "isisssO", fd, mode,
                                  buffering, encoding, errors,
                                  newline, closefd ? Py_True : Py_False);
    Py_DECREF(open);
    if (stream == NULL)
        return NULL;
    /* ignore name attribute because the name attribute of _BufferedIOMixin
       and TextIOWrapper is read only */
    return stream;
}

PyObject *
PyFile_GetLine(PyObject *f, int n)
{
    PyObject *result;

    if (f == NULL) {
        PyErr_BadInternalCall();
        return NULL;
    }

    if (n <= 0) {
        result = PyObject_CallMethodNoArgs(f, &_Py_ID(readline));
    }
    else {
        result = _PyObject_CallMethod(f, &_Py_ID(readline), "i", n);
    }
    if (result != NULL && !PyBytes_Check(result) &&
        !PyUnicode_Check(result)) {
        Py_DECREF(result);
        result = NULL;
        PyErr_SetString(PyExc_TypeError,
                   "object.readline() returned non-string");
    }

    if (n < 0 && result != NULL && PyBytes_Check(result)) {
        const char *s = PyBytes_AS_STRING(result);
        Py_ssize_t len = PyBytes_GET_SIZE(result);
        if (len == 0) {
            Py_DECREF(result);
            result = NULL;
            PyErr_SetString(PyExc_EOFError,
                            "EOF when reading a line");
        }
        else if (s[len-1] == '\n') {
            if (Py_REFCNT(result) == 1)
                _PyBytes_Resize(&result, len-1);
            else {
                PyObject *v;
                v = PyBytes_FromStringAndSize(s, len-1);
                Py_DECREF(result);
                result = v;
            }
        }
    }
    if (n < 0 && result != NULL && PyUnicode_Check(result)) {
        Py_ssize_t len = PyUnicode_GET_LENGTH(result);
        if (len == 0) {
            Py_DECREF(result);
            result = NULL;
            PyErr_SetString(PyExc_EOFError,
                            "EOF when reading a line");
        }
        else if (PyUnicode_READ_CHAR(result, len-1) == '\n') {
            PyObject *v;
            v = PyUnicode_Substring(result, 0, len-1);
            Py_DECREF(result);
            result = v;
        }
    }
    return result;
}

/* Interfaces to write objects/strings to file-like objects */

int
PyFile_WriteObject(PyObject *v, PyObject *f, int flags)
{
    PyObject *writer, *value, *result;

    if (f == NULL) {
        PyErr_SetString(PyExc_TypeError, "writeobject with NULL file");
        return -1;
    }
    writer = PyObject_GetAttr(f, &_Py_ID(write));
    if (writer == NULL)
        return -1;
    if (flags & Py_PRINT_RAW) {
        value = PyObject_Str(v);
    }
    else
        value = PyObject_Repr(v);
    if (value == NULL) {
        Py_DECREF(writer);
        return -1;
    }
    result = PyObject_CallOneArg(writer, value);
    Py_DECREF(value);
    Py_DECREF(writer);
    if (result == NULL)
        return -1;
    Py_DECREF(result);
    return 0;
}

int
PyFile_WriteString(const char *s, PyObject *f)
{
    if (f == NULL) {
        /* Should be caused by a pre-existing error */
        if (!PyErr_Occurred())
            PyErr_SetString(PyExc_SystemError,
                            "null file for PyFile_WriteString");
        return -1;
    }
    else if (!PyErr_Occurred()) {
        PyObject *v = PyUnicode_FromString(s);
        int err;
        if (v == NULL)
            return -1;
        err = PyFile_WriteObject(v, f, Py_PRINT_RAW);
        Py_DECREF(v);
        return err;
    }
    else
        return -1;
}

/* Try to get a file-descriptor from a Python object.  If the object
   is an integer, its value is returned.  If not, the
   object's fileno() method is called if it exists; the method must return
   an integer, which is returned as the file descriptor value.
   -1 is returned on failure.
*/

int
PyObject_AsFileDescriptor(PyObject *o)
{
    int fd;
    PyObject *meth;

    if (PyLong_Check(o)) {
        fd = _PyLong_AsInt(o);
    }
    else if (_PyObject_LookupAttr(o, &_Py_ID(fileno), &meth) < 0) {
        return -1;
    }
    else if (meth != NULL) {
        PyObject *fno = _PyObject_CallNoArgs(meth);
        Py_DECREF(meth);
        if (fno == NULL)
            return -1;

        if (PyLong_Check(fno)) {
            fd = _PyLong_AsInt(fno);
            Py_DECREF(fno);
        }
        else {
            PyErr_SetString(PyExc_TypeError,
                            "fileno() returned a non-integer");
            Py_DECREF(fno);
            return -1;
        }
    }
    else {
        PyErr_SetString(PyExc_TypeError,
                        "argument must be an int, or have a fileno() method.");
        return -1;
    }

    if (fd == -1 && PyErr_Occurred())
        return -1;
    if (fd < 0) {
        PyErr_Format(PyExc_ValueError,
                     "file descriptor cannot be a negative integer (%i)",
                     fd);
        return -1;
    }
    return fd;
}

int
_PyLong_FileDescriptor_Converter(PyObject *o, void *ptr)
{
    int fd = PyObject_AsFileDescriptor(o);
    if (fd == -1) {
        return 0;
    }
    *(int *)ptr = fd;
    return 1;
}

char *
_Py_UniversalNewlineFgetsWithSize(char *buf, int n, FILE *stream, PyObject *fobj, size_t* size)
{
    char *p = buf;
    int c;

    if (fobj) {
        errno = ENXIO;          /* What can you do... */
        return NULL;
    }
    FLOCKFILE(stream);
    while (--n > 0 && (c = GETC(stream)) != EOF ) {
        if (c == '\r') {
            // A \r is translated into a \n, and we skip an adjacent \n, if any.
            c = GETC(stream);
            if (c != '\n') {
                ungetc(c, stream);
                c = '\n';
            }
        }
        *p++ = c;
        if (c == '\n') {
            break;
        }
    }
    FUNLOCKFILE(stream);
    *p = '\0';
    if (p == buf) {
        return NULL;
    }
    *size = p - buf;
    return buf;
}

/*
** Py_UniversalNewlineFgets is an fgets variation that understands
** all of \r, \n and \r\n conventions.
** The stream should be opened in binary mode.
** The fobj parameter exists solely for legacy reasons and must be NULL.
** Note that we need no error handling: fgets() treats error and eof
** identically.
*/

char *
Py_UniversalNewlineFgets(char *buf, int n, FILE *stream, PyObject *fobj) {
    size_t size;
    return _Py_UniversalNewlineFgetsWithSize(buf, n, stream, fobj, &size);
}

/* **************************** std printer ****************************
 * The stdprinter is used during the boot strapping phase as a preliminary
 * file like object for sys.stderr.
 */

typedef struct {
    PyObject_HEAD
    int fd;
} PyStdPrinter_Object;

PyObject *
PyFile_NewStdPrinter(int fd)
{
    PyStdPrinter_Object *self;

    if (fd != fileno(stdout) && fd != fileno(stderr)) {
        /* not enough infrastructure for PyErr_BadInternalCall() */
        return NULL;
    }

    self = PyObject_New(PyStdPrinter_Object,
                        &PyStdPrinter_Type);
    if (self != NULL) {
        self->fd = fd;
    }
    return (PyObject*)self;
}

static PyObject *
stdprinter_write(PyStdPrinter_Object *self, PyObject *args)
{
    PyObject *unicode;
    PyObject *bytes = NULL;
    const char *str;
    Py_ssize_t n;
    int err;

    /* The function can clear the current exception */
    assert(!PyErr_Occurred());

    if (self->fd < 0) {
        /* fd might be invalid on Windows
         * I can't raise an exception here. It may lead to an
         * unlimited recursion in the case stderr is invalid.
         */
        Py_RETURN_NONE;
    }

    if (!PyArg_ParseTuple(args, "U", &unicode)) {
        return NULL;
    }

    /* Encode Unicode to UTF-8/backslashreplace */
    str = PyUnicode_AsUTF8AndSize(unicode, &n);
    if (str == NULL) {
        PyErr_Clear();
        bytes = _PyUnicode_AsUTF8String(unicode, "backslashreplace");
        if (bytes == NULL)
            return NULL;
        str = PyBytes_AS_STRING(bytes);
        n = PyBytes_GET_SIZE(bytes);
    }

    n = _Py_write(self->fd, str, n);
    /* save errno, it can be modified indirectly by Py_XDECREF() */
    err = errno;

    Py_XDECREF(bytes);

    if (n == -1) {
        if (err == EAGAIN) {
            PyErr_Clear();
            Py_RETURN_NONE;
        }
        return NULL;
    }

    return PyLong_FromSsize_t(n);
}

static PyObject *
stdprinter_fileno(PyStdPrinter_Object *self, PyObject *Py_UNUSED(ignored))
{
    return PyLong_FromLong((long) self->fd);
}

static PyObject *
stdprinter_repr(PyStdPrinter_Object *self)
{
    return PyUnicode_FromFormat("<stdprinter(fd=%d) object at %p>",
                                self->fd, self);
}

static PyObject *
stdprinter_noop(PyStdPrinter_Object *self, PyObject *Py_UNUSED(ignored))
{
    Py_RETURN_NONE;
}

static PyObject *
stdprinter_isatty(PyStdPrinter_Object *self, PyObject *Py_UNUSED(ignored))
{
    long res;
    if (self->fd < 0) {
        Py_RETURN_FALSE;
    }

    Py_BEGIN_ALLOW_THREADS
    res = isatty(self->fd);
    Py_END_ALLOW_THREADS

    return PyBool_FromLong(res);
}

static PyMethodDef stdprinter_methods[] = {
    {"close",           (PyCFunction)stdprinter_noop, METH_NOARGS, ""},
    {"flush",           (PyCFunction)stdprinter_noop, METH_NOARGS, ""},
    {"fileno",          (PyCFunction)stdprinter_fileno, METH_NOARGS, ""},
    {"isatty",          (PyCFunction)stdprinter_isatty, METH_NOARGS, ""},
    {"write",           (PyCFunction)stdprinter_write, METH_VARARGS, ""},
    {NULL,              NULL}  /*sentinel */
};

static PyObject *
get_closed(PyStdPrinter_Object *self, void *closure)
{
    Py_RETURN_FALSE;
}

static PyObject *
get_mode(PyStdPrinter_Object *self, void *closure)
{
    return PyUnicode_FromString("w");
}

static PyObject *
get_encoding(PyStdPrinter_Object *self, void *closure)
{
    Py_RETURN_NONE;
}

static PyGetSetDef stdprinter_getsetlist[] = {
    {"closed", (getter)get_closed, NULL, "True if the file is closed"},
    {"encoding", (getter)get_encoding, NULL, "Encoding of the file"},
    {"mode", (getter)get_mode, NULL, "String giving the file mode"},
    {0},
};

PyTypeObject PyStdPrinter_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "stderrprinter",                            /* tp_name */
    sizeof(PyStdPrinter_Object),                /* tp_basicsize */
    0,                                          /* tp_itemsize */
    /* methods */
    0,                                          /* tp_dealloc */
    0,                                          /* tp_vectorcall_offset */
    0,                                          /* tp_getattr */
    0,                                          /* tp_setattr */
    0,                                          /* tp_as_async */
    (reprfunc)stdprinter_repr,                  /* 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_DISALLOW_INSTANTIATION, /* tp_flags */
    0,                                          /* tp_doc */
    0,                                          /* tp_traverse */
    0,                                          /* tp_clear */
    0,                                          /* tp_richcompare */
    0,                                          /* tp_weaklistoffset */
    0,                                          /* tp_iter */
    0,                                          /* tp_iternext */
    stdprinter_methods,                         /* tp_methods */
    0,                                          /* tp_members */
    stdprinter_getsetlist,                      /* tp_getset */
    0,                                          /* tp_base */
    0,                                          /* tp_dict */
    0,                                          /* tp_descr_get */
    0,                                          /* tp_descr_set */
    0,                                          /* tp_dictoffset */
    0,                                          /* tp_init */
    PyType_GenericAlloc,                        /* tp_alloc */
    0,                                          /* tp_new */
    PyObject_Del,                               /* tp_free */
};


/* ************************** open_code hook ***************************
 * The open_code hook allows embedders to override the method used to
 * open files that are going to be used by the runtime to execute code
 */

int
PyFile_SetOpenCodeHook(Py_OpenCodeHookFunction hook, void *userData) {
    if (Py_IsInitialized() &&
        PySys_Audit("setopencodehook", NULL) < 0) {
        return -1;
    }

    if (_PyRuntime.open_code_hook) {
        if (Py_IsInitialized()) {
            PyErr_SetString(PyExc_SystemError,
                "failed to change existing open_code hook");
        }
        return -1;
    }

    _PyRuntime.open_code_hook = hook;
    _PyRuntime.open_code_userdata = userData;
    return 0;
}

PyObject *
PyFile_OpenCodeObject(PyObject *path)
{
    PyObject *f = NULL;

    if (!PyUnicode_Check(path)) {
        PyErr_Format(PyExc_TypeError, "'path' must be 'str', not '%.200s'",
                     Py_TYPE(path)->tp_name);
        return NULL;
    }

    Py_OpenCodeHookFunction hook = _PyRuntime.open_code_hook;
    if (hook) {
        f = hook(path, _PyRuntime.open_code_userdata);
    } else {
        PyObject *open = _PyImport_GetModuleAttrString("_io", "open");
        if (open) {
            f = PyObject_CallFunction(open, "Os", path, "rb");
            Py_DECREF(open);
        }
    }

    return f;
}

PyObject *
PyFile_OpenCode(const char *utf8path)
{
    PyObject *pathobj = PyUnicode_FromString(utf8path);
    PyObject *f;
    if (!pathobj) {
        return NULL;
    }
    f = PyFile_OpenCodeObject(pathobj);
    Py_DECREF(pathobj);
    return f;
}


#ifdef __cplusplus
}
#endif