1 /* File object implementation (what's left of it -- see io.py) */
2
3 #define PY_SSIZE_T_CLEAN
4 #include "Python.h"
5 #include "pycore_runtime.h" // _PyRuntime
6
7 #if defined(HAVE_GETC_UNLOCKED) && !defined(_Py_MEMORY_SANITIZER)
8 /* clang MemorySanitizer doesn't yet understand getc_unlocked. */
9 #define GETC(f) getc_unlocked(f)
10 #define FLOCKFILE(f) flockfile(f)
11 #define FUNLOCKFILE(f) funlockfile(f)
12 #else
13 #define GETC(f) getc(f)
14 #define FLOCKFILE(f)
15 #define FUNLOCKFILE(f)
16 #endif
17
18 /* Newline flags */
19 #define NEWLINE_UNKNOWN 0 /* No newline seen, yet */
20 #define NEWLINE_CR 1 /* \r newline seen */
21 #define NEWLINE_LF 2 /* \n newline seen */
22 #define NEWLINE_CRLF 4 /* \r\n newline seen */
23
24 #ifdef __cplusplus
25 extern "C" {
26 #endif
27
28 _Py_IDENTIFIER(open);
29
30 /* External C interface */
31
32 PyObject *
PyFile_FromFd(int fd,const char * name,const char * mode,int buffering,const char * encoding,const char * errors,const char * newline,int closefd)33 PyFile_FromFd(int fd, const char *name, const char *mode, int buffering, const char *encoding,
34 const char *errors, const char *newline, int closefd)
35 {
36 PyObject *io, *stream;
37
38 /* import _io in case we are being used to open io.py */
39 io = PyImport_ImportModule("_io");
40 if (io == NULL)
41 return NULL;
42 stream = _PyObject_CallMethodId(io, &PyId_open, "isisssO", fd, mode,
43 buffering, encoding, errors,
44 newline, closefd ? Py_True : Py_False);
45 Py_DECREF(io);
46 if (stream == NULL)
47 return NULL;
48 /* ignore name attribute because the name attribute of _BufferedIOMixin
49 and TextIOWrapper is read only */
50 return stream;
51 }
52
53 PyObject *
PyFile_GetLine(PyObject * f,int n)54 PyFile_GetLine(PyObject *f, int n)
55 {
56 _Py_IDENTIFIER(readline);
57 PyObject *result;
58
59 if (f == NULL) {
60 PyErr_BadInternalCall();
61 return NULL;
62 }
63
64 if (n <= 0) {
65 result = _PyObject_CallMethodIdNoArgs(f, &PyId_readline);
66 }
67 else {
68 result = _PyObject_CallMethodId(f, &PyId_readline, "i", n);
69 }
70 if (result != NULL && !PyBytes_Check(result) &&
71 !PyUnicode_Check(result)) {
72 Py_DECREF(result);
73 result = NULL;
74 PyErr_SetString(PyExc_TypeError,
75 "object.readline() returned non-string");
76 }
77
78 if (n < 0 && result != NULL && PyBytes_Check(result)) {
79 const char *s = PyBytes_AS_STRING(result);
80 Py_ssize_t len = PyBytes_GET_SIZE(result);
81 if (len == 0) {
82 Py_DECREF(result);
83 result = NULL;
84 PyErr_SetString(PyExc_EOFError,
85 "EOF when reading a line");
86 }
87 else if (s[len-1] == '\n') {
88 if (Py_REFCNT(result) == 1)
89 _PyBytes_Resize(&result, len-1);
90 else {
91 PyObject *v;
92 v = PyBytes_FromStringAndSize(s, len-1);
93 Py_DECREF(result);
94 result = v;
95 }
96 }
97 }
98 if (n < 0 && result != NULL && PyUnicode_Check(result)) {
99 Py_ssize_t len = PyUnicode_GET_LENGTH(result);
100 if (len == 0) {
101 Py_DECREF(result);
102 result = NULL;
103 PyErr_SetString(PyExc_EOFError,
104 "EOF when reading a line");
105 }
106 else if (PyUnicode_READ_CHAR(result, len-1) == '\n') {
107 PyObject *v;
108 v = PyUnicode_Substring(result, 0, len-1);
109 Py_DECREF(result);
110 result = v;
111 }
112 }
113 return result;
114 }
115
116 /* Interfaces to write objects/strings to file-like objects */
117
118 int
PyFile_WriteObject(PyObject * v,PyObject * f,int flags)119 PyFile_WriteObject(PyObject *v, PyObject *f, int flags)
120 {
121 PyObject *writer, *value, *result;
122 _Py_IDENTIFIER(write);
123
124 if (f == NULL) {
125 PyErr_SetString(PyExc_TypeError, "writeobject with NULL file");
126 return -1;
127 }
128 writer = _PyObject_GetAttrId(f, &PyId_write);
129 if (writer == NULL)
130 return -1;
131 if (flags & Py_PRINT_RAW) {
132 value = PyObject_Str(v);
133 }
134 else
135 value = PyObject_Repr(v);
136 if (value == NULL) {
137 Py_DECREF(writer);
138 return -1;
139 }
140 result = PyObject_CallOneArg(writer, value);
141 Py_DECREF(value);
142 Py_DECREF(writer);
143 if (result == NULL)
144 return -1;
145 Py_DECREF(result);
146 return 0;
147 }
148
149 int
PyFile_WriteString(const char * s,PyObject * f)150 PyFile_WriteString(const char *s, PyObject *f)
151 {
152 if (f == NULL) {
153 /* Should be caused by a pre-existing error */
154 if (!PyErr_Occurred())
155 PyErr_SetString(PyExc_SystemError,
156 "null file for PyFile_WriteString");
157 return -1;
158 }
159 else if (!PyErr_Occurred()) {
160 PyObject *v = PyUnicode_FromString(s);
161 int err;
162 if (v == NULL)
163 return -1;
164 err = PyFile_WriteObject(v, f, Py_PRINT_RAW);
165 Py_DECREF(v);
166 return err;
167 }
168 else
169 return -1;
170 }
171
172 /* Try to get a file-descriptor from a Python object. If the object
173 is an integer, its value is returned. If not, the
174 object's fileno() method is called if it exists; the method must return
175 an integer, which is returned as the file descriptor value.
176 -1 is returned on failure.
177 */
178
179 int
PyObject_AsFileDescriptor(PyObject * o)180 PyObject_AsFileDescriptor(PyObject *o)
181 {
182 int fd;
183 PyObject *meth;
184 _Py_IDENTIFIER(fileno);
185
186 if (PyLong_Check(o)) {
187 fd = _PyLong_AsInt(o);
188 }
189 else if (_PyObject_LookupAttrId(o, &PyId_fileno, &meth) < 0) {
190 return -1;
191 }
192 else if (meth != NULL) {
193 PyObject *fno = _PyObject_CallNoArg(meth);
194 Py_DECREF(meth);
195 if (fno == NULL)
196 return -1;
197
198 if (PyLong_Check(fno)) {
199 fd = _PyLong_AsInt(fno);
200 Py_DECREF(fno);
201 }
202 else {
203 PyErr_SetString(PyExc_TypeError,
204 "fileno() returned a non-integer");
205 Py_DECREF(fno);
206 return -1;
207 }
208 }
209 else {
210 PyErr_SetString(PyExc_TypeError,
211 "argument must be an int, or have a fileno() method.");
212 return -1;
213 }
214
215 if (fd == -1 && PyErr_Occurred())
216 return -1;
217 if (fd < 0) {
218 PyErr_Format(PyExc_ValueError,
219 "file descriptor cannot be a negative integer (%i)",
220 fd);
221 return -1;
222 }
223 return fd;
224 }
225
226 int
_PyLong_FileDescriptor_Converter(PyObject * o,void * ptr)227 _PyLong_FileDescriptor_Converter(PyObject *o, void *ptr)
228 {
229 int fd = PyObject_AsFileDescriptor(o);
230 if (fd == -1) {
231 return 0;
232 }
233 *(int *)ptr = fd;
234 return 1;
235 }
236
237 /*
238 ** Py_UniversalNewlineFgets is an fgets variation that understands
239 ** all of \r, \n and \r\n conventions.
240 ** The stream should be opened in binary mode.
241 ** If fobj is NULL the routine always does newline conversion, and
242 ** it may peek one char ahead to gobble the second char in \r\n.
243 ** If fobj is non-NULL it must be a PyFileObject. In this case there
244 ** is no readahead but in stead a flag is used to skip a following
245 ** \n on the next read. Also, if the file is open in binary mode
246 ** the whole conversion is skipped. Finally, the routine keeps track of
247 ** the different types of newlines seen.
248 ** Note that we need no error handling: fgets() treats error and eof
249 ** identically.
250 */
251 char *
Py_UniversalNewlineFgets(char * buf,int n,FILE * stream,PyObject * fobj)252 Py_UniversalNewlineFgets(char *buf, int n, FILE *stream, PyObject *fobj)
253 {
254 char *p = buf;
255 int c;
256 int newlinetypes = 0;
257 int skipnextlf = 0;
258
259 if (fobj) {
260 errno = ENXIO; /* What can you do... */
261 return NULL;
262 }
263 FLOCKFILE(stream);
264 c = 'x'; /* Shut up gcc warning */
265 while (--n > 0 && (c = GETC(stream)) != EOF ) {
266 if (skipnextlf ) {
267 skipnextlf = 0;
268 if (c == '\n') {
269 /* Seeing a \n here with skipnextlf true
270 ** means we saw a \r before.
271 */
272 newlinetypes |= NEWLINE_CRLF;
273 c = GETC(stream);
274 if (c == EOF) break;
275 } else {
276 /*
277 ** Note that c == EOF also brings us here,
278 ** so we're okay if the last char in the file
279 ** is a CR.
280 */
281 newlinetypes |= NEWLINE_CR;
282 }
283 }
284 if (c == '\r') {
285 /* A \r is translated into a \n, and we skip
286 ** an adjacent \n, if any. We don't set the
287 ** newlinetypes flag until we've seen the next char.
288 */
289 skipnextlf = 1;
290 c = '\n';
291 } else if ( c == '\n') {
292 newlinetypes |= NEWLINE_LF;
293 }
294 *p++ = c;
295 if (c == '\n') break;
296 }
297 /* if ( c == EOF && skipnextlf )
298 newlinetypes |= NEWLINE_CR; */
299 FUNLOCKFILE(stream);
300 *p = '\0';
301 if ( skipnextlf ) {
302 /* If we have no file object we cannot save the
303 ** skipnextlf flag. We have to readahead, which
304 ** will cause a pause if we're reading from an
305 ** interactive stream, but that is very unlikely
306 ** unless we're doing something silly like
307 ** exec(open("/dev/tty").read()).
308 */
309 c = GETC(stream);
310 if ( c != '\n' )
311 ungetc(c, stream);
312 }
313 if (p == buf)
314 return NULL;
315 return buf;
316 }
317
318 /* **************************** std printer ****************************
319 * The stdprinter is used during the boot strapping phase as a preliminary
320 * file like object for sys.stderr.
321 */
322
323 typedef struct {
324 PyObject_HEAD
325 int fd;
326 } PyStdPrinter_Object;
327
328 PyObject *
PyFile_NewStdPrinter(int fd)329 PyFile_NewStdPrinter(int fd)
330 {
331 PyStdPrinter_Object *self;
332
333 if (fd != fileno(stdout) && fd != fileno(stderr)) {
334 /* not enough infrastructure for PyErr_BadInternalCall() */
335 return NULL;
336 }
337
338 self = PyObject_New(PyStdPrinter_Object,
339 &PyStdPrinter_Type);
340 if (self != NULL) {
341 self->fd = fd;
342 }
343 return (PyObject*)self;
344 }
345
346 static PyObject *
stdprinter_write(PyStdPrinter_Object * self,PyObject * args)347 stdprinter_write(PyStdPrinter_Object *self, PyObject *args)
348 {
349 PyObject *unicode;
350 PyObject *bytes = NULL;
351 const char *str;
352 Py_ssize_t n;
353 int err;
354
355 /* The function can clear the current exception */
356 assert(!PyErr_Occurred());
357
358 if (self->fd < 0) {
359 /* fd might be invalid on Windows
360 * I can't raise an exception here. It may lead to an
361 * unlimited recursion in the case stderr is invalid.
362 */
363 Py_RETURN_NONE;
364 }
365
366 if (!PyArg_ParseTuple(args, "U", &unicode)) {
367 return NULL;
368 }
369
370 /* Encode Unicode to UTF-8/backslashreplace */
371 str = PyUnicode_AsUTF8AndSize(unicode, &n);
372 if (str == NULL) {
373 PyErr_Clear();
374 bytes = _PyUnicode_AsUTF8String(unicode, "backslashreplace");
375 if (bytes == NULL)
376 return NULL;
377 str = PyBytes_AS_STRING(bytes);
378 n = PyBytes_GET_SIZE(bytes);
379 }
380
381 n = _Py_write(self->fd, str, n);
382 /* save errno, it can be modified indirectly by Py_XDECREF() */
383 err = errno;
384
385 Py_XDECREF(bytes);
386
387 if (n == -1) {
388 if (err == EAGAIN) {
389 PyErr_Clear();
390 Py_RETURN_NONE;
391 }
392 return NULL;
393 }
394
395 return PyLong_FromSsize_t(n);
396 }
397
398 static PyObject *
stdprinter_fileno(PyStdPrinter_Object * self,PyObject * Py_UNUSED (ignored))399 stdprinter_fileno(PyStdPrinter_Object *self, PyObject *Py_UNUSED(ignored))
400 {
401 return PyLong_FromLong((long) self->fd);
402 }
403
404 static PyObject *
stdprinter_repr(PyStdPrinter_Object * self)405 stdprinter_repr(PyStdPrinter_Object *self)
406 {
407 return PyUnicode_FromFormat("<stdprinter(fd=%d) object at %p>",
408 self->fd, self);
409 }
410
411 static PyObject *
stdprinter_noop(PyStdPrinter_Object * self,PyObject * Py_UNUSED (ignored))412 stdprinter_noop(PyStdPrinter_Object *self, PyObject *Py_UNUSED(ignored))
413 {
414 Py_RETURN_NONE;
415 }
416
417 static PyObject *
stdprinter_isatty(PyStdPrinter_Object * self,PyObject * Py_UNUSED (ignored))418 stdprinter_isatty(PyStdPrinter_Object *self, PyObject *Py_UNUSED(ignored))
419 {
420 long res;
421 if (self->fd < 0) {
422 Py_RETURN_FALSE;
423 }
424
425 Py_BEGIN_ALLOW_THREADS
426 res = isatty(self->fd);
427 Py_END_ALLOW_THREADS
428
429 return PyBool_FromLong(res);
430 }
431
432 static PyMethodDef stdprinter_methods[] = {
433 {"close", (PyCFunction)stdprinter_noop, METH_NOARGS, ""},
434 {"flush", (PyCFunction)stdprinter_noop, METH_NOARGS, ""},
435 {"fileno", (PyCFunction)stdprinter_fileno, METH_NOARGS, ""},
436 {"isatty", (PyCFunction)stdprinter_isatty, METH_NOARGS, ""},
437 {"write", (PyCFunction)stdprinter_write, METH_VARARGS, ""},
438 {NULL, NULL} /*sentinel */
439 };
440
441 static PyObject *
get_closed(PyStdPrinter_Object * self,void * closure)442 get_closed(PyStdPrinter_Object *self, void *closure)
443 {
444 Py_RETURN_FALSE;
445 }
446
447 static PyObject *
get_mode(PyStdPrinter_Object * self,void * closure)448 get_mode(PyStdPrinter_Object *self, void *closure)
449 {
450 return PyUnicode_FromString("w");
451 }
452
453 static PyObject *
get_encoding(PyStdPrinter_Object * self,void * closure)454 get_encoding(PyStdPrinter_Object *self, void *closure)
455 {
456 Py_RETURN_NONE;
457 }
458
459 static PyGetSetDef stdprinter_getsetlist[] = {
460 {"closed", (getter)get_closed, NULL, "True if the file is closed"},
461 {"encoding", (getter)get_encoding, NULL, "Encoding of the file"},
462 {"mode", (getter)get_mode, NULL, "String giving the file mode"},
463 {0},
464 };
465
466 PyTypeObject PyStdPrinter_Type = {
467 PyVarObject_HEAD_INIT(&PyType_Type, 0)
468 "stderrprinter", /* tp_name */
469 sizeof(PyStdPrinter_Object), /* tp_basicsize */
470 0, /* tp_itemsize */
471 /* methods */
472 0, /* tp_dealloc */
473 0, /* tp_vectorcall_offset */
474 0, /* tp_getattr */
475 0, /* tp_setattr */
476 0, /* tp_as_async */
477 (reprfunc)stdprinter_repr, /* tp_repr */
478 0, /* tp_as_number */
479 0, /* tp_as_sequence */
480 0, /* tp_as_mapping */
481 0, /* tp_hash */
482 0, /* tp_call */
483 0, /* tp_str */
484 PyObject_GenericGetAttr, /* tp_getattro */
485 0, /* tp_setattro */
486 0, /* tp_as_buffer */
487 Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION, /* tp_flags */
488 0, /* tp_doc */
489 0, /* tp_traverse */
490 0, /* tp_clear */
491 0, /* tp_richcompare */
492 0, /* tp_weaklistoffset */
493 0, /* tp_iter */
494 0, /* tp_iternext */
495 stdprinter_methods, /* tp_methods */
496 0, /* tp_members */
497 stdprinter_getsetlist, /* tp_getset */
498 0, /* tp_base */
499 0, /* tp_dict */
500 0, /* tp_descr_get */
501 0, /* tp_descr_set */
502 0, /* tp_dictoffset */
503 0, /* tp_init */
504 PyType_GenericAlloc, /* tp_alloc */
505 0, /* tp_new */
506 PyObject_Del, /* tp_free */
507 };
508
509
510 /* ************************** open_code hook ***************************
511 * The open_code hook allows embedders to override the method used to
512 * open files that are going to be used by the runtime to execute code
513 */
514
515 int
PyFile_SetOpenCodeHook(Py_OpenCodeHookFunction hook,void * userData)516 PyFile_SetOpenCodeHook(Py_OpenCodeHookFunction hook, void *userData) {
517 if (Py_IsInitialized() &&
518 PySys_Audit("setopencodehook", NULL) < 0) {
519 return -1;
520 }
521
522 if (_PyRuntime.open_code_hook) {
523 if (Py_IsInitialized()) {
524 PyErr_SetString(PyExc_SystemError,
525 "failed to change existing open_code hook");
526 }
527 return -1;
528 }
529
530 _PyRuntime.open_code_hook = hook;
531 _PyRuntime.open_code_userdata = userData;
532 return 0;
533 }
534
535 PyObject *
PyFile_OpenCodeObject(PyObject * path)536 PyFile_OpenCodeObject(PyObject *path)
537 {
538 PyObject *iomod, *f = NULL;
539
540 if (!PyUnicode_Check(path)) {
541 PyErr_Format(PyExc_TypeError, "'path' must be 'str', not '%.200s'",
542 Py_TYPE(path)->tp_name);
543 return NULL;
544 }
545
546 Py_OpenCodeHookFunction hook = _PyRuntime.open_code_hook;
547 if (hook) {
548 f = hook(path, _PyRuntime.open_code_userdata);
549 } else {
550 iomod = PyImport_ImportModule("_io");
551 if (iomod) {
552 f = _PyObject_CallMethodId(iomod, &PyId_open, "Os",
553 path, "rb");
554 Py_DECREF(iomod);
555 }
556 }
557
558 return f;
559 }
560
561 PyObject *
PyFile_OpenCode(const char * utf8path)562 PyFile_OpenCode(const char *utf8path)
563 {
564 PyObject *pathobj = PyUnicode_FromString(utf8path);
565 PyObject *f;
566 if (!pathobj) {
567 return NULL;
568 }
569 f = PyFile_OpenCodeObject(pathobj);
570 Py_DECREF(pathobj);
571 return f;
572 }
573
574
575 #ifdef __cplusplus
576 }
577 #endif
578