Python/modsupport.c

   1
   2 /* Module support implementation */
   3
   4 #include "Python.h"
   5
   6 #define FLAG_SIZE_T 1
   7 typedef double va_double;
   8
   9 static PyObject *va_build_value(const char *, va_list, int);
  10
  11 /* Package context -- the full module name for package imports */
  12 char *_Py_PackageContext = NULL;
  13
  14 /* Py_InitModule4() parameters:
  15    - name is the module name
  16    - methods is the list of top-level functions
  17    - doc is the documentation string
  18    - passthrough is passed as self to functions defined in the module
  19    - api_version is the value of PYTHON_API_VERSION at the time the
  20      module was compiled
  21
  22    Return value is a borrowed reference to the module object; or NULL
  23    if an error occurred (in Python 1.4 and before, errors were fatal).
  24    Errors may still leak memory.
  25 */
  26
  27 static char api_version_warning[] =
  28 "Python C API version mismatch for module %.100s:\
  29  This Python has API version %d, module %.100s has version %d.";
  30
  31 PyObject *
  32 Py_InitModule4(const char *name, PyMethodDef *methods, const char *doc,
  33                PyObject *passthrough, int module_api_version)
  34 {
  35         PyObject *m, *d, *v, *n;
  36         PyMethodDef *ml;
  37         if (!Py_IsInitialized())
  38             Py_FatalError("Interpreter not initialized (version mismatch?)");
  39         if (module_api_version != PYTHON_API_VERSION) {
  40                 char message[512];
  41                 PyOS_snprintf(message, sizeof(message),
  42                               api_version_warning, name,
  43                               PYTHON_API_VERSION, name,
  44                               module_api_version);
  45                 if (PyErr_Warn(PyExc_RuntimeWarning, message))
  46                         return NULL;
  47         }
  48         /* Make sure name is fully qualified.
  49
  50            This is a bit of a hack: when the shared library is loaded,
  51            the module name is "package.module", but the module calls
  52            Py_InitModule*() with just "module" for the name.  The shared
  53            library loader squirrels away the true name of the module in
  54            _Py_PackageContext, and Py_InitModule*() will substitute this
  55            (if the name actually matches).
  56         */
  57         if (_Py_PackageContext != NULL) {
  58                 char *p = strrchr(_Py_PackageContext, '.');
  59                 if (p != NULL && strcmp(name, p+1) == 0) {
  60                         name = _Py_PackageContext;
  61                         _Py_PackageContext = NULL;
  62                 }
  63         }
  64         if ((m = PyImport_AddModule(name)) == NULL)
  65                 return NULL;
  66         d = PyModule_GetDict(m);
  67         if (methods != NULL) {
  68                 n = PyString_FromString(name);
  69                 if (n == NULL)
  70                         return NULL;
  71                 for (ml = methods; ml->ml_name != NULL; ml++) {
  72                         if ((ml->ml_flags & METH_CLASS) ||
  73                             (ml->ml_flags & METH_STATIC)) {
  74                                 PyErr_SetString(PyExc_ValueError,
  75                                                 "module functions cannot set"
  76                                                 " METH_CLASS or METH_STATIC");
  77                                 Py_DECREF(n);
  78                                 return NULL;
  79                         }
  80                         v = PyCFunction_NewEx(ml, passthrough, n);
  81                         if (v == NULL) {
  82                                 Py_DECREF(n);
  83                                 return NULL;
  84                         }
  85                         if (PyDict_SetItemString(d, ml->ml_name, v) != 0) {
  86                                 Py_DECREF(v);
  87                                 Py_DECREF(n);
  88                                 return NULL;
  89                         }
  90                         Py_DECREF(v);
  91                 }
  92                 Py_DECREF(n);
  93         }
  94         if (doc != NULL) {
  95                 v = PyString_FromString(doc);
  96                 if (v == NULL || PyDict_SetItemString(d, "__doc__", v) != 0) {
  97                         Py_XDECREF(v);
  98                         return NULL;
  99                 }
 100                 Py_DECREF(v);
 101         }
 102         return m;
 103 }
 104
 105
 106 /* Helper for mkvalue() to scan the length of a format */
 107
 108 static int
 109 countformat(const char *format, int endchar)
 110 {
 111         int count = 0;
 112         int level = 0;
 113         while (level > 0 || *format != endchar) {
 114                 switch (*format) {
 115                 case '\0':
 116                         /* Premature end */
 117                         PyErr_SetString(PyExc_SystemError,
 118                                         "unmatched paren in format");
 119                         return -1;
 120                 case '(':
 121                 case '[':
 122                 case '{':
 123                         if (level == 0)
 124                                 count++;
 125                         level++;
 126                         break;
 127                 case ')':
 128                 case ']':
 129                 case '}':
 130                         level--;
 131                         break;
 132                 case '#':
 133                 case '&':
 134                 case ',':
 135                 case ':':
 136                 case ' ':
 137                 case '\t':
 138                         break;
 139                 default:
 140                         if (level == 0)
 141                                 count++;
 142                 }
 143                 format++;
 144         }
 145         return count;
 146 }
 147
 148
 149 /* Generic function to create a value -- the inverse of getargs() */
 150 /* After an original idea and first implementation by Steven Miale */
 151
 152 static PyObject *do_mktuple(const char**, va_list *, int, int, int);
 153 static PyObject *do_mklist(const char**, va_list *, int, int, int);
 154 static PyObject *do_mkdict(const char**, va_list *, int, int, int);
 155 static PyObject *do_mkvalue(const char**, va_list *, int);
 156
 157
 158 static PyObject *
 159 do_mkdict(const char **p_format, va_list *p_va, int endchar, int n, int flags)
 160 {
 161         PyObject *d;
 162         int i;
 163         int itemfailed = 0;
 164         if (n < 0)
 165                 return NULL;
 166         if ((d = PyDict_New()) == NULL)
 167                 return NULL;
 168         /* Note that we can't bail immediately on error as this will leak
 169            refcounts on any 'N' arguments. */
 170         for (i = 0; i < n; i+= 2) {
 171                 PyObject *k, *v;
 172                 int err;
 173                 k = do_mkvalue(p_format, p_va, flags);
 174                 if (k == NULL) {
 175                         itemfailed = 1;
 176                         Py_INCREF(Py_None);
 177                         k = Py_None;
 178                 }
 179                 v = do_mkvalue(p_format, p_va, flags);
 180                 if (v == NULL) {
 181                         itemfailed = 1;
 182                         Py_INCREF(Py_None);
 183                         v = Py_None;
 184                 }
 185                 err = PyDict_SetItem(d, k, v);
 186                 Py_DECREF(k);
 187                 Py_DECREF(v);
 188                 if (err < 0 || itemfailed) {
 189                         Py_DECREF(d);
 190                         return NULL;
 191                 }
 192         }
 193         if (d != NULL && **p_format != endchar) {
 194                 Py_DECREF(d);
 195                 d = NULL;
 196                 PyErr_SetString(PyExc_SystemError,
 197                                 "Unmatched paren in format");
 198         }
 199         else if (endchar)
 200                 ++*p_format;
 201         return d;
 202 }
 203
 204 static PyObject *
 205 do_mklist(const char **p_format, va_list *p_va, int endchar, int n, int flags)
 206 {
 207         PyObject *v;
 208         int i;
 209         int itemfailed = 0;
 210         if (n < 0)
 211                 return NULL;
 212         v = PyList_New(n);
 213         if (v == NULL)
 214                 return NULL;
 215         /* Note that we can't bail immediately on error as this will leak
 216            refcounts on any 'N' arguments. */
 217         for (i = 0; i < n; i++) {
 218                 PyObject *w = do_mkvalue(p_format, p_va, flags);
 219                 if (w == NULL) {
 220                         itemfailed = 1;
 221                         Py_INCREF(Py_None);
 222                         w = Py_None;
 223                 }
 224                 PyList_SET_ITEM(v, i, w);
 225         }
 226
 227         if (itemfailed) {
 228                 /* do_mkvalue() should have already set an error */
 229                 Py_DECREF(v);
 230                 return NULL;
 231         }
 232         if (**p_format != endchar) {
 233                 Py_DECREF(v);
 234                 PyErr_SetString(PyExc_SystemError,
 235                                 "Unmatched paren in format");
 236                 return NULL;
 237         }
 238         if (endchar)
 239                 ++*p_format;
 240         return v;
 241 }
 242
 243 #ifdef Py_USING_UNICODE
 244 static int
 245 _ustrlen(Py_UNICODE *u)
 246 {
 247         int i = 0;
 248         Py_UNICODE *v = u;
 249         while (*v != 0) { i++; v++; }
 250         return i;
 251 }
 252 #endif
 253
 254 static PyObject *
 255 do_mktuple(const char **p_format, va_list *p_va, int endchar, int n, int flags)
 256 {
 257         PyObject *v;
 258         int i;
 259         int itemfailed = 0;
 260         if (n < 0)
 261                 return NULL;
 262         if ((v = PyTuple_New(n)) == NULL)
 263                 return NULL;
 264         /* Note that we can't bail immediately on error as this will leak
 265            refcounts on any 'N' arguments. */
 266         for (i = 0; i < n; i++) {
 267                 PyObject *w = do_mkvalue(p_format, p_va, flags);
 268                 if (w == NULL) {
 269                         itemfailed = 1;
 270                         Py_INCREF(Py_None);
 271                         w = Py_None;
 272                 }
 273                 PyTuple_SET_ITEM(v, i, w);
 274         }
 275         if (itemfailed) {
 276                 /* do_mkvalue() should have already set an error */
 277                 Py_DECREF(v);
 278                 return NULL;
 279         }
 280         if (**p_format != endchar) {
 281                 Py_DECREF(v);
 282                 PyErr_SetString(PyExc_SystemError,
 283                                 "Unmatched paren in format");
 284                 return NULL;
 285         }
 286         if (endchar)
 287                 ++*p_format;
 288         return v;
 289 }
 290
 291 static PyObject *
 292 do_mkvalue(const char **p_format, va_list *p_va, int flags)
 293 {
 294         for (;;) {
 295                 switch (*(*p_format)++) {
 296                 case '(':
 297                         return do_mktuple(p_format, p_va, ')',
 298                                           countformat(*p_format, ')'), flags);
 299
 300                 case '[':
 301                         return do_mklist(p_format, p_va, ']',
 302                                          countformat(*p_format, ']'), flags);
 303
 304                 case '{':
 305                         return do_mkdict(p_format, p_va, '}',
 306                                          countformat(*p_format, '}'), flags);
 307
 308                 case 'b':
 309                 case 'B':
 310                 case 'h':
 311                 case 'i':
 312                         return PyInt_FromLong((long)va_arg(*p_va, int));
 313
 314                 case 'H':
 315                         return PyInt_FromLong((long)va_arg(*p_va, unsigned int));
 316
 317                 case 'I':
 318                 {
 319                         unsigned int n;
 320                         n = va_arg(*p_va, unsigned int);
 321                         if (n > (unsigned long)PyInt_GetMax())
 322                                 return PyLong_FromUnsignedLong((unsigned long)n);
 323                         else
 324                                 return PyInt_FromLong(n);
 325                 }
 326
 327                 case 'n':
 328 #if SIZEOF_SIZE_T!=SIZEOF_LONG
 329                         return PyInt_FromSsize_t(va_arg(*p_va, Py_ssize_t));
 330 #endif
 331                         /* Fall through from 'n' to 'l' if Py_ssize_t is long */
 332                 case 'l':
 333                         return PyInt_FromLong(va_arg(*p_va, long));
 334
 335                 case 'k':
 336                 {
 337                         unsigned long n;
 338                         n = va_arg(*p_va, unsigned long);
 339                         if (n > (unsigned long)PyInt_GetMax())
 340                                 return PyLong_FromUnsignedLong(n);
 341                         else
 342                                 return PyInt_FromLong(n);
 343                 }
 344
 345 #ifdef HAVE_LONG_LONG
 346                 case 'L':
 347                         return PyLong_FromLongLong((PY_LONG_LONG)va_arg(*p_va, PY_LONG_LONG));
 348
 349                 case 'K':
 350                         return PyLong_FromUnsignedLongLong((PY_LONG_LONG)va_arg(*p_va, unsigned PY_LONG_LONG));
 351 #endif
 352 #ifdef Py_USING_UNICODE
 353                 case 'u':
 354                 {
 355                         PyObject *v;
 356                         Py_UNICODE *u = va_arg(*p_va, Py_UNICODE *);
 357                         Py_ssize_t n;
 358                         if (**p_format == '#') {
 359                                 ++*p_format;
 360                                 if (flags & FLAG_SIZE_T)
 361                                         n = va_arg(*p_va, Py_ssize_t);
 362                                 else
 363                                         n = va_arg(*p_va, int);
 364                         }
 365                         else
 366                                 n = -1;
 367                         if (u == NULL) {
 368                                 v = Py_None;
 369                                 Py_INCREF(v);
 370                         }
 371                         else {
 372                                 if (n < 0)
 373                                         n = _ustrlen(u);
 374                                 v = PyUnicode_FromUnicode(u, n);
 375                         }
 376                         return v;
 377                 }
 378 #endif
 379                 case 'f':
 380                 case 'd':
 381                         return PyFloat_FromDouble(
 382                                 (double)va_arg(*p_va, va_double));
 383
 384 #ifndef WITHOUT_COMPLEX
 385                 case 'D':
 386                         return PyComplex_FromCComplex(
 387                                 *((Py_complex *)va_arg(*p_va, Py_complex *)));
 388 #endif /* WITHOUT_COMPLEX */
 389
 390                 case 'c':
 391                 {
 392                         char p[1];
 393                         p[0] = (char)va_arg(*p_va, int);
 394                         return PyString_FromStringAndSize(p, 1);
 395                 }
 396
 397                 case 's':
 398                 case 'z':
 399                 {
 400                         PyObject *v;
 401                         char *str = va_arg(*p_va, char *);
 402                         Py_ssize_t n;
 403                         if (**p_format == '#') {
 404                                 ++*p_format;
 405                                 if (flags & FLAG_SIZE_T)
 406                                         n = va_arg(*p_va, Py_ssize_t);
 407                                 else
 408                                         n = va_arg(*p_va, int);
 409                         }
 410                         else
 411                                 n = -1;
 412                         if (str == NULL) {
 413                                 v = Py_None;
 414                                 Py_INCREF(v);
 415                         }
 416                         else {
 417                                 if (n < 0) {
 418                                         size_t m = strlen(str);
 419                                         if (m > PY_SSIZE_T_MAX) {
 420                                                 PyErr_SetString(PyExc_OverflowError,
 421                                                         "string too long for Python string");
 422                                                 return NULL;
 423                                         }
 424                                         n = (Py_ssize_t)m;
 425                                 }
 426                                 v = PyString_FromStringAndSize(str, n);
 427                         }
 428                         return v;
 429                 }
 430
 431                 case 'N':
 432                 case 'S':
 433                 case 'O':
 434                 if (**p_format == '&') {
 435                         typedef PyObject *(*converter)(void *);
 436                         converter func = va_arg(*p_va, converter);
 437                         void *arg = va_arg(*p_va, void *);
 438                         ++*p_format;
 439                         return (*func)(arg);
 440                 }
 441                 else {
 442                         PyObject *v;
 443                         v = va_arg(*p_va, PyObject *);
 444                         if (v != NULL) {
 445                                 if (*(*p_format - 1) != 'N')
 446                                         Py_INCREF(v);
 447                         }
 448                         else if (!PyErr_Occurred())
 449                                 /* If a NULL was passed
 450                                  * because a call that should
 451                                  * have constructed a value
 452                                  * failed, that's OK, and we
 453                                  * pass the error on; but if
 454                                  * no error occurred it's not
 455                                  * clear that the caller knew
 456                                  * what she was doing. */
 457                                 PyErr_SetString(PyExc_SystemError,
 458                                         "NULL object passed to Py_BuildValue");
 459                         return v;
 460                 }
 461
 462                 case ':':
 463                 case ',':
 464                 case ' ':
 465                 case '\t':
 466                         break;
 467
 468                 default:
 469                         PyErr_SetString(PyExc_SystemError,
 470                                 "bad format char passed to Py_BuildValue");
 471                         return NULL;
 472
 473                 }
 474         }
 475 }
 476
 477
 478 PyObject *
 479 Py_BuildValue(const char *format, ...)
 480 {
 481         va_list va;
 482         PyObject* retval;
 483         va_start(va, format);
 484         retval = va_build_value(format, va, 0);
 485         va_end(va);
 486         return retval;
 487 }
 488
 489 PyObject *
 490 _Py_BuildValue_SizeT(const char *format, ...)
 491 {
 492         va_list va;
 493         PyObject* retval;
 494         va_start(va, format);
 495         retval = va_build_value(format, va, FLAG_SIZE_T);
 496         va_end(va);
 497         return retval;
 498 }
 499
 500 PyObject *
 501 Py_VaBuildValue(const char *format, va_list va)
 502 {
 503         return va_build_value(format, va, 0);
 504 }
 505
 506 PyObject *
 507 _Py_VaBuildValue_SizeT(const char *format, va_list va)
 508 {
 509         return va_build_value(format, va, FLAG_SIZE_T);
 510 }
 511
 512 static PyObject *
 513 va_build_value(const char *format, va_list va, int flags)
 514 {
 515         const char *f = format;
 516         int n = countformat(f, '\0');
 517         va_list lva;
 518
 519 #ifdef VA_LIST_IS_ARRAY
 520         memcpy(lva, va, sizeof(va_list));
 521 #else
 522 #ifdef __va_copy
 523         __va_copy(lva, va);
 524 #else
 525         lva = va;
 526 #endif
 527 #endif
 528
 529         if (n < 0)
 530                 return NULL;
 531         if (n == 0) {
 532                 Py_INCREF(Py_None);
 533                 return Py_None;
 534         }
 535         if (n == 1)
 536                 return do_mkvalue(&f, &lva, flags);
 537         return do_mktuple(&f, &lva, '\0', n, flags);
 538 }
 539
 540
 541 PyObject *
 542 PyEval_CallFunction(PyObject *obj, const char *format, ...)
 543 {
 544         va_list vargs;
 545         PyObject *args;
 546         PyObject *res;
 547
 548         va_start(vargs, format);
 549
 550         args = Py_VaBuildValue(format, vargs);
 551         va_end(vargs);
 552
 553         if (args == NULL)
 554                 return NULL;
 555
 556         res = PyEval_CallObject(obj, args);
 557         Py_DECREF(args);
 558
 559         return res;
 560 }
 561
 562
 563 PyObject *
 564 PyEval_CallMethod(PyObject *obj, const char *methodname, const char *format, ...)
 565 {
 566         va_list vargs;
 567         PyObject *meth;
 568         PyObject *args;
 569         PyObject *res;
 570
 571         meth = PyObject_GetAttrString(obj, methodname);
 572         if (meth == NULL)
 573                 return NULL;
 574
 575         va_start(vargs, format);
 576
 577         args = Py_VaBuildValue(format, vargs);
 578         va_end(vargs);
 579
 580         if (args == NULL) {
 581                 Py_DECREF(meth);
 582                 return NULL;
 583         }
 584
 585         res = PyEval_CallObject(meth, args);
 586         Py_DECREF(meth);
 587         Py_DECREF(args);
 588
 589         return res;
 590 }
 591
 592 int
 593 PyModule_AddObject(PyObject *m, const char *name, PyObject *o)
 594 {
 595         PyObject *dict;
 596         if (!PyModule_Check(m)) {
 597                 PyErr_SetString(PyExc_TypeError,
 598                             "PyModule_AddObject() needs module as first arg");
 599                 return -1;
 600         }
 601         if (!o) {
 602                 if (!PyErr_Occurred())
 603                         PyErr_SetString(PyExc_TypeError,
 604                                         "PyModule_AddObject() needs non-NULL value");
 605                 return -1;
 606         }
 607
 608         dict = PyModule_GetDict(m);
 609         if (dict == NULL) {
 610                 /* Internal error -- modules must have a dict! */
 611                 PyErr_Format(PyExc_SystemError, "module '%s' has no __dict__",
 612                              PyModule_GetName(m));
 613                 return -1;
 614         }
 615         if (PyDict_SetItemString(dict, name, o))
 616                 return -1;
 617         Py_DECREF(o);
 618         return 0;
 619 }
 620
 621 int
 622 PyModule_AddIntConstant(PyObject *m, const char *name, long value)
 623 {
 624         PyObject *o = PyInt_FromLong(value);
 625         if (!o)
 626                 return -1;
 627         if (PyModule_AddObject(m, name, o) == 0)
 628                 return 0;
 629         Py_DECREF(o);
 630         return -1;
 631 }
 632
 633 int
 634 PyModule_AddStringConstant(PyObject *m, const char *name, const char *value)
 635 {
 636         PyObject *o = PyString_FromString(value);
 637         if (!o)
 638                 return -1;
 639         if (PyModule_AddObject(m, name, o) == 0)
 640                 return 0;
 641         Py_DECREF(o);
 642         return -1;
 643 }