Python/modsupport.c

   1
   2 /* Module support implementation */
   3
   4 #include "Python.h"
   5
   6 #ifdef MPW /* MPW pushes 'extended' for float and double types with varargs */
   7 typedef extended va_double;
   8 #else
   9 typedef double va_double;
  10 #endif
  11
  12 /* Package context -- the full module name for package imports */
  13 char *_Py_PackageContext = NULL;
  14
  15 /* Py_InitModule4() parameters:
  16    - name is the module name
  17    - methods is the list of top-level functions
  18    - doc is the documentation string
  19    - passthrough is passed as self to functions defined in the module
  20    - api_version is the value of PYTHON_API_VERSION at the time the
  21      module was compiled
  22
  23    Return value is a borrowed reference to the module object; or NULL
  24    if an error occurred (in Python 1.4 and before, errors were fatal).
  25    Errors may still leak memory.
  26 */
  27
  28 static char api_version_warning[] =
  29 "WARNING: Python C API version mismatch for module %s:\n\
  30   This Python has API version %d, module %s has version %d.\n";
  31
  32 PyObject *
  33 Py_InitModule4(char *name, PyMethodDef *methods, char *doc,
  34                PyObject *passthrough, int module_api_version)
  35 {
  36         PyObject *m, *d, *v;
  37         PyMethodDef *ml;
  38         if (!Py_IsInitialized())
  39             Py_FatalError("Interpreter not initialized (version mismatch?)");
  40         if (module_api_version != PYTHON_API_VERSION)
  41                 fprintf(stderr, api_version_warning,
  42                         name, PYTHON_API_VERSION, name, module_api_version);
  43         if (_Py_PackageContext != NULL) {
  44                 char *p = strrchr(_Py_PackageContext, '.');
  45                 if (p != NULL && strcmp(name, p+1) == 0) {
  46                         name = _Py_PackageContext;
  47                         _Py_PackageContext = NULL;
  48                 }
  49         }
  50         if ((m = PyImport_AddModule(name)) == NULL)
  51                 return NULL;
  52         d = PyModule_GetDict(m);
  53         for (ml = methods; ml->ml_name != NULL; ml++) {
  54                 v = PyCFunction_New(ml, passthrough);
  55                 if (v == NULL)
  56                         return NULL;
  57                 if (PyDict_SetItemString(d, ml->ml_name, v) != 0)
  58                         return NULL;
  59                 Py_DECREF(v);
  60         }
  61         if (doc != NULL) {
  62                 v = PyString_FromString(doc);
  63                 if (v == NULL || PyDict_SetItemString(d, "__doc__", v) != 0)
  64                         return NULL;
  65                 Py_DECREF(v);
  66         }
  67         return m;
  68 }
  69
  70
  71 /* Helper for mkvalue() to scan the length of a format */
  72
  73 static int countformat(char *format, int endchar)
  74 {
  75         int count = 0;
  76         int level = 0;
  77         while (level > 0 || *format != endchar) {
  78                 switch (*format) {
  79                 case '\0':
  80                         /* Premature end */
  81                         PyErr_SetString(PyExc_SystemError,
  82                                         "unmatched paren in format");
  83                         return -1;
  84                 case '(':
  85                 case '[':
  86                 case '{':
  87                         if (level == 0)
  88                                 count++;
  89                         level++;
  90                         break;
  91                 case ')':
  92                 case ']':
  93                 case '}':
  94                         level--;
  95                         break;
  96                 case '#':
  97                 case '&':
  98                 case ',':
  99                 case ':':
 100                 case ' ':
 101                 case '\t':
 102                         break;
 103                 default:
 104                         if (level == 0)
 105                                 count++;
 106                 }
 107                 format++;
 108         }
 109         return count;
 110 }
 111
 112
 113 /* Generic function to create a value -- the inverse of getargs() */
 114 /* After an original idea and first implementation by Steven Miale */
 115
 116 static PyObject *do_mktuple(char**, va_list *, int, int);
 117 static PyObject *do_mklist(char**, va_list *, int, int);
 118 static PyObject *do_mkdict(char**, va_list *, int, int);
 119 static PyObject *do_mkvalue(char**, va_list *);
 120
 121
 122 static PyObject *
 123 do_mkdict(char **p_format, va_list *p_va, int endchar, int n)
 124 {
 125         PyObject *d;
 126         int i;
 127         if (n < 0)
 128                 return NULL;
 129         if ((d = PyDict_New()) == NULL)
 130                 return NULL;
 131         for (i = 0; i < n; i+= 2) {
 132                 PyObject *k, *v;
 133                 int err;
 134                 k = do_mkvalue(p_format, p_va);
 135                 if (k == NULL) {
 136                         Py_DECREF(d);
 137                         return NULL;
 138                 }
 139                 v = do_mkvalue(p_format, p_va);
 140                 if (v == NULL) {
 141                         Py_DECREF(k);
 142                         Py_DECREF(d);
 143                         return NULL;
 144                 }
 145                 err = PyDict_SetItem(d, k, v);
 146                 Py_DECREF(k);
 147                 Py_DECREF(v);
 148                 if (err < 0) {
 149                         Py_DECREF(d);
 150                         return NULL;
 151                 }
 152         }
 153         if (d != NULL && **p_format != endchar) {
 154                 Py_DECREF(d);
 155                 d = NULL;
 156                 PyErr_SetString(PyExc_SystemError,
 157                                 "Unmatched paren in format");
 158         }
 159         else if (endchar)
 160                 ++*p_format;
 161         return d;
 162 }
 163
 164 static PyObject *
 165 do_mklist(char **p_format, va_list *p_va, int endchar, int n)
 166 {
 167         PyObject *v;
 168         int i;
 169         if (n < 0)
 170                 return NULL;
 171         if ((v = PyList_New(n)) == NULL)
 172                 return NULL;
 173         for (i = 0; i < n; i++) {
 174                 PyObject *w = do_mkvalue(p_format, p_va);
 175                 if (w == NULL) {
 176                         Py_DECREF(v);
 177                         return NULL;
 178                 }
 179                 PyList_SetItem(v, i, w);
 180         }
 181         if (v != NULL && **p_format != endchar) {
 182                 Py_DECREF(v);
 183                 v = NULL;
 184                 PyErr_SetString(PyExc_SystemError,
 185                                 "Unmatched paren in format");
 186         }
 187         else if (endchar)
 188                 ++*p_format;
 189         return v;
 190 }
 191
 192 static int
 193 _ustrlen(Py_UNICODE *u)
 194 {
 195         int i = 0;
 196         Py_UNICODE *v = u;
 197         while (*v != 0) { i++; v++; }
 198         return i;
 199 }
 200
 201 static PyObject *
 202 do_mktuple(char **p_format, va_list *p_va, int endchar, int n)
 203 {
 204         PyObject *v;
 205         int i;
 206         if (n < 0)
 207                 return NULL;
 208         if ((v = PyTuple_New(n)) == NULL)
 209                 return NULL;
 210         for (i = 0; i < n; i++) {
 211                 PyObject *w = do_mkvalue(p_format, p_va);
 212                 if (w == NULL) {
 213                         Py_DECREF(v);
 214                         return NULL;
 215                 }
 216                 PyTuple_SetItem(v, i, w);
 217         }
 218         if (v != NULL && **p_format != endchar) {
 219                 Py_DECREF(v);
 220                 v = NULL;
 221                 PyErr_SetString(PyExc_SystemError,
 222                                 "Unmatched paren in format");
 223         }
 224         else if (endchar)
 225                 ++*p_format;
 226         return v;
 227 }
 228
 229 static PyObject *
 230 do_mkvalue(char **p_format, va_list *p_va)
 231 {
 232         for (;;) {
 233                 switch (*(*p_format)++) {
 234                 case '(':
 235                         return do_mktuple(p_format, p_va, ')',
 236                                           countformat(*p_format, ')'));
 237
 238                 case '[':
 239                         return do_mklist(p_format, p_va, ']',
 240                                          countformat(*p_format, ']'));
 241
 242                 case '{':
 243                         return do_mkdict(p_format, p_va, '}',
 244                                          countformat(*p_format, '}'));
 245
 246                 case 'b':
 247                 case 'B':
 248                 case 'h':
 249                 case 'i':
 250                         return PyInt_FromLong((long)va_arg(*p_va, int));
 251
 252                 case 'H':
 253                         return PyInt_FromLong((long)va_arg(*p_va, unsigned int));
 254
 255                 case 'l':
 256                         return PyInt_FromLong((long)va_arg(*p_va, long));
 257
 258 #ifdef HAVE_LONG_LONG
 259                 case 'L':
 260                         return PyLong_FromLongLong((LONG_LONG)va_arg(*p_va, LONG_LONG));
 261 #endif
 262                 case 'u':
 263                 {
 264                         PyObject *v;
 265                         Py_UNICODE *u = va_arg(*p_va, Py_UNICODE *);
 266                         int n;
 267                         if (**p_format == '#') {
 268                                 ++*p_format;
 269                                 n = va_arg(*p_va, int);
 270                         }
 271                         else
 272                                 n = -1;
 273                         if (u == NULL) {
 274                                 v = Py_None;
 275                                 Py_INCREF(v);
 276                         }
 277                         else {
 278                                 if (n < 0)
 279                                         n = _ustrlen(u);
 280                                 v = PyUnicode_FromUnicode(u, n);
 281                         }
 282                         return v;
 283                 }
 284                 case 'f':
 285                 case 'd':
 286                         return PyFloat_FromDouble(
 287                                 (double)va_arg(*p_va, va_double));
 288
 289                 case 'c':
 290                 {
 291                         char p[1];
 292                         p[0] = va_arg(*p_va, int);
 293                         return PyString_FromStringAndSize(p, 1);
 294                 }
 295
 296                 case 's':
 297                 case 'z':
 298                 {
 299                         PyObject *v;
 300                         char *str = va_arg(*p_va, char *);
 301                         int n;
 302                         if (**p_format == '#') {
 303                                 ++*p_format;
 304                                 n = va_arg(*p_va, int);
 305                         }
 306                         else
 307                                 n = -1;
 308                         if (str == NULL) {
 309                                 v = Py_None;
 310                                 Py_INCREF(v);
 311                         }
 312                         else {
 313                                 if (n < 0) {
 314                                         size_t m = strlen(str);
 315                                         if (m > INT_MAX) {
 316                                                 PyErr_SetString(PyExc_OverflowError,
 317                                                         "string too long for Python string");
 318                                                 return NULL;
 319                                         }
 320                                         n = (int)m;
 321                                 }
 322                                 v = PyString_FromStringAndSize(str, n);
 323                         }
 324                         return v;
 325                 }
 326
 327                 case 'N':
 328                 case 'S':
 329                 case 'O':
 330                 if (**p_format == '&') {
 331                         typedef PyObject *(*converter)(void *);
 332                         converter func = va_arg(*p_va, converter);
 333                         void *arg = va_arg(*p_va, void *);
 334                         ++*p_format;
 335                         return (*func)(arg);
 336                 }
 337                 else {
 338                         PyObject *v;
 339                         v = va_arg(*p_va, PyObject *);
 340                         if (v != NULL) {
 341                                 if (*(*p_format - 1) != 'N')
 342                                         Py_INCREF(v);
 343                         }
 344                         else if (!PyErr_Occurred())
 345                                 /* If a NULL was passed
 346                                  * because a call that should
 347                                  * have constructed a value
 348                                  * failed, that's OK, and we
 349                                  * pass the error on; but if
 350                                  * no error occurred it's not
 351                                  * clear that the caller knew
 352                                  * what she was doing. */
 353                                 PyErr_SetString(PyExc_SystemError,
 354                                         "NULL object passed to Py_BuildValue");
 355                         return v;
 356                 }
 357
 358                 case ':':
 359                 case ',':
 360                 case ' ':
 361                 case '\t':
 362                         break;
 363
 364                 default:
 365                         PyErr_SetString(PyExc_SystemError,
 366                                 "bad format char passed to Py_BuildValue");
 367                         return NULL;
 368
 369                 }
 370         }
 371 }
 372
 373
 374 PyObject *Py_BuildValue(char *format, ...)
 375 {
 376         va_list va;
 377         PyObject* retval;
 378         va_start(va, format);
 379         retval = Py_VaBuildValue(format, va);
 380         va_end(va);
 381         return retval;
 382 }
 383
 384 PyObject *
 385 Py_VaBuildValue(char *format, va_list va)
 386 {
 387         char *f = format;
 388         int n = countformat(f, '\0');
 389         va_list lva;
 390
 391 #ifdef VA_LIST_IS_ARRAY
 392         memcpy(lva, va, sizeof(va_list));
 393 #else
 394         lva = va;
 395 #endif
 396
 397         if (n < 0)
 398                 return NULL;
 399         if (n == 0) {
 400                 Py_INCREF(Py_None);
 401                 return Py_None;
 402         }
 403         if (n == 1)
 404                 return do_mkvalue(&f, &lva);
 405         return do_mktuple(&f, &lva, '\0', n);
 406 }
 407
 408
 409 PyObject *
 410 PyEval_CallFunction(PyObject *obj, char *format, ...)
 411 {
 412         va_list vargs;
 413         PyObject *args;
 414         PyObject *res;
 415
 416         va_start(vargs, format);
 417
 418         args = Py_VaBuildValue(format, vargs);
 419         va_end(vargs);
 420
 421         if (args == NULL)
 422                 return NULL;
 423
 424         res = PyEval_CallObject(obj, args);
 425         Py_DECREF(args);
 426
 427         return res;
 428 }
 429
 430
 431 PyObject *
 432 PyEval_CallMethod(PyObject *obj, char *methodname, char *format, ...)
 433 {
 434         va_list vargs;
 435         PyObject *meth;
 436         PyObject *args;
 437         PyObject *res;
 438
 439         meth = PyObject_GetAttrString(obj, methodname);
 440         if (meth == NULL)
 441                 return NULL;
 442
 443         va_start(vargs, format);
 444
 445         args = Py_VaBuildValue(format, vargs);
 446         va_end(vargs);
 447
 448         if (args == NULL) {
 449                 Py_DECREF(meth);
 450                 return NULL;
 451         }
 452
 453         res = PyEval_CallObject(meth, args);
 454         Py_DECREF(meth);
 455         Py_DECREF(args);
 456
 457         return res;
 458 }
 459
 460 int
 461 PyModule_AddObject(PyObject *m, char *name, PyObject *o)
 462 {
 463         PyObject *dict;
 464         if (!PyModule_Check(m) || o == NULL)
 465                 return -1;
 466         dict = PyModule_GetDict(m);
 467         if (dict == NULL)
 468                 return -1;
 469         if (PyDict_SetItemString(dict, name, o))
 470                 return -1;
 471         Py_DECREF(o);
 472         return 0;
 473 }
 474
 475 int
 476 PyModule_AddIntConstant(PyObject *m, char *name, long value)
 477 {
 478         return PyModule_AddObject(m, name, PyInt_FromLong(value));
 479 }
 480
 481 int
 482 PyModule_AddStringConstant(PyObject *m, char *name, char *value)
 483 {
 484         return PyModule_AddObject(m, name, PyString_FromString(value));
 485 }