mdw@git.distorted.org.uk Git - pyke/blob - pyke.c

   1 /* -*-c-*-
   2  *
   3  * Pyke: the Python Kit for Extensions
   4  *
   5  * (c) 2019 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Pyke: the Python Kit for Extensions.
  11  *
  12  * Pyke is free software: you can redistribute it and/or modify it under
  13  * the terms of the GNU General Public License as published by the Free
  14  * Software Foundation; either version 2 of the License, or (at your
  15  * option) any later version.
  16  *
  17  * Pyke is distributed in the hope that it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with Pyke.  If not, write to the Free Software Foundation, Inc.,
  24  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 /*----- Header files ------------------------------------------------------*/
  28
  29 #include "pyke.h"
  30
  31 /*----- External variables ------------------------------------------------*/
  32
  33 PyObject *modname;
  34 PyObject *home_module;
  35
  36 /*----- Conversions -------------------------------------------------------*/
  37
  38 PyObject *getulong(unsigned long w)
  39 {
  40   if (w <= LONG_MAX) return (PyInt_FromLong(w));
  41   else return (PyLong_FromUnsignedLong(w));
  42 }
  43
  44 PyObject *getbool(int b)
  45   { if (b) RETURN_TRUE; else RETURN_FALSE; }
  46
  47 int convulong(PyObject *o, void *pp)
  48 {
  49   unsigned long *p = pp;
  50   PyObject *t;
  51
  52   if (!o) VALERR("can't delete");
  53 #ifdef PY2
  54   if (PyInt_Check(o)) {
  55     long i = PyInt_AS_LONG(o);
  56     if (i < 0) VALERR("must be nonnegative");
  57     *p = i;
  58   } else
  59 #endif
  60   {
  61     if ((t = PyNumber_Long(o)) == 0) goto end;
  62     *p = PyLong_AsUnsignedLong(t);
  63     Py_DECREF(t);
  64     if (PyErr_Occurred()) goto end;
  65   }
  66   return (1);
  67 end:
  68   return (0);
  69 }
  70
  71 int convuint(PyObject *o, void *pp)
  72 {
  73   unsigned long u;
  74   unsigned *p = pp;
  75
  76   if (!convulong(o, &u)) goto end;
  77   if (u > UINT_MAX) VALERR("out of range");
  78   *p = u;
  79   return (1);
  80 end:
  81   return (0);
  82 }
  83
  84 int convszt(PyObject *o, void *pp)
  85 {
  86   unsigned long u;
  87   size_t *p = pp;
  88
  89   if (!convulong(o, &u)) goto end;
  90   if (u > ~(size_t)0) VALERR("out of range");
  91   *p = u;
  92   return (1);
  93 end:
  94   return (0);
  95 }
  96
  97 int convbool(PyObject *o, void *pp)
  98 {
  99   if (!o) VALERR("can't delete");
 100   *(int *)pp = PyObject_IsTrue(o);
 101   return (1);
 102 end:
 103   return (0);
 104 }
 105
 106 int convbin(PyObject *o, void *pp)
 107 {
 108   struct bin *r = pp;
 109
 110   if (BIN_CHECK(o)) {
 111     r->p = BIN_PTR(o);
 112     r->sz = BIN_LEN(o);
 113     return (1);
 114   }
 115 #ifdef PY2
 116   if (PyUnicode_Check(o)) {
 117     o = _PyUnicode_AsDefaultEncodedString(o, 0);
 118     if (!o) return (0);
 119     r->p = PyString_AS_STRING(o);
 120     r->sz = PyString_GET_SIZE(o);
 121     return (1);
 122   }
 123 #endif
 124   return (PyObject_AsReadBuffer(o, &r->p, &r->sz) ? 0 : 1);
 125 }
 126
 127 /*----- Miscellaneous utilities -------------------------------------------*/
 128
 129 PyObject *abstract_pynew(PyTypeObject *ty, PyObject *arg, PyObject *kw)
 130 {
 131   PyErr_SetString(PyExc_TypeError, "can't instantiate this class");
 132   return (0);
 133 }
 134
 135 PyObject *enrich_compare(int op, int cmp)
 136 {
 137   int r = -1;
 138
 139   switch (op) {
 140     case Py_LT: r = cmp <  0; break;
 141     case Py_LE: r = cmp <= 0; break;
 142     case Py_EQ: r = cmp == 0; break;
 143     case Py_NE: r = cmp != 0; break;
 144     case Py_GE: r = cmp >= 0; break;
 145     case Py_GT: r = cmp >  0; break;
 146     default: assert(0);
 147   }
 148   return (getbool(r));
 149 }
 150
 151 /*----- Saving and restoring exceptions ----------------------------------*/
 152
 153 void report_lost_exception_v(struct excinfo *exc,
 154                              const char *why, va_list ap)
 155 {
 156   PyObject *hookfn = 0;
 157   PyObject *whyobj = 0;
 158   PyObject *obj = 0;
 159
 160   /* Make sure we start out without a pending exception, or this will get
 161    * really confusing.
 162    */
 163   assert(!PyErr_Occurred());
 164
 165   /* Format the explanation. */
 166   if (why) whyobj = TEXT_VFORMAT(why, ap);
 167   else { whyobj = Py_None; Py_INCREF(whyobj); }
 168
 169   /* Find our home module's `lostexchook' function.  This won't work if
 170    * there's no module, or the function isn't defined, or it's `None'.
 171    */
 172   if (!home_module) goto sys;
 173   hookfn = PyObject_GetAttrString(home_module, "lostexchook");
 174   if (hookfn == Py_None) goto sys;
 175   else if (hookfn) ;
 176   else if (!PyErr_ExceptionMatches(PyExc_AttributeError)) goto ouch;
 177   else { PyErr_Clear(); goto sys; }
 178
 179   /* Call the hook function. */
 180   obj = PyObject_CallFunction(hookfn, "(OOOO)",
 181                               whyobj, exc->ty, exc->val, exc->tb);
 182   if (!obj) goto ouch;
 183   goto end;
 184
 185   /* Something went wrong reporting the problem. */
 186 ouch:
 187   PySys_WriteStderr("\n!!! FAILURE REPORTING LOST EXCEPTION\n");
 188   PyErr_Print();
 189   /* drop through... */
 190
 191   /* There was no hook, so try to do something sensible using
 192    * `sys.excepthook'.
 193    */
 194 sys:
 195   PySys_WriteStderr("\n!!! LOST EXCEPTION: %s\n", TEXT_PTR(whyobj));
 196   RESTORE_EXCINFO(exc);
 197   PyErr_Print();
 198   /* drop through... */
 199
 200   /* Clean up afterwards. */
 201 end:
 202   Py_XDECREF(hookfn);
 203   Py_XDECREF(whyobj);
 204   Py_XDECREF(obj);
 205 }
 206
 207 void report_lost_exception(struct excinfo *exc, const char *why, ...)
 208 {
 209   va_list ap;
 210
 211   va_start(ap, why);
 212   report_lost_exception_v(exc, why, ap);
 213   va_end(ap);
 214 }
 215
 216 void stash_exception(struct excinfo *exc, const char *why, ...)
 217 {
 218   va_list ap;
 219   struct excinfo stash;
 220
 221   if (!exc->ty)
 222     STASH_EXCINFO(exc);
 223   else {
 224     va_start(ap, why);
 225     STASH_EXCINFO(&stash);
 226     report_lost_exception_v(&stash, why, ap);
 227     va_end(ap);
 228   }
 229 }
 230
 231 void restore_exception(struct excinfo *exc, const char *why, ...)
 232 {
 233   va_list ap;
 234   struct excinfo stash;
 235
 236   if (!PyErr_Occurred())
 237     RESTORE_EXCINFO(exc);
 238   else {
 239     va_start(ap, why);
 240     STASH_EXCINFO(&stash);
 241     report_lost_exception_v(exc, why, ap);
 242     RESTORE_EXCINFO(&stash);
 243     va_end(ap);
 244   }
 245 }
 246
 247 /*----- Type definitions --------------------------------------------------*/
 248
 249 static const PyTypeObject emptytype = { 0 };
 250
 251 void *newtype(PyTypeObject *metaty,
 252               const PyTypeObject *skel,
 253               const char *name)
 254 {
 255   PyHeapTypeObject *ty =
 256     (PyHeapTypeObject *)_PyObject_GC_Malloc(_PyObject_VAR_SIZE(metaty, 0));
 257   if (!skel) skel = &emptytype;
 258   memcpy(ty, skel, sizeof(*skel));
 259 #define COPY(blah) do {                                                 \
 260     if (ty->ht_type.tp_as_##blah) {                                     \
 261       memcpy(&ty->as_##blah,                                            \
 262              ty->ht_type.tp_as_##blah,                                  \
 263              sizeof(ty->as_##blah));                                    \
 264       ty->ht_type.tp_as_##blah = &ty->as_##blah;                        \
 265     }                                                                   \
 266   } while (0)
 267   COPY(number);
 268   COPY(sequence);
 269   COPY(mapping);
 270   COPY(buffer);
 271 #undef COPY
 272   if (name)
 273     ty->ht_name = TEXT_FROMSTR(name);
 274   else if (ty->ht_type.tp_name)
 275     ty->ht_name = TEXT_FROMSTR(ty->ht_type.tp_name);
 276   else
 277     ty->ht_name = 0;
 278   if (ty->ht_name)
 279     ty->ht_type.tp_name = TEXT_STR(ty->ht_name);
 280   ty->ht_slots = 0;
 281 #ifdef PY3
 282   ty->ht_qualname = 0;
 283 #endif
 284   (void)PyObject_INIT(&ty->ht_type, metaty);
 285   Py_INCREF(metaty);
 286   return (ty);
 287 }
 288
 289 void typeready(PyTypeObject *ty)
 290 {
 291 #ifdef PY3
 292   PyHeapTypeObject *hty = (PyHeapTypeObject *)ty;
 293   hty->ht_qualname = hty->ht_name;
 294 #endif
 295   PyType_Ready(ty);
 296   PyDict_SetItemString(ty->tp_dict, "__module__", modname);
 297 }
 298
 299 PyTypeObject *inittype(const PyTypeObject *tyskel,
 300                        PyTypeObject *base, PyTypeObject *meta)
 301 {
 302   PyTypeObject *ty = newtype(meta, tyskel, 0);
 303   if (base) { ty->tp_base = base; Py_INCREF(base); }
 304   ty->tp_flags |= Py_TPFLAGS_HEAPTYPE;
 305   typeready(ty);
 306   return (ty);
 307 }
 308
 309 /*----- Populating modules ------------------------------------------------*/
 310
 311 PyObject *mkexc(PyObject *mod, PyObject *base,
 312                 const char *name, const PyMethodDef *mm)
 313 {
 314   PyObject *nameobj = 0;
 315   PyObject *dict = 0;
 316   PyObject *exc = 0;
 317   PyObject *func = 0;
 318   PyObject *meth = 0;
 319
 320   if ((dict = PyDict_New()) == 0) goto fail;
 321
 322   if (mm) {
 323     while (mm->ml_name) {
 324       if ((func = PyCFunction_NewEx((/*unconst*/ PyMethodDef *)mm,
 325                                     0, mod)) == 0 ||
 326           (meth = PY23(PyMethod_New(func, 0, exc),
 327                        PyInstanceMethod_New(func))) == 0 ||
 328           PyDict_SetItemString(dict, mm->ml_name, meth))
 329         goto fail;
 330       Py_DECREF(func); func = 0;
 331       Py_DECREF(meth); meth = 0;
 332       mm++;
 333     }
 334   }
 335
 336   if ((nameobj = TEXT_FORMAT("%s.%s", PyModule_GetName(mod), name)) == 0 ||
 337       (exc = PyErr_NewException(TEXT_STR(nameobj), base, dict)) == 0)
 338     goto fail;
 339
 340 done:
 341   Py_XDECREF(nameobj);
 342   Py_XDECREF(dict);
 343   return (exc);
 344
 345 fail:
 346   Py_XDECREF(exc);
 347   Py_XDECREF(func);
 348   Py_XDECREF(meth);
 349   exc = 0;
 350   goto done;
 351 }
 352
 353 void setconstants(PyObject *mod, const struct nameval *c)
 354 {
 355   PyObject *x;
 356   unsigned long u;
 357
 358   while (c->name) {
 359     u = c->value;
 360     if (u <= LONG_MAX) x = PyInt_FromLong(u);
 361     else if (c->f&CF_SIGNED) x = PyInt_FromLong(-1 - (long)(ULONG_MAX - u));
 362     else x = PyLong_FromUnsignedLong(u);
 363     PyModule_AddObject(mod, (/*unconst*/ char *)c->name, x);
 364     c++;
 365   }
 366 }
 367
 368 /*----- Submodules --------------------------------------------------------*/
 369
 370 static PyMethodDef *global_methods;
 371 static size_t nmethods, methodsz;
 372
 373 void addmethods(const PyMethodDef *m)
 374 {
 375   size_t n, want, newsz;
 376
 377   for (n = 0; m[n].ml_name; n++);
 378   want = nmethods + n + 1;
 379   if (want > methodsz) {
 380     newsz = methodsz ? 2*methodsz : 16;
 381     while (want > newsz) newsz *= 2;
 382     if (!global_methods)
 383       global_methods = PyObject_Malloc(newsz*sizeof(PyMethodDef));
 384     else
 385       global_methods = PyObject_Realloc(global_methods,
 386                                         newsz*sizeof(PyMethodDef));
 387     assert(global_methods);
 388     methodsz = newsz;
 389   }
 390   memcpy(global_methods + nmethods, m, n*sizeof(PyMethodDef));
 391   nmethods += n;
 392   global_methods[nmethods].ml_name = 0;
 393 }
 394
 395 PyMethodDef *donemethods(void) { return (global_methods); }
 396
 397 /*----- Low-level Python interface ----------------------------------------*/
 398
 399 static PyObject *meth__set_home_module(PyObject *me, PyObject *arg)
 400 {
 401   PyObject *mod;
 402
 403   if (!PyArg_ParseTuple(arg, "O!:_set_home_module", &PyModule_Type, &mod))
 404     return (0);
 405   Py_XDECREF(home_module); home_module = mod; Py_INCREF(home_module);
 406   RETURN_NONE;
 407 }
 408
 409 static const PyMethodDef methods[] = {
 410 #define METHNAME(func) meth_##func
 411   METH  (_set_home_module, "_set_home_module(MOD)")
 412 #undef METHNAME
 413   { 0 }
 414 };
 415
 416 void pyke_core_pyinit(void) { addmethods(methods); }
 417 void pyke_core_pyinsert(PyObject *mod) { ; }
 418
 419 /*----- That's all, folks -------------------------------------------------*/