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