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   long i;
  50   unsigned long *p = pp;
  51   PyObject *t;
  52
  53   if (!o) VALERR("can't delete");
  54   if (PyInt_Check(o)) {
  55     i = PyInt_AS_LONG(o);
  56     if (i < 0) VALERR("must be nonnegative");
  57     *p = i;
  58   } else {
  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 (PyString_Check(o)) {
 109     r->p = PyString_AS_STRING(o);
 110     r->sz = PyString_GET_SIZE(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 /*----- Saving and restoring exceptions ----------------------------------*/
 132
 133 void report_lost_exception_v(struct excinfo *exc,
 134                              const char *why, va_list ap)
 135 {
 136   PyObject *hookfn = 0;
 137   PyObject *whyobj = 0;
 138   PyObject *obj = 0;
 139
 140   /* Make sure we start out without a pending exception, or this will get
 141    * really confusing.
 142    */
 143   assert(!PyErr_Occurred());
 144
 145   /* Format the explanation. */
 146   if (why) whyobj = PyString_FromFormatV(why, ap);
 147   else { whyobj = Py_None; Py_INCREF(whyobj); }
 148
 149   /* Find our home module's `lostexchook' function.  This won't work if
 150    * there's no module, or the function isn't defined, or it's `None'.
 151    */
 152   if (!home_module) goto sys;
 153   hookfn = PyObject_GetAttrString(home_module, "lostexchook");
 154   if (hookfn == Py_None) goto sys;
 155   else if (hookfn) ;
 156   else if (!PyErr_ExceptionMatches(PyExc_AttributeError)) goto ouch;
 157   else { PyErr_Clear(); goto sys; }
 158
 159   /* Call the hook function. */
 160   obj = PyObject_CallFunction(hookfn, "(OOOO)",
 161                               whyobj, exc->ty, exc->val, exc->tb);
 162   if (!obj) goto ouch;
 163   goto end;
 164
 165   /* Something went wrong reporting the problem. */
 166 ouch:
 167   PySys_WriteStderr("\n!!! FAILURE REPORTING LOST EXCEPTION\n");
 168   PyErr_Print();
 169   /* drop through... */
 170
 171   /* There was no hook, so try to do something sensible using
 172    * `sys.excepthook'.
 173    */
 174 sys:
 175   PySys_WriteStderr("\n!!! LOST EXCEPTION: %s\n",
 176                     PyString_AS_STRING(whyobj));
 177   RESTORE_EXCINFO(exc);
 178   PyErr_Print();
 179   /* drop through... */
 180
 181   /* Clean up afterwards. */
 182 end:
 183   Py_XDECREF(hookfn);
 184   Py_XDECREF(whyobj);
 185   Py_XDECREF(obj);
 186 }
 187
 188 void report_lost_exception(struct excinfo *exc, const char *why, ...)
 189 {
 190   va_list ap;
 191
 192   va_start(ap, why);
 193   report_lost_exception_v(exc, why, ap);
 194   va_end(ap);
 195 }
 196
 197 void stash_exception(struct excinfo *exc, const char *why, ...)
 198 {
 199   va_list ap;
 200   struct excinfo stash;
 201
 202   if (!exc->ty)
 203     STASH_EXCINFO(exc);
 204   else {
 205     va_start(ap, why);
 206     STASH_EXCINFO(&stash);
 207     report_lost_exception_v(&stash, why, ap);
 208     va_end(ap);
 209   }
 210 }
 211
 212 void restore_exception(struct excinfo *exc, const char *why, ...)
 213 {
 214   va_list ap;
 215   struct excinfo stash;
 216
 217   if (!PyErr_Occurred())
 218     RESTORE_EXCINFO(exc);
 219   else {
 220     va_start(ap, why);
 221     STASH_EXCINFO(&stash);
 222     report_lost_exception_v(exc, why, ap);
 223     RESTORE_EXCINFO(&stash);
 224     va_end(ap);
 225   }
 226 }
 227
 228 /*----- Type definitions --------------------------------------------------*/
 229
 230 static const PyTypeObject emptytype = { 0 };
 231
 232 void *newtype(PyTypeObject *metaty,
 233               const PyTypeObject *skel,
 234               const char *name)
 235 {
 236   PyHeapTypeObject *ty =
 237     (PyHeapTypeObject *)_PyObject_GC_Malloc(_PyObject_VAR_SIZE(metaty, 0));
 238   if (!skel) skel = &emptytype;
 239   memcpy(ty, skel, sizeof(*skel));
 240 #define COPY(blah) do {                                                 \
 241     if (ty->ht_type.tp_as_##blah) {                                     \
 242       memcpy(&ty->as_##blah,                                            \
 243              ty->ht_type.tp_as_##blah,                                  \
 244              sizeof(ty->as_##blah));                                    \
 245       ty->ht_type.tp_as_##blah = &ty->as_##blah;                        \
 246     }                                                                   \
 247   } while (0)
 248   COPY(number);
 249   COPY(sequence);
 250   COPY(mapping);
 251   COPY(buffer);
 252 #undef COPY
 253   if (name)
 254     ty->ht_name = PyString_FromString(name);
 255   else if (ty->ht_type.tp_name)
 256     ty->ht_name = PyString_FromString(ty->ht_type.tp_name);
 257   if (ty->ht_name)
 258     ty->ht_type.tp_name = PyString_AS_STRING(ty->ht_name);
 259   ty->ht_slots = 0;
 260   (void)PyObject_INIT(&ty->ht_type, metaty);
 261   Py_INCREF(metaty);
 262   return (ty);
 263 }
 264
 265 void typeready(PyTypeObject *ty)
 266 {
 267   PyType_Ready(ty);
 268   PyDict_SetItemString(ty->tp_dict, "__module__", modname);
 269 }
 270
 271 PyTypeObject *inittype(const PyTypeObject *tyskel,
 272                        PyTypeObject *base, PyTypeObject *meta)
 273 {
 274   PyTypeObject *ty = newtype(meta, tyskel, 0);
 275   if (base) { ty->tp_base = base; Py_INCREF(base); }
 276   ty->tp_flags |= Py_TPFLAGS_HEAPTYPE;
 277   typeready(ty);
 278   return (ty);
 279 }
 280
 281 /*----- Populating modules ------------------------------------------------*/
 282
 283 PyObject *mkexc(PyObject *mod, PyObject *base,
 284                 const char *name, const PyMethodDef *mm)
 285 {
 286   PyObject *nameobj = 0;
 287   PyObject *dict = 0;
 288   PyObject *exc = 0;
 289   PyObject *func = 0;
 290   PyObject *meth = 0;
 291
 292   if ((dict = PyDict_New()) == 0) goto fail;
 293
 294   if (mm) {
 295     while (mm->ml_name) {
 296       if ((func = PyCFunction_NewEx((/*unconst*/ PyMethodDef *)mm,
 297                                     0, mod)) == 0 ||
 298           (meth = PyMethod_New(func, 0, exc)) == 0 ||
 299           PyDict_SetItemString(dict, mm->ml_name, meth))
 300         goto fail;
 301       Py_DECREF(func); func = 0;
 302       Py_DECREF(meth); meth = 0;
 303       mm++;
 304     }
 305   }
 306
 307   if ((nameobj = PyString_FromFormat("%s.%s",
 308                                      PyModule_GetName(mod),
 309                                      name)) == 0 ||
 310       (exc = PyErr_NewException(PyString_AS_STRING(nameobj),
 311                                 base, dict)) == 0)
 312     goto fail;
 313
 314 done:
 315   Py_XDECREF(nameobj);
 316   Py_XDECREF(dict);
 317   return (exc);
 318
 319 fail:
 320   Py_XDECREF(exc);
 321   Py_XDECREF(func);
 322   Py_XDECREF(meth);
 323   exc = 0;
 324   goto done;
 325 }
 326
 327 void setconstants(PyObject *mod, const struct nameval *c)
 328 {
 329   PyObject *x;
 330   unsigned long u;
 331
 332   while (c->name) {
 333     u = c->value;
 334     if (u <= LONG_MAX) x = PyInt_FromLong(u);
 335     else if (c->f&CF_SIGNED) x = PyInt_FromLong(-1 - (long)(ULONG_MAX - u));
 336     else x = PyLong_FromUnsignedLong(u);
 337     PyModule_AddObject(mod, (/*unconst*/ char *)c->name, x);
 338     c++;
 339   }
 340 }
 341
 342 /*----- Submodules --------------------------------------------------------*/
 343
 344 static PyMethodDef *global_methods;
 345 static size_t nmethods, methodsz;
 346
 347 void addmethods(const PyMethodDef *m)
 348 {
 349   size_t n, want, newsz;
 350
 351   for (n = 0; m[n].ml_name; n++);
 352   want = nmethods + n + 1;
 353   if (want > methodsz) {
 354     newsz = methodsz ? 2*methodsz : 16;
 355     while (want > newsz) newsz *= 2;
 356     if (!global_methods)
 357       global_methods = PyObject_Malloc(newsz*sizeof(PyMethodDef));
 358     else
 359       global_methods = PyObject_Realloc(global_methods,
 360                                         newsz*sizeof(PyMethodDef));
 361     assert(global_methods);
 362     methodsz = newsz;
 363   }
 364   memcpy(global_methods + nmethods, m, n*sizeof(PyMethodDef));
 365   nmethods += n;
 366   global_methods[nmethods].ml_name = 0;
 367 }
 368
 369 PyMethodDef *donemethods(void) { return (global_methods); }
 370
 371 /*----- Low-level Python interface ----------------------------------------*/
 372
 373 static PyObject *meth__set_home_module(PyObject *me, PyObject *arg)
 374 {
 375   PyObject *mod;
 376
 377   if (!PyArg_ParseTuple(arg, "O!:_set_home_module", &PyModule_Type, &mod))
 378     return (0);
 379   Py_XDECREF(home_module); home_module = mod; Py_INCREF(home_module);
 380   RETURN_NONE;
 381 }
 382
 383 static const PyMethodDef methods[] = {
 384 #define METHNAME(func) meth_##func
 385   METH  (_set_home_module, "_set_home_module(MOD)")
 386 #undef METHNAME
 387   { 0 }
 388 };
 389
 390 void pyke_core_pyinit(void) { addmethods(methods); }
 391 void pyke_core_pyinsert(PyObject *mod) { ; }
 392
 393 /*----- That's all, folks -------------------------------------------------*/