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 (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 /*----- 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 = TEXT_VFORMAT(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", TEXT_PTR(whyobj));
 176   RESTORE_EXCINFO(exc);
 177   PyErr_Print();
 178   /* drop through... */
 179
 180   /* Clean up afterwards. */
 181 end:
 182   Py_XDECREF(hookfn);
 183   Py_XDECREF(whyobj);
 184   Py_XDECREF(obj);
 185 }
 186
 187 void report_lost_exception(struct excinfo *exc, const char *why, ...)
 188 {
 189   va_list ap;
 190
 191   va_start(ap, why);
 192   report_lost_exception_v(exc, why, ap);
 193   va_end(ap);
 194 }
 195
 196 void stash_exception(struct excinfo *exc, const char *why, ...)
 197 {
 198   va_list ap;
 199   struct excinfo stash;
 200
 201   if (!exc->ty)
 202     STASH_EXCINFO(exc);
 203   else {
 204     va_start(ap, why);
 205     STASH_EXCINFO(&stash);
 206     report_lost_exception_v(&stash, why, ap);
 207     va_end(ap);
 208   }
 209 }
 210
 211 void restore_exception(struct excinfo *exc, const char *why, ...)
 212 {
 213   va_list ap;
 214   struct excinfo stash;
 215
 216   if (!PyErr_Occurred())
 217     RESTORE_EXCINFO(exc);
 218   else {
 219     va_start(ap, why);
 220     STASH_EXCINFO(&stash);
 221     report_lost_exception_v(exc, why, ap);
 222     RESTORE_EXCINFO(&stash);
 223     va_end(ap);
 224   }
 225 }
 226
 227 /*----- Type definitions --------------------------------------------------*/
 228
 229 static const PyTypeObject emptytype = { 0 };
 230
 231 void *newtype(PyTypeObject *metaty,
 232               const PyTypeObject *skel,
 233               const char *name)
 234 {
 235   PyHeapTypeObject *ty =
 236     (PyHeapTypeObject *)_PyObject_GC_Malloc(_PyObject_VAR_SIZE(metaty, 0));
 237   if (!skel) skel = &emptytype;
 238   memcpy(ty, skel, sizeof(*skel));
 239 #define COPY(blah) do {                                                 \
 240     if (ty->ht_type.tp_as_##blah) {                                     \
 241       memcpy(&ty->as_##blah,                                            \
 242              ty->ht_type.tp_as_##blah,                                  \
 243              sizeof(ty->as_##blah));                                    \
 244       ty->ht_type.tp_as_##blah = &ty->as_##blah;                        \
 245     }                                                                   \
 246   } while (0)
 247   COPY(number);
 248   COPY(sequence);
 249   COPY(mapping);
 250   COPY(buffer);
 251 #undef COPY
 252   if (name)
 253     ty->ht_name = TEXT_FROMSTR(name);
 254   else if (ty->ht_type.tp_name)
 255     ty->ht_name = TEXT_FROMSTR(ty->ht_type.tp_name);
 256   else
 257     ty->ht_name = 0;
 258   if (ty->ht_name)
 259     ty->ht_type.tp_name = TEXT_STR(ty->ht_name);
 260   ty->ht_slots = 0;
 261   (void)PyObject_INIT(&ty->ht_type, metaty);
 262   Py_INCREF(metaty);
 263   return (ty);
 264 }
 265
 266 void typeready(PyTypeObject *ty)
 267 {
 268   PyType_Ready(ty);
 269   PyDict_SetItemString(ty->tp_dict, "__module__", modname);
 270 }
 271
 272 PyTypeObject *inittype(const PyTypeObject *tyskel,
 273                        PyTypeObject *base, PyTypeObject *meta)
 274 {
 275   PyTypeObject *ty = newtype(meta, tyskel, 0);
 276   if (base) { ty->tp_base = base; Py_INCREF(base); }
 277   ty->tp_flags |= Py_TPFLAGS_HEAPTYPE;
 278   typeready(ty);
 279   return (ty);
 280 }
 281
 282 /*----- Populating modules ------------------------------------------------*/
 283
 284 PyObject *mkexc(PyObject *mod, PyObject *base,
 285                 const char *name, const PyMethodDef *mm)
 286 {
 287   PyObject *nameobj = 0;
 288   PyObject *dict = 0;
 289   PyObject *exc = 0;
 290   PyObject *func = 0;
 291   PyObject *meth = 0;
 292
 293   if ((dict = PyDict_New()) == 0) goto fail;
 294
 295   if (mm) {
 296     while (mm->ml_name) {
 297       if ((func = PyCFunction_NewEx((/*unconst*/ PyMethodDef *)mm,
 298                                     0, mod)) == 0 ||
 299           (meth = PyMethod_New(func, 0, exc)) == 0 ||
 300           PyDict_SetItemString(dict, mm->ml_name, meth))
 301         goto fail;
 302       Py_DECREF(func); func = 0;
 303       Py_DECREF(meth); meth = 0;
 304       mm++;
 305     }
 306   }
 307
 308   if ((nameobj = TEXT_FORMAT("%s.%s", PyModule_GetName(mod), name)) == 0 ||
 309       (exc = PyErr_NewException(TEXT_STR(nameobj), base, dict)) == 0)
 310     goto fail;
 311
 312 done:
 313   Py_XDECREF(nameobj);
 314   Py_XDECREF(dict);
 315   return (exc);
 316
 317 fail:
 318   Py_XDECREF(exc);
 319   Py_XDECREF(func);
 320   Py_XDECREF(meth);
 321   exc = 0;
 322   goto done;
 323 }
 324
 325 void setconstants(PyObject *mod, const struct nameval *c)
 326 {
 327   PyObject *x;
 328   unsigned long u;
 329
 330   while (c->name) {
 331     u = c->value;
 332     if (u <= LONG_MAX) x = PyInt_FromLong(u);
 333     else if (c->f&CF_SIGNED) x = PyInt_FromLong(-1 - (long)(ULONG_MAX - u));
 334     else x = PyLong_FromUnsignedLong(u);
 335     PyModule_AddObject(mod, (/*unconst*/ char *)c->name, x);
 336     c++;
 337   }
 338 }
 339
 340 /*----- Submodules --------------------------------------------------------*/
 341
 342 static PyMethodDef *global_methods;
 343 static size_t nmethods, methodsz;
 344
 345 void addmethods(const PyMethodDef *m)
 346 {
 347   size_t n, want, newsz;
 348
 349   for (n = 0; m[n].ml_name; n++);
 350   want = nmethods + n + 1;
 351   if (want > methodsz) {
 352     newsz = methodsz ? 2*methodsz : 16;
 353     while (want > newsz) newsz *= 2;
 354     if (!global_methods)
 355       global_methods = PyObject_Malloc(newsz*sizeof(PyMethodDef));
 356     else
 357       global_methods = PyObject_Realloc(global_methods,
 358                                         newsz*sizeof(PyMethodDef));
 359     assert(global_methods);
 360     methodsz = newsz;
 361   }
 362   memcpy(global_methods + nmethods, m, n*sizeof(PyMethodDef));
 363   nmethods += n;
 364   global_methods[nmethods].ml_name = 0;
 365 }
 366
 367 PyMethodDef *donemethods(void) { return (global_methods); }
 368
 369 /*----- Low-level Python interface ----------------------------------------*/
 370
 371 static PyObject *meth__set_home_module(PyObject *me, PyObject *arg)
 372 {
 373   PyObject *mod;
 374
 375   if (!PyArg_ParseTuple(arg, "O!:_set_home_module", &PyModule_Type, &mod))
 376     return (0);
 377   Py_XDECREF(home_module); home_module = mod; Py_INCREF(home_module);
 378   RETURN_NONE;
 379 }
 380
 381 static const PyMethodDef methods[] = {
 382 #define METHNAME(func) meth_##func
 383   METH  (_set_home_module, "_set_home_module(MOD)")
 384 #undef METHNAME
 385   { 0 }
 386 };
 387
 388 void pyke_core_pyinit(void) { addmethods(methods); }
 389 void pyke_core_pyinsert(PyObject *mod) { ; }
 390
 391 /*----- That's all, folks -------------------------------------------------*/