mdw@git.distorted.org.uk Git - catacomb-python/blob - pyke/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   int rc;
 110
 111   if (BIN_CHECK(o)) {
 112     r->vw.obj = 0;
 113     r->p = BIN_PTR(o);
 114     r->sz = BIN_LEN(o);
 115     return (1);
 116   }
 117 #ifdef PY2
 118   if (PyUnicode_Check(o)) {
 119     o = _PyUnicode_AsDefaultEncodedString(o, 0);
 120     if (!o) return (0);
 121     r->vw.obj = 0;
 122     r->p = PyString_AS_STRING(o);
 123     r->sz = PyString_GET_SIZE(o);
 124     return (1);
 125   }
 126 #endif
 127 #if PY_VERSION_HEX < 0x02060000
 128   r->vw.buf = 0;
 129   return (PyObject_AsReadBuffer(o, &r->p, &r->sz) ? 0 : 1);
 130 #else
 131   rc = PyObject_GetBuffer(o, &r->vw, PyBUF_SIMPLE); if (rc) return (0);
 132   o->p = o->vw.buf; o->sz = o->vw.len;
 133   return (1);
 134 #endif
 135 }
 136
 137 void freebin(struct bin *r)
 138   { if (r->vw.obj) PyBuffer_Release(&r->vw); }
 139
 140 /*----- Miscellaneous utilities -------------------------------------------*/
 141
 142 PyObject *abstract_pynew(PyTypeObject *ty, PyObject *arg, PyObject *kw)
 143 {
 144   PyErr_SetString(PyExc_TypeError, "can't instantiate this class");
 145   return (0);
 146 }
 147
 148 PyObject *enrich_compare(int op, int cmp)
 149 {
 150   int r = -1;
 151
 152   switch (op) {
 153     case Py_LT: r = cmp <  0; break;
 154     case Py_LE: r = cmp <= 0; break;
 155     case Py_EQ: r = cmp == 0; break;
 156     case Py_NE: r = cmp != 0; break;
 157     case Py_GE: r = cmp >= 0; break;
 158     case Py_GT: r = cmp >  0; break;
 159     default: assert(0);
 160   }
 161   return (getbool(r));
 162 }
 163
 164 /*----- Saving and restoring exceptions ----------------------------------*/
 165
 166 void report_lost_exception_v(struct excinfo *exc,
 167                              const char *why, va_list ap)
 168 {
 169   PyObject *hookfn = 0;
 170   PyObject *whyobj = 0;
 171   PyObject *obj = 0;
 172
 173   /* Make sure we start out without a pending exception, or this will get
 174    * really confusing.
 175    */
 176   assert(!PyErr_Occurred());
 177
 178   /* Format the explanation. */
 179   if (why) whyobj = TEXT_VFORMAT(why, ap);
 180   else { whyobj = Py_None; Py_INCREF(whyobj); }
 181
 182   /* Find our home module's `lostexchook' function.  This won't work if
 183    * there's no module, or the function isn't defined, or it's `None'.
 184    */
 185   if (!home_module) goto sys;
 186   hookfn = PyObject_GetAttrString(home_module, "lostexchook");
 187   if (hookfn == Py_None) goto sys;
 188   else if (hookfn) ;
 189   else if (!PyErr_ExceptionMatches(PyExc_AttributeError)) goto ouch;
 190   else { PyErr_Clear(); goto sys; }
 191
 192   /* Call the hook function. */
 193   obj = PyObject_CallFunction(hookfn, "(OOOO)",
 194                               whyobj, exc->ty, exc->val, exc->tb);
 195   if (!obj) goto ouch;
 196   goto end;
 197
 198   /* Something went wrong reporting the problem. */
 199 ouch:
 200   PySys_WriteStderr("\n!!! FAILURE REPORTING LOST EXCEPTION\n");
 201   PyErr_Print();
 202   /* drop through... */
 203
 204   /* There was no hook, so try to do something sensible using
 205    * `sys.excepthook'.
 206    */
 207 sys:
 208   PySys_WriteStderr("\n!!! LOST EXCEPTION: %s\n", TEXT_PTR(whyobj));
 209   RESTORE_EXCINFO(exc);
 210   PyErr_Print();
 211   /* drop through... */
 212
 213   /* Clean up afterwards. */
 214 end:
 215   Py_XDECREF(hookfn);
 216   Py_XDECREF(whyobj);
 217   Py_XDECREF(obj);
 218 }
 219
 220 void report_lost_exception(struct excinfo *exc, const char *why, ...)
 221 {
 222   va_list ap;
 223
 224   va_start(ap, why);
 225   report_lost_exception_v(exc, why, ap);
 226   va_end(ap);
 227 }
 228
 229 void stash_exception(struct excinfo *exc, const char *why, ...)
 230 {
 231   va_list ap;
 232   struct excinfo stash;
 233
 234   if (!exc->ty)
 235     STASH_EXCINFO(exc);
 236   else {
 237     va_start(ap, why);
 238     STASH_EXCINFO(&stash);
 239     report_lost_exception_v(&stash, why, ap);
 240     va_end(ap);
 241   }
 242 }
 243
 244 void restore_exception(struct excinfo *exc, const char *why, ...)
 245 {
 246   va_list ap;
 247   struct excinfo stash;
 248
 249   if (!PyErr_Occurred())
 250     RESTORE_EXCINFO(exc);
 251   else {
 252     va_start(ap, why);
 253     STASH_EXCINFO(&stash);
 254     report_lost_exception_v(exc, why, ap);
 255     RESTORE_EXCINFO(&stash);
 256     va_end(ap);
 257   }
 258 }
 259
 260 /*----- Type definitions --------------------------------------------------*/
 261
 262 static const PyTypeObject emptytype = { 0 };
 263
 264 void *newtype(PyTypeObject *metaty,
 265               const PyTypeObject *skel,
 266               const char *name)
 267 {
 268   PyHeapTypeObject *ty =
 269     (PyHeapTypeObject *)_PyObject_GC_Malloc(_PyObject_VAR_SIZE(metaty, 0));
 270   if (!skel) skel = &emptytype;
 271   memcpy(ty, skel, sizeof(*skel));
 272 #define COPY(blah) do {                                                 \
 273     if (ty->ht_type.tp_as_##blah) {                                     \
 274       memcpy(&ty->as_##blah,                                            \
 275              ty->ht_type.tp_as_##blah,                                  \
 276              sizeof(ty->as_##blah));                                    \
 277       ty->ht_type.tp_as_##blah = &ty->as_##blah;                        \
 278     }                                                                   \
 279   } while (0)
 280   COPY(number);
 281   COPY(sequence);
 282   COPY(mapping);
 283   COPY(buffer);
 284 #undef COPY
 285   if (name)
 286     ty->ht_name = TEXT_FROMSTR(name);
 287   else if (ty->ht_type.tp_name)
 288     ty->ht_name = TEXT_FROMSTR(ty->ht_type.tp_name);
 289   else
 290     ty->ht_name = 0;
 291   if (ty->ht_name)
 292     ty->ht_type.tp_name = TEXT_STR(ty->ht_name);
 293   ty->ht_slots = 0;
 294 #ifdef PY3
 295   ty->ht_qualname = 0;
 296 #endif
 297   (void)PyObject_INIT(&ty->ht_type, metaty);
 298   Py_INCREF(metaty);
 299   return (ty);
 300 }
 301
 302 void typeready(PyTypeObject *ty)
 303 {
 304 #ifdef PY3
 305   PyHeapTypeObject *hty = (PyHeapTypeObject *)ty;
 306   hty->ht_qualname = hty->ht_name;
 307 #endif
 308   PyType_Ready(ty);
 309   PyDict_SetItemString(ty->tp_dict, "__module__", modname);
 310 }
 311
 312 PyTypeObject *inittype(const PyTypeObject *tyskel,
 313                        PyTypeObject *base, PyTypeObject *meta)
 314 {
 315   PyTypeObject *ty = newtype(meta, tyskel, 0);
 316   if (base) { ty->tp_base = base; Py_INCREF(base); }
 317   ty->tp_flags |= Py_TPFLAGS_HEAPTYPE;
 318   typeready(ty);
 319   return (ty);
 320 }
 321
 322 /*----- Populating modules ------------------------------------------------*/
 323
 324 PyObject *mkexc(PyObject *mod, PyObject *base,
 325                 const char *name, const PyMethodDef *mm)
 326 {
 327   PyObject *nameobj = 0;
 328   PyObject *dict = 0;
 329   PyObject *exc = 0;
 330   PyObject *func = 0;
 331   PyObject *meth = 0;
 332
 333   if ((dict = PyDict_New()) == 0) goto fail;
 334
 335   if (mm) {
 336     while (mm->ml_name) {
 337       if ((func = PyCFunction_NewEx((/*unconst*/ PyMethodDef *)mm,
 338                                     0, mod)) == 0 ||
 339           (meth = PY23(PyMethod_New(func, 0, exc),
 340                        PyInstanceMethod_New(func))) == 0 ||
 341           PyDict_SetItemString(dict, mm->ml_name, meth))
 342         goto fail;
 343       Py_DECREF(func); func = 0;
 344       Py_DECREF(meth); meth = 0;
 345       mm++;
 346     }
 347   }
 348
 349   if ((nameobj = TEXT_FORMAT("%s.%s", PyModule_GetName(mod), name)) == 0 ||
 350       (exc = PyErr_NewException(TEXT_STR(nameobj), base, dict)) == 0)
 351     goto fail;
 352
 353 done:
 354   Py_XDECREF(nameobj);
 355   Py_XDECREF(dict);
 356   return (exc);
 357
 358 fail:
 359   Py_XDECREF(exc);
 360   Py_XDECREF(func);
 361   Py_XDECREF(meth);
 362   exc = 0;
 363   goto done;
 364 }
 365
 366 void setconstants(PyObject *mod, const struct nameval *c)
 367 {
 368   PyObject *x;
 369   unsigned long u;
 370
 371   while (c->name) {
 372     u = c->value;
 373     if (u <= LONG_MAX) x = PyInt_FromLong(u);
 374     else if (c->f&CF_SIGNED) x = PyInt_FromLong(-1 - (long)(ULONG_MAX - u));
 375     else x = PyLong_FromUnsignedLong(u);
 376     PyModule_AddObject(mod, (/*unconst*/ char *)c->name, x);
 377     c++;
 378   }
 379 }
 380
 381 /*----- Submodules --------------------------------------------------------*/
 382
 383 static PyMethodDef *global_methods;
 384 static size_t nmethods, methodsz;
 385
 386 void addmethods(const PyMethodDef *m)
 387 {
 388   size_t n, want, newsz;
 389
 390   for (n = 0; m[n].ml_name; n++);
 391   want = nmethods + n + 1;
 392   if (want > methodsz) {
 393     newsz = methodsz ? 2*methodsz : 16;
 394     while (want > newsz) newsz *= 2;
 395     if (!global_methods)
 396       global_methods = PyObject_Malloc(newsz*sizeof(PyMethodDef));
 397     else
 398       global_methods = PyObject_Realloc(global_methods,
 399                                         newsz*sizeof(PyMethodDef));
 400     assert(global_methods);
 401     methodsz = newsz;
 402   }
 403   memcpy(global_methods + nmethods, m, n*sizeof(PyMethodDef));
 404   nmethods += n;
 405   global_methods[nmethods].ml_name = 0;
 406 }
 407
 408 PyMethodDef *donemethods(void) { return (global_methods); }
 409
 410 /*----- Low-level Python interface ----------------------------------------*/
 411
 412 static PyObject *meth__set_home_module(PyObject *me, PyObject *arg)
 413 {
 414   PyObject *mod;
 415
 416   if (!PyArg_ParseTuple(arg, "O!:_set_home_module", &PyModule_Type, &mod))
 417     return (0);
 418   Py_XDECREF(home_module); home_module = mod; Py_INCREF(home_module);
 419   RETURN_NONE;
 420 }
 421
 422 static const PyMethodDef methods[] = {
 423 #define METHNAME(func) meth_##func
 424   METH  (_set_home_module, "_set_home_module(MOD)")
 425 #undef METHNAME
 426   { 0 }
 427 };
 428
 429 void pyke_core_pyinit(void) { addmethods(methods); }
 430 void pyke_core_pyinsert(PyObject *mod) { ; }
 431
 432 /*----- That's all, folks -------------------------------------------------*/