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

   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 #ifndef PYKE_H
  28 #define PYKE_H
  29
  30 #ifdef __cplusplus
  31   extern "C" {
  32 #endif
  33
  34 /*----- Header files ------------------------------------------------------*/
  35
  36 #define PY_SSIZE_T_CLEAN
  37
  38 #include <Python.h>
  39 #include <structmember.h>
  40
  41 /*----- Other preliminaries -----------------------------------------------*/
  42
  43 #define NOTHING
  44 #define COMMA ,
  45
  46 /*----- Symbol visibility -------------------------------------------------*
  47  *
  48  * This library is very messy regarding symbol namespace.  Keep this mess
  49  * within our shared-object.
  50  */
  51
  52 #define GOBBLE_SEMI extern int notexist
  53 #if defined(__GNUC__) && defined(__ELF__)
  54 #  define PRIVATE_SYMBOLS _Pragma("GCC visibility push(hidden)") GOBBLE_SEMI
  55 #  define PUBLIC_SYMBOLS _Pragma("GCC visibility pop") GOBBLE_SEMI
  56 #  define EXPORT __attribute__((__visibility__("default")))
  57 #else
  58 #  define PRIVATE_SYMBOLS GOBBLE_SEMI
  59 #  define PUBLIC_SYMBOLS GOBBLE_SEMI
  60 #  define EXPORT
  61 #endif
  62
  63 PRIVATE_SYMBOLS;
  64
  65 /*----- Python version compatibility hacks --------------------------------*/
  66
  67 /* The handy `Py_TYPE' and `Py_SIZE' macros turned up in 2.6.  Define them if
  68  * they're not already here.
  69  */
  70 #ifndef Py_TYPE
  71 #  define Py_TYPE(obj) (((PyObject *)(obj))->ob_type)
  72 #endif
  73 #ifndef Py_SIZE
  74 #  define Py_SIZE(obj) (((PyVarObject *)(obj))->ob_size)
  75 #endif
  76
  77 /* Python 3 added internal structure to the various object headers, and
  78  * defined a new macro `PyVarObject_HEAD_INIT' to initialize variable-length
  79  * static instances correctly.  Define it if it's not already here.
  80  */
  81 #ifndef PyVarObject_HEAD_INIT
  82 #  define PyVarObject_HEAD_INIT(super, sz) PyObject_HEAD_INIT(super) sz,
  83 #endif
  84
  85 /* Python 3.2 changed the type of hash values, so paper over this annoying
  86  * difference.
  87  */
  88 #if PY_VERSION_HEX < 0x03020000
  89   typedef long Py_hash_t;
  90 #endif
  91
  92 /* Plain octet strings.  Python 2 calls these `str', while Python 3 calls
  93  * them `bytes'.  We call them `bin' here, and define the following.
  94  *
  95  *   * `BINOBJ' is the C type of a `bin' object.
  96  *   * `BIN_TYPE' is the Python `type' object for `bin'.
  97  *   * `BIN_CHECK(OBJ)' is true if OBJ is a `bin' object.
  98  *   * `BIN_PTR(OBJ)' points to the first octet of OBJ, without checking!
  99  *   * `BIN_LEN(OBJ)' yields the length of OBJ in octets, without checking!
 100  *   * `BIN_FROMSTR(STR)' makes a `bin' object from a null-terminated string.
 101  *   * `BIN_FORMAT(FMT, ARGS...)' and `BIN_VFORMAT(FMT, AP)' make a `bin'
 102  *     object from a `printf'-like format string and arguments.
 103  *   * `BIN_PREPAREWRITE(OBJ, PTR, LEN)' prepares to make a `bin' object: it
 104  *     sets PTR to point to a buffer of LEN bytes; call `BIN_DONEWRITE' when
 105  *     finished.  The variable OBJ will eventually be the resulting object,
 106  *     but until `BIN_DONEWRITE' is called, it may in fact be some different
 107  *     object.
 108  *   * `BIN_DONEWRITE(OBJ, LEN)' completes making a `bin' object: it adjusts
 109  *     its length to be LEN, which must not be larger than the LEN given to
 110  *     `BIN_PREPAREWRITE', and sets OBJ to point to the finished object.
 111  *   * `BIN_SETLEN(OBJ, LEN)' adjusts the length of OBJ downwards to LEN,
 112  *     without checking!
 113  #   * `Y' is a format character for `PyArg_ParseTuple...' for retrieving a
 114  *     null-terminated octet string from a `bin' object.
 115  #   * `YN' is a format character for `PyArg_ParseTuple...' for retrieving an
 116  *     octet string and length from any sort-of vaguely binary-ish object.
 117  */
 118 #  define BINOBJ PyStringObject
 119 #  define BIN_TYPE PyString_Type
 120 #  define BIN_CHECK(obj) PyString_Check(obj)
 121 #  define BIN_PTR(obj) PyString_AS_STRING(obj)
 122 #  define BIN_LEN(obj) PyString_GET_SIZE(obj)
 123 #  define BIN_FROMSTR(str) PyString_FromString(str)
 124 #  define BIN_FROMSTRLEN(str, len) PyString_FromStringAndSize(str, len)
 125 #  define BIN_FORMAT PyString_FromFormat
 126 #  define BIN_VFORMAT PyString_FromFormatV
 127 #  define BIN_PREPAREWRITE(obj, ptr, sz) do {                           \
 128      (obj) = PyString_FromStringAndSize(0, (sz));                       \
 129      (ptr) = PyString_AS_STRING(obj);                                   \
 130    } while (0)
 131 #  define BIN_DONEWRITE(obj, sz) do Py_SIZE(obj) = (sz); while (0)
 132 #  define BIN_SETLEN(obj, len) do Py_SIZE(obj) = (len); while (0)
 133 #  define Y "s"
 134 #  define YN "s#"
 135
 136 /* Text strings.  Both Python 2 and Python 3 call these `str', but they're
 137  * very different because a Python 3 `str' is Unicode inside.  When dealing
 138  * with Python 3 text, the data is UTF-8 encoded.  We call them `text' here,
 139  * and define the following.
 140  *
 141  *   * `TEXTOBJ' is the C type of a `text' object.
 142  *   * `TEXT_TYPE' is the Python `type' object for `text'.
 143  *   * `TEXT_CHECK(OBJ)' is true if OBJ is a `text' object.
 144  *   * `TEXT_STR(OBJ)' points to the first byte of a null-terminated string
 145  *     OBJ, or is null.
 146  *   * `TEXT_PTR(OBJ)' points to the first byte of OBJ, without checking!
 147  *   * `TEXT_LEN(OBJ)' yields the length of OBJ in octets, without checking!
 148  *   * `TEXT_FROMSTR(STR)' makes a `text' object from a null-terminated
 149  *     string.
 150  *   * `TEXT_FORMAT(FMT, ARGS...)' and `TEST_VFORMAT(FMT, AP)' make a `text'
 151  *     object from a `printf'-like format string and arguments.
 152  *   * `TEXT_PREPAREWRITE(OBJ, PTR, LEN)' prepares to make a `text' object:
 153  *     it sets PTR to point to a buffer of LEN bytes; call `TEXT_DONEWRITE'
 154  *     when finished.  The variable OBJ will eventually be the resulting
 155  *     object, but until `TEXT_DONEWRITE' is called, it may in fact be some
 156  *     different object.
 157  *   * `TEXT_DONEWRITE(OBJ, LEN)' completes making a `text' object: it
 158  *     adjusts its length to be LEN, which must not be larger than the LEN
 159  *     given to `TEXT_PREPAREWRITE', and sets OBJ to point to the finished
 160  *     object.
 161  *
 162  * (Use `s' and `s#' in `PyArg_ParseTuple...'.)
 163  */
 164 #  define TEXTOBJ PyStringObject
 165 #  define TEXT_TYPE PyString_Type
 166 #  define TEXT_CHECK(obj) PyString_Check(obj)
 167 #  define TEXT_PTR(obj) PyString_AS_STRING(obj)
 168 #  define TEXT_STR(obj) PyString_AsString(obj)
 169 #  define TEXT_PTRLEN(obj, ptr, len) do {                               \
 170      (ptr) = PyString_AS_STRING(obj);                                   \
 171      (len) = PyString_GET_SIZE(obj);                                    \
 172    } while (0)
 173 #  define TEXT_FORMAT PyString_FromFormat
 174 #  define TEXT_VFORMAT PyString_FromFormatV
 175 #  define TEXT_PREPAREWRITE(obj, ptr, sz) do {                          \
 176      (obj) = PyString_FromStringAndSize(0, (sz));                       \
 177      (ptr) = PyString_AS_STRING(obj);                                   \
 178    } while (0)
 179 #  define TEXT_DONEWRITE(obj, sz) do { Py_SIZE(obj) = (sz); } while (0)
 180 #  define TEXT_FROMSTR(str) PyString_FromString(str)
 181 #  define TEXT_FROMSTRLEN(str, len) PyString_FromStringAndSize(str, len)
 182
 183 /*----- Utilities for returning values and exceptions ---------------------*/
 184
 185 /* Returning values. */
 186 #define RETURN_OBJ(obj) do { Py_INCREF(obj); return (obj); } while (0)
 187 #define RETURN_NONE RETURN_OBJ(Py_None)
 188 #define RETURN_NOTIMPL RETURN_OBJ(Py_NotImplemented)
 189 #define RETURN_TRUE RETURN_OBJ(Py_True)
 190 #define RETURN_FALSE RETURN_OBJ(Py_False)
 191 #define RETURN_ME RETURN_OBJ(me)
 192
 193 /* Returning exceptions.  (Note that `KeyError' is `MAPERR' here, because
 194  * Catacomb has its own kind of `KeyError'.)
 195  */
 196 #define EXCERR(exc, str) do {                                           \
 197   PyErr_SetString(exc, str);                                            \
 198   goto end;                                                             \
 199 } while (0)
 200 #define VALERR(str) EXCERR(PyExc_ValueError, str)
 201 #define OVFERR(str) EXCERR(PyExc_OverflowError, str)
 202 #define TYERR(str) EXCERR(PyExc_TypeError, str)
 203 #define IXERR(str) EXCERR(PyExc_IndexError, str)
 204 #define ZDIVERR(str) EXCERR(PyExc_ZeroDivisionError, str)
 205 #define SYSERR(str) EXCERR(PyExc_SystemError, str)
 206 #define NIERR(str) EXCERR(PyExc_NotImplementedError, str)
 207 #define MAPERR(idx) do {                                                \
 208   PyErr_SetObject(PyExc_KeyError, idx);                                 \
 209   goto end;                                                             \
 210 } while (0)
 211 #define OSERR(name) do {                                                \
 212   PyErr_SetFromErrnoWithFilename(PyExc_OSError, name);                  \
 213   goto end;                                                             \
 214 } while (0)
 215
 216 /* Saving and restoring exceptions. */
 217 struct excinfo { PyObject *ty, *val, *tb; };
 218 #define EXCINFO_INIT { 0, 0, 0 }
 219 #define INIT_EXCINFO(exc) do {                                          \
 220   struct excinfo *_exc = (exc); _exc->ty = _exc->val = _exc->tb = 0;    \
 221 } while (0)
 222 #define RELEASE_EXCINFO(exc) do {                                       \
 223   struct excinfo *_exc = (exc);                                         \
 224   Py_XDECREF(_exc->ty);  _exc->ty  = 0;                                 \
 225   Py_XDECREF(_exc->val); _exc->val = 0;                                 \
 226   Py_XDECREF(_exc->tb);  _exc->tb  = 0;                                 \
 227 } while (0)
 228 #define STASH_EXCINFO(exc) do {                                         \
 229   struct excinfo *_exc = (exc);                                         \
 230   PyErr_Fetch(&_exc->ty, &_exc->val, &_exc->tb);                        \
 231   PyErr_NormalizeException(&_exc->ty, &_exc->val, &_exc->tb);           \
 232 } while (0)
 233 #define RESTORE_EXCINFO(exc) do {                                       \
 234   struct excinfo *_exc = (exc);                                         \
 235   PyErr_Restore(_exc->ty, _exc->val, _exc->tb);                         \
 236   _exc->ty = _exc->val = _exc->tb = 0;                                  \
 237 } while (0)
 238 extern void report_lost_exception(struct excinfo *, const char *, ...);
 239 extern void report_lost_exception_v(struct excinfo *, const char *, va_list);
 240 extern void stash_exception(struct excinfo *, const char *, ...);
 241 extern void restore_exception(struct excinfo *, const char *, ...);
 242
 243 /*----- Conversions -------------------------------------------------------*/
 244
 245 /* Define an input conversion (`O&') function: check that the object has
 246  * Python type TY, and extract a C pointer to CTY by calling EXT on the
 247  * object (which may well be a macro).
 248  */
 249 #define CONVFUNC(ty, cty, ext)                                          \
 250   int conv##ty(PyObject *o, void *p)                                    \
 251   {                                                                     \
 252     if (!PyObject_TypeCheck(o, ty##_pytype))                            \
 253       TYERR("wanted a " #ty);                                           \
 254     *(cty *)p = ext(o);                                                 \
 255     return (1);                                                         \
 256   end:                                                                  \
 257     return (0);                                                         \
 258   }
 259
 260 /* Input conversion functions for standard kinds of objects, with overflow
 261  * checking where applicable.
 262  */
 263 struct bin { const void *p; Py_ssize_t sz; };
 264 extern int convulong(PyObject *, void *); /* unsigned long */
 265 extern int convuint(PyObject *, void *); /* unsigned int */
 266 extern int convszt(PyObject *, void *); /* size_t */
 267 extern int convbool(PyObject *, void *); /* bool */
 268 extern int convbin(PyObject *, void *); /* read buffer holding bytes */
 269
 270 /* Output conversions. */
 271 extern PyObject *getbool(int);          /* bool */
 272 extern PyObject *getulong(unsigned long); /* any kind of unsigned integer */
 273
 274 /*----- Miscellaneous utilities -------------------------------------------*/
 275
 276 #define FREEOBJ(obj) (Py_TYPE(obj)->tp_free((PyObject *)(obj)))
 277   /* Actually free OBJ, e.g., in a deallocation function. */
 278
 279 extern PyObject *abstract_pynew(PyTypeObject *, PyObject *, PyObject *);
 280   /* A `tp_new' function which refuses to make the object. */
 281
 282 extern PyObject *enrich_compare(int /*op*/, int /*cmp*/);
 283   /* Use a traditional compare-against-zero comparison result CMP to answer a
 284    * modern Python `tp_richcompare' operation OP.
 285    */
 286
 287 #ifndef CONVERT_CAREFULLY
 288 #  define CONVERT_CAREFULLY(newty, expty, obj)                          \
 289      (!sizeof(*(expty *)0 = (obj)) + (/*unconst*/ newty)(obj))
 290   /* Convert OBJ to the type NEWTY, having previously checked that it is
 291    * convertible to the expected type EXPTY.
 292    *
 293    * Because of the way we set up types, we can make many kinds of tables be
 294    * `const' which can't usually be so (because Python will want to fiddle
 295    * with their reference counts); and, besides, Python's internals are
 296    * generally quite bad at being `const'-correct about tables.  One frequent
 297    * application of this macro, then, is in removing `const' from a type
 298    * without sacrificing all type safety.  The other common use is in
 299    * checking that method function types match up with the signatures
 300    * expected in their method definitions.
 301    */
 302 #endif
 303
 304 #define KWLIST CONVERT_CAREFULLY(char **, const char *const *, kwlist)
 305   /* Strip `const' qualifiers from the keyword list `kwlist'.  Useful when
 306    * calling `PyArg_ParseTupleAndKeywords', which isn't `const'-correct.
 307    */
 308
 309 /*----- Type definitions --------------------------------------------------*
 310  *
 311  * Pyke types are defined in a rather unusual way.
 312  *
 313  * The main code defines a `type skeleton' of type `PyTypeObject',
 314  * conventionally named `TY_pytype_skel'.  Unlike typical Python type
 315  * definitions in extensions, this can (and should) be read-only.  Also,
 316  * there's no point in setting the `tp_base' pointer here, because the actual
 317  * runtime base type object won't, in general, be known at compile time.
 318  * Instead, the type skeletons are converted into Python `heap types' by the
 319  * `INITTYPE' macro.  The main difference is that Python code can add
 320  * attributes to heap types, and we make extensive use of this ability.
 321  */
 322
 323 extern void *newtype(PyTypeObject */*meta*/,
 324                      const PyTypeObject */*skel*/, const char */*name*/);
 325   /* Make and return a new Python type object, of type META (typically
 326    * `PyType_Type', but may be a subclass), filled in from the skeleton SKEL
 327    * (null to inherit everything), and named NAME.  The caller can mess with
 328    * the type object further at this time: call `typeready' when it's set up
 329    * properly.
 330    */
 331
 332 extern void typeready(PyTypeObject *);
 333   /* The type object is now ready to be used. */
 334
 335 extern PyTypeObject *inittype(const PyTypeObject */*skel*/,
 336                               PyTypeObject */*base*/,
 337                               PyTypeObject */*meta*/);
 338   /* All-in-one function to construct a working type from a type skeleton
 339    * SKEL, with known base type BASE (null for `object') and metaclass.
 340    */
 341
 342 /* Alias for built-in types, to fit in with Pyke naming conventions. */
 343 #define root_pytype 0
 344 #define type_pytype &PyType_Type
 345
 346 #define INITTYPE_META(ty, base, meta) do {                              \
 347   ty##_pytype = inittype(&ty##_pytype_skel, base##_pytype, meta##_pytype); \
 348 } while (0)
 349 #define INITTYPE(ty, base) INITTYPE_META(ty, base, type)
 350   /* Macros to initialize a type from its skeleton. */
 351
 352 /* Macros for filling in `PyMethodDef' tables, ensuring that functions have
 353  * the expected signatures.
 354  */
 355 #define STD_METHOD(decor, func, flags, doc)                             \
 356   { #func, decor(func), METH_VARARGS | flags, doc },
 357 #define KEYWORD_METHOD(decor, func, flags, doc)                         \
 358   { #func,                                                              \
 359     CONVERT_CAREFULLY(PyCFunction, PyCFunctionWithKeywords, decor(func)), \
 360     METH_VARARGS | METH_KEYWORDS | flags,                               \
 361     doc },
 362 #define NOARG_METHOD(decor, func, flags, doc)                           \
 363   { #func,                                                              \
 364     CONVERT_CAREFULLY(PyCFunction, PyNoArgsFunction, decor(func)),      \
 365     METH_NOARGS | flags,                                                \
 366     doc },
 367
 368 /* Convenience wrappers for filling in `PyMethodDef' tables, following
 369  * Pyke naming convention.  Define `METHNAME' locally as
 370  *
 371  *      #define METHNAME(name) foometh_##func
 372  *
 373  * around the method table.
 374  */
 375 #define METH(func, doc) STD_METHOD(METHNAME, func, 0, doc)
 376 #define KWMETH(func, doc) KEYWORD_METHOD(METHNAME, func, 0, doc)
 377 #define NAMETH(func, doc) NOARG_METHOD(METHNAME, func, 0, doc)
 378 #define CMTH(func, doc) STD_METHOD(METHNAME, func, METH_CLASS, doc)
 379 #define KWCMTH(func, doc) KEYWORD_METHOD(METHNAME, func, METH_CLASS, doc)
 380 #define NACMTH(func, doc) NOARG_METHOD(METHNAME, func, METH_CLASS, doc)
 381 #define SMTH(func, doc) STD_METHOD(METHNAME, func, METH_STATIC, doc)
 382 #define KWSMTH(func, doc) KEYWORD_METHOD(METHNAME, func, METH_STATIC, doc)
 383 #define NASMTH(func, doc) NOARG_METHOD(METHNAME, func, METH_STATIC, doc)
 384
 385 /* Convenience wrappers for filling in `PyGetSetDef' tables, following Pyke
 386  * naming convention.  Define `GETSETNAME' locally as
 387  *
 388  *      #define GETSETNAME(op, name) foo##op##_##func
 389  *
 390  * around the get/set table.
 391  */
 392 #define GET(func, doc)                                                  \
 393   { #func, GETSETNAME(get, func), 0, doc },
 394 #define GETSET(func, doc)                                               \
 395   { #func, GETSETNAME(get, func), GETSETNAME(set, func), doc },
 396
 397 /* Convenience wrappers for filling in `PyMemberDef' tables.  Define
 398  * `MEMBERSTRUCT' locally as
 399  *
 400  *      #define MEMBERSTRUCT foo_pyobj
 401  *
 402  * around the member table.
 403  */
 404 #define MEMRNM(name, ty, mem, f, doc)                                   \
 405   { #name, ty, offsetof(MEMBERSTRUCT, mem), f, doc },
 406 #define MEMBER(name, ty, f, doc) MEMRNM(name, ty, name, f, doc)
 407
 408 /* Wrappers for filling in pointers in a `PyTypeObject' structure, (a)
 409  * following Pyke naming convention, and (b) stripping `const' from the types
 410  * without losing type safety.
 411  */
 412 #define UNCONST_TYPE_SLOT(type, suffix, op, ty)                         \
 413   CONVERT_CAREFULLY(type *, const type *, op ty##_py##suffix)
 414 #define PYGETSET(ty) UNCONST_TYPE_SLOT(PyGetSetDef, getset, NOTHING, ty)
 415 #define PYMETHODS(ty) UNCONST_TYPE_SLOT(PyMethodDef, methods, NOTHING, ty)
 416 #define PYMEMBERS(ty) UNCONST_TYPE_SLOT(PyMemberDef, members, NOTHING, ty)
 417 #define PYNUMBER(ty) UNCONST_TYPE_SLOT(PyNumberMethods, number, &, ty)
 418 #define PYSEQUENCE(ty) UNCONST_TYPE_SLOT(PySequenceMethods, sequence, &, ty)
 419 #define PYMAPPING(ty) UNCONST_TYPE_SLOT(PyMappingMethods, mapping, &, ty)
 420 #define PYBUFFER(ty) UNCONST_TYPE_SLOT(PyBufferProcs, buffer, &, ty)
 421
 422 /*----- Populating modules ------------------------------------------------*/
 423
 424 extern PyObject *modname;
 425   /* The overall module name.  Set this with `TEXT_FROMSTR'. */
 426
 427 extern PyObject *home_module;
 428   /* The overall module object. */
 429
 430 extern PyObject *mkexc(PyObject */*mod*/, PyObject */*base*/,
 431                        const char */*name*/, const PyMethodDef */*methods*/);
 432   /* Make and return an exception class called NAME, which will end up in
 433    * module MOD (though it is not added at this time).  The new class is a
 434    * subclass of BASE.  Attach the METHODS to it.
 435    */
 436
 437 #define INSERT(name, ob) do {                                           \
 438   PyObject *_o = (PyObject *)(ob);                                      \
 439   Py_INCREF(_o);                                                        \
 440   PyModule_AddObject(mod, name, _o);                                    \
 441 } while (0)
 442   /* Insert a Python object OB into the module `mod' under the given NAME. */
 443
 444 /* Numeric constants. */
 445 struct nameval { const char *name; unsigned f; unsigned long value; };
 446 #define CF_SIGNED 1u
 447 extern void setconstants(PyObject *, const struct nameval *);
 448 #define CONST(x) { #x, (x) >= 0 ? 0 : CF_SIGNED, x }
 449 #define CONSTFLAG(f, x) { #x, f, x }
 450
 451 #define INSEXC(name, var, base, meth)                                   \
 452   INSERT(name, var = mkexc(mod, base, name, meth))
 453   /* Insert an exception class into the module `mod'; other arguments are as
 454    * for `mkexc'.
 455    */
 456
 457 /*----- Submodules --------------------------------------------------------*
 458  *
 459  * It's useful to split the Python module up into multiple source files, and
 460  * have each one contribute its definitions into the main module.
 461  *
 462  * Define a list-macro `MODULES' in the master header file naming the
 463  * submodules to be processed, and run
 464  *
 465  *      MODULES(DECLARE_MODINIT)
 466  *
 467  * to declare the interface functions.
 468  *
 469  * Each submodule FOO defines two functions: `FOO_pyinit' initializes types
 470  * (see `INITTYPE' above) and accumulates methods (`addmethods' below), while
 471  * `FOO_pyinsert' populates the module with additional definitions
 472  * (especially types, though also constants).
 473  *
 474  * The top-level module initialization should call `INIT_MODULES' before
 475  * creating the Python module, and `INSERT_MODULES' afterwards to make
 476  * everything work.
 477  */
 478
 479 extern void addmethods(const PyMethodDef *);
 480 extern PyMethodDef *donemethods(void);
 481   /* Accumulate method-table fragments, and return the combined table of all
 482    * of the fragments.
 483    */
 484
 485 #define DECLARE_MODINIT(m)                                              \
 486   extern void m##_pyinit(void);                                         \
 487   extern void m##_pyinsert(PyObject *);
 488   /* Declare submodule interface functions. */
 489
 490 #define DOMODINIT(m) m##_pyinit();
 491 #define DOMODINSERT(m) m##_pyinsert(mod);
 492 #define INIT_MODULES do { MODULES(DOMODINIT) } while (0)
 493 #define INSERT_MODULES do { MODULES(DOMODINSERT) } while (0)
 494   /* Top-level dispatch to the various submodules. */
 495
 496 /*----- Generic mapping support -------------------------------------------*/
 497
 498 /* Operations table.  ME is the mapping object throughout. */
 499 typedef struct gmap_ops {
 500   size_t isz;                           /* iterator size */
 501
 502   void *(*lookup)(PyObject *me, PyObject *key, unsigned *f);
 503     /* Lookup the KEY.  If it is found, return an entry pointer for it; if F
 504      * is not null, set *F nonzero.  Otherwise, if F is null, return a null
 505      * pointer (without setting a pending exception); if F is not null, then
 506      * set *F zero and return a fresh entry pointer.  Return null on a Python
 507      * exception (the caller will notice the difference.)
 508      */
 509
 510   void (*iter_init)(PyObject *me, void *i);
 511     /* Initialize an iterator at I. */
 512
 513   void *(*iter_next)(PyObject *me, void *i);
 514     /* Return an entry pointer for a different item, or null if all have been
 515      * visited.
 516      */
 517
 518   PyObject *(*entry_key)(PyObject *me, void *e);
 519     /* Return the key object for a mapping entry. */
 520
 521   PyObject *(*entry_value)(PyObject *me, void *e);
 522     /* Return the value object for a mapping entry. */
 523
 524   int (*set_entry)(PyObject *me, void *e, PyObject *val);
 525     /* Modify the entry by storing VAL in its place.  Return 0 on success,
 526      * or -1 on a Python error.
 527      */
 528
 529   int (*del_entry)(PyObject *me, void *e);
 530     /* Delete the entry.  (It may be necessary to delete a freshly allocated
 531      * entry, e.g., if `set_entry' failed.)  Return 0 on success, or -1 on a
 532      * Python error.
 533      */
 534 } gmap_ops;
 535
 536 /* The intrusion at the head of a mapping object. */
 537 #define GMAP_PYOBJ_HEAD                                                 \
 538   PyObject_HEAD                                                         \
 539   const gmap_ops *gmops;
 540
 541 typedef struct gmap_pyobj {
 542   GMAP_PYOBJ_HEAD
 543 } gmap_pyobj;
 544 #define GMAP_OPS(obj) (((gmap_pyobj *)(obj))->gmops)
 545   /* Discover the operations from a mapping object. */
 546
 547 /* Mapping methods. */
 548 #define GMAP_METMNAME(func) gmapmeth_##func
 549 #define GMAP_METH(func, doc) STD_METHOD(GMAP_METMNAME, func, 0, doc)
 550 #define GMAP_KWMETH(func, doc) KEYWORD_METHOD(GMAP_METMNAME, func, 0, doc)
 551 #define GMAP_NAMETH(func, doc) NOARG_METHOD(GMAP_METMNAME, func, 0, doc)
 552 #define GMAP_METHDECL(func, doc)                                        \
 553   extern PyObject *gmapmeth_##func(PyObject *, PyObject *);
 554 #define GMAP_KWMETHDECL(func, doc)                                      \
 555   extern PyObject *gmapmeth_##func(PyObject *, PyObject *, PyObject *);
 556 #define GMAP_NAMETHDECL(func, doc)                                      \
 557   extern PyObject *gmapmeth_##func(PyObject *);
 558
 559 #  define GMAP_DOROMETHODS(METH, KWMETH, NAMETH)                        \
 560     METH  (has_key,     "D.has_key(KEY) -> BOOL")                       \
 561     NAMETH(keys,        "D.keys() -> LIST")                             \
 562     NAMETH(values,      "D.values() -> LIST")                           \
 563     NAMETH(items,       "D.items() -> LIST")                            \
 564     NAMETH(iterkeys,    "D.iterkeys() -> ITER")                         \
 565     NAMETH(itervalues,  "D.itervalues() -> ITER")                       \
 566     NAMETH(iteritems,   "D.iteritems() -> ITER")                        \
 567     KWMETH(get,         "D.get(KEY, [default = None]) -> VALUE")
 568
 569 #define GMAP_DOMETHODS(METH, KWMETH, NAMETH)                            \
 570   GMAP_DOROMETHODS(METH, KWMETH, NAMETH)                                \
 571   NAMETH(clear,         "D.clear()")                                    \
 572   KWMETH(setdefault,    "D.setdefault(K, [default = None]) -> VALUE")   \
 573   KWMETH(pop,           "D.pop(KEY, [default = <error>]) -> VALUE")     \
 574   NAMETH(popitem,       "D.popitem() -> (KEY, VALUE)")                  \
 575   KWMETH(update,        "D.update(MAP)")
 576
 577 GMAP_DOMETHODS(GMAP_METHDECL, GMAP_KWMETHDECL, GMAP_NAMETHDECL)
 578 #define GMAP_ROMETHODS GMAP_DOROMETHODS(GMAP_METH, GMAP_KWMETH, GMAP_NAMETH)
 579 #define GMAP_METHODS GMAP_DOMETHODS(GMAP_METH, GMAP_KWMETH, GMAP_NAMETH)
 580
 581 /* Mapping protocol implementation. */
 582 extern Py_ssize_t gmap_pysize(PyObject *); /* for `mp_length' */
 583 extern PyObject *gmap_pyiter(PyObject *); /* for `tp_iter' */
 584 extern PyObject *gmap_pylookup(PyObject *, PyObject *); /* for `mp_subscript' */
 585 extern int gmap_pystore(PyObject *, PyObject *, PyObject *); /* for `mp_ass_subscript' */
 586 extern int gmap_pyhaskey(PyObject *, PyObject *); /* for `sq_contains' */
 587 extern const PySequenceMethods gmap_pysequence; /* for `tp_as_sequence' */
 588 extern const PyMethodDef gmapro_pymethods[]; /* read-only methods */
 589 extern const PyMethodDef gmap_pymethods[]; /* all the standard methods */
 590
 591 /*----- That's all, folks -------------------------------------------------*/
 592
 593 #ifdef __cplusplus
 594   }
 595 #endif
 596
 597 #endif