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Added some files for the python port
author windel
date Tue, 27 Dec 2011 18:59:02 +0100
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26:dcce92b1efbc 27:7f74363f4c82
1 #ifndef Py_OBJECT_H
2 #define Py_OBJECT_H
3
4 /* Object and type object interface */
5
6 /*
7 Objects are structures allocated on the heap. Special rules apply to
8 the use of objects to ensure they are properly garbage-collected.
9 Objects are never allocated statically or on the stack; they must be
10 accessed through special macros and functions only. (Type objects are
11 exceptions to the first rule; the standard types are represented by
12 statically initialized type objects, although work on type/class unification
13 for Python 2.2 made it possible to have heap-allocated type objects too).
14
15 An object has a 'reference count' that is increased or decreased when a
16 pointer to the object is copied or deleted; when the reference count
17 reaches zero there are no references to the object left and it can be
18 removed from the heap.
19
20 An object has a 'type' that determines what it represents and what kind
21 of data it contains. An object's type is fixed when it is created.
22 Types themselves are represented as objects; an object contains a
23 pointer to the corresponding type object. The type itself has a type
24 pointer pointing to the object representing the type 'type', which
25 contains a pointer to itself!).
26
27 Objects do not float around in memory; once allocated an object keeps
28 the same size and address. Objects that must hold variable-size data
29 can contain pointers to variable-size parts of the object. Not all
30 objects of the same type have the same size; but the size cannot change
31 after allocation. (These restrictions are made so a reference to an
32 object can be simply a pointer -- moving an object would require
33 updating all the pointers, and changing an object's size would require
34 moving it if there was another object right next to it.)
35
36 Objects are always accessed through pointers of the type 'PyObject *'.
37 The type 'PyObject' is a structure that only contains the reference count
38 and the type pointer. The actual memory allocated for an object
39 contains other data that can only be accessed after casting the pointer
40 to a pointer to a longer structure type. This longer type must start
41 with the reference count and type fields; the macro PyObject_HEAD should be
42 used for this (to accommodate for future changes). The implementation
43 of a particular object type can cast the object pointer to the proper
44 type and back.
45
46 A standard interface exists for objects that contain an array of items
47 whose size is determined when the object is allocated.
48 */
49
50 /* PyObject_HEAD defines the initial segment of every PyObject. */
51 #define PyObject_HEAD PyObject ob_base;
52
53 #define PyObject_HEAD_INIT(type) { 1, type },
54
55 #define PyVarObject_HEAD_INIT(type, size) \
56 { PyObject_HEAD_INIT(type) size },
57
58 /* PyObject_VAR_HEAD defines the initial segment of all variable-size
59 * container objects. These end with a declaration of an array with 1
60 * element, but enough space is malloc'ed so that the array actually
61 * has room for ob_size elements. Note that ob_size is an element count,
62 * not necessarily a byte count.
63 */
64 #define PyObject_VAR_HEAD PyVarObject ob_base;
65 #define Py_INVALID_SIZE (Py_ssize_t)-1
66
67 /* Nothing is actually declared to be a PyObject, but every pointer to
68 * a Python object can be cast to a PyObject*. This is inheritance built
69 * by hand. Similarly every pointer to a variable-size Python object can,
70 * in addition, be cast to PyVarObject*.
71 */
72 typedef struct _object {
73 int ob_refcnt;
74 struct _typeobject *ob_type;
75 } PyObject;
76
77 typedef struct {
78 PyObject ob_base;
79 int ob_size; /* Number of items in variable part */
80 } PyVarObject;
81
82 #define Py_REFCNT(ob) (((PyObject*)(ob))->ob_refcnt)
83 #define Py_TYPE(ob) (((PyObject*)(ob))->ob_type)
84 #define Py_SIZE(ob) (((PyVarObject*)(ob))->ob_size)
85
86 /*
87 Type objects contain a string containing the type name (to help somewhat
88 in debugging), the allocation parameters (see PyObject_New() and
89 PyObject_NewVar()),
90 and methods for accessing objects of the type. Methods are optional, a
91 nil pointer meaning that particular kind of access is not available for
92 this type. The Py_DECREF() macro uses the tp_dealloc method without
93 checking for a nil pointer; it should always be implemented except if
94 the implementation can guarantee that the reference count will never
95 reach zero (e.g., for statically allocated type objects).
96
97 NB: the methods for certain type groups are now contained in separate
98 method blocks.
99 */
100
101 typedef PyObject * (*unaryfunc)(PyObject *);
102 typedef PyObject * (*binaryfunc)(PyObject *, PyObject *);
103 typedef PyObject * (*ternaryfunc)(PyObject *, PyObject *, PyObject *);
104 typedef int (*inquiry)(PyObject *);
105 typedef int (*lenfunc)(PyObject *);
106 typedef PyObject *(*ssizeargfunc)(PyObject *, int);
107 typedef PyObject *(*ssizessizeargfunc)(PyObject *, int, int);
108 typedef int(*ssizeobjargproc)(PyObject *, int, PyObject *);
109 typedef int(*ssizessizeobjargproc)(PyObject *, int, int, PyObject *);
110 typedef int(*objobjargproc)(PyObject *, PyObject *, PyObject *);
111
112 /* buffer interface */
113 typedef struct bufferinfo {
114 void *buf;
115 PyObject *obj; /* owned reference */
116 Py_ssize_t len;
117 Py_ssize_t itemsize; /* This is Py_ssize_t so it can be
118 pointed to by strides in simple case.*/
119 int readonly;
120 int ndim;
121 char *format;
122 Py_ssize_t *shape;
123 Py_ssize_t *strides;
124 Py_ssize_t *suboffsets;
125 Py_ssize_t smalltable[2]; /* static store for shape and strides of
126 mono-dimensional buffers. */
127 void *internal;
128 } Py_buffer;
129
130 typedef int (*getbufferproc)(PyObject *, Py_buffer *, int);
131 typedef void (*releasebufferproc)(PyObject *, Py_buffer *);
132
133 /* Flags for getting buffers */
134 #define PyBUF_SIMPLE 0
135 #define PyBUF_WRITABLE 0x0001
136 /* we used to include an E, backwards compatible alias */
137 #define PyBUF_WRITEABLE PyBUF_WRITABLE
138 #define PyBUF_FORMAT 0x0004
139 #define PyBUF_ND 0x0008
140 #define PyBUF_STRIDES (0x0010 | PyBUF_ND)
141 #define PyBUF_C_CONTIGUOUS (0x0020 | PyBUF_STRIDES)
142 #define PyBUF_F_CONTIGUOUS (0x0040 | PyBUF_STRIDES)
143 #define PyBUF_ANY_CONTIGUOUS (0x0080 | PyBUF_STRIDES)
144 #define PyBUF_INDIRECT (0x0100 | PyBUF_STRIDES)
145
146 #define PyBUF_CONTIG (PyBUF_ND | PyBUF_WRITABLE)
147 #define PyBUF_CONTIG_RO (PyBUF_ND)
148
149 #define PyBUF_STRIDED (PyBUF_STRIDES | PyBUF_WRITABLE)
150 #define PyBUF_STRIDED_RO (PyBUF_STRIDES)
151
152 #define PyBUF_RECORDS (PyBUF_STRIDES | PyBUF_WRITABLE | PyBUF_FORMAT)
153 #define PyBUF_RECORDS_RO (PyBUF_STRIDES | PyBUF_FORMAT)
154
155 #define PyBUF_FULL (PyBUF_INDIRECT | PyBUF_WRITABLE | PyBUF_FORMAT)
156 #define PyBUF_FULL_RO (PyBUF_INDIRECT | PyBUF_FORMAT)
157
158
159 #define PyBUF_READ 0x100
160 #define PyBUF_WRITE 0x200
161
162 /* End buffer interface */
163
164 typedef int (*objobjproc)(PyObject *, PyObject *);
165 typedef int (*visitproc)(PyObject *, void *);
166 typedef int (*traverseproc)(PyObject *, visitproc, void *);
167
168 typedef struct {
169 /* Number implementations must check *both*
170 arguments for proper type and implement the necessary conversions
171 in the slot functions themselves. */
172
173 binaryfunc nb_add;
174 binaryfunc nb_subtract;
175 binaryfunc nb_multiply;
176 binaryfunc nb_remainder;
177 binaryfunc nb_divmod;
178 ternaryfunc nb_power;
179 unaryfunc nb_negative;
180 unaryfunc nb_positive;
181 unaryfunc nb_absolute;
182 inquiry nb_bool;
183 unaryfunc nb_invert;
184 binaryfunc nb_lshift;
185 binaryfunc nb_rshift;
186 binaryfunc nb_and;
187 binaryfunc nb_xor;
188 binaryfunc nb_or;
189 unaryfunc nb_int;
190 void *nb_reserved; /* the slot formerly known as nb_long */
191 unaryfunc nb_float;
192
193 binaryfunc nb_inplace_add;
194 binaryfunc nb_inplace_subtract;
195 binaryfunc nb_inplace_multiply;
196 binaryfunc nb_inplace_remainder;
197 ternaryfunc nb_inplace_power;
198 binaryfunc nb_inplace_lshift;
199 binaryfunc nb_inplace_rshift;
200 binaryfunc nb_inplace_and;
201 binaryfunc nb_inplace_xor;
202 binaryfunc nb_inplace_or;
203
204 binaryfunc nb_floor_divide;
205 binaryfunc nb_true_divide;
206 binaryfunc nb_inplace_floor_divide;
207 binaryfunc nb_inplace_true_divide;
208
209 unaryfunc nb_index;
210 } PyNumberMethods;
211
212 typedef struct {
213 lenfunc sq_length;
214 binaryfunc sq_concat;
215 ssizeargfunc sq_repeat;
216 ssizeargfunc sq_item;
217 void *was_sq_slice;
218 ssizeobjargproc sq_ass_item;
219 void *was_sq_ass_slice;
220 objobjproc sq_contains;
221
222 binaryfunc sq_inplace_concat;
223 ssizeargfunc sq_inplace_repeat;
224 } PySequenceMethods;
225
226 typedef struct {
227 lenfunc mp_length;
228 binaryfunc mp_subscript;
229 objobjargproc mp_ass_subscript;
230 } PyMappingMethods;
231
232
233 typedef struct {
234 getbufferproc bf_getbuffer;
235 releasebufferproc bf_releasebuffer;
236 } PyBufferProcs;
237
238 typedef void (*freefunc)(void *);
239 typedef void (*destructor)(PyObject *);
240 /* We can't provide a full compile-time check that limited-API
241 users won't implement tp_print. However, not defining printfunc
242 and making tp_print of a different function pointer type
243 should at least cause a warning in most cases. */
244 typedef int (*printfunc)(PyObject *, FILE *, int);
245 typedef PyObject *(*getattrfunc)(PyObject *, char *);
246 typedef PyObject *(*getattrofunc)(PyObject *, PyObject *);
247 typedef int (*setattrfunc)(PyObject *, char *, PyObject *);
248 typedef int (*setattrofunc)(PyObject *, PyObject *, PyObject *);
249 typedef PyObject *(*reprfunc)(PyObject *);
250 typedef Py_hash_t (*hashfunc)(PyObject *);
251 typedef PyObject *(*richcmpfunc) (PyObject *, PyObject *, int);
252 typedef PyObject *(*getiterfunc) (PyObject *);
253 typedef PyObject *(*iternextfunc) (PyObject *);
254 typedef PyObject *(*descrgetfunc) (PyObject *, PyObject *, PyObject *);
255 typedef int (*descrsetfunc) (PyObject *, PyObject *, PyObject *);
256 typedef int (*initproc)(PyObject *, PyObject *, PyObject *);
257 typedef PyObject *(*newfunc)(struct _typeobject *, PyObject *, PyObject *);
258 typedef PyObject *(*allocfunc)(struct _typeobject *, int);
259
260 typedef struct _typeobject PyTypeObject; /* opaque */
261 typedef struct _typeobject {
262 PyObject_VAR_HEAD
263 const char *tp_name; /* For printing, in format "<module>.<name>" */
264 int tp_basicsize, tp_itemsize; /* For allocation */
265
266 /* Methods to implement standard operations */
267
268 destructor tp_dealloc;
269 printfunc tp_print;
270 getattrfunc tp_getattr;
271 setattrfunc tp_setattr;
272 void *tp_reserved; /* formerly known as tp_compare */
273 reprfunc tp_repr;
274
275 /* Method suites for standard classes */
276
277 PyNumberMethods *tp_as_number;
278 PySequenceMethods *tp_as_sequence;
279 PyMappingMethods *tp_as_mapping;
280
281 /* More standard operations (here for binary compatibility) */
282
283 hashfunc tp_hash;
284 ternaryfunc tp_call;
285 reprfunc tp_str;
286 getattrofunc tp_getattro;
287 setattrofunc tp_setattro;
288
289 /* Functions to access object as input/output buffer */
290 PyBufferProcs *tp_as_buffer;
291
292 /* Flags to define presence of optional/expanded features */
293 long tp_flags;
294
295 const char *tp_doc; /* Documentation string */
296
297 /* Assigned meaning in release 2.0 */
298 /* call function for all accessible objects */
299 traverseproc tp_traverse;
300
301 /* delete references to contained objects */
302 inquiry tp_clear;
303
304 /* Assigned meaning in release 2.1 */
305 /* rich comparisons */
306 richcmpfunc tp_richcompare;
307
308 /* weak reference enabler */
309 Py_ssize_t tp_weaklistoffset;
310
311 /* Iterators */
312 getiterfunc tp_iter;
313 iternextfunc tp_iternext;
314
315 /* Attribute descriptor and subclassing stuff */
316 struct PyMethodDef *tp_methods;
317 struct PyMemberDef *tp_members;
318 struct PyGetSetDef *tp_getset;
319 struct _typeobject *tp_base;
320 PyObject *tp_dict;
321 descrgetfunc tp_descr_get;
322 descrsetfunc tp_descr_set;
323 Py_ssize_t tp_dictoffset;
324 initproc tp_init;
325 allocfunc tp_alloc;
326 newfunc tp_new;
327 freefunc tp_free; /* Low-level free-memory routine */
328 inquiry tp_is_gc; /* For PyObject_IS_GC */
329 PyObject *tp_bases;
330 PyObject *tp_mro; /* method resolution order */
331 PyObject *tp_cache;
332 PyObject *tp_subclasses;
333 PyObject *tp_weaklist;
334 destructor tp_del;
335
336 /* Type attribute cache version tag. Added in version 2.6 */
337 unsigned int tp_version_tag;
338
339 } PyTypeObject;
340
341 typedef struct{
342 int slot; /* slot id, see below */
343 void *pfunc; /* function pointer */
344 } PyType_Slot;
345
346 typedef struct{
347 const char* name;
348 int basicsize;
349 int itemsize;
350 int flags;
351 PyType_Slot *slots; /* terminated by slot==0. */
352 } PyType_Spec;
353
354 PyAPI_FUNC(PyObject*) PyType_FromSpec(PyType_Spec*);
355
356 #ifndef Py_LIMITED_API
357 /* The *real* layout of a type object when allocated on the heap */
358 typedef struct _heaptypeobject {
359 /* Note: there's a dependency on the order of these members
360 in slotptr() in typeobject.c . */
361 PyTypeObject ht_type;
362 PyNumberMethods as_number;
363 PyMappingMethods as_mapping;
364 PySequenceMethods as_sequence; /* as_sequence comes after as_mapping,
365 so that the mapping wins when both
366 the mapping and the sequence define
367 a given operator (e.g. __getitem__).
368 see add_operators() in typeobject.c . */
369 PyBufferProcs as_buffer;
370 PyObject *ht_name, *ht_slots, *ht_qualname;
371 /* here are optional user slots, followed by the members. */
372 } PyHeapTypeObject;
373
374 /* access macro to the members which are floating "behind" the object */
375 #define PyHeapType_GET_MEMBERS(etype) \
376 ((PyMemberDef *)(((char *)etype) + Py_TYPE(etype)->tp_basicsize))
377 #endif
378
379 /* Generic type check */
380 PyAPI_FUNC(int) PyType_IsSubtype(PyTypeObject *, PyTypeObject *);
381 #define PyObject_TypeCheck(ob, tp) \
382 (Py_TYPE(ob) == (tp) || PyType_IsSubtype(Py_TYPE(ob), (tp)))
383
384 PyAPI_DATA(PyTypeObject) PyType_Type; /* built-in 'type' */
385 PyAPI_DATA(PyTypeObject) PyBaseObject_Type; /* built-in 'object' */
386 PyAPI_DATA(PyTypeObject) PySuper_Type; /* built-in 'super' */
387
388 PyAPI_FUNC(long) PyType_GetFlags(PyTypeObject*);
389
390 #define PyType_Check(op) \
391 PyType_FastSubclass(Py_TYPE(op), Py_TPFLAGS_TYPE_SUBCLASS)
392 #define PyType_CheckExact(op) (Py_TYPE(op) == &PyType_Type)
393
394 PyAPI_FUNC(int) PyType_Ready(PyTypeObject *);
395 PyAPI_FUNC(PyObject *) PyType_GenericAlloc(PyTypeObject *, Py_ssize_t);
396 PyAPI_FUNC(PyObject *) PyType_GenericNew(PyTypeObject *,
397 PyObject *, PyObject *);
398 #ifndef Py_LIMITED_API
399 PyAPI_FUNC(PyObject *) _PyType_Lookup(PyTypeObject *, PyObject *);
400 PyAPI_FUNC(PyObject *) _PyObject_LookupSpecial(PyObject *, char *, PyObject **);
401 PyAPI_FUNC(PyTypeObject *) _PyType_CalculateMetaclass(PyTypeObject *, PyObject *);
402 #endif
403 PyAPI_FUNC(unsigned int) PyType_ClearCache(void);
404 PyAPI_FUNC(void) PyType_Modified(PyTypeObject *);
405
406 /* Generic operations on objects */
407 struct _Py_Identifier;
408 #ifndef Py_LIMITED_API
409 PyAPI_FUNC(int) PyObject_Print(PyObject *, FILE *, int);
410 PyAPI_FUNC(void) _Py_BreakPoint(void);
411 PyAPI_FUNC(void) _PyObject_Dump(PyObject *);
412 #endif
413 PyAPI_FUNC(PyObject *) PyObject_Repr(PyObject *);
414 PyAPI_FUNC(PyObject *) PyObject_Str(PyObject *);
415 PyAPI_FUNC(PyObject *) PyObject_ASCII(PyObject *);
416 PyAPI_FUNC(PyObject *) PyObject_Bytes(PyObject *);
417 PyAPI_FUNC(PyObject *) PyObject_RichCompare(PyObject *, PyObject *, int);
418 PyAPI_FUNC(int) PyObject_RichCompareBool(PyObject *, PyObject *, int);
419 PyAPI_FUNC(PyObject *) PyObject_GetAttrString(PyObject *, const char *);
420 PyAPI_FUNC(int) PyObject_SetAttrString(PyObject *, const char *, PyObject *);
421 PyAPI_FUNC(int) PyObject_HasAttrString(PyObject *, const char *);
422 PyAPI_FUNC(PyObject *) PyObject_GetAttr(PyObject *, PyObject *);
423 PyAPI_FUNC(int) PyObject_SetAttr(PyObject *, PyObject *, PyObject *);
424 PyAPI_FUNC(int) PyObject_HasAttr(PyObject *, PyObject *);
425 PyAPI_FUNC(PyObject *) _PyObject_GetAttrId(PyObject *, struct _Py_Identifier *);
426 PyAPI_FUNC(int) _PyObject_SetAttrId(PyObject *, struct _Py_Identifier *, PyObject *);
427 PyAPI_FUNC(int) _PyObject_HasAttrId(PyObject *, struct _Py_Identifier *);
428 #ifndef Py_LIMITED_API
429 PyAPI_FUNC(PyObject **) _PyObject_GetDictPtr(PyObject *);
430 #endif
431 PyAPI_FUNC(PyObject *) PyObject_SelfIter(PyObject *);
432 #ifndef Py_LIMITED_API
433 PyAPI_FUNC(PyObject *) _PyObject_NextNotImplemented(PyObject *);
434 #endif
435 PyAPI_FUNC(PyObject *) PyObject_GenericGetAttr(PyObject *, PyObject *);
436 PyAPI_FUNC(int) PyObject_GenericSetAttr(PyObject *,
437 PyObject *, PyObject *);
438 PyAPI_FUNC(Py_hash_t) PyObject_Hash(PyObject *);
439 PyAPI_FUNC(Py_hash_t) PyObject_HashNotImplemented(PyObject *);
440 PyAPI_FUNC(int) PyObject_IsTrue(PyObject *);
441 PyAPI_FUNC(int) PyObject_Not(PyObject *);
442 PyAPI_FUNC(int) PyCallable_Check(PyObject *);
443
444 PyAPI_FUNC(void) PyObject_ClearWeakRefs(PyObject *);
445
446 /* Same as PyObject_Generic{Get,Set}Attr, but passing the attributes
447 dict as the last parameter. */
448 PyAPI_FUNC(PyObject *)
449 _PyObject_GenericGetAttrWithDict(PyObject *, PyObject *, PyObject *);
450 PyAPI_FUNC(int)
451 _PyObject_GenericSetAttrWithDict(PyObject *, PyObject *,
452 PyObject *, PyObject *);
453
454
455 /* PyObject_Dir(obj) acts like Python builtins.dir(obj), returning a
456 list of strings. PyObject_Dir(NULL) is like builtins.dir(),
457 returning the names of the current locals. In this case, if there are
458 no current locals, NULL is returned, and PyErr_Occurred() is false.
459 */
460 PyAPI_FUNC(PyObject *) PyObject_Dir(PyObject *);
461
462
463 /* Helpers for printing recursive container types */
464 PyAPI_FUNC(int) Py_ReprEnter(PyObject *);
465 PyAPI_FUNC(void) Py_ReprLeave(PyObject *);
466
467 /* Helpers for hash functions */
468 PyAPI_FUNC(Py_hash_t) _Py_HashDouble(double);
469 PyAPI_FUNC(Py_hash_t) _Py_HashPointer(void*);
470 PyAPI_FUNC(Py_hash_t) _Py_HashBytes(unsigned char*, Py_ssize_t);
471
472 /* Helper for passing objects to printf and the like */
473 #define PyObject_REPR(obj) _PyUnicode_AsString(PyObject_Repr(obj))
474
475 /* Flag bits for printing: */
476 #define Py_PRINT_RAW 1 /* No string quotes etc. */
477
478 /*
479 `Type flags (tp_flags)
480
481 These flags are used to extend the type structure in a backwards-compatible
482 fashion. Extensions can use the flags to indicate (and test) when a given
483 type structure contains a new feature. The Python core will use these when
484 introducing new functionality between major revisions (to avoid mid-version
485 changes in the PYTHON_API_VERSION).
486
487 Arbitration of the flag bit positions will need to be coordinated among
488 all extension writers who publically release their extensions (this will
489 be fewer than you might expect!)..
490
491 Most flags were removed as of Python 3.0 to make room for new flags. (Some
492 flags are not for backwards compatibility but to indicate the presence of an
493 optional feature; these flags remain of course.)
494
495 Type definitions should use Py_TPFLAGS_DEFAULT for their tp_flags value.
496
497 Code can use PyType_HasFeature(type_ob, flag_value) to test whether the
498 given type object has a specified feature.
499 */
500
501 /* Set if the type object is dynamically allocated */
502 #define Py_TPFLAGS_HEAPTYPE (1L<<9)
503
504 /* Set if the type allows subclassing */
505 #define Py_TPFLAGS_BASETYPE (1L<<10)
506
507 /* Set if the type is 'ready' -- fully initialized */
508 #define Py_TPFLAGS_READY (1L<<12)
509
510 /* Set while the type is being 'readied', to prevent recursive ready calls */
511 #define Py_TPFLAGS_READYING (1L<<13)
512
513 /* Objects support garbage collection (see objimp.h) */
514 #define Py_TPFLAGS_HAVE_GC (1L<<14)
515
516 /* These two bits are preserved for Stackless Python, next after this is 17 */
517 #ifdef STACKLESS
518 #define Py_TPFLAGS_HAVE_STACKLESS_EXTENSION (3L<<15)
519 #else
520 #define Py_TPFLAGS_HAVE_STACKLESS_EXTENSION 0
521 #endif
522
523 /* Objects support type attribute cache */
524 #define Py_TPFLAGS_HAVE_VERSION_TAG (1L<<18)
525 #define Py_TPFLAGS_VALID_VERSION_TAG (1L<<19)
526
527 /* Type is abstract and cannot be instantiated */
528 #define Py_TPFLAGS_IS_ABSTRACT (1L<<20)
529
530 /* These flags are used to determine if a type is a subclass. */
531 #define Py_TPFLAGS_INT_SUBCLASS (1L<<23)
532 #define Py_TPFLAGS_LONG_SUBCLASS (1L<<24)
533 #define Py_TPFLAGS_LIST_SUBCLASS (1L<<25)
534 #define Py_TPFLAGS_TUPLE_SUBCLASS (1L<<26)
535 #define Py_TPFLAGS_BYTES_SUBCLASS (1L<<27)
536 #define Py_TPFLAGS_UNICODE_SUBCLASS (1L<<28)
537 #define Py_TPFLAGS_DICT_SUBCLASS (1L<<29)
538 #define Py_TPFLAGS_BASE_EXC_SUBCLASS (1L<<30)
539 #define Py_TPFLAGS_TYPE_SUBCLASS (1L<<31)
540
541 #define Py_TPFLAGS_DEFAULT ( \
542 Py_TPFLAGS_HAVE_STACKLESS_EXTENSION | \
543 Py_TPFLAGS_HAVE_VERSION_TAG | \
544 0)
545
546 #ifdef Py_LIMITED_API
547 #define PyType_HasFeature(t,f) ((PyType_GetFlags(t) & (f)) != 0)
548 #else
549 #define PyType_HasFeature(t,f) (((t)->tp_flags & (f)) != 0)
550 #endif
551 #define PyType_FastSubclass(t,f) PyType_HasFeature(t,f)
552
553
554 /*
555 The macros Py_INCREF(op) and Py_DECREF(op) are used to increment or decrement
556 reference counts. Py_DECREF calls the object's deallocator function when
557 the refcount falls to 0; for
558 objects that don't contain references to other objects or heap memory
559 this can be the standard function free(). Both macros can be used
560 wherever a void expression is allowed. The argument must not be a
561 NULL pointer. If it may be NULL, use Py_XINCREF/Py_XDECREF instead.
562 The macro _Py_NewReference(op) initialize reference counts to 1, and
563 in special builds (Py_REF_DEBUG, Py_TRACE_REFS) performs additional
564 bookkeeping appropriate to the special build.
565
566 We assume that the reference count field can never overflow; this can
567 be proven when the size of the field is the same as the pointer size, so
568 we ignore the possibility. Provided a C int is at least 32 bits (which
569 is implicitly assumed in many parts of this code), that's enough for
570 about 2**31 references to an object.
571
572 XXX The following became out of date in Python 2.2, but I'm not sure
573 XXX what the full truth is now. Certainly, heap-allocated type objects
574 XXX can and should be deallocated.
575 Type objects should never be deallocated; the type pointer in an object
576 is not considered to be a reference to the type object, to save
577 complications in the deallocation function. (This is actually a
578 decision that's up to the implementer of each new type so if you want,
579 you can count such references to the type object.)
580
581 *** WARNING*** The Py_DECREF macro must have a side-effect-free argument
582 since it may evaluate its argument multiple times. (The alternative
583 would be to mace it a proper function or assign it to a global temporary
584 variable first, both of which are slower; and in a multi-threaded
585 environment the global variable trick is not safe.)
586 */
587
588 /* First define a pile of simple helper macros, one set per special
589 * build symbol. These either expand to the obvious things, or to
590 * nothing at all when the special mode isn't in effect. The main
591 * macros can later be defined just once then, yet expand to different
592 * things depending on which special build options are and aren't in effect.
593 * Trust me <wink>: while painful, this is 20x easier to understand than,
594 * e.g, defining _Py_NewReference five different times in a maze of nested
595 * #ifdefs (we used to do that -- it was impenetrable).
596 */
597 #define _Py_INC_REFTOTAL
598 #define _Py_DEC_REFTOTAL
599 #define _Py_REF_DEBUG_COMMA
600 #define _Py_CHECK_REFCNT(OP) /* a semicolon */;
601
602 #define _Py_INC_TPALLOCS(OP)
603 #define _Py_INC_TPFREES(OP)
604 #define _Py_DEC_TPFREES(OP)
605 #define _Py_COUNT_ALLOCS_COMMA
606
607 /* Without Py_TRACE_REFS, there's little enough to do that we expand code
608 * inline.
609 */
610 #define _Py_NewReference(op) ( \
611 _Py_INC_TPALLOCS(op) \
612 _Py_INC_REFTOTAL \
613 Py_REFCNT(op) = 1)
614
615 #define _Py_ForgetReference(op) _Py_INC_TPFREES(op)
616
617 #define _Py_Dealloc(op) ( \
618 _Py_INC_TPFREES(op) _Py_COUNT_ALLOCS_COMMA \
619 (*Py_TYPE(op)->tp_dealloc)((PyObject *)(op)))
620
621 #define Py_INCREF(op) ( \
622 _Py_INC_REFTOTAL \
623 ((PyObject*)(op))->ob_refcnt++)
624
625 #define Py_DECREF(op) \
626 do { \
627 if (_Py_DEC_REFTOTAL _Py_REF_DEBUG_COMMA \
628 --((PyObject*)(op))->ob_refcnt != 0) \
629 _Py_CHECK_REFCNT(op) \
630 else \
631 _Py_Dealloc((PyObject *)(op)); \
632 } while (0)
633
634 /* Safely decref `op` and set `op` to NULL, especially useful in tp_clear
635 * and tp_dealloc implementatons.
636 *
637 * Note that "the obvious" code can be deadly:
638 *
639 * Py_XDECREF(op);
640 * op = NULL;
641 *
642 * Typically, `op` is something like self->containee, and `self` is done
643 * using its `containee` member. In the code sequence above, suppose
644 * `containee` is non-NULL with a refcount of 1. Its refcount falls to
645 * 0 on the first line, which can trigger an arbitrary amount of code,
646 * possibly including finalizers (like __del__ methods or weakref callbacks)
647 * coded in Python, which in turn can release the GIL and allow other threads
648 * to run, etc. Such code may even invoke methods of `self` again, or cause
649 * cyclic gc to trigger, but-- oops! --self->containee still points to the
650 * object being torn down, and it may be in an insane state while being torn
651 * down. This has in fact been a rich historic source of miserable (rare &
652 * hard-to-diagnose) segfaulting (and other) bugs.
653 *
654 * The safe way is:
655 *
656 * Py_CLEAR(op);
657 *
658 * That arranges to set `op` to NULL _before_ decref'ing, so that any code
659 * triggered as a side-effect of `op` getting torn down no longer believes
660 * `op` points to a valid object.
661 *
662 * There are cases where it's safe to use the naive code, but they're brittle.
663 * For example, if `op` points to a Python integer, you know that destroying
664 * one of those can't cause problems -- but in part that relies on that
665 * Python integers aren't currently weakly referencable. Best practice is
666 * to use Py_CLEAR() even if you can't think of a reason for why you need to.
667 */
668 #define Py_CLEAR(op) \
669 do { \
670 if (op) { \
671 PyObject *_py_tmp = (PyObject *)(op); \
672 (op) = NULL; \
673 Py_DECREF(_py_tmp); \
674 } \
675 } while (0)
676
677 /* Macros to use in case the object pointer may be NULL: */
678 #define Py_XINCREF(op) do { if ((op) == NULL) ; else Py_INCREF(op); } while (0)
679 #define Py_XDECREF(op) do { if ((op) == NULL) ; else Py_DECREF(op); } while (0)
680
681 /*
682 These are provided as conveniences to Python runtime embedders, so that
683 they can have object code that is not dependent on Python compilation flags.
684 */
685 PyAPI_FUNC(void) Py_IncRef(PyObject *);
686 PyAPI_FUNC(void) Py_DecRef(PyObject *);
687
688 /*
689 _Py_NoneStruct is an object of undefined type which can be used in contexts
690 where NULL (nil) is not suitable (since NULL often means 'error').
691
692 Don't forget to apply Py_INCREF() when returning this value!!!
693 */
694 PyAPI_DATA(PyObject) _Py_NoneStruct; /* Don't use this directly */
695 #define Py_None (&_Py_NoneStruct)
696
697 /* Macro for returning Py_None from a function */
698 #define Py_RETURN_NONE return Py_INCREF(Py_None), Py_None
699
700 /*
701 Py_NotImplemented is a singleton used to signal that an operation is
702 not implemented for a given type combination.
703 */
704 PyAPI_DATA(PyObject) _Py_NotImplementedStruct; /* Don't use this directly */
705 #define Py_NotImplemented (&_Py_NotImplementedStruct)
706
707 /* Macro for returning Py_NotImplemented from a function */
708 #define Py_RETURN_NOTIMPLEMENTED \
709 return Py_INCREF(Py_NotImplemented), Py_NotImplemented
710
711 /* Rich comparison opcodes */
712 #define Py_LT 0
713 #define Py_LE 1
714 #define Py_EQ 2
715 #define Py_NE 3
716 #define Py_GT 4
717 #define Py_GE 5
718
719 /* Maps Py_LT to Py_GT, ..., Py_GE to Py_LE.
720 * Defined in object.c.
721 */
722 PyAPI_DATA(int) _Py_SwappedOp[];
723
724
725 /*
726 More conventions
727 ================
728
729 Argument Checking
730 -----------------
731
732 Functions that take objects as arguments normally don't check for nil
733 arguments, but they do check the type of the argument, and return an
734 error if the function doesn't apply to the type.
735
736 Failure Modes
737 -------------
738
739 Functions may fail for a variety of reasons, including running out of
740 memory. This is communicated to the caller in two ways: an error string
741 is set (see errors.h), and the function result differs: functions that
742 normally return a pointer return NULL for failure, functions returning
743 an integer return -1 (which could be a legal return value too!), and
744 other functions return 0 for success and -1 for failure.
745 Callers should always check for errors before using the result. If
746 an error was set, the caller must either explicitly clear it, or pass
747 the error on to its caller.
748
749 Reference Counts
750 ----------------
751
752 It takes a while to get used to the proper usage of reference counts.
753
754 Functions that create an object set the reference count to 1; such new
755 objects must be stored somewhere or destroyed again with Py_DECREF().
756 Some functions that 'store' objects, such as PyTuple_SetItem() and
757 PyList_SetItem(),
758 don't increment the reference count of the object, since the most
759 frequent use is to store a fresh object. Functions that 'retrieve'
760 objects, such as PyTuple_GetItem() and PyDict_GetItemString(), also
761 don't increment
762 the reference count, since most frequently the object is only looked at
763 quickly. Thus, to retrieve an object and store it again, the caller
764 must call Py_INCREF() explicitly.
765
766 NOTE: functions that 'consume' a reference count, like
767 PyList_SetItem(), consume the reference even if the object wasn't
768 successfully stored, to simplify error handling.
769
770 It seems attractive to make other functions that take an object as
771 argument consume a reference count; however, this may quickly get
772 confusing (even the current practice is already confusing). Consider
773 it carefully, it may save lots of calls to Py_INCREF() and Py_DECREF() at
774 times.
775 */
776
777
778 /* Trashcan mechanism, thanks to Christian Tismer.
779
780 When deallocating a container object, it's possible to trigger an unbounded
781 chain of deallocations, as each Py_DECREF in turn drops the refcount on "the
782 next" object in the chain to 0. This can easily lead to stack faults, and
783 especially in threads (which typically have less stack space to work with).
784
785 A container object that participates in cyclic gc can avoid this by
786 bracketing the body of its tp_dealloc function with a pair of macros:
787
788 static void
789 mytype_dealloc(mytype *p)
790 {
791 ... declarations go here ...
792
793 PyObject_GC_UnTrack(p); // must untrack first
794 Py_TRASHCAN_SAFE_BEGIN(p)
795 ... The body of the deallocator goes here, including all calls ...
796 ... to Py_DECREF on contained objects. ...
797 Py_TRASHCAN_SAFE_END(p)
798 }
799
800 CAUTION: Never return from the middle of the body! If the body needs to
801 "get out early", put a label immediately before the Py_TRASHCAN_SAFE_END
802 call, and goto it. Else the call-depth counter (see below) will stay
803 above 0 forever, and the trashcan will never get emptied.
804
805 How it works: The BEGIN macro increments a call-depth counter. So long
806 as this counter is small, the body of the deallocator is run directly without
807 further ado. But if the counter gets large, it instead adds p to a list of
808 objects to be deallocated later, skips the body of the deallocator, and
809 resumes execution after the END macro. The tp_dealloc routine then returns
810 without deallocating anything (and so unbounded call-stack depth is avoided).
811
812 When the call stack finishes unwinding again, code generated by the END macro
813 notices this, and calls another routine to deallocate all the objects that
814 may have been added to the list of deferred deallocations. In effect, a
815 chain of N deallocations is broken into N / PyTrash_UNWIND_LEVEL pieces,
816 with the call stack never exceeding a depth of PyTrash_UNWIND_LEVEL.
817 */
818
819 PyAPI_FUNC(void) _PyTrash_deposit_object(PyObject*);
820 PyAPI_FUNC(void) _PyTrash_destroy_chain(void);
821 PyAPI_DATA(int) _PyTrash_delete_nesting;
822 PyAPI_DATA(PyObject *) _PyTrash_delete_later;
823
824 #define PyTrash_UNWIND_LEVEL 50
825
826 #define Py_TRASHCAN_SAFE_BEGIN(op) \
827 if (_PyTrash_delete_nesting < PyTrash_UNWIND_LEVEL) { \
828 ++_PyTrash_delete_nesting;
829 /* The body of the deallocator is here. */
830 #define Py_TRASHCAN_SAFE_END(op) \
831 --_PyTrash_delete_nesting; \
832 if (_PyTrash_delete_later && _PyTrash_delete_nesting <= 0) \
833 _PyTrash_destroy_chain(); \
834 } \
835 else \
836 _PyTrash_deposit_object((PyObject*)op);
837
838 #endif /* !Py_OBJECT_H */