cosmopolitan/third_party/python/Include/objimpl.h

#ifndef Py_OBJIMPL_H
#define Py_OBJIMPL_H
#include "libc/assert.h"
#include "third_party/python/Include/object.h"
#include "third_party/python/Include/pyerrors.h"
#include "third_party/python/Include/pymacro.h"
#include "third_party/python/Include/pymem.h"
#include "third_party/python/Include/tupleobject.h"
COSMOPOLITAN_C_START_
/* clang-format off */

void * PyObject_Malloc(size_t size);
#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03050000
void * PyObject_Calloc(size_t nelem, size_t elsize);
#endif
void * PyObject_Realloc(void *ptr, size_t new_size);
void PyObject_Free(void *ptr);

#ifndef Py_LIMITED_API
/* This function returns the number of allocated memory blocks, regardless of size */
Py_ssize_t _Py_GetAllocatedBlocks(void);
#endif /* !Py_LIMITED_API */

/* Macros */
#ifdef WITH_PYMALLOC
#ifndef Py_LIMITED_API
void _PyObject_DebugMallocStats(FILE *out);
#endif /* #ifndef Py_LIMITED_API */
#endif

/* Macros */
#define PyObject_MALLOC         PyObject_Malloc
#define PyObject_REALLOC        PyObject_Realloc
#define PyObject_FREE           PyObject_Free
#define PyObject_Del            PyObject_Free
#define PyObject_DEL            PyObject_Free


/*
 * Generic object allocator interface
 * ==================================
 */

/* Functions */
PyObject * PyObject_Init(PyObject *, PyTypeObject *);
PyVarObject * PyObject_InitVar(PyVarObject *,
                                                 PyTypeObject *, Py_ssize_t);
PyObject * _PyObject_New(PyTypeObject *);
PyVarObject * _PyObject_NewVar(PyTypeObject *, Py_ssize_t);

#define PyObject_New(type, typeobj) \
                ( (type *) _PyObject_New(typeobj) )
#define PyObject_NewVar(type, typeobj, n) \
                ( (type *) _PyObject_NewVar((typeobj), (n)) )

/* Macros trading binary compatibility for speed. See also pymem.h.
   Note that these macros expect non-NULL object pointers.*/
#define PyObject_INIT(op, typeobj) \
    ( Py_TYPE(op) = (typeobj), _Py_NewReference((PyObject *)(op)), (op) )
#define PyObject_INIT_VAR(op, typeobj, size) \
    ( Py_SIZE(op) = (size), PyObject_INIT((op), (typeobj)) )

#define _PyObject_SIZE(typeobj) ( (typeobj)->tp_basicsize )

/* _PyObject_VAR_SIZE returns the number of bytes (as size_t) allocated for a
   vrbl-size object with nitems items, exclusive of gc overhead (if any).  The
   value is rounded up to the closest multiple of sizeof(void *), in order to
   ensure that pointer fields at the end of the object are correctly aligned
   for the platform (this is of special importance for subclasses of, e.g.,
   str or int, so that pointers can be stored after the embedded data).

   Note that there's no memory wastage in doing this, as malloc has to
   return (at worst) pointer-aligned memory anyway.
*/
#if ((SIZEOF_VOID_P - 1) & SIZEOF_VOID_P) != 0
#   error "_PyObject_VAR_SIZE requires SIZEOF_VOID_P be a power of 2"
#endif

#define _PyObject_VAR_SIZE(typeobj, nitems)     \
    _Py_SIZE_ROUND_UP((typeobj)->tp_basicsize + \
        (nitems)*(typeobj)->tp_itemsize,        \
        SIZEOF_VOID_P)

#define PyObject_NEW(type, typeobj) \
( (type *) PyObject_Init( \
    (PyObject *) PyObject_MALLOC( _PyObject_SIZE(typeobj) ), (typeobj)) )

#define PyObject_NEW_VAR(type, typeobj, n) \
( (type *) PyObject_InitVar( \
      (PyVarObject *) PyObject_MALLOC(_PyObject_VAR_SIZE((typeobj),(n)) ),\
      (typeobj), (n)) )

/* This example code implements an object constructor with a custom
   allocator, where PyObject_New is inlined, and shows the important
   distinction between two steps (at least):
       1) the actual allocation of the object storage;
       2) the initialization of the Python specific fields
      in this storage with PyObject_{Init, InitVar}.

   PyObject *
   YourObject_New(...)
   {
       PyObject *op;

       op = (PyObject *) Your_Allocator(_PyObject_SIZE(YourTypeStruct));
       if (op == NULL)
       return PyErr_NoMemory();

       PyObject_Init(op, &YourTypeStruct);

       op->ob_field = value;
       ...
       return op;
   }

   Note that in C++, the use of the new operator usually implies that
   the 1st step is performed automatically for you, so in a C++ class
   constructor you would start directly with PyObject_Init/InitVar
*/

#ifndef Py_LIMITED_API
typedef struct {
    /* user context passed as the first argument to the 2 functions */
    void *ctx;

    /* allocate an arena of size bytes */
    void* (*alloc) (void *ctx, size_t size);

    /* free an arena */
    void (*free) (void *ctx, void *ptr, size_t size);
} PyObjectArenaAllocator;

/* Get the arena allocator. */
void PyObject_GetArenaAllocator(PyObjectArenaAllocator *allocator);

/* Set the arena allocator. */
void PyObject_SetArenaAllocator(PyObjectArenaAllocator *allocator);
#endif


/*
 * Garbage Collection Support
 * ==========================
 */

/* C equivalent of gc.collect() which ignores the state of gc.enabled. */
Py_ssize_t PyGC_Collect(void);

#ifndef Py_LIMITED_API
Py_ssize_t _PyGC_CollectNoFail(void);
Py_ssize_t _PyGC_CollectIfEnabled(void);
#endif

/* Test if a type has a GC head */
#define PyType_IS_GC(t) PyType_HasFeature((t), Py_TPFLAGS_HAVE_GC)

/* Test if an object has a GC head */
#define PyObject_IS_GC(o) (PyType_IS_GC(Py_TYPE(o)) && \
    (Py_TYPE(o)->tp_is_gc == NULL || Py_TYPE(o)->tp_is_gc(o)))

PyVarObject * _PyObject_GC_Resize(PyVarObject *, Py_ssize_t);
#define PyObject_GC_Resize(type, op, n) \
                ( (type *) _PyObject_GC_Resize((PyVarObject *)(op), (n)) )

/* GC information is stored BEFORE the object structure. */
#ifndef Py_LIMITED_API
typedef union _gc_head {
    struct {
        union _gc_head *gc_next;
        union _gc_head *gc_prev;
        Py_ssize_t gc_refs;
    } gc;
    double dummy;  /* force worst-case alignment */
} PyGC_Head;

extern PyGC_Head *_PyGC_generation0;

#define _Py_AS_GC(o) ((PyGC_Head *)(o)-1)

/* Bit 0 is set when tp_finalize is called */
#define _PyGC_REFS_MASK_FINALIZED  (1 << 0)
/* The (N-1) most significant bits contain the gc state / refcount */
#define _PyGC_REFS_SHIFT           (1)
#define _PyGC_REFS_MASK            (((size_t) -1) << _PyGC_REFS_SHIFT)

#define _PyGCHead_REFS(g) ((g)->gc.gc_refs >> _PyGC_REFS_SHIFT)
#define _PyGCHead_SET_REFS(g, v) do { \
    (g)->gc.gc_refs = ((g)->gc.gc_refs & ~_PyGC_REFS_MASK) \
        | (((size_t)(v)) << _PyGC_REFS_SHIFT);             \
    } while (0)
#define _PyGCHead_DECREF(g) ((g)->gc.gc_refs -= 1 << _PyGC_REFS_SHIFT)

#define _PyGCHead_FINALIZED(g) (((g)->gc.gc_refs & _PyGC_REFS_MASK_FINALIZED) != 0)
#define _PyGCHead_SET_FINALIZED(g, v) do {  \
    (g)->gc.gc_refs = ((g)->gc.gc_refs & ~_PyGC_REFS_MASK_FINALIZED) \
        | (v != 0); \
    } while (0)

#define _PyGC_FINALIZED(o) _PyGCHead_FINALIZED(_Py_AS_GC(o))
#define _PyGC_SET_FINALIZED(o, v) _PyGCHead_SET_FINALIZED(_Py_AS_GC(o), v)

#define _PyGC_REFS(o) _PyGCHead_REFS(_Py_AS_GC(o))

#define _PyGC_REFS_UNTRACKED                    (-2)
#define _PyGC_REFS_REACHABLE                    (-3)
#define _PyGC_REFS_TENTATIVELY_UNREACHABLE      (-4)

/* Tell the GC to track this object.  NB: While the object is tracked the
 * collector it must be safe to call the ob_traverse method. */
#define _PyObject_GC_TRACK(o) do { \
    PyGC_Head *g = _Py_AS_GC(o); \
    if (_PyGCHead_REFS(g) != _PyGC_REFS_UNTRACKED) \
        Py_FatalError("GC object already tracked"); \
    _PyGCHead_SET_REFS(g, _PyGC_REFS_REACHABLE); \
    g->gc.gc_next = _PyGC_generation0; \
    g->gc.gc_prev = _PyGC_generation0->gc.gc_prev; \
    g->gc.gc_prev->gc.gc_next = g; \
    _PyGC_generation0->gc.gc_prev = g; \
    } while (0);

/* Tell the GC to stop tracking this object.
 * gc_next doesn't need to be set to NULL, but doing so is a good
 * way to provoke memory errors if calling code is confused.
 */
#define _PyObject_GC_UNTRACK(o) do { \
    PyGC_Head *g = _Py_AS_GC(o); \
    assert(_PyGCHead_REFS(g) != _PyGC_REFS_UNTRACKED); \
    _PyGCHead_SET_REFS(g, _PyGC_REFS_UNTRACKED); \
    g->gc.gc_prev->gc.gc_next = g->gc.gc_next; \
    g->gc.gc_next->gc.gc_prev = g->gc.gc_prev; \
    g->gc.gc_next = NULL; \
    } while (0);

/* True if the object is currently tracked by the GC. */
#define _PyObject_GC_IS_TRACKED(o) \
    (_PyGC_REFS(o) != _PyGC_REFS_UNTRACKED)

/* True if the object may be tracked by the GC in the future, or already is.
   This can be useful to implement some optimizations. */
#define _PyObject_GC_MAY_BE_TRACKED(obj) \
    (PyObject_IS_GC(obj) && \
        (!PyTuple_CheckExact(obj) || _PyObject_GC_IS_TRACKED(obj)))
#endif /* Py_LIMITED_API */

#ifndef Py_LIMITED_API
PyObject * _PyObject_GC_Malloc(size_t size);
PyObject * _PyObject_GC_Calloc(size_t size);
#endif /* !Py_LIMITED_API */
PyObject * _PyObject_GC_New(PyTypeObject *);
PyVarObject * _PyObject_GC_NewVar(PyTypeObject *, Py_ssize_t);
void PyObject_GC_Track(void *);
void PyObject_GC_UnTrack(void *);
void PyObject_GC_Del(void *);

#define PyObject_GC_New(type, typeobj) \
                ( (type *) _PyObject_GC_New(typeobj) )
#define PyObject_GC_NewVar(type, typeobj, n) \
                ( (type *) _PyObject_GC_NewVar((typeobj), (n)) )


/* Utility macro to help write tp_traverse functions.
 * To use this macro, the tp_traverse function must name its arguments
 * "visit" and "arg".  This is intended to keep tp_traverse functions
 * looking as much alike as possible.
 */
#define Py_VISIT(op)                                                    \
    do {                                                                \
        if (op) {                                                       \
            int vret = visit((PyObject *)(op), arg);                    \
            if (vret)                                                   \
                return vret;                                            \
        }                                                               \
    } while (0)


/* Test if a type supports weak references */
#define PyType_SUPPORTS_WEAKREFS(t) ((t)->tp_weaklistoffset > 0)

#define PyObject_GET_WEAKREFS_LISTPTR(o) \
    ((PyObject **) (((char *) (o)) + Py_TYPE(o)->tp_weaklistoffset))

COSMOPOLITAN_C_END_
#endif /* !Py_OBJIMPL_H */