cpython/Include/frameobject.h

/* Frame object interface */

#ifndef Py_FRAMEOBJECT_H
#define Py_FRAMEOBJECT_H
#ifdef __cplusplus
extern "C" {
#endif

typedef struct {
    int b_type;			/* what kind of block this is */
    int b_handler;		/* where to jump to find handler */
    int b_level;		/* value stack level to pop to */
} PyTryBlock;

typedef struct _frame {
    PyObject_VAR_HEAD
    struct _frame *f_back;	/* previous frame, or NULL */
    PyCodeObject *f_code;	/* code segment */
    PyObject *f_builtins;	/* builtin symbol table (PyDictObject) */
    PyObject *f_globals;	/* global symbol table (PyDictObject) */
    PyObject *f_locals;		/* local symbol table (PyDictObject) */
    PyObject **f_valuestack;	/* points after the last local */
    /* Next free slot in f_valuestack.  Frame creation sets to f_valuestack.
       Frame evaluation usually NULLs it, but a frame that yields sets it
       to the current stack top. */
    PyObject **f_stacktop;
    PyObject *f_trace;		/* Trace function */
    PyObject *f_exc_type, *f_exc_value, *f_exc_traceback;
    PyThreadState *f_tstate;
    int f_lasti;		/* Last instruction if called */
    int f_lineno;		/* Current line number */
    int f_restricted;		/* Flag set if restricted operations
				   in this scope */
    int f_iblock;		/* index in f_blockstack */
    PyTryBlock f_blockstack[CO_MAXBLOCKS]; /* for try and loop blocks */
    int f_nlocals;		/* number of locals */
    int f_ncells;
    int f_nfreevars;
    int f_stacksize;		/* size of value stack */
    PyObject *f_localsplus[1];	/* locals+stack, dynamically sized */
} PyFrameObject;


/* Standard object interface */

extern DL_IMPORT(PyTypeObject) PyFrame_Type;

#define PyFrame_Check(op) ((op)->ob_type == &PyFrame_Type)

DL_IMPORT(PyFrameObject *) PyFrame_New(PyThreadState *, PyCodeObject *,
                                       PyObject *, PyObject *);


/* The rest of the interface is specific for frame objects */

/* Tuple access macros */

#ifndef Py_DEBUG
#define GETITEM(v, i) PyTuple_GET_ITEM((PyTupleObject *)(v), (i))
#define GETITEMNAME(v, i) \
	PyString_AS_STRING((PyStringObject *)GETITEM((v), (i)))
#else
#define GETITEM(v, i) PyTuple_GetItem((v), (i))
#define GETITEMNAME(v, i) PyString_AsString(GETITEM(v, i))
#endif

#define GETUSTRINGVALUE(s) ((unsigned char *)PyString_AS_STRING(s))

/* Code access macros */

#define Getconst(f, i)	(GETITEM((f)->f_code->co_consts, (i)))
#define Getname(f, i)	(GETITEMNAME((f)->f_code->co_names, (i)))
#define Getnamev(f, i)	(GETITEM((f)->f_code->co_names, (i)))


/* Block management functions */

DL_IMPORT(void) PyFrame_BlockSetup(PyFrameObject *, int, int, int);
DL_IMPORT(PyTryBlock *) PyFrame_BlockPop(PyFrameObject *);

/* Extend the value stack */

DL_IMPORT(PyObject **) PyFrame_ExtendStack(PyFrameObject *, int, int);

/* Conversions between "fast locals" and locals in dictionary */

DL_IMPORT(void) PyFrame_LocalsToFast(PyFrameObject *, int);
DL_IMPORT(void) PyFrame_FastToLocals(PyFrameObject *);

#ifdef __cplusplus
}
#endif
#endif /* !Py_FRAMEOBJECT_H */