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 */

PyAPI_DATA(PyTypeObject) PyFrame_Type;

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

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


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

/* Block management functions */

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

/* Extend the value stack */

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

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

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

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