1
2/* Frame object interface */
3
4#ifndef Py_FRAMEOBJECT_H
5#define Py_FRAMEOBJECT_H
6#ifdef __cplusplus
7extern "C" {
8#endif
9
10typedef struct {
11    int b_type;			/* what kind of block this is */
12    int b_handler;		/* where to jump to find handler */
13    int b_level;		/* value stack level to pop to */
14} PyTryBlock;
15
16typedef struct _frame {
17    PyObject_VAR_HEAD
18    struct _frame *f_back;	/* previous frame, or NULL */
19    PyCodeObject *f_code;	/* code segment */
20    PyObject *f_builtins;	/* builtin symbol table (PyDictObject) */
21    PyObject *f_globals;	/* global symbol table (PyDictObject) */
22    PyObject *f_locals;		/* local symbol table (any mapping) */
23    PyObject **f_valuestack;	/* points after the last local */
24    /* Next free slot in f_valuestack.  Frame creation sets to f_valuestack.
25       Frame evaluation usually NULLs it, but a frame that yields sets it
26       to the current stack top. */
27    PyObject **f_stacktop;
28    PyObject *f_trace;		/* Trace function */
29
30    /* If an exception is raised in this frame, the next three are used to
31     * record the exception info (if any) originally in the thread state.  See
32     * comments before set_exc_info() -- it's not obvious.
33     * Invariant:  if _type is NULL, then so are _value and _traceback.
34     * Desired invariant:  all three are NULL, or all three are non-NULL.  That
35     * one isn't currently true, but "should be".
36     */
37    PyObject *f_exc_type, *f_exc_value, *f_exc_traceback;
38
39    PyThreadState *f_tstate;
40    int f_lasti;		/* Last instruction if called */
41    /* Call PyFrame_GetLineNumber() instead of reading this field
42       directly.  As of 2.3 f_lineno is only valid when tracing is
43       active (i.e. when f_trace is set).  At other times we use
44       PyCode_Addr2Line to calculate the line from the current
45       bytecode index. */
46    int f_lineno;		/* Current line number */
47    int f_iblock;		/* index in f_blockstack */
48    PyTryBlock f_blockstack[CO_MAXBLOCKS]; /* for try and loop blocks */
49    PyObject *f_localsplus[1];	/* locals+stack, dynamically sized */
50} PyFrameObject;
51
52
53/* Standard object interface */
54
55PyAPI_DATA(PyTypeObject) PyFrame_Type;
56
57#define PyFrame_Check(op) ((op)->ob_type == &PyFrame_Type)
58#define PyFrame_IsRestricted(f) \
59	((f)->f_builtins != (f)->f_tstate->interp->builtins)
60
61PyAPI_FUNC(PyFrameObject *) PyFrame_New(PyThreadState *, PyCodeObject *,
62                                       PyObject *, PyObject *);
63
64
65/* The rest of the interface is specific for frame objects */
66
67/* Block management functions */
68
69PyAPI_FUNC(void) PyFrame_BlockSetup(PyFrameObject *, int, int, int);
70PyAPI_FUNC(PyTryBlock *) PyFrame_BlockPop(PyFrameObject *);
71
72/* Extend the value stack */
73
74PyAPI_FUNC(PyObject **) PyFrame_ExtendStack(PyFrameObject *, int, int);
75
76/* Conversions between "fast locals" and locals in dictionary */
77
78PyAPI_FUNC(void) PyFrame_LocalsToFast(PyFrameObject *, int);
79PyAPI_FUNC(void) PyFrame_FastToLocals(PyFrameObject *);
80
81PyAPI_FUNC(int) PyFrame_ClearFreeList(void);
82
83/* Return the line of code the frame is currently executing. */
84PyAPI_FUNC(int) PyFrame_GetLineNumber(PyFrameObject *);
85
86#ifdef __cplusplus
87}
88#endif
89#endif /* !Py_FRAMEOBJECT_H */
90