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      1 
      2 /* Frame object interface */
      3 
      4 #ifndef Py_FRAMEOBJECT_H
      5 #define Py_FRAMEOBJECT_H
      6 #ifdef __cplusplus
      7 extern "C" {
      8 #endif
      9 
     10 typedef 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 
     16 typedef 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 
     55 PyAPI_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 
     61 PyAPI_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 
     69 PyAPI_FUNC(void) PyFrame_BlockSetup(PyFrameObject *, int, int, int);
     70 PyAPI_FUNC(PyTryBlock *) PyFrame_BlockPop(PyFrameObject *);
     71 
     72 /* Extend the value stack */
     73 
     74 PyAPI_FUNC(PyObject **) PyFrame_ExtendStack(PyFrameObject *, int, int);
     75 
     76 /* Conversions between "fast locals" and locals in dictionary */
     77 
     78 PyAPI_FUNC(void) PyFrame_LocalsToFast(PyFrameObject *, int);
     79 PyAPI_FUNC(void) PyFrame_FastToLocals(PyFrameObject *);
     80 
     81 PyAPI_FUNC(int) PyFrame_ClearFreeList(void);
     82 
     83 /* Return the line of code the frame is currently executing. */
     84 PyAPI_FUNC(int) PyFrame_GetLineNumber(PyFrameObject *);
     85 
     86 #ifdef __cplusplus
     87 }
     88 #endif
     89 #endif /* !Py_FRAMEOBJECT_H */
     90