Include/frameobject.h

   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 */