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LibrePilot/flight/Libraries/PyMite/vm/obj.h

375 lines
10 KiB
C

/*
# This file is Copyright 2003, 2006, 2007, 2009, 2010 Dean Hall.
#
# This file is part of the PyMite VM.
# The PyMite VM is free software: you can redistribute it and/or modify
# it under the terms of the GNU GENERAL PUBLIC LICENSE Version 2.
#
# The PyMite VM is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# A copy of the GNU GENERAL PUBLIC LICENSE Version 2
# is seen in the file COPYING in this directory.
*/
#ifndef __OBJ_H__
#define __OBJ_H__
/**
* \file
* \brief Object Type
*
* Object type header.
*/
/** Object descriptor field constants */
#define OD_MARK_SHIFT 14
#define OD_FREE_SHIFT 15
#define OD_MARK_BIT (uint16_t)(1 << OD_MARK_SHIFT)
#define OD_FREE_BIT (uint16_t)(1 << OD_FREE_SHIFT)
#define OD_SIZE_MASK (uint16_t)(0x01FF)
#define OD_TYPE_MASK (uint16_t)(0x3E00)
#define OD_TYPE_SHIFT 9
/** Heap descriptor size mask */
#define HD_SIZE_MASK (uint16_t)(0x3FFF)
/**
* Gets the free bit of the given object to the given value.
* If the object is marked free, it is not being used by the VM.
*/
#define OBJ_GET_FREE(pobj) \
((((pPmObj_t)pobj)->od >> OD_FREE_SHIFT) & (uint8_t)1)
/**
* Sets the free bit of the given object to the given value.
* Setting the free bit means that the object will use the heap descriptor
* structure instead of the object descriptor structure.
*/
#define OBJ_SET_FREE(pobj, free) \
do \
{ \
((pPmObj_t)pobj)->od = ((uint8_t)free) \
? ((pPmObj_t)pobj)->od | OD_FREE_BIT \
: ((pPmObj_t)pobj)->od & ~OD_FREE_BIT;\
} \
while (0)
/*
* #99: od_size bits are shifted because size is a scaled value
* True size is always a multiple of 4, so the lower two bits are ignored
* and two more significant bits are gained.
*/
/**
* Gets the size of the chunk in bytes.
* Tests whether the object is free as that determines whether the chunk is
* using an object descriptor or a heap descriptor. Heap descriptors have
* a larger size field and use a different bit mask than object descriptors.
*/
#define OBJ_GET_SIZE(pobj) \
((((pPmObj_t)pobj)->od & OD_FREE_BIT) \
? ((((pPmObj_t)pobj)->od & HD_SIZE_MASK) << 2) \
: ((((pPmObj_t)pobj)->od & OD_SIZE_MASK) << 2))
/**
* Sets the size of the chunk in bytes.
* Tests whether the object is free as that determines whether the chunk is
* using an object descriptor or a heap descriptor. Heap descriptors have
* a larger size field and use a different bit mask than object descriptors.
*/
#define OBJ_SET_SIZE(pobj, size) \
do \
{ \
if (((pPmObj_t)pobj)->od & OD_FREE_BIT) \
{ \
((pPmObj_t)pobj)->od &= ~HD_SIZE_MASK; \
((pPmObj_t)pobj)->od |= (((size) >> 2) & HD_SIZE_MASK); \
} \
else \
{ \
((pPmObj_t)pobj)->od &= ~OD_SIZE_MASK; \
((pPmObj_t)pobj)->od |= (((size) >> 2) & OD_SIZE_MASK); \
} \
} \
while (0)
/**
* Gets the type of the object
* This MUST NOT be called on objects that are free.
*/
#define OBJ_GET_TYPE(pobj) \
(((((pPmObj_t)pobj)->od) & OD_TYPE_MASK) >> OD_TYPE_SHIFT)
/**
* Sets the type of the object
* This MUST NOT be called on objects that are free.
*/
#define OBJ_SET_TYPE(pobj, type) \
do \
{ \
((pPmObj_t)pobj)->od &= ~OD_TYPE_MASK; \
((pPmObj_t)pobj)->od |= (((type) << OD_TYPE_SHIFT) & OD_TYPE_MASK); \
} \
while (0)
/**
* Object type enum
*
* These values go in the od_type fields of the obj descriptor.
* Be sure these values correspond to those in the image creator
* tool.
* The hashable types are grouped together for convenience.
*
* WARNING: od_type must be at most 5 bits! (must be < 0x20)
*/
typedef enum PmType_e
{
OBJ_TYPE_HASHABLE_MIN = 0x00,
/** None */
OBJ_TYPE_NON = 0x00,
/** Signed integer */
OBJ_TYPE_INT = 0x01,
/** Floating point 32b */
OBJ_TYPE_FLT = 0x02,
/** String */
OBJ_TYPE_STR = 0x03,
/** Tuple (immutable sequence) */
OBJ_TYPE_TUP = 0x04,
/** Code obj */
OBJ_TYPE_COB = 0x05,
/** Module obj */
OBJ_TYPE_MOD = 0x06,
/** Class obj */
OBJ_TYPE_CLO = 0x07,
/** Function obj (callable) */
OBJ_TYPE_FXN = 0x08,
/** Class instance */
OBJ_TYPE_CLI = 0x09,
/** Code image in static memory */
OBJ_TYPE_CIM = 0x0A,
/** Native function image */
OBJ_TYPE_NIM = 0x0B,
/** Native function object */
OBJ_TYPE_NOB = 0x0C,
/** Thread */
OBJ_TYPE_THR = 0x0D,
/** Boolean object */
OBJ_TYPE_BOOL = 0x0F,
/** Code image object */
OBJ_TYPE_CIO = 0x10,
/** Method object */
OBJ_TYPE_MTH = 0x11,
/* All types after this are not hashable */
OBJ_TYPE_HASHABLE_MAX = 0x11,
/** List (mutable sequence) */
OBJ_TYPE_LST = 0x12,
/** Dictionary (hash table) */
OBJ_TYPE_DIC = 0x13,
#ifdef HAVE_BYTEARRAY
/** Bytearray (mutable) */
OBJ_TYPE_BYA = 0x14,
#endif /* HAVE_BYTEARRAY */
/* All types after this are not accessible to the user */
OBJ_TYPE_ACCESSIBLE_MAX = 0x18,
#ifdef HAVE_BYTEARRAY
/** Bytes (mutable container for Bytearray type) */
OBJ_TYPE_BYS = 0x18,
#endif /* HAVE_BYTEARRAY */
/** Frame type */
OBJ_TYPE_FRM = 0x19,
/** Block type (for,while,try,etc) */
OBJ_TYPE_BLK = 0x1A,
/** Segment (within a seglist) */
OBJ_TYPE_SEG = 0x1B,
/** Seglist */
OBJ_TYPE_SGL = 0x1C,
/** Sequence iterator */
OBJ_TYPE_SQI = 0x1D,
/** Native frame (there is only one) */
OBJ_TYPE_NFM = 0x1E,
} PmType_t, *pPmType_t;
/**
* Object Descriptor
*
* All active PyMite "objects" must have this at the top of their struct.
* (CodeObj, Frame, Dict, List, Tuple, etc.).
*
* The following is a diagram of the object descriptor:
* \verbatim
* MSb LSb
* 7 6 5 4 3 2 1 0
* pchunk-> +-+-+-+-+-+-+-+-+ S := Size of the chunk (2 LSbs dropped)
* | S[9:2] | F := Free bit
* +-+-+---------+-+ M := GC Mark bit
* |F|M| T |S| T := Object type (PyMite specific)
* +-+-+---------+-+
* | object data |
* ... ...
* | end data | Theoretical min size == 2
* +---------------+ Effective min size == 8
* (due to pmHeapDesc_t)
* \endverbatim
* Macros are used to get and set field values.
* Using macros eliminates declaring bit fields which fails on some compilers.
*/
typedef uint16_t PmObjDesc_t,
*pPmObjDesc_t;
/**
* Object
*
* The abstract empty object type for PyMite.
*/
typedef struct PmObj_s
{
/** Object descriptor */
PmObjDesc_t od;
} PmObj_t,
*pPmObj_t;
/** Boolean object */
typedef struct PmBoolean_s
{
/** Object descriptor */
PmObjDesc_t od;
/** Boolean value */
int32_t val;
}
PmBoolean_t, *pPmBoolean_t;
/**
* Loads an object from an image in memory.
* Return pointer to object.
* Leave add pointing one byte past end of obj.
*
* The following lists the simple object types
* and their image structures:
* -None:
* -type: int8_t - OBJ_TYPE_NON
*
* -Int:
* -type: int8_t - OBJ_TYPE_INT
* -value: int32_t - signed integer value
*
* -Float:
* -type: int8_t - OBJ_TYPE_FLOAT
* -value: float32_t - 32-bit floating point value
*
* -Slice (is this allowed in img?):
* -type: int8_t - OBJ_TYPE_SLICE
* -index1: int16_t - first index.
* -index2: int16_t - second index.
*
* @param memspace memory space/type
* @param paddr ptr to ptr to obj
* return by reference: paddr pts to
* first byte after obj
* @param r_pobj Return arg, the loaded object.
* @return Return status
*/
PmReturn_t obj_loadFromImg(PmMemSpace_t memspace,
uint8_t const **paddr, pPmObj_t *r_pobj);
/**
* Loads a code object from a code image object
*
* @param pimg Ptr to a code image object
* @param r_pobj Return arg, the loaded object
* @return Returns status
*/
PmReturn_t obj_loadFromImgObj(pPmObj_t pimg, pPmObj_t *r_pobj);
/**
* Finds the boolean value of the given object.
*
* @param pobj Ptr to object to test.
* @return Nonzero value if object is False.
*/
int8_t obj_isFalse(pPmObj_t pobj);
/**
* Returns the boolean true if the item is in the object
*
* @param pobj Ptr to container object
* @param pitem Ptr to item
*/
PmReturn_t obj_isIn(pPmObj_t pobj, pPmObj_t pitem);
/**
* Compares two objects for equality.
*
* @param pobj1 Ptr to first object.
* @param pobj2 Ptr to second object.
* @return C_SAME if the items are equivalent, C_DIFFER otherwise.
*/
int8_t obj_compare(pPmObj_t pobj1, pPmObj_t pobj2);
/**
* Print an object, thereby using objects helpers.
*
* @param pobj Ptr to object for printing.
* @param is_expr_repr Influences the way None and strings are printed.
* If 0, None is printed, strings are printed.
* If 1, None is not printed and strings are printed
* surrounded with single quotes and unprintable
* characters are escaped.
* @param is_nested Influences the way None and strings are printed.
* If 1, None will be printed and strings will be
* surrounded with single quotes and escaped.
* This argument overrides the is_expr_repr argument.
* @return Return status
*/
PmReturn_t obj_print(pPmObj_t pobj, uint8_t is_expr_repr, uint8_t is_nested);
#ifdef HAVE_BACKTICK
/**
* Returns by reference a string object that is the human-readable
* representation of the object. Used by the backtick operation (UNARY_CONVERT).
*
* @param pobj Ptr to object to represent
* @param r_pstr Return arg, the string object
* @return Return status
*/
PmReturn_t obj_repr(pPmObj_t pobj, pPmObj_t *r_pstr);
#endif /* HAVE_BACKTICK */
#endif /* __OBJ_H__ */