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/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
/*
* v8dbg.h: macros for use by V8 heap inspection tools. The consumer must
* define values for various tags and shifts. The MDB module gets these
* constants from information encoded in the binary itself.
*/
#ifndef _V8DBG_H
#define _V8DBG_H
/*
* Recall that while V8 heap objects are always 4-byte aligned, heap object
* pointers always have the last bit set. So when looking for a field nominally
* at offset X, one must be sure to clear the tag bit first.
*/
#define V8_OFF_HEAP(x) ((x) - V8_HeapObjectTag)
/*
* Determine whether a given pointer refers to a SMI, Failure, or HeapObject.
*/
#define V8_IS_SMI(ptr) (((ptr) & V8_SmiTagMask) == V8_SmiTag)
#define V8_IS_FAILURE(ptr) (((ptr) & V8_FailureTagMask) == V8_FailureTag)
#define V8_IS_HEAPOBJECT(ptr) \
(((ptr) & V8_HeapObjectTagMask) == V8_HeapObjectTag)
/*
* Extract the value of a SMI "pointer". Recall that small integers are stored
* using the upper 31 bits.
*/
#define V8_SMI_VALUE(smi) ((smi) >> (V8_SmiValueShift + V8_SmiShiftSize))
/*
* Determine the encoding and representation of a V8 string.
*/
#define V8_TYPE_STRING(type) (((type) & V8_IsNotStringMask) == V8_StringTag)
#define V8_STRENC_ASCII(type) \
(((type) & V8_StringEncodingMask) == V8_AsciiStringTag)
#define V8_STRREP_SEQ(type) \
(((type) & V8_StringRepresentationMask) == V8_SeqStringTag)
#define V8_STRREP_CONS(type) \
(((type) & V8_StringRepresentationMask) == V8_ConsStringTag)
#define V8_STRREP_SLICED(type) \
(((type) & V8_StringRepresentationMask) == V8_SlicedStringTag)
#define V8_STRREP_EXT(type) \
(((type) & V8_StringRepresentationMask) == V8_ExternalStringTag)
/*
* Several of the following constants and transformations are hardcoded in V8 as
* well, so there's no way to extract them programmatically from the binary.
*/
#define V8_DESC_KEYIDX(x) ((x) + V8_PROP_IDX_FIRST)
#define V8_DESC_VALIDX(x) ((x) << 1)
#define V8_DESC_DETIDX(x) (((x) << 1) + 1)
#define V8_DESC_ISFIELD(x) \
((V8_SMI_VALUE(x) & V8_PROP_TYPE_MASK) == V8_PROP_TYPE_FIELD)
#endif /* _V8DBG_H */