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+ − 1 /* Fundamental definitions for XEmacs Lisp interpreter -- non-union objects.
+ − 2 Copyright (C) 1985, 1986, 1987, 1992, 1993 Free Software Foundation, Inc.
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+ − 3 Copyright (C) 2001, 2002 Ben Wing.
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+ − 4
+ − 5 This file is part of XEmacs.
+ − 6
+ − 7 XEmacs is free software; you can redistribute it and/or modify it
+ − 8 under the terms of the GNU General Public License as published by the
+ − 9 Free Software Foundation; either version 2, or (at your option) any
+ − 10 later version.
+ − 11
+ − 12 XEmacs is distributed in the hope that it will be useful, but WITHOUT
+ − 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ − 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ − 15 for more details.
+ − 16
+ − 17 You should have received a copy of the GNU General Public License
+ − 18 along with XEmacs; see the file COPYING. If not, write to
+ − 19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ − 20 Boston, MA 02111-1307, USA. */
+ − 21
+ − 22 /* Synched up with: FSF 19.30. Split out from lisp.h. */
+ − 23 /* This file has diverged greatly from FSF Emacs. Syncing is no
+ − 24 longer desirable or possible */
+ − 25
+ − 26 /*
+ − 27 Format of a non-union-type Lisp Object
+ − 28
+ − 29 3 2 1 0
+ − 30 bit 10987654321098765432109876543210
+ − 31 --------------------------------
+ − 32 VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVTT
+ − 33
+ − 34 Integers are treated specially, and look like this:
+ − 35
+ − 36 3 2 1 0
+ − 37 bit 10987654321098765432109876543210
+ − 38 --------------------------------
+ − 39 VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVT
+ − 40
+ − 41 For integral Lisp types, i.e. integers and characters, the value
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+ − 42 bits are the Lisp object. Some people call such Lisp_Objects "immediate".
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+ − 43
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+ − 44 The object is obtained by masking off the type bits.
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+ − 45 Bit 1 is used as a value bit by splitting the Lisp integer type
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+ − 46 into two subtypes, Lisp_Type_Int_Even and Lisp_Type_Int_Odd.
+ − 47 By this trickery we get 31 bits for integers instead of 30.
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+ − 48
+ − 49 For non-integral types, the value bits of a Lisp_Object contain
+ − 50 a pointer to a structure containing the object. The pointer is
+ − 51 obtained by masking off the type and mark bits.
+ − 52
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+ − 53 All pointer-based types are coalesced under a single type called
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+ − 54 Lisp_Type_Record. The type bits for this type are required by the
+ − 55 implementation to be 00, just like the least significant bits of
+ − 56 word-aligned struct pointers on 32-bit hardware. This requires that
+ − 57 all structs implementing Lisp_Objects have an alignment of at least 4
+ − 58 bytes. Because of this, Lisp_Object pointers don't have to be masked
+ − 59 and are full-sized.
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+ − 60
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+ − 61 There are no mark bits in the Lisp_Object itself (there used to be).
+ − 62
+ − 63 Integers and characters don't need to be marked. All other types are
+ − 64 lrecord-based, which means they get marked by setting the mark bit in
+ − 65 the struct lrecord_header.
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+ − 66
+ − 67 Here is a brief description of the following macros:
+ − 68
+ − 69 XTYPE The type bits of a Lisp_Object
+ − 70 XPNTRVAL The value bits of a Lisp_Object storing a pointer
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+ − 71 XCHARVAL The value bits of a Lisp_Object storing a Ichar
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+ − 72 XREALINT The value bits of a Lisp_Object storing an integer, signed
+ − 73 XUINT The value bits of a Lisp_Object storing an integer, unsigned
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+ − 74 INTP Non-zero if this Lisp_Object is an integer
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+ − 75 Qzero Lisp Integer 0
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+ − 76 EQ Non-zero if two Lisp_Objects are identical, not merely equal. */
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+ − 77
+ − 78
+ − 79 typedef EMACS_INT Lisp_Object;
+ − 80
+ − 81 #define Lisp_Type_Int_Bit (Lisp_Type_Int_Even & Lisp_Type_Int_Odd)
+ − 82 #define VALMASK (((1UL << VALBITS) - 1UL) << GCTYPEBITS)
+ − 83 #define XTYPE(x) ((enum Lisp_Type) (((EMACS_UINT)(x)) & ~VALMASK))
+ − 84 #define XPNTRVAL(x) (x) /* This depends on Lisp_Type_Record == 0 */
+ − 85 #define XCHARVAL(x) ((x) >> GCBITS)
+ − 86 #define XREALINT(x) ((x) >> INT_GCBITS)
+ − 87 #define XUINT(x) ((EMACS_UINT)(x) >> INT_GCBITS)
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+ − 88
+ − 89 #define wrap_pointer_1(ptr) ((Lisp_Object) (ptr))
+ − 90
+ − 91 DECLARE_INLINE_HEADER (
+ − 92 Lisp_Object
+ − 93 make_int_verify (EMACS_INT val)
+ − 94 )
+ − 95 {
+ − 96 Lisp_Object obj = (Lisp_Object) ((val << INT_GCBITS) | Lisp_Type_Int_Bit);
+ − 97 type_checking_assert (XREALINT (obj) == val);
+ − 98 return obj;
+ − 99 }
+ − 100
+ − 101 #define make_int(x) ((Lisp_Object) (((x) << INT_GCBITS) | Lisp_Type_Int_Bit))
+ − 102
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+ − 103 #define make_char_1(x) ((Lisp_Object) (((x) << GCBITS) | Lisp_Type_Char))
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+ − 104
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+ − 105 #define INTP(x) ((EMACS_UINT)(x) & Lisp_Type_Int_Bit)
+ − 106 #define INT_PLUS(x,y) ((x)+(y)-Lisp_Type_Int_Bit)
+ − 107 #define INT_MINUS(x,y) ((x)-(y)+Lisp_Type_Int_Bit)
+ − 108 #define INT_PLUS1(x) INT_PLUS (x, make_int (1))
+ − 109 #define INT_MINUS1(x) INT_MINUS (x, make_int (1))
+ − 110
+ − 111 #define Qzero make_int (0)
+ − 112 #define Qnull_pointer ((Lisp_Object) 0)
+ − 113 #define EQ(x,y) ((x) == (y))
+ − 114
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+ − 115 /* WARNING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+ − 116
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+ − 117 You can only GET_LISP_FROM_VOID something that had previously been
+ − 118 STORE_LISP_IN_VOID'd. If you want to go the other way, use
+ − 119 STORE_VOID_IN_LISP and GET_VOID_FROM_LISP, or use make_opaque_ptr(). */
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+ − 120
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+ − 121 /* Convert a Lisp object to a void * pointer, as when it needs to be passed
+ − 122 to a toolkit callback function */
+ − 123 #define STORE_LISP_IN_VOID(larg) ((void *) (larg))
+ − 124
+ − 125 /* Convert a void * pointer back into a Lisp object, assuming that the
+ − 126 pointer was generated by STORE_LISP_IN_VOID. */
+ − 127 #define GET_LISP_FROM_VOID(varg) ((Lisp_Object) (varg))
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+ − 128
+ − 129 /* Convert a Lisp_Object into something that can't be used as an
+ − 130 lvalue. Useful for type-checking. */
+ − 131 #define NON_LVALUE(larg) ((larg) + 0)
