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1 | \ @(#) member.fth 98/01/26 1.2 |
2 | \ This files, along with c_struct.fth, supports the definition of | |
3 | \ structure members similar to those used in 'C'. | |
4 | \ | |
5 | \ Some of this same code is also used by ODE, | |
6 | \ the Object Development Environment. | |
7 | \ | |
8 | \ Author: Phil Burk | |
1a088514 | 9 | \ Copyright 1994 3DO, Phil Burk, Larry Polansky, David Rosenboom |
8e9db35f PB |
10 | \ |
11 | \ The pForth software code is dedicated to the public domain, | |
12 | \ and any third party may reproduce, distribute and modify | |
13 | \ the pForth software code or any derivative works thereof | |
14 | \ without any compensation or license. The pForth software | |
15 | \ code is provided on an "as is" basis without any warranty | |
16 | \ of any kind, including, without limitation, the implied | |
17 | \ warranties of merchantability and fitness for a particular | |
18 | \ purpose and their equivalents under the laws of any jurisdiction. | |
19 | \ | |
20 | \ MOD: PLB 1/16/87 Use abort" instead of er.report. | |
21 | \ MOD: PLB 2/19/87 Made OB.MEMBER immediate, use literal. | |
22 | \ MOD: PLB/MDH 6/7/88 Use 16 bit values in member defs. | |
23 | \ MOD: PLB 7/31/88 Add USHORT and UBYTE. | |
24 | \ MOD: PLB 1/20/89 Treat LITERAL as state sensitive. | |
25 | \ MOD: RDG 9/19/90 Add floating point member support. | |
26 | \ MOD: PLB 6/10/91 Add RPTR | |
27 | \ 00001 PLB 8/3/92 Make RPTR a -4 for S@ and S! | |
28 | \ 941102 RDG port to pforth | |
29 | \ 941108 PLB more porting to pforth. Use ?LITERAL instead os smart literal. | |
30 | \ 960710 PLB align long members for SUN | |
31 | ||
32 | ANEW TASK-MEMBER.FTH | |
33 | decimal | |
34 | ||
35 | : FIND.BODY ( -- , pfa true | $name false , look for word in dict. ) | |
36 | \ Return address of parameter data. | |
37 | bl word find | |
38 | IF >body true | |
39 | ELSE false | |
40 | THEN | |
41 | ; | |
42 | ||
43 | \ Variables shared with object oriented code. | |
44 | VARIABLE OB-STATE ( Compilation state. ) | |
45 | VARIABLE OB-CURRENT-CLASS ( ABS_CLASS_BASE of current class ) | |
46 | 1 constant OB_DEF_CLASS ( defining a class ) | |
47 | 2 constant OB_DEF_STRUCT ( defining a structure ) | |
48 | ||
49 | 4 constant OB_OFFSET_SIZE | |
50 | ||
51 | : OB.OFFSET@ ( member_def -- offset ) @ ; | |
52 | : OB.OFFSET, ( value -- ) , ; | |
53 | : OB.SIZE@ ( member_def -- offset ) | |
54 | ob_offset_size + @ ; | |
55 | : OB.SIZE, ( value -- ) , ; | |
56 | ||
57 | ( Members are associated with an offset from the base of a structure. ) | |
58 | : OB.MAKE.MEMBER ( +-bytes -- , make room in an object at compile time) | |
59 | dup >r ( -- +-b , save #bytes ) | |
60 | ABS ( -- |+-b| ) | |
61 | ob-current-class @ ( -- b addr-space) | |
62 | tuck @ ( as #b c , current space needed ) | |
63 | over 3 and 0= ( multiple of four? ) | |
64 | IF | |
65 | aligned | |
66 | ELSE | |
67 | over 1 and 0= ( multiple of two? ) | |
68 | IF | |
69 | even-up | |
70 | THEN | |
71 | THEN | |
72 | swap over + rot ! ( update space needed ) | |
73 | \ Save data in member definition. %M | |
74 | ob.offset, ( save old offset for ivar ) | |
75 | r> ob.size, ( store size in bytes for ..! and ..@ ) | |
76 | ; | |
77 | ||
78 | \ Unions allow one to address the same memory as different members. | |
79 | \ Unions work by saving the current offset for members on | |
80 | \ the stack and then reusing it for different members. | |
81 | : UNION{ ( -- offset , Start union definition. ) | |
82 | ob-current-class @ @ | |
83 | ; | |
84 | ||
85 | : }UNION{ ( old-offset -- new-offset , Middle of union ) | |
86 | union{ ( Get current for }UNION to compare ) | |
87 | swap ob-current-class @ ! ( Set back to old ) | |
88 | ; | |
89 | ||
90 | : }UNION ( offset -- , Terminate union definition, check lengths. ) | |
91 | union{ = NOT | |
92 | abort" }UNION - Two parts of UNION are not the same size!" | |
93 | ; | |
94 | ||
95 | \ Make members compile their offset, for "disposable includes". | |
96 | : OB.MEMBER ( #bytes -- , make room in an object at compile time) | |
97 | ( -- offset , run time for structure ) | |
98 | CREATE ob.make.member immediate | |
99 | DOES> ob.offset@ ( get offset ) ?literal | |
100 | ; | |
101 | ||
102 | : OB.FINDIT ( <thing> -- pfa , get pfa of thing or error ) | |
103 | find.body not | |
104 | IF cr count type ." ???" | |
105 | true abort" OB.FINDIT - Word not found!" | |
106 | THEN | |
107 | ; | |
108 | ||
109 | : OB.STATS ( member_pfa -- offset #bytes ) | |
110 | dup ob.offset@ swap | |
111 | ob.size@ | |
112 | ; | |
113 | ||
114 | : OB.STATS? ( <member> -- offset #bytes ) | |
115 | ob.findit ob.stats | |
116 | ; | |
117 | ||
118 | : SIZEOF() ( <struct>OR<class> -- #bytes , lookup size of object ) | |
119 | ob.findit @ | |
120 | ?literal | |
121 | ; immediate | |
122 | ||
123 | \ Basic word for defining structure members. | |
124 | : BYTES ( #bytes -- , error check for structure only ) | |
125 | ob-state @ ob_def_struct = not | |
126 | abort" BYTES - Only valid in :STRUCT definitions." | |
127 | ob.member | |
128 | ; | |
129 | ||
130 | \ Declare various types of structure members. | |
131 | \ Negative size indicates a signed member. | |
132 | : BYTE ( <name> -- , declare space for a byte ) | |
133 | -1 bytes ; | |
134 | ||
135 | : SHORT ( <name> -- , declare space for a 16 bit value ) | |
136 | -2 bytes ; | |
137 | ||
138 | : LONG ( <name> -- ) | |
139 | cell bytes ; | |
140 | ||
141 | : UBYTE ( <name> -- , declare space for signed byte ) | |
142 | 1 bytes ; | |
143 | ||
144 | : USHORT ( <name> -- , declare space for signed 16 bit value ) | |
145 | 2 bytes ; | |
146 | ||
147 | ||
148 | \ Aliases | |
149 | : APTR ( <name> -- ) long ; | |
150 | : RPTR ( <name> -- ) -4 bytes ; \ relative relocatable pointer 00001 | |
151 | : ULONG ( <name> -- ) long ; | |
152 | ||
153 | : STRUCT ( <struct> <new_ivar> -- , define a structure as an ivar ) | |
154 | [compile] sizeof() bytes | |
155 | ; |