1: \ VARS.FS Kernal variables
2:
3: \ Copyright (C) 1995,1996,1997,1998,2000,2003,2006,2007,2011 Free Software Foundation, Inc.
4:
5: \ This file is part of Gforth.
6:
7: \ Gforth is free software; you can redistribute it and/or
8: \ modify it under the terms of the GNU General Public License
9: \ as published by the Free Software Foundation, either version 3
10: \ of the License, or (at your option) any later version.
11:
12: \ This program is distributed in the hope that it will be useful,
13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15: \ GNU General Public License for more details.
16:
17: \ You should have received a copy of the GNU General Public License
18: \ along with this program. If not, see http://www.gnu.org/licenses/.
19:
20: hex \ everything now hex! 11may93jaw
21:
22: \ important constants 17dec92py
23:
24: \ dpANS6 (sect 3.1.3.1) says
25: \ "a true flag ... [is] a single-cell value with all bits set"
26: \ better definition: 0 0= constant true ( no dependence on 2's compl)
27: -1 Constant true ( -- f ) \ core-ext
28: \G @code{Constant} -- @i{f} is a cell with all bits set.
29: \ see starts looking for primitives after this word!
30:
31: 0 Constant false ( -- f ) \ core-ext
32: \G @code{Constant} -- @i{f} is a cell with all bits clear.
33:
34: [IFUNDEF] cell
35: 1 cells Constant cell ( -- u ) \ gforth
36: \G @code{Constant} -- @code{1 cells}
37: [THEN]
38:
39: has? floating [IF]
40: 1 floats Constant float ( -- u ) \ gforth
41: \G @code{Constant} -- the number of address units corresponding to a floating-point number.
42: [THEN]
43:
44: 20 Constant bl ( -- c-char ) \ core b-l
45: \G @i{c-char} is the character value for a space.
46: \ used by docon:, must be constant
47:
48: has? EC [IF] 20 cells [ELSE] FF [THEN] Constant /line
49:
50: has? file [IF]
51: 40 Constant c/l
52: 10 Constant l/s
53: 400 Constant chars/block
54: [THEN]
55:
56: 20 8 2* cells + 2 + cell+ constant word-pno-size ( -- u )
57:
58: 84 constant pad-minsize ( -- u )
59:
60: $400 Value def#tib
61: \G default size of terminal input buffer. Default size is 1K
62:
63: \ that's enough so long
64:
65: \ User variables 13feb93py
66:
67: \ initialized by COLD
68:
69: has? no-userspace 0= [IF]
70: Create main-task has? OS [IF] 100 [ELSE] 40 [THEN] cells dup allot
71:
72: \ set user-pointer from cross-compiler right
73: main-task
74: UNLOCK swap region user-region user-region setup-region LOCK
75:
76: Variable udp ( -- a-addr ) \ gforth
77: \G user area size
78:
79: AUser next-task main-task next-task !
80: AUser prev-task main-task prev-task !
81: AUser save-task 0 save-task !
82: [THEN]
83: AUser sp0 ( -- a-addr ) \ gforth
84: \G @code{User} variable -- initial value of the data stack pointer.
85: \ sp0 is used by douser:, must be user
86: \ ' sp0 Alias s0 ( -- a-addr ) \ gforth
87: \G OBSOLETE alias of @code{sp0}
88:
89: AUser rp0 ( -- a-addr ) \ gforth
90: \G @code{User} variable -- initial value of the return stack pointer.
91: \ ' rp0 Alias r0 ( -- a-addr ) \ gforth
92: \G OBSOLETE alias of @code{rp0}
93:
94: has? floating [IF]
95: AUser fp0 ( -- a-addr ) \ gforth
96: \G @code{User} variable -- initial value of the floating-point stack pointer.
97: \ no f0, because this leads to unexpected results when using hex
98: [THEN]
99:
100: has? glocals [IF]
101: AUser lp0 ( -- a-addr ) \ gforth
102: \G @code{User} variable -- initial value of the locals stack pointer.
103: \ ' lp0 Alias l0 ( -- a-addr ) \ gforth
104: \G OBSOLETE alias of @code{lp0}
105: [THEN]
106:
107: AUser handler \ pointer to last throw frame
108: has? backtrace [IF]
109: AUser backtrace-rp0 \ rp at last call of interpret
110: [THEN]
111: \ AUser output
112: \ AUser input
113:
114: AUser errorhandler
115:
116: AUser "error 0 "error !
117:
118: has? EC 0= [IF]
119: auser holdbufptr
120: here word-pno-size chars allot dup holdbufptr !
121: word-pno-size chars +
122: : holdbuf ( -- addr ) holdbufptr @ ;
123: : holdbuf-end holdbuf word-pno-size chars + ;
124: auser holdptr dup holdptr a!
125: auser holdend holdend a!
126: [THEN]
127:
128: has? new-input [IF]
129: User current-input
130: [ELSE]
131: [IFUNDEF] #tib \ in ec-Version we may define this ourself
132: User tibstack \ saves >tib in execute
133: User >tib \ pointer to terminal input buffer
134: User #tib ( -- a-addr ) \ core-ext number-t-i-b
135: \G @code{User} variable -- @i{a-addr} is the address of a cell containing
136: \G the number of characters in the terminal input buffer.
137: \G OBSOLESCENT: @code{source} superceeds the function of this word.
138:
139: User >in ( -- a-addr ) \ core to-in
140: \G @code{User} variable -- @i{a-addr} is the address of a cell containing the
141: \G char offset from the start of the input buffer to the start of the
142: \G parse area.
143: 0 >in ! \ char number currently processed in tib
144: [THEN]
145:
146: has? file [IF]
147: User blk ( -- a-addr ) \ block b-l-k
148: \G @code{User} variable -- @i{a-addr} is the address of a cell containing zero
149: \G (in which case the input source is not a block and can be identified
150: \G by @code{source-id}) or the number of the block currently being
151: \G interpreted. A Standard program should not alter @code{blk} directly.
152: 0 blk !
153:
154: User loadfile 0 loadfile !
155:
156: 2user loadfilename 0 0 loadfilename 2! \ addr u for sourcefilename
157:
158: User loadline \ number of the currently interpreted
159: \ (in TIB) line if the interpretation
160: \ is in a textfile
161: \ the first line is 1
162:
163: 2User linestart \ starting file postition of
164: \ the current interpreted line (in TIB)
165: [THEN]
166: [THEN]
167:
168: 2user includefilename 0 0 includefilename 2! \ innermost included file
169:
170:
171: User base ( -- a-addr ) \ core
172: \G @code{User} variable -- @i{a-addr} is the address of a cell that
173: \G stores the number base used by default for number conversion during
174: \G input and output. Don't store to @code{base}, use
175: \G @code{base-execute} instead.
176: A base !
177: User dpl ( -- a-addr ) \ gforth
178: \G @code{User} variable -- @i{a-addr} is the address of a cell that stores the
179: \G position of the decimal point in the most recent numeric conversion.
180: \G Initialised to -1. After the conversion of a number containing no
181: \G decimal point, @code{dpl} is -1. After the conversion of @code{2.} it holds
182: \G 0. After the conversion of 234123.9 it contains 1, and so forth.
183: -1 dpl !
184:
185: User state ( -- a-addr ) \ core,tools-ext
186: \G @code{User} variable -- @i{a-addr} is the address of a cell
187: \G containing the compilation state flag. 0 => interpreting, -1 =>
188: \G compiling. A program shall not directly alter the value of
189: \G @code{state}. The following Standard words alter the value in
190: \G @code{state}: @code{:} (colon) @code{;} (semicolon) @code{abort}
191: \G @code{quit} @code{:noname} @code{[} (left-bracket) @code{]}
192: \G (right-bracket) @code{;code}. Don't use @code{state}! For an
193: \G alternative see @ref{Interpretation and Compilation Semantics}.
194: \ Recommended reading: @cite{@code{State}-smartness--Why it is evil
195: \ and how to exorcise it},
196: \ @url{http://www.complang.tuwien.ac.at/papers/ertl98.ps.gz}; short
197: \ version: Don't use @code{state}!
198: 0 state !
199:
200: AUser normal-dp \ the usual dictionary pointer
201: AUser dpp normal-dp dpp !
202: \ the pointer to the current dictionary pointer
203: \ ist reset to normal-dp on (doerror)
204: \ (i.e. any throw caught by quit)
205: has? ec [IF]
206: AUser LastCFA
207: [THEN]
208: AUser Last
209:
210: has? flash [IF]
211: AUser flash-dp
212: : rom flash-dp dpp ! ;
213: : ram normal-dp dpp ! ;
214: [THEN]
215:
216: User max-name-length \ maximum length of all names defined yet
217: 32 max-name-length !
218:
219: \ has? peephole [IF]
220: \ 0 value peeptable \ initialized in boot
221: \ [THEN]
222:
223: has? glocals [IF]
224: User locals-size \ this is the current size of the locals stack
225: \ frame of the current word
226: [THEN]
227:
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