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 Value c/l
52: 10 Value l/s
53: 400 Value 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 throw-entry \ pointer to task-specific signal handler
108:
109: AUser handler \ pointer to last throw frame
110: has? backtrace [IF]
111: AUser backtrace-rp0 \ rp at last call of interpret
112: [THEN]
113: \ AUser output
114: \ AUser input
115:
116: AUser errorhandler
117:
118: AUser "error 0 "error !
119:
120: has? EC 0= [IF]
121: auser holdbufptr
122: here word-pno-size chars allot dup holdbufptr !
123: word-pno-size chars +
124: : holdbuf ( -- addr ) holdbufptr @ ;
125: : holdbuf-end holdbuf word-pno-size chars + ;
126: auser holdptr dup holdptr a!
127: auser holdend holdend a!
128: [THEN]
129:
130: has? new-input [IF]
131: User current-input
132: [ELSE]
133: [IFUNDEF] #tib \ in ec-Version we may define this ourself
134: User tibstack \ saves >tib in execute
135: User >tib \ pointer to terminal input buffer
136: User #tib ( -- a-addr ) \ core-ext number-t-i-b
137: \G @code{User} variable -- @i{a-addr} is the address of a cell containing
138: \G the number of characters in the terminal input buffer.
139: \G OBSOLESCENT: @code{source} superceeds the function of this word.
140:
141: User >in ( -- a-addr ) \ core to-in
142: \G @code{User} variable -- @i{a-addr} is the address of a cell containing the
143: \G char offset from the start of the input buffer to the start of the
144: \G parse area.
145: 0 >in ! \ char number currently processed in tib
146: [THEN]
147:
148: has? file [IF]
149: User blk ( -- a-addr ) \ block b-l-k
150: \G @code{User} variable -- @i{a-addr} is the address of a cell containing zero
151: \G (in which case the input source is not a block and can be identified
152: \G by @code{source-id}) or the number of the block currently being
153: \G interpreted. A Standard program should not alter @code{blk} directly.
154: 0 blk !
155:
156: User loadfile 0 loadfile !
157:
158: 2user loadfilename 0 0 loadfilename 2! \ addr u for sourcefilename
159:
160: User loadline \ number of the currently interpreted
161: \ (in TIB) line if the interpretation
162: \ is in a textfile
163: \ the first line is 1
164:
165: 2User linestart \ starting file postition of
166: \ the current interpreted line (in TIB)
167: [THEN]
168: [THEN]
169:
170: 2user includefilename 0 0 includefilename 2! \ innermost included file
171:
172:
173: User base ( -- a-addr ) \ core
174: \G @code{User} variable -- @i{a-addr} is the address of a cell that
175: \G stores the number base used by default for number conversion during
176: \G input and output. Don't store to @code{base}, use
177: \G @code{base-execute} instead.
178: A base !
179: User dpl ( -- a-addr ) \ gforth
180: \G @code{User} variable -- @i{a-addr} is the address of a cell that stores the
181: \G position of the decimal point in the most recent numeric conversion.
182: \G Initialised to -1. After the conversion of a number containing no
183: \G decimal point, @code{dpl} is -1. After the conversion of @code{2.} it holds
184: \G 0. After the conversion of 234123.9 it contains 1, and so forth.
185: -1 dpl !
186:
187: User dp-char ( -- a-addr ) \ VFX
188: \G @code{User} variable -- @i{a-addr} is the address of a cell that stores the
189: \G decimal point character for double number conversion
190: '.' dp-char !
191:
192: User fp-char ( -- a-addr ) \ VFX
193: \G @code{User} variable -- @i{a-addr} is the address of a cell that stores the
194: \G decimal point character for floating point number conversion
195: '.' fp-char !
196:
197: User state ( -- a-addr ) \ core,tools-ext
198: \G @code{User} variable -- @i{a-addr} is the address of a cell
199: \G containing the compilation state flag. 0 => interpreting, -1 =>
200: \G compiling. A program shall not directly alter the value of
201: \G @code{state}. The following Standard words alter the value in
202: \G @code{state}: @code{:} (colon) @code{;} (semicolon) @code{abort}
203: \G @code{quit} @code{:noname} @code{[} (left-bracket) @code{]}
204: \G (right-bracket) @code{;code}. Don't use @code{state}! For an
205: \G alternative see @ref{Interpretation and Compilation Semantics}.
206: \ Recommended reading: @cite{@code{State}-smartness--Why it is evil
207: \ and how to exorcise it},
208: \ @url{http://www.complang.tuwien.ac.at/papers/ertl98.ps.gz}; short
209: \ version: Don't use @code{state}!
210: 0 state !
211:
212: AUser normal-dp \ the usual dictionary pointer
213: AUser dpp normal-dp dpp !
214: \ the pointer to the current dictionary pointer
215: \ ist reset to normal-dp on (doerror)
216: \ (i.e. any throw caught by quit)
217: has? ec [IF]
218: AUser LastCFA
219: [THEN]
220: AUser Last
221:
222: has? flash [IF]
223: AUser flash-dp
224: : rom flash-dp dpp ! ;
225: : ram normal-dp dpp ! ;
226: [THEN]
227:
228: User max-name-length \ maximum length of all names defined yet
229: 32 max-name-length !
230:
231: \ has? peephole [IF]
232: \ 0 value peeptable \ initialized in boot
233: \ [THEN]
234:
235: has? glocals [IF]
236: User locals-size \ this is the current size of the locals stack
237: \ frame of the current word
238: [THEN]
239:
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>