Annotation of gforth/kernel/vars.fs, revision 1.52
1.1 anton 1: \ VARS.FS Kernal variables
2:
1.50 anton 3: \ Copyright (C) 1995,1996,1997,1998,2000,2003,2006,2007,2011 Free Software Foundation, Inc.
1.1 anton 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
1.47 anton 9: \ as published by the Free Software Foundation, either version 3
1.1 anton 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
1.47 anton 18: \ along with this program. If not, see http://www.gnu.org/licenses/.
1.1 anton 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)
1.10 crook 27: -1 Constant true ( -- f ) \ core-ext
1.19 crook 28: \G @code{Constant} -- @i{f} is a cell with all bits set.
1.10 crook 29: \ see starts looking for primitives after this word!
30:
31: 0 Constant false ( -- f ) \ core-ext
1.19 crook 32: \G @code{Constant} -- @i{f} is a cell with all bits clear.
1.1 anton 33:
1.16 jwilke 34: [IFUNDEF] cell
1.1 anton 35: 1 cells Constant cell ( -- u ) \ gforth
1.22 anton 36: \G @code{Constant} -- @code{1 cells}
1.16 jwilke 37: [THEN]
1.17 crook 38:
1.25 pazsan 39: has? floating [IF]
1.1 anton 40: 1 floats Constant float ( -- u ) \ gforth
1.19 crook 41: \G @code{Constant} -- the number of address units corresponding to a floating-point number.
1.25 pazsan 42: [THEN]
1.1 anton 43:
1.20 crook 44: 20 Constant bl ( -- c-char ) \ core b-l
1.17 crook 45: \G @i{c-char} is the character value for a space.
1.10 crook 46: \ used by docon:, must be constant
1.1 anton 47:
1.48 pazsan 48: has? EC [IF] 20 cells [ELSE] FF [THEN] Constant /line
1.1 anton 49:
1.39 pazsan 50: has? file [IF]
1.1 anton 51: 40 Constant c/l
52: 10 Constant l/s
53: 400 Constant chars/block
1.38 pazsan 54: [THEN]
1.1 anton 55:
1.18 jwilke 56: 20 8 2* cells + 2 + cell+ constant word-pno-size ( -- u )
1.40 pazsan 57:
1.2 anton 58: 84 constant pad-minsize ( -- u )
1.11 anton 59:
1.25 pazsan 60: $400 Value def#tib
61: \G default size of terminal input buffer. Default size is 1K
1.2 anton 62:
1.1 anton 63: \ that's enough so long
64:
65: \ User variables 13feb93py
66:
67: \ initialized by COLD
68:
1.38 pazsan 69: has? no-userspace 0= [IF]
1.35 jwilke 70: Create main-task has? OS [IF] 100 [ELSE] 40 [THEN] cells dup allot
1.3 jwilke 71:
72: \ set user-pointer from cross-compiler right
73: main-task
1.35 jwilke 74: UNLOCK swap region user-region user-region setup-region LOCK
1.1 anton 75:
1.19 crook 76: Variable udp ( -- a-addr ) \ gforth
1.28 pazsan 77: \G user area size
1.1 anton 78:
79: AUser next-task main-task next-task !
80: AUser prev-task main-task prev-task !
81: AUser save-task 0 save-task !
1.38 pazsan 82: [THEN]
1.10 crook 83: AUser sp0 ( -- a-addr ) \ gforth
1.19 crook 84: \G @code{User} variable -- initial value of the data stack pointer.
1.10 crook 85: \ sp0 is used by douser:, must be user
1.38 pazsan 86: \ ' sp0 Alias s0 ( -- a-addr ) \ gforth
1.10 crook 87: \G OBSOLETE alias of @code{sp0}
88:
89: AUser rp0 ( -- a-addr ) \ gforth
1.19 crook 90: \G @code{User} variable -- initial value of the return stack pointer.
1.38 pazsan 91: \ ' rp0 Alias r0 ( -- a-addr ) \ gforth
1.10 crook 92: \G OBSOLETE alias of @code{rp0}
93:
1.25 pazsan 94: has? floating [IF]
1.10 crook 95: AUser fp0 ( -- a-addr ) \ gforth
1.19 crook 96: \G @code{User} variable -- initial value of the floating-point stack pointer.
1.10 crook 97: \ no f0, because this leads to unexpected results when using hex
1.25 pazsan 98: [THEN]
1.10 crook 99:
1.25 pazsan 100: has? glocals [IF]
1.10 crook 101: AUser lp0 ( -- a-addr ) \ gforth
1.19 crook 102: \G @code{User} variable -- initial value of the locals stack pointer.
1.38 pazsan 103: \ ' lp0 Alias l0 ( -- a-addr ) \ gforth
1.10 crook 104: \G OBSOLETE alias of @code{lp0}
1.25 pazsan 105: [THEN]
1.10 crook 106:
1.52 ! pazsan 107: AUser throw-entry \ pointer to task-specific signal handler
! 108:
1.3 jwilke 109: AUser handler \ pointer to last throw frame
1.18 jwilke 110: has? backtrace [IF]
1.13 anton 111: AUser backtrace-rp0 \ rp at last call of interpret
1.18 jwilke 112: [THEN]
1.1 anton 113: \ AUser output
114: \ AUser input
115:
116: AUser errorhandler
117:
118: AUser "error 0 "error !
119:
1.51 pazsan 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:
1.25 pazsan 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:
1.7 pazsan 148: has? file [IF]
1.20 crook 149: User blk ( -- a-addr ) \ block b-l-k
1.19 crook 150: \G @code{User} variable -- @i{a-addr} is the address of a cell containing zero
1.10 crook 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:
1.1 anton 156: User loadfile 0 loadfile !
157:
1.32 anton 158: 2user loadfilename 0 0 loadfilename 2! \ addr u for sourcefilename
1.37 anton 159:
1.1 anton 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)
1.25 pazsan 167: [THEN]
1.7 pazsan 168: [THEN]
1.37 anton 169:
170: 2user includefilename 0 0 includefilename 2! \ innermost included file
171:
1.1 anton 172:
1.26 anton 173: User base ( -- a-addr ) \ core
1.45 anton 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.
1.26 anton 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
1.36 anton 183: \G decimal point, @code{dpl} is -1. After the conversion of @code{2.} it holds
1.26 anton 184: \G 0. After the conversion of 234123.9 it contains 1, and so forth.
185: -1 dpl !
1.1 anton 186:
1.26 anton 187: User state ( -- a-addr ) \ core,tools-ext
188: \G @code{User} variable -- @i{a-addr} is the address of a cell
189: \G containing the compilation state flag. 0 => interpreting, -1 =>
190: \G compiling. A program shall not directly alter the value of
191: \G @code{state}. The following Standard words alter the value in
192: \G @code{state}: @code{:} (colon) @code{;} (semicolon) @code{abort}
193: \G @code{quit} @code{:noname} @code{[} (left-bracket) @code{]}
194: \G (right-bracket) @code{;code}. Don't use @code{state}! For an
195: \G alternative see @ref{Interpretation and Compilation Semantics}.
196: \ Recommended reading: @cite{@code{State}-smartness--Why it is evil
197: \ and how to exorcise it},
198: \ @url{http://www.complang.tuwien.ac.at/papers/ertl98.ps.gz}; short
199: \ version: Don't use @code{state}!
200: 0 state !
1.10 crook 201:
1.1 anton 202: AUser normal-dp \ the usual dictionary pointer
203: AUser dpp normal-dp dpp !
204: \ the pointer to the current dictionary pointer
205: \ ist reset to normal-dp on (doerror)
206: \ (i.e. any throw caught by quit)
1.49 pazsan 207: has? ec [IF]
208: AUser LastCFA
209: [THEN]
1.1 anton 210: AUser Last
1.26 anton 211:
1.41 pazsan 212: has? flash [IF]
213: AUser flash-dp
214: : rom flash-dp dpp ! ;
215: : ram normal-dp dpp ! ;
216: [THEN]
217:
1.33 anton 218: User max-name-length \ maximum length of all names defined yet
219: 32 max-name-length !
220:
221: \ has? peephole [IF]
222: \ 0 value peeptable \ initialized in boot
223: \ [THEN]
1.1 anton 224:
1.7 pazsan 225: has? glocals [IF]
1.1 anton 226: User locals-size \ this is the current size of the locals stack
227: \ frame of the current word
1.7 pazsan 228: [THEN]
1.1 anton 229:
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>