File:  [gforth] / gforth / kernel / vars.fs
Revision 1.11: download - view: text, annotated - select for diffs
Sun Feb 21 14:55:45 1999 UTC (22 years, 7 months ago) by anton
Branches: MAIN
CVS tags: HEAD
gforth-ditc is now installed with "make install"
bugfix in print-backtrace
rewrote number output: now uses a fixed buffer HOLDBUF; added <<# and
	#>> to deal with nested number output (e.g., AT-XY), and fixed
	ud.r and d.r (and thus all the "." words) and DUMP to use
	them.  Other words using <# still have to be fixed.
removed COMPACT// and its use; it did not work, and anyway, it's a bad
	idea for Cygwin, Domain/OS (Apollo's OS), and possibly other OSs.

    1: \ VARS.FS      Kernal variables
    2: 
    3: \ Copyright (C) 1995,1996,1997,1998 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 2
   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, write to the Free Software
   19: \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   20: 
   21: hex \ everything now hex!                               11may93jaw
   22: 
   23: \ important constants                                  17dec92py
   24: 
   25: \ dpANS6 (sect 3.1.3.1) says 
   26: \ "a true flag ... [is] a single-cell value with all bits set"
   27: \ better definition: 0 0= constant true ( no dependence on 2's compl)
   28:  -1 Constant true ( -- f ) \ core-ext
   29: \G CONSTANT: f is a cell with all bits set.
   30: \ see starts looking for primitives after this word!
   31: 
   32:   0 Constant false ( -- f ) \ core-ext
   33: \G CONSTANT: f is a cell with all bits clear.
   34: 
   35: 1 cells Constant cell ( -- u ) \ gforth
   36: 1 floats Constant float ( -- u ) \ gforth
   37: 
   38: 20 Constant bl ( -- c-char ) \ core
   39: \G c-char is the character value for a space.
   40: \ used by docon:, must be constant
   41: 
   42: FF Constant /line
   43: 
   44: 40 Constant c/l
   45: 10 Constant l/s
   46: 400 Constant chars/block
   47: 
   48: $20 8 2* cells + 2 + cell+ constant word-pno-size ( -- u )
   49: create holdbuf word-pno-size chars allot
   50: holdbuf word-pno-size chars + aconstant holdbuf-end
   51: avariable holdptr holdbuf-end holdptr a!
   52: 
   53: 84 constant pad-minsize ( -- u )
   54: 
   55: 
   56: \ that's enough so long
   57: 
   58: \ User variables                                       13feb93py
   59: 
   60: \ initialized by COLD
   61: 
   62: Create main-task  has? OS [IF] 100 [ELSE] 40 [THEN] cells allot
   63: 
   64: \ set user-pointer from cross-compiler right
   65: main-task 
   66: UNLOCK tup ! LOCK
   67: 
   68: Variable udp \ user area size? -anton
   69: 
   70: AUser next-task        main-task next-task !
   71: AUser prev-task        main-task prev-task !
   72: AUser save-task        0 save-task !
   73: AUser sp0 ( -- a-addr ) \ gforth
   74: \G USER VARIABLE: Initial value of the data stack pointer.
   75: \ sp0 is used by douser:, must be user
   76:     ' sp0 Alias s0 ( -- a-addr ) \ gforth
   77: \G OBSOLETE alias of @code{sp0}
   78: 
   79: AUser rp0 ( -- a-addr ) \ gforth
   80: \G USER VARIABLE: Initial value of the return stack pointer.
   81:     ' rp0 Alias r0 ( -- a-addr ) \ gforth
   82: \G OBSOLETE alias of @code{rp0}
   83: 
   84: AUser fp0 ( -- a-addr ) \ gforth
   85: \G USER VARIABLE: Initial value of the floating-point stack pointer.
   86: \ no f0, because this leads to unexpected results when using hex
   87: 
   88: AUser lp0 ( -- a-addr ) \ gforth
   89: \G USER VARIABLE: Initial value of the locals stack pointer.
   90:     ' lp0 Alias l0 ( -- a-addr ) \ gforth
   91: \G OBSOLETE alias of @code{lp0}
   92: 
   93: AUser handler	\ pointer to last throw frame
   94: AUser backtrace-empty \ true if the next THROW should store a backtrace
   95: \ AUser output
   96: \ AUser input
   97: 
   98: AUser errorhandler
   99: 
  100: AUser "error            0 "error !
  101: 
  102: [IFUNDEF] #tib		\ in ec-Version we may define this ourself
  103:  User tibstack		\ saves >tib in execute
  104:  User >tib		\ pointer to terminal input buffer
  105:  User #tib ( -- a-addr ) \ core-ext
  106:  \G USER VARIABLE: a-addr is the address of a cell containing
  107:  \G the number of characters in the terminal input buffer.
  108:  \G OBSOLESCENT: @code{source} superceeds the function of this word.
  109: 
  110:  User >in ( -- a-addr ) \ core
  111:  \G USER VARIABLE: a-addr is the address of a cell containing the
  112:  \G char offset from the start of the terminal input buffer to the
  113:  \G start of the parse area
  114:                         0 >in ! \ char number currently processed in tib
  115: [THEN]
  116: has? file [IF]
  117:  User blk ( -- a-addr ) \ block
  118:  \G USER VARIABLE: a-addr is the address of a cell containing zero
  119:  \G (in which case the input source is not a block and can be identified
  120:  \G by @code{source-id}) or the number of the block currently being
  121:  \G interpreted. A Standard program should not alter @code{blk} directly.
  122: 			0 blk !
  123: 
  124:  User loadfile          0 loadfile !
  125: 
  126:  User loadfilename#	0 loadfilename# !
  127: 
  128:  User loadline          \ number of the currently interpreted
  129:                         \ (in TIB) line if the interpretation
  130:                         \ is in a textfile
  131:                         \ the first line is 1
  132: 
  133: 2User linestart         \ starting file postition of
  134:                         \ the current interpreted line (in TIB)
  135: [THEN]
  136: 
  137:  User base ( -- a-addr ) \ core
  138:  \G USER VARIABLE: a-addr is the address of a cell that stores the
  139:  \G number base used by default for number conversion during input and output.
  140:                         A base !
  141:  User dpl               -1 dpl !
  142: 
  143:  User state ( -- a-addr ) \ core,tools-ext
  144:  \G USER VARIABLE: a-addr is the address of a cell containing
  145:  \G the compilation state flag. 0 => interpreting, -1 => compiling.
  146:  \G A program shall not directly alter the value of @code{state}. The
  147:  \G following Standard words alter the value in @code{state}:
  148:  \G @code{:} (colon) @code{;} (semicolon) @code{abort} @code{quit}
  149:  \G @code{:noname} @code{[} (left-bracket) @code{]} (right-bracket)
  150:  \G @code{;code}
  151: 			0 state !
  152: 
  153: AUser normal-dp		\ the usual dictionary pointer
  154: AUser dpp		normal-dp dpp !
  155: 			\ the pointer to the current dictionary pointer
  156:                         \ ist reset to normal-dp on (doerror)
  157:                         \  (i.e. any throw caught by quit)
  158: AUser LastCFA
  159: AUser Last
  160: 
  161: has? glocals [IF]
  162: User locals-size \ this is the current size of the locals stack
  163: 		 \ frame of the current word
  164: [THEN]
  165: 

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>