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|
\ catch, throw, etc.
\ Copyright (C) 1999,2000,2003 Free Software Foundation, Inc.
\ This file is part of Gforth.
\ Gforth is free software; you can redistribute it and/or
\ modify it under the terms of the GNU General Public License
\ as published by the Free Software Foundation; either version 2
\ of the License, or (at your option) any later version.
\ This program is distributed in the hope that it will be useful,
\ but WITHOUT ANY WARRANTY; without even the implied warranty of
\ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
\ GNU General Public License for more details.
\ You should have received a copy of the GNU General Public License
\ along with this program; if not, write to the Free Software
\ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
\ !! use a separate exception stack? anton
\ user-definable rollback actions
Defer 'catch
Defer 'throw
' noop IS 'catch
' noop IS 'throw
\ has? backtrace [IF]
Defer store-backtrace
' noop IS store-backtrace
\ [THEN]
: (try) ( ahandler -- )
r>
swap >r \ recovery address
rp@ 'catch >r
sp@ >r
fp@ >r
lp@ >r
handler @ >r
rp@ handler !
backtrace-empty on
>r ;
: try ( compilation -- orig ; run-time -- ) \ gforth
\ !! does not work correctly for gforth-native
POSTPONE lit >mark POSTPONE (try) ; immediate compile-only
: (recover) ( -- )
\ normal end of try block: restore handler, forget rest
r>
r> handler !
rdrop \ lp
rdrop \ fp
rdrop \ sp
r> rp!
rdrop \ recovery address
>r ;
: recover ( compilation orig1 -- orig2 ; run-time -- ) \ gforth
\ !! check using a special tag
POSTPONE (recover)
POSTPONE else ; immediate compile-only
: endtry ( compilation orig -- ; run-time -- ) \ gforth
POSTPONE then ; immediate compile-only
:noname ( x1 .. xn xt -- y1 .. ym 0 / z1 .. zn error ) \ exception
try
execute 0
recover
nip
endtry ;
is catch
:noname ( y1 .. ym error/0 -- y1 .. ym / z1 .. zn error ) \ exception
?DUP IF
[ here forthstart 9 cells + ! ]
store-backtrace
handler @ ?dup-0=-IF
>stderr cr ." uncaught exception: " .error cr
2 (bye)
\ quit
THEN
rp!
r> handler !
r> lp!
r> fp!
r> swap >r sp! drop r>
rdrop 'throw
THEN ;
is throw
|
