--- gforth/glocals.fs 1996/09/24 19:15:02 1.27 +++ gforth/glocals.fs 2003/01/20 17:07:37 1.51 @@ -1,6 +1,6 @@ \ A powerful locals implementation -\ Copyright (C) 1995 Free Software Foundation, Inc. +\ Copyright (C) 1995,1996,1997,1998,2000 Free Software Foundation, Inc. \ This file is part of Gforth. @@ -16,7 +16,7 @@ \ 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., 675 Mass Ave, Cambridge, MA 02139, USA. +\ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. \ More documentation can be found in the manual and in @@ -85,8 +85,9 @@ \ Currently locals may only be \ defined at the outer level and TO is not supported. -require search-order.fs +require search.fs require float.fs +require extend.fs \ for case : compile-@local ( n -- ) \ gforth compile-fetch-local case @@ -129,7 +130,7 @@ require float.fs slowvoc @ slowvoc on \ we want a linked list for the vocabulary locals vocabulary locals \ this contains the local variables -' locals >body ' locals-list >body ! +' locals >body wordlist-id ' locals-list >body ! slowvoc ! create locals-buffer 1000 allot \ !! limited and unsafe @@ -183,20 +184,20 @@ variable locals-dp \ so here's the speci = ; : list-size ( list -- u ) \ gforth-internal -\ size of the locals frame represented by list - 0 ( list n ) - begin - over 0<> - while - over - ((name>)) >body @ max - swap @ swap ( get next ) - repeat - faligned nip ; + \ size of the locals frame represented by list + 0 ( list n ) + begin + over 0<> + while + over + ((name>)) >body @ max + swap @ swap ( get next ) + repeat + faligned nip ; : set-locals-size-list ( list -- ) - dup locals-list ! - list-size locals-size ! ; + dup locals-list ! + list-size locals-size ! ; : check-begin ( list -- ) \ warn if list is not a sublist of locals-list @@ -292,8 +293,21 @@ locals-types definitions postpone laddr# @ lp-offset, ; \ you may want to make comments in a locals definitions group: -' \ alias \ immediate -' ( alias ( immediate +' \ alias \ ( compilation 'ccc' -- ; run-time -- ) \ core-ext,block-ext backslash +\G Comment till the end of the line if @code{BLK} contains 0 (i.e., +\G while not loading a block), parse and discard the remainder of the +\G parse area. Otherwise, parse and discard all subsequent characters +\G in the parse area corresponding to the current line. +immediate + +' ( alias ( ( compilation 'ccc' -- ; run-time -- ) \ core,file paren +\G Comment, usually till the next @code{)}: parse and discard all +\G subsequent characters in the parse area until ")" is +\G encountered. During interactive input, an end-of-line also acts as +\G a comment terminator. For file input, it does not; if the +\G end-of-file is encountered whilst parsing for the ")" delimiter, +\G Gforth will generate a warning. +immediate forth definitions @@ -311,7 +325,7 @@ also locals-types \ the returned nfa denotes a word that produces what W: produces \ !! do the whole thing without nextname drop nextname - ['] W: >name ; + ['] W: >head-noprim ; previous @@ -319,28 +333,34 @@ previous true abort" this should not happen: new-locals-reveal" ; create new-locals-map ( -- wordlist-map ) -' new-locals-find A, ' new-locals-reveal A, - -slowvoc @ -slowvoc on -vocabulary new-locals -slowvoc ! -new-locals-map ' new-locals >body cell+ A! \ !! use special access words +' new-locals-find A, +' new-locals-reveal A, +' drop A, \ rehash method +' drop A, + +new-locals-map mappedwordlist Constant new-locals-wl + +\ slowvoc @ +\ slowvoc on +\ vocabulary new-locals +\ slowvoc ! +\ new-locals-map ' new-locals >body wordlist-map A! \ !! use special access words variable old-dpp \ and now, finally, the user interface words -: { ( -- addr wid 0 ) \ gforth open-brace +: { ( -- lastxt wid 0 ) \ gforth open-brace dp old-dpp ! locals-dp dpp ! - also new-locals - also get-current locals definitions locals-types + lastxt get-current + get-order new-locals-wl swap 1+ set-order + also locals definitions locals-types 0 TO locals-wordlist 0 postpone [ ; immediate locals-types definitions -: } ( addr wid 0 a-addr1 xt1 ... -- ) \ gforth close-brace +: } ( lastxt wid 0 a-addr1 xt1 ... -- ) \ gforth close-brace \ ends locals definitions ] old-dpp @ dpp ! begin @@ -350,9 +370,9 @@ locals-types definitions repeat drop locals-size @ alignlp-f locals-size ! \ the strictest alignment - set-current previous previous - locals-list TO locals-wordlist ; + set-current lastcfa ! + locals-list 0 wordlist-id - TO locals-wordlist ; : -- ( addr wid 0 ... -- ) \ gforth dash-dash } @@ -448,32 +468,21 @@ forth definitions \ If this assumption is too optimistic, the compiler will warn the user. -\ Implementation: migrated to kernel.fs - -\ THEN (another control flow from before joins the current one): -\ The new locals-list is the intersection of the current locals-list and -\ the orig-local-list. The new locals-size is the (alignment-adjusted) -\ size of the new locals-list. The following code is generated: -\ lp+!# (current-locals-size - orig-locals-size) -\ : -\ lp+!# (orig-locals-size - new-locals-size) - -\ Of course "lp+!# 0" is not generated. Still this is admittedly a bit -\ inefficient, e.g. if there is a locals declaration between IF and -\ ELSE. However, if ELSE generates an appropriate "lp+!#" before the -\ branch, there will be none after the target . +\ Implementation: \ explicit scoping : scope ( compilation -- scope ; run-time -- ) \ gforth - cs-push-part scopestart ; immediate + cs-push-part scopestart ; immediate + +: adjust-locals-list ( wid -- ) + locals-list @ common-list + dup list-size adjust-locals-size + locals-list ! ; : endscope ( compilation scope -- ; run-time -- ) \ gforth - scope? - drop - locals-list @ common-list - dup list-size adjust-locals-size - locals-list ! ; immediate + scope? + drop adjust-locals-list ; immediate \ adapt the hooks @@ -495,18 +504,31 @@ forth definitions lastcfa ! last ! DEFERS ;-hook ; -: (then-like) ( orig -- addr ) - swap -rot dead-orig = +\ THEN (another control flow from before joins the current one): +\ The new locals-list is the intersection of the current locals-list and +\ the orig-local-list. The new locals-size is the (alignment-adjusted) +\ size of the new locals-list. The following code is generated: +\ lp+!# (current-locals-size - orig-locals-size) +\ : +\ lp+!# (orig-locals-size - new-locals-size) + +\ Of course "lp+!# 0" is not generated. Still this is admittedly a bit +\ inefficient, e.g. if there is a locals declaration between IF and +\ ELSE. However, if ELSE generates an appropriate "lp+!#" before the +\ branch, there will be none after the target . + +: (then-like) ( orig -- ) + dead-orig = if - drop + >resolve drop else dead-code @ if - set-locals-size-list dead-code off + >resolve set-locals-size-list dead-code off else \ both live - dup list-size adjust-locals-size - locals-list @ common-list dup list-size adjust-locals-size - locals-list ! + over list-size adjust-locals-size + >resolve + adjust-locals-list then then ; @@ -570,10 +592,6 @@ forth definitions \ things above are not control flow joins. Everything should be taken \ over from the live flow. No lp+!# is generated. -\ !! The lp gymnastics for UNTIL are also a real problem: locals cannot be -\ used in signal handlers (or anything else that may be called while -\ locals live beyond the lp) without changing the locals stack. - \ About warning against uses of dead locals. There are several options: \ 1) Do not complain (After all, this is Forth;-) @@ -615,19 +633,20 @@ forth definitions endif ; : >definer ( xt -- definer ) - \ this gives a unique identifier for the way the xt was defined - \ words defined with different does>-codes have different definers - \ the definer can be used for comparison and in definer! - dup >code-address [ ' spaces >code-address ] Literal = - \ !! this definition will not work on some implementations for `bits' - if \ if >code-address delivers the same value for all does>-def'd words - >does-code 1 or \ bit 0 marks special treatment for does codes + \G @var{Definer} is a unique identifier for the way the @var{xt} + \G was defined. Words defined with different @code{does>}-codes + \G have different definers. The definer can be used for + \G comparison and in @code{definer!}. + dup >does-code + ?dup-if + nip 1 or else >code-address then ; : definer! ( definer xt -- ) - \ gives the word represented by xt the behaviour associated with definer + \G The word represented by @var{xt} changes its behaviour to the + \G behaviour associated with @var{definer}. over 1 and if swap [ 1 invert ] literal and does-code! else @@ -635,7 +654,7 @@ forth definitions then ; :noname - ' dup >definer [ ' locals-wordlist >definer ] literal = + ' dup >definer [ ' locals-wordlist ] literal >definer = if >body ! else @@ -643,10 +662,13 @@ forth definitions endif ; :noname 0 0 0. 0.0e0 { c: clocal w: wlocal d: dlocal f: flocal } - ' dup >definer + comp' drop dup >definer case - [ ' locals-wordlist >definer ] literal \ value + [ ' locals-wordlist ] literal >definer \ value OF >body POSTPONE Aliteral POSTPONE ! ENDOF + \ !! dependent on c: etc. being does>-defining words + \ this works, because >definer uses >does-code in this case, + \ which produces a relocatable address [ comp' clocal drop >definer ] literal OF POSTPONE laddr# >body @ lp-offset, POSTPONE c! ENDOF [ comp' wlocal drop >definer ] literal @@ -663,7 +685,7 @@ interpret/compile: TO ( c|w|d|r "name" - \ don't use 'locals|'! use '{'! A portable and free '{' \ implementation is compat/anslocals.fs BEGIN - name 2dup s" |" compare 0<> + name 2dup s" |" str= 0= WHILE (local) REPEAT