Diff for /gforth/glocals.fs between versions 1.27 and 1.33

version 1.27, 1996/09/24 19:15:02 version 1.33, 1997/05/21 20:39:30
Line 85 Line 85
 \ Currently locals may only be  \ Currently locals may only be
 \ defined at the outer level and TO is not supported.  \ defined at the outer level and TO is not supported.
   
 require search-order.fs  require search.fs
 require float.fs  require float.fs
   
 : compile-@local ( n -- ) \ gforth compile-fetch-local  : compile-@local ( n -- ) \ gforth compile-fetch-local
Line 319  previous Line 319  previous
   true abort" this should not happen: new-locals-reveal" ;    true abort" this should not happen: new-locals-reveal" ;
   
 create new-locals-map ( -- wordlist-map )  create new-locals-map ( -- wordlist-map )
 ' new-locals-find A, ' new-locals-reveal A,  ' new-locals-find A,
   ' new-locals-reveal A,
   ' drop A, \ rehash method
   
 slowvoc @  slowvoc @
 slowvoc on  slowvoc on
Line 330  new-locals-map ' new-locals >body cell+ Line 332  new-locals-map ' new-locals >body cell+
 variable old-dpp  variable old-dpp
   
 \ and now, finally, the user interface words  \ and now, finally, the user interface words
 : { ( -- addr wid 0 ) \ gforth open-brace  : { ( -- lastxt wid 0 ) \ gforth open-brace
     dp old-dpp !      dp old-dpp !
     locals-dp dpp !      locals-dp dpp !
       lastxt get-current
     also new-locals      also new-locals
     also get-current locals definitions  locals-types      also locals definitions locals-types
     0 TO locals-wordlist      0 TO locals-wordlist
     0 postpone [ ; immediate      0 postpone [ ; immediate
   
 locals-types definitions  locals-types definitions
   
 : } ( addr wid 0 a-addr1 xt1 ... -- ) \ gforth close-brace  : } ( lastxt wid 0 a-addr1 xt1 ... -- ) \ gforth close-brace
     \ ends locals definitions      \ ends locals definitions
     ] old-dpp @ dpp !      ] old-dpp @ dpp !
     begin      begin
Line 350  locals-types definitions Line 353  locals-types definitions
     repeat      repeat
     drop      drop
     locals-size @ alignlp-f locals-size ! \ the strictest alignment      locals-size @ alignlp-f locals-size ! \ the strictest alignment
     set-current  
     previous previous      previous previous
       set-current lastcfa !
     locals-list TO locals-wordlist ;      locals-list TO locals-wordlist ;
   
 : -- ( addr wid 0 ... -- ) \ gforth dash-dash  : -- ( addr wid 0 ... -- ) \ gforth dash-dash
Line 448  forth definitions Line 451  forth definitions
   
 \ If this assumption is too optimistic, the compiler will warn the user.  \ If this assumption is too optimistic, the compiler will warn the user.
   
 \ Implementation: migrated to kernel.fs  \ Implementation:
   
 \ 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)  
 \ <then>:  
 \ 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>.  
   
 \ explicit scoping  \ explicit scoping
   
Line 495  forth definitions Line 485  forth definitions
     lastcfa ! last !      lastcfa ! last !
     DEFERS ;-hook ;      DEFERS ;-hook ;
   
 : (then-like) ( orig -- addr )  \ THEN (another control flow from before joins the current one):
     swap -rot dead-orig =  \ 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)
   \ <then>:
   \ 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>.
   
   : (then-like) ( orig -- )
       dead-orig =
     if      if
         drop          >resolve drop
     else      else
         dead-code @          dead-code @
         if          if
             set-locals-size-list dead-code off              >resolve set-locals-size-list dead-code off
         else \ both live          else \ both live
             dup list-size adjust-locals-size              over list-size adjust-locals-size
               >resolve
             locals-list @ common-list dup list-size adjust-locals-size              locals-list @ common-list dup list-size adjust-locals-size
             locals-list !              locals-list !
         then          then
Line 570  forth definitions Line 574  forth definitions
 \ things above are not control flow joins. Everything should be taken  \ things above are not control flow joins. Everything should be taken
 \ over from the live flow. No lp+!# is generated.  \ 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:  \ About warning against uses of dead locals. There are several options:
   
 \ 1) Do not complain (After all, this is Forth;-)  \ 1) Do not complain (After all, this is Forth;-)
Line 618  forth definitions Line 618  forth definitions
     \ this gives a unique identifier for the way the xt was defined      \ this gives a unique identifier for the way the xt was defined
     \ words defined with different does>-codes have different definers      \ words defined with different does>-codes have different definers
     \ the definer can be used for comparison and in definer!      \ the definer can be used for comparison and in definer!
     dup >code-address [ ' spaces >code-address ] Literal =      dup >does-code
     \ !! this definition will not work on some implementations for `bits'      ?dup-if
     if  \ if >code-address delivers the same value for all does>-def'd words          nip 1 or
         >does-code 1 or \ bit 0 marks special treatment for does codes  
     else      else
         >code-address          >code-address
     then ;      then ;
Line 635  forth definitions Line 634  forth definitions
     then ;      then ;
   
 :noname  :noname
     ' dup >definer [ ' locals-wordlist >definer ] literal =      ' dup >definer [ ' locals-wordlist ] literal >definer =
     if      if
         >body !          >body !
     else      else
Line 643  forth definitions Line 642  forth definitions
     endif ;      endif ;
 :noname  :noname
     0 0 0. 0.0e0 { c: clocal w: wlocal d: dlocal f: flocal }      0 0 0. 0.0e0 { c: clocal w: wlocal d: dlocal f: flocal }
     ' dup >definer      comp' drop dup >definer
     case      case
         [ ' locals-wordlist >definer ] literal \ value          [ ' locals-wordlist ] literal >definer \ value
         OF >body POSTPONE Aliteral POSTPONE ! ENDOF          OF >body POSTPONE Aliteral POSTPONE ! ENDOF
         [ comp' clocal drop >definer ] literal          [ comp' clocal drop ] literal >definer
         OF POSTPONE laddr# >body @ lp-offset, POSTPONE c! ENDOF          OF POSTPONE laddr# >body @ lp-offset, POSTPONE c! ENDOF
         [ comp' wlocal drop >definer ] literal          [ comp' wlocal drop ] literal >definer
         OF POSTPONE laddr# >body @ lp-offset, POSTPONE ! ENDOF          OF POSTPONE laddr# >body @ lp-offset, POSTPONE ! ENDOF
         [ comp' dlocal drop >definer ] literal          [ comp' dlocal drop ] literal >definer
         OF POSTPONE laddr# >body @ lp-offset, POSTPONE 2! ENDOF          OF POSTPONE laddr# >body @ lp-offset, POSTPONE 2! ENDOF
         [ comp' flocal drop >definer ] literal          [ comp' flocal drop ] literal >definer
         OF POSTPONE laddr# >body @ lp-offset, POSTPONE f! ENDOF          OF POSTPONE laddr# >body @ lp-offset, POSTPONE f! ENDOF
         -&32 throw          -&32 throw
     endcase ;      endcase ;

Removed from v.1.27  
changed lines
  Added in v.1.33


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