--- gforth/glocals.fs 1996/09/24 19:15:02 1.27 +++ gforth/glocals.fs 1996/09/30 13:16:10 1.28 @@ -448,20 +448,7 @@ 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 @@ -495,6 +482,19 @@ forth definitions lastcfa ! last ! DEFERS ;-hook ; +\ 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 -- addr ) swap -rot dead-orig = if @@ -570,10 +570,6 @@ 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;-) @@ -643,7 +639,7 @@ 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 OF >body POSTPONE Aliteral POSTPONE ! ENDOF