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Diff for /gforth/glocals.fs between versions 1.27 and 1.30

version 1.27, 1996/09/24 19:15:02	version 1.30, 1997/03/04 17:49:51
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 448 forth definitions	Line 450 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 484 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 573 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 617 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 643 forth definitions	Line 641 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 ;

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Removed from v.1.27
changed lines
	Added in v.1.30