| |
|
| \ 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 |
| |
|
| lastcfa ! last ! |
lastcfa ! last ! |
| DEFERS ;-hook ; |
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) |
| |
\ <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 -- addr ) |
: (then-like) ( orig -- addr ) |
| swap -rot dead-orig = |
swap -rot dead-orig = |
| if |
if |
| \ 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;-) |
| 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 >definer ] literal \ value |
| OF >body POSTPONE Aliteral POSTPONE ! ENDOF |
OF >body POSTPONE Aliteral POSTPONE ! ENDOF |
