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cod3b453



Joined: 25 Aug 2004
Posts: 619
cod3b453
I've hit some issues with postpone that may not be immediately clear at a quick glance; hopefully this will save someone some time one day Razz. The first is passing ".labels" can be disassociated with its [intended] parent "label:" unless fully qualified to begin with. (side note: this is a useful feature to track the last occurrence of a block with a ".property" when playing with interleaved blocks)
Code:
macro do_thing x
{
        postpone
        \{
        db x
        \}
}
labelA:
.thing:
do_thing .thing ; this will actually be labelB.thing unless fully qualified to labelA.thing
db 0
labelB:
.thing:
db 0    
The second is that when using org things also go wrong. Here the only workaround I've found is to revert to the "old" way of performing do_thing after _end without postpone (incidentally this can be done with yet more postpone without changing the macro Very Happy).
Code:
macro do_thing s,e,d
{
        postpone
        \{
        local b
        local x

        x = $FF
        repeat (e-s)
                load b byte from s+(%-1)
                x = x xor b
        end repeat
        store byte x at d
        \}
}
_start:
xor ax,ax
mov al,0
.here:
do_thing _start,_end,_start.here-1
not ax
ret
_end:
;;postpone { ; this works around the org issue
;org $100 ; this causes a problem
fn:
inc eax
ret
;;} ; this works around the org issue    
Post 13 Jun 2015, 11:47
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 17279
Location: In your JS exploiting you and your system
revolution
The issue with org is the address space difference. I expect you can attach an address space label there also (untested):
Code:
my_address_space::
do_thing my_address_space:_start,my_address_space:_end,my_address_space:_start.here-1    
Post 13 Jun 2015, 12:25
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cod3b453



Joined: 25 Aug 2004
Posts: 619
cod3b453
revolution wrote:
The issue with org is the address space difference. I expect you can attach an address space label there also (untested):
Code:
my_address_space::
do_thing my_address_space:_start,my_address_space:_end,my_address_space:_start.here-1    
Nailed it, thank you revolution Cool I had tried something similar but not with both the address space and start/end labels with the fully-fully qualified path (I've also fixed a load = vs eq issues that got exposed by this too which probably weren't helping). Even better is this fixes my real code which stored the result in the current address space but processed the other address space (this was impossible to resolve with the hack in my previous post).
Post 13 Jun 2015, 12:51
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