what can be local?

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asmfan

Joined: 11 Aug 2006
Posts: 392
Location: Russian

asmfan 04 Nov 2006, 23:51

i discovered to myself that local can be:
1. labels
in macroses

Code:

  local some_label, ..some_label2
  some_label:
  ..some_label2:

in procs

Code:

  .some_label:

2. local data - in procedures

Code:

 local my_data[260]:BYTE

3. local numeric constants(!?) - in macroses

Code:

 local my_num
  my_num = 5

the question is that i haven't found any documentation of 3. - local num constants. But tests show that local directive have influence on num consts in macroses. Is that all right?

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04 Nov 2006, 23:51

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8266
Location: Kraków, Poland

Tomasz Grysztar 05 Nov 2006, 01:32

From the preprocessor's point of view there is no difference between your 3 and 1a. While 1b - "locals in procs", as you called it, is a completely different mechanism, happening at the assembly time, not preprocessing.

05 Nov 2006, 01:32

asmfan

Joined: 11 Aug 2006
Posts: 392
Location: Russian

asmfan 05 Nov 2006, 06:18

thanks, just start understanding more attractive dark corners and snippets because of lack of knowledge in fasm macroses

05 Nov 2006, 06:18

vid
Verbosity in development

Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia

vid 05 Nov 2006, 16:46

there are 2 things that can be local.

symbols local to macro, using "local" directive:

Code:

local a, ..c

. Their name is extended by "?" and random number. Thus, if another macro uses same local name, it will be extended by another number, and so it will have different name. more here: http://decard.net/article.php?body=tajga&chapter=preproc#local

symbol local to another symbol. This is when symbol starts with ".", then it's name is prefixed by name of last (non-local) label. eg. these two codes are same:

Code:

a:
.b:
.c:

Code:

a:
a.b:
a.c:

"local"| used to declare procedure's local variables is just macro, unfortunately names same as directive

05 Nov 2006, 16:46

asmfan

Joined: 11 Aug 2006
Posts: 392
Location: Russian

asmfan 07 Nov 2006, 20:42

So i conclude that making a numeric/symbolic constants in macroses to be LOCAL

Code:

macro some_macro
{
  local my_const
  my_const = BYTE -1
}

is a good practice to prevent the global numeric/symbolic consts from propagation... Right?
;; as a good practice of using "OR" instead of "+" in complicated types definition, e.g.

Code:

wnd_style = WS_VISIBLE OR WS_POPUP

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07 Nov 2006, 20:42

vid
Verbosity in development

Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia

vid 08 Nov 2006, 00:13

in fact, you should also prefix local name with ".."

see the link i provided in my previous post

08 Nov 2006, 00:13

asmfan

Joined: 11 Aug 2006
Posts: 392
Location: Russian

asmfan 08 Nov 2006, 19:52

Quote:

in fact, you should also prefix local name with ".."

for local labels yes, but local constants don't need to be prefixed

08 Nov 2006, 19:52

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