Struct implementation question...

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IronFelix

Joined: 09 Dec 2004
Posts: 141
Location: Russia, Murmansk region

IronFelix 03 Mar 2006, 08:42

Hi all!
The question is about 'struct ' macro implementation. For example:

Code:

struct Rec

 Val1 dd ?
 Val2 dd ?

ends

mov eax,[ecx+Rec.Val1] ; <- got Rec.Val1 offset defined

In earlier versions of FASM this was achieved by this code:

Code:

struc Rec
{
 .Val1 dd ?
 .Val2 dd ?

 virtual at 0
  Rec Rec
 sizeof.Rec = $ - Rec
 end virtual

}

But how can i get structure offsets defined now?

Thanks and regards.

_________________
Flat Assembler is the best!

03 Mar 2006, 08:42

vid
Verbosity in development

Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia

vid 03 Mar 2006, 10:22

same way as earlier, but proper way is (and was):

Code:

struc Rec 
{ 
 .Val1 dd ? 
 .Val2 dd ? 
}

 virtual at 0 
  Rec Rec 
 sizeof.Rec = $ - Rec 
 end virtual

03 Mar 2006, 10:22

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8356
Location: Kraków, Poland

Tomasz Grysztar 03 Mar 2006, 11:25

The "struct" macro defines all the offsets automatically, see documentation.

03 Mar 2006, 11:25

IronFelix

Joined: 09 Dec 2004
Posts: 141
Location: Russia, Murmansk region

IronFelix 03 Mar 2006, 13:36

I know it, Tomasz, it is very powerful macro, thank you, but i need to do it with 'struc' manually.
Thanks and regards.

03 Mar 2006, 13:36

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8356
Location: Kraków, Poland

Tomasz Grysztar 03 Mar 2006, 14:07

Sorry, I misunderstood your question. Note that except for the "fix" (and some other minor changes) fasm keeps all the old features.

03 Mar 2006, 14:07

IronFelix

Joined: 09 Dec 2004
Posts: 141
Location: Russia, Murmansk region

IronFelix 06 Mar 2006, 06:39

Tomasz, please explain, why this doesn't work and. if it is not hard for you, explain your "struct" macro implementaion. It will be very helpful i think.

Code:

macro ins_field [Name]
{
 forward
   .#Name dd ?
}


struc A
{
 ins_field a,b,c
}

struc B
{
 .aa A
 ins_field a,b,c
}

a A
b B

Thanks.

_________________
Flat Assembler is the best!

06 Mar 2006, 06:39

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8356
Location: Kraków, Poland

Tomasz Grysztar 06 Mar 2006, 08:49

The preceding of dotted symbols by structure name is done only in the lines generated by the structure macro itself - the child macros invoked then by those lines are already independent (thus you can always be sure that with regular macro the symbol starting with dot will stay what it is).
Thus it should be rather done like

Code:

macro ins_field Struc,[Name]
{
 forward
   Struc#.#Name dd ?
}


struc A
{
 ins_field .,a,b,c
}

struc B
{
 .aa A
 ins_field .,a,b,c
}

a A
b B

As for the "struct" macro explanation, please give me some more time.

06 Mar 2006, 08:49

IronFelix

Joined: 09 Dec 2004
Posts: 141
Location: Russia, Murmansk region

IronFelix 06 Mar 2006, 09:37

Thanks for so quick reply!
As for the time - as much as you need of course Smile

Thanks again, will try to use your answer in my OOP macroses.

06 Mar 2006, 09:37

IronFelix

Joined: 09 Dec 2004
Posts: 141
Location: Russia, Murmansk region

IronFelix 06 Mar 2006, 12:12

Tomasz, excuse me for so much questions, but please explain, how must be implemented such thing:

Code:

macro ins_field str,[Name,Type,Value]
{
 forward
  str#.#Name Type Value
}

struc A
{
 ins_field .,a,dd,?, b,dd,? ,c,db,?
}

struc B
{
 ins_field ., aa,A,, a,dd,?, b,dd,? ,c,db,? ; <- try to declare uninitialize structure here
}

a A
b B

Thanks.

_________________
Flat Assembler is the best!

06 Mar 2006, 12:12

IronFelix

Joined: 09 Dec 2004
Posts: 141
Location: Russia, Murmansk region

IronFelix 06 Mar 2006, 13:36

Solve this problem, just remember about "enable_xxx" and "purge xxx" technique. But have got another one: why doesn't work this:

Code:

macro enable_ins_field
{
 macro ins_field str,[Name,Type,Value]
 \{
  \forward
   str\#.\#Name Type Value
 \}

}
enable_ins_field

macro A_ins
{
 ins_field .,a,dd,?, b,dd,?, c,db,?
}

struc A
{

 enable_ins_field
 A_ins
 purge ins_field
}

macro B_ins
{
 ins_field .,aa,A, , a1,dd,?, b1,dd,?, c1,db,?
}

struc B
{
 enable_ins_field
 B_ins
 purge ins_field
}

a A
b B

Thanks.

_________________
Flat Assembler is the best!

06 Mar 2006, 13:36

IronFelix

Joined: 09 Dec 2004
Posts: 141
Location: Russia, Murmansk region

IronFelix 09 Mar 2006, 08:33

Hi all!
Have another question: why "sizeof" doesn't work in this case?

Code:

macro enable_ins_field
{
 macro ins_field str,[Name,Type,Value]
 \{
  \forward
   str\#.\#Name Type Value
 \}

}

struc A
{
 macro A_ins
 \{
  ins_field .,a,dd,?, b,dd,?, c,db,?
 \}

 enable_ins_field
 A_ins
 purge ins_field
}

struc B
{

 macro B_ins
 \{
  ins_field .,a1,dd,?, b1,dd,?, c1,db,?, aa,A,
 \}

 enable_ins_field
 B_ins
 purge ins_field
}

virtual at 0
 A A
 sizeof.A  =  $ - A
end virtual

virtual at 0
 B B
 sizeof.B  =  $ - B
end virtual

Thanks and regards.

_________________
Flat Assembler is the best!

09 Mar 2006, 08:33

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8356
Location: Kraków, Poland

Tomasz Grysztar 09 Mar 2006, 09:33

When you use the "." symbol inside the STRUC macro, the preprocessor abstains from generating the label for structure automatically and leaves it to you. Thus while using the "." somewhere inside the STRUC macro you need to put something like:

Code:

.:

Code:

label .

in the beginning (or other place you find suitable) of it.

This behavior was introduced to allow declaring the "." label in any way you want, not as it is with automatically generated one.

09 Mar 2006, 09:33

IronFelix

Joined: 09 Dec 2004
Posts: 141
Location: Russia, Murmansk region

IronFelix 10 Mar 2006, 06:35

Thank you, Tomasz! FASM is really the best!
Regards.

10 Mar 2006, 06:35

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