how to separate strings and pointers

Index > Macroinstructions > how to separate strings and pointers

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qeos

Joined: 15 Jan 2008
Posts: 15

qeos 01 Jun 2010, 19:02

Documentation is an example of a table of addresses to strings:

Code:

    macro strtbl name,[string]
     {
      common
        label name dword
      forward
        local label
        dd label
      forward
        label db string,0
     }

But when adding a few data, they mixed the pointers and lines. Like:

Code:

<ptr1><str1><ptr2><str2>...<ptrN><strN>

How to separate the lines and pointers of the data? How do I make that would get data in the form of:

Code:

<ptr1><ptr2>...<ptrN><str1><str2>...<strN>

01 Jun 2010, 19:02

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20299
Location: In your JS exploiting you and your system

revolution 01 Jun 2010, 19:54

Code:

strtbl Table1,\
    'String1',\
    'String2',\
    'String3',\
    'String4'

01 Jun 2010, 19:54

qeos

Joined: 15 Jan 2008
Posts: 15

qeos 01 Jun 2010, 20:17

2revolution this is no what I need

I wrote this:

Code:

.dvars equ
.dstrs equ db 0

macro cdata name, [string]{
 local z
     .dvars equ .dvars,name dd z
 .dstrs equ .dstrs,z db string
}

macro ddata{
    match names,.dvars \{
         irp inames,names \\{
                 inames
              \\}
  \}
    match names,.dstrs \{
         irp inames,names \\{
                 inames, 0
           \\}
  \}
}


cdata data01, 'str1'
cdata data02, 'str2'

rb 0x100-$
DataS:
ddata

It's a bit ugly, but it works

Thanks to Tomasz Grysztar for his programm. They show preprocessed datas as:

Quote:

data01 dd z?0000000
data02 dd z?0000001

db 0,0
z?0000000 db 'str1',0
z?0000001 db 'str2',0

01 Jun 2010, 20:17

LocoDelAssembly
Your code has a bug

Joined: 06 May 2005
Posts: 4624
Location: Argentina

LocoDelAssembly 01 Jun 2010, 21:35

Quote:

2revolution this is no what I need

It is worth mentioning however that the macro you extracted from the documentation puts the data as you requested in your first post and not as you reported how it works.

From your new code I assume you want to provide a symbol for each pointer? In that case you could use this:

Code:

    macro strtbl name, [label,string]
     {
      forward
        dd label
      forward
        label db string,0
     }

Usage example:

Code:

strtbl DataS,\
alpha, 'alpha',\
someName, 'delta'

01 Jun 2010, 21:35

qeos

Joined: 15 Jan 2008
Posts: 15

qeos 01 Jun 2010, 21:45

LocoDelAssembly wrote:

It is worth mentioning however that the macro you extracted from the documentation puts the data as you requested in your first post and not as you reported how it works.

I have bad english.. sorry..

LocoDelAssembly wrote:

Usage example:

Code:

strtbl DataS,\
alpha, 'alpha',\
someName, 'delta'

Your code puts the data in local places, and my code makes it possible to declare variables at different locations.. and then assemble all in one place ..

01 Jun 2010, 21:45

baldr

Joined: 19 Mar 2008
Posts: 1651

baldr 02 Jun 2010, 07:02

qeos wrote:

Thanks to Tomasz Grysztar for his programm.

I've managed to compile it for current codebase.

Description:	FASMPRE for 1.69.14 2010-05-10 build	Download
Filename:	fasmpre.asm.rar
Filesize:	1.76 KB
Downloaded:	228 Time(s)

02 Jun 2010, 07:02

cod3b453

Joined: 25 Aug 2004
Posts: 618

cod3b453 02 Jun 2010, 09:12

Thanks baldr Very Happy

- seriously, I tried to compile it before reading your reply and failed Laughing

02 Jun 2010, 09:12

baldr

Joined: 19 Mar 2008
Posts: 1651

baldr 02 Jun 2010, 09:30

cod3b453,

That small utility saves me several hundred times: unless Tomasz will make FASM write .fas even if assembly is failed, we have to stick with it. Due to reworked .Inc structure it contains unused code, though. Wink

02 Jun 2010, 09:30

qeos

Joined: 15 Jan 2008
Posts: 15

qeos 09 Mar 2011, 04:16

I has new way to define strings and collect they at the end of binary. But I get new trouble with macro and I dont know how it made..

I has this macro:

Code:

.d_str_data equ
macro idata_s name, [var]{
 local pdata
 .d_str_data equ .d_str_data name db var,
}
macro ddata{
     common .d_str_data equ .d_str_data db ''
  match names,.d_str_data \{
            irp inames,names \\{
                 inames, 0
           \\}
  \}
}

And used code:

Code:

idata_s Strings_init_heap_0,<'Found '>
idata_s Strings_init_heap_1,<' Mb of memory', db 10, db 13>

ddata

and I get code (by fasmpre):

Code:

Strings_init_heap_0 db 'Found ',0
Strings_init_heap_1 db ' Mb of memory',0
db 10,0
db 13,0
db '',0

It is a little not that that is necessary for me, since it is necessary for me in such kind:

Code:

Strings_init_heap_0 db 'Found ',0
Strings_init_heap_1 db ' Mb of memory',10,13,0

Whether there is any way for use of a divider a comma, but something else?
or how still it is possible to collect all line variables in one place?

09 Mar 2011, 04:16

edfed

Joined: 20 Feb 2006
Posts: 4330
Location: Now

edfed 09 Mar 2011, 04:34

prefer

crlf equ 10,13

09 Mar 2011, 04:34

qeos

Joined: 15 Jan 2008
Posts: 15

qeos 09 Mar 2011, 17:34

yep! thanx, it works!

09 Mar 2011, 17:34

edfed

Joined: 20 Feb 2006
Posts: 4330
Location: Now

edfed 09 Mar 2011, 18:19

but in asm, one important thing is the separation of declaration and referencing.

it is not a limitation, but a very good feature that lets you declare a lot of strings in some data section, and only reference those you need.
and more...
create a dictionary, and reference the words you need in other parts of the code.

it is some asm basics.

what can be good in this idea of referencing strings is a macro to generate an equate file, containing all references for the strings inside the compiled string file.

then, for this kind of file:

Code:

string db "string",0
hello db "hello",0
world db "world",0
assembler db "assembler",0

obtain a equate file like this:

Code:

string equ 0
hello equ 7
world equ 13
assembler equ 19

and then, be able to just reference everystrings from the dictionary that is supposed to be loaded somewhere in ram. a sort of text library, something more like the real definition of what is a library...a group of texts.

09 Mar 2011, 18:19

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