macro to support "#define constant value" like in C

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alorent

Joined: 05 Dec 2005
Posts: 221

alorent 15 Apr 2017, 11:56

Hi,

I need to create a "constant" file that is shared between a C source code file and a FASM source code file. So, I don't have to deal with 2 different constants file (for C and FASM) and the chances to introduce errors when a value is changed in a file and forgotten to be updated into the other file.

I was wondering if it's possible to create in FASM a macro to support:

Code:

#define my_constant my_value

and it should be equivalent to:

Code:

my_constant = my_value

Thanks!

15 Apr 2017, 11:56

cod3b453

Joined: 25 Aug 2004
Posts: 618

cod3b453 16 Apr 2017, 18:03

You could write a parser using virtual/load macros (I personally gave up on this very quickly due to the grammar) but I've managed to do this the other way round, where the definitions are in FASM and a separate build stage generates C headers:

definition.fash This is the FASM generator

Code:

macro @define id,val
{
        id equ val
}

fas2c.fash This is the C generator

Code:

macro @define id,val
{
        db '#define '
        db `id
        db ' '
        db `val
        db NEWLINE
}

def.fash This is the shared/common definition

Code:

@define CONST,1

def.h.fasm This will generate a C header

Code:

        format binary as ''

        include 'fas2c.fash'

db NEWLINE
db '#ifndef H_DEF',NEWLINE
db '#define H_DEF,NEWLINE
db NEWLINE
db NEWLINE

        include 'def.fash'

db NEWLINE
db '#endif',NEWLINE

FASM builds use the def(inition).fash and C builds can use the def.h. (Same trick can be applied to enum/struct/class as well as some meta-programming style stuff)

16 Apr 2017, 18:03

alorent

Joined: 05 Dec 2005
Posts: 221

alorent 18 Apr 2017, 11:59

Thanks a lot! That's hard stuff for me Smile

I will do some tests with it.

Thanks!

18 Apr 2017, 11:59

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