Author Topic: NASMX typedef system update  (Read 6456 times)

Offline Rob Neff

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NASMX typedef system update
« on: August 02, 2010, 12:30:04 AM »
The new NASMX typedef system is slowing moving into place. To give you a brief overview of how powerful (and easy) it is to use just look at the following Windows demo2 code snippet (but can be easily applied to all systems):

Code: [Select]
NX_STRUC WNDCLASSEX
    NX_RESERVE .cbSize,        uint32_t, 1
    NX_RESERVE .style,         uint32_t, 1
    NX_RESERVE .lpfnWndProc,   NX_PTR, 1
    NX_RESERVE .cbClsExtra,    int32_t, 1
    NX_RESERVE .cbWndExtra,    int32_t, 1
    NX_RESERVE .hInstance,     NX_PTR, 1
    NX_RESERVE .hIcon,         NX_PTR, 1
    NX_RESERVE .hCursor,       NX_PTR, 1
    NX_RESERVE .hbrBackground, NX_PTR, 1
    NX_RESERVE .lpszMenuName,  NX_PTR, 1
    NX_RESERVE .lpszClassName, NX_PTR, 1
    NX_RESERVE .hIconSm,       NX_PTR, 1
NX_ENDSTRUC WNDCLASSEX

This code defines the in-memory layout of the structure named WNDCLASSEX. Notice that it is now using the new typedefs. Examining the definition in more detail your notice that some structure fields contain an NX_PTR type. This type is defined to expand automatically depending on the output format specified. Thus the NX_PTR fields will be either 32-bit or 64-bit.

To create and instance of this struct we use the new NX_ISTRUC macro:
Code: [Select]
wc:
NX_ISTRUC WNDCLASSEX
    NX_AT .style, CS_VREDRAW + CS_HREDRAW
    NX_AT .cbSize, WNDCLASSEX_size
    NX_AT .lpfnWndProc,   NULL
    NX_AT .cbClsExtra,    NULL
    NX_AT .cbWndExtra,    NULL
    NX_AT .hInstance,     NULL
    NX_AT .hIcon,         NULL
    NX_AT .hCursor,       NULL
    NX_AT .hbrBackground, COLOR_BTNFACE + 1
    NX_AT .lpszMenuName,  NULL
    NX_AT .lpszClassName, NULL
    NX_AT .hIconSm,       NULL
NX_IENDSTRUC WNDCLASSEX

Compare this version to the old way:
Code: [Select]
wc:
istruc WNDCLASSEX
    at WNDCLASSEX.cbSize,           dd    WNDCLASSEX_size
    at WNDCLASSEX.style,            dd    CS_VREDRAW + CS_HREDRAW
    at WNDCLASSEX.lpfnWndProc,      dd    NULL
    at WNDCLASSEX.cbClsExtra,       dd    NULL
    at WNDCLASSEX.cbWndExtra,       dd    NULL
    at WNDCLASSEX.hInstance,        dd    NULL
    at WNDCLASSEX.hIcon,            dd    NULL
    at WNDCLASSEX.hCursor,          dd    NULL
    at WNDCLASSEX.hbrBackground,    dd    COLOR_BTNFACE + 1
    at WNDCLASSEX.lpszMenuName,     dd    NULL
    at WNDCLASSEX.lpszClassName,    dd    NULL
    at WNDCLASSEX.hIconSm,          dd    NULL
iend

As you can see, the new typedef system is doing a lot for you. Since it already knows at definition what the structure field sizes are it doesn't ask you to repeat them. This is especially important when creating code for both 32-bit and 64-bit systems because of structure field pointer expansion! Notice that your code won't change one bit! Write once, run on both :)

I am maintaining this code on sourceforge.net so if you're interested in following the development you can check out the code via svn:

Code: [Select]
svn co https://nasmx.svn.sourceforge.net/svnroot/nasmx/branches/rob nasmx

It's not quite ready for primetime just yet but it should give you a glimpse of the many things Keith, Bryant, and myself have for this project.

*Edit to show my dev branch for svn co. Again, this is not for usage, just reading! :)


« Last Edit: August 02, 2010, 12:55:07 AM by Rob Neff »

Klod

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Re: NASMX typedef system update
« Reply #1 on: August 02, 2010, 04:06:38 AM »
Thanks for sharing.

The NASMX link has been removed. I checked
http://www.asmcommunity.net/projects/nasmx

All the downloads are from last year.

Where can I download the latest release?

Klod

Offline Keith Kanios

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Re: NASMX typedef system update
« Reply #2 on: August 02, 2010, 05:11:59 AM »
Where can I download the latest release?

Rob's SVN branch (given in his last post) is essentially the current dev branch.

There isn't any packaged release, as of yet. You'll have to grab it from SVN.

Offline Rob Neff

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Re: NASMX typedef system update
« Reply #3 on: August 02, 2010, 08:08:50 PM »
Before I finish up nasmx typedef'ing I have another need. That need is for structures and unions within other structures and unions.  To use another example from the windows.inc include let's look at a before and after of what the new code should look like, ideally:

Code: [Select]
    message:
    NX_ISTRUC MSG
        NX_AT .hwnd,     NULL
        NX_AT .message,  NULL
        NX_AT .wParam,   NULL
        NX_AT .lParam,   NULL
        NX_AT .time,     NULL
        NX_AT .pt,       NULL
    NX_IENDSTRUC MSG

Notice the MSG.pt structure field. Currently, to access the member var POINT.y in the message structure you have to code as follows:
Code: [Select]
   mov  ecx, message + MSG.pt + POINT.y
   mov  [ecx], 42  ; Answer to the Ultimate Question of Life, the Universe, and Everything

   ; - or - maybe this:

   mov  ecx, message
   .
   . do stuff
   .
   xor  eax, eax
   mov  [ecx + MSG.pt], eax       ; PT.x
   mov  [ecx + MSG.pt + 4], 42    ; PT.y

Wouldn't it make much more sense to code:
Code: [Select]
    mov  ecx, message
    mov  [ecx + MSG.pt.y], 42

So what's the big deal here? For this trivial example not much. However, when you have to deal with structures containing structures of structures and unions things can start getting a bit "hairy". You may be asking yourself - "Why do I care about this? I'll just keep my structures simple". Well, in your own code you are free to define and instantiate however you please. But at soon as you need to access operating system defined structures which are deeply nested what are your choices? What if those structure sizes change between OS releases or between 32 and 64 bit versions? Wouldn't it be nice if somebody else already did the hard part and made it simple to access those system definitions? NASMX to the rescue.

So a slight change is in order, specifically, allowing the nesting of structures and unions. Let's create the proper definition of the POINT and MSG structures:

Code: [Select]
NX_STRUC POINT
    NX_RESERVE .x, int32_t, 1
    NX_RESERVE .y, int32_t, 1
NX_ENDSTRUC POINT

NX_STRUC MSG
    NX_RESERVE .hwnd, NX_PTR, 1
    NX_RESERVE .message, uint32_t, 1
    NX_RESERVE .wParam, size_t, 1
    NX_RESERVE .lParam, size_t, 1
    NX_RESERVE .time, uint32_t, 1
    NX_RESERVE .pt, POINT, 1
NX_ENDSTRUC

When processing the MSG structure NASMX will see that field .pt is an embedded POINT structure. It will reserve POINT size space and define the following offsets accordingly:

Code: [Select]
   MSG.pt.x
   MSG.pt.y

Notice that the field .hwnd is defined as an NX_PTR, and fields .wParam and .lParam are size_t. This means that these particular fields will expand in size depending on the bitness of the current build ( ie: 32 or 64 bits ). When creating your code on 32 bit platforms the sizes are defined as DWORD but on 64 bit platforms they become QWORDs. The offsets of embedded structure members will be automatically adjusted accordingly freeing you from the task of modifying your own code.

This is all currently being designed and developed right now. No code is yet available to play around with but I'm hoping to have an alpha release within the next week or two. Comments, questions, or suggestions are welcome. Stay tuned for further developments. :)

Klod

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Re: NASMX typedef system update
« Reply #4 on: August 06, 2010, 12:16:49 AM »
stupid question,

how do you "grab" a copy  from svn

https://nasmx.svn.sourceforge.net/svnroot/nasmx/branches/rob nasmx

this does not work

regards klod


Offline Rob Neff

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Re: NASMX typedef system update
« Reply #5 on: August 06, 2010, 01:53:39 AM »
I've made it easy to download the software now.
To get the complete package for win32 development click the following link:

http://sourceforge.net/projects/nasmx/

Click the big green download button and you'll get a nicely pre-packaged .zip file that you can download, extract, and play around with.

If you need a zip unpacker get 7-Zip: http://sourceforge.net/projects/sevenzip/

Make sure you: SET PATH=YOURNASMXINSTALLPATH\bin;%PATH%

All 13 demos are now fully Unicode aware and NASMX v1.0b2 provides full support of nested structures and unions.
Demo 13 currently shows a nice example of how you can put this in your source code although the syntax "may" change slightly as I feel it is a bit "wordy".

The compile time is rather slow due to the way Nasm itself performs preprocessing. The preprocessor IS being worked on and hopefully we'll see it in the next "official" Nasm v2.09 release.

Thank you for your interest in this project.  ;)


Klod

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Re: NASMX typedef system update
« Reply #6 on: August 06, 2010, 02:41:19 AM »
Hi Rob,
thanks for the quick response. I downloaded the package and I will experiment with it.

Regards
Klod