Calling imported functions

[Darmani]

The following toy example illustrates my problem:

Code Select Expand


.686p
.model flat
OPTION LANGUAGE:C

include advapi32.inc
includelib advapi32.lib

_text segment para public 'CODE' use32
assume cs:_text

_start proc near
call RegCreateKey
_start endp

_text ends

_data segment para public 'DATA' use32
assume cs:_data
_data ends

end  _start


MASM is giving "error A2107: cannot have implicit far jump or call to near label" on the "call RegCreateKey" line. I have something of an understanding of what this means, but, after rereading several chapters in the MASM Programmer's Guide, no idea why it's occuring or how to fix it. I've been stuck on this for two days! Help would be appreciated.

[MichaelW]

Darmani,

You need to explain what you are trying to do here, because your code looks too much like a malware experiment.

[Darmani]

?

I am.....trying to import a function and call it. It says in the topic title.

(Yes, the start method may make absolutely no sense -- it's just the minimal thing I came up with that produces the assembly error that's been confusing me.)

[MichaelW]

I am.....trying to import a function and call it. It says in the topic title.

Yes, I saw that and understood it, and your repeating it does not explain what you are trying to do. Why the odd segment structure, and out of all the functions that you could have selected, why RegCreateKey?

[Darmani]

For the "odd" segment structure, I currently don't understand what a normal segment structure is, so the answer is the same as why an 8 year-old would fail a calculus test: there are a lot of segment structures, but only one of them is "normal." I got an error when I tried to omit the _data segment. I've been fiddling around with many of the segment and assume directives and whatnot a lot over the past few days, thinking the error had something to do with that, so, if it's left with something that looks odd, that's to be expected.

(And I got errors last time I tried to delete either segment.)

As for RegCreateKey, I believe I'm getting these errors from all imported functions, but I started my investigation with the functions in advapi32 because it's first on the include list because it comes first alphabetically. Of the functions in advapi32, I started my investigation with RegCreateKey because it gives the first assembly error, because it comes first in the file.

[BogdanOntanu]

Can you please explain why you did not start your tests / learning with one of the fully functional and simple examples in MASM32 examples folder?

They show you the "normal" and modern way to define .code and .data sections in your file, basic needed includes, how to invoke API's and a functional template to base your new tests / applications on it.

Choosing random code from the net and then asking why it does not work is not a very honest action when you have a lot of examples in your MASM32 folders.

[Darmani]

BogdanOntanu: Because I didn't think of it, and instead went straight to the manuals. Thanks for the suggestion; I'll be back here in a few days if I still can't figure it out.

[japheth]

Can you please explain why you did not start your tests / learning with one of the fully functional and simple examples in MASM32 examples folder?

They show you the "normal" and modern way to define .code and .data sections in your file, basic needed includes, how to invoke API's and a functional template to base your new tests / applications on it.

I don't use Masm32 and I don't agree that that's the "normal" or "modern" way. There exist better ways to program for Windows in Masm-style.

[sinsi]

The code looks like some from a book I have about 386 programming, not necessarily windows programming.
I think it seems fair enough adding an include and trying to call an external proc.

[hutch--]

 :bg

> There exist better ways to program for Windows in Masm-style.

The Gospel according to japheth ?

[ToutEnMasm]

The code have a real old look.
Nobodies is obliged to use the .code .data ...
The translation of c++ code for masm can give it a better look
sample:

EXTRN   __imp__GetSystemTimeAsFileTime@4:PROC
EXTRN   __aulldiv:PROC
; Function compile flags: /Odtp
_TEXT   SEGMENT
_tim$ = -16                  ; size = 8
_nt_time$ = -8                  ; size = 8
........................................

; Line 72
   mov   esp, ebp
   pop   ebp
   ret   0
__time64 ENDP
_TEXT   ENDS
END

And it's not a virus !!

[japheth]

:bg

> There exist better ways to program for Windows in Masm-style.

The Gospel according to japheth ?

I didn't say Masm32 doesn't work. It's just a bit old-fashioned with its "all's a DWORD"-philosophy. :toothy

[dedndave]

it has a "real old look", as Yves said, because he is mixing 16-bit and 32-bit code, which doesn't work all that well
i doubt it came from a book, or from some hacker code, for that matter
it didn't come from anyplace   :P

but - the registry is no place to fart around learning code, especially writing to it - lol
screw it up, and you may find yourself rebuilding the hard drive
if you must play in the registry...
1) start with a 32-bit program
2) start with RegOpenKeyEx/RegQueryValueEx or something
3) there are examples in the masm32\examples folder - and you can find several more by using the forum search tool

[ToutEnMasm]

In case it is 32 bits code,here is a sample on how to start

.NOLIST            
   include \masm32\include\masm32rt.inc
   .const
   .data
   Hkey dd 0
   mykey db ".acl",0
   .code
   start:
   invoke RegOpenKeyEx,HKEY_CLASSES_ROOT,addr mykey,NULL,KEY_READ,addr Hkey
   invoke ExitProcess,0
   ;------- proc içi ------------
   end start

[MichaelW]

The only things in the code that could be viewed as 16-bit are the ASSUME statements, and they could be made to work with the right seglocation keyword (although the first one would still serve no useful purpose).