From:	"MarKol" <markol4 AT wp DOT pl>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Help me : DJGPP + assembly
Date:	Fri, 27 Apr 2001 12:06:17 +0200
Organization:	Technical University of Gdansk
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To:	djgpp AT delorie DOT com
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Reply-To:	djgpp AT delorie DOT com

Hello.
I encountered problem and I can't cope with it.
I use DJGPP under DOS and link "C" code with assembly (MASM format).
It's very important to use MASM format. I generate COFF format instead
OBJ like this:

    ml /coff  /Fo asm_file.o /c asm_file.asm

and I get asm_file.o in COFF format,

Then I compile my "C" program:

    gcc -c c_file.c

and another .o file appears,

and link:
    gcc -o ex_file.exe asm_file.o c_file.o

Success, no erros.

I run ex_file.exe but it doesn't work correctly.

Please consider this:

;---------------- asm test file -----------------
.586P
.model flat
.data
public _main_asm
.code

  extrn _func_c:near

  _func_asm_2 proc near
    nop
    nop
    nop
    nop
    nop
    ret
  _func_asm_2 endp

  _func_asm_1 proc near
    lea   eax, _func_c
    call  eax
    ret
  _func_asm_1 endp


  _main_asm proc near
    call   _func_asm_1
    lea    eax, _func_c
    call   eax

;    call   _func_c              ; (1)
;    lea    eax, _func_asm_1     ; (2)
;    call   eax                  ; (2)
    ret
  _main_asm endp
END

/*########## C file ########### */
#include <stdio.h>

extern void main_asm(void);

void
func_c(void){
  printf("Ok\n");
}

int
main()
{
  func_c();
  main_asm();
  return 0;
}
/*######## C file end ########*/

If you compile, link and run this program, you'll get 3x "Ok" on
screen, and that is right.

Problem appears after removing comments from lines marked (1) and (2).
After this modification program doesn't work correct ( and it doesn't
work correctly when comment is removed only from line marked (1) or
lines marked (2)! )
No errors, no warnings during compilation and link. Program should
write 5x "Ok" on screen but it doesn't. It crashes or writes "Ok" but
not 5x. (When I build program using MS compiler VC6, I get 5x "Ok" on
my monitor)

What's wrong? Please, help me. I must somehow use this MASM-format
assembly files with DJGPP (these files include SSE and MMX
instructions, I'm afraid there is no masm 2 as converter with SSE and
MMX instructions).
I suspect that problem is in relocation, but I don't know how to fix
it.

Please, help

Thanks

 ---

 |-|-|-|-|
  \     /    Marek Kolacz - MarKol
   |   |
   |   |        (markol4 AT wp DOT pl)
  (     )
 (       )
(_________)

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