Home » Forums » MAIN » masm v.9 EXTERNDEF link failed why?

masm v.9 EXTERNDEF link failed why?
module1.asm =>

.686                       
.model flat, stdcall       
option scoped             
option casemap :none       

.data
string  db "Order in Chaos",0
align 4

.code
myproc  proc
mov edx,7
mov eax,3
ret
myproc  endp

start:
main    proc
        call myproc
ret
main    endp
end start

-------------------------------------------------

module2.asm =>

.686                       
.model flat, stdcall       
option scoped             
option casemap :none       

  INCLUDE modinc.inc
   
.data
align 4
.code
start:
main    proc
        call  myproc
ret
main    endp
end start

--------------------------

modinc.inc =>

externdef myproc : proc

--------------------------
ml /c module1.asm
ml /c module2.asm
link module1.obj module2.obj  /out:test.exe

module1.obj : warning LNK4033: converting object format from OMF to COFF
module2.obj : warning LNK4033: converting object format from OMF to COFF
module2.obj : error LNK2005: _main@0 already defined in module1.obj
LINK : fatal error LNK1561: entry point must be defined

:sad:

What's going on???



Posted on 2008-01-16 13:16:07 by sittingduck
Re: masm v.9 EXTERNDEF link failed why?
What's going on???

it says: you have two "main"-s AND you have two entrypoints!

module1.asm =>

.686                        
.model flat, stdcall
option casemap :none        

externdef main : proc

.data
string  db "Order in Chaos",0
align 4

.code
myproc  proc            
   mov edx,7
   mov eax,3 
   ret
myproc  endp

start:   
   call main
   ret
end start

-------------------------------------------------

module2.asm => 

.686                        
.model flat, stdcall        
option casemap :none        
INCLUDE modinc.inc
.code
main    proc               
   call   myproc
   ret
main    endp                  
end

--------------------------

modinc.inc =>

externdef myproc : proc
Posted on 2008-01-16 15:25:01 by drizz
Re: masm v.9 EXTERNDEF link failed why?

What's going on???

it says: you have two "main"-s AND you have two entrypoints!


And if i remove one of the main:s i will get main missing when assemble?
Posted on 2008-01-16 15:37:45 by sittingduck
Re: masm v.9 EXTERNDEF link failed why?

And if i remove one of the main:s i will get main missing when assemble?
did you try that?

1. Make one module your main module, ie the starting point of your exe
this defines your entrypoint, have this in the main module
start:   ;; the label can be anything
end start

2. In other modules just put procedures or data
.686                        
.model flat, stdcall
option casemap :none
.code
;; function definitons go here
end;; <- nothing else here

3. Add a header file (.inc) to the main module, which defins all external procedures and or data
4. Make sure the names are different in each module even for unexported functions ( unless you use proc private)
5. If you are going to link a C runtime library, remove the entrypoint labels and write the appropriate entry functions (_main or _WinMain@16)
Posted on 2008-01-16 16:01:34 by drizz
Re: masm v.9 EXTERNDEF link failed why?


start:   ;; the label can be anything
end start

2. In other modules just put procedures or data                     


Thank you, now it works - lovely.

But can you check if i missed anything?
var1 & var2 are not in myinc.inc but it works anyway strange.



---------------------------------------------------
module1.asm 
---------------------------------------------------
.686                        
.model flat, stdcall         
option scoped               
option casemap :none        

    include myinc.inc
    externdef	var1:dword,var2:dword,proc1:near
.data

align 4
.code

start:	
      mov   eax,2
      mov   edx,5
      mov   var1,eax
      mov   var2,edx
      call proc1					
      ret
end start

---------------------------------------------------
module2.asm 
---------------------------------------------------
.686                        
.model flat, stdcall         
option scoped               
option casemap :none        

    public  var1,var2,proc1

.data
var1    dd    ?
var2    dd    ?
align 4

.code

proc1  proc 				
	mov eax,var1
	add eax,var2 
	ret
proc1  endp
end

---------------------------------------------------
myinc.inc 
---------------------------------------------------
	proc1	PROTO




Posted on 2008-01-17 03:36:40 by sittingduck
Re: masm v.9 EXTERNDEF link failed why?

var1 & var2 are not in myinc.inc but it works anyway strange.

external definitions don't have to be in an .inc file, it's just convenient that way for multiple inclusion




yeh looks ok  :thumbsup:
Posted on 2008-01-17 10:21:56 by drizz