Hi,
I'm using Turbo c++ 4.0, and get this error:
"Linker error: Undefined symbol _Add_Ext in module ..\PROJECTS\ADD.C in
module ADD.OBJ"
This are the steps I've done before compilation (and please correct me):
1) compiling the Assembly code file ADD_EXT.ASM with MASM 6.11:
masm ADD_EXT.ASM
I didn't do the linking so i had ADD_EXT.OBJ
This is the Assembly code:
; Listing 2.7. The MASM portion of an external example.
.MODEL MEDIUM ; This tells the procedure to use the
; MEDIUM memory model.
EXTRN first:WORD,second:WORD,third:WORD
.CODE ; This is the beginning of the code.
_Add_Ext PROC FAR ; The procedure is type FAR.
mov AX,first ; This moves the first number into the
; accumulator.
add AX,second ; This adds the second number to the
; accumulator.
mov third,AX ; This stores the result back into
; third.
_Add_Ext ENDP ; This procedure ends here.
END ; This is the end of the code segment.
2) This is the C ADD.C code
// Listing 2.6 The C portion of an external example.
#include <stdio.h>
int first=1,second=2,third=0; // These are the integers with
// which we want to work.
extern Add_Ext();
void main(void)
{
printf("\nBefore adding third = %d",third);
Add_Ext(); // This calls the assembly
// program that will add
// externals.
printf("\nAfter adding third = %d",third);
getchar();
}// end main
3) Compiling the ADD.C file and getting the error I mentioned.
The ADD_EXT.OBJ and ADD_EXT.ASM are in the same directory.
There isn't any problem with the #include <stdio.h> since
I managed to compile and run a simple "Hello World" program.
Thanks in advance for your help.
