; Writed for board.flatassembler.net by Nikso

; CppAndAsm
;
; x86-64 GCC calling convention (ABI 0.9
;   GCC will use the following register (in order) for parameters passing:
;   RDI, RSI, RDX, RCX, R8, R9, (stack)
;   this is true only if the parameter fit in a register.
;   Return registers are: RAX, RDX
;   For more informations: http://www.x86-64.org/documentation

format ELF64 

section '.text' executable

; void write(char*)
extrn "_Z5writePc" as write

; int sum(int a, int b)
public sum
sum:
        MOV EAX,EDI
        ADD EAX,ESI
;???    ADD EAX,[num]
        
        PUSH RAX
        MOV EDI,strg
        CALL write
        POP RAX
        
        RET




section '.data' writeable

extrn "num" as num
;public strg
strg DB "everything!",0
    

fasm AsmPart.asm AsmPart.o    

// Writed for board.flatassembler.net by Nikso

#include <iostream>

using namespace std;

extern "C" int sum(int a, int b);

//extern char* strg;

int num = 10;

void write(char* cosa)
{
        cout << "Calculate within ASM " << cosa << endl;
}

int main()
{
//      cout << strg << endl;
        cout << "2 + 3 = " << sum(2,3) << endl;
        return 0;
}
    

gcc -o CppPart.o -c CppPart.cpp    

gcc -o cppandfasm AsmPart.o CppPart.o    

gcc -S -c CppPart.cpp
    

$ nm CppPart.o | grep <func_name>
    

$ nm <.o_file> | grep <func_name> | c++filt
    

$ nm CppPart.o | grep write
000000000000006c T _Z5writePc
$ nm CppPart.o | grep write | c++filt
000000000000006c T write(char*)