I am unable to compile an assembly file in Visual Studio 2017. I am unsure weather this is due to visual studio or because i made some mistakes in the code, pls help me.
I have a c++ main file in which I go for the call:
#include "stdafx.h"
#include "myStruct.h"
extern "C" __int64 CalcStructSum_(const myStruct *kekStruct);
int _tmain(int argc, _TCHAR* argv[])
{
myStruct kek;
kek.Val8 = 8;
kek.Val16 = 16;
kek.Val32 = 32;
kek.Val64 = 64;
__int64 summe = CalcStructSum_(&kek);
printf("summe betraegt: %d", summe);
getchar();
return 0;
}
mystruct.h :
#pragma once
typedef struct
{
__int8 Val8;
__int8 Pad8;
__int16 Val16;
__int32 Val32;
__int64 Val64;
}myStruct;
here the assembly equivalent:
myStruct struct
Val8 byte ?
Pad8 byte ?
Val16 word ?
Val32 dword ?
Val64 qword ?
myStruct ends
and here is the assembly file:
.model flat,c
include myStruct_.inc
.code
;prolog and function start
CalcStructSum_ proc
push ebp
mov ebp,esp
push ebx
push esi
; das struct liegt auf dem stack
; alle felder wurden auf 32 bit sign-extended
; in esi kommt anfang des speicherbereichs rein
; später wird quasi [basereg + dispatch] daraus interpretiert
mov esi, [ebp+8] ; get a pointer to "mystruct"
; load 8- and 16bit sources into 32bit registers (movsx)
; this is necassery to load struct-fields from the stack
movsx eax, byte ptr [esi + myStruct.Val8] ; [baser. + disp]
movsx ecx, word ptr [esi + myStruct.Val16]
add eax, ecx
; now sign-extend eax register to 64bit
; high part: edx , low part: eax
cdq
;save result for later
mov ebx, eax
mov ecx, edx
; now load the int-part of the struct and add it
; (it must be sign-extended to edx:eax again)
mov eax, [esi + myStruct.Val32]
cdq
; (the high-part must be added with carry, if overflown)
add eax, ebx
adc edx, ecx
; now, get the long from stack
add eax, dword ptr [esi + myStruct.Val64] ; low part
adc edx, dwprd ptr [esi + myStruct.Val64 + 4] ; high part
; we now have the sum of all structure fields in the register pair edx:eax
pop esi
pop ebx
pop ebp
ret
CalcStructSum_ endp
end
Also, I included the files in my explorer window like this (and, of course, set build dependencies):
I also tried assembling from powershell with ml.exe, but no luck here either. Also, it would be nice if someone could point out a simple method to capture the output of ml.exe, it is instantly away after execution (am a cmd-noob).
Finally, I tried putting the files in ANSI mode, but this should not be an issue at all, I just read through old stackoverflow answerers.
What am I missing? Should I turn back to VS2010 maybe? Or is it just an idiotic syntax error? This really freaks me out since such a simple proof-of-concept program should not be so hard to write -.-
Ok, problem is solved:
Turned out it was a by typo in line 50 [ "dwprd" instead of "dword" ].
Fixed and solved. If anybody comes accross a situation like mine, where they just can't find any usefull hints provided by the assembler / IDE , then here is how i found the solution:
[ in windows OS ]
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