Question

how in c++ visual can i set labels for when i need to use inline assembly, so it would look like something like this for example…

__asm
{
    PUSH EAX
    PUSH VAR1
    MOV ECX,DWORD PTR DS:[VAR2]
    CALL DWORD PTR DS:[VAR3]
    JMP VAR4
}

where the VAR varables link to a value or address?

i have tried the following

DWORD   VAR2 = 0x991770;    //0x991770 is the location of the function

__asm
{
    ..code
    MOV ECX,DWORD PTR DS:[VAR2]
    ..code
}

but then the app crashes, how is this done?

Answer 1

Use offset variableName to access variables from inline assembly. See reference here.

Example:

char format[] = "%s %s\n";
char hello[] = "Hello";
char world[] = "world";
int main( void )
{
   __asm
   {
      mov  eax, offset world
      push eax
      mov  eax, offset hello
      push eax
      mov  eax, offset format
      push eax
      call printf
      //clean up the stack so that main can exit cleanly
      //use the unused register ebx to do the cleanup
      pop  ebx
      pop  ebx
      pop  ebx
   }
}