nice hexrays thing

[Shub-Nigurrath]

Hi all,
I was testing the newest leaked hexrays with this example:

int main(int argc, char* argv[])
{
  int firstvalue = 5;
  int *p1;
  p1 = &firstvalue;
  *p1 = 10;
  return 0;
}

which produces this simple assembler:

push    ebp
mov     ebp, esp
sub     esp, 8
mov     [ebp+var_4], 5
lea     eax, [ebp+var_4]
mov     [ebp+var_8], eax
mov     ecx, [ebp+var_8]
mov     dword ptr [ecx], 0Ah
xor     eax, eax
mov     esp, ebp
pop     ebp
retn

the strange is that if you try to decompile it with hexrays you get only this:

int __cdecl main(int argc, const char **argv, const char **envp)
{
  return 0;
}

Even if it doesn't seem at first sight, the code is, by the logical point of view, exactly the same because the variables are local therefore lost, the stack is restored. This is imho a nice view of how powerful is this plugin even for this simple case.

[ZeNiX]

I did not know that Hex-rays is so clever.
It can tell the arguements not used and variables lost.

[redbull]

Yeah seems to have been optimized. Awesome