CODEWITHSUNDEEP
c++visual-studiopointersinline-assembly
Fyxe
Fyxe

Reputation: 87

Pointer to inline __asm block in c++

So I've been screwing around with the __asm block in VS2010 and I haven't been able to find a better way to get the pointer to the start of the assembly block.

The only way I know how to do this, is to declare a void function. One problem with this is that the void function will have its own assembly before and after my assembly block and I would have to compensate by getting the real address of the function and adding an offset.

Example:

c++

void myfunc(){
    __asm{
        nop
        nop
        nop
        ret
    }
}

Would result in assembly similar to this:

push ebp
mov ebp,esp
add esp,8
nop
nop
nop
retn
mov esp,ebp
pop ebp
retn

myfunc() would most likely error if executed.

Upvotes: 4

Views: 416

Answers (1)

Andy Finkenstadt
Andy Finkenstadt

Reputation: 3587

You basically want to enable __declspec(naked) on your function, to avoid the compiler-generated prologue and epilog.

See also: http://msdn.microsoft.com/en-us/library/h5w10wxs(v=vs.80).aspx

Upvotes: 4

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