using namespace std;

int main(){

	int a;
	int b;
	asm("jmp c\n\t");
	cout<< a<< endl<< b<< endl;
	return 0;

int pewp(){

	int a;
	int b;
	a = 3;
	b = 2;
	asm("jmp d\n\t");

this will output


what I don't get is why although it jumps to the middle of the pewp() functions, it still sets the variables properly...
does this mean that, when the rest of the code gets compiled, the a= and b= in pewp() get sent to the same spot in memory that the a= and b= in main() would have? If I name the variables in pewp() c and d it still sets a and b in main(), so are these variables put on the stack or what? I guess I have lots to learn about what happens to the data in different declarations -.-

7 Years
Discussion Span
Last Post by winrawr

Yes, a and b in both main() and pewp() are declared on the stack in the same way. As you have identical declarations (just a and b) for each function you can jump into pewp() and it uses the stack allocated by main(). This may be an interesting exercise, but I hope you don't need me to tell you that doing anything close to this in software you might want to use is a complete no-no. Have fun experimenting though!


yeah, I know it's definitely a no-no, I just thought it was kind of cool, being able to cheat the compiler. Get back at it, for all these years of yelling at me, and telling me how wrong I am. Take that!

And the inline-assembly portion of it is compiler specific, since I just use a text editor and not an IDE I had to look up how to do it with my compiler, I'm using gcc- I believe vc++ uses __asm__ either followed by an instruction or followed by several, on separate lines between braces (without the \n\t or quotes)--also, I believe gcc uses at&t assembly format while vc++ uses something else...

and yeah, it would be better done with references but I just thought it was awesome. I wonder what would happen if the a and b in pewp() were defined as strings, or something else--how that would affect the stack in main().

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