function task exit

[RyanC]

Hi , I'm wondering whenever I have a function with specific task lets say the task to our analogues life drinking water , how does the PC knows that the function/task is terminated?! meaning whenever I finish the task how the compiler knows that the task is terminated? is there any command that the compiler is depending on and sending it to the CPU for letting it knows that task is finished successfully?
because it's really weird how the compiler work.


thanks for your help again

[laserlight]

Perhaps if you posted example code that you're puzzling about instead of an "analogy from real life", we could have a basis for explanation. If not, my answer from analogy would be: "anyone can see that I've finished drinking the water, duh!"

[Kernelpanic]

. . .
because it's really weird how the compiler work.

If you want know how a compiler work: Learning by doing!

Compilers: Amazon.de: Alfred V. Aho, Ravi Sethi, Jeffrey D. Ullman: Fremdsprachige Bucher

[RyanC]

Perhaps if you posted example code that you're puzzling about instead of an "analogy from real life", we could have a basis for explanation. If not, my answer from analogy would be: "anyone can see that I've finished drinking the water, duh!"

Maybe I didn't clear it well, but I'm meaning whenever a function is done and all alright, how CPU knows that the function has been successfully finished?! for example, lets assume there is a function

void doing_something()
{
   printf("Hello world");
}

whenever I call the function the pc will read what's inside the function, my question is how does he know that he arrived to the end of the function successfully ?!


thanks!

[christop]

whenever I call the function the pc will read what's inside the function, my question is how does he know that he arrived to the end of the function successfully ?!

The compiler tells the computer where the function ends. This is usually done with some type of "return from subroutine" instruction to go back to the calling function.