如果函数没有返回，调用堆栈是否会泄漏内存？

Question

I'm not sure how language specific this is, but in PHP in particular, can you leak memory in the call stack if some functions never return?

For example, suppose you have a long function with redirect() (or gotos in C) statement(s), how does the language or environment know to delete that frame of the stack? Is there a method it uses to determine a stack frame will never be returned to?

Answer 1

If your function does not return anything is some situations, then that sounds to me like a bad design issue. And no it should not cause any memory leak just by not returning anything.

Whether the return value of your function ends up being used or not, you should either always have a path that return something (null, false, or any value). Or you could never ever return anything ... in which case your function will be more like a method or a procedure as other programming languages would refer to it.

If you are having a memory leak in the function you are working with, than you need to scrutinize the code of the function to see what could be causing the leak.

Answer 2

This question answered by Memory leak on the stack Note: I did come across that question before I posted this one but I didn't understand the answers until doing more research.

Tl;Dr: PHP maintains a stack for each page. In C/C++ "automatic duration" storage is cleaned up automatically by the compiler telling the operating system to delete automatic duration allocations when program execution moves outside the scope of those allocations.

So I guess the compiler can detect execution paths that result in the function not returning and also 'marks'(?) those paths as moving out of scope in the same way that returns are marked as moving out of scope.

https://en.cppreference.com/w/cpp/language/storage_duration