Yes this is decided at compile time. If you build your program with `-gcflags '-m'` the compiler will print out detailed escape analysis information. Here's more information: http://www.agardner.me/golang/garbage/collection/gc/escape/a...

Nice! So this could presumably be built into a linter (or similar) and be flagged in the editor ... interesting...

As a heuristic it would be OK, however, there are some situations where the escape analysis algorithms don't detect certain scenarios so a linter may lead you to believe things are not escaping but in reality they really are, it's also implementation specific, so something that may have escaped in go 1.10 may no longer escape in 1.11 for example.

It's easy enough to profile and benchmark in go, so I would always treat that as the source of truth.

It would be better to spend this effort to add generational GC with a bump allocator to Go. That way memory allocation becomes faster for everyone, not just the tiny subset of people who use fancy tools.

I think you've made yourself clear. You've jumped into half a dozen threads in this post with some variation of the same comment as you do with every Go GC post. Your comment is interesting, but repeating it over and over is tiresome. Have you reached out to the Go GC team? What is their response?

IIRC you can't really flag an object as normally escaping so it would be very noisy.

You could do it with a subtle colouring scheme.

very nice idea.

There are heuristics — and they improve from version to version — but they're necessarily conservative: heap allocating something which doesn't escape is a performance hit, stack-allocating something which does breaks software.

The compiler can in certain conditions prove that a value does not escape to the heap.

Ergo, this value is safe to allocate on stack.