Does order of errdefer matter?

[late edge]

Does the ordering of errdefer matter when cleaning up memory? For example, technically the struct variable should be freed before the struct that holds it. i.e. Does the order matter here? or can we assume that the memory is ok until we loose scope?

pub fn create(font: *Font, text: []const u8, box: Box, color: ray.Color, update_helper: TextUpdateFunc, allocator: std.mem.Allocator) !*TextElement {
    var element = try allocator.create(TextElement);
    errdefer allocator.destroy(element);
    element.text = try allocator.dupeZ(u8, text);
    errdefer allocator.free(element.text);
    ....
    error happens

[paper copper]

the memory is invalidated as soon as free/destroy is called. did you mean to do errdefer allocator.free(element.text)? if that's what you meant then the order does matter because if you put it in reverse order you would invalidate element and then try to access text on a dead pointer

[late edge]

Yes thats a typo in my example. I have updated it for the example. So in the example, does the order matter? And is errdefer called in the right order if an error occurs later?

The documentation explains what errdefer is, but it doesnt explain how the errdefer calls are ordered when trying to "unwind" the mallocs that occurred. https://ziglang.org/documentation/master/#errdefer

I assume that element.text would normally need to be freed, then element itself. I don`t know if that is what would happen here and if it matters.

[noble fulcrum]

the order is same as defers

[late edge]

Aaaaah, thanks, https://ziglang.org/documentation/master/#defer The documentation does say the defers are called in reverse, which is whatg would be needed for the errdefer to unwind my example correctly, thanks.