What is the ".scatterload" file in macOS?

Question

I've downloaded Apple's TextEdit example app (here) and I'm a bit puzzled by one thing I see there: the TextEdit.scatterload file. It contains a list of functions and methods. My guess is that it provides information to the linker as to which functions/methods will be needed, and in what order, when the app launches, and that this is used to order the binary generated by the linker for maximum efficiency. Oddly, I seem to be unable to find any information whatsoever about this file through Google. So. First of all, is my guess as to the function of this file correct? And second, if so, can I generate a .scatterload file for my own macOS app, to make it launch faster? How would I do that? Seems like a good idea! (I am using Objective-C, but perhaps this question is not specific to that, so I'm not going to tag for it here.)

Answer 1

Scatter loading refers to a way to organize the mapping of your code in memory by specifying which part of code must be near which one, etc. This is to optimize page faults, etc. You can read about it here Improving locality of reference (HTML) or here Improving locality of reference (PDF).

.scatterload file is used by the linker to position code in memory layout of the executable.

Except if your app really need tight performance tuning, I would not encourage you to have a look at this.