swift-mixin | An intuitive library for hooking functions in Swift

Using this library in your project requires that you have capstone installed on your system. Capstone can be installed using homebrew with the following command;. The next few steps depend on what sort of project you have. Installation is different for Swift Package Manager projects and Xcode projects.
Below is an example Package.swift with SwiftMixin as a dependency;.
Add this package as a dependency in your Package.swift.
Optional: Run swift package generate-xcodeproj because using an xcodeproj makes your life easier later on.
Navigate to File > Swift Packages > Add Package Dependency....
Enter https://github.com/stackotter/swift-mixin as the url.
On the next screen choose branch rule and leave the default value (it should be 'main').
Click next. Once it finishes loading, choose your package in the Add to Target column and click done.
In more recent versions of macOS, Apple changed the default maxProt level of the text segment of MachO executables to be 5 (it used to be 7). In short; we need to change this value back to 7 otherwise we can't write to the memory that contains functions. I don't know which macOS version the change was made in so it's safest just to do the following steps anyway.
Add a run script phase to your project containing the following;. This will patch the binary correctly everytime you build your project.
If you have a swift package manager project and don't use a .xcodeproj then there are two options (both are not that good, it's not too late to run swift package generate-xcodeproj). Option 1: Run printf '\x07' | dd of=./path/to/compiled/binary bs=1 seek=160 count=1 conv=notrunc everytime you build your project (an example build and run script is listed below). Option 2: Or, each time you want to build and run your project; First build and run it (you will get an error), and then run it again and it should work. Your executable will automatically patch itself, but it requires a restart of the program for the changes to take effect. This autopatching requires that your program calls Mixin.setup() when it starts up.
Each time your app starts it should check that it's memory protection bit it correctly patched. This sounds scary but SwiftMixin makes it easy. Just add the following line to your app's startup;. This will automatically check your executable's text segment's maximum protection level (should be 7 but is 5 by default). If the protection level is not set correctly the executable will patch itself and Mixin.setup() will throw an error. The next time the executable is run it should work properly.