A presentation about the build process in Xcode, and how to optimize it.

1. Exploring the Xcode Build Process

2. 1. Compile source code
2. Compile resources such as storyboards, assets, xibs
3. Run scripts
4. Linking process
5. Code sign
Build steps

3. All tasks executes in
particular order. Order is
determent from dependency
information.

4. For example compilation task assumes compile code
file and produce object file (.o).

5. Linker task takes .o files and produces single
executable file.

6. > Build system takes build description (Xcode project file)
> Parse it
> Take all file of you project and analyse dependency relationships
and build settings

7. Build process graph

8. Tasks
order

9. llbuild - low level execution
engine
https://github.com/apple/swift-llbuild

10. C
c++
objective-c
objective-c++
Swift

12. Linking process
The swift compiler generates the object file (*.o) from the source file
(*.swift). To build an executable, the system linker combines the generated
object file, swift libraries (cygswiftCore.dll, cygswiftGlibc.dll,
cygswiftSwiftOnoneSupport.dll, libFoundation.dll, etc) and other system
libraries.

13. There are two types of input files:
- Object files (.o)
- Libraries

14. Build time optimisation

15. 1. Turn on settings for paralelize build

16. 2. Reduce dependency between modules

18. 3. Turn off Whole Module
Mode For Debug Builds

19. Incremental Builds Are File-
Based

20. 4. Declare Inputs and Outputs for Run Scripts

21. 5. Measuring Build Time

22. 6. Add warnings for type
checking time

23. 7. Use Explicit Types for Complex Properties

24. 8. Break Apart Complex Expressions

25. 10. Don’t use AnyObject
Methods and Properties

26. 11. Keep Your Generated Header Minimal

27. 11. Keep Your Generated Header Minimal