Debugging in Swift

This talk will give you some helpful tips and tricks when you struggle with Debugging

Transcript

1. Debugging in Swift how hard can it be @_Caro _N, 22/3/2015
2. Why do we struggle with debugging? @_Caro _N, 22/3/2015
3. Output is not helpful (lldb) po objectiveCString 0x00007fbaa1f24910 (ObjectiveC.NSObject = {}) @_Caro _N, 22/3/2015
4. Error messages make no sense @_Caro _N, 22/3/2015
5. What?! That tool exists? @_Caro _N, 22/3/2015
6. How debugging should be like • Get to the content of interest @_Caro _N, 22/3/2015
7. How debugging should be like • Get to the content of interest • Get helpful error messages @_Caro _N, 22/3/2015
8. How debugging should be like • Get to the content of interest • Get helpful error messages • Display additional information where needed @_Caro _N, 22/3/2015
9. How debugging should be like • Get to the content of interest • Get helpful error messages • Display additional information where needed • Know about debugging tools @_Caro _N, 22/3/2015
10. LLDB @_Caro _N, 22/3/2015
11. Expression (lldb) po objectiveCString 0x00007fbaa1f24910 (ObjectiveC.NSObject = {}) @_Caro _N, 22/3/2015
12. Expression (lldb) expression -O -- objectiveCString 0x00007fbaa1f24910 (ObjectiveC.NSObject = {}) @_Caro _N, 22/3/2015
13. Magic command (lldb) expression -l objc -O -- (id) 0x00007fbaa1f24910 @_Caro _N, 22/3/2015
14. Magic command (lldb) expression -l objc -O -- (id) 0x00007fbaa1f24910 I'm a fancy Objective-C String @_Caro _N, 22/3/2015
15. Breakpoints @_Caro _N, 22/3/2015
16. Editing Breakpoints @_Caro _N, 22/3/2015
17. Editing Breakpoints @_Caro _N, 22/3/2015
18. Editing Breakpoints @_Caro _N, 22/3/2015
19. Projectwide Breakpoints • Catch Objective-C or C++ Exceptions on throw or catch @_Caro _N, 22/3/2015
20. Projectwide Breakpoints • Catch Objective-C or C++ Exceptions on throw or catch @_Caro _N, 22/3/2015
21. Projectwide Breakpoints • Catch Objective-C or C++ Exceptions on throw or catch • Catch OpenGL ES errors @_Caro _N, 22/3/2015
22. Projectwide Breakpoints • Catch Objective-C or C++ Exceptions on throw or catch • Catch OpenGL ES errors • Stop when executing a specific function or method @_Caro _N, 22/3/2015
23. Projectwide Breakpoints • Catch Objective-C or C++ Exceptions on throw or catch • Catch OpenGL ES errors • Stop when executing a specific function or method • Stop when test Assertions fail @_Caro _N, 22/3/2015
24. Symbolic Breakpoints @_Caro _N, 22/3/2015
25. Symbolic Breakpoints @_Caro _N, 22/3/2015
26. Compiler errors @_Caro _N, 22/3/2015
27. Approach? @_Caro _N, 22/3/2015
28. 1. Remove variables @_Caro _N, 22/3/2015
29. 2. Split instructions @_Caro _N, 22/3/2015
30. Add return type @_Caro _N, 22/3/2015
31. Launch arguments @_Caro _N, 22/3/2015
32. Adding arguments in the scheme editor @_Caro _N, 22/3/2015
33. Concurrency -com.apple.CoreData.ConcurrencyDebug 1 @_Caro _N, 22/3/2015
34. SQL Statements -com.apple.CoreData.SQLDebug 3 @_Caro _N, 22/3/2015
35. Many more -com.apple.CoreData.MigrationDebug -com.apple.CoreData.SQLiteDebugSynchronous [0,1,2] -com.apple.CoreData.SQLiteIntegrityCheck 1 -com.apple.CoreData.ThreadingDebug [1,2,3] http://matthewmorey.com/tools-for-core-data/ @_Caro _N, 22/3/2015
36. Localization • -NSDoubleLocalizedStrings 1 @_Caro _N, 22/3/2015
37. Localization • -NSDoubleLocalizedStrings 1 • -NSShowNonLocalizedStrings 1 @_Caro _N, 22/3/2015
38. Localization • -NSDoubleLocalizedStrings 1 • -NSShowNonLocalizedStrings 1 • -AppleLanguages (es de) Technical Note TN2239 iOS Debugging Magic @_Caro _N, 22/3/2015
39. Debugging tools @_Caro _N, 22/3/2015
40. Charles • Debug http/https requests • Throttle traffic • Record download statistics @_Caro _N, 22/3/2015
41. Swift REPL • Test and interact with your app • Add new code • Clean slate xcrun swift in the terminal @_Caro _N, 22/3/2015
42. Activity Tracing Trace crashes in asynchonous code os_activity_t activity = os_activity_start("activity name", OS_ACTIVITY_FLAG_DEFAULT); // [...] os_activity_set_breadcrumb("event description"); // [...] os_trace("Received %d creates, %d updates, %d deletes", created, updated, deleted); // [...] os_activity_end(activity); @_Caro _N, 22/3/2015
43. Activity Tracing @_Caro _N, 22/3/2015
44. Activity Tracing http://www.objc.io/issue-19/activity-tracing.html @_Caro _N, 22/3/2015
45. Summary • expression -l objc -O -- (id) 0x00007fbaa1f24910 • Edit Breakpoints, add symbolic and exception breakpoints • Tackle incomprehensive compiler errors • Launch arguments • Charles, REPL, Activity tracing @_Caro _N, 22/3/2015
46. Thanks @_Caro _N, 22/3/2015