advanced ios debbuging

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Massimo Oliviero

Advanced iOS Debugging

@maxoly #code12

mailto:[email protected]


Massimo Oliviero - [email protected] - www.massimooliviero.net - @maxoly

Massimo Oliviero

Freelance Software Developer

Co-founder of #pragma mark http://pragmamark.org

Online

web http://www.massimooliviero.net

email [email protected]

twitter @maxoly

slide http://www.slideshare.net/MassimoOliviero



http://www.massimooliviero.net


http://pragmamark.org

http://pragmamark.org





http://www.slideshare.net/MassimoOliviero



Agenda

• Code, some tips for standard functions

• Xcode, the best tools for debugging

• LLDB, your great friend

• Tools, network debugging how to and more

• Remote, over the air debugging






Code


It all began...

NSLog(@"Error :( %@", error);

NSLog(@"User: %@", user);

NSLog(@"Array: %@", array);NSLog(@"URL: %@", url);

NSLog(@"Count: %i", count);NSLog(@"User %@", user);

NSLog(@"Array %@", array);



NSLog(@"URL: %@", url);

NSLog(@"Array: %@", array);

NSLog(@"Array: %@", array);


NSLog(@"User: %@", user);NSLog(@"User: %@", user);










NSLog

• It prints debugs output only to the console

• It’s a simple native Foundation function

• It’s not too bad, but It’s an ancient technique

• It slows things down considerably (if not handled)






NSLog optimization

• Use convenient macro

• Use string conversions

• Try alternative frameworks






NSLog macro

#if defined DEBUG#define MYNSLog(s, ...) NSLog((@"%s [Line %d] " s), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)#else #define MYNSLog(s, ...)#endif

-[TestViewController viewDidLoad] [Line 33] message

- (void)viewDidLoad{ [super viewDidLoad]; MYNSLog(@"message");}

MyGreatApp-prefix.pch

TestViewController.m

Console






NSLog macro

• Enables DEBUG mode output only

• Outputs function name and line number

• Place macro into .pch file or in a header file

• You can use other macros like __ FILE__ (for example)






String conversion functions

CGPoint point = CGPointMake(10.5f, 12.3f);NSLog(@"point: %@", NSStringFromCGPoint(point));

AdvanceDebuggingExample[3050:c07] point: {10.5, 12.3}

AdvanceDebuggingExample.m

Console






String conversion functions

Returns a string formatted to contain the data from a structure:

• NSStringFromCGAffineTransform

• NSStringFromCGPoint

• NSStringFromCGRect

• NSStringFromCGSize

• NSStringFromUIEdgeInsets

• NSStringFromUIOffset





http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromCGAffineTransform

http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromCGAffineTransform

http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromCGPoint

http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromCGPoint

http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromCGRect

http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromCGRect

http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromCGSize

http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromCGSize

http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromUIEdgeInsets

http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromUIEdgeInsets

http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromUIOffset

http://developer.apple.com/library/ios/documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html#//apple_ref/c/func/NSStringFromUIOffset


Try alternative frameworks

• CocoaLumberjackhttps://github.com/robbiehanson/CocoaLumberjack

• NSLoggerhttps://github.com/fpillet/NSLogger

• DMLoggerhttps://github.com/malcommac/DMLogger





https://github.com/robbiehanson/CocoaLumberjack

https://github.com/robbiehanson/CocoaLumberjack

https://github.com/fpillet/NSLogger

https://github.com/fpillet/NSLogger

https://github.com/malcommac/DMLogger

https://github.com/malcommac/DMLogger


Demo


Xcode


Xcode

• Configure your Behaviors

• Print more information with Arguments

• Go beyond logging with Breakpoints






Behaviors

Xcode default Behaviors

Debugger bar

Xcode default Behaviors

Variables View Console

Debugger Navigator


Xcode Behaviors

• Match Xcode to your Workflow

• Use Behaviors to control Xcode

• Behaviors lets you specify what should happen when a variety of events occur (like Run)





Behaviors

When pauses

Show Debug NavigatorShow debugger views


Change default Behavior

For example, when Running pauses:

• show the Breakpoint Navigator instead of Debug Navigator

• show only Variable Views

• open another tab only with Console view






Demo


Arguments

Arguments

Product > Scheme > Edit Scheme > Arguments

Core Data Logging

-com.apple.CoreData.SQLDebug 1

Core Data and iCloud

-com.apple.coredata.ubiquity.logLevel 3


Breakpoints

Creating and editing breakpoint

Breakpoint Navigator

Exception Breakpoint

Symbolic Breakpoint

Breakpoint Action

Breakpoint action

Condition to evaluateThe num of time to ignore breakpoint before stoping

Log Message Action

Debugger Command Action

Play soundContinue program execution

Debugger Command Action

po variable

expr (void)NSLog(@”variable: %@”, variable)

breakpoint set -f ADEMasterViewController.m -l 83

Sharing Breakpoint

Share breakpoints with the team, so that all can benefit from it

This action will create a new directory to be committed in the repositoryAdvanceDebuggingExample.xcodeproj/xcshareddata/


Demo


LLDB


Why LLDB

• Consistent Command Syntax

• Scriptability with Python

• Performance

• ...






LLDB Commands

print object po [object]

print variable print [variable]

assign value expr [variable] = [value]

(lldb) <command>






LLDB Commands

set breakpoint breakpoint set -f [file] -l [line]

load script command script import ~/test.py

evaluate expression expr <expression>

<noun> <verb> [-options [option-value]] [argument [argument...]]





Custom object, the problem

No summary for custom object

@interface ADEEvent : NSObject

@property (nonatomic, strong) NSString *title;@property (nonatomic, strong) NSDate *when;

@endADEEvent *event = [[ADEEvent alloc] init];event.title = @"Codemotion Conference";event.when = [NSDate date];

Init object

Custom object


Custom summary

• Create a Python script that will instruct LLDB on how to display a summary of your custom object

• Load your Python script via command line or ~/.lldbinit file






Custom summary

import lldb

def ade_summary(valobj, internal_dict):! titleAsString = valobj.GetChildMemberWithName('_title').GetSummary()! whenAsString = valobj.GetChildMemberWithName('_when').GetSummary()! return 'Title: ' + titleAsString + ' - when: ' + whenAsString

def __lldb_init_module(debugger, dict): debugger.HandleCommand('type summary add ADEEvent -F CustomSummaries1.ade_summary')

• Create “ADEEvent_summary.py” in Xcode project

• Then load script:(lldb) command script import /path/to/ADEEvent_summary.py






Console tips

(lldb) po [self.view recursiveDescription]$7 = 0x082a2c60 <UITableView: 0x8971000; frame = (0 0; 320 504); clipsToBounds = YES; autoresize = W+H; gestureRecognizers = <NSArray: 0x8184be0>; layer = <CALayer: 0x8184570>; contentOffset: {0, 0}> | <UITableViewCell: 0x8282900; frame = (0 176; 320 44); text = '2013-03-12 21:22:34 +0000'; autoresize = W; layer = <CALayer: 0x8282a30>> | | <UITableViewCellContentView: 0x8282a60; frame = (0 0; 300 43); gestureRecognizers = <NSArray: 0x8282c30>; layer = <CALayer: 0x8282ac0>> | | | <UILabel: 0x8282e50; frame = (10 0; 280 43); text = '2013-03-12 21:22:34 +0000'; clipsToBounds = YES; userInteractionEnabled = NO; layer = <CALayer: 0x8282ee0>>

| | <UIButton: 0x8282c80; frame = (290 0; 30 43); opaque = NO; userInteractionEnabled = NO; layer = ...

(lldb) po [[UIWindow keyWindow] recursiveDescription]$5 = 0x08273bc0 <UIWindow: 0x8181010; frame = (0 0; 320 568); layer = <UIWindowLayer: 0x81810e0>> | <UILayoutContainerView: 0xd06eed0; frame = (0 0; 320 568); autoresize = W+H; layer = <CALayer: 0xd071460>> | | <UINavigationTransitionView: 0xd09e850; frame = (0 0; 320 568); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0xd09e920>> | | | <UIViewControllerWrapperView: 0x846e160; frame = (0 64; 320 504); autoresize = W+H; layer = <CALayer: 0x846e210>>...






Demo


Tools


Tools

• Network Link Conditioner

• Charles

• PonyDebugger

• Deploymate






Network Link Conditioner

• It’s a utility that enables you to simulate network conditions

• To install just select Xcode > Open Developer Tool > More Developer Tools. You’ll be taken to Apple’s developer downloads site

• Download “Hardware IO Tools for Xcode”





Network Link Conditioner


Charles

• It’s a web debugging proxy

• You can inspect, modify and record requests & responses

• SSL Proxing (http://www.charlesproxy.com/documentation/faqs/ssl-connections-from-within-iphone-applications/)

http://www.charlesproxy.com/





http://www.charlesproxy.com/documentation/faqs/ssl-connections-from-within-iphone-applications/








Charles


PonyDebugger

• Network Traffic Debugger

• Core Data Browser

• It is a client library and gateway server combination that uses Chrome Developer Tools on your browser to debug your application's network traffic and managed object contexts.

https://github.com/square/PonyDebugger







PonyDebugger


Deploymate

• If using an API introduced later than your target OS but your app is targeting an older OS version, Xcode doesn't warn you about it

• It helps identify unavailable, deprecated and obsolete API





Deploymate


Demo


Remote


Remote debugging

• Apple Crash Reports

• PLCrashReporter

• TestFlight






Apple Crash Reports


Apple Crash Reports

• For app published on App Store, you can acquire crash log from iTunes Connect and import it into Organizer for symbolication

• To symbolicate a crash log, Xcode needs to have access to the matching application binary that was uploaded to the App Store, and the .dSYM file that was generated when that binary was built. This must be an exact match

https://itunesconnect.apple.com







Apple Crash Reports

Xcode Symbolication


PLCrashReporter


PLCrashReporter

• In-process CrashReporter framework for the iPhone and Mac OS X

• Handles both uncaught Objective-C exceptions and fatal signals

• Backtraces for all active threads are provided

https://code.google.com/p/plcrashreporter/












- (void) handleCrashReport { PLCrashReporter *crashReporter = [PLCrashReporter sharedReporter]; NSData *crashData; NSError *error; // Try loading the crash report crashData = [crashReporter loadPendingCrashReportDataAndReturnError: &error]; if (crashData == nil) { NSLog(@"Could not load crash report: %@", error); goto finish; } PLCrashReport *report = [[[PLCrashReport alloc] initWithData: crashData error: &error] autorelease]; if (report == nil) { NSLog(@"Could not parse crash report"); goto finish; } .... return;}

// from UIApplicationDelegate protocol- (void) applicationDidFinishLaunching: (UIApplication *) application { PLCrashReporter *crashReporter = [PLCrashReporter sharedReporter]; NSError *error; // Check if we previously crashed if ([crashReporter hasPendingCrashReport]) [self handleCrashReport]; // Enable the Crash Reporter if (![crashReporter enableCrashReporterAndReturnError: &error]) NSLog(@"Warning: Could not enable crash reporter: %@", error); }





http://plcrashreporter.googlecode.com/svn/tags/plcrashreporter-1.1-rc1/Documentation/API/interface_p_l_crash_reporter.html




http://plcrashreporter.googlecode.com/svn/tags/plcrashreporter-1.1-rc1/Documentation/API/interface_p_l_crash_report.html









TestFlight


TestFlight

• Invite your testers, drop in the SDK and start uploading your builds.

• Upload your builds and TestFlight takes care of the rest. Painless over-the-air distribution to your testers and distribution lists.

• Complete tracking of your build, from distribution to sessions, checkpoints and crashes.

https://testflightapp.com/





https://testflightapp.com

https://testflightapp.com

TestFlight Apps Managment

TestFlight Crashes


Final Thoughts


Final Thoughts

• Don’t use NSLog anymore ;)

• Create your Xcode Behaviors

• Breakpoints are your friends

• LLDB is a promising youngster

• Tools can save your life

• The QA phase is essential






Thank you!

Massimo [email protected]


follow me on twitter @maxolyhttp://www.slideshare.net/MassimoOlivierohttps://speakerdeck.com/massimooliviero







https://speakerdeck.com/massimooliviero

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