How to enable NSZombie in Xcode? - xcode

I have an app that is crashing with no error tracing. I can see part of what is going on if I debug, but can't figure out which object is "zombie-ing".
Does anybody know how to enable NSZombie in Xcode 4?

Environment variables are now part of the "scheme".
To edit the scheme and turn on zombies:
In the "Product" menu, select "Scheme" > "Edit Scheme...".
Go to the "Run Foo.app" stage in the left panel, and the "Arguments" tab on the right.
Add NSZombieEnabled to the "Environment Variables" section and set the value to YES, as you could in Xcode 3.
In Xcode 4.1 and above, there's also a checkbox on the "Diagnostics" tab of the "Run" stage to "Enable Zombie Objects".
With Xcode 6.4:

I encountered the same problem with troubleshooting EXC_BAD_ACCESS and had hard time to find the setting with Xcode 4.2 (the latest one that comes with iOS5 SDK). Apple keeps on moving things and the settings are no longer where they used to be.
Fortunately, I've found it and it works for the device, not just Simulator. You need to open the Product menu in the Xcode, select Edit scheme and then choose the Diagnostics tab. There you have "Enable Zombie Objects". Once selected and run in debugger will point you to the double released object! Enjoy!
In short
Product->Edit Scheme->Diagnostics-> Click Enable Zombie Objects

Product > Profile will launch Instruments and then you there should be a "Trace Template" named "Zombies". However this trace template is only available if the current build destination is the simulator - it will not be available if you have the destination set to your iOS device.
Also another thing to note is that there is no actual Zombies instrument in the instrument library. The zombies trace template actually consists of the Allocations instrument with the "Enable NSZombie detection" launch configuration set.

It's a simple matter of setting an environment variable on your executable (NSZombieEnabled = YES), and then running/debugging your app as normal.If you message a zombie, your app will crash/break to debugger and NSLog a message for you.
For more information, check out this CocoaDev page: http://www.cocoadev.com/index.pl?NSZombieEnabled
Also, this process will become much easier with the release of 10.6 and the next versions of Xcode and Instruments. Just saying'. =)

Product > Profile will pop up Instruments. Select zombies from the panel and go nuts.

Go to Product - Scheme - edit scheme - Arguments - Environment Variables set NSZombieEnabled = YES

In xcode 4.2
Goto, Product -> edit scheme -> click Run yourappname.app -> Diagonostics -> Enable Zombie object.

Here's a video and explaination how to use Instruments and NSZombie to find and fix memory crashes on iOS:
http://www.markj.net/iphone-memory-debug-nszombie/

As of Xcode 3.2.5 and Snow Leopard (Mac OS X 10.6), you can run your code through the Zombies instrument: Run > Run with Performance Tool > Zombies. That allows you to see particular objects and their retain counts on a timeline.

In Xcode 4.5.2 goto Product -> Edit Scheme -> and Under the Diagnostics tab check the check box in between Objective C and Enable Zombie Objects and Click on OK

To enable Zombie logging double-click the executable in the executables group of your Xcode project. At this point click the Arguments tab and in the Variables to be set in the environment: section, make a variable called NSZombieEnabled and set its value to YES.

In XCode 4.0: To detect NSZombie in Instruments, select the Simulator as your target (can't detect NSZomboe on device). Run Instruments (CMD+I) and select "Zombies" trace template. Enjoy.

In the preferences of your executable add the environment variable NSZombieEnabled and set the value to YES.

in ur XCODE (4.3) next the play button :) (run)
select : edit scheme
the scheme management window will open
click on the Arguments tab
you should see : 1- Arguments passed on launch
2- environment variables
inside the the (2- environment variables) place
Name: NSZombieEnabled
Value: YES
And its done....

NSZombieEnabled is used for Debugging BAD_ACCESS,
enable the NSZombiesEnabled environment variable from Xcode’s schemes sheet.
Click on Product⇒Edit Scheme to open the sheet and set the Enable Zombie Objects check box
this video will help you to see what i'm trying to say.

Related

how to show variable value in Xcode's debug inspector

New to Xcode, but I want to check the value of variables in Xcode's inspector, like following, buttonFrame has origin and size property, but they are not displayed in the inspector, is there a way to show that?
The real solution here is using debug mode instead of release mode to build the app to the device, to change the mode:
project -> scheme -> check the target -> edit scheme -> run -> select the debug mode in the drop-down selector
You can use the po command as described in apple's documentation:
According to apple:
Print Description of “{variable}”. An equivalent to using po in the
console or using the Print Description button in a tool tip.
XCode Debugging Tools
But keep in mind, that if you don't see values for the button's frame and size, it could be that they haven't been set yet. Make sure that the break point you are using to inspect these variables is being set at a point in your code in which you are certain the view has been laid out viewDidAppear for example.

In Xcode is there code that will open up the console for you?

Is there a way in Xcode to have your software open up the console for you? I would like to have it when my code compiles and runs in Debug to have the console open up automatically but in release for it to not open.
Thanks in advance.
A common way to achieve this is :
Open a new tab, and rename it 'Console' (or what name you want)
In this tab, show only the panes you want (in your case the console)
Go to Preferences>Behaviors
Tell Xcode to 'Show tab' and give it the name you set in 1. (you can set this at various moments, when build starts, or when app runs).
Now, each you will either compile or run your app, Xcode will switch to the tab you have set in Prefs.
You dont use code, you go to xcode pref's and do it there
This is where I came for the answer given and marked correct (although it's not clear it was what the asker quite wanted).
Arguably, a simpler version of the answer given is to set the Behaviors preferences to show the Debugger when a run starts. With the settings in the image below, this opens up the console (or the console + variable views or the variables view, depending on how it was last set - that's what 'Current Views' means).

Does Xcode have a watch window?

Does Xcode have a watch window for variables? It has a window for local variables but that's not much help when I want to watch the value of a global.
I've been spoiled by VisualStudio, I know.
Solved! Right-clicking in the local variables window brings a menu option of "Add Expression". Type your variable name and now you are watching your variable/expression.
The language of "expression" instead of the more familiar "variable" threw me quite a bit. Hard to search for a solution when I have the terminology wrong. Seems obvious now.
Xcode Expression window
Open Debug Area via View -> Debug Area -> Activate Console (Xcode 9)
Right click -> Add Expression

Xcode doesn't show recent projects in recent projects list

Every time I start Xcode it gives me a window where my recent projects supposedly should be. It would come in handy but unfortunately it's always empty.
Does it have anything to do with the location where I store my projects? I hope not.
Thanks for any help!
I would think it's because you could have your recent items set to 0 in System Preferences -> Appearance.
Update - If you are using Yosemite the correct path is System Preferences -> General -> Recent items (Thanks to #karim)
EDIT: Based on comments : Then Reboot
#Mellson answer is correct. But there is no menu in OS X Yosemite, System Preferences -> Appearance.
It should be, System Preferences -> General -> Recent items. Set e.g. 5 items.
or in command line,
defaults write com.apple.Xcode NSRecentDocumentsLimit 5
However, to my experience the first one works more correctly.
Restart your mac.
Earlier, I faced the same issue after I did Xcode 7.3 update. It showed me empty (Clear) Xcode File -> Open Recents menu.
You disabled the Welcome to Xcode screen. Press shift+command+1, and then reselect the checkbox as shown below. You can also start a new project from the File menu : New > Project… without the Welcome to Xcode screen.

Why aren't Xcode breakpoints functioning?

I have breakpoints set but Xcode appears to ignore them.
First of all, I agree 100% with the earlier folks that said turn OFF Load Symbols Lazily.
I have two more things to add.
(My first suggestion sounds obvious, but the first time someone suggested it to me, my reaction went along these lines: "come on, please, you really think I wouldn't know better...... oh.")
Make sure you haven't accidentally set "Active Build Configuration" to "Release."
Under "Targets" in the graphical tree display of your project, right click on your Target and do "Get Info." Look for a property named "Generate Debug Symbols" (or similar) and make sure this is CHECKED (aka ON). Also, you might try finding (also in Target >> Get Info) a property called "Debug Information Format" and setting it to "Dwarf with dsym file."
There are a number of other properties under Target >> Get Info that might affect you. Look for things like optimizing or compressing code and turn that stuff OFF (I assume you are working in a debug mode, so that this is not bad advice). Also, look for things like stripping symbols and make sure that is also OFF. For example, "Strip Linked Product" should be set to "No" for the Debug target.
In Xcode 7, what worked for me was:
Make sure that the Target > Scheme > Run - is in Debug mode (was Release)
Make sure to check the option "Debug executable":
Go to the Xcode Debugging preferences.
Make sure that "Load Symbols lazily" is NOT selected.
I was just having this same issue (again). After triple-checking "Load symbols lazily" and stripping and debug info generation flags, I did the following:
quit Xcode
open a terminal window and cd to the project directory
cd into the .xcodeproj directory
delete everything except the .pbxproj file (I had frank.mode1v3 and frank.pbxuser)
You can accomplish the same task in finder by right/option-clicking on the .xcodeproj bundle and picking "Show Package Contents".
When I restarted Xcode, all of my windows had reset to default positions, etc, but breakpoints worked!
One of the possible solutions for this could be ....go to Product>Scheme>Edit scheme>..Under Run>info>Executable
check "Debug executable".
For Xcode 4.x:
Goto Product>Debug Workflow and uncheck "Show Disassembly When Debugging".
For Xcode 5.x
Goto Debug>Debug Workflow and uncheck "Show Disassembly When Debugging".
Another reason
Set DeploymentPostprocessing to NO in BuildSettings - details here
In short -
Activating this setting indicates that binaries should be stripped and
file mode, owner, and group information should be set to standard
values. [DEPLOYMENT_POSTPROCESSING]
See this post: Breakpoints not working in Xcode?. You might be pushing "Run" instead of "Debug" in which case your program is not running with the help of gdb, in which case you cannot expect breakpoints to work!
Issue
Background
Xcode: 13.0
code: Objective-C
Issue: added breakpoint, but not work
(possible) Reason and Solution
Reason: Xcode bug
Solution: Product ->Clean Build Folder, then retry debug (multiple time)
Reason: disabled Debug
Solution: enable it: Product->Scheme->Edit Scheme->Run->Info
Build Configuration set to Debug
choose/select/enable: Debug executable
Reason: disabled all breakpoint
Solution: enable it: Debug panel -> click breakpoint icon
Reason: debug info be optimized
Solution: not optimize
click Project -> Build Settings -> Apple Clang - Code Generation -> Optimization Level -> Debug make sure is None[-O0]
Related
XCode's Symbolic breakpoint not work
Background
XCode crash log
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSCFConstantString stringByAppendingString:]: nil argument'
add XCode symbolic breakpoint
-[__NSCFConstantString stringByAppendingString:]:
but breakpoint not working
Solution
change to:
-[NSString stringByAppendingString:]
related doc: stringByAppendingString:
Solution for me with XCode 9.4.1 (did not stop at any breakpoint):
Under build Target -> Build Settings -> Optimization Level:
Switched from "Optimize for speed" -> "No optimization" (now it's slower but works)
What solved it in my case was quite simple, in Xcode - Product - Clean Build Folder followed by Product - Run (not the Play Xcode button).
(Had the issue on Xcode 11 -beta 4 after switching to unit testing with Xcode play button long press)
This had me in Xcode 9 for half a frustrating day. It ended up been a simple debug setting.
Go Debug > Debug Workflow and make sure 'Always Show Disassembly' is turned off. Simple as that. :(
Came to this page with the same problem (C code in Xcode 6 not stopping at breakpoints) and none of the solutions above worked (the project was practically out of the box, settings-wise, so little chance for any of the debugger settings to be set to the wrong value)...
After wasting quite some time reducing the problem, I finally figured out the culprit (for my code):
Xcode (/LLVM) does not like Bison-style #line preprocessor commands.
Removing them fixed the problem (debugger stopped at my breakpoints).
For Xcode 4:
go Product -> Debug -> Activate Breakpoints
This is applicable for all Xcode version. Shortcut key is: command key + Y. Press this key combination to activate/deactivate breakpoints.
I have a lot of problems with breakpoints in Xcode (2.4.1). I use a project that just contains other projects (like a Solution in Visual Studio). I find sometimes that breakpoints don't work at all unless there is at least one breakpoint set in the starting project (i.e. the one containing the entry point for my code). If the only breakpoints are in "lower level" projects, they just get ignored.
It also seems as if Xcode only handles breakpoint operations correctly if you act on the breakpoint when you're in the project that contains the source line the breakpoint's on.
If I try deleting or disabling breakpoints via another project, the action sometimes doesn't take effect, even though the debugger indicates that it has. So I will find myself breaking on disabled breakpoints, or on a (now invisible) breakpoint that I removed earlier.
I've had my breakpoints not work and then done Build / Clean All Targets to get them working again.
I think the problem could be incompatibility between device versions and Xcode. I have this problem when attempting to debug on my iPhone 4S running iOS 5.0.1. I am still using Xcode 3.2.5. I got the symbols from the handset by selecting "use this device for development" in the Organiser window. This phone refuses to breakpoint however. My old 3GS will breakpoint, same Xcode project, same settings... just different device and it's running iOS 4.0. I guess this is an Xcode bug in 3.2.5, since I have the symbols. Having tried all the solutions posted here so far, I have decided the solution to my problem is to go ahead and upgrade to XCode 4. Perhaps you cannot debug effectively unless your base SDK is at least as high as the system on which to debug. Maybe that's obvious - can anyone confirm?
Edit: I will update when I can confirm this is true.
Deleting my Build folder solved the problem for me.
If all else fails, instead of a breakpoint, you can call the following function:
void BreakPoint(void) {
int i=1;
#if !__OPTIMIZE__
printf("Code is waiting; hit pause to see.\n");
while(i);
#endif
}
To resume, manually set i to zero, then hit the resume button.
It has happened the same thing to me in XCode 6.3.1.
I managed to fix it by:
Going to View->Navigators->Show Debug Navigators
Right click in the project root -> Move Breakpoints (If selected the User option)
(I also Selected the option share breakpoints, even though I'm not sure if that necessary).
After doing that change I set the Move breakpoints options back to the project, and unselecting the Share breakpoints option, and still works.
I don't exactly know why but this get my breakpoints back.
For this, and also for Xcode 6 and above make sure that the breakpoint state button is activated (the blue arrow-like button):
In Xcode 4
- Product menu > Manage Schemes
- Select the scheme thats having debugging problems (if only one choose that)
- Click Edit button at bottom
- Edit Scheme dialog appears
- in left panel click on Run APPNAME.app
- on Right hand panel make sure youre on INFO tab
- look for drop down DEBUGGER:
- someone had set this to None
- set to LLDB if this is your preferred debugger
- can also change BUILD CONFIGURATION drop down to Debug
- but I have other targets set to AdHoc which debug fine once Debugger is set
I found the problem. Somehow the "Show Disassembly when debugging" was enabled in my XCode which creates that problem. When I disabled it, all my debugger stopped in my source code.
You can find it under: Product->Debug Workflow->Show Disassembly when debugging.
You can Activate / Disactivate Breakpoints in dropdown menu
I tried all the above things but for me only deactivating the debugging breakpoints once and then activating them worked.
When setting your break point, right click and you should get several options about how the break point is handled (log vars and continue, pause execution, etc)
Also make sure the "Load Symbols lazily" is not selected in the debug preferences.
(Applies to Xcode 3.1, not sure about past/future versions)
Also make sure that the AppStore distribution of the app is not also installed on the device.
Another thing to check is that if you have an "Entitlements" plist file for your debug mode (possibly because you're doing stuff with the Keychain), make sure that plist file has the "get-task-allow" = YES row. Without it, debugging and logging will be broken.
There appears to be 3 states for the breakpoints in Xcode. If you click on them they'll go through the different settings. Dark blue is enabled, grayed out is disabled and I've seen a pale blue sometimes that required me to click on the breakpoint again to get it to go to the dark blue color.
Other than this make sure that you're launching it with the debug command not the run command. You can do that by either hitting option + command + return, or the Go (debug) option from the run menu.
I have Xcode 3.2.3 SDK 4.1 Breakpoints will fail at random. I have found if you clean the build and use the touch command under build they work again.

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