I have a project that is already transitioned to ARC. Now I'm trying to include an existing file from the other project, which is not using ARC and I want it to be ARC-compliant too: release-retains, [super dealloc]s gone from this file, quick fixes, other stuff "Convert to Objective-C ARC..." does.
The problem is I can't use the Edit->Refactor->"Convert to Objective-C ARC..." tool for this. If I select only this file in "Select Targets to Convert" screen I'm getting "Cannot Convert to Objective-C ARC" message because of errors like: "#synthesize of 'weak' property is only allowed in ARC or GC mode". But they are already in ARC mode indeed! Also numerous warnings: "Method possibly missing a [super dealloc] call"
If I select all files except marked with -fno-objc-arc while converting, I get only errors about weak properties.
Of course I can build and delete the release-retains manually but why to walk if there is a bus (Conversion tool)... So can I auto-transition a separate file to ARC?
Update: I do not want ARC to be turned off for this file with -fno-objc-arc flag, I want ARC used in this file.
If you insist on making Xcode do the work, create a new Xcode project and deselect "Use ARC" when creating it. Add the files to convert, and convert the project to ARC. Take the modified files and import them into your other project.
It's probably simpler, however, to convert the file manually. This is not difficult, even for a large file or an entire project. Just lean on the compiler: build your app, walk through the errors and simply delete all retain/release calls and convert any NSAutoreleasePools to #autoreleasepool {}. You may also need to add __bridge casts if interacting with core foundation types.
It sounds like you'll have to convert this file to ARC manually, instead of relying on the automatic conversion tool. You'll need to go through the file and remove all of the release, retain etc. I've done this before, and while it takes a while, it's not too painful. Rely on the error messages from Xcode to guide you what needs to be fixed/removed in the code.
Here's a couple of links I found that may help. Also look at Apple's ARC docs and WWDC 2011 talks (referenced at the bottom of the second link).
Xcode ARC conversion tool issue
http://blog.mugunthkumar.com/articles/migrating-your-code-to-objective-c-arc/
Related
I am maintaining a static iOS library i inherited from a former coworker using Xcode and Objective-C. The code contains a lot of
#if __has_feature(objc_arc)
and i was wondering if i can just assume that arc is always available? The library gets distributed to customers so another question would be: Do they maybe have to change something to use my library after i "forced" it to use arc? I already tried to find something about it and so far it seems to me that you can use arc frameworks in non-arc projects. But i'm not completely sure if i got that right and also i don't want any customer to do extra work because of that.
If you're distributing it in compiled form, then yes, it either has ARC on or it doesn't, and that's completely under your control. The user of the binary can't change it afterwards; ARC "happens" at compile-time.
If you're distributing it as source, you could document the requirement for ARC, and issue a compilation error if it's lacking by putting a similar guard in just one place:
#if !__has_feature(objc_arc)
#error "MyLibrary requires compilation with ARC"
#endif
and remove all the others scattered around.
Finally, code that's compiled with ARC can be freely linked with non-ARC code. The only problem arises if the MRR code does not do proper memory management, but I would classify that as an exposition of an existing bug in that code rather than a problem caused by using ARC.
In XCode (version 5.1.1 in my case), when you click Edit/Refactor/Convert to Objective-C ARC, what exactly is supposed to happen?
My goal here was to convert my old code to use ARC.
I basically set Objective-C Automatic Reference Counting to Yes, then I did the above to "refactor" my code. It failed and I ended up spending 5 hours commenting out anything with autorelease, retain, release etc... from my code.
When I finally got all that done, I was able to proceed with the Convert to Objective-C ARC operation, which ended up telling me that no changes to my code were necessary, which was true because I had done it all manually.
Is it supposed to do what I did manually, but automatically? Why didn't it?
By turning "Automatic Reference Counting" on manually you told the compiler that the project was already using ARC. Therefore, conversion did nothing - you told the compiler it was already converted.
Obviously all the non-ARC features you used were now errors and you had to fix them.
The normal method is that you do not change to Automatic Reference counting. The compiler will then check out your code, make sure that it can convert everything (it won't convert your code if the static analyser finds reference counting bugs, or when things are too complicated), you fix all the things that it refuses to convert, and once everything is Ok you convert everything.
And the answer to your question is "NO".
i have this problem for a while now. I have iPhone project which was built with non ARC. And now somehow i need to add another smaller project to it, but that project was built with ARC. I have tried to copy files one by one, but ass soon as i was done, i got lots of ARC errors and some with Security.framework... Can someone help me? Or give me some ideas how should i proceed?
I have tried this but it didnt solvet issius with ARC...
ARC is done at compile time. ARC-enabled source code files need to be compiled with ARC, non-ARC source files need to be compiled without. It is a s simple as that. ARC is nothing but syntactic sugar injected by the compiler.
I have had this problem with some third parties not entirely migrated to ARC. Just create a static library around these files.
You could also try to change the per-file compiler options (see this question: How to disable ARC for a single file in Xcode 5?), but I would recommend against it since it will just become a maintenance burden in the end.
And of course, if it is your source code and not some third party: Migrate it to ARC. It is worth it.
Basically, I have an IOS app that functioned without issue.
While following the instructions at http://docs.urbanairship.com/build/ios.html#ios-push-getting-started, I reached the "Register Your Device" section asking me to compile.
After attempting to build the code in xCode 5 I received the following error "#implementation UAPushSettingsAddTagViewController #synthesize of 'weak' property is only allowed in ARC or GC mode".
Note:ARC mode is not in use.
Search for "weak" in your project code and the libraries you include. Change it to a "assign"
Edit:
As #TaylorHalliday points out in his comment below, my answer was rather incomplete.
Changing weak properties to assign will get rid of compiler errors, but it will potentially cause memory management problems if you don't understand how to use manual reference counting.
Since you're using manual reference counting you will need to go through your code and make sure that you retain objects that you need to persist, and then release all owning references to objects when you are done with them. Explaining the details is beyond the scope of a forum post. I suggest you search on "About Memory Management" in the Xcode help system, and read the entire Advanced Memory Management Guide.
You should probably also run the Analyze tool on your project to look for possible memory management problems.
Better yet, convert your project to use ARC. It's much easier to avoid memory management problems when using ARC.
I got same error when I added these two files to my project. My project wasn't enabled for ARC. I had to remove these files first and then had to convert my project to ARC. Then adding these files caused no error.
I have a project previously built in iOS 4.3. When I tried to invoke the “ARC” conversion tool with
Edit > Refactor > Convert to Objective-C ARC
from XCode 4.5.2, the tool reports many errors. Some are supposed to be modified automatically by itself, for example the keywords autorelease/release/retain should not be used.
The errors seem too many (1,987 occurrences) to resolve by hand. Are there any configuration options that i am missing or should something else be done?
If you are using existing libraries you can simply not use ARC for those libraries and begin using it throughout your app by using a flag.
Add this to your library or files in question to ignore ARC
-fno-objc-arc
i think you have used any third party libraries, if you have used any third party libraries then it won't helps you.that means in this situation it wont automatically converts it to ARC.
Unfortunately ARC manages memory only for objective-c objects, if you have used any C or C++ files then in this case you have to handle memory management yourself