Xcode "Use of undeclared identifier" errors, compiles/runs just fine - iphone

I've got an incredibly annoying issue that is hampering my workflow. In my project I have "User of undeclared identifier" errors all over. They are all in reference to a single class, specifically a Theme class. I checked for any circular referencing with my imports, none. I'm really confused.
Here is a screenshot of the errors. I would post errors in the Build Log for more detail, but there aren't any. It builds and runs just fine...
I've tried cleaning, deleting the derived data... Any ideas?

I was having the same problem and noticed that all of the undeclared identifiers were declared in files that were in my pch file.
With this in mind I deleted one of the #import lines from the pch file and recompiled which failed as expected. I then put the deleted line back in, recompiled and it compiled normally with all the false errors gone.
Hopefully this simple solution helps a few of you out if the above solutions don't.

These kinds of errors are quite common with Xcode, unfortunately. It would be great if it would auto-refresh its error list all the time, but it doesn't always. When this happens, I strongly suggest that you restart Xcode, which will flush its error cache and hopefully solve your issues.

How are you including this class? In most cases I just include the class explicitly in header and/or body - instead of the *.pch file. Then this error goes away in my case.
Also deleting the derived data workes once in a while. Did you change the location in preferences recently by any chance. I also got this error when I use a ramdisk for derived data and then go back to default. This is the most annoying case - since it causes this error to appear then in almost every file.
This error seems to happen more often in Xcode 4.4 than the prior versions.

Have you included the library files correctly? Take a look at that. Sometimes ARC issues might occur if we don't include the correct file, or something's missing or not connecting UI.

For me the issue was that I created UnityInterface.h/m file to handle the obj-c to c# interface. UnityInterface.h is already defined by Unity. I renamed my own UnityInterface to _UnityInterface and now everything works.

Just posting this for anyone who might have this problem later and doesn't find any of these solutions to work:
If you have any pragma marked #if statements that only execute if the program is in debug mode it will obviously cause anything declared inside of them to not be declared when you try to archive/export.

I had the same problem. Closing and opening XCode didn't help.
I solved it by checking errors in other targets and fixing them (I had tons of errors in my unit testing target). Also I moved header links from h files to m files. But I'm pretty sure, that the first thing was critical.

For others who experienced the same problem and tried all solution above with no result, perhaps you should try something like I did. I solved the problem simply by unplugging my iPhone USB cable from my Mac and then replugged again those cable. After that, rebuilt again and all undeclared identifier errors were gone.

I had the same error. In my case, it was on this line of code:
- (void)playerItemDidReachEnd:(NSNotification *)notification {
// some code
}
My error message said:
Use of undeclared identifier 'playerItemDidReachEnd'
I tried added this line to the .h file:
- (void)playerItemDidReachEnd:(NSNotification *)notification;
I cleaned it, I re-booted my macbook, and I was still getting the error.
Finally, I decided to try to delete the line in the .h file. I then pasted it into a text file, and then copied and pasted it back in to the .h file.
Now I cleaned and VOILA' !!! no more errors. Go figure. This happens sometimes in VBA. Somehow there seems to be unseen formatting in a line of code. So I thought it might be happening with xCode. Cutting it out, pasting into a text file, cutting out of the text file, and pasting it back in right where it was - fixed it in my case.
---- UPDATE -----
The above was posted as my answer. Apologies, apparently there's something else wrong.
After cleaning - my ERRORS were gone. Now I tried to build and run my app. THE ERRORS CAME BACK! So this time I re-created the class files after cutting out all the text, and pasting it into a text file. I did it for both my .m and .h files. But now the errors are back again after trying to run. SORRY. I don't know how to delete this text altogether cuz it is not an answer.
Tried to build and run my app. THE ERRORS CAME BACK!
There was also an error msg that I was missing a bracket ( } ). Finally I looking at the method just before this method, and sure enought it was missing the ending bracket! That was it!

Might be little late in answering.
I had this issue very recently. I fix this by updating my OS and then updating Xcode. I tried updating Xcode alone but did not happen because Xcode 9.4 requires OS High Sierra 10.13.*
Happy Updating :)

It it compile time error
Use of undeclared identifier '<class_name>'
I was run into this issue when developing own framework and app. Objective-C consumer -> Objective-C static framework
Report Navigator had a clear description
umbrella header for module '<module_name>' does not include header '<class_name>.h'
The solution was just to add #import <class_name>.h into umbrella header in a framework target

Try to click Product -> Analyze, after that to Product -> Build. This helped for me.

Related

Xcode is marking all symbols as 'undeclared type' yet they are visible and the project compiles fine

Just to get some context here is a screenshot, though you probably gathered this from the title:
Xcode is marking all symbols as undeclared, usually this would be because it doesn't exist or isn't imported, but in this case it was working fine 20 minutes ago and weirdly the project compiles and runs with no problems.
When I compile the errors go away but there is no syntax highlighting, as soon as I start to edit the file the errors all come back. I can work if I remember the exact signatures for anything that I need to use but with the lack of code completion and errors this is very hard.
Notably this is only a problem in a few source files, its not even the whole project. Nothing has changed that I am aware of that could cause this.
Before anyone suggests it, I have tried cleaning, deleting derived data/build folder, restarting Xcode etc...
My colleague is seeing the exact same issue on his machine.
So I managed to fix the offending source files, I just compared their attributes to those of a working source file and it turns out that the problem files included the tests project in their target membership and the working file did not. I'm not sure why this is causing the issue as other projects use automated testing without a problem. Nonetheless this solved it for me, at least until I start writing test cases...

Missing Swift files

I don't really understand what's hapening but I'm not able to see all my Swift files on Xcode project navigator, but when I open my project directory I see them all, it looks like reference problems.
I'm receiving some invalid redeclaration problems.
Are you using the one of the xcode-beta builds? They seem to have some problems with file handling every now and then. Restarting fixes it for me most of the times.

Mysterious compile error with groovy eclipse plugin

So, I am developing with eclipse 4.2 and groovy 2.3 / jdk 1.6.0_35.
I just worked on one of my classes when suddenly eclipse showed me a dozen compile errors in different classes out of nowhere. It says e.g. it can't find a class in an import statement, although the class is there. Running the code works fine even though the errors are shown. If I add a comment to one of the classes and save it, some errors go away but may come back as soon as I change another (totally different) class.
It also shows me some errors like these:
error description:
As you see, the error is totally unrelated (Optional is totally independent of any other class, also of course independend of the mentioned classes in the error message). If I add a comment somewhere and save Optional, the error goes away but comes back as soon as I save any other class.
I cleaned the project, deleted the bin-directory and restarted eclipse/computer but it didnt' help. Does anyone already experienced this behaviour? How to fix it?
I got similar problem and error was in file above one with compilation error. So try to comment file before and check if this solve problem.

<<error type>> Strange Error

I have encountered a situation where xcode stops auto-completing and if you try to write a variable that already been defined xcode says << error type>>.
Here is my error:
I have started to see same errors after Xcode 6.1 and iOS 8.1 update. I have found that if you delete ModuleCache file at /Users/username/Library/Developer/Xcode/DerivedData/ModuleCache path, it fixes the error temporarily. And you don't have to close Xcode or the project while doing that. After deleting the file, just wait for Xcode a little to index the project files again. After that, the problem mostly resolves for some time.
As it doesn't solve the problem permanently, you should avoid writing codes causing this according to other answers till Apple solves this.
Often this indicates that your code doesn't currently compile. Swift often has trouble computing types on code that itself isn't correct. In some cases it's a bug in the compiler. Use of AnyObject can be particularly confusing to the compiler, and should be avoided as much as possible. In this case, AnyObject is required, but you should try to get it converted to a specific type quickly. Don't return [AnyType] for instance if you can possibly help it.
But the short answer is that the Swift compiler is still evolving, and it can't always work out types in complex situations, particularly on partial or (currently) incorrect code.
Note that you're using var for a lot of things that should be let. Unless you actually need to modify the variable, you should prefer let. It helps you prevent many kinds of bugs, and can be easier on the compiler to deal with (since the variable has fewer ways it can change).
<<error type>> can result from the Swift compiler not finding the header file.
Same module:
Do you have some sort of folder structure that your source code is in? If so, try setting Scan All Source Files for Includes to YES.
This will make Xcode look through all of those folders when trying to find the Header file.
Embedded Projects, multiple modules etc:
1. Check the Search Paths
Have a look where the file in which your type is defined is stored.
In your Build Settings make sure that this location is included in the Search Paths.
If it is part of the User Header Search Paths, make sure, that Always Search User Paths is turned on.
2. Check dependencies
Have a look at superclasses etc of your type. Are they included in the Search Path as well?
Found out that the error goes away and autocomplete works again if i initialised the variable like this:
var name: String = "my name"
instead of :
var name = "my name" as String
Firstly, try CMD-SHIFT-K followed CMD-R to clean and then run the build.
If that doesn't work, close XCode, delete derived data, and reopen XCode.
I faced the same issue recently. I tried running the whole project on an emulator, it resolved all the <<error type>>
I switched my build destination from Any iOS Device (arm64) to one of the available iOS Simulators, and that fixed the issue for me.
For me, simply restarting my computer resolved this issue.

Xcode 4 autocomplete buggy

do you face also the problems with Xcode 4 autocomplete feature that used to work great on version 3.x.x?
I've imported in the Prefix some classes and Xcode doesn't want to help me with the code entry. I have to manually add above #implementation
import "myclass.h"
To make Xcode help me entering the class name, properties, methods, macros defined in the myclass.h. On 3.x.x I could import those important classes once in the prefix and the autocomplete feature worked without any problems anywhere in the project.
Sometimes Xcode goes even more stupid, it doesn't want me to help typing the classes like UIButton, UIView and the common method like
addTarget:action:forControlEvents: for my buttons.
Do you also has the problems I mentioned in the Xcode 4, any solutions?
I was able to correct this issue by setting Precompile Prefix Header to No in the build settings.
EDIT 3: Note that this indexing issues has mostly disappeared in recent versions of Xcode (4.1 for sure, latest pre-Lion 4.0.x I think), and that I do not use this workaround anymore, using pch... And in fact not using Xcode anymore... AppCode ftw! :)
An easy, but quite dirty workaround imho is not using precompiled header .pch file to do global includes, but instead go a global header .h, that you include... everywhere. That way indexing will work flawlessly...
I Know that's dirty, don't downvote me please :) I'll delete this answer as soon as someone propose something better! Which I would love.
Off-topic, but related, read somewhere llvm2 is not supposed to get a gain speed with .pch files. which kind of deprecate them.
EDIT: Just checked to be sure of my answer, latest version of Xcode (4.0.1 when writing this) looks like fixing that bug for me. Did you upgrade to latest version?
EDIT 2: Removed my global import header .h, all its references, and moved my global imports into .pch file... That doesn't work as well I expected, latest Xcode 4.0.1 improved on this part but still have some cases where it fails. (I'm working on a project with hundreds of files). Looks like cleaning index/restarting Xcode fix it. I might consider reverting to my dirty workaround...
I have found that changing compilers, building, and then changing back, and building again works relatively consistently. Wrote a post about it on my blog:
http://rhappsody.wordpress.com/2011/08/03/xcode-4-code-colouring-and-auto-completion/
I found that sometimes the autocompletion gets broken when dealing with stuff defined in the prefix header. One way to get Xcode to index those again correctly is to use the touch command in the Terminal, e.g.:
touch /Users/someguy/Document/Foo-App/Foo-Prefix.pch
Or add a new line to the prefix for the same effect. Xcode then gets busy reindexing and things work again.
I've faced the same issued as soon as I moved to XCode4. What I realised was that I needed to install iOS's documentation to have the code completion fully working.
Go to Xcode -> Preferences -> Documentation and click GET on the iOS 4.3 Documentation. In the iTunes-style status window, the download progress will be shown.