I have code for a VST plugin and need to port some of it to an iOS app.
I have tried building the OSX version and using the lib.a and it doesnt work. When I open the iOS version of it, Xcode shows that it is missing the tagret.
If I copy the code directly into Xcode with all the JUCE modules, and I set the header search paths, I get compilation errors on things like no such type for String
After this latest JUCE update, Xcode would give the same errors until I updated the JUCE file itself, so I think the JUCE build settings or configuration of the new version is doing something differently. How can I get this code into a different Xcode project, so that I can use it?
Can I compile it as a library and use the objects through the header?
JUCE is designed to be included in projects generated by the Introjucer / Projucer (the JUCE project management tool). Without this, the correct preprocessor definitions will not be set up.
If you really needed to include JUCE source code inside your program, you could manually set up these preprocessor definitions (take a look at the AppConfig.h header from a generated project to get an idea of how much work this will be), but you'd really be going against the normal "JUCE way".
Simply including the headers and linking against the library will not work without considerable effort, as the include structure is ... odd ... and there isn't any library to link against directly anyway (the generated projects contain all the JUCE source normally, so there's no need).
Adding the JUCE source files (i.e. .cpp and .mm) to be compiled in a project directly will result in compilation errors, as they need to be compiled in a very specific order which is mandated by the header file (the header files #include certain implementation files after setting up their dependencies).
In short, if you can at all I would advise generating the project with the Projucer and adding other source files in as you need them, rather than the other way around.
Related
First of all, my project builds fine initially.
Then I integrate VideoStream SDK for iOS into a standalone app, and it works.
Then I integrate VideoStream SDK into my actual project, and set up search paths for header files for the library, but then my project gets these issues:
I'd have a look if one of your source header files has the same name as a standard C++ or C header file. Quite possibly this prevents inclusion of the standard header file that defines struct tm. Look if there is a file "time.h" or "locale.h" or something like that has become part of your project.
I have not seen this solution posted ANYWHERE after so much time googling since the time I posted, but I disabled Always Search User Paths under Search Paths of Build Settings, and the project built.
I'm new to iOS dev (Java native) and I was kinda confused on how an app is compiled. I'm assuming it goes from the main.m file in the Supporting Files folder, which hands off command to the AppDelegate. Then depending on the state of the app (like didFinishLaunchingWithOptions, or applicationWillResignActive) it runs the commands in that method.
So if like my didFinishLaunchingWithOptions sets the window.rootViewController to another file - WXController, for example, it then passes control to WXController and runs all the methods in there in a sort of 'while-loop-esque' way?
Is my understanding even close to how compiling and building actually is?
You did assume wrong. But this is neither the case for Java!
If you are interested what happens when you build your project, you can click in Xcode on your project file (usually the top most in the file menu, unless you are using workspaces). These are the project settings. One of it's tabs is calles 'Build Phases'. Here you can see listed what the compiler will do and in which order!
But to give you a quick introduction on how things work in C and C similar programming languages: There are the source files and the header files. Usually all source files ( the ones that contain your actual code in case of objective-C these are the .m-files) are compiled in random order (ofc. there is an order, but it is not important since the source files should never reference each other! ). The header files (.h-files) are used to tell the compiler about all the variables and methods that are supposed to be contained in other source files. This information will be kept as references while compiling the sources and then later used for linking everything together. After everything is compiled (result are the object files *.o),the references generated from the header files linker flags are used to link all your objects together.
I'm having trouble linking to a static library in Xcode 5. I did read the chapter on building and using a static library in the Pro iOS 5 Tools. What it told me to do after creating your static library, was to link against the framework in the Build Phases tab. That part is pretty straight forward. Then it says in the Build Settings, under "Header Search Paths", to add:
$(BUILT_PRODUCTS_DIR)
Then in order to use my static library, I just import it like so:
#import "ConversionCalculator/ConversionCalculator.h"
So this used to work up until yesterday. I tried adding a new static library to my project which didn't seem to work. So I cleaned my project, and tried rebuilding again, but now Xcode complains about #import "ConversionCalculator/ConversionCalculator.h". It says
Lexical or Preprocessor issue. 'ConversionCalculator/ConversionCalculator.h' file could not be found.
I was wondering if anyone has any tips on debugging this. I've looked through different tutorials like this:
http://blog.stevex.net/2012/04/static-libraries-in-xcode/
http://cocoamanifest.net/articles/2011/06/library-management-with-xcode-workspaces.html
http://www.raywenderlich.com/41377/creating-a-status-library-in-ios-tutorial
But I can't seem to find the "golden way" to link to a static lib, or how to troubleshoot why Xcode cannot find my file. My file structure is setup on my machine like so:
Projects\
DistanceCalculator\DistanceCalculator.xcodeproj
ConversionCalculator\ConversionCalculator.xcodeproj
DistanceCalculator.workspace
Like I said, this all used to work too when I followed the tutorial in Pro iOS 5 Tools book. Now I don't know why my workspace cannot find ConversionCalculator when it has used it before. The part I find hard is different articles say different things about the header search path, and I'm not sure what the best way to populate that field is. Any thoughts? Thanks in advance!
Edit:
I'll add that I can build for the device without errors. But when I switch to the iPhone simulator, it gives me that error about not being able to find the file. I also see that I get this warning:
ConversionCalculator was rejected as an implicit dependency for 'libConversionCalculator.a' because its architectures 'i386' didn't contain all required architectures 'i386 x86_64'
Looking at that, I'm not sure what that means. If it means that my library is not being built for all architectures, I just tried creating a Target that builds for all architectures according to the wenderlich article in the above link. That seems to work as when I go to the dervieddata folder, I see for debug, release, and universal, I see the libConversionCalculator.a file. But then when I go back into the workspace and try to rebuild the project for the simulator, I get that could not find file error and the implicit warning.
Edit #2:
I just saw a warning flag on Xcode that says upgrade to recommended Build Settings. Now I get no errors. Not sure what happened... but I guess no errors is good.
I would follow the description available in Xcode's Help topic "Linking Against Your Library" in chapter Configuration Your Application in Introduction to Using Static Libraries in iOS
(you may search within Xcode Help, too).
Except that I would recommend to include your headers from libraries always using angle brackets:
#import <ConversionCalculator/ConversionCalculator.h>
Using double quotes may inadvertently search and find files with the same name in some sub-folder relative to the file where this import directive is written. Only after there was no file in any sub-folder the preprocessor starts searching with the specified header search paths.
Using angle brackets, the preprocessor immediately searches only at the specified header search paths.
So, since you actually want to find headers for the corresponding library, always use angle brackets.
Note: If you follow the recommendation to create a static library project, you don't need to explicitly set a header search path in the target that links agains the library: Xcode will already add a search path:
$(BUILT_PRODUCTS_DIR)/includes
Your library headers are located in
$(BUILT_PRODUCTS_DIR)/includes/<product-name>
which are placed there through the "Copy-Files" phase of the iOS static library target, whose "Destination" is set to "Products Directory" and whose "Subpath" is set to "includes/${PRODUCT_NAME}" per default.
You may change these default settings to other reasonable and sensible values. (if you do, consider the the consequences for Xcode's default search paths!)
I am currently building a library which should be used internally in a few iOS projects but should also be distributed to customers accessing our services with the library. The Library itself consists purely of C++ code and I am basically able to create Apps with it on iOS which work fine. My problem is creating a single, easily distributable file that can be given out to customers which can easily install them, use the provided headers and don't need to have the headaches that I am currently facing when it comes to linking.
Our code depends on two other projects, namely boost and websocketpp. For boost there is the script on github which I took to generate a framework. For websocketpp, I imported it into XCode and used the scripts from this github project to build a framework. I added both frameworks to my (potential) framework as dependencies and used the same script to build one.
I have an app using my library as a sub-project working fine. Even including the framework into the project and running it on a device works fine. So far so good.
However, trying to create an archive of the App project lead to several questions and headaches.
My library did not seem to contain the code for all architectures. So I tried to archive the Framework projects, which after small modifications in the build scripts to use different locations to search for headers worked fine.
It does not seem to contain all binary code or references to local files (i.e. my specific location of boost). I gathered that from Linker errors that I still get that tell me that some boost calls could not be satisfied.
The second issue made me think that I am must be doing something fundamentally wrong and my intuition tells me that it can't be that difficult and "hackish" to create frameworks or libraries for others for iOS development.
As you probably have found out by now, I am not very experienced when it comes to iOS and I am wondering if I am missing something fundamentally. So, I am sure that this question is rather broad, so some more concrete questsions:
Is there a(nother) way to generate some kind of distributable (preferably a framework) which contains: my public headers, my binary code compiled for all platforms supported for iOS development, the binary code of dependencies?
Is the only way to do that by adding some handwritten scripts to the build process?
I have the feeling that the information I found is quite outdated since it's older than a year and mostly refers to Xcode 4.2 or 4.3 -- so has there anything changed in this regard recently?
For example one error I get is:
File is universal (2 slices) but does not contain a(n) armv7s slice: <file>
The <file> slice is the path to the file in the framework in the Products folder of a different XCode workspace (the library was build in a different workspace then the app). I dropped the framework folder into the project for this test from a completely different location.
What is going on here?
Why does it keep referencing to some internal XCode directory?
How do I properly export it?
Since I guess my setup is probably skrewed up and weird from all the different things I tried up to now: How does this setup look like in a ideal situation?
Yes, there are some questions regarding this on SO already, however, either I don't see or don't understand in those replies:
...how to handle depencies of my code to other third-party code properly.
...how to generate a distributable file.
Have you checked your project build phase under Compile Sources and Copy Files to see if you are including your framework source files in your build?
You may also try the C/C++ Library template under OSX -> Framework & Library.
Finally, there's also kstenerud’s iOS Universal Framework, which I found very useful. I wrote a few articles in my blog on using it.
I am testing an image capture library that sent over their code library as a regular header file and a file ending in a "*.a" extension. I am not familiar with using a file in this format and can't seem to find the right "magic" to search for.
What does this file extension stand for?
What if any extra steps are needed to get it integrated with my XCode project?
Maybe a bit more of theory can get you in the right track so you'll know how to search next time:
.a files are archives of object (.o) files. These object files are generally produced by an assembler, compiler, or other language translator; They contain machine code that is usually not directly executable, but are used by linker tools to generate an executable or yet another library by combining parts of these object files.
Another important thing you should know is that since these files contain machine code, they must have been compiled for the correct architecture you're targeting for (ex.: armv7, i386, etc). That can be the reason why sometimes you will be able build your project for one device but not to another if you don't have the right set of files for the targeted platform (e.g. iPhone simulator vs. actual iPhone).
It is also possible to have "universal binaries", which are files that in turn package together archives of object files (.a) for different architectures (e.g. using tools such as lipo), so that the same library file can be given to the linker for multiple architectures. Or, you may have a different linker configuration for each target (e.g. using conditional build settings in XCode). All of these files can be analyzed with certain tools (e.g. "file", "otool", "lipo -info", etc), and each has several parameters to play with. Debuggers will also check the symbols within these files for their own purposes.
When you drag the '.a' file to your project's directory within Xcode, you can notice that it will automatically add this file to the list of "Link Binary With Libraries" items under your target's "Build Phases".
Since the header files allows us to separate certain elements of a program's source code into reusable files, that commonly contain forward declarations of classes, subroutines, variables, and other identifiers that are needed for reference during the compilation step, it is common to have libraries provided as archives of compiled objects (.o) in ".a" files along with their respective headers. For instance, as soon as you include the headers files in your XCode project, the editor will provide auto-complete for these new functions.
Sometimes, you might also consider having the actual source code of the library instead of binaries inside your project as this * might * make debugging easier in case an unexpected behavior is happening inside that "library" package. Many times this is not an option though (when you have no access to the sources) when the binary distribution is made in purpose to hide implementation details (commercial libraries).
.a stands for archive. It is also known as a static library. I believe you should be able just to drag it and the header files into Xcode. Xcode should pick up the right thing to do from its extension.
Example, see appr. from 30 sec here
http://memention.com/ac3dreader/usage/quickstart.html
Another example from Google Analytics, under Setup
Drag GANTracker.h and libGoogleAnalytics.a from the SDK's Library directory into your new project.
https://developers.google.com/analytics/devguides/collection/ios/devguide