I've workspace with two project: static lib and cocoa application. Static library link some system frameworks(libcrypto.dylib) and include dynamic lib's .h files(openssl/bn.h openssl/rsa.h). My static library compiles successfully.
Cocoa application uses this static library and at compile time gives an error: "undefined symbols, symbols not found" (bn, new rsa etc).
But when I include libcrypto.dylib also into cocoa application project then there is no error.
Question: Xcode can do this automatically, by taking dependency from the static link library?
Thanks.
The answer is unfortunately no. It is common practice to include each single static library in the project that requires the code. That is just the way it is done.
There is an interesting article on how to handle multiple static libraries in an XCode project.
Related
I have workspace contains subprojects and one of the subprojects generates static lib which contains both ObjC and swift which is linked to main application project. I am unable to access a swift class from a static library in ObjC file in application target.
How can I access a swift class from the static library in ObjC file in application target?
I figure it out.
The issue was module-swift.h of subproject static library is generated in derivedData intermediate DerviedSource folder which is not known to main application target.
The issue resolved :)
I think, it is not possible. Xcode doesn't support Swift static libraries. You can read about it here: https://forums.developer.apple.com/thread/73900
I have a problem with cmake target_link_libraries.
I have 3 libs. The first is static compiled, the second one (shared lib) link to it and the third one is an executable which use the second lib.
My problem is that my first lib is automatically added to the third lib and leads into a "object already defined" problem.
Is it possible to hide away the first lib from the third one?
I use cmake 3.4.x
Compiler: msvc 2010 x64
Thanks in advance
Tonka
Your third "lib" isn't a library, but an application. You need to add this using add_executable, not add_library.
If your shared library links in a static library, and then you want to link an application to both the static library and that shared library, you get two copies of the static library. Never link static libraries you plan to use elsewhere into a shared library, for this reason. Either make the first shared as well (the name implies that's what you want, as it is exactly what you are describing), or a workaround for this design problem could be to not explicitly link the application to the static library.
I've solved it. I can link to a library private, so f.e.
target_link_libraries(MyLib2 PRIVATE MyLib1)
will hide MyLib1 from everybody linking to MyLib2
I'm very new at Objective-C programming, I have a MacOSX project, with a simple UI code. It has a login function.
I have a .a extension c++11 static library, with two public headers. One includes . I d like to import the library with the headers to my project. It makes the login to my server.
I made a c++ static library target to the code, and imported the needed files, set the c++ flags (stdlib=libstdc++ and -std=c++11) and added gcc49 to search paths. But I get file not found exception to #include in my c++ header.
Have somebody a good tutorial how to solve my problem?
I've build a Framework for an Objective-C App. I've tested it on minimalistic Programs where it worked. I was trying to use it in a real App now. Unfortunately the linker can't find the definition of my classes. =(
When I try to run it, I get the following Error Message:
Undefined symbols for architecture x86_64:
"_OBJC_CLASS_$_ClassInMyFramework", referenced from:
objc-class-ref in libMyLib.a(MyLib.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
The Dependency:
App -> libMyLib.a -> MyFramework.framework
The usual suggestion for this error message is to add the framework into the "Link Binary with Library" Build Phase... I can assure you that this has happened ;)
My first thought is that something might be wrong with the Build Settings which results in this linking error.
On second thought It may have to do with the Project-Setup. Is it possible to statically link a framework into an '.a' library file?
Update:
I've linked the Framework into the App and now it's working. But I don't consider this a clean solution. Help still appriciated. =)
The short answer is no, you can't link the framework statically into your .a file. See this discussion.
The reason is, the static library doesn't include the object code (the definition) of classes from the dynamic framework. The static library links to object code in the framework the same way the app links to the framework code: at run-time.
From Apple's Framework Programming Guide: "Dynamic shared libraries have characteristics that set them apart from static linked shared libraries. For static linked shared libraries, the symbols in the library are checked at link time to make sure they exist. If they don’t exist, link errors occur. With dynamic shared libraries, the binding of undefined symbols is delayed until the execution of the program."
It depends on what you want to be able to do with your code. You could add a static "target" for your framework project, so your framework project outputs both a framework and a static library. You could include this static library into apps.
But, one benefit of frameworks is that you can include nibs, images, headers, etc. So, linking your framework into your apps directly is not a bad way to go. Otherwise, you need to include these assets directly into your project. If you want this framework to be distributed with your app, you'll need to package it inside the app wrapper.
It looks like some people create a "static framework" for inclusion into an iOS project, but this looks a bit hacky to me.
As an interesting exercise, you can explore the symbols in your object code. Let's say you are using a ClassInMyFramework (from your framework) somewhere in your static library, like:
ClassInMyFramework *myFramework = [[ClassInMyFramework alloc] init];
The static library will then include the _OBJC_CLASS_$_ClassInMyFramework symbol. You can see the list of symbols in your static library file at the command line:
$ nm /path/to/libMyLib.a
This will output a list of symbols, which will show that _OBJC_CLASS_$_ClassInMyFramework is undefined (note, the "U" designates that the class is undefined):
U _OBJC_CLASS_$_ClassInMyFramework
Whereas, if you were do to the nm command on your framework:
$ nm /path/to/MyFramework.framework/Versions/A/MyFramework
Your output would show that the symbol is defined in your framework (though the definition will still only linked at run-time), which would look something like this, showing an address of the definition:
0000000000001100 S _OBJC_CLASS_$_ClassInMyFramework
We can use iOS Static Libraries without adding header files into the project.
But i want to use the Static Libraries without adding .a files into the project
Finally, I found the solution
Path of the static library should be added in ->target->build settings-> Other Linker Flags
eg.)
/Source/iPhoneApp/libs/Connection/build/Debug-iphonesimulator/libConnection.a /Source/iPhoneApp/libs/SocialNetwork/build/Debug-iphonesimulator/libSocialNetwork.a
If you built the library, you can use dependencies to add the library project to your app project without the hassle of configuring stuff.
To do so, just drag the .xcodeproj file from your library to the app project, go to the app target properties, and add a dependency on that library, just as you'd add a public framework such as MapKit.