I am trying to clean up some of my projects, and one of the things that are puzzling me is how to deal with header files in static libraries that I have added as "project dependencies" (by adding the project file itself). The basic structure is like this:
MyProject.xcodeproj
Contrib
thirdPartyLibrary.xcodeproj
Classes
MyClass1.h
MyClass1.m
...
Now, the dependencies are all set up and built correctly, but how can I specify the public headers for "thirdPartyLibrary.xcodeproj" so that they are on the search path when building MyProject.xcodeproj. Right now, I have hard-coded the include directory in the thirdPartyLibrary.xcodeproj, but obviously this is clumsy and non-portable. I assume that, since the headers are public and already built to some temporary location in ~/Library (where the .a file goes as well), there is a neat way to reference this directory. Only.. how? An hour of Googling turned up blank, so any help is greatly appreciated!
If I understand correctly, I believe you want to add a path containing $(BUILT_PRODUCTS_DIR) to the HEADER_SEARCH_PATHS in your projects build settings.
As an example, I took an existing iOS project which contains a static library, which is included just in the way you describe, and set the libraries header files to public. I also noted that the PUBLIC_HEADERS_FOLDER_PATH for this project was set to "/usr/local/include" and these files are copied to $(BUILT_PRODUCTS_DIR)/usr/local/include when the parent project builds the dependent project. So, the solution was to add $(BUILT_PRODUCTS_DIR)/usr/local/include to HEADER_SEARCH_PATHS in my project's build settings.
HEADER_SEARCH_PATHS = $(BUILT_PRODUCTS_DIR)/usr/local/include
Your situation may be slightly different but the exact path your looking for can probably be found in Xcode's build settings. Also you may find it helpful to add a Run Script build phase to your target and note the values of various settings at build time with something like:
echo "BUILT_PRODUCTS_DIR " $BUILT_PRODUCTS_DIR
echo "HEADER_SEARCH_PATHS " $HEADER_SEARCH_PATHS
echo "PUBLIC_HEADERS_FOLDER_PATH " $PUBLIC_HEADERS_FOLDER_PATH
.
.
.
etc.
I think that your solution is sufficient and a generally accepted one. One alternative would be to have all header files located under an umbrella directory that can describe the interface to using the depended-on libraries and put that in your include path. I see this as being similar to /usr/include. Another alternative that I have never personally tried, but I think would work would be to create references to all the headers of thirdPartyLibrary from MyProject so that they appear to be members of the MyProject. You would do this by dragging them from some location into MyProject, and then deselecting the checkbox that says to copy them into the project's top level directory. From one perspective this seems feasible to me because it is as if you are explicitly declaring that your project depends on those specific classes, but it is not directly responsible for compiling them.
One of the things to be wary of when addressing this issue is depending on implementation-specific details of Xcode for locating libraries automatically. Doing so may seem innocuous in the meantime but the workflows that it uses to build projects are subject to change with updates and could potentially break your project in subtle and confusing ways. If they are not well-defined in some documentation, I would take any effect as being coincidental and not worth leveraging in your project when you can enforce the desired behavior by some other means. In the end, you may have to define a convention that you follow or find one that you adopt from someone else. By doing so, you can rest assured that if your solution is documented and reproducible, any developer (including yourself in the future) can pick it up and proceed without tripping over it, and that it will stand the testament of time.
The way we do it is to go into build target settings for the main project and add:
User Header Search Path = "Contrib"
and check that it searches recursively. We don't see performance problems with searching recursively even with many (10-15 in some projects) dependencies.
Related
I have this project that I have done for experimentation with Qt and shared libraries. This is basically a couple of Qt Widgets from the tutorials for Qt and what I think is the right CMakeLists configuration so a MylibConfig.cmake is automatically generated from a MylibConfig.cmake.in to share the library. The problem is that I don't want the end user to add the dependencies of my library to its own CMakeLists.txt. This is, in my case, the library depends on Qt4, but I want that the end user to not have to do find_package(Qt 4 REQUIRED). Imagine that I want to provide an enclosed functionality to someone that does not need or want to know about what my library is built on. Is there a way in the automatic generation of the MylibConfig.cmake that it automatically finds all necessary packages or is the only option to add the fin package manually in the MylibConfig.cmake.in?
Thank you very much.
In fact, both mentioned projects do find of dependencies from their *Config.cmake files. And nowadays that is the only option -- CMake can't help you to do it "automatically".
So, some way or another, your config module should do the same.
The easy way is to add find_dependency() calls (cuz you know exactly what other packages, your project is based on).
A little bit harder is to do it "automatically" (writing your own helper function) -- for example by inspecting properties of your target(s), "searching" where all that libraries come from and finally generating find_dependency() calls anyway.
I would like to add into project some files that shouldn't be compiled. I mean mainly text files with for example notes, concepts, comments etc.
I realized that it is possible only at module level. But it is not very convenient. I'd rather prefer to keep them on project level. Is it possible in any way?
And if not:
I have another idea: to create special module, name it for example "other_stuff", do not create src directory and put files there. Is it ok? I'm afraid of potential compilation problems when one of modules is artificial, with no sources but still has sdk assigned (it is probably impossible to leave module without sdk assigned).
While generating artifacts you can add any file into your artifact. Also, in modules you can have folders not declared as source, and they will not be compiled.
I'm learning/vetting CMake at the moment as I'm thinking of migrating our code to it. One thing we do a lot of with our current make system is to "subproject" common code files. For example, we have a lot of shared, generic headers (plus some c/cpp files) which get included in every project we create. I want to replicate this in CMake but I don't see an easy way of doing it. To be precise, I want to do something like:
Parent CMakeLists.txt
add_subdirectory(shared_folder shared_build_folder)
#Next line should somehow add in the files reference in the shared_folder
add_executable([specific files for this project] build_folder)
Child CMakeLists.txt (shared_folder)
#Somehow have a list of files here that get added to the parent project
So far I've found various "ways" of doing this, but all seem a little hacky. I'm coming to the conclusion that this is in fact the way I have to do things and CMake isn't really geared towards this style of development. For clarity, most of my solutions involve doing something like creating a variable at the parent level which consists of a list of files. This variable (via some shenanigans) can get "passed" to/from any children, filled in and then when I call add_exectuable I use that variable to add the files.
All my solutions involve quite a few macros/functions and seemingly quite a bit of overhead. Is this something other people have tried? Any clues on the best approach for doing this?
Thanks
Andrew
We were facing the exact same problem and after some time of crying we accepted the CMake-way and it resulted in a better structured project even if it meant to change some parts of our structure.
When using sub-directories the targets are automatically exported throughout the whole project (even in subsequent other add_subdirectory-calls) once the add_subdirectory-statement was processed: sub-projects which contain common code are creating libraries.
There is also the PARENT_SCOPE which you can use to export variables to parent CMakeLists.txt
For "other" things we simulated the FindPackage-mechanism by including .cmake-files into the main CMakeLists.txt with include. In doing so we can provide variables easily, change the include_directories and do other fancy things global to the project.
As there are no dependencies between cmake-variables, we don't use cmake to configure the source (features of the project), but only the build (compiler, includes, libraries...). This split was the key element of our build-system-refactoring.
There is code that I want to include in most of my projects. Things like AFNetworking, categories for CoreData and unit testing, etc.
It seems logical to include all of these in a static library, and then use it in each project. I've noticed though, that many third-party libraries (like AFNetworking, and it's predecessor ASIHTTP) are included in projects by copying over all of their source files and then manually linking the necessary libraries to the project target.
This seems to me like the easiest way. It took a fair amount of time to figure out how to include an existing static library into a project. Even after I knew how, it still seems like a pain to do it for every new project. Also, the header search paths that you specify are to a local directory with the static library's files. Wouldn't it be easier, and is there a way, to copy the static library's files into the project? This is the same idea as including the class files directly like most libraries seem to do already, but it would be more organized because everything would be lumped into one library project, instead of having class files everywhere and having to include every one of them.
Static libraries feel like they should be the right way to go. Make a library that can be used with all projects that includes classes that every project will need. Makes sense. I am just conflicted because it seems like the right way to go is to leave everything out of a 'formal' library, and just copy over all of the class files instead.
I guess I am just looking for what experienced developers find to be the best option.
I would be among the first to admit that the process of referencing a static library in Xcode is not entirely intuitive. However, using a static library is the best option, without a doubt.
The main reason is maintainability: when you copy source code of a library to many places, you must remember to update all of them to the latest code when you upgrade to the next version of the library. This may be a rather error-prone process, especially when the underlying library source changes significantly (e.g. new files are added, old files are renamed, etc.)
There's a halfway solution - make an XCode project that builds your static library from source and put that into a shared repository (ie.. git submodule etc) which is included from each project's main repository.
Each of your projects would include this submodule and project. Then they get the latest source code each time they pull that submodule. If you set this up as a build dependency it will build a static library the first time you build and then XCode is smart enough just to include it each subsequent build so you get the benefit of fast build times.
You also get the advantage of having the source right there for stepping though / debugging.
If it's in a separate XCode project and a new version of a library adds or removes a source file you would only need to change that shared project - all your individual projects wouldn't change at all.
What about using CocoaPods? This tool does exactly what you want in a declarative way: you have a file (Podfile) where you declare your dependencies, and the tool downloads all the dependencies and builds a static library that gets added to your project.
I would agree that static libraries feel like they might be the correct way to go for a number of reasons, but can also introduce some issues.
The positives would be creating an easy way to add a library to a project. Although not completely intuitive, it is rather trivial to add a static library to a project after one does it a few times. Add the files, add the search path, done. This could also be useful in certain source control situations. Also, updating a library may be easier.
I think the real problem here is for the open source community. By including, say AFNetworking, for example, as a static library, you lose all access to the implementation files. This is a great feature of including source rather than a library. It lets you change code to how you see fit, and hopefully give back.
An iPad project I have been working on has become bloated with a huge number of files. The application is a prototype and we are considering ways to prevent this when we rewrite it.
One of the members of our team suggests dividing all of the components into separate Xcode projects which will be included in a master Xcode project.
Is this a good idea? What are the reasons, if any, to avoid dividing features/components/controls into separate Xcode projects?
You can add a subsidiary project file to a master project file in Xcode. Just choose "Add File" and add it. When Xcode builds the master it will build the subsidiary as well if needed.
I use a similar system. I often break a project into sub projects just so I can focus on and enforce encapsulation. I write the data model first, then add the app delegate, then specific UI elements. I add each project to the next in turn. This also allows me to go back and change things without as much risk of breaking.
Really, a properly designed objective-c app should be easy to decompose into multiple project. Ideally, all the components are so encapsulate that they don't need any others save the data model.
We have put some of the code in its own project, building a framework which we link against at some of the other projects. It's sometimes annoying that you won't see the implementation files of the framework code right away in another project (by cmd+clicking or cmd+shift+D, or whatever you do normally to navigate). Xcode will only show you the header, you'll have to open the other project and find your file there manually. Not a big deal, but if you look up the code often, it will bother you.
A real problem is that you change the scope of some operations. Stuff like "Find in project" will work on a different file set, which might not be what you want sometimes (trying to find where this method is called / key is used in your whole code, or something); well, there remains Finder / find, so it might be okay. Refactoring is not - all the renaming stuff just breaks, as it will change only the code of the current project, but not of projects referencing this one. If you change interfaces often, better avoid splitting up the project.
A good thing is that you will get less conflicts on your .xcodeproj files (if stored in a shared repository) as someone removing a file from project X won't create a conflict with someone else adding a target on project Y, which where previously the same .xcodeproj (not exactly sure this is a conflict case, but there definitely are some).
Now with Xcode4 you can create a workspace and add all your projects there. Only for documentation purpose :)
To view and modify subproject implementation files, you should add the sub projects directly into the main project.
1 step - Drag and drop the .xcode project files to main project.
2 step - Go to main project TARGETS - > Build Phases. Add subproject target in Target Dependencies. You can also add binary files in Link Binary With Libraries.
3 step - Add subproject source path to main projects header search path.
Go to main project - > Build Settings - > Header Search Paths (e.g $(SRCROOT)/../CoconutKit-master/CoconutKit/Sources )
An Xcode project can have any number of build targets within it, and you can arbitrarily group source files into folders. What makes you think that multiple projects are necessary?