How does the target know which headers it should include? - xcode

I do not understand how Xcode knows which headers should be included into which target? For example if I add a new File to my Xcode Project it adds the .m File to the compile sources of the selected targets but what about the .h files? How does my target know which header files should be used?

Only .m files and resource files are part of the targets, not .h. Headers only need to be copied for a framework target, and only because they are part of the framework release (they allow users to know how to use the framework). Apps don't need the headers because they're compiled stand alone entities. The headers (and the pch file) are used during compilation but aren't required at runtime.
You want files to be members of your target when they:
Form part of the executable (e.g. implementation (.m) files or libraries), or
Are included as files in the application bundle (e.g. images).
Just to give an example via screenshot, the way we control headers in Xcode for libraries is in build phase something like this:
You may further read out this Apple Documentation for setting the visibility of header files in Xcode.

Related

Xcode using per-target headers with the same name

I am using Xcode 12.4. My project builds an app with two targets, one for the Mac App Store and one for "Retail" (downloaded from my website). My project folder looks like:
-Project
--Classes
---AppStore
----MyClass.h
----MyClass.m
---Retail
----MyClass.h
----MyClass.m
---Shared
----OtherClass.h
----OtherClass.m
All six source files appear in the left side file manager of Xcode and each project has two source files, OtherClass.m and the relevant MyClass.m.
When I build, the Retail version uses the correct MyClass.m source, but when it refers to the header with #import "MyClass.h", it wants to use the header from the AppStore version. Why does Xcode not look first in the directory where the .m file is located to see if a matching .h file is in the same directory?
How can I ensure that the right header files is used for each project, especially considering that ALWAYS_SEARCH_USER_PATHS is deprecated?

Make Xcode headers group

I am generating Xcode project with CMake. In Xcode it compiles, executes, and debugs fine. But it shows only the cpp files in the Source Files group. Is there any way to add another Header Files group ? My project is compiling fine on Linux, and in Linux I am using KDevelop, there everything works just fine, and I don't want to break that. I don't want to put headers in ADD_EXECUTABLE.
Is there any macro in CMake that creates such files group only for a specific IDE ? Then I would create a group for headers, another group for ui files, another groups for resources etc.
You can easily differentiate between project types in CMake. However, you must include the headers in the add_executable statement for them to be present in the project. I'm not really sure why you wouldn't want to add the headers in the add_executable statement, it shouldn't have any effect on compilation (the whole point of CMake is to be operational across multiple compilers!). However, you could easily do:
if (defined XCODE_VERSION)
add_executable(<ExeName> ${SOURCES} ${HEADERS});
else()
add_executable(<ExeName> ${SOURCES});
endif()
Thus only affecting XCode projects. If you want to arrange the sources (headers, etc), in different groups within the IDE, the generic CMake command for doing that is source_group. So, you could do:
source_group("Source Files" FILES ${SOURCES});
source_group("Header Files" FILES ${HEADERS});

Managing Static Library project as a module like Framework on iOS project in Xcode4

Many people including me trying to make a kind of Static Library framework for iOS to archive some kind of modularity. Framework is best way to do this, but it doesn't provided by Apple, and workarounds don't work well.
https://github.com/kstenerud/iOS-Universal-Framework/tree/master/Fake%20Framework/Templates
Fake framework cannot be referenced from linking tab in Build Phases.
Real framework needs modification of system setting. And still not work smoothly on every parts.
Problem is static library need header files, and it's impossible to reference header files on project at another location on different project without some script. And script breaks IDE's file management abstraction.
How can I use static library project like a convenient module manner? (just dragging project into another project to complete embedding)
I've since updated the template to do away with the script target. It now builds the universal framework from your regular target, so you can include it in workspaces or as a project dependency.
With a real framework target, you can just add it to "Link Binary With Libraries", and it will show up fine.
With a fake framework, Xcode doesn't recognize the target type, so you need to add the link command manually. For example, assuming your framework is called Foo:
Expand the "Products" group of your framework project, then drag "Foo.framework" into the "Link Binary With Libraries" build phase of your app target.
In your app target, edit "Other Linker Flags" in the build settings and add: "-framework Foo"
Framework template link for anyone not sure what we're talking about: https://github.com/kstenerud/iOS-Universal-Framework
Solution.
Goto Project or Target's Build Settings.
Find Public Headers Folder Path. (definition name = PUBLIC_HEADERS_FOLDER_PATH)
Set it as YourLibrary.framework/Headers. I have used ${PRODUCT_NAME}.framework/Headers for automatic syncing with project name.
Goto Build Phases and find Copy Headers step.
Move all required headers to Public pane.
Now all header files will be formed like Framework and copied with product binary. IDE will copy all of them as a unit into some temporary folder like app's build folder. So referencing app project can use the headers automatically.
This is a trick. The created directory structure is not real framework. Because it doesn't contain any binary. However we don't need real framework to archive just this functionality. IDE works with frameworks without any binary. And I don't want to hack IDE without documentation about internal structure.
This works well, however you'll experience some problem when you Archive. This happens because Xcode4 behaves specially when Archiving. Here's workaround.
For each embedded library project, SKIP_INSTALL = YES in target build settings.
For final product project, FRAMEWORK_SEARCH_PATHS = "${OBJROOT}/UninstalledProducts". Take care about this setting should be set only for Release build mode.
Now it'll be archived well.
At the case of cross platform library, there can be many projects for many platforms. But sometime Xcode will show some product as red color even it compiled successfully.
This is a bug of Xcode. IDE display depends SDKROOT of Project build setting. So if you set the SDKROOT differently on Target, it won't work. You can check the the product will become black color after changing the SDKROOT of the Project build setting. See this Open Radar entry for details.
http://openradar.appspot.com/9636211
If you wish to fix this bug, please report this to Apple's Radar. Duplicated bugs will make attention of Apple. Just copy & paste my report :)
I found this : http://db-in.com/blog/2011/05/creating-universal-framework-to-iphone-ios/
It seems to work.

Xcode 4 and nested projects -- header files not found

I'm having a myriad of problems with Xcode 4 and nested projects that worked just well under Xcode 3.2. Here's a very basic one I cannot solve:
I'm building a cocoa framework that requires another cocoa framework for which I have the source. So I perform the usual steps:
Drag the .xcodeproj file of the required framework into my main framework project
In my main framework under TARGETS > MyFramework > Build Phases > Target Dependencies: Add the nested project's target
Make sure the header files of the nested framework are public
In Xcode Settings > Locations > Build Location I have it set to Place build products in derived data location (recommended)
Build products path of both targets are set to ${BUILT_PRODUCTS_DIR} and tell me they are at the DerivedData/Debug (or Release) location
Architecture settings for both targets are identical
Then I hit [CMD] + B to build and it tells me that it doesn't find the header files of the nested framework. When I check the settings, User Header Search Paths contain the path to DerivedData/Debug, and inside there is the nested framework target with the header files in Versions/A/Headers.
I'm sitting here, anybody an idea what I'm doing wrong?
The issue goes away when building for Debug when I change the User header search paths to ${BUILT_PRODUCTS_DIR}/MyFramework.framework/Headers. However this doesn't work when building for Distribution as the frameworks then use their Release settings, which ends up in a different subdirectory...
My temporary solution is to also define a Distribution configuration for the nested projects. This way the headers are found and the linker can link successfully.
Here's my synthesized knowledge so far:
Forget the whole public header thing with Xcode, it's a PITA and doesn't work correctly when archiving your app. Instead, have all static library header files on the project level and tell your app where to find it.
Ease your pain by making sure all targets have the same name for the build configuration (i.e. add an "AdHoc" and "Deployment" configuration to the static libraries).
In build settings, point the Header Search Paths (if you use #include <file.h>) or User Header Search Paths (if you use #include "file.h") to the directory of the static library project. If the static library project is inside your app directory, use this:
"$(PROJECT_DIR)" (recursive enabled)
If you have a directory which contains a) the static library project and b) your app, then this should work:
"$(PROJECT_DIR)/.." (recursive enabled)
If the submodule contains compiled libraries, set your Library Search Paths to:
"$(TARGET_BUILD_DIR)"
Make sure all the static library projects that you use have Skip Install set to YES.
Again, no public header files (Build Phases » Copy Headers) in any of the static libraries, otherwise Xcode will not be able to archive an app.
Make sure to tell Xcode when to build the static libraries, as shown in this Tech Doc from Apple.
Old Answer:
I still haven't found a real solution to this problem with static libraries. What works for me is:
Create an "AdHoc" Configuration for the static library
Add $(BUILT_PRODUCTS_DIR) to User Header Search paths for the application (with recursive checked) -> this is used when running the app
In the Xcode menu, select Product > Build For > Build For Archiving
This works, the app finds the header files and builds itself, it ends up in DerivedData//Build/Products/AdHoc-iphoneos/ as an App bundle. Following these simple instructions (dead link) from TestFlightApp.com I can pack this App into an IPA and send it around. Simply selecting to Archive the app from Xcode does again not find the headers, even if they truly are in the AdHoc-iphoneos build directory.
(As of Xcode 5.1)
When the subproject is built by XCode, the subproject header files are copied into the build directory. When archiving, it seems that this copy destination directory is not added to the header/include search path. You'll want to go to your Build Settings and add
$(BUILD_ROOT)/../IntermediateBuildFilesPath/UninstalledProducts/include
to the "Header Search Paths" for the scheme that you use for archiving.
If you're not sure which scheme is used for archiving, go to Product -> Scheme -> Edit Schemes and look for Archive in the left column.
Make sure your third party framework is added as «group» to your main project, so you can see it in your project's hierarchy...
I had the same problem here and I could solve the problem by setting "Build Location" to Place build products in locations specified by targets"
I had this problem: I could build both Debug and App Store configurations, but not Ad Hoc. Building Ad Hoc gave me errors because it couldn't find .h files needed by nested projects.
Turned out I had an expired provisioning lingering in my Release configuration. I updated that provisioning link and now I can both build Ad Hoc and use the Archive feature to package it.
Took me hours to figure it out! My mind just didn't jump from missing .h files to provisioning errors just by itself. =) There might have been an error or warning complaining about the missing provisioning, but if so it was well buried among the hundreds of .h related errors.
I was having the same issue with a Configuration named "Ad Hoc" (as per TestFlight recommendation at http://help.testflightapp.com/customer/portal/articles/402782-how-to-create-an-ipa-xcode-4) and the main project could not find some of the headers from the nested projects. I renamed the project to "AdHoc" (no spaces) and the problem went away; seems like spaces can mess up header search paths in some cases, although I haven't figured out the specifics of when that might happen and why.
I was having this issue with a nested project that built a static library. I found this doc on apples site that completely saved my life.
http://developer.apple.com/library/ios/#DOCUMENTATION/Xcode/Conceptual/ios_development_workflow/AA-Developing_a_Static_Library_and_Incorporating_It_in_Your_Application/archiving_an_application_that_uses_a_static_library.html
I'm so glad I didn't have to muck around with the derived data paths.
For me, this happened after a GIT merge, which created many conflicts, one of them related to the project file. After the merge, I'm sure the structure of the project file changed.
What I ended up doing was going into the project "Build Settings", then looking for "Always Search User Paths" and turning it to Yes.
I guess the merge turned this boolean to No, therefore the project wasn't looking in the right places for the header files.

How should I structure my Qt based project so as to have a clean qmake generated xcode project?

If I add sources and headers in my .pro file that arn't in the same directory, the resulting xcode project groups the files by it's default Sources, Headers, etc. but then puts the files in a subdir of those folders indicating the subdirectory where the files are. This make non-flat projects look exceedingly ugly when generated for xcode (notice all the Qt examples are flat).
How do I prevent it from doing that? Or am I stuck with either an ugly xcode layout, or a flat project?
You can create your own configuration features for qmake by adding a new CONFIG argument variable in a .prf file.
Check out this Qt wiki.
Also it looks like you can use different variable names to generate different group names in xcode.
I'm going to figure out both these methods and generate a nice report.

Resources