I have bunch of frameworks included in my XCode project.
I'm wondering what happens when I have these frameworks on the project but never #import them or use them. Do they get excluded from the final binary? Or are they still included even though I never call them?
Basically I'm wondering if I should go through and remove these frameworks whenever I don't need them (My current approach is to simply NOT include them, assuming they would be automatically excluded from the build if I never import/use/call them anywhere in the code. But suddenly just became curious if I'm mistaken)
No Doubt, answer is YES or TRUE ;)
All libraries, frameworks and lib files you add to project are get included in build you create.
Go to TARGET -> SELECT YOUR TARGET -> Build Phases then you can see multiple files and frameworks under Compile Sources, Link Binary With Libraries and Copy Bundle Resources, those all are responsible in increasing your build size as they are part of final build.
Yes, all added libs or frameworks are included in final build.
If you are not using it at all you should remove it manually to exclude it otherwise final binary or build take it into count and your build size will increase.
Related
Do xcode 7 compiles all files upon build action while only few files are modified?
If YES, does XcodeBuild provides any support to customize building process by compiling only modified files ?
Thanks
No. Xcode, by default, will not recompile unchanged files.
You can force a recompile of all files in the target, by first issuing a "clean" command.
Also note that Xcode will only compile files which are members of the current target.
No, Xcode tracks dependencies and only compiles those files that need to be recompiled. If you're working in Objective-C it's a good idea to put your #import statements in your .m files where possible, since it prevents your project from becoming dependent on every single header file. (I don't know as much about how dependencies are determined in Swift.)
Xcode finds dependencies automatically sometimes. I think is is ok when I am the one who is defining the relationships and when I get lazy ...
But more than often I find myself facing an existent (medium to large size) project with several targets. Since the project has been made by someone else I find it very difficult to understand what targets depends on what since not all the relationships are explicit.
What are the rules Xcode use to find such relationships? ( I hope I can understand the logic so run it in my mind and maybe save me some time in the future) Or What makes a target qualifiable to be implicitly dependant of another?
A target and the product it creates can be related to another target. If a target requires the output of another target in order to build, the first target is said to depend upon the second. If both targets are in the same workspace, Xcode can discover the dependency, in which case it builds the products in the required order. Such a relationship is referred to as an implicit dependency.
Source: iOS Developer Library → Xcode Concepts → Xcode Target
This answer applies to Xcode 8.x, and I think for Xcode 9.0.
First off, you need to be sure that "Find Implicit Dependencies" is enabled in the the Build panel of the Scheme that you are attempting to build.
A target "A" can be made "implicitly" dependent on target "B" in two ways:
Target A has a "Link Binary With Libraries" build phase that has a library in its list that has the same name as a Product of B. This product can either be in the same project or another project in the workspace. Note that I said "same name". Just because you chose libA.a from target A doesn't mean that implicit dependencies will build it if you have another libA.a product in a different target. See below for details.
Target A has a "Copy Files Phase" that copies a file with a base name that matches a product of B. Normally a "Copy files" build phase cannot refer to a file that isn't in the same project as its target, but you can set up a dependency across projects if you create a dummy file for the "copy file" phase to copy that has the same name as a product of B. For example, if you have a workspace that contains two projects ProjectA and ProjectB. ProjectA has TargetA that creates libA.a, and ProjectB has TargetB that creates libB.a. TargetA could get TargetB to build libB.a by having a "fake" zero byte file as part of TargetA that happened to be named libB.a, and this would be sufficient to get libB.a made, even though the libB.a referred to in the "Copy Files" phase is a totally different file than the product output of the TargetB build. If you check the "Copy Only When Installing" box, Xcode won't actually perform the copy, but will still resolve the dependency. You can actually delete the fake file off your drive that you created solely to have something to put in the "Copy Files" phase (but you must leave it in your project).
So why would anyone ever want to do the horror that is "2"? I can come up with a couple of reasons.
TargetA needs some some files copied/generated by TargetB, but TargetB doesn't generate a library to link to. You could probably work around this by having TargetB generate up a small dummy library, but that may be painful for other reasons.
Let's say I had projectA, targetA and libA.a (and equivalents for project B, C and D), and libA.a depended on libB.a and libC.a which both needed libD.a to be built first (possibly some headers and/or sources generated). You could do it all using the "Link With Libraries" phase (aka solution #1) but in that case you would end up with two copies of the .o files in libD in the final linked version of libA. If you do this deep enough (eg a workspace that has 40 projects that have varying levels of dependencies on one another) you will quickly end up with huge library files with several identical .o files in them, and your link times will become horrific.
If you think these are contrived situations, I'm currently hitting both of them moving some legacy code from a series of explicit dependencies to implicit dependencies. Why am I moving to implicit dependencies? Because explicit dependencies in Xcode require project nesting, and once you get enough explicit dependencies, the project browser gets extremely slow, and you will see a lot of beachballs inside of Xcode for random things.
What happens if you happen to have two targets inside the same workspace that generate products with the same name and depend upon them from a third target? Implicit dependencies will pick one. It appears to do a match based on the base name of the product (so foo/bar.a and baz/bar.a are the same), and will pick the first one it finds.
Xcode Implicit Dependency
Xcode Dependency[About] is a dependency required to build a selected target.
Implicit dependency
source code aka Non-compiled dependencies. Xcode allows to add a dependency from the whole workspace. A good example is a Project from GitHub or CocoaPods[About] with source code
closed code aka Precompiled dependencies aka External - external binary, CocoaPods, Carthage with closed code
Implicit dependency is a dependency that is necessary to successfully build a target, but aren’t explicitly defined.
Specified in General -> Framework, Libraries, and Embedded Content or `Embedded Binaries and Linked Frameworks and Libraries[Link vs Embed]
No dependency in Build Phases -> Dependencies || Target Dependencies
To turn on this functionality[No such module]
Edit Scheme -> Build -> Find Implicit Dependencies
[Explicit dependency]
[Vocabulary]
From the beginning of my project, I use a custom framework, let's call it "custom.framework". But there was a bug in this framework and now I want to use another version of the "custom.framework".
At first, I simply removed the "custom.framework" file from my project and added the new one. But nothing changed, the bug was still there.
After multiple tries and hours, I understood that Xcode add the old version in memory and used this one instead of the new version. I know it because in the new version I added a method and when I cmd+click the class I've add the method into, it's not there and the file's path is unavailable.
Searching through the web, I tried to change some version parameters to my framework projects: Compatibility version, Curent Library version, Framework version. But this didn't change anything to Xcode which keeps using the old version.
I also tried to make the framework's project as a sub-project and add resulting framework as a dependency to my target. It worked well, but as the framework's project is on a separated remote git repository, I don't think this is an acceptable solution.
So my last try was to build a "custom2.framework", to force Xcode to use the real file and not some cached version. But again, it doesn't work and when building I get errors telling me that all my classes in custom2.framework are duplicated symbols of its cached version of "custom.framework".
So my question is simple: how can I finally tell Xcode to deleted its cached old version and let me use the file I gave him? I already tried to delete my project's derivedData but it seems cached frameworks aren't there.... I'm so desperate :(
Edit: Here are 2 screenshots to illustrate the issue
First screenshot is the path as shown by Xcode when I opened the file from the .framework object in the project navigator.
Second screenshot is the path as shown by Xcode when I opened the file from a cmd+click to a "DCEquipmentManager" in code.
As you can see, the framework linked with the code is not the framework in the project.
it seems problem with binding in new framework, your project still linked with old framework files.
try to remove all files and folder related to your "custom.framework and also remove path for that framework from project setting--> build setting --> search Path
Then after Drag and Drop Your "custom.framework" files in project.
it works for me.hope it resolve your problem.
Please try to clear derrived data:
Window -> Organizer
at the right side you will see projects list. Find your project and tap on it. I the top part of window you will see button delete in front of Derrived data, tap on it.
I guess it will solve your problem.
It might sound silly, but sometimes restarting XCode or the whole machine fix things.
Did you remove the old framework from Build Phases --> Link Binary With Libraries?
Use Clean Build Folder: option-shift-command-K, or select it from the Product menu when holding down the alt/option key.
First lets say something upfront. The build stage is a(are) command line tool(s) that is managed by Xcode according to your Build Settings.
So when Xcode doesn't find your Framework - the Build System will usually also not find it. This forces you to act but may end up in confused Xcode to catch an older reference.
Yes it may happen that the Header Xcode is pointing to is correct but the build system still uses an old copy somewhere. An outdated copy can dangle around literally anywhere depending on the steps you took before.
It (Xcode) assumes where it is located but the Build System still uses another version or the Search Paths just pointing in the wrong Locations even if they are visible to you and even your Framework icons are visible in the lists. So when you erase the last build you actually only force Xcode to rebuild from the known arguments, the settings stay the same, the lists stay the same. Even restarting Xcode does not change anything, the problem persists.
Ergo: Compiler Instructions, Xcode settings and Build System settings don't match what the code tells with #import <NAME/Name.h>
So you will check at least those 6 stages again:
Is your Framework Header File published in your Framework project?
are Build Settings really pointing to the right Framework Search Paths or System Framework Search Paths?
Is your Framework in linking list?
Is your Framework in Embed Framework list?
Does your framework appear in the Framework Group Folder in Workspace/Project Browser? (usually the very last Group Folder in the Browser below all your other files)
Is my Folder Structure correct?
At least 1 to 4 must be right otherwise it will fail.
Here a random list of common causes
Framework is located outside your Source Paths structure
Structure got changed after you added it to the project
You use Workspace's where Framework development and Final Application can appear side by side but you assume Xcode uses this to change its Search Paths
The contained build settings are misleading from former drag and drop operations, ending up tricking Xcode in the "wrong" corner. In this case recreating a project is just one of the possible ways to fix it but not the solution.
Also dragging a Framework into your Project > General or separated in Build Phases > Link Binary list or Embed Framework lists does not make Xcode aware of the wrong Build Settings.
The Linking works, embedding works, but compiling does not. The Header information is still missing.
The solution must be to correct your Build Settings.
As mentioned above Build System and Xcode are two different things. In particular only setting the right Framework Search Paths will solve those issues, even if you managed to kick your derived data manually.
Erasing Derived data?
Derived data is the place where precompiler collects data to compile. So it can be seen as expression of what all the settings are told to do. Erasing it does of course not change the settings but may fix inconsistencies related to former Build Settings. It would erase the derived data and rebuild from the Build System Settings you gave.
Correcting Linking?
Also Linking is not the same as making Xcode aware of the desired Headers. Linking is for your final Product to know where Symbols are to call on them at runtime, it does not change Framework Search Paths and System Framework Search Paths, they stay the same as given.
But it is not wrong to start fixing first with
Product > Clean Build Folder, it forces your build to parse all and compile all again on the next Build.
When the troubles come up because of folder structure in parallel or Frameworks are simply placed outside the Source Directory then you must point to them directly or relative.
Most likely you should place one extra entry in your Framework Search Paths like $(SRCROOT)/../Yourframeworksource/build/Debug. expression to point to relative higher folder structure.
Needless to say that a Release Build likely needs another entry ending in "/Release".Hint: Well you can have different Search Paths for different Compile Schemes..
This works particular good after you cleaned Linking List, Embed Frameworks List and then also check the very last Group Folder "Frameworks" for double entries to drag and drop a fresh Framework reference in there.
How to know if leading /../ will fix it?
Click on the dropped Framework Icon inside the workspace Framework Group Folder (lower most) while your Project is the active selected to work on, now watch for the relative Path information on the very upper right side of Xcode, if there is some /../ you know you need it as well.
Sorting of Framework Search Paths
play a role of course, just the same as #import/#include rule sorting matters.
Remember the first found, first wins rule because often we use #import that works different then #include but ignores second attempts to declare. This leads to once wrongfully declared headers to hide corrected declarations later on in parsing that share the same filename or define rules
#ifndef xyz
#define xyz
// all your code here.
// a second read attempt would be ignored
// a second read is hidden also when you use #include then.
#endif
So you can sort those entries either by code and/or in the build settings if needed because of course it matters what is declared before other declarations depend on it.
I have a static library xcode project (.a) and a bundle xcode project (.bundle)
I added the (.a) as a sub project of (.bundle) and added to [Target Dependencies] and [Link Binary With Libraries].
After run the bulid the (.bundle) still not contain any binary file inside (.bundle).
It's work if I add the .c and .h files to under (.bundle) directly, but that make me need to handle two project files. Any way can make (.bundle) just build with the (.a) ?
This question same as what I asked, I tried to follow his 11 steps without the step 10 because he said lastly no need that step. But the generated (.bundle) still without contain any binary
Finally, I make it work.
The step 10 still important and below is corrected step 10.
create a dummy.c under (.bundle) project and the dummy.c can just totally empty. remove the setting for the library you want to link inside Link Binary With Libraries instead use -Wl,-force_load,$(CONFIGURATION_BUILD_DIR)/libYourLib.a or -all_load to Other Linker Flags
PS: And also can use sub-project instead of workspace. and use Target Dependencies instead of Edit Scheme to achieve the same effect.
The testing project
Situation: Linking against an SDK (which I'm building) that has Release, Debug, & Distribution versions of it's static library (.a file). There doesn't seem to be a way in Xcode GUI to indicate that a static library is only used for a given Configuration.
I can use "Other Linker Flags" (OTHER_LDFLAGS) in the Build pane of the target or project settings like this:
-all_load -ObjC "${SRCROOT}/MySDKFolder/${CONFIGURATION}-universal/libMYsdk.a"
which seems to work. Just wondering if anyone knows a better way. ( the -all_load and -ObjC are to get ObjC categories linked in properly).
I'm using gcc 4.2 at this point (SDK default for 4.3 sdk and 3.x.x Xcode).
So, it turns out I was letting the Xcode UI confuse me. If you add the generic search path with the ${CONFIGURATION} variables and then add one of the static library instances to the project and target it'll do the right thing and link with the right one even though if you get info on that library in the project it'll show you the specific path.
However, if you want it to actually have Xcode notice changes made to one of the static libraries, you'll need to add ALL versions of your static library to the project and target (yes, it'll look like it's linking with all three, no worries!).
To have Xcode detect the the .a file changed as the result of a build script phase you have to actually have all the source files that are used to build the .a file in the Run Script Input pane (a pain!) to not have to run your build script every time; And all three variants of the .a file in the output pane so Xcode knows what to check after your script runs to see if it needs to relink the project.