Fix issue that caused static framework target dependencies from having their default link value inferred as true

[liamnichols]

I'm updating our project to statically link some framework targets instead of using dynamic linking for everything and I spotted some warnings appearing in CI when doing do:

[...]/usr/bin/libtool: file: /[...]/MyFramework1.framework/MyFramework1 is a dynamic library, not added to the static library

It appears that this happens when I have three targets:

1. MyFramework1 - Dynamic Framework (framework)
2. MyFramework2 - Static Framework (framework.static) with dependency on MyFramework1
3. MyApp - iOS app target with dependency on MyFramework2 (and a transitive dependency on MyFramework1)

In this setup, the MyFramework2 target should not have a "Link Binary With Libraries" build phase because the libraries should be linked into the executable target MyApp instead. After looking at the docs, and digging into the current fixtures, it appeared that this was defaulting the link property to the correct value if MyFramework2 was a static library (library.static) but not for framework.static or framework with the MACH_O_TYPE build setting set to staticlib.

After setting up some extra targets in the fixtures to reproduce the setup (1f391f1), i tracked the issue down to PBXProjectGenerator and updated it to use the defaultLinkage property that is also used for figuring out if the dependency should be embedded or not (159f719). You can find the fixtures regenerated after making the changes in
8e19482.

[liamnichols]

Before I mark this as ready for review, there are a couple of other places in PBXProjGenerator that also perform similar checks and I'm wondering if they also need similar patches? I've personally only ever used the target type of dependency so i'm not 100% sure how these other areas need to behave.

Requires ObjC Linking

XcodeGen/Sources/XcodeGenKit/PBXProjGenerator.swift

Line 456 in a4d7a61

let requiresObjCLinking = (buildSettings["OTHER_LDFLAGS"] as? String)?.contains("-ObjC") ?? (productType == .staticLibrary)

XcodeGen/Sources/XcodeGenKit/PBXProjGenerator.swift

Lines 720 to 723 in a4d7a61

	if !anyDependencyRequiresObjCLinking
	&& dependencyTarget.requiresObjCLinking ?? (dependencyTarget.type == .staticLibrary) {
	anyDependencyRequiresObjCLinking = true
	}

I'm not completely sure if "ObjC linking" is the same and if it applies to static frameworks or not?

Other Dependency Types

.framework

XcodeGen/Sources/XcodeGenKit/PBXProjGenerator.swift

Lines 802 to 808 in a4d7a61

	if dependency.link ?? (target.type != .staticLibrary) {
	let pbxBuildFile = PBXBuildFile(file: fileReference, settings: getDependencyFrameworkSettings(dependency: dependency))
	pbxBuildFile.platformFilter = platform
	let buildFile = addObject(pbxBuildFile)
	targetFrameworkBuildFiles.append(buildFile)
	}

I think this is intentionally specific to libraries so can remain 👍

.carthage

XcodeGen/Sources/XcodeGenKit/PBXProjGenerator.swift

Lines 897 to 904 in a4d7a61

	let isStaticLibrary = target.type == .staticLibrary
	let isCarthageStaticLink = dependency.carthageLinkType == .static
	if dependency.link ?? (!isStaticLibrary && !isCarthageStaticLink) {
	let pbxBuildFile = PBXBuildFile(file: fileReference, settings: getDependencyFrameworkSettings(dependency: dependency))
	pbxBuildFile.platformFilter = platform
	let buildFile = addObject(pbxBuildFile)
	targetFrameworkBuildFiles.append(buildFile)
	}

I think maybe this needs patching, but i've not used Carthage in a longgg time so I can't be sure

.package

XcodeGen/Sources/XcodeGenKit/PBXProjGenerator.swift

Lines 926 to 937 in a4d7a61

	let link = dependency.link ?? (target.type != .staticLibrary)
	if link {
	let buildFile = addObject(
	PBXBuildFile(product: packageDependency, settings: getDependencyFrameworkSettings(dependency: dependency))
	)
	targetFrameworkBuildFiles.append(buildFile)
	} else {
	let targetDependency = addObject(
	PBXTargetDependency(platformFilter: platform, product: packageDependency)
	)
	dependencies.append(targetDependency)
	}

Again, I don't have enough context to know the right answer

.bundle

XcodeGen/Sources/XcodeGenKit/PBXProjGenerator.swift

Lines 951 to 953 in a4d7a61

	case .bundle:
	// Static and dynamic libraries can't copy resources
	guard target.type != .staticLibrary && target.type != .dynamicLibrary else { break }

Looks good, its specifically checking for libraries (not link types).

---

@yonaskolb: Any input on the bits above would be great, thanks! 🙏

[yonaskolb]

Hi @liamnichols. Thanks for this, your change makes sense. As for the other places, I'm honestly not sure. Maybe just go with your change, and someone else might bring up if something else is not working. For this could you add a changelog entry, might need to rebase off master to get the latest changelog.
I know it's a been a while, but if you had the time to add some a unit test for this case it would be great too