[swift-users] How to optionally link swift framework into another framework

[Jonathan Prescott]

I think the process is the same as C/C++/Obj-C/Obj-C++, except it’s labelled differently for Swift.  In Xcode, users set “C Pre-processor Macro Definitions” with things like USE_LOGGING.  In Swift, since it doesn’t use the C pre-processor, Xcode has a separate build setting called “Active Compilation Conditions,” as Rien has noted, probably to keeps consistent with the language.  Operationally, behavior is the same as C pre-processor defines.

Jonathan

> On Mar 6, 2017, at 12:09 PM, Jakub Bednář via swift-users <swift-users at swift.org> wrote:
> 
> Hi Rien,
> 
> looks like a good way around my problem.
> 
> Still I wonder why this does not work in Swift as it does work in Objective-C or even in strongly typed checked C++.
> 
> Maybe it is some kind of Swift’s security measure to avoid hard-to-debug bugs in C++ caused by virtual table inconsistencies.
> 
> Anyway, thanks for the help.
> 
> J.
> 
> 
>> On Mar 6, 2017, at 6:01 PM, Rien <Rien at Balancingrock.nl> wrote:
>> 
>> Well, that was a bit short…
>> 
>> When you want to use logging, define the ACC “USE_LOGGING” in the build settings.
>> When you don’t want to use logging, don’t define the ACC.
>> 
>> PS: You can get my logging framework from github: https://github.com/Balancingrock/SwifterLog
>> 
>> Regards,
>> Rien
>> 
>> Site: http://balancingrock.nl
>> Blog: http://swiftrien.blogspot.com
>> Github: http://github.com/Balancingrock
>> Project: http://swiftfire.nl
>> 
>> 
>> 
>> 
>> 
>>> On 06 Mar 2017, at 17:58, Rien <Rien at Balancingrock.nl> wrote:
>>> 
>>> You need conditional compilation.
>>> 
>>> Called “Active Compilation Conditions” in the build settings.
>>> 
>>> For example define a ACC of “USE_LOGGING”
>>> 
>>> Then in your code:
>>> 
>>> #if USE_LOGGING
>>> 
>>> import Logging
>>> 
>>> #else
>>> 
>>> struct Logging {
>>> 	func debug(message: string) {}
>>> }
>>> 
>>> #endif
>>> 
>>> 
>>> 
>>> 
>>> Regards,
>>> Rien
>>> 
>>> Site: http://balancingrock.nl
>>> Blog: http://swiftrien.blogspot.com
>>> Github: http://github.com/Balancingrock
>>> Project: http://swiftfire.nl
>>> 
>>> 
>>> 
>>> 
>>> 
>>>> On 06 Mar 2017, at 17:26, Jakub Bednář via swift-users <swift-users at swift.org> wrote:
>>>> 
>>>> Hello everyone,
>>>> 
>>>> I am trying to add optional logging into my framework, but for sake of this question, lets assume I want to add optional logging into an app. I have created an example with following setup:
>>>> 
>>>> 1. Logging.framework declares
>>>> 
>>>> 	public protocol Logging {
>>>> 		func debug(message: String)
>>>> 	}
>>>> 
>>>> 	and I have build the framework for the app to see it.
>>>> 
>>>> 2. Application has 
>>>> 
>>>> 	import Logging
>>>> 	
>>>> 	public class Engine {
>>>> 
>>>> 		let logger: Logging?
>>>> 
>>>> 		public init(withLogger logger: Logging? = nil) {
>>>> 			self.logger = logger 
>>>> 		}
>>>> 
>>>> 		public work() {
>>>> 			self.logger?.debug(“Working”)
>>>> 		}
>>>> 	} 
>>>> 
>>>> Now I don’t have the Logging.framework in Embed Binaries nor Link Frameworks lists. My app builds ok, but then fails to start telling me that Logging.framework was not loaded. I checked the binary using otool -L and Logging.framework is still referenced by the binary. Is there any way how to achieve my goal? This would be trivial with Objective-C and I still can’t figure it out in Swift.
>>>> 
>>>> Thanks a lot,
>>>> 
>>>> J.
>>>> 
>>>> _______________________________________________
>>>> swift-users mailing list
>>>> swift-users at swift.org
>>>> https://lists.swift.org/mailman/listinfo/swift-users
>>> 
>> 
> 
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