What to do when I deleted swift.main

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Created Jun ’15

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I had a Swift 1.2 OS X document based (and CoreData FWTW) app, that when I updated to 2.0 gave me errors because in my swift.main there was a reference to two C_<something> variables which were not defined (I think they would have pointed to the old standby number of args and list of args argument that C main entry points had.)

I created a test document based Swift 2.0 app to see what the now approved format for swift.main, and I was surprised to see that there is no longer one created at all! Alrighty, I think, I'll just delete my swift.main and everything should be OK. Nope... Now I get a linker error...

Undefined symbols for architecture x86_64:
  "_main", referenced from:
     implicit entry/start for main executable
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

So what SHOULD I put in my swift.main to make things OK, now?

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Answer 1

ahltorp OP

Jun ’15

Accepted Answer

What you really need is a call to NSApplicationMain. The normal way is to call it this way:

NSApplicationMain(Process.argc, Process.unsafeArgv)

You will also have to import AppKit or Cocoa.

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Answer 2

Schubert OP

Jun ’15

You simply add @NSApplicationMain to your application delegate's file and not have a main file at all.

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Answer 3

Rick Shafer OP

Jun ’15

That works. I am curious, though, where this is documented, in particular the existence of the Process module namespace with those very useful variables. (Well not useful for a regular app, but for command line targets.) Are there other things squireled away worth knowing?

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Answer 4

Jens OP

Jun ’15

Here:

https://developer.apple.com/library/prerelease/ios/documentation/Swift/Reference/Swift_Process_Enumeration/index.html

Also cmd-click (or ctrl-cmd-J) on something (eg "Process" or "Swift") to open the generated interface for that module.

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Answer 5

Rick Shafer OP

Jun ’15

Thank you, thank you, thank you. It is good to see that the documentation is gradually getting filled in, including the "obvious" stuff.

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Answer 6

Rick Shafer OP

Jun ’15

Thank you. If I could mark two replies as "answering" the question, I would have done so with this one as well.

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