[4.2][migrator] Migrate UIApplicationMain #17640
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In Swift 4.2 the second parameter of UIApplicationMain exactly matches the type
of CommandLine.unsafeArgv so it can be called as below:
UIApplicationMain(CommandLine.argc, CommandLine.unsafeArgv, ...)
This is how it was intended to be in Swift 4 as well, but the types had
optionality differences, so callers instead had to do something like the below
example from the Firefox-iOS project:
let pointer = UnsafeMutableRawPointer(CommandLine.unsafeArgv).bindMemory(
to: UnsafeMutablePointer<Int8>.self, capacity: Int(CommandLine.argc))
UIApplicationMain(CommandLine.argc, pointer, ...)
This migration simply replaces the the second argument with
CommandLine.unsafeArgv if the first argument is CommandLine.argc.
There is an open issue for providing a deprecated version with the old type so
we simply leave as is any callers that don't pass argc for the first argument.
Resolves rdar://problem/40045693.
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Cherry-pick of #17619 |
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@swift-ci please test |
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CCC Info
Explanation
In Swift 4.2 the type of second parameter of
UIApplicationMainexactly matches the type ofCommandLine.unsafeArgvso it can be called as below:This is how it was intended to be in Swift 4 as well, but the types had optionality differences, so callers instead had to do something similar to the below example, from the Firefox-iOS project:
Now that the type of
UIApplicationMain's second parameter has been updated to matchCommandLine.unsafeArgv, this workaround is no longer needed. This patch adds a new migration that simply replaces the second argument withCommandLine.unsafeArgvat all call sites whereCommandLine.argcis passed as the first argument, as in 99% of cases this is what users would have written had the types matched.There is an open issue for providing a deprecated version with the old type signature, so we simply leave any callers that don't pass
CommandLine.argcfor the first argument as they are.