Missing compiler check on try

[Loradim]

Description

Reproducible crash of compiled code, but without a compiler warning or error.
(Usage of try outside of do - catch block)

enum AnotherError: Error {
    case badThing
}

func alwaysThrows() throws {
    throw AnotherError.badThing
}

do {
    try alwaysThrows() // this try is fine
} catch {
    print("It did throw fine")
}
try alwaysThrows() // <-- compiler should give a warning or an error, forcing try? or try!

Steps to reproduce
Run the code above, the marked line will not generate a compiler warning or error, but will crash the program.

Expected behavior
I would prefer the compiler to not allow try outside of a do-catch block (error). If for some reason that is not feasible, at least an warning should be thrown (though I would prefer an error, to make it clear to the user)

Environment
swift-driver version: 1.62.15 Apple Swift version 5.7.1 (swiftlang-5.7.1.135.3 clang-1400.0.29.51)
Target: x86_64-apple-macosx12.0

Xcode 14.1
Build version 14B47b

I also upgraded to latest Xcode version to ensure it hasn't been fixed already_
swift-driver version: 1.62.15 Apple Swift version 5.7.2 (swiftlang-5.7.2.135.5 clang-1400.0.29.51)
Target: x86_64-apple-macosx12.0

Xcode 14.2
Build version 14C18

Issue still present with latest version.

Deployment target was MacOS 12.6 (21G115) - but probably doesn't matter

Please let me know if you need any additional information on this report.

Kind regards,
Heiko

[AnthonyLatsis]

@slavapestov Is there a complication with effects checking in top-level code?

https://github.com/apple/swift/blob/dfe6fd940e88b87a2e85a84d820632dfad5149d2/stdlib/public/core/ErrorType.swift#L197-L201

[slavapestov]

I think this is intentional, since top-level code is meant for quick and dirty scripts and such.