[SR-1952] Implement SE-0103: Make non-escaping closures the default

[lattner]

Previous ID	SR-1952
Radar	None
Original Reporter	@lattner
Type	Bug
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug
Assignee	@milseman
Priority	Medium

md5: 1cc9c8e0e14e6e4c7c3f195393b327f5

relates to:

• SR-2180 withUnsafeMutablePointer methods should accept noescape closures

Issue Description:

SE-0103 was accepted, now we need an implementation. It would make sense to stage this in in the following steps:

• Introduce the new @escaping attribute.

• Introduce a new compiler warning that triggers on parameters that are not marked @NoEscape, which fixits to introducing the @escaping attribute.

• Update other swift.org projects to use @escaping where necessary.

• Switch the default, and start warning about @NoEscape with a fixit to remove it.

• Upgrade the warning about @NoEscape to be an error with a fixit to remove it.

[gribozavr]

withoutActuallyEscaping() needs to be re-throwing.

[swift-ci]

Comment by Trent Nadeau (JIRA)

I updated the proposal to add withoutActuallyEscaping and included the rethrows.

[swift-ci]

Comment by Trent Nadeau (JIRA)

PR to add parsing for the new @escaping attribute: #3425

[milseman]

tanadeau (JIRA User) Trent, are you planning on completing this in time for the Swift 3 source-breaking deadline? Otherwise, I can take over from here.

[swift-ci]

Comment by Trent Nadeau (JIRA)

Given my work schedule right now, I doubt I'm going to get it done before the Swift 3 deadline at the end of the month.

[milseman]

tanadeau (JIRA User) Do you have any un-merged code?

[swift-ci]

Comment by Trent Nadeau (JIRA)

Nothing significant. I was starting to work on importing decls with @escaping.

[swift-ci]

Comment by Trent Nadeau (JIRA)

If there's anything I can help with, let me know.

[swift-ci]

Comment by Trent Nadeau (JIRA)

@milseman I haven't seen any commits or PRs related to this. Can this still be implemented by the Swift 3 cutoff?

[milseman]

Yes, and I have an implementation (needs polish and tests). It should be part of Swift 3.

[milseman]

Opened PR: #3853

I might be doing more test fixes on it.

[milseman]

PR for QoI fixes: #3939 and #3948
PR for the autoclusure syntax: #4031 and #4052

Only thing remaining is the stdlib function `withoutActuallyEscaping`

[milseman]

`withoutActuallyEscaping` is an additive construct, so I'll spin off a separate JIRA task to track that.