swiftlang/swift

[SR-8536] Warn on member assignments capturing self

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#51,055 opened on Aug 14, 2018

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 (2 comments) (0 reactions) (0 assignees)Swift (10,719 forks)batch import
compilergood first issueimprovementtype checker

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Description
Previous ID SR-8536
Radar None
Original Reporter @CodaFi
Type Improvement
Votes 2
Component/s Compiler
Labels Improvement, StarterBug, TypeChecker
Assignee tt (JIRA)
Priority Medium

md5: cb331d15432b248f57b7b7bce4d077f7

Issue Description:

class Foo {
  let bar: () -> ()

  func baz() {}

  init() {
    self.bar = baz // We oughta warn about capturing 'self' implicitly.
  }
}

In the example above, we should warn about capturing `self` implicitly and, rather than suggest the user make it explicit, probably offer a fixit that provides a closure with a weak or unowned capture.

Contributor guide

Research direction
Investigate how the Swift type checker handles implicit self captures in member assignments and implement a warning with a fix it for weak/unowned capture.
Tech stack
swift
Domain
backend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Swift
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70