swiftlang/swift

Incorrect fix-it for static member access on instance

Open

#85,157 opened on Oct 27, 2025

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 (2 comments) (0 reactions) (1 assignee)Swift (69,989 stars) (10,719 forks)batch import
compilerdiagnostics qualityfix-itsgenericsgood first issueopaque parameter typesstatic declarationstype checker

Description

Description

In the following example the compiler offers to replace p with some P, which is obviously not going to work. The same applies to any P.

Reproduction

protocol P {
  static var x: Int {get}
}
func foo(p: some P) -> Int {
  p.x
}

Expected behavior

We should probably make it wrap the base in type(of:) instead.

Environment

Swift version 6.3-dev (1ae8ef0004e7405)

Additional information

No response

Contributor guide

Tech stack
swift
Domain
tooling
Issue type
bug
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.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Understanding of Swift protocols and genericsFamiliarity with compiler fix it mechanism
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
The issue requires modifying the fix it logic in the Swift compiler. When a static member is accessed on an instance of a protocol existential (e.g., `some P`), the current fix it incorrectly suggests replacing the instance with a concrete type. The correct behavior is to wrap the base expression in `type(of:)`. The relevant code is likely in the diagnostics or constraint solver module. Check the issue comments for any additional context or pointers.