[SR-6556] Sourcery source breakage: error: ambiguous use of 'trackDifference(actual:expected:)' #49106

lplarson · 2017-12-07T20:00:11Z


Previous ID	SR-6556
Radar	rdar://problem/37504986
Original Reporter	@lplarson
Type	Bug

Additional Detail from JIRA


Votes	0
Component/s	Compiler
Labels	Bug, 4.1Regression, TypeChecker
Assignee	@xedin
Priority	Medium

md5: a7a0e42ecf3510a78ad35bf7c54853b1

relates to:

SR-7273 Sourcery source breakage: dependency on SourceKitten that uses IUOs in ways that are disallowed

Issue Description:

To reproduce:

Install latest GM/Beta Xcode
$ git clone git@github.com:apple/swift-source-compat-suite.git
$ cd swift-source-compat-suite

To build Swift from scratch before testing:
4. $ ./reproduce.py master --project-path Sourcery --assertions

Or if you've already built Swift:
4. $ ./reproduce.py master --project-path Sourcery --assertions --swiftc path/to/swiftc

https://ci.swift.org/job/swift-PR-source-compat-suite-test-macOS/60/artifact/swift-source-compat-suite/FAIL_BuildSwiftPackage_Sourcery.log

/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.generated.swift:26:36: error: ambiguous use of 'trackDifference(actual:expected:)'
        results.append(contentsOf: DiffableResult(identifier: "annotations").trackDifference(actual: self.annotations, expected: rhs.annotations))
                                   ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:69:29: note: found this candidate
    @discardableResult func trackDifference<T: Equatable>(actual: T, expected: T) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:166:29: note: found this candidate
    @discardableResult func trackDifference<K: Equatable, T: NSObjectProtocol>(actual: [K: T], expected: [K: T]) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.generated.swift:38:36: error: ambiguous use of 'trackDifference(actual:expected:)'
        results.append(contentsOf: DiffableResult(identifier: "arguments").trackDifference(actual: self.arguments, expected: rhs.arguments))
                                   ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:69:29: note: found this candidate
    @discardableResult func trackDifference<T: Equatable>(actual: T, expected: T) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:166:29: note: found this candidate
    @discardableResult func trackDifference<K: Equatable, T: NSObjectProtocol>(actual: [K: T], expected: [K: T]) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.generated.swift:104:36: error: ambiguous use of 'trackDifference(actual:expected:)'
        results.append(contentsOf: DiffableResult(identifier: "annotations").trackDifference(actual: self.annotations, expected: rhs.annotations))
                                   ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:69:29: note: found this candidate
    @discardableResult func trackDifference<T: Equatable>(actual: T, expected: T) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:166:29: note: found this candidate
    @discardableResult func trackDifference<K: Equatable, T: NSObjectProtocol>(actual: [K: T], expected: [K: T]) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.generated.swift:142:36: error: ambiguous use of 'trackDifference(actual:expected:)'
        results.append(contentsOf: DiffableResult(identifier: "annotations").trackDifference(actual: self.annotations, expected: rhs.annotations))
                                   ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:69:29: note: found this candidate
    @discardableResult func trackDifference<T: Equatable>(actual: T, expected: T) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:166:29: note: found this candidate
    @discardableResult func trackDifference<K: Equatable, T: NSObjectProtocol>(actual: [K: T], expected: [K: T]) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.generated.swift:160:36: error: ambiguous use of 'trackDifference(actual:expected:)'
        results.append(contentsOf: DiffableResult(identifier: "annotations").trackDifference(actual: self.annotations, expected: rhs.annotations))
                                   ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:69:29: note: found this candidate
    @discardableResult func trackDifference<T: Equatable>(actual: T, expected: T) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:166:29: note: found this candidate
    @discardableResult func trackDifference<K: Equatable, T: NSObjectProtocol>(actual: [K: T], expected: [K: T]) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.generated.swift:194:36: error: ambiguous use of 'trackDifference(actual:expected:)'
        results.append(contentsOf: DiffableResult(identifier: "arguments").trackDifference(actual: self.arguments, expected: rhs.arguments))
                                   ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:69:29: note: found this candidate
    @discardableResult func trackDifference<T: Equatable>(actual: T, expected: T) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:166:29: note: found this candidate
    @discardableResult func trackDifference<K: Equatable, T: NSObjectProtocol>(actual: [K: T], expected: [K: T]) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.generated.swift:237:36: error: ambiguous use of 'trackDifference(actual:expected:)'
        results.append(contentsOf: DiffableResult(identifier: "annotations").trackDifference(actual: self.annotations, expected: rhs.annotations))
                                   ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:69:29: note: found this candidate
    @discardableResult func trackDifference<T: Equatable>(actual: T, expected: T) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:166:29: note: found this candidate
    @discardableResult func trackDifference<K: Equatable, T: NSObjectProtocol>(actual: [K: T], expected: [K: T]) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.generated.swift:299:36: error: ambiguous use of 'trackDifference(actual:expected:)'
        results.append(contentsOf: DiffableResult(identifier: "annotations").trackDifference(actual: self.annotations, expected: rhs.annotations))
                                   ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:69:29: note: found this candidate
    @discardableResult func trackDifference<T: Equatable>(actual: T, expected: T) -> DiffableResult {
                            ^
/Users/buildnode/jenkins/workspace-private/swift-PR-source-compat-suite-test-macOS/project_cache/Sourcery/Sources/SourceryRuntime/Diffable.swift:166:29: note: found this candidate
    @discardableResult func trackDifference<K: Equatable, T: NSObjectProtocol>(actual: [K: T], expected: [K: T]) -> DiffableResult {
                            ^

belkadan · 2017-12-08T17:22:57Z

cc @rudkx, @xedin

rudkx · 2017-12-08T18:25:42Z

Pavel, can you take a look at this?

I recall you made some changes related to ranking recently and I wonder if that caused this.

xedin · 2017-12-08T23:05:02Z

@rudkx This appears to be actually ambiguous if we account for Dictionary to be Equatable, here is the reduced example:

import Foundation

func foo<T: Equatable>(actual: T, expected: T) {}
func foo<K: Equatable, T: NSObjectProtocol>(actual: [K: T], expected: [K: T]) {}

let x: [String: NSObject] = [:]
foo(actual: x, expected: x)

I think it might be due to the missing break in SolutionDiff I've fixed, but I think it's a legitimate problem which needs to be addressed by the project.

xedin · 2017-12-19T05:04:30Z

@DougGregor Can this actually be related to conditional conformances? Since I think @moiseev mentioned that dictionary is equatable how if the elements are.

DougGregor · 2017-12-19T06:07:22Z

The second foo should be more specific, because you can use its parameters to call the first foo, but not vice-versa. It'd be interesting to know why that isn't working.

xedin · 2017-12-19T07:09:50Z

@DougGregor It looks like we currently don't have ranking rules for that (were they removed?):

Comparing 2 viable solutions
--- Solution #&#8203;0 ---
Fixed score: 0 0 0 0 0 0 0 0 0 0 0
Type variables:
  $T2 as [String : NSObject] @ locator@0x7f9caa523dc0 [DeclRef@<REPL Input>:1:26]
  $T9 as String @ locator@0x7f9caa524178 [OverloadedDeclRef@<REPL Input>:1:1 -> archetype 'T' -> archetype 'Key']
  $T10 as NSObject @ locator@0x7f9caa5241c8 [OverloadedDeclRef@<REPL Input>:1:1 -> archetype 'T' -> archetype 'Value']
  $T1 as [String : NSObject] @ locator@0x7f9caa523d40 [DeclRef@<REPL Input>:1:13]
  $T0 as ([String : NSObject], [String : NSObject]) -> () @ locator@0x7f9caa523c00 [OverloadedDeclRef@<REPL Input>:1:1]
  $T8 as [String : NSObject] @ locator@0x7f9caa523eb0 [OverloadedDeclRef@<REPL Input>:1:1 -> archetype 'T']

Overload choices:
  locator@0x7f9caa523dc0 [DeclRef@<REPL Input>:1:26] with REPL.(file).x@<REPL Input>:1:5 as x: [String : NSObject]

  locator@0x7f9caa523d40 [DeclRef@<REPL Input>:1:13] with REPL.(file).x@<REPL Input>:1:5 as x: [String : NSObject]

  locator@0x7f9caa523c00 [OverloadedDeclRef@<REPL Input>:1:1] with REPL.(file).foo(actual:expected:)@<REPL Input>:1:6 as foo: ($T8, $T8) -> ()


Constraint restrictions:
  Dictionary<String, NSObject> to Dictionary<String, NSObject> is [deep equality]

Disjunction choices:

Opened types:
  locator@0x7f9caa523c00 [OverloadedDeclRef@<REPL Input>:1:1] opens τ_0_0 -> $T8
--- Solution #&#8203;1 ---
Fixed score: 0 0 0 0 0 0 0 0 0 0 0
Type variables:
  $T2 as [String : NSObject] @ locator@0x7f9caa523dc0 [DeclRef@<REPL Input>:1:26]
  $T1 as [String : NSObject] @ locator@0x7f9caa523d40 [DeclRef@<REPL Input>:1:13]
  $T0 as ([String : NSObject], [String : NSObject]) -> () @ locator@0x7f9caa523c00 [OverloadedDeclRef@<REPL Input>:1:1]
  $T12 as NSObject @ locator@0x7f9caa5248a8 [OverloadedDeclRef@<REPL Input>:1:1 -> archetype 'T']
  $T11 as String @ locator@0x7f9caa524860 [OverloadedDeclRef@<REPL Input>:1:1 -> archetype 'K']

Overload choices:
  locator@0x7f9caa523dc0 [DeclRef@<REPL Input>:1:26] with REPL.(file).x@<REPL Input>:1:5 as x: [String : NSObject]

  locator@0x7f9caa523d40 [DeclRef@<REPL Input>:1:13] with REPL.(file).x@<REPL Input>:1:5 as x: [String : NSObject]

  locator@0x7f9caa523c00 [OverloadedDeclRef@<REPL Input>:1:1] with REPL.(file).foo(actual:expected:)@<REPL Input>:1:6 as foo: ([$T11 : $T12], [$T11 : $T12]) -> ()


Constraint restrictions:
  Dictionary<String, NSObject> to Dictionary<String, NSObject> is [deep equality]

Disjunction choices:

Opened types:
  locator@0x7f9caa523c00 [OverloadedDeclRef@<REPL Input>:1:1] opens τ_0_0 -> $T11, τ_0_1 -> $T12
comparing solutions 1 and 0
Comparing declarations
func foo<K, T>(actual: [K : T], expected: [K : T]) where K : Hashable, T : NSObjectProtocol {
}
and
func foo<T>(actual: T, expected: T) where T : Equatable {
}
Found cached comparison: 0
comparison result: not better
Comparing declarations
func foo<T>(actual: T, expected: T) where T : Equatable {
}
and
func foo<K, T>(actual: [K : T], expected: [K : T]) where K : Hashable, T : NSObjectProtocol {
}
Found cached comparison: 0
comparison result: not better
comparing solutions 0 and 1
Comparing declarations
func foo<T>(actual: T, expected: T) where T : Equatable {
}
and
func foo<K, T>(actual: [K : T], expected: [K : T]) where K : Hashable, T : NSObjectProtocol {
}
Found cached comparison: 0
comparison result: not better
Comparing declarations
func foo<K, T>(actual: [K : T], expected: [K : T]) where K : Hashable, T : NSObjectProtocol {
}
and
func foo<T>(actual: T, expected: T) where T : Equatable {
}
Found cached comparison: 0
comparison result: not better
comparing solutions 0 and 1
Comparing declarations
func foo<T>(actual: T, expected: T) where T : Equatable {
}
and
func foo<K, T>(actual: [K : T], expected: [K : T]) where K : Hashable, T : NSObjectProtocol {
}
Found cached comparison: 0
comparison result: not better
Comparing declarations
func foo<K, T>(actual: [K : T], expected: [K : T]) where K : Hashable, T : NSObjectProtocol {
}
and
func foo<T>(actual: T, expected: T) where T : Equatable {
}
Found cached comparison: 0
comparison result: not better

rudkx · 2017-12-19T08:08:03Z

@xedin I believe you want to be looking at isDeclAsSpecializedAs.

DougGregor · 2017-12-19T22:02:05Z

`isDeclAsSpecializedAs` is doing the right thing here, and the code is actually truly ambiguous due to the conditional conformance of `Dictionary` to `Equatable`. Neither of the two overloads in the reduced test case is more specialized than the other:

func foo<T: Equatable>(actual: T, expected: T) {}
func foo<K: Equatable, T: NSObjectProtocol>(actual: [K: T], expected: [K: T]) {}

because `NSObjectProtocol` is not `Equatable`. The backward- and forward-compatible fix here is to replace `NSObjectProtocol` with `NSObject`; once Swift 4.1 comes with its conditional conformances, the second overload can be removed entirely.

belkadan · 2018-01-25T17:59:22Z

Is this still an issue?

swift-ci · 2018-02-13T19:15:39Z

Comment by Nicole Jacque (JIRA)

@swift-ci create

lplarson · 2018-02-13T19:39:57Z

Still seeing it in 4.1:

https://ci.swift.org/view/Source%20Compatibility/job/swift-4.1-source-compat-suite/197/artifact/swift-source-compat-suite/XFAIL_Sourcery_4.0_BuildSwiftPackage.log

But not master:

https://ci.swift.org/view/Source%20Compatibility/job/swift-master-source-compat-suite/1259/artifact/swift-source-compat-suite/XFAIL_Sourcery_4.0_BuildSwiftPackage.log

lplarson · 2018-02-13T19:45:01Z

@DougGregor/@xedin Does this issue require a project change?

xedin · 2018-02-13T20:55:43Z

@lplarson It seems to me that it would be required yes, but @DougGregor is a better person to reply to that...

lplarson · 2018-02-15T23:20:41Z

Reached out to project maintainer requesting a hash update containing a fix.

swift-ci · 2018-02-19T20:09:08Z

Comment by Krzysztof Zabłocki (JIRA)

Should be fixed on Master, via commit: 3041ba7ed84138f13e7973d34973dce2b10259be

lplarson · 2018-02-19T20:15:44Z

merowing (JIRA User), thanks! Please open a PR on the swift-source-compat-suite projects.json file updating the project hash.

lplarson · 2018-02-21T20:46:34Z

Hash update PR merged.

swift-ci transferred this issue from apple/swift-issues Apr 25, 2022

AnthonyLatsis added regression swift 4.1 and removed 4.1 regression labels Nov 19, 2022

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[SR-6556] Sourcery source breakage: error: ambiguous use of 'trackDifference(actual:expected:)' #49106

[SR-6556] Sourcery source breakage: error: ambiguous use of 'trackDifference(actual:expected:)' #49106

lplarson commented Dec 7, 2017

belkadan commented Dec 8, 2017

rudkx commented Dec 8, 2017

xedin commented Dec 8, 2017

xedin commented Dec 19, 2017

DougGregor commented Dec 19, 2017

xedin commented Dec 19, 2017

rudkx commented Dec 19, 2017

DougGregor commented Dec 19, 2017

belkadan commented Jan 25, 2018

swift-ci commented Feb 13, 2018

lplarson commented Feb 13, 2018

lplarson commented Feb 13, 2018

xedin commented Feb 13, 2018

lplarson commented Feb 15, 2018

swift-ci commented Feb 19, 2018

lplarson commented Feb 19, 2018

lplarson commented Feb 21, 2018

[SR-6556] Sourcery source breakage: error: ambiguous use of 'trackDifference(actual:expected:)' #49106

[SR-6556] Sourcery source breakage: error: ambiguous use of 'trackDifference(actual:expected:)' #49106

Comments

lplarson commented Dec 7, 2017

belkadan commented Dec 8, 2017

rudkx commented Dec 8, 2017

xedin commented Dec 8, 2017

xedin commented Dec 19, 2017

DougGregor commented Dec 19, 2017

xedin commented Dec 19, 2017

rudkx commented Dec 19, 2017

DougGregor commented Dec 19, 2017

belkadan commented Jan 25, 2018

swift-ci commented Feb 13, 2018

lplarson commented Feb 13, 2018

lplarson commented Feb 13, 2018

xedin commented Feb 13, 2018

lplarson commented Feb 15, 2018

swift-ci commented Feb 19, 2018

lplarson commented Feb 19, 2018

lplarson commented Feb 21, 2018