[SR-1158] Sub-subclass doesn't conform to protocol

[swift-ci]

Previous ID	SR-1158
Radar	None
Original Reporter	diegosanchezr (JIRA User)
Type	Bug
Status	Closed
Resolution	Done

Attachment: Download

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug, OptimizedOnly
Assignee	@jckarter
Priority	Medium

md5: 88d26548a43585e6ea0dfa127129503d

Issue Description:

Module 1:

public protocol MyProtocol  {}
public class ClassLevel1: MyProtocol {
    public init() {}
}
public class ClassLevel2: ClassLevel1 {
    public override init () {}
}

Modue 2:

class ClassLevel3: ClassLevel2 {
    override init() {
        super.init()
    }
}

func createClassLevel3() -> MyProtocol {
    let class3 =  ClassLevel3()
    return class3 // <- Compiler error. Says doesn't conform to MyProtocol
}

Workaround:

func createClassLevel3() -> MyProtocol {
    let class3 =  ClassLevel3()
    return class3 as! MyProtocol
}

Only happens with whole-module-optimization. Affected versions: swift-2.2, swift-2.2.1-SNAPSHOT-2016-03-28-a.

Doesn't affect swift-DEVELOPMENT-SNAPSHOT-2016-03-24-a

[swift-ci]

Comment by Diego (JIRA)

Related: badoo/Chatto#60

As this seems to be solved in master, is there any chance to cherry-pick the fix for swift-2.2.1?

[swift-ci]

Comment by Diego (JIRA)

Also, in the screenshot in badoo/Chatto#60 the error message says "DemoMessagePresenter.swift:124:38: error: cannot convert value of type 'InteractionHandlerT?' to expected argument type '_?'" which is quite misleading. In that screenshot-code, taking the return value into a let variable changes the error to "Return expression of type 'DemoMessagePresenter<ViewModelBuilderT, InteractionHandlerT>' does not conform to 'ChatItemPresenterProtocol'" which is more sensible.

[belkadan]

@atrick, any idea which recent commit might have fixed this?

[jckarter]

diegosanchezr (JIRA User), would you be able to provide a project that reproduces the problem? I was trying to put together a test case, but I can't get it to fail against swift-2.2-branch:

diff --git a/test/decl/class/Inputs/inheritance_protocol_multi_file_2.swift b/test/decl/class/Inputs/inheritance_protocol_multi_file_2.swift
new file mode 100644
index 0000000..3180548
--- /dev/null
+++ b/test/decl/class/Inputs/inheritance_protocol_multi_file_2.swift
@@ -0,0 +1,10 @@
+class ClassLevel3: ClassLevel2 {
+    override init() {
+        super.init()
+    }
+}
+
+public func createClassLevel3() -> MyProtocol {
+    let class3 =  ClassLevel3()
+    return class3 // <- Compiler error. Says doesn't conform to MyProtocol
+}
diff --git a/test/decl/class/inheritance_protocol_multi_file.swift b/test/decl/class/inheritance_protocol_multi_file.swift
new file mode 100644
index 0000000..179bc5d
--- /dev/null
+++ b/test/decl/class/inheritance_protocol_multi_file.swift
@@ -0,0 +1,12 @@
+// RUN: %target-swift-frontend -parse -verify -primary-file %s %S/Inputs/inheritance_protocol_multi_file_2.swift
+// RUN: %target-swift-frontend -parse -verify %s -primary-file %S/Inputs/inheritance_protocol_multi_file_2.swift
+// RUN: %target-swift-frontend -emit-ir -verify -whole-module-optimization %s %S/Inputs/inheritance_protocol_multi_file_2.swift && false
+// RUN: %target-swift-frontend -emit-ir -verify -whole-module-optimization %S/Inputs/inheritance_protocol_multi_file_2.swift %s
+
+public protocol MyProtocol  {}
+public class ClassLevel1: MyProtocol {
+    public init() {}
+}
+public class ClassLevel2: ClassLevel1 {
+    public override init () {}
+}

[swift-ci]

Comment by Diego (JIRA)

@jckarter Take a look at Example.zip. When I mean different modules I mean frameworks, not just different files

[jckarter]

Thanks for the clarification diegosanchezr (JIRA User).

[jckarter]

Got a reproducer. Only affects swift-2.2-branch, not master:

diff --git a/test/decl/class/Inputs/inheritance_protocol_multi_module_2.swift b/test/decl/class/Inputs/inheritance_protocol_multi_module_2.swift
new file mode 100644
index 0000000..7a6ebb4
--- /dev/null
+++ b/test/decl/class/Inputs/inheritance_protocol_multi_module_2.swift
@@ -0,0 +1,12 @@
+import Mod
+
+class ClassLevel3: ClassLevel2 {
+    override init() {
+        super.init()
+    }
+}
+
+public func createClassLevel3() -> MyProtocol {
+    let class3 =  ClassLevel3()
+    return class3 // <- Compiler error. Says doesn't conform to MyProtocol
+}
diff --git a/test/decl/class/inheritance_protocol_multi_module.swift b/test/decl/class/inheritance_protocol_multi_module.swift
new file mode 100644
index 0000000..cb4b029
--- /dev/null
+++ b/test/decl/class/inheritance_protocol_multi_module.swift
@@ -0,0 +1,14 @@
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+// RUN: %target-swift-frontend -emit-module-path %t/Mod.swiftmodule -module-name Mod %s
+// RUN: %target-swift-frontend -parse -verify -I %t %S/Inputs/inheritance_protocol_multi_module_2.swift
+
+/* module Mod */
+
+public protocol MyProtocol  {}
+public class ClassLevel1: MyProtocol {
+    public init() {}
+}
+public class ClassLevel2: ClassLevel1 {
+    public override init () {}
+}

[jckarter]

Testing a fix (borrowed from @bitjammer's fix to master): #2075

[swift-ci]

Comment by Diego (JIRA)

Confirming it's fixed in swift-2.2.1-SNAPSHOT-2016-04-12-a, thank u