Declarations referenced from a public @inlinable function must also b…

…e public, closes #690

CHANGELOG.md

@@ -16,6 +16,7 @@
 - `--external-codable-protocols` now retains enums that conform to `CodingKey`.
 - Fix redundant public accessibility analysis false-positive for actors. 
 - Fix redundant public accessibility analysis false-positive for property wrappers.
+- Fix redundant public accessibility analysis false-positive for declarations referenced from a public `@inlinable` function.
 
 ## 2.17.1 (2023-12-04)
 

Sources/PeripheryKit/SourceGraph/Mutators/RedundantExplicitPublicAccessibilityMarker.swift

@@ -109,6 +109,10 @@ final class RedundantExplicitPublicAccessibilityMarker: SourceGraphMutator {
                     return $0.parent
                 } else if decl.attributes.contains("propertyWrapper") {
                     return $0.parent
+                } else if let parent = $0.parent, parent.attributes.contains("inlinable") {
+                    // Declarations referenced within a public @inlinable function must either be
+                    // public or @useableFromInline.
+                    return parent
                 }
 
                 return nil

Tests/AccessibilityTests/AccessibilityProject/Sources/MainTarget/main.swift

@@ -68,3 +68,7 @@ Task {
 // Property wrappers
 
 _ = PublicWrappedProperty().wrappedProperty
+
+// Inline
+
+inlinableFunction()

Tests/AccessibilityTests/AccessibilityProject/Sources/TargetA/PublicInlinableFunction.swift

@@ -0,0 +1,12 @@
+import Foundation
+
+public class ClassReferencedFromPublicInlinableFunction {}
+
+@usableFromInline
+class ClassReferencedFromPublicInlinableFunction_UsableFromInline {}
+
+@inlinable
+public func inlinableFunction() {
+    _ = ClassReferencedFromPublicInlinableFunction.self
+    _ = ClassReferencedFromPublicInlinableFunction_UsableFromInline.self
+}

Tests/AccessibilityTests/RedundantPublicAccessibilityTest.swift

@@ -272,4 +272,11 @@ class RedundantPublicAccessibilityTest: SourceGraphTestCase {
             self.assertNotRedundantPublicAccessibility(.varInstance("wrappedProperty"))
         }
     }
+
+    func testPublicInlinableFunction() {
+        Self.index()
+
+        assertNotRedundantPublicAccessibility(.class("ClassReferencedFromPublicInlinableFunction"))
+        assertNotRedundantPublicAccessibility(.class("ClassReferencedFromPublicInlinableFunction_UsableFromInline"))
+    }
 }