KT-13961 REDECLARATION not reported on private-in-file 'foo' vs public 'foo' in different file

Private-in-file declarations conflict with public overload-equivalent declarations
in other files in the same package.

Move functions for grouping possible redeclarations to OverloadResolver
(since they are used only there).

Refactor redeclarations / conflicting overloads reporting.

compiler/testData/diagnostics/tests/redeclarations/ClassRedeclarationInDifferentFiles.kt

@@ -1,11 +1,11 @@
 // FILE: f1.kt
 package test
 
-class <!REDECLARATION!>A<!>
+class <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>A<!>
 class F1
 
 // FILE: f2.kt
 package test
 
-class <!REDECLARATION!>A<!>
+class <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>A<!>
 class F2

compiler/testData/diagnostics/tests/redeclarations/MultiFilePackageRedeclaration.kt

@@ -1,7 +1,7 @@
 // FILE: f.kt
 package a
-class <!REDECLARATION!>b<!> {}
+class <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>b<!> {}
 // FILE: f.kt
-package a.<!REDECLARATION!>b<!>
+package a.<!PACKAGE_OR_CLASSIFIER_REDECLARATION!>b<!>
 // FILE: f.kt
-package a.<!REDECLARATION!>b<!>
+package a.<!PACKAGE_OR_CLASSIFIER_REDECLARATION!>b<!>

compiler/testData/diagnostics/tests/redeclarations/Redeclarations.kt

@@ -1,15 +1,15 @@
 // FILE: f.kt
 package redeclarations
-  object <!REDECLARATION, REDECLARATION!>A<!> {
+  object <!PACKAGE_OR_CLASSIFIER_REDECLARATION, REDECLARATION!>A<!> {
     val x : Int = 0
 
     val A = 1
   }
 
-  class <!REDECLARATION!>A<!> {}
+  class <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>A<!> {}
 
-  val <!REDECLARATION, REDECLARATION!>A<!> = 1
+  val <!PACKAGE_OR_CLASSIFIER_REDECLARATION, REDECLARATION!>A<!> = 1
 
 // FILE: f.kt
-  package redeclarations.<!REDECLARATION!>A<!>
+  package redeclarations.<!PACKAGE_OR_CLASSIFIER_REDECLARATION!>A<!>
     class A {}

compiler/testData/diagnostics/tests/redeclarations/RedeclaringPrivateToFile.kt

@@ -5,8 +5,14 @@ interface A
 interface B : A
 
 private fun validFun() {}
+private val validVal = 1
 
-private val validProp = 1
+<!CONFLICTING_OVERLOADS!>private fun invalidFun0()<!> {}
+private val <!REDECLARATION!>invalidProp0<!> = 1
+
+// NB invalidFun0 and invalidProp0 are conflicting overloads, since the following is an ambiguity:
+fun useInvalidFun0() = <!OVERLOAD_RESOLUTION_AMBIGUITY!>invalidFun0<!>()
+fun useInvalidProp0() = <!OVERLOAD_RESOLUTION_AMBIGUITY!>invalidProp0<!>
 
 <!CONFLICTING_OVERLOADS!>private fun invalidFun1()<!> {}
 <!CONFLICTING_OVERLOADS!>private fun invalidFun1()<!> {}
@@ -17,7 +23,7 @@ private val validProp = 1
 <!CONFLICTING_OVERLOADS!>public fun invalidFun3()<!> {}
 
 <!CONFLICTING_OVERLOADS!>private fun invalidFun4()<!> {}
-<!CONFLICTING_OVERLOADS, CONFLICTING_OVERLOADS!>public fun invalidFun4()<!> {}
+<!CONFLICTING_OVERLOADS!>public fun invalidFun4()<!> {}
 
 public fun validFun2(a: A) = a
 public fun validFun2(b: B) = b
@@ -26,8 +32,11 @@ public fun validFun2(b: B) = b
 package a
 
 private fun validFun() {}
+private val validVal = 1
 
-private val validProp = 1
+<!CONFLICTING_OVERLOADS!>private fun invalidFun0()<!> {}
+
+private val <!REDECLARATION!>invalidProp0<!> = 1
 
 <!CONFLICTING_OVERLOADS!>internal fun invalidFun3()<!> {}
 <!CONFLICTING_OVERLOADS!>internal fun invalidFun4()<!> {}
@@ -35,6 +44,6 @@ private val validProp = 1
 // FILE: c.kt
 package a
 
-public fun validFun() {}
+<!CONFLICTING_OVERLOADS!>public fun invalidFun0()<!> {}
 
-public val validProp = 1
+public val <!REDECLARATION!>invalidProp0<!> = 1

compiler/testData/diagnostics/tests/redeclarations/RedeclaringPrivateToFile.txt

@@ -1,9 +1,14 @@
 package
 
 package a {
-    private val validProp: kotlin.Int = 1
-    private val validProp: kotlin.Int = 1
-    public val validProp: kotlin.Int = 1
+    private val invalidProp0: kotlin.Int = 1
+    private val invalidProp0: kotlin.Int = 1
+    public val invalidProp0: kotlin.Int = 1
+    private val validVal: kotlin.Int = 1
+    private val validVal: kotlin.Int = 1
+    private fun invalidFun0(): kotlin.Unit
+    private fun invalidFun0(): kotlin.Unit
+    public fun invalidFun0(): kotlin.Unit
     private fun invalidFun1(): kotlin.Unit
     private fun invalidFun1(): kotlin.Unit
     private fun invalidFun2(): kotlin.Unit
@@ -13,9 +18,10 @@ package a {
     internal fun invalidFun4(): kotlin.Unit
     private fun invalidFun4(): kotlin.Unit
     public fun invalidFun4(): kotlin.Unit
+    public fun useInvalidFun0(): [ERROR : Error function type]
+    public fun useInvalidProp0(): [ERROR : Error function type]
     private fun validFun(): kotlin.Unit
     private fun validFun(): kotlin.Unit
-    public fun validFun(): kotlin.Unit
     public fun validFun2(/*0*/ a: a.A): a.A
     public fun validFun2(/*0*/ b: a.B): a.B
 

compiler/testData/diagnostics/tests/redeclarations/ScriptAndClassConflict.kt

@@ -1,7 +1,7 @@
 // FILE: f1.kt
 package test
 
-class <!REDECLARATION!>A<!>
+class <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>A<!>
 class F1
 
 // FILE: A.kts

compiler/testData/diagnostics/tests/redeclarations/TopLevelPropertyVsClassifier.kt

@@ -7,7 +7,7 @@ interface <!REDECLARATION!>Test2<!>
 val <!REDECLARATION!>Test3<!> = null
 object <!REDECLARATION!>Test3<!>
 
-val <!REDECLARATION, REDECLARATION!>Test4<!> = null
-class <!REDECLARATION, REDECLARATION!>Test4<!>
-interface <!REDECLARATION!>Test4<!>
-object <!REDECLARATION!>Test4<!>
+val <!PACKAGE_OR_CLASSIFIER_REDECLARATION, REDECLARATION!>Test4<!> = null
+class <!PACKAGE_OR_CLASSIFIER_REDECLARATION, REDECLARATION!>Test4<!>
+interface <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>Test4<!>
+object <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>Test4<!>

compiler/testData/diagnostics/tests/redeclarations/TypeAliasVsClass.kt

@@ -1,9 +1,9 @@
 // FILE: file1.kt
-class <!REDECLARATION!>SomeClass<!>
+class <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>SomeClass<!>
 
-typealias <!REDECLARATION!>SomeClass<!> = Any
-typealias <!REDECLARATION!>SomeClass<!> = Any
-typealias <!REDECLARATION!>SomeClass<!> = Any
+typealias <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>SomeClass<!> = Any
+typealias <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>SomeClass<!> = Any
+typealias <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>SomeClass<!> = Any
 
 class Outer {
     class <!REDECLARATION!>Nested<!>
@@ -14,4 +14,4 @@ class Outer {
 }
 
 // FILE: file2.kt
-typealias <!REDECLARATION!>SomeClass<!> = Any
+typealias <!PACKAGE_OR_CLASSIFIER_REDECLARATION!>SomeClass<!> = Any