[FIR] Move tracking candidate applicability from CheckerSink to Candidate

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/FirOverloadByLambdaReturnTypeResolver.kt

@@ -158,7 +158,7 @@ class FirOverloadByLambdaReturnTypeResolver(
             val successfulCandidates = mutableSetOf<Candidate>()
 
             for (candidate in candidates) {
-                if (candidate.isSuccessful()) {
+                if (candidate.isSuccessful) {
                     successfulCandidates += candidate
                 } else {
                     errorCandidates += candidate

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/Candidate.kt

@@ -109,17 +109,22 @@ class Candidate(
     lateinit var typeArgumentMapping: TypeArgumentMapping
     val postponedAtoms = mutableListOf<PostponedResolvedAtom>()
 
-    val diagnostics: MutableList<ResolutionDiagnostic> = mutableListOf()
+    var currentApplicability = CandidateApplicability.RESOLVED
+        private set
+
+    private val _diagnostics: MutableList<ResolutionDiagnostic> = mutableListOf()
+    val diagnostics: List<ResolutionDiagnostic>
+        get() = _diagnostics
 
     fun addDiagnostic(diagnostic: ResolutionDiagnostic) {
-        diagnostics += diagnostic
+        _diagnostics += diagnostic
+        if (diagnostic.applicability < currentApplicability) {
+            currentApplicability = diagnostic.applicability
+        }
     }
 
-    fun isSuccessful(): Boolean {
+    val isSuccessful: Boolean
-        if (system.hasContradiction) return false
+        get() = currentApplicability.isSuccess && (!systemInitialized || !system.hasContradiction)
-        val currentApplicability = diagnostics.map { it.applicability }.minOrNull() ?: CandidateApplicability.RESOLVED
-        return currentApplicability.isSuccess
-    }
 
     var passedStages: Int = 0
 

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/CheckerSink.kt

@@ -32,20 +32,12 @@ suspend inline fun CheckerSink.yieldDiagnostic(diagnostic: ResolutionDiagnostic)
 }
 
 class CheckerSinkImpl(
+    private val candidate: Candidate,
     var continuation: Continuation<Unit>? = null,
-    val stopOnFirstError: Boolean = true
+    val stopOnFirstError: Boolean = true,
 ) : CheckerSink() {
-    var currentApplicability = CandidateApplicability.RESOLVED
-        private set
-
-    private val _diagnostics: MutableList<ResolutionDiagnostic> = mutableListOf()
-
-    val diagnostics: List<ResolutionDiagnostic>
-        get() = _diagnostics
-
     override fun reportDiagnostic(diagnostic: ResolutionDiagnostic) {
-        _diagnostics += diagnostic
+        candidate.addDiagnostic(diagnostic)
-        if (diagnostic.applicability < currentApplicability) currentApplicability = diagnostic.applicability
     }
 
     @PrivateForInline
@@ -55,6 +47,5 @@ class CheckerSinkImpl(
     }
 
     override val needYielding: Boolean
-        get() = stopOnFirstError && !currentApplicability.isSuccess
+        get() = stopOnFirstError && !candidate.isSuccessful
-
 }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/ResolutionStageRunner.kt

@@ -15,7 +15,7 @@ import kotlin.coroutines.resume
 
 class ResolutionStageRunner {
     fun processCandidate(candidate: Candidate, context: ResolutionContext, stopOnFirstError: Boolean = true): CandidateApplicability {
-        val sink = CheckerSinkImpl(stopOnFirstError = stopOnFirstError)
+        val sink = CheckerSinkImpl(candidate, stopOnFirstError = stopOnFirstError)
         var finished = false
         sink.continuation = suspend {
             candidate.callInfo.callKind.resolutionSequence.forEachIndexed { index, stage ->
@@ -35,11 +35,10 @@ class ResolutionStageRunner {
 
         while (!finished) {
             sink.continuation!!.resume(Unit)
-            if (!sink.currentApplicability.isSuccess) {
+            if (!candidate.isSuccessful) {
                 break
             }
         }
-        candidate.diagnostics += sink.diagnostics
+        return candidate.currentApplicability
-        return sink.currentApplicability
     }
 }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/PostponedArgumentsAnalyzer.kt

@@ -162,7 +162,7 @@ class PostponedArgumentsAnalyzer(
 
         returnArguments.forEach { c.addSubsystemFromExpression(it) }
 
-        val checkerSink: CheckerSink = CheckerSinkImpl()
+        val checkerSink: CheckerSink = CheckerSinkImpl(candidate)
 
         var hasExpressionInReturnArguments = false
         val lambdaReturnType = lambda.returnType.let(substitute).takeUnless { it.isUnit }

compiler/testData/diagnostics/tests/declarationChecks/localVariablesWithTypeParameters_1_3.fir.kt

@@ -11,7 +11,7 @@ fun test() {
     const val <T> a3 = 0
     <!INAPPLICABLE_LATEINIT_MODIFIER!>lateinit val <T> a4 = 0<!>
     val <T> a5 by Delegate<Int>()
-    val <T> a6 by <!INAPPLICABLE_CANDIDATE!>Delegate<<!UNRESOLVED_REFERENCE!>T<!>>()<!>
+    val <T> a6 by Delegate<<!UNRESOLVED_REFERENCE!>T<!>>()
 }
 
 class Delegate<F> {

compiler/testData/diagnostics/tests/declarationChecks/localVariablesWithTypeParameters_1_4.fir.kt

@@ -11,7 +11,7 @@ fun test() {
     const val <T> a3 = 0
     <!INAPPLICABLE_LATEINIT_MODIFIER!>lateinit val <T> a4 = 0<!>
     val <T> a5 by Delegate<Int>()
-    val <T> a6 by <!INAPPLICABLE_CANDIDATE!>Delegate<<!UNRESOLVED_REFERENCE!>T<!>>()<!>
+    val <T> a6 by Delegate<<!UNRESOLVED_REFERENCE!>T<!>>()
 }
 
 class Delegate<F> {

compiler/testData/diagnostics/tests/delegatedProperty/propertyDefferedType.fir.kt

@@ -5,7 +5,7 @@
 import kotlin.reflect.KProperty
 
 class B {
-    val c by <!INAPPLICABLE_CANDIDATE!><!INAPPLICABLE_CANDIDATE!>Delegate<!>(<!UNRESOLVED_REFERENCE!>ag<!>)<!>
+    val c by <!INAPPLICABLE_CANDIDATE!>Delegate<!>(<!UNRESOLVED_REFERENCE!>ag<!>)
 }
 
 class Delegate<T: Any>(val init: T) {

compiler/testData/diagnostics/tests/funInterface/funInterfaceConversionOnReceiver.fir.kt

@@ -5,5 +5,5 @@ fun interface Bar {
 operator fun Bar.plus(b: Bar): String = invoke() + b.invoke()
 
 fun box(): String {
-    return { "O" } <!INAPPLICABLE_CANDIDATE!>+<!> { "K" }
+    return { "O" } + { "K" }
 }

compiler/testData/diagnostics/tests/generics/projectionsScope/typeParameterBounds.fir.kt

@@ -14,14 +14,14 @@ class A<T> {
 
 fun foo2(a: A<out CharSequence>, b: A<in CharSequence>) {
     a.<!INAPPLICABLE_CANDIDATE!>foo1<!>(Out<CharSequence>())
-    a.<!INAPPLICABLE_CANDIDATE!>foo1<!><Out<CharSequence>>(Out())
+    a.foo1<<!UPPER_BOUND_VIOLATED!>Out<CharSequence><!>>(Out())
 
     a.foo1(Out())
     a.foo1(Out<Nothing>())
 
     a.foo2(Inv())
     a.<!INAPPLICABLE_CANDIDATE!>foo2<!>(Inv<CharSequence>())
-    a.<!INAPPLICABLE_CANDIDATE!>foo2<!><Inv<CharSequence>>(Inv())
+    a.foo2<<!UPPER_BOUND_VIOLATED!>Inv<CharSequence><!>>(Inv())
 
     a.foo3(In())
     a.foo3(In<CharSequence>())
@@ -33,11 +33,11 @@ fun foo2(a: A<out CharSequence>, b: A<in CharSequence>) {
 
     b.foo2(Inv())
     b.<!INAPPLICABLE_CANDIDATE!>foo2<!>(Inv<CharSequence>())
-    b.<!INAPPLICABLE_CANDIDATE!>foo2<!><Inv<CharSequence>>(Inv())
+    b.foo2<<!UPPER_BOUND_VIOLATED!>Inv<CharSequence><!>>(Inv())
 
 
     b.<!INAPPLICABLE_CANDIDATE!>foo3<!>(In<CharSequence>())
-    b.<!INAPPLICABLE_CANDIDATE!>foo3<!><In<CharSequence>>(In())
+    b.foo3<<!UPPER_BOUND_VIOLATED!>In<CharSequence><!>>(In())
 
     b.foo3(In<Any?>())
     b.foo3(In())