[FIR] Report deprecations on typealias constructor calls

Typealias constructor calls are now always wrapped with synthetic
FirConstructorCalls so that the referenced typeAlias can be extracted.
Previously, it was only necessary to map type arguments.

#KT-57780 Fixed

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirDeprecationChecker.kt

@@ -12,13 +12,17 @@ import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.diagnostics.reportOn
 import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.getContainingClassSymbol
 import org.jetbrains.kotlin.fir.analysis.checkers.toRegularClassSymbol
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.declarations.FutureApiDeprecationInfo
 import org.jetbrains.kotlin.fir.analysis.checkers.isLhsOfAssignment
+import org.jetbrains.kotlin.fir.analysis.checkers.type.FirDeprecatedTypeChecker
 import org.jetbrains.kotlin.fir.declarations.getDeprecation
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.references.resolved
+import org.jetbrains.kotlin.fir.resolve.firClassLike
+import org.jetbrains.kotlin.fir.resolve.typeAliasForConstructor
 import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirConstructorSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirTypeAliasSymbol
@@ -39,14 +43,31 @@ object FirDeprecationChecker : FirBasicExpressionChecker() {
 
         val calleeReference = expression.calleeReference ?: return
         val resolvedReference = calleeReference.resolved ?: return
+        val source = resolvedReference.source
         val referencedSymbol = resolvedReference.resolvedSymbol
 
+        // If this is a constructor call through a typealias, we want to check deprecations on the typealias itself as well as any
+        // intermediary expansions.
+        // However, we'll already check the final expansion below, so we don't want to do it here as well to prevent duplicate diagnostics.
+        val typeAliasForConstructor = (referencedSymbol as? FirConstructorSymbol)?.typeAliasForConstructor
+        if (typeAliasForConstructor != null && expression is FirQualifiedAccessExpression) {
+            FirDeprecatedTypeChecker.reportDeprecationsRecursively(
+                typeAliasForConstructor,
+                source,
+                context,
+                reporter,
+                // We pass the containing class symbol to ignore the final expansion.
+                symbolToIgnore = referencedSymbol.getContainingClassSymbol(context.session)
+            )
+        }
+
         if (expression is FirDelegatedConstructorCall) {
             // Report deprecations on the constructor itself, not on the declaring class as that will be handled by FirDeprecatedTypeChecker
             val constructorOnlyDeprecation = referencedSymbol.getDeprecation(context.session, expression) ?: return
-            reportApiStatus(resolvedReference.source, referencedSymbol, null, constructorOnlyDeprecation, reporter, context)
+            val typealiasSymbol = expression.constructedTypeRef.firClassLike(context.session)?.symbol as? FirTypeAliasSymbol
+            reportApiStatus(source, referencedSymbol, typealiasSymbol, constructorOnlyDeprecation, reporter, context)
         } else {
-            reportApiStatusIfNeeded(resolvedReference.source, referencedSymbol, context, reporter, callSite = expression)
+            reportApiStatusIfNeeded(source, referencedSymbol, context, reporter, typeAliasForConstructor, callSite = expression)
         }
     }
 
@@ -83,7 +104,7 @@ object FirDeprecationChecker : FirBasicExpressionChecker() {
         typealiasSymbol: FirTypeAliasSymbol?,
         deprecationInfo: DeprecationInfo,
         reporter: DiagnosticReporter,
-        context: CheckerContext
+        context: CheckerContext,
     ) {
         if (typealiasSymbol == null) {
             val diagnostic = when (deprecationInfo.deprecationLevel) {
@@ -118,7 +139,7 @@ object FirDeprecationChecker : FirBasicExpressionChecker() {
     private fun getWorstDeprecation(
         callSite: FirElement?,
         symbol: FirBasedSymbol<*>,
-        context: CheckerContext
+        context: CheckerContext,
     ): DeprecationInfo? {
         val deprecationInfos = listOfNotNull(
             symbol.getDeprecation(context.session, callSite),

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/type/FirDeprecatedTypeChecker.kt

@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.fir.analysis.checkers.expression.FirDeprecationCheck
 import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
 import org.jetbrains.kotlin.fir.resolve.toSymbol
 import org.jetbrains.kotlin.fir.symbols.SymbolInternals
+import org.jetbrains.kotlin.fir.symbols.impl.FirClassLikeSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirTypeAliasSymbol
 import org.jetbrains.kotlin.fir.symbols.lazyResolveToPhase
 import org.jetbrains.kotlin.fir.types.*
@@ -23,28 +24,58 @@ object FirDeprecatedTypeChecker : FirTypeRefChecker() {
         if (source.kind is KtFakeSourceElementKind) return
 
         val resolved = typeRef.coneTypeSafe<ConeClassLikeType>() ?: return
-        checkType(resolved, null, source, context, reporter)
+        checkType(resolved, null, source, context, reporter, symbolToIgnore = null)
     }
 
-    @OptIn(SymbolInternals::class)
     private fun checkType(
         type: ConeClassLikeType,
         typeAliasSymbol: FirTypeAliasSymbol?,
-        source: KtSourceElement,
+        source: KtSourceElement?,
         context: CheckerContext,
-        reporter: DiagnosticReporter
+        reporter: DiagnosticReporter,
+        symbolToIgnore: FirClassLikeSymbol<*>?,
     ) {
         val symbol = type.lookupTag.toSymbol(context.session) ?: return
-        FirDeprecationChecker.reportApiStatusIfNeeded(source, symbol, context, reporter, typealiasSymbol = typeAliasSymbol)
+        reportDeprecationsRecursively(symbol, typeAliasSymbol, source, context, reporter, symbolToIgnore)
+    }
 
+    @OptIn(SymbolInternals::class)
+    private fun reportDeprecationsRecursively(
+        symbol: FirClassLikeSymbol<*>,
+        // If not-null, TYPEALIAS_EXPANSION_DEPRECATION will be reported instead of DEPRECATION.
+        typeAliasSymbol: FirTypeAliasSymbol?,
+        source: KtSourceElement?,
+        context: CheckerContext,
+        reporter: DiagnosticReporter,
+        symbolToIgnore: FirClassLikeSymbol<*>?,
+    ) {
+        if (symbol == symbolToIgnore) return
+
+        FirDeprecationChecker.reportApiStatusIfNeeded(source, symbol, context, reporter, typealiasSymbol = typeAliasSymbol)
         if (symbol is FirTypeAliasSymbol) {
             val typeAlias = symbol.fir
             typeAlias.lazyResolveToPhase(FirResolvePhase.TYPES)
             typeAlias.expandedTypeRef.coneType.forEachType {
-                if (it is ConeClassLikeType) checkType(it, symbol, source, context, reporter)
+                if (it is ConeClassLikeType) checkType(it, symbol, source, context, reporter, symbolToIgnore)
             }
         }
     }
 
+    /**
+     * Reports deprecations on [symbol]. If [symbol] is a typealias, deprecations will be reported on the expansions recursively.
+     *
+     * @param symbolToIgnore If equal to [symbol], no deprecations on the [symbol] and its expansions will be reported.
+     * It's passed to recursive calls and can be used to only report deprecations on a typealias and its intermediary expansions
+     * but not on the final expansion if set to the fully expanded class symbol.
+     */
+    fun reportDeprecationsRecursively(
+        symbol: FirClassLikeSymbol<*>,
+        source: KtSourceElement?,
+        context: CheckerContext,
+        reporter: DiagnosticReporter,
+        symbolToIgnore: FirClassLikeSymbol<*>?,
+    ) {
+        reportDeprecationsRecursively(symbol, typeAliasSymbol = null, source, context, reporter, symbolToIgnore)
+    }
 }
 

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

@@ -857,20 +857,27 @@ class FirCallResolver(
 /** A candidate in the overload candidate set. */
 data class OverloadCandidate(val candidate: Candidate, val isInBestCandidates: Boolean)
 
+/** Used for IDE */
 class AllCandidatesCollector(
     components: BodyResolveComponents,
     resolutionStageRunner: ResolutionStageRunner
 ) : CandidateCollector(components, resolutionStageRunner) {
-    private val allCandidatesSet = mutableSetOf<Candidate>()
+    private val allCandidatesMap = mutableMapOf<FirBasedSymbol<*>, Candidate>()
 
     override fun consumeCandidate(group: TowerGroup, candidate: Candidate, context: ResolutionContext): CandidateApplicability {
-        allCandidatesSet += candidate
+        // Filter duplicate symbols. In the case of typealias constructor calls, we consider the original constructor for uniqueness.
+        val key = (candidate.symbol.fir as? FirConstructor)?.originalConstructorIfTypeAlias?.symbol
+            ?: candidate.symbol
+
+        // To preserve the behavior of a HashSet which keeps the first added item, we use getOrPut instead of put.
+        // Changing this behavior breaks testData/components/callResolver/resolveCandidates/singleCandidate/functionTypeVariableCall_extensionReceiver.kt
+        allCandidatesMap.getOrPut(key) { candidate }
         return super.consumeCandidate(group, candidate, context)
     }
 
     // We want to get candidates at all tower levels.
     override fun shouldStopAtTheGroup(group: TowerGroup): Boolean = false
 
-    val allCandidates: List<Candidate>
+    val allCandidates: Collection<Candidate>
-        get() = allCandidatesSet.toList()
+        get() = allCandidatesMap.values
 }

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

@@ -182,15 +182,15 @@ private fun processConstructors(
 
                 val outerType = bodyResolveComponents.outerClassManager.outerType(type)
 
-                if (basicScope != null &&
+                if (basicScope != null) {
-                    (matchedSymbol.fir.typeParameters.isNotEmpty() || outerType != null || type.typeArguments.isNotEmpty())
-                ) {
                     TypeAliasConstructorsSubstitutingScope(
                         matchedSymbol,
                         basicScope,
                         outerType
                     )
-                } else basicScope
+                } else {
+                    null
+                }
             }
             is FirClassSymbol -> {
                 val firClass = matchedSymbol.fir as FirClass
@@ -232,7 +232,7 @@ private class TypeAliasConstructorsSubstitutingScope(
                     origin = FirDeclarationOrigin.Synthetic.TypeAliasConstructor
 
                     this.typeParameters.clear()
-                    this.typeParameters += typeParameters.map { buildConstructedClassTypeParameterRef { symbol = it.symbol } }
+                    typeParameters.mapTo(this.typeParameters) { buildConstructedClassTypeParameterRef { symbol = it.symbol } }
 
                     if (outerType != null) {
                         // If the matched symbol is a type alias, and the expanded type is a nested class, e.g.,

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/DeclarationUtils.kt

@@ -93,6 +93,9 @@ private object TypeAliasForConstructorKey : FirDeclarationDataKey()
 
 var FirConstructor.typeAliasForConstructor: FirTypeAliasSymbol? by FirDeclarationDataRegistry.data(TypeAliasForConstructorKey)
 
+val FirConstructorSymbol.typeAliasForConstructor: FirTypeAliasSymbol?
+    get() = fir.typeAliasForConstructor
+
 interface FirCodeFragmentContext {
     val towerDataContext: FirTowerDataContext
     val variables: Map<FirBasedSymbol<*>, Set<ConeKotlinType>>

compiler/testData/diagnostics/tests/deprecated/typealiasConstructor.fir.kt

@@ -1,17 +0,0 @@
-@Deprecated("Deprecated class")
-open class DeprecatedClass
-
-open class WithDeprecatedCtor(val x: Int) {
-    @Deprecated("Deprecated constructor")
-    constructor() : this(0)
-}
-
-typealias DeprecatedClassAlias = <!DEPRECATION!>DeprecatedClass<!>
-typealias WithDeprecatedCtorAlias = WithDeprecatedCtor
-typealias ArrayListOfDeprecatedClass = ArrayList<<!DEPRECATION!>DeprecatedClass<!>>
-
-class Test1 : <!TYPEALIAS_EXPANSION_DEPRECATION!>DeprecatedClassAlias<!>()
-
-class Test2 : <!DEPRECATION!>WithDeprecatedCtorAlias<!>()
-
-val test3 = ArrayListOfDeprecatedClass()

compiler/testData/diagnostics/tests/deprecated/typealiasConstructor.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 @Deprecated("Deprecated class")
 open class DeprecatedClass
 
@@ -11,7 +12,9 @@ typealias WithDeprecatedCtorAlias = WithDeprecatedCtor
 typealias ArrayListOfDeprecatedClass = ArrayList<<!DEPRECATION!>DeprecatedClass<!>>
 
 class Test1 : <!TYPEALIAS_EXPANSION_DEPRECATION!>DeprecatedClassAlias<!>()
+val test1_1 = <!TYPEALIAS_EXPANSION_DEPRECATION!>DeprecatedClassAlias<!>()
 
 class Test2 : <!TYPEALIAS_EXPANSION_DEPRECATION!>WithDeprecatedCtorAlias<!>()
+val test2_1 = <!TYPEALIAS_EXPANSION_DEPRECATION!>WithDeprecatedCtorAlias<!>()
 
 val test3 = <!TYPEALIAS_EXPANSION_DEPRECATION!>ArrayListOfDeprecatedClass<!>()

compiler/testData/diagnostics/tests/deprecated/typealiasConstructor.txt

@@ -1,5 +1,7 @@
 package
 
+public val test1_1: DeprecatedClassAlias /* = DeprecatedClass */
+public val test2_1: WithDeprecatedCtorAlias /* = WithDeprecatedCtor */
 public val test3: ArrayListOfDeprecatedClass /* = java.util.ArrayList<DeprecatedClass> */
 
 @kotlin.Deprecated(message = "Deprecated class") public open class DeprecatedClass {

compiler/testData/diagnostics/tests/deprecated/typealiasUsage.fir.kt

@@ -1,24 +0,0 @@
-open class Base {
-    companion object
-}
-interface IFoo
-open class CG<T>
-interface IG<T>
-
-@Deprecated("Obsolete")
-typealias Obsolete = Base
-
-@Deprecated("Obsolete")
-typealias IObsolete = IFoo
-
-fun test1(x: <!DEPRECATION!>Obsolete<!>) = x
-fun test1a(x: List<<!DEPRECATION!>Obsolete<!>>) = x
-
-val test2 = Obsolete()
-
-val test3 = <!DEPRECATION!>Obsolete<!>
-
-class Test4: <!DEPRECATION!>Obsolete<!>()
-class Test4a: <!DEPRECATION!>IObsolete<!>
-class Test4b: IG<<!DEPRECATION!>Obsolete<!>>
-class Test4c: CG<<!DEPRECATION!>Obsolete<!>>()

compiler/testData/diagnostics/tests/deprecated/typealiasUsage.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 open class Base {
     companion object
 }