FIR checkers: simplify hasPrimaryConstructor by source element check

compiler/fir/analysis-tests/testData/resolve/typeAliasWithTypeArguments.kt

@@ -10,7 +10,7 @@ interface C {
     fun baz()
 }
 
-interface Inv<K, T>() {
+interface <!CONSTRUCTOR_IN_INTERFACE!>Inv<K, T>()<!> {
     fun k(): K
     fun t(): T
 }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConstructorInInterfaceChecker.kt

@@ -5,22 +5,14 @@
 
 package org.jetbrains.kotlin.fir.analysis.checkers.declaration
 
-import com.intellij.lang.LighterASTNode
-import com.intellij.openapi.util.Ref
-import com.intellij.psi.PsiElement
-import com.intellij.psi.PsiErrorElement
-import com.intellij.util.diff.FlyweightCapableTreeStructure
-import org.jetbrains.kotlin.KtNodeTypes.PRIMARY_CONSTRUCTOR
 import org.jetbrains.kotlin.descriptors.ClassKind
-import org.jetbrains.kotlin.fir.FirLightSourceElement
 import org.jetbrains.kotlin.fir.FirSourceElement
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.analysis.diagnostics.hasPrimaryConstructor
 import org.jetbrains.kotlin.fir.declarations.FirClass
 import org.jetbrains.kotlin.fir.declarations.FirDeclaration
-import org.jetbrains.kotlin.fir.psi
-import org.jetbrains.kotlin.psi.KtPrimaryConstructor
 
 object FirConstructorInInterfaceChecker : FirBasicDeclarationChecker() {
     override fun check(declaration: FirDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
@@ -33,34 +25,6 @@ object FirConstructorInInterfaceChecker : FirBasicDeclarationChecker() {
         }
     }
 
-    private fun FirSourceElement.hasPrimaryConstructor(): Boolean {
-        val localPsi = psi
-        val localLightNode = lighterASTNode
-
-        if (localPsi != null && localPsi !is PsiErrorElement) {
-            return localPsi.hasPrimaryConstructor()
-        } else if (this is FirLightSourceElement) {
-            return localLightNode.hasPrimaryConstructor(treeStructure)
-        }
-
-        return false
-    }
-
-    private fun PsiElement.hasPrimaryConstructor(): Boolean {
-        return lastChild !is PsiErrorElement && lastChild is KtPrimaryConstructor
-    }
-
-    private fun LighterASTNode.hasPrimaryConstructor(tree: FlyweightCapableTreeStructure<LighterASTNode>): Boolean {
-        val children = getChildren(tree)
-        return children.lastOrNull()?.tokenType == PRIMARY_CONSTRUCTOR
-    }
-
-    private fun LighterASTNode.getChildren(tree: FlyweightCapableTreeStructure<LighterASTNode>): List<LighterASTNode> {
-        val children = Ref<Array<LighterASTNode?>>()
-        val count = tree.getChildren(this, children)
-        return if (count > 0) children.get().filterNotNull() else emptyList()
-    }
-
     private fun DiagnosticReporter.report(source: FirSourceElement?) {
         source?.let { report(FirErrors.CONSTRUCTOR_IN_INTERFACE.on(it)) }
     }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/diagnostics/LightTreePositioningStrategies.kt

@@ -150,6 +150,9 @@ fun FirSourceElement.hasValOrVar(): Boolean =
 fun FirSourceElement.hasVar(): Boolean =
     treeStructure.findChildByType(lighterASTNode, KtTokens.VAR_KEYWORD) != null
 
+fun FirSourceElement.hasPrimaryConstructor(): Boolean =
+    treeStructure.primaryConstructor(lighterASTNode) != null
+
 private fun FlyweightCapableTreeStructure<LighterASTNode>.constructorKeyword(node: LighterASTNode): LighterASTNode? =
     findChildByType(node, KtTokens.CONSTRUCTOR_KEYWORD)
 

compiler/testData/diagnostics/tests/SupertypeListChecks.fir.kt

@@ -21,7 +21,7 @@ interface T1 {}
 
 interface T2<T> {}
 
-interface Test() {
+interface <!CONSTRUCTOR_IN_INTERFACE!>Test()<!> {
 }
 
 interface Test1 : <!INTERFACE_WITH_SUPERCLASS, SUPERTYPE_INITIALIZED_IN_INTERFACE!>C2<!>() {}

compiler/testData/diagnostics/tests/TraitWithConstructor.fir.kt

@@ -2,11 +2,11 @@
 
 class C(val a: String) {}
 
-interface T1(val x: String) {}
+interface <!CONSTRUCTOR_IN_INTERFACE!>T1(val x: String)<!> {}
 
-interface T2 constructor() {}
+interface <!CONSTRUCTOR_IN_INTERFACE!>T2 constructor()<!> {}
 
-interface T3 private constructor(a: Int) {}
+interface <!CONSTRUCTOR_IN_INTERFACE!>T3 private constructor(a: Int)<!> {}
 
 interface T4 {
     <!CONSTRUCTOR_IN_INTERFACE!>constructor(a: Int)<!> {
@@ -14,5 +14,5 @@ interface T4 {
     }
 }
 
-interface T5 private () : T4 {}
+interface <!CONSTRUCTOR_IN_INTERFACE!>T5 private ()<!> : T4 {}
-interface T6 private<!SYNTAX!><!> : T5 {}
+interface <!CONSTRUCTOR_IN_INTERFACE!>T6<!> private<!SYNTAX!><!> : T5 {}

compiler/testData/diagnostics/tests/traitWithRequired/traitSupertypeList.fir.kt

@@ -1,6 +1,6 @@
 open class bar()
 
-interface Foo() : <!INTERFACE_WITH_SUPERCLASS!>bar<!>(), bar, bar {
+interface <!CONSTRUCTOR_IN_INTERFACE!>Foo()<!> : <!INTERFACE_WITH_SUPERCLASS!>bar<!>(), bar, bar {
 }
 
 interface Foo2 : <!INTERFACE_WITH_SUPERCLASS!>bar<!>, Foo {