[FIR IDE] LC Fix generating unique field names

compiler/testData/asJava/lightClasses/compilationErrors/SameName.kt

@@ -13,3 +13,5 @@ class A {
     private val j: String = { "a" }()
     private val j: String = { "b" }()
 }
+
+// FIR_COMPARISON

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/asJava/classes/FirLightClassForFacade.kt

@@ -114,6 +114,7 @@ class FirLightClassForFacade(
 
     private fun loadFieldsFromFile(
         file: KtFile,
+        usedFieldNames: MutableSet<String>,
         result: MutableList<KtLightField>
     ) {
 
@@ -130,13 +131,14 @@ class FirLightClassForFacade(
             }
         }
 
-        createFields(symbols.asSequence(), isTopLevel = true, result)
+        createFields(symbols.asSequence(), usedFieldNames, isTopLevel = true, result)
     }
 
     private val _ownFields: List<KtLightField> by lazyPub {
         val result = mutableListOf<KtLightField>()
+        val usedFieldNames = mutableSetOf<String>()
         for (file in files) {
-            loadFieldsFromFile(file, result)
+            loadFieldsFromFile(file, usedFieldNames, result)
         }
         result
     }

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/asJava/classes/FirLightClassForSymbol.kt

@@ -133,6 +133,8 @@ internal class FirLightClassForSymbol(
 
         result.addCompanionObjectFieldIfNeeded()
 
+        val usedNames = mutableSetOf<String>()
+
         classOrObjectSymbol.companionObject?.run {
             analyzeWithSymbolAsContext(this) {
                 getDeclaredMemberScope().getCallableSymbols()
@@ -141,6 +143,7 @@ internal class FirLightClassForSymbol(
                     .mapTo(result) {
                         FirLightFieldForPropertySymbol(
                             propertySymbol = it,
+                            usedNames = usedNames,
                             containingClass = this@FirLightClassForSymbol,
                             lightMemberOrigin = null,
                             isTopLevel = false,
@@ -161,7 +164,7 @@ internal class FirLightClassForSymbol(
                 .applyIf(classOrObjectSymbol.classKind == KtClassKind.COMPANION_OBJECT) {
                     filterNot { it.hasJvmFieldAnnotation() || it.isConst }
                 }
-            createFields(propertySymbols, isTopLevel = false, result)
+            createFields(propertySymbols, usedNames, isTopLevel = false, result)
 
             if (isEnum) {
                 classOrObjectSymbol.getDeclaredMemberScope().getCallableSymbols()

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/asJava/classes/firLightClassUtils.kt

@@ -10,29 +10,24 @@ import com.intellij.psi.util.CachedValuesManager
 import org.jetbrains.kotlin.analyzer.KotlinModificationTrackerService
 import org.jetbrains.kotlin.asJava.classes.KtLightClass
 import org.jetbrains.kotlin.asJava.classes.METHOD_INDEX_BASE
-import org.jetbrains.kotlin.asJava.classes.safeIsLocal
 import org.jetbrains.kotlin.asJava.classes.shouldNotBeVisibleAsLightClass
 import org.jetbrains.kotlin.asJava.elements.KtLightField
 import org.jetbrains.kotlin.asJava.elements.KtLightMethod
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
-import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
 import org.jetbrains.kotlin.idea.asJava.*
-import org.jetbrains.kotlin.idea.asJava.FirLightClassForSymbol
 import org.jetbrains.kotlin.idea.asJava.fields.FirLightFieldForEnumEntry
 import org.jetbrains.kotlin.idea.frontend.api.analyze
-import org.jetbrains.kotlin.idea.frontend.api.fir.symbols.KtFirSymbol
-import org.jetbrains.kotlin.idea.frontend.api.fir.utils.firRef
 import org.jetbrains.kotlin.idea.frontend.api.symbols.*
 import org.jetbrains.kotlin.idea.frontend.api.symbols.markers.KtAnnotatedSymbol
 import org.jetbrains.kotlin.idea.frontend.api.symbols.markers.KtCommonSymbolModality
 import org.jetbrains.kotlin.idea.frontend.api.symbols.markers.KtSymbolVisibility
-import org.jetbrains.kotlin.idea.frontend.api.symbols.markers.KtSymbolWithVisibility
 import org.jetbrains.kotlin.lexer.KtTokens
-import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.KtClassOrObject
+import org.jetbrains.kotlin.psi.KtCodeFragment
+import org.jetbrains.kotlin.psi.KtEnumEntry
+import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.psi.psiUtil.containingClass
-import org.jetbrains.kotlin.psi.psiUtil.isLambdaOutsideParentheses
 import org.jetbrains.kotlin.psi.psiUtil.isObjectLiteral
-import org.jetbrains.kotlin.util.containingNonLocalDeclaration
 import java.util.*
 
 fun getOrCreateFirLightClass(classOrObject: KtClassOrObject): KtLightClass? =
@@ -199,6 +194,7 @@ internal fun FirLightClassBase.createMethods(
 
 internal fun FirLightClassBase.createFields(
     declarations: Sequence<KtCallableSymbol>,
+    usedNames: MutableSet<String>,
     isTopLevel: Boolean,
     result: MutableList<KtLightField>
 ) {
@@ -211,7 +207,6 @@ internal fun FirLightClassBase.createFields(
         return property.hasBackingField
     }
 
-    //TODO isHiddenByDeprecation
     for (declaration in declarations) {
         if (declaration !is KtPropertySymbol) continue
         if (!hasBackingField(declaration)) continue
@@ -219,6 +214,7 @@ internal fun FirLightClassBase.createFields(
         result.add(
             FirLightFieldForPropertySymbol(
                 propertySymbol = declaration,
+                usedNames = usedNames,
                 containingClass = this@createFields,
                 lightMemberOrigin = null,
                 isTopLevel = isTopLevel

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/asJava/fields/FirLightFieldForPropertySymbol.kt

@@ -16,12 +16,15 @@ import org.jetbrains.kotlin.psi.KtDeclaration
 
 internal class FirLightFieldForPropertySymbol(
     private val propertySymbol: KtPropertySymbol,
+    usedNames: MutableSet<String>,
     containingClass: FirLightClassBase,
     lightMemberOrigin: LightMemberOrigin?,
     isTopLevel: Boolean,
     forceStatic: Boolean = false
 ) : FirLightField(containingClass, lightMemberOrigin) {
 
+    private val _name: String = generateUniqueFieldName(usedNames, propertySymbol.name.asString())
+
     override val kotlinOrigin: KtDeclaration? = propertySymbol.psi as? KtDeclaration
 
     private val _returnedType: PsiType by lazyPub {
@@ -46,7 +49,6 @@ internal class FirLightFieldForPropertySymbol(
 
     override fun getType(): PsiType = _returnedType
 
-    private val _name = propertySymbol.name.asString()
     override fun getName(): String = _name
 
     private val _modifierList: PsiModifierList by lazyPub {
@@ -105,4 +107,16 @@ internal class FirLightFieldForPropertySymbol(
                         propertySymbol == other.propertySymbol)
 
     override fun hashCode(): Int = kotlinOrigin.hashCode()
+
+    companion object {
+        private fun generateUniqueFieldName(usedNames: MutableSet<String>, base: String): String {
+            if (usedNames.add(base)) return base
+            var i = 1
+            while (true) {
+                val suggestion = "$base$$i"
+                if (usedNames.add(suggestion)) return suggestion
+                i++
+            }
+        }
+    }
 }