[FIR] Add VARIABLE_WITH_NO_TYPE_NO_INITIALIZER diagnostic

compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt

@@ -938,6 +938,7 @@ object DIAGNOSTICS_LIST : DiagnosticList("FirErrors") {
             parameter<Symbol>("lambda")
         }
         val WRONG_IMPLIES_CONDITION by warning<PsiElement>()
+        val VARIABLE_WITH_NO_TYPE_NO_INITIALIZER by error<KtVariableDeclaration>(PositioningStrategy.DECLARATION_NAME)
     }
 
     val NULLABILITY by object : DiagnosticGroup("Nullability") {

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrors.kt

@@ -69,6 +69,7 @@ import org.jetbrains.kotlin.psi.KtTypeParameter
 import org.jetbrains.kotlin.psi.KtTypeProjection
 import org.jetbrains.kotlin.psi.KtTypeReference
 import org.jetbrains.kotlin.psi.KtValueArgument
+import org.jetbrains.kotlin.psi.KtVariableDeclaration
 import org.jetbrains.kotlin.psi.KtWhenCondition
 import org.jetbrains.kotlin.psi.KtWhenEntry
 import org.jetbrains.kotlin.psi.KtWhenExpression
@@ -496,6 +497,7 @@ object FirErrors {
     val WRONG_INVOCATION_KIND by warning3<PsiElement, FirBasedSymbol<*>, EventOccurrencesRange, EventOccurrencesRange>()
     val LEAKED_IN_PLACE_LAMBDA by error1<PsiElement, FirBasedSymbol<*>>()
     val WRONG_IMPLIES_CONDITION by warning0<PsiElement>()
+    val VARIABLE_WITH_NO_TYPE_NO_INITIALIZER by error0<KtVariableDeclaration>(SourceElementPositioningStrategies.DECLARATION_NAME)
 
     // Nullability
     val UNSAFE_CALL by error2<PsiElement, ConeKotlinType, FirExpression?>(SourceElementPositioningStrategies.DOT_BY_QUALIFIED)

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

@@ -21,8 +21,10 @@ import org.jetbrains.kotlin.fir.containingClassAttr
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyAccessor
 import org.jetbrains.kotlin.fir.declarations.utils.*
+import org.jetbrains.kotlin.fir.resolve.diagnostics.ConeLocalVariableNoTypeOrInitializer
 import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.*
+import org.jetbrains.kotlin.fir.types.FirErrorTypeRef
 import org.jetbrains.kotlin.fir.types.FirImplicitTypeRef
 import org.jetbrains.kotlin.lexer.KtTokens
 
@@ -106,7 +108,12 @@ internal fun checkPropertyInitializer(
     val hasAbstractModifier = KtTokens.ABSTRACT_KEYWORD in modifierList
     val isAbstract = property.isAbstract || hasAbstractModifier
     if (isAbstract) {
-        if (property.initializer == null && property.delegate == null && property.returnTypeRef is FirImplicitTypeRef) {
+        val returnTypeRef = property.returnTypeRef
+        if (property.initializer == null &&
+            property.delegate == null &&
+            (returnTypeRef is FirImplicitTypeRef ||
+                    (returnTypeRef is FirErrorTypeRef && returnTypeRef.diagnostic is ConeLocalVariableNoTypeOrInitializer))
+        ) {
             property.source?.let {
                 reporter.reportOn(it, FirErrors.PROPERTY_WITH_NO_TYPE_NO_INITIALIZER, context)
             }

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

@@ -416,6 +416,7 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VARARG_OUTSIDE_PA
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VARIABLE_EXPECTED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VARIABLE_INITIALIZER_IS_REDUNDANT
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VARIABLE_NEVER_READ
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VARIABLE_WITH_NO_TYPE_NO_INITIALIZER
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VARIANCE_ON_TYPE_PARAMETER_NOT_ALLOWED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VAR_ANNOTATION_PARAMETER
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VAR_OVERRIDDEN_BY_VAL
@@ -1128,6 +1129,8 @@ class FirDefaultErrorMessages {
                 "This property must either have a type annotation, be initialized or be delegated"
             )
 
+            map.put(VARIABLE_WITH_NO_TYPE_NO_INITIALIZER, "This variable must either have a type annotation or be initialized")
+
             map.put(MUST_BE_INITIALIZED, "Property must be initialized")
             map.put(MUST_BE_INITIALIZED_OR_BE_ABSTRACT, "Property must be initialized or be abstract")
             map.put(EXTENSION_PROPERTY_MUST_HAVE_ACCESSORS_OR_BE_ABSTRACT, "Extension property must have accessors or be abstract")

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

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.fir.analysis.diagnostics
 import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.FirSourceElement
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.isLocalMember
 import org.jetbrains.kotlin.fir.analysis.getChild
 import org.jetbrains.kotlin.fir.declarations.utils.isInfix
 import org.jetbrains.kotlin.fir.declarations.utils.isOperator
@@ -29,6 +30,7 @@ import org.jetbrains.kotlin.resolve.calls.tower.CandidateApplicability
 import org.jetbrains.kotlin.resolve.calls.tower.isSuccess
 import org.jetbrains.kotlin.utils.addIfNotNull
 import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstance
+import org.jetbrains.kotlin.utils.addToStdlib.runIf
 
 private fun ConeDiagnostic.toFirDiagnostic(
     source: FirSourceElement,
@@ -86,6 +88,8 @@ private fun ConeDiagnostic.toFirDiagnostic(
     is ConeNotAnnotationContainer -> null
     is ConeImportFromSingleton -> FirErrors.CANNOT_ALL_UNDER_IMPORT_FROM_SINGLETON.createOn(source, this.name)
     is ConeUnsupportedDynamicType -> FirErrors.UNSUPPORTED.createOn(source, this.reason)
+    is ConeLocalVariableNoTypeOrInitializer ->
+        runIf(variable.isLocalMember) { FirErrors.VARIABLE_WITH_NO_TYPE_NO_INITIALIZER.createOn(source) }
     else -> throw IllegalArgumentException("Unsupported diagnostic type: ${this.javaClass}")
 }
 

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/diagnostics/FirDiagnostics.kt

@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.fir.FirSourceElement
 import org.jetbrains.kotlin.fir.declarations.Deprecation
 import org.jetbrains.kotlin.fir.declarations.FirCallableDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.declarations.FirVariable
 import org.jetbrains.kotlin.fir.diagnostics.ConeDiagnostic
 import org.jetbrains.kotlin.fir.render
 import org.jetbrains.kotlin.fir.resolve.calls.Candidate
@@ -152,6 +153,10 @@ class ConeDeprecated(val source: FirSourceElement?, val symbol: FirBasedSymbol<*
     override val reason: String get() = "Deprecated: ${deprecation.message}"
 }
 
+class ConeLocalVariableNoTypeOrInitializer(val variable: FirVariable) : ConeDiagnostic() {
+    override val reason: String get() = "Cannot infer variable type without initializer / getter / delegate"
+}
+
 private fun describeSymbol(symbol: FirBasedSymbol<*>): String {
     return when (symbol) {
         is FirClassLikeSymbol<*> -> symbol.classId.asString()

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/FirDeclarationsResolveTransformer.kt

@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.fir.resolve.calls.FirNamedReferenceWithCandidate
 import org.jetbrains.kotlin.fir.resolve.constructFunctionalTypeRef
 import org.jetbrains.kotlin.fir.resolve.dfa.FirControlFlowGraphReferenceImpl
 import org.jetbrains.kotlin.fir.resolve.dfa.unwrapSmartcastExpression
+import org.jetbrains.kotlin.fir.resolve.diagnostics.ConeLocalVariableNoTypeOrInitializer
 import org.jetbrains.kotlin.fir.resolve.inference.extractLambdaInfoFromFunctionalType
 import org.jetbrains.kotlin.fir.resolve.inference.isSuspendFunctionType
 import org.jetbrains.kotlin.fir.resolve.mode
@@ -841,10 +842,8 @@ open class FirDeclarationsResolveTransformer(transformer: FirBodyResolveTransfor
                     transformer,
                     withExpectedType(
                         buildErrorTypeRef {
-                            diagnostic = ConeSimpleDiagnostic(
+                            diagnostic = ConeLocalVariableNoTypeOrInitializer(variable)
-                                "Cannot infer variable type without initializer / getter / delegate",
+                            source = variable.source
-                                DiagnosticKind.InferenceError,
-                            )
                         },
                     )
                 )

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

@@ -1,3 +0,0 @@
-fun test() {
-    val a
-}

compiler/testData/diagnostics/tests/declarationChecks/LocalVariableWithNoTypeInformation.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 fun test() {
     val <!VARIABLE_WITH_NO_TYPE_NO_INITIALIZER!>a<!>
 }

compiler/testData/diagnostics/tests/declarationChecks/kt2096.fir.kt

@@ -1,7 +0,0 @@
-//KT-2096 Abstract property with no type specified causes compiler to crash
-
-package c
-
-abstract class Foo{
-    protected abstract val prop
-}

compiler/testData/diagnostics/tests/declarationChecks/kt2096.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 //KT-2096 Abstract property with no type specified causes compiler to crash
 
 package c

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

@@ -6,7 +6,7 @@ class T {
 
 fun foo() {
     public val i = 11
-    abstract val j
+    abstract val <!VARIABLE_WITH_NO_TYPE_NO_INITIALIZER!>j<!>
     override fun T.baz() = 2
     private fun bar() = 2
 }

compiler/testData/diagnostics/tests/when/withSubjectVariable/unsupportedVariableDeclarationsInWhenSubject.fir.kt

@@ -23,6 +23,6 @@ fun testVarInWhenSubject() {
 }
 
 fun testDelegatedValInWhenSubject() {
-    when (<!ILLEGAL_DECLARATION_IN_WHEN_SUBJECT!>val y by lazy { 42 }<!>) {
+    when (<!ILLEGAL_DECLARATION_IN_WHEN_SUBJECT!>val <!VARIABLE_WITH_NO_TYPE_NO_INITIALIZER!>y<!> by lazy { 42 }<!>) {
     }
 }

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDataClassConverters.kt

@@ -54,6 +54,7 @@ import org.jetbrains.kotlin.psi.KtTypeParameter
 import org.jetbrains.kotlin.psi.KtTypeProjection
 import org.jetbrains.kotlin.psi.KtTypeReference
 import org.jetbrains.kotlin.psi.KtValueArgument
+import org.jetbrains.kotlin.psi.KtVariableDeclaration
 import org.jetbrains.kotlin.psi.KtWhenCondition
 import org.jetbrains.kotlin.psi.KtWhenEntry
 import org.jetbrains.kotlin.psi.KtWhenExpression
@@ -2547,6 +2548,12 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.VARIABLE_WITH_NO_TYPE_NO_INITIALIZER) { firDiagnostic ->
+        VariableWithNoTypeNoInitializerImpl(
+            firDiagnostic as FirPsiDiagnostic,
+            token,
+        )
+    }
     add(FirErrors.UNSAFE_CALL) { firDiagnostic ->
         UnsafeCallImpl(
             firSymbolBuilder.typeBuilder.buildKtType(firDiagnostic.a),

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDiagnostics.kt

@@ -63,6 +63,7 @@ import org.jetbrains.kotlin.psi.KtTypeParameter
 import org.jetbrains.kotlin.psi.KtTypeProjection
 import org.jetbrains.kotlin.psi.KtTypeReference
 import org.jetbrains.kotlin.psi.KtValueArgument
+import org.jetbrains.kotlin.psi.KtVariableDeclaration
 import org.jetbrains.kotlin.psi.KtWhenCondition
 import org.jetbrains.kotlin.psi.KtWhenEntry
 import org.jetbrains.kotlin.psi.KtWhenExpression
@@ -1785,6 +1786,10 @@ sealed class KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         override val diagnosticClass get() = WrongImpliesCondition::class
     }
 
+    abstract class VariableWithNoTypeNoInitializer : KtFirDiagnostic<KtVariableDeclaration>() {
+        override val diagnosticClass get() = VariableWithNoTypeNoInitializer::class
+    }
+
     abstract class UnsafeCall : KtFirDiagnostic<PsiElement>() {
         override val diagnosticClass get() = UnsafeCall::class
         abstract val receiverType: KtType

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDiagnosticsImpl.kt

@@ -65,6 +65,7 @@ import org.jetbrains.kotlin.psi.KtTypeParameter
 import org.jetbrains.kotlin.psi.KtTypeProjection
 import org.jetbrains.kotlin.psi.KtTypeReference
 import org.jetbrains.kotlin.psi.KtValueArgument
+import org.jetbrains.kotlin.psi.KtVariableDeclaration
 import org.jetbrains.kotlin.psi.KtWhenCondition
 import org.jetbrains.kotlin.psi.KtWhenEntry
 import org.jetbrains.kotlin.psi.KtWhenExpression
@@ -2875,6 +2876,13 @@ internal class WrongImpliesConditionImpl(
     override val firDiagnostic: FirPsiDiagnostic by weakRef(firDiagnostic)
 }
 
+internal class VariableWithNoTypeNoInitializerImpl(
+    firDiagnostic: FirPsiDiagnostic,
+    override val token: ValidityToken,
+) : KtFirDiagnostic.VariableWithNoTypeNoInitializer(), KtAbstractFirDiagnostic<KtVariableDeclaration> {
+    override val firDiagnostic: FirPsiDiagnostic by weakRef(firDiagnostic)
+}
+
 internal class UnsafeCallImpl(
     override val receiverType: KtType,
     override val receiverExpression: KtExpression?,