FIR: support separate ANONYMOUS_FUNCTION_WITH_NAME

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

@@ -471,6 +471,7 @@ object DIAGNOSTICS_LIST : DiagnosticList() {
         }
 
         val FUNCTION_DECLARATION_WITH_NO_NAME by error<KtFunction>(PositioningStrategy.DECLARATION_SIGNATURE)
+        val ANONYMOUS_FUNCTION_WITH_NAME by error<FirSourceElement, KtFunction>()
 
         // TODO: val ANONYMOUS_FUNCTION_WITH_NAME by error1<PsiElement, Name>(SourceElementPositioningStrategies.DECLARATION_NAME)
         val ANONYMOUS_FUNCTION_PARAMETER_WITH_DEFAULT_VALUE by error<KtParameter>(PositioningStrategy.PARAMETER_DEFAULT_VALUE)

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

@@ -292,6 +292,7 @@ object FirErrors {
     val PRIVATE_FUNCTION_WITH_NO_BODY by error1<KtFunction, FirMemberDeclaration>(SourceElementPositioningStrategies.VISIBILITY_MODIFIER)
     val NON_MEMBER_FUNCTION_NO_BODY by error1<KtFunction, FirMemberDeclaration>(SourceElementPositioningStrategies.DECLARATION_SIGNATURE)
     val FUNCTION_DECLARATION_WITH_NO_NAME by error0<KtFunction>(SourceElementPositioningStrategies.DECLARATION_SIGNATURE)
+    val ANONYMOUS_FUNCTION_WITH_NAME by error0<FirSourceElement, KtFunction>()
     val ANONYMOUS_FUNCTION_PARAMETER_WITH_DEFAULT_VALUE by error0<KtParameter>(SourceElementPositioningStrategies.PARAMETER_DEFAULT_VALUE)
     val USELESS_VARARG_ON_PARAMETER by warning0<KtParameter>()
     val MULTIPLE_VARARG_PARAMETERS by error0<KtParameter>(SourceElementPositioningStrategies.PARAMETER_VARARG_MODIFIER)

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

@@ -174,10 +174,10 @@ private fun ConeSimpleDiagnostic.getFactory(source: FirSourceElement): FirDiagno
         DiagnosticKind.RecursionInImplicitTypes -> FirErrors.RECURSION_IN_IMPLICIT_TYPES
         DiagnosticKind.Java -> FirErrors.ERROR_FROM_JAVA_RESOLUTION
         DiagnosticKind.SuperNotAllowed -> FirErrors.SUPER_IS_NOT_AN_EXPRESSION
-        DiagnosticKind.ExpressionExpected -> if (source.elementType == KtNodeTypes.BINARY_EXPRESSION) {
-            FirErrors.ASSIGNMENT_IN_EXPRESSION_CONTEXT
-        } else {
-            FirErrors.EXPRESSION_EXPECTED
+        DiagnosticKind.ExpressionExpected -> when (source.elementType) {
+            KtNodeTypes.BINARY_EXPRESSION -> FirErrors.ASSIGNMENT_IN_EXPRESSION_CONTEXT
+            KtNodeTypes.FUN -> FirErrors.ANONYMOUS_FUNCTION_WITH_NAME
+            else -> FirErrors.EXPRESSION_EXPECTED
         }
         DiagnosticKind.JumpOutsideLoop -> FirErrors.BREAK_OR_CONTINUE_OUTSIDE_A_LOOP
         DiagnosticKind.NotLoopLabel -> FirErrors.NOT_A_LOOP_LABEL

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

@@ -4,7 +4,7 @@
 fun foo(block: () -> (() -> Int)) {}
 
 fun test() {
-    val x = <!EXPRESSION_EXPECTED!>fun named1(x: Int): Int { return 1 }<!>
+    val x = <!ANONYMOUS_FUNCTION_WITH_NAME!>fun named1(x: Int): Int { return 1 }<!>
     x <!INAPPLICABLE_CANDIDATE!>checkType<!> { <!INAPPLICABLE_CANDIDATE!>_<!><Function1<Int, Int>>() }
 
     foo { fun named2(): Int {return 1} }
@@ -45,12 +45,12 @@ fun test() {
     x4 checkType { _<Function1<Int, Unit>>() }
 
     { y: Int -> fun named14(): Int {return 1} }
-    val b = (<!EXPRESSION_EXPECTED, UNRESOLVED_REFERENCE!>fun named15(): Boolean { return true }<!>)()
+    val b = (<!ANONYMOUS_FUNCTION_WITH_NAME, UNRESOLVED_REFERENCE!>fun named15(): Boolean { return true }<!>)()
 
-    baz(<!EXPRESSION_EXPECTED!>fun named16(){}<!>)
+    baz(<!ANONYMOUS_FUNCTION_WITH_NAME!>fun named16(){}<!>)
 }
 
-fun bar() = <!EXPRESSION_EXPECTED!>fun named() {}<!>
+fun bar() = <!ANONYMOUS_FUNCTION_WITH_NAME!>fun named() {}<!>
 
 fun <T> run(block: () -> T): T = null!!
 fun run2(block: () -> Unit): Unit = null!!

compiler/testData/diagnostics/tests/functionAsExpression/NameDeprecation.fir.kt

@@ -5,5 +5,5 @@ fun foo() {
     fun A.foo() {}
     (fun A.foo() {})
 
-    run(<!EXPRESSION_EXPECTED!>fun foo() {}<!>)
+    run(<!ANONYMOUS_FUNCTION_WITH_NAME!>fun foo() {}<!>)
 }

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

@@ -1320,6 +1320,12 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.ANONYMOUS_FUNCTION_WITH_NAME) { firDiagnostic ->
+        AnonymousFunctionWithNameImpl(
+            firDiagnostic as FirPsiDiagnostic<*>,
+            token,
+        )
+    }
     add(FirErrors.ANONYMOUS_FUNCTION_PARAMETER_WITH_DEFAULT_VALUE) { firDiagnostic ->
         AnonymousFunctionParameterWithDefaultValueImpl(
             firDiagnostic as FirPsiDiagnostic<*>,

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

@@ -937,6 +937,10 @@ sealed class KtFirDiagnostic<PSI: PsiElement> : KtDiagnosticWithPsi<PSI> {
         override val diagnosticClass get() = FunctionDeclarationWithNoName::class
     }
 
+    abstract class AnonymousFunctionWithName : KtFirDiagnostic<KtFunction>() {
+        override val diagnosticClass get() = AnonymousFunctionWithName::class
+    }
+
     abstract class AnonymousFunctionParameterWithDefaultValue : KtFirDiagnostic<KtParameter>() {
         override val diagnosticClass get() = AnonymousFunctionParameterWithDefaultValue::class
     }

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

@@ -1508,6 +1508,13 @@ internal class FunctionDeclarationWithNoNameImpl(
     override val firDiagnostic: FirPsiDiagnostic<*> by weakRef(firDiagnostic)
 }
 
+internal class AnonymousFunctionWithNameImpl(
+    firDiagnostic: FirPsiDiagnostic<*>,
+    override val token: ValidityToken,
+) : KtFirDiagnostic.AnonymousFunctionWithName(), KtAbstractFirDiagnostic<KtFunction> {
+    override val firDiagnostic: FirPsiDiagnostic<*> by weakRef(firDiagnostic)
+}
+
 internal class AnonymousFunctionParameterWithDefaultValueImpl(
     firDiagnostic: FirPsiDiagnostic<*>,
     override val token: ValidityToken,