FIR IDE: do not collect diagnostics for generated declarations

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/file/structure/FileStructureElement.kt

@@ -11,6 +11,7 @@ import org.jetbrains.kotlin.fir.analysis.collectors.DiagnosticCollectorDeclarati
 import org.jetbrains.kotlin.fir.containingClass
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.psi
+import org.jetbrains.kotlin.fir.realPsi
 import org.jetbrains.kotlin.fir.resolve.toSymbol
 import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirFunctionSymbol
@@ -18,6 +19,7 @@ import org.jetbrains.kotlin.idea.fir.low.level.api.diagnostics.FirIdeStructureEl
 import org.jetbrains.kotlin.idea.fir.low.level.api.file.builder.ModuleFileCache
 import org.jetbrains.kotlin.idea.fir.low.level.api.lazy.resolve.FirLazyDeclarationResolver
 import org.jetbrains.kotlin.idea.fir.low.level.api.providers.FirIdeProvider
+import org.jetbrains.kotlin.idea.fir.low.level.api.util.isGeneratedDeclaration
 import org.jetbrains.kotlin.idea.fir.low.level.api.util.ktDeclaration
 import org.jetbrains.kotlin.idea.fir.low.level.api.util.replaceFirst
 import org.jetbrains.kotlin.psi.*
@@ -138,6 +140,7 @@ internal class NonReanalyzableDeclarationStructureElement(
             firFile,
             onDeclarationEnter = { firDeclaration ->
                 when {
+                    firDeclaration.isGeneratedDeclaration -> DiagnosticCollectorDeclarationAction.SKIP
                     firDeclaration is FirFile -> DiagnosticCollectorDeclarationAction.CHECK_CURRENT_DECLARATION_AND_CHECK_NESTED
                     firDeclaration == fir -> {
                         inCurrentDeclaration = true

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/util/declarationUtils.kt

@@ -128,3 +128,5 @@ private fun KtTypeAlias.findFir(firSymbolProvider: FirSymbolProvider): FirTypeAl
     }
 }
 
+val FirDeclaration.isGeneratedDeclaration
+    get() = realPsi == null

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/util/utils.kt

@@ -13,8 +13,10 @@ import org.jetbrains.kotlin.fir.diagnostics.FirDiagnosticHolder
 import org.jetbrains.kotlin.fir.psi
 import org.jetbrains.kotlin.fir.render
 import org.jetbrains.kotlin.idea.caches.project.IdeaModuleInfo
-import org.jetbrains.kotlin.psi.KtDeclaration
+import org.jetbrains.kotlin.idea.util.getElementTextInContext
 import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.KtDeclaration
+import org.jetbrains.kotlin.psi.KtElement
 import java.util.concurrent.TimeUnit
 import java.util.concurrent.locks.Lock
 
@@ -61,7 +63,15 @@ internal val FirDeclaration.ktDeclaration: KtDeclaration
     get() {
         val psi = psi
             ?: error("PSI element was not found for${render()}")
-        return psi as KtDeclaration
+        return psi as? KtDeclaration
+            ?: error(
+                """
+                   FirDeclaration.psi (${this::class.simpleName}) should be KtDeclaration but was ${psi::class.simpleName}
+                   ${(psi as? KtElement)?.getElementTextInContext() ?: psi.text}
+                   
+                   ${render()}
+                   """.trimIndent()
+            )
     }
 
 internal val FirDeclaration.containingKtFileIfAny: KtFile?