KSP1: Try to invalidate KotlinCliJavaFileManagerImpl.topLevelClassesC…

…ache

See JetBrains/kotlin#5369 for more details.

compiler-plugin/src/main/kotlin/com/google/devtools/ksp/KotlinSymbolProcessingExtension.kt

@@ -50,8 +50,10 @@ import com.intellij.openapi.vfs.StandardFileSystems
 import com.intellij.openapi.vfs.VirtualFileManager
 import com.intellij.psi.PsiJavaFile
 import com.intellij.psi.PsiManager
+import com.intellij.psi.impl.file.impl.JavaFileManager
 import org.jetbrains.kotlin.analyzer.AnalysisResult
 import org.jetbrains.kotlin.cli.common.messages.CompilerMessageSeverity
+import org.jetbrains.kotlin.cli.jvm.compiler.KotlinCliJavaFileManagerImpl
 import org.jetbrains.kotlin.config.JvmAnalysisFlags
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.container.ComponentProvider
@@ -157,6 +159,8 @@ abstract class AbstractKotlinSymbolProcessingExtension(
         val psiManager = PsiManager.getInstance(project)
         if (initialized) {
             psiManager.dropPsiCaches()
+            psiManager.dropResolveCaches()
+            invalidateKotlinCliJavaFileManagerCache(project)
         } else {
             // In case of broken builds.
             if (javaShadowBase.exists()) {
@@ -509,3 +513,13 @@ fun findTargetInfos(languageVersionSettings: LanguageVersionSettings, module: Mo
             else -> UnknownPlatformInfoImpl(platform.toString())
         }
     } ?: emptyList()
+
+// FIXME: remove as soon as possible.
+private fun invalidateKotlinCliJavaFileManagerCache(project: Project): Boolean {
+    val javaFileManager = (JavaFileManager.getInstance(project) as? KotlinCliJavaFileManagerImpl) ?: return false
+    val privateCacheField = KotlinCliJavaFileManagerImpl::class.java.getDeclaredField("topLevelClassesCache")
+    if (!privateCacheField.trySetAccessible())
+        return false
+    (privateCacheField.get(javaFileManager) as? MutableMap<*, *>)?.clear() ?: return false
+    return true
+}