K2 LL API: implement automatic diagnostic suppression

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostics/FileStructureElementDiagnosticsCollector.kt

@@ -27,6 +27,10 @@ internal class FileStructureElementDiagnosticsCollector private constructor(priv
             useExtendedCheckers,
         )
         collector.collectDiagnostics(firDeclaration, reporter)
-        return FileStructureElementDiagnosticList(reporter.diagnostics)
+        val source = firDeclaration.source
+        if (source != null) {
+            reporter.checkAndCommitReportsOn(source, null)
+        }
+        return FileStructureElementDiagnosticList(reporter.committedDiagnostics)
     }
 }

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostics/LLFirDiagnosticReporter.kt

@@ -6,11 +6,13 @@
 package org.jetbrains.kotlin.analysis.low.level.api.fir.diagnostics
 
 import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.AbstractKtSourceElement
 import org.jetbrains.kotlin.analysis.low.level.api.fir.util.addValueFor
 import org.jetbrains.kotlin.diagnostics.*
 
 internal class LLFirDiagnosticReporter : DiagnosticReporter() {
-    val diagnostics = mutableMapOf<PsiElement, MutableList<KtPsiDiagnostic>>()
+    private val pendingDiagnostics = mutableMapOf<PsiElement, MutableList<KtPsiDiagnostic>>()
+    val committedDiagnostics = mutableMapOf<PsiElement, MutableList<KtPsiDiagnostic>>()
 
     override fun report(diagnostic: KtDiagnostic?, context: DiagnosticContext) {
         if (diagnostic == null) return
@@ -21,7 +23,31 @@ internal class LLFirDiagnosticReporter : DiagnosticReporter() {
             is KtLightDiagnostic -> diagnostic.toPsiDiagnostic()
             else -> error("Unknown diagnostic type ${diagnostic::class.simpleName}")
         }
-        diagnostics.addValueFor(psiDiagnostic.psiElement, psiDiagnostic)
+        pendingDiagnostics.addValueFor(psiDiagnostic.psiElement, psiDiagnostic)
+    }
+
+    override fun checkAndCommitReportsOn(element: AbstractKtSourceElement, context: DiagnosticContext?) {
+        val commitEverything = context == null
+        for ((diagnosticElement, pendingList) in pendingDiagnostics) {
+            val committedList = committedDiagnostics.getOrPut(diagnosticElement) { mutableListOf() }
+            val iterator = pendingList.iterator()
+            while (iterator.hasNext()) {
+                val diagnostic = iterator.next()
+                when {
+                    context?.isDiagnosticSuppressed(diagnostic as KtDiagnostic) == true -> {
+                        if (diagnostic.element == element ||
+                            diagnostic.element.startOffset >= element.startOffset && diagnostic.element.endOffset <= element.endOffset
+                        ) {
+                            iterator.remove()
+                        }
+                    }
+                    diagnostic.element == element || commitEverything -> {
+                        iterator.remove()
+                        committedList += diagnostic
+                    }
+                }
+            }
+        }
     }
 }
 

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/collectors/components/AbstractDiagnosticCollectorComponent.kt

@@ -10,7 +10,6 @@ import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
-import org.jetbrains.kotlin.diagnostics.impl.PendingDiagnosticsCollectorWithSuppress
 import org.jetbrains.kotlin.fir.declarations.FirFile
 import org.jetbrains.kotlin.fir.visitors.FirVisitor
 
@@ -21,10 +20,8 @@ abstract class AbstractDiagnosticCollectorComponent(
     override fun visitElement(element: FirElement, data: CheckerContext) {}
 
     protected fun checkAndCommitReportsOn(element: FirElement, context: DiagnosticContext?) {
-        if (reporter is PendingDiagnosticsCollectorWithSuppress) {
-            val source = element.source ?: return
-            reporter.checkAndCommitReportsOn(source, context, context == null)
-        }
+        val source = element.source ?: return
+        reporter.checkAndCommitReportsOn(source, context)
     }
 
     open fun endOfFile(file: FirFile) {}

compiler/frontend.common/src/org/jetbrains/kotlin/diagnostics/DiagnosticReporter.kt

@@ -27,6 +27,9 @@ abstract class MutableDiagnosticContext : DiagnosticContext {
 
 abstract class DiagnosticReporter {
     abstract fun report(diagnostic: KtDiagnostic?, context: DiagnosticContext)
+
+    open fun checkAndCommitReportsOn(element: AbstractKtSourceElement, context: DiagnosticContext?) {
+    }
 }
 
 open class KtDiagnosticReporterWithContext(

compiler/frontend.common/src/org/jetbrains/kotlin/diagnostics/impl/PendingDiagnosticsCollectorWithSuppress.kt

@@ -29,11 +29,11 @@ class PendingDiagnosticsCollectorWithSuppress : BaseDiagnosticsCollector() {
         }
     }
 
-    fun checkAndCommitReportsOn(
+    override fun checkAndCommitReportsOn(
         element: AbstractKtSourceElement,
-        context: DiagnosticContext?,
-        commitEverything: Boolean
+        context: DiagnosticContext?
     ) {
+        val commitEverything = context == null
         for ((path, pendingList) in pendingDiagnosticsByFilePath) {
             val committedList = _diagnosticsByFilePath.getOrPut(path) { mutableListOf() }
             val iterator = pendingList.iterator()