From 38575cdbc145aeab2c07b7c61a25f70368866d03 Mon Sep 17 00:00:00 2001
From: Dmitrii Gridin <dmitry.gridin@jetbrains.com>
Date: Tue, 31 Jan 2023 14:23:57 +0100
Subject: [PATCH] [FIR] FirBasedSymbol: iterate annotations by index instead of
 iterator to avoid possible ConcurrentModificationException

^KT-56046
---
 .../api/fir/annotations/firAnnotationUtils.kt | 29 +++++++++++++------
 .../kotlin/fir/symbols/FirBasedSymbol.kt      | 12 +++++++-
 2 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/annotations/firAnnotationUtils.kt b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/annotations/firAnnotationUtils.kt
index af4977b0eaa..04d656ce1dd 100644
--- a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/annotations/firAnnotationUtils.kt
+++ b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/annotations/firAnnotationUtils.kt
@@ -51,12 +51,15 @@ internal fun annotationsByClassId(
     annotationContainer: FirAnnotationContainer = firSymbol.fir,
 ): List<KtAnnotationApplicationWithArgumentsInfo> =
     if (firSymbol.isFromCompilerRequiredAnnotationsPhase(classId)) {
-        annotationContainer.resolvedCompilerRequiredAnnotations(firSymbol).mapIndexedNotNull { index, annotation ->
-            if (!useSiteTargetFilter.isAllowed(annotation.useSiteTarget) || annotation.toAnnotationClassIdSafe(useSiteSession) != classId) {
-                return@mapIndexedNotNull null
+        buildList {
+            // this loop by index is required to avoid possible ConcurrentModificationException
+            val annotations = annotationContainer.resolvedCompilerRequiredAnnotations(firSymbol)
+            for (index in annotations.indices) {
+                val annotation = annotations[index]
+                if (useSiteTargetFilter.isAllowed(annotation.useSiteTarget) && annotation.toAnnotationClassIdSafe(useSiteSession) == classId) {
+                    add(annotation.toKtAnnotationApplication(useSiteSession, index))
+                }
             }
-
-            annotation.toKtAnnotationApplication(useSiteSession, index)
         }
     } else {
         annotationContainer.resolvedAnnotationsWithArguments(firSymbol).mapIndexedNotNull { index, annotation ->
@@ -99,16 +102,24 @@ internal fun hasAnnotation(
     useSiteTargetFilter: AnnotationUseSiteTargetFilter,
     useSiteSession: FirSession,
     annotationContainer: FirAnnotationContainer = firSymbol.fir,
-): Boolean =
-    if (firSymbol.isFromCompilerRequiredAnnotationsPhase(classId)) {
-        annotationContainer.resolvedCompilerRequiredAnnotations(firSymbol).any {
-            useSiteTargetFilter.isAllowed(it.useSiteTarget) && it.toAnnotationClassIdSafe(useSiteSession) == classId
+): Boolean {
+    return if (firSymbol.isFromCompilerRequiredAnnotationsPhase(classId)) {
+        // this loop by index is required to avoid possible ConcurrentModificationException
+        val annotations = annotationContainer.resolvedCompilerRequiredAnnotations(firSymbol)
+        for (index in annotations.indices) {
+            val annotation = annotations[index]
+            if (useSiteTargetFilter.isAllowed(annotation.useSiteTarget) && annotation.toAnnotationClassIdSafe(useSiteSession) == classId) {
+                return true
+            }
         }
+
+        false
     } else {
         annotationContainer.resolvedAnnotationsWithClassIds(firSymbol).any {
             useSiteTargetFilter.isAllowed(it.useSiteTarget) && it.toAnnotationClassId(useSiteSession) == classId
         }
     }
+}
 
 private fun FirBasedSymbol<*>.isFromCompilerRequiredAnnotationsPhase(classId: ClassId): Boolean =
     fir.resolvePhase < FirResolvePhase.TYPES && classId in CompilerRequiredAnnotationsHelper.REQUIRED_ANNOTATIONS
\ No newline at end of file
diff --git a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/symbols/FirBasedSymbol.kt b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/symbols/FirBasedSymbol.kt
index 5c978618d32..08c2d46b248 100644
--- a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/symbols/FirBasedSymbol.kt
+++ b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/symbols/FirBasedSymbol.kt
@@ -79,7 +79,17 @@ fun FirAnnotationContainer.resolvedAnnotationsWithArguments(anchorElement: FirBa
 fun List<FirAnnotation>.resolvedAnnotationsWithArguments(anchorElement: FirBasedSymbol<*>): List<FirAnnotation> {
     if (isEmpty()) return emptyList()
 
-    val phase = if (any { it is FirAnnotationCall && it.arguments.isNotEmpty() }) {
+    // this loop by index is required to avoid possible ConcurrentModificationException
+    var hasAnnotationCallWithArguments = false
+    for (i in indices) {
+        val currentAnnotation = get(i)
+        if (currentAnnotation is FirAnnotationCall && currentAnnotation.arguments.isNotEmpty()) {
+            hasAnnotationCallWithArguments = true
+            break
+        }
+    }
+
+    val phase = if (hasAnnotationCallWithArguments) {
         FirResolvePhase.ANNOTATIONS_ARGUMENTS_MAPPING
     } else {
         FirResolvePhase.TYPES