From cd4a08cb185cc4bb58c50b579506d28e42054f6e Mon Sep 17 00:00:00 2001
From: Jinseong Jeon <jsjeon@google.com>
Date: Thu, 26 Aug 2021 11:41:13 -0700
Subject: [PATCH] Migrate ReadWriteAccess and checker logic (from
 frontend-independent)

---
 .../kotlin/idea/references/referenceUtils.kt  | 43 +++++++++++++++++--
 .../resolve/references/ReferenceAccess.kt     | 15 +++++++
 2 files changed, 55 insertions(+), 3 deletions(-)
 create mode 100644 core/compiler.common/src/org/jetbrains/kotlin/resolve/references/ReferenceAccess.kt

diff --git a/compiler/psi/src/org/jetbrains/kotlin/idea/references/referenceUtils.kt b/compiler/psi/src/org/jetbrains/kotlin/idea/references/referenceUtils.kt
index 8aacfc0ced1..6fccada43c9 100644
--- a/compiler/psi/src/org/jetbrains/kotlin/idea/references/referenceUtils.kt
+++ b/compiler/psi/src/org/jetbrains/kotlin/idea/references/referenceUtils.kt
@@ -6,9 +6,12 @@
 package org.jetbrains.kotlin.idea.references
 
 import org.jetbrains.kotlin.kdoc.psi.impl.KDocName
-import org.jetbrains.kotlin.psi.KtElement
-import org.jetbrains.kotlin.psi.KtReferenceExpression
-import org.jetbrains.kotlin.psi.KtSimpleNameExpression
+import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.psiUtil.getAssignmentByLHS
+import org.jetbrains.kotlin.psi.psiUtil.getQualifiedExpressionForSelectorOrThis
+import org.jetbrains.kotlin.resolve.references.ReferenceAccess
+import org.jetbrains.kotlin.utils.addToStdlib.constant
 import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstance
 import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstanceOrNull
 
@@ -27,3 +30,37 @@ val KtElement.mainReference: KtReference?
         is KDocName -> mainReference
         else -> references.firstIsInstanceOrNull()
     }
+
+fun KtExpression.readWriteAccess(useResolveForReadWrite: Boolean) =
+    readWriteAccessWithFullExpression(useResolveForReadWrite).first
+
+fun KtExpression.readWriteAccessWithFullExpression(
+    useResolveForReadWrite: Boolean,
+    readWriteAccessWithFullExpressionByResolve: (KtBinaryExpression) -> Pair<ReferenceAccess, KtExpression>? = { null },
+): Pair<ReferenceAccess, KtExpression> {
+    var expression = getQualifiedExpressionForSelectorOrThis()
+    loop@ while (true) {
+        when (val parent = expression.parent) {
+            is KtParenthesizedExpression, is KtAnnotatedExpression, is KtLabeledExpression -> expression = parent as KtExpression
+            else -> break@loop
+        }
+    }
+
+    val assignment = expression.getAssignmentByLHS()
+    if (assignment != null) {
+        return when (assignment.operationToken) {
+            KtTokens.EQ -> ReferenceAccess.WRITE to assignment
+
+            else -> {
+                (if (useResolveForReadWrite) readWriteAccessWithFullExpressionByResolve(assignment) else null)
+                    ?: (ReferenceAccess.READ_WRITE to assignment)
+            }
+        }
+    }
+
+    val unaryExpression = expression.parent as? KtUnaryExpression
+    return if (unaryExpression != null && unaryExpression.operationToken in constant { setOf(KtTokens.PLUSPLUS, KtTokens.MINUSMINUS) })
+        ReferenceAccess.READ_WRITE to unaryExpression
+    else
+        ReferenceAccess.READ to expression
+}
diff --git a/core/compiler.common/src/org/jetbrains/kotlin/resolve/references/ReferenceAccess.kt b/core/compiler.common/src/org/jetbrains/kotlin/resolve/references/ReferenceAccess.kt
new file mode 100644
index 00000000000..b855a7dba1c
--- /dev/null
+++ b/core/compiler.common/src/org/jetbrains/kotlin/resolve/references/ReferenceAccess.kt
@@ -0,0 +1,15 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.resolve.references
+
+enum class ReferenceAccess(
+    val isRead: Boolean,
+    val isWrite: Boolean
+) {
+    READ(true, false),
+    WRITE(false, true),
+    READ_WRITE(true, true)
+}