From 0c81173b71dcbbbaade762d488764813f981289a Mon Sep 17 00:00:00 2001
From: Dmitry Gridin <dmitry.gridin@jetbrains.com>
Date: Thu, 5 Sep 2019 17:08:36 +0700
Subject: [PATCH] idea-core.Utils: add extension to `FqName` to support root
 prefix

---
 .../src/org/jetbrains/kotlin/idea/core/Utils.kt   | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/Utils.kt b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/Utils.kt
index 2a53166632b..cbacdaba8a3 100644
--- a/idea/idea-core/src/org/jetbrains/kotlin/idea/core/Utils.kt
+++ b/idea/idea-core/src/org/jetbrains/kotlin/idea/core/Utils.kt
@@ -17,10 +17,12 @@ import org.jetbrains.kotlin.idea.resolve.frontendService
 import org.jetbrains.kotlin.idea.util.getImplicitReceiversWithInstanceToExpression
 import org.jetbrains.kotlin.idea.util.getResolutionScope
 import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.parentOrNull
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.*
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DelegatingBindingTrace
+import org.jetbrains.kotlin.resolve.QualifiedExpressionResolver
 import org.jetbrains.kotlin.resolve.bindingContextUtil.getDataFlowInfoBefore
 import org.jetbrains.kotlin.resolve.calls.CallResolver
 import org.jetbrains.kotlin.resolve.calls.context.BasicCallResolutionContext
@@ -158,6 +160,19 @@ fun FqName.quoteSegmentsIfNeeded(): String {
 
 fun FqName.quoteIfNeeded() = FqName(quoteSegmentsIfNeeded())
 
+fun FqName.withRootPrefixIfNeeded(targetElement: KtElement? = null) =
+    if (canAddRootPrefix() && targetElement?.canAddRootPrefix() != false)
+        FqName(QualifiedExpressionResolver.ROOT_PREFIX_FOR_IDE_RESOLUTION_MODE_WITH_DOT + asString())
+    else
+        this
+
+fun FqName.canAddRootPrefix(): Boolean =
+    !asString().startsWith(QualifiedExpressionResolver.ROOT_PREFIX_FOR_IDE_RESOLUTION_MODE_WITH_DOT) && !thisOrParentIsRoot()
+
+fun FqName.thisOrParentIsRoot(): Boolean = parentOrNull()?.isRoot != false
+
+fun KtElement.canAddRootPrefix(): Boolean = getParentOfTypes2<KtImportDirective, KtPackageDirective>() == null
+
 fun isEnumCompanionPropertyWithEntryConflict(element: PsiElement, expectedName: String): Boolean {
     if (element !is KtProperty) return false