From 269420a0e0312d3017f603549b603fa32689449d Mon Sep 17 00:00:00 2001
From: Valentin Kipyatkov <valentin@jetbrains.com>
Date: Sat, 11 Apr 2020 13:43:16 +0300
Subject: [PATCH] Processing implicit extension receiver usages in outflow
 processing

---
 .../kotlin/idea/slicer/OutflowSlicer.kt       | 20 +++++++++++++++++--
 .../slicer/outflow/implicitReceiver.kt        | 13 ++++++++++++
 .../outflow/implicitReceiver.results.txt      |  7 +++++++
 .../idea/slicer/SlicerTreeTestGenerated.java  |  5 +++++
 4 files changed, 43 insertions(+), 2 deletions(-)
 create mode 100644 idea/testData/slicer/outflow/implicitReceiver.kt
 create mode 100644 idea/testData/slicer/outflow/implicitReceiver.results.txt

diff --git a/idea/src/org/jetbrains/kotlin/idea/slicer/OutflowSlicer.kt b/idea/src/org/jetbrains/kotlin/idea/slicer/OutflowSlicer.kt
index f9413f9f41c..9058bec5033 100644
--- a/idea/src/org/jetbrains/kotlin/idea/slicer/OutflowSlicer.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/slicer/OutflowSlicer.kt
@@ -153,16 +153,32 @@ class OutflowSlicer(
 
     private fun processExtensionReceiver(declaration: KtCallableDeclaration, declarationWithBody: KtDeclarationWithBody) {
         //TODO: overriders
-        //TODO: implicit receivers
         val resolutionFacade = declaration.getResolutionFacade()
         val callableDescriptor = declaration.resolveToDescriptorIfAny(resolutionFacade) as? CallableDescriptor ?: return
         val extensionReceiver = callableDescriptor.extensionReceiverParameter ?: return
-        declarationWithBody.bodyExpression?.forEachDescendantOfType<KtThisExpression> { thisExpression ->
+        val body = declarationWithBody.bodyExpression ?: return
+
+        body.forEachDescendantOfType<KtThisExpression> { thisExpression ->
             val receiverDescriptor = thisExpression.resolveToCall(resolutionFacade)?.resultingDescriptor
             if (receiverDescriptor == extensionReceiver) {
                 thisExpression.passToProcessor()
             }
         }
+
+        // process implicit receiver usages
+        val pseudocode = pseudocodeCache[body]
+        if (pseudocode != null) {
+            for (instruction in pseudocode.instructions) {
+                if (instruction is MagicInstruction && instruction.kind == MagicKind.IMPLICIT_RECEIVER) {
+                    val receiverPseudoValue = instruction.outputValue
+                    pseudocode.getUsages(receiverPseudoValue).forEach { receiverUseInstruction ->
+                        if (receiverUseInstruction is KtElementInstruction) {
+                            processIfReceiverValue(receiverUseInstruction, receiverPseudoValue)
+                        }
+                    }
+                }
+            }
+        }
     }
 
     private fun processExpression(expression: KtExpression) {
diff --git a/idea/testData/slicer/outflow/implicitReceiver.kt b/idea/testData/slicer/outflow/implicitReceiver.kt
new file mode 100644
index 00000000000..a47eaef831f
--- /dev/null
+++ b/idea/testData/slicer/outflow/implicitReceiver.kt
@@ -0,0 +1,13 @@
+// FLOW: OUT
+
+fun Any.extensionFun(): Any {
+    return this
+}
+
+fun String.foo() {
+    val v = extensionFun()
+}
+
+fun main() {
+    <caret>"A".foo()
+}
diff --git a/idea/testData/slicer/outflow/implicitReceiver.results.txt b/idea/testData/slicer/outflow/implicitReceiver.results.txt
new file mode 100644
index 00000000000..f8b80bc6114
--- /dev/null
+++ b/idea/testData/slicer/outflow/implicitReceiver.results.txt
@@ -0,0 +1,7 @@
+12 <bold>"A"</bold>.foo()
+7 	fun <bold>String</bold>.foo() {
+3 		fun <bold>Any</bold>.extensionFun(): Any {
+4 			return <bold>this</bold>
+3 				fun Any.<bold>extensionFun(): Any {</bold>
+8 					val v = <bold>extensionFun()</bold>
+8 						val <bold>v = extensionFun()</bold>
diff --git a/idea/tests/org/jetbrains/kotlin/idea/slicer/SlicerTreeTestGenerated.java b/idea/tests/org/jetbrains/kotlin/idea/slicer/SlicerTreeTestGenerated.java
index bde4ff07e78..a7efb332f2a 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/slicer/SlicerTreeTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/slicer/SlicerTreeTestGenerated.java
@@ -583,6 +583,11 @@ public class SlicerTreeTestGenerated extends AbstractSlicerTreeTest {
             runTest("idea/testData/slicer/outflow/ifExpression.kt");
         }
 
+        @TestMetadata("implicitReceiver.kt")
+        public void testImplicitReceiver() throws Exception {
+            runTest("idea/testData/slicer/outflow/implicitReceiver.kt");
+        }
+
         @TestMetadata("indexingDereferences.kt")
         public void testIndexingDereferences() throws Exception {
             runTest("idea/testData/slicer/outflow/indexingDereferences.kt");