Analyze Data Flow: Support val/var parameters

#KT-11994 In Progress

idea/src/org/jetbrains/kotlin/idea/slicer/Slicer.kt

@@ -34,7 +34,6 @@ import org.jetbrains.kotlin.cfg.pseudocode.instructions.jumps.ReturnValueInstruc
 import org.jetbrains.kotlin.cfg.pseudocodeTraverser.TraversalOrder
 import org.jetbrains.kotlin.cfg.pseudocodeTraverser.traverse
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptorWithSource
-import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
 import org.jetbrains.kotlin.descriptors.VariableDescriptorWithAccessors
 import org.jetbrains.kotlin.descriptors.impl.SyntheticFieldDescriptor
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
@@ -43,6 +42,8 @@ import org.jetbrains.kotlin.idea.caches.resolve.resolveToDescriptor
 import org.jetbrains.kotlin.idea.findUsages.KotlinFunctionFindUsagesOptions
 import org.jetbrains.kotlin.idea.findUsages.KotlinPropertyFindUsagesOptions
 import org.jetbrains.kotlin.idea.findUsages.processAllUsages
+import org.jetbrains.kotlin.idea.refactoring.changeSignature.KotlinValVar
+import org.jetbrains.kotlin.idea.refactoring.changeSignature.toValVar
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.idea.search.ideaExtensions.KotlinReadWriteAccessDetector
 import org.jetbrains.kotlin.psi.*
@@ -89,7 +90,7 @@ private fun KtDeclaration.processVariableAccesses(
 }
 
 private fun KtParameter.canProcess(): Boolean {
-    return !(isLoopParameter || isVarArg || hasValOrVar())
+    return !(isLoopParameter || isVarArg)
 }
 
 abstract class Slicer(
@@ -127,12 +128,7 @@ class InflowSlicer(
 ) : Slicer(element, processor, parentUsage) {
     private fun PsiElement.passToProcessorAsValue(lambdaLevel: Int = parentUsage.lambdaLevel) = passToProcessor(lambdaLevel, true)
 
-    private fun KtProperty.processAssignments() {
+    private fun KtDeclaration.processAssignments(accessSearchScope: SearchScope) {
-        val analysisScope = parentUsage.scope.toSearchScope()
-        val accessSearchScope = if (isVar) analysisScope else {
-            val containerScope = getStrictParentOfType<KtDeclaration>()?.let { LocalSearchScope(it) } ?: return
-            analysisScope.intersectWith(containerScope)
-        }
         processVariableAccesses(accessSearchScope, Access.Write) body@ {
             val refExpression = it.element as? KtExpression ?: return@body
             val rhs = KtPsiUtil.safeDeparenthesize(refExpression).getAssignmentByLHS()?.right ?: return@body
@@ -150,6 +146,15 @@ class InflowSlicer(
         }
     }
 
+    private fun KtProperty.processPropertyAssignments() {
+        val analysisScope = parentUsage.scope.toSearchScope()
+        val accessSearchScope = if (isVar) analysisScope else {
+            val containerScope = getStrictParentOfType<KtDeclaration>()?.let { LocalSearchScope(it) } ?: return
+            analysisScope.intersectWith(containerScope)
+        }
+        processAssignments(accessSearchScope)
+    }
+
     private fun KtProperty.processProperty() {
         val bindingContext by lazy { analyzeFully() }
 
@@ -168,7 +173,7 @@ class InflowSlicer(
         val isDefaultSetter = setter?.bodyExpression == null
         if (isDefaultGetter) {
             if (isDefaultSetter) {
-                processAssignments()
+                processPropertyAssignments()
             }
             else {
                 setter!!.processBackingFieldAssignments()
@@ -183,11 +188,11 @@ class InflowSlicer(
         if (function.isOverridable()) return
 
         if (function is KtPropertyAccessor && function.isSetter) {
-            function.property.processAssignments()
+            function.property.processPropertyAssignments()
             return
         }
 
-        val parameterDescriptor = resolveToDescriptor() as ValueParameterDescriptor
+        val parameterDescriptor = analyze()[BindingContext.VALUE_PARAMETER, this] ?: return
 
         (function as? KtFunction)?.processCalls(parentUsage.scope.toSearchScope()) body@ {
             val refExpression = it.element as? KtExpression ?: return@body
@@ -201,6 +206,10 @@ class InflowSlicer(
                                   } ?: return@body
             flownExpression.passToProcessorAsValue()
         }
+
+        if (valOrVarKeyword.toValVar() == KotlinValVar.Var) {
+            processAssignments(parentUsage.scope.toSearchScope())
+        }
     }
 
     private fun KtDeclarationWithBody.processFunction() {
@@ -257,7 +266,7 @@ class InflowSlicer(
                 if (accessedDescriptor is SyntheticFieldDescriptor) {
                     val property = accessedDeclaration as? KtProperty ?: return
                     if (accessedDescriptor.propertyDescriptor.setter?.isDefault ?: true) {
-                        property.processAssignments()
+                        property.processPropertyAssignments()
                     }
                     else {
                         property.setter?.processBackingFieldAssignments()

idea/testData/slicer/inflow/valParameter.kt

@@ -0,0 +1,9 @@
+// FLOW: IN
+
+open class A(val <caret>n: Int)
+
+class B : A(1)
+
+fun test() {
+    val z = A(2).n
+}

idea/testData/slicer/inflow/valParameter.results.txt

@@ -0,0 +1,3 @@
+3 open class A(val <bold>n: Int</bold>)
+5 	class B : A(<bold>1</bold>)
+8 	val z = A(<bold>2</bold>).n

idea/testData/slicer/inflow/varParameter.kt

@@ -0,0 +1,25 @@
+// FLOW: IN
+
+open class A(var <caret>n: Int) {
+    val x = n
+
+    val y: Int
+
+    init {
+        y = n
+
+        bar(n)
+    }
+
+    fun bar(m: Int) {
+        val z = n
+        n = 1
+    }
+}
+
+class B : A(1)
+
+fun test() {
+    val z = A(2).n
+    A(3).n = 2
+}

idea/testData/slicer/inflow/varParameter.results.txt

@@ -0,0 +1,5 @@
+3 open class A(var <bold>n: Int</bold>) {
+20 	class B : A(<bold>1</bold>)
+23 	val z = A(<bold>2</bold>).n
+24 	A(<bold>3</bold>).n = 2
+16 	n = <bold>1</bold>

idea/testData/slicer/outflow/valParameter.kt

@@ -0,0 +1,21 @@
+// FLOW: OUT
+
+class A(val <caret>n: Int) {
+    val x = n
+
+    val y: Int
+
+    init {
+        y = n
+
+        bar(n)
+    }
+
+    fun bar(m: Int) {
+        val z = n
+    }
+}
+
+fun test() {
+    val z = A(1).n
+}

idea/testData/slicer/outflow/valParameter.results.txt

@@ -0,0 +1,6 @@
+3 class A(val <bold>n: Int</bold>) {
+4 	val <bold>x = n</bold>
+6 	val <bold>y: Int</bold>
+14 	fun bar(<bold>m: Int</bold>) {
+15 	val <bold>z = n</bold>
+20 	val <bold>z = A(1).n</bold>

idea/testData/slicer/outflow/varParameter.kt

@@ -0,0 +1,23 @@
+// FLOW: OUT
+
+class A(var <caret>n: Int) {
+    val x = n
+
+    val y: Int
+
+    init {
+        y = n
+
+        bar(n)
+    }
+
+    fun bar(m: Int) {
+        val z = n
+        n = 1
+    }
+}
+
+fun test() {
+    val z = A(1).n
+    A(1).n = 2
+}

idea/testData/slicer/outflow/varParameter.results.txt

@@ -0,0 +1,6 @@
+3 class A(var <bold>n: Int</bold>) {
+4 	val <bold>x = n</bold>
+6 	val <bold>y: Int</bold>
+14 	fun bar(<bold>m: Int</bold>) {
+15 	val <bold>z = n</bold>
+21 	val <bold>z = A(1).n</bold>

idea/tests/org/jetbrains/kotlin/idea/slicer/SlicerTestGenerated.java

@@ -258,6 +258,18 @@ public class SlicerTestGenerated extends AbstractSlicerTest {
         doTest(fileName);
     }
 
+    @TestMetadata("inflow/valParameter.kt")
+    public void testInflow_ValParameter() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/slicer/inflow/valParameter.kt");
+        doTest(fileName);
+    }
+
+    @TestMetadata("inflow/varParameter.kt")
+    public void testInflow_VarParameter() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/slicer/inflow/varParameter.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("inflow/whenExpression.kt")
     public void testInflow_WhenExpression() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/testData/slicer/inflow/whenExpression.kt");
@@ -468,6 +480,18 @@ public class SlicerTestGenerated extends AbstractSlicerTest {
         doTest(fileName);
     }
 
+    @TestMetadata("outflow/valParameter.kt")
+    public void testOutflow_ValParameter() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/slicer/outflow/valParameter.kt");
+        doTest(fileName);
+    }
+
+    @TestMetadata("outflow/varParameter.kt")
+    public void testOutflow_VarParameter() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/slicer/outflow/varParameter.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("outflow/whenExpression.kt")
     public void testOutflow_WhenExpression() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/testData/slicer/outflow/whenExpression.kt");