From 10b86fbc300227f3bd784b15ab34b951cce464b4 Mon Sep 17 00:00:00 2001
From: Tagir Valeev <Tagir.Valeev@jetbrains.com>
Date: Thu, 9 Jan 2020 18:22:19 +0700
Subject: [PATCH] IDEA-230315 Control flow for record compact constructor
 should take into account implicit assignments

GitOrigin-RevId: 31f268e2ffdb4a2d4d42288e5075e1eb52f4c137
---
 .../psi/controlFlow/ControlFlowAnalyzer.java  | 33 +++++++++++++++++++
 .../unusedAssignment/afterRecordCompact2.java |  6 ++++
 .../unusedAssignment/beforeRecordCompact.java |  6 ++++
 .../beforeRecordCompact2.java                 |  7 ++++
 4 files changed, 52 insertions(+)
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/afterRecordCompact2.java
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/beforeRecordCompact.java
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/beforeRecordCompact2.java

diff --git a/java/java-psi-impl/src/com/intellij/psi/controlFlow/ControlFlowAnalyzer.java b/java/java-psi-impl/src/com/intellij/psi/controlFlow/ControlFlowAnalyzer.java
index 306c63111a22..b58fca3ab6ee 100644
--- a/java/java-psi-impl/src/com/intellij/psi/controlFlow/ControlFlowAnalyzer.java
+++ b/java/java-psi-impl/src/com/intellij/psi/controlFlow/ControlFlowAnalyzer.java
@@ -9,6 +9,7 @@ import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Comparing;
 import com.intellij.psi.*;
 import com.intellij.psi.tree.IElementType;
+import com.intellij.psi.util.JavaPsiRecordUtil;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.util.PsiUtil;
 import com.intellij.util.ObjectUtils;
@@ -59,6 +60,7 @@ class ControlFlowAnalyzer extends JavaElementVisitor {
   private final ControlFlowFactory myControlFlowFactory;
   private final Map<PsiElement, ControlFlowSubRange> mySubRanges = new THashMap<>();
   private final PsiConstantEvaluationHelper myConstantEvaluationHelper;
+  private final Map<PsiField, PsiParameter> myImplicitCompactConstructorAssignments;
 
   ControlFlowAnalyzer(@NotNull PsiElement codeFragment,
                       @NotNull ControlFlowPolicy policy,
@@ -80,6 +82,24 @@ class ControlFlowAnalyzer extends JavaElementVisitor {
     Project project = codeFragment.getProject();
     myControlFlowFactory = ControlFlowFactory.getInstance(project);
     myConstantEvaluationHelper = JavaPsiFacade.getInstance(project).getConstantEvaluationHelper();
+    myImplicitCompactConstructorAssignments = getImplicitCompactConstructorAssignmentsMap();
+  }
+
+  private Map<PsiField, PsiParameter> getImplicitCompactConstructorAssignmentsMap() {
+    PsiMethod ctor = ObjectUtils.tryCast(myCodeFragment.getParent(), PsiMethod.class);
+    if (ctor == null || !JavaPsiRecordUtil.isCompactConstructor(ctor)) return Collections.emptyMap();
+    PsiClass containingClass = ctor.getContainingClass();
+    if (containingClass == null) return Collections.emptyMap();
+    PsiParameter[] parameters = ctor.getParameterList().getParameters();
+    PsiRecordComponent[] components = containingClass.getRecordComponents();
+    Map<PsiField, PsiParameter> map = new HashMap<>();
+    for (int i = 0; i < Math.min(components.length, parameters.length); i++) {
+      PsiRecordComponent component = components[i];
+      PsiField field = JavaPsiRecordUtil.getFieldForComponent(component);
+      PsiParameter parameter = parameters[i];
+      map.put(field, parameter);
+    }
+    return map;
   }
 
   @NotNull
@@ -105,6 +125,10 @@ class ControlFlowAnalyzer extends JavaElementVisitor {
     return myCurrentFlow;
   }
 
+  private void generateCompactConstructorAssignments() {
+    myImplicitCompactConstructorAssignments.values().stream().filter(myPolicy::isParameterAccepted).forEach(this::generateReadInstruction);
+  }
+
   private static class StatementStack {
     private final Stack<PsiElement> myStatements = new Stack<>();
     private final TIntArrayList myAtStart = new TIntArrayList();
@@ -370,6 +394,9 @@ class ControlFlowAnalyzer extends JavaElementVisitor {
     if (!(block.getParent() instanceof PsiSwitchStatement) && prevOffset == nextOffset) {
       emitEmptyInstruction();
     }
+    if (block == myCodeFragment) {
+      generateCompactConstructorAssignments();
+    }
 
     finishElement(block);
     if (prevOffset != 0) {
@@ -1370,6 +1397,12 @@ class ControlFlowAnalyzer extends JavaElementVisitor {
     boolean generatedWriteInstruction = false;
     PsiExpression lExpr = PsiUtil.skipParenthesizedExprDown(expression.getLExpression());
     if (lExpr instanceof PsiReferenceExpression) {
+      if (!myImplicitCompactConstructorAssignments.isEmpty()) {
+        PsiElement target = ((PsiReferenceExpression)lExpr).resolve();
+        if (target instanceof PsiField) {
+          myImplicitCompactConstructorAssignments.remove(target);
+        }
+      }
       PsiVariable variable = getUsedVariable((PsiReferenceExpression)lExpr);
       if (variable != null) {
         if (myAssignmentTargetsAreElements) {
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/afterRecordCompact2.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/afterRecordCompact2.java
new file mode 100644
index 000000000000..5ac539930abc
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/afterRecordCompact2.java
@@ -0,0 +1,6 @@
+// "Remove redundant assignment" "true"
+record R2(int y) {
+  public R2 {
+    this.y = y;
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/beforeRecordCompact.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/beforeRecordCompact.java
new file mode 100644
index 000000000000..da13763b9fc7
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/beforeRecordCompact.java
@@ -0,0 +1,6 @@
+// "Remove redundant assignment" "false"
+record R(int x) {
+  R {
+    <caret>x = x + 1;
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/beforeRecordCompact2.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/beforeRecordCompact2.java
new file mode 100644
index 000000000000..0a0380381d4e
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unusedAssignment/beforeRecordCompact2.java
@@ -0,0 +1,7 @@
+// "Remove redundant assignment" "true"
+record R2(int y) {
+  public R2 {
+    this.y = y;
+    <caret>y = y + 1;
+  }
+}
\ No newline at end of file