From 488ef11fd4c9d39c702564cdee7ec9e6b6d53c2e Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Mon, 26 Oct 2015 16:12:23 +0100
Subject: [PATCH] dfa: support (i)++ (IDEA-146805)

---
 .../dataFlow/ControlFlowAnalyzer.java         | 49 +++++++++----------
 .../fixture/IncrementParenthesized.java       |  7 +++
 .../DataFlowInspectionTest.java               |  1 +
 3 files changed, 32 insertions(+), 25 deletions(-)
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/IncrementParenthesized.java

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/ControlFlowAnalyzer.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/ControlFlowAnalyzer.java
index 1a6e9214f603..209d0e91634c 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/ControlFlowAnalyzer.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/ControlFlowAnalyzer.java
@@ -1217,7 +1217,7 @@ public class ControlFlowAnalyzer extends JavaElementVisitor {
     }
   }
 
-  private void generateBoxingUnboxingInstructionFor(PsiExpression expression, PsiType expectedType) {
+  private void generateBoxingUnboxingInstructionFor(@NotNull PsiExpression expression, PsiType expectedType) {
     if (expectedType == PsiType.VOID) return;
 
     PsiType exprType = expression.getType();
@@ -1617,23 +1617,18 @@ public class ControlFlowAnalyzer extends JavaElementVisitor {
   @Override public void visitPostfixExpression(PsiPostfixExpression expression) {
     startElement(expression);
 
-    PsiExpression operand = expression.getOperand();
-    operand.accept(this);
-    generateBoxingUnboxingInstructionFor(operand, PsiType.INT);
+    PsiExpression operand = PsiUtil.skipParenthesizedExprDown(expression.getOperand());
+    if (operand != null) {
+      operand.accept(this);
+      generateBoxingUnboxingInstructionFor(operand, PsiType.INT);
+    } else {
+      pushUnknown();
+    }
 
     addInstruction(new PopInstruction());
     pushUnknown();
 
-    if (operand instanceof PsiReferenceExpression) {
-      PsiVariable psiVariable = DfaValueFactory.resolveUnqualifiedVariable((PsiReferenceExpression)expression.getOperand());
-      if (psiVariable != null) {
-        DfaVariableValue dfaVariable = myFactory.getVarFactory().createVariableValue(psiVariable, false);
-        addInstruction(new FlushVariableInstruction(dfaVariable));
-        if (psiVariable instanceof PsiField) {
-          addInstruction(new FlushVariableInstruction(null));
-        }
-      }
-    }
+    flushIncrementedValue(operand);
 
     finishElement(expression);
   }
@@ -1643,7 +1638,7 @@ public class ControlFlowAnalyzer extends JavaElementVisitor {
 
     DfaValue dfaValue = myFactory.createValue(expression);
     if (dfaValue == null) {
-      PsiExpression operand = expression.getOperand();
+      PsiExpression operand = PsiUtil.skipParenthesizedExprDown(expression.getOperand());
 
       if (operand == null) {
         pushUnknown();
@@ -1660,16 +1655,7 @@ public class ControlFlowAnalyzer extends JavaElementVisitor {
           addInstruction(new PopInstruction());
           pushUnknown();
 
-          if (operand instanceof PsiReferenceExpression) {
-            PsiVariable psiVariable = DfaValueFactory.resolveUnqualifiedVariable((PsiReferenceExpression)operand);
-            if (psiVariable != null) {
-              DfaVariableValue dfaVariable = myFactory.getVarFactory().createVariableValue(psiVariable, false);
-              addInstruction(new FlushVariableInstruction(dfaVariable));
-              if (psiVariable instanceof PsiField) {
-                addInstruction(new FlushVariableInstruction(null));
-              }
-            }
-          }
+          flushIncrementedValue(operand);
         }
       }
     }
@@ -1680,6 +1666,19 @@ public class ControlFlowAnalyzer extends JavaElementVisitor {
     finishElement(expression);
   }
 
+  private void flushIncrementedValue(@Nullable PsiExpression operand) {
+    if (operand instanceof PsiReferenceExpression) {
+      PsiVariable psiVariable = DfaValueFactory.resolveUnqualifiedVariable((PsiReferenceExpression)operand);
+      if (psiVariable != null) {
+        DfaVariableValue dfaVariable = myFactory.getVarFactory().createVariableValue(psiVariable, false);
+        addInstruction(new FlushVariableInstruction(dfaVariable));
+        if (psiVariable instanceof PsiField) {
+          addInstruction(new FlushVariableInstruction(null));
+        }
+      }
+    }
+  }
+
   @Override public void visitReferenceExpression(PsiReferenceExpression expression) {
     startElement(expression);
 
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/IncrementParenthesized.java b/java/java-tests/testData/inspection/dataFlow/fixture/IncrementParenthesized.java
new file mode 100644
index 000000000000..b5871d3fd07b
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/IncrementParenthesized.java
@@ -0,0 +1,7 @@
+class Test {
+  public static void main(String[] args) {
+    for (int i = 0; i < 30; (i)++) {
+      System.out.println(i);
+    }
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java b/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java
index fdcb1a6d2c10..0d56a084a577 100644
--- a/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java
+++ b/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java
@@ -245,6 +245,7 @@ public class DataFlowInspectionTest extends LightCodeInsightFixtureTestCase {
   public void testDoubleCCEWarning() { doTest(); }
   public void testLongCircuitOperations() { doTest(); }
   public void testUnconditionalForLoop() { doTest(); }
+  public void testIncrementParenthesized() { doTest(); }
   public void testAnonymousMethodIndependence() { doTest(); }
   public void testAnonymousFieldIndependence() { doTest(); }
   public void testNoConfusionWithAnonymousConstantInitializer() { doTest(); }