DEA-91189 ("Numeric cast that loses precision" should have "ignore for equals" checkbox)

plugins/InspectionGadgets/src/com/siyeh/ig/numeric/CastThatLosesPrecisionInspection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2009 Dave Griffith, Bas Leijdekkers
+ * Copyright 2003-2012 Dave Griffith, Bas Leijdekkers
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,18 +16,17 @@
 package com.siyeh.ig.numeric;
 
 import com.intellij.codeInspection.ui.SingleCheckboxOptionsPanel;
-import com.intellij.psi.PsiExpression;
-import com.intellij.psi.PsiType;
-import com.intellij.psi.PsiTypeCastExpression;
-import com.intellij.psi.PsiTypeElement;
+import com.intellij.psi.*;
+import com.intellij.psi.util.PsiTreeUtil;
 import com.siyeh.InspectionGadgetsBundle;
 import com.siyeh.ig.BaseInspection;
 import com.siyeh.ig.BaseInspectionVisitor;
 import com.siyeh.ig.psiutils.ClassUtils;
 import com.siyeh.ig.psiutils.ExpressionUtils;
+import com.siyeh.ig.psiutils.MethodUtils;
 import org.jetbrains.annotations.NotNull;
 
-import javax.swing.JComponent;
+import javax.swing.*;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -36,8 +35,7 @@ public class CastThatLosesPrecisionInspection extends BaseInspection {
   /**
    * @noinspection StaticCollection
    */
-  private static final Map<PsiType, Integer> typePrecisions =
-    new HashMap<PsiType, Integer>(7);
+  private static final Map<PsiType, Integer> typePrecisions = new HashMap<PsiType, Integer>(7);
 
   static {
     typePrecisions.put(PsiType.BYTE, 1);
@@ -69,15 +67,12 @@ public class CastThatLosesPrecisionInspection extends BaseInspection {
   @NotNull
   public String buildErrorString(Object... infos) {
     final PsiType operandType = (PsiType)infos[0];
-    return InspectionGadgetsBundle.message(
-      "cast.that.loses.precision.problem.descriptor",
-      operandType.getPresentableText());
+    return InspectionGadgetsBundle.message("cast.that.loses.precision.problem.descriptor", operandType.getPresentableText());
   }
 
   @Override
   public JComponent createOptionsPanel() {
-    return new SingleCheckboxOptionsPanel(InspectionGadgetsBundle.message(
-      "cast.that.loses.precision.option"),
+    return new SingleCheckboxOptionsPanel(InspectionGadgetsBundle.message("cast.that.loses.precision.option"),
                                           this, "ignoreIntegerCharCasts");
   }
 
@@ -90,8 +85,7 @@ public class CastThatLosesPrecisionInspection extends BaseInspection {
     extends BaseInspectionVisitor {
 
     @Override
-    public void visitTypeCastExpression(
-      @NotNull PsiTypeCastExpression expression) {
+    public void visitTypeCastExpression(@NotNull PsiTypeCastExpression expression) {
       final PsiType castType = expression.getType();
       if (!ClassUtils.isPrimitiveNumericType(castType)) {
         return;
@@ -112,8 +106,13 @@ public class CastThatLosesPrecisionInspection extends BaseInspection {
           return;
         }
       }
-      Object result =
-        ExpressionUtils.computeConstantExpression(operand);
+      if (PsiType.LONG.equals(operandType) && PsiType.INT.equals(castType)) {
+        final PsiMethod method = PsiTreeUtil.getParentOfType(expression, PsiMethod.class, true, PsiClass.class);
+        if (MethodUtils.isHashCode(method)) {
+          return;
+        }
+      }
+      Object result = ExpressionUtils.computeConstantExpression(operand);
       if (result instanceof Character) {
         result = Integer.valueOf(((Character)result).charValue());
       }
@@ -130,15 +129,13 @@ public class CastThatLosesPrecisionInspection extends BaseInspection {
       registerError(castTypeElement, operandType);
     }
 
-    private boolean hasLowerPrecision(PsiType operandType,
-                                      PsiType castType) {
+    private boolean hasLowerPrecision(PsiType operandType, PsiType castType) {
       final Integer operandPrecision = typePrecisions.get(operandType);
       final Integer castPrecision = typePrecisions.get(castType);
-      return operandPrecision <= castPrecision;
+      return operandPrecision.intValue() <= castPrecision.intValue();
     }
 
-    private boolean valueIsContainableInType(Number value,
-                                             PsiType type) {
+    private boolean valueIsContainableInType(Number value, PsiType type) {
       final long longValue = value.longValue();
       final double doubleValue = value.doubleValue();
       if (PsiType.BYTE.equals(type)) {

plugins/InspectionGadgets/test/com/siyeh/igtest/numeric/cast_that_loses_precision/CastThatLosesPrecision.java

@@ -1,8 +1,8 @@
-package com.siyeh.igtest.confusing;
+package com.siyeh.igtest.numeric.cast_that_loses_precision;
 
-public class CastThatLosesPrecisionInspection
+public class CastThatLosesPrecision
 {
-    public CastThatLosesPrecisionInspection()
+    public CastThatLosesPrecision()
     {
     }
 
@@ -67,4 +67,15 @@ public class CastThatLosesPrecisionInspection
         System.out.println("f = " + f);
     }
 
+
+  private long aLong = 2L;
+  private double d = 1.0;
+
+  @Override
+  public int hashCode() {
+    int result = (int) (aLong ^ (aLong >>> 32));
+    long temp = d != +0.0d ? (int) d : 0L;
+    result = 31 * result + (int) (temp ^ temp >>> 32);
+    return result;
+  }
 }

plugins/InspectionGadgets/test/com/siyeh/igtest/numeric/cast_that_loses_precision/expected.xml

@@ -0,0 +1,72 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<problems>
+  <problem>
+    <file>CastThatLosesPrecision.java</file>
+    <line>18</line>
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Numeric cast that loses precision</problem_class>
+    <description>Cast to &lt;code&gt;int&lt;/code&gt; from 'float' may result in loss of precision #loc</description>
+  </problem>
+
+  <problem>
+    <file>CastThatLosesPrecision.java</file>
+    <line>20</line>
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Numeric cast that loses precision</problem_class>
+    <description>Cast to &lt;code&gt;char&lt;/code&gt; from 'double' may result in loss of precision #loc</description>
+  </problem>
+
+  <problem>
+    <file>CastThatLosesPrecision.java</file>
+    <line>22</line>
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Numeric cast that loses precision</problem_class>
+    <description>Cast to &lt;code&gt;int&lt;/code&gt; from 'double' may result in loss of precision #loc</description>
+  </problem>
+
+  <problem>
+    <file>CastThatLosesPrecision.java</file>
+    <line>24</line>
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Numeric cast that loses precision</problem_class>
+    <description>Cast to &lt;code&gt;int&lt;/code&gt; from 'long' may result in loss of precision #loc</description>
+  </problem>
+
+  <problem>
+    <file>CastThatLosesPrecision.java</file>
+    <line>26</line>
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Numeric cast that loses precision</problem_class>
+    <description>Cast to &lt;code&gt;byte&lt;/code&gt; from 'long' may result in loss of precision #loc</description>
+  </problem>
+
+  <problem>
+    <file>CastThatLosesPrecision.java</file>
+    <line>29</line>
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Numeric cast that loses precision</problem_class>
+    <description>Cast to &lt;code&gt;long&lt;/code&gt; from 'double' may result in loss of precision #loc</description>
+  </problem>
+
+  <problem>
+    <file>CastThatLosesPrecision.java</file>
+    <line>31</line>
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Numeric cast that loses precision</problem_class>
+    <description>Cast to &lt;code&gt;long&lt;/code&gt; from 'float' may result in loss of precision #loc</description>
+  </problem>
+
+  <problem>
+    <file>CastThatLosesPrecision.java</file>
+    <line>37</line>
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Numeric cast that loses precision</problem_class>
+    <description>Cast to &lt;code&gt;float&lt;/code&gt; from 'double' may result in loss of precision #loc</description>
+  </problem>
+
+  <problem>
+    <file>CastThatLosesPrecision.java</file>
+    <line>55</line>
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Numeric cast that loses precision</problem_class>
+    <description>Cast to &lt;code&gt;byte&lt;/code&gt; from 'long' may result in loss of precision #loc</description>
+  </problem>
+
+  <problem>
+    <file>CastThatLosesPrecision.java</file>
+    <line>77</line>
+    <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">Numeric cast that loses precision</problem_class>
+    <description>Cast to &lt;code&gt;int&lt;/code&gt; from 'double' may result in loss of precision #loc</description>
+  </problem>
+</problems>

plugins/InspectionGadgets/testsrc/com/siyeh/ig/numeric/CastThatLosesPrecisionInspectionTest.java

@@ -0,0 +1,10 @@
+package com.siyeh.ig.numeric;
+
+import com.siyeh.ig.IGInspectionTestCase;
+
+public class CastThatLosesPrecisionInspectionTest extends IGInspectionTestCase {
+
+  public void test() throws Exception {
+    doTest("com/siyeh/igtest/numeric/cast_that_loses_precision", new CastThatLosesPrecisionInspection());
+  }
+}