From feee0b8f9174bbbb52c70acefc88a6df3702d673 Mon Sep 17 00:00:00 2001
From: Andreas Dangel <andreas.dangel@pmd-code.org>
Date: Thu, 16 Apr 2020 18:57:10 +0200
Subject: [PATCH] [java] Replace XPath ProperCloneImplementation with Java Rule

---
 .../ProperCloneImplementationRule.java        | 52 +++++++++++++++++++
 .../resources/category/java/errorprone.xml    | 17 +-----
 2 files changed, 53 insertions(+), 16 deletions(-)
 create mode 100644 pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/errorprone/ProperCloneImplementationRule.java

diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/errorprone/ProperCloneImplementationRule.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/errorprone/ProperCloneImplementationRule.java
new file mode 100644
index 0000000000..19262a5535
--- /dev/null
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/errorprone/ProperCloneImplementationRule.java
@@ -0,0 +1,52 @@
+/*
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+
+package net.sourceforge.pmd.lang.java.rule.errorprone;
+
+import java.util.List;
+
+import net.sourceforge.pmd.lang.java.ast.ASTAllocationExpression;
+import net.sourceforge.pmd.lang.java.ast.ASTBlock;
+import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceDeclaration;
+import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceType;
+import net.sourceforge.pmd.lang.java.ast.ASTMethodDeclaration;
+import net.sourceforge.pmd.lang.java.rule.AbstractJavaRule;
+
+public class ProperCloneImplementationRule extends AbstractJavaRule {
+
+    public ProperCloneImplementationRule() {
+        addRuleChainVisit(ASTMethodDeclaration.class);
+    }
+
+    @Override
+    public Object visit(ASTMethodDeclaration node, Object data) {
+        if (!"clone".equals(node.getName()) || node.getArity() > 0) {
+            return data;
+        }
+        
+        ASTBlock block = node.getFirstChildOfType(ASTBlock.class);
+        if (block == null) {
+            return data;
+        }
+        
+        String enclosingClassName = node.getFirstParentOfType(ASTClassOrInterfaceDeclaration.class).getSimpleName();
+        if (blockHasAllocations(block, enclosingClassName)) {
+            addViolation(data, node);
+        }
+        
+        return data;
+    }
+
+    private boolean blockHasAllocations(ASTBlock block, String enclosingClassName) {
+        List<ASTAllocationExpression> allocations = block.findDescendantsOfType(ASTAllocationExpression.class);
+        for (ASTAllocationExpression alloc : allocations) {
+            ASTClassOrInterfaceType type = alloc.getFirstChildOfType(ASTClassOrInterfaceType.class);
+            if (type.hasImageEqualTo(enclosingClassName)) {
+                return true;
+            }
+        }
+        return false;
+    }
+}
diff --git a/pmd-java/src/main/resources/category/java/errorprone.xml b/pmd-java/src/main/resources/category/java/errorprone.xml
index 15c60185ea..3617a84f41 100644
--- a/pmd-java/src/main/resources/category/java/errorprone.xml
+++ b/pmd-java/src/main/resources/category/java/errorprone.xml
@@ -2719,27 +2719,12 @@ public class Foo {        // perfect, both methods provided
           language="java"
           since="1.4"
           message="Object clone() should be implemented with super.clone()"
-          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          class="net.sourceforge.pmd.lang.java.rule.errorprone.ProperCloneImplementationRule"
           externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_errorprone.html#propercloneimplementation">
         <description>
 Object clone() should be implemented with super.clone().
         </description>
         <priority>2</priority>
-        <properties>
-            <property name="version" value="2.0"/>
-            <property name="xpath">
-                <value>
-<![CDATA[
-//MethodDeclaration
-[@Name = 'clone']
-[@Arity = 0]
-[Block
-  [.//AllocationExpression[ClassOrInterfaceType[@Image = ancestor::ClassOrInterfaceDeclaration[1]/@SimpleName]]]
-]
-]]>
-                </value>
-            </property>
-        </properties>
         <example>
 <![CDATA[
 class Foo{