From cb1b5c16bffd63c954702907ae2e6fbf2193cfa4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Mart=C3=ADn=20Sotuyo=20Dodero?=
 <juansotuyo@gmail.com>
Date: Tue, 16 Apr 2019 16:51:15 -0300
Subject: [PATCH] [java] Have symbol table recognize concise resources

 - Concise resources are valid usages.
 - Fixes #1190
---
 .../java/symboltable/JavaNameOccurrence.java  |  6 ++++-
 .../java/symboltable/OccurrenceFinder.java    | 17 ++++++++++++++
 .../bestpractices/xml/UnusedLocalVariable.xml | 19 +++++++++++++++
 .../bestpractices/xml/UnusedPrivateField.xml  | 23 +++++++++++++++++++
 4 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symboltable/JavaNameOccurrence.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symboltable/JavaNameOccurrence.java
index 7dcc57fe91..4e7033de52 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symboltable/JavaNameOccurrence.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symboltable/JavaNameOccurrence.java
@@ -14,6 +14,7 @@ import net.sourceforge.pmd.lang.java.ast.ASTPreDecrementExpression;
 import net.sourceforge.pmd.lang.java.ast.ASTPreIncrementExpression;
 import net.sourceforge.pmd.lang.java.ast.ASTPrimaryExpression;
 import net.sourceforge.pmd.lang.java.ast.ASTPrimaryPrefix;
+import net.sourceforge.pmd.lang.java.ast.ASTResource;
 import net.sourceforge.pmd.lang.java.ast.ASTStatementExpression;
 import net.sourceforge.pmd.lang.java.ast.JavaNode;
 import net.sourceforge.pmd.lang.symboltable.NameOccurrence;
@@ -87,9 +88,12 @@ public class JavaNameOccurrence implements NameOccurrence {
             primaryExpression = location.jjtGetParent().jjtGetParent();
         } else if (location.jjtGetParent().jjtGetParent() instanceof ASTPrimaryExpression) {
             primaryExpression = location.jjtGetParent().jjtGetParent().jjtGetParent();
+        } else if (location.jjtGetParent() instanceof ASTResource) {
+            return false;
         } else {
             throw new RuntimeException(
-                    "Found a NameOccurrence (" + location + ") that didn't have an ASTPrimary Expression as parent or grandparent.  Parent = "
+                    "Found a NameOccurrence (" + location + ") that didn't have an ASTPrimary Expression"
+                            + " as parent or grandparent nor is a concise resource.  Parent = "
                             + location.jjtGetParent() + " and grandparent = " + location.jjtGetParent().jjtGetParent()
                             + " (location line " + location.getBeginLine() + " col " + location.getBeginColumn() + ")");
         }
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symboltable/OccurrenceFinder.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symboltable/OccurrenceFinder.java
index 37b6b819a5..13c770ab7e 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symboltable/OccurrenceFinder.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symboltable/OccurrenceFinder.java
@@ -7,8 +7,11 @@ package net.sourceforge.pmd.lang.java.symboltable;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.StringTokenizer;
 
+import net.sourceforge.pmd.lang.java.ast.ASTName;
 import net.sourceforge.pmd.lang.java.ast.ASTPrimaryExpression;
+import net.sourceforge.pmd.lang.java.ast.ASTResource;
 import net.sourceforge.pmd.lang.java.ast.JavaParserVisitorAdapter;
 import net.sourceforge.pmd.lang.symboltable.NameDeclaration;
 import net.sourceforge.pmd.lang.symboltable.Scope;
@@ -21,6 +24,20 @@ public class OccurrenceFinder extends JavaParserVisitorAdapter {
 
     private final Set<NameDeclaration> additionalDeclarations = new HashSet<>();
 
+    @Override
+    public Object visit(ASTResource node, Object data) {
+        // is this a concise resource reference?
+        if (node.jjtGetNumChildren() == 1) {
+            ASTName nameNode = (ASTName) node.jjtGetChild(0);
+            for (StringTokenizer st = new StringTokenizer(nameNode.getImage(), "."); st.hasMoreTokens();) {
+                JavaNameOccurrence occ = new JavaNameOccurrence(nameNode, st.nextToken());
+                new Search(occ).execute();
+            }
+        }
+        
+        return super.visit(node, data);
+    }
+    
     @Override
     public Object visit(ASTPrimaryExpression node, Object data) {
         NameFinder nameFinder = new NameFinder(node);
diff --git a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/bestpractices/xml/UnusedLocalVariable.xml b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/bestpractices/xml/UnusedLocalVariable.xml
index 4883375d4e..32c62ecf2d 100644
--- a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/bestpractices/xml/UnusedLocalVariable.xml
+++ b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/bestpractices/xml/UnusedLocalVariable.xml
@@ -386,6 +386,25 @@ public class Test {
         double result = Math.sqrt((a) - b);
         System.out.println(result);
     }
+}
+        ]]></code>
+    </test-code>
+    
+    <test-code>
+        <description>#1190 [java] UnusedLocalVariable/UnusedPrivateField false-positive</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+import java.io.InputStream;
+
+public class UnusedLocalVariable {
+
+    public void testSomething() {
+        InputStream is = new InputStream();
+        
+        try (is) {
+            System.out.println("foo!");
+        }
+    }
 }
         ]]></code>
     </test-code>
diff --git a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/bestpractices/xml/UnusedPrivateField.xml b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/bestpractices/xml/UnusedPrivateField.xml
index 3124ab44b1..f5ff621713 100644
--- a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/bestpractices/xml/UnusedPrivateField.xml
+++ b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/bestpractices/xml/UnusedPrivateField.xml
@@ -597,6 +597,29 @@ public class IssueUnusedPrivateField {
         String helper = "some new string";  // hidden here
         System.out.println("helper = " + helper);
     }
+}
+        ]]></code>
+    </test-code>
+    
+    <test-code>
+        <description>#1190 [java] UnusedLocalVariable/UnusedPrivateField false-positive</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+import java.io.InputStream;
+
+public class IssueUnusedPrivateField {
+
+    private InputStream is;
+    
+    public IssueUnusedPrivateField(InputStream is) {
+        this.is = is;
+    }
+
+    public void testSomething() {
+        try (is) {
+            System.out.println("foo!");
+        }
+    }
 }
         ]]></code>
     </test-code>