Merge branch 'issue-257'

pmd-java/etc/grammar/Java.jjt

@@ -1,4 +1,9 @@
 /**
+ * Provide a better fix for CastExpression, getting rid of most hacks.
+ * Bug #257
+ *
+ * Juan Martin Sotuyo Dodero 02/2017
+ *====================================================================
  * Allow local classes to carry more than one annotation.
  * Bug #208
  *
@@ -1558,7 +1563,7 @@ void ReferenceType():
 
 void ClassOrInterfaceType():
 {
-  StringBuffer s = new StringBuffer();
+  StringBuilder s = new StringBuilder();
   Token t;
 }
 {
@@ -1789,9 +1794,13 @@ void UnaryExpressionNotPlusMinus() #UnaryExpressionNotPlusMinus((jjtn000.getImag
 {}
 {
  ( "~" {jjtThis.setImage("~");} | "!" {jjtThis.setImage("!");} ) UnaryExpression()
-| LOOKAHEAD( { getToken(1).kind == LPAREN && getToken(2).kind == IDENTIFIER && getToken(3).kind == RPAREN && getToken(4).kind == PLUS } ) PostfixExpression()
+/*
-| LOOKAHEAD( CastExpression() ) CastExpression()
+ * This is really ugly... we are repeting the CastExpression lookahead and full expression...
-| LOOKAHEAD("(" Type() ")" "(") CastExpression()
+ * If we don't the lookahead within CastExpression is ignored, and it simply looks for the expression,
+ * meaning we can't be explicit as to what can be casted depending on the cast type (primitive or otherwhise)
+*/
+| LOOKAHEAD("(" (Annotation())* PrimitiveType() ")") CastExpression()
+| LOOKAHEAD("(" (Annotation())* Type() ( "&" ReferenceType() )* ")" UnaryExpressionNotPlusMinus()) CastExpression()
 | PostfixExpression()
 }
 
@@ -1801,12 +1810,13 @@ void PostfixExpression() #PostfixExpression((jjtn000.getImage() != null)):
   PrimaryExpression() [ "++" {jjtThis.setImage("++");} | "--" {jjtThis.setImage("--");} ]
 }
 
-void CastExpression() #CastExpression(>1):
+void CastExpression() :
 {}
 {
-  LOOKAHEAD("(" (Annotation())* Type() ")") "(" (Annotation() {checkForBadTypeAnnotations();})* Type() ")" UnaryExpression()
+  LOOKAHEAD(
-| LOOKAHEAD("(" (Annotation())* Type() "&") "(" (Annotation() {checkForBadTypeAnnotations();})* Type() ( "&" {checkForBadIntersectionTypesInCasts(); jjtThis.setIntersectionTypes(true);} ReferenceType() )+ ")" UnaryExpressionNotPlusMinus()
+    "(" (Annotation())* PrimitiveType() ")"
-| "(" (Annotation() {checkForBadTypeAnnotations();})* Type() ")" UnaryExpressionNotPlusMinus()
+  ) "(" (Annotation() {checkForBadTypeAnnotations();})* Type() ")" UnaryExpression()
+| "(" (Annotation() {checkForBadTypeAnnotations();})* Type() ( "&" {checkForBadIntersectionTypesInCasts(); jjtThis.setIntersectionTypes(true);} ReferenceType() )* ")" UnaryExpressionNotPlusMinus()
 }
 
 void PrimaryExpression() :
@@ -2010,12 +2020,9 @@ void StatementExpression() :
 |
   PreDecrementExpression()
 |
-  LOOKAHEAD( PrimaryExpression() ("++" | "--") ) PostfixExpression()
+  LOOKAHEAD( PrimaryExpression() AssignmentOperator() ) PrimaryExpression() AssignmentOperator() Expression()
 |
-  PrimaryExpression()
+  PostfixExpression()
-  [
-  AssignmentOperator() Expression()
-  ]
 }
 
 void SwitchStatement() :

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/strings/InsufficientStringBufferDeclarationRule.java

@@ -26,7 +26,6 @@ import net.sourceforge.pmd.lang.java.ast.ASTPrimaryPrefix;
 import net.sourceforge.pmd.lang.java.ast.ASTPrimarySuffix;
 import net.sourceforge.pmd.lang.java.ast.ASTSwitchLabel;
 import net.sourceforge.pmd.lang.java.ast.ASTSwitchStatement;
-import net.sourceforge.pmd.lang.java.ast.ASTType;
 import net.sourceforge.pmd.lang.java.ast.ASTVariableDeclarator;
 import net.sourceforge.pmd.lang.java.ast.ASTVariableDeclaratorId;
 import net.sourceforge.pmd.lang.java.ast.ASTVariableInitializer;
@@ -204,7 +203,7 @@ public class InsufficientStringBufferDeclarationRule extends AbstractJavaRule {
                             // but only if we are not inside a cast expression
                             Node parentNode = literal.jjtGetParent().jjtGetParent().jjtGetParent();
                             if (parentNode instanceof ASTCastExpression
-                                    && parentNode.getFirstChildOfType(ASTType.class).getType() == char.class) {
+                                    && ((ASTCastExpression) parentNode).getType() == char.class) {
                                 anticipatedLength += 1;
                             } else {
                                 // e.g. 0xdeadbeef -> will be converted to a

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/unusedcode/UnusedLocalVariableRule.java

@@ -15,6 +15,10 @@ import net.sourceforge.pmd.lang.symboltable.NameOccurrence;
 
 public class UnusedLocalVariableRule extends AbstractJavaRule {
 
+    public UnusedLocalVariableRule() {
+        addRuleChainVisit(ASTLocalVariableDeclaration.class);
+    }
+
     public Object visit(ASTLocalVariableDeclaration decl, Object data) {
         for (int i = 0; i < decl.jjtGetNumChildren(); i++) {
             if (!(decl.jjtGetChild(i) instanceof ASTVariableDeclarator)) {
@@ -34,9 +38,7 @@ public class UnusedLocalVariableRule extends AbstractJavaRule {
     private boolean actuallyUsed(List<NameOccurrence> usages) {
         for (NameOccurrence occ : usages) {
             JavaNameOccurrence jocc = (JavaNameOccurrence) occ;
-            if (jocc.isOnLeftHandSide()) {
+            if (!jocc.isOnLeftHandSide()) {
-                continue;
-            } else {
                 return true;
             }
         }

pmd-java/src/test/java/net/sourceforge/pmd/lang/java/ast/ParserCornersTest.java

@@ -158,6 +158,20 @@ public class ParserCornersTest extends ParserTst {
         parseJava15(c);
     }
     
+    @Test
+    public void testGitHubBug257NonExistingCast() throws Exception {
+        String code = "public class Test {" + PMD.EOL
+                + "     public static void main(String[] args) {" + PMD.EOL
+                + "         double a = 4.0;" + PMD.EOL
+                + "         double b = 2.0;" + PMD.EOL
+                + "         double result = Math.sqrt((a)   - b);" + PMD.EOL
+                + "         System.out.println(result);" + PMD.EOL
+                + "     }" + PMD.EOL
+                + "}";
+        ASTCompilationUnit compilationUnit = parseJava15(code);
+        assertEquals("A cast was found when none expected", 0, compilationUnit.findDescendantsOfType(ASTCastExpression.class).size());
+    }
+
     /**
      * This triggered bug #1484 UnusedLocalVariable - false positive -
      * parenthesis

pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/unusedcode/xml/UnusedLocalVariable.xml

@@ -368,6 +368,21 @@ public class Test {
 
         System.out.println(list.size() + " (" + (notEmpty) + " not empty)");
     }
+}
+        ]]></code>
+    </test-code>
+    
+    <test-code>
+        <description>#257 UnusedLocalVariable - false positive - parenthesis</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+public class Test {
+    public static void main(String[] args) {
+        double a = 4.0;
+        double b = 2.0;
+        double result = Math.sqrt((a) - b);
+        System.out.println(result);
+    }
 }
         ]]></code>
     </test-code>

src/site/markdown/overview/changelog.md

@@ -345,6 +345,7 @@ For example:
     *   [#246](https://github.com/pmd/pmd/issues/246): \[java] UnusedModifier doesn't check annotations
     *   [#247](https://github.com/pmd/pmd/issues/247): \[java] UnusedModifier doesn't check annotations inner classes
     *   [#248](https://github.com/pmd/pmd/issues/248): \[java] UnusedModifier doesn't check static keyword on nested enum declaration
+    *   [#257](https://github.com/pmd/pmd/issues/257): \[java] UnusedLocalVariable false positive
 *   XML
     *   [#1518](https://sourceforge.net/p/pmd/bugs/1518/): \[xml] Error while processing xml file with ".webapp" in the file or directory name
 *   psql