Fixed false positive in UnusedImports: javadoc comments are parsed to check @see and other tags

git-svn-id: https://pmd.svn.sourceforge.net/svnroot/pmd/branches/pmd/4.2.x@6018 51baf565-9d33-0410-a72c-fc3788e3496d

pmd/etc/changelog.txt

@@ -1,3 +1,7 @@
+???? - 4.2.2:
+
+Fixed false positive in UnusedImports: javadoc comments are parsed to check @see and other tags
+
 April 11, 2008 - 4.2.1:
 
 '41' and '42' shortcuts for rulesets added

pmd/etc/grammar/Java.jjt

@@ -163,6 +163,8 @@ public class JavaParser {
 }
 PARSER_END(JavaParser)
 TOKEN_MGR_DECLS : {
+    protected List<Token> formalComments = new ArrayList<Token>();
+
     private Map<Integer, String> excludeMap = new HashMap<Integer, String>();
     private String excludeMarker = PMD.EXCLUDE_MARKER;
 
@@ -204,7 +206,7 @@ MORE :
 <IN_FORMAL_COMMENT>
 SPECIAL_TOKEN :
 {
-  <FORMAL_COMMENT: "*/" > : DEFAULT
+  <FORMAL_COMMENT: "*/" > { formalComments.add(matchedToken); } : DEFAULT
 }
 
 <IN_MULTI_LINE_COMMENT>
@@ -1077,6 +1079,7 @@ ASTCompilationUnit CompilationUnit() :
   ( < "~[]" > )?
   <EOF>
 {
+ jjtThis.setFormalComments(token_source.formalComments);
  return jjtThis;
 }
 }

pmd/regress/test/net/sourceforge/pmd/rules/imports/xml/UnusedImports.xml

@@ -178,6 +178,27 @@ On demand import
 import java.util.*;
 public class Foo {
 	List list = new ArrayList();
+}
+     ]]></code>
+    </test-code>
+    <test-code>
+        <description><![CDATA[
+imports used in javadoc comment
+     ]]></description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+import java.util.ArrayList;
+import java.util.Calendar;
+import java.util.List;
+import java.util.File;
+public class Foo {
+	/**
+	 * {@linkplain  List list} 
+	 * {@link  ArrayList  arraylist} 
+	 * {@value  Calendar#DATE} 
+	 * @see File
+	 */
+	public void test() {}
 }
      ]]></code>
     </test-code>

pmd/regress/test/net/sourceforge/pmd/rules/typeresolution/xml/UnusedImports.xml

@@ -154,4 +154,25 @@ public class Foo {
 }
      ]]></code>
     </test-code>
+    <test-code>
+        <description><![CDATA[
+imports used in javadoc comment
+        ]]></description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+import java.util.ArrayList;
+import java.util.Calendar;
+import java.util.List;
+import java.util.File;
+public class Foo {
+    /**
+     * {@linkplain  List list}
+     * {@link  ArrayList  arraylist}
+     * {@value  Calendar#DATE}
+     * @see File
+     */
+     public void test() {}
+}
+        ]]></code>
+    </test-code>
 </test-data>

pmd/src/net/sourceforge/pmd/ast/ASTCompilationUnit.java

@@ -2,6 +2,7 @@
 
 package net.sourceforge.pmd.ast;
 
+import java.util.List;
 import net.sourceforge.pmd.typeresolution.ClassTypeResolver;
 
 // FUTURE Change this class to extend from SimpleJavaNode, as TypeNode is not appropriate (unless I'm wrong)
@@ -17,6 +18,15 @@ public class ASTCompilationUnit extends SimpleJavaTypeNode implements Compilatio
         super(p, id);
     }
 
+    private List<Token> formalComments;
+
+    public List<Token> getFormalComments() {
+        return formalComments;
+    }
+
+    public void setFormalComments(List<Token> formalComments) {
+        this.formalComments = formalComments;
+    }
 
     /**
      * Accept the visitor. *

pmd/src/net/sourceforge/pmd/ast/JavaParser.java

@@ -169,6 +169,7 @@ public class JavaParser/*@bgen(jjtree)*/implements JavaParserTreeConstants, Java
       jj_consume_token(0);
   jjtree.closeNodeScope(jjtn000, true);
   jjtc000 = false;
+ jjtn000.setFormalComments(token_source.formalComments);
  {if (true) return jjtn000;}
     } catch (Throwable jjte000) {
     if (jjtc000) {
@@ -8001,6 +8002,15 @@ jjtn000.setModifiers(modifiers);
     return false;
   }
 
+  private boolean jj_3R_188() {
+    if (jj_scan_token(WHILE)) return true;
+    if (jj_scan_token(LPAREN)) return true;
+    if (jj_3R_88()) return true;
+    if (jj_scan_token(RPAREN)) return true;
+    if (jj_3R_91()) return true;
+    return false;
+  }
+
   private boolean jj_3_1() {
     Token xsp;
     while (true) {
@@ -8011,15 +8021,6 @@ jjtn000.setModifiers(modifiers);
     return false;
   }
 
-  private boolean jj_3R_188() {
-    if (jj_scan_token(WHILE)) return true;
-    if (jj_scan_token(LPAREN)) return true;
-    if (jj_3R_88()) return true;
-    if (jj_scan_token(RPAREN)) return true;
-    if (jj_3R_91()) return true;
-    return false;
-  }
-
   private boolean jj_3_44() {
     if (jj_3R_74()) return true;
     return false;

pmd/src/net/sourceforge/pmd/ast/JavaParserTokenManager.java

@@ -6,6 +6,8 @@ import net.sourceforge.pmd.PMD;
 /** Token Manager. */
 public class JavaParserTokenManager implements JavaParserConstants
 {
+    protected List<Token> formalComments = new ArrayList<Token>();
+
     private Map<Integer, String> excludeMap = new HashMap<Integer, String>();
     private String excludeMarker = PMD.EXCLUDE_MARKER;
 
@@ -2051,6 +2053,10 @@ void SkipLexicalActions(Token matchedToken)
             excludeMap.put(matchedToken.beginLine, matchedToken.image.substring(startOfNOPMD + excludeMarker.length()));
         }
          break;
+      case 9 :
+         image.append(input_stream.GetSuffix(jjimageLen + (lengthOfMatch = jjmatchedPos + 1)));
+                            formalComments.add(matchedToken);
+         break;
       default :
          break;
    }

pmd/src/net/sourceforge/pmd/rules/imports/UnusedImportsRule.java

@@ -10,10 +10,14 @@ import net.sourceforge.pmd.ast.ASTImportDeclaration;
 import net.sourceforge.pmd.ast.ASTName;
 import net.sourceforge.pmd.ast.SimpleJavaNode;
 import net.sourceforge.pmd.ast.SimpleNode;
+import net.sourceforge.pmd.ast.Token;
 import net.sourceforge.pmd.rules.ImportWrapper;
 
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 public class UnusedImportsRule extends AbstractRule {
 
@@ -22,12 +26,55 @@ public class UnusedImportsRule extends AbstractRule {
     public Object visit(ASTCompilationUnit node, Object data) {
         imports.clear();
         super.visit(node, data);
+        visitFormalComments(node);
         for (ImportWrapper wrapper : imports) {
             addViolation(data, wrapper.getNode(), wrapper.getFullName());
         }
         return data;
     }
 
+    /*
+     * Patterns to match the following constructs:
+     *
+     * @see  package.class#member  label
+     * {@linkplain  package.class#member  label}
+     * {@link  package.class#member  label}
+     * {@value  package.class#field}
+     */
+    private static final Pattern SEE_PATTERN = Pattern.compile(
+            "@see\\s+(\\p{Alpha}\\p{Alnum}*)[\\s#]");
+
+    private static final Pattern LINK_PATTERNS = Pattern.compile(
+            "\\{@link(?:plain)?\\s+(\\p{Alpha}\\p{Alnum}*)[\\s#]");
+
+    private static final Pattern VALUE_PATTERN = Pattern.compile(
+            "\\{@value\\s+(\\p{Alpha}\\p{Alnum}*)[\\s#]");
+
+    private static final Pattern[] PATTERNS = { SEE_PATTERN, LINK_PATTERNS, VALUE_PATTERN };
+
+    private void visitFormalComments(ASTCompilationUnit node) {
+        if (imports.isEmpty()) {
+            return;
+        }
+        List<Token> formals = node.getFormalComments();
+        for (Token formal: formals) {
+            for (Pattern p: PATTERNS) {
+                Matcher m = p.matcher(formal.image);
+                while (m.find()) {
+                    String s = m.group(1);
+                    ImportWrapper candidate = new ImportWrapper(s, s, new SimpleJavaNode(-1));
+
+                    if (imports.contains(candidate)) {
+                        imports.remove(candidate);
+                        if (imports.isEmpty()) {
+                            return;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
     public Object visit(ASTImportDeclaration node, Object data) {
         if (!node.isImportOnDemand()) {
             ASTName importedType = (ASTName) node.jjtGetChild(0);