////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2010 Oliver Burn
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.puppycrawl.tools.checkstyle.api.Check;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import java.util.HashSet;
import java.util.LinkedList;
/**
* Abstract class for chekcs which need to collect information about
* declared members/parameters/variables.
*
* @author o_sukhodolsky
*/
public abstract class DeclarationCollector extends Check
{
/** Stack of variable declaration frames. */
private FrameStack mFrames;
@Override
public void beginTree(DetailAST aRootAST)
{
mFrames = new FrameStack();
}
@Override
public void visitToken(DetailAST aAST)
{
switch (aAST.getType()) {
case TokenTypes.PARAMETER_DEF :
case TokenTypes.VARIABLE_DEF : {
final DetailAST nameAST = aAST.findFirstToken(TokenTypes.IDENT);
this.mFrames.current().addName(nameAST.getText());
break;
}
case TokenTypes.CLASS_DEF :
case TokenTypes.INTERFACE_DEF :
case TokenTypes.ENUM_DEF :
case TokenTypes.ANNOTATION_DEF : {
final DetailAST nameAST = aAST.findFirstToken(TokenTypes.IDENT);
this.mFrames.current().addName(nameAST.getText());
this.mFrames.enter(new ClassFrame());
break;
}
case TokenTypes.SLIST :
this.mFrames.enter(new BlockFrame());
break;
case TokenTypes.METHOD_DEF :
case TokenTypes.CTOR_DEF :
this.mFrames.enter(new MethodFrame());
break;
default:
// do nothing
}
}
@Override
public void leaveToken(DetailAST aAST)
{
switch (aAST.getType()) {
case TokenTypes.CLASS_DEF :
case TokenTypes.INTERFACE_DEF :
case TokenTypes.ENUM_DEF :
case TokenTypes.ANNOTATION_DEF :
case TokenTypes.SLIST :
case TokenTypes.METHOD_DEF :
case TokenTypes.CTOR_DEF :
this.mFrames.leave();
break;
default :
// do nothing
}
}
/**
* Check if given name is a name for declafred variable/parameter/member in
* current environment.
* @param aName a name to check
* @return true is the given name is declare one.
*/
protected final boolean isDeclared(String aName)
{
return (null != mFrames.findFrame(aName));
}
/**
* Check if given name is a name for class field in current environment.
* @param aName a name to check
* @return true is the given name is name of method or member.
*/
protected final boolean isClassField(String aName)
{
return (mFrames.findFrame(aName) instanceof ClassFrame);
}
/**
* A declaration frame.
* @author Stephen Bloch
* June 19, 2003
*/
private abstract static class LexicalFrame
{
/** Set of name of variables declared in this frame. */
private final HashSet<String> mVarNames;
/** constructor -- invocable only via super() from subclasses */
protected LexicalFrame()
{
mVarNames = Sets.newHashSet();
}
/** add a name to the frame.
* @param aNameToAdd the name we're adding
*/
void addName(String aNameToAdd)
{
mVarNames.add(aNameToAdd);
}
/** check whether the frame contains a given name.
* @param aNameToFind the name we're looking for
* @return whether it was found
*/
boolean contains(String aNameToFind)
{
return mVarNames.contains(aNameToFind);
}
}
/**
* The global frame; should hold only class names.
* @author Stephen Bloch
*/
private static class GlobalFrame extends LexicalFrame
{
}
/**
* A frame initiated at method definition; holds parameter names.
* @author Stephen Bloch
*/
private static class MethodFrame extends LexicalFrame
{
}
/**
* A frame initiated at class definition; holds instance variable
* names. For the present, I'm not worried about other class names,
* method names, etc.
* @author Stephen Bloch
*/
private static class ClassFrame extends LexicalFrame
{
}
/**
* A frame initiated on entering a statement list; holds local variable
* names. For the present, I'm not worried about other class names,
* method names, etc.
* @author Stephen Bloch
*/
private static class BlockFrame extends LexicalFrame
{
}
/**
* A stack of LexicalFrames. Standard issue....
* @author Stephen Bloch
*/
private static class FrameStack
{
/** List of lexical frames. */
private final LinkedList<LexicalFrame> mFrameList;
/** Creates an empty FrameStack. */
FrameStack()
{
mFrameList = Lists.newLinkedList();
this.enter(new GlobalFrame());
}
/**
* Enter a scope, i.e. push a frame on the stack.
* @param aNewFrame the already-created frame to push
*/
void enter(LexicalFrame aNewFrame)
{
mFrameList.addFirst(aNewFrame);
}
/** Leave a scope, i.e. pop a frame from the stack. */
void leave()
{
mFrameList.removeFirst();
}
/**
* Get current scope, i.e. top frame on the stack.
* @return the current frame
*/
LexicalFrame current()
{
return mFrameList.getFirst();
}
/**
* Search this and containing frames for a given name.
* @param aNameToFind the name we're looking for
* @return the frame in which it was found, or null if not found
*/
LexicalFrame findFrame(String aNameToFind)
{
for (LexicalFrame thisFrame : mFrameList) {
if (thisFrame.contains(aNameToFind)) {
return thisFrame;
}
}
return null;
}
}
}
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