Address some performance issues regarding opening inclusions in the resource tree for both the new and old parser framework.

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/AbstractGNUSourceCodeParser.java

@@ -390,9 +390,16 @@ public abstract class AbstractGNUSourceCodeParser implements ISourceCodeParser {
                 + (++parseCount) + ": " //$NON-NLS-1$
                 + (System.currentTimeMillis() - startTime) + "ms" //$NON-NLS-1$
                 + (parsePassed ? "" : " - parse failure")); //$NON-NLS-1$ //$NON-NLS-2$
-        return getTranslationUnit();
+        IASTTranslationUnit result = getTranslationUnit();
+        nullifyTranslationUnit();
+        return result;
     }
 
+    /**
+     * 
+     */
+    protected abstract void nullifyTranslationUnit();
+
     protected void skipOverCompoundStatement() throws BacktrackException,
             EndOfFileException {
         // speed up the parser by skiping the body

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/c/GNUCSourceParser.java

@@ -2101,4 +2101,11 @@ public class GNUCSourceParser extends AbstractGNUSourceCodeParser {
     
     }
 
+    /* (non-Javadoc)
+     * @see org.eclipse.cdt.internal.core.dom.parser.AbstractGNUSourceCodeParser#nullifyTranslationUnit()
+     */
+    protected void nullifyTranslationUnit() {
+        translationUnit = null;
+    }
+
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/GNUCPPSourceParser.java

@@ -4497,5 +4497,12 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
         return new CPPASTTryBlockStatement();
     }
 
+    /* (non-Javadoc)
+     * @see org.eclipse.cdt.internal.core.dom.parser.AbstractGNUSourceCodeParser#nullifyTranslationUnit()
+     */
+    protected void nullifyTranslationUnit() {
+        translationUnit = null;
+    }
+
     
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/FileCodeReaderFactory.java

@@ -0,0 +1,58 @@
+/**********************************************************************
+ * Copyright (c) 2004 IBM Corporation and others.
+ * All rights reserved.   This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * IBM - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.internal.core.parser.scanner2;
+
+import org.eclipse.cdt.core.dom.ICodeReaderFactory;
+import org.eclipse.cdt.core.parser.CodeReader;
+import org.eclipse.cdt.internal.core.parser.InternalParserUtil;
+
+/**
+ * @author jcamelon
+ */
+public class FileCodeReaderFactory implements ICodeReaderFactory {
+
+    private static FileCodeReaderFactory instance;
+
+    private FileCodeReaderFactory()
+    {
+    }
+    
+    /* (non-Javadoc)
+     * @see org.eclipse.cdt.core.dom.ICodeReaderFactory#getUniqueIdentifier()
+     */
+    public int getUniqueIdentifier() {
+        return 3;
+    }
+
+    /* (non-Javadoc)
+     * @see org.eclipse.cdt.core.dom.ICodeReaderFactory#createCodeReaderForTranslationUnit(java.lang.String)
+     */
+    public CodeReader createCodeReaderForTranslationUnit(String path) {
+        return InternalParserUtil.createFileReader(path);
+    }
+
+    /* (non-Javadoc)
+     * @see org.eclipse.cdt.core.dom.ICodeReaderFactory#createCodeReaderForInclusion(java.lang.String)
+     */
+    public CodeReader createCodeReaderForInclusion(String path) {
+        return InternalParserUtil.createFileReader(path);
+    }
+
+    /**
+     * @return
+     */
+    public static FileCodeReaderFactory getInstance() {
+        if( instance == null )
+            instance = new FileCodeReaderFactory();
+        return instance;
+    }
+
+}

core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/parser/ParserUtil.java

@@ -21,6 +21,7 @@ import org.eclipse.cdt.internal.core.parser.ParserLogService;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.IWorkspace;
+import org.eclipse.core.resources.IWorkspaceRoot;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
@@ -98,11 +99,14 @@ public class ParserUtil
 			return null;
 		IPath path = new Path( finalPath );
 		
-		if( workspace.getRoot().getLocation().isPrefixOf( path ) )
+		IWorkspaceRoot root = workspace.getRoot();
-			path = path.removeFirstSegments(workspace.getRoot().getLocation().segmentCount() );
+        if( root.getLocation().isPrefixOf( path ) )
+			path = path.removeFirstSegments(root.getLocation().segmentCount() );
 
-		IResource resultingResource = workspace.getRoot().findMember(path);
+		IResource resultingResource = root.getFile(path);
-		return resultingResource;
+		if( resultingResource.exists() ) 
+		    return resultingResource;
+		return null;
 	}
 
 	/**