Implementation of an heuristics to resolve include files, bug 213562

core/org.eclipse.cdt.core.tests/misc/org/eclipse/cdt/core/internal/tests/PositionTrackerTests.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2006, 2007 Wind River Systems, Inc. and others.
+ * Copyright (c) 2006, 2008 Wind River Systems, Inc. and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -23,7 +23,7 @@ import org.eclipse.jface.text.Region;
 
 public class PositionTrackerTests extends TestCase {
     public static Test suite() {
-        return new TestSuite(PositionTrackerTests.class, "PositionTrackerTests");
+        return new TestSuite(PositionTrackerTests.class);
     }
 
     public void testInitialFailures() {

core/org.eclipse.cdt.core.tests/misc/org/eclipse/cdt/core/internal/tests/ResourceLookupTests.java

@@ -0,0 +1,205 @@
+/*******************************************************************************
+ * Copyright (c) 2008 Wind River Systems, Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Markus Schorn - initial API and implementation
+ *******************************************************************************/ 
+package org.eclipse.cdt.core.internal.tests;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;
+
+import junit.framework.Test;
+import junit.framework.TestCase;
+import junit.framework.TestSuite;
+
+import org.eclipse.cdt.internal.core.resources.ResourceLookup;
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IFolder;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IWorkspaceRoot;
+import org.eclipse.core.resources.ResourcesPlugin;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.core.runtime.Path;
+
+public class ResourceLookupTests extends TestCase {
+    public static Test suite() {
+        return new TestSuite(ResourceLookupTests.class);
+    }
+
+	private IProject fProject;
+
+    @Override
+	protected void setUp() {
+		final IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
+		fProject= root.getProject("reslookup");
+    }
+    
+    @Override
+	protected void tearDown() throws Exception {
+		fProject.delete(true, new NullProgressMonitor());
+    }
+    
+	protected IFolder createFolder(IProject project, String filename) throws CoreException {
+		IFolder folder= project.getFolder(filename);
+		folder.create(true, false, new NullProgressMonitor());
+		return folder;
+	}
+
+	protected IFile createFile(IProject project, String filename) throws CoreException {
+		IFile file= project.getFile(filename);
+		file.create(new InputStream() {
+			@Override
+			public int read() throws IOException {
+				return -1;
+			}}, true, new NullProgressMonitor());
+		return file;
+	}
+    
+	public void testNameLookup() throws CoreException {
+		IProject[] prjs= new IProject[]{fProject};
+
+		fProject.create(new NullProgressMonitor());
+		fProject.open(new NullProgressMonitor());
+		createFolder(fProject, "folder1");
+		createFolder(fProject, "folder2");
+		createFile(fProject, "abc.h");
+		createFile(fProject, "folder1/abc.h");
+		createFile(fProject, "folder2/abC.h");
+
+		IFile[] files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, false);
+		assertEquals(2, files.length);
+		files= ResourceLookup.findFilesByName(new Path("bla/../abc.h"), prjs, false);
+		assertEquals(2, files.length);
+		files= ResourceLookup.findFilesByName(new Path("../abc.h"), prjs, false);
+		assertEquals(2, files.length);
+		files= ResourceLookup.findFilesByName(new Path("../../abc.h"), prjs, false);
+		assertEquals(2, files.length);
+
+		files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(3, files.length);
+
+		files= ResourceLookup.findFilesByName(new Path("folder1/abc.h"), prjs, false);
+		assertEquals(1, files.length);
+		files= ResourceLookup.findFilesByName(new Path("folder1/abC.h"), prjs, false);
+		assertEquals(0, files.length);
+		files= ResourceLookup.findFilesByName(new Path("fOlder1/abc.h"), prjs, false);
+		assertEquals(0, files.length);
+
+		files= ResourceLookup.findFilesByName(new Path("folder1/abc.h"), prjs, true);
+		assertEquals(1, files.length);
+		files= ResourceLookup.findFilesByName(new Path("folder1/abC.h"), prjs, true);
+		assertEquals(1, files.length);
+		files= ResourceLookup.findFilesByName(new Path("fOlder1/abc.h"), prjs, true);
+		assertEquals(1, files.length);
+
+		files= ResourceLookup.findFilesByName(new Path("bla/../abc.h"), prjs, true);
+		assertEquals(3, files.length);
+	}
+
+	public void testResourceDelta() throws CoreException {
+		IProject[] prjs= new IProject[]{fProject};
+		fProject.create(new NullProgressMonitor());
+		fProject.open(new NullProgressMonitor());
+
+		IFile[] files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(0, files.length);
+
+		IFolder f1= createFolder(fProject, "folder1");
+		createFolder(fProject, "folder2");
+		IFile f2= createFile(fProject, "abc.h");
+		files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(1, files.length);
+
+		createFile(fProject, "folder1/abc.h");
+		files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(2, files.length);
+
+		createFile(fProject, "folder2/abC.h");
+		files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(3, files.length);
+		
+		f1.delete(true, new NullProgressMonitor());
+		files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(2, files.length);
+		
+		f2.delete(true, new NullProgressMonitor());
+		files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(1, files.length);
+	}
+
+	public void testDeref() throws CoreException {
+		IProject[] prjs= new IProject[]{fProject};
+
+		fProject.create(new NullProgressMonitor());
+		fProject.open(new NullProgressMonitor());
+		createFolder(fProject, "folder1");
+		createFolder(fProject, "folder2");
+		createFile(fProject, "abc.h");
+		IFile[] files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(1, files.length);
+		
+		ResourceLookup.unrefNodeMap();
+		createFile(fProject, "folder1/abc.h");
+		createFile(fProject, "folder2/abC.h");
+
+		files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(3, files.length);
+		
+		ResourceLookup.unrefNodeMap();
+		files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(3, files.length);		
+	}
+	
+	public void testCollected() throws CoreException {
+		IProject[] prjs= new IProject[]{fProject};
+
+		fProject.create(new NullProgressMonitor());
+		fProject.open(new NullProgressMonitor());
+		createFolder(fProject, "folder1");
+		createFolder(fProject, "folder2");
+		createFile(fProject, "abc.h");
+		IFile[] files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(1, files.length);
+		
+		ResourceLookup.simulateNodeMapCollection();
+		createFile(fProject, "folder1/abc.h");
+		createFile(fProject, "folder2/abC.h");
+
+		files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(3, files.length);
+		
+		ResourceLookup.simulateNodeMapCollection();
+		files= ResourceLookup.findFilesByName(new Path("abc.h"), prjs, true);
+		assertEquals(3, files.length);		
+	}
+	
+	public void testFindFilesByLocation() throws Exception {
+		IProject[] prjs= new IProject[]{fProject};
+
+		fProject.create(new NullProgressMonitor());
+		fProject.open(new NullProgressMonitor());
+		createFolder(fProject, "folder1");
+		createFolder(fProject, "folder2");
+		IFile file= createFile(fProject, "abc.h");
+		createFile(fProject, "folder1/abc.h");
+		createFile(fProject, "folder2/abC.h");
+
+		URI uri= file.getLocationURI();
+		IFile[] files= ResourceLookup.findFilesForLocation(uri, prjs);
+		assertEquals(1, files.length);
+
+		if (new File("a").equals(new File("A"))) {
+			URI upperCase= new URI(uri.getScheme(), uri.getSchemeSpecificPart().toUpperCase(), uri.getFragment());
+			files= ResourceLookup.findFilesForLocation(upperCase, prjs);
+			assertEquals(1, files.length);
+		}		
+	}
+}

core/org.eclipse.cdt.core.tests/misc/org/eclipse/cdt/core/internal/tests/StringBuilderTest.java

@@ -19,7 +19,7 @@ import junit.framework.TestSuite;
 
 public class StringBuilderTest extends TestCase {
     public static Test suite() {
-        return new TestSuite(StringBuilderTest.class, "StringBuilderTest");
+        return new TestSuite(StringBuilderTest.class);
     }
 
     public void testSafe() {

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/scanner/LocationMapTests.java

@@ -334,8 +334,8 @@ public class LocationMapTests extends BaseTestCase {
 
 	public void testIncludes() {
 		init(DIGITS);
-		fLocationMap.encounterPoundInclude(0, 0, 0, 0, "n1".toCharArray(), null, true, false);
+		fLocationMap.encounterPoundInclude(0, 0, 0, 0, "n1".toCharArray(), null, true, false, false);
-		fLocationMap.encounterPoundInclude(0, 1, 3, 16, "n2".toCharArray(), "f2", false , true);
+		fLocationMap.encounterPoundInclude(0, 1, 3, 16, "n2".toCharArray(), "f2", false , true, false);
 		IASTPreprocessorIncludeStatement[] includes= fLocationMap.getIncludeDirectives();
 		assertEquals(2, includes.length);
 		checkInclude(includes[0], "", "", "n1", "", true, false, FN, 0, 0, 1, 0, 0);
@@ -495,11 +495,11 @@ public class LocationMapTests extends BaseTestCase {
 		assertEquals(FN, fLocationMap.getCurrentFilePath());
 		fLocationMap.encounteredComment(0,2,true);
 		// number: [6,15)[25,26)
-		ILocationCtx i1= fLocationMap.pushInclusion(0, 2, 4, 6, "b1b2b3b4b5".toCharArray(), "pre1", "pre1".toCharArray(), false);
+		ILocationCtx i1= fLocationMap.pushInclusion(0, 2, 4, 6, "b1b2b3b4b5".toCharArray(), "pre1", "pre1".toCharArray(), false, false);
 		assertEquals("pre1", fLocationMap.getCurrentFilePath());
 		fLocationMap.encounteredComment(2,4,true);
 		// number: [15,25)
-		ILocationCtx i2= fLocationMap.pushInclusion(6, 7, 8, 9, "c1c2c3c4c5".toCharArray(), "pre11", "pre11".toCharArray(), false);
+		ILocationCtx i2= fLocationMap.pushInclusion(6, 7, 8, 9, "c1c2c3c4c5".toCharArray(), "pre11", "pre11".toCharArray(), false, false);
 		assertEquals("pre11", fLocationMap.getCurrentFilePath());
 		fLocationMap.encounteredComment(2,6,true);
 		fLocationMap.popContext(i2);
@@ -512,7 +512,7 @@ public class LocationMapTests extends BaseTestCase {
 		fLocationMap.popContext(pre2);
 		assertEquals(FN, fLocationMap.getCurrentFilePath());
 		// number [36, 46)
-		ILocationCtx i3= fLocationMap.pushInclusion(0, 2, 4, 6, "d1d2d3d4d5".toCharArray(), "pre2", "pre2".toCharArray(), false);
+		ILocationCtx i3= fLocationMap.pushInclusion(0, 2, 4, 6, "d1d2d3d4d5".toCharArray(), "pre2", "pre2".toCharArray(), false, false);
 		assertEquals("pre2", fLocationMap.getCurrentFilePath());
 		fLocationMap.encounteredComment(0,2,true);
 		fLocationMap.popContext(i3);

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexBugsTests.java

@@ -1350,4 +1350,53 @@ public class IndexBugsTests extends BaseTestCase {
 			fIndex.releaseReadLock();
 		}
 	}
+	
+	
+	// #include <header.h>
+	// #define _CONCAT(x,y) x##y
+	// #define CONCAT(x,y) _CONCAT(x,y)
+	public void testIncludeHeuristics_Bug213562() throws Exception {
+		String contents= getContentsForTest(1)[0];
+		final IIndexManager indexManager = CCorePlugin.getIndexManager();
+		TestSourceReader.createFile(fCProject.getProject(), "f1/g/header.h", "#define ID one\n");
+		TestSourceReader.createFile(fCProject.getProject(), "f2/header.h",    "#define ID two\n");
+		TestSourceReader.createFile(fCProject.getProject(), "f1/g/h/header.h", "#define ID three\n");
+		TestSourceReader.createFile(fCProject.getProject(), "f1/g/source.cpp", contents + "int CONCAT(one, ID);\n");
+		TestSourceReader.createFile(fCProject.getProject(), "f2/g/source.cpp", contents + "int CONCAT(two, ID);\n");
+		TestSourceReader.createFile(fCProject.getProject(), "f1/g/h/source.cpp", contents + "int CONCAT(three, ID);\n");
+		indexManager.reindex(fCProject);
+		waitForIndexer();
+		fIndex.acquireReadLock();
+		try {
+			IIndexBinding[] bindings= fIndex.findBindings("oneone".toCharArray(), IndexFilter.ALL_DECLARED, new NullProgressMonitor());
+			assertEquals(1, bindings.length);
+			bindings= fIndex.findBindings("twotwo".toCharArray(), IndexFilter.ALL_DECLARED, new NullProgressMonitor());
+			assertEquals(1, bindings.length);
+			bindings= fIndex.findBindings("threethree".toCharArray(), IndexFilter.ALL_DECLARED, new NullProgressMonitor());
+			assertEquals(1, bindings.length);
+		} finally {
+			fIndex.releaseReadLock();
+		}
+	}
+	
+	public void testIncludeHeuristicsFlag_Bug213562() throws Exception {
+		final IIndexManager indexManager = CCorePlugin.getIndexManager();
+		TestSourceReader.createFile(fCProject.getProject(), "f1/header.h", "");
+		IFile f1= TestSourceReader.createFile(fCProject.getProject(), "source1.cpp", "#include \"header.h\"\n");
+		IFile f2= TestSourceReader.createFile(fCProject.getProject(), "source2.cpp", "#include \"f1/header.h\"\n");
+		indexManager.reindex(fCProject);
+		waitForIndexer();
+		fIndex.acquireReadLock();
+		try {
+			IIndexFile f= fIndex.getFile(ILinkage.CPP_LINKAGE_ID, IndexLocationFactory.getWorkspaceIFL(f1));
+			IIndexInclude i= f.getIncludes()[0];
+			assertTrue(i.isResolvedByHeuristics());
+
+			f= fIndex.getFile(ILinkage.CPP_LINKAGE_ID, IndexLocationFactory.getWorkspaceIFL(f2));
+			i= f.getIncludes()[0];
+			assertFalse(i.isResolvedByHeuristics());
+		} finally {
+			fIndex.releaseReadLock();
+		}
+	}
 }

core/org.eclipse.cdt.core.tests/suite/org/eclipse/cdt/core/suite/AutomatedIntegrationSuite.java

@@ -18,6 +18,7 @@ import junit.framework.TestSuite;
 import org.eclipse.cdt.core.cdescriptor.tests.CDescriptorTests;
 import org.eclipse.cdt.core.internal.errorparsers.tests.ErrorParserTests;
 import org.eclipse.cdt.core.internal.tests.PositionTrackerTests;
+import org.eclipse.cdt.core.internal.tests.ResourceLookupTests;
 import org.eclipse.cdt.core.internal.tests.StringBuilderTest;
 import org.eclipse.cdt.core.language.AllLanguageTests;
 import org.eclipse.cdt.core.model.tests.AllCoreTests;
@@ -61,6 +62,7 @@ public class AutomatedIntegrationSuite extends TestSuite {
 		suite.addTest(ElementDeltaTests.suite());
 		suite.addTest(WorkingCopyTests.suite());
         suite.addTest(PositionTrackerTests.suite());
+        suite.addTest(ResourceLookupTests.suite());
         suite.addTest(StringBuilderTest.suite());
         suite.addTest(AllLanguageTests.suite());
         suite.addTest(RewriteTests.suite());

core/org.eclipse.cdt.core/META-INF/MANIFEST.MF

@@ -71,6 +71,7 @@ Export-Package: org.eclipse.cdt.core,
  org.eclipse.cdt.internal.core.pdom.dom.cpp;x-internal:=true,
  org.eclipse.cdt.internal.core.pdom.export;x-internal:=true,
  org.eclipse.cdt.internal.core.pdom.indexer;x-friends:="org.eclipse.cdt.ui",
+ org.eclipse.cdt.internal.core.resources;x-internal:=true,
  org.eclipse.cdt.internal.core.util;x-internal:=true,
  org.eclipse.cdt.internal.errorparsers;x-internal:=true,
  org.eclipse.cdt.internal.formatter;x-internal:=true,

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/TranslationUnit.java

@@ -70,6 +70,7 @@ import org.eclipse.cdt.internal.core.dom.NullCodeReaderFactory;
 import org.eclipse.cdt.internal.core.dom.SavedCodeReaderFactory;
 import org.eclipse.cdt.internal.core.index.IndexBasedCodeReaderFactory;
 import org.eclipse.cdt.internal.core.parser.ParserLogService;
+import org.eclipse.cdt.internal.core.pdom.indexer.ProjectIndexerIncludeResolutionHeuristics;
 import org.eclipse.cdt.internal.core.pdom.indexer.ProjectIndexerInputAdapter;
 import org.eclipse.cdt.internal.core.util.ICanceler;
 import org.eclipse.cdt.internal.core.util.MementoTokenizer;
@@ -835,15 +836,20 @@ public class TranslationUnit extends Openable implements ITranslationUnit {
 	}
 
 	private ICodeReaderFactory getCodeReaderFactory(int style, IIndex index, int linkageID) {
+		final ICProject cprj= getCProject();
+		final ProjectIndexerInputAdapter pathResolver = new ProjectIndexerInputAdapter(cprj);
+		final ProjectIndexerIncludeResolutionHeuristics heuristics = new ProjectIndexerIncludeResolutionHeuristics(cprj.getProject(), pathResolver);
 		ICodeReaderFactory codeReaderFactory;
 		if ((style & AST_SKIP_NONINDEXED_HEADERS) != 0) {
 			codeReaderFactory= NullCodeReaderFactory.getInstance();
 		} else {
-			codeReaderFactory= SavedCodeReaderFactory.getInstance();
+			codeReaderFactory= SavedCodeReaderFactory.createInstance(heuristics);
 		}
 		
 		if (index != null && (style & AST_SKIP_INDEXED_HEADERS) != 0) {
-			IndexBasedCodeReaderFactory ibcf= new IndexBasedCodeReaderFactory(index, new ProjectIndexerInputAdapter(getCProject()), linkageID, codeReaderFactory);
+			IndexBasedCodeReaderFactory ibcf= new IndexBasedCodeReaderFactory(index, 
+					heuristics,
+					pathResolver, linkageID, codeReaderFactory);
 			if ((style & AST_CONFIGURE_USING_SOURCE_CONTEXT) != 0) {
 				ibcf.setSupportFillGapFromContextToHeader(true);
 			}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/IASTPreprocessorIncludeStatement.java

@@ -1,20 +1,20 @@
 /*******************************************************************************
- * Copyright (c) 2004, 2007 IBM Corporation and others.
+ * Copyright (c) 2004, 2008 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
- * IBM - Initial API and implementation
+ *    IBM - Initial API and implementation
- * Markus Schorn (Wind River Systems)
+ *    Markus Schorn (Wind River Systems)
  *******************************************************************************/
 package org.eclipse.cdt.core.dom.ast;
 
 /**
  * This interface represent a preprocessor #include statement.
  * 
- * @author jcamelon
+ * @noimplement This interface is not intended to be implemented by clients.
  */
 public interface IASTPreprocessorIncludeStatement extends
 		IASTPreprocessorStatement {
@@ -57,4 +57,10 @@ public interface IASTPreprocessorIncludeStatement extends
 	 * @since 4.0
 	 */
 	public boolean isResolved();
+	
+	/**
+	 * Returns whether the inclusion was resolved using a heuristics.
+	 * @since 5.1
+	 */
+	public boolean isResolvedByHeuristics();
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/index/IIndexInclude.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2006, 2007 Wind River Systems, Inc. and others.
+ * Copyright (c) 2006, 2008 Wind River Systems, Inc. and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -9,23 +9,14 @@
  *    Markus Schorn - initial API and implementation
  *    Andrew Ferguson (Symbian)
  *******************************************************************************/
-
 package org.eclipse.cdt.core.index;
 
 import org.eclipse.core.runtime.CoreException;
 
 /**
  * Interface for an include directive stored in the index.
- * <p>
- * This interface is not intended to be implemented by clients.
- * </p>
- * <p>
- * <strong>EXPERIMENTAL</strong>. This class or interface has been added as
- * part of a work in progress. There is no guarantee that this API will work or
- * that it will remain the same. Please do not use this API without consulting
- * with the CDT team.
- * </p>
  * 
+ * @noimplement This interface is not intended to be implemented by clients.
  * @since 4.0
  */
 public interface IIndexInclude {
@@ -106,4 +97,11 @@ public interface IIndexInclude {
 	 * @throws CoreException
 	 */
 	boolean isResolved() throws CoreException;
+	
+	/**
+	 * Tests whether this include has been resolved using a heuristics rather than relying on
+	 * the include search path.
+	 * @since 5.1
+	 */
+	boolean isResolvedByHeuristics() throws CoreException;
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/IndexBasedCodeReaderFactory.java

@@ -34,6 +34,8 @@ import org.eclipse.cdt.core.index.IIndexMacro;
 import org.eclipse.cdt.core.parser.CodeReader;
 import org.eclipse.cdt.core.parser.ICodeReaderCache;
 import org.eclipse.cdt.core.parser.ParserUtil;
+import org.eclipse.cdt.internal.core.dom.AbstractCodeReaderFactory;
+import org.eclipse.cdt.internal.core.dom.IIncludeFileResolutionHeuristics;
 import org.eclipse.cdt.internal.core.parser.scanner.IIndexBasedCodeReaderFactory;
 import org.eclipse.cdt.internal.core.parser.scanner.IncludeFileContent;
 import org.eclipse.cdt.internal.core.parser.scanner.IncludeFileContent.InclusionKind;
@@ -46,7 +48,7 @@ import org.eclipse.core.runtime.CoreException;
  * Code reader factory, that fakes code readers for header files already stored in the 
  * index.
  */
-public final class IndexBasedCodeReaderFactory implements IIndexBasedCodeReaderFactory {
+public final class IndexBasedCodeReaderFactory extends AbstractCodeReaderFactory implements IIndexBasedCodeReaderFactory {
 	private static final class NeedToParseException extends Exception {}
 	private static final String GAP = "__gap__"; //$NON-NLS-1$
 
@@ -59,13 +61,15 @@ public final class IndexBasedCodeReaderFactory implements IIndexBasedCodeReaderF
 	private final AbstractIndexerTask fRelatedIndexerTask;
 	private boolean fSupportFillGapFromContextToHeader= false;
 	
-	public IndexBasedCodeReaderFactory(IIndex index, ASTFilePathResolver pathResolver, int linkage, 
+	public IndexBasedCodeReaderFactory(IIndex index, IIncludeFileResolutionHeuristics heuristics,
-			ICodeReaderFactory fallbackFactory) {
+			ASTFilePathResolver pathResolver, int linkage, ICodeReaderFactory fallbackFactory) {
-		this(index, pathResolver, linkage, fallbackFactory, null);
+		this(index, heuristics, pathResolver, linkage, fallbackFactory, null);
 	}
 
-	public IndexBasedCodeReaderFactory(IIndex index, ASTFilePathResolver pathResolver, int linkage,
+	public IndexBasedCodeReaderFactory(IIndex index, IIncludeFileResolutionHeuristics heuristics,
+			ASTFilePathResolver pathResolver, int linkage,
 			ICodeReaderFactory fallbackFactory, AbstractIndexerTask relatedIndexerTask) {
+		super(heuristics);
 		fIndex= index;
 		fFallBackFactory= fallbackFactory;
 		fPathResolver= pathResolver;

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/indexer/StandaloneFastIndexerTask.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2006, 2007 QNX Software Systems and others.
+ * Copyright (c) 2006, 2008 QNX Software Systems and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -16,6 +16,7 @@ package org.eclipse.cdt.internal.core.indexer;
 import java.util.List;
 
 import org.eclipse.cdt.core.dom.ICodeReaderFactory;
+import org.eclipse.cdt.internal.core.dom.IIncludeFileResolutionHeuristics;
 
 /**
  * A task for index updates.
@@ -38,4 +39,9 @@ public class StandaloneFastIndexerTask extends StandaloneIndexerTask {
 	protected ICodeReaderFactory createReaderFactory() {
 		return new StandaloneIndexerFallbackReaderFactory();
 	}
+
+	@Override
+	protected IIncludeFileResolutionHeuristics createIncludeHeuristics() {
+		return null;
+	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/indexer/StandaloneFullIndexerTask.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2006, 2007 QNX Software Systems and others.
+ * Copyright (c) 2006, 2008 QNX Software Systems and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -16,6 +16,7 @@ package org.eclipse.cdt.internal.core.indexer;
 import java.util.List;
 
 import org.eclipse.cdt.core.dom.ICodeReaderFactory;
+import org.eclipse.cdt.internal.core.dom.IIncludeFileResolutionHeuristics;
 
 /**
  * A task for index updates.
@@ -39,4 +40,9 @@ public class StandaloneFullIndexerTask extends StandaloneIndexerTask {
 	protected ICodeReaderFactory createReaderFactory() {
 		return ((StandaloneFullIndexer)fIndexer).getCodeReaderFactory();
 	}
+
+	@Override
+	protected IIncludeFileResolutionHeuristics createIncludeHeuristics() {
+		return null;
+	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/ASTPreprocessorNode.java

@@ -212,16 +212,18 @@ class ASTInclusionStatement extends ASTPreprocessorNode implements IASTPreproces
 	private final boolean fIsActive;
 	private final boolean fIsResolved;
 	private final boolean fIsSystemInclude;
+	private final boolean fFoundByHeuristics;
 
 	public ASTInclusionStatement(IASTTranslationUnit parent, 
 			int startNumber, int nameStartNumber, int nameEndNumber, int endNumber,
-			char[] headerName, String filePath, boolean userInclude, boolean active) {
+			char[] headerName, String filePath, boolean userInclude, boolean active, boolean heuristic) {
 		super(parent, IASTTranslationUnit.PREPROCESSOR_STATEMENT, startNumber, endNumber);
 		fName= new ASTPreprocessorName(this, IASTPreprocessorIncludeStatement.INCLUDE_NAME, nameStartNumber, nameEndNumber, headerName, null);
 		fPath= filePath == null ? "" : filePath; //$NON-NLS-1$
 		fIsActive= active;
 		fIsResolved= filePath != null;
 		fIsSystemInclude= !userInclude;
+		fFoundByHeuristics= heuristic;
 	}
 
 	public IASTName getName() {
@@ -249,6 +251,10 @@ class ASTInclusionStatement extends ASTPreprocessorNode implements IASTPreproces
 		super.findNode(nodeSpec);
 		nodeSpec.visit(fName);
 	}
+
+	public boolean isResolvedByHeuristics() {
+		return fFoundByHeuristics;
+	}
 }
 
 class ASTMacroDefinition extends ASTPreprocessorNode implements IASTPreprocessorObjectStyleMacroDefinition {

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/CPreprocessor.java

@@ -44,6 +44,7 @@ import org.eclipse.cdt.core.parser.ParserLanguage;
 import org.eclipse.cdt.core.parser.util.CharArrayIntMap;
 import org.eclipse.cdt.core.parser.util.CharArrayMap;
 import org.eclipse.cdt.core.parser.util.CharArrayUtils;
+import org.eclipse.cdt.internal.core.dom.IIncludeFileResolutionHeuristics;
 import org.eclipse.cdt.internal.core.parser.scanner.ExpressionEvaluator.EvalException;
 import org.eclipse.cdt.internal.core.parser.scanner.IncludeFileContent.InclusionKind;
 import org.eclipse.cdt.internal.core.parser.scanner.Lexer.LexerOptions;
@@ -87,21 +88,29 @@ public class CPreprocessor implements ILexerLog, IScanner, IAdaptable {
     private static final DynamicMacro __LINE__ = new LineMacro("__LINE__".toCharArray()); //$NON-NLS-1$
 
 	private interface IIncludeFileTester<T> {
-    	T checkFile(String path, String fileName);
+    	T checkFile(String path, String fileName, boolean isHeuristicMatch);
     }
 
     final private IIncludeFileTester<IncludeFileContent> createCodeReaderTester= new IIncludeFileTester<IncludeFileContent>() { 
-    	public IncludeFileContent checkFile(String path, String fileName) {
+    	public IncludeFileContent checkFile(String path, String fileName, boolean isHeuristicMatch) {
-    		String finalPath = ScannerUtility.createReconciledPath(path, fileName);
+    		final String finalPath = ScannerUtility.createReconciledPath(path, fileName);
-			return fCodeReaderFactory.getContentForInclusion(finalPath);
+			final IncludeFileContent fc= fCodeReaderFactory.getContentForInclusion(finalPath);
+			if (fc != null) {
+				fc.setFoundByHeuristics(isHeuristicMatch);
+			}
+			return fc;
     	}
     };
     
-    final private IIncludeFileTester<String> createPathTester= new IIncludeFileTester<String>() { 
+    private static class IncludeResolution {String fLocation; boolean fHeuristic;}
-    	public String checkFile(String path, String fileName) {
+    final private IIncludeFileTester<IncludeResolution> createPathTester= new IIncludeFileTester<IncludeResolution>() { 
+    	public IncludeResolution checkFile(String path, String fileName, boolean isHeuristicMatch) {
     		String finalPath= ScannerUtility.createReconciledPath(path, fileName);
     		if (fCodeReaderFactory.getInclusionExists(finalPath)) {
-    			return finalPath;
+    			IncludeResolution res= new IncludeResolution();
+    			res.fHeuristic= isHeuristicMatch;
+    			res.fLocation= finalPath;
+    			return res;
     		}
     		return null;
     	}
@@ -109,6 +118,8 @@ public class CPreprocessor implements ILexerLog, IScanner, IAdaptable {
 
     final private IParserLogService fLog;
     final private IIndexBasedCodeReaderFactory fCodeReaderFactory;
+
+    private IIncludeFileResolutionHeuristics fIncludeFileResolutionHeuristics;
     private final ExpressionEvaluator fExpressionEvaluator;
 	private final MacroDefinitionParser fMacroDefinitionParser;
 	private final MacroExpander fMacroExpander;
@@ -142,7 +153,6 @@ public class CPreprocessor implements ILexerLog, IScanner, IAdaptable {
 	private Token fPrefetchedTokens;
     private Token fLastToken;
 
-
     public CPreprocessor(CodeReader reader, IScannerInfo info, ParserLanguage language, IParserLogService log,
             IScannerExtensionConfiguration configuration, ICodeReaderFactory readerFactory) {
         fLog = log;
@@ -162,6 +172,9 @@ public class CPreprocessor implements ILexerLog, IScanner, IAdaptable {
         fMacroDefinitionParser= new MacroDefinitionParser();
         fMacroExpander= new MacroExpander(this, fMacroDictionary, fLocationMap, fLexOptions);
         fCodeReaderFactory= wrapReaderFactory(readerFactory);
+        if (readerFactory instanceof IAdaptable) {
+        	fIncludeFileResolutionHeuristics= (IIncludeFileResolutionHeuristics) ((IAdaptable) readerFactory).getAdapter(IIncludeFileResolutionHeuristics.class);
+        }
 
         setupMacroDictionary(configuration, info, language);		
                 
@@ -746,43 +759,50 @@ public class CPreprocessor implements ILexerLog, IScanner, IAdaptable {
         }
     }
 
-    private IncludeFileContent findInclusion(final String filename, final boolean quoteInclude, 
-    		final boolean includeNext, final File currentDir) {
-    	return findInclusion(filename, quoteInclude, includeNext, currentDir, createCodeReaderTester);
-    }
-
     private <T> T findInclusion(final String filename, final boolean quoteInclude, 
-    		final boolean includeNext, final File currentDirectory, final IIncludeFileTester<T> tester) {
+    		final boolean includeNext, final String currentFile, final IIncludeFileTester<T> tester) {
         T reader = null;
 		// filename is an absolute path or it is a Linux absolute path on a windows machine
 		if (new File(filename).isAbsolute() || filename.startsWith("/")) {  //$NON-NLS-1$
-		    return tester.checkFile( EMPTY_STRING, filename );
+		    return tester.checkFile(EMPTY_STRING, filename, false);
 		}
 		                
-        if (currentDirectory != null && quoteInclude && !includeNext) {
+        if (currentFile != null && quoteInclude && !includeNext) {
             // Check to see if we find a match in the current directory
-        	String absolutePath = currentDirectory.getAbsolutePath();
+    		final File currentDir= new File(currentFile).getParentFile();
-        	reader = tester.checkFile(absolutePath, filename);
+    		if (currentDir != null) {
-        	if (reader != null) {
+    			String absolutePath = currentDir.getAbsolutePath();
-        		return reader;
+    			reader = tester.checkFile(absolutePath, filename, false);
-        	}
+    			if (reader != null) {
+    				return reader;
+    			}
+    		}
         }
         
         // if we're not include_next, then we are looking for the first occurrence of 
         // the file, otherwise, we ignore all the paths before the current directory
         final String[] isp= quoteInclude ? fQuoteIncludePaths : fIncludePaths;
-        if (isp != null ) {
+        if (isp != null) {
         	int i=0;
-        	if (includeNext && currentDirectory != null) {
+        	if (includeNext && currentFile != null) {
-        		i= findIncludePos(isp, currentDirectory) + 1;
+        		final File currentDir= new File(currentFile).getParentFile();
+        		if (currentDir != null) {
+        			i= findIncludePos(isp, currentDir) + 1;
+        		}
         	}
         	for (; i < isp.length; ++i) {
-        		reader= tester.checkFile(isp[i], filename);
+        		reader= tester.checkFile(isp[i], filename, false);
         		if (reader != null) {
         			return reader;
         		}
         	}
         }
+        if (fIncludeFileResolutionHeuristics != null) {
+        	String location= fIncludeFileResolutionHeuristics.findInclusion(filename, currentFile);
+        	if (location != null) {
+        		return tester.checkFile(null, location, true);
+        	}
+        }
         return null;
     }
 
@@ -1027,20 +1047,21 @@ public class CPreprocessor implements ILexerLog, IScanner, IAdaptable {
 
 		String path= null;
 		boolean reported= false;
+		boolean isHeuristic= false;
 		
 		if (!active) {
 			// test if the include is inactive just because it was included before (bug 167100)
-			final File currentDir= userInclude || include_next ? new File(String.valueOf(getCurrentFilename())).getParentFile() : null;
+			final IncludeResolution resolved= findInclusion(new String(headerName), userInclude, include_next, getCurrentFilename(), createPathTester);
-			final String resolved= findInclusion(new String(headerName), userInclude, include_next, currentDir, createPathTester);
+			if (resolved != null && fCodeReaderFactory.hasFileBeenIncludedInCurrentTranslationUnit(resolved.fLocation)) {
-			if (resolved != null && fCodeReaderFactory.hasFileBeenIncludedInCurrentTranslationUnit(resolved)) {
+				path= resolved.fLocation;
-				path= resolved;
+				isHeuristic= resolved.fHeuristic;
 			}
 		}
 		else {
-			final File currentDir= userInclude || include_next ? new File(String.valueOf(getCurrentFilename())).getParentFile() : null;
+			final IncludeFileContent fi= findInclusion(new String(headerName), userInclude, include_next, getCurrentFilename(), createCodeReaderTester);
-			final IncludeFileContent fi= findInclusion(new String(headerName), userInclude, include_next, currentDir);
 			if (fi != null) {
 				path= fi.getFileLocation();
+				isHeuristic= fi.isFoundByHeuristics();
 				switch(fi.getKind()) {
 				case FOUND_IN_INDEX:
 					processInclusionFromIndex(poundOffset, path, fi);
@@ -1050,7 +1071,7 @@ public class CPreprocessor implements ILexerLog, IScanner, IAdaptable {
 					if (reader != null && !isCircularInclusion(path)) {
 						reported= true;
 						fAllIncludedFiles.add(path);
-						ILocationCtx ctx= fLocationMap.pushInclusion(poundOffset, nameOffsets[0], nameOffsets[1], condEndOffset, reader.buffer, path, headerName, userInclude);
+						ILocationCtx ctx= fLocationMap.pushInclusion(poundOffset, nameOffsets[0], nameOffsets[1], condEndOffset, reader.buffer, path, headerName, userInclude, isHeuristic);
 						ScannerContext fctx= new ScannerContext(ctx, fCurrentContext, new Lexer(reader.buffer, fLexOptions, this, this));
 						fCurrentContext= fctx;
 					}
@@ -1074,7 +1095,7 @@ public class CPreprocessor implements ILexerLog, IScanner, IAdaptable {
 		}
 
 		if (!reported) {
-			fLocationMap.encounterPoundInclude(poundOffset, nameOffsets[0], nameOffsets[1], condEndOffset, headerName, path, userInclude, active); 
+			fLocationMap.encounterPoundInclude(poundOffset, nameOffsets[0], nameOffsets[1], condEndOffset, headerName, path, userInclude, active, isHeuristic); 
 		}
 	}
 

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/IncludeFileContent.java

@@ -43,6 +43,7 @@ public class IncludeFileContent {
 	private final List<IIndexMacro> fMacroDefinitions;
 	private final List<ICPPUsingDirective> fUsingDirectives;
 	private final String fFileLocation;
+	private boolean fHeuristic;
 	private List<IIndexFile> fFiles;
 	
 	/**
@@ -144,4 +145,15 @@ public class IncludeFileContent {
 	public List<IIndexFile> getFilesIncluded() {
 		return fFiles;
 	}
+
+	/**
+	 * Returns whether this inclusion was found by a heuristics.
+	 */
+	public boolean isFoundByHeuristics() {
+		return fHeuristic;
+	}
+	
+	public void setFoundByHeuristics(boolean val) {
+		fHeuristic= val;
+	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/LocationMap.java

@@ -116,14 +116,14 @@ public class LocationMap implements ILocationResolver {
 	 * @param userInclude <code>true</code> when specified with double-quotes.
 	 */
 	public ILocationCtx pushInclusion(int startOffset,	int nameOffset, int nameEndOffset, int endOffset, 
-			char[] buffer, String filename, char[] name, boolean userInclude) {
+			char[] buffer, String filename, char[] name, boolean userInclude, boolean heuristic) {
 		assert fCurrentContext instanceof LocationCtxContainer;
 		int startNumber= getSequenceNumberForOffset(startOffset);	
 		int nameNumber= getSequenceNumberForOffset(nameOffset);		
 		int nameEndNumber= getSequenceNumberForOffset(nameEndOffset);
 		int endNumber= getSequenceNumberForOffset(endOffset);
 		final ASTInclusionStatement inclusionStatement= 
-			new ASTInclusionStatement(fTranslationUnit, startNumber, nameNumber, nameEndNumber, endNumber, name, filename, userInclude, true);
+			new ASTInclusionStatement(fTranslationUnit, startNumber, nameNumber, nameEndNumber, endNumber, name, filename, userInclude, true, heuristic);
 		fDirectives.add(inclusionStatement);
 		fCurrentContext= new LocationCtxFile((LocationCtxContainer) fCurrentContext, filename, buffer, startOffset, endOffset, endNumber, inclusionStatement);
 		fLastChildInsertionOffset= 0;
@@ -218,12 +218,12 @@ public class LocationMap implements ILocationResolver {
 	 * @param active <code>true</code> when include appears in active code.
 	 */
 	public void encounterPoundInclude(int startOffset, int nameOffset, int nameEndOffset, int endOffset,
-			char[] name, String filename, boolean userInclude, boolean active) {
+			char[] name, String filename, boolean userInclude, boolean active, boolean heuristic) {
 		startOffset= getSequenceNumberForOffset(startOffset);	
 		nameOffset= getSequenceNumberForOffset(nameOffset);		
 		nameEndOffset= getSequenceNumberForOffset(nameEndOffset);
 		endOffset= getSequenceNumberForOffset(endOffset);
-		fDirectives.add(new ASTInclusionStatement(fTranslationUnit, startOffset, nameOffset, nameEndOffset, endOffset, name, filename, userInclude, active));
+		fDirectives.add(new ASTInclusionStatement(fTranslationUnit, startOffset, nameOffset, nameEndOffset, endOffset, name, filename, userInclude, active, heuristic));
 	}
 
 	public void encounteredComment(int offset, int endOffset, boolean isBlockComment) {

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/AbstractIndexerTask.java

@@ -43,6 +43,7 @@ import org.eclipse.cdt.core.parser.IParserLogService;
 import org.eclipse.cdt.core.parser.IScannerInfo;
 import org.eclipse.cdt.core.parser.ParserUtil;
 import org.eclipse.cdt.core.parser.ScannerInfo;
+import org.eclipse.cdt.internal.core.dom.IIncludeFileResolutionHeuristics;
 import org.eclipse.cdt.internal.core.index.IIndexFragmentFile;
 import org.eclipse.cdt.internal.core.index.IWritableIndex;
 import org.eclipse.cdt.internal.core.index.IndexBasedCodeReaderFactory;
@@ -134,6 +135,7 @@ public abstract class AbstractIndexerTask extends PDOMWriter {
 	}
 
 	protected abstract IWritableIndex createIndex();
+	protected abstract IIncludeFileResolutionHeuristics createIncludeHeuristics();
 	protected abstract ICodeReaderFactory createReaderFactory();
 	protected abstract AbstractLanguage[] getLanguages(String fileName);
 
@@ -178,7 +180,7 @@ public abstract class AbstractIndexerTask extends PDOMWriter {
 			IScannerInfo scanInfo, int options, IProgressMonitor pm) throws CoreException {
 		if (fCodeReaderFactory == null) {
 			if (fIsFastIndexer) {
-				fCodeReaderFactory= new IndexBasedCodeReaderFactory(fIndex, fResolver, language.getLinkageID(), createReaderFactory(), this);
+				fCodeReaderFactory= new IndexBasedCodeReaderFactory(fIndex, createIncludeHeuristics(), fResolver, language.getLinkageID(), createReaderFactory(), this);
 			}
 			else {
 				fCodeReaderFactory= createReaderFactory();

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/PDOMWriter.java

@@ -89,6 +89,10 @@ abstract public class PDOMWriter {
 		fResolver= resolver;
 	}
 	
+	protected IndexerInputAdapter getInputAdapter() {
+		return fResolver;
+	}
+	
 	public void setShowActivity(boolean val) {
 		fShowActivity= val;
 	}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/PDOMInclude.java

@@ -44,6 +44,7 @@ public class PDOMInclude implements IIndexFragmentInclude {
 	private static final int FLAG_SYSTEM_INCLUDE 		= 1;
 	private static final int FLAG_INACTIVE_INCLUDE 		= 2;
 	private static final int FLAG_UNRESOLVED_INCLUDE 	= 4;
+	private static final int FLAG_RESOLVED_BY_HEURISTICS= 8;
 	
 	private final PDOM pdom;
 	private final int record;
@@ -81,6 +82,8 @@ public class PDOMInclude implements IIndexFragmentInclude {
 		}
 		if (unresolved) {
 			flags |= FLAG_UNRESOLVED_INCLUDE;
+		} else if (include.isResolvedByHeuristics()) {
+			flags |= FLAG_RESOLVED_BY_HEURISTICS;
 		}
 		return flags;
 	}
@@ -225,6 +228,10 @@ public class PDOMInclude implements IIndexFragmentInclude {
 		return (getFlag() & FLAG_UNRESOLVED_INCLUDE) == 0;
 	}
 
+	public boolean isResolvedByHeuristics() throws CoreException {
+		return (getFlag() & FLAG_RESOLVED_BY_HEURISTICS) != 0;
+	}
+
 	public int getNameOffset() throws CoreException {
 		return pdom.getDB().getInt(record + NODE_OFFSET_OFFSET);
 	}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/indexer/AbstractPDOMIndexer.java

@@ -27,6 +27,7 @@ public abstract class AbstractPDOMIndexer implements IPDOMIndexer {
 		
 	public AbstractPDOMIndexer() {
 		fProperties.put(IndexerPreferences.KEY_INDEX_ALL_FILES, String.valueOf(false));
+		fProperties.put(IndexerPreferences.KEY_INCLUDE_HEURISTICS, String.valueOf(true));
 		fProperties.put(IndexerPreferences.KEY_FILES_TO_PARSE_UP_FRONT, ""); //$NON-NLS-1$
 		fProperties.put(IndexerPreferences.KEY_SKIP_ALL_REFERENCES, String.valueOf(false)); 
 		fProperties.put(IndexerPreferences.KEY_SKIP_TYPE_REFERENCES, String.valueOf(false)); 

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/indexer/IndexerPreferences.java

@@ -45,6 +45,7 @@ public class IndexerPreferences {
 	
 	public static final String KEY_INDEXER_ID= "indexerId"; //$NON-NLS-1$
 	public static final String KEY_INDEX_ALL_FILES= "indexAllFiles"; //$NON-NLS-1$
+	public static final String KEY_INCLUDE_HEURISTICS= "useHeuristicIncludeResolution"; //$NON-NLS-1$
 	public static final String KEY_FILES_TO_PARSE_UP_FRONT= "filesToParseUpFront"; //$NON-NLS-1$
 	public static final String KEY_SKIP_ALL_REFERENCES= "skipReferences"; //$NON-NLS-1$
 	public static final String KEY_SKIP_TYPE_REFERENCES= "skipTypeReferences"; //$NON-NLS-1$
@@ -156,7 +157,7 @@ public class IndexerPreferences {
 		Preferences[] prefs= getPreferences(project, scope);
 		Properties props= new Properties();
 		for (int i=prefs.length-1; i>=0; i--) {
-			addProperties(prefs[i], props);
+			readProperties(prefs[i], props);
 		}
 		return props;
 	}
@@ -164,7 +165,7 @@ public class IndexerPreferences {
 	public static Properties getDefaultIndexerProperties() {
 		Preferences prefs= getDefaultPreferences();
 		Properties props= new Properties();
-		addProperties(prefs, props);
+		readProperties(prefs, props);
 		return props;
 	}
 
@@ -280,7 +281,7 @@ public class IndexerPreferences {
 		return new LocalProjectScope(project).getNode(QUALIFIER).node(INDEXER_NODE);
 	}
 	
-	private static void addProperties(Preferences preferences, Properties props) {
+	private static void readProperties(Preferences preferences, Properties props) {
 		try {
 			String[] keys = preferences.keys();
 			for (int i=0; i < keys.length; i++) {
@@ -298,6 +299,7 @@ public class IndexerPreferences {
 		Preferences prefs= defaultPreferences.node(INDEXER_NODE);
 		prefs.put(KEY_INDEXER_ID, IPDOMManager.ID_FAST_INDEXER);
 		prefs.putBoolean(KEY_INDEX_ALL_FILES, false);
+		prefs.putBoolean(KEY_INCLUDE_HEURISTICS, true);
 		prefs.putBoolean(KEY_SKIP_ALL_REFERENCES, false);
 		prefs.putBoolean(KEY_SKIP_TYPE_REFERENCES, false);
 		prefs.putBoolean(KEY_SKIP_MACRO_REFERENCES, false);

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/indexer/PDOMFastIndexerTask.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2006, 2007 QNX Software Systems and others.
+ * Copyright (c) 2006, 2008 QNX Software Systems and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -14,6 +14,7 @@ package org.eclipse.cdt.internal.core.pdom.indexer;
 
 import org.eclipse.cdt.core.dom.ICodeReaderFactory;
 import org.eclipse.cdt.core.model.ITranslationUnit;
+import org.eclipse.cdt.internal.core.dom.IIncludeFileResolutionHeuristics;
 
 /**
  * Configures the abstract indexer to return tasks suitable for fast indexing.
@@ -28,4 +29,9 @@ class PDOMFastIndexerTask extends PDOMIndexerTask {
 	protected ICodeReaderFactory createReaderFactory() {
 		return null;
 	}
+
+	@Override
+	protected IIncludeFileResolutionHeuristics createIncludeHeuristics() {
+		return new ProjectIndexerIncludeResolutionHeuristics(getCProject().getProject(), getInputAdapter());
+	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/indexer/PDOMFullIndexerTask.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2006, 2007 QNX Software Systems and others.
+ * Copyright (c) 2006, 2008 QNX Software Systems and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -14,6 +14,7 @@ package org.eclipse.cdt.internal.core.pdom.indexer;
 
 import org.eclipse.cdt.core.dom.ICodeReaderFactory;
 import org.eclipse.cdt.core.model.ITranslationUnit;
+import org.eclipse.cdt.internal.core.dom.IIncludeFileResolutionHeuristics;
 import org.eclipse.cdt.internal.core.dom.SavedCodeReaderFactory;
 
 
@@ -28,6 +29,11 @@ class PDOMFullIndexerTask extends PDOMIndexerTask {
 
 	@Override
 	protected ICodeReaderFactory createReaderFactory() {
-		return SavedCodeReaderFactory.getInstance();
+		return SavedCodeReaderFactory.createInstance(createIncludeHeuristics());
+	}
+	
+	@Override
+	protected IIncludeFileResolutionHeuristics createIncludeHeuristics() {
+		return new ProjectIndexerIncludeResolutionHeuristics(getCProject().getProject(), getInputAdapter());
 	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/indexer/ProjectIndexerIncludeResolutionHeuristics.java

@@ -0,0 +1,130 @@
+/*******************************************************************************
+ * Copyright (c) 2008 Wind River Systems, Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Markus Schorn - initial API and implementation
+ *******************************************************************************/ 
+package org.eclipse.cdt.internal.core.pdom.indexer;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.eclipse.cdt.core.index.IIndexFileLocation;
+import org.eclipse.cdt.internal.core.dom.IIncludeFileResolutionHeuristics;
+import org.eclipse.cdt.internal.core.pdom.ASTFilePathResolver;
+import org.eclipse.cdt.internal.core.resources.ResourceLookup;
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.Path;
+
+/**
+ * Heuristics for picking up includes from the project
+ */
+public class ProjectIndexerIncludeResolutionHeuristics implements IIncludeFileResolutionHeuristics {
+	private static final String TRUE = "true"; //$NON-NLS-1$
+
+	@SuppressWarnings("nls")
+	private static final boolean IGNORE_CASE = new File("a").equals(new File("A"));
+	
+	private IProject fProject;
+	private IProject[] fProjects;
+	private final ASTFilePathResolver fResolver;
+
+	public ProjectIndexerIncludeResolutionHeuristics(IProject project, ASTFilePathResolver resolver) {
+		fProject= project;
+		fResolver= resolver;
+	}
+
+	public String findInclusion(String include, String currentFile) {
+		final IIndexFileLocation ifl= fResolver.resolveASTPath(currentFile);
+		if (ifl == null || ifl.getFullPath() == null) {
+			return null;
+		}
+		
+		if (fProject == null)
+			return null;
+		
+		
+		if (fProjects == null) {
+			if (fProject.isOpen()) {
+				String val= IndexerPreferences.get(fProject, IndexerPreferences.KEY_INCLUDE_HEURISTICS, TRUE);
+				if (TRUE.equals(val)) {
+					fProjects= getOpenReferencedProjects(fProject);
+				}
+			} 
+			if (fProjects == null) { 
+				fProject= null;
+				return null;
+			}
+		}
+		
+		IFile[] files= ResourceLookup.findFilesByName(new Path(include), fProjects, IGNORE_CASE);
+		if (files.length == 0)
+			return null;
+		
+		return selectBest(files, ifl.getFullPath().toCharArray()).getLocation().toString();
+	}
+	
+	
+	private IResource selectBest(IFile[] files, char[] currentFullPath) {
+		IFile best= files[0];
+		int bestScore= computeScore(best.getFullPath().toString().toCharArray(), currentFullPath);
+		
+		for (int i = 1; i < files.length; i++) {
+			IFile file= files[i];
+			int score= computeScore(file.getFullPath().toString().toCharArray(), currentFullPath);
+			if (score > bestScore) {
+				bestScore= score;
+				best= file;
+			}
+		}
+		return best;
+	}
+
+	private int computeScore(char[] path1, char[] path2) {
+		final int limit= Math.min(path1.length, path2.length);
+		int match=0;
+		for (int i = 0; i < limit; i++) {
+			if (path1[i] != path2[i])
+				break;
+			if (path1[i] == '/')
+				match= i;
+		}
+		// prefer shortest path with longest matches with 
+		return (match << 16) - path1.length; 
+	}
+
+	private IProject[] getOpenReferencedProjects(IProject prj) {
+		Set<IProject> result= new HashSet<IProject>();
+		
+		if (prj.isOpen()) {
+			result.add(prj);
+
+			List<IProject> projectsToSearch= new ArrayList<IProject>();
+			projectsToSearch.add(prj);
+			for (int i=0; i<projectsToSearch.size(); i++) {
+				IProject project= projectsToSearch.get(i);
+				IProject[] nextLevel;
+				try {
+					nextLevel= project.getReferencedProjects();
+					for (IProject prjNextLevel : nextLevel) {
+						if (prjNextLevel.isOpen() && result.add(prjNextLevel)) {
+							projectsToSearch.add(prjNextLevel);
+						}
+					}
+				} catch (CoreException e) {
+				}
+			}
+		}
+		return result.toArray(new IProject[result.size()]);
+	}
+}

core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/CCorePlugin.java

@@ -55,6 +55,7 @@ import org.eclipse.cdt.internal.core.model.IBufferFactory;
 import org.eclipse.cdt.internal.core.model.Util;
 import org.eclipse.cdt.internal.core.model.WorkingCopy;
 import org.eclipse.cdt.internal.core.pdom.PDOMManager;
+import org.eclipse.cdt.internal.core.resources.ResourceLookup;
 import org.eclipse.cdt.internal.core.settings.model.CProjectDescriptionManager;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IProjectDescription;
@@ -322,6 +323,7 @@ public class CCorePlugin extends Plugin {
 			}
 
             fNewCProjectDescriptionManager.shutdown();
+            ResourceLookup.shutdown();
 
 			savePluginPreferences();
 		} finally {
@@ -340,6 +342,7 @@ public class CCorePlugin extends Plugin {
 		cdtLog = new CDTLogWriter(CCorePlugin.getDefault().getStateLocation().append(".log").toFile()); //$NON-NLS-1$
 		configurePluginDebugOptions();
         PositionTrackerManager.getInstance().install();
+        ResourceLookup.startup();
         
         // new project model needs to register the resource listener first.
 		fNewCProjectDescriptionManager= CProjectDescriptionManager.getInstance();

core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/dom/CDOM.java

@@ -1,12 +1,12 @@
 /*******************************************************************************
- * Copyright (c) 2004, 2007 IBM Corporation and others.
+ * Copyright (c) 2004, 2008 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
- * IBM - Initial API and implementation
+ *    IBM - Initial API and implementation
  *******************************************************************************/
 package org.eclipse.cdt.core.dom;
 import org.eclipse.cdt.core.dom.ast.IASTCompletionNode;
@@ -105,9 +105,9 @@ public class CDOM implements IASTServiceProvider {
         	case PARSE_SAVED_RESOURCES: 
         	    return SavedCodeReaderFactory.getInstance();
         	case PARSE_WORKING_COPY_WITH_SAVED_INCLUSIONS:
-        	    return new PartialWorkingCopyCodeReaderFactory( provider );
+        	    return new PartialWorkingCopyCodeReaderFactory(provider, null);
         	case PARSE_WORKING_COPY_WHENEVER_POSSIBLE:
-        	    return new WorkingCopyCodeReaderFactory( provider );
+        	    return new WorkingCopyCodeReaderFactory( provider, null );
         }
         return null;
     }

core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/dom/AbstractCodeReaderFactory.java

@@ -0,0 +1,34 @@
+/*******************************************************************************
+ * Copyright (c) 2008 Wind River Systems, Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Markus Schorn - initial API and implementation
+ *******************************************************************************/ 
+package org.eclipse.cdt.internal.core.dom;
+
+import org.eclipse.cdt.core.dom.ICodeReaderFactory;
+import org.eclipse.core.runtime.IAdaptable;
+
+/**
+ * Base implementation for all code reader factories.
+ */
+public abstract class AbstractCodeReaderFactory implements ICodeReaderFactory, IAdaptable {
+
+	private final IIncludeFileResolutionHeuristics fHeuristics;
+
+	public AbstractCodeReaderFactory(IIncludeFileResolutionHeuristics heuristics) {
+		fHeuristics= heuristics;
+	}
+	
+	@SuppressWarnings("unchecked")
+	public Object getAdapter(Class adapter) {
+		if (adapter.isAssignableFrom(IIncludeFileResolutionHeuristics.class)) {
+			return fHeuristics;
+		}
+		return null;
+	}
+}

core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/dom/IIncludeFileResolutionHeuristics.java

@@ -0,0 +1,26 @@
+/*******************************************************************************
+ * Copyright (c) 2008 Wind River Systems, Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Markus Schorn - initial API and implementation
+ *******************************************************************************/ 
+package org.eclipse.cdt.internal.core.dom;
+
+
+/**
+ * Abstract base class for heuristic include file resolution.
+ */
+public interface IIncludeFileResolutionHeuristics {
+
+	/**
+	 * Attempt to find a file for the given include without using an include search path.
+	 * @param include the include as provided in the directive
+	 * @param currentFile the file the inclusion belongs to.
+	 * @return a location for the inclusion or null.
+	 */
+	String findInclusion(String include, String currentFile);
+}

core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/dom/NullCodeReaderFactory.java

@@ -19,7 +19,7 @@ import org.eclipse.cdt.core.parser.ICodeReaderCache;
  *
  * @since 4.0
  */
-public class NullCodeReaderFactory implements ICodeReaderFactory {
+public class NullCodeReaderFactory extends AbstractCodeReaderFactory {
 
 	private static final char[] EMPTY_CHARS = new char[0];
 	private static final ICodeReaderFactory INSTANCE= new NullCodeReaderFactory();
@@ -29,7 +29,7 @@ public class NullCodeReaderFactory implements ICodeReaderFactory {
 	}
 
 	private NullCodeReaderFactory() {
-		// singleton
+		super(null);
 	}
 
 	/*

core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/dom/PartialWorkingCopyCodeReaderFactory.java

@@ -14,7 +14,6 @@ import java.util.Arrays;
 import java.util.Iterator;
 
 import org.eclipse.cdt.core.dom.CDOM;
-import org.eclipse.cdt.core.dom.ICodeReaderFactory;
 import org.eclipse.cdt.core.model.ITranslationUnit;
 import org.eclipse.cdt.core.model.IWorkingCopy;
 import org.eclipse.cdt.core.model.IWorkingCopyProvider;
@@ -26,8 +25,7 @@ import org.eclipse.cdt.internal.core.parser.EmptyIterator;
 /**
  * @author jcamelon
  */
-public class PartialWorkingCopyCodeReaderFactory 
+public class PartialWorkingCopyCodeReaderFactory extends AbstractCodeReaderFactory {
-        implements ICodeReaderFactory {
 
     private final IWorkingCopyProvider provider;
 	private ICodeReaderCache cache = null;
@@ -35,7 +33,8 @@ public class PartialWorkingCopyCodeReaderFactory
     /**
      * @param provider
      */
-    public PartialWorkingCopyCodeReaderFactory(IWorkingCopyProvider provider) {
+    public PartialWorkingCopyCodeReaderFactory(IWorkingCopyProvider provider, IIncludeFileResolutionHeuristics heuristics) {
+    	super(heuristics);
         this.provider = provider;
 		cache = SavedCodeReaderFactory.getInstance().getCodeReaderCache();
     }

core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/dom/SavedCodeReaderFactory.java

@@ -12,7 +12,6 @@ package org.eclipse.cdt.internal.core.dom;
 
 import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.dom.CDOM;
-import org.eclipse.cdt.core.dom.ICodeReaderFactory;
 import org.eclipse.cdt.core.model.ITranslationUnit;
 import org.eclipse.cdt.core.parser.CodeReader;
 import org.eclipse.cdt.core.parser.CodeReaderCache;
@@ -22,43 +21,49 @@ import org.eclipse.core.runtime.Preferences;
 /**
  * @author jcamelon
  */
-public class SavedCodeReaderFactory implements ICodeReaderFactory {
+public class SavedCodeReaderFactory extends AbstractCodeReaderFactory {
 
-	private ICodeReaderCache cache = null;
+	private static ICodeReaderCache cache;
+    private static SavedCodeReaderFactory instance = new SavedCodeReaderFactory(null);
 	
-    public static SavedCodeReaderFactory getInstance()
+    public static SavedCodeReaderFactory getInstance() {
-    {
         return instance;
     }
     
-    private static SavedCodeReaderFactory instance = new SavedCodeReaderFactory();
+    public static SavedCodeReaderFactory createInstance(IIncludeFileResolutionHeuristics heuristics) {
+    	return new SavedCodeReaderFactory(heuristics);
+    }
     
-    private SavedCodeReaderFactory()
+    
-    {
+    private SavedCodeReaderFactory(IIncludeFileResolutionHeuristics heuristics) {
-		int size= CodeReaderCache.DEFAULT_CACHE_SIZE_IN_MB;
+    	super(heuristics);
-		final CCorePlugin corePlugin = CCorePlugin.getDefault();
+    	
-		if (corePlugin != null) {
+		if (cache == null) {
-			Preferences pluginPreferences = corePlugin.getPluginPreferences();
+			int size= CodeReaderCache.DEFAULT_CACHE_SIZE_IN_MB;
-			if (pluginPreferences != null) {
+			final CCorePlugin corePlugin = CCorePlugin.getDefault();
-				size = pluginPreferences.getInt(CodeReaderCache.CODE_READER_BUFFER);
+			if (corePlugin != null) {
-				if (size == 0) {
+				Preferences pluginPreferences = corePlugin.getPluginPreferences();
-					String [] properties = pluginPreferences.propertyNames();
+				if (pluginPreferences != null) {
-					boolean found = false;
+					size = pluginPreferences.getInt(CodeReaderCache.CODE_READER_BUFFER);
-					for (int j = 0; j < properties.length; ++j) {
+					if (size == 0) {
-						if (properties[j].equals( CodeReaderCache.CODE_READER_BUFFER)) {
+						String [] properties = pluginPreferences.propertyNames();
-							found = true;
+						boolean found = false;
-							break;
+						for (int j = 0; j < properties.length; ++j) {
+							if (properties[j].equals( CodeReaderCache.CODE_READER_BUFFER)) {
+								found = true;
+								break;
+							}
 						}
-					}
+						if (!found) {
-					if (!found) {
+							size= CodeReaderCache.DEFAULT_CACHE_SIZE_IN_MB;
+						}
+					} else if (size < 0) {
 						size= CodeReaderCache.DEFAULT_CACHE_SIZE_IN_MB;
 					}
-				} else if (size < 0) {
-					size= CodeReaderCache.DEFAULT_CACHE_SIZE_IN_MB;
 				}
 			}
+			cache= new CodeReaderCache(size);
 		}
-		cache = new CodeReaderCache(size);
     }
     /* (non-Javadoc)
      * @see org.eclipse.cdt.core.dom.ICodeReaderFactory#getUniqueIdentifier()

core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/dom/WorkingCopyCodeReaderFactory.java

@@ -6,7 +6,7 @@
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
- * IBM - Initial API and implementation
+ *    IBM - Initial API and implementation
  *******************************************************************************/
 package org.eclipse.cdt.internal.core.dom;
 
@@ -23,8 +23,8 @@ public class WorkingCopyCodeReaderFactory extends PartialWorkingCopyCodeReaderFa
     /**
      * @param provider
      */
-    public WorkingCopyCodeReaderFactory(IWorkingCopyProvider provider) {
+    public WorkingCopyCodeReaderFactory(IWorkingCopyProvider provider, IIncludeFileResolutionHeuristics heuristics) {
-        super(provider);
+        super(provider, heuristics);
     }
     
     /* (non-Javadoc)

core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/resources/ResourceLookup.java

@@ -0,0 +1,65 @@
+/*******************************************************************************
+ * Copyright (c) 2008 Wind River Systems, Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Markus Schorn - initial API and implementation
+ *******************************************************************************/ 
+package org.eclipse.cdt.internal.core.resources;
+
+import java.net.URI;
+
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.runtime.IPath;
+
+/**
+ * Allows for looking up resources by location or name.
+ */
+public class ResourceLookup {
+	private static ResourceLookupImpl sInstance= new ResourceLookupImpl();
+
+	public static void startup() {
+		sInstance.startup();
+	}
+	
+	public static void shutdown() {
+		sInstance.shutdown();
+	}
+	
+	public static IFile[] findFilesForLocation(URI location, IProject[] projects) {
+		return sInstance.findFilesForLocation(location, projects);
+	}
+	
+	/**
+	 * Searches for files with the given location suffix. 
+	 * @param locationSuffix the suffix to match, always used as relative path.
+	 * @param projects the projects to search
+	 * @param ignoreCase whether or not to ignore case when comparing the suffix.
+	 */
+	public static IFile[] findFilesByName(IPath locationSuffix, IProject[] projects, boolean ignoreCase) {
+		return sInstance.findFilesByName(locationSuffix, projects, ignoreCase);
+	}
+
+	/** 
+	 * For testing, only.
+	 */
+	public static void dump() {
+		sInstance.dump();
+	}
+	/** 
+	 * For testing, only.
+	 */
+	public static void unrefNodeMap() {
+		sInstance.unrefNodeMap();
+	}
+	/** 
+	 * For testing, only.
+	 */
+	public static void simulateNodeMapCollection() {
+		sInstance.simulateNodeMapCollection();
+	}
+}

core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/resources/ResourceLookupImpl.java

@@ -0,0 +1,809 @@
+/*******************************************************************************
+ * Copyright (c) 2008 Wind River Systems, Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Markus Schorn - initial API and implementation
+ *******************************************************************************/ 
+package org.eclipse.cdt.internal.core.resources;
+
+import java.io.File;
+import java.io.IOException;
+import java.lang.ref.SoftReference;
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.eclipse.cdt.core.CCorePlugin;
+import org.eclipse.cdt.core.CProjectNature;
+import org.eclipse.cdt.core.model.CoreModel;
+import org.eclipse.cdt.core.parser.util.CharArrayUtils;
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.resources.IResourceChangeEvent;
+import org.eclipse.core.resources.IResourceChangeListener;
+import org.eclipse.core.resources.IResourceDelta;
+import org.eclipse.core.resources.IResourceDeltaVisitor;
+import org.eclipse.core.resources.IResourceProxy;
+import org.eclipse.core.resources.IResourceProxyVisitor;
+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;
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Path;
+import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.content.IContentType;
+import org.eclipse.core.runtime.content.IContentTypeManager;
+import org.eclipse.core.runtime.jobs.Job;
+
+/**
+ * Allows for looking up resources by location or name. When using this class 100 bytes per resource
+ * are needed. Therefore the support is limited to header-files int non-cdt projects and all files 
+ * except non-cdt-files in CDT projects.
+ *
+ * The information for a project is initialized when first requested and then it is kept up to date
+ * using a resource change listener. No memory is used, as long as the class is not used.
+ * When information is not used for more than 10 minutes, the data-structures will be held via a weak
+ * reference, only and are subject to garbage collection.
+ * 
+ * The node map stores a map from hash-code of file-names to nodes.
+ * A node contains the name of a file plus a link to the parent resource. From that we can compute
+ * the resource path and obtain further information via the resource.
+ */
+class ResourceLookupImpl implements IResourceChangeListener, IResourceDeltaVisitor, IResourceProxyVisitor {
+	private static final int UNREF_DELAY = 10 * 60000; // 10 min
+	
+	private static final boolean VISIT_CHILDREN = true;
+	private static final boolean SKIP_CHILDREN = false;
+	private static final IFile[] NO_FILES = new IFile[0];
+	private static final int TRIGGER_RECALC= 
+		IResourceDelta.TYPE | IResourceDelta.REPLACED | 
+		IResourceDelta.LOCAL_CHANGED | IResourceDelta.OPEN;
+	
+	private static class Extensions {
+		private final boolean fInvert;
+		private final Set<String> fExtensions;
+		Extensions(Set<String> extensions, boolean invert) {
+			fInvert= invert;
+			fExtensions= extensions;
+		}
+		boolean isRelevant(String filename) {
+			// accept all files without extension
+			final int idx= filename.lastIndexOf('.');
+			if (idx < 0)
+				return true;
+			
+			return fExtensions.contains(filename.substring(idx+1)) != fInvert;
+		}
+	}
+	
+	private static class Node {
+		final Node fParent;
+		final char[] fResourceName;
+		final boolean fIsFolder;
+		
+		boolean fDeleted;
+		boolean fHasChildren;
+		private int fCanonicHash;
+		
+		Node(Node parent, char[] name, boolean isFolder) {
+			fParent= parent;
+			fResourceName= name;
+			fIsFolder= isFolder;
+			if (parent != null)
+				parent.fHasChildren= true;
+		}
+	}
+
+	private final Object fLock= new Object();
+	private final Job fUnrefJob;
+	private SoftReference<Map<Integer, Object>> fNodeMapRef;
+	private Map<Integer, Object> fNodeMap;
+	private final Map<String, Extensions> fFileExtensions;
+	private Extensions fCDTProjectExtensions;
+	private Extensions fDefaultExtensions;
+	private Extensions fCurrentExtensions;
+	private Node fRootNode;
+	private boolean fNeedCleanup;
+	private Node fLastFolderNode;
+	
+	public ResourceLookupImpl() {
+		fRootNode= new Node(null, CharArrayUtils.EMPTY, true) {};
+		fFileExtensions= new HashMap<String, Extensions>();
+		fUnrefJob= new Job("Timer") { //$NON-NLS-1$
+			@Override
+			protected IStatus run(IProgressMonitor monitor) {
+				unrefNodeMap();
+				return Status.OK_STATUS;
+			}
+		};
+		fUnrefJob.setSystem(true);
+	}
+
+	public void startup() {
+		final IWorkspace workspace = ResourcesPlugin.getWorkspace();
+		workspace.addResourceChangeListener(this, IResourceChangeEvent.POST_CHANGE);
+	}
+
+	public void shutdown() {
+		ResourcesPlugin.getWorkspace().removeResourceChangeListener(this);
+		synchronized (fLock) {
+			fNodeMap= null;
+			fNodeMapRef= null;
+			fFileExtensions.clear();
+		}
+	}
+
+	/**
+	 * Handle resource change notifications.
+	 */
+	public void resourceChanged(IResourceChangeEvent event) {
+		IResourceDelta delta= event.getDelta();
+		synchronized (fLock) {
+			if (fNodeMapRef == null)
+				return;
+			boolean unsetMap= false;
+			if (fNodeMap == null) {
+				fNodeMap= fNodeMapRef.get();
+				if (fNodeMap == null)
+					return;
+				unsetMap= true;
+			}
+			try {
+				delta.accept(this);
+			} catch (CoreException e) {
+				CCorePlugin.log(e);
+			} finally {
+				if (fNeedCleanup)
+					cleanup();
+				fCurrentExtensions= null;
+				fNeedCleanup= false;
+				if (unsetMap)
+					fNodeMap= null;
+			}
+		}
+	}
+	
+	/**
+	 * Handles resource change notifications by visiting the delta.
+	 */
+	public boolean visit(IResourceDelta delta) throws CoreException {
+		assert Thread.holdsLock(fLock);
+		
+		final IResource res= delta.getResource();
+		if (res instanceof IWorkspaceRoot)
+			return VISIT_CHILDREN;
+		
+		if (res instanceof IProject) {
+			// project not yet handled
+			final String name = res.getName();
+			final Extensions exts= fFileExtensions.get(name);
+			if (exts == null)
+				return SKIP_CHILDREN;
+			
+			switch (delta.getKind()) {
+			case IResourceDelta.ADDED:	// new projects should not yet be part of the tree
+			case IResourceDelta.REMOVED:
+				fFileExtensions.remove(name);
+				remove(res);
+				return SKIP_CHILDREN;
+				
+			case IResourceDelta.CHANGED:
+				if ((delta.getFlags() & (TRIGGER_RECALC | IResourceDelta.DESCRIPTION)) != 0) {
+					fFileExtensions.remove(name);
+					remove(res);
+					return SKIP_CHILDREN;
+				}
+				break;
+			}
+			fCurrentExtensions= exts;
+			return VISIT_CHILDREN;
+		}
+				
+		// file or folder
+		switch (delta.getKind()) {
+		case IResourceDelta.ADDED:
+			add(res);
+			return SKIP_CHILDREN;
+			
+		case IResourceDelta.CHANGED:
+			if ((delta.getFlags() & TRIGGER_RECALC) != 0) {
+				remove(res);
+				add(res);
+				return SKIP_CHILDREN;
+			}
+			return VISIT_CHILDREN;
+			
+		case IResourceDelta.REMOVED:
+			
+			remove(res);
+			return SKIP_CHILDREN;
+		}
+		return VISIT_CHILDREN;
+	}
+
+
+	/**
+	 * Add a resource to the tree.
+	 */
+	private void add(IResource res) {
+		assert Thread.holdsLock(fLock);
+		
+		if (res instanceof IFile) {
+			if (fCurrentExtensions.isRelevant(res.getName())) {
+				createFileNode(res.getFullPath());
+			}
+		} else {
+			try {
+				res.accept(this, 0);
+			} catch (CoreException e) {
+				CCorePlugin.log(e);
+			}
+		}
+	}
+	
+	/**
+	 * Add a resource tree by using a resource proxy visitor.
+	 */
+	public boolean visit(IResourceProxy proxy) throws CoreException {
+		if (proxy.getType() == IResource.FILE) {
+			if (fCurrentExtensions.isRelevant(proxy.getName())) {
+				createFileNode(proxy.requestFullPath());
+			}
+		}
+		return true;
+	}
+
+	
+	public void unrefNodeMap() {
+		synchronized (fLock) {
+			fNodeMap= null;
+		}
+	}
+
+	public void simulateNodeMapCollection() {
+		synchronized (fLock) {
+			fNodeMap= null;
+			fNodeMapRef= new SoftReference<Map<Integer, Object>>(null);
+		}
+	}
+
+	/**
+	 * Initializes nodes for the given projects. Also creates the node map if it was collected.
+	 */
+	private void initializeProjects(IProject[] projects) {
+		assert Thread.holdsLock(fLock);
+		
+		if (fNodeMap == null) {
+			if (fNodeMapRef != null) {
+				fNodeMap= fNodeMapRef.get();
+			}
+
+			if (fNodeMap == null) {
+				fFileExtensions.clear();
+				fNodeMap= new HashMap<Integer, Object>();
+				fNodeMapRef= new SoftReference<Map<Integer, Object>>(fNodeMap);
+			}
+		}
+		fUnrefJob.cancel();
+		fUnrefJob.schedule(UNREF_DELAY); 
+
+		for (IProject project : projects) {
+			if (project.isOpen() && !fFileExtensions.containsKey(project.getName())) {
+				Extensions ext= fDefaultExtensions;
+				try {
+					if (project.hasNature(CProjectNature.C_NATURE_ID)) {
+						ext= fCDTProjectExtensions;
+					}
+				} catch (CoreException e) {
+					CCorePlugin.log(e);
+					// treat as non-cdt project
+				}
+				fCurrentExtensions= ext;
+				add(project);
+				fFileExtensions.put(project.getName(), ext);
+				fCurrentExtensions= null;
+			}
+		}
+	}
+
+	/**
+	 * Initializes file-extensions and node map
+	 */
+	private void initFileExtensions() {
+		if (fDefaultExtensions == null) {
+			HashSet<String> select= new HashSet<String>();
+			String[] registeredContentTypes= CoreModel.getRegistedContentTypeIds();
+			select.addAll(Arrays.asList(registeredContentTypes));
+
+			final IContentTypeManager ctm= Platform.getContentTypeManager();
+			final IContentType[] ctts= ctm.getAllContentTypes();
+			Set<String> result= new HashSet<String>();
+			outer: for (IContentType ctt : ctts) {
+				IContentType basedOn= ctt;
+				while (basedOn != null) {
+					if (select.contains(basedOn.getId())) 
+						continue outer;
+					basedOn= basedOn.getBaseType();
+				}
+				// this is a non-cdt content type
+				String[] fspecs= ctt.getFileSpecs(IContentType.FILE_EXTENSION_SPEC);
+				result.addAll(Arrays.asList(fspecs));
+			}
+			fCDTProjectExtensions= new Extensions(result, true);
+
+			result= new HashSet<String>();
+			select.clear();
+			select.add(CCorePlugin.CONTENT_TYPE_CHEADER);
+			select.add(CCorePlugin.CONTENT_TYPE_CXXHEADER);
+			for (IContentType ctt : ctts) {
+				IContentType basedOn= ctt;
+				boolean selectme= false;
+				while (basedOn != null) {
+					if (select.contains(basedOn.getId())) {
+						selectme= true;
+						break;
+					}
+					basedOn= basedOn.getBaseType();
+				}
+				if (selectme) {
+					// this is content type for a header file
+					String[] fspecs= ctt.getFileSpecs(IContentType.FILE_EXTENSION_SPEC);
+					result.addAll(Arrays.asList(fspecs));
+				}
+			}
+			fDefaultExtensions= new Extensions(result, false);
+		}
+	}
+
+	/**
+	 * Inserts a node for the given path.
+	 */
+	private void createFileNode(IPath fullPath) {
+		final String[] segments= fullPath.segments();
+		createNode(toCharArrayArray(segments), segments.length, false);
+	}
+
+	private char[][] toCharArrayArray(String[] segments) {
+		final int len= segments.length;
+		char[][] chsegs= new char[len][];
+		for (int i = 0; i < segments.length; i++) {
+			chsegs[i]= segments[i].toCharArray();
+		}
+		return chsegs;
+	}
+
+	/**
+	 * Inserts a node for the given path.
+	 */
+	private Node createNode(char[][] segments, int segmentCount, boolean folder) {
+		assert Thread.holdsLock(fLock);
+		
+		if (segmentCount == 0)
+			return fRootNode;
+
+		if (folder && fLastFolderNode != null) {
+			if (isNodeForSegments(fLastFolderNode, segments, segmentCount))
+				return fLastFolderNode;
+		}
+		
+		final char[] name= segments[segmentCount-1];
+		final int hash= hashCode(name);
+		
+		// search for existing node
+		Object obj= fNodeMap.get(hash);
+
+		Node[] nodes= null;
+		int len= 0;
+		if (obj != null) {
+			if (obj instanceof Node) {
+				Node node= (Node) obj;
+				if (isNodeForSegments(node, segments, segmentCount)) {
+					if (folder)
+						fLastFolderNode= node;
+					return node;
+				}
+				nodes= new Node[]{node, null};
+				fNodeMap.put(hash, nodes);
+				len= 1;
+			} else {
+				nodes= (Node[]) obj;
+				for (len=0; len < nodes.length; len++) {
+					Node node = nodes[len];
+					if (node == null) 
+						break;
+					if (isNodeForSegments(node, segments, segmentCount)) {
+						if (folder)
+							fLastFolderNode= node;
+						return node;
+					}
+				}
+			}
+		}		
+		final Node parent= createNode(segments, segmentCount-1, true);
+		Node node= new Node(parent, name, folder);
+		if (nodes == null) {
+			fNodeMap.put(hash, node);
+		} else { 
+			if (len == nodes.length) {
+				Node[] newNodes= new Node[len+2];
+				System.arraycopy(nodes, 0, newNodes, 0, len);
+				nodes= newNodes;
+				fNodeMap.put(hash, nodes);
+			}
+			nodes[len]= node;
+		}
+		
+		if (folder)
+			fLastFolderNode= node;
+		return node;
+	}
+
+	/**
+	 * Checks whether the given node matches the given segments.
+	 */
+	private boolean isNodeForSegments(Node node, char[][] segments, int segmentLength) {
+		assert Thread.holdsLock(fLock);
+		
+		while(segmentLength > 0 && node != null) {
+			if (!CharArrayUtils.equals(segments[--segmentLength], node.fResourceName))
+				return false;
+			node= node.fParent;
+		}
+		return node == fRootNode;
+	}
+	
+	/**
+	 * Remove a resource from the tree
+	 */
+	private void remove(IResource res) {
+		assert Thread.holdsLock(fLock);
+		
+		final char[] name= res.getName().toCharArray();
+		final int hash= hashCode(name);
+		
+		Object obj= fNodeMap.get(hash);
+		if (obj == null)
+			return;
+		
+		final IPath fullPath= res.getFullPath();
+		final int segmentCount= fullPath.segmentCount();
+		if (segmentCount == 0)
+			return;
+		
+		final char[][]segments= toCharArrayArray(fullPath.segments());
+		if (obj instanceof Node) {
+			final Node node= (Node) obj;
+			if (!node.fDeleted && isNodeForSegments(node, segments, segmentCount)) {
+				node.fDeleted= true;
+				if (node.fHasChildren)
+					fNeedCleanup= true;
+				fNodeMap.remove(hash);
+			}
+		} else {
+			final Node[] nodes= (Node[]) obj;
+			for (int i= 0; i < nodes.length; i++) {
+				Node node = nodes[i];
+				if (node == null)
+					return;
+				if (!node.fDeleted && isNodeForSegments(node, segments, segmentCount)) {
+					remove(nodes, i);
+
+					if (nodes[0] == null) 
+						fNodeMap.remove(hash);
+
+					node.fDeleted= true;
+					if (node.fHasChildren)
+						fNeedCleanup= true;
+
+					return;
+				}
+			}
+		}
+	}
+
+	private void remove(Node[] nodes, int i) {
+    	int idx= lastValid(nodes, i);
+    	if (idx > 0) { 
+    		nodes[i]= nodes[idx];
+    		nodes[idx]= null;
+    	}
+	}
+
+	private int lastValid(Node[] nodes, int left) {
+		int right= nodes.length-1;
+    	while (left < right) {
+    		int mid= (left+right+1)/2;  // ==> mid > left
+    		if (nodes[mid] == null) 
+    			right= mid-1;
+    		else 
+    			left= mid;
+    	}
+		return right;
+	}
+
+	private void cleanup() {
+		assert Thread.holdsLock(fLock);
+		fLastFolderNode= null;
+		
+		for (Iterator<Object> iterator = fNodeMap.values().iterator(); iterator.hasNext();) {
+			Object obj= iterator.next();
+			if (obj instanceof Node) {
+				if (isDeleted((Node) obj)) {
+					iterator.remove();
+				}
+			} else {
+				Node[] nodes= (Node[]) obj;
+				int j= 0;
+				for (int i = 0; i < nodes.length; i++) {
+					final Node node = nodes[i];
+					if (node == null) {
+						if (j==0) {
+							iterator.remove();
+						} 
+						break;
+					}
+					if (!isDeleted(node)) {
+						if (i != j) {
+							nodes[j]= node;
+							nodes[i]= null;
+						}
+						j++;
+					} else {
+						nodes[i]= null;
+					}
+				}
+			}
+		}
+	}
+	
+	private boolean isDeleted(Node node) {
+		while(node != null) {
+			if (node.fDeleted)
+				return true;
+			node= node.fParent;
+		}
+		return false;
+	}
+
+	/**
+	 * Computes a case insensitive hash-code for file names.
+	 */
+	private int hashCode(char[] name) {
+		int h= 0;
+		final int len = name.length;
+		for (int i = 0; i < len; i++) {
+			h = 31*h + Character.toUpperCase(name[i]);
+		}
+		return h;
+	}
+
+	/**
+	 * Searches for all files with the given location.
+	 */
+	public IFile[] findFilesForLocation(URI location, IProject[] projects) {
+		initFileExtensions();
+		String name= extractName(location);
+		Node[] candidates;
+		synchronized (fLock) {
+			initializeProjects(projects);
+			Object obj= fNodeMap.get(hashCode(name.toCharArray()));
+			if (obj == null) {
+				return NO_FILES;
+			}
+			candidates= convert(obj);
+		}	
+		return extractMatchesForLocation(candidates, location);
+	}
+
+	private Node[] convert(Object obj) {
+		if (obj instanceof Node)
+			return new Node[] {(Node) obj};
+
+		final Node[] nodes= (Node[]) obj;
+		final int len= lastValid(nodes, -1)+1;
+		final Node[] result= new Node[len];
+		System.arraycopy(nodes, 0, result, 0, len);
+		return result;
+	}
+
+	/**
+	 * Returns an array of files for the given name. Search is limited to the supplied projects.
+	 */
+	public IFile[] findFilesByName(IPath relativeLocation, IProject[] projects, boolean ignoreCase) {
+		final int segCount= relativeLocation.segmentCount();
+		if (segCount < 1)
+			return NO_FILES;
+		
+		final String name= relativeLocation.lastSegment();
+		Node[] candidates;
+
+		initFileExtensions();
+		synchronized (fLock) {
+			initializeProjects(projects);
+			Object obj= fNodeMap.get(hashCode(name.toCharArray()));
+			if (obj == null) {
+				return NO_FILES;
+			}
+			candidates= convert(obj);
+		}	
+		String suffix= relativeLocation.toString();
+		while(suffix.startsWith("../")) { //$NON-NLS-1$
+			suffix= suffix.substring(3);
+		}
+		return extractMatchesForName(candidates, name, suffix, ignoreCase);
+	}
+	
+	private String extractName(URI location) {
+		String path= location.getPath();
+		int idx= path.lastIndexOf('/');
+		return path.substring(idx+1);
+	}
+
+	/**
+	 * Selects the actual matches for the list of candidate nodes.
+	 */
+	private IFile[] extractMatchesForName(Node[] candidates, String name, String suffix, boolean ignoreCase) {
+		final char[] n1= name.toCharArray();
+		final int namelen = n1.length;
+		int resultIdx= 0;
+		
+		if (ignoreCase) {
+			for (int j = 0; j < namelen; j++) {
+				n1[j]= Character.toUpperCase(n1[j]);
+			}
+		}
+		final int suffixLen= suffix.length();
+		final IWorkspaceRoot root= ResourcesPlugin.getWorkspace().getRoot();
+		IFile[] result= null;
+		outer: for (int i = 0; i < candidates.length; i++) {
+			final Node node = candidates[i];
+			if (!node.fIsFolder) {
+				final char[] n2= node.fResourceName;
+				if (namelen == n2.length) {
+					for (int j = 0; j < n2.length; j++) {
+						final char c= ignoreCase ? Character.toUpperCase(n2[j]) : n2[j];
+						if (c != n1[j]) 
+							continue outer;
+					}
+					final IFile file= root.getFile(createPath(node));
+					final URI loc= file.getLocationURI();
+					if (loc != null) {
+						String path= loc.getPath();
+						final int len= path.length();
+						if (len >= suffixLen && 
+								suffix.regionMatches(ignoreCase, 0, path, len-suffixLen, suffixLen)) {
+							if (result == null) 
+								result= new IFile[candidates.length-i];
+							result[resultIdx++]= root.getFile(createPath(node));
+						} 
+					}
+				}
+			}
+		}
+		if (result==null)
+			return NO_FILES;
+		
+		if (resultIdx < result.length) {
+			IFile[] copy= new IFile[resultIdx];
+			System.arraycopy(result, 0, copy, 0, resultIdx);
+			return copy;
+		}
+		return result;
+	}
+
+	private IPath createPath(Node node) {
+		if (node == fRootNode)
+			return Path.ROOT;
+		
+		return createPath(node.fParent).append(new String(node.fResourceName));
+	}
+	
+	/**
+	 * Selects the actual matches from the list of candidates
+	 */
+	private IFile[] extractMatchesForLocation(Node[] candidates, URI location) {
+		final IWorkspaceRoot root= ResourcesPlugin.getWorkspace().getRoot();
+		final String searchPath= getCanonicalPath(location);
+		IFile[] result= null;
+		int resultIdx= 0;
+		for (int i = 0; i < candidates.length; i++) {
+			final Node node = candidates[i];
+			if (!node.fIsFolder) {
+				final IFile file= root.getFile(createPath(node));
+				final URI loc= file.getLocationURI();
+				if (loc != null) {
+					if (!loc.equals(location)) {
+						if (searchPath == null) 
+							continue;
+						
+						if (node.fCanonicHash != 0 && node.fCanonicHash != searchPath.hashCode())
+							continue;
+						
+						final String candPath= getCanonicalPath(loc);
+						if (candPath == null)
+							continue;
+						
+						node.fCanonicHash= candPath.hashCode();
+						if (!candPath.equals(searchPath))
+							continue;
+					}
+					if (result == null) 
+						result= new IFile[candidates.length-i];
+					result[resultIdx++]= root.getFile(createPath(node));
+				}
+			}
+		}
+		if (result==null)
+			return NO_FILES;
+		
+		if (resultIdx < result.length) {
+			IFile[] copy= new IFile[resultIdx];
+			System.arraycopy(result, 0, copy, 0, resultIdx);
+			return copy;
+		}
+		return result;
+	}
+
+	private String getCanonicalPath(URI location) {
+		if (!"file".equals(location.getScheme()))  //$NON-NLS-1$
+			return null;
+		
+		String path= location.getPath();
+		try {
+			path= new File(path).getCanonicalPath();
+		} catch (IOException e) {
+			// use non-canonical version
+		}
+		return path;
+	}
+
+
+
+	@SuppressWarnings("nls")
+	public void dump() {
+		List<String> lines= new ArrayList<String>();
+		synchronized (fLock) {
+			for (Iterator<Object> iterator = fNodeMap.values().iterator(); iterator.hasNext();) {
+				Node[] nodes= convert(iterator.next());	
+				for (int i = 0; i < nodes.length; i++) {
+					final Node node = nodes[i];
+					if (node == null) {
+						break;
+					}
+					lines.add(toString(node));
+				}
+			}
+		}
+		Collections.sort(lines);
+		System.out.println("Dumping files:");
+		for (Iterator<String> iterator = lines.iterator(); iterator.hasNext();) {
+			String line = iterator.next();
+			System.out.println(line);
+		}
+		System.out.flush();
+	}
+
+	@SuppressWarnings("nls")
+	private String toString(Node node) {
+		if (node == fRootNode)
+			return "";
+		
+		return toString(node.fParent) + "/" + new String(node.fResourceName);
+	}
+}

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/dialogs/AbstractIndexerPage.java

@@ -36,6 +36,7 @@ public abstract class AbstractIndexerPage extends AbstractCOptionPage {
 	protected static final String TRUE = String.valueOf(true);
 
 	private Button fAllFiles;
+	private Button fIncludeHeuristics;
 	private Text fFilesToParseUpFront;
 	private Button fSkipReferences;
 	private Button fSkipTypeReferences;
@@ -57,6 +58,7 @@ public abstract class AbstractIndexerPage extends AbstractCOptionPage {
 	public void createControl(Composite parent) {
 		Composite page = ControlFactory.createComposite(parent, 1);
 		fAllFiles= createAllFilesButton(page);
+		fIncludeHeuristics= createIncludeHeuristicsButton(page);
 		fSkipReferences= createSkipReferencesButton(page);
 		fSkipTypeReferences= createSkipTypeReferencesButton(page);
 		fSkipMacroReferences= createSkipMacroReferencesButton(page);
@@ -81,6 +83,11 @@ public abstract class AbstractIndexerPage extends AbstractCOptionPage {
 			boolean indexAllFiles= TRUE.equals(properties.get(IndexerPreferences.KEY_INDEX_ALL_FILES));
 			fAllFiles.setSelection(indexAllFiles);
 		}
+		if (fIncludeHeuristics != null) {
+			Object prop= properties.get(IndexerPreferences.KEY_INCLUDE_HEURISTICS);
+			boolean use= prop == null || TRUE.equals(prop);
+			fIncludeHeuristics.setSelection(use);
+		}
 		if (fSkipReferences != null) {
 			boolean skipReferences= TRUE.equals(properties.get(IndexerPreferences.KEY_SKIP_ALL_REFERENCES));
 			fSkipReferences.setSelection(skipReferences);
@@ -109,6 +116,9 @@ public abstract class AbstractIndexerPage extends AbstractCOptionPage {
 		if (fAllFiles != null) {
 			props.put(IndexerPreferences.KEY_INDEX_ALL_FILES, String.valueOf(fAllFiles.getSelection()));
 		}
+		if (fIncludeHeuristics != null) {
+			props.put(IndexerPreferences.KEY_INCLUDE_HEURISTICS, String.valueOf(fIncludeHeuristics.getSelection()));
+		}
 		if (fFilesToParseUpFront != null) {
 			props.put(IndexerPreferences.KEY_FILES_TO_PARSE_UP_FRONT, fFilesToParseUpFront.getText());
 		}
@@ -169,6 +179,10 @@ public abstract class AbstractIndexerPage extends AbstractCOptionPage {
 		return ControlFactory.createCheckBox(page, INDEX_ALL_FILES);
 	}
 
+	private Button createIncludeHeuristicsButton(Composite page) {
+		return ControlFactory.createCheckBox(page, DialogsMessages.AbstractIndexerPage_heuristicIncludes);
+	}
+
 	private Button createSkipReferencesButton(Composite page) {
 		return ControlFactory.createCheckBox(page, DialogsMessages.AbstractIndexerPage_skipAllReferences);
 	}

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/dialogs/DialogsMessages.java

@@ -16,6 +16,10 @@ import org.eclipse.osgi.util.NLS;
 
 public class DialogsMessages extends NLS {
 	private static final String BUNDLE_NAME = "org.eclipse.cdt.ui.dialogs.DialogsMessages"; //$NON-NLS-1$
+	/**
+	 * @since 5.1
+	 */
+	public static String AbstractIndexerPage_heuristicIncludes;
 	public static String AbstractIndexerPage_indexAllFiles;
 	public static String AbstractIndexerPage_indexUpFront;
 	public static String AbstractIndexerPage_skipAllReferences;

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/dialogs/DialogsMessages.properties

@@ -13,6 +13,7 @@
 PreferenceScopeBlock_enableProjectSettings=Enable project specific settings
 PreferenceScopeBlock_storeWithProject=Store settings with project
 PreferenceScopeBlock_preferenceLink=<a>Configure Workspace Settings...</a>
+AbstractIndexerPage_heuristicIncludes=Allow heuristic resolution of includes
 AbstractIndexerPage_indexAllFiles=Index all files (files neither built nor included, also)
 AbstractIndexerPage_skipAllReferences=Skip all references (Call Hierarchy and Search will not work)
 AbstractIndexerPage_skipTypeReferences=Skip type references (Search for type references will not work)