Index distinct typedef from header file

GDB sources contain private portable regex implementation which provides own
regmatch_t typedef. If another project file references system regex.h which
provides regmatch_t typedef too, indexer would not adapt that binding and
instead reuse first one it encountered.

Later when that other file is parsed, attempt to resolve binding for ASTName
referring to regmatch_t would fail because found PDOM binding is reachable only
via private implementation header which is not included.

Fix this by adapting unique typedef name to make both typedefs availabe to
lookup procedure which will then filter by reachable index fragment.

Author: i-garrison

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

@@ -202,8 +202,12 @@ private static boolean isPartOfSource(IASTNode decl) {
 	}
 
 	private static IASTNode resolveConflict(IASTNode n1, IASTNode n2) {
-		if (n1 == null)
+		if (n1 == n2) {
+			// No need to dig deeper
+			return n1;
+		} else if (n1 == null) {
 			return n2;
+		}
 
 		IASTFileLocation loc1 = n1.getFileLocation();
 		if (loc1 == null)

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

@@ -23,10 +23,12 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.TreeSet;
 import java.util.regex.Pattern;
 
 import org.eclipse.cdt.core.CCorePlugin;
@@ -46,11 +48,13 @@
 import org.eclipse.cdt.core.index.IIndexName;
 import org.eclipse.cdt.core.index.IndexFilter;
 import org.eclipse.cdt.core.parser.ISignificantMacros;
+import org.eclipse.cdt.core.parser.util.ArrayUtil;
 import org.eclipse.cdt.internal.core.dom.Linkage;
 import org.eclipse.cdt.internal.core.index.composite.CompositingNotImplementedError;
 import org.eclipse.cdt.internal.core.index.composite.ICompositesFactory;
 import org.eclipse.cdt.internal.core.index.composite.c.CCompositesFactory;
 import org.eclipse.cdt.internal.core.index.composite.cpp.CPPCompositesFactory;
+import org.eclipse.cdt.internal.core.pdom.dom.PDOMNode;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.NullProgressMonitor;
@@ -162,8 +166,65 @@ public IIndexBinding[] findMacroContainers(Pattern pattern, IndexFilter filter,
 		}
 	}
 
+	private static class BindingAndLocationComparator implements Comparator<IIndexName> {
+		@Override
+		public int compare(IIndexName f1, IIndexName f2) {
+			if (f1.equals(f2)) {
+				return 0;
+			}
+			try {
+				IIndexFile file1 = f1.getFile();
+				IIndexFile file2 = f2.getFile();
+				if (file1 != null && file2 != null) {
+					return file1.getLocation().getURI().compareTo(file2.getLocation().getURI());
+				}
+			} catch (CoreException e) {
+			}
+			return -1;
+		}
+	}
+
 	@Override
 	public IIndexName[] findNames(IBinding binding, int flags) throws CoreException {
+		ArrayList<IIndexName> result = new ArrayList<>();
+		PDOMNode pdomNode = binding.getAdapter(PDOMNode.class);
+		if (pdomNode instanceof final IIndexFragmentBinding foreignIndexFragmeintBinding
+				&& foreignIndexFragmeintBinding.isFileLocal()) {
+			// same name in header file included from multiple projects will have multiple
+			// distinct fragment bindings private to index fragments belonging to projects
+
+			// 1. extract all fragment bindings with same name from all index fragments
+
+			ILinkage linkage = foreignIndexFragmeintBinding.getLinkage();
+			IIndexFragmentBinding[][] allBindings = findAllBindingsForLinkage(linkage, binding.getNameCharArray(),
+					false, IndexFilter.ALL, new NullProgressMonitor());
+
+			// 2. pick ones comparing equal to search argument and get names for each
+
+			ICompositesFactory factory = getCompositesFactory(linkage.getLinkageID());
+			for (IIndexFragmentBinding[] parts : allBindings) {
+				if (parts == null) {
+					continue;
+				}
+				for (IIndexFragmentBinding part : parts) {
+					if (part == null) {
+						continue;
+					}
+					if (factory.compareCompositeBindings(foreignIndexFragmeintBinding, part) == 0) {
+						// found another fragment binding which looks like search argument
+						ArrayUtil.addAll(result, findNamesForBinding(part, flags));
+					}
+				}
+			}
+		} else {
+			ArrayUtil.addAll(result, findNamesForBinding(binding, flags));
+		}
+
+		// return all found names
+		return result.toArray(new IIndexName[result.size()]);
+	}
+
+	private IIndexName[] findNamesForBinding(IBinding binding, int flags) throws CoreException {
 		ArrayList<IIndexFragmentName> result = new ArrayList<>();
 		if (binding instanceof ICPPUsingDeclaration) {
 			IBinding[] bindings = ((ICPPUsingDeclaration) binding).getDelegates();
@@ -212,7 +273,16 @@ public IIndexName[] findNames(IBinding binding, int flags) throws CoreException
 
 	@Override
 	public IIndexName[] findDeclarations(IBinding binding) throws CoreException {
-		return findNames(binding, FIND_DECLARATIONS_DEFINITIONS);
+		IIndexName[] names = findNames(binding, FIND_DECLARATIONS_DEFINITIONS);
+
+		// callers expect single entry per file if it is included multiple times, deduplicate by file location
+
+		TreeSet<IIndexName> ts = new TreeSet<>(new BindingAndLocationComparator());
+		for (IIndexName name : names) {
+			ts.add(name);
+		}
+
+		return ts.toArray(new IIndexName[ts.size()]);
 	}
 
 	@Override
@@ -652,27 +722,35 @@ public IIndexBinding[] findBindings(char[] name, boolean filescope, IndexFilter
 			List<IIndexBinding[]> result = new ArrayList<>();
 			ILinkage[] linkages = Linkage.getIndexerLinkages();
 			for (ILinkage linkage : linkages) {
-				if (filter.acceptLinkage(linkage)) {
-					IIndexFragmentBinding[][] fragmentBindings = new IIndexFragmentBinding[fFragments.length][];
-					for (int i = 0; i < fFragments.length; i++) {
-						try {
-							IBinding[] part = fFragments[i].findBindings(name, filescope,
-									retargetFilter(linkage, filter), monitor);
-							fragmentBindings[i] = new IIndexFragmentBinding[part.length];
-							System.arraycopy(part, 0, fragmentBindings[i], 0, part.length);
-						} catch (CoreException e) {
-							CCorePlugin.log(e);
-							fragmentBindings[i] = IIndexFragmentBinding.EMPTY_INDEX_BINDING_ARRAY;
-						}
-					}
-					ICompositesFactory factory = getCompositesFactory(linkage.getLinkageID());
-					result.add(factory.getCompositeBindings(fragmentBindings));
-				}
+				IIndexFragmentBinding[][] fragmentBindings = findAllBindingsForLinkage(linkage, name, filescope, filter,
+						monitor);
+				ICompositesFactory factory = getCompositesFactory(linkage.getLinkageID());
+				result.add(factory.getCompositeBindings(fragmentBindings));
 			}
 			return flatten(result);
 		}
 	}
 
+	private IIndexFragmentBinding[][] findAllBindingsForLinkage(ILinkage linkage, char[] name, boolean filescope,
+			IndexFilter filter, IProgressMonitor monitor) throws CoreException {
+		if (!filter.acceptLinkage(linkage)) {
+			return new IIndexFragmentBinding[0][];
+		}
+
+		IIndexFragmentBinding[][] fragmentBindings = new IIndexFragmentBinding[fFragments.length][];
+		for (int i = 0; i < fFragments.length; i++) {
+			try {
+				IBinding[] part = fFragments[i].findBindings(name, filescope, retargetFilter(linkage, filter), monitor);
+				fragmentBindings[i] = new IIndexFragmentBinding[part.length];
+				System.arraycopy(part, 0, fragmentBindings[i], 0, part.length);
+			} catch (CoreException e) {
+				CCorePlugin.log(e);
+				fragmentBindings[i] = IIndexFragmentBinding.EMPTY_INDEX_BINDING_ARRAY;
+			}
+		}
+		return fragmentBindings;
+	}
+
 	@Override
 	public IIndexMacro[] findMacros(char[] name, IndexFilter filter, IProgressMonitor monitor) throws CoreException {
 		return findMacros(name, false, true, filter, monitor);

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/composite/AbstractCompositeFactory.java

@@ -104,6 +104,11 @@ protected IIndexFragmentBinding[] mergeBindingArrays(IIndexFragmentBinding[][] f
 		return ts.toArray(new IIndexFragmentBinding[ts.size()]);
 	}
 
+	@Override
+	public int compareCompositeBindings(IIndexFragmentBinding lhs, IIndexFragmentBinding rhs) {
+		return fragmentComparator.compare(lhs, rhs);
+	}
+
 	/**
 	 * Convenience method for finding a binding with a definition (in the specified index
 	 * context) which is equivalent to the specified binding. If no definition is found,

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/composite/ICompositesFactory.java

@@ -54,4 +54,12 @@ public interface ICompositesFactory {
 	 * Converts values.
 	 */
 	public IValue getCompositeValue(IValue v);
+
+	/**
+	 * Compares bindings
+	 * @param lhs
+	 * @param rhs
+	 * @return
+	 */
+	public int compareCompositeBindings(IIndexFragmentBinding lhs, IIndexFragmentBinding rhs);
 }

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

@@ -1343,6 +1343,11 @@ public IIndexFragmentInclude[] findIncludedBy(IIndexFragmentFile file) throws Co
 		return new PDOMInclude[0];
 	}
 
+	public boolean hasFileForLocation(int linkageId, IIndexFileLocation location) throws CoreException {
+		PDOMFile pdomFile = getFile(linkageId, location, null);
+		return pdomFile != null;
+	}
+
 	private PDOMFile adaptFile(IIndexFragmentFile file) throws CoreException {
 		if (file.getIndexFragment() == this && file instanceof PDOMFile) {
 			return (PDOMFile) file;

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/cpp/PDOMCPPLinkage.java

@@ -1300,7 +1300,10 @@ private final PDOMNode adaptOrAddParent(boolean add, IBinding binding) throws Co
 			IIndexBinding ib = (IIndexBinding) binding;
 			// Don't adapt file local bindings from other fragments to this one.
 			if (ib.isFileLocal()) {
-				return null;
+				if (!getPDOM().hasFileForLocation(ib.getLinkage().getLinkageID(), ib.getLocalToFile().getLocation())) {
+					// location not indexed here
+					return null;
+				}
 			}
 		}
 
@@ -1602,6 +1605,11 @@ protected PDOMFile getLocalToFile(IBinding binding, PDOMBinding glob) throws Cor
 				if (node != null) {
 					file = wpdom.getFileForASTNode(getLinkageID(), node);
 				}
+			} else if (binding instanceof ITypedef) {
+				IASTNode node = ASTInternal.getDeclaredInOneFileOnly(binding);
+				if (node != null) {
+					file = wpdom.getFileForASTNode(getLinkageID(), node);
+				}
 			} else if (binding instanceof ICPPNamespaceAlias) {
 				IASTNode node = ASTInternal.getDeclaredInSourceFileOnly(getPDOM(), binding, false, glob);
 				if (node != null) {
@@ -1610,6 +1618,7 @@ protected PDOMFile getLocalToFile(IBinding binding, PDOMBinding glob) throws Cor
 			}
 			if (file == null && !(binding instanceof IIndexBinding)) {
 				IBinding owner = binding.getOwner();
+				// TODO: maybe do the same for anonymous class type?
 				if (owner instanceof ICPPNamespace && owner.getNameCharArray().length == 0) {
 					IASTNode node = ASTInternal.getDefinitionOfBinding(binding);
 					if (node != null) {