Always check overloader signature of name segment while comparing PDOMBinding fully qualified names

Signature checking was already implemented in pdomCompareTo for specific cases
PDOMFunction and PDOMCPPFunctionSpecialization, but trying to compare two PDOM
bindings where intermediate name seqments are a class template and related class
template specialization fails because DBname is the same.

Allow differentiating bindings in this case by always comparing signatures.
Clean up special cases since base method now would always compare signatures.

This fixes CppCallHierarcyTests.testTemplates() if base lookup in index is
perfomed by just "m" and results in both class template CT::m and CT<char>::m
which are now considered distinct PDOM bindings.

Author: i-garrison

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

@@ -395,6 +395,9 @@ private static int comparePDOMBindingQNs(PDOMBinding b0, PDOMBinding b1) {
 			do {
 				IString s0 = b0.getDBName(), s1 = b1.getDBName();
 				cmp = s0.compare(s1, true);
+				if (cmp == 0) {
+					cmp = compareSignatures(b0, b1);
+				}
 				if (cmp == 0) {
 					long l1 = b0.getLocalToFileRec();
 					long l2 = b1.getLocalToFileRec();
@@ -415,6 +418,23 @@ private static int comparePDOMBindingQNs(PDOMBinding b0, PDOMBinding b1) {
 		}
 	}
 
+	protected static int compareSignatures(PDOMBinding a, PDOMBinding b) {
+		try {
+			final IPDOMOverloader bo0 = a instanceof final IPDOMOverloader xa ? xa : null;
+			final IPDOMOverloader bo1 = b instanceof final IPDOMOverloader xb ? xb : null;
+			if (bo0 == null || bo1 == null) {
+				return bo0 == bo1 ? 0 : (bo0 == null ? -1 : 1);
+			} else {
+				int mySM = bo0.getSignatureHash();
+				int otherSM = bo1.getSignatureHash();
+				return mySM == otherSM ? 0 : mySM < otherSM ? -1 : 1;
+			}
+		} catch (CoreException e) {
+			CCorePlugin.log(e);
+		}
+		return 0;
+	}
+
 	/**
 	 * Compares two PDOMBinding objects in accordance with
 	 * {@link IIndexFragmentBindingComparator#compare(IIndexFragmentBinding, IIndexFragmentBinding)}

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

@@ -28,7 +28,6 @@
 import org.eclipse.cdt.internal.core.index.IndexCPPSignatureUtil;
 import org.eclipse.cdt.internal.core.pdom.db.Database;
 import org.eclipse.cdt.internal.core.pdom.dom.IPDOMOverloader;
-import org.eclipse.cdt.internal.core.pdom.dom.PDOMBinding;
 import org.eclipse.cdt.internal.core.pdom.dom.PDOMLinkage;
 import org.eclipse.cdt.internal.core.pdom.dom.PDOMNode;
 import org.eclipse.core.runtime.CoreException;
@@ -126,27 +125,6 @@ public ICPPTemplateArgument[] getTemplateArguments() {
 		}
 	}
 
-	@Override
-	public int pdomCompareTo(PDOMBinding other) {
-		int cmp = super.pdomCompareTo(other);
-		if (cmp == 0) {
-			if (other instanceof PDOMCPPClassTemplatePartialSpecialization) {
-				try {
-					PDOMCPPClassTemplatePartialSpecialization otherSpec = (PDOMCPPClassTemplatePartialSpecialization) other;
-					int mySM = getSignatureHash();
-					int otherSM = otherSpec.getSignatureHash();
-					return mySM == otherSM ? 0 : mySM < otherSM ? -1 : 1;
-				} catch (CoreException e) {
-					CCorePlugin.log("Comparison failure for " + getName(), e); //$NON-NLS-1$
-				}
-			} else {
-				assert false;
-				CCorePlugin.log(new AssertionError("Assertion failure for " + getName())); //$NON-NLS-1$
-			}
-		}
-		return cmp;
-	}
-
 	@Override
 	public boolean isSameType(IType type) {
 		if (type instanceof ITypedef) {

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

@@ -34,7 +34,6 @@
 import org.eclipse.cdt.internal.core.index.IndexCPPSignatureUtil;
 import org.eclipse.cdt.internal.core.pdom.db.Database;
 import org.eclipse.cdt.internal.core.pdom.dom.IPDOMOverloader;
-import org.eclipse.cdt.internal.core.pdom.dom.PDOMBinding;
 import org.eclipse.cdt.internal.core.pdom.dom.PDOMLinkage;
 import org.eclipse.cdt.internal.core.pdom.dom.PDOMNode;
 import org.eclipse.core.runtime.CoreException;
@@ -404,28 +403,6 @@ public Object clone() {
 		throw new UnsupportedOperationException();
 	}
 
-	@Override
-	public int pdomCompareTo(PDOMBinding other) {
-		int cmp = super.pdomCompareTo(other);
-		return cmp == 0 ? compareSignatures(this, other) : cmp;
-	}
-
-	protected static int compareSignatures(IPDOMOverloader a, Object b) {
-		if (b instanceof IPDOMOverloader) {
-			IPDOMOverloader bb = (IPDOMOverloader) b;
-			try {
-				int mySM = a.getSignatureHash();
-				int otherSM = bb.getSignatureHash();
-				return mySM == otherSM ? 0 : mySM < otherSM ? -1 : 1;
-			} catch (CoreException e) {
-				CCorePlugin.log(e);
-			}
-		} else {
-			assert false;
-		}
-		return 0;
-	}
-
 	@Override
 	public IType[] getExceptionSpecification() {
 		try {

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

@@ -309,12 +309,6 @@ public boolean isDeleted() {
 		return PDOMCPPAnnotations.isDeletedFunction(getAnnotations());
 	}
 
-	@Override
-	public int pdomCompareTo(PDOMBinding other) {
-		int cmp = super.pdomCompareTo(other);
-		return cmp == 0 ? PDOMCPPFunction.compareSignatures(this, other) : cmp;
-	}
-
 	@Override
 	public IType[] getExceptionSpecification() {
 		try {