GP-5480 Additinal improvement/fixes for ExternalLocation merge support

to address test failures.

Ghidra/Features/Base/src/main/java/ghidra/app/merge/listing/ExternalFunctionMerger.java

@@ -556,7 +556,7 @@ public class ExternalFunctionMerger extends AbstractFunctionMerger implements Li
 			Symbol originalSymbol = symbolTables[ORIGINAL].getSymbol(originalID);
 			Address originalAddress = originalSymbol.getAddress();
 			Symbol latestSymbol = SimpleDiffUtility.getMatchingExternalSymbol(programs[ORIGINAL],
-				originalSymbol, programs[LATEST], latestAddIDs);
+				originalSymbol, programs[LATEST], false, latestAddIDs);
 			if (latestSymbol != null) {
 				Address latestAddress = latestSymbol.getAddress();
 				// Check the external space addresses to ensure they are the same.
@@ -577,7 +577,7 @@ public class ExternalFunctionMerger extends AbstractFunctionMerger implements Li
 			Symbol originalSymbol = symbolTables[ORIGINAL].getSymbol(originalID);
 			Address originalAddress = originalSymbol.getAddress();
 			Symbol mySymbol = SimpleDiffUtility.getMatchingExternalSymbol(programs[ORIGINAL],
-				originalSymbol, programs[MY], myAddIDs);
+				originalSymbol, programs[MY], false, myAddIDs);
 			if (mySymbol != null) {
 				Address myAddress = mySymbol.getAddress();
 				// Check the external space addresses to ensure they are the same.
@@ -1560,7 +1560,7 @@ public class ExternalFunctionMerger extends AbstractFunctionMerger implements Li
 			// Get the external symbol in LATEST that we think most likely matches MY external.
 			// Only try to match it with externals that were also added in LATEST.
 			Symbol latestSymbol = SimpleDiffUtility.getMatchingExternalSymbol(programs[MY],
-				mySymbol, programs[LATEST], latestAddIDs);
+				mySymbol, programs[LATEST], false, latestAddIDs);
 			ExternalLocation latestExternalLocation = null;
 			if (latestSymbol != null) {
 				// We have a possible matching external from LATEST.
@@ -4045,7 +4045,7 @@ public class ExternalFunctionMerger extends AbstractFunctionMerger implements Li
 	 */
 	private void removeExternal(Program sourceProgram, ExternalLocation sourceExternalLocation) {
 		ExternalLocation resultExternalLocation = SimpleDiffUtility.getMatchingExternalLocation(
-			sourceProgram, sourceExternalLocation, programs[RESULT]);
+			sourceProgram, sourceExternalLocation, programs[RESULT], false);
 		if (resultExternalLocation == null) {
 			return;
 		}
@@ -4054,7 +4054,7 @@ public class ExternalFunctionMerger extends AbstractFunctionMerger implements Li
 			functionManagers[RESULT].removeFunction(externalSpaceAddress);
 			// See if the location is now just a label.
 			resultExternalLocation = SimpleDiffUtility.getMatchingExternalLocation(sourceProgram,
-				sourceExternalLocation, programs[RESULT]);
+				sourceExternalLocation, programs[RESULT], false);
 			if (resultExternalLocation == null) {
 				return;
 			}

Ghidra/Features/Base/src/main/java/ghidra/app/merge/listing/FunctionMerger.java

@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -212,12 +212,12 @@ class FunctionMerger extends AbstractFunctionMerger implements ListingMerger {
 	public void autoMerge(int progressMin, int progressMax, TaskMonitor monitor)
 			throws ProgramConflictException, MemoryAccessException, CancelledException {
 
-		latestResolvedDts = (Map<Long, DataType>) mergeManager.getResolveInformation(
+		latestResolvedDts = (Map<Long, DataType>) mergeManager
-			MergeConstants.RESOLVED_LATEST_DTS);
+				.getResolveInformation(MergeConstants.RESOLVED_LATEST_DTS);
-		myResolvedDts = (Map<Long, DataType>) mergeManager.getResolveInformation(
+		myResolvedDts = (Map<Long, DataType>) mergeManager
-			MergeConstants.RESOLVED_MY_DTS);
+				.getResolveInformation(MergeConstants.RESOLVED_MY_DTS);
-		origResolvedDts = (Map<Long, DataType>) mergeManager.getResolveInformation(
+		origResolvedDts = (Map<Long, DataType>) mergeManager
-			MergeConstants.RESOLVED_ORIGINAL_DTS);
+				.getResolveInformation(MergeConstants.RESOLVED_ORIGINAL_DTS);
 
 		initializeAutoMerge("Auto-merging Functions and determining conflicts.", progressMin,
 			progressMax, monitor);
@@ -450,8 +450,8 @@ class FunctionMerger extends AbstractFunctionMerger implements ListingMerger {
 						conflictingMyEntries.add(latestOnly.intersect(changeMy));
 						if (!conflictingMyEntries.isEmpty()) {
 							entryConflictSet.add(latestBody); // Add Latest function's body.
-							entryConflictSet.add(
+							entryConflictSet
-								getBodies(functionManagers[MY], conflictingMyEntries)); // Add My conflicting function bodies.
+									.add(getBodies(functionManagers[MY], conflictingMyEntries)); // Add My conflicting function bodies.
 						}
 						newEntries.add(conflictingMyEntries);
 					}
@@ -613,7 +613,7 @@ class FunctionMerger extends AbstractFunctionMerger implements ListingMerger {
 		Function myThunkedFunction = functions[MY].getThunkedFunction(false);
 		Address myThunkedEntry = myThunkedFunction.getEntryPoint();
 		Address myThunkedEntryAsLatest = SimpleDiffUtility.getCompatibleAddress(
-			functions[MY].getProgram(), myThunkedEntry, functions[LATEST].getProgram());
+			functions[MY].getProgram(), myThunkedEntry, functions[RESULT].getProgram());
 		if (!latestThunkedEntry.equals(myThunkedEntryAsLatest)) {
 			// Save the thunk conflict
 			saveThunkConflict(functions[RESULT]);
@@ -1065,10 +1065,8 @@ class FunctionMerger extends AbstractFunctionMerger implements ListingMerger {
 				mergeParamInfo(addr, paramInfoConflicts, parameterInfoChoice, monitor);
 			}
 			else if (askUser && mergeManager != null) {
-				Iterator<ParamInfoConflict> iter = paramInfoConflicts.iterator();
+				for (ParamInfoConflict pc : paramInfoConflicts) {
-				while (iter.hasNext()) {
 					monitor.checkCancelled();
-					ParamInfoConflict pc = iter.next();
 					boolean useForAll = (parameterInfoChoice != ASK_USER);
 					if (useForAll) {
 						mergeParamInfo(addr, pc, parameterInfoChoice, monitor);
@@ -1356,11 +1354,9 @@ class FunctionMerger extends AbstractFunctionMerger implements ListingMerger {
 
 	protected void mergeParameters(Address entryPtAddress, int chosenConflictOption,
 			TaskMonitor monitor) {
-		Function resultFunction =
+		Function resultFunction = listingMergeManager.mergeLatest.getResultProgram()
-			listingMergeManager.mergeLatest.getResultProgram()
+				.getFunctionManager()
-					.getFunctionManager()
+				.getFunctionAt(entryPtAddress);
-					.getFunctionAt(
-						entryPtAddress);
 		if (resultFunction == null) {
 			return;
 		}

Ghidra/Features/Base/src/main/java/ghidra/program/util/ProgramMerge.java

@@ -1317,7 +1317,7 @@ public class ProgramMerge {
 			Program fromPgm = fromExtLoc.getSymbol().getProgram();
 			Namespace toNamespace = DiffUtility.createNamespace(fromPgm, fromNamespace, toPgm);
 			ExternalLocation toExternalLocation =
-				SimpleDiffUtility.getMatchingExternalLocation(fromPgm, fromExtLoc, toPgm);
+				SimpleDiffUtility.getMatchingExternalLocation(fromPgm, fromExtLoc, toPgm, false);
 			if (toExternalLocation == null) {
 				toExtMgr.addExtLocation(toNamespace, fromExtLabel, fromExtAddr, fromSourceType);
 			}

Ghidra/Features/Base/src/test.slow/java/ghidra/app/merge/listing/ExternalMergerTest.java

@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -242,13 +242,16 @@ public class ExternalMergerTest extends AbstractExternalMergerTest {
 		});
 
 		executeMerge(ASK_USER);
-		chooseButtonAndApply("Resolve External Add Conflict", LATEST_BUTTON);// Add Conflict
+		// NOTE: Duplicate external program address is not treated as conflict, bot external
+		// locations will be added.
+		chooseButtonAndApply("Resolve Reference Conflict", LATEST_BUTTON);// Add Conflict
 		waitForMergeCompletion();
 
 		ExternalManager externalManager = resultProgram.getExternalManager();
 		ExternalLocation extLocApples =
 			externalManager.getUniqueExternalLocation("advapi32.dll", "apples");
-		assertNull(extLocApples);
+		assertNotNull(extLocApples);
+
 		ExternalLocation extLocOranges =
 			externalManager.getUniqueExternalLocation("advapi32.dll", "oranges");
 		assertNotNull(extLocOranges);
@@ -303,16 +306,19 @@ public class ExternalMergerTest extends AbstractExternalMergerTest {
 		});
 
 		executeMerge(ASK_USER);
-		chooseButtonAndApply("Resolve External Add Conflict", MY_BUTTON);// Add Conflict
+		// NOTE: Duplicate external program address is not treated as conflict, bot external
+		// locations will be added.
+		chooseButtonAndApply("Resolve Reference Conflict", MY_BUTTON);// Add Conflict
 		waitForMergeCompletion();
 
 		ExternalManager externalManager = resultProgram.getExternalManager();
 		ExternalLocation extLocApples =
 			externalManager.getUniqueExternalLocation("advapi32.dll", "apples");
 		assertNotNull(extLocApples);
+
 		ExternalLocation extLocOranges =
 			externalManager.getUniqueExternalLocation("advapi32.dll", "oranges");
-		assertNull(extLocOranges);
+		assertNotNull(extLocOranges);
 
 		ReferenceManager refMgr = resultProgram.getReferenceManager();
 		Reference[] refs;
@@ -1406,7 +1412,7 @@ public class ExternalMergerTest extends AbstractExternalMergerTest {
 	public void testExtLabelRefAddDiffAddressConflictPickMy() throws Exception {
 
 		mtf.initialize("NotepadMergeListingTest", new ProgramModifierListener() {
-			
+
 			@Override
 			public void modifyLatest(ProgramDB program) {
 				try {

Ghidra/Features/Base/src/test.slow/java/ghidra/app/merge/listing/FunctionMergerThunkTest.java

@@ -929,7 +929,9 @@ public class FunctionMergerThunkTest extends AbstractExternalMergerTest {
 		});
 
 		executeMerge(ASK_USER);
+		// Two diiferent external program addresses for the same external location (name match)
 		chooseButtonAndApply("Resolve External Add Conflict", KEEP_BOTH_BUTTON);
+		chooseButtonAndApply("Resolve Thunk Function Conflict", LATEST_BUTTON);
 		waitForMergeCompletion();
 
 		Function thunkFunction = getFunction(resultProgram, THUNK_A_ENTRY);

Ghidra/Features/Base/src/test.slow/java/ghidra/app/merge/listing/RefMergerExtTest.java

@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -147,7 +147,6 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 
 		mtf.initialize("NotepadMergeListingTest", new ProgramModifierListener() {
 
-
 			@Override
 			public void modifyLatest(ProgramDB program) {
 				try {
@@ -656,8 +655,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013cc"), 0);
 					assertEquals(0, refs.length);
 					refMgr.addExternalReference(addr(program, "0x10013cc"), "USER32.DLL", "printf",
-						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0,
+						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0, RefType.DATA);
-						RefType.DATA);
 
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013d8"), 0);
 					assertEquals(0, refs.length);
@@ -678,8 +676,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013cc"), 0);
 					assertEquals(0, refs.length);
 					refMgr.addExternalReference(addr(program, "0x10013cc"), "USER32.DLL", "printf",
-						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0,
+						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0, RefType.DATA);
-						RefType.DATA);
 
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013d8"), 0);
 					assertEquals(0, refs.length);
@@ -741,8 +738,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013cc"), 0);
 					assertEquals(0, refs.length);
 					refMgr.addExternalReference(addr(program, "0x10013cc"), "USER32.DLL", "printf",
-						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0,
+						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0, RefType.DATA);
-						RefType.DATA);
 
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013d8"), 0);
 					assertEquals(0, refs.length);
@@ -828,8 +824,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013cc"), 0);
 					assertEquals(0, refs.length);
 					refMgr.addExternalReference(addr(program, "0x10013cc"), "USER32.DLL", "printf",
-						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0,
+						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0, RefType.DATA);
-						RefType.DATA);
 
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013d8"), 0);
 					assertEquals(0, refs.length);
@@ -913,8 +908,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013cc"), 0);
 					assertEquals(0, refs.length);
 					refMgr.addExternalReference(addr(program, "0x10013cc"), "USER32.DLL", "printf",
-						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0,
+						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0, RefType.DATA);
-						RefType.DATA);
 
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013d8"), 0);
 					assertEquals(0, refs.length);
@@ -949,7 +943,8 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 		});
 
 		executeMerge(ASK_USER);
-		chooseButtonAndApply("Resolve External Add Conflict", LATEST_BUTTON);
+		// The two external locations are not in conflict and can both exist
+		chooseButtonAndApply("Resolve Reference Conflict", LATEST_BUTTON);
 		waitForMergeCompletion();
 
 		ReferenceManager refMgr = resultProgram.getReferenceManager();
@@ -999,8 +994,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013cc"), 0);
 					assertEquals(0, refs.length);
 					refMgr.addExternalReference(addr(program, "0x10013cc"), "USER32.DLL", "printf",
-						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0,
+						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0, RefType.DATA);
-						RefType.DATA);
 
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013d8"), 0);
 					assertEquals(0, refs.length);
@@ -1035,7 +1029,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 		});
 
 		executeMerge(ASK_USER);
-		chooseButtonAndApply("Resolve External Add Conflict", MY_BUTTON);
+		chooseButtonAndApply("Resolve Reference Conflict", MY_BUTTON);
 		waitForMergeCompletion();
 
 		ReferenceManager refMgr = resultProgram.getReferenceManager();
@@ -1084,8 +1078,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013cc"), 0);
 					assertEquals(0, refs.length);
 					refMgr.addExternalReference(addr(program, "0x10013cc"), "USER32.DLL", "printf",
-						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0,
+						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0, RefType.DATA);
-						RefType.DATA);
 
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013d8"), 0);
 					assertEquals(0, refs.length);
@@ -1130,7 +1123,6 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 		});
 
 		executeMerge(ASK_USER);
-		chooseButtonAndApply("Resolve External Add Conflict", KEEP_BOTH_BUTTON);
 		chooseRadioButton("Resolve Reference Conflict", LATEST_BUTTON);// Since kept both, now choose reference conflict.
 		waitForMergeCompletion();
 
@@ -1188,8 +1180,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013cc"), 0);
 					assertEquals(0, refs.length);
 					refMgr.addExternalReference(addr(program, "0x10013cc"), "USER32.DLL", "printf",
-						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0,
+						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0, RefType.DATA);
-						RefType.DATA);
 
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013d8"), 0);
 					assertEquals(0, refs.length);
@@ -1234,7 +1225,6 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 		});
 
 		executeMerge(ASK_USER);
-		chooseButtonAndApply("Resolve External Add Conflict", KEEP_BOTH_BUTTON);
 		chooseRadioButton("Resolve Reference Conflict", MY_BUTTON);// Since kept both, now choose reference conflict.
 		waitForMergeCompletion();
 
@@ -1280,8 +1270,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013cc"), 0);
 					assertEquals(0, refs.length);
 					refMgr.addExternalReference(addr(program, "0x10013cc"), "USER32.DLL", "printf",
-						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0,
+						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0, RefType.DATA);
-						RefType.DATA);
 
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013d8"), 0);
 					assertEquals(0, refs.length);
@@ -1316,9 +1305,10 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 		});
 
 		executeMerge(ASK_USER);
-		chooseButtonAndApply("Resolve External Add Conflict", MERGE_BOTH_BUTTON);
+		chooseButtonAndApply("Resolve Reference Conflict", MY_BUTTON);
-		chooseVariousOptionsForConflictType("Resolve External Detail Conflict",
+		// NOTE: Locations are not considered conflicts since both get added
-			new int[] { INFO_ROW, KEEP_LATEST, KEEP_MY });// Namespace, Name
+//		chooseVariousOptionsForConflictType("Resolve External Detail Conflict",
+//			new int[] { INFO_ROW, KEEP_LATEST, KEEP_MY });// Namespace, Name
 		waitForMergeCompletion();
 
 		ReferenceManager refMgr = resultProgram.getReferenceManager();
@@ -1333,11 +1323,10 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 
 		refs = refMgr.getReferencesFrom(addr("0x10013d8"), -1);
 		assertEquals(1, refs.length);
-		assertEquals("ADVAPI32.DLL::getName",
+		assertEquals("USER32.DLL::getName",
 			((ExternalReference) refs[0]).getExternalLocation().toString());
-		assertEquals("77db2233",
+		assertNull(((ExternalReference) refs[0]).getExternalLocation().getAddress());
-			((ExternalReference) refs[0]).getExternalLocation().getAddress().toString());
+		assertEquals(SourceType.USER_DEFINED, refs[0].getSource());
-		assertEquals(SourceType.DEFAULT, refs[0].getSource());
 	}
 
 	@Test
@@ -1357,8 +1346,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013cc"), 0);
 					assertEquals(0, refs.length);
 					refMgr.addExternalReference(addr(program, "0x10013cc"), "USER32.DLL", "printf",
-						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0,
+						addr(program, "0x01234567"), SourceType.USER_DEFINED, 0, RefType.DATA);
-						RefType.DATA);
 
 					refs = refMgr.getReferencesFrom(addr(program, "0x10013d8"), 0);
 					assertEquals(0, refs.length);
@@ -1393,9 +1381,10 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 		});
 
 		executeMerge(ASK_USER);
-		chooseButtonAndApply("Resolve External Add Conflict", MERGE_BOTH_BUTTON);
+		// NOTE: Locations are not considered conflicts since both get added
-		chooseVariousOptionsForConflictType("Resolve External Detail Conflict",
+		chooseButtonAndApply("Resolve Reference Conflict", LATEST_BUTTON);
-			new int[] { INFO_ROW, KEEP_MY, KEEP_LATEST });// Namespace, Name
+//		chooseVariousOptionsForConflictType("Resolve External Detail Conflict",
+//			new int[] { INFO_ROW, KEEP_MY, KEEP_LATEST });// Namespace, Name
 		waitForMergeCompletion();
 
 		ReferenceManager refMgr = resultProgram.getReferenceManager();
@@ -1410,7 +1399,7 @@ public class RefMergerExtTest extends AbstractExternalMergerTest {
 
 		refs = refMgr.getReferencesFrom(addr("0x10013d8"), -1);
 		assertEquals(1, refs.length);
-		assertEquals("USER32.DLL::EXT_77db2233",
+		assertEquals("ADVAPI32.DLL::EXT_77db2233",
 			((ExternalReference) refs[0]).getExternalLocation().toString());
 		assertEquals("77db2233",
 			((ExternalReference) refs[0]).getExternalLocation().getAddress().toString());

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/util/SimpleDiffUtility.java

@@ -190,7 +190,14 @@ public class SimpleDiffUtility {
 
 	/**
 	 * Convert an address from the specified program to a comparable address in the
-	 * specified otherProgram.
+	 * specified otherProgram.  
+	 * <br>
+	 * For external locations the match-up is very fuzzy and
+	 * will use correlated references.  If an exact match is required for an external location
+	 * the {@link #getMatchingExternalLocation(Program, ExternalLocation, Program, boolean)} or 
+	 * {@link #getMatchingExternalSymbol(Program, Symbol, Program, boolean, Set)} should be used 
+	 * directly.
+	 * 
 	 * @param program program which contains the specified address instance
 	 * @param addr address in program
 	 * @param otherProgram other program
@@ -250,7 +257,7 @@ public class SimpleDiffUtility {
 		else if (addr.isExternalAddress()) {
 			Symbol s = program.getSymbolTable().getPrimarySymbol(addr);
 			if (s != null && s.isExternal()) {
-				s = getMatchingExternalSymbol(program, s, otherProgram, null);
+				s = getMatchingExternalSymbol(program, s, otherProgram, true, null);
 				if (s != null) {
 					return s.getAddress();
 				}
@@ -314,6 +321,10 @@ public class SimpleDiffUtility {
 	/**
 	 * Given a symbol for a specified program, get the corresponding symbol from the
 	 * specified otherProgram.
+	 * <br>
+	 * In the case of external locations this performs an exact match based upon symbol name, 
+	 * namespace and symbol type.
+	 * 
 	 * @param symbol symbol to look for
 	 * @param otherProgram other program
 	 * @return corresponding symbol for otherProgram or null if no such symbol exists.
@@ -405,6 +416,12 @@ public class SimpleDiffUtility {
 
 		ExternalLocation external = getExternalLocation(symbol);
 
+		// TODO: This match-up is exact based upon name and namespace and does not consider 
+		// the original imported name or address, however these attributes must match. 
+
+		// TODO: It is rather confusing to have two sets of methods for finding external
+		// locations.  This should be simplified.  getOther... getMatchingExternal...
+
 		SymbolTable otherSymbolTable = otherProgram.getSymbolTable();
 		List<Symbol> otherSymbols = otherSymbolTable.getSymbols(symbol.getName(), otherNamespace);
 
@@ -595,16 +612,24 @@ public class SimpleDiffUtility {
 	/**
 	 * Given an external symbol for a specified program, get the corresponding symbol,
 	 * which has the same name and path,  from the specified otherProgram.<br>
-	 * Note: The type of the returned symbol may be different than the type of the symbol
+	 * Note: In The type of the returned symbol may be different than the type of the symbol
+	 * (i.e., Function vs Label).
 	 * @param program program which contains the specified symbol instance
 	 * @param symbol symbol to look for
 	 * @param otherProgram other program
+	 * @param allowInferredMatch if true an inferred match may be performed using reference
+	 * correlation (NOTE: reference correlation is only possible if the exact same binary
+	 * is in use).  This option is ignored if the two programs do not have the same 
+	 * original binary hash. 
 	 * @param otherRestrictedSymbolIds an optional set of symbol ID's from the other program
 	 * which will be treated as the exclusive set of candidate symbols to consider.
 	 * @return corresponding external symbol for otherProgram or null if no such symbol exists.
 	 */
 	public static Symbol getMatchingExternalSymbol(Program program, Symbol symbol,
-			Program otherProgram, Set<Long> otherRestrictedSymbolIds) {
+			Program otherProgram, boolean allowInferredMatch, Set<Long> otherRestrictedSymbolIds) {
+
+		// TODO: It is rather confusing to have two sets of methods for finding external
+		// locations.  This should be simplified.  getOther... getMatchingExternal...
 
 		if (symbol == null) {
 			return null;
@@ -614,7 +639,13 @@ public class SimpleDiffUtility {
 			return null;
 		}
 
-		ReferenceManager refMgr = program.getReferenceManager();
+		if (allowInferredMatch) {
+			// Inferred reference-based match only valid for the same program (i.e., multi-user merge)
+			if (program.getUniqueProgramID() != otherProgram.getUniqueProgramID()) {
+				allowInferredMatch = false;
+			}
+		}
+
 		ExternalManager extMgr = program.getExternalManager();
 		ExternalLocation extLoc = extMgr.getExternalLocation(symbol);
 
@@ -626,80 +657,111 @@ public class SimpleDiffUtility {
 		}
 		Address targetAddr = extLoc.getAddress();
 
-		ReferenceManager otherRefMgr = otherProgram.getReferenceManager();
 		SymbolTable otherSymbMgr = otherProgram.getSymbolTable();
 		ExternalManager otherExtMgr = otherProgram.getExternalManager();
 
-		// Process references
-		ReferenceIterator refIter = refMgr.getReferencesTo(symbol.getAddress());
 		HashMap<Address, ExternalReferenceCount> matchesMap = new HashMap<>();
-		int totalMatchCnt = 0;
+
-		while (refIter.hasNext()) {
+		// Search by name
-			Reference ref = refIter.next();
+		if (symbol.getSource() != SourceType.DEFAULT) {
-			Reference otherRef =
+
-				otherRefMgr.getPrimaryReferenceFrom(ref.getFromAddress(), ref.getOperandIndex());
+			// TODO: Need to improve support for lookup based upon other fields
-			if (otherRef == null || !otherRef.isExternalReference()) {
+			// Need separate Symbol DB indexing of ExternalLocation fields (address,originalImportName)
-				continue;
+
-			}
+			Symbol otherParent = getSymbol(symbol.getParentSymbol(), otherProgram);
-			Address otherExtAddr = otherRef.getToAddress();
+			if (otherParent != null) {
-			ExternalReferenceCount refMatch = matchesMap.get(otherExtAddr);
+				SymbolIterator symbols =
-			if (refMatch == null) {
+					otherProgram.getSymbolTable().getExternalSymbols(symbol.getName());
-				Symbol otherSym = otherSymbMgr.getPrimarySymbol(otherExtAddr);
+				for (Symbol otherSym : symbols) {
-				if (otherRestrictedSymbolIds != null &&
+					ExternalLocation otherExtLoc = otherExtMgr.getExternalLocation(otherSym);
-					!otherRestrictedSymbolIds.contains(otherSym.getID())) {
+					if (otherExtLoc != null) {
-					continue;
+						ExternalMatchType matchType = testExternalMatch(otherExtLoc, extLoc);
+						if (matchType == ExternalMatchType.NONE) {
+							continue;
+						}
+						ExternalReferenceCount refMatch =
+							new ExternalReferenceCount(otherExtLoc, matchType);
+						refMatch.setRelativeRank(targetAddr, targetNamespace, targetName,
+							targetOrigImportedName);
+						matchesMap.put(otherSym.getAddress(), refMatch);
+					}
 				}
-				ExternalLocation otherExtLoc = otherExtMgr.getExternalLocation(otherSym);
-				ExternalMatchType matchType = testExternalMatch(otherExtLoc, extLoc);
-				refMatch = new ExternalReferenceCount(otherExtLoc, matchType);
-				if (matchType != ExternalMatchType.NONE) {
-					refMatch.setRelativeRank(targetAddr, targetNamespace, targetName,
-						targetOrigImportedName);
-				}
-				matchesMap.put(otherExtAddr, refMatch);
-			}
-			else {
-				++refMatch.refCount;
-			}
-			if (++totalMatchCnt == 20) {
-				break;
 			}
 		}
 
-		// Process thunk-references (include all)
+		if (allowInferredMatch && matchesMap.isEmpty()) {
-		if (extLoc.isFunction()) {
+			// Process references
-			Address[] thunkAddrs = extLoc.getFunction().getFunctionThunkAddresses();
+			ReferenceManager refMgr = program.getReferenceManager();
-			if (thunkAddrs != null) {
+			ReferenceManager otherRefMgr = otherProgram.getReferenceManager();
-				for (Address thunkAddr : thunkAddrs) {
+			ReferenceIterator refIter = refMgr.getReferencesTo(symbol.getAddress());
-					Symbol otherThunkSym = otherSymbMgr.getPrimarySymbol(thunkAddr);
+			int totalMatchCnt = 0;
-					if (otherThunkSym == null ||
+			while (refIter.hasNext()) {
-						otherThunkSym.getSymbolType() != SymbolType.FUNCTION) {
+				Reference ref = refIter.next();
+				Reference otherRef = otherRefMgr.getPrimaryReferenceFrom(ref.getFromAddress(),
+					ref.getOperandIndex());
+				if (otherRef == null || !otherRef.isExternalReference()) {
+					continue;
+				}
+				Address otherExtAddr = otherRef.getToAddress();
+				ExternalReferenceCount refMatch = matchesMap.get(otherExtAddr);
+				if (refMatch == null) {
+					Symbol otherSym = otherSymbMgr.getPrimarySymbol(otherExtAddr);
+					if (otherRestrictedSymbolIds != null &&
+						!otherRestrictedSymbolIds.contains(otherSym.getID())) {
 						continue;
 					}
-					Function otherFunc = (Function) otherThunkSym.getObject();
+					ExternalLocation otherExtLoc = otherExtMgr.getExternalLocation(otherSym);
-					Function otherThunkedFunc = otherFunc.getThunkedFunction(false);
+					ExternalMatchType matchType = testExternalMatch(otherExtLoc, extLoc);
-					if (otherThunkedFunc == null || !otherThunkedFunc.isExternal()) {
+					refMatch = new ExternalReferenceCount(otherExtLoc, matchType);
-						continue;
+					if (matchType != ExternalMatchType.NONE) {
+						refMatch.setRelativeRank(targetAddr, targetNamespace, targetName,
+							targetOrigImportedName);
 					}
-					ExternalReferenceCount refMatch =
+					matchesMap.put(otherExtAddr, refMatch);
-						matchesMap.get(otherThunkedFunc.getEntryPoint());
+				}
-					if (refMatch == null) {
+				else {
-						if (otherRestrictedSymbolIds != null &&
+					++refMatch.refCount;
-							!otherRestrictedSymbolIds.contains(otherThunkedFunc.getID())) {
+				}
+				if (++totalMatchCnt == 20) {
+					break;
+				}
+			}
+
+			// Process thunk-references (include all)
+			if (extLoc.isFunction()) {
+				Address[] thunkAddrs = extLoc.getFunction().getFunctionThunkAddresses();
+				if (thunkAddrs != null) {
+					for (Address thunkAddr : thunkAddrs) {
+						Symbol otherThunkSym = otherSymbMgr.getPrimarySymbol(thunkAddr);
+						if (otherThunkSym == null ||
+							otherThunkSym.getSymbolType() != SymbolType.FUNCTION) {
 							continue;
 						}
-						ExternalLocation otherExtLoc =
+						Function otherFunc = (Function) otherThunkSym.getObject();
-							otherExtMgr.getExternalLocation(otherThunkedFunc.getSymbol());
+						Function otherThunkedFunc = otherFunc.getThunkedFunction(false);
-						ExternalMatchType matchType = testExternalMatch(otherExtLoc, extLoc);
+						if (otherThunkedFunc == null || !otherThunkedFunc.isExternal()) {
-						refMatch = new ExternalReferenceCount(otherExtLoc, matchType);
+							continue;
-						if (matchType != ExternalMatchType.NONE) {
+						}
-							refMatch.setRelativeRank(targetAddr, targetNamespace, targetName,
+						ExternalReferenceCount refMatch =
-								targetOrigImportedName);
+							matchesMap.get(otherThunkedFunc.getEntryPoint());
+						if (refMatch == null) {
+							if (otherRestrictedSymbolIds != null &&
+								!otherRestrictedSymbolIds.contains(otherThunkedFunc.getID())) {
+								continue;
+							}
+							ExternalLocation otherExtLoc =
+								otherExtMgr.getExternalLocation(otherThunkedFunc.getSymbol());
+							ExternalMatchType matchType = testExternalMatch(otherExtLoc, extLoc);
+							refMatch = new ExternalReferenceCount(otherExtLoc, matchType);
+							if (matchType != ExternalMatchType.NONE) {
+								refMatch.setRelativeRank(targetAddr, targetNamespace, targetName,
+									targetOrigImportedName);
+							}
+							matchesMap.put(otherThunkedFunc.getEntryPoint(), refMatch);
+						}
+						else {
+							++refMatch.refCount;
 						}
-						matchesMap.put(otherThunkedFunc.getEntryPoint(), refMatch);
-					}
-					else {
-						++refMatch.refCount;
 					}
 				}
 			}
@@ -751,10 +813,14 @@ public class SimpleDiffUtility {
 	 * @param program program which contains the specified external location instance
 	 * @param externalLocation external location to look for
 	 * @param otherProgram other program
+	 * @param allowInferredMatch if true an inferred match may be performed using reference
+	 * correlation.  NOTE: reference correlation is only possible if the exact same binary
+	 * is in use.  This option is ignored if the two programs do not have the same 
+	 * original binary hash and reference correlation will not be performed.
 	 * @return corresponding external location for otherProgram or null if no such external location exists.
 	 */
 	public static ExternalLocation getMatchingExternalLocation(Program program,
-			ExternalLocation externalLocation, Program otherProgram) {
+			ExternalLocation externalLocation, Program otherProgram, boolean allowInferredMatch) {
 		if (externalLocation == null) {
 			return null;
 		}
@@ -763,7 +829,7 @@ public class SimpleDiffUtility {
 			return null;
 		}
 		Symbol matchingExternalSymbol =
-			getMatchingExternalSymbol(program, symbol, otherProgram, null);
+			getMatchingExternalSymbol(program, symbol, otherProgram, allowInferredMatch, null);
 		if (matchingExternalSymbol == null) {
 			return null;
 		}