Merge branch 'GP-0_ghidra1_EmptyAddressSetIterators' into patch

Ghidra/Features/Base/src/test.slow/java/ghidra/program/database/map/AddressKeyIteratorTest.java

@@ -115,7 +115,7 @@ public class AddressKeyIteratorTest extends AbstractGhidraHeadedIntegrationTest
 
 	@Test
 	public void testIterator0() throws Exception {
-		AddressKeyIterator it = new AddressKeyIterator();
+		AddressKeyIterator it = AddressKeyIterator.EMPTY_ITERATOR;
 		assertTrue(!it.hasNext());
 		assertTrue(!it.hasPrevious());
 		try {
@@ -123,12 +123,14 @@ public class AddressKeyIteratorTest extends AbstractGhidraHeadedIntegrationTest
 			Assert.fail();
 		}
 		catch (NoSuchElementException e) {
+			// expected
 		}
 		try {
 			it.previous();
 			Assert.fail();
 		}
 		catch (NoSuchElementException e) {
+			// expected
 		}
 	}
 

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/code/CodeManager.java

@@ -1174,6 +1174,9 @@ public class CodeManager implements ErrorHandler, ManagerDB {
 		if (addrSetView == null) {
 			addrSetView = program.getMemory();
 		}
+		else if (addrSetView.isEmpty()) {
+			return CodeUnitIterator.EMPTY_ITERATOR;
+		}
 
 		if (property.equals(CodeUnit.COMMENT_PROPERTY)) {
 			try {
@@ -1219,7 +1222,8 @@ public class CodeManager implements ErrorHandler, ManagerDB {
 	/**
 	 * Get a forward iterator over code units that have comments of the given type.
 	 * @param commentType comment type defined in CodeUnit
-	 * @param set address set
+	 * @param set address set (null for all defined memory)
+	 * @return code unit iterator
 	 */
 	public CodeUnitIterator getCommentCodeUnitIterator(int commentType, AddressSetView set) {
 		CodeUnitIterator it = getCodeUnitIterator(CodeUnit.COMMENT_PROPERTY, set, true);
@@ -1229,10 +1233,15 @@ public class CodeManager implements ErrorHandler, ManagerDB {
 	/**
 	 * Get a forward iterator over addresses that have comments of the given type.
 	 * @param commentType comment type defined in CodeUnit
-	 * @param set address set
+	 * @param set address set (null for all defined memory)
+	 * @param forward true to iterate in the direction of increasing addresses.
+	 * @return address iterator
 	 */
 	public AddressIterator getCommentAddressIterator(int commentType, AddressSetView set,
 			boolean forward) {
+		if (set != null && set.isEmpty()) {
+			return AddressIterator.EMPTY_ITERATOR;
+		}
 		try {
 			AddressKeyIterator keyIter = commentAdapter.getKeys(set, forward);
 			AddressIterator addrIter =
@@ -1251,6 +1260,9 @@ public class CodeManager implements ErrorHandler, ManagerDB {
 	 * @param forward true to iterate in the direction of increasing addresses.
 	 */
 	public AddressIterator getCommentAddressIterator(AddressSetView addrSet, boolean forward) {
+		if (addrSet != null && addrSet.isEmpty()) {
+			return AddressIterator.EMPTY_ITERATOR;
+		}
 		try {
 			AddressKeyIterator keyIter = commentAdapter.getKeys(addrSet, forward);
 			return new AddressKeyAddressIterator(keyIter, forward, addrMap, program);
@@ -1632,6 +1644,9 @@ public class CodeManager implements ErrorHandler, ManagerDB {
 				searchSet = new AddressSet(
 					initializedMemoryOnly ? mem.getLoadedAndInitializedAddressSet() : mem);
 			}
+			else if (set.isEmpty()) {
+				return set;
+			}
 			else {
 				searchSet = new AddressSet(set);
 				searchSet = searchSet.intersect(
@@ -1855,13 +1870,19 @@ public class CodeManager implements ErrorHandler, ManagerDB {
 	 * Returns the next undefined data whose min address falls within the address set
 	 * searching in the forward direction {@code (e.g., 0 -> 0xfff).}
 	 *
-	 * @param set the address set to look within.
+	 * @param set the address set to look within (required).
 	 * @param monitor the current monitor.
 	 * @return Data the first undefined data within the address set, or null if there is none.
 	 */
 	public Data getFirstUndefinedData(AddressSetView set, TaskMonitor monitor) {
+		if (set.isEmpty()) {
+			return null;
+		}
 		Memory mem = program.getMemory();
 		set = mem.intersect(set);
+		if (set.isEmpty()) {
+			return null;
+		}
 
 		int i = 0;
 		CodeUnitIterator it = getCodeUnits(set, true);
@@ -2172,8 +2193,7 @@ public class CodeManager implements ErrorHandler, ManagerDB {
 	private boolean exceedsLimitOn64BitAddressSegments(List<Address> longSegmentAddressList,
 			Address toAddr) {
 		long maskedOffset = toAddr.getOffset() & 0xffffffff00000000L;
-		for (int i = 0; i < longSegmentAddressList.size(); i++) {
-			Address address = longSegmentAddressList.get(i);
+		for (Address address : longSegmentAddressList) {
 			long offset = address.getOffset();
 			if ((offset & 0xffffffff00000000L) == maskedOffset) {
 				return false;
@@ -2419,6 +2439,7 @@ public class CodeManager implements ErrorHandler, ManagerDB {
 	 * @param forward if true the iterator returns all codeUnits from the given
 	 * start address to the end of the program, otherwise it returns all codeUnits
 	 * from the given start address to the start of the program.
+	 * @return code unit iterator
 	 */
 	public CodeUnitIterator getCodeUnits(Address start, boolean forward) {
 
@@ -2439,6 +2460,10 @@ public class CodeManager implements ErrorHandler, ManagerDB {
 			bounds = program.getAddressFactory().getAddressSet(min, start);
 		}
 
+		AddressSet set = mem.intersect(bounds);
+		if (set.isEmpty()) {
+			return CodeUnitIterator.EMPTY_ITERATOR;
+		}
 		return new CodeUnitRecordIterator(this, getInstructions(start, forward),
 			getDefinedData(start, forward), mem.intersect(bounds), forward);
 	}
@@ -2447,10 +2472,15 @@ public class CodeManager implements ErrorHandler, ManagerDB {
 	 * Returns an iterator over all codeUnits in the given addressSet. The iterator
 	 * will go from the lowest address to the largest or from the largest to the
 	 * lowest depending on the forward parameter.
+	 * @param set the memory address set over which code units should be iterated (required)
 	 * @param forward determines if the iterator goes from lowest address to highest
 	 * or the other way around.
+	 * @return code unit iterator
 	 */
 	public CodeUnitIterator getCodeUnits(AddressSetView set, boolean forward) {
+		if (set.isEmpty()) {
+			return CodeUnitIterator.EMPTY_ITERATOR;
+		}
 		return new CodeUnitRecordIterator(this, getInstructions(set, forward),
 			getDefinedData(set, forward), set, forward);
 	}
@@ -2677,9 +2707,8 @@ public class CodeManager implements ErrorHandler, ManagerDB {
 					}
 				}
 			}
-			for (int i = 0; i < addrs.size(); i++) {
+			for (Address addr : addrs) {
 				monitor.checkCanceled();
-				Address addr = addrs.get(i);
 				clearCodeUnits(addr, addr, false, monitor);
 			}
 		}

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/code/CodeUnitRecordIterator.java

@@ -1,6 +1,5 @@
 /* ###
  * IP: GHIDRA
- * REVIEWED: YES
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,11 +15,11 @@
  */
 package ghidra.program.database.code;
 
+import java.util.Iterator;
+
 import ghidra.program.model.address.*;
 import ghidra.program.model.listing.*;
 
-import java.util.Iterator;
-
 /**
  * Combines an Instruction iterator and Data iterator into a codeunit iterator
  */
@@ -42,7 +41,7 @@ class CodeUnitRecordIterator implements CodeUnitIterator {
 	 * @param codeMgr the code managaer
 	 * @param instIt the instruction iterator
 	 * @param dataIt the data iterator
-	 * @param set the address set
+	 * @param set the address set (required)
 	 * @param forward the iterator direction
 	 */
 	CodeUnitRecordIterator(CodeManager codeMgr, InstructionIterator instIt, DataIterator dataIt,

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/code/CommentsDBAdapter.java

@@ -235,7 +235,7 @@ abstract class CommentsDBAdapter {
 
 	/**
 	 * Returns an address key iterator over the given address set in the given direction.
-	 * @param addrSetView the set to iterator over.
+	 * @param addrSetView the set to iterator over (null for all defined memory).
 	 * @param forward the direction to iterate.
 	 */
 	abstract AddressKeyIterator getKeys(AddressSetView set, boolean forward) throws IOException;

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/map/AddressIndexKeyIterator.java

@@ -1,6 +1,5 @@
 /* ###
  * IP: GHIDRA
- * REVIEWED: YES
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,13 +15,12 @@
  */
 package ghidra.program.database.map;
 
-import ghidra.program.model.address.*;
-
 import java.io.IOException;
 import java.util.List;
 import java.util.NoSuchElementException;
 
 import db.*;
+import ghidra.program.model.address.*;
 
 /**
  * Iterator of indexed fields that are addresses. The longs returned are the address longs.
@@ -95,7 +93,7 @@ public class AddressIndexKeyIterator implements DBLongIterator {
 	 * @param addrMap the address map
 	 * @param absolute if true, only absolute memory address encodings are considered, otherwise 
 	 * only standard/relocatable address encodings are considered.
-	 * @param set the set of addresses to iterator over.
+	 * @param set the set of addresses to iterator over or null for all addresses.
 	 * @param atStart if true, iterates forward, otherwise iterates backwards.
 	 * @throws IOException if a database io error occurs.
 	 */
@@ -192,6 +190,7 @@ public class AddressIndexKeyIterator implements DBLongIterator {
 	/**
 	 * @see db.DBLongIterator#hasNext()
 	 */
+	@Override
 	public boolean hasNext() throws IOException {
 		if (it == null) {
 			return false;
@@ -217,6 +216,7 @@ public class AddressIndexKeyIterator implements DBLongIterator {
 	/**
 	 * @see db.DBLongIterator#hasPrevious()
 	 */
+	@Override
 	public boolean hasPrevious() throws IOException {
 		if (it == null) {
 			return false;
@@ -242,6 +242,7 @@ public class AddressIndexKeyIterator implements DBLongIterator {
 	/**
 	 * @see db.DBLongIterator#next()
 	 */
+	@Override
 	public long next() throws IOException {
 		if (hasNext()) {
 			return ((LongField) it.next()).getLongValue();
@@ -252,6 +253,7 @@ public class AddressIndexKeyIterator implements DBLongIterator {
 	/**
 	 * @see db.DBLongIterator#previous()
 	 */
+	@Override
 	public long previous() throws IOException {
 		if (hasPrevious()) {
 			return ((LongField) it.previous()).getLongValue();
@@ -262,6 +264,7 @@ public class AddressIndexKeyIterator implements DBLongIterator {
 	/**
 	 * @see db.DBLongIterator#delete()
 	 */
+	@Override
 	public boolean delete() throws IOException {
 		if (it != null) {
 			return it.delete();

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/map/AddressIndexPrimaryKeyIterator.java

@@ -93,7 +93,7 @@ public class AddressIndexPrimaryKeyIterator implements DBFieldIterator {
 	 * @param addrMap the address map
 	 * @param absolute if true, only absolute memory address encodings are considered, otherwise 
 	 * only standard/relocatable address encodings are considered.
-	 * @param set the set of addresses to iterator over.
+	 * @param set the set of addresses to iterator over or null for all addresses.
 	 * @param atStart if true, iterates forward, otherwise iterates backwards.
 	 * @throws IOException if a database io error occurs.
 	 */

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/map/AddressKeyAddressIterator.java

@@ -1,6 +1,5 @@
 /* ###
  * IP: GHIDRA
- * REVIEWED: YES
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,15 +15,14 @@
  */
 package ghidra.program.database.map;
 
-import ghidra.program.model.address.Address;
-import ghidra.program.model.address.AddressIterator;
-
 import java.io.IOException;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 
 import db.DBLongIterator;
 import db.util.ErrorHandler;
+import ghidra.program.model.address.Address;
+import ghidra.program.model.address.AddressIterator;
 
 /**
  * Converts an AddressKeyIterator or an addressKeyAddressIterator into an AddressIterator
@@ -39,6 +37,7 @@ public class AddressKeyAddressIterator implements AddressIterator {
 	/**
 	 * Constructor.
 	 * @param keyIter address key iterator, may be null.  All long values must decode properly with the specified addrMap.
+	 * @param forward true to iterate in the direction of increasing addresses.
 	 * @param addrMap address map
 	 * @param errHandler IO error handler (may be null)
 	 */

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/map/AddressKeyIterator.java

@@ -1,6 +1,5 @@
 /* ###
  * IP: GHIDRA
- * REVIEWED: YES
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,14 +15,13 @@
  */
 package ghidra.program.database.map;
 
-import ghidra.program.model.address.*;
-
 import java.io.IOException;
 import java.util.List;
 import java.util.NoSuchElementException;
 
 import db.DBLongIterator;
 import db.Table;
+import ghidra.program.model.address.*;
 
 /**
  * Iterator of primary keys that are addresses. The longs returned are the address longs.
@@ -31,6 +29,8 @@ import db.Table;
 
 public class AddressKeyIterator implements DBLongIterator {
 
+	public static final AddressKeyIterator EMPTY_ITERATOR = new AddressKeyIterator();
+
 	private Table table;
 
 	private List<KeyRange> keyRangeList;
@@ -40,7 +40,7 @@ public class AddressKeyIterator implements DBLongIterator {
 	/**
 	 * Constructs an empty iterator.
 	 */
-	public AddressKeyIterator() {
+	private AddressKeyIterator() {
 	}
 
 	/**
@@ -96,7 +96,7 @@ public class AddressKeyIterator implements DBLongIterator {
 	 * Memory addresses encoded as Absolute are not included.
 	 * @param table the database table key by addresses
 	 * @param addrMap the address map
-	 * @param set the address set to iterator over
+	 * @param set the address set to iterator over (may be null for all defined memory)
 	 * @param startAddr the address at which to position the iterator, can be null. The exact
 	 * position of the iterator depends on the before parameter.
 	 * @param before positions the iterator before the start address,otherwise after
@@ -115,7 +115,7 @@ public class AddressKeyIterator implements DBLongIterator {
 	 * @param addrMap the address map
 	 * @param absolute if true, only absolute memory address encodings are considered, otherwise 
 	 * only standard/relocatable address encodings are considered.
-	 * @param set the address set to iterator over
+	 * @param set the address set to iterator over or null for all addresses.
 	 * @param startAddr the address at which to position the iterator, can be null. The exact
 	 * position of the iterator depends on the before parameter.
 	 * @param before positions the iterator before the start address,otherwise after
@@ -180,6 +180,7 @@ public class AddressKeyIterator implements DBLongIterator {
 	/**
 	 * @see db.DBLongIterator#hasNext()
 	 */
+	@Override
 	public boolean hasNext() throws IOException {
 		if (it == null) {
 			return false;
@@ -203,6 +204,7 @@ public class AddressKeyIterator implements DBLongIterator {
 	/**
 	 * @see db.DBLongIterator#hasPrevious()
 	 */
+	@Override
 	public boolean hasPrevious() throws IOException {
 		if (it == null) {
 			return false;
@@ -226,6 +228,7 @@ public class AddressKeyIterator implements DBLongIterator {
 	/**
 	 * @see db.DBLongIterator#next()
 	 */
+	@Override
 	public long next() throws IOException {
 		if (hasNext()) {
 			return it.next();
@@ -236,6 +239,7 @@ public class AddressKeyIterator implements DBLongIterator {
 	/**
 	 * @see db.DBLongIterator#previous()
 	 */
+	@Override
 	public long previous() throws IOException {
 		if (hasPrevious()) {
 			return it.previous();
@@ -246,6 +250,7 @@ public class AddressKeyIterator implements DBLongIterator {
 	/**
 	 * @see db.DBLongIterator#delete()
 	 */
+	@Override
 	public boolean delete() throws IOException {
 		if (it != null) {
 			return it.delete();

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/map/AddressKeyRecordIterator.java

@@ -15,13 +15,12 @@
  */
 package ghidra.program.database.map;
 
-import ghidra.program.model.address.*;
-
 import java.io.IOException;
 import java.util.Iterator;
 import java.util.List;
 
 import db.*;
+import ghidra.program.model.address.*;
 
 /**
  * Returns a RecordIterator over records that are address keyed.  Various constructors allow
@@ -116,7 +115,7 @@ public class AddressKeyRecordIterator implements RecordIterator {
 	 * @param addrMap the address map
 	 * @param absolute if true, only absolute memory address encodings are considered, otherwise 
 	 * only standard/relocatable address encodings are considered.
-	 * @param set the address set to iterate over.
+	 * @param set the address set to iterate over or null for all addresses
 	 * @param startAddr the address at which to position the iterator.  The iterator will be positioned 
 	 * either before or after the start address depending on the before parameter. If this parameter
 	 * is null, then the iterator will start either before the min address or after the max address 
@@ -174,6 +173,7 @@ public class AddressKeyRecordIterator implements RecordIterator {
 	/**
 	 * @see db.RecordIterator#hasNext()
 	 */
+	@Override
 	public boolean hasNext() throws IOException {
 		if (it == null) {
 			return false;
@@ -197,6 +197,7 @@ public class AddressKeyRecordIterator implements RecordIterator {
 	/**
 	 * @see db.RecordIterator#hasPrevious()
 	 */
+	@Override
 	public boolean hasPrevious() throws IOException {
 		if (it == null) {
 			return false;
@@ -220,6 +221,7 @@ public class AddressKeyRecordIterator implements RecordIterator {
 	/**
 	 * @see db.RecordIterator#next()
 	 */
+	@Override
 	public DBRecord next() throws IOException {
 		if (hasNext()) {
 			return it.next();
@@ -230,6 +232,7 @@ public class AddressKeyRecordIterator implements RecordIterator {
 	/**
 	 * @see db.RecordIterator#previous()
 	 */
+	@Override
 	public DBRecord previous() throws IOException {
 		if (hasPrevious()) {
 			return it.previous();
@@ -240,6 +243,7 @@ public class AddressKeyRecordIterator implements RecordIterator {
 	/**
 	 * @see db.RecordIterator#delete()
 	 */
+	@Override
 	public boolean delete() throws IOException {
 		if (it != null) {
 			return it.delete();

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/map/AddressMap.java

@@ -65,7 +65,7 @@ public interface AddressMap {
 	/**
 	 * Search for addr within the "sorted" keyRangeList and return the index of the
 	 * keyRange which contains the specified addr.
-	 * @param keyRangeList
+	 * @param keyRangeList key range list to search
 	 * @param addr address or null
 	 * @return index of the keyRange within the keyRangeList which contains addr 
 	 * if it is contained in the list; otherwise, <code>(-(<i>insertion point</i>) - 1)</code>. 
@@ -100,7 +100,7 @@ public interface AddressMap {
 	 * Generates a properly ordered list of database key ranges for a
 	 * a specified address set.  If absolute encodings are requested, 
 	 * only memory addresses will be included.
-	 * @param set address set or null for all real address.
+	 * @param set address set or null for all addresses.  May not be null if <code>create</code> is true.
 	 * @param create true if a new keys may be generated, otherwise returned 
 	 * key-ranges will be limited to those already defined.
 	 * @return "sorted" list of KeyRange objects
@@ -113,12 +113,14 @@ public interface AddressMap {
 	 * "absoluteEncoding" method.  If the program's default address space is segmented (i.e., SegmentedAddressSpace).
 	 * the address returned will be always be normalized to defined segmented memory blocks if possible.
 	 * @param value the long value to convert to an address.
+	 * @return address decoded from long 
 	 */
 	public Address decodeAddress(long value);
 
 	/**
 	 * Returns the address factory associated with this map.
 	 * Null may be returned if map not associated with a specific address factory.
+	 * @return associated {@link AddressFactory} or null
 	 */
 	public AddressFactory getAddressFactory();
 
@@ -140,7 +142,7 @@ public interface AddressMap {
 	 * Generates a properly ordered list of database key ranges for a
 	 * a specified address set.  If absolute encodings are requested, 
 	 * only memory addresses will be included.
-	 * @param set address set or null for all real address.
+	 * @param set address set or null for all addresses.  May not be null if <code>create</code> is true.
 	 * @param absolute if true, absolute key encodings are returned, otherwise 
 	 * standard/relocatable address key encodings are returned.
 	 * @param create true if a new keys may be generated, otherwise returned 

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/properties/PropertyMapDB.java

@@ -434,7 +434,7 @@ public abstract class PropertyMapDB implements PropertyMap {
 
 	/**
 	 * Get an iterator over the long address keys which contain a property value.
-	 * @param set
+	 * @param set addresses over which to iterate (null indicates all defined memory regions)
 	 * @param atStart true if the iterator should be positioned at the start
 	 * of the range
 	 * @return long address iterator.
@@ -442,9 +442,8 @@ public abstract class PropertyMapDB implements PropertyMap {
 	 */
 	public AddressKeyIterator getAddressKeyIterator(AddressSetView set, boolean atStart)
 			throws IOException {
-
-		if (propertyTable == null) {
-			return new AddressKeyIterator();
+		if (propertyTable == null || (set != null && set.isEmpty())) {
+			return AddressKeyIterator.EMPTY_ITERATOR;
 		}
 		if (atStart) {
 			return new AddressKeyIterator(propertyTable, addrMap, set, set.getMinAddress(), true);
@@ -463,7 +462,7 @@ public abstract class PropertyMapDB implements PropertyMap {
 			throws IOException {
 
 		if (propertyTable == null) {
-			return new AddressKeyIterator();
+			return AddressKeyIterator.EMPTY_ITERATOR;
 		}
 		return new AddressKeyIterator(propertyTable, addrMap, start, before);
 	}
@@ -481,7 +480,7 @@ public abstract class PropertyMapDB implements PropertyMap {
 			throws IOException {
 
 		if (propertyTable == null) {
-			return new AddressKeyIterator();
+			return AddressKeyIterator.EMPTY_ITERATOR;
 		}
 		if (atStart) {
 			return new AddressKeyIterator(propertyTable, addrMap, start, end, start, true);
@@ -561,8 +560,8 @@ public abstract class PropertyMapDB implements PropertyMap {
 	 */
 	@Override
 	public AddressIterator getPropertyIterator(AddressSetView asv, boolean forward) {
-		if (propertyTable == null) {
-			return new EmptyAddressIterator();
+		if (propertyTable == null || (asv != null && asv.isEmpty())) {
+			return AddressIterator.EMPTY_ITERATOR;
 		}
 		AddressKeyIterator keyIter = null;
 		try {

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/references/ReferenceDBManager.java

@@ -946,6 +946,9 @@ public class ReferenceDBManager implements ReferenceManager, ManagerDB, ErrorHan
 	@Override
 	public AddressIterator getReferenceDestinationIterator(AddressSetView addrSet,
 			boolean forward) {
+		if (addrSet != null && addrSet.isEmpty()) {
+			return AddressIterator.EMPTY_ITERATOR;
+		}
 		try {
 			return toAdapter.getToIterator(addrSet, forward);
 		}
@@ -973,6 +976,9 @@ public class ReferenceDBManager implements ReferenceManager, ManagerDB, ErrorHan
 
 	@Override
 	public AddressIterator getReferenceSourceIterator(AddressSetView addrSet, boolean forward) {
+		if (addrSet != null && addrSet.isEmpty()) {
+			return AddressIterator.EMPTY_ITERATOR;
+		}
 		try {
 			return fromAdapter.getFromIterator(addrSet, forward);
 		}

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/symbol/AddressSetFilteredSymbolIterator.java

@@ -44,7 +44,7 @@ class AddressSetFilteredSymbolIterator implements SymbolIterator {
 	/**
 	 * Construct a new AddressSetFilteredSymbolIterator.
 	 * @param symbolMgr the symbol manager
-	 * @param set the address set to iterator over.
+	 * @param set the address set to iterator over (required).
 	 * @param query the query to use as a filter
 	 * @param forward the direction of the iterator.
 	 */

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/symbol/SymbolManager.java

@@ -1204,6 +1204,9 @@ public class SymbolManager implements SymbolTable, ManagerDB {
 
 	@Override
 	public SymbolIterator getPrimarySymbolIterator(AddressSetView set, boolean forward) {
+		if (set.isEmpty()) {
+			return SymbolIterator.EMPTY_ITERATOR;
+		}
 		Query query1 = new FieldMatchQuery(SymbolDatabaseAdapter.SYMBOL_DATA2_COL, new IntField(1));
 		Query query2 = new FieldMatchQuery(SymbolDatabaseAdapter.SYMBOL_TYPE_COL,
 			new ByteField(SymbolType.LABEL.getID()));
@@ -1216,6 +1219,9 @@ public class SymbolManager implements SymbolTable, ManagerDB {
 
 	@Override
 	public SymbolIterator getSymbols(AddressSetView set, SymbolType type, boolean forward) {
+		if (set.isEmpty()) {
+			return SymbolIterator.EMPTY_ITERATOR;
+		}
 		Query query =
 			new FieldMatchQuery(SymbolDatabaseAdapter.SYMBOL_TYPE_COL, new ByteField(type.getID()));
 		return new AddressSetFilteredSymbolIterator(this, set, query, forward);

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/address/AddressIterator.java

@@ -16,6 +16,7 @@
 package ghidra.program.model.address;
 
 import java.util.Iterator;
+import java.util.NoSuchElementException;
 
 import util.CollectionUtils;
 
@@ -30,20 +31,24 @@ import util.CollectionUtils;
  */
 
 public interface AddressIterator extends Iterator<Address>, Iterable<Address> {
-	/**
-	 * Get the next address.
-	 * 
-	 * @return the next address in the iteration.
-	 */
-	@Override
-	public Address next();
 
-	/**
-	 * Checks if there is a next address in the iteration.
-	 * 
-	 * @return true if there is a next address.
-	 */
+	public static final AddressIterator EMPTY_ITERATOR = new AddressIterator() {
+
 		@Override
-	public boolean hasNext();
+		public boolean hasNext() {
+			return false;
+		}
+
+		@Override
+		public Address next() {
+			throw new NoSuchElementException();
+		}
+
+		@Override
+		public Iterator<Address> iterator() {
+			return this;
+		}
+
+	};
 
 }

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/listing/CodeUnitIterator.java

@@ -26,14 +26,35 @@ import util.CollectionUtils;
  */
 public interface CodeUnitIterator extends Iterator<CodeUnit>, Iterable<CodeUnit> {
 
+	public static final CodeUnitIterator EMPTY_ITERATOR = new CodeUnitIterator() {
+
+		@Override
+		public boolean hasNext() {
+			return false;
+		}
+
+		@Override
+		public CodeUnit next() {
+			return null;
+		}
+
+		@Override
+		public Iterator<CodeUnit> iterator() {
+			return this;
+		}
+
+	};
+
 	/**
-	 * Returns true if the iteration has more elements.
+	 * Return true if there is a next CodeUnit.
 	 */
 	@Override
 	public boolean hasNext();
 
 	/**
-	 * Return the next code unit in the iteration.
+	 * Get the next CodeUnit or null if no more CodeUnits.
+	 * <P>NOTE: This deviates from the standard {@link Iterator} interface
+	 * by returning null instead of throwing an exception.
 	 */
 	@Override
 	public CodeUnit next();

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/listing/Listing.java

@@ -213,7 +213,7 @@ public interface Listing {
 	 * addresses are contained in the given address set will be returned by the
 	 * iterator.
 	 *
-	 * @param addrSet the AddressRangeSet to iterate over.
+	 * @param addrSet the AddressRangeSet to iterate over (required).
 	 * @param forward true means get iterator in forward direction
 	 * @return a CodeUnitIterator that is restricted to the give
 	 *         AddressRangeSet.

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/symbol/ReferenceManager.java

@@ -288,7 +288,7 @@ public interface ReferenceManager {
 	/**
 	 * Returns an iterator over all addresses that are the "From" address in a
 	 * reference, restricted by the given address set.
-	 * @param addrSet the set of address to restrict the iterator.
+	 * @param addrSet the set of address to restrict the iterator or null for all addresses.
 	 * @param forward true means to iterate in the forward direction
 	 */
 	public AddressIterator getReferenceSourceIterator(AddressSetView addrSet, boolean forward);
@@ -304,7 +304,7 @@ public interface ReferenceManager {
 	/**
 	 * Returns an iterator over all addresses that are the "To" address in a
 	 * memory reference, restricted by the given address set.
-	 * @param addrSet the set of address to restrict the iterator.
+	 * @param addrSet the set of address to restrict the iterator or null for all addresses.
 	 * @param forward true means to iterate in the forward direction
 	 */
 	public AddressIterator getReferenceDestinationIterator(AddressSetView addrSet, boolean forward);

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/symbol/SymbolIterator.java

@@ -25,13 +25,37 @@ import util.CollectionUtils;
  * @see CollectionUtils#asIterable
  */
 public interface SymbolIterator extends Iterator<Symbol>, Iterable<Symbol> {
+
+	public static final SymbolIterator EMPTY_ITERATOR = new SymbolIterator() {
+
+		@Override
+		public Iterator<Symbol> iterator() {
+			return this;
+		}
+
+		@Override
+		public Symbol next() {
+			return null;
+		}
+
+		@Override
+		public boolean hasNext() {
+			return false;
+		}
+	};
+
 	/**
 	 * Return true if there is a next symbol.
 	 */
+	@Override
 	public boolean hasNext();
 
 	/**
-	 * Get the next symbol.
+	 * Get the next symbol or null if no more symbols.
+	 * <P>NOTE: This deviates from the standard {@link Iterator} interface
+	 * by returning null instead of throwing an exception.
 	 */
+	@Override
 	public Symbol next();
+
 }

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/symbol/SymbolTable.java

@@ -420,7 +420,7 @@ public interface SymbolTable {
 
 	/**
 	 * Returns all the symbols of the given type within the given address set.
-	 * @param set the address set in which to look for symbols of the given type
+	 * @param set the address set in which to look for symbols of the given type (required).
 	 * @param type the SymbolType to look for.
 	 * @param forward the direction within the addressSet to search
 	 * @return symbol iterator
@@ -500,7 +500,7 @@ public interface SymbolTable {
 
 	/**
 	 * Get an iterator over symbols at addresses in the given addressSet
-	 * @param asv the set of address over which to iterate symbols.
+	 * @param asv the set of address over which to iterate symbols (required).
 	 * @param forward true means the iterator is in the forward direction
 	 * @return symbol iterator
 	 */