diff --git a/pom.xml b/pom.xml
index 0146de442..e4abd072c 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,8 +5,8 @@
     <modelVersion>4.0.0</modelVersion>
 
     <properties>
-        <maven.compiler.source>8</maven.compiler.source>
-        <maven.compiler.target>8</maven.compiler.target>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <argLine>-Xmx2048m</argLine>
     </properties>
@@ -47,24 +47,24 @@
         <dependency>
             <groupId>org.antlr</groupId>
             <artifactId>antlr4</artifactId>
-            <version>4.9.3</version>
+            <version>4.12.0</version>
             <scope>provided</scope>
         </dependency>
         <dependency>
             <groupId>org.antlr</groupId>
             <artifactId>antlr4-runtime</artifactId>
-            <version>4.9.3</version>
+            <version>4.12.0</version>
         </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>
-            <version>5.8.2</version>
+            <version>5.9.2</version>
             <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>info.picocli</groupId>
             <artifactId>picocli</artifactId>
-            <version>4.6.2</version>
+            <version>4.7.1</version>
         </dependency>
         <dependency>
             <groupId>javax.json</groupId>
@@ -124,7 +124,7 @@
             <plugin>
                 <groupId>org.antlr</groupId>
                 <artifactId>antlr4-maven-plugin</artifactId>
-                <version>4.9.3</version>
+                <version>4.12.0</version>
                 <executions>
                     <execution>
                         <id>antlr</id>
@@ -152,7 +152,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>3.0.0-M5</version>
+                <version>3.0.0-M9</version>
                 <configuration>
                     <excludes>
                         <exclude>**/TestFragments.java</exclude>
@@ -167,7 +167,7 @@
             <plugin>
                 <groupId>org.jacoco</groupId>
                 <artifactId>jacoco-maven-plugin</artifactId>
-                <version>0.8.7</version>
+                <version>0.8.9</version>
                 <executions>
                     <execution>
                         <id>pre-unit-test</id>
@@ -187,7 +187,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-jar-plugin</artifactId>
-                <version>3.2.0</version>
+                <version>3.3.0</version>
                 <configuration>
                     <archive>
                         <manifest>
@@ -201,7 +201,7 @@
             <plugin>
                 <groupId>org.apache.felix</groupId>
                 <artifactId>maven-bundle-plugin</artifactId>
-                <version>3.5.0</version>
+                <version>5.1.8</version>
                 <executions>
                     <execution>
                         <id>bundle-manifest</id>
@@ -214,7 +214,7 @@
             </plugin>
             <plugin>
                 <artifactId>maven-assembly-plugin</artifactId>
-                <version>3.3.0</version>
+                <version>3.5.0</version>
                 <configuration>
                     <finalName>kickc</finalName>
                     <tarLongFileMode>posix</tarLongFileMode>
diff --git a/src/main/java/dk/camelot64/kickc/model/statements/StatementPhiBlock.java b/src/main/java/dk/camelot64/kickc/model/statements/StatementPhiBlock.java
index 11cdbb587..bb1d018ee 100644
--- a/src/main/java/dk/camelot64/kickc/model/statements/StatementPhiBlock.java
+++ b/src/main/java/dk/camelot64/kickc/model/statements/StatementPhiBlock.java
@@ -1,13 +1,11 @@
 package dk.camelot64.kickc.model.statements;
 
 import dk.camelot64.kickc.model.Comment;
-import dk.camelot64.kickc.model.values.LabelRef;
 import dk.camelot64.kickc.model.Program;
+import dk.camelot64.kickc.model.values.LabelRef;
 import dk.camelot64.kickc.model.values.RValue;
 import dk.camelot64.kickc.model.values.VariableRef;
-import org.antlr.v4.runtime.RuleContext;
 
-import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -24,7 +22,7 @@ public class StatementPhiBlock extends StatementBase {
    private List<PhiVariable> phiVariables;
 
    public StatementPhiBlock(List<Comment> comments) {
-      super(new StatementSource(RuleContext.EMPTY), comments);
+      super(StatementSource.NONE, comments);
       this.phiVariables = new ArrayList<>();
    }
 
diff --git a/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java b/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
index 3f570bead..c8604b28d 100644
--- a/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
@@ -136,7 +136,7 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
          initProc.setParameters(new ArrayList<>());
          program.getScope().add(initProc);
          program.createProcedureCompilation(initProc.getRef());
-         program.getProcedureCompilation(initProc.getRef()).getStatementSequence().addStatement(new StatementProcedureBegin(initProc.getRef(), new StatementSource(RuleContext.EMPTY), Comment.NO_COMMENTS));
+         program.getProcedureCompilation(initProc.getRef()).getStatementSequence().addStatement(new StatementProcedureBegin(initProc.getRef(), StatementSource.NONE, Comment.NO_COMMENTS));
       }
       return initProc;
    }
@@ -180,9 +180,9 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
       if(initCompilation != null) {
          final StatementSequence initSequence = initCompilation.getStatementSequence();
          final Label initReturnLabel = program.getScope().getProcedure(initProcedureRef).addLabel(SymbolRef.PROCEXIT_BLOCK_NAME);
-         initSequence.addStatement(new StatementLabel(initReturnLabel.getRef(), new StatementSource(RuleContext.EMPTY), Comment.NO_COMMENTS));
-         initSequence.addStatement(new StatementReturn(null, new StatementSource(RuleContext.EMPTY), Comment.NO_COMMENTS));
-         initSequence.addStatement(new StatementProcedureEnd(initProcedureRef, new StatementSource(RuleContext.EMPTY), Comment.NO_COMMENTS));
+         initSequence.addStatement(new StatementLabel(initReturnLabel.getRef(), StatementSource.NONE, Comment.NO_COMMENTS));
+         initSequence.addStatement(new StatementReturn(null, StatementSource.NONE, Comment.NO_COMMENTS));
+         initSequence.addStatement(new StatementProcedureEnd(initProcedureRef, StatementSource.NONE, Comment.NO_COMMENTS));
       }
 
       // Add the _start() procedure to the program
@@ -193,16 +193,16 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
          program.getScope().add(startProcedure);
          final ProcedureCompilation startProcedureCompilation = program.createProcedureCompilation(startProcedure.getRef());
          final StatementSequence startSequence = startProcedureCompilation.getStatementSequence();
-         startSequence.addStatement(new StatementProcedureBegin(startProcedure.getRef(), new StatementSource(RuleContext.EMPTY), Comment.NO_COMMENTS));
+         startSequence.addStatement(new StatementProcedureBegin(startProcedure.getRef(), StatementSource.NONE, Comment.NO_COMMENTS));
          if(initCompilation != null)
-            startSequence.addStatement(new StatementCall(null, SymbolRef.INIT_PROC_NAME, new ArrayList<>(), new StatementSource(RuleContext.EMPTY), Comment.NO_COMMENTS));
+            startSequence.addStatement(new StatementCall(null, SymbolRef.INIT_PROC_NAME, new ArrayList<>(), StatementSource.NONE, Comment.NO_COMMENTS));
          final Procedure mainProc = program.getScope().getLocalProcedure(SymbolRef.MAIN_PROC_NAME);
          if(mainProc == null)
             throw new CompileError("Required main() not defined in program.");
          if(!SymbolType.VOID.equals(mainProc.getReturnType()) && !SymbolType.SWORD.equals(mainProc.getReturnType()))
             throw new CompileError("return of main() must be 'void' or of type 'int'.", mainProc.getDefinitionSource());
          if(mainProc.getParameterNames().size() == 0) {
-            startSequence.addStatement(new StatementCall(null, SymbolRef.MAIN_PROC_NAME, new ArrayList<>(), new StatementSource(RuleContext.EMPTY), Comment.NO_COMMENTS));
+            startSequence.addStatement(new StatementCall(null, SymbolRef.MAIN_PROC_NAME, new ArrayList<>(), StatementSource.NONE, Comment.NO_COMMENTS));
          } else if(mainProc.getParameterNames().size() == 2) {
             final List<Variable> parameters = mainProc.getParameters();
             final Variable argc = parameters.get(0);
@@ -214,15 +214,15 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
             final ArrayList<RValue> params = new ArrayList<>();
             params.add(new ConstantInteger(0L, SymbolType.SWORD));
             params.add(new ConstantPointer(0L, new SymbolTypePointer(SymbolType.BYTE)));
-            startSequence.addStatement(new StatementCall(null, SymbolRef.MAIN_PROC_NAME, params, new StatementSource(RuleContext.EMPTY), Comment.NO_COMMENTS));
+            startSequence.addStatement(new StatementCall(null, SymbolRef.MAIN_PROC_NAME, params, StatementSource.NONE, Comment.NO_COMMENTS));
          } else
             throw new CompileError("main() has wrong number of parameters. It must have zero or 2 parameters.", mainProc.getDefinitionSource());
 
 
          final Label startReturnLabel = startProcedure.addLabel(SymbolRef.PROCEXIT_BLOCK_NAME);
-         startSequence.addStatement(new StatementLabel(startReturnLabel.getRef(), new StatementSource(RuleContext.EMPTY), Comment.NO_COMMENTS));
-         startSequence.addStatement(new StatementReturn(null, new StatementSource(RuleContext.EMPTY), Comment.NO_COMMENTS));
-         startSequence.addStatement(new StatementProcedureEnd(startProcedure.getRef(), new StatementSource(RuleContext.EMPTY), Comment.NO_COMMENTS));
+         startSequence.addStatement(new StatementLabel(startReturnLabel.getRef(), StatementSource.NONE, Comment.NO_COMMENTS));
+         startSequence.addStatement(new StatementReturn(null, StatementSource.NONE, Comment.NO_COMMENTS));
+         startSequence.addStatement(new StatementProcedureEnd(startProcedure.getRef(), StatementSource.NONE, Comment.NO_COMMENTS));
       }
 
    }
diff --git a/src/main/java/dk/camelot64/kickc/passes/Pass4RegistersFinalize.java b/src/main/java/dk/camelot64/kickc/passes/Pass4RegistersFinalize.java
index 545eb23e9..59c1a1480 100644
--- a/src/main/java/dk/camelot64/kickc/passes/Pass4RegistersFinalize.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass4RegistersFinalize.java
@@ -212,7 +212,7 @@ public class Pass4RegistersFinalize extends Pass2Base {
          reserved = false;
          int candidateZp = currentZp;
          for(int i=0;i<size;i++) {
-            if(reservedZp.contains(new Integer(candidateZp+i))) {
+            if(reservedZp.contains(Integer.valueOf(candidateZp+i))) {
                reserved = true;
                currentZp++;
                break;