Merge pull request 'code-generator' (#8) from code-generator into main

Reviewed-on: #8
Reviewed-by: Johannes Ehlert <i22005@hb.dhbw-stuttgart.de>

src/main/java/CompilerInput.txt

@@ -5,9 +5,7 @@ public class Example {
     public static int testMethod(char b){
 
          int a;
-         boolean b;
+         int a;
-         char c;
-         b = 3;
 
 
     }

src/main/java/Main.java

@@ -1,3 +1,4 @@
+import ast.ASTNode;
 import ast.ClassNode;
 import ast.ProgramNode;
 import bytecode.ByteCodeGenerator;
@@ -17,14 +18,14 @@ public class Main {
     public static void main(String[] args) throws Exception {
         try {
             CharStream codeCharStream = CharStreams.fromPath(Paths.get("src/main/java/CompilerInput.txt"));
-            parsefile(codeCharStream);
+            parseFile(codeCharStream);
         } catch (IOException e) {
             System.err.println("Error reading the file: " + e.getMessage());
         }
     }
 
 
-    static void parsefile(CharStream codeCharStream){
+    static void parseFile(CharStream codeCharStream){
         SimpleJavaLexer lexer = new SimpleJavaLexer(codeCharStream);
         CommonTokenStream tokens = new CommonTokenStream(lexer);
         SimpleJavaParser parser = new SimpleJavaParser(tokens);
@@ -34,9 +35,9 @@ public class Main {
         ASTBuilder builder = new ASTBuilder();
         ProgramNode ast = (ProgramNode) builder.visit(tree); // build the AST
 
-        SemanticAnalyzer.generateTast(ast);
+        ProgramNode typedAst = (ProgramNode) SemanticAnalyzer.generateTast(ast);
 
         ByteCodeGenerator byteCodeGenerator = new ByteCodeGenerator();
-        byteCodeGenerator.visit(ast);
+        byteCodeGenerator.visit(typedAst);
     }
 }

src/main/java/ast/ClassNode.java

@@ -11,7 +11,7 @@ import java.util.List;
 import bytecode.visitor.ClassVisitor;
 import semantic.SemanticVisitor;
 import typechecker.TypeCheckResult;
-import typechecker.Visitable;
+import visitor.Visitable;
 
 public class ClassNode implements ASTNode, Visitable {
     public String identifier;

src/main/java/ast/LiteralNode.java

@@ -1,8 +1,10 @@
 package ast;
 
 import ast.expression.ExpressionNode;
+import semantic.SemanticVisitor;
+import typechecker.TypeCheckResult;
 
-public class LiteralNode extends ExpressionNode {
+public class LiteralNode implements ExpressionNode {
 
   int value;
   private String type;
@@ -20,4 +22,8 @@ public class LiteralNode extends ExpressionNode {
   }
 
 
+  @Override
+  public TypeCheckResult accept(SemanticVisitor visitor) {
+    return null;
+  }
 }

src/main/java/ast/ProgramNode.java

@@ -6,7 +6,7 @@ import java.util.List;
 import bytecode.visitor.ProgramVisitor;
 import semantic.SemanticVisitor;
 import typechecker.TypeCheckResult;
-import typechecker.Visitable;
+import visitor.Visitable;
 
 public class ProgramNode implements ASTNode, Visitable{
     public List<ClassNode> classes = new ArrayList<>();

src/main/java/ast/VarNode.java

@@ -1,6 +1,10 @@
 package ast;
 
-public class VarNode implements ASTNode{
+import semantic.SemanticVisitor;
+import typechecker.TypeCheckResult;
+import visitor.Visitable;
+
+public class VarNode implements ASTNode, Visitable {
 
   private String identifier;
   private String type;
@@ -18,4 +22,8 @@ public class VarNode implements ASTNode{
     return identifier;
   }
 
+  @Override
+  public TypeCheckResult accept(SemanticVisitor visitor) {
+    return visitor.analyze(this);
+  }
 }

src/main/java/ast/expression/BinaryExpressionNode.java

@@ -1,6 +1,10 @@
 package ast.expression;
 
-public class BinaryExpressionNode extends ExpressionNode {
+import semantic.SemanticVisitor;
+import typechecker.TypeCheckResult;
+import visitor.Visitable;
+
+public class BinaryExpressionNode implements ExpressionNode, Visitable {
     public ExpressionNode left;
     public ExpressionNode right;
     public String operator;  // Stores the operator as a string (e.g., "+", "-", "&&")
@@ -10,4 +14,9 @@ public class BinaryExpressionNode extends ExpressionNode {
         this.right = right;
         this.operator = operator;
     }
+
+    @Override
+    public TypeCheckResult accept(SemanticVisitor visitor) {
+        return visitor.analyze(this);
+    }
 }

src/main/java/ast/expression/ExpressionNode.java

@@ -1,9 +1,8 @@
 package ast.expression;
 
 import ast.ASTNode;
+import visitor.Visitable;
 
-public class ExpressionNode implements ASTNode {
+public interface ExpressionNode extends ASTNode, Visitable {
-
-
 
 }

src/main/java/ast/expression/IdentifierExpressionNode.java

@@ -1,9 +1,22 @@
 package ast.expression;
 
-public class IdentifierExpressionNode extends ExpressionNode {
+import ast.type.TypeNode;
+import semantic.SemanticVisitor;
+
+import typechecker.TypeCheckResult;
+import visitor.Visitable;
+
+public class IdentifierExpressionNode implements ExpressionNode, Visitable {
     public String name;
+    public TypeNode type;
+
 
     public IdentifierExpressionNode(String name) {
         this.name = name;
     }
+
+    @Override
+    public TypeCheckResult accept(SemanticVisitor visitor) {
+        return visitor.analyze(this);
+    }
 }

src/main/java/ast/expression/UnaryExpressionNode.java

@@ -1,6 +1,10 @@
 package ast.expression;
 
-public class UnaryExpressionNode extends ExpressionNode {
+import semantic.SemanticVisitor;
+import typechecker.TypeCheckResult;
+import visitor.Visitable;
+
+public class UnaryExpressionNode implements ExpressionNode, Visitable {
     public ExpressionNode expression;
     public String operator;  // Stores the operator (e.g., "-", "!")
 
@@ -8,4 +12,9 @@ public class UnaryExpressionNode extends ExpressionNode {
         this.expression = expression;
         this.operator = operator;
     }
+
+    @Override
+    public TypeCheckResult accept(SemanticVisitor visitor) {
+        return visitor.analyze(this);
+    }
 }

src/main/java/ast/member/ConstructorNode.java

@@ -2,7 +2,7 @@ package ast.member;
 
 import ast.type.AccessTypeNode;
 import bytecode.visitor.MethodVisitor;
-import typechecker.Visitable;
+import visitor.Visitable;
 
 public class ConstructorNode extends MethodNode implements Visitable {
     public ConstructorNode(AccessTypeNode visibility, String name) {

src/main/java/ast/member/FieldNode.java

@@ -5,7 +5,7 @@ import ast.type.TypeNode;
 import bytecode.visitor.ClassVisitor;
 import semantic.SemanticVisitor;
 import typechecker.TypeCheckResult;
-import typechecker.Visitable;
+import visitor.Visitable;
 
 public class FieldNode implements MemberNode, Visitable {
     public AccessTypeNode accessTypeNode;

src/main/java/ast/member/MethodNode.java

@@ -3,15 +3,15 @@ package ast.member;
 import ast.parameter.ParameterListNode;
 import ast.statement.StatementNode;
 import ast.type.AccessTypeNode;
-import ast.type.TypeNode;
 
 import java.util.ArrayList;
 import java.util.List;
 
+import ast.type.TypeNode;
 import bytecode.visitor.MethodVisitor;
 import semantic.SemanticVisitor;
 import typechecker.TypeCheckResult;
-import typechecker.Visitable;
+import visitor.Visitable;
 
 public class MethodNode implements MemberNode, Visitable {
     public AccessTypeNode visibility;

src/main/java/ast/parameter/ParameterListNode.java

@@ -6,7 +6,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 public class ParameterListNode implements ASTNode {
-    List<ParameterNode> parameters = new ArrayList<>();
+    public List<ParameterNode> parameters = new ArrayList<>();
 
     public ParameterListNode(List<ParameterNode> parameters){
         this.parameters = parameters;

src/main/java/ast/statement/AssignmentStatementNode.java

@@ -4,7 +4,7 @@ import ast.VarNode;
 import ast.expression.ExpressionNode;
 import semantic.SemanticVisitor;
 import typechecker.TypeCheckResult;
-import typechecker.Visitable;
+import visitor.Visitable;
 
 public class AssignmentStatementNode extends StatementNode implements Visitable {
   public VarNode varNode;

src/main/java/ast/statement/IfStatementNode.java

@@ -1,6 +1,8 @@
 package ast.statement;
 
 import ast.expression.ExpressionNode;
+import semantic.SemanticVisitor;
+import typechecker.TypeCheckResult;
 
 public class IfStatementNode extends StatementNode {
     public ExpressionNode condition;
@@ -12,4 +14,9 @@ public class IfStatementNode extends StatementNode {
         this.thenStatement = thenStatement;
         this.elseStatement = elseStatement;
     }
+
+    @Override
+    public TypeCheckResult accept(SemanticVisitor visitor) {
+        return visitor.analyze(this);
+    }
 }

src/main/java/ast/statement/ReturnStatementNode.java

@@ -1,6 +1,8 @@
 package ast.statement;
 
 import ast.expression.ExpressionNode;
+import semantic.SemanticVisitor;
+import typechecker.TypeCheckResult;
 
 public class ReturnStatementNode extends StatementNode {
     public ExpressionNode expression;
@@ -8,4 +10,9 @@ public class ReturnStatementNode extends StatementNode {
     public ReturnStatementNode(ExpressionNode expression) {
         this.expression = expression;
     }
+
+    @Override
+    public TypeCheckResult accept(SemanticVisitor visitor) {
+        return visitor.analyze(this);
+    }
 }

src/main/java/ast/statement/StatementNode.java

@@ -1,7 +1,8 @@
 package ast.statement;
 
 import ast.ASTNode;
+import visitor.Visitable;
 
-public abstract class StatementNode implements ASTNode {
+public abstract class StatementNode implements ASTNode, Visitable {
 }
 

src/main/java/ast/statement/VariableDeclarationStatementNode.java

@@ -1,7 +1,9 @@
 package ast.statement;
 
-import ast.type.TypeNode;
 import ast.expression.ExpressionNode;
+import ast.type.TypeNode;
+import semantic.SemanticVisitor;
+import typechecker.TypeCheckResult;
 
 public class VariableDeclarationStatementNode extends StatementNode {
     public TypeNode type;
@@ -12,4 +14,9 @@ public class VariableDeclarationStatementNode extends StatementNode {
         this.identifier = identifier;
         this.expression = expression;
     }
+
+    @Override
+    public TypeCheckResult accept(SemanticVisitor visitor) {
+        return visitor.analyze(this);
+    }
 }

src/main/java/ast/statement/WhileStatementNode.java

@@ -1,6 +1,8 @@
 package ast.statement;
 
 import ast.expression.ExpressionNode;
+import semantic.SemanticVisitor;
+import typechecker.TypeCheckResult;
 
 public class WhileStatementNode extends StatementNode {
     public ExpressionNode condition;
@@ -10,4 +12,9 @@ public class WhileStatementNode extends StatementNode {
         this.condition = condition;
         this.body = body;
     }
+
+    @Override
+    public TypeCheckResult accept(SemanticVisitor visitor) {
+        return visitor.analyze(this);
+    }
 }

src/main/java/ast/type/BaseTypeNode.java

@@ -1,6 +1,8 @@
 package ast.type;
 
-public class BaseTypeNode implements TypeNode{
+import ast.ASTNode;
+
+public class BaseTypeNode implements ASTNode, TypeNode {
 
     public EnumTypeNode enumType;
 

src/main/java/ast/type/ReferenceTypeNode.java

@@ -1,4 +1,6 @@
 package ast.type;
 
-public class ReferenceTypeNode implements TypeNode{
+import ast.ASTNode;
+
+public class ReferenceTypeNode implements ASTNode, TypeNode {
 }

src/main/java/bytecode/ClassCodeGen.java

@@ -4,6 +4,7 @@ import ast.ClassNode;
 import ast.member.FieldNode;
 import ast.member.MemberNode;
 import ast.member.MethodNode;
+import ast.type.BaseTypeNode;
 import bytecode.visitor.ClassVisitor;
 import java.io.File;
 import org.objectweb.asm.ClassWriter;
@@ -12,14 +13,19 @@ import org.objectweb.asm.Opcodes;
 import java.io.FileOutputStream;
 import java.io.IOException;
 
+
 public class ClassCodeGen implements ClassVisitor {
-    Mapper mapper = new Mapper();
+    private Mapper mapper;
-    ClassWriter classWriter;
+    private ClassWriter classWriter;
+
+    public ClassCodeGen() {
+        mapper = new Mapper();
+    }
 
     @Override
     public void visit(ClassNode classNode) {
         classWriter = new ClassWriter(ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);
-        classWriter.visit(Opcodes.V1_8, mapper.mapAccesTypeToOpcode(classNode.accessType), classNode.identifier, null,
+        classWriter.visit(Opcodes.V1_5, mapper.mapAccessTypeToOpcode(classNode.accessType), classNode.identifier, null,
                 "java/lang/Object", null);
 
         for (MemberNode memberNode : classNode.members) {
@@ -39,7 +45,9 @@ public class ClassCodeGen implements ClassVisitor {
 
     @Override
     public void visit(FieldNode fieldNode) {
-        classWriter.visitField(mapper.mapAccesTypeToOpcode(fieldNode.accessTypeNode), fieldNode.identifier, mapper.getTypeChar(fieldNode.type.enumTypeNode), null, null );
+        if(fieldNode.type instanceof BaseTypeNode baseTypeNode){
+            classWriter.visitField(mapper.mapAccessTypeToOpcode(fieldNode.accessTypeNode), fieldNode.identifier, mapper.getTypeChar(baseTypeNode.enumType), null, null );
+        }
         classWriter.visitEnd();
     }
 

src/main/java/bytecode/FieldCodeGen.java

@@ -1,13 +0,0 @@
-package bytecode;
-
-import ast.member.FieldNode;
-import org.objectweb.asm.ClassWriter;
-import org.objectweb.asm.FieldVisitor;
-
-public class FieldCodeGen {
-
-    public void generateFieldCode(ClassWriter classWriter, FieldNode fieldNode) {
-        Mapper mapper = new Mapper();
-        FieldVisitor fieldVisitor = classWriter.visitField(mapper.mapAccesTypeToOpcode(fieldNode.accessTypeNode), fieldNode.identifier, "", null, null);
-    }
-}

src/main/java/bytecode/Mapper.java

@@ -1,13 +1,13 @@
 package bytecode;
 
-import ast.type.AccessTypeNode;
+import ast.parameter.ParameterListNode;
-import ast.type.EnumAccessTypeNode;
+import ast.parameter.ParameterNode;
-import ast.type.EnumTypeNode;
+import ast.type.*;
-import ast.type.TypeNode;
 import org.objectweb.asm.Opcodes;
+import ast.type.BaseTypeNode;
 
 public class Mapper {
-    public int mapAccesTypeToOpcode(AccessTypeNode type) {
+    public int mapAccessTypeToOpcode(AccessTypeNode type) {
         switch (type.enumAccessTypeNode) {
             case EnumAccessTypeNode.PUBLIC:
                 return Opcodes.ACC_PUBLIC;
@@ -17,9 +17,13 @@ public class Mapper {
         return 0;
     }
 
-    public String generateMethodDescriptor(TypeNode typeNode) {
+    public String generateMethodDescriptor(BaseTypeNode baseTypeNode, ParameterListNode parameterListNode) {
-        String descriptor = "()";
+        String descriptor = "(";
-        descriptor += getTypeChar(typeNode.enumTypeNode);
+        for(ParameterNode parameterNode : parameterListNode.parameters) {
+            descriptor += getTypeChar(EnumTypeNode.INT);
+        }
+        descriptor += ")";
+        descriptor += getTypeChar(baseTypeNode.enumType);
         return descriptor;
     }
 

src/main/java/bytecode/MethodCodeGen.java

@@ -2,37 +2,99 @@ package bytecode;
 
 import ast.member.ConstructorNode;
 import ast.member.MethodNode;
+import ast.parameter.ParameterListNode;
+import ast.parameter.ParameterNode;
+import ast.type.BaseTypeNode;
+import ast.type.EnumTypeNode;
 import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.Label;
 import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.objectweb.asm.Opcodes.*;
+
 
 public class MethodCodeGen implements bytecode.visitor.MethodVisitor {
 
     private ClassWriter classWriter;
-    Mapper mapper = new Mapper();
+    private Mapper mapper;
+    private MethodVisitor methodVisitor;
+
+    private List<String> localVaribales;
 
     public MethodCodeGen(ClassWriter classWriter) {
         this.classWriter = classWriter;
+        mapper = new Mapper();
+        localVaribales = new ArrayList<>();
     }
 
     @Override
     public void visit(ConstructorNode constructorNode) {
-        MethodVisitor constructor =
+        methodVisitor =
-                classWriter.visitMethod(mapper.mapAccesTypeToOpcode(constructorNode.visibility),
+                classWriter.visitMethod(mapper.mapAccessTypeToOpcode(constructorNode.visibility),
                         "<init>",
                         "()V",
                         null,
                         null);
-        constructor.visitEnd();
+        methodVisitor.visitCode();
+        methodVisitor.visitVarInsn(ALOAD, 0);
+        methodVisitor.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
+        methodVisitor.visitInsn(RETURN);
+        methodVisitor.visitMaxs(1, 1);
+        methodVisitor.visitEnd();
     }
 
     @Override
     public void visit(MethodNode methodNode) {
-        MethodVisitor method = classWriter.visitMethod(mapper.mapAccesTypeToOpcode(methodNode.visibility),
+        if (methodNode.type instanceof BaseTypeNode baseTypeNode) {
+            methodVisitor = classWriter.visitMethod(mapper.mapAccessTypeToOpcode(methodNode.visibility),
                     methodNode.identifier,
-                mapper.generateMethodDescriptor(methodNode.type),
+                    mapper.generateMethodDescriptor(baseTypeNode, methodNode.parameters),
                     null,
                     null);
 
-        method.visitEnd();
+            methodVisitor.visitCode();
+            localVaribales.add("this");
+            for (ParameterNode parameterNode : methodNode.parameters.parameters) {
+                localVaribales.add(parameterNode.identifier);
+            }
+
+            //test();
+            methodVisitor.visitMaxs(1, localVaribales.size());
+            methodVisitor.visitEnd();
+        }
+    }
+
+    public void test() {
+        Label start = new Label();
+        Label loop = new Label();
+        Label end = new Label();
+        methodVisitor.visitLabel(start);
+        //methodVisitor.visitVarInsn(Opcodes.ICONST_M1, 99);
+        //methodVisitor.visitInsn(Opcodes.ICONST_5);
+        methodVisitor.visitLdcInsn(99);
+        // methodVisitor.visitInsn(Opcodes.ICONST_0);
+        //methodVisitor.visitVarInsn(Opcodes.ILOAD, 2);
+        methodVisitor.visitVarInsn(Opcodes.ISTORE, 1);
+        methodVisitor.visitLabel(loop);
+        methodVisitor.visitVarInsn(Opcodes.ILOAD, 1);
+        methodVisitor.visitInsn(Opcodes.ICONST_5);
+        methodVisitor.visitJumpInsn(Opcodes.IF_ICMPGE, end);
+        methodVisitor.visitFieldInsn(Opcodes.GETSTATIC,
+                "java/lang/System", "out",
+                "Ljava/io/PrintStream;");
+        methodVisitor.visitLdcInsn("Bytecode");
+        methodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL,
+                "java/io/PrintStream", "println",
+                "(Ljava/lang/String;)V", false);
+        methodVisitor.visitIincInsn(1, 1);
+        methodVisitor.visitJumpInsn(Opcodes.GOTO, loop);
+        methodVisitor.visitLabel(end);
+        methodVisitor.visitVarInsn(Opcodes.ILOAD, 1);
+        methodVisitor.visitInsn(Opcodes.IRETURN);
+        methodVisitor.visitEnd();
     }
 }

src/main/java/parser/ASTBuilder.java

@@ -13,10 +13,12 @@ import ast.parameter.ParameterNode;
 import ast.statement.*;
 import ast.type.*;
 import org.antlr.v4.runtime.tree.TerminalNode;
+
 import java.util.ArrayList;
 import java.util.List;
 import parser.generated.*;
 import parser.generated.SimpleJavaParser.LiteralContext;
+import ast.type.BaseTypeNode;
 
 public class ASTBuilder extends SimpleJavaBaseVisitor<ASTNode> {
     @Override
@@ -74,9 +76,9 @@ public class ASTBuilder extends SimpleJavaBaseVisitor<ASTNode> {
 
     @Override
     public ASTNode visitParameter(SimpleJavaParser.ParameterContext ctx) {
-        TypeNode type = (TypeNode) visit(ctx.type());
+        TypeNode typeNode = (TypeNode) visit(ctx.type());
         String identifier = ctx.IDENTIFIER().getText();
-        return new ParameterNode(type, identifier);
+        return new ParameterNode(typeNode, identifier);
     }
 
     @Override
@@ -204,6 +206,7 @@ public class ASTBuilder extends SimpleJavaBaseVisitor<ASTNode> {
         try {
             int intValue = Integer.parseInt(literalContext.getText());
             LiteralNode literalNode = new LiteralNode(intValue);
+
             literalNode.setType("int");
             return literalNode;
         } catch (NumberFormatException ignored) {}

src/main/java/semantic/Scope.java

@@ -0,0 +1,36 @@
+package semantic;
+
+import ast.type.TypeNode;
+
+import java.util.HashMap;
+import java.util.Stack;
+
+public class Scope {
+
+    private Stack<HashMap<String, TypeNode>> localVars;
+
+    public void addLocalVar(String name, TypeNode type) {
+        if (this.contains(name)) {
+            throw new RuntimeException("Variable " + name + " already exists in this scope");
+        }
+        localVars.peek().put(name, type);
+    }
+
+    public boolean contains(String name) {
+        for (HashMap<String, TypeNode> map : localVars) {
+            if (map.containsKey(name)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public void pushScope() {
+        localVars.push(new HashMap<String, TypeNode>());
+    }
+
+    public void popScope() {
+        localVars.pop();
+    }
+
+}

src/main/java/semantic/SemanticAnalyzer.java

@@ -2,22 +2,26 @@ package semantic;
 
 
 import ast.*;
-import ast.expression.ExpressionNode;
+import ast.expression.BinaryExpressionNode;
-import ast.member.ConstructorNode;
+import ast.expression.IdentifierExpressionNode;
+import ast.expression.UnaryExpressionNode;
 import ast.member.FieldNode;
 import ast.member.MemberNode;
 
 import ast.member.MethodNode;
-import ast.statement.AssignmentStatementNode;
+import ast.statement.*;
-import ast.statement.StatementNode;
+
 import java.util.ArrayList;
 import java.util.List;
+
 import typechecker.TypeCheckResult;
 
 public class SemanticAnalyzer implements SemanticVisitor {
 
     private ArrayList<String> currentFields = new ArrayList<>();
 
+    private Scope currentScope;
+
     public static ASTNode generateTast(ASTNode node) throws RuntimeException {
         SemanticAnalyzer semanticCheck = new SemanticAnalyzer();
         ProgramNode programNode = (ProgramNode) node;
@@ -36,34 +40,47 @@ public class SemanticAnalyzer implements SemanticVisitor {
 
         List<ClassNode> classes = node.classes;
         for (ClassNode classNode : classes) {
-      classNode.accept(this);
+            var result = classNode.accept(this);
+            valid = valid && result.isValid();
         }
         return new TypeCheckResult(valid, null);
     }
 
     @Override
     public TypeCheckResult analyze(ClassNode classNode) {
+        var valid = true;
         List<MemberNode> members = classNode.members;
         for (MemberNode memberNode : members) {
             if (memberNode instanceof FieldNode fieldNode) {
-        fieldNode.accept(this);
+                var result = fieldNode.accept(this);
+                valid = valid && result.isValid();
             } else if (memberNode instanceof MethodNode methodNode) {
-        methodNode.accept(this);
+                var result = methodNode.accept(this);
+                valid = valid && result.isValid();
             }
         }
 
-    return null;
+        return new TypeCheckResult(valid, null);
+
     }
 
     @Override
     public TypeCheckResult analyze(MethodNode methodNode) {
+        var valid = true;
+
+        currentLocalScope.pushScope();
+
         List<StatementNode> statements = methodNode.statements;
         for (StatementNode statement : statements) {
             if (statement instanceof AssignmentStatementNode assignmentStatementNode) {
-        assignmentStatementNode.accept(this);
+                var result = assignmentStatementNode.accept(this);
+                valid = valid && result.isValid();
+            } else if (statement instanceof VariableDeclarationStatementNode variableDeclarationStatementNode) {
+                var result = variableDeclarationStatementNode.accept(this);
+                valid = valid && result.isValid();
             }
         }
-    return null;
+        return new TypeCheckResult(valid, null);
     }
 
     @Override
@@ -73,19 +90,56 @@ public class SemanticAnalyzer implements SemanticVisitor {
         } else {
             currentFields.add(toCheck.identifier);
         }
-    return null;
+        return new TypeCheckResult(true, null);
     }
 
     @Override
     public TypeCheckResult analyze(AssignmentStatementNode assignmentStatementNode) {
         if (assignmentStatementNode.expression instanceof LiteralNode literalNode) {
-      VarNode varNode = assignmentStatementNode.varNode;
+            TypeCheckResult varResult = assignmentStatementNode.varNode.accept(this);
-      if(varNode.getType().equals(literalNode.getType())) {
+            TypeCheckResult expressionResult = assignmentStatementNode.expression.accept(this);
-        System.out.println("Type is same");
-      } else {
-        throw new RuntimeException("Type mismatch");
         }
+        return new TypeCheckResult(true, null);
     }
+
+    @Override
+    public TypeCheckResult analyze(VarNode toCheck) {
+        return new TypeCheckResult(true, null);
+    }
+
+    @Override
+    public TypeCheckResult analyze(BinaryExpressionNode toCheck) {
+        return null;
+    }
+
+    @Override
+    public TypeCheckResult analyze(IdentifierExpressionNode toCheck) {
+        return null;
+    }
+
+    @Override
+    public TypeCheckResult analyze(UnaryExpressionNode toCheck) {
+        return null;
+    }
+
+    @Override
+    public TypeCheckResult analyze(VariableDeclarationStatementNode toCheck) {
+
+        return new TypeCheckResult(true, null);
+    }
+
+    @Override
+    public TypeCheckResult analyze(IfStatementNode toCheck) {
+        return null;
+    }
+
+    @Override
+    public TypeCheckResult analyze(ReturnStatementNode toCheck) {
+        return null;
+    }
+
+    @Override
+    public TypeCheckResult analyze(WhileStatementNode toCheck) {
         return null;
     }
 

src/main/java/semantic/SemanticVisitor.java

@@ -3,13 +3,16 @@ package semantic;
 
 import ast.ClassNode;
 import ast.ProgramNode;
+import ast.VarNode;
+import ast.expression.BinaryExpressionNode;
+import ast.expression.IdentifierExpressionNode;
+import ast.expression.UnaryExpressionNode;
 import ast.member.FieldNode;
 import ast.member.MethodNode;
-import ast.statement.AssignmentStatementNode;
+import ast.statement.*;
 import typechecker.TypeCheckResult;
 
 public interface SemanticVisitor {
-//    TypeCheckResult typeCheck(ASTNode toCheck);
 
     TypeCheckResult analyze(ProgramNode toCheck);
 
@@ -20,43 +23,20 @@ public interface SemanticVisitor {
     TypeCheckResult analyze(FieldNode toCheck);
 
     TypeCheckResult analyze(AssignmentStatementNode toCheck);
-//
-//    TypeCheckResult typeCheck(MethodParameter toCheck);
-//
-//    TypeCheckResult typeCheck(ForStmt forStmt);
-//
-//    TypeCheckResult typeCheck(WhileStmt whileStmt);
-//
-//    TypeCheckResult typeCheck(ReturnStmt returnStmt);
-//
-//    TypeCheckResult typeCheck(LocalVarDecl localVarDecl);
-//
-//    TypeCheckResult typeCheck(IfStmt ifStmt);
-//
-//    TypeCheckResult typeCheck(Block block);
-//
-//    TypeCheckResult typeCheck(NewDecl newDecl);
-//
-//    TypeCheckResult typeCheck(MethodCall methodCall);
-//
-//    TypeCheckResult typeCheck(Unary unary);
-//
-//    TypeCheckResult typeCheck(This aThis);
-//
-//    TypeCheckResult typeCheck(Null aNull);
-//
-//    TypeCheckResult typeCheck(LocalOrFieldVar localOrFieldVar);
-//
-//    TypeCheckResult typeCheck(IntegerExpr integerExpr);
-//
-//    TypeCheckResult typeCheck(InstVar instVar);
-//
-//    TypeCheckResult typeCheck(CharExpr charExpr);
-//
-//    TypeCheckResult typeCheck(BoolExpr boolExpr);
-//
-//    TypeCheckResult typeCheck(Binary binary);
-//
-//    TypeCheckResult typeCheck(StringExpr instVar);
 
+    TypeCheckResult analyze(VarNode toCheck);
+
+    TypeCheckResult analyze(BinaryExpressionNode toCheck);
+
+    TypeCheckResult analyze(IdentifierExpressionNode toCheck);
+
+    TypeCheckResult analyze(UnaryExpressionNode toCheck);
+
+    TypeCheckResult analyze(VariableDeclarationStatementNode toCheck);
+
+    TypeCheckResult analyze(IfStatementNode toCheck);
+
+    TypeCheckResult analyze(ReturnStatementNode toCheck);
+
+    TypeCheckResult analyze(WhileStatementNode toCheck);
 }

src/main/java/typechecker/Type.java

@@ -1,5 +0,0 @@
-package typechecker;
-
-public interface Type {
-    boolean equals(Object obj);
-}

src/main/java/typechecker/TypeCheckResult.java

@@ -1,12 +1,14 @@
 package typechecker;
 
 
+import ast.type.TypeNode;
+
 public class TypeCheckResult {
 
   private boolean valid;
-  private Type type;
+  private TypeNode type;
 
-  public TypeCheckResult(boolean valid, Type type) {
+  public TypeCheckResult(boolean valid, TypeNode type) {
     this.valid = valid;
     this.type = type;
   }
@@ -15,7 +17,7 @@ public class TypeCheckResult {
     return valid;
   }
 
-  public Type getType() {
+  public TypeNode getType() {
     return type;
   }
 }

src/main/java/typechecker/Typer.java

@@ -1,9 +0,0 @@
-package typechecker;
-
-public class Typer {
-
-    public static void Typeify(){
-
-    }
-
-}

src/main/java/visitor/Visitable.java

@@ -1,9 +1,10 @@
-package typechecker;
+package visitor;
 
 import bytecode.visitor.ClassVisitor;
 import bytecode.visitor.MethodVisitor;
 import bytecode.visitor.ProgramVisitor;
 import semantic.SemanticVisitor;
+import typechecker.TypeCheckResult;
 
 public interface Visitable {
     default void accept(ProgramVisitor programVisitor) {