From 6eb26e70d5f9e7813e10e97a4f8f52026b716c5a Mon Sep 17 00:00:00 2001
From: Jochen Seyfried <j.seyfriedj@gmail.com>
Date: Tue, 14 May 2024 14:13:43 +0200
Subject: [PATCH] Deleted ICLass and updated the MethodDecl codeGen

---
 .../java/abstractSyntaxTree/Class/IClass.java | 16 ------
 .../abstractSyntaxTree/Class/MethodDecl.java  | 51 ++++++++++++++-----
 2 files changed, 37 insertions(+), 30 deletions(-)
 delete mode 100644 src/main/java/abstractSyntaxTree/Class/IClass.java

diff --git a/src/main/java/abstractSyntaxTree/Class/IClass.java b/src/main/java/abstractSyntaxTree/Class/IClass.java
deleted file mode 100644
index e71c991..0000000
--- a/src/main/java/abstractSyntaxTree/Class/IClass.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package abstractSyntaxTree.Class;
-
-import TypeCheck.TypeCheckResult;
-import org.objectweb.asm.ClassWriter;
-import org.objectweb.asm.TypeReference;
-
-import java.util.HashMap;
-import java.util.List;
-
-public interface IClass {
-    // visit method for code generation
-
-
-    void codeGen(ClassWriter cw) throws Exception;
-
-}
diff --git a/src/main/java/abstractSyntaxTree/Class/MethodDecl.java b/src/main/java/abstractSyntaxTree/Class/MethodDecl.java
index c1a30e0..c943cf6 100644
--- a/src/main/java/abstractSyntaxTree/Class/MethodDecl.java
+++ b/src/main/java/abstractSyntaxTree/Class/MethodDecl.java
@@ -44,6 +44,7 @@ public class MethodDecl implements Node {
     }
 
 
+    //Need to get the returnType of the method if it is an object
     // methodContext (class, (returnType, (identifier, parameter)))
     public void codeGen(ClassWriter cw, HashMap<String, HashMap<String, HashMap<String, ParameterList>>> methodContext) throws Exception {
 
@@ -54,11 +55,24 @@ public class MethodDecl implements Node {
 
         // check if the method is a constructor
         if (classThatContainsMethod.equals(name) && returnType == null) {
-            MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "<init>", getMethodDescriptor(), null, null);
+            String descriptor = getMethodDescriptor(methodContext);
+
+            MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "<init>", descriptor, null, null);
 
             //Call the superclass constructor
             mv.visitVarInsn(Opcodes.ALOAD, 0);
-            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
+
+            //Load the parameters onto the stack
+            int localVarIndex = 1;
+            for (Parameter param : parameters.parameterList) {
+                String paramType = param.type;
+                switch(paramType) {
+                    case "int", "boolean", "char" -> mv.visitVarInsn(Opcodes.ILOAD, localVarIndex);
+                    default -> mv.visitVarInsn(Opcodes.ALOAD, localVarIndex);
+                }
+                localVarIndex++;
+            }
+            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", descriptor, false);
 
             mv.visitCode();
             codeBlock.codeGen(mv, localVars);
@@ -66,7 +80,7 @@ public class MethodDecl implements Node {
 
             //automatically computed max stack and max locals
             mv.visitMaxs(0, 0);
-            mv.visitEnd();
+
         } else if (name.equals("main")) {
             int access = Opcodes.ACC_PUBLIC + Opcodes.ACC_STATIC;
 
@@ -80,7 +94,7 @@ public class MethodDecl implements Node {
             mv.visitEnd();
 
         } else {
-            MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PUBLIC, name, getMethodDescriptor(), null, null);
+            MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PUBLIC, name, getMethodDescriptor(methodContext), null, null);
 
             mv.visitCode();
             codeBlock.codeGen(mv, localVars);
@@ -95,7 +109,7 @@ public class MethodDecl implements Node {
         }
     }
 
-    private String getMethodDescriptor() {
+    private String getMethodDescriptor(HashMap<String, HashMap<String, HashMap<String, ParameterList>>> methodContext) {
         // get the method descriptor
         StringBuilder descriptor = new StringBuilder("(");
 
@@ -106,17 +120,18 @@ public class MethodDecl implements Node {
                 case "boolean" -> descriptor.append("Z");
                 case "char" -> descriptor.append("C");
                 case "void" -> descriptor.append("V");
-                default ->
+                default -> {
                     // object
-                    //TODO: This is not finished
-                        descriptor.append("L").append(param.type).append(";");
+                    //TODO: This is not finished for objects --> classes and methods
+                    if (returnType != null) descriptor.append("L").append(returnType).append(";");
+                }
             }
         }
         descriptor.append(")");
 
 
         // Get the return type
-        // If the return type is null, it is a constructor and we need to append V
+        // If the return type is null, it is a constructor, and we need to append V
         if (returnType == null) {
             descriptor.append("V");
         } else {
@@ -125,12 +140,20 @@ public class MethodDecl implements Node {
                 case "boolean" -> descriptor.append("Z");
                 case "char" -> descriptor.append("C");
                 case "void" -> descriptor.append("V");
-
-                //TODO: This is not finished --> we need to append the fully qualified name of the object
-                // Need to make sure what we get
-                default ->
+                default -> {
                     // object
-                        descriptor.append("L").append(returnType).append(";");
+                    HashMap<String, HashMap<String, ParameterList>> classMethods = methodContext.get(classThatContainsMethod);
+                    HashMap<String, ParameterList> methodDetails = classMethods.get(name);
+
+                    String fullReturnType = null;
+                    for (Map.Entry<String, ParameterList> entry : methodDetails.entrySet()) {
+                        fullReturnType = entry.getKey();
+                    }
+                    // If it is a class reference replace the "." with "/" and return it
+                    if (returnType.contains(".")) fullReturnType = fullReturnType.replaceAll("\\.", "/");
+
+                    if (fullReturnType != null) descriptor.append("L").append(fullReturnType).append(";");
+                }
             }
         }
         return descriptor.toString();