From 86e15b58567da3aebdf152f61c68bb82caa6914c Mon Sep 17 00:00:00 2001
From: mrab <matthiasÂ@raba.live>
Date: Tue, 14 May 2024 11:12:12 +0200
Subject: [PATCH] method assembly is actually used (yay)

---
 src/ByteCode/ClassFile/Generator.hs | 39 +++++++++++++++++------------
 src/Main.hs                         |  2 +-
 2 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/src/ByteCode/ClassFile/Generator.hs b/src/ByteCode/ClassFile/Generator.hs
index 8f7287a..a482f16 100644
--- a/src/ByteCode/ClassFile/Generator.hs
+++ b/src/ByteCode/ClassFile/Generator.hs
@@ -140,13 +140,7 @@ methodBuilder (MethodDeclaration returntype name parameters statement) input = l
             memberAccessFlags = accessPublic,
             memberNameIndex = (fromIntegral baseIndex),
             memberDescriptorIndex = (fromIntegral (baseIndex + 1)),
-            memberAttributes = [
-                   CodeAttribute {
-                        attributeMaxStack = 420,
-                        attributeMaxLocals = 420,
-                        attributeCode = [Opreturn]
-                    }
-                ]
+            memberAttributes = []
             }
     in
         input {
@@ -157,14 +151,26 @@ methodBuilder (MethodDeclaration returntype name parameters statement) input = l
 
 methodAssembler :: ClassFileBuilder MethodDeclaration
 methodAssembler (MethodDeclaration returntype name parameters statement) input = let
-        code = CodeAttribute {
-            attributeMaxStack = 420,
-            attributeMaxLocals = 420,
-            attributeCode = [Opiadd]
-        }
-        --methodConstantIndex = 
-    in
-        input
+        methodConstantIndex = findMethodIndex input name
+    in case methodConstantIndex of
+        Nothing -> error ("Cannot find method entry in method pool for method: " ++ name)
+        Just index -> let
+                declaration = MethodDeclaration returntype name parameters statement
+                (pre, method : post) = splitAt index (methods input)
+                (_, bytecode) = assembleMethod declaration (constantPool input, [])
+                assembledMethod = method {
+                    memberAttributes = [
+                        CodeAttribute {
+                            attributeMaxStack = 420,
+                            attributeMaxLocals = 420,
+                            attributeCode = bytecode
+                        }
+                    ]
+                }
+            in
+                input {
+                    methods = pre ++ (assembledMethod : post)
+                }
         
 
 
@@ -195,8 +201,9 @@ comparisonOperation CompareGreaterOrEqual branchLocation = Opif_icmpge branchLoc
 
 
 assembleMethod :: Assembler MethodDeclaration
-assembleMethod (MethodDeclaration _ _ _ (Block statements)) (constants, ops) =
+assembleMethod (MethodDeclaration _ _ _ (TypedStatement _ (Block statements))) (constants, ops) =
     foldr assembleStatement (constants, ops) statements
+assembleMethod (MethodDeclaration _ _ _ stmt) (_, _) = error ("Block expected for method body, got: " ++ show stmt)
 
 assembleStatement :: Assembler Statement
 assembleStatement (TypedStatement stype (Return expr)) (constants, ops) = case expr of
diff --git a/src/Main.hs b/src/Main.hs
index 130ed20..c2ffd1b 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -9,7 +9,7 @@ import ByteCode.ClassFile
 import Data.ByteString (pack, writeFile)
 
 main = do
-    let untypedAST = parse $ alexScanTokens "class Testklasse {int a; int b; void something(){} void something_else(){}}"
+    let untypedAST = parse $ alexScanTokens "class Testklasse {void something(){return;}}"
     let typedAST = head (typeCheckCompilationUnit untypedAST)
     let abstractClassFile = classBuilder typedAST emptyClassFile
     let assembledClassFile = pack (serialize abstractClassFile)