feat: user functions and calls

src/main/wacc/backend/asmGenerator.scala

@@ -42,6 +42,7 @@ object asmGenerator {
   val RCX = Register(RegSize.R64, RegName.CX)
   val R8 = Register(RegSize.R64, RegName.Reg8)
   val R9 = Register(RegSize.R64, RegName.Reg9)
+  val argRegs = List(RDI, RSI, RDX, RCX, R8, R9)
 
   val _8_BIT_MASK = 0xff
 
@@ -75,7 +76,8 @@ object asmGenerator {
       main.foldMap(generateStmt(_)),
       Chain.one(Move(RAX, ImmediateVal(0))),
       funcEpilogue(),
-      generateBuiltInFuncs()
+      generateBuiltInFuncs(),
+      funcs.foldMap(generateUserFunc(_))
     )
 
     val strDirs = strings.toList.zipWithIndex.foldMap { case (str, i) =>
@@ -111,6 +113,22 @@ object asmGenerator {
     chain
   }
 
+  def generateUserFunc(func: FuncDecl)(using
+      strings: ListBuffer[String],
+      labelGenerator: LabelGenerator
+  ): Chain[AsmLine] = {
+    given stack: Stack = Stack()
+    // Setup the stack with param 7 and up
+    func.params.drop(argRegs.size).foreach(stack.reserve(_))
+    var chain = Chain.empty[AsmLine]
+    // Push the rest of params onto the stack for simplicity
+    argRegs.zip(func.params).foreach { (reg, param) =>
+      chain += stack.push(param, reg)
+    }
+    chain ++= func.body.foldMap(generateStmt(_))
+    wrapFunc(labelGenerator.getLabel(func.name), chain)
+  }
+
   def generateBuiltInFuncs()(using
       stack: Stack,
       strings: ListBuffer[String],
@@ -223,7 +241,7 @@ object asmGenerator {
       case microWacc.Return(expr) =>
         chain ++= evalExprOntoStack(expr)
         chain += stack.pop(RAX)
-        chain += assemblyIR.Return()
+        chain ++= funcEpilogue()
 
       case call: microWacc.Call =>
         chain ++= generateCall(call)
@@ -321,7 +339,6 @@ object asmGenerator {
       labelGenerator: LabelGenerator
   ): Chain[AsmLine] = {
     var chain = Chain.empty[AsmLine]
-    val argRegs = List(RDI, RSI, RDX, RCX, R8, R9)
     val microWacc.Call(target, args) = call
 
     argRegs.zip(args).foldMap { (reg, expr) =>
@@ -373,7 +390,7 @@ object asmGenerator {
   def funcEpilogue()(using stack: Stack): Chain[AsmLine] = {
     var chain = Chain.empty[AsmLine]
     chain += Move(Register(RegSize.R64, RegName.SP), RBP)
-    chain += stack.pop(RBP)
+    chain += Pop(RBP)
     chain += assemblyIR.Return()
     chain
   }
@@ -382,7 +399,7 @@ object asmGenerator {
     private val stack = LinkedHashMap[Expr | Int, Int]()
     private val RSP = Register(RegSize.R64, RegName.SP)
 
-    def next: Int = stack.size + 1
+    private def next: Int = stack.size + 1
     def push(expr: Expr, src: Src): AsmLine = {
       stack += expr -> next
       Push(src)

src/main/wacc/frontend/typeChecker.scala

@@ -110,7 +110,7 @@ object typeChecker {
         microWacc.FuncDecl(
           microWacc.Ident(name.v, name.uid)(retType),
           params.zip(paramTypes).map { case (ast.Param(_, ident), ty) =>
-            microWacc.Ident(ident.v, name.uid)(ty)
+            microWacc.Ident(ident.v, ident.uid)(ty)
           },
           stmts.toList
             .flatMap(