Added call registers

src/build/Execute.go

@@ -33,6 +33,32 @@ func (f *Function) Execute(operation token.Token, register cpu.Register, value *
 	return f.ExecuteRegisterRegister(operation, register, temporary)
 }
 
+// ExecuteFunctionCall executes a function call.
+func (f *Function) ExecuteFunctionCall(expr *expression.Expression) error {
+	funcName := expr.Children[0].Token.Text()
+	parameters := expr.Children[1:]
+
+	if funcName == "syscall" {
+		err := f.ExpressionsToRegisters(parameters, f.CPU.Syscall)
+
+		if err != nil {
+			return err
+		}
+
+		f.Assembler.Syscall()
+	} else {
+		err := f.ExpressionsToRegisters(parameters, f.CPU.Call)
+
+		if err != nil {
+			return err
+		}
+
+		f.Assembler.Call(funcName)
+	}
+
+	return nil
+}
+
 // ExecuteLeaf performs an operation on a register with the given leaf operand.
 func (f *Function) ExecuteLeaf(operation token.Token, register cpu.Register, operand token.Token) error {
 	switch operand.Kind {