nightshade

ast_lower.adb (2215B)

---

with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
with Ada.Text_IO;           use Ada.Text_IO;

package body AST_Lower is

   procedure Print_IR (LL : in out Lowerer) is
      Program : Unbounded_String;
      Footer  : Unbounded_String;
   begin
      Put_Line ("printing IR");

      -- init --

      Program := To_Unbounded_String ("export function w $main() {\n " & "@start\n ");

      Footer := To_Unbounded_String ("\n}");

      Put (To_String (Program));
      Put_Line (To_String (Footer));
   end;

   function Init
     (File_Name : File_Name_Ref; Source : Source_Ref; AST : Declaration_Vectors.Vector) return Lowerer is
   begin
      return Lowerer'(File_Name => File_Name, Source => Source, AST => AST, Module => null, Pos => 0);
   end Init;

   function Lower_Expr (LL : in out Lowerer; Expr : Expr) return IR_Value is
   begin
      LL.Pos := LL.Pos + 1;
      return IR_Value'(Id => LL.Pos, Typ => IR_Void);
   end;

   function Lower_Call (LL : in out Lowerer; Call : Call_Expr) return IR_Instruction is
      C : IR_Instruction;
   begin
      Fields := Lower_Arguments (LL, Call.Params);
      C := IR_Instruction'(Kind => CALL, Call_Name => Call.Name, Call_Has_Dest => false, Call_Args => Fields);
   end;

   function Lower_Function (LL : in out Lowerer; Func : Func_Decl) return IR_Function is
      F : IR_Function;
      T : IR_Type;
   begin
      if Func.Return_Kind = "" then
         -- TODO assess more typechecked types to IR Type.
         T := IR_VOID;
      else
         T := IR_VOID;
      end if;

      for SS : Stmt of Func.Stmts loop
         if SS.Kind = Stmt_Call_Kind then
            Lower_Call (LL, SS.Call);
         end if;
      end loop;

      return IR_function'(Name => Func.Name, Return_Type => T);

   end Lower_Function;

   procedure Lower (LL : in out Lowerer) is
      Func : IR_Function :=
        (Name => To_Unbounded_String ("main"), Instructions => Instructions_Vector.Empty_Vector);
   begin
      LL.Module := new IR_Module;
      LL.Module.Functions.Append (Func);

      for D : Decl of LL.AST loop
         if D.Kind = Function_Kind then
            Lower_Function (LL, Decl.Func);
         end if;
      end loop;
   end;

end AST_Lower;