--  Nodes recognizer for ieee.std_logic_unsigned and ieee.std_logic_signed
--  Copyright (C) 2021 Tristan Gingold
--
--  GHDL is free software; you can redistribute it and/or modify it under
--  the terms of the GNU General Public License as published by the Free
--  Software Foundation; either version 2, or (at your option) any later
--  version.
--
--  GHDL is distributed in the hope that it will be useful, but WITHOUT ANY
--  WARRANTY; without even the implied warranty of MERCHANTABILITY or
--  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
--  for more details.
--
--  You should have received a copy of the GNU General Public License
--  along with GHDL; see the file COPYING.  If not, write to the Free
--  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
--  02111-1307, USA.

with Vhdl.Std_Package;
with Std_Names; use Std_Names;
with Vhdl.Ieee.Std_Logic_1164;
with Vhdl.Errors;

package body Vhdl.Ieee.Numeric_Std_Unsigned is
   type Arg_Kind is (Arg_Slv, Arg_Int, Arg_Log);

   Error : exception;

   procedure Classify_Arg (Arg : Iir; Kind : out Arg_Kind)
   is
      Arg_Type : constant Iir := Get_Type (Arg);
   begin
      if Arg_Type = Vhdl.Std_Package.Integer_Subtype_Definition
        or else Arg_Type = Vhdl.Std_Package.Natural_Subtype_Definition
      then
         Kind := Arg_Int;
      elsif Arg_Type = Ieee.Std_Logic_1164.Std_Logic_Type
        or else Arg_Type = Ieee.Std_Logic_1164.Std_Ulogic_Type
      then
         Kind := Arg_Log;
      elsif Arg_Type = Ieee.Std_Logic_1164.Std_Logic_Vector_Type
        or else Arg_Type = Ieee.Std_Logic_1164.Std_Ulogic_Vector_Type
      then
         Kind := Arg_Slv;
      else
         raise Error;
      end if;
   end Classify_Arg;

   procedure Extract_Declaration (Decl : Iir)
   is
      Arg1, Arg2 : Iir;
      Arg1_Kind  : Arg_Kind;
      Res : Iir_Predefined_Functions;
   begin
      Arg1 := Get_Interface_Declaration_Chain (Decl);
      if Is_Null (Arg1) then
         raise Error;
      end if;

      Res := Iir_Predefined_None;

      Classify_Arg (Arg1, Arg1_Kind);
      Arg2 := Get_Chain (Arg1);
      if Is_Valid (Arg2) then
         --  Dyadic function.
         null;
      else
         --  Monadic function.
         case Get_Identifier (Decl) is
            when Name_To_Integer =>
               pragma Assert (Arg1_Kind = Arg_Slv);
               Res :=
                 Iir_Predefined_Ieee_Numeric_Std_Unsigned_To_Integer_Slv_Nat;
            when others =>
               null;
         end case;
      end if;
      Set_Implicit_Definition (Decl, Res);
   end Extract_Declaration;

   procedure Extract_Declarations (Pkg : Iir_Package_Declaration)
   is
      Decl : Iir;
   begin
      Decl := Get_Declaration_Chain (Pkg);

      Decl := Skip_Copyright_Notice (Decl);

      --  Handle functions.
      while Is_Valid (Decl) loop
         case Get_Kind (Decl) is
            when Iir_Kind_Function_Declaration =>
               Extract_Declaration (Decl);
            when Iir_Kind_Non_Object_Alias_Declaration =>
               null;
            when others =>
               Vhdl.Errors.Error_Kind ("extract_declarations", Decl);
               raise Error;
         end case;

         Decl := Get_Chain (Decl);
      end loop;
   end Extract_Declarations;
end Vhdl.Ieee.Numeric_Std_Unsigned;