------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                                S T Y L E                                 --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2021, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT 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  distributed with GNAT; see file COPYING3.  If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license.          --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

with Atree;          use Atree;
with Casing;         use Casing;
with Csets;          use Csets;
with Einfo;          use Einfo;
with Einfo.Entities; use Einfo.Entities;
with Einfo.Utils;    use Einfo.Utils;
with Errout;         use Errout;
with Namet;          use Namet;
with Nlists;         use Nlists;
with Opt;            use Opt;
with Sinfo;          use Sinfo;
with Sinfo.Nodes;    use Sinfo.Nodes;
with Sinfo.Utils;    use Sinfo.Utils;
with Sinput;         use Sinput;
with Stand;          use Stand;
with Stylesw;        use Stylesw;

package body Style is

   -----------------------
   -- Body_With_No_Spec --
   -----------------------

   --  If the check specs mode (-gnatys) is set, then all subprograms must
   --  have specs unless they are parameterless procedures at the library
   --  level (i.e. they are possible main programs).

   procedure Body_With_No_Spec (N : Node_Id) is
   begin
      if Style_Check_Specs then
         if Nkind (Parent (N)) = N_Compilation_Unit then
            declare
               Spec  : constant Node_Id := Specification (N);
               Defnm : constant Node_Id := Defining_Unit_Name (Spec);

            begin
               if Nkind (Spec) = N_Procedure_Specification
                 and then Nkind (Defnm) = N_Defining_Identifier
                 and then No (First_Formal (Defnm))
               then
                  return;
               end if;
            end;
         end if;

         Error_Msg_N ("(style) subprogram body has no previous spec", N);
      end if;
   end Body_With_No_Spec;

   ---------------------------------
   -- Check_Array_Attribute_Index --
   ---------------------------------

   procedure Check_Array_Attribute_Index
     (N  : Node_Id;
      E1 : Node_Id;
      D  : Int)
   is
   begin
      if Style_Check_Array_Attribute_Index then
         if D = 1 and then Present (E1) then
            Error_Msg_N -- CODEFIX
              ("(style) index number not allowed for one dimensional array",
               E1);
         elsif D > 1 and then No (E1) then
            Error_Msg_N -- CODEFIX
              ("(style) index number required for multi-dimensional array",
               N);
         end if;
      end if;
   end Check_Array_Attribute_Index;

   ----------------------
   -- Check_Identifier --
   ----------------------

   --  In check references mode (-gnatyr), identifier uses must be cased
   --  the same way as the corresponding identifier declaration. If standard
   --  references are checked (-gnatyn), then identifiers from Standard must
   --  be cased as in the Reference Manual.

   procedure Check_Identifier
     (Ref : Node_Or_Entity_Id;
      Def : Node_Or_Entity_Id)
   is
      Sref : Source_Ptr := Sloc (Ref);
      Sdef : Source_Ptr := Sloc (Def);
      Tref : Source_Buffer_Ptr;
      Tdef : Source_Buffer_Ptr;
      Nlen : Nat;
      Cas  : Casing_Type;

   begin
      --  If reference does not come from source, nothing to check

      if not Comes_From_Source (Ref) then
         return;

      --  If previous error on either node/entity, ignore

      elsif Error_Posted (Ref) or else Error_Posted (Def) then
         return;

      --  Case of definition comes from source

      elsif Comes_From_Source (Def) then

         --  Check same casing if we are checking references

         if Style_Check_References then
            Tref := Source_Text (Get_Source_File_Index (Sref));
            Tdef := Source_Text (Get_Source_File_Index (Sdef));

            --  Ignore operator name case completely. This also catches the
            --  case of where one is an operator and the other is not. This
            --  is a phenomenon from rewriting of operators as functions,
            --  and is to be ignored.

            if Tref (Sref) = '"' or else Tdef (Sdef) = '"' then
               return;

            else
               while Tref (Sref) = Tdef (Sdef) loop

                  --  If end of identifier, all done

                  if not Identifier_Char (Tref (Sref)) then
                     return;

                  --  Otherwise loop continues

                  else
                     Sref := Sref + 1;
                     Sdef := Sdef + 1;
                  end if;
               end loop;

               --  Fall through loop when mismatch between identifiers
               --  If either identifier is not terminated, error.

               if Identifier_Char (Tref (Sref))
                    or else
                  Identifier_Char (Tdef (Sdef))
               then
                  Error_Msg_Node_1 := Def;
                  Error_Msg_Sloc := Sloc (Def);
                  Error_Msg -- CODEFIX
                    ("(style) bad casing of & declared#", Sref, Ref);
                  return;

               --  Else end of identifiers, and they match

               else
                  return;
               end if;
            end if;
         end if;

      --  Case of definition in package Standard

      elsif Sdef = Standard_Location
              or else
            Sdef = Standard_ASCII_Location
      then
         --  Check case of identifiers in Standard

         if Style_Check_Standard then
            Tref := Source_Text (Get_Source_File_Index (Sref));

            --  Ignore operators

            if Tref (Sref) = '"' then
               null;

            --  Otherwise determine required casing of Standard entity

            else
               --  ASCII is all upper case

               if Entity (Ref) = Standard_ASCII then
                  Cas := All_Upper_Case;

               --  Special handling for names in package ASCII

               elsif Sdef = Standard_ASCII_Location then
                  declare
                     Nam : constant String := Get_Name_String (Chars (Def));

                  begin
                     --  Bar is mixed case

                     if Nam = "bar" then
                        Cas := Mixed_Case;

                     --  All names longer than 4 characters are mixed case

                     elsif Nam'Length > 4 then
                        Cas := Mixed_Case;

                     --  All names shorter than 4 characters (other than Bar,
                     --  which we already tested for specially) are Upper case.

                     else
                        Cas := All_Upper_Case;
                     end if;
                  end;

               --  All other entities are in mixed case

               else
                  Cas := Mixed_Case;
               end if;

               Nlen := Length_Of_Name (Chars (Ref));

               --  Now check if we have the right casing

               if Determine_Casing
                    (Tref (Sref .. Sref + Source_Ptr (Nlen) - 1)) = Cas
               then
                  null;
               else
                  Name_Len := Integer (Nlen);
                  Name_Buffer (1 .. Name_Len) :=
                    String (Tref (Sref .. Sref + Source_Ptr (Nlen) - 1));
                  Set_Casing (Cas);
                  Error_Msg_Name_1 := Name_Enter;
                  Error_Msg_N -- CODEFIX
                    ("(style) bad casing of %% declared in Standard", Ref);
               end if;
            end if;
         end if;
      end if;
   end Check_Identifier;

   ------------------------
   -- Missing_Overriding --
   ------------------------

   procedure Missing_Overriding (N : Node_Id; E : Entity_Id) is
      Nod : Node_Id;

   begin
      --  Perform the check on source subprograms and on subprogram instances,
      --  because these can be primitives of untagged types. Note that such
      --  indicators were introduced in Ada 2005. We apply Comes_From_Source
      --  to Original_Node to catch the case of a procedure body declared with
      --  "is null" that has been rewritten as a normal empty body.

      if Style_Check_Missing_Overriding
        and then (Comes_From_Source (Original_Node (N))
                   or else Is_Generic_Instance (E))
        and then Ada_Version_Explicit >= Ada_2005
      then
         --  If the subprogram is an instantiation,  its declaration appears
         --  within a wrapper package that precedes the instance node. Place
         --  warning on the node to avoid references to the original generic.

         if Nkind (N) = N_Subprogram_Declaration
           and then Is_Generic_Instance (E)
         then
            Nod := Next (Parent (Parent (List_Containing (N))));
         else
            Nod := N;
         end if;

         if Nkind (N) = N_Subprogram_Body then
            Error_Msg_NE -- CODEFIX
              ("(style) missing OVERRIDING indicator in body of&", N, E);

         elsif Nkind (N) = N_Abstract_Subprogram_Declaration then
            Error_Msg_NE -- CODEFIX
              ("(style) missing OVERRIDING indicator in declaration of&",
                Specification (N), E);

         else
            Error_Msg_NE -- CODEFIX
              ("(style) missing OVERRIDING indicator in declaration of&",
               Nod, E);
         end if;
      end if;
   end Missing_Overriding;

   -----------------------------------
   -- Subprogram_Not_In_Alpha_Order --
   -----------------------------------

   procedure Subprogram_Not_In_Alpha_Order (Name : Node_Id) is
   begin
      if Style_Check_Order_Subprograms then
         Error_Msg_N -- CODEFIX
           ("(style) subprogram body& not in alphabetical order", Name);
      end if;
   end Subprogram_Not_In_Alpha_Order;
end Style;