------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                               S I N P U T                                --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2012, 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.                                     --
--                                                                          --
--                                                                          --
--                                                                          --
--                                                                          --
--                                                                          --
-- You should have received a copy of the GNU General Public License and    --
-- a copy of the GCC Runtime Library Exception along with this program;     --
-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
-- <http://www.gnu.org/licenses/>.                                          --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

pragma Style_Checks (All_Checks);
--  Subprograms not all in alpha order

with Atree;    use Atree;
with Debug;    use Debug;
with Opt;      use Opt;
with Output;   use Output;
with Scans;    use Scans;
with Tree_IO;  use Tree_IO;
with Widechar; use Widechar;

with GNAT.Byte_Order_Mark; use GNAT.Byte_Order_Mark;

with System;         use System;
with System.Memory;
with System.WCh_Con; use System.WCh_Con;

with Unchecked_Conversion;
with Unchecked_Deallocation;

package body Sinput is

   use ASCII;
   --  Make control characters visible

   First_Time_Around : Boolean := True;
   --  This needs a comment ???

   --  Routines to support conversion between types Lines_Table_Ptr,
   --  Logical_Lines_Table_Ptr and System.Address.

   pragma Warnings (Off);
   --  These unchecked conversions are aliasing safe, since they are never
   --  used to construct improperly aliased pointer values.

   function To_Address is
     new Unchecked_Conversion (Lines_Table_Ptr, Address);

   function To_Address is
     new Unchecked_Conversion (Logical_Lines_Table_Ptr, Address);

   function To_Pointer is
     new Unchecked_Conversion (Address, Lines_Table_Ptr);

   function To_Pointer is
     new Unchecked_Conversion (Address, Logical_Lines_Table_Ptr);

   pragma Warnings (On);

   ---------------------------
   -- Add_Line_Tables_Entry --
   ---------------------------

   procedure Add_Line_Tables_Entry
     (S : in out Source_File_Record;
      P : Source_Ptr)
   is
      LL : Physical_Line_Number;

   begin
      --  Reallocate the lines tables if necessary

      --  Note: the reason we do not use the normal Table package
      --  mechanism is that we have several of these tables. We could
      --  use the new GNAT.Dynamic_Tables package and that would probably
      --  be a good idea ???

      if S.Last_Source_Line = S.Lines_Table_Max then
         Alloc_Line_Tables
           (S,
            Int (S.Last_Source_Line) *
              ((100 + Alloc.Lines_Increment) / 100));

         if Debug_Flag_D then
            Write_Str ("--> Reallocating lines table, size = ");
            Write_Int (Int (S.Lines_Table_Max));
            Write_Eol;
         end if;
      end if;

      S.Last_Source_Line := S.Last_Source_Line + 1;
      LL := S.Last_Source_Line;

      S.Lines_Table (LL) := P;

      --  Deal with setting new entry in logical lines table if one is
      --  present. Note that there is always space (because the call to
      --  Alloc_Line_Tables makes sure both tables are the same length),

      if S.Logical_Lines_Table /= null then

         --  We can always set the entry from the previous one, because
         --  the processing for a Source_Reference pragma ensures that
         --  at least one entry following the pragma is set up correctly.

         S.Logical_Lines_Table (LL) := S.Logical_Lines_Table (LL - 1) + 1;
      end if;
   end Add_Line_Tables_Entry;

   -----------------------
   -- Alloc_Line_Tables --
   -----------------------

   procedure Alloc_Line_Tables
     (S       : in out Source_File_Record;
      New_Max : Nat)
   is
      subtype size_t is Memory.size_t;

      New_Table : Lines_Table_Ptr;

      New_Logical_Table : Logical_Lines_Table_Ptr;

      New_Size : constant size_t :=
                   size_t (New_Max * Lines_Table_Type'Component_Size /
                                                             Storage_Unit);

   begin
      if S.Lines_Table = null then
         New_Table := To_Pointer (Memory.Alloc (New_Size));

      else
         New_Table :=
           To_Pointer (Memory.Realloc (To_Address (S.Lines_Table), New_Size));
      end if;

      if New_Table = null then
         raise Storage_Error;
      else
         S.Lines_Table     := New_Table;
         S.Lines_Table_Max := Physical_Line_Number (New_Max);
      end if;

      if S.Num_SRef_Pragmas /= 0 then
         if S.Logical_Lines_Table = null then
            New_Logical_Table := To_Pointer (Memory.Alloc (New_Size));
         else
            New_Logical_Table := To_Pointer
              (Memory.Realloc (To_Address (S.Logical_Lines_Table), New_Size));
         end if;

         if New_Logical_Table = null then
            raise Storage_Error;
         else
            S.Logical_Lines_Table := New_Logical_Table;
         end if;
      end if;
   end Alloc_Line_Tables;

   -----------------
   -- Backup_Line --
   -----------------

   procedure Backup_Line (P : in out Source_Ptr) is
      Sindex : constant Source_File_Index := Get_Source_File_Index (P);
      Src    : constant Source_Buffer_Ptr :=
                 Source_File.Table (Sindex).Source_Text;
      Sfirst : constant Source_Ptr :=
                 Source_File.Table (Sindex).Source_First;

   begin
      P := P - 1;

      if P = Sfirst then
         return;
      end if;

      if Src (P) = CR then
         if Src (P - 1) = LF then
            P := P - 1;
         end if;

      else -- Src (P) = LF
         if Src (P - 1) = CR then
            P := P - 1;
         end if;
      end if;

      --  Now find first character of the previous line

      while P > Sfirst
        and then Src (P - 1) /= LF
        and then Src (P - 1) /= CR
      loop
         P := P - 1;
      end loop;
   end Backup_Line;

   ---------------------------
   -- Build_Location_String --
   ---------------------------

   procedure Build_Location_String (Loc : Source_Ptr) is
      Ptr : Source_Ptr;

   begin
      --  Loop through instantiations

      Ptr := Loc;
      loop
         Get_Name_String_And_Append
           (Reference_Name (Get_Source_File_Index (Ptr)));
         Add_Char_To_Name_Buffer (':');
         Add_Nat_To_Name_Buffer (Nat (Get_Logical_Line_Number (Ptr)));

         Ptr := Instantiation_Location (Ptr);
         exit when Ptr = No_Location;
         Add_Str_To_Name_Buffer (" instantiated at ");
      end loop;

      Name_Buffer (Name_Len + 1) := NUL;
      return;
   end Build_Location_String;

   function Build_Location_String (Loc : Source_Ptr) return String is
   begin
      Name_Len := 0;
      Build_Location_String (Loc);
      return Name_Buffer (1 .. Name_Len);
   end Build_Location_String;

   -------------------
   -- Check_For_BOM --
   -------------------

   procedure Check_For_BOM is
      BOM : BOM_Kind;
      Len : Natural;
      Tst : String (1 .. 5);

   begin
      for J in 1 .. 5 loop
         Tst (J) := Source (Scan_Ptr + Source_Ptr (J) - 1);
      end loop;

      Read_BOM (Tst, Len, BOM, False);

      case BOM is
         when UTF8_All =>
            Scan_Ptr := Scan_Ptr + Source_Ptr (Len);
            Wide_Character_Encoding_Method := WCEM_UTF8;
            Upper_Half_Encoding := True;

         when UTF16_LE | UTF16_BE =>
            Set_Standard_Error;
            Write_Line ("UTF-16 encoding format not recognized");
            Set_Standard_Output;
            raise Unrecoverable_Error;

         when UTF32_LE | UTF32_BE =>
            Set_Standard_Error;
            Write_Line ("UTF-32 encoding format not recognized");
            Set_Standard_Output;
            raise Unrecoverable_Error;

         when Unknown =>
            null;

         when others =>
            raise Program_Error;
      end case;
   end Check_For_BOM;

   -----------------------
   -- Get_Column_Number --
   -----------------------

   function Get_Column_Number (P : Source_Ptr) return Column_Number is
      S      : Source_Ptr;
      C      : Column_Number;
      Sindex : Source_File_Index;
      Src    : Source_Buffer_Ptr;

   begin
      --  If the input source pointer is not a meaningful value then return
      --  at once with column number 1. This can happen for a file not found
      --  condition for a file loaded indirectly by RTE, and also perhaps on
      --  some unknown internal error conditions. In either case we certainly
      --  don't want to blow up.

      if P < 1 then
         return 1;

      else
         Sindex := Get_Source_File_Index (P);
         Src := Source_File.Table (Sindex).Source_Text;
         S := Line_Start (P);
         C := 1;

         while S < P loop
            if Src (S) = HT then
               C := (C - 1) / 8 * 8 + (8 + 1);
            else
               C := C + 1;
            end if;

            S := S + 1;
         end loop;

         return C;
      end if;
   end Get_Column_Number;

   -----------------------------
   -- Get_Logical_Line_Number --
   -----------------------------

   function Get_Logical_Line_Number
     (P : Source_Ptr) return Logical_Line_Number
   is
      SFR : Source_File_Record
              renames Source_File.Table (Get_Source_File_Index (P));

      L : constant Physical_Line_Number := Get_Physical_Line_Number (P);

   begin
      if SFR.Num_SRef_Pragmas = 0 then
         return Logical_Line_Number (L);
      else
         return SFR.Logical_Lines_Table (L);
      end if;
   end Get_Logical_Line_Number;

   ---------------------------------
   -- Get_Logical_Line_Number_Img --
   ---------------------------------

   function Get_Logical_Line_Number_Img
     (P : Source_Ptr) return String
   is
   begin
      Name_Len := 0;
      Add_Nat_To_Name_Buffer (Nat (Get_Logical_Line_Number (P)));
      return Name_Buffer (1 .. Name_Len);
   end Get_Logical_Line_Number_Img;

   ------------------------------
   -- Get_Physical_Line_Number --
   ------------------------------

   function Get_Physical_Line_Number
     (P : Source_Ptr) return Physical_Line_Number
   is
      Sfile : Source_File_Index;
      Table : Lines_Table_Ptr;
      Lo    : Physical_Line_Number;
      Hi    : Physical_Line_Number;
      Mid   : Physical_Line_Number;
      Loc   : Source_Ptr;

   begin
      --  If the input source pointer is not a meaningful value then return
      --  at once with line number 1. This can happen for a file not found
      --  condition for a file loaded indirectly by RTE, and also perhaps on
      --  some unknown internal error conditions. In either case we certainly
      --  don't want to blow up.

      if P < 1 then
         return 1;

      --  Otherwise we can do the binary search

      else
         Sfile := Get_Source_File_Index (P);
         Loc   := P + Source_File.Table (Sfile).Sloc_Adjust;
         Table := Source_File.Table (Sfile).Lines_Table;
         Lo    := 1;
         Hi    := Source_File.Table (Sfile).Last_Source_Line;

         loop
            Mid := (Lo + Hi) / 2;

            if Loc < Table (Mid) then
               Hi := Mid - 1;

            else -- Loc >= Table (Mid)

               if Mid = Hi or else
                  Loc < Table (Mid + 1)
               then
                  return Mid;
               else
                  Lo := Mid + 1;
               end if;

            end if;

         end loop;
      end if;
   end Get_Physical_Line_Number;

   ---------------------------
   -- Get_Source_File_Index --
   ---------------------------

   Source_Cache_First : Source_Ptr := 1;
   Source_Cache_Last  : Source_Ptr := 0;
   --  Records the First and Last subscript values for the most recently
   --  referenced entry in the source table, to optimize the common case of
   --  repeated references to the same entry. The initial values force an
   --  initial search to set the cache value.

   Source_Cache_Index : Source_File_Index := No_Source_File;
   --  Contains the index of the entry corresponding to Source_Cache

   function Get_Source_File_Index (S : Source_Ptr) return Source_File_Index is
   begin
      if S in Source_Cache_First .. Source_Cache_Last then
         return Source_Cache_Index;

      else
         pragma Assert (Source_File_Index_Table (Int (S) / Chunk_Size)
                          /=
                        No_Source_File);
         for J in Source_File_Index_Table (Int (S) / Chunk_Size)
                                                    .. Source_File.Last
         loop
            if S in Source_File.Table (J).Source_First ..
                    Source_File.Table (J).Source_Last
            then
               Source_Cache_Index := J;
               Source_Cache_First :=
                 Source_File.Table (Source_Cache_Index).Source_First;
               Source_Cache_Last :=
                 Source_File.Table (Source_Cache_Index).Source_Last;
               return Source_Cache_Index;
            end if;
         end loop;
      end if;

      --  We must find a matching entry in the above loop!

      raise Program_Error;
   end Get_Source_File_Index;

   ----------------
   -- Initialize --
   ----------------

   procedure Initialize is
   begin
      Source_Cache_First := 1;
      Source_Cache_Last  := 0;
      Source_Cache_Index := No_Source_File;
      Source_gnat_adc    := No_Source_File;
      First_Time_Around  := True;

      Source_File.Init;
   end Initialize;

   -------------------------
   -- Instantiation_Depth --
   -------------------------

   function Instantiation_Depth (S : Source_Ptr) return Nat is
      Sind  : Source_File_Index;
      Sval  : Source_Ptr;
      Depth : Nat;

   begin
      Sval := S;
      Depth := 0;

      loop
         Sind := Get_Source_File_Index (Sval);
         Sval := Instantiation (Sind);
         exit when Sval = No_Location;
         Depth := Depth + 1;
      end loop;

      return Depth;
   end Instantiation_Depth;

   ----------------------------
   -- Instantiation_Location --
   ----------------------------

   function Instantiation_Location (S : Source_Ptr) return Source_Ptr is
   begin
      return Instantiation (Get_Source_File_Index (S));
   end Instantiation_Location;

   ----------------------
   -- Last_Source_File --
   ----------------------

   function Last_Source_File return Source_File_Index is
   begin
      return Source_File.Last;
   end Last_Source_File;

   ----------------
   -- Line_Start --
   ----------------

   function Line_Start (P : Source_Ptr) return Source_Ptr is
      Sindex : constant Source_File_Index := Get_Source_File_Index (P);
      Src    : constant Source_Buffer_Ptr :=
                 Source_File.Table (Sindex).Source_Text;
      Sfirst : constant Source_Ptr :=
                 Source_File.Table (Sindex).Source_First;
      S      : Source_Ptr;

   begin
      S := P;
      while S > Sfirst
        and then Src (S - 1) /= CR
        and then Src (S - 1) /= LF
      loop
         S := S - 1;
      end loop;

      return S;
   end Line_Start;

   function Line_Start
     (L : Physical_Line_Number;
      S : Source_File_Index) return Source_Ptr
   is
   begin
      return Source_File.Table (S).Lines_Table (L);
   end Line_Start;

   ----------
   -- Lock --
   ----------

   procedure Lock is
   begin
      Source_File.Locked := True;
      Source_File.Release;
   end Lock;

   ----------------------
   -- Num_Source_Files --
   ----------------------

   function Num_Source_Files return Nat is
   begin
      return Int (Source_File.Last) - Int (Source_File.First) + 1;
   end Num_Source_Files;

   ----------------------
   -- Num_Source_Lines --
   ----------------------

   function Num_Source_Lines (S : Source_File_Index) return Nat is
   begin
      return Nat (Source_File.Table (S).Last_Source_Line);
   end Num_Source_Lines;

   -----------------------
   -- Original_Location --
   -----------------------

   function Original_Location (S : Source_Ptr) return Source_Ptr is
      Sindex : Source_File_Index;
      Tindex : Source_File_Index;

   begin
      if S <= No_Location then
         return S;

      else
         Sindex := Get_Source_File_Index (S);

         if Instantiation (Sindex) = No_Location then
            return S;

         else
            Tindex := Template (Sindex);
            while Instantiation (Tindex) /= No_Location loop
               Tindex := Template (Tindex);
            end loop;

            return S - Source_First (Sindex) + Source_First (Tindex);
         end if;
      end if;
   end Original_Location;

   -------------------------
   -- Physical_To_Logical --
   -------------------------

   function Physical_To_Logical
     (Line : Physical_Line_Number;
      S    : Source_File_Index) return Logical_Line_Number
   is
      SFR : Source_File_Record renames Source_File.Table (S);

   begin
      if SFR.Num_SRef_Pragmas = 0 then
         return Logical_Line_Number (Line);
      else
         return SFR.Logical_Lines_Table (Line);
      end if;
   end Physical_To_Logical;

   --------------------------------
   -- Register_Source_Ref_Pragma --
   --------------------------------

   procedure Register_Source_Ref_Pragma
     (File_Name          : File_Name_Type;
      Stripped_File_Name : File_Name_Type;
      Mapped_Line        : Nat;
      Line_After_Pragma  : Physical_Line_Number)
   is
      subtype size_t is Memory.size_t;

      SFR : Source_File_Record renames Source_File.Table (Current_Source_File);

      ML : Logical_Line_Number;

   begin
      if File_Name /= No_File then
         SFR.Reference_Name := Stripped_File_Name;
         SFR.Full_Ref_Name  := File_Name;

         if not Debug_Generated_Code then
            SFR.Debug_Source_Name := Stripped_File_Name;
            SFR.Full_Debug_Name   := File_Name;
         end if;

         SFR.Num_SRef_Pragmas := SFR.Num_SRef_Pragmas + 1;
      end if;

      if SFR.Num_SRef_Pragmas = 1 then
         SFR.First_Mapped_Line := Logical_Line_Number (Mapped_Line);
      end if;

      if SFR.Logical_Lines_Table = null then
         SFR.Logical_Lines_Table := To_Pointer
           (Memory.Alloc
             (size_t (SFR.Lines_Table_Max *
                        Logical_Lines_Table_Type'Component_Size /
                                                        Storage_Unit)));
      end if;

      SFR.Logical_Lines_Table (Line_After_Pragma - 1) := No_Line_Number;

      ML := Logical_Line_Number (Mapped_Line);
      for J in Line_After_Pragma .. SFR.Last_Source_Line loop
         SFR.Logical_Lines_Table (J) := ML;
         ML := ML + 1;
      end loop;
   end Register_Source_Ref_Pragma;

   ---------------------------------
   -- Set_Source_File_Index_Table --
   ---------------------------------

   procedure Set_Source_File_Index_Table (Xnew : Source_File_Index) is
      Ind : Int;
      SP  : Source_Ptr;
      SL  : constant Source_Ptr := Source_File.Table (Xnew).Source_Last;

   begin
      SP  := (Source_File.Table (Xnew).Source_First + Chunk_Size - 1)
                                                    / Chunk_Size * Chunk_Size;
      Ind := Int (SP) / Chunk_Size;

      while SP <= SL loop
         Source_File_Index_Table (Ind) := Xnew;
         SP := SP + Chunk_Size;
         Ind := Ind + 1;
      end loop;
   end Set_Source_File_Index_Table;

   ---------------------------
   -- Skip_Line_Terminators --
   ---------------------------

   procedure Skip_Line_Terminators
     (P        : in out Source_Ptr;
      Physical : out Boolean)
   is
      Chr : constant Character := Source (P);

   begin
      if Chr = CR then
         if Source (P + 1) = LF then
            P := P + 2;
         else
            P := P + 1;
         end if;

      elsif Chr = LF then
         P := P + 1;

      elsif Chr = FF or else Chr = VT then
         P := P + 1;
         Physical := False;
         return;

         --  Otherwise we have a wide character

      else
         Skip_Wide (Source, P);
      end if;

      --  Fall through in the physical line terminator case. First deal with
      --  making a possible entry into the lines table if one is needed.

      --  Note: we are dealing with a real source file here, this cannot be
      --  the instantiation case, so we need not worry about Sloc adjustment.

      declare
         S : Source_File_Record
               renames Source_File.Table (Current_Source_File);

      begin
         Physical := True;

         --  Make entry in lines table if not already made (in some scan backup
         --  cases, we will be rescanning previously scanned source, so the
         --  entry may have already been made on the previous forward scan).

         if Source (P) /= EOF
           and then P > S.Lines_Table (S.Last_Source_Line)
         then
            Add_Line_Tables_Entry (S, P);
         end if;
      end;
   end Skip_Line_Terminators;

   ----------------
   -- Sloc_Range --
   ----------------

   procedure Sloc_Range (N : Node_Id; Min, Max : out Source_Ptr) is

      function Process (N : Node_Id) return Traverse_Result;
      --  Process function for traversing the node tree

      procedure Traverse is new Traverse_Proc (Process);

      -------------
      -- Process --
      -------------

      function Process (N : Node_Id) return Traverse_Result is
      begin
         if Sloc (N) < Min then
            if Sloc (N) > No_Location then
               Min := Sloc (N);
            end if;
         elsif Sloc (N) > Max then
            if Sloc (N) > No_Location then
               Max := Sloc (N);
            end if;
         end if;

         return OK;
      end Process;

   --  Start of processing for Sloc_Range

   begin
      Min := Sloc (N);
      Max := Sloc (N);
      Traverse (N);
   end Sloc_Range;

   -------------------
   -- Source_Offset --
   -------------------

   function Source_Offset (S : Source_Ptr) return Nat is
      Sindex : constant Source_File_Index := Get_Source_File_Index (S);
      Sfirst : constant Source_Ptr :=
                 Source_File.Table (Sindex).Source_First;
   begin
      return Nat (S - Sfirst);
   end Source_Offset;

   ------------------------
   -- Top_Level_Location --
   ------------------------

   function Top_Level_Location (S : Source_Ptr) return Source_Ptr is
      Oldloc : Source_Ptr;
      Newloc : Source_Ptr;

   begin
      Newloc := S;
      loop
         Oldloc := Newloc;
         Newloc := Instantiation_Location (Oldloc);
         exit when Newloc = No_Location;
      end loop;

      return Oldloc;
   end Top_Level_Location;

   ---------------
   -- Tree_Read --
   ---------------

   procedure Tree_Read is
   begin
      --  First we must free any old source buffer pointers

      if not First_Time_Around then
         for J in Source_File.First .. Source_File.Last loop
            declare
               S : Source_File_Record renames Source_File.Table (J);

               procedure Free_Ptr is new Unchecked_Deallocation
                 (Big_Source_Buffer, Source_Buffer_Ptr);

               pragma Warnings (Off);
               --  This unchecked conversion is aliasing safe, since it is not
               --  used to create improperly aliased pointer values.

               function To_Source_Buffer_Ptr is new
                 Unchecked_Conversion (Address, Source_Buffer_Ptr);

               pragma Warnings (On);

               Tmp1 : Source_Buffer_Ptr;

            begin
               if S.Instantiation /= No_Location then
                  null;

               else
                  --  Free the buffer, we use Free here, because we used malloc
                  --  or realloc directly to allocate the tables. That is
                  --  because we were playing the big array trick.

                  --  We have to recreate a proper pointer to the actual array
                  --  from the zero origin pointer stored in the source table.

                  Tmp1 :=
                    To_Source_Buffer_Ptr
                      (S.Source_Text (S.Source_First)'Address);
                  Free_Ptr (Tmp1);

                  if S.Lines_Table /= null then
                     Memory.Free (To_Address (S.Lines_Table));
                     S.Lines_Table := null;
                  end if;

                  if S.Logical_Lines_Table /= null then
                     Memory.Free (To_Address (S.Logical_Lines_Table));
                     S.Logical_Lines_Table := null;
                  end if;
               end if;
            end;
         end loop;
      end if;

      --  Reset source cache pointers to force new read

      Source_Cache_First := 1;
      Source_Cache_Last  := 0;

      --  Read in source file table

      Source_File.Tree_Read;

      --  The pointers we read in there for the source buffer and lines
      --  table pointers are junk. We now read in the actual data that
      --  is referenced by these two fields.

      for J in Source_File.First .. Source_File.Last loop
         declare
            S : Source_File_Record renames Source_File.Table (J);

         begin
            --  For the instantiation case, we do not read in any data. Instead
            --  we share the data for the generic template entry. Since the
            --  template always occurs first, we can safely refer to its data.

            if S.Instantiation /= No_Location then
               declare
                  ST : Source_File_Record renames
                         Source_File.Table (S.Template);

               begin
                  --  The lines tables are copied from the template entry

                  S.Lines_Table :=
                    Source_File.Table (S.Template).Lines_Table;
                  S.Logical_Lines_Table :=
                    Source_File.Table (S.Template).Logical_Lines_Table;

                  --  In the case of the source table pointer, we share the
                  --  same data as the generic template, but the virtual origin
                  --  is adjusted. For example, if the first subscript of the
                  --  template is 100, and that of the instantiation is 200,
                  --  then the instantiation pointer is obtained by subtracting
                  --  100 from the template pointer.

                  declare
                     pragma Suppress (All_Checks);

                     pragma Warnings (Off);
                     --  This unchecked conversion is aliasing safe since it
                     --  not used to create improperly aliased pointer values.

                     function To_Source_Buffer_Ptr is new
                       Unchecked_Conversion (Address, Source_Buffer_Ptr);

                     pragma Warnings (On);

                  begin
                     S.Source_Text :=
                       To_Source_Buffer_Ptr
                          (ST.Source_Text
                            (ST.Source_First - S.Source_First)'Address);
                  end;
               end;

            --  Normal case (non-instantiation)

            else
               First_Time_Around := False;
               S.Lines_Table := null;
               S.Logical_Lines_Table := null;
               Alloc_Line_Tables (S, Int (S.Last_Source_Line));

               for J in 1 .. S.Last_Source_Line loop
                  Tree_Read_Int (Int (S.Lines_Table (J)));
               end loop;

               if S.Num_SRef_Pragmas /= 0 then
                  for J in 1 .. S.Last_Source_Line loop
                     Tree_Read_Int (Int (S.Logical_Lines_Table (J)));
                  end loop;
               end if;

               --  Allocate source buffer and read in the data and then set the
               --  virtual origin to point to the logical zero'th element. This
               --  address must be computed with subscript checks turned off.

               declare
                  subtype B is Text_Buffer (S.Source_First .. S.Source_Last);
                  type Text_Buffer_Ptr is access B;
                  T : Text_Buffer_Ptr;

                  pragma Suppress (All_Checks);

                  pragma Warnings (Off);
                  --  This unchecked conversion is aliasing safe, since it is
                  --  never used to create improperly aliased pointer values.

                  function To_Source_Buffer_Ptr is new
                    Unchecked_Conversion (Address, Source_Buffer_Ptr);

                  pragma Warnings (On);

               begin
                  T := new B;

                  Tree_Read_Data (T (S.Source_First)'Address,
                     Int (S.Source_Last) - Int (S.Source_First) + 1);

                  S.Source_Text := To_Source_Buffer_Ptr (T (0)'Address);
               end;
            end if;
         end;

         Set_Source_File_Index_Table (J);
      end loop;
   end Tree_Read;

   ----------------
   -- Tree_Write --
   ----------------

   procedure Tree_Write is
   begin
      Source_File.Tree_Write;

      --  The pointers we wrote out there for the source buffer and lines
      --  table pointers are junk, we now write out the actual data that
      --  is referenced by these two fields.

      for J in Source_File.First .. Source_File.Last loop
         declare
            S : Source_File_Record renames Source_File.Table (J);

         begin
            --  For instantiations, there is nothing to do, since the data is
            --  shared with the generic template. When the tree is read, the
            --  pointers must be set, but no extra data needs to be written.

            if S.Instantiation /= No_Location then
               null;

            --  For the normal case, write out the data of the tables

            else
               --  Lines table

               for J in 1 .. S.Last_Source_Line loop
                  Tree_Write_Int (Int (S.Lines_Table (J)));
               end loop;

               --  Logical lines table if present

               if S.Num_SRef_Pragmas /= 0 then
                  for J in 1 .. S.Last_Source_Line loop
                     Tree_Write_Int (Int (S.Logical_Lines_Table (J)));
                  end loop;
               end if;

               --  Source buffer

               Tree_Write_Data
                 (S.Source_Text (S.Source_First)'Address,
                   Int (S.Source_Last) - Int (S.Source_First) + 1);
            end if;
         end;
      end loop;
   end Tree_Write;

   --------------------
   -- Write_Location --
   --------------------

   procedure Write_Location (P : Source_Ptr) is
   begin
      if P = No_Location then
         Write_Str ("<no location>");

      elsif P <= Standard_Location then
         Write_Str ("<standard location>");

      else
         declare
            SI : constant Source_File_Index := Get_Source_File_Index (P);

         begin
            Write_Name (Debug_Source_Name (SI));
            Write_Char (':');
            Write_Int (Int (Get_Logical_Line_Number (P)));
            Write_Char (':');
            Write_Int (Int (Get_Column_Number (P)));

            if Instantiation (SI) /= No_Location then
               Write_Str (" [");
               Write_Location (Instantiation (SI));
               Write_Char (']');
            end if;
         end;
      end if;
   end Write_Location;

   ----------------------
   -- Write_Time_Stamp --
   ----------------------

   procedure Write_Time_Stamp (S : Source_File_Index) is
      T : constant Time_Stamp_Type := Time_Stamp (S);
      P : Natural;

   begin
      if T (1) = '9' then
         Write_Str ("19");
         P := 0;
      else
         Write_Char (T (1));
         Write_Char (T (2));
         P := 2;
      end if;

      Write_Char (T (P + 1));
      Write_Char (T (P + 2));
      Write_Char ('-');

      Write_Char (T (P + 3));
      Write_Char (T (P + 4));
      Write_Char ('-');

      Write_Char (T (P + 5));
      Write_Char (T (P + 6));
      Write_Char (' ');

      Write_Char (T (P + 7));
      Write_Char (T (P + 8));
      Write_Char (':');

      Write_Char (T (P + 9));
      Write_Char (T (P + 10));
      Write_Char (':');

      Write_Char (T (P + 11));
      Write_Char (T (P + 12));
   end Write_Time_Stamp;

   ----------------------------------------------
   -- Access Subprograms for Source File Table --
   ----------------------------------------------

   function Debug_Source_Name (S : SFI) return File_Name_Type is
   begin
      return Source_File.Table (S).Debug_Source_Name;
   end Debug_Source_Name;

   function File_Name (S : SFI) return File_Name_Type is
   begin
      return Source_File.Table (S).File_Name;
   end File_Name;

   function File_Type (S : SFI) return Type_Of_File is
   begin
      return Source_File.Table (S).File_Type;
   end File_Type;

   function First_Mapped_Line (S : SFI) return Logical_Line_Number is
   begin
      return Source_File.Table (S).First_Mapped_Line;
   end First_Mapped_Line;

   function Full_Debug_Name (S : SFI) return File_Name_Type is
   begin
      return Source_File.Table (S).Full_Debug_Name;
   end Full_Debug_Name;

   function Full_File_Name (S : SFI) return File_Name_Type is
   begin
      return Source_File.Table (S).Full_File_Name;
   end Full_File_Name;

   function Full_Ref_Name (S : SFI) return File_Name_Type is
   begin
      return Source_File.Table (S).Full_Ref_Name;
   end Full_Ref_Name;

   function Identifier_Casing (S : SFI) return Casing_Type is
   begin
      return Source_File.Table (S).Identifier_Casing;
   end Identifier_Casing;

   function Inlined_Body (S : SFI) return Boolean is
   begin
      return Source_File.Table (S).Inlined_Body;
   end Inlined_Body;

   function Instantiation (S : SFI) return Source_Ptr is
   begin
      return Source_File.Table (S).Instantiation;
   end Instantiation;

   function Keyword_Casing (S : SFI) return Casing_Type is
   begin
      return Source_File.Table (S).Keyword_Casing;
   end Keyword_Casing;

   function Last_Source_Line (S : SFI) return Physical_Line_Number is
   begin
      return Source_File.Table (S).Last_Source_Line;
   end Last_Source_Line;

   function License (S : SFI) return License_Type is
   begin
      return Source_File.Table (S).License;
   end License;

   function Num_SRef_Pragmas (S : SFI) return Nat is
   begin
      return Source_File.Table (S).Num_SRef_Pragmas;
   end Num_SRef_Pragmas;

   function Reference_Name (S : SFI) return File_Name_Type is
   begin
      return Source_File.Table (S).Reference_Name;
   end Reference_Name;

   function Source_Checksum (S : SFI) return Word is
   begin
      return Source_File.Table (S).Source_Checksum;
   end Source_Checksum;

   function Source_First (S : SFI) return Source_Ptr is
   begin
      if S = Internal_Source_File then
         return Internal_Source'First;
      else
         return Source_File.Table (S).Source_First;
      end if;
   end Source_First;

   function Source_Last (S : SFI) return Source_Ptr is
   begin
      if S = Internal_Source_File then
         return Internal_Source'Last;
      else
         return Source_File.Table (S).Source_Last;
      end if;
   end Source_Last;

   function Source_Text (S : SFI) return Source_Buffer_Ptr is
   begin
      if S = Internal_Source_File then
         return Internal_Source_Ptr;
      else
         return Source_File.Table (S).Source_Text;
      end if;
   end Source_Text;

   function Template (S : SFI) return SFI is
   begin
      return Source_File.Table (S).Template;
   end Template;

   function Time_Stamp (S : SFI) return Time_Stamp_Type is
   begin
      return Source_File.Table (S).Time_Stamp;
   end Time_Stamp;

   function Unit (S : SFI) return Unit_Number_Type is
   begin
      return Source_File.Table (S).Unit;
   end Unit;

   ------------------------------------------
   -- Set Procedures for Source File Table --
   ------------------------------------------

   procedure Set_Identifier_Casing (S : SFI; C : Casing_Type) is
   begin
      Source_File.Table (S).Identifier_Casing := C;
   end Set_Identifier_Casing;

   procedure Set_Keyword_Casing (S : SFI; C : Casing_Type) is
   begin
      Source_File.Table (S).Keyword_Casing := C;
   end Set_Keyword_Casing;

   procedure Set_License (S : SFI; L : License_Type) is
   begin
      Source_File.Table (S).License := L;
   end Set_License;

   procedure Set_Unit (S : SFI; U : Unit_Number_Type) is
   begin
      Source_File.Table (S).Unit := U;
   end Set_Unit;

   ----------------------
   -- Trim_Lines_Table --
   ----------------------

   procedure Trim_Lines_Table (S : Source_File_Index) is
      Max : constant Nat := Nat (Source_File.Table (S).Last_Source_Line);

   begin
      --  Release allocated storage that is no longer needed

      Source_File.Table (S).Lines_Table := To_Pointer
        (Memory.Realloc
          (To_Address (Source_File.Table (S).Lines_Table),
           Memory.size_t
            (Max * (Lines_Table_Type'Component_Size / System.Storage_Unit))));
      Source_File.Table (S).Lines_Table_Max := Physical_Line_Number (Max);
   end Trim_Lines_Table;

   ------------
   -- Unlock --
   ------------

   procedure Unlock is
   begin
      Source_File.Locked := False;
      Source_File.Release;
   end Unlock;

   --------
   -- wl --
   --------

   procedure wl (P : Source_Ptr) is
   begin
      Write_Location (P);
      Write_Eol;
   end wl;

end Sinput;
