------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- T A B L E -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2004 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 2, 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 COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Debug; use Debug; with Opt; use Opt; with Output; use Output; with System; use System; with Tree_IO; use Tree_IO; with System.Memory; use System.Memory; with Unchecked_Conversion; pragma Elaborate_All (Output); package body Table is package body Table is Min : constant Int := Int (Table_Low_Bound); -- Subscript of the minimum entry in the currently allocated table Length : Int := 0; -- Number of entries in currently allocated table. The value of zero -- ensures that we initially allocate the table. ----------------------- -- Local Subprograms -- ----------------------- procedure Reallocate; -- Reallocate the existing table according to the current value stored -- in Max. Works correctly to do an initial allocation if the table -- is currently null. function Tree_Get_Table_Address return Address; -- Return Null_Address if the table length is zero, -- Table (First)'Address if not. pragma Warnings (Off); -- Turn off warnings. The following unchecked conversions are only used -- internally in this package, and cannot never result in any instances -- of improperly aliased pointers for the client of the package. function To_Address is new Unchecked_Conversion (Table_Ptr, Address); function To_Pointer is new Unchecked_Conversion (Address, Table_Ptr); pragma Warnings (On); ------------ -- Append -- ------------ procedure Append (New_Val : Table_Component_Type) is begin Increment_Last; Table (Table_Index_Type (Last_Val)) := New_Val; end Append; -------------------- -- Decrement_Last -- -------------------- procedure Decrement_Last is begin Last_Val := Last_Val - 1; end Decrement_Last; ---------- -- Free -- ---------- procedure Free is begin Free (To_Address (Table)); Table := null; Length := 0; end Free; -------------------- -- Increment_Last -- -------------------- procedure Increment_Last is begin Last_Val := Last_Val + 1; if Last_Val > Max then Reallocate; end if; end Increment_Last; ---------- -- Init -- ---------- procedure Init is Old_Length : constant Int := Length; begin Locked := False; Last_Val := Min - 1; Max := Min + (Table_Initial * Table_Factor) - 1; Length := Max - Min + 1; -- If table is same size as before (happens when table is never -- expanded which is a common case), then simply reuse it. Note -- that this also means that an explicit Init call right after -- the implicit one in the package body is harmless. if Old_Length = Length then return; -- Otherwise we can use Reallocate to get a table of the right size. -- Note that Reallocate works fine to allocate a table of the right -- initial size when it is first allocated. else Reallocate; end if; end Init; ---------- -- Last -- ---------- function Last return Table_Index_Type is begin return Table_Index_Type (Last_Val); end Last; ---------------- -- Reallocate -- ---------------- procedure Reallocate is New_Size : Memory.size_t; begin if Max < Last_Val then pragma Assert (not Locked); -- Make sure that we have at least the initial allocation. This -- is needed in cases where a zero length table is written out. Length := Int'Max (Length, Table_Initial); -- Now increment table length until it is sufficiently large while Max < Last_Val loop Length := Length * (100 + Table_Increment) / 100; Max := Min + Length - 1; end loop; if Debug_Flag_D then Write_Str ("--> Allocating new "); Write_Str (Table_Name); Write_Str (" table, size = "); Write_Int (Max - Min + 1); Write_Eol; end if; end if; New_Size := Memory.size_t ((Max - Min + 1) * (Table_Type'Component_Size / Storage_Unit)); if Table = null then Table := To_Pointer (Alloc (New_Size)); elsif New_Size > 0 then Table := To_Pointer (Realloc (Ptr => To_Address (Table), Size => New_Size)); end if; if Length /= 0 and then Table = null then Set_Standard_Error; Write_Str ("available memory exhausted"); Write_Eol; Set_Standard_Output; raise Unrecoverable_Error; end if; end Reallocate; ------------- -- Release -- ------------- procedure Release is begin Length := Last_Val - Int (Table_Low_Bound) + 1; Max := Last_Val; Reallocate; end Release; ------------- -- Restore -- ------------- procedure Restore (T : Saved_Table) is begin Free (To_Address (Table)); Last_Val := T.Last_Val; Max := T.Max; Table := T.Table; Length := Max - Min + 1; end Restore; ---------- -- Save -- ---------- function Save return Saved_Table is Res : Saved_Table; begin Res.Last_Val := Last_Val; Res.Max := Max; Res.Table := Table; Table := null; Length := 0; Init; return Res; end Save; -------------- -- Set_Item -- -------------- procedure Set_Item (Index : Table_Index_Type; Item : Table_Component_Type) is begin if Int (Index) > Max then Set_Last (Index); end if; Table (Index) := Item; end Set_Item; -------------- -- Set_Last -- -------------- procedure Set_Last (New_Val : Table_Index_Type) is begin if Int (New_Val) < Last_Val then Last_Val := Int (New_Val); else Last_Val := Int (New_Val); if Last_Val > Max then Reallocate; end if; end if; end Set_Last; ---------------------------- -- Tree_Get_Table_Address -- ---------------------------- function Tree_Get_Table_Address return Address is begin if Length = 0 then return Null_Address; else return Table (First)'Address; end if; end Tree_Get_Table_Address; --------------- -- Tree_Read -- --------------- -- Note: we allocate only the space required to accommodate the data -- actually written, which means that a Tree_Write/Tree_Read sequence -- does an implicit Release. procedure Tree_Read is begin Tree_Read_Int (Max); Last_Val := Max; Length := Max - Min + 1; Reallocate; Tree_Read_Data (Tree_Get_Table_Address, (Last_Val - Int (First) + 1) * Table_Type'Component_Size / Storage_Unit); end Tree_Read; ---------------- -- Tree_Write -- ---------------- -- Note: we write out only the currently valid data, not the entire -- contents of the allocated array. See note above on Tree_Read. procedure Tree_Write is begin Tree_Write_Int (Int (Last)); Tree_Write_Data (Tree_Get_Table_Address, (Last_Val - Int (First) + 1) * Table_Type'Component_Size / Storage_Unit); end Tree_Write; begin Init; end Table; end Table;