1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 with Debug; use Debug;
36 with Output; use Output;
37 with System; use System;
38 with Tree_IO; use Tree_IO;
40 with System.Memory; use System.Memory;
42 with Unchecked_Conversion;
44 pragma Elaborate_All (Output);
49 Min : constant Int := Int (Table_Low_Bound);
50 -- Subscript of the minimum entry in the currently allocated table
53 -- Number of entries in currently allocated table. The value of zero
54 -- ensures that we initially allocate the table.
56 -----------------------
57 -- Local Subprograms --
58 -----------------------
61 -- Reallocate the existing table according to the current value stored
62 -- in Max. Works correctly to do an initial allocation if the table
65 function Tree_Get_Table_Address return Address;
66 -- Return Null_Address if the table length is zero,
67 -- Table (First)'Address if not.
69 pragma Warnings (Off);
70 -- Turn off warnings. The following unchecked conversions are only used
71 -- internally in this package, and cannot never result in any instances
72 -- of improperly aliased pointers for the client of the package.
74 function To_Address is new Unchecked_Conversion (Table_Ptr, Address);
75 function To_Pointer is new Unchecked_Conversion (Address, Table_Ptr);
83 procedure Append (New_Val : Table_Component_Type) is
86 Table (Table_Index_Type (Last_Val)) := New_Val;
93 procedure Decrement_Last is
95 Last_Val := Last_Val - 1;
104 Free (To_Address (Table));
113 procedure Increment_Last is
115 Last_Val := Last_Val + 1;
117 if Last_Val > Max then
127 Old_Length : constant Int := Length;
132 Max := Min + (Table_Initial * Table_Factor) - 1;
133 Length := Max - Min + 1;
135 -- If table is same size as before (happens when table is never
136 -- expanded which is a common case), then simply reuse it. Note
137 -- that this also means that an explicit Init call right after
138 -- the implicit one in the package body is harmless.
140 if Old_Length = Length then
143 -- Otherwise we can use Reallocate to get a table of the right size.
144 -- Note that Reallocate works fine to allocate a table of the right
145 -- initial size when it is first allocated.
156 function Last return Table_Index_Type is
158 return Table_Index_Type (Last_Val);
165 procedure Reallocate is
166 New_Size : Memory.size_t;
169 if Max < Last_Val then
170 pragma Assert (not Locked);
172 -- Make sure that we have at least the initial allocation. This
173 -- is needed in cases where a zero length table is written out.
175 Length := Int'Max (Length, Table_Initial);
177 -- Now increment table length until it is sufficiently large. Use
178 -- the increment value or 10, which ever is larger (the reason
179 -- for the use of 10 here is to ensure that the table does really
180 -- increase in size (which would not be the case for a table of
181 -- length 10 increased by 3% for instance).
183 while Max < Last_Val loop
184 Length := Int'Max (Length * (100 + Table_Increment) / 100,
186 Max := Min + Length - 1;
190 Write_Str ("--> Allocating new ");
191 Write_Str (Table_Name);
192 Write_Str (" table, size = ");
193 Write_Int (Max - Min + 1);
199 Memory.size_t ((Max - Min + 1) *
200 (Table_Type'Component_Size / Storage_Unit));
203 Table := To_Pointer (Alloc (New_Size));
205 elsif New_Size > 0 then
207 To_Pointer (Realloc (Ptr => To_Address (Table),
211 if Length /= 0 and then Table = null then
213 Write_Str ("available memory exhausted");
216 raise Unrecoverable_Error;
227 Length := Last_Val - Int (Table_Low_Bound) + 1;
236 procedure Restore (T : Saved_Table) is
238 Free (To_Address (Table));
239 Last_Val := T.Last_Val;
242 Length := Max - Min + 1;
249 function Save return Saved_Table is
253 Res.Last_Val := Last_Val;
268 (Index : Table_Index_Type;
269 Item : Table_Component_Type)
272 if Int (Index) > Max then
276 Table (Index) := Item;
283 procedure Set_Last (New_Val : Table_Index_Type) is
285 if Int (New_Val) < Last_Val then
286 Last_Val := Int (New_Val);
288 Last_Val := Int (New_Val);
290 if Last_Val > Max then
296 ----------------------------
297 -- Tree_Get_Table_Address --
298 ----------------------------
300 function Tree_Get_Table_Address return Address is
305 return Table (First)'Address;
307 end Tree_Get_Table_Address;
313 -- Note: we allocate only the space required to accommodate the data
314 -- actually written, which means that a Tree_Write/Tree_Read sequence
315 -- does an implicit Release.
317 procedure Tree_Read is
321 Length := Max - Min + 1;
325 (Tree_Get_Table_Address,
326 (Last_Val - Int (First) + 1) *
327 Table_Type'Component_Size / Storage_Unit);
334 -- Note: we write out only the currently valid data, not the entire
335 -- contents of the allocated array. See note above on Tree_Read.
337 procedure Tree_Write is
339 Tree_Write_Int (Int (Last));
341 (Tree_Get_Table_Address,
342 (Last_Val - Int (First) + 1) *
343 Table_Type'Component_Size / Storage_Unit);