1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- T A B L E -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2002 Free Software Foundation, Inc. -- 10-- -- 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, 59 Temple Place - Suite 330, Boston, -- 20-- MA 02111-1307, USA. -- 21-- -- 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. -- 28-- -- 29-- GNAT was originally developed by the GNAT team at New York University. -- 30-- Extensive contributions were provided by Ada Core Technologies Inc. -- 31-- -- 32------------------------------------------------------------------------------ 33 34with Debug; use Debug; 35with Opt; use Opt; 36with Output; use Output; 37with System; use System; 38with Tree_IO; use Tree_IO; 39 40with System.Memory; use System.Memory; 41 42with Unchecked_Conversion; 43 44pragma Elaborate_All (Output); 45 46package body Table is 47 package body Table is 48 49 Min : constant Int := Int (Table_Low_Bound); 50 -- Subscript of the minimum entry in the currently allocated table 51 52 Length : Int := 0; 53 -- Number of entries in currently allocated table. The value of zero 54 -- ensures that we initially allocate the table. 55 56 ----------------------- 57 -- Local Subprograms -- 58 ----------------------- 59 60 procedure Reallocate; 61 -- Reallocate the existing table according to the current value stored 62 -- in Max. Works correctly to do an initial allocation if the table 63 -- is currently null. 64 65 function Tree_Get_Table_Address return Address; 66 -- Return Null_Address if the table length is zero, 67 -- Table (First)'Address if not. 68 69 function To_Address is new Unchecked_Conversion (Table_Ptr, Address); 70 function To_Pointer is new Unchecked_Conversion (Address, Table_Ptr); 71 72 ------------ 73 -- Append -- 74 ------------ 75 76 procedure Append (New_Val : Table_Component_Type) is 77 begin 78 Increment_Last; 79 Table (Table_Index_Type (Last_Val)) := New_Val; 80 end Append; 81 82 -------------------- 83 -- Decrement_Last -- 84 -------------------- 85 86 procedure Decrement_Last is 87 begin 88 Last_Val := Last_Val - 1; 89 end Decrement_Last; 90 91 ---------- 92 -- Free -- 93 ---------- 94 95 procedure Free is 96 begin 97 Free (To_Address (Table)); 98 Table := null; 99 Length := 0; 100 end Free; 101 102 -------------------- 103 -- Increment_Last -- 104 -------------------- 105 106 procedure Increment_Last is 107 begin 108 Last_Val := Last_Val + 1; 109 110 if Last_Val > Max then 111 Reallocate; 112 end if; 113 end Increment_Last; 114 115 ---------- 116 -- Init -- 117 ---------- 118 119 procedure Init is 120 Old_Length : constant Int := Length; 121 122 begin 123 Locked := False; 124 Last_Val := Min - 1; 125 Max := Min + (Table_Initial * Table_Factor) - 1; 126 Length := Max - Min + 1; 127 128 -- If table is same size as before (happens when table is never 129 -- expanded which is a common case), then simply reuse it. Note 130 -- that this also means that an explicit Init call right after 131 -- the implicit one in the package body is harmless. 132 133 if Old_Length = Length then 134 return; 135 136 -- Otherwise we can use Reallocate to get a table of the right size. 137 -- Note that Reallocate works fine to allocate a table of the right 138 -- initial size when it is first allocated. 139 140 else 141 Reallocate; 142 end if; 143 end Init; 144 145 ---------- 146 -- Last -- 147 ---------- 148 149 function Last return Table_Index_Type is 150 begin 151 return Table_Index_Type (Last_Val); 152 end Last; 153 154 ---------------- 155 -- Reallocate -- 156 ---------------- 157 158 procedure Reallocate is 159 New_Size : Memory.size_t; 160 161 begin 162 if Max < Last_Val then 163 pragma Assert (not Locked); 164 165 -- Make sure that we have at least the initial allocation. This 166 -- is needed in cases where a zero length table is written out. 167 168 Length := Int'Max (Length, Table_Initial); 169 170 -- Now increment table length until it is sufficiently large 171 172 while Max < Last_Val loop 173 Length := Length * (100 + Table_Increment) / 100; 174 Max := Min + Length - 1; 175 end loop; 176 177 if Debug_Flag_D then 178 Write_Str ("--> Allocating new "); 179 Write_Str (Table_Name); 180 Write_Str (" table, size = "); 181 Write_Int (Max - Min + 1); 182 Write_Eol; 183 end if; 184 end if; 185 186 New_Size := 187 Memory.size_t ((Max - Min + 1) * 188 (Table_Type'Component_Size / Storage_Unit)); 189 190 if Table = null then 191 Table := To_Pointer (Alloc (New_Size)); 192 193 elsif New_Size > 0 then 194 Table := 195 To_Pointer (Realloc (Ptr => To_Address (Table), 196 Size => New_Size)); 197 end if; 198 199 if Length /= 0 and then Table = null then 200 Set_Standard_Error; 201 Write_Str ("available memory exhausted"); 202 Write_Eol; 203 Set_Standard_Output; 204 raise Unrecoverable_Error; 205 end if; 206 207 end Reallocate; 208 209 ------------- 210 -- Release -- 211 ------------- 212 213 procedure Release is 214 begin 215 Length := Last_Val - Int (Table_Low_Bound) + 1; 216 Max := Last_Val; 217 Reallocate; 218 end Release; 219 220 ------------- 221 -- Restore -- 222 ------------- 223 224 procedure Restore (T : Saved_Table) is 225 begin 226 Free (To_Address (Table)); 227 Last_Val := T.Last_Val; 228 Max := T.Max; 229 Table := T.Table; 230 Length := Max - Min + 1; 231 end Restore; 232 233 ---------- 234 -- Save -- 235 ---------- 236 237 function Save return Saved_Table is 238 Res : Saved_Table; 239 240 begin 241 Res.Last_Val := Last_Val; 242 Res.Max := Max; 243 Res.Table := Table; 244 245 Table := null; 246 Length := 0; 247 Init; 248 return Res; 249 end Save; 250 251 -------------- 252 -- Set_Item -- 253 -------------- 254 255 procedure Set_Item 256 (Index : Table_Index_Type; 257 Item : Table_Component_Type) 258 is 259 begin 260 if Int (Index) > Max then 261 Set_Last (Index); 262 end if; 263 264 Table (Index) := Item; 265 end Set_Item; 266 267 -------------- 268 -- Set_Last -- 269 -------------- 270 271 procedure Set_Last (New_Val : Table_Index_Type) is 272 begin 273 if Int (New_Val) < Last_Val then 274 Last_Val := Int (New_Val); 275 else 276 Last_Val := Int (New_Val); 277 278 if Last_Val > Max then 279 Reallocate; 280 end if; 281 end if; 282 end Set_Last; 283 284 ---------------------------- 285 -- Tree_Get_Table_Address -- 286 ---------------------------- 287 288 function Tree_Get_Table_Address return Address is 289 begin 290 if Length = 0 then 291 return Null_Address; 292 else 293 return Table (First)'Address; 294 end if; 295 end Tree_Get_Table_Address; 296 297 --------------- 298 -- Tree_Read -- 299 --------------- 300 301 -- Note: we allocate only the space required to accommodate the data 302 -- actually written, which means that a Tree_Write/Tree_Read sequence 303 -- does an implicit Release. 304 305 procedure Tree_Read is 306 begin 307 Tree_Read_Int (Max); 308 Last_Val := Max; 309 Length := Max - Min + 1; 310 Reallocate; 311 312 Tree_Read_Data 313 (Tree_Get_Table_Address, 314 (Last_Val - Int (First) + 1) * 315 Table_Type'Component_Size / Storage_Unit); 316 end Tree_Read; 317 318 ---------------- 319 -- Tree_Write -- 320 ---------------- 321 322 -- Note: we write out only the currently valid data, not the entire 323 -- contents of the allocated array. See note above on Tree_Read. 324 325 procedure Tree_Write is 326 begin 327 Tree_Write_Int (Int (Last)); 328 Tree_Write_Data 329 (Tree_Get_Table_Address, 330 (Last_Val - Int (First) + 1) * 331 Table_Type'Component_Size / Storage_Unit); 332 end Tree_Write; 333 334 begin 335 Init; 336 end Table; 337end Table; 338