gcc/ada/i-cpp.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                       I N T E R F A C E S . C P P                        --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --                                                                          --
  10 --          Copyright (C) 1992-2002, Free Software Foundation, Inc.         --
  11 --                                                                          --
  12 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  13 -- terms of the  GNU General Public License as published  by the Free Soft- --
  14 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  15 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  16 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  17 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  18 -- for  more details.  You should have  received  a copy of the GNU General --
  19 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  20 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  21 -- MA 02111-1307, USA.                                                      --
  22 --                                                                          --
  23 -- As a special exception,  if other files  instantiate  generics from this --
  24 -- unit, or you link  this unit with other files  to produce an executable, --
  25 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  26 -- covered  by the  GNU  General  Public  License.  This exception does not --
  27 -- however invalidate  any other reasons why  the executable file  might be --
  28 -- covered by the  GNU Public License.                                      --
  29 --                                                                          --
  30 -- GNAT was originally developed  by the GNAT team at  New York University. --
  31 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
  32 --                                                                          --
  33 ------------------------------------------------------------------------------
  34
  35 with Ada.Tags;                use Ada.Tags;
  36 with Interfaces.C;            use Interfaces.C;
  37 with System;                  use System;
  38 with System.Storage_Elements; use System.Storage_Elements;
  39 with Unchecked_Conversion;
  40
  41 package body Interfaces.CPP is
  42
  43    subtype Cstring is String (Positive);
  44    type Cstring_Ptr is access all Cstring;
  45    type Tag_Table is array (Natural range <>) of Vtable_Ptr;
  46    pragma Suppress_Initialization (Tag_Table);
  47
  48    type Type_Specific_Data is record
  49       Idepth        : Natural;
  50       Expanded_Name : Cstring_Ptr;
  51       External_Tag  : Cstring_Ptr;
  52       HT_Link       : Tag;
  53       Ancestor_Tags : Tag_Table (Natural);
  54    end record;
  55
  56    type Vtable_Entry is record
  57      Pfn    : System.Address;
  58    end record;
  59
  60    type Type_Specific_Data_Ptr is access all Type_Specific_Data;
  61    type Vtable_Entry_Array is array (Positive range <>) of Vtable_Entry;
  62
  63    type VTable is record
  64       Unused1   : C.short;
  65       Unused2   : C.short;
  66       TSD       : Type_Specific_Data_Ptr;
  67       Prims_Ptr : Vtable_Entry_Array (Positive);
  68    end record;
  69
  70    --------------------------------------------------------
  71    -- Unchecked Conversions for Tag, Vtable_Ptr, and TSD --
  72    --------------------------------------------------------
  73
  74    function To_Type_Specific_Data_Ptr is
  75      new Unchecked_Conversion (Address, Type_Specific_Data_Ptr);
  76
  77    function To_Address is
  78      new Unchecked_Conversion (Type_Specific_Data_Ptr, Address);
  79
  80    ---------------------------------------------
  81    -- Unchecked Conversions for String Fields --
  82    ---------------------------------------------
  83
  84    function To_Cstring_Ptr is
  85      new Unchecked_Conversion (Address, Cstring_Ptr);
  86
  87    function To_Address is
  88      new Unchecked_Conversion (Cstring_Ptr, Address);
  89
  90    -----------------------
  91    -- Local Subprograms --
  92    -----------------------
  93
  94    function Length (Str : Cstring_Ptr) return Natural;
  95    --  Length of string represented by the given pointer (treating the
  96    --  string as a C-style string, which is Nul terminated).
  97
  98    -----------------------
  99    -- CPP_CW_Membership --
 100    -----------------------
 101
 102    function CPP_CW_Membership
 103      (Obj_Tag : Vtable_Ptr;
 104       Typ_Tag : Vtable_Ptr)
 105       return Boolean
 106    is
 107       Pos : constant Integer := Obj_Tag.TSD.Idepth - Typ_Tag.TSD.Idepth;
 108    begin
 109       return Pos >= 0 and then Obj_Tag.TSD.Ancestor_Tags (Pos) = Typ_Tag;
 110    end CPP_CW_Membership;
 111
 112    ---------------------------
 113    -- CPP_Get_Expanded_Name --
 114    ---------------------------
 115
 116    function CPP_Get_Expanded_Name (T : Vtable_Ptr) return Address is
 117    begin
 118       return To_Address (T.TSD.Expanded_Name);
 119    end CPP_Get_Expanded_Name;
 120
 121    --------------------------
 122    -- CPP_Get_External_Tag --
 123    --------------------------
 124
 125    function CPP_Get_External_Tag (T : Vtable_Ptr) return Address is
 126    begin
 127       return To_Address (T.TSD.External_Tag);
 128    end CPP_Get_External_Tag;
 129
 130    -------------------------------
 131    -- CPP_Get_Inheritance_Depth --
 132    -------------------------------
 133
 134    function CPP_Get_Inheritance_Depth (T : Vtable_Ptr) return Natural is
 135    begin
 136       return T.TSD.Idepth;
 137    end CPP_Get_Inheritance_Depth;
 138
 139    -------------------------
 140    -- CPP_Get_Prim_Op_Address --
 141    -------------------------
 142
 143    function CPP_Get_Prim_Op_Address
 144      (T        : Vtable_Ptr;
 145       Position : Positive)
 146       return Address is
 147    begin
 148       return T.Prims_Ptr (Position).Pfn;
 149    end CPP_Get_Prim_Op_Address;
 150
 151    -----------------------
 152    -- CPP_Get_RC_Offset --
 153    -----------------------
 154
 155    function CPP_Get_RC_Offset (T : Vtable_Ptr) return SSE.Storage_Offset is
 156       pragma Warnings (Off, T);
 157
 158    begin
 159       return 0;
 160    end CPP_Get_RC_Offset;
 161
 162    -------------------------------
 163    -- CPP_Get_Remotely_Callable --
 164    -------------------------------
 165
 166    function CPP_Get_Remotely_Callable (T : Vtable_Ptr) return Boolean is
 167       pragma Warnings (Off, T);
 168
 169    begin
 170       return True;
 171    end CPP_Get_Remotely_Callable;
 172
 173    -----------------
 174    -- CPP_Get_TSD --
 175    -----------------
 176
 177    function CPP_Get_TSD  (T : Vtable_Ptr) return Address is
 178    begin
 179       return To_Address (T.TSD);
 180    end CPP_Get_TSD;
 181
 182    --------------------
 183    -- CPP_Inherit_DT --
 184    --------------------
 185
 186    procedure CPP_Inherit_DT
 187     (Old_T   : Vtable_Ptr;
 188      New_T   : Vtable_Ptr;
 189      Entry_Count : Natural)
 190    is
 191    begin
 192       if Old_T /= null then
 193          New_T.Prims_Ptr (1 .. Entry_Count)
 194            := Old_T.Prims_Ptr (1 .. Entry_Count);
 195       end if;
 196    end CPP_Inherit_DT;
 197
 198    ---------------------
 199    -- CPP_Inherit_TSD --
 200    ---------------------
 201
 202    procedure CPP_Inherit_TSD
 203      (Old_TSD : Address;
 204       New_Tag : Vtable_Ptr)
 205    is
 206       TSD : constant Type_Specific_Data_Ptr
 207         := To_Type_Specific_Data_Ptr (Old_TSD);
 208
 209       New_TSD : Type_Specific_Data renames New_Tag.TSD.all;
 210
 211    begin
 212       if TSD /= null then
 213          New_TSD.Idepth := TSD.Idepth + 1;
 214          New_TSD.Ancestor_Tags (1 .. New_TSD.Idepth)
 215            := TSD.Ancestor_Tags (0 .. TSD.Idepth);
 216       else
 217          New_TSD.Idepth := 0;
 218       end if;
 219
 220       New_TSD.Ancestor_Tags (0) := New_Tag;
 221    end CPP_Inherit_TSD;
 222
 223    ---------------------------
 224    -- CPP_Set_Expanded_Name --
 225    ---------------------------
 226
 227    procedure CPP_Set_Expanded_Name (T : Vtable_Ptr; Value : Address) is
 228    begin
 229       T.TSD.Expanded_Name := To_Cstring_Ptr (Value);
 230    end CPP_Set_Expanded_Name;
 231
 232    --------------------------
 233    -- CPP_Set_External_Tag --
 234    --------------------------
 235
 236    procedure CPP_Set_External_Tag (T : Vtable_Ptr; Value : Address) is
 237    begin
 238       T.TSD.External_Tag := To_Cstring_Ptr (Value);
 239    end CPP_Set_External_Tag;
 240
 241    -------------------------------
 242    -- CPP_Set_Inheritance_Depth --
 243    -------------------------------
 244
 245    procedure CPP_Set_Inheritance_Depth
 246      (T     : Vtable_Ptr;
 247       Value : Natural)
 248    is
 249    begin
 250       T.TSD.Idepth := Value;
 251    end CPP_Set_Inheritance_Depth;
 252
 253    -----------------------------
 254    -- CPP_Set_Prim_Op_Address --
 255    -----------------------------
 256
 257    procedure CPP_Set_Prim_Op_Address
 258      (T        : Vtable_Ptr;
 259       Position : Positive;
 260       Value    : Address)
 261    is
 262    begin
 263       T.Prims_Ptr (Position).Pfn := Value;
 264    end CPP_Set_Prim_Op_Address;
 265
 266    -----------------------
 267    -- CPP_Set_RC_Offset --
 268    -----------------------
 269
 270    procedure CPP_Set_RC_Offset (T : Vtable_Ptr; Value : SSE.Storage_Offset) is
 271       pragma Warnings (Off, T);
 272       pragma Warnings (Off, Value);
 273
 274    begin
 275       null;
 276    end CPP_Set_RC_Offset;
 277
 278    -------------------------------
 279    -- CPP_Set_Remotely_Callable --
 280    -------------------------------
 281
 282    procedure CPP_Set_Remotely_Callable (T : Vtable_Ptr; Value : Boolean) is
 283       pragma Warnings (Off, T);
 284       pragma Warnings (Off, Value);
 285
 286    begin
 287       null;
 288    end CPP_Set_Remotely_Callable;
 289
 290    -----------------
 291    -- CPP_Set_TSD --
 292    -----------------
 293
 294    procedure CPP_Set_TSD (T : Vtable_Ptr; Value : Address) is
 295    begin
 296       T.TSD := To_Type_Specific_Data_Ptr (Value);
 297    end CPP_Set_TSD;
 298
 299    --------------------
 300    -- Displaced_This --
 301    --------------------
 302
 303    function Displaced_This
 304     (Current_This : System.Address;
 305      Vptr         : Vtable_Ptr;
 306      Position     : Positive)
 307      return         System.Address
 308    is
 309       pragma Warnings (Off, Vptr);
 310       pragma Warnings (Off, Position);
 311
 312    begin
 313       return Current_This;
 314
 315       --  why is the following here commented out ???
 316       --  + Storage_Offset (Vptr.Prims_Ptr (Position).Delta1);
 317    end Displaced_This;
 318
 319    -------------------
 320    -- Expanded_Name --
 321    -------------------
 322
 323    function Expanded_Name (T : Vtable_Ptr) return String is
 324       Result : Cstring_Ptr := T.TSD.Expanded_Name;
 325
 326    begin
 327       return Result (1 .. Length (Result));
 328    end Expanded_Name;
 329
 330    ------------------
 331    -- External_Tag --
 332    ------------------
 333
 334    function External_Tag (T : Vtable_Ptr) return String is
 335       Result : Cstring_Ptr := T.TSD.External_Tag;
 336
 337    begin
 338       return Result (1 .. Length (Result));
 339    end External_Tag;
 340
 341    ------------
 342    -- Length --
 343    ------------
 344
 345    function Length (Str : Cstring_Ptr) return Natural is
 346       Len : Integer := 1;
 347
 348    begin
 349       while Str (Len) /= ASCII.Nul loop
 350          Len := Len + 1;
 351       end loop;
 352
 353       return Len - 1;
 354    end Length;
 355 end Interfaces.CPP;