gcc/ada/i-cpp-vms.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 --         Copyright (C) 2000-2004, 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
  34 --  This is the OpenVMS/Alpha DEC C++ (cxx) version of this package
  35
  36 with Ada.Tags;                use Ada.Tags;
  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       Prims_Ptr : Vtable_Entry_Array (Positive);
  65       TSD       : Type_Specific_Data_Ptr;
  66       --  Location of TSD is unknown so it got moved here to be out of the
  67       --  way of Prims_Ptr. Find it later. ???
  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    -- Displaced_This --
 100    --------------------
 101
 102    function Displaced_This
 103     (Current_This : System.Address;
 104      Vptr         : Vtable_Ptr;
 105      Position     : Positive) return System.Address
 106    is
 107       pragma Warnings (Off, Vptr);
 108       pragma Warnings (Off, Position);
 109    begin
 110       return Current_This;
 111       --        + Storage_Offset (Vptr.Prims_Ptr (Position).Delta1);
 112       --  why is above line commented out ???
 113    end Displaced_This;
 114
 115    -----------------------
 116    -- CPP_CW_Membership --
 117    -----------------------
 118
 119    function CPP_CW_Membership
 120      (Obj_Tag : Vtable_Ptr;
 121       Typ_Tag : Vtable_Ptr) return Boolean
 122    is
 123       Pos : constant Integer := Obj_Tag.TSD.Idepth - Typ_Tag.TSD.Idepth;
 124    begin
 125       return Pos >= 0 and then Obj_Tag.TSD.Ancestor_Tags (Pos) = Typ_Tag;
 126    end CPP_CW_Membership;
 127
 128    ---------------------------
 129    -- CPP_Get_Expanded_Name --
 130    ---------------------------
 131
 132    function CPP_Get_Expanded_Name (T : Vtable_Ptr) return Address is
 133    begin
 134       return To_Address (T.TSD.Expanded_Name);
 135    end CPP_Get_Expanded_Name;
 136
 137    --------------------------
 138    -- CPP_Get_External_Tag --
 139    --------------------------
 140
 141    function CPP_Get_External_Tag (T : Vtable_Ptr) return Address is
 142    begin
 143       return To_Address (T.TSD.External_Tag);
 144    end CPP_Get_External_Tag;
 145
 146    -------------------------------
 147    -- CPP_Get_Inheritance_Depth --
 148    -------------------------------
 149
 150    function CPP_Get_Inheritance_Depth (T : Vtable_Ptr) return Natural is
 151    begin
 152       return T.TSD.Idepth;
 153    end CPP_Get_Inheritance_Depth;
 154
 155    -----------------------
 156    -- CPP_Get_RC_Offset --
 157    -----------------------
 158
 159    function CPP_Get_RC_Offset (T : Vtable_Ptr) return SSE.Storage_Offset is
 160       pragma Warnings (Off, T);
 161    begin
 162       return 0;
 163    end CPP_Get_RC_Offset;
 164
 165    -----------------------------
 166    -- CPP_Get_Prim_Op_Address --
 167    -----------------------------
 168
 169    function CPP_Get_Prim_Op_Address
 170      (T        : Vtable_Ptr;
 171       Position : Positive) return Address
 172    is
 173    begin
 174       return T.Prims_Ptr (Position).Pfn;
 175    end CPP_Get_Prim_Op_Address;
 176
 177    -------------------------------
 178    -- CPP_Get_Remotely_Callable --
 179    -------------------------------
 180
 181    function CPP_Get_Remotely_Callable (T : Vtable_Ptr) return Boolean is
 182       pragma Warnings (Off, T);
 183    begin
 184       return True;
 185    end CPP_Get_Remotely_Callable;
 186
 187    -----------------
 188    -- CPP_Get_TSD --
 189    -----------------
 190
 191    function CPP_Get_TSD  (T : Vtable_Ptr) return Address is
 192    begin
 193       return To_Address (T.TSD);
 194    end CPP_Get_TSD;
 195
 196    --------------------
 197    -- CPP_Inherit_DT --
 198    --------------------
 199
 200    procedure CPP_Inherit_DT
 201     (Old_T       : Vtable_Ptr;
 202      New_T       : Vtable_Ptr;
 203      Entry_Count : Natural)
 204    is
 205    begin
 206       if Old_T /= null then
 207          New_T.Prims_Ptr (1 .. Entry_Count) :=
 208            Old_T.Prims_Ptr (1 .. Entry_Count);
 209       end if;
 210    end CPP_Inherit_DT;
 211
 212    ---------------------
 213    -- CPP_Inherit_TSD --
 214    ---------------------
 215
 216    procedure CPP_Inherit_TSD
 217      (Old_TSD : Address;
 218       New_Tag : Vtable_Ptr)
 219    is
 220       TSD : constant Type_Specific_Data_Ptr :=
 221               To_Type_Specific_Data_Ptr (Old_TSD);
 222
 223       New_TSD : Type_Specific_Data renames New_Tag.TSD.all;
 224
 225    begin
 226       if TSD /= null then
 227          New_TSD.Idepth := TSD.Idepth + 1;
 228          New_TSD.Ancestor_Tags (1 .. New_TSD.Idepth)
 229            := TSD.Ancestor_Tags (0 .. TSD.Idepth);
 230       else
 231          New_TSD.Idepth := 0;
 232       end if;
 233
 234       New_TSD.Ancestor_Tags (0) := New_Tag;
 235    end CPP_Inherit_TSD;
 236
 237    ---------------------------
 238    -- CPP_Set_Expanded_Name --
 239    ---------------------------
 240
 241    procedure CPP_Set_Expanded_Name (T : Vtable_Ptr; Value : Address) is
 242    begin
 243       T.TSD.Expanded_Name := To_Cstring_Ptr (Value);
 244    end CPP_Set_Expanded_Name;
 245
 246    --------------------------
 247    -- CPP_Set_External_Tag --
 248    --------------------------
 249
 250    procedure CPP_Set_External_Tag (T : Vtable_Ptr; Value : Address) is
 251    begin
 252       T.TSD.External_Tag := To_Cstring_Ptr (Value);
 253    end CPP_Set_External_Tag;
 254
 255    -------------------------------
 256    -- CPP_Set_Inheritance_Depth --
 257    -------------------------------
 258
 259    procedure CPP_Set_Inheritance_Depth
 260      (T     : Vtable_Ptr;
 261       Value : Natural)
 262    is
 263    begin
 264       T.TSD.Idepth := Value;
 265    end CPP_Set_Inheritance_Depth;
 266
 267    -----------------------------
 268    -- CPP_Set_Prim_Op_Address --
 269    -----------------------------
 270
 271    procedure CPP_Set_Prim_Op_Address
 272      (T        : Vtable_Ptr;
 273       Position : Positive;
 274       Value    : Address)
 275    is
 276    begin
 277       T.Prims_Ptr (Position).Pfn := Value;
 278    end CPP_Set_Prim_Op_Address;
 279
 280    -----------------------
 281    -- CPP_Set_RC_Offset --
 282    -----------------------
 283
 284    procedure CPP_Set_RC_Offset (T : Vtable_Ptr; Value : SSE.Storage_Offset) is
 285       pragma Warnings (Off, T);
 286       pragma Warnings (Off, Value);
 287    begin
 288       null;
 289    end CPP_Set_RC_Offset;
 290
 291    -------------------------------
 292    -- CPP_Set_Remotely_Callable --
 293    -------------------------------
 294
 295    procedure CPP_Set_Remotely_Callable (T : Vtable_Ptr; Value : Boolean) is
 296       pragma Warnings (Off, T);
 297       pragma Warnings (Off, Value);
 298    begin
 299       null;
 300    end CPP_Set_Remotely_Callable;
 301
 302    -----------------
 303    -- CPP_Set_TSD --
 304    -----------------
 305
 306    procedure CPP_Set_TSD (T : Vtable_Ptr; Value : Address) is
 307    begin
 308       T.TSD := To_Type_Specific_Data_Ptr (Value);
 309    end CPP_Set_TSD;
 310
 311    -------------------
 312    -- Expanded_Name --
 313    -------------------
 314
 315    function Expanded_Name (T : Vtable_Ptr) return String is
 316       Result : constant Cstring_Ptr := T.TSD.Expanded_Name;
 317    begin
 318       return Result (1 .. Length (Result));
 319    end Expanded_Name;
 320
 321    ------------------
 322    -- External_Tag --
 323    ------------------
 324
 325    function External_Tag (T : Vtable_Ptr) return String is
 326       Result : constant Cstring_Ptr := T.TSD.External_Tag;
 327    begin
 328       return Result (1 .. Length (Result));
 329    end External_Tag;
 330
 331    ------------
 332    -- Length --
 333    ------------
 334
 335    function Length (Str : Cstring_Ptr) return Natural is
 336       Len : Integer := 1;
 337
 338    begin
 339       while Str (Len) /= ASCII.Nul loop
 340          Len := Len + 1;
 341       end loop;
 342
 343       return Len - 1;
 344    end Length;
 345
 346 end Interfaces.CPP;