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 --          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
  34 with Ada.Tags;                use Ada.Tags;
  35 with Interfaces.C;            use Interfaces.C;
  36 with System;                  use System;
  37 with System.Storage_Elements; use System.Storage_Elements;
  38 with Unchecked_Conversion;
  39
  40 package body Interfaces.CPP is
  41
  42    subtype Cstring is String (Positive);
  43    type Cstring_Ptr is access all Cstring;
  44    type Tag_Table is array (Natural range <>) of Vtable_Ptr;
  45    pragma Suppress_Initialization (Tag_Table);
  46
  47    type Type_Specific_Data is record
  48       Idepth        : Natural;
  49       Expanded_Name : Cstring_Ptr;
  50       External_Tag  : Cstring_Ptr;
  51       HT_Link       : Tag;
  52       Ancestor_Tags : Tag_Table (Natural);
  53    end record;
  54
  55    type Vtable_Entry is record
  56      Pfn    : System.Address;
  57    end record;
  58
  59    type Type_Specific_Data_Ptr is access all Type_Specific_Data;
  60    type Vtable_Entry_Array is array (Positive range <>) of Vtable_Entry;
  61
  62    type VTable is record
  63       Unused1   : C.short;
  64       Unused2   : C.short;
  65       TSD       : Type_Specific_Data_Ptr;
  66       Prims_Ptr : Vtable_Entry_Array (Positive);
  67    end record;
  68
  69    --------------------------------------------------------
  70    -- Unchecked Conversions for Tag, Vtable_Ptr, and TSD --
  71    --------------------------------------------------------
  72
  73    function To_Type_Specific_Data_Ptr is
  74      new Unchecked_Conversion (Address, Type_Specific_Data_Ptr);
  75
  76    function To_Address is
  77      new Unchecked_Conversion (Type_Specific_Data_Ptr, Address);
  78
  79    ---------------------------------------------
  80    -- Unchecked Conversions for String Fields --
  81    ---------------------------------------------
  82
  83    function To_Cstring_Ptr is
  84      new Unchecked_Conversion (Address, Cstring_Ptr);
  85
  86    function To_Address is
  87      new Unchecked_Conversion (Cstring_Ptr, Address);
  88
  89    -----------------------
  90    -- Local Subprograms --
  91    -----------------------
  92
  93    function Length (Str : Cstring_Ptr) return Natural;
  94    --  Length of string represented by the given pointer (treating the
  95    --  string as a C-style string, which is Nul terminated).
  96
  97    -----------------------
  98    -- CPP_CW_Membership --
  99    -----------------------
 100
 101    function CPP_CW_Membership
 102      (Obj_Tag : Vtable_Ptr;
 103       Typ_Tag : Vtable_Ptr)
 104       return Boolean
 105    is
 106       Pos : constant Integer := Obj_Tag.TSD.Idepth - Typ_Tag.TSD.Idepth;
 107    begin
 108       return Pos >= 0 and then Obj_Tag.TSD.Ancestor_Tags (Pos) = Typ_Tag;
 109    end CPP_CW_Membership;
 110
 111    ---------------------------
 112    -- CPP_Get_Expanded_Name --
 113    ---------------------------
 114
 115    function CPP_Get_Expanded_Name (T : Vtable_Ptr) return Address is
 116    begin
 117       return To_Address (T.TSD.Expanded_Name);
 118    end CPP_Get_Expanded_Name;
 119
 120    --------------------------
 121    -- CPP_Get_External_Tag --
 122    --------------------------
 123
 124    function CPP_Get_External_Tag (T : Vtable_Ptr) return Address is
 125    begin
 126       return To_Address (T.TSD.External_Tag);
 127    end CPP_Get_External_Tag;
 128
 129    -------------------------------
 130    -- CPP_Get_Inheritance_Depth --
 131    -------------------------------
 132
 133    function CPP_Get_Inheritance_Depth (T : Vtable_Ptr) return Natural is
 134    begin
 135       return T.TSD.Idepth;
 136    end CPP_Get_Inheritance_Depth;
 137
 138    -------------------------
 139    -- CPP_Get_Prim_Op_Address --
 140    -------------------------
 141
 142    function CPP_Get_Prim_Op_Address
 143      (T        : Vtable_Ptr;
 144       Position : Positive)
 145       return Address is
 146    begin
 147       return T.Prims_Ptr (Position).Pfn;
 148    end CPP_Get_Prim_Op_Address;
 149
 150    -----------------------
 151    -- CPP_Get_RC_Offset --
 152    -----------------------
 153
 154    function CPP_Get_RC_Offset (T : Vtable_Ptr) return SSE.Storage_Offset is
 155       pragma Warnings (Off, T);
 156
 157    begin
 158       return 0;
 159    end CPP_Get_RC_Offset;
 160
 161    -------------------------------
 162    -- CPP_Get_Remotely_Callable --
 163    -------------------------------
 164
 165    function CPP_Get_Remotely_Callable (T : Vtable_Ptr) return Boolean is
 166       pragma Warnings (Off, T);
 167
 168    begin
 169       return True;
 170    end CPP_Get_Remotely_Callable;
 171
 172    -----------------
 173    -- CPP_Get_TSD --
 174    -----------------
 175
 176    function CPP_Get_TSD  (T : Vtable_Ptr) return Address is
 177    begin
 178       return To_Address (T.TSD);
 179    end CPP_Get_TSD;
 180
 181    --------------------
 182    -- CPP_Inherit_DT --
 183    --------------------
 184
 185    procedure CPP_Inherit_DT
 186     (Old_T   : Vtable_Ptr;
 187      New_T   : Vtable_Ptr;
 188      Entry_Count : Natural)
 189    is
 190    begin
 191       if Old_T /= null then
 192          New_T.Prims_Ptr (1 .. Entry_Count)
 193            := Old_T.Prims_Ptr (1 .. Entry_Count);
 194       end if;
 195    end CPP_Inherit_DT;
 196
 197    ---------------------
 198    -- CPP_Inherit_TSD --
 199    ---------------------
 200
 201    procedure CPP_Inherit_TSD
 202      (Old_TSD : Address;
 203       New_Tag : Vtable_Ptr)
 204    is
 205       TSD : constant Type_Specific_Data_Ptr
 206         := To_Type_Specific_Data_Ptr (Old_TSD);
 207
 208       New_TSD : Type_Specific_Data renames New_Tag.TSD.all;
 209
 210    begin
 211       if TSD /= null then
 212          New_TSD.Idepth := TSD.Idepth + 1;
 213          New_TSD.Ancestor_Tags (1 .. New_TSD.Idepth)
 214            := TSD.Ancestor_Tags (0 .. TSD.Idepth);
 215       else
 216          New_TSD.Idepth := 0;
 217       end if;
 218
 219       New_TSD.Ancestor_Tags (0) := New_Tag;
 220    end CPP_Inherit_TSD;
 221
 222    ---------------------------
 223    -- CPP_Set_Expanded_Name --
 224    ---------------------------
 225
 226    procedure CPP_Set_Expanded_Name (T : Vtable_Ptr; Value : Address) is
 227    begin
 228       T.TSD.Expanded_Name := To_Cstring_Ptr (Value);
 229    end CPP_Set_Expanded_Name;
 230
 231    --------------------------
 232    -- CPP_Set_External_Tag --
 233    --------------------------
 234
 235    procedure CPP_Set_External_Tag (T : Vtable_Ptr; Value : Address) is
 236    begin
 237       T.TSD.External_Tag := To_Cstring_Ptr (Value);
 238    end CPP_Set_External_Tag;
 239
 240    -------------------------------
 241    -- CPP_Set_Inheritance_Depth --
 242    -------------------------------
 243
 244    procedure CPP_Set_Inheritance_Depth
 245      (T     : Vtable_Ptr;
 246       Value : Natural)
 247    is
 248    begin
 249       T.TSD.Idepth := Value;
 250    end CPP_Set_Inheritance_Depth;
 251
 252    -----------------------------
 253    -- CPP_Set_Prim_Op_Address --
 254    -----------------------------
 255
 256    procedure CPP_Set_Prim_Op_Address
 257      (T        : Vtable_Ptr;
 258       Position : Positive;
 259       Value    : Address)
 260    is
 261    begin
 262       T.Prims_Ptr (Position).Pfn := Value;
 263    end CPP_Set_Prim_Op_Address;
 264
 265    -----------------------
 266    -- CPP_Set_RC_Offset --
 267    -----------------------
 268
 269    procedure CPP_Set_RC_Offset (T : Vtable_Ptr; Value : SSE.Storage_Offset) is
 270       pragma Warnings (Off, T);
 271       pragma Warnings (Off, Value);
 272
 273    begin
 274       null;
 275    end CPP_Set_RC_Offset;
 276
 277    -------------------------------
 278    -- CPP_Set_Remotely_Callable --
 279    -------------------------------
 280
 281    procedure CPP_Set_Remotely_Callable (T : Vtable_Ptr; Value : Boolean) is
 282       pragma Warnings (Off, T);
 283       pragma Warnings (Off, Value);
 284
 285    begin
 286       null;
 287    end CPP_Set_Remotely_Callable;
 288
 289    -----------------
 290    -- CPP_Set_TSD --
 291    -----------------
 292
 293    procedure CPP_Set_TSD (T : Vtable_Ptr; Value : Address) is
 294    begin
 295       T.TSD := To_Type_Specific_Data_Ptr (Value);
 296    end CPP_Set_TSD;
 297
 298    --------------------
 299    -- Displaced_This --
 300    --------------------
 301
 302    function Displaced_This
 303     (Current_This : System.Address;
 304      Vptr         : Vtable_Ptr;
 305      Position     : Positive)
 306      return         System.Address
 307    is
 308       pragma Warnings (Off, Vptr);
 309       pragma Warnings (Off, Position);
 310
 311    begin
 312       return Current_This;
 313
 314       --  why is the following here commented out ???
 315       --  + Storage_Offset (Vptr.Prims_Ptr (Position).Delta1);
 316    end Displaced_This;
 317
 318    -------------------
 319    -- Expanded_Name --
 320    -------------------
 321
 322    function Expanded_Name (T : Vtable_Ptr) return String is
 323       Result : Cstring_Ptr := T.TSD.Expanded_Name;
 324
 325    begin
 326       return Result (1 .. Length (Result));
 327    end Expanded_Name;
 328
 329    ------------------
 330    -- External_Tag --
 331    ------------------
 332
 333    function External_Tag (T : Vtable_Ptr) return String is
 334       Result : Cstring_Ptr := T.TSD.External_Tag;
 335
 336    begin
 337       return Result (1 .. Length (Result));
 338    end External_Tag;
 339
 340    ------------
 341    -- Length --
 342    ------------
 343
 344    function Length (Str : Cstring_Ptr) return Natural is
 345       Len : Integer := 1;
 346
 347    begin
 348       while Str (Len) /= ASCII.Nul loop
 349          Len := Len + 1;
 350       end loop;
 351
 352       return Len - 1;
 353    end Length;
 354 end Interfaces.CPP;