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) 1992-2004, 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 with Ada.Tags;                use Ada.Tags;
  35 with System;                  use System;
  36 with System.Storage_Elements; use System.Storage_Elements;
  37 with Unchecked_Conversion;
  38
  39 package body Interfaces.CPP is
  40
  41    --  The declarations below need (extensive) comments ???
  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    end record;
  67
  68    --------------------------------------------------------
  69    -- Unchecked Conversions for Tag, Vtable_Ptr, and TSD --
  70    --------------------------------------------------------
  71
  72    function To_Type_Specific_Data_Ptr is
  73      new Unchecked_Conversion (Address, Type_Specific_Data_Ptr);
  74
  75    function To_Address is
  76      new Unchecked_Conversion (Type_Specific_Data_Ptr, Address);
  77
  78    ---------------------------------------------
  79    -- Unchecked Conversions for String Fields --
  80    ---------------------------------------------
  81
  82    function To_Cstring_Ptr is
  83      new Unchecked_Conversion (Address, Cstring_Ptr);
  84
  85    function To_Address is
  86      new Unchecked_Conversion (Cstring_Ptr, Address);
  87
  88    -----------------------
  89    -- Local Subprograms --
  90    -----------------------
  91
  92    function Length (Str : Cstring_Ptr) return Natural;
  93    --  Length of string represented by the given pointer (treating the
  94    --  string as a C-style string, which is Nul terminated).
  95
  96    -----------------------
  97    -- CPP_CW_Membership --
  98    -----------------------
  99
 100    function CPP_CW_Membership
 101      (Obj_Tag : Vtable_Ptr;
 102       Typ_Tag : Vtable_Ptr) return Boolean
 103    is
 104       Pos : constant Integer := Obj_Tag.TSD.Idepth - Typ_Tag.TSD.Idepth;
 105    begin
 106       return Pos >= 0 and then Obj_Tag.TSD.Ancestor_Tags (Pos) = Typ_Tag;
 107    end CPP_CW_Membership;
 108
 109    ---------------------------
 110    -- CPP_Get_Expanded_Name --
 111    ---------------------------
 112
 113    function CPP_Get_Expanded_Name (T : Vtable_Ptr) return Address is
 114    begin
 115       return To_Address (T.TSD.Expanded_Name);
 116    end CPP_Get_Expanded_Name;
 117
 118    --------------------------
 119    -- CPP_Get_External_Tag --
 120    --------------------------
 121
 122    function CPP_Get_External_Tag (T : Vtable_Ptr) return Address is
 123    begin
 124       return To_Address (T.TSD.External_Tag);
 125    end CPP_Get_External_Tag;
 126
 127    -------------------------------
 128    -- CPP_Get_Inheritance_Depth --
 129    -------------------------------
 130
 131    function CPP_Get_Inheritance_Depth (T : Vtable_Ptr) return Natural is
 132    begin
 133       return T.TSD.Idepth;
 134    end CPP_Get_Inheritance_Depth;
 135
 136    -------------------------
 137    -- CPP_Get_Prim_Op_Address --
 138    -------------------------
 139
 140    function CPP_Get_Prim_Op_Address
 141      (T        : Vtable_Ptr;
 142       Position : Positive) return Address
 143    is
 144    begin
 145       return T.Prims_Ptr (Position).Pfn;
 146    end CPP_Get_Prim_Op_Address;
 147
 148    -----------------------
 149    -- CPP_Get_RC_Offset --
 150    -----------------------
 151
 152    function CPP_Get_RC_Offset (T : Vtable_Ptr) return SSE.Storage_Offset is
 153       pragma Warnings (Off, T);
 154    begin
 155       return 0;
 156    end CPP_Get_RC_Offset;
 157
 158    -------------------------------
 159    -- CPP_Get_Remotely_Callable --
 160    -------------------------------
 161
 162    function CPP_Get_Remotely_Callable (T : Vtable_Ptr) return Boolean is
 163       pragma Warnings (Off, T);
 164    begin
 165       return True;
 166    end CPP_Get_Remotely_Callable;
 167
 168    -----------------
 169    -- CPP_Get_TSD --
 170    -----------------
 171
 172    function CPP_Get_TSD  (T : Vtable_Ptr) return Address is
 173    begin
 174       return To_Address (T.TSD);
 175    end CPP_Get_TSD;
 176
 177    --------------------
 178    -- CPP_Inherit_DT --
 179    --------------------
 180
 181    procedure CPP_Inherit_DT
 182     (Old_T   : Vtable_Ptr;
 183      New_T   : Vtable_Ptr;
 184      Entry_Count : Natural)
 185    is
 186    begin
 187       if Old_T /= null then
 188          New_T.Prims_Ptr (1 .. Entry_Count)
 189            := Old_T.Prims_Ptr (1 .. Entry_Count);
 190       end if;
 191    end CPP_Inherit_DT;
 192
 193    ---------------------
 194    -- CPP_Inherit_TSD --
 195    ---------------------
 196
 197    procedure CPP_Inherit_TSD
 198      (Old_TSD : Address;
 199       New_Tag : Vtable_Ptr)
 200    is
 201       TSD : constant Type_Specific_Data_Ptr :=
 202               To_Type_Specific_Data_Ptr (Old_TSD);
 203
 204       New_TSD : Type_Specific_Data renames New_Tag.TSD.all;
 205
 206    begin
 207       if TSD /= null then
 208          New_TSD.Idepth := TSD.Idepth + 1;
 209          New_TSD.Ancestor_Tags (1 .. New_TSD.Idepth)
 210            := TSD.Ancestor_Tags (0 .. TSD.Idepth);
 211       else
 212          New_TSD.Idepth := 0;
 213       end if;
 214
 215       New_TSD.Ancestor_Tags (0) := New_Tag;
 216    end CPP_Inherit_TSD;
 217
 218    ---------------------------
 219    -- CPP_Set_Expanded_Name --
 220    ---------------------------
 221
 222    procedure CPP_Set_Expanded_Name (T : Vtable_Ptr; Value : Address) is
 223    begin
 224       T.TSD.Expanded_Name := To_Cstring_Ptr (Value);
 225    end CPP_Set_Expanded_Name;
 226
 227    --------------------------
 228    -- CPP_Set_External_Tag --
 229    --------------------------
 230
 231    procedure CPP_Set_External_Tag (T : Vtable_Ptr; Value : Address) is
 232    begin
 233       T.TSD.External_Tag := To_Cstring_Ptr (Value);
 234    end CPP_Set_External_Tag;
 235
 236    -------------------------------
 237    -- CPP_Set_Inheritance_Depth --
 238    -------------------------------
 239
 240    procedure CPP_Set_Inheritance_Depth
 241      (T     : Vtable_Ptr;
 242       Value : Natural)
 243    is
 244    begin
 245       T.TSD.Idepth := Value;
 246    end CPP_Set_Inheritance_Depth;
 247
 248    -----------------------------
 249    -- CPP_Set_Prim_Op_Address --
 250    -----------------------------
 251
 252    procedure CPP_Set_Prim_Op_Address
 253      (T        : Vtable_Ptr;
 254       Position : Positive;
 255       Value    : Address)
 256    is
 257    begin
 258       T.Prims_Ptr (Position).Pfn := Value;
 259    end CPP_Set_Prim_Op_Address;
 260
 261    -----------------------
 262    -- CPP_Set_RC_Offset --
 263    -----------------------
 264
 265    procedure CPP_Set_RC_Offset (T : Vtable_Ptr; Value : SSE.Storage_Offset) is
 266       pragma Warnings (Off, T);
 267       pragma Warnings (Off, Value);
 268    begin
 269       null;
 270    end CPP_Set_RC_Offset;
 271
 272    -------------------------------
 273    -- CPP_Set_Remotely_Callable --
 274    -------------------------------
 275
 276    procedure CPP_Set_Remotely_Callable (T : Vtable_Ptr; Value : Boolean) is
 277       pragma Warnings (Off, T);
 278       pragma Warnings (Off, Value);
 279    begin
 280       null;
 281    end CPP_Set_Remotely_Callable;
 282
 283    -----------------
 284    -- CPP_Set_TSD --
 285    -----------------
 286
 287    procedure CPP_Set_TSD (T : Vtable_Ptr; Value : Address) is
 288    begin
 289       T.TSD := To_Type_Specific_Data_Ptr (Value);
 290    end CPP_Set_TSD;
 291
 292    --------------------
 293    -- Displaced_This --
 294    --------------------
 295
 296    function Displaced_This
 297     (Current_This : System.Address;
 298      Vptr         : Vtable_Ptr;
 299      Position     : Positive)
 300      return         System.Address
 301    is
 302       pragma Warnings (Off, Vptr);
 303       pragma Warnings (Off, Position);
 304
 305    begin
 306       return Current_This;
 307
 308       --  why is the following here commented out ???
 309       --  + Storage_Offset (Vptr.Prims_Ptr (Position).Delta1);
 310    end Displaced_This;
 311
 312    -------------------
 313    -- Expanded_Name --
 314    -------------------
 315
 316    function Expanded_Name (T : Vtable_Ptr) return String is
 317       Result : constant Cstring_Ptr := T.TSD.Expanded_Name;
 318    begin
 319       return Result (1 .. Length (Result));
 320    end Expanded_Name;
 321
 322    ------------------
 323    -- External_Tag --
 324    ------------------
 325
 326    function External_Tag (T : Vtable_Ptr) return String is
 327       Result : constant Cstring_Ptr := T.TSD.External_Tag;
 328    begin
 329       return Result (1 .. Length (Result));
 330    end External_Tag;
 331
 332    ------------
 333    -- Length --
 334    ------------
 335
 336    function Length (Str : Cstring_Ptr) return Natural is
 337       Len : Integer := 1;
 338
 339    begin
 340       while Str (Len) /= ASCII.Nul loop
 341          Len := Len + 1;
 342       end loop;
 343
 344       return Len - 1;
 345    end Length;
 346
 347 end Interfaces.CPP;