gcc/ada/exp_tss.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                              E X P _ T S S                               --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2005, 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,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- GNAT was originally developed  by the GNAT team at  New York University. --
  23 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  24 --                                                                          --
  25 ------------------------------------------------------------------------------
  26
  27 with Atree;    use Atree;
  28 with Einfo;    use Einfo;
  29 with Elists;   use Elists;
  30 with Exp_Util; use Exp_Util;
  31 with Lib;      use Lib;
  32 with Namet;    use Namet;
  33 with Sem_Util; use Sem_Util;
  34 with Sinfo;    use Sinfo;
  35
  36 package body Exp_Tss is
  37
  38    --------------------
  39    -- Base_Init_Proc --
  40    --------------------
  41
  42    function Base_Init_Proc (Typ : Entity_Id) return Entity_Id is
  43       Full_Type : E;
  44       Proc      : Entity_Id;
  45
  46    begin
  47       pragma Assert (Ekind (Typ) in Type_Kind);
  48
  49       if Is_Private_Type (Typ) then
  50          Full_Type := Underlying_Type (Base_Type (Typ));
  51       else
  52          Full_Type := Typ;
  53       end if;
  54
  55       if No (Full_Type) then
  56          return Empty;
  57       elsif Is_Concurrent_Type (Full_Type)
  58         and then Present (Corresponding_Record_Type (Base_Type (Full_Type)))
  59       then
  60          return Init_Proc (Corresponding_Record_Type (Base_Type (Full_Type)));
  61
  62       else
  63          Proc := Init_Proc (Base_Type (Full_Type));
  64
  65          if No (Proc)
  66            and then Is_Composite_Type (Full_Type)
  67            and then Is_Derived_Type (Full_Type)
  68          then
  69             return Init_Proc (Root_Type (Full_Type));
  70          else
  71             return Proc;
  72          end if;
  73       end if;
  74    end Base_Init_Proc;
  75
  76    --------------
  77    -- Copy_TSS --
  78    --------------
  79
  80    --  Note: internally this routine is also used to initially set up
  81    --  a TSS entry for a new type (case of being called from Set_TSS)
  82
  83    procedure Copy_TSS (TSS : Entity_Id; Typ : Entity_Id) is
  84       FN : Node_Id;
  85
  86    begin
  87       Ensure_Freeze_Node (Typ);
  88       FN := Freeze_Node (Typ);
  89
  90       if No (TSS_Elist (FN)) then
  91          Set_TSS_Elist (FN, New_Elmt_List);
  92       end if;
  93
  94       --  We prepend here, so that a second call overrides the first, it
  95       --  is not clear that this is required, but it seems reasonable.
  96
  97       Prepend_Elmt (TSS, TSS_Elist (FN));
  98    end Copy_TSS;
  99
 100    ------------------------
 101    -- Find_Inherited_TSS --
 102    ------------------------
 103
 104    function Find_Inherited_TSS
 105      (Typ : Entity_Id;
 106       Nam : TSS_Name_Type) return Entity_Id
 107    is
 108       Btyp : Entity_Id := Typ;
 109       Proc : Entity_Id;
 110
 111    begin
 112       loop
 113          Btyp := Base_Type (Btyp);
 114          Proc :=  TSS (Btyp, Nam);
 115
 116          exit when Present (Proc)
 117            or else not Is_Derived_Type (Btyp);
 118
 119          --  If Typ is a derived type, it may inherit attributes from some
 120          --  ancestor.
 121
 122          Btyp := Etype (Btyp);
 123       end loop;
 124
 125       if No (Proc) then
 126
 127          --  If nothing else, use the TSS of the root type
 128
 129          Proc := TSS (Base_Type (Underlying_Type (Typ)), Nam);
 130       end if;
 131
 132       return Proc;
 133    end Find_Inherited_TSS;
 134
 135    -----------------------
 136    -- Get_TSS_Name_Type --
 137    -----------------------
 138
 139    function Get_TSS_Name (E : Entity_Id) return TSS_Name_Type is
 140       C1 : Character;
 141       C2 : Character;
 142       Nm : TSS_Name_Type;
 143
 144    begin
 145       Get_Last_Two_Chars (Chars (E), C1, C2);
 146
 147       if C1 in 'A' .. 'Z' and then C2 in 'A' .. 'Z' then
 148          Nm := (C1, C2);
 149
 150          for J in TSS_Names'Range loop
 151             if Nm = TSS_Names (J) then
 152                return Nm;
 153             end if;
 154          end loop;
 155       end if;
 156
 157       return TSS_Null;
 158    end Get_TSS_Name;
 159
 160    ---------------------------------
 161    -- Has_Non_Null_Base_Init_Proc --
 162    ---------------------------------
 163
 164    function Has_Non_Null_Base_Init_Proc (Typ : Entity_Id) return Boolean is
 165       BIP : constant Entity_Id := Base_Init_Proc (Typ);
 166
 167    begin
 168       return Present (BIP) and then not Is_Null_Init_Proc (BIP);
 169    end Has_Non_Null_Base_Init_Proc;
 170
 171    ---------------
 172    -- Init_Proc --
 173    ---------------
 174
 175    function Init_Proc (Typ : Entity_Id) return Entity_Id is
 176       FN   : constant Node_Id := Freeze_Node (Typ);
 177       Elmt : Elmt_Id;
 178
 179    begin
 180       if No (FN) then
 181          return Empty;
 182
 183       elsif No (TSS_Elist (FN)) then
 184          return Empty;
 185
 186       else
 187          Elmt := First_Elmt (TSS_Elist (FN));
 188          while Present (Elmt) loop
 189             if Is_Init_Proc (Node (Elmt)) then
 190                return Node (Elmt);
 191             end if;
 192
 193             Next_Elmt (Elmt);
 194          end loop;
 195       end if;
 196
 197       return Empty;
 198    end Init_Proc;
 199
 200    ------------------
 201    -- Is_Init_Proc --
 202    ------------------
 203
 204    function Is_Init_Proc (E : Entity_Id) return Boolean is
 205       C1 : Character;
 206       C2 : Character;
 207    begin
 208       Get_Last_Two_Chars (Chars (E), C1, C2);
 209       return C1 = TSS_Init_Proc (1) and then C2 = TSS_Init_Proc (2);
 210    end Is_Init_Proc;
 211
 212    ------------
 213    -- Is_TSS --
 214    ------------
 215
 216    function Is_TSS (E : Entity_Id; Nam : TSS_Name_Type) return Boolean is
 217       C1 : Character;
 218       C2 : Character;
 219    begin
 220       Get_Last_Two_Chars (Chars (E), C1, C2);
 221       return C1 = Nam (1) and then C2 = Nam (2);
 222    end Is_TSS;
 223
 224    function Is_TSS (N : Name_Id; Nam : TSS_Name_Type) return Boolean is
 225       C1 : Character;
 226       C2 : Character;
 227    begin
 228       Get_Last_Two_Chars (N, C1, C2);
 229       return C1 = Nam (1) and then C2 = Nam (2);
 230    end Is_TSS;
 231
 232    -------------------------
 233    -- Make_Init_Proc_Name --
 234    -------------------------
 235
 236    function Make_Init_Proc_Name (Typ : Entity_Id) return Name_Id is
 237    begin
 238       return Make_TSS_Name (Typ, TSS_Init_Proc);
 239    end Make_Init_Proc_Name;
 240
 241    -------------------------
 242    -- Make_TSS_Name_Local --
 243    -------------------------
 244
 245    function Make_TSS_Name_Local
 246      (Typ : Entity_Id;
 247       Nam : TSS_Name_Type) return Name_Id
 248    is
 249    begin
 250       Get_Name_String (Chars (Typ));
 251       Add_Char_To_Name_Buffer ('_');
 252       Add_Nat_To_Name_Buffer (Increment_Serial_Number);
 253       Add_Char_To_Name_Buffer (Nam (1));
 254       Add_Char_To_Name_Buffer (Nam (2));
 255       return Name_Find;
 256    end Make_TSS_Name_Local;
 257
 258    -------------------
 259    -- Make_TSS_Name --
 260    -------------------
 261
 262    function Make_TSS_Name
 263      (Typ : Entity_Id;
 264       Nam : TSS_Name_Type) return Name_Id
 265    is
 266    begin
 267       Get_Name_String (Chars (Typ));
 268       Add_Char_To_Name_Buffer (Nam (1));
 269       Add_Char_To_Name_Buffer (Nam (2));
 270       return Name_Find;
 271    end Make_TSS_Name;
 272
 273    --------------
 274    -- Same_TSS --
 275    --------------
 276
 277    function Same_TSS (E1, E2 : Entity_Id) return Boolean is
 278       E1C1 : Character;
 279       E1C2 : Character;
 280       E2C1 : Character;
 281       E2C2 : Character;
 282
 283    begin
 284       Get_Last_Two_Chars (Chars (E1), E1C1, E1C2);
 285       Get_Last_Two_Chars (Chars (E2), E2C1, E2C2);
 286
 287       return
 288         E1C1 = E2C1
 289           and then
 290         E1C2 = E2C2
 291           and then
 292         E1C1 in 'A' .. 'Z'
 293           and then
 294         E1C2 in 'A' .. 'Z';
 295    end Same_TSS;
 296
 297    -------------------
 298    -- Set_Init_Proc --
 299    -------------------
 300
 301    procedure Set_Init_Proc (Typ : Entity_Id; Init : Entity_Id) is
 302    begin
 303       Set_TSS (Typ, Init);
 304    end Set_Init_Proc;
 305
 306    -------------
 307    -- Set_TSS --
 308    -------------
 309
 310    procedure Set_TSS (Typ : Entity_Id; TSS : Entity_Id) is
 311       Subprog_Body : constant Node_Id := Unit_Declaration_Node (TSS);
 312
 313    begin
 314       --  Case of insertion location is in unit defining the type
 315
 316       if In_Same_Code_Unit (Typ, TSS) then
 317          Append_Freeze_Action (Typ, Subprog_Body);
 318
 319       --  Otherwise, we are using an already existing TSS in another unit
 320
 321       else
 322          null;
 323       end if;
 324
 325       Copy_TSS (TSS, Typ);
 326    end Set_TSS;
 327
 328    ---------
 329    -- TSS --
 330    ---------
 331
 332    function TSS (Typ : Entity_Id; Nam : TSS_Name_Type) return Entity_Id is
 333       FN   : constant Node_Id := Freeze_Node (Typ);
 334       Elmt : Elmt_Id;
 335       Subp : Entity_Id;
 336
 337    begin
 338       if No (FN) then
 339          return Empty;
 340
 341       elsif No (TSS_Elist (FN)) then
 342          return Empty;
 343
 344       else
 345          Elmt := First_Elmt (TSS_Elist (FN));
 346          while Present (Elmt) loop
 347             if Is_TSS (Node (Elmt), Nam) then
 348                Subp := Node (Elmt);
 349
 350                --  For stream subprograms, the TSS entity may be a renaming-
 351                --  as-body of an already generated entity. Use that one rather
 352                --  the one introduced by the renaming, which is an artifact of
 353                --  current stream handling.
 354
 355                if Nkind (Parent (Parent (Subp))) =
 356                                            N_Subprogram_Renaming_Declaration
 357                  and then
 358                    Present (Corresponding_Spec (Parent (Parent (Subp))))
 359                then
 360                   return Corresponding_Spec (Parent (Parent (Subp)));
 361                else
 362                   return Subp;
 363                end if;
 364
 365             else
 366                Next_Elmt (Elmt);
 367             end if;
 368          end loop;
 369       end if;
 370
 371       return Empty;
 372    end TSS;
 373
 374    function TSS (Typ : Entity_Id; Nam : Name_Id) return Entity_Id is
 375       FN   : constant Node_Id := Freeze_Node (Typ);
 376       Elmt : Elmt_Id;
 377       Subp : Entity_Id;
 378
 379    begin
 380       if No (FN) then
 381          return Empty;
 382
 383       elsif No (TSS_Elist (FN)) then
 384          return Empty;
 385
 386       else
 387          Elmt := First_Elmt (TSS_Elist (FN));
 388          while Present (Elmt) loop
 389             if Chars (Node (Elmt)) =  Nam then
 390                Subp := Node (Elmt);
 391
 392                --  For stream subprograms, the TSS entity may be a renaming-
 393                --  as-body of an already generated entity. Use that one rather
 394                --  the one introduced by the renaming, which is an artifact of
 395                --  current stream handling.
 396
 397                if Nkind (Parent (Parent (Subp))) =
 398                                            N_Subprogram_Renaming_Declaration
 399                  and then
 400                    Present (Corresponding_Spec (Parent (Parent (Subp))))
 401                then
 402                   return Corresponding_Spec (Parent (Parent (Subp)));
 403                else
 404                   return Subp;
 405                end if;
 406
 407             else
 408                Next_Elmt (Elmt);
 409             end if;
 410          end loop;
 411       end if;
 412
 413       return Empty;
 414    end TSS;
 415
 416 end Exp_Tss;