gcc/ada/sem_dist.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             S E M _ D I S T                              --
   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 -- 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 Casing;   use Casing;
  29 with Einfo;    use Einfo;
  30 with Errout;   use Errout;
  31 with Exp_Dist; use Exp_Dist;
  32 with Exp_Tss;  use Exp_Tss;
  33 with Nlists;   use Nlists;
  34 with Nmake;    use Nmake;
  35 with Namet;    use Namet;
  36 with Opt;      use Opt;
  37 with Rtsfind;  use Rtsfind;
  38 with Sem;      use Sem;
  39 with Sem_Res;  use Sem_Res;
  40 with Sem_Util; use Sem_Util;
  41 with Sinfo;    use Sinfo;
  42 with Snames;   use Snames;
  43 with Stand;    use Stand;
  44 with Stringt;  use Stringt;
  45 with Tbuild;   use Tbuild;
  46 with Uname;    use Uname;
  47
  48 package body Sem_Dist is
  49
  50    -----------------------
  51    -- Local Subprograms --
  52    -----------------------
  53
  54    procedure RAS_E_Dereference (Pref : Node_Id);
  55    --  Handles explicit dereference of Remote Access to Subprograms.
  56
  57    function Full_Qualified_Name (E : Entity_Id) return String_Id;
  58    --  returns the full qualified name of the entity in lower case.
  59
  60    -------------------------
  61    -- Add_Stub_Constructs --
  62    -------------------------
  63
  64    procedure Add_Stub_Constructs (N : Node_Id) is
  65       U    : constant Node_Id := Unit (N);
  66       Spec : Entity_Id        := Empty;
  67       Exp  : Node_Id          := U;         --  Unit that will be expanded
  68
  69    begin
  70       pragma Assert (Distribution_Stub_Mode /= No_Stubs);
  71
  72       if Nkind (U) = N_Package_Declaration then
  73          Spec := Defining_Entity (Specification (U));
  74
  75       elsif Nkind (U) = N_Package_Body then
  76          Spec := Corresponding_Spec (U);
  77
  78       else pragma Assert (Nkind (U) = N_Package_Instantiation);
  79          Exp  := Instance_Spec (U);
  80          Spec := Defining_Entity (Specification (Exp));
  81       end if;
  82
  83       pragma Assert (Is_Shared_Passive (Spec)
  84         or else Is_Remote_Call_Interface (Spec));
  85
  86       if Distribution_Stub_Mode = Generate_Caller_Stub_Body then
  87
  88          if Is_Shared_Passive (Spec) then
  89             null;
  90          elsif Nkind (U) = N_Package_Body then
  91             Error_Msg_N
  92               ("Specification file expected from command line", U);
  93          else
  94             Expand_Calling_Stubs_Bodies (Exp);
  95          end if;
  96
  97       else
  98
  99          if Is_Shared_Passive (Spec) then
 100             Build_Passive_Partition_Stub (Exp);
 101          else
 102             Expand_Receiving_Stubs_Bodies (Exp);
 103          end if;
 104
 105       end if;
 106    end Add_Stub_Constructs;
 107
 108    -------------------------
 109    -- Full_Qualified_Name --
 110    -------------------------
 111
 112    function Full_Qualified_Name (E : Entity_Id) return String_Id is
 113       Ent         : Entity_Id := E;
 114       Parent_Name : String_Id := No_String;
 115
 116    begin
 117       --  Deals properly with child units
 118
 119       if Nkind (Ent) = N_Defining_Program_Unit_Name then
 120          Ent := Defining_Identifier (Ent);
 121       end if;
 122
 123       --  Compute recursively the qualification. Only "Standard" has no scope.
 124
 125       if Present (Scope (Scope (Ent))) then
 126          Parent_Name := Full_Qualified_Name (Scope (Ent));
 127       end if;
 128
 129       --  Every entity should have a name except some expanded blocks
 130       --  don't bother about those.
 131
 132       if Chars (Ent) = No_Name then
 133          return Parent_Name;
 134       end if;
 135
 136       --  Add a period between Name and qualification
 137
 138       if Parent_Name /= No_String then
 139          Start_String (Parent_Name);
 140          Store_String_Char (Get_Char_Code ('.'));
 141
 142       else
 143          Start_String;
 144       end if;
 145
 146       --  Generates the entity name in upper case
 147
 148       Get_Name_String (Chars (Ent));
 149       Set_Casing (All_Lower_Case);
 150       Store_String_Chars (Name_Buffer (1 .. Name_Len));
 151       return End_String;
 152    end Full_Qualified_Name;
 153
 154    -----------------------
 155    -- Get_Subprogram_Id --
 156    -----------------------
 157
 158    function Get_Subprogram_Id (E : Entity_Id) return Int is
 159       Current_Declaration : Node_Id;
 160       Result              : Int := 0;
 161
 162    begin
 163       pragma Assert
 164         (Is_Remote_Call_Interface (Scope (E))
 165            and then
 166              (Nkind (Parent (E)) = N_Procedure_Specification
 167                 or else
 168               Nkind (Parent (E)) = N_Function_Specification));
 169
 170       Current_Declaration :=
 171         First (Visible_Declarations
 172           (Package_Specification_Of_Scope (Scope (E))));
 173
 174       while Current_Declaration /= Empty loop
 175          if Nkind (Current_Declaration) = N_Subprogram_Declaration
 176            and then Comes_From_Source (Current_Declaration)
 177          then
 178             if Defining_Unit_Name
 179                  (Specification (Current_Declaration)) = E
 180             then
 181                return Result;
 182             end if;
 183
 184             Result := Result + 1;
 185          end if;
 186
 187          Next (Current_Declaration);
 188       end loop;
 189
 190       --  Error if we do not find it
 191
 192       raise Program_Error;
 193    end Get_Subprogram_Id;
 194
 195    ------------------------
 196    -- Is_All_Remote_Call --
 197    ------------------------
 198
 199    function Is_All_Remote_Call (N : Node_Id) return Boolean is
 200       Par : Node_Id;
 201
 202    begin
 203       if (Nkind (N) = N_Function_Call
 204               or else Nkind (N) = N_Procedure_Call_Statement)
 205         and then Nkind (Name (N)) in N_Has_Entity
 206         and then Is_Remote_Call_Interface (Entity (Name (N)))
 207         and then Has_All_Calls_Remote (Scope (Entity (Name (N))))
 208         and then Comes_From_Source (N)
 209       then
 210          Par := Parent (Entity (Name (N)));
 211
 212          while Present (Par)
 213            and then (Nkind (Par) /= N_Package_Specification
 214                        or else Is_Wrapper_Package (Defining_Entity (Par)))
 215          loop
 216             Par := Parent (Par);
 217          end loop;
 218
 219          if Present (Par) then
 220             return
 221               not Scope_Within_Or_Same (Current_Scope, Defining_Entity (Par));
 222          else
 223             return False;
 224          end if;
 225       else
 226          return False;
 227       end if;
 228    end Is_All_Remote_Call;
 229
 230    ------------------------------------
 231    -- Package_Specification_Of_Scope --
 232    ------------------------------------
 233
 234    function Package_Specification_Of_Scope (E : Entity_Id) return Node_Id is
 235       N : Node_Id := Parent (E);
 236    begin
 237       while Nkind (N) /= N_Package_Specification loop
 238          N := Parent (N);
 239       end loop;
 240
 241       return N;
 242    end Package_Specification_Of_Scope;
 243
 244    --------------------------
 245    -- Process_Partition_ID --
 246    --------------------------
 247
 248    procedure Process_Partition_Id (N : Node_Id) is
 249       Loc            : constant Source_Ptr := Sloc (N);
 250       Ety            : Entity_Id;
 251       Get_Pt_Id      : Node_Id;
 252       Get_Pt_Id_Call : Node_Id;
 253       Prefix_String  : String_Id;
 254       Typ            : constant Entity_Id := Etype (N);
 255
 256    begin
 257       Ety := Entity (Prefix (N));
 258
 259       --  In case prefix is not a library unit entity, get the entity
 260       --  of library unit.
 261
 262       while (Present (Scope (Ety))
 263         and then Scope (Ety) /= Standard_Standard)
 264         and not Is_Child_Unit (Ety)
 265       loop
 266          Ety := Scope (Ety);
 267       end loop;
 268
 269       --  Retrieve the proper function to call.
 270
 271       if Is_Remote_Call_Interface (Ety) then
 272          Get_Pt_Id := New_Occurrence_Of
 273            (RTE (RE_Get_Active_Partition_Id), Loc);
 274
 275       elsif Is_Shared_Passive (Ety) then
 276          Get_Pt_Id := New_Occurrence_Of
 277            (RTE (RE_Get_Passive_Partition_Id), Loc);
 278
 279       else
 280          Get_Pt_Id := New_Occurrence_Of
 281            (RTE (RE_Get_Local_Partition_Id), Loc);
 282       end if;
 283
 284       --  Get and store the String_Id corresponding to the name of the
 285       --  library unit whose Partition_Id is needed
 286
 287       Get_Unit_Name_String (Get_Unit_Name (Unit_Declaration_Node (Ety)));
 288
 289       --  Remove seven last character ("(spec)" or " (body)").
 290       --  (this is a bit nasty, should have interface for this ???)
 291
 292       Name_Len := Name_Len - 7;
 293
 294       Start_String;
 295       Store_String_Chars (Name_Buffer (1 .. Name_Len));
 296       Prefix_String := End_String;
 297
 298       --  Build the function call which will replace the attribute
 299
 300       if Is_Remote_Call_Interface (Ety)
 301         or else Is_Shared_Passive (Ety)
 302       then
 303          Get_Pt_Id_Call :=
 304            Make_Function_Call (Loc,
 305              Name => Get_Pt_Id,
 306              Parameter_Associations =>
 307                New_List (Make_String_Literal (Loc, Prefix_String)));
 308
 309       else
 310          Get_Pt_Id_Call := Make_Function_Call (Loc, Get_Pt_Id);
 311
 312       end if;
 313
 314       --  Replace the attribute node by a conversion of the function call
 315       --  to the target type.
 316
 317       Rewrite (N, Convert_To (Typ, Get_Pt_Id_Call));
 318       Analyze_And_Resolve (N, Typ);
 319    end Process_Partition_Id;
 320
 321    ----------------------------------
 322    -- Process_Remote_AST_Attribute --
 323    ----------------------------------
 324
 325    procedure Process_Remote_AST_Attribute
 326      (N        : Node_Id;
 327       New_Type : Entity_Id)
 328    is
 329       Loc                   : constant Source_Ptr := Sloc (N);
 330       Remote_Subp           : Entity_Id;
 331       Tick_Access_Conv_Call : Node_Id;
 332       Remote_Subp_Decl      : Node_Id;
 333       RS_Pkg_Specif         : Node_Id;
 334       RS_Pkg_E              : Entity_Id;
 335       RAS_Type              : Entity_Id;
 336       Async_E               : Entity_Id;
 337       Subp_Id               : Int;
 338       Attribute_Subp        : Entity_Id;
 339       Parameter             : Node_Id;
 340
 341    begin
 342       --  Check if we have to expand the access attribute
 343
 344       Remote_Subp := Entity (Prefix (N));
 345
 346       if not Expander_Active then
 347          return;
 348
 349       elsif Ekind (New_Type) = E_Record_Type then
 350          RAS_Type := New_Type;
 351
 352       else
 353          --  If the remote type has not been constructed yet, create
 354          --  it and its attributes now.
 355
 356          Attribute_Subp := TSS (New_Type, TSS_RAS_Access);
 357
 358          if No (Attribute_Subp) then
 359             Add_RAST_Features (Parent (New_Type));
 360          end if;
 361
 362          RAS_Type := Equivalent_Type (New_Type);
 363       end if;
 364
 365       Attribute_Subp := TSS (RAS_Type, TSS_RAS_Access);
 366       Remote_Subp_Decl := Unit_Declaration_Node (Remote_Subp);
 367
 368       if Nkind (Remote_Subp_Decl) = N_Subprogram_Body then
 369          Remote_Subp := Corresponding_Spec (Remote_Subp_Decl);
 370          Remote_Subp_Decl := Unit_Declaration_Node (Remote_Subp);
 371       end if;
 372
 373       RS_Pkg_Specif := Parent (Remote_Subp_Decl);
 374       RS_Pkg_E := Defining_Entity (RS_Pkg_Specif);
 375
 376       Subp_Id := Get_Subprogram_Id (Remote_Subp);
 377
 378       if Ekind (Remote_Subp) = E_Procedure
 379         and then Is_Asynchronous (Remote_Subp)
 380       then
 381          Async_E := Standard_True;
 382       else
 383          Async_E := Standard_False;
 384       end if;
 385
 386       Parameter := New_Occurrence_Of (RTE (RE_Null_Address), Loc);
 387
 388       Tick_Access_Conv_Call :=
 389         Make_Function_Call (Loc,
 390           Name => New_Occurrence_Of (Attribute_Subp, Loc),
 391           Parameter_Associations =>
 392             New_List (
 393               Parameter,
 394               Make_String_Literal (Loc, Full_Qualified_Name (RS_Pkg_E)),
 395               Make_Integer_Literal (Loc, Subp_Id),
 396               New_Occurrence_Of (Async_E, Loc)));
 397
 398       Rewrite (N, Tick_Access_Conv_Call);
 399       Analyze_And_Resolve (N, RAS_Type);
 400    end Process_Remote_AST_Attribute;
 401
 402    ------------------------------------
 403    -- Process_Remote_AST_Declaration --
 404    ------------------------------------
 405
 406    procedure Process_Remote_AST_Declaration (N : Node_Id) is
 407       Loc           : constant Source_Ptr := Sloc (N);
 408       User_Type     : constant Node_Id := Defining_Identifier (N);
 409       Fat_Type      : constant Entity_Id :=
 410                         Make_Defining_Identifier
 411                           (Loc, Chars (User_Type));
 412       New_Type_Decl : Node_Id;
 413
 414    begin
 415       --  We add a record type declaration for the equivalent fat pointer type
 416
 417       New_Type_Decl :=
 418         Make_Full_Type_Declaration (Loc,
 419           Defining_Identifier => Fat_Type,
 420           Type_Definition =>
 421             Make_Record_Definition (Loc,
 422               Component_List =>
 423                 Make_Component_List (Loc,
 424                   Component_Items => New_List (
 425
 426                     Make_Component_Declaration (Loc,
 427                       Defining_Identifier =>
 428                         Make_Defining_Identifier (Loc,
 429                           Chars => Name_Ras),
 430                       Component_Definition =>
 431                         Make_Component_Definition (Loc,
 432                           Aliased_Present    => False,
 433                           Subtype_Indication =>
 434                             New_Occurrence_Of (RTE (RE_Unsigned_64), Loc))),
 435
 436                     Make_Component_Declaration (Loc,
 437                       Defining_Identifier =>
 438                         Make_Defining_Identifier (Loc,
 439                           Chars => Name_Origin),
 440                       Component_Definition =>
 441                         Make_Component_Definition (Loc,
 442                           Aliased_Present    => False,
 443                           Subtype_Indication =>
 444                             New_Reference_To (Standard_Integer, Loc))),
 445
 446                     Make_Component_Declaration (Loc,
 447                       Defining_Identifier =>
 448                         Make_Defining_Identifier (Loc,
 449                           Chars => Name_Receiver),
 450                       Component_Definition =>
 451                         Make_Component_Definition (Loc,
 452                           Aliased_Present    => False,
 453                           Subtype_Indication =>
 454                             New_Reference_To (RTE (RE_Unsigned_64), Loc))),
 455
 456                     Make_Component_Declaration (Loc,
 457                       Defining_Identifier =>
 458                         Make_Defining_Identifier (Loc,
 459                           Chars => Name_Subp_Id),
 460                       Component_Definition =>
 461                         Make_Component_Definition (Loc,
 462                           Aliased_Present    => False,
 463                           Subtype_Indication =>
 464                             New_Reference_To (Standard_Natural, Loc))),
 465
 466                     Make_Component_Declaration (Loc,
 467                       Defining_Identifier =>
 468                         Make_Defining_Identifier (Loc,
 469                           Chars => Name_Async),
 470                       Component_Definition =>
 471                         Make_Component_Definition (Loc,
 472                           Aliased_Present    => False,
 473                           Subtype_Indication =>
 474                             New_Reference_To (Standard_Boolean, Loc)))))));
 475
 476       Insert_After (N, New_Type_Decl);
 477       Set_Equivalent_Type (User_Type, Fat_Type);
 478       Set_Corresponding_Remote_Type (Fat_Type, User_Type);
 479
 480       --  The reason we suppress the initialization procedure is that we know
 481       --  that no initialization is required (even if Initialize_Scalars mode
 482       --  is active), and there are order of elaboration problems if we do try
 483       --  to generate an init proc for this created record type.
 484
 485       Set_Suppress_Init_Proc (Fat_Type);
 486
 487       if Expander_Active then
 488          Add_RAST_Features (Parent (User_Type));
 489       end if;
 490    end Process_Remote_AST_Declaration;
 491
 492    -----------------------
 493    -- RAS_E_Dereference --
 494    -----------------------
 495
 496    procedure RAS_E_Dereference (Pref : Node_Id) is
 497       Loc             : constant Source_Ptr := Sloc (Pref);
 498       Call_Node       : Node_Id;
 499       New_Type        : constant Entity_Id := Etype (Pref);
 500       RAS             : constant Entity_Id :=
 501                           Corresponding_Remote_Type (New_Type);
 502       RAS_Decl        : constant Node_Id   := Parent (RAS);
 503       Explicit_Deref  : constant Node_Id   := Parent (Pref);
 504       Deref_Subp_Call : constant Node_Id   := Parent (Explicit_Deref);
 505       Deref_Proc      : Entity_Id;
 506       Params          : List_Id;
 507
 508    begin
 509       if Nkind (Deref_Subp_Call) = N_Procedure_Call_Statement then
 510          Params := Parameter_Associations (Deref_Subp_Call);
 511
 512          if Present (Params) then
 513             Prepend (Pref, Params);
 514          else
 515             Params := New_List (Pref);
 516          end if;
 517
 518       elsif Nkind (Deref_Subp_Call) = N_Indexed_Component then
 519
 520          Params := Expressions (Deref_Subp_Call);
 521
 522          if Present (Params) then
 523             Prepend (Pref, Params);
 524          else
 525             Params := New_List (Pref);
 526          end if;
 527
 528       else
 529          --  Context is not a call.
 530
 531          return;
 532       end if;
 533
 534       Deref_Proc := TSS (New_Type, TSS_RAS_Dereference);
 535
 536       if not Expander_Active then
 537          return;
 538
 539       elsif No (Deref_Proc) then
 540          Add_RAST_Features (RAS_Decl);
 541          Deref_Proc := TSS (New_Type, TSS_RAS_Dereference);
 542       end if;
 543
 544       if Ekind (Deref_Proc) = E_Function then
 545          Call_Node :=
 546            Make_Function_Call (Loc,
 547               Name => New_Occurrence_Of (Deref_Proc, Loc),
 548               Parameter_Associations => Params);
 549
 550       else
 551          Call_Node :=
 552            Make_Procedure_Call_Statement (Loc,
 553               Name => New_Occurrence_Of (Deref_Proc, Loc),
 554               Parameter_Associations => Params);
 555       end if;
 556
 557       Rewrite (Deref_Subp_Call, Call_Node);
 558       Analyze (Deref_Subp_Call);
 559    end RAS_E_Dereference;
 560
 561    ------------------------------
 562    -- Remote_AST_E_Dereference --
 563    ------------------------------
 564
 565    function Remote_AST_E_Dereference (P : Node_Id) return Boolean
 566    is
 567       ET : constant Entity_Id  := Etype (P);
 568
 569    begin
 570       --  Perform the changes only on original dereferences, and only if
 571       --  we are generating code.
 572
 573       if Comes_From_Source (P)
 574         and then Is_Record_Type (ET)
 575         and then (Is_Remote_Call_Interface (ET)
 576                    or else Is_Remote_Types (ET))
 577         and then Present (Corresponding_Remote_Type (ET))
 578         and then (Nkind (Parent (Parent (P))) = N_Procedure_Call_Statement
 579                    or else Nkind (Parent (Parent (P))) = N_Indexed_Component)
 580         and then Expander_Active
 581       then
 582          RAS_E_Dereference (P);
 583          return True;
 584       else
 585          return False;
 586       end if;
 587    end Remote_AST_E_Dereference;
 588
 589    ------------------------------
 590    -- Remote_AST_I_Dereference --
 591    ------------------------------
 592
 593    function Remote_AST_I_Dereference (P : Node_Id) return Boolean
 594    is
 595       ET     : constant Entity_Id  := Etype (P);
 596       Deref  : Node_Id;
 597    begin
 598
 599       if Comes_From_Source (P)
 600         and then (Is_Remote_Call_Interface (ET)
 601                    or else Is_Remote_Types (ET))
 602         and then Present (Corresponding_Remote_Type (ET))
 603         and then Ekind (Entity (P)) /= E_Function
 604       then
 605          Deref :=
 606            Make_Explicit_Dereference (Sloc (P),
 607              Prefix => Relocate_Node (P));
 608          Rewrite (P, Deref);
 609          Set_Etype (P, ET);
 610          RAS_E_Dereference (Prefix (P));
 611          return True;
 612       end if;
 613
 614       return False;
 615    end Remote_AST_I_Dereference;
 616
 617    ---------------------------
 618    -- Remote_AST_Null_Value --
 619    ---------------------------
 620
 621    function Remote_AST_Null_Value
 622      (N    : Node_Id;
 623       Typ  : Entity_Id)
 624       return Boolean
 625    is
 626       Loc         : constant Source_Ptr := Sloc (N);
 627       Target_Type : Entity_Id;
 628
 629    begin
 630       if not Expander_Active then
 631          return False;
 632
 633       elsif Ekind (Typ) = E_Access_Subprogram_Type
 634         and then (Is_Remote_Call_Interface (Typ)
 635                     or else Is_Remote_Types (Typ))
 636         and then Comes_From_Source (N)
 637         and then Expander_Active
 638       then
 639          --  Any null that comes from source and is of the RAS type must
 640          --  be expanded, except if expansion is not active (nothing
 641          --  gets expanded into the equivalent record type).
 642
 643          Target_Type := Equivalent_Type (Typ);
 644
 645       elsif Ekind (Typ) = E_Record_Type
 646         and then Present (Corresponding_Remote_Type (Typ))
 647       then
 648          --  This is a record type representing a RAS type, this must be
 649          --  expanded.
 650
 651          Target_Type := Typ;
 652
 653       else
 654          --  We do not have to handle this case
 655
 656          return False;
 657
 658       end if;
 659
 660       Rewrite (N,
 661         Make_Aggregate (Loc,
 662           Expressions => New_List (
 663             Make_Integer_Literal (Loc, 0),                  -- Ras
 664             Make_Integer_Literal (Loc, 0),                  -- Origin
 665             Make_Integer_Literal (Loc, 0),                  -- Receiver
 666             Make_Integer_Literal (Loc, 0),                  -- Subp_Id
 667             New_Occurrence_Of (Standard_False, Loc))));     -- Asyn
 668       Analyze_And_Resolve (N, Target_Type);
 669       return True;
 670    end Remote_AST_Null_Value;
 671
 672 end Sem_Dist;