1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                               E X P _ C G                                --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--          Copyright (C) 2010-2014, 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 3,  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 COPYING3.  If not, go to --
19-- http://www.gnu.org/licenses for a complete copy of the license.          --
20--                                                                          --
21-- GNAT was originally developed  by the GNAT team at  New York University. --
22-- Extensive contributions were provided by Ada Core Technologies Inc.      --
23--                                                                          --
24------------------------------------------------------------------------------
25
26with Atree;    use Atree;
27with Einfo;    use Einfo;
28with Elists;   use Elists;
29with Exp_Disp; use Exp_Disp;
30with Exp_Dbug; use Exp_Dbug;
31with Exp_Tss;  use Exp_Tss;
32with Lib;      use Lib;
33with Namet;    use Namet;
34with Opt;      use Opt;
35with Output;   use Output;
36with Sem_Aux;  use Sem_Aux;
37with Sem_Disp; use Sem_Disp;
38with Sem_Type; use Sem_Type;
39with Sem_Util; use Sem_Util;
40with Sinfo;    use Sinfo;
41with Sinput;   use Sinput;
42with Snames;   use Snames;
43with System;   use System;
44with Table;
45with Uintp;    use Uintp;
46
47package body Exp_CG is
48
49   --  We duplicate here some declarations from packages Interfaces.C and
50   --  Interfaces.C_Streams because adding their dependence to the frontend
51   --  causes bootstrapping problems with old versions of the compiler.
52
53   subtype FILEs is System.Address;
54   --  Corresponds to the C type FILE*
55
56   subtype C_chars is System.Address;
57   --  Pointer to null-terminated array of characters
58
59   function fputs (Strng : C_chars; Stream : FILEs) return Integer;
60   pragma Import (C, fputs, "fputs");
61
62   --  Import the file stream associated with the "ci" output file. Done to
63   --  generate the output in the file created and left opened by routine
64   --  toplev.c before calling gnat1drv.
65
66   Callgraph_Info_File : FILEs;
67   pragma Import (C, Callgraph_Info_File);
68
69   package Call_Graph_Nodes is new Table.Table (
70      Table_Component_Type => Node_Id,
71      Table_Index_Type     => Natural,
72      Table_Low_Bound      => 1,
73      Table_Initial        => 50,
74      Table_Increment      => 100,
75      Table_Name           => "Call_Graph_Nodes");
76   --  This table records nodes associated with dispatching calls and tagged
77   --  type declarations found in the main compilation unit. Used as an
78   --  auxiliary storage because the call-graph output requires fully qualified
79   --  names and they are not available until the backend is called.
80
81   function Is_Predefined_Dispatching_Operation (E : Entity_Id) return Boolean;
82   --  Determines if E is a predefined primitive operation.
83   --  Note: This routine should replace the routine with the same name that is
84   --  currently available in exp_disp because it extends its functionality to
85   --  handle fully qualified names ???
86
87   function Slot_Number (Prim : Entity_Id) return Uint;
88   --  Returns the slot number associated with Prim. For predefined primitives
89   --  the slot is returned as a negative number.
90
91   procedure Write_Output (Str : String);
92   --  Used to print a line in the output file (this is used as the
93   --  argument for a call to Set_Special_Output in package Output).
94
95   procedure Write_Call_Info (Call : Node_Id);
96   --  Subsidiary of Generate_CG_Output that generates the output associated
97   --  with a dispatching call.
98
99   procedure Write_Type_Info (Typ : Entity_Id);
100   --  Subsidiary of Generate_CG_Output that generates the output associated
101   --  with a tagged type declaration.
102
103   ------------------------
104   -- Generate_CG_Output --
105   ------------------------
106
107   procedure Generate_CG_Output is
108      N : Node_Id;
109
110   begin
111      --  No output if the "ci" output file has not been previously opened
112      --  by toplev.c
113
114      if Callgraph_Info_File = Null_Address then
115         return;
116      end if;
117
118      --  Setup write routine, create the output file and generate the output
119
120      Set_Special_Output (Write_Output'Access);
121
122      for J in Call_Graph_Nodes.First .. Call_Graph_Nodes.Last loop
123         N := Call_Graph_Nodes.Table (J);
124
125         if Nkind (N) in N_Subprogram_Call then
126            Write_Call_Info (N);
127
128         else pragma Assert (Nkind (N) = N_Defining_Identifier);
129
130            --  The type may be a private untagged type whose completion is
131            --  tagged, in which case we must use the full tagged view.
132
133            if not Is_Tagged_Type (N) and then Is_Private_Type (N) then
134               N := Full_View (N);
135            end if;
136
137            pragma Assert (Is_Tagged_Type (N));
138
139            Write_Type_Info (N);
140         end if;
141      end loop;
142
143      Set_Special_Output (null);
144   end Generate_CG_Output;
145
146   ----------------
147   -- Initialize --
148   ----------------
149
150   procedure Initialize is
151   begin
152      Call_Graph_Nodes.Init;
153   end Initialize;
154
155   -----------------------------------------
156   -- Is_Predefined_Dispatching_Operation --
157   -----------------------------------------
158
159   function Is_Predefined_Dispatching_Operation
160     (E : Entity_Id) return Boolean
161   is
162      function Homonym_Suffix_Length (E : Entity_Id) return Natural;
163      --  Returns the length of the homonym suffix corresponding to E.
164      --  Note: This routine relies on the functionality provided by routines
165      --  of Exp_Dbug. Further work needed here to decide if it should be
166      --  located in that package???
167
168      ---------------------------
169      -- Homonym_Suffix_Length --
170      ---------------------------
171
172      function Homonym_Suffix_Length (E : Entity_Id) return Natural is
173         Prefix_Length : constant := 2;
174         --  Length of prefix "__"
175
176         H  : Entity_Id;
177         Nr : Nat := 1;
178
179      begin
180         if not Has_Homonym (E) then
181            return 0;
182
183         else
184            H := Homonym (E);
185            while Present (H) loop
186               if Scope (H) = Scope (E) then
187                  Nr := Nr + 1;
188               end if;
189
190               H := Homonym (H);
191            end loop;
192
193            if Nr = 1 then
194               return 0;
195
196            --  Prefix "__" followed by number
197
198            else
199               declare
200                  Result : Natural := Prefix_Length + 1;
201
202               begin
203                  while Nr >= 10 loop
204                     Result := Result + 1;
205                     Nr := Nr / 10;
206                  end loop;
207
208                  return Result;
209               end;
210            end if;
211         end if;
212      end Homonym_Suffix_Length;
213
214      --  Local variables
215
216      Full_Name     : constant String := Get_Name_String (Chars (E));
217      Suffix_Length : Natural;
218      TSS_Name      : TSS_Name_Type;
219
220   --  Start of processing for Is_Predefined_Dispatching_Operation
221
222   begin
223      if not Is_Dispatching_Operation (E) then
224         return False;
225      end if;
226
227      --  Search for and strip suffix for body-nested package entities
228
229      Suffix_Length := Homonym_Suffix_Length (E);
230      for J in reverse Full_Name'First + 2 .. Full_Name'Last loop
231         if Full_Name (J) = 'X' then
232
233            --  Include the "X", "Xb", "Xn", ... in the part of the
234            --  suffix to be removed.
235
236            Suffix_Length := Suffix_Length + Full_Name'Last - J + 1;
237            exit;
238         end if;
239
240         exit when Full_Name (J) /= 'b' and then Full_Name (J) /= 'n';
241      end loop;
242
243      --  Most predefined primitives have internally generated names. Equality
244      --  must be treated differently; the predefined operation is recognized
245      --  as a homogeneous binary operator that returns Boolean.
246
247      if Full_Name'Length > TSS_Name_Type'Length then
248         TSS_Name :=
249           TSS_Name_Type
250             (Full_Name
251               (Full_Name'Last - TSS_Name'Length - Suffix_Length + 1
252                  .. Full_Name'Last - Suffix_Length));
253
254         if        TSS_Name = TSS_Stream_Read
255           or else TSS_Name = TSS_Stream_Write
256           or else TSS_Name = TSS_Stream_Input
257           or else TSS_Name = TSS_Stream_Output
258           or else TSS_Name = TSS_Deep_Adjust
259           or else TSS_Name = TSS_Deep_Finalize
260         then
261            return True;
262
263         elsif not Has_Fully_Qualified_Name (E) then
264            if Nam_In (Chars (E), Name_uSize, Name_uAlignment, Name_uAssign)
265              or else
266                (Chars (E) = Name_Op_Eq
267                  and then Etype (First_Formal (E)) = Etype (Last_Formal (E)))
268              or else Is_Predefined_Interface_Primitive (E)
269            then
270               return True;
271            end if;
272
273         --  Handle fully qualified names
274
275         else
276            declare
277               type Names_Table is array (Positive range <>) of Name_Id;
278
279               Predef_Names_95 : constant Names_Table :=
280                                   (Name_uSize,
281                                    Name_uAlignment,
282                                    Name_Op_Eq,
283                                    Name_uAssign);
284
285               Predef_Names_05 : constant Names_Table :=
286                                   (Name_uDisp_Asynchronous_Select,
287                                    Name_uDisp_Conditional_Select,
288                                    Name_uDisp_Get_Prim_Op_Kind,
289                                    Name_uDisp_Get_Task_Id,
290                                    Name_uDisp_Requeue,
291                                    Name_uDisp_Timed_Select);
292
293            begin
294               for J in Predef_Names_95'Range loop
295                  Get_Name_String (Predef_Names_95 (J));
296
297                  --  The predefined primitive operations are identified by the
298                  --  names "_size", "_alignment", etc. If we try a pattern
299                  --  matching against this string, we can wrongly match other
300                  --  primitive operations like "get_size". To avoid this, we
301                  --  add the "__" scope separator, which can only prepend
302                  --  predefined primitive operations because other primitive
303                  --  operations can neither start with an underline nor
304                  --  contain two consecutive underlines in its name.
305
306                  if Full_Name'Last - Suffix_Length > Name_Len + 2
307                    and then
308                      Full_Name
309                        (Full_Name'Last - Name_Len - 2 - Suffix_Length + 1
310                           .. Full_Name'Last - Suffix_Length) =
311                      "__" & Name_Buffer (1 .. Name_Len)
312                  then
313                     --  For the equality operator the type of the two operands
314                     --  must also match.
315
316                     return Predef_Names_95 (J) /= Name_Op_Eq
317                       or else
318                         Etype (First_Formal (E)) = Etype (Last_Formal (E));
319                  end if;
320               end loop;
321
322               if Ada_Version >= Ada_2005 then
323                  for J in Predef_Names_05'Range loop
324                     Get_Name_String (Predef_Names_05 (J));
325
326                     if Full_Name'Last - Suffix_Length > Name_Len + 2
327                       and then
328                         Full_Name
329                           (Full_Name'Last - Name_Len - 2 - Suffix_Length + 1
330                              .. Full_Name'Last - Suffix_Length) =
331                         "__" & Name_Buffer (1 .. Name_Len)
332                     then
333                        return True;
334                     end if;
335                  end loop;
336               end if;
337            end;
338         end if;
339      end if;
340
341      return False;
342   end Is_Predefined_Dispatching_Operation;
343
344   ----------------------
345   -- Register_CG_Node --
346   ----------------------
347
348   procedure Register_CG_Node (N : Node_Id) is
349   begin
350      if Nkind (N) in N_Subprogram_Call then
351         if Current_Scope = Main_Unit_Entity
352           or else Entity_Is_In_Main_Unit (Current_Scope)
353         then
354            --  Register a copy of the dispatching call node. Needed since the
355            --  node containing a dispatching call is rewritten by the
356            --  expander.
357
358            declare
359               Copy : constant Node_Id := New_Copy (N);
360               Par  : Node_Id;
361
362            begin
363               --  Determine the enclosing scope to use when generating the
364               --  call graph. This must be done now to avoid problems with
365               --  control structures that may be rewritten during expansion.
366
367               Par := Parent (N);
368               while Nkind (Par) /= N_Subprogram_Body
369                 and then Nkind (Parent (Par)) /= N_Compilation_Unit
370               loop
371                  Par := Parent (Par);
372                  pragma Assert (Present (Par));
373               end loop;
374
375               Set_Parent (Copy, Par);
376               Call_Graph_Nodes.Append (Copy);
377            end;
378         end if;
379
380      else pragma Assert (Nkind (N) = N_Defining_Identifier);
381         if Entity_Is_In_Main_Unit (N) then
382            Call_Graph_Nodes.Append (N);
383         end if;
384      end if;
385   end Register_CG_Node;
386
387   -----------------
388   -- Slot_Number --
389   -----------------
390
391   function Slot_Number (Prim : Entity_Id) return Uint is
392      E : constant Entity_Id := Ultimate_Alias (Prim);
393   begin
394      if Is_Predefined_Dispatching_Operation (E) then
395         return -DT_Position (E);
396      else
397         return DT_Position (E);
398      end if;
399   end Slot_Number;
400
401   ------------------
402   -- Write_Output --
403   ------------------
404
405   procedure Write_Output (Str : String) is
406      Nul   : constant Character := Character'First;
407      Line  : String (Str'First .. Str'Last + 1);
408      Errno : Integer;
409
410   begin
411      --  Add the null character to the string as required by fputs
412
413      Line  := Str & Nul;
414      Errno := fputs (Line'Address, Callgraph_Info_File);
415      pragma Assert (Errno >= 0);
416   end Write_Output;
417
418   ---------------------
419   -- Write_Call_Info --
420   ---------------------
421
422   procedure Write_Call_Info (Call : Node_Id) is
423      Ctrl_Arg : constant Node_Id   := Controlling_Argument (Call);
424      Ctrl_Typ : constant Entity_Id := Base_Type (Etype (Ctrl_Arg));
425      Prim     : constant Entity_Id := Entity (Sinfo.Name (Call));
426      P        : constant Node_Id   := Parent (Call);
427
428   begin
429      Write_Str ("edge: { sourcename: ");
430      Write_Char ('"');
431
432      --  The parent node is the construct that contains the call: subprogram
433      --  body or library-level package. Display the qualified name of the
434      --  entity of the construct. For a subprogram, it is the entity of the
435      --  spec, which carries a homonym counter when it is overloaded.
436
437      if Nkind (P) = N_Subprogram_Body
438        and then not Acts_As_Spec (P)
439      then
440         Get_External_Name (Corresponding_Spec (P));
441
442      else
443         Get_External_Name (Defining_Entity (P));
444      end if;
445
446      Write_Str (Name_Buffer (1 .. Name_Len));
447
448      if Nkind (P) = N_Package_Declaration then
449         Write_Str ("___elabs");
450
451      elsif Nkind (P) = N_Package_Body then
452         Write_Str ("___elabb");
453      end if;
454
455      Write_Char ('"');
456      Write_Eol;
457
458      --  The targetname is a triple:
459      --     N:  the index in a vtable used for dispatch
460      --     V:  the type who's vtable is used
461      --     S:  the static type of the expression
462
463      Write_Str  ("  targetname: ");
464      Write_Char ('"');
465
466      pragma Assert (No (Interface_Alias (Prim)));
467
468      --  The check on Is_Ancestor is done here to avoid problems with
469      --  renamings of primitives. For example:
470
471      --    type Root is tagged ...
472      --    procedure Base   (Obj : Root);
473      --    procedure Base2  (Obj : Root) renames Base;
474
475      if Present (Alias (Prim))
476        and then
477          Is_Ancestor
478            (Find_Dispatching_Type (Ultimate_Alias (Prim)),
479             Root_Type (Ctrl_Typ),
480             Use_Full_View => True)
481      then
482         --  This is a special case in which we generate in the ci file the
483         --  slot number of the renaming primitive (i.e. Base2) but instead of
484         --  generating the name of this renaming entity we reference directly
485         --  the renamed entity (i.e. Base).
486
487         Write_Int (UI_To_Int (Slot_Number (Prim)));
488         Write_Char (':');
489         Write_Name
490           (Chars (Find_Dispatching_Type (Ultimate_Alias (Prim))));
491      else
492         Write_Int (UI_To_Int (Slot_Number (Prim)));
493         Write_Char (':');
494         Write_Name (Chars (Root_Type (Ctrl_Typ)));
495      end if;
496
497      Write_Char (',');
498      Write_Name (Chars (Root_Type (Ctrl_Typ)));
499
500      Write_Char ('"');
501      Write_Eol;
502
503      Write_Str  ("  label: ");
504      Write_Char ('"');
505      Write_Location (Sloc (Call));
506      Write_Char ('"');
507      Write_Eol;
508
509      Write_Char ('}');
510      Write_Eol;
511   end Write_Call_Info;
512
513   ---------------------
514   -- Write_Type_Info --
515   ---------------------
516
517   procedure Write_Type_Info (Typ : Entity_Id) is
518      Elmt : Elmt_Id;
519      Prim : Node_Id;
520
521      Parent_Typ       : Entity_Id;
522      Separator_Needed : Boolean := False;
523
524   begin
525      --  Initialize Parent_Typ handling private types
526
527      Parent_Typ := Etype (Typ);
528
529      if Present (Full_View (Parent_Typ)) then
530         Parent_Typ := Full_View (Parent_Typ);
531      end if;
532
533      Write_Str ("class {");
534      Write_Eol;
535
536      Write_Str ("  classname: ");
537      Write_Char ('"');
538      Write_Name (Chars (Typ));
539      Write_Char ('"');
540      Write_Eol;
541
542      Write_Str  ("  label: ");
543      Write_Char ('"');
544      Write_Name (Chars (Typ));
545      Write_Char ('\');
546      Write_Location (Sloc (Typ));
547      Write_Char ('"');
548      Write_Eol;
549
550      if Parent_Typ /= Typ then
551         Write_Str  ("  parent: ");
552         Write_Char ('"');
553         Write_Name (Chars (Parent_Typ));
554
555         --  Note: Einfo prefix not needed if this routine is moved to
556         --  exp_disp???
557
558         if Present (Einfo.Interfaces (Typ))
559           and then not Is_Empty_Elmt_List (Einfo.Interfaces (Typ))
560         then
561            Elmt := First_Elmt (Einfo.Interfaces (Typ));
562            while Present (Elmt) loop
563               Write_Str  (", ");
564               Write_Name (Chars (Node (Elmt)));
565               Next_Elmt  (Elmt);
566            end loop;
567         end if;
568
569         Write_Char ('"');
570         Write_Eol;
571      end if;
572
573      Write_Str ("  virtuals: ");
574      Write_Char ('"');
575
576      Elmt := First_Elmt (Primitive_Operations (Typ));
577      while Present (Elmt) loop
578         Prim := Node (Elmt);
579
580         --  Skip internal entities associated with overridden interface
581         --  primitives, and also inherited primitives.
582
583         if Present (Interface_Alias (Prim))
584           or else
585             (Present (Alias (Prim))
586               and then Find_Dispatching_Type (Prim) /=
587                        Find_Dispatching_Type (Alias (Prim)))
588         then
589            goto Continue;
590         end if;
591
592         --  Do not generate separator for output of first primitive
593
594         if Separator_Needed then
595            Write_Str ("\n");
596            Write_Eol;
597            Write_Str ("             ");
598         else
599            Separator_Needed := True;
600         end if;
601
602         Write_Int (UI_To_Int (Slot_Number (Prim)));
603         Write_Char (':');
604
605         --  Handle renamed primitives
606
607         if Present (Alias (Prim)) then
608            Write_Name (Chars (Ultimate_Alias (Prim)));
609         else
610            Write_Name (Chars (Prim));
611         end if;
612
613         --  Display overriding of parent primitives
614
615         if Present (Overridden_Operation (Prim))
616           and then
617             Is_Ancestor
618               (Find_Dispatching_Type (Overridden_Operation (Prim)), Typ,
619                Use_Full_View => True)
620         then
621            Write_Char (',');
622            Write_Int
623              (UI_To_Int (Slot_Number (Overridden_Operation (Prim))));
624            Write_Char (':');
625            Write_Name
626              (Chars (Find_Dispatching_Type (Overridden_Operation (Prim))));
627         end if;
628
629         --  Display overriding of interface primitives
630
631         if Has_Interfaces (Typ) then
632            declare
633               Prim_Elmt : Elmt_Id;
634               Prim_Op   : Node_Id;
635               Int_Alias : Entity_Id;
636
637            begin
638               Prim_Elmt := First_Elmt (Primitive_Operations (Typ));
639               while Present (Prim_Elmt) loop
640                  Prim_Op := Node (Prim_Elmt);
641                  Int_Alias := Interface_Alias (Prim_Op);
642
643                  if Present (Int_Alias)
644                    and then
645                      not Is_Ancestor (Find_Dispatching_Type (Int_Alias), Typ,
646                                       Use_Full_View => True)
647                    and then (Alias (Prim_Op)) = Prim
648                  then
649                     Write_Char (',');
650                     Write_Int (UI_To_Int (Slot_Number (Int_Alias)));
651                     Write_Char (':');
652                     Write_Name (Chars (Find_Dispatching_Type (Int_Alias)));
653                  end if;
654
655                  Next_Elmt (Prim_Elmt);
656               end loop;
657            end;
658         end if;
659
660         <<Continue>>
661         Next_Elmt (Elmt);
662      end loop;
663
664      Write_Char ('"');
665      Write_Eol;
666
667      Write_Char ('}');
668      Write_Eol;
669   end Write_Type_Info;
670
671end Exp_CG;
672