Imported GNU Classpath 0.90
[official-gcc.git] / gcc / ada / restrict.adb
blobf12c1eb1c832df1e9d91a15d10c5529483514cfc
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- R E S T R I C T --
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 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Casing; use Casing;
29 with Errout; use Errout;
30 with Fname; use Fname;
31 with Fname.UF; use Fname.UF;
32 with Lib; use Lib;
33 with Namet; use Namet;
34 with Opt; use Opt;
35 with Sinfo; use Sinfo;
36 with Sinput; use Sinput;
37 with Snames; use Snames;
38 with Uname; use Uname;
40 package body Restrict is
42 Restricted_Profile_Result : Boolean := False;
43 -- This switch memoizes the result of Restricted_Profile function
44 -- calls for improved efficiency. Its setting is valid only if
45 -- Restricted_Profile_Cached is True. Note that if this switch
46 -- is ever set True, it need never be turned off again.
48 Restricted_Profile_Cached : Boolean := False;
49 -- This flag is set to True if the Restricted_Profile_Result
50 -- contains the correct cached result of Restricted_Profile calls.
52 -----------------------
53 -- Local Subprograms --
54 -----------------------
56 procedure Restriction_Msg (Msg : String; R : String; N : Node_Id);
57 -- Output error message at node N with given text, replacing the
58 -- '%' in the message with the name of the restriction given as R,
59 -- cased according to the current identifier casing. We do not use
60 -- the normal insertion mechanism, since this requires an entry
61 -- in the Names table, and this table will be locked if we are
62 -- generating a message from gigi.
64 function Same_Unit (U1, U2 : Node_Id) return Boolean;
65 -- Returns True iff U1 and U2 represent the same library unit. Used for
66 -- handling of No_Dependence => Unit restriction case.
68 function Suppress_Restriction_Message (N : Node_Id) return Boolean;
69 -- N is the node for a possible restriction violation message, but
70 -- the message is to be suppressed if this is an internal file and
71 -- this file is not the main unit.
73 -------------------
74 -- Abort_Allowed --
75 -------------------
77 function Abort_Allowed return Boolean is
78 begin
79 if Restrictions.Set (No_Abort_Statements)
80 and then Restrictions.Set (Max_Asynchronous_Select_Nesting)
81 and then Restrictions.Value (Max_Asynchronous_Select_Nesting) = 0
82 then
83 return False;
84 else
85 return True;
86 end if;
87 end Abort_Allowed;
89 ------------------------------------
90 -- Check_Elaboration_Code_Allowed --
91 ------------------------------------
93 procedure Check_Elaboration_Code_Allowed (N : Node_Id) is
94 begin
95 -- Avoid calling Namet.Unlock/Lock except when there is an error.
96 -- Even in the error case it is a bit dubious, either gigi needs
97 -- the table locked or it does not! ???
99 if Restrictions.Set (No_Elaboration_Code)
100 and then not Suppress_Restriction_Message (N)
101 then
102 Namet.Unlock;
103 Check_Restriction (Restriction_Id'(No_Elaboration_Code), N);
104 Namet.Lock;
105 end if;
106 end Check_Elaboration_Code_Allowed;
108 ----------------------------------
109 -- Check_No_Implicit_Heap_Alloc --
110 ----------------------------------
112 procedure Check_No_Implicit_Heap_Alloc (N : Node_Id) is
113 begin
114 Check_Restriction (Restriction_Id'(No_Implicit_Heap_Allocations), N);
115 end Check_No_Implicit_Heap_Alloc;
117 ---------------------------
118 -- Check_Restricted_Unit --
119 ---------------------------
121 procedure Check_Restricted_Unit (U : Unit_Name_Type; N : Node_Id) is
122 begin
123 if Suppress_Restriction_Message (N) then
124 return;
126 elsif Is_Spec_Name (U) then
127 declare
128 Fnam : constant File_Name_Type :=
129 Get_File_Name (U, Subunit => False);
131 begin
132 if not Is_Predefined_File_Name (Fnam) then
133 return;
135 -- Predefined spec, needs checking against list
137 else
138 -- Pad name to 8 characters with blanks
140 Get_Name_String (Fnam);
141 Name_Len := Name_Len - 4;
143 while Name_Len < 8 loop
144 Name_Len := Name_Len + 1;
145 Name_Buffer (Name_Len) := ' ';
146 end loop;
148 for J in Unit_Array'Range loop
149 if Name_Len = 8
150 and then Name_Buffer (1 .. 8) = Unit_Array (J).Filenm
151 then
152 Check_Restriction (Unit_Array (J).Res_Id, N);
153 end if;
154 end loop;
155 end if;
156 end;
157 end if;
158 end Check_Restricted_Unit;
160 -----------------------
161 -- Check_Restriction --
162 -----------------------
164 procedure Check_Restriction
165 (R : Restriction_Id;
166 N : Node_Id;
167 V : Uint := Uint_Minus_1)
169 Rimage : constant String := Restriction_Id'Image (R);
171 VV : Integer;
172 -- V converted to integer form. If V is greater than Integer'Last,
173 -- it is reset to minus 1 (unknown value).
175 procedure Update_Restrictions (Info : in out Restrictions_Info);
176 -- Update violation information in Info.Violated and Info.Count
178 -------------------------
179 -- Update_Restrictions --
180 -------------------------
182 procedure Update_Restrictions (Info : in out Restrictions_Info) is
183 begin
184 -- If not violated, set as violated now
186 if not Info.Violated (R) then
187 Info.Violated (R) := True;
189 if R in All_Parameter_Restrictions then
190 if VV < 0 then
191 Info.Unknown (R) := True;
192 Info.Count (R) := 1;
193 else
194 Info.Count (R) := VV;
195 end if;
196 end if;
198 -- Otherwise if violated already and a parameter restriction,
199 -- update count by maximizing or summing depending on restriction.
201 elsif R in All_Parameter_Restrictions then
203 -- If new value is unknown, result is unknown
205 if VV < 0 then
206 Info.Unknown (R) := True;
208 -- If checked by maximization, do maximization
210 elsif R in Checked_Max_Parameter_Restrictions then
211 Info.Count (R) := Integer'Max (Info.Count (R), VV);
213 -- If checked by adding, do add, checking for overflow
215 elsif R in Checked_Add_Parameter_Restrictions then
216 declare
217 pragma Unsuppress (Overflow_Check);
218 begin
219 Info.Count (R) := Info.Count (R) + VV;
220 exception
221 when Constraint_Error =>
222 Info.Count (R) := Integer'Last;
223 Info.Unknown (R) := True;
224 end;
226 -- Should not be able to come here, known counts should only
227 -- occur for restrictions that are Checked_max or Checked_Sum.
229 else
230 raise Program_Error;
231 end if;
232 end if;
233 end Update_Restrictions;
235 -- Start of processing for Check_Restriction
237 begin
238 if UI_Is_In_Int_Range (V) then
239 VV := Integer (UI_To_Int (V));
240 else
241 VV := -1;
242 end if;
244 -- Count can only be specified in the checked val parameter case
246 pragma Assert (VV < 0 or else R in Checked_Val_Parameter_Restrictions);
248 -- Nothing to do if value of zero specified for parameter restriction
250 if VV = 0 then
251 return;
252 end if;
254 -- Update current restrictions
256 Update_Restrictions (Restrictions);
258 -- If in main extended unit, update main restrictions as well
260 if Current_Sem_Unit = Main_Unit
261 or else In_Extended_Main_Source_Unit (N)
262 then
263 Update_Restrictions (Main_Restrictions);
264 end if;
266 -- Nothing to do if restriction message suppressed
268 if Suppress_Restriction_Message (N) then
269 null;
271 -- If restriction not set, nothing to do
273 elsif not Restrictions.Set (R) then
274 null;
276 -- Here if restriction set, check for violation (either this is a
277 -- Boolean restriction, or a parameter restriction with a value of
278 -- zero and an unknown count, or a parameter restriction with a
279 -- known value that exceeds the restriction count).
281 elsif R in All_Boolean_Restrictions
282 or else (Restrictions.Unknown (R)
283 and then Restrictions.Value (R) = 0)
284 or else Restrictions.Count (R) > Restrictions.Value (R)
285 then
286 Error_Msg_Sloc := Restrictions_Loc (R);
288 -- If we have a location for the Restrictions pragma, output it
290 if Error_Msg_Sloc > No_Location
291 or else Error_Msg_Sloc = System_Location
292 then
293 if Restriction_Warnings (R) then
294 Restriction_Msg ("|violation of restriction %#?", Rimage, N);
295 else
296 Restriction_Msg ("|violation of restriction %#", Rimage, N);
297 end if;
299 -- Otherwise we have the case of an implicit restriction
300 -- (e.g. a restriction implicitly set by another pragma)
302 else
303 Restriction_Msg
304 ("|violation of implicit restriction %", Rimage, N);
305 end if;
306 end if;
307 end Check_Restriction;
309 -------------------------------------
310 -- Check_Restriction_No_Dependence --
311 -------------------------------------
313 procedure Check_Restriction_No_Dependence (U : Node_Id; Err : Node_Id) is
314 DU : Node_Id;
316 begin
317 for J in No_Dependence.First .. No_Dependence.Last loop
318 DU := No_Dependence.Table (J).Unit;
320 if Same_Unit (U, DU) then
321 Error_Msg_Sloc := Sloc (DU);
322 Error_Msg_Node_1 := DU;
324 if No_Dependence.Table (J).Warn then
325 Error_Msg
326 ("?violation of restriction `No_Dependence '='> &`#",
327 Sloc (Err));
328 else
329 Error_Msg
330 ("|violation of restriction `No_Dependence '='> &`#",
331 Sloc (Err));
332 end if;
334 return;
335 end if;
336 end loop;
337 end Check_Restriction_No_Dependence;
339 ----------------------------------------
340 -- Cunit_Boolean_Restrictions_Restore --
341 ----------------------------------------
343 procedure Cunit_Boolean_Restrictions_Restore
344 (R : Save_Cunit_Boolean_Restrictions)
346 begin
347 for J in Cunit_Boolean_Restrictions loop
348 Restrictions.Set (J) := R (J);
349 end loop;
350 end Cunit_Boolean_Restrictions_Restore;
352 -------------------------------------
353 -- Cunit_Boolean_Restrictions_Save --
354 -------------------------------------
356 function Cunit_Boolean_Restrictions_Save
357 return Save_Cunit_Boolean_Restrictions
359 R : Save_Cunit_Boolean_Restrictions;
361 begin
362 for J in Cunit_Boolean_Restrictions loop
363 R (J) := Restrictions.Set (J);
364 Restrictions.Set (J) := False;
365 end loop;
367 return R;
368 end Cunit_Boolean_Restrictions_Save;
370 ------------------------
371 -- Get_Restriction_Id --
372 ------------------------
374 function Get_Restriction_Id
375 (N : Name_Id) return Restriction_Id
377 begin
378 Get_Name_String (N);
379 Set_Casing (All_Upper_Case);
381 for J in All_Restrictions loop
382 declare
383 S : constant String := Restriction_Id'Image (J);
384 begin
385 if S = Name_Buffer (1 .. Name_Len) then
386 return J;
387 end if;
388 end;
389 end loop;
391 return Not_A_Restriction_Id;
392 end Get_Restriction_Id;
394 -------------------------------
395 -- No_Exception_Handlers_Set --
396 -------------------------------
398 function No_Exception_Handlers_Set return Boolean is
399 begin
400 return Restrictions.Set (No_Exception_Handlers);
401 end No_Exception_Handlers_Set;
403 ----------------------------------
404 -- Process_Restriction_Synonyms --
405 ----------------------------------
407 -- Note: body of this function must be coordinated with list of
408 -- renaming declarations in System.Rident.
410 function Process_Restriction_Synonyms (N : Node_Id) return Name_Id
412 Old_Name : constant Name_Id := Chars (N);
413 New_Name : Name_Id;
415 begin
416 case Old_Name is
417 when Name_Boolean_Entry_Barriers =>
418 New_Name := Name_Simple_Barriers;
420 when Name_Max_Entry_Queue_Depth =>
421 New_Name := Name_Max_Entry_Queue_Length;
423 when Name_No_Dynamic_Interrupts =>
424 New_Name := Name_No_Dynamic_Attachment;
426 when Name_No_Requeue =>
427 New_Name := Name_No_Requeue_Statements;
429 when Name_No_Task_Attributes =>
430 New_Name := Name_No_Task_Attributes_Package;
432 when others =>
433 return Old_Name;
434 end case;
436 if Warn_On_Obsolescent_Feature then
437 Error_Msg_Name_1 := Old_Name;
438 Error_Msg_N ("restriction identifier % is obsolescent?", N);
439 Error_Msg_Name_1 := New_Name;
440 Error_Msg_N ("|use restriction identifier % instead", N);
441 end if;
443 return New_Name;
444 end Process_Restriction_Synonyms;
446 ------------------------
447 -- Restricted_Profile --
448 ------------------------
450 function Restricted_Profile return Boolean is
451 begin
452 if Restricted_Profile_Cached then
453 return Restricted_Profile_Result;
455 else
456 Restricted_Profile_Result := True;
457 Restricted_Profile_Cached := True;
459 declare
460 R : Restriction_Flags renames Profile_Info (Restricted).Set;
461 V : Restriction_Values renames Profile_Info (Restricted).Value;
462 begin
463 for J in R'Range loop
464 if R (J)
465 and then (Restrictions.Set (J) = False
466 or else Restriction_Warnings (J)
467 or else
468 (J in All_Parameter_Restrictions
469 and then Restrictions.Value (J) > V (J)))
470 then
471 Restricted_Profile_Result := False;
472 exit;
473 end if;
474 end loop;
476 return Restricted_Profile_Result;
477 end;
478 end if;
479 end Restricted_Profile;
481 ------------------------
482 -- Restriction_Active --
483 ------------------------
485 function Restriction_Active (R : All_Restrictions) return Boolean is
486 begin
487 return Restrictions.Set (R);
488 end Restriction_Active;
490 ---------------------
491 -- Restriction_Msg --
492 ---------------------
494 procedure Restriction_Msg (Msg : String; R : String; N : Node_Id) is
495 B : String (1 .. Msg'Length + 2 * R'Length + 1);
496 P : Natural := 1;
498 begin
499 Name_Buffer (1 .. R'Last) := R;
500 Name_Len := R'Length;
501 Set_Casing (Identifier_Casing (Get_Source_File_Index (Sloc (N))));
503 P := 0;
504 for J in Msg'Range loop
505 if Msg (J) = '%' then
506 P := P + 1;
507 B (P) := '`';
509 -- Put characters of image in message, quoting upper case letters
511 for J in 1 .. Name_Len loop
512 if Name_Buffer (J) in 'A' .. 'Z' then
513 P := P + 1;
514 B (P) := ''';
515 end if;
517 P := P + 1;
518 B (P) := Name_Buffer (J);
519 end loop;
521 P := P + 1;
522 B (P) := '`';
524 else
525 P := P + 1;
526 B (P) := Msg (J);
527 end if;
528 end loop;
530 Error_Msg_N (B (1 .. P), N);
531 end Restriction_Msg;
533 ---------------
534 -- Same_Unit --
535 ---------------
537 function Same_Unit (U1, U2 : Node_Id) return Boolean is
538 begin
539 if Nkind (U1) = N_Identifier then
540 return Nkind (U2) = N_Identifier and then Chars (U1) = Chars (U2);
542 elsif Nkind (U2) = N_Identifier then
543 return False;
545 elsif (Nkind (U1) = N_Selected_Component
546 or else Nkind (U1) = N_Expanded_Name)
547 and then
548 (Nkind (U2) = N_Selected_Component
549 or else Nkind (U2) = N_Expanded_Name)
550 then
551 return Same_Unit (Prefix (U1), Prefix (U2))
552 and then Same_Unit (Selector_Name (U1), Selector_Name (U2));
553 else
554 return False;
555 end if;
556 end Same_Unit;
558 ------------------------------
559 -- Set_Profile_Restrictions --
560 ------------------------------
562 procedure Set_Profile_Restrictions
563 (P : Profile_Name;
564 N : Node_Id;
565 Warn : Boolean)
567 R : Restriction_Flags renames Profile_Info (P).Set;
568 V : Restriction_Values renames Profile_Info (P).Value;
570 begin
571 for J in R'Range loop
572 if R (J) then
573 if J in All_Boolean_Restrictions then
574 Set_Restriction (J, N);
575 else
576 Set_Restriction (J, N, V (J));
577 end if;
579 Restriction_Warnings (J) := Warn;
580 end if;
581 end loop;
582 end Set_Profile_Restrictions;
584 ---------------------
585 -- Set_Restriction --
586 ---------------------
588 -- Case of Boolean restriction
590 procedure Set_Restriction
591 (R : All_Boolean_Restrictions;
592 N : Node_Id)
594 begin
595 Restrictions.Set (R) := True;
597 if Restricted_Profile_Cached and Restricted_Profile_Result then
598 null;
599 else
600 Restricted_Profile_Cached := False;
601 end if;
603 -- Set location, but preserve location of system
604 -- restriction for nice error msg with run time name
606 if Restrictions_Loc (R) /= System_Location then
607 Restrictions_Loc (R) := Sloc (N);
608 end if;
610 -- Record the restriction if we are in the main unit,
611 -- or in the extended main unit. The reason that we
612 -- test separately for Main_Unit is that gnat.adc is
613 -- processed with Current_Sem_Unit = Main_Unit, but
614 -- nodes in gnat.adc do not appear to be the extended
615 -- main source unit (they probably should do ???)
617 if Current_Sem_Unit = Main_Unit
618 or else In_Extended_Main_Source_Unit (N)
619 then
620 if not Restriction_Warnings (R) then
621 Main_Restrictions.Set (R) := True;
622 end if;
623 end if;
624 end Set_Restriction;
626 -- Case of parameter restriction
628 procedure Set_Restriction
629 (R : All_Parameter_Restrictions;
630 N : Node_Id;
631 V : Integer)
633 begin
634 if Restricted_Profile_Cached and Restricted_Profile_Result then
635 null;
636 else
637 Restricted_Profile_Cached := False;
638 end if;
640 if Restrictions.Set (R) then
641 if V < Restrictions.Value (R) then
642 Restrictions.Value (R) := V;
643 Restrictions_Loc (R) := Sloc (N);
644 end if;
646 else
647 Restrictions.Set (R) := True;
648 Restrictions.Value (R) := V;
649 Restrictions_Loc (R) := Sloc (N);
650 end if;
652 -- Record the restriction if we are in the main unit,
653 -- or in the extended main unit. The reason that we
654 -- test separately for Main_Unit is that gnat.adc is
655 -- processed with Current_Sem_Unit = Main_Unit, but
656 -- nodes in gnat.adc do not appear to be the extended
657 -- main source unit (they probably should do ???)
659 if Current_Sem_Unit = Main_Unit
660 or else In_Extended_Main_Source_Unit (N)
661 then
662 if Main_Restrictions.Set (R) then
663 if V < Main_Restrictions.Value (R) then
664 Main_Restrictions.Value (R) := V;
665 end if;
667 elsif not Restriction_Warnings (R) then
668 Main_Restrictions.Set (R) := True;
669 Main_Restrictions.Value (R) := V;
670 end if;
671 end if;
672 end Set_Restriction;
674 -----------------------------------
675 -- Set_Restriction_No_Dependence --
676 -----------------------------------
678 procedure Set_Restriction_No_Dependence
679 (Unit : Node_Id;
680 Warn : Boolean)
682 begin
683 -- Loop to check for duplicate entry
685 for J in No_Dependence.First .. No_Dependence.Last loop
687 -- Case of entry already in table
689 if Same_Unit (Unit, No_Dependence.Table (J).Unit) then
691 -- Error has precedence over warning
693 if not Warn then
694 No_Dependence.Table (J).Warn := False;
695 end if;
697 return;
698 end if;
699 end loop;
701 -- Entry is in table
703 No_Dependence.Append ((Unit, Warn));
704 end Set_Restriction_No_Dependence;
706 ----------------------------------
707 -- Suppress_Restriction_Message --
708 ----------------------------------
710 function Suppress_Restriction_Message (N : Node_Id) return Boolean is
711 begin
712 -- We only output messages for the extended main source unit
714 if In_Extended_Main_Source_Unit (N) then
715 return False;
717 -- If loaded by rtsfind, then suppress message
719 elsif Sloc (N) <= No_Location then
720 return True;
722 -- Otherwise suppress message if internal file
724 else
725 return Is_Internal_File_Name (Unit_File_Name (Get_Source_Unit (N)));
726 end if;
727 end Suppress_Restriction_Message;
729 ---------------------
730 -- Tasking_Allowed --
731 ---------------------
733 function Tasking_Allowed return Boolean is
734 begin
735 return not Restrictions.Set (No_Tasking)
736 and then (not Restrictions.Set (Max_Tasks)
737 or else Restrictions.Value (Max_Tasks) > 0);
738 end Tasking_Allowed;
740 end Restrict;