1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1999-2009, Free Software Foundation, Inc. --
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. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree
; use Atree
;
27 with Debug
; use Debug
;
28 with Einfo
; use Einfo
;
29 with Errout
; use Errout
;
30 with Exp_Code
; use Exp_Code
;
31 with Fname
; use Fname
;
33 with Namet
; use Namet
;
34 with Nlists
; use Nlists
;
36 with Par_SCO
; use Par_SCO
;
37 with Rtsfind
; use Rtsfind
;
39 with Sem_Ch8
; use Sem_Ch8
;
40 with Sem_Aux
; use Sem_Aux
;
41 with Sem_Eval
; use Sem_Eval
;
42 with Sem_Util
; use Sem_Util
;
43 with Sinfo
; use Sinfo
;
44 with Sinput
; use Sinput
;
45 with Snames
; use Snames
;
46 with Stand
; use Stand
;
47 with Stringt
; use Stringt
;
48 with Uintp
; use Uintp
;
50 package body Sem_Warn
is
52 -- The following table collects Id's of entities that are potentially
53 -- unreferenced. See Check_Unset_Reference for further details.
54 -- ??? Check_Unset_Reference has zero information about this table.
56 package Unreferenced_Entities
is new Table
.Table
(
57 Table_Component_Type
=> Entity_Id
,
58 Table_Index_Type
=> Nat
,
60 Table_Initial
=> Alloc
.Unreferenced_Entities_Initial
,
61 Table_Increment
=> Alloc
.Unreferenced_Entities_Increment
,
62 Table_Name
=> "Unreferenced_Entities");
64 -- The following table collects potential warnings for IN OUT parameters
65 -- that are referenced but not modified. These warnings are processed when
66 -- the front end calls the procedure Output_Non_Modified_In_Out_Warnings.
67 -- The reason that we defer output of these messages is that we want to
68 -- detect the case where the relevant procedure is used as a generic actual
69 -- in an instantiation, since we suppress the warnings in this case. The
70 -- flag Used_As_Generic_Actual will be set in this case, but only at the
71 -- point of usage. Similarly, we suppress the message if the address of the
72 -- procedure is taken, where the flag Address_Taken may be set later.
74 package In_Out_Warnings
is new Table
.Table
(
75 Table_Component_Type
=> Entity_Id
,
76 Table_Index_Type
=> Nat
,
78 Table_Initial
=> Alloc
.In_Out_Warnings_Initial
,
79 Table_Increment
=> Alloc
.In_Out_Warnings_Increment
,
80 Table_Name
=> "In_Out_Warnings");
82 --------------------------------------------------------
83 -- Handling of Warnings Off, Unmodified, Unreferenced --
84 --------------------------------------------------------
86 -- The functions Has_Warnings_Off, Has_Unmodified, Has_Unreferenced must
87 -- generally be used instead of Warnings_Off, Has_Pragma_Unmodified and
88 -- Has_Pragma_Unreferenced, as noted in the specs in Einfo.
90 -- In order to avoid losing warnings in -gnatw.w (warn on unnecessary
91 -- warnings off pragma) mode, i.e. to avoid false negatives, the code
92 -- must follow some important rules.
94 -- Call these functions as late as possible, after completing all other
95 -- tests, just before the warnings is given. For example, don't write:
97 -- if not Has_Warnings_Off (E)
98 -- and then some-other-predicate-on-E then ..
100 -- Instead the following is preferred
102 -- if some-other-predicate-on-E
103 -- and then Has_Warnings_Off (E)
105 -- This way if some-other-predicate is false, we avoid a false indication
106 -- that a Warnings (Off,E) pragma was useful in preventing a warning.
108 -- The second rule is that if both Has_Unmodified and Has_Warnings_Off, or
109 -- Has_Unreferenced and Has_Warnings_Off are called, make sure that the
110 -- call to Has_Unmodified/Has_Unreferenced comes first, this way we record
111 -- that the Warnings (Off) could have been Unreferenced or Unmodified. In
112 -- fact Has_Unmodified/Has_Unreferenced includes a test for Warnings Off,
113 -- and so a subsequent test is not needed anyway (though it is harmless).
115 -----------------------
116 -- Local Subprograms --
117 -----------------------
119 function Generic_Package_Spec_Entity
(E
: Entity_Id
) return Boolean;
120 -- This returns true if the entity E is declared within a generic package.
121 -- The point of this is to detect variables which are not assigned within
122 -- the generic, but might be assigned outside the package for any given
123 -- instance. These are cases where we leave the warnings to be posted for
124 -- the instance, when we will know more.
126 function Goto_Spec_Entity
(E
: Entity_Id
) return Entity_Id
;
127 -- If E is a parameter entity for a subprogram body, then this function
128 -- returns the corresponding spec entity, if not, E is returned unchanged.
130 function Has_Pragma_Unmodified_Check_Spec
(E
: Entity_Id
) return Boolean;
131 -- Tests Has_Pragma_Unmodified flag for entity E. If E is not a formal,
132 -- this is simply the setting of the flag Has_Pragma_Unmodified. If E is
133 -- a body formal, the setting of the flag in the corresponding spec is
134 -- also checked (and True returned if either flag is True).
136 function Has_Pragma_Unreferenced_Check_Spec
(E
: Entity_Id
) return Boolean;
137 -- Tests Has_Pragma_Unreferenced flag for entity E. If E is not a formal,
138 -- this is simply the setting of the flag Has_Pragma_Unreferenced. If E is
139 -- a body formal, the setting of the flag in the corresponding spec is
140 -- also checked (and True returned if either flag is True).
142 function Never_Set_In_Source_Check_Spec
(E
: Entity_Id
) return Boolean;
143 -- Tests Never_Set_In_Source status for entity E. If E is not a formal,
144 -- this is simply the setting of the flag Never_Set_In_Source. If E is
145 -- a body formal, the setting of the flag in the corresponding spec is
146 -- also checked (and False returned if either flag is False).
148 function Operand_Has_Warnings_Suppressed
(N
: Node_Id
) return Boolean;
149 -- This function traverses the expression tree represented by the node N
150 -- and determines if any sub-operand is a reference to an entity for which
151 -- the Warnings_Off flag is set. True is returned if such an entity is
152 -- encountered, and False otherwise.
154 function Referenced_Check_Spec
(E
: Entity_Id
) return Boolean;
155 -- Tests Referenced status for entity E. If E is not a formal, this is
156 -- simply the setting of the flag Referenced. If E is a body formal, the
157 -- setting of the flag in the corresponding spec is also checked (and True
158 -- returned if either flag is True).
160 function Referenced_As_LHS_Check_Spec
(E
: Entity_Id
) return Boolean;
161 -- Tests Referenced_As_LHS status for entity E. If E is not a formal, this
162 -- is simply the setting of the flag Referenced_As_LHS. If E is a body
163 -- formal, the setting of the flag in the corresponding spec is also
164 -- checked (and True returned if either flag is True).
166 function Referenced_As_Out_Parameter_Check_Spec
167 (E
: Entity_Id
) return Boolean;
168 -- Tests Referenced_As_Out_Parameter status for entity E. If E is not a
169 -- formal, this is simply the setting of Referenced_As_Out_Parameter. If E
170 -- is a body formal, the setting of the flag in the corresponding spec is
171 -- also checked (and True returned if either flag is True).
173 procedure Warn_On_Unreferenced_Entity
175 Body_E
: Entity_Id
:= Empty
);
176 -- Output warnings for unreferenced entity E. For the case of an entry
177 -- formal, Body_E is the corresponding body entity for a particular
178 -- accept statement, and the message is posted on Body_E. In all other
179 -- cases, Body_E is ignored and must be Empty.
181 function Warnings_Off_Check_Spec
(E
: Entity_Id
) return Boolean;
182 -- Returns True if Warnings_Off is set for the entity E or (in the case
183 -- where there is a Spec_Entity), Warnings_Off is set for the Spec_Entity.
185 --------------------------
186 -- Check_Code_Statement --
187 --------------------------
189 procedure Check_Code_Statement
(N
: Node_Id
) is
191 -- If volatile, nothing to worry about
193 if Is_Asm_Volatile
(N
) then
197 -- Warn if no input or no output
199 Setup_Asm_Inputs
(N
);
201 if No
(Asm_Input_Value
) then
203 ("?code statement with no inputs should usually be Volatile!", N
);
207 Setup_Asm_Outputs
(N
);
209 if No
(Asm_Output_Variable
) then
211 ("?code statement with no outputs should usually be Volatile!", N
);
215 -- Check multiple code statements in a row
217 if Is_List_Member
(N
)
218 and then Present
(Prev
(N
))
219 and then Nkind
(Prev
(N
)) = N_Code_Statement
222 ("?code statements in sequence should usually be Volatile!", N
);
224 ("\?(suggest using template with multiple instructions)!", N
);
226 end Check_Code_Statement
;
228 ---------------------------------
229 -- Check_Infinite_Loop_Warning --
230 ---------------------------------
232 -- The case we look for is a while loop which tests a local variable, where
233 -- there is no obvious direct or possible indirect update of the variable
234 -- within the body of the loop.
236 procedure Check_Infinite_Loop_Warning
(Loop_Statement
: Node_Id
) is
237 Iter
: constant Node_Id
:= Iteration_Scheme
(Loop_Statement
);
239 Ref
: Node_Id
:= Empty
;
240 -- Reference in iteration scheme to variable that might not be modified
241 -- in loop, indicating a possible infinite loop.
243 Var
: Entity_Id
:= Empty
;
244 -- Corresponding entity (entity of Ref)
246 Function_Call_Found
: Boolean := False;
247 -- True if Find_Var found a function call in the condition
249 procedure Find_Var
(N
: Node_Id
);
250 -- Inspect condition to see if it depends on a single entity reference.
251 -- If so, Ref is set to point to the reference node, and Var is set to
252 -- the referenced Entity.
254 function Has_Indirection
(T
: Entity_Id
) return Boolean;
255 -- If the controlling variable is an access type, or is a record type
256 -- with access components, assume that it is changed indirectly and
257 -- suppress the warning. As a concession to low-level programming, in
258 -- particular within Declib, we also suppress warnings on a record
259 -- type that contains components of type Address or Short_Address.
261 function Is_Suspicious_Function_Name
(E
: Entity_Id
) return Boolean;
262 -- Given an entity name, see if the name appears to have something to
263 -- do with I/O or network stuff, and if so, return True. Used to kill
264 -- some false positives on a heuristic basis that such functions will
265 -- likely have some strange side effect dependencies. A rather funny
266 -- kludge, but warning messages are in the heuristics business.
268 function Test_Ref
(N
: Node_Id
) return Traverse_Result
;
269 -- Test for reference to variable in question. Returns Abandon if
270 -- matching reference found.
272 function Find_Ref
is new Traverse_Func
(Test_Ref
);
273 -- Function to traverse body of procedure. Returns Abandon if matching
280 procedure Find_Var
(N
: Node_Id
) is
282 -- Condition is a direct variable reference
284 if Is_Entity_Name
(N
) then
288 -- Case of condition is a comparison with compile time known value
290 elsif Nkind
(N
) in N_Op_Compare
then
291 if Compile_Time_Known_Value
(Right_Opnd
(N
)) then
292 Find_Var
(Left_Opnd
(N
));
294 elsif Compile_Time_Known_Value
(Left_Opnd
(N
)) then
295 Find_Var
(Right_Opnd
(N
));
297 -- Ignore any other comparison
303 -- If condition is a negation, check its operand
305 elsif Nkind
(N
) = N_Op_Not
then
306 Find_Var
(Right_Opnd
(N
));
308 -- Case of condition is function call
310 elsif Nkind
(N
) = N_Function_Call
then
312 Function_Call_Found
:= True;
314 -- Forget it if function name is not entity, who knows what
315 -- we might be calling?
317 if not Is_Entity_Name
(Name
(N
)) then
320 -- Forget it if function name is suspicious. A strange test
321 -- but warning generation is in the heuristics business!
323 elsif Is_Suspicious_Function_Name
(Entity
(Name
(N
))) then
326 -- Forget it if warnings are suppressed on function entity
328 elsif Has_Warnings_Off
(Entity
(Name
(N
))) then
332 -- OK, see if we have one argument
335 PA
: constant List_Id
:= Parameter_Associations
(N
);
338 -- One argument, so check the argument
341 and then List_Length
(PA
) = 1
343 if Nkind
(First
(PA
)) = N_Parameter_Association
then
344 Find_Var
(Explicit_Actual_Parameter
(First
(PA
)));
346 Find_Var
(First
(PA
));
356 -- Any other kind of node is not something we warn for
363 ---------------------
364 -- Has_Indirection --
365 ---------------------
367 function Has_Indirection
(T
: Entity_Id
) return Boolean is
372 if Is_Access_Type
(T
) then
375 elsif Is_Private_Type
(T
)
376 and then Present
(Full_View
(T
))
377 and then Is_Access_Type
(Full_View
(T
))
381 elsif Is_Record_Type
(T
) then
384 elsif Is_Private_Type
(T
)
385 and then Present
(Full_View
(T
))
386 and then Is_Record_Type
(Full_View
(T
))
388 Rec
:= Full_View
(T
);
393 Comp
:= First_Component
(Rec
);
394 while Present
(Comp
) loop
395 if Is_Access_Type
(Etype
(Comp
))
396 or else Is_Descendent_Of_Address
(Etype
(Comp
))
401 Next_Component
(Comp
);
407 ---------------------------------
408 -- Is_Suspicious_Function_Name --
409 ---------------------------------
411 function Is_Suspicious_Function_Name
(E
: Entity_Id
) return Boolean is
414 function Substring_Present
(S
: String) return Boolean;
415 -- Returns True if name buffer has given string delimited by non-
416 -- alphabetic characters or by end of string. S is lower case.
418 -----------------------
419 -- Substring_Present --
420 -----------------------
422 function Substring_Present
(S
: String) return Boolean is
423 Len
: constant Natural := S
'Length;
426 for J
in 1 .. Name_Len
- (Len
- 1) loop
427 if Name_Buffer
(J
.. J
+ (Len
- 1)) = S
430 or else Name_Buffer
(J
- 1) not in 'a' .. 'z')
433 or else Name_Buffer
(J
+ Len
) not in 'a' .. 'z')
440 end Substring_Present
;
442 -- Start of processing for Is_Suspicious_Function_Name
446 while Present
(S
) and then S
/= Standard_Standard
loop
447 Get_Name_String
(Chars
(S
));
449 if Substring_Present
("io")
450 or else Substring_Present
("file")
451 or else Substring_Present
("network")
460 end Is_Suspicious_Function_Name
;
466 function Test_Ref
(N
: Node_Id
) return Traverse_Result
is
468 -- Waste of time to look at iteration scheme
473 -- Direct reference to variable in question
475 elsif Is_Entity_Name
(N
)
476 and then Present
(Entity
(N
))
477 and then Entity
(N
) = Var
479 -- If this is an lvalue, then definitely abandon, since
480 -- this could be a direct modification of the variable.
482 if May_Be_Lvalue
(N
) then
486 -- If we appear in the context of a procedure call, then also
487 -- abandon, since there may be issues of non-visible side
488 -- effects going on in the call.
497 exit when P
= Loop_Statement
;
499 -- Abandon if at procedure call, or something strange is
500 -- going on (perhaps a node with no parent that should
501 -- have one but does not?) As always, for a warning we
502 -- prefer to just abandon the warning than get into the
503 -- business of complaining about the tree structure here!
505 if No
(P
) or else Nkind
(P
) = N_Procedure_Call_Statement
then
511 -- Reference to variable renaming variable in question
513 elsif Is_Entity_Name
(N
)
514 and then Present
(Entity
(N
))
515 and then Ekind
(Entity
(N
)) = E_Variable
516 and then Present
(Renamed_Object
(Entity
(N
)))
517 and then Is_Entity_Name
(Renamed_Object
(Entity
(N
)))
518 and then Entity
(Renamed_Object
(Entity
(N
))) = Var
519 and then May_Be_Lvalue
(N
)
523 -- Call to subprogram
525 elsif Nkind
(N
) = N_Procedure_Call_Statement
526 or else Nkind
(N
) = N_Function_Call
528 -- If subprogram is within the scope of the entity we are dealing
529 -- with as the loop variable, then it could modify this parameter,
530 -- so we abandon in this case. In the case of a subprogram that is
531 -- not an entity we also abandon. The check for no entity being
532 -- present is a defense against previous errors.
534 if not Is_Entity_Name
(Name
(N
))
535 or else No
(Entity
(Name
(N
)))
536 or else Scope_Within
(Entity
(Name
(N
)), Scope
(Var
))
542 -- All OK, continue scan
547 -- Start of processing for Check_Infinite_Loop_Warning
550 -- We need a while iteration with no condition actions. Condition
551 -- actions just make things too complicated to get the warning right.
554 or else No
(Condition
(Iter
))
555 or else Present
(Condition_Actions
(Iter
))
556 or else Debug_Flag_Dot_W
561 -- Initial conditions met, see if condition is of right form
563 Find_Var
(Condition
(Iter
));
565 -- Nothing to do if local variable from source not found. If it's a
566 -- renaming, it is probably renaming something too complicated to deal
570 or else Ekind
(Var
) /= E_Variable
571 or else Is_Library_Level_Entity
(Var
)
572 or else not Comes_From_Source
(Var
)
573 or else Nkind
(Parent
(Var
)) = N_Object_Renaming_Declaration
577 -- Nothing to do if there is some indirection involved (assume that the
578 -- designated variable might be modified in some way we don't see).
579 -- However, if no function call was found, then we don't care about
580 -- indirections, because the condition must be something like "while X
581 -- /= null loop", so we don't care if X.all is modified in the loop.
583 elsif Function_Call_Found
and then Has_Indirection
(Etype
(Var
)) then
586 -- Same sort of thing for volatile variable, might be modified by
587 -- some other task or by the operating system in some way.
589 elsif Is_Volatile
(Var
) then
593 -- Filter out case of original statement sequence starting with delay.
594 -- We assume this is a multi-tasking program and that the condition
595 -- is affected by other threads (some kind of busy wait).
598 Fstm
: constant Node_Id
:=
599 Original_Node
(First
(Statements
(Loop_Statement
)));
601 if Nkind
(Fstm
) = N_Delay_Relative_Statement
602 or else Nkind
(Fstm
) = N_Delay_Until_Statement
608 -- We have a variable reference of the right form, now we scan the loop
609 -- body to see if it looks like it might not be modified
611 if Find_Ref
(Loop_Statement
) = OK
then
613 ("?variable& is not modified in loop body!", Ref
, Var
);
615 ("\?possible infinite loop!", Ref
);
617 end Check_Infinite_Loop_Warning
;
619 ----------------------------
620 -- Check_Low_Bound_Tested --
621 ----------------------------
623 procedure Check_Low_Bound_Tested
(Expr
: Node_Id
) is
625 if Comes_From_Source
(Expr
) then
627 L
: constant Node_Id
:= Left_Opnd
(Expr
);
628 R
: constant Node_Id
:= Right_Opnd
(Expr
);
630 if Nkind
(L
) = N_Attribute_Reference
631 and then Attribute_Name
(L
) = Name_First
632 and then Is_Entity_Name
(Prefix
(L
))
633 and then Is_Formal
(Entity
(Prefix
(L
)))
635 Set_Low_Bound_Tested
(Entity
(Prefix
(L
)));
638 if Nkind
(R
) = N_Attribute_Reference
639 and then Attribute_Name
(R
) = Name_First
640 and then Is_Entity_Name
(Prefix
(R
))
641 and then Is_Formal
(Entity
(Prefix
(R
)))
643 Set_Low_Bound_Tested
(Entity
(Prefix
(R
)));
647 end Check_Low_Bound_Tested
;
649 ----------------------
650 -- Check_References --
651 ----------------------
653 procedure Check_References
(E
: Entity_Id
; Anod
: Node_Id
:= Empty
) is
660 Accept_Statement
: Node_Id
) return Entity_Id
;
661 -- For an entry formal entity from an entry declaration, find the
662 -- corresponding body formal from the given accept statement.
664 function Missing_Subunits
return Boolean;
665 -- We suppress warnings when there are missing subunits, because this
666 -- may generate too many false positives: entities in a parent may only
667 -- be referenced in one of the subunits. We make an exception for
668 -- subunits that contain no other stubs.
670 procedure Output_Reference_Error
(M
: String);
671 -- Used to output an error message. Deals with posting the error on the
672 -- body formal in the accept case.
674 function Publicly_Referenceable
(Ent
: Entity_Id
) return Boolean;
675 -- This is true if the entity in question is potentially referenceable
676 -- from another unit. This is true for entities in packages that are at
677 -- the library level.
679 function Warnings_Off_E1
return Boolean;
680 -- Return True if Warnings_Off is set for E1, or for its Etype (E1T),
681 -- or for the base type of E1T.
689 Accept_Statement
: Node_Id
) return Entity_Id
691 Body_Param
: Node_Id
;
695 -- Loop to find matching parameter in accept statement
697 Body_Param
:= First
(Parameter_Specifications
(Accept_Statement
));
698 while Present
(Body_Param
) loop
699 Body_E
:= Defining_Identifier
(Body_Param
);
701 if Chars
(Body_E
) = Chars
(E
) then
708 -- Should never fall through, should always find a match
713 ----------------------
714 -- Missing_Subunits --
715 ----------------------
717 function Missing_Subunits
return Boolean is
721 if not Unloaded_Subunits
then
723 -- Normal compilation, all subunits are present
727 elsif E
/= Main_Unit_Entity
then
729 -- No warnings on a stub that is not the main unit
733 elsif Nkind
(Unit_Declaration_Node
(E
)) in N_Proper_Body
then
734 D
:= First
(Declarations
(Unit_Declaration_Node
(E
)));
735 while Present
(D
) loop
737 -- No warnings if the proper body contains nested stubs
739 if Nkind
(D
) in N_Body_Stub
then
749 -- Missing stubs elsewhere
753 end Missing_Subunits
;
755 ----------------------------
756 -- Output_Reference_Error --
757 ----------------------------
759 procedure Output_Reference_Error
(M
: String) is
761 -- Never issue messages for internal names
763 if Is_Internal_Name
(Chars
(E1
)) then
767 -- Don't output message for IN OUT formal unless we have the warning
768 -- flag specifically set. It is a bit odd to distinguish IN OUT
769 -- formals from other cases. This distinction is historical in
770 -- nature. Warnings for IN OUT formals were added fairly late.
772 if Ekind
(E1
) = E_In_Out_Parameter
773 and then not Check_Unreferenced_Formals
778 -- Other than accept case, post error on defining identifier
783 -- Accept case, find body formal to post the message
786 Error_Msg_NE
(M
, Body_Formal
(E1
, Accept_Statement
=> Anod
), E1
);
789 end Output_Reference_Error
;
791 ----------------------------
792 -- Publicly_Referenceable --
793 ----------------------------
795 function Publicly_Referenceable
(Ent
: Entity_Id
) return Boolean is
800 -- A formal parameter is never referenceable outside the body of its
801 -- subprogram or entry.
803 if Is_Formal
(Ent
) then
807 -- Examine parents to look for a library level package spec. But if
808 -- we find a body or block or other similar construct along the way,
809 -- we cannot be referenced.
816 -- If we get to top of tree, then publicly referenceable
821 -- If we reach a generic package declaration, then always
822 -- consider this referenceable, since any instantiation will
823 -- have access to the entities in the generic package. Note
824 -- that the package itself may not be instantiated, but then
825 -- we will get a warning for the package entity.
827 -- Note that generic formal parameters are themselves not
828 -- publicly referenceable in an instance, and warnings on them
831 when N_Generic_Package_Declaration
=>
833 not Is_List_Member
(Prev
)
834 or else List_Containing
(Prev
)
835 /= Generic_Formal_Declarations
(P
);
837 -- Similarly, the generic formals of a generic subprogram are
840 when N_Generic_Subprogram_Declaration
=>
841 if Is_List_Member
(Prev
)
842 and then List_Containing
(Prev
) =
843 Generic_Formal_Declarations
(P
)
850 -- If we reach a subprogram body, entity is not referenceable
851 -- unless it is the defining entity of the body. This will
852 -- happen, e.g. when a function is an attribute renaming that
853 -- is rewritten as a body.
855 when N_Subprogram_Body
=>
856 if Ent
/= Defining_Entity
(P
) then
862 -- If we reach any other body, definitely not referenceable
864 when N_Package_Body |
872 -- For all other cases, keep looking up tree
879 end Publicly_Referenceable
;
881 ---------------------
882 -- Warnings_Off_E1 --
883 ---------------------
885 function Warnings_Off_E1
return Boolean is
887 return Has_Warnings_Off
(E1T
)
888 or else Has_Warnings_Off
(Base_Type
(E1T
))
889 or else Warnings_Off_Check_Spec
(E1
);
892 -- Start of processing for Check_References
895 -- No messages if warnings are suppressed, or if we have detected any
896 -- real errors so far (this last check avoids junk messages resulting
897 -- from errors, e.g. a subunit that is not loaded).
899 if Warning_Mode
= Suppress
900 or else Serious_Errors_Detected
/= 0
905 -- We also skip the messages if any subunits were not loaded (see
906 -- comment in Sem_Ch10 to understand how this is set, and why it is
907 -- necessary to suppress the warnings in this case).
909 if Missing_Subunits
then
913 -- Otherwise loop through entities, looking for suspicious stuff
915 E1
:= First_Entity
(E
);
916 while Present
(E1
) loop
919 -- We are only interested in source entities. We also don't issue
920 -- warnings within instances, since the proper place for such
921 -- warnings is on the template when it is compiled.
923 if Comes_From_Source
(E1
)
924 and then Instantiation_Location
(Sloc
(E1
)) = No_Location
926 -- We are interested in variables and out/in-out parameters, but
927 -- we exclude protected types, too complicated to worry about.
929 if Ekind
(E1
) = E_Variable
931 ((Ekind
(E1
) = E_Out_Parameter
932 or else Ekind
(E1
) = E_In_Out_Parameter
)
933 and then not Is_Protected_Type
(Current_Scope
))
935 -- Case of an unassigned variable
937 -- First gather any Unset_Reference indication for E1. In the
938 -- case of a parameter, it is the Spec_Entity that is relevant.
940 if Ekind
(E1
) = E_Out_Parameter
941 and then Present
(Spec_Entity
(E1
))
943 UR
:= Unset_Reference
(Spec_Entity
(E1
));
945 UR
:= Unset_Reference
(E1
);
948 -- Special processing for access types
951 and then Is_Access_Type
(E1T
)
953 -- For access types, the only time we made a UR entry was
954 -- for a dereference, and so we post the appropriate warning
955 -- here (note that the dereference may not be explicit in
956 -- the source, for example in the case of a dispatching call
957 -- with an anonymous access controlling formal, or of an
958 -- assignment of a pointer involving discriminant check on
959 -- the designated object).
961 if not Warnings_Off_E1
then
962 Error_Msg_NE
("?& may be null!", UR
, E1
);
967 -- Case of variable that could be a constant. Note that we
968 -- never signal such messages for generic package entities,
969 -- since a given instance could have modifications outside
972 elsif Warn_On_Constant
973 and then (Ekind
(E1
) = E_Variable
974 and then Has_Initial_Value
(E1
))
975 and then Never_Set_In_Source_Check_Spec
(E1
)
976 and then not Address_Taken
(E1
)
977 and then not Generic_Package_Spec_Entity
(E1
)
979 -- A special case, if this variable is volatile and not
980 -- imported, it is not helpful to tell the programmer
981 -- to mark the variable as constant, since this would be
982 -- illegal by virtue of RM C.6(13).
984 if (Is_Volatile
(E1
) or else Has_Volatile_Components
(E1
))
985 and then not Is_Imported
(E1
)
988 ("?& is not modified, volatile has no effect!", E1
);
990 -- Another special case, Exception_Occurrence, this catches
991 -- the case of exception choice (and a bit more too, but not
992 -- worth doing more investigation here).
994 elsif Is_RTE
(E1T
, RE_Exception_Occurrence
) then
997 -- Here we give the warning if referenced and no pragma
998 -- Unreferenced or Unmodified is present.
1003 if Ekind
(E1
) = E_Variable
then
1004 if Referenced_Check_Spec
(E1
)
1005 and then not Has_Pragma_Unreferenced_Check_Spec
(E1
)
1006 and then not Has_Pragma_Unmodified_Check_Spec
(E1
)
1008 if not Warnings_Off_E1
then
1009 Error_Msg_N
-- CODEFIX
1010 ("?& is not modified, "
1011 & "could be declared constant!",
1018 -- Other cases of a variable or parameter never set in source
1020 elsif Never_Set_In_Source_Check_Spec
(E1
)
1022 -- No warning if warning for this case turned off
1024 and then Warn_On_No_Value_Assigned
1026 -- No warning if address taken somewhere
1028 and then not Address_Taken
(E1
)
1030 -- No warning if explicit initial value
1032 and then not Has_Initial_Value
(E1
)
1034 -- No warning for generic package spec entities, since we
1035 -- might set them in a child unit or something like that
1037 and then not Generic_Package_Spec_Entity
(E1
)
1039 -- No warning if fully initialized type, except that for
1040 -- this purpose we do not consider access types to qualify
1041 -- as fully initialized types (relying on an access type
1042 -- variable being null when it is never set is a bit odd!)
1044 -- Also we generate warning for an out parameter that is
1045 -- never referenced, since again it seems odd to rely on
1046 -- default initialization to set an out parameter value.
1048 and then (Is_Access_Type
(E1T
)
1049 or else Ekind
(E1
) = E_Out_Parameter
1050 or else not Is_Fully_Initialized_Type
(E1T
))
1052 -- Do not output complaint about never being assigned a
1053 -- value if a pragma Unmodified applies to the variable
1054 -- we are examining, or if it is a parameter, if there is
1055 -- a pragma Unreferenced for the corresponding spec, or
1056 -- if the type is marked as having unreferenced objects.
1057 -- The last is a little peculiar, but better too few than
1058 -- too many warnings in this situation.
1060 if Has_Pragma_Unreferenced_Objects
(E1T
)
1061 or else Has_Pragma_Unmodified_Check_Spec
(E1
)
1065 -- IN OUT parameter case where parameter is referenced. We
1066 -- separate this out, since this is the case where we delay
1067 -- output of the warning until more information is available
1068 -- (about use in an instantiation or address being taken).
1070 elsif Ekind
(E1
) = E_In_Out_Parameter
1071 and then Referenced_Check_Spec
(E1
)
1073 -- Suppress warning if private type, and the procedure
1074 -- has a separate declaration in a different unit. This
1075 -- is the case where the client of a package sees only
1076 -- the private type, and it may be quite reasonable
1077 -- for the logical view to be IN OUT, even if the
1078 -- implementation ends up using access types or some
1079 -- other method to achieve the local effect of a
1080 -- modification. On the other hand if the spec and body
1081 -- are in the same unit, we are in the package body and
1082 -- there we have less excuse for a junk IN OUT parameter.
1084 if Has_Private_Declaration
(E1T
)
1085 and then Present
(Spec_Entity
(E1
))
1086 and then not In_Same_Source_Unit
(E1
, Spec_Entity
(E1
))
1090 -- Suppress warning for any parameter of a dispatching
1091 -- operation, since it is quite reasonable to have an
1092 -- operation that is overridden, and for some subclasses
1093 -- needs the formal to be IN OUT and for others happens
1094 -- not to assign it.
1096 elsif Is_Dispatching_Operation
1097 (Scope
(Goto_Spec_Entity
(E1
)))
1101 -- Suppress warning if composite type contains any access
1102 -- component, since the logical effect of modifying a
1103 -- parameter may be achieved by modifying a referenced
1106 elsif Is_Composite_Type
(E1T
)
1107 and then Has_Access_Values
(E1T
)
1111 -- Suppress warning on formals of an entry body. All
1112 -- references are attached to the formal in the entry
1113 -- declaration, which are marked Is_Entry_Formal.
1115 elsif Ekind
(Scope
(E1
)) = E_Entry
1116 and then not Is_Entry_Formal
(E1
)
1120 -- OK, looks like warning for an IN OUT parameter that
1121 -- could be IN makes sense, but we delay the output of
1122 -- the warning, pending possibly finding out later on
1123 -- that the associated subprogram is used as a generic
1124 -- actual, or its address/access is taken. In these two
1125 -- cases, we suppress the warning because the context may
1126 -- force use of IN OUT, even if in this particular case
1127 -- the formal is not modified.
1130 In_Out_Warnings
.Append
(E1
);
1133 -- Other cases of formals
1135 elsif Is_Formal
(E1
) then
1136 if not Is_Trivial_Subprogram
(Scope
(E1
)) then
1137 if Referenced_Check_Spec
(E1
) then
1138 if not Has_Pragma_Unmodified_Check_Spec
(E1
)
1139 and then not Warnings_Off_E1
1141 Output_Reference_Error
1142 ("?formal parameter& is read but "
1143 & "never assigned!");
1146 elsif not Has_Pragma_Unreferenced_Check_Spec
(E1
)
1147 and then not Warnings_Off_E1
1149 Output_Reference_Error
1150 ("?formal parameter& is not referenced!");
1157 if Referenced
(E1
) then
1158 if not Has_Unmodified
(E1
)
1159 and then not Warnings_Off_E1
1161 Output_Reference_Error
1162 ("?variable& is read but never assigned!");
1165 elsif not Has_Unreferenced
(E1
)
1166 and then not Warnings_Off_E1
1168 Output_Reference_Error
-- CODEFIX
1169 ("?variable& is never read and never assigned!");
1172 -- Deal with special case where this variable is hidden
1173 -- by a loop variable.
1175 if Ekind
(E1
) = E_Variable
1176 and then Present
(Hiding_Loop_Variable
(E1
))
1177 and then not Warnings_Off_E1
1180 ("?for loop implicitly declares loop variable!",
1181 Hiding_Loop_Variable
(E1
));
1183 Error_Msg_Sloc
:= Sloc
(E1
);
1185 ("\?declaration hides & declared#!",
1186 Hiding_Loop_Variable
(E1
));
1193 -- Check for unset reference
1195 if Warn_On_No_Value_Assigned
and then Present
(UR
) then
1197 -- For other than access type, go back to original node to
1198 -- deal with case where original unset reference has been
1199 -- rewritten during expansion.
1201 -- In some cases, the original node may be a type conversion
1202 -- or qualification, and in this case we want the object
1205 UR
:= Original_Node
(UR
);
1206 while Nkind
(UR
) = N_Type_Conversion
1207 or else Nkind
(UR
) = N_Qualified_Expression
1209 UR
:= Expression
(UR
);
1212 -- Here we issue the warning, all checks completed
1214 -- If we have a return statement, this was a case of an OUT
1215 -- parameter not being set at the time of the return. (Note:
1216 -- it can't be N_Extended_Return_Statement, because those
1217 -- are only for functions, and functions do not allow OUT
1220 if not Is_Trivial_Subprogram
(Scope
(E1
)) then
1221 if Nkind
(UR
) = N_Simple_Return_Statement
1222 and then not Has_Pragma_Unmodified_Check_Spec
(E1
)
1224 if not Warnings_Off_E1
then
1226 ("?OUT parameter& not set before return", UR
, E1
);
1229 -- If the unset reference is a selected component
1230 -- prefix from source, mention the component as well.
1231 -- If the selected component comes from expansion, all
1232 -- we know is that the entity is not fully initialized
1233 -- at the point of the reference. Locate a random
1234 -- uninitialized component to get a better message.
1236 elsif Nkind
(Parent
(UR
)) = N_Selected_Component
then
1237 Error_Msg_Node_2
:= Selector_Name
(Parent
(UR
));
1239 if not Comes_From_Source
(Parent
(UR
)) then
1244 Comp
:= First_Entity
(E1T
);
1245 while Present
(Comp
) loop
1246 if Ekind
(Comp
) = E_Component
1247 and then Nkind
(Parent
(Comp
)) =
1248 N_Component_Declaration
1249 and then No
(Expression
(Parent
(Comp
)))
1251 Error_Msg_Node_2
:= Comp
;
1260 -- Issue proper warning. This is a case of referencing
1261 -- a variable before it has been explicitly assigned.
1262 -- For access types, UR was only set for dereferences,
1263 -- so the issue is that the value may be null.
1265 if not Is_Trivial_Subprogram
(Scope
(E1
)) then
1266 if not Warnings_Off_E1
then
1267 if Is_Access_Type
(Etype
(Parent
(UR
))) then
1268 Error_Msg_N
("?`&.&` may be null!", UR
);
1271 ("?`&.&` may be referenced before "
1272 & "it has a value!", UR
);
1277 -- All other cases of unset reference active
1279 elsif not Warnings_Off_E1
then
1281 ("?& may be referenced before it has a value!",
1290 -- Then check for unreferenced entities. Note that we are only
1291 -- interested in entities whose Referenced flag is not set.
1293 if not Referenced_Check_Spec
(E1
)
1295 -- If Referenced_As_LHS is set, then that's still interesting
1296 -- (potential "assigned but never read" case), but not if we
1297 -- have pragma Unreferenced, which cancels this warning.
1299 and then (not Referenced_As_LHS_Check_Spec
(E1
)
1300 or else not Has_Unreferenced
(E1
))
1302 -- Check that warnings on unreferenced entities are enabled
1305 ((Check_Unreferenced
and then not Is_Formal
(E1
))
1307 -- Case of warning on unreferenced formal
1310 (Check_Unreferenced_Formals
and then Is_Formal
(E1
))
1312 -- Case of warning on unread variables modified by an
1313 -- assignment, or an OUT parameter if it is the only one.
1316 (Warn_On_Modified_Unread
1317 and then Referenced_As_LHS_Check_Spec
(E1
))
1319 -- Case of warning on any unread OUT parameter (note
1320 -- such indications are only set if the appropriate
1321 -- warning options were set, so no need to recheck here.
1324 Referenced_As_Out_Parameter_Check_Spec
(E1
))
1326 -- Labels, and enumeration literals, and exceptions. The
1327 -- warnings are also placed on local packages that cannot be
1328 -- referenced from elsewhere, including those declared within a
1331 and then (Is_Object
(E1
)
1335 Ekind
(E1
) = E_Label
1337 Ekind
(E1
) = E_Exception
1339 Ekind
(E1
) = E_Named_Integer
1341 Ekind
(E1
) = E_Named_Real
1343 Is_Overloadable
(E1
)
1345 -- Package case, if the main unit is a package spec
1346 -- or generic package spec, then there may be a
1347 -- corresponding body that references this package
1348 -- in some other file. Otherwise we can be sure
1349 -- that there is no other reference.
1352 (Ekind
(E1
) = E_Package
1354 not Is_Package_Or_Generic_Package
1355 (Cunit_Entity
(Current_Sem_Unit
))))
1357 -- Exclude instantiations, since there is no reason why every
1358 -- entity in an instantiation should be referenced.
1360 and then Instantiation_Location
(Sloc
(E1
)) = No_Location
1362 -- Exclude formal parameters from bodies if the corresponding
1363 -- spec entity has been referenced in the case where there is
1366 and then not (Is_Formal
(E1
)
1368 Ekind
(Scope
(E1
)) = E_Subprogram_Body
1370 Present
(Spec_Entity
(E1
))
1372 Referenced
(Spec_Entity
(E1
)))
1374 -- Consider private type referenced if full view is referenced.
1375 -- If there is not full view, this is a generic type on which
1376 -- warnings are also useful.
1379 not (Is_Private_Type
(E1
)
1381 Present
(Full_View
(E1
))
1382 and then Referenced
(Full_View
(E1
)))
1384 -- Don't worry about full view, only about private type
1386 and then not Has_Private_Declaration
(E1
)
1388 -- Eliminate dispatching operations from consideration, we
1389 -- cannot tell if these are referenced or not in any easy
1390 -- manner (note this also catches Adjust/Finalize/Initialize).
1392 and then not Is_Dispatching_Operation
(E1
)
1394 -- Check entity that can be publicly referenced (we do not give
1395 -- messages for such entities, since there could be other
1396 -- units, not involved in this compilation, that contain
1397 -- relevant references.
1399 and then not Publicly_Referenceable
(E1
)
1401 -- Class wide types are marked as source entities, but they are
1402 -- not really source entities, and are always created, so we do
1403 -- not care if they are not referenced.
1405 and then Ekind
(E1
) /= E_Class_Wide_Type
1407 -- Objects other than parameters of task types are allowed to
1408 -- be non-referenced, since they start up tasks!
1410 and then ((Ekind
(E1
) /= E_Variable
1411 and then Ekind
(E1
) /= E_Constant
1412 and then Ekind
(E1
) /= E_Component
)
1413 or else not Is_Task_Type
(E1T
))
1415 -- For subunits, only place warnings on the main unit itself,
1416 -- since parent units are not completely compiled.
1418 and then (Nkind
(Unit
(Cunit
(Main_Unit
))) /= N_Subunit
1420 Get_Source_Unit
(E1
) = Main_Unit
)
1422 -- No warning on a return object, because these are often
1423 -- created with a single expression and an implicit return.
1424 -- If the object is a variable there will be a warning
1425 -- indicating that it could be declared constant.
1428 (Ekind
(E1
) = E_Constant
and then Is_Return_Object
(E1
))
1430 -- Suppress warnings in internal units if not in -gnatg mode
1431 -- (these would be junk warnings for an applications program,
1432 -- since they refer to problems in internal units).
1436 Is_Internal_File_Name
1437 (Unit_File_Name
(Get_Source_Unit
(E1
)))
1439 -- We do not immediately flag the error. This is because we
1440 -- have not expanded generic bodies yet, and they may have
1441 -- the missing reference. So instead we park the entity on a
1442 -- list, for later processing. However for the case of an
1443 -- accept statement we want to output messages now, since
1444 -- we know we already have all information at hand, and we
1445 -- also want to have separate warnings for each accept
1446 -- statement for the same entry.
1448 if Present
(Anod
) then
1449 pragma Assert
(Is_Formal
(E1
));
1451 -- The unreferenced entity is E1, but post the warning
1452 -- on the body entity for this accept statement.
1454 if not Warnings_Off_E1
then
1455 Warn_On_Unreferenced_Entity
1456 (E1
, Body_Formal
(E1
, Accept_Statement
=> Anod
));
1459 elsif not Warnings_Off_E1
then
1460 Unreferenced_Entities
.Append
(E1
);
1464 -- Generic units are referenced in the generic body, but if they
1465 -- are not public and never instantiated we want to force a
1466 -- warning on them. We treat them as redundant constructs to
1469 elsif Is_Generic_Subprogram
(E1
)
1470 and then not Is_Instantiated
(E1
)
1471 and then not Publicly_Referenceable
(E1
)
1472 and then Instantiation_Depth
(Sloc
(E1
)) = 0
1473 and then Warn_On_Redundant_Constructs
1475 if not Warnings_Off_E1
then
1476 Unreferenced_Entities
.Append
(E1
);
1478 -- Force warning on entity
1480 Set_Referenced
(E1
, False);
1485 -- Recurse into nested package or block. Do not recurse into a formal
1486 -- package, because the corresponding body is not analyzed.
1489 if (Is_Package_Or_Generic_Package
(E1
)
1490 and then Nkind
(Parent
(E1
)) = N_Package_Specification
1492 Nkind
(Original_Node
(Unit_Declaration_Node
(E1
)))
1493 /= N_Formal_Package_Declaration
)
1495 or else Ekind
(E1
) = E_Block
1497 Check_References
(E1
);
1502 end Check_References
;
1504 ---------------------------
1505 -- Check_Unset_Reference --
1506 ---------------------------
1508 procedure Check_Unset_Reference
(N
: Node_Id
) is
1509 Typ
: constant Entity_Id
:= Etype
(N
);
1511 function Is_OK_Fully_Initialized
return Boolean;
1512 -- This function returns true if the given node N is fully initialized
1513 -- so that the reference is safe as far as this routine is concerned.
1514 -- Safe generally means that the type of N is a fully initialized type.
1515 -- The one special case is that for access types, which are always fully
1516 -- initialized, we don't consider a dereference OK since it will surely
1517 -- be dereferencing a null value, which won't do.
1519 function Prefix_Has_Dereference
(Pref
: Node_Id
) return Boolean;
1520 -- Used to test indexed or selected component or slice to see if the
1521 -- evaluation of the prefix depends on a dereference, and if so, returns
1522 -- True, in which case we always check the prefix, even if we know that
1523 -- the referenced component is initialized. Pref is the prefix to test.
1525 -----------------------------
1526 -- Is_OK_Fully_Initialized --
1527 -----------------------------
1529 function Is_OK_Fully_Initialized
return Boolean is
1531 if Is_Access_Type
(Typ
) and then Is_Dereferenced
(N
) then
1534 return Is_Fully_Initialized_Type
(Typ
);
1536 end Is_OK_Fully_Initialized
;
1538 ----------------------------
1539 -- Prefix_Has_Dereference --
1540 ----------------------------
1542 function Prefix_Has_Dereference
(Pref
: Node_Id
) return Boolean is
1544 -- If prefix is of an access type, it certainly needs a dereference
1546 if Is_Access_Type
(Etype
(Pref
)) then
1549 -- If prefix is explicit dereference, that's a dereference for sure
1551 elsif Nkind
(Pref
) = N_Explicit_Dereference
then
1554 -- If prefix is itself a component reference or slice check prefix
1556 elsif Nkind
(Pref
) = N_Slice
1557 or else Nkind
(Pref
) = N_Indexed_Component
1558 or else Nkind
(Pref
) = N_Selected_Component
1560 return Prefix_Has_Dereference
(Prefix
(Pref
));
1562 -- All other cases do not involve a dereference
1567 end Prefix_Has_Dereference
;
1569 -- Start of processing for Check_Unset_Reference
1572 -- Nothing to do if warnings suppressed
1574 if Warning_Mode
= Suppress
then
1578 -- Ignore reference unless it comes from source. Almost always if we
1579 -- have a reference from generated code, it is bogus (e.g. calls to init
1580 -- procs to set default discriminant values).
1582 if not Comes_From_Source
(N
) then
1586 -- Otherwise see what kind of node we have. If the entity already has an
1587 -- unset reference, it is not necessarily the earliest in the text,
1588 -- because resolution of the prefix of selected components is completed
1589 -- before the resolution of the selected component itself. As a result,
1590 -- given (R /= null and then R.X > 0), the occurrences of R are examined
1591 -- in right-to-left order. If there is already an unset reference, we
1592 -- check whether N is earlier before proceeding.
1596 -- For identifier or expanded name, examine the entity involved
1598 when N_Identifier | N_Expanded_Name
=>
1600 E
: constant Entity_Id
:= Entity
(N
);
1603 if (Ekind
(E
) = E_Variable
1605 Ekind
(E
) = E_Out_Parameter
)
1606 and then Never_Set_In_Source_Check_Spec
(E
)
1607 and then not Has_Initial_Value
(E
)
1608 and then (No
(Unset_Reference
(E
))
1610 Earlier_In_Extended_Unit
1611 (Sloc
(N
), Sloc
(Unset_Reference
(E
))))
1612 and then not Has_Pragma_Unmodified_Check_Spec
(E
)
1613 and then not Warnings_Off_Check_Spec
(E
)
1615 -- We may have an unset reference. The first test is whether
1616 -- this is an access to a discriminant of a record or a
1617 -- component with default initialization. Both of these
1618 -- cases can be ignored, since the actual object that is
1619 -- referenced is definitely initialized. Note that this
1620 -- covers the case of reading discriminants of an OUT
1621 -- parameter, which is OK even in Ada 83.
1623 -- Note that we are only interested in a direct reference to
1624 -- a record component here. If the reference is through an
1625 -- access type, then the access object is being referenced,
1626 -- not the record, and still deserves an unset reference.
1628 if Nkind
(Parent
(N
)) = N_Selected_Component
1629 and not Is_Access_Type
(Typ
)
1632 ES
: constant Entity_Id
:=
1633 Entity
(Selector_Name
(Parent
(N
)));
1635 if Ekind
(ES
) = E_Discriminant
1637 (Present
(Declaration_Node
(ES
))
1639 Present
(Expression
(Declaration_Node
(ES
))))
1646 -- Exclude fully initialized types
1648 if Is_OK_Fully_Initialized
then
1652 -- Here we have a potential unset reference. But before we
1653 -- get worried about it, we have to make sure that the
1654 -- entity declaration is in the same procedure as the
1655 -- reference, since if they are in separate procedures, then
1656 -- we have no idea about sequential execution.
1658 -- The tests in the loop below catch all such cases, but do
1659 -- allow the reference to appear in a loop, block, or
1660 -- package spec that is nested within the declaring scope.
1661 -- As always, it is possible to construct cases where the
1662 -- warning is wrong, that is why it is a warning!
1664 Potential_Unset_Reference
: declare
1666 SE
: constant Entity_Id
:= Scope
(E
);
1668 function Within_Postcondition
return Boolean;
1669 -- Returns True iff N is within a Precondition
1671 --------------------------
1672 -- Within_Postcondition --
1673 --------------------------
1675 function Within_Postcondition
return Boolean is
1680 while Present
(Nod
) loop
1681 if Nkind
(Nod
) = N_Pragma
1682 and then Pragma_Name
(Nod
) = Name_Postcondition
1687 Nod
:= Parent
(Nod
);
1691 end Within_Postcondition
;
1693 -- Start of processing for Potential_Unset_Reference
1696 SR
:= Current_Scope
;
1698 if SR
= Standard_Standard
1699 or else Is_Subprogram
(SR
)
1700 or else Is_Concurrent_Body
(SR
)
1701 or else Is_Concurrent_Type
(SR
)
1709 -- Case of reference has an access type. This is a
1710 -- special case since access types are always set to null
1711 -- so cannot be truly uninitialized, but we still want to
1712 -- warn about cases of obvious null dereference.
1714 if Is_Access_Type
(Typ
) then
1715 Access_Type_Case
: declare
1719 (N
: Node_Id
) return Traverse_Result
;
1720 -- Process function for instantiation of Traverse
1721 -- below. Checks if N contains reference to E other
1722 -- than a dereference.
1724 function Ref_In
(Nod
: Node_Id
) return Boolean;
1725 -- Determines whether Nod contains a reference to
1726 -- the entity E that is not a dereference.
1733 (N
: Node_Id
) return Traverse_Result
1736 if Is_Entity_Name
(N
)
1737 and then Entity
(N
) = E
1738 and then not Is_Dereferenced
(N
)
1750 function Ref_In
(Nod
: Node_Id
) return Boolean is
1751 function Traverse
is new Traverse_Func
(Process
);
1753 return Traverse
(Nod
) = Abandon
;
1756 -- Start of processing for Access_Type_Case
1759 -- Don't bother if we are inside an instance, since
1760 -- the compilation of the generic template is where
1761 -- the warning should be issued.
1767 -- Don't bother if this is not the main unit. If we
1768 -- try to give this warning for with'ed units, we
1769 -- get some false positives, since we do not record
1770 -- references in other units.
1772 if not In_Extended_Main_Source_Unit
(E
)
1774 not In_Extended_Main_Source_Unit
(N
)
1779 -- We are only interested in dereferences
1781 if not Is_Dereferenced
(N
) then
1785 -- One more check, don't bother with references
1786 -- that are inside conditional statements or WHILE
1787 -- loops if the condition references the entity in
1788 -- question. This avoids most false positives.
1795 if (Nkind
(P
) = N_If_Statement
1797 Nkind
(P
) = N_Elsif_Part
)
1798 and then Ref_In
(Condition
(P
))
1802 elsif Nkind
(P
) = N_Loop_Statement
1803 and then Present
(Iteration_Scheme
(P
))
1805 Ref_In
(Condition
(Iteration_Scheme
(P
)))
1810 end Access_Type_Case
;
1813 -- One more check, don't bother if we are within a
1814 -- postcondition pragma, since the expression occurs
1815 -- in a place unrelated to the actual test.
1817 if not Within_Postcondition
then
1819 -- Here we definitely have a case for giving a warning
1820 -- for a reference to an unset value. But we don't
1821 -- give the warning now. Instead set Unset_Reference
1822 -- in the identifier involved. The reason for this is
1823 -- that if we find the variable is never ever assigned
1824 -- a value then that warning is more important and
1825 -- there is no point in giving the reference warning.
1827 -- If this is an identifier, set the field directly
1829 if Nkind
(N
) = N_Identifier
then
1830 Set_Unset_Reference
(E
, N
);
1832 -- Otherwise it is an expanded name, so set the field
1833 -- of the actual identifier for the reference.
1836 Set_Unset_Reference
(E
, Selector_Name
(N
));
1839 end Potential_Unset_Reference
;
1843 -- Indexed component or slice
1845 when N_Indexed_Component | N_Slice
=>
1847 -- If prefix does not involve dereferencing an access type, then
1848 -- we know we are OK if the component type is fully initialized,
1849 -- since the component will have been set as part of the default
1852 if not Prefix_Has_Dereference
(Prefix
(N
))
1853 and then Is_OK_Fully_Initialized
1857 -- Look at prefix in access type case, or if the component is not
1858 -- fully initialized.
1861 Check_Unset_Reference
(Prefix
(N
));
1866 when N_Selected_Component
=>
1868 Pref
: constant Node_Id
:= Prefix
(N
);
1869 Ent
: constant Entity_Id
:= Entity
(Selector_Name
(N
));
1872 -- If prefix involves dereferencing an access type, always
1873 -- check the prefix, since the issue then is whether this
1874 -- access value is null.
1876 if Prefix_Has_Dereference
(Pref
) then
1879 -- Always go to prefix if no selector entity is set. Can this
1880 -- happen in the normal case? Not clear, but it definitely can
1881 -- happen in error cases.
1886 -- For a record component, check some cases where we have
1887 -- reasonable cause to consider that the component is known to
1888 -- be or probably is initialized. In this case, we don't care
1889 -- if the prefix itself was explicitly initialized.
1891 -- Discriminants are always considered initialized
1893 elsif Ekind
(Ent
) = E_Discriminant
then
1896 -- An explicitly initialized component is certainly initialized
1898 elsif Nkind
(Parent
(Ent
)) = N_Component_Declaration
1899 and then Present
(Expression
(Parent
(Ent
)))
1903 -- A fully initialized component is initialized
1905 elsif Is_OK_Fully_Initialized
then
1909 -- If none of those cases apply, check the record type prefix
1911 Check_Unset_Reference
(Pref
);
1914 -- For type conversions or qualifications examine the expression
1916 when N_Type_Conversion | N_Qualified_Expression
=>
1917 Check_Unset_Reference
(Expression
(N
));
1919 -- For explicit dereference, always check prefix, which will generate
1920 -- an unset reference (since this is a case of dereferencing null).
1922 when N_Explicit_Dereference
=>
1923 Check_Unset_Reference
(Prefix
(N
));
1925 -- All other cases are not cases of an unset reference
1931 end Check_Unset_Reference
;
1933 ------------------------
1934 -- Check_Unused_Withs --
1935 ------------------------
1937 procedure Check_Unused_Withs
(Spec_Unit
: Unit_Number_Type
:= No_Unit
) is
1943 Munite
: constant Entity_Id
:= Cunit_Entity
(Main_Unit
);
1944 -- This is needed for checking the special renaming case
1946 procedure Check_One_Unit
(Unit
: Unit_Number_Type
);
1947 -- Subsidiary procedure, performs checks for specified unit
1949 --------------------
1950 -- Check_One_Unit --
1951 --------------------
1953 procedure Check_One_Unit
(Unit
: Unit_Number_Type
) is
1954 Is_Visible_Renaming
: Boolean := False;
1957 procedure Check_Inner_Package
(Pack
: Entity_Id
);
1958 -- Pack is a package local to a unit in a with_clause. Both the unit
1959 -- and Pack are referenced. If none of the entities in Pack are
1960 -- referenced, then the only occurrence of Pack is in a USE clause
1961 -- or a pragma, and a warning is worthwhile as well.
1963 function Check_System_Aux
return Boolean;
1964 -- Before giving a warning on a with_clause for System, check wheter
1965 -- a system extension is present.
1967 function Find_Package_Renaming
1969 L
: Entity_Id
) return Entity_Id
;
1970 -- The only reference to a context unit may be in a renaming
1971 -- declaration. If this renaming declares a visible entity, do not
1972 -- warn that the context clause could be moved to the body, because
1973 -- the renaming may be intended to re-export the unit.
1975 function Has_Visible_Entities
(P
: Entity_Id
) return Boolean;
1976 -- This function determines if a package has any visible entities.
1977 -- True is returned if there is at least one declared visible entity,
1978 -- otherwise False is returned (e.g. case of only pragmas present).
1980 -------------------------
1981 -- Check_Inner_Package --
1982 -------------------------
1984 procedure Check_Inner_Package
(Pack
: Entity_Id
) is
1986 Un
: constant Node_Id
:= Sinfo
.Unit
(Cnode
);
1988 function Check_Use_Clause
(N
: Node_Id
) return Traverse_Result
;
1989 -- If N is a use_clause for Pack, emit warning
1991 procedure Check_Use_Clauses
is new
1992 Traverse_Proc
(Check_Use_Clause
);
1994 ----------------------
1995 -- Check_Use_Clause --
1996 ----------------------
1998 function Check_Use_Clause
(N
: Node_Id
) return Traverse_Result
is
2002 if Nkind
(N
) = N_Use_Package_Clause
then
2003 Nam
:= First
(Names
(N
));
2004 while Present
(Nam
) loop
2005 if Entity
(Nam
) = Pack
then
2006 Error_Msg_Qual_Level
:= 1;
2008 ("?no entities of package& are referenced!",
2010 Error_Msg_Qual_Level
:= 0;
2018 end Check_Use_Clause
;
2020 -- Start of processing for Check_Inner_Package
2023 E
:= First_Entity
(Pack
);
2024 while Present
(E
) loop
2025 if Referenced_Check_Spec
(E
) then
2032 -- No entities of the package are referenced. Check whether the
2033 -- reference to the package itself is a use clause, and if so
2034 -- place a warning on it.
2036 Check_Use_Clauses
(Un
);
2037 end Check_Inner_Package
;
2039 ----------------------
2040 -- Check_System_Aux --
2041 ----------------------
2043 function Check_System_Aux
return Boolean is
2047 if Chars
(Lunit
) = Name_System
2048 and then Scope
(Lunit
) = Standard_Standard
2049 and then Present_System_Aux
2051 Ent
:= First_Entity
(System_Aux_Id
);
2052 while Present
(Ent
) loop
2053 if Referenced_Check_Spec
(Ent
) then
2062 end Check_System_Aux
;
2064 ---------------------------
2065 -- Find_Package_Renaming --
2066 ---------------------------
2068 function Find_Package_Renaming
2070 L
: Entity_Id
) return Entity_Id
2076 Is_Visible_Renaming
:= False;
2078 E1
:= First_Entity
(P
);
2079 while Present
(E1
) loop
2080 if Ekind
(E1
) = E_Package
2081 and then Renamed_Object
(E1
) = L
2083 Is_Visible_Renaming
:= not Is_Hidden
(E1
);
2086 elsif Ekind
(E1
) = E_Package
2087 and then No
(Renamed_Object
(E1
))
2088 and then not Is_Generic_Instance
(E1
)
2090 R
:= Find_Package_Renaming
(E1
, L
);
2093 Is_Visible_Renaming
:= not Is_Hidden
(R
);
2102 end Find_Package_Renaming
;
2104 --------------------------
2105 -- Has_Visible_Entities --
2106 --------------------------
2108 function Has_Visible_Entities
(P
: Entity_Id
) return Boolean is
2112 -- If unit in context is not a package, it is a subprogram that
2113 -- is not called or a generic unit that is not instantiated
2114 -- in the current unit, and warning is appropriate.
2116 if Ekind
(P
) /= E_Package
then
2120 -- If unit comes from a limited_with clause, look for declaration
2121 -- of shadow entities.
2123 if Present
(Limited_View
(P
)) then
2124 E
:= First_Entity
(Limited_View
(P
));
2126 E
:= First_Entity
(P
);
2130 and then E
/= First_Private_Entity
(P
)
2132 if Comes_From_Source
(E
)
2133 or else Present
(Limited_View
(P
))
2142 end Has_Visible_Entities
;
2144 -- Start of processing for Check_One_Unit
2147 Cnode
:= Cunit
(Unit
);
2149 -- Only do check in units that are part of the extended main unit.
2150 -- This is actually a necessary restriction, because in the case of
2151 -- subprogram acting as its own specification, there can be with's in
2152 -- subunits that we will not see.
2154 if not In_Extended_Main_Source_Unit
(Cnode
) then
2157 -- In configurable run time mode, we remove the bodies of non-inlined
2158 -- subprograms, which may lead to spurious warnings, which are
2159 -- clearly undesirable.
2161 elsif Configurable_Run_Time_Mode
2162 and then Is_Predefined_File_Name
(Unit_File_Name
(Unit
))
2167 -- Loop through context items in this unit
2169 Item
:= First
(Context_Items
(Cnode
));
2170 while Present
(Item
) loop
2171 if Nkind
(Item
) = N_With_Clause
2172 and then not Implicit_With
(Item
)
2173 and then In_Extended_Main_Source_Unit
(Item
)
2175 Lunit
:= Entity
(Name
(Item
));
2177 -- Check if this unit is referenced (skip the check if this
2178 -- is explicitly marked by a pragma Unreferenced).
2180 if not Referenced
(Lunit
)
2181 and then not Has_Unreferenced
(Lunit
)
2183 -- Suppress warnings in internal units if not in -gnatg mode
2184 -- (these would be junk warnings for an application program,
2185 -- since they refer to problems in internal units).
2188 or else not Is_Internal_File_Name
(Unit_File_Name
(Unit
))
2190 -- Here we definitely have a non-referenced unit. If it
2191 -- is the special call for a spec unit, then just set the
2192 -- flag to be read later.
2194 if Unit
= Spec_Unit
then
2195 Set_Unreferenced_In_Spec
(Item
);
2197 -- Otherwise simple unreferenced message, but skip this
2198 -- if no visible entities, because that is most likely a
2199 -- case where warning would be false positive (e.g. a
2200 -- package with only a linker options pragma and nothing
2201 -- else or a pragma elaborate with a body library task).
2203 elsif Has_Visible_Entities
(Entity
(Name
(Item
))) then
2205 ("?unit& is not referenced!", Name
(Item
));
2209 -- If main unit is a renaming of this unit, then we consider
2210 -- the with to be OK (obviously it is needed in this case!)
2211 -- This may be transitive: the unit in the with_clause may
2212 -- itself be a renaming, in which case both it and the main
2213 -- unit rename the same ultimate package.
2215 elsif Present
(Renamed_Entity
(Munite
))
2217 (Renamed_Entity
(Munite
) = Lunit
2218 or else Renamed_Entity
(Munite
) = Renamed_Entity
(Lunit
))
2222 -- If this unit is referenced, and it is a package, we do
2223 -- another test, to see if any of the entities in the package
2224 -- are referenced. If none of the entities are referenced, we
2225 -- still post a warning. This occurs if the only use of the
2226 -- package is in a use clause, or in a package renaming
2227 -- declaration. This check is skipped for packages that are
2228 -- renamed in a spec, since the entities in such a package are
2229 -- visible to clients via the renaming.
2231 elsif Ekind
(Lunit
) = E_Package
2232 and then not Renamed_In_Spec
(Lunit
)
2234 -- If Is_Instantiated is set, it means that the package is
2235 -- implicitly instantiated (this is the case of parent
2236 -- instance or an actual for a generic package formal), and
2237 -- this counts as a reference.
2239 if Is_Instantiated
(Lunit
) then
2242 -- If no entities in package, and there is a pragma
2243 -- Elaborate_Body present, then assume that this with is
2244 -- done for purposes of this elaboration.
2246 elsif No
(First_Entity
(Lunit
))
2247 and then Has_Pragma_Elaborate_Body
(Lunit
)
2251 -- Otherwise see if any entities have been referenced
2254 if Limited_Present
(Item
) then
2255 Ent
:= First_Entity
(Limited_View
(Lunit
));
2257 Ent
:= First_Entity
(Lunit
);
2261 -- No more entities, and we did not find one that was
2262 -- referenced. Means we have a definite case of a with
2263 -- none of whose entities was referenced.
2267 -- If in spec, just set the flag
2269 if Unit
= Spec_Unit
then
2270 Set_No_Entities_Ref_In_Spec
(Item
);
2272 elsif Check_System_Aux
then
2275 -- Else give the warning
2279 Has_Unreferenced
(Entity
(Name
(Item
)))
2282 ("?no entities of & are referenced!",
2286 -- Look for renamings of this package, and flag
2287 -- them as well. If the original package has
2288 -- warnings off, we suppress the warning on the
2289 -- renaming as well.
2291 Pack
:= Find_Package_Renaming
(Munite
, Lunit
);
2294 and then not Has_Warnings_Off
(Lunit
)
2295 and then not Has_Unreferenced
(Pack
)
2298 ("?no entities of & are referenced!",
2299 Unit_Declaration_Node
(Pack
),
2306 -- Case of entity being referenced. The reference may
2307 -- come from a limited_with_clause, in which case the
2308 -- limited view of the entity carries the flag.
2310 elsif Referenced_Check_Spec
(Ent
)
2311 or else Referenced_As_LHS_Check_Spec
(Ent
)
2312 or else Referenced_As_Out_Parameter_Check_Spec
(Ent
)
2314 (From_With_Type
(Ent
)
2315 and then Is_Incomplete_Type
(Ent
)
2316 and then Present
(Non_Limited_View
(Ent
))
2317 and then Referenced
(Non_Limited_View
(Ent
)))
2319 -- This means that the with is indeed fine, in that
2320 -- it is definitely needed somewhere, and we can
2321 -- quit worrying about this one...
2323 -- Except for one little detail: if either of the
2324 -- flags was set during spec processing, this is
2325 -- where we complain that the with could be moved
2326 -- from the spec. If the spec contains a visible
2327 -- renaming of the package, inhibit warning to move
2328 -- with_clause to body.
2330 if Ekind
(Munite
) = E_Package_Body
then
2332 Find_Package_Renaming
2333 (Spec_Entity
(Munite
), Lunit
);
2336 if Unreferenced_In_Spec
(Item
) then
2338 ("?unit& is not referenced in spec!",
2341 elsif No_Entities_Ref_In_Spec
(Item
) then
2343 ("?no entities of & are referenced in spec!",
2347 if Ekind
(Ent
) = E_Package
then
2348 Check_Inner_Package
(Ent
);
2354 if not Is_Visible_Renaming
then
2355 Error_Msg_N
-- CODEFIX
2356 ("\?with clause might be moved to body!",
2362 -- Move to next entity to continue search
2370 -- For a generic package, the only interesting kind of
2371 -- reference is an instantiation, since entities cannot be
2372 -- referenced directly.
2374 elsif Is_Generic_Unit
(Lunit
) then
2376 -- Unit was never instantiated, set flag for case of spec
2377 -- call, or give warning for normal call.
2379 if not Is_Instantiated
(Lunit
) then
2380 if Unit
= Spec_Unit
then
2381 Set_Unreferenced_In_Spec
(Item
);
2383 Error_Msg_N
-- CODEFIX
2384 ("?unit& is never instantiated!", Name
(Item
));
2387 -- If unit was indeed instantiated, make sure that flag is
2388 -- not set showing it was uninstantiated in the spec, and if
2389 -- so, give warning.
2391 elsif Unreferenced_In_Spec
(Item
) then
2393 ("?unit& is not instantiated in spec!", Name
(Item
));
2394 Error_Msg_N
-- CODEFIX
2395 ("\?with clause can be moved to body!", Name
(Item
));
2404 -- Start of processing for Check_Unused_Withs
2407 if not Opt
.Check_Withs
2408 or else Operating_Mode
= Check_Syntax
2413 -- Flag any unused with clauses, but skip this step if we are compiling
2414 -- a subunit on its own, since we do not have enough information to
2415 -- determine whether with's are used. We will get the relevant warnings
2416 -- when we compile the parent. This is the normal style of GNAT
2417 -- compilation in any case.
2419 if Nkind
(Unit
(Cunit
(Main_Unit
))) = N_Subunit
then
2423 -- Process specified units
2425 if Spec_Unit
= No_Unit
then
2427 -- For main call, check all units
2429 for Unit
in Main_Unit
.. Last_Unit
loop
2430 Check_One_Unit
(Unit
);
2434 -- For call for spec, check only the spec
2436 Check_One_Unit
(Spec_Unit
);
2438 end Check_Unused_Withs
;
2440 ---------------------------------
2441 -- Generic_Package_Spec_Entity --
2442 ---------------------------------
2444 function Generic_Package_Spec_Entity
(E
: Entity_Id
) return Boolean is
2448 if Is_Package_Body_Entity
(E
) then
2454 if S
= Standard_Standard
then
2457 elsif Ekind
(S
) = E_Generic_Package
then
2460 elsif Ekind
(S
) = E_Package
then
2468 end Generic_Package_Spec_Entity
;
2470 ----------------------
2471 -- Goto_Spec_Entity --
2472 ----------------------
2474 function Goto_Spec_Entity
(E
: Entity_Id
) return Entity_Id
is
2477 and then Present
(Spec_Entity
(E
))
2479 return Spec_Entity
(E
);
2483 end Goto_Spec_Entity
;
2485 --------------------------------------
2486 -- Has_Pragma_Unmodified_Check_Spec --
2487 --------------------------------------
2489 function Has_Pragma_Unmodified_Check_Spec
2490 (E
: Entity_Id
) return Boolean
2493 if Is_Formal
(E
) and then Present
(Spec_Entity
(E
)) then
2495 -- Note: use of OR instead of OR ELSE here is deliberate, we want
2496 -- to mess with Unmodified flags on both body and spec entities.
2498 return Has_Unmodified
(E
)
2500 Has_Unmodified
(Spec_Entity
(E
));
2503 return Has_Unmodified
(E
);
2505 end Has_Pragma_Unmodified_Check_Spec
;
2507 ----------------------------------------
2508 -- Has_Pragma_Unreferenced_Check_Spec --
2509 ----------------------------------------
2511 function Has_Pragma_Unreferenced_Check_Spec
2512 (E
: Entity_Id
) return Boolean
2515 if Is_Formal
(E
) and then Present
(Spec_Entity
(E
)) then
2517 -- Note: use of OR here instead of OR ELSE is deliberate, we want
2518 -- to mess with flags on both entities.
2520 return Has_Unreferenced
(E
)
2522 Has_Unreferenced
(Spec_Entity
(E
));
2525 return Has_Unreferenced
(E
);
2527 end Has_Pragma_Unreferenced_Check_Spec
;
2533 procedure Initialize
is
2535 Warnings_Off_Pragmas
.Init
;
2536 Unreferenced_Entities
.Init
;
2537 In_Out_Warnings
.Init
;
2540 ------------------------------------
2541 -- Never_Set_In_Source_Check_Spec --
2542 ------------------------------------
2544 function Never_Set_In_Source_Check_Spec
(E
: Entity_Id
) return Boolean is
2546 if Is_Formal
(E
) and then Present
(Spec_Entity
(E
)) then
2547 return Never_Set_In_Source
(E
)
2549 Never_Set_In_Source
(Spec_Entity
(E
));
2551 return Never_Set_In_Source
(E
);
2553 end Never_Set_In_Source_Check_Spec
;
2555 -------------------------------------
2556 -- Operand_Has_Warnings_Suppressed --
2557 -------------------------------------
2559 function Operand_Has_Warnings_Suppressed
(N
: Node_Id
) return Boolean is
2561 function Check_For_Warnings
(N
: Node_Id
) return Traverse_Result
;
2562 -- Function used to check one node to see if it is or was originally
2563 -- a reference to an entity for which Warnings are off. If so, Abandon
2564 -- is returned, otherwise OK_Orig is returned to continue the traversal
2565 -- of the original expression.
2567 function Traverse
is new Traverse_Func
(Check_For_Warnings
);
2568 -- Function used to traverse tree looking for warnings
2570 ------------------------
2571 -- Check_For_Warnings --
2572 ------------------------
2574 function Check_For_Warnings
(N
: Node_Id
) return Traverse_Result
is
2575 R
: constant Node_Id
:= Original_Node
(N
);
2578 if Nkind
(R
) in N_Has_Entity
2579 and then Present
(Entity
(R
))
2580 and then Has_Warnings_Off
(Entity
(R
))
2586 end Check_For_Warnings
;
2588 -- Start of processing for Operand_Has_Warnings_Suppressed
2591 return Traverse
(N
) = Abandon
;
2593 -- If any exception occurs, then something has gone wrong, and this is
2594 -- only a minor aesthetic issue anyway, so just say we did not find what
2595 -- we are looking for, rather than blow up.
2600 end Operand_Has_Warnings_Suppressed
;
2602 -----------------------------------------
2603 -- Output_Non_Modified_In_Out_Warnings --
2604 -----------------------------------------
2606 procedure Output_Non_Modified_In_Out_Warnings
is
2608 function No_Warn_On_In_Out
(E
: Entity_Id
) return Boolean;
2609 -- Given a formal parameter entity E, determines if there is a reason to
2610 -- suppress IN OUT warnings (not modified, could be IN) for formals of
2611 -- the subprogram. We suppress these warnings if Warnings Off is set, or
2612 -- if we have seen the address of the subprogram being taken, or if the
2613 -- subprogram is used as a generic actual (in the latter cases the
2614 -- context may force use of IN OUT, even if the parameter is not
2615 -- modifies for this particular case.
2617 -----------------------
2618 -- No_Warn_On_In_Out --
2619 -----------------------
2621 function No_Warn_On_In_Out
(E
: Entity_Id
) return Boolean is
2622 S
: constant Entity_Id
:= Scope
(E
);
2623 SE
: constant Entity_Id
:= Spec_Entity
(E
);
2626 -- Do not warn if address is taken, since funny business may be going
2627 -- on in treating the parameter indirectly as IN OUT.
2629 if Address_Taken
(S
)
2630 or else (Present
(SE
) and then Address_Taken
(Scope
(SE
)))
2634 -- Do not warn if used as a generic actual, since the generic may be
2635 -- what is forcing the use of an "unnecessary" IN OUT.
2637 elsif Used_As_Generic_Actual
(S
)
2638 or else (Present
(SE
) and then Used_As_Generic_Actual
(Scope
(SE
)))
2642 -- Else test warnings off
2644 elsif Warnings_Off_Check_Spec
(S
) then
2647 -- All tests for suppressing warning failed
2652 end No_Warn_On_In_Out
;
2654 -- Start of processing for Output_Non_Modified_In_Out_Warnings
2657 -- Loop through entities for which a warning may be needed
2659 for J
in In_Out_Warnings
.First
.. In_Out_Warnings
.Last
loop
2661 E1
: constant Entity_Id
:= In_Out_Warnings
.Table
(J
);
2664 -- Suppress warning in specific cases (see details in comments for
2665 -- No_Warn_On_In_Out), or if there is a pragma Unmodified.
2667 if Has_Pragma_Unmodified_Check_Spec
(E1
)
2668 or else No_Warn_On_In_Out
(E1
)
2672 -- Here we generate the warning
2675 -- If -gnatwc is set then output message that we could be IN
2677 if not Is_Trivial_Subprogram
(Scope
(E1
)) then
2678 if Warn_On_Constant
then
2680 ("?formal parameter & is not modified!", E1
);
2682 ("\?mode could be IN instead of `IN OUT`!", E1
);
2684 -- We do not generate warnings for IN OUT parameters
2685 -- unless we have at least -gnatwu. This is deliberately
2686 -- inconsistent with the treatment of variables, but
2687 -- otherwise we get too many unexpected warnings in
2690 elsif Check_Unreferenced
then
2691 Error_Msg_N
("?formal parameter& is read but "
2692 & "never assigned!", E1
);
2696 -- Kill any other warnings on this entity, since this is the
2697 -- one that should dominate any other unreferenced warning.
2699 Set_Warnings_Off
(E1
);
2703 end Output_Non_Modified_In_Out_Warnings
;
2705 ----------------------------------------
2706 -- Output_Obsolescent_Entity_Warnings --
2707 ----------------------------------------
2709 procedure Output_Obsolescent_Entity_Warnings
(N
: Node_Id
; E
: Entity_Id
) is
2710 P
: constant Node_Id
:= Parent
(N
);
2716 -- Do not output message if we are the scope of standard. This means
2717 -- we have a reference from a context clause from when it is originally
2718 -- processed, and that's too early to tell whether it is an obsolescent
2719 -- unit doing the with'ing. In Sem_Ch10.Analyze_Compilation_Unit we make
2720 -- sure that we have a later call when the scope is available. This test
2721 -- also eliminates all messages for use clauses, which is fine (we do
2722 -- not want messages for use clauses, since they are always redundant
2723 -- with respect to the associated with clause).
2725 if S
= Standard_Standard
then
2729 -- Do not output message if we are in scope of an obsolescent package
2733 if Is_Obsolescent
(S
) then
2738 exit when S
= Standard_Standard
;
2741 -- Here we will output the message
2743 Error_Msg_Sloc
:= Sloc
(E
);
2745 -- Case of with clause
2747 if Nkind
(P
) = N_With_Clause
then
2748 if Ekind
(E
) = E_Package
then
2750 ("?with of obsolescent package& declared#", N
, E
);
2751 elsif Ekind
(E
) = E_Procedure
then
2753 ("?with of obsolescent procedure& declared#", N
, E
);
2756 ("?with of obsolescent function& declared#", N
, E
);
2759 -- If we do not have a with clause, then ignore any reference to an
2760 -- obsolescent package name. We only want to give the one warning of
2761 -- withing the package, not one each time it is used to qualify.
2763 elsif Ekind
(E
) = E_Package
then
2766 -- Procedure call statement
2768 elsif Nkind
(P
) = N_Procedure_Call_Statement
then
2770 ("?call to obsolescent procedure& declared#", N
, E
);
2774 elsif Nkind
(P
) = N_Function_Call
then
2776 ("?call to obsolescent function& declared#", N
, E
);
2778 -- Reference to obsolescent type
2780 elsif Is_Type
(E
) then
2782 ("?reference to obsolescent type& declared#", N
, E
);
2784 -- Reference to obsolescent component
2786 elsif Ekind
(E
) = E_Component
2787 or else Ekind
(E
) = E_Discriminant
2790 ("?reference to obsolescent component& declared#", N
, E
);
2792 -- Reference to obsolescent variable
2794 elsif Ekind
(E
) = E_Variable
then
2796 ("?reference to obsolescent variable& declared#", N
, E
);
2798 -- Reference to obsolescent constant
2800 elsif Ekind
(E
) = E_Constant
2801 or else Ekind
(E
) in Named_Kind
2804 ("?reference to obsolescent constant& declared#", N
, E
);
2806 -- Reference to obsolescent enumeration literal
2808 elsif Ekind
(E
) = E_Enumeration_Literal
then
2810 ("?reference to obsolescent enumeration literal& declared#", N
, E
);
2812 -- Generic message for any other case we missed
2816 ("?reference to obsolescent entity& declared#", N
, E
);
2819 -- Output additional warning if present
2821 for J
in Obsolescent_Warnings
.First
.. Obsolescent_Warnings
.Last
loop
2822 if Obsolescent_Warnings
.Table
(J
).Ent
= E
then
2823 String_To_Name_Buffer
(Obsolescent_Warnings
.Table
(J
).Msg
);
2824 Error_Msg_Strlen
:= Name_Len
;
2825 Error_Msg_String
(1 .. Name_Len
) := Name_Buffer
(1 .. Name_Len
);
2826 Error_Msg_N
("\\?~", N
);
2830 end Output_Obsolescent_Entity_Warnings
;
2832 ----------------------------------
2833 -- Output_Unreferenced_Messages --
2834 ----------------------------------
2836 procedure Output_Unreferenced_Messages
is
2838 for J
in Unreferenced_Entities
.First
..
2839 Unreferenced_Entities
.Last
2841 Warn_On_Unreferenced_Entity
(Unreferenced_Entities
.Table
(J
));
2843 end Output_Unreferenced_Messages
;
2845 -----------------------------------------
2846 -- Output_Unused_Warnings_Off_Warnings --
2847 -----------------------------------------
2849 procedure Output_Unused_Warnings_Off_Warnings
is
2851 for J
in Warnings_Off_Pragmas
.First
.. Warnings_Off_Pragmas
.Last
loop
2853 Wentry
: Warnings_Off_Entry
renames Warnings_Off_Pragmas
.Table
(J
);
2854 N
: Node_Id
renames Wentry
.N
;
2855 E
: Node_Id
renames Wentry
.E
;
2858 -- Turn off Warnings_Off, or we won't get the warning!
2860 Set_Warnings_Off
(E
, False);
2862 -- Nothing to do if pragma was used to suppress a general warning
2864 if Warnings_Off_Used
(E
) then
2867 -- If pragma was used both in unmodified and unreferenced contexts
2868 -- then that's as good as the general case, no warning.
2870 elsif Warnings_Off_Used_Unmodified
(E
)
2872 Warnings_Off_Used_Unreferenced
(E
)
2876 -- Used only in context where Unmodified would have worked
2878 elsif Warnings_Off_Used_Unmodified
(E
) then
2880 ("?could use Unmodified instead of "
2881 & "Warnings Off for &", Pragma_Identifier
(N
), E
);
2883 -- Used only in context where Unreferenced would have worked
2885 elsif Warnings_Off_Used_Unreferenced
(E
) then
2887 ("?could use Unreferenced instead of "
2888 & "Warnings Off for &", Pragma_Identifier
(N
), E
);
2894 ("?pragma Warnings Off for & unused, "
2895 & "could be omitted", N
, E
);
2899 end Output_Unused_Warnings_Off_Warnings
;
2901 ---------------------------
2902 -- Referenced_Check_Spec --
2903 ---------------------------
2905 function Referenced_Check_Spec
(E
: Entity_Id
) return Boolean is
2907 if Is_Formal
(E
) and then Present
(Spec_Entity
(E
)) then
2908 return Referenced
(E
) or else Referenced
(Spec_Entity
(E
));
2910 return Referenced
(E
);
2912 end Referenced_Check_Spec
;
2914 ----------------------------------
2915 -- Referenced_As_LHS_Check_Spec --
2916 ----------------------------------
2918 function Referenced_As_LHS_Check_Spec
(E
: Entity_Id
) return Boolean is
2920 if Is_Formal
(E
) and then Present
(Spec_Entity
(E
)) then
2921 return Referenced_As_LHS
(E
)
2922 or else Referenced_As_LHS
(Spec_Entity
(E
));
2924 return Referenced_As_LHS
(E
);
2926 end Referenced_As_LHS_Check_Spec
;
2928 --------------------------------------------
2929 -- Referenced_As_Out_Parameter_Check_Spec --
2930 --------------------------------------------
2932 function Referenced_As_Out_Parameter_Check_Spec
2933 (E
: Entity_Id
) return Boolean
2936 if Is_Formal
(E
) and then Present
(Spec_Entity
(E
)) then
2937 return Referenced_As_Out_Parameter
(E
)
2938 or else Referenced_As_Out_Parameter
(Spec_Entity
(E
));
2940 return Referenced_As_Out_Parameter
(E
);
2942 end Referenced_As_Out_Parameter_Check_Spec
;
2944 ----------------------------
2945 -- Set_Dot_Warning_Switch --
2946 ----------------------------
2948 function Set_Dot_Warning_Switch
(C
: Character) return Boolean is
2952 Warn_On_Assertion_Failure
:= True;
2955 Warn_On_Assertion_Failure
:= False;
2958 Warn_On_Biased_Representation
:= True;
2961 Warn_On_Biased_Representation
:= False;
2964 Warn_On_Unrepped_Components
:= True;
2967 Warn_On_Unrepped_Components
:= False;
2970 Address_Clause_Overlay_Warnings
:= True;
2971 Check_Unreferenced
:= True;
2972 Check_Unreferenced_Formals
:= True;
2973 Check_Withs
:= True;
2974 Constant_Condition_Warnings
:= True;
2975 Elab_Warnings
:= True;
2976 Implementation_Unit_Warnings
:= True;
2977 Ineffective_Inline_Warnings
:= True;
2978 Warn_On_Ada_2005_Compatibility
:= True;
2979 Warn_On_All_Unread_Out_Parameters
:= True;
2980 Warn_On_Assertion_Failure
:= True;
2981 Warn_On_Assumed_Low_Bound
:= True;
2982 Warn_On_Bad_Fixed_Value
:= True;
2983 Warn_On_Biased_Representation
:= True;
2984 Warn_On_Constant
:= True;
2985 Warn_On_Deleted_Code
:= True;
2986 Warn_On_Dereference
:= True;
2987 Warn_On_Export_Import
:= True;
2988 Warn_On_Hiding
:= True;
2989 Warn_On_Modified_Unread
:= True;
2990 Warn_On_No_Value_Assigned
:= True;
2991 Warn_On_Non_Local_Exception
:= True;
2992 Warn_On_Object_Renames_Function
:= True;
2993 Warn_On_Obsolescent_Feature
:= True;
2994 Warn_On_Overlap
:= True;
2995 Warn_On_Parameter_Order
:= True;
2996 Warn_On_Questionable_Missing_Parens
:= True;
2997 Warn_On_Redundant_Constructs
:= True;
2998 Warn_On_Reverse_Bit_Order
:= True;
2999 Warn_On_Unchecked_Conversion
:= True;
3000 Warn_On_Unrecognized_Pragma
:= True;
3001 Warn_On_Unrepped_Components
:= True;
3002 Warn_On_Warnings_Off
:= True;
3005 Set_GNAT_Mode_Warnings
;
3008 Warn_On_Overlap
:= True;
3011 Warn_On_Overlap
:= False;
3014 Warn_On_Suspicious_Modulus_Value
:= True;
3017 Warn_On_Suspicious_Modulus_Value
:= False;
3020 Warn_On_All_Unread_Out_Parameters
:= True;
3023 Warn_On_All_Unread_Out_Parameters
:= False;
3026 Warn_On_Parameter_Order
:= True;
3029 Warn_On_Parameter_Order
:= False;
3032 Warn_On_Object_Renames_Function
:= True;
3035 Warn_On_Object_Renames_Function
:= False;
3038 Warn_On_Reverse_Bit_Order
:= True;
3041 Warn_On_Reverse_Bit_Order
:= False;
3044 Warn_On_Warnings_Off
:= True;
3047 Warn_On_Warnings_Off
:= False;
3050 Warn_On_Non_Local_Exception
:= True;
3053 Warn_On_Non_Local_Exception
:= False;
3054 No_Warn_On_Non_Local_Exception
:= True;
3061 end Set_Dot_Warning_Switch
;
3063 ----------------------------
3064 -- Set_GNAT_Mode_Warnings --
3065 ----------------------------
3067 procedure Set_GNAT_Mode_Warnings
is
3069 Address_Clause_Overlay_Warnings
:= True;
3070 Check_Unreferenced
:= True;
3071 Check_Unreferenced_Formals
:= True;
3072 Check_Withs
:= True;
3073 Constant_Condition_Warnings
:= True;
3074 Elab_Warnings
:= False;
3075 Implementation_Unit_Warnings
:= False;
3076 Ineffective_Inline_Warnings
:= True;
3077 Warn_On_Ada_2005_Compatibility
:= True;
3078 Warn_On_All_Unread_Out_Parameters
:= False;
3079 Warn_On_Assertion_Failure
:= True;
3080 Warn_On_Assumed_Low_Bound
:= True;
3081 Warn_On_Bad_Fixed_Value
:= True;
3082 Warn_On_Biased_Representation
:= True;
3083 Warn_On_Constant
:= True;
3084 Warn_On_Deleted_Code
:= False;
3085 Warn_On_Dereference
:= False;
3086 Warn_On_Export_Import
:= True;
3087 Warn_On_Hiding
:= False;
3088 Warn_On_Modified_Unread
:= True;
3089 Warn_On_No_Value_Assigned
:= True;
3090 Warn_On_Non_Local_Exception
:= False;
3091 Warn_On_Object_Renames_Function
:= False;
3092 Warn_On_Obsolescent_Feature
:= True;
3093 Warn_On_Questionable_Missing_Parens
:= True;
3094 Warn_On_Redundant_Constructs
:= True;
3095 Warn_On_Reverse_Bit_Order
:= False;
3096 Warn_On_Object_Renames_Function
:= True;
3097 Warn_On_Unchecked_Conversion
:= True;
3098 Warn_On_Unrecognized_Pragma
:= True;
3099 Warn_On_Unrepped_Components
:= False;
3100 Warn_On_Warnings_Off
:= False;
3101 end Set_GNAT_Mode_Warnings
;
3103 ------------------------
3104 -- Set_Warning_Switch --
3105 ------------------------
3107 function Set_Warning_Switch
(C
: Character) return Boolean is
3111 Check_Unreferenced
:= True;
3112 Check_Unreferenced_Formals
:= True;
3113 Check_Withs
:= True;
3114 Constant_Condition_Warnings
:= True;
3115 Implementation_Unit_Warnings
:= True;
3116 Ineffective_Inline_Warnings
:= True;
3117 Warn_On_Ada_2005_Compatibility
:= True;
3118 Warn_On_Assertion_Failure
:= True;
3119 Warn_On_Assumed_Low_Bound
:= True;
3120 Warn_On_Bad_Fixed_Value
:= True;
3121 Warn_On_Biased_Representation
:= True;
3122 Warn_On_Constant
:= True;
3123 Warn_On_Export_Import
:= True;
3124 Warn_On_Modified_Unread
:= True;
3125 Warn_On_No_Value_Assigned
:= True;
3126 Warn_On_Non_Local_Exception
:= True;
3127 Warn_On_Object_Renames_Function
:= True;
3128 Warn_On_Obsolescent_Feature
:= True;
3129 Warn_On_Parameter_Order
:= True;
3130 Warn_On_Questionable_Missing_Parens
:= True;
3131 Warn_On_Redundant_Constructs
:= True;
3132 Warn_On_Reverse_Bit_Order
:= True;
3133 Warn_On_Unchecked_Conversion
:= True;
3134 Warn_On_Unrecognized_Pragma
:= True;
3135 Warn_On_Unrepped_Components
:= True;
3138 Address_Clause_Overlay_Warnings
:= False;
3139 Check_Unreferenced
:= False;
3140 Check_Unreferenced_Formals
:= False;
3141 Check_Withs
:= False;
3142 Constant_Condition_Warnings
:= False;
3143 Elab_Warnings
:= False;
3144 Implementation_Unit_Warnings
:= False;
3145 Ineffective_Inline_Warnings
:= False;
3146 Warn_On_Ada_2005_Compatibility
:= False;
3147 Warn_On_All_Unread_Out_Parameters
:= False;
3148 Warn_On_Assertion_Failure
:= False;
3149 Warn_On_Assumed_Low_Bound
:= False;
3150 Warn_On_Bad_Fixed_Value
:= False;
3151 Warn_On_Biased_Representation
:= False;
3152 Warn_On_Constant
:= False;
3153 Warn_On_Deleted_Code
:= False;
3154 Warn_On_Dereference
:= False;
3155 Warn_On_Export_Import
:= False;
3156 Warn_On_Hiding
:= False;
3157 Warn_On_Modified_Unread
:= False;
3158 Warn_On_No_Value_Assigned
:= False;
3159 Warn_On_Non_Local_Exception
:= False;
3160 Warn_On_Object_Renames_Function
:= False;
3161 Warn_On_Obsolescent_Feature
:= False;
3162 Warn_On_Overlap
:= False;
3163 Warn_On_Parameter_Order
:= False;
3164 Warn_On_Questionable_Missing_Parens
:= False;
3165 Warn_On_Redundant_Constructs
:= False;
3166 Warn_On_Reverse_Bit_Order
:= False;
3167 Warn_On_Unchecked_Conversion
:= False;
3168 Warn_On_Unrecognized_Pragma
:= False;
3169 Warn_On_Unrepped_Components
:= False;
3170 Warn_On_Warnings_Off
:= False;
3172 No_Warn_On_Non_Local_Exception
:= True;
3175 Warn_On_Bad_Fixed_Value
:= True;
3178 Warn_On_Bad_Fixed_Value
:= False;
3181 Constant_Condition_Warnings
:= True;
3184 Constant_Condition_Warnings
:= False;
3187 Warn_On_Dereference
:= True;
3190 Warn_On_Dereference
:= False;
3193 Warning_Mode
:= Treat_As_Error
;
3196 Check_Unreferenced_Formals
:= True;
3199 Check_Unreferenced_Formals
:= False;
3202 Warn_On_Unrecognized_Pragma
:= True;
3205 Warn_On_Unrecognized_Pragma
:= False;
3208 Warn_On_Hiding
:= True;
3211 Warn_On_Hiding
:= False;
3214 Implementation_Unit_Warnings
:= True;
3217 Implementation_Unit_Warnings
:= False;
3220 Warn_On_Obsolescent_Feature
:= True;
3223 Warn_On_Obsolescent_Feature
:= False;
3226 Warn_On_Constant
:= True;
3229 Warn_On_Constant
:= False;
3232 Elab_Warnings
:= True;
3235 Elab_Warnings
:= False;
3238 Warn_On_Modified_Unread
:= True;
3241 Warn_On_Modified_Unread
:= False;
3244 Warning_Mode
:= Normal
;
3247 Address_Clause_Overlay_Warnings
:= True;
3250 Address_Clause_Overlay_Warnings
:= False;
3253 Ineffective_Inline_Warnings
:= True;
3256 Ineffective_Inline_Warnings
:= False;
3259 Warn_On_Questionable_Missing_Parens
:= True;
3262 Warn_On_Questionable_Missing_Parens
:= False;
3265 Warn_On_Redundant_Constructs
:= True;
3268 Warn_On_Redundant_Constructs
:= False;
3271 Warning_Mode
:= Suppress
;
3274 Warn_On_Deleted_Code
:= True;
3277 Warn_On_Deleted_Code
:= False;
3280 Check_Unreferenced
:= True;
3281 Check_Withs
:= True;
3282 Check_Unreferenced_Formals
:= True;
3285 Check_Unreferenced
:= False;
3286 Check_Withs
:= False;
3287 Check_Unreferenced_Formals
:= False;
3290 Warn_On_No_Value_Assigned
:= True;
3293 Warn_On_No_Value_Assigned
:= False;
3296 Warn_On_Assumed_Low_Bound
:= True;
3299 Warn_On_Assumed_Low_Bound
:= False;
3302 Warn_On_Export_Import
:= True;
3305 Warn_On_Export_Import
:= False;
3308 Warn_On_Ada_2005_Compatibility
:= True;
3311 Warn_On_Ada_2005_Compatibility
:= False;
3314 Warn_On_Unchecked_Conversion
:= True;
3317 Warn_On_Unchecked_Conversion
:= False;
3324 end Set_Warning_Switch
;
3326 -----------------------------
3327 -- Warn_On_Known_Condition --
3328 -----------------------------
3330 procedure Warn_On_Known_Condition
(C
: Node_Id
) is
3332 Orig
: constant Node_Id
:= Original_Node
(C
);
3333 Test_Result
: Boolean;
3335 function Is_Known_Branch
return Boolean;
3336 -- If the type of the condition is Boolean, the constant value of the
3337 -- condition is a boolean literal. If the type is a derived boolean
3338 -- type, the constant is wrapped in a type conversion of the derived
3339 -- literal. If the value of the condition is not a literal, no warnings
3340 -- can be produced. This function returns True if the result can be
3341 -- determined, and Test_Result is set True/False accordingly. Otherwise
3342 -- False is returned, and Test_Result is unchanged.
3344 procedure Track
(N
: Node_Id
; Loc
: Node_Id
);
3345 -- Adds continuation warning(s) pointing to reason (assignment or test)
3346 -- for the operand of the conditional having a known value (or at least
3347 -- enough is known about the value to issue the warning). N is the node
3348 -- which is judged to have a known value. Loc is the warning location.
3350 ---------------------
3351 -- Is_Known_Branch --
3352 ---------------------
3354 function Is_Known_Branch
return Boolean is
3356 if Etype
(C
) = Standard_Boolean
3357 and then Is_Entity_Name
(C
)
3359 (Entity
(C
) = Standard_False
or else Entity
(C
) = Standard_True
)
3361 Test_Result
:= Entity
(C
) = Standard_True
;
3364 elsif Is_Boolean_Type
(Etype
(C
))
3365 and then Nkind
(C
) = N_Unchecked_Type_Conversion
3366 and then Is_Entity_Name
(Expression
(C
))
3367 and then Ekind
(Entity
(Expression
(C
))) = E_Enumeration_Literal
3370 Chars
(Entity
(Expression
(C
))) = Chars
(Standard_True
);
3376 end Is_Known_Branch
;
3382 procedure Track
(N
: Node_Id
; Loc
: Node_Id
) is
3383 Nod
: constant Node_Id
:= Original_Node
(N
);
3386 if Nkind
(Nod
) in N_Op_Compare
then
3387 Track
(Left_Opnd
(Nod
), Loc
);
3388 Track
(Right_Opnd
(Nod
), Loc
);
3390 elsif Is_Entity_Name
(Nod
)
3391 and then Is_Object
(Entity
(Nod
))
3394 CV
: constant Node_Id
:= Current_Value
(Entity
(Nod
));
3397 if Present
(CV
) then
3398 Error_Msg_Sloc
:= Sloc
(CV
);
3400 if Nkind
(CV
) not in N_Subexpr
then
3401 Error_Msg_N
("\\?(see test #)", Loc
);
3403 elsif Nkind
(Parent
(CV
)) =
3404 N_Case_Statement_Alternative
3406 Error_Msg_N
("\\?(see case alternative #)", Loc
);
3409 Error_Msg_N
("\\?(see assignment #)", Loc
);
3416 -- Start of processing for Warn_On_Known_Condition
3419 -- Adjust SCO condition if from source
3422 and then Comes_From_Source
(Orig
)
3423 and then Is_Known_Branch
3432 Sloc_Range
(Orig
, Start
, Dummy
);
3433 Atrue
:= Test_Result
;
3435 if Present
(Parent
(C
))
3436 and then Nkind
(Parent
(C
)) = N_Op_Not
3447 Set_SCO_Condition
(Start
, Typ
);
3451 -- Argument replacement in an inlined body can make conditions static.
3452 -- Do not emit warnings in this case.
3454 if In_Inlined_Body
then
3458 if Constant_Condition_Warnings
3459 and then Is_Known_Branch
3460 and then Comes_From_Source
(Original_Node
(C
))
3461 and then not In_Instance
3463 -- See if this is in a statement or a declaration
3467 -- If tree is not attached, do not issue warning (this is very
3468 -- peculiar, and probably arises from some other error condition)
3473 -- If we are in a declaration, then no warning, since in practice
3474 -- conditionals in declarations are used for intended tests which
3475 -- may be known at compile time, e.g. things like
3477 -- x : constant Integer := 2 + (Word'Size = 32);
3479 -- And a warning is annoying in such cases
3481 elsif Nkind
(P
) in N_Declaration
3483 Nkind
(P
) in N_Later_Decl_Item
3487 -- Don't warn in assert or check pragma, since presumably tests in
3488 -- such a context are very definitely intended, and might well be
3489 -- known at compile time. Note that we have to test the original
3490 -- node, since assert pragmas get rewritten at analysis time.
3492 elsif Nkind
(Original_Node
(P
)) = N_Pragma
3493 and then (Pragma_Name
(Original_Node
(P
)) = Name_Assert
3495 Pragma_Name
(Original_Node
(P
)) = Name_Check
)
3500 exit when Is_Statement
(P
);
3504 -- Here we issue the warning unless some sub-operand has warnings
3505 -- set off, in which case we suppress the warning for the node. If
3506 -- the original expression is an inequality, it has been expanded
3507 -- into a negation, and the value of the original expression is the
3508 -- negation of the equality. If the expression is an entity that
3509 -- appears within a negation, it is clearer to flag the negation
3510 -- itself, and report on its constant value.
3512 if not Operand_Has_Warnings_Suppressed
(C
) then
3514 True_Branch
: Boolean := Test_Result
;
3515 Cond
: Node_Id
:= C
;
3518 if Present
(Parent
(C
))
3519 and then Nkind
(Parent
(C
)) = N_Op_Not
3521 True_Branch
:= not True_Branch
;
3526 if Is_Entity_Name
(Original_Node
(C
))
3527 and then Nkind
(Cond
) /= N_Op_Not
3530 ("object & is always True?", Cond
, Original_Node
(C
));
3531 Track
(Original_Node
(C
), Cond
);
3534 Error_Msg_N
("condition is always True?", Cond
);
3539 Error_Msg_N
("condition is always False?", Cond
);
3545 end Warn_On_Known_Condition
;
3547 ---------------------------------------
3548 -- Warn_On_Modified_As_Out_Parameter --
3549 ---------------------------------------
3551 function Warn_On_Modified_As_Out_Parameter
(E
: Entity_Id
) return Boolean is
3554 (Warn_On_Modified_Unread
and then Is_Only_Out_Parameter
(E
))
3555 or else Warn_On_All_Unread_Out_Parameters
;
3556 end Warn_On_Modified_As_Out_Parameter
;
3558 ---------------------------------
3559 -- Warn_On_Overlapping_Actuals --
3560 ---------------------------------
3562 procedure Warn_On_Overlapping_Actuals
(Subp
: Entity_Id
; N
: Node_Id
) is
3563 Act1
, Act2
: Node_Id
;
3564 Form1
, Form2
: Entity_Id
;
3567 if not Warn_On_Overlap
then
3571 -- Exclude calls rewritten as enumeration literals
3573 if not Nkind_In
(N
, N_Function_Call
, N_Procedure_Call_Statement
) then
3577 -- Exclude calls to library subprograms. Container operations specify
3578 -- safe behavior when source and target coincide.
3580 if Is_Predefined_File_Name
3581 (Unit_File_Name
(Get_Source_Unit
(Sloc
(Subp
))))
3586 Form1
:= First_Formal
(Subp
);
3587 Act1
:= First_Actual
(N
);
3588 while Present
(Form1
) and then Present
(Act1
) loop
3589 if Ekind
(Form1
) = E_In_Out_Parameter
then
3590 Form2
:= First_Formal
(Subp
);
3591 Act2
:= First_Actual
(N
);
3592 while Present
(Form2
) and then Present
(Act2
) loop
3594 and then Ekind
(Form2
) /= E_Out_Parameter
3596 (Denotes_Same_Object
(Act1
, Act2
)
3598 Denotes_Same_Prefix
(Act1
, Act2
))
3600 -- Exclude generic types and guard against previous errors.
3603 or else No
(Etype
(Act1
))
3604 or else No
(Etype
(Act2
))
3608 elsif Is_Generic_Type
(Etype
(Act1
))
3610 Is_Generic_Type
(Etype
(Act2
))
3614 -- If the actual is a function call in prefix notation,
3615 -- there is no real overlap.
3617 elsif Nkind
(Act2
) = N_Function_Call
then
3620 -- If either type is elementary the aliasing is harmless.
3622 elsif Is_Elementary_Type
(Underlying_Type
(Etype
(Form1
)))
3624 Is_Elementary_Type
(Underlying_Type
(Etype
(Form2
)))
3634 -- Find matching actual
3636 Act
:= First_Actual
(N
);
3637 Form
:= First_Formal
(Subp
);
3638 while Act
/= Act2
loop
3643 -- If the call was written in prefix notation, and
3644 -- thus its prefix before rewriting was a selected
3645 -- component, count only visible actuals in the call.
3647 if Is_Entity_Name
(First_Actual
(N
))
3648 and then Nkind
(Original_Node
(N
)) = Nkind
(N
)
3649 and then Nkind
(Name
(Original_Node
(N
))) =
3650 N_Selected_Component
3652 Is_Entity_Name
(Prefix
(Name
(Original_Node
(N
))))
3654 Entity
(Prefix
(Name
(Original_Node
(N
)))) =
3655 Entity
(First_Actual
(N
))
3657 if Act1
= First_Actual
(N
) then
3659 ("`IN OUT` prefix overlaps with actual for&?",
3663 ("writable actual overlaps with actual for&?",
3669 ("writable actual overlaps with actual for&?",
3678 Next_Formal
(Form2
);
3683 Next_Formal
(Form1
);
3686 end Warn_On_Overlapping_Actuals
;
3688 ------------------------------
3689 -- Warn_On_Suspicious_Index --
3690 ------------------------------
3692 procedure Warn_On_Suspicious_Index
(Name
: Entity_Id
; X
: Node_Id
) is
3695 -- Set to lower bound for a suspicious type
3698 -- Entity for array reference
3703 function Is_Suspicious_Type
(Typ
: Entity_Id
) return Boolean;
3704 -- Tests to see if Typ is a type for which we may have a suspicious
3705 -- index, namely an unconstrained array type, whose lower bound is
3706 -- either zero or one. If so, True is returned, and Low_Bound is set
3707 -- to this lower bound. If not, False is returned, and Low_Bound is
3708 -- undefined on return.
3710 -- For now, we limit this to standard string types, so any other
3711 -- unconstrained types return False. We may change our minds on this
3712 -- later on, but strings seem the most important case.
3714 procedure Test_Suspicious_Index
;
3715 -- Test if index is of suspicious type and if so, generate warning
3717 ------------------------
3718 -- Is_Suspicious_Type --
3719 ------------------------
3721 function Is_Suspicious_Type
(Typ
: Entity_Id
) return Boolean is
3725 if Is_Array_Type
(Typ
)
3726 and then not Is_Constrained
(Typ
)
3727 and then Number_Dimensions
(Typ
) = 1
3728 and then (Root_Type
(Typ
) = Standard_String
3730 Root_Type
(Typ
) = Standard_Wide_String
3732 Root_Type
(Typ
) = Standard_Wide_Wide_String
)
3733 and then not Has_Warnings_Off
(Typ
)
3735 LB
:= Type_Low_Bound
(Etype
(First_Index
(Typ
)));
3737 if Compile_Time_Known_Value
(LB
) then
3738 Low_Bound
:= Expr_Value
(LB
);
3739 return Low_Bound
= Uint_0
or else Low_Bound
= Uint_1
;
3744 end Is_Suspicious_Type
;
3746 ---------------------------
3747 -- Test_Suspicious_Index --
3748 ---------------------------
3750 procedure Test_Suspicious_Index
is
3752 function Length_Reference
(N
: Node_Id
) return Boolean;
3753 -- Check if node N is of the form Name'Length
3756 -- Generate first warning line
3758 ----------------------
3759 -- Length_Reference --
3760 ----------------------
3762 function Length_Reference
(N
: Node_Id
) return Boolean is
3763 R
: constant Node_Id
:= Original_Node
(N
);
3766 Nkind
(R
) = N_Attribute_Reference
3767 and then Attribute_Name
(R
) = Name_Length
3768 and then Is_Entity_Name
(Prefix
(R
))
3769 and then Entity
(Prefix
(R
)) = Ent
;
3770 end Length_Reference
;
3778 Error_Msg_Uint_1
:= Low_Bound
;
3779 Error_Msg_FE
("?index for& may assume lower bound of^", X
, Ent
);
3782 -- Start of processing for Test_Suspicious_Index
3785 -- Nothing to do if subscript does not come from source (we don't
3786 -- want to give garbage warnings on compiler expanded code, e.g. the
3787 -- loops generated for slice assignments. Such junk warnings would
3788 -- be placed on source constructs with no subscript in sight!)
3790 if not Comes_From_Source
(Original_Node
(X
)) then
3794 -- Case where subscript is a constant integer
3796 if Nkind
(X
) = N_Integer_Literal
then
3799 -- Case where original form of subscript is an integer literal
3801 if Nkind
(Original_Node
(X
)) = N_Integer_Literal
then
3802 if Intval
(X
) = Low_Bound
then
3803 Error_Msg_FE
-- CODEFIX
3804 ("\suggested replacement: `&''First`", X
, Ent
);
3806 Error_Msg_Uint_1
:= Intval
(X
) - Low_Bound
;
3807 Error_Msg_FE
-- CODEFIX
3808 ("\suggested replacement: `&''First + ^`", X
, Ent
);
3812 -- Case where original form of subscript is more complex
3815 -- Build string X'First - 1 + expression where the expression
3816 -- is the original subscript. If the expression starts with "1
3817 -- + ", then the "- 1 + 1" is elided.
3819 Error_Msg_String
(1 .. 13) := "'First - 1 + ";
3820 Error_Msg_Strlen
:= 13;
3823 Sref
: Source_Ptr
:= Sloc
(First_Node
(Original_Node
(X
)));
3824 Tref
: constant Source_Buffer_Ptr
:=
3825 Source_Text
(Get_Source_File_Index
(Sref
));
3826 -- Tref (Sref) is used to scan the subscript
3829 -- Parentheses counter when scanning subscript
3832 -- Tref (Sref) points to start of subscript
3834 -- Elide - 1 if subscript starts with 1 +
3836 if Tref
(Sref
.. Sref
+ 2) = "1 +" then
3837 Error_Msg_Strlen
:= Error_Msg_Strlen
- 6;
3840 elsif Tref
(Sref
.. Sref
+ 1) = "1+" then
3841 Error_Msg_Strlen
:= Error_Msg_Strlen
- 6;
3845 -- Now we will copy the subscript to the string buffer
3849 -- Count parens, exit if terminating right paren. Note
3850 -- check to ignore paren appearing as character literal.
3852 if Tref
(Sref
+ 1) = '''
3854 Tref
(Sref
- 1) = '''
3858 if Tref
(Sref
) = '(' then
3860 elsif Tref
(Sref
) = ')' then
3866 -- Done if terminating double dot (slice case)
3869 and then (Tref
(Sref
.. Sref
+ 1) = ".."
3871 Tref
(Sref
.. Sref
+ 2) = " ..");
3873 -- Quit if we have hit EOF character, something wrong
3875 if Tref
(Sref
) = EOF
then
3879 -- String literals are too much of a pain to handle
3881 if Tref
(Sref
) = '"' or else Tref
(Sref
) = '%' then
3885 -- If we have a 'Range reference, then this is a case
3886 -- where we cannot easily give a replacement. Don't try!
3888 if Tref
(Sref
.. Sref
+ 4) = "range"
3889 and then Tref
(Sref
- 1) < 'A'
3890 and then Tref
(Sref
+ 5) < 'A'
3895 -- Else store next character
3897 Error_Msg_Strlen
:= Error_Msg_Strlen
+ 1;
3898 Error_Msg_String
(Error_Msg_Strlen
) := Tref
(Sref
);
3901 -- If we get more than 40 characters then the expression
3902 -- is too long to copy, or something has gone wrong. In
3903 -- either case, just skip the attempt at a suggested fix.
3905 if Error_Msg_Strlen
> 40 then
3911 -- Replacement subscript is now in string buffer
3913 Error_Msg_FE
-- CODEFIX
3914 ("\suggested replacement: `&~`", Original_Node
(X
), Ent
);
3917 -- Case where subscript is of the form X'Length
3919 elsif Length_Reference
(X
) then
3921 Error_Msg_Node_2
:= Ent
;
3923 ("\suggest replacement of `&''Length` by `&''Last`",
3926 -- Case where subscript is of the form X'Length - expression
3928 elsif Nkind
(X
) = N_Op_Subtract
3929 and then Length_Reference
(Left_Opnd
(X
))
3932 Error_Msg_Node_2
:= Ent
;
3934 ("\suggest replacement of `&''Length` by `&''Last`",
3935 Left_Opnd
(X
), Ent
);
3937 end Test_Suspicious_Index
;
3939 -- Start of processing for Warn_On_Suspicious_Index
3942 -- Only process if warnings activated
3944 if Warn_On_Assumed_Low_Bound
then
3946 -- Test if array is simple entity name
3948 if Is_Entity_Name
(Name
) then
3950 -- Test if array is parameter of unconstrained string type
3952 Ent
:= Entity
(Name
);
3956 and then Is_Suspicious_Type
(Typ
)
3957 and then not Low_Bound_Tested
(Ent
)
3959 Test_Suspicious_Index
;
3963 end Warn_On_Suspicious_Index
;
3965 --------------------------------------
3966 -- Warn_On_Unassigned_Out_Parameter --
3967 --------------------------------------
3969 procedure Warn_On_Unassigned_Out_Parameter
3970 (Return_Node
: Node_Id
;
3971 Scope_Id
: Entity_Id
)
3977 -- Ignore if procedure or return statement does not come from source
3979 if not Comes_From_Source
(Scope_Id
)
3980 or else not Comes_From_Source
(Return_Node
)
3985 -- Loop through formals
3987 Form
:= First_Formal
(Scope_Id
);
3988 while Present
(Form
) loop
3990 -- We are only interested in OUT parameters that come from source
3991 -- and are never set in the source, and furthermore only in scalars
3992 -- since non-scalars generate too many false positives.
3994 if Ekind
(Form
) = E_Out_Parameter
3995 and then Never_Set_In_Source_Check_Spec
(Form
)
3996 and then Is_Scalar_Type
(Etype
(Form
))
3997 and then not Present
(Unset_Reference
(Form
))
3999 -- Before we issue the warning, an add ad hoc defence against the
4000 -- most common case of false positives with this warning which is
4001 -- the case where there is a Boolean OUT parameter that has been
4002 -- set, and whose meaning is "ignore the values of the other
4003 -- parameters". We can't of course reliably tell this case at
4004 -- compile time, but the following test kills a lot of false
4005 -- positives, without generating a significant number of false
4006 -- negatives (missed real warnings).
4008 Form2
:= First_Formal
(Scope_Id
);
4009 while Present
(Form2
) loop
4010 if Ekind
(Form2
) = E_Out_Parameter
4011 and then Root_Type
(Etype
(Form2
)) = Standard_Boolean
4012 and then not Never_Set_In_Source_Check_Spec
(Form2
)
4017 Next_Formal
(Form2
);
4020 -- Here all conditions are met, record possible unset reference
4022 Set_Unset_Reference
(Form
, Return_Node
);
4027 end Warn_On_Unassigned_Out_Parameter
;
4029 ---------------------------------
4030 -- Warn_On_Unreferenced_Entity --
4031 ---------------------------------
4033 procedure Warn_On_Unreferenced_Entity
4034 (Spec_E
: Entity_Id
;
4035 Body_E
: Entity_Id
:= Empty
)
4037 E
: Entity_Id
:= Spec_E
;
4040 if not Referenced_Check_Spec
(E
)
4041 and then not Has_Pragma_Unreferenced_Check_Spec
(E
)
4042 and then not Warnings_Off_Check_Spec
(E
)
4047 -- Case of variable that is assigned but not read. We suppress
4048 -- the message if the variable is volatile, has an address
4049 -- clause, is aliased, or is a renaming, or is imported.
4051 if Referenced_As_LHS_Check_Spec
(E
)
4052 and then No
(Address_Clause
(E
))
4053 and then not Is_Volatile
(E
)
4055 if Warn_On_Modified_Unread
4056 and then not Is_Imported
(E
)
4057 and then not Is_Aliased
(E
)
4058 and then No
(Renamed_Object
(E
))
4060 if not Has_Pragma_Unmodified_Check_Spec
(E
) then
4061 Error_Msg_N
-- CODEFIX
4062 ("?variable & is assigned but never read!", E
);
4065 Set_Last_Assignment
(E
, Empty
);
4068 -- Normal case of neither assigned nor read (exclude variables
4069 -- referenced as out parameters, since we already generated
4070 -- appropriate warnings at the call point in this case).
4072 elsif not Referenced_As_Out_Parameter
(E
) then
4074 -- We suppress the message for types for which a valid
4075 -- pragma Unreferenced_Objects has been given, otherwise
4076 -- we go ahead and give the message.
4078 if not Has_Pragma_Unreferenced_Objects
(Etype
(E
)) then
4080 -- Distinguish renamed case in message
4082 if Present
(Renamed_Object
(E
))
4083 and then Comes_From_Source
(Renamed_Object
(E
))
4086 ("?renamed variable & is not referenced!", E
);
4089 ("?variable & is not referenced!", E
);
4095 if Present
(Renamed_Object
(E
))
4096 and then Comes_From_Source
(Renamed_Object
(E
))
4099 ("?renamed constant & is not referenced!", E
);
4101 Error_Msg_N
("?constant & is not referenced!", E
);
4104 when E_In_Parameter |
4105 E_In_Out_Parameter
=>
4107 -- Do not emit message for formals of a renaming, because
4108 -- they are never referenced explicitly.
4110 if Nkind
(Original_Node
(Unit_Declaration_Node
(Scope
(E
))))
4111 /= N_Subprogram_Renaming_Declaration
4113 -- Suppress this message for an IN OUT parameter of a
4114 -- non-scalar type, since it is normal to have only an
4115 -- assignment in such a case.
4117 if Ekind
(E
) = E_In_Parameter
4118 or else not Referenced_As_LHS_Check_Spec
(E
)
4119 or else Is_Scalar_Type
(Etype
(E
))
4121 if Present
(Body_E
) then
4125 if not Is_Trivial_Subprogram
(Scope
(E
)) then
4127 ("?formal parameter & is not referenced!",
4133 when E_Out_Parameter
=>
4136 when E_Discriminant
=>
4137 Error_Msg_N
("?discriminant & is not referenced!", E
);
4139 when E_Named_Integer |
4141 Error_Msg_N
("?named number & is not referenced!", E
);
4143 when Formal_Object_Kind
=>
4144 Error_Msg_N
("?formal object & is not referenced!", E
);
4146 when E_Enumeration_Literal
=>
4147 Error_Msg_N
("?literal & is not referenced!", E
);
4150 Error_Msg_N
("?function & is not referenced!", E
);
4153 Error_Msg_N
("?procedure & is not referenced!", E
);
4156 Error_Msg_N
("?package & is not referenced!", E
);
4159 Error_Msg_N
("?exception & is not referenced!", E
);
4162 Error_Msg_N
("?label & is not referenced!", E
);
4164 when E_Generic_Procedure
=>
4165 Error_Msg_N
-- CODEFIX
4166 ("?generic procedure & is never instantiated!", E
);
4168 when E_Generic_Function
=>
4169 Error_Msg_N
-- CODEFIX
4170 ("?generic function & is never instantiated!", E
);
4173 Error_Msg_N
("?type & is not referenced!", E
);
4176 Error_Msg_N
("?& is not referenced!", E
);
4179 -- Kill warnings on the entity on which the message has been posted
4181 Set_Warnings_Off
(E
);
4183 end Warn_On_Unreferenced_Entity
;
4185 --------------------------------
4186 -- Warn_On_Useless_Assignment --
4187 --------------------------------
4189 procedure Warn_On_Useless_Assignment
4191 N
: Node_Id
:= Empty
)
4196 function Check_Ref
(N
: Node_Id
) return Traverse_Result
;
4197 -- Used to instantiate Traverse_Func. Returns Abandon if a reference to
4198 -- the entity in question is found.
4200 function Test_No_Refs
is new Traverse_Func
(Check_Ref
);
4206 function Check_Ref
(N
: Node_Id
) return Traverse_Result
is
4208 -- Check reference to our identifier. We use name equality here
4209 -- because the exception handlers have not yet been analyzed. This
4210 -- is not quite right, but it really does not matter that we fail
4211 -- to output the warning in some obscure cases of name clashes.
4213 if Nkind
(N
) = N_Identifier
4214 and then Chars
(N
) = Chars
(Ent
)
4222 -- Start of processing for Warn_On_Useless_Assignment
4225 -- Check if this is a case we want to warn on, a scalar or access
4226 -- variable with the last assignment field set, with warnings enabled,
4227 -- and which is not imported or exported. We also check that it is OK
4228 -- to capture the value. We are not going to capture any value, but
4229 -- the warning message depends on the same kind of conditions.
4231 if Is_Assignable
(Ent
)
4232 and then not Is_Return_Object
(Ent
)
4233 and then Present
(Last_Assignment
(Ent
))
4234 and then not Is_Imported
(Ent
)
4235 and then not Is_Exported
(Ent
)
4236 and then Safe_To_Capture_Value
(N
, Ent
)
4237 and then not Has_Pragma_Unreferenced_Check_Spec
(Ent
)
4239 -- Before we issue the message, check covering exception handlers.
4240 -- Search up tree for enclosing statement sequences and handlers.
4242 P
:= Parent
(Last_Assignment
(Ent
));
4243 while Present
(P
) loop
4245 -- Something is really wrong if we don't find a handled statement
4246 -- sequence, so just suppress the warning.
4249 Set_Last_Assignment
(Ent
, Empty
);
4252 -- When we hit a package/subprogram body, issue warning and exit
4254 elsif Nkind
(P
) = N_Subprogram_Body
4255 or else Nkind
(P
) = N_Package_Body
4257 -- Case of assigned value never referenced
4261 -- Don't give this for OUT and IN OUT formals, since
4262 -- clearly caller may reference the assigned value. Also
4263 -- never give such warnings for internal variables.
4265 if Ekind
(Ent
) = E_Variable
4266 and then not Is_Internal_Name
(Chars
(Ent
))
4268 if Referenced_As_Out_Parameter
(Ent
) then
4270 ("?& modified by call, but value never referenced",
4271 Last_Assignment
(Ent
), Ent
);
4274 ("?useless assignment to&, value never referenced!",
4275 Last_Assignment
(Ent
), Ent
);
4279 -- Case of assigned value overwritten
4282 Error_Msg_Sloc
:= Sloc
(N
);
4284 if Referenced_As_Out_Parameter
(Ent
) then
4286 ("?& modified by call, but value overwritten #!",
4287 Last_Assignment
(Ent
), Ent
);
4290 ("?useless assignment to&, value overwritten #!",
4291 Last_Assignment
(Ent
), Ent
);
4295 -- Clear last assignment indication and we are done
4297 Set_Last_Assignment
(Ent
, Empty
);
4300 -- Enclosing handled sequence of statements
4302 elsif Nkind
(P
) = N_Handled_Sequence_Of_Statements
then
4304 -- Check exception handlers present
4306 if Present
(Exception_Handlers
(P
)) then
4308 -- If we are not at the top level, we regard an inner
4309 -- exception handler as a decisive indicator that we should
4310 -- not generate the warning, since the variable in question
4311 -- may be accessed after an exception in the outer block.
4313 if Nkind
(Parent
(P
)) /= N_Subprogram_Body
4314 and then Nkind
(Parent
(P
)) /= N_Package_Body
4316 Set_Last_Assignment
(Ent
, Empty
);
4319 -- Otherwise we are at the outer level. An exception
4320 -- handler is significant only if it references the
4321 -- variable in question, or if the entity in question
4322 -- is an OUT or IN OUT parameter, which which case
4323 -- the caller can reference it after the exception
4324 -- hanlder completes
4327 if Is_Formal
(Ent
) then
4328 Set_Last_Assignment
(Ent
, Empty
);
4332 X
:= First
(Exception_Handlers
(P
));
4333 while Present
(X
) loop
4334 if Test_No_Refs
(X
) = Abandon
then
4335 Set_Last_Assignment
(Ent
, Empty
);
4349 end Warn_On_Useless_Assignment
;
4351 ---------------------------------
4352 -- Warn_On_Useless_Assignments --
4353 ---------------------------------
4355 procedure Warn_On_Useless_Assignments
(E
: Entity_Id
) is
4358 if Warn_On_Modified_Unread
4359 and then In_Extended_Main_Source_Unit
(E
)
4361 Ent
:= First_Entity
(E
);
4362 while Present
(Ent
) loop
4363 Warn_On_Useless_Assignment
(Ent
);
4367 end Warn_On_Useless_Assignments
;
4369 -----------------------------
4370 -- Warnings_Off_Check_Spec --
4371 -----------------------------
4373 function Warnings_Off_Check_Spec
(E
: Entity_Id
) return Boolean is
4375 if Is_Formal
(E
) and then Present
(Spec_Entity
(E
)) then
4377 -- Note: use of OR here instead of OR ELSE is deliberate, we want
4378 -- to mess with flags on both entities.
4380 return Has_Warnings_Off
(E
)
4382 Has_Warnings_Off
(Spec_Entity
(E
));
4385 return Has_Warnings_Off
(E
);
4387 end Warnings_Off_Check_Spec
;