===================================================================
@@ -748,7 +748,25 @@
if Nkind_In (Par, N_Aggregate, N_Extension_Aggregate) then
if Etype (Par) = Typ then
Set_Has_Self_Reference (Par);
- return True;
+
+ -- Check the context: the aggregate must be part of the
+ -- initialization of a type or component, or it is the
+ -- resulting expansion in an initialization procedure.
+
+ if Is_Init_Proc (Current_Scope) then
+ return True;
+ else
+ Par := Parent (Par);
+ while Present (Par) loop
+ if Nkind (Par) = N_Full_Type_Declaration then
+ return True;
+ end if;
+
+ Par := Parent (Par);
+ end loop;
+ end if;
+
+ return False;
end if;
end if;
This patch fixes an omission in the code that checks the legality of a type name as a prefix of 'access. These uses are allowed when the type name is a current instance, but previously the compiler allowed these uses within aggregates not within the declarative region of the type. Compiling priority_queues.adb must yield: priority_queues.adb:85:48: "Unchecked_Access" attribute cannot be applied to type priority_queues.adb:86:48: "Unchecked_Access" attribute cannot be applied to type --- with System; with Ada.Containers.Synchronized_Queue_Interfaces; with Ada.Finalization; with Ada.Containers; use Ada.Containers; generic with package Queue_Interfaces is new Ada.Containers.Synchronized_Queue_Interfaces (<>); type Queue_Priority is private; with function Get_Priority (Element : Queue_Interfaces.Element_Type) return Queue_Priority is <>; with function Before (Left, Right : Queue_Priority) return Boolean is <>; Default_Ceiling : System.Any_Priority := System.Priority'Last; package Priority_Queues is pragma Preelaborate; package Implementation is -- All identifiers in this unit are implementation defined pragma Implementation_Defined; type List_Type is tagged limited private; procedure Enqueue (List : in out List_Type; New_Item : Queue_Interfaces.Element_Type); procedure Dequeue (List : in out List_Type; Element : out Queue_Interfaces.Element_Type); procedure Dequeue (List : in out List_Type; At_Least : Queue_Priority; Element : in out Queue_Interfaces.Element_Type; Success : out Boolean); function Length (List : List_Type) return Count_Type; function Max_Length (List : List_Type) return Count_Type; private type Node_Type; type Node_Access is access all Node_Type; type Node_Type is limited record Element : Queue_Interfaces.Element_Type; Next : Node_Access; First_Equal, Last_Equal : Node_Access; end record; type List_Type is new Ada.Finalization.Limited_Controlled with record First, Last : Node_Access; Length : Count_Type := 0; Max_Length : Count_Type := 0; end record; overriding procedure Finalize (List : in out List_Type); end Implementation; protected type Queue (Ceiling : System.Any_Priority := Default_Ceiling) with Priority => Ceiling is new Queue_Interfaces.Queue with overriding entry Enqueue (New_Item : Queue_Interfaces.Element_Type); overriding entry Dequeue (Element : out Queue_Interfaces.Element_Type); -- The priority queue operation Dequeue_Only_High_Priority had been a -- protected entry in early drafts of AI05-0159, but it was discovered -- that that operation as specified was not in fact implementable. The -- operation was changed from an entry to a protected procedure per the -- ARG meeting in Edinburgh (June 2011), with a different signature and -- semantics. procedure Dequeue_Only_High_Priority (At_Least : Queue_Priority; Element : in out Queue_Interfaces.Element_Type; Success : out Boolean); overriding function Current_Use return Count_Type; overriding function Peak_Use return Count_Type; private List : Implementation.List_Type; end Queue; end Priority_Queues; --- with Ada.Unchecked_Deallocation; package body Priority_Queues is package body Implementation is ----------------------- -- Local Subprograms -- ----------------------- procedure Free is new Ada.Unchecked_Deallocation (Node_Type, Node_Access); ------------- -- Dequeue -- ------------- procedure Dequeue (List : in out List_Type; Element : out Queue_Interfaces.Element_Type) is X : Node_Access; begin Element := List.First.Element; X := List.First; if X.Last_Equal = X then -- Nothing to do null; else -- new First_Equal is next node X.Last_Equal.First_Equal := X.Next; -- update First_Equal / Last_Equal of next node with current last X.Next.Last_Equal := X.Last_Equal; X.Next.First_Equal := X.Next; end if; List.First := List.First.Next; if List.First = null then List.Last := null; end if; List.Length := List.Length - 1; pragma Warnings (Off, """X"" modified by call, but never referenced"); Free (X); pragma Warnings (On, """X"" modified by call, but never referenced"); end Dequeue; procedure Dequeue (List : in out List_Type; At_Least : Queue_Priority; Element : in out Queue_Interfaces.Element_Type; Success : out Boolean) is begin if List.Length = 0 or else Before (At_Least, Get_Priority (List.First.Element)) then Success := False; return; end if; List.Dequeue (Element); Success := True; end Dequeue; ------------- -- Enqueue -- ------------- procedure Enqueue (List : in out List_Type; New_Item : Queue_Interfaces.Element_Type) is P : constant Queue_Priority := Get_Priority (New_Item); Node : Node_Access; Prev : Node_Access; begin Node := new Node_Type'(Element => New_Item, Next => null, First_Equal => Node_Type'Unchecked_Access, Last_Equal => Node_Type'Unchecked_Access); if List.First = null then List.First := Node; List.Last := List.First; else Prev := List.First; if Before (P, Get_Priority (Prev.Element)) then Node.Next := List.First; List.First := Node; else Prev := Prev.Last_Equal; while Prev.Next /= null and then Before (P, Get_Priority (Prev.Next.Element)) = False loop -- Set Prev as last element of same priority than -- next element (next priority) Prev := Prev.Next.Last_Equal; end loop; if Prev.Next = null then -- Last element of queue reached: new element is last List.Last.Next := Node; List.Last := Node; else -- Element after which new element must be inserted found Node.Next := Prev.Next; Prev.Next := Node; if Before (Get_Priority (Prev.Element), P) then -- Precedent element has not same priority null; else Node.First_Equal := Prev.First_Equal; -- update only Last_Equal of First_Equal node: Node.First_Equal.Last_Equal := Node; end if; end if; end if; end if; List.Length := List.Length + 1; if List.Length > List.Max_Length then List.Max_Length := List.Length; end if; end Enqueue; -------------- -- Finalize -- -------------- overriding procedure Finalize (List : in out List_Type) is X : Node_Access; begin while List.First /= null loop X := List.First; List.First := List.First.Next; Free (X); end loop; end Finalize; ------------ -- Length -- ------------ function Length (List : List_Type) return Count_Type is begin return List.Length; end Length; ---------------- -- Max_Length -- ---------------- function Max_Length (List : List_Type) return Count_Type is begin return List.Max_Length; end Max_Length; end Implementation; protected body Queue is ----------------- -- Current_Use -- ----------------- function Current_Use return Count_Type is begin return List.Length; end Current_Use; ------------- -- Dequeue -- ------------- entry Dequeue (Element : out Queue_Interfaces.Element_Type) when List.Length > 0 is begin List.Dequeue (Element); end Dequeue; -------------------------------- -- Dequeue_Only_High_Priority -- -------------------------------- procedure Dequeue_Only_High_Priority (At_Least : Queue_Priority; Element : in out Queue_Interfaces.Element_Type; Success : out Boolean) is begin List.Dequeue (At_Least, Element, Success); end Dequeue_Only_High_Priority; ------------- -- Enqueue -- ------------- entry Enqueue (New_Item : Queue_Interfaces.Element_Type) when True is begin List.Enqueue (New_Item); end Enqueue; -------------- -- Peak_Use -- -------------- function Peak_Use return Count_Type is begin return List.Max_Length; end Peak_Use; end Queue; end Priority_Queues; Tested on x86_64-pc-linux-gnu, committed on trunk 2016-04-19 Ed Schonberg <schonberg@adacore.com> * sem_attr.adb (Analyze_Access_Attribute, OK_Self_Reference): Reject use of type name as a prefix to 'access within an aggregate in a context that is not the declarative region of a type.