------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- A S P E C T S -- -- -- -- B o d y -- -- -- -- Copyright (C) 2010-2020, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Einfo; use Einfo; with Nlists; use Nlists; with Sinfo; use Sinfo; with GNAT.HTable; package body Aspects is -- The following array indicates aspects that a subtype inherits from its -- base type. True means that the subtype inherits the aspect from its base -- type. False means it is not inherited. Base_Aspect : constant array (Aspect_Id) of Boolean := (Aspect_Atomic => True, Aspect_Atomic_Components => True, Aspect_Constant_Indexing => True, Aspect_Default_Iterator => True, Aspect_Discard_Names => True, Aspect_Independent_Components => True, Aspect_Iterator_Element => True, Aspect_Stable_Properties => True, Aspect_Type_Invariant => True, Aspect_Unchecked_Union => True, Aspect_Variable_Indexing => True, Aspect_Volatile => True, Aspect_Volatile_Full_Access => True, others => False); -- The following array indicates type aspects that are inherited and apply -- to the class-wide type as well. Inherited_Aspect : constant array (Aspect_Id) of Boolean := (Aspect_Constant_Indexing => True, Aspect_Default_Iterator => True, Aspect_Implicit_Dereference => True, Aspect_Iterator_Element => True, Aspect_Remote_Types => True, Aspect_Variable_Indexing => True, others => False); ------------------------------------------ -- Hash Table for Aspect Specifications -- ------------------------------------------ type AS_Hash_Range is range 0 .. 510; -- Size of hash table headers function AS_Hash (F : Node_Id) return AS_Hash_Range; -- Hash function for hash table function AS_Hash (F : Node_Id) return AS_Hash_Range is begin return AS_Hash_Range (F mod 511); end AS_Hash; package Aspect_Specifications_Hash_Table is new GNAT.HTable.Simple_HTable (Header_Num => AS_Hash_Range, Element => List_Id, No_Element => No_List, Key => Node_Id, Hash => AS_Hash, Equal => "="); ------------------------------------- -- Hash Table for Aspect Id Values -- ------------------------------------- type AI_Hash_Range is range 0 .. 112; -- Size of hash table headers function AI_Hash (F : Name_Id) return AI_Hash_Range; -- Hash function for hash table function AI_Hash (F : Name_Id) return AI_Hash_Range is begin return AI_Hash_Range (F mod 113); end AI_Hash; package Aspect_Id_Hash_Table is new GNAT.HTable.Simple_HTable (Header_Num => AI_Hash_Range, Element => Aspect_Id, No_Element => No_Aspect, Key => Name_Id, Hash => AI_Hash, Equal => "="); --------------------------- -- Aspect_Specifications -- --------------------------- function Aspect_Specifications (N : Node_Id) return List_Id is begin if Has_Aspects (N) then return Aspect_Specifications_Hash_Table.Get (N); else return No_List; end if; end Aspect_Specifications; -------------------------------- -- Aspects_On_Body_Or_Stub_OK -- -------------------------------- function Aspects_On_Body_Or_Stub_OK (N : Node_Id) return Boolean is Aspect : Node_Id; Aspects : List_Id; begin -- The routine should be invoked on a body [stub] with aspects pragma Assert (Has_Aspects (N)); pragma Assert (Nkind (N) in N_Body_Stub | N_Entry_Body | N_Package_Body | N_Protected_Body | N_Subprogram_Body | N_Task_Body); -- Look through all aspects and see whether they can be applied to a -- body [stub]. Aspects := Aspect_Specifications (N); Aspect := First (Aspects); while Present (Aspect) loop if not Aspect_On_Body_Or_Stub_OK (Get_Aspect_Id (Aspect)) then return False; end if; Next (Aspect); end loop; return True; end Aspects_On_Body_Or_Stub_OK; ---------------------- -- Exchange_Aspects -- ---------------------- procedure Exchange_Aspects (N1 : Node_Id; N2 : Node_Id) is begin pragma Assert (Permits_Aspect_Specifications (N1) and then Permits_Aspect_Specifications (N2)); -- Perform the exchange only when both nodes have lists to be swapped if Has_Aspects (N1) and then Has_Aspects (N2) then declare L1 : constant List_Id := Aspect_Specifications (N1); L2 : constant List_Id := Aspect_Specifications (N2); begin Set_Parent (L1, N2); Set_Parent (L2, N1); Aspect_Specifications_Hash_Table.Set (N1, L2); Aspect_Specifications_Hash_Table.Set (N2, L1); end; end if; end Exchange_Aspects; ----------------- -- Find_Aspect -- ----------------- function Find_Aspect (Id : Entity_Id; A : Aspect_Id; Class_Present : Boolean := False) return Node_Id is Decl : Node_Id; Item : Node_Id; Owner : Entity_Id; Spec : Node_Id; begin Owner := Id; -- Handle various cases of base or inherited aspects for types if Is_Type (Id) then if Base_Aspect (A) then Owner := Base_Type (Owner); end if; if Is_Class_Wide_Type (Owner) and then Inherited_Aspect (A) then Owner := Root_Type (Owner); end if; if Is_Private_Type (Owner) and then Present (Full_View (Owner)) and then not Operational_Aspect (A) then Owner := Full_View (Owner); end if; end if; -- Search the representation items for the desired aspect Item := First_Rep_Item (Owner); while Present (Item) loop if Nkind (Item) = N_Aspect_Specification and then Get_Aspect_Id (Item) = A and then Class_Present = Sinfo.Class_Present (Item) then return Item; end if; Next_Rep_Item (Item); end loop; -- Note that not all aspects are added to the chain of representation -- items. In such cases, search the list of aspect specifications. First -- find the declaration node where the aspects reside. This is usually -- the parent or the parent of the parent. Decl := Parent (Owner); if not Permits_Aspect_Specifications (Decl) then Decl := Parent (Decl); end if; -- Search the list of aspect specifications for the desired aspect if Permits_Aspect_Specifications (Decl) then Spec := First (Aspect_Specifications (Decl)); while Present (Spec) loop if Get_Aspect_Id (Spec) = A and then Class_Present = Sinfo.Class_Present (Spec) then return Spec; end if; Next (Spec); end loop; end if; -- The entity does not carry any aspects or the desired aspect was not -- found. return Empty; end Find_Aspect; -------------------------- -- Find_Value_Of_Aspect -- -------------------------- function Find_Value_Of_Aspect (Id : Entity_Id; A : Aspect_Id; Class_Present : Boolean := False) return Node_Id is Spec : constant Node_Id := Find_Aspect (Id, A, Class_Present => Class_Present); begin if Present (Spec) then if A = Aspect_Default_Iterator then return Expression (Aspect_Rep_Item (Spec)); else return Expression (Spec); end if; end if; return Empty; end Find_Value_Of_Aspect; ------------------- -- Get_Aspect_Id -- ------------------- function Get_Aspect_Id (Name : Name_Id) return Aspect_Id is begin return Aspect_Id_Hash_Table.Get (Name); end Get_Aspect_Id; function Get_Aspect_Id (Aspect : Node_Id) return Aspect_Id is begin pragma Assert (Nkind (Aspect) = N_Aspect_Specification); return Aspect_Id_Hash_Table.Get (Chars (Identifier (Aspect))); end Get_Aspect_Id; ---------------- -- Has_Aspect -- ---------------- function Has_Aspect (Id : Entity_Id; A : Aspect_Id; Class_Present : Boolean := False) return Boolean is begin return Present (Find_Aspect (Id, A, Class_Present => Class_Present)); end Has_Aspect; ------------------ -- Move_Aspects -- ------------------ procedure Move_Aspects (From : Node_Id; To : Node_Id) is pragma Assert (not Has_Aspects (To)); begin if Has_Aspects (From) then Set_Aspect_Specifications (To, Aspect_Specifications (From)); Aspect_Specifications_Hash_Table.Remove (From); Set_Has_Aspects (From, False); end if; end Move_Aspects; --------------------------- -- Move_Or_Merge_Aspects -- --------------------------- procedure Move_Or_Merge_Aspects (From : Node_Id; To : Node_Id) is procedure Relocate_Aspect (Asp : Node_Id); -- Move aspect specification Asp to the aspect specifications of node To --------------------- -- Relocate_Aspect -- --------------------- procedure Relocate_Aspect (Asp : Node_Id) is Asps : List_Id; begin if Has_Aspects (To) then Asps := Aspect_Specifications (To); -- Create a new aspect specification list for node To else Asps := New_List; Set_Aspect_Specifications (To, Asps); Set_Has_Aspects (To); end if; -- Remove the aspect from its original owner and relocate it to node -- To. Remove (Asp); Append (Asp, Asps); end Relocate_Aspect; -- Local variables Asp : Node_Id; Asp_Id : Aspect_Id; Next_Asp : Node_Id; -- Start of processing for Move_Or_Merge_Aspects begin if Has_Aspects (From) then Asp := First (Aspect_Specifications (From)); while Present (Asp) loop -- Store the next aspect now as a potential relocation will alter -- the contents of the list. Next_Asp := Next (Asp); -- When moving or merging aspects from a subprogram body stub that -- also acts as a spec, relocate only those aspects that may apply -- to a body [stub]. Note that a precondition must also be moved -- to the proper body as the pre/post machinery expects it to be -- there. if Nkind (From) = N_Subprogram_Body_Stub and then No (Corresponding_Spec_Of_Stub (From)) then Asp_Id := Get_Aspect_Id (Asp); if Aspect_On_Body_Or_Stub_OK (Asp_Id) or else Asp_Id = Aspect_Pre or else Asp_Id = Aspect_Precondition then Relocate_Aspect (Asp); end if; -- When moving or merging aspects from a single concurrent type -- declaration, relocate only those aspects that may apply to the -- anonymous object created for the type. -- Note: It is better to use Is_Single_Concurrent_Type_Declaration -- here, but Aspects and Sem_Util have incompatible licenses. elsif Nkind (Original_Node (From)) in N_Single_Protected_Declaration | N_Single_Task_Declaration then Asp_Id := Get_Aspect_Id (Asp); if Aspect_On_Anonymous_Object_OK (Asp_Id) then Relocate_Aspect (Asp); end if; -- Default case - relocate the aspect to its new owner else Relocate_Aspect (Asp); end if; Asp := Next_Asp; end loop; -- The relocations may have left node From's aspect specifications -- list empty. If this is the case, simply remove the aspects. if Is_Empty_List (Aspect_Specifications (From)) then Remove_Aspects (From); end if; end if; end Move_Or_Merge_Aspects; ----------------------------------- -- Permits_Aspect_Specifications -- ----------------------------------- Has_Aspect_Specifications_Flag : constant array (Node_Kind) of Boolean := (N_Abstract_Subprogram_Declaration => True, N_Component_Declaration => True, N_Entry_Body => True, N_Entry_Declaration => True, N_Exception_Declaration => True, N_Exception_Renaming_Declaration => True, N_Expression_Function => True, N_Formal_Abstract_Subprogram_Declaration => True, N_Formal_Concrete_Subprogram_Declaration => True, N_Formal_Object_Declaration => True, N_Formal_Package_Declaration => True, N_Formal_Type_Declaration => True, N_Full_Type_Declaration => True, N_Function_Instantiation => True, N_Generic_Package_Declaration => True, N_Generic_Renaming_Declaration => True, N_Generic_Subprogram_Declaration => True, N_Object_Declaration => True, N_Object_Renaming_Declaration => True, N_Package_Body => True, N_Package_Body_Stub => True, N_Package_Declaration => True, N_Package_Instantiation => True, N_Package_Specification => True, N_Package_Renaming_Declaration => True, N_Parameter_Specification => True, N_Private_Extension_Declaration => True, N_Private_Type_Declaration => True, N_Procedure_Instantiation => True, N_Protected_Body => True, N_Protected_Body_Stub => True, N_Protected_Type_Declaration => True, N_Single_Protected_Declaration => True, N_Single_Task_Declaration => True, N_Subprogram_Body => True, N_Subprogram_Body_Stub => True, N_Subprogram_Declaration => True, N_Subprogram_Renaming_Declaration => True, N_Subtype_Declaration => True, N_Task_Body => True, N_Task_Body_Stub => True, N_Task_Type_Declaration => True, others => False); function Permits_Aspect_Specifications (N : Node_Id) return Boolean is begin return Has_Aspect_Specifications_Flag (Nkind (N)); end Permits_Aspect_Specifications; -------------------- -- Remove_Aspects -- -------------------- procedure Remove_Aspects (N : Node_Id) is begin if Has_Aspects (N) then Aspect_Specifications_Hash_Table.Remove (N); Set_Has_Aspects (N, False); end if; end Remove_Aspects; ----------------- -- Same_Aspect -- ----------------- -- Table used for Same_Aspect, maps aspect to canonical aspect type Aspect_To_Aspect_Mapping is array (Aspect_Id) of Aspect_Id; function Init_Canonical_Aspect return Aspect_To_Aspect_Mapping; -- Initialize the Canonical_Aspect mapping below function Init_Canonical_Aspect return Aspect_To_Aspect_Mapping is Result : Aspect_To_Aspect_Mapping; begin -- They all map to themselves... for Aspect in Aspect_Id loop Result (Aspect) := Aspect; end loop; -- ...except for these: Result (Aspect_Dynamic_Predicate) := Aspect_Predicate; Result (Aspect_Inline_Always) := Aspect_Inline; Result (Aspect_Interrupt_Priority) := Aspect_Priority; Result (Aspect_Postcondition) := Aspect_Post; Result (Aspect_Precondition) := Aspect_Pre; Result (Aspect_Shared) := Aspect_Atomic; Result (Aspect_Static_Predicate) := Aspect_Predicate; Result (Aspect_Type_Invariant) := Aspect_Invariant; return Result; end Init_Canonical_Aspect; Canonical_Aspect : constant Aspect_To_Aspect_Mapping := Init_Canonical_Aspect; function Same_Aspect (A1 : Aspect_Id; A2 : Aspect_Id) return Boolean is begin return Canonical_Aspect (A1) = Canonical_Aspect (A2); end Same_Aspect; ------------------------------- -- Set_Aspect_Specifications -- ------------------------------- procedure Set_Aspect_Specifications (N : Node_Id; L : List_Id) is begin pragma Assert (Permits_Aspect_Specifications (N)); pragma Assert (not Has_Aspects (N)); pragma Assert (L /= No_List); Set_Has_Aspects (N); Set_Parent (L, N); Aspect_Specifications_Hash_Table.Set (N, L); end Set_Aspect_Specifications; -- Package initialization sets up Aspect Id hash table begin for J in Aspect_Id loop Aspect_Id_Hash_Table.Set (Aspect_Names (J), J); end loop; end Aspects;