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------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- E X P _ C H 7 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2009, 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. -- -- -- ------------------------------------------------------------------------------ -- This package contains virtually all expansion mechanisms related to -- - controlled types -- - transient scopes with Atree; use Atree; with Debug; use Debug; with Einfo; use Einfo; with Errout; use Errout; with Exp_Ch9; use Exp_Ch9; with Exp_Ch11; use Exp_Ch11; with Exp_Dbug; use Exp_Dbug; with Exp_Dist; use Exp_Dist; with Exp_Disp; use Exp_Disp; with Exp_Tss; use Exp_Tss; with Exp_Util; use Exp_Util; with Freeze; use Freeze; with Lib; use Lib; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Output; use Output; with Restrict; use Restrict; with Rident; use Rident; with Rtsfind; use Rtsfind; with Sinfo; use Sinfo; with Sem; use Sem; with Sem_Aux; use Sem_Aux; with Sem_Ch3; use Sem_Ch3; with Sem_Ch7; use Sem_Ch7; with Sem_Ch8; use Sem_Ch8; with Sem_Res; use Sem_Res; with Sem_SCIL; use Sem_SCIL; with Sem_Type; use Sem_Type; with Sem_Util; use Sem_Util; with Snames; use Snames; with Stand; use Stand; with Targparm; use Targparm; with Tbuild; use Tbuild; with Uintp; use Uintp; package body Exp_Ch7 is -------------------------------- -- Transient Scope Management -- -------------------------------- -- A transient scope is created when temporary objects are created by the -- compiler. These temporary objects are allocated on the secondary stack -- and the transient scope is responsible for finalizing the object when -- appropriate and reclaiming the memory at the right time. The temporary -- objects are generally the objects allocated to store the result of a -- function returning an unconstrained or a tagged value. Expressions -- needing to be wrapped in a transient scope (functions calls returning -- unconstrained or tagged values) may appear in 3 different contexts which -- lead to 3 different kinds of transient scope expansion: -- 1. In a simple statement (procedure call, assignment, ...). In -- this case the instruction is wrapped into a transient block. -- (See Wrap_Transient_Statement for details) -- 2. In an expression of a control structure (test in a IF statement, -- expression in a CASE statement, ...). -- (See Wrap_Transient_Expression for details) -- 3. In a expression of an object_declaration. No wrapping is possible -- here, so the finalization actions, if any, are done right after the -- declaration and the secondary stack deallocation is done in the -- proper enclosing scope (see Wrap_Transient_Declaration for details) -- Note about functions returning tagged types: it has been decided to -- always allocate their result in the secondary stack, even though is not -- absolutely mandatory when the tagged type is constrained because the -- caller knows the size of the returned object and thus could allocate the -- result in the primary stack. An exception to this is when the function -- builds its result in place, as is done for functions with inherently -- limited result types for Ada 2005. In that case, certain callers may -- pass the address of a constrained object as the target object for the -- function result. -- By allocating tagged results in the secondary stack a number of -- implementation difficulties are avoided: -- - If it is a dispatching function call, the computation of the size of -- the result is possible but complex from the outside. -- - If the returned type is controlled, the assignment of the returned -- value to the anonymous object involves an Adjust, and we have no -- easy way to access the anonymous object created by the back end. -- - If the returned type is class-wide, this is an unconstrained type -- anyway. -- Furthermore, the small loss in efficiency which is the result of this -- decision is not such a big deal because functions returning tagged types -- are not as common in practice compared to functions returning access to -- a tagged type. -------------------------------------------------- -- Transient Blocks and Finalization Management -- -------------------------------------------------- function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id; -- N is a node which may generate a transient scope. Loop over the parent -- pointers of N until it find the appropriate node to wrap. If it returns -- Empty, it means that no transient scope is needed in this context. function Make_Clean (N : Node_Id; Clean : Entity_Id; Mark : Entity_Id; Flist : Entity_Id; Is_Task : Boolean; Is_Master : Boolean; Is_Protected_Subprogram : Boolean; Is_Task_Allocation_Block : Boolean; Is_Asynchronous_Call_Block : Boolean; Chained_Cleanup_Action : Node_Id) return Node_Id; -- Expand the clean-up procedure for a controlled and/or transient block, -- and/or task master or task body, or a block used to implement task -- allocation or asynchronous entry calls, or a procedure used to implement -- protected procedures. Clean is the entity for such a procedure. Mark -- is the entity for the secondary stack mark, if empty only controlled -- block clean-up will be performed. Flist is the entity for the local -- final list, if empty only transient scope clean-up will be performed. -- The flags Is_Task and Is_Master control the calls to the corresponding -- finalization actions for a task body or for an entity that is a task -- master. Finally if Chained_Cleanup_Action is present, it is a reference -- to a previous cleanup procedure, a call to which is appended at the -- end of the generated one. procedure Set_Node_To_Be_Wrapped (N : Node_Id); -- Set the field Node_To_Be_Wrapped of the current scope procedure Insert_Actions_In_Scope_Around (N : Node_Id); -- Insert the before-actions kept in the scope stack before N, and the -- after-actions after N, which must be a member of a list. function Make_Transient_Block (Loc : Source_Ptr; Action : Node_Id) return Node_Id; -- Create a transient block whose name is Scope, which is also a controlled -- block if Flist is not empty and whose only code is Action (either a -- single statement or single declaration). type Final_Primitives is (Initialize_Case, Adjust_Case, Finalize_Case); -- This enumeration type is defined in order to ease sharing code for -- building finalization procedures for composite types. Name_Of : constant array (Final_Primitives) of Name_Id := (Initialize_Case => Name_Initialize, Adjust_Case => Name_Adjust, Finalize_Case => Name_Finalize); Deep_Name_Of : constant array (Final_Primitives) of TSS_Name_Type := (Initialize_Case => TSS_Deep_Initialize, Adjust_Case => TSS_Deep_Adjust, Finalize_Case => TSS_Deep_Finalize); procedure Build_Record_Deep_Procs (Typ : Entity_Id); -- Build the deep Initialize/Adjust/Finalize for a record Typ with -- Has_Component_Component set and store them using the TSS mechanism. procedure Build_Array_Deep_Procs (Typ : Entity_Id); -- Build the deep Initialize/Adjust/Finalize for a record Typ with -- Has_Controlled_Component set and store them using the TSS mechanism. function Make_Deep_Proc (Prim : Final_Primitives; Typ : Entity_Id; Stmts : List_Id) return Node_Id; -- This function generates the tree for Deep_Initialize, Deep_Adjust or -- Deep_Finalize procedures according to the first parameter, these -- procedures operate on the type Typ. The Stmts parameter gives the body -- of the procedure. function Make_Deep_Array_Body (Prim : Final_Primitives; Typ : Entity_Id) return List_Id; -- This function generates the list of statements for implementing -- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures according to -- the first parameter, these procedures operate on the array type Typ. function Make_Deep_Record_Body (Prim : Final_Primitives; Typ : Entity_Id) return List_Id; -- This function generates the list of statements for implementing -- Deep_Initialize, Deep_Adjust or Deep_Finalize procedures according to -- the first parameter, these procedures operate on the record type Typ. procedure Check_Visibly_Controlled (Prim : Final_Primitives; Typ : Entity_Id; E : in out Entity_Id; Cref : in out Node_Id); -- The controlled operation declared for a derived type may not be -- overriding, if the controlled operations of the parent type are -- hidden, for example when the parent is a private type whose full -- view is controlled. For other primitive operations we modify the -- name of the operation to indicate that it is not overriding, but -- this is not possible for Initialize, etc. because they have to be -- retrievable by name. Before generating the proper call to one of -- these operations we check whether Typ is known to be controlled at -- the point of definition. If it is not then we must retrieve the -- hidden operation of the parent and use it instead. This is one -- case that might be solved more cleanly once Overriding pragmas or -- declarations are in place. function Convert_View (Proc : Entity_Id; Arg : Node_Id; Ind : Pos := 1) return Node_Id; -- Proc is one of the Initialize/Adjust/Finalize operations, and -- Arg is the argument being passed to it. Ind indicates which -- formal of procedure Proc we are trying to match. This function -- will, if necessary, generate an conversion between the partial -- and full view of Arg to match the type of the formal of Proc, -- or force a conversion to the class-wide type in the case where -- the operation is abstract. ----------------------------- -- Finalization Management -- ----------------------------- -- This part describe how Initialization/Adjustment/Finalization procedures -- are generated and called. Two cases must be considered, types that are -- Controlled (Is_Controlled flag set) and composite types that contain -- controlled components (Has_Controlled_Component flag set). In the first -- case the procedures to call are the user-defined primitive operations -- Initialize/Adjust/Finalize. In the second case, GNAT generates -- Deep_Initialize, Deep_Adjust and Deep_Finalize that are in charge -- of calling the former procedures on the controlled components. -- For records with Has_Controlled_Component set, a hidden "controller" -- component is inserted. This controller component contains its own -- finalization list on which all controlled components are attached -- creating an indirection on the upper-level Finalization list. This -- technique facilitates the management of objects whose number of -- controlled components changes during execution. This controller -- component is itself controlled and is attached to the upper-level -- finalization chain. Its adjust primitive is in charge of calling adjust -- on the components and adjusting the finalization pointer to match their -- new location (see a-finali.adb). -- It is not possible to use a similar technique for arrays that have -- Has_Controlled_Component set. In this case, deep procedures are -- generated that call initialize/adjust/finalize + attachment or -- detachment on the finalization list for all component. -- Initialize calls: they are generated for declarations or dynamic -- allocations of Controlled objects with no initial value. They are always -- followed by an attachment to the current Finalization Chain. For the -- dynamic allocation case this the chain attached to the scope of the -- access type definition otherwise, this is the chain of the current -- scope. -- Adjust Calls: They are generated on 2 occasions: (1) for -- declarations or dynamic allocations of Controlled objects with an -- initial value. (2) after an assignment. In the first case they are -- followed by an attachment to the final chain, in the second case -- they are not. -- Finalization Calls: They are generated on (1) scope exit, (2) -- assignments, (3) unchecked deallocations. In case (3) they have to -- be detached from the final chain, in case (2) they must not and in -- case (1) this is not important since we are exiting the scope anyway. -- Other details: -- Type extensions will have a new record controller at each derivation -- level containing controlled components. The record controller for -- the parent/ancestor is attached to the finalization list of the -- extension's record controller (i.e. the parent is like a component -- of the extension). -- For types that are both Is_Controlled and Has_Controlled_Components, -- the record controller and the object itself are handled separately. -- It could seem simpler to attach the object at the end of its record -- controller but this would not tackle view conversions properly. -- A classwide type can always potentially have controlled components -- but the record controller of the corresponding actual type may not -- be known at compile time so the dispatch table contains a special -- field that allows to compute the offset of the record controller -- dynamically. See s-finimp.Deep_Tag_Attach and a-tags.RC_Offset. -- Here is a simple example of the expansion of a controlled block : -- declare -- X : Controlled; -- Y : Controlled := Init; -- -- type R is record -- C : Controlled; -- end record; -- W : R; -- Z : R := (C => X); -- begin -- X := Y; -- W := Z; -- end; -- -- is expanded into -- -- declare -- _L : System.FI.Finalizable_Ptr; -- procedure _Clean is -- begin -- Abort_Defer; -- System.FI.Finalize_List (_L); -- Abort_Undefer; -- end _Clean; -- X : Controlled; -- begin -- Abort_Defer; -- Initialize (X); -- Attach_To_Final_List (_L, Finalizable (X), 1); -- at end: Abort_Undefer; -- Y : Controlled := Init; -- Adjust (Y); -- Attach_To_Final_List (_L, Finalizable (Y), 1); -- -- type R is record -- _C : Record_Controller; -- C : Controlled; -- end record; -- W : R; -- begin -- Abort_Defer; -- Deep_Initialize (W, _L, 1); -- at end: Abort_Under; -- Z : R := (C => X); -- Deep_Adjust (Z, _L, 1); -- begin -- _Assign (X, Y); -- Deep_Finalize (W, False); -- <save W's final pointers> -- W := Z; -- <restore W's final pointers> -- Deep_Adjust (W, _L, 0); -- at end -- _Clean; -- end; function Global_Flist_Ref (Flist_Ref : Node_Id) return Boolean; -- Return True if Flist_Ref refers to a global final list, either the -- object Global_Final_List which is used to attach standalone objects, -- or any of the list controllers associated with library-level access -- to controlled objects. procedure Clean_Simple_Protected_Objects (N : Node_Id); -- Protected objects without entries are not controlled types, and the -- locks have to be released explicitly when such an object goes out -- of scope. Traverse declarations in scope to determine whether such -- objects are present. ---------------------------- -- Build_Array_Deep_Procs -- ---------------------------- procedure Build_Array_Deep_Procs (Typ : Entity_Id) is begin Set_TSS (Typ, Make_Deep_Proc ( Prim => Initialize_Case, Typ => Typ, Stmts => Make_Deep_Array_Body (Initialize_Case, Typ))); if not Is_Inherently_Limited_Type (Typ) then Set_TSS (Typ, Make_Deep_Proc ( Prim => Adjust_Case, Typ => Typ, Stmts => Make_Deep_Array_Body (Adjust_Case, Typ))); end if; Set_TSS (Typ, Make_Deep_Proc ( Prim => Finalize_Case, Typ => Typ, Stmts => Make_Deep_Array_Body (Finalize_Case, Typ))); end Build_Array_Deep_Procs; ----------------------------- -- Build_Controlling_Procs -- ----------------------------- procedure Build_Controlling_Procs (Typ : Entity_Id) is begin if Is_Array_Type (Typ) then Build_Array_Deep_Procs (Typ); else pragma Assert (Is_Record_Type (Typ)); Build_Record_Deep_Procs (Typ); end if; end Build_Controlling_Procs; ---------------------- -- Build_Final_List -- ---------------------- procedure Build_Final_List (N : Node_Id; Typ : Entity_Id) is Loc : constant Source_Ptr := Sloc (N); Decl : Node_Id; begin Set_Associated_Final_Chain (Typ, Make_Defining_Identifier (Loc, New_External_Name (Chars (Typ), 'L'))); Decl := Make_Object_Declaration (Loc, Defining_Identifier => Associated_Final_Chain (Typ), Object_Definition => New_Reference_To (RTE (RE_List_Controller), Loc)); -- If the type is declared in a package declaration and designates a -- Taft amendment type that requires finalization, place declaration -- of finalization list in the body, because no client of the package -- can create objects of the type and thus make use of this list. This -- ensures the tree for the spec is identical whenever it is compiled. if Has_Completion_In_Body (Directly_Designated_Type (Typ)) and then In_Package_Body (Current_Scope) and then Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Body and then Nkind (Parent (Declaration_Node (Typ))) = N_Package_Specification then Insert_Action (Parent (Designated_Type (Typ)), Decl); -- The type may have been frozen already, and this is a late freezing -- action, in which case the declaration must be elaborated at once. -- If the call is for an allocator, the chain must also be created now, -- because the freezing of the type does not build one. Otherwise, the -- declaration is one of the freezing actions for a user-defined type. elsif Is_Frozen (Typ) or else (Nkind (N) = N_Allocator and then Ekind (Etype (N)) = E_Anonymous_Access_Type) then Insert_Action (N, Decl); else Append_Freeze_Action (Typ, Decl); end if; end Build_Final_List; --------------------- -- Build_Late_Proc -- --------------------- procedure Build_Late_Proc (Typ : Entity_Id; Nam : Name_Id) is begin for Final_Prim in Name_Of'Range loop if Name_Of (Final_Prim) = Nam then Set_TSS (Typ, Make_Deep_Proc ( Prim => Final_Prim, Typ => Typ, Stmts => Make_Deep_Record_Body (Final_Prim, Typ))); end if; end loop; end Build_Late_Proc; ----------------------------- -- Build_Record_Deep_Procs -- ----------------------------- procedure Build_Record_Deep_Procs (Typ : Entity_Id) is begin Set_TSS (Typ, Make_Deep_Proc ( Prim => Initialize_Case, Typ => Typ, Stmts => Make_Deep_Record_Body (Initialize_Case, Typ))); if not Is_Inherently_Limited_Type (Typ) then Set_TSS (Typ, Make_Deep_Proc ( Prim => Adjust_Case, Typ => Typ, Stmts => Make_Deep_Record_Body (Adjust_Case, Typ))); end if; Set_TSS (Typ, Make_Deep_Proc ( Prim => Finalize_Case, Typ => Typ, Stmts => Make_Deep_Record_Body (Finalize_Case, Typ))); end Build_Record_Deep_Procs; ------------------- -- Cleanup_Array -- ------------------- function Cleanup_Array (N : Node_Id; Obj : Node_Id; Typ : Entity_Id) return List_Id is Loc : constant Source_Ptr := Sloc (N); Index_List : constant List_Id := New_List; function Free_Component return List_Id; -- Generate the code to finalize the task or protected subcomponents -- of a single component of the array. function Free_One_Dimension (Dim : Int) return List_Id; -- Generate a loop over one dimension of the array -------------------- -- Free_Component -- -------------------- function Free_Component return List_Id is Stmts : List_Id := New_List; Tsk : Node_Id; C_Typ : constant Entity_Id := Component_Type (Typ); begin -- Component type is known to contain tasks or protected objects Tsk := Make_Indexed_Component (Loc, Prefix => Duplicate_Subexpr_No_Checks (Obj), Expressions => Index_List); Set_Etype (Tsk, C_Typ); if Is_Task_Type (C_Typ) then Append_To (Stmts, Cleanup_Task (N, Tsk)); elsif Is_Simple_Protected_Type (C_Typ) then Append_To (Stmts, Cleanup_Protected_Object (N, Tsk)); elsif Is_Record_Type (C_Typ) then Stmts := Cleanup_Record (N, Tsk, C_Typ); elsif Is_Array_Type (C_Typ) then Stmts := Cleanup_Array (N, Tsk, C_Typ); end if; return Stmts; end Free_Component; ------------------------ -- Free_One_Dimension -- ------------------------ function Free_One_Dimension (Dim : Int) return List_Id is Index : Entity_Id; begin if Dim > Number_Dimensions (Typ) then return Free_Component; -- Here we generate the required loop else Index := Make_Defining_Identifier (Loc, New_Internal_Name ('J')); Append (New_Reference_To (Index, Loc), Index_List); return New_List ( Make_Implicit_Loop_Statement (N, Identifier => Empty, Iteration_Scheme => Make_Iteration_Scheme (Loc, Loop_Parameter_Specification => Make_Loop_Parameter_Specification (Loc, Defining_Identifier => Index, Discrete_Subtype_Definition => Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr (Obj), Attribute_Name => Name_Range, Expressions => New_List ( Make_Integer_Literal (Loc, Dim))))), Statements => Free_One_Dimension (Dim + 1))); end if; end Free_One_Dimension; -- Start of processing for Cleanup_Array begin return Free_One_Dimension (1); end Cleanup_Array; -------------------- -- Cleanup_Record -- -------------------- function Cleanup_Record (N : Node_Id; Obj : Node_Id; Typ : Entity_Id) return List_Id is Loc : constant Source_Ptr := Sloc (N); Tsk : Node_Id; Comp : Entity_Id; Stmts : constant List_Id := New_List; U_Typ : constant Entity_Id := Underlying_Type (Typ); begin if Has_Discriminants (U_Typ) and then Nkind (Parent (U_Typ)) = N_Full_Type_Declaration and then Nkind (Type_Definition (Parent (U_Typ))) = N_Record_Definition and then Present (Variant_Part (Component_List (Type_Definition (Parent (U_Typ))))) then -- For now, do not attempt to free a component that may appear in -- a variant, and instead issue a warning. Doing this "properly" -- would require building a case statement and would be quite a -- mess. Note that the RM only requires that free "work" for the -- case of a task access value, so already we go way beyond this -- in that we deal with the array case and non-discriminated -- record cases. Error_Msg_N ("task/protected object in variant record will not be freed?", N); return New_List (Make_Null_Statement (Loc)); end if; Comp := First_Component (Typ); while Present (Comp) loop if Has_Task (Etype (Comp)) or else Has_Simple_Protected_Object (Etype (Comp)) then Tsk := Make_Selected_Component (Loc, Prefix => Duplicate_Subexpr_No_Checks (Obj), Selector_Name => New_Occurrence_Of (Comp, Loc)); Set_Etype (Tsk, Etype (Comp)); if Is_Task_Type (Etype (Comp)) then Append_To (Stmts, Cleanup_Task (N, Tsk)); elsif Is_Simple_Protected_Type (Etype (Comp)) then Append_To (Stmts, Cleanup_Protected_Object (N, Tsk)); elsif Is_Record_Type (Etype (Comp)) then -- Recurse, by generating the prefix of the argument to -- the eventual cleanup call. Append_List_To (Stmts, Cleanup_Record (N, Tsk, Etype (Comp))); elsif Is_Array_Type (Etype (Comp)) then Append_List_To (Stmts, Cleanup_Array (N, Tsk, Etype (Comp))); end if; end if; Next_Component (Comp); end loop; return Stmts; end Cleanup_Record; ------------------------------ -- Cleanup_Protected_Object -- ------------------------------ function Cleanup_Protected_Object (N : Node_Id; Ref : Node_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (N); begin return Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_Finalize_Protection), Loc), Parameter_Associations => New_List ( Concurrent_Ref (Ref))); end Cleanup_Protected_Object; ------------------------------------ -- Clean_Simple_Protected_Objects -- ------------------------------------ procedure Clean_Simple_Protected_Objects (N : Node_Id) is Stmts : constant List_Id := Statements (Handled_Statement_Sequence (N)); Stmt : Node_Id := Last (Stmts); E : Entity_Id; begin E := First_Entity (Current_Scope); while Present (E) loop if (Ekind (E) = E_Variable or else Ekind (E) = E_Constant) and then Has_Simple_Protected_Object (Etype (E)) and then not Has_Task (Etype (E)) and then Nkind (Parent (E)) /= N_Object_Renaming_Declaration then declare Typ : constant Entity_Id := Etype (E); Ref : constant Node_Id := New_Occurrence_Of (E, Sloc (Stmt)); begin if Is_Simple_Protected_Type (Typ) then Append_To (Stmts, Cleanup_Protected_Object (N, Ref)); elsif Has_Simple_Protected_Object (Typ) then if Is_Record_Type (Typ) then Append_List_To (Stmts, Cleanup_Record (N, Ref, Typ)); elsif Is_Array_Type (Typ) then Append_List_To (Stmts, Cleanup_Array (N, Ref, Typ)); end if; end if; end; end if; Next_Entity (E); end loop; -- Analyze inserted cleanup statements if Present (Stmt) then Stmt := Next (Stmt); while Present (Stmt) loop Analyze (Stmt); Next (Stmt); end loop; end if; end Clean_Simple_Protected_Objects; ------------------ -- Cleanup_Task -- ------------------ function Cleanup_Task (N : Node_Id; Ref : Node_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (N); begin return Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_Free_Task), Loc), Parameter_Associations => New_List (Concurrent_Ref (Ref))); end Cleanup_Task; --------------------------------- -- Has_Simple_Protected_Object -- --------------------------------- function Has_Simple_Protected_Object (T : Entity_Id) return Boolean is Comp : Entity_Id; begin if Is_Simple_Protected_Type (T) then return True; elsif Is_Array_Type (T) then return Has_Simple_Protected_Object (Component_Type (T)); elsif Is_Record_Type (T) then Comp := First_Component (T); while Present (Comp) loop if Has_Simple_Protected_Object (Etype (Comp)) then return True; end if; Next_Component (Comp); end loop; return False; else return False; end if; end Has_Simple_Protected_Object; ------------------------------ -- Is_Simple_Protected_Type -- ------------------------------ function Is_Simple_Protected_Type (T : Entity_Id) return Boolean is begin return Is_Protected_Type (T) and then not Has_Entries (T); end Is_Simple_Protected_Type; ------------------------------ -- Check_Visibly_Controlled -- ------------------------------ procedure Check_Visibly_Controlled (Prim : Final_Primitives; Typ : Entity_Id; E : in out Entity_Id; Cref : in out Node_Id) is Parent_Type : Entity_Id; Op : Entity_Id; begin if Is_Derived_Type (Typ) and then Comes_From_Source (E) and then not Is_Overriding_Operation (E) then -- We know that the explicit operation on the type does not override -- the inherited operation of the parent, and that the derivation -- is from a private type that is not visibly controlled. Parent_Type := Etype (Typ); Op := Find_Prim_Op (Parent_Type, Name_Of (Prim)); if Present (Op) then E := Op; -- Wrap the object to be initialized into the proper -- unchecked conversion, to be compatible with the operation -- to be called. if Nkind (Cref) = N_Unchecked_Type_Conversion then Cref := Unchecked_Convert_To (Parent_Type, Expression (Cref)); else Cref := Unchecked_Convert_To (Parent_Type, Cref); end if; end if; end if; end Check_Visibly_Controlled; ------------------------------- -- CW_Or_Has_Controlled_Part -- ------------------------------- function CW_Or_Has_Controlled_Part (T : Entity_Id) return Boolean is begin return Is_Class_Wide_Type (T) or else Needs_Finalization (T); end CW_Or_Has_Controlled_Part; -------------------------- -- Controller_Component -- -------------------------- function Controller_Component (Typ : Entity_Id) return Entity_Id is T : Entity_Id := Base_Type (Typ); Comp : Entity_Id; Comp_Scop : Entity_Id; Res : Entity_Id := Empty; Res_Scop : Entity_Id := Empty; begin if Is_Class_Wide_Type (T) then T := Root_Type (T); end if; if Is_Private_Type (T) then T := Underlying_Type (T); end if; -- Fetch the outermost controller Comp := First_Entity (T); while Present (Comp) loop if Chars (Comp) = Name_uController then Comp_Scop := Scope (Original_Record_Component (Comp)); -- If this controller is at the outermost level, no need to -- look for another one if Comp_Scop = T then return Comp; -- Otherwise record the outermost one and continue looking elsif Res = Empty or else Is_Ancestor (Res_Scop, Comp_Scop) then Res := Comp; Res_Scop := Comp_Scop; end if; end if; Next_Entity (Comp); end loop; -- If we fall through the loop, there is no controller component return Res; end Controller_Component; ------------------ -- Convert_View -- ------------------ function Convert_View (Proc : Entity_Id; Arg : Node_Id; Ind : Pos := 1) return Node_Id is Fent : Entity_Id := First_Entity (Proc); Ftyp : Entity_Id; Atyp : Entity_Id; begin for J in 2 .. Ind loop Next_Entity (Fent); end loop; Ftyp := Etype (Fent); if Nkind_In (Arg, N_Type_Conversion, N_Unchecked_Type_Conversion) then Atyp := Entity (Subtype_Mark (Arg)); else Atyp := Etype (Arg); end if; if Is_Abstract_Subprogram (Proc) and then Is_Tagged_Type (Ftyp) then return Unchecked_Convert_To (Class_Wide_Type (Ftyp), Arg); elsif Ftyp /= Atyp and then Present (Atyp) and then (Is_Private_Type (Ftyp) or else Is_Private_Type (Atyp)) and then Base_Type (Underlying_Type (Atyp)) = Base_Type (Underlying_Type (Ftyp)) then return Unchecked_Convert_To (Ftyp, Arg); -- If the argument is already a conversion, as generated by -- Make_Init_Call, set the target type to the type of the formal -- directly, to avoid spurious typing problems. elsif Nkind_In (Arg, N_Unchecked_Type_Conversion, N_Type_Conversion) and then not Is_Class_Wide_Type (Atyp) then Set_Subtype_Mark (Arg, New_Occurrence_Of (Ftyp, Sloc (Arg))); Set_Etype (Arg, Ftyp); return Arg; else return Arg; end if; end Convert_View; ------------------------------- -- Establish_Transient_Scope -- ------------------------------- -- This procedure is called each time a transient block has to be inserted -- that is to say for each call to a function with unconstrained or tagged -- result. It creates a new scope on the stack scope in order to enclose -- all transient variables generated procedure Establish_Transient_Scope (N : Node_Id; Sec_Stack : Boolean) is Loc : constant Source_Ptr := Sloc (N); Wrap_Node : Node_Id; begin -- Nothing to do for virtual machines where memory is GCed if VM_Target /= No_VM then return; end if; -- Do not create a transient scope if we are already inside one for S in reverse Scope_Stack.First .. Scope_Stack.Last loop if Scope_Stack.Table (S).Is_Transient then if Sec_Stack then Set_Uses_Sec_Stack (Scope_Stack.Table (S).Entity); end if; return; -- If we have encountered Standard there are no enclosing -- transient scopes. elsif Scope_Stack.Table (S).Entity = Standard_Standard then exit; end if; end loop; Wrap_Node := Find_Node_To_Be_Wrapped (N); -- Case of no wrap node, false alert, no transient scope needed if No (Wrap_Node) then null; -- If the node to wrap is an iteration_scheme, the expression is -- one of the bounds, and the expansion will make an explicit -- declaration for it (see Analyze_Iteration_Scheme, sem_ch5.adb), -- so do not apply any transformations here. elsif Nkind (Wrap_Node) = N_Iteration_Scheme then null; else Push_Scope (New_Internal_Entity (E_Block, Current_Scope, Loc, 'B')); Set_Scope_Is_Transient; if Sec_Stack then Set_Uses_Sec_Stack (Current_Scope); Check_Restriction (No_Secondary_Stack, N); end if; Set_Etype (Current_Scope, Standard_Void_Type); Set_Node_To_Be_Wrapped (Wrap_Node); if Debug_Flag_W then Write_Str (" <Transient>"); Write_Eol; end if; end if; end Establish_Transient_Scope; ---------------------------- -- Expand_Cleanup_Actions -- ---------------------------- procedure Expand_Cleanup_Actions (N : Node_Id) is S : constant Entity_Id := Current_Scope; Flist : constant Entity_Id := Finalization_Chain_Entity (S); Is_Task : constant Boolean := Nkind (Original_Node (N)) = N_Task_Body; Is_Master : constant Boolean := Nkind (N) /= N_Entry_Body and then Is_Task_Master (N); Is_Protected : constant Boolean := Nkind (N) = N_Subprogram_Body and then Is_Protected_Subprogram_Body (N); Is_Task_Allocation : constant Boolean := Nkind (N) = N_Block_Statement and then Is_Task_Allocation_Block (N); Is_Asynchronous_Call : constant Boolean := Nkind (N) = N_Block_Statement and then Is_Asynchronous_Call_Block (N); Previous_At_End_Proc : constant Node_Id := At_End_Proc (Handled_Statement_Sequence (N)); Clean : Entity_Id; Loc : Source_Ptr; Mark : Entity_Id := Empty; New_Decls : constant List_Id := New_List; Blok : Node_Id; End_Lab : Node_Id; Wrapped : Boolean; Chain : Entity_Id := Empty; Decl : Node_Id; Old_Poll : Boolean; begin -- If we are generating expanded code for debugging purposes, use -- the Sloc of the point of insertion for the cleanup code. The Sloc -- will be updated subsequently to reference the proper line in the -- .dg file. If we are not debugging generated code, use instead -- No_Location, so that no debug information is generated for the -- cleanup code. This makes the behavior of the NEXT command in GDB -- monotonic, and makes the placement of breakpoints more accurate. if Debug_Generated_Code then Loc := Sloc (S); else Loc := No_Location; end if; -- There are cleanup actions only if the secondary stack needs -- releasing or some finalizations are needed or in the context -- of tasking if Uses_Sec_Stack (Current_Scope) and then not Sec_Stack_Needed_For_Return (Current_Scope) then null; elsif No (Flist) and then not Is_Master and then not Is_Task and then not Is_Protected and then not Is_Task_Allocation and then not Is_Asynchronous_Call then Clean_Simple_Protected_Objects (N); return; end if; -- If the current scope is the subprogram body that is the rewriting -- of a task body, and the descriptors have not been delayed (due to -- some nested instantiations) do not generate redundant cleanup -- actions: the cleanup procedure already exists for this body. if Nkind (N) = N_Subprogram_Body and then Nkind (Original_Node (N)) = N_Task_Body and then not Delay_Subprogram_Descriptors (Corresponding_Spec (N)) then return; end if; -- Set polling off, since we don't need to poll during cleanup -- actions, and indeed for the cleanup routine, which is executed -- with aborts deferred, we don't want polling. Old_Poll := Polling_Required; Polling_Required := False; -- Make sure we have a declaration list, since we will add to it if No (Declarations (N)) then Set_Declarations (N, New_List); end if; -- The task activation call has already been built for task -- allocation blocks. if not Is_Task_Allocation then Build_Task_Activation_Call (N); end if; if Is_Master then Establish_Task_Master (N); end if; -- If secondary stack is in use, expand: -- _Mxx : constant Mark_Id := SS_Mark; -- Suppress calls to SS_Mark and SS_Release if VM_Target, -- since we never use the secondary stack on the VM. if Uses_Sec_Stack (Current_Scope) and then not Sec_Stack_Needed_For_Return (Current_Scope) and then VM_Target = No_VM then Mark := Make_Defining_Identifier (Loc, New_Internal_Name ('M')); Append_To (New_Decls, Make_Object_Declaration (Loc, Defining_Identifier => Mark, Object_Definition => New_Reference_To (RTE (RE_Mark_Id), Loc), Expression => Make_Function_Call (Loc, Name => New_Reference_To (RTE (RE_SS_Mark), Loc)))); Set_Uses_Sec_Stack (Current_Scope, False); end if; -- If finalization list is present then expand: -- Local_Final_List : System.FI.Finalizable_Ptr; if Present (Flist) then Append_To (New_Decls, Make_Object_Declaration (Loc, Defining_Identifier => Flist, Object_Definition => New_Reference_To (RTE (RE_Finalizable_Ptr), Loc))); end if; -- Clean-up procedure definition Clean := Make_Defining_Identifier (Loc, Name_uClean); Set_Suppress_Elaboration_Warnings (Clean); Append_To (New_Decls, Make_Clean (N, Clean, Mark, Flist, Is_Task, Is_Master, Is_Protected, Is_Task_Allocation, Is_Asynchronous_Call, Previous_At_End_Proc)); -- The previous AT END procedure, if any, has been captured in Clean: -- reset it to Empty now because we check further on that we never -- overwrite an existing AT END call. Set_At_End_Proc (Handled_Statement_Sequence (N), Empty); -- If exception handlers are present, wrap the Sequence of statements in -- a block because it is not possible to get exception handlers and an -- AT END call in the same scope. if Present (Exception_Handlers (Handled_Statement_Sequence (N))) then -- Preserve end label to provide proper cross-reference information End_Lab := End_Label (Handled_Statement_Sequence (N)); Blok := Make_Block_Statement (Loc, Handled_Statement_Sequence => Handled_Statement_Sequence (N)); Set_Handled_Statement_Sequence (N, Make_Handled_Sequence_Of_Statements (Loc, New_List (Blok))); Set_End_Label (Handled_Statement_Sequence (N), End_Lab); Wrapped := True; -- Comment needed here, see RH for 1.306 ??? if Nkind (N) = N_Subprogram_Body then Set_Has_Nested_Block_With_Handler (Current_Scope); end if; -- Otherwise we do not wrap else Wrapped := False; Blok := Empty; end if; -- Don't move the _chain Activation_Chain declaration in task -- allocation blocks. Task allocation blocks use this object -- in their cleanup handlers, and gigi complains if it is declared -- in the sequence of statements of the scope that declares the -- handler. if Is_Task_Allocation then Chain := Activation_Chain_Entity (N); Decl := First (Declarations (N)); while Nkind (Decl) /= N_Object_Declaration or else Defining_Identifier (Decl) /= Chain loop Next (Decl); pragma Assert (Present (Decl)); end loop; Remove (Decl); Prepend_To (New_Decls, Decl); end if; -- Now we move the declarations into the Sequence of statements -- in order to get them protected by the AT END call. It may seem -- weird to put declarations in the sequence of statement but in -- fact nothing forbids that at the tree level. We also set the -- First_Real_Statement field so that we remember where the real -- statements (i.e. original statements) begin. Note that if we -- wrapped the statements, the first real statement is inside the -- inner block. If the First_Real_Statement is already set (as is -- the case for subprogram bodies that are expansions of task bodies) -- then do not reset it, because its declarative part would migrate -- to the statement part. if not Wrapped then if No (First_Real_Statement (Handled_Statement_Sequence (N))) then Set_First_Real_Statement (Handled_Statement_Sequence (N), First (Statements (Handled_Statement_Sequence (N)))); end if; else Set_First_Real_Statement (Handled_Statement_Sequence (N), Blok); end if; Append_List_To (Declarations (N), Statements (Handled_Statement_Sequence (N))); Set_Statements (Handled_Statement_Sequence (N), Declarations (N)); -- We need to reset the Sloc of the handled statement sequence to -- properly reflect the new initial "statement" in the sequence. Set_Sloc (Handled_Statement_Sequence (N), Sloc (First (Declarations (N)))); -- The declarations of the _Clean procedure and finalization chain -- replace the old declarations that have been moved inward. Set_Declarations (N, New_Decls); Analyze_Declarations (New_Decls); -- The At_End call is attached to the sequence of statements declare HSS : Node_Id; begin -- If the construct is a protected subprogram, then the call to -- the corresponding unprotected subprogram appears in a block which -- is the last statement in the body, and it is this block that must -- be covered by the At_End handler. if Is_Protected then HSS := Handled_Statement_Sequence (Last (Statements (Handled_Statement_Sequence (N)))); else HSS := Handled_Statement_Sequence (N); end if; -- Never overwrite an existing AT END call pragma Assert (No (At_End_Proc (HSS))); Set_At_End_Proc (HSS, New_Occurrence_Of (Clean, Loc)); Expand_At_End_Handler (HSS, Empty); end; -- Restore saved polling mode Polling_Required := Old_Poll; end Expand_Cleanup_Actions; ------------------------------- -- Expand_Ctrl_Function_Call -- ------------------------------- procedure Expand_Ctrl_Function_Call (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Rtype : constant Entity_Id := Etype (N); Utype : constant Entity_Id := Underlying_Type (Rtype); Ref : Node_Id; Action : Node_Id; Action2 : Node_Id := Empty; Attach_Level : Uint := Uint_1; Len_Ref : Node_Id := Empty; function Last_Array_Component (Ref : Node_Id; Typ : Entity_Id) return Node_Id; -- Creates a reference to the last component of the array object -- designated by Ref whose type is Typ. -------------------------- -- Last_Array_Component -- -------------------------- function Last_Array_Component (Ref : Node_Id; Typ : Entity_Id) return Node_Id is Index_List : constant List_Id := New_List; begin for N in 1 .. Number_Dimensions (Typ) loop Append_To (Index_List, Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr_No_Checks (Ref), Attribute_Name => Name_Last, Expressions => New_List ( Make_Integer_Literal (Loc, N)))); end loop; return Make_Indexed_Component (Loc, Prefix => Duplicate_Subexpr (Ref), Expressions => Index_List); end Last_Array_Component; -- Start of processing for Expand_Ctrl_Function_Call begin -- Optimization, if the returned value (which is on the sec-stack) is -- returned again, no need to copy/readjust/finalize, we can just pass -- the value thru (see Expand_N_Simple_Return_Statement), and thus no -- attachment is needed if Nkind (Parent (N)) = N_Simple_Return_Statement then return; end if; -- Resolution is now finished, make sure we don't start analysis again -- because of the duplication. Set_Analyzed (N); Ref := Duplicate_Subexpr_No_Checks (N); -- Now we can generate the Attach Call. Note that this value is always -- on the (secondary) stack and thus is attached to a singly linked -- final list: -- Resx := F (X)'reference; -- Attach_To_Final_List (_Lx, Resx.all, 1); -- or when there are controlled components: -- Attach_To_Final_List (_Lx, Resx._controller, 1); -- or when it is both Is_Controlled and Has_Controlled_Components: -- Attach_To_Final_List (_Lx, Resx._controller, 1); -- Attach_To_Final_List (_Lx, Resx, 1); -- or if it is an array with Is_Controlled (and Has_Controlled) -- Attach_To_Final_List (_Lx, Resx (Resx'last), 3); -- An attach level of 3 means that a whole array is to be attached to -- the finalization list (including the controlled components). -- or if it is an array with Has_Controlled_Components but not -- Is_Controlled: -- Attach_To_Final_List (_Lx, Resx (Resx'last)._controller, 3); -- Case where type has controlled components if Has_Controlled_Component (Rtype) then declare T1 : Entity_Id := Rtype; T2 : Entity_Id := Utype; begin if Is_Array_Type (T2) then Len_Ref := Make_Attribute_Reference (Loc, Prefix => Duplicate_Subexpr_Move_Checks (Unchecked_Convert_To (T2, Ref)), Attribute_Name => Name_Length); end if; while Is_Array_Type (T2) loop if T1 /= T2 then Ref := Unchecked_Convert_To (T2, Ref); end if; Ref := Last_Array_Component (Ref, T2); Attach_Level := Uint_3; T1 := Component_Type (T2); T2 := Underlying_Type (T1); end loop; -- If the type has controlled components, go to the controller -- except in the case of arrays of controlled objects since in -- this case objects and their components are already chained -- and the head of the chain is the last array element. if Is_Array_Type (Rtype) and then Is_Controlled (T2) then null; elsif Has_Controlled_Component (T2) then if T1 /= T2 then Ref := Unchecked_Convert_To (T2, Ref); end if; Ref := Make_Selected_Component (Loc, Prefix => Ref, Selector_Name => Make_Identifier (Loc, Name_uController)); end if; end; -- Here we know that 'Ref' has a controller so we may as well attach -- it directly. Action := Make_Attach_Call ( Obj_Ref => Ref, Flist_Ref => Find_Final_List (Current_Scope), With_Attach => Make_Integer_Literal (Loc, Attach_Level)); -- If it is also Is_Controlled we need to attach the global object if Is_Controlled (Rtype) then Action2 := Make_Attach_Call ( Obj_Ref => Duplicate_Subexpr_No_Checks (N), Flist_Ref => Find_Final_List (Current_Scope), With_Attach => Make_Integer_Literal (Loc, Attach_Level)); end if; -- Here, we have a controlled type that does not seem to have controlled -- components but it could be a class wide type whose further -- derivations have controlled components. So we don't know if the -- object itself needs to be attached or if it has a record controller. -- We need to call a runtime function (Deep_Tag_Attach) which knows what -- to do thanks to the RC_Offset in the dispatch table. else Action := Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_Deep_Tag_Attach), Loc), Parameter_Associations => New_List ( Find_Final_List (Current_Scope), Make_Attribute_Reference (Loc, Prefix => Ref, Attribute_Name => Name_Address), Make_Integer_Literal (Loc, Attach_Level))); end if; if Present (Len_Ref) then Action := Make_Implicit_If_Statement (N, Condition => Make_Op_Gt (Loc, Left_Opnd => Len_Ref, Right_Opnd => Make_Integer_Literal (Loc, 0)), Then_Statements => New_List (Action)); end if; Insert_Action (N, Action); if Present (Action2) then Insert_Action (N, Action2); end if; end Expand_Ctrl_Function_Call; --------------------------- -- Expand_N_Package_Body -- --------------------------- -- Add call to Activate_Tasks if body is an activator (actual processing -- is in chapter 9). -- Generate subprogram descriptor for elaboration routine -- Encode entity names in package body procedure Expand_N_Package_Body (N : Node_Id) is Ent : constant Entity_Id := Corresponding_Spec (N); begin -- This is done only for non-generic packages if Ekind (Ent) = E_Package then Push_Scope (Corresponding_Spec (N)); -- Build dispatch tables of library level tagged types if Is_Library_Level_Entity (Ent) then Build_Static_Dispatch_Tables (N); end if; Build_Task_Activation_Call (N); Pop_Scope; end if; Set_Elaboration_Flag (N, Corresponding_Spec (N)); Set_In_Package_Body (Ent, False); -- Set to encode entity names in package body before gigi is called Qualify_Entity_Names (N); end Expand_N_Package_Body; ---------------------------------- -- Expand_N_Package_Declaration -- ---------------------------------- -- Add call to Activate_Tasks if there are tasks declared and the package -- has no body. Note that in Ada83, this may result in premature activation -- of some tasks, given that we cannot tell whether a body will eventually -- appear. procedure Expand_N_Package_Declaration (N : Node_Id) is Spec : constant Node_Id := Specification (N); Id : constant Entity_Id := Defining_Entity (N); Decls : List_Id; No_Body : Boolean := False; -- True in the case of a package declaration that is a compilation unit -- and for which no associated body will be compiled in -- this compilation. begin -- Case of a package declaration other than a compilation unit if Nkind (Parent (N)) /= N_Compilation_Unit then null; -- Case of a compilation unit that does not require a body elsif not Body_Required (Parent (N)) and then not Unit_Requires_Body (Id) then No_Body := True; -- Special case of generating calling stubs for a remote call interface -- package: even though the package declaration requires one, the -- body won't be processed in this compilation (so any stubs for RACWs -- declared in the package must be generated here, along with the -- spec). elsif Parent (N) = Cunit (Main_Unit) and then Is_Remote_Call_Interface (Id) and then Distribution_Stub_Mode = Generate_Caller_Stub_Body then No_Body := True; end if; -- For a package declaration that implies no associated body, generate -- task activation call and RACW supporting bodies now (since we won't -- have a specific separate compilation unit for that). if No_Body then Push_Scope (Id); if Has_RACW (Id) then -- Generate RACW subprogram bodies Decls := Private_Declarations (Spec); if No (Decls) then Decls := Visible_Declarations (Spec); end if; if No (Decls) then Decls := New_List; Set_Visible_Declarations (Spec, Decls); end if; Append_RACW_Bodies (Decls, Id); Analyze_List (Decls); end if; if Present (Activation_Chain_Entity (N)) then -- Generate task activation call as last step of elaboration Build_Task_Activation_Call (N); end if; Pop_Scope; end if; -- Build dispatch tables of library level tagged types if Is_Compilation_Unit (Id) or else (Is_Generic_Instance (Id) and then Is_Library_Level_Entity (Id)) then Build_Static_Dispatch_Tables (N); end if; -- Note: it is not necessary to worry about generating a subprogram -- descriptor, since the only way to get exception handlers into a -- package spec is to include instantiations, and that would cause -- generation of subprogram descriptors to be delayed in any case. -- Set to encode entity names in package spec before gigi is called Qualify_Entity_Names (N); end Expand_N_Package_Declaration; --------------------- -- Find_Final_List -- --------------------- function Find_Final_List (E : Entity_Id; Ref : Node_Id := Empty) return Node_Id is Loc : constant Source_Ptr := Sloc (Ref); S : Entity_Id; Id : Entity_Id; R : Node_Id; begin -- If the restriction No_Finalization applies, then there's not any -- finalization list available to return, so return Empty. if Restriction_Active (No_Finalization) then return Empty; -- Case of an internal component. The Final list is the record -- controller of the enclosing record. elsif Present (Ref) then R := Ref; loop case Nkind (R) is when N_Unchecked_Type_Conversion | N_Type_Conversion => R := Expression (R); when N_Indexed_Component | N_Explicit_Dereference => R := Prefix (R); when N_Selected_Component => R := Prefix (R); exit; when N_Identifier => exit; when others => raise Program_Error; end case; end loop; return Make_Selected_Component (Loc, Prefix => Make_Selected_Component (Loc, Prefix => R, Selector_Name => Make_Identifier (Loc, Name_uController)), Selector_Name => Make_Identifier (Loc, Name_F)); -- Case of a dynamically allocated object whose access type has an -- Associated_Final_Chain. The final list is the corresponding list -- controller (the next entity in the scope of the access type with -- the right type). If the type comes from a With_Type clause, no -- controller was created, we use the global chain instead. (The code -- related to with_type clauses should presumably be removed at some -- point since that feature is obsolete???) -- An anonymous access type either has a list created for it when the -- allocator is a for an access parameter or an access discriminant, -- or else it uses the list of the enclosing dynamic scope, when the -- context is a declaration or an assignment. elsif Is_Access_Type (E) and then (Present (Associated_Final_Chain (E)) or else From_With_Type (E)) then if From_With_Type (E) then return New_Reference_To (RTE (RE_Global_Final_List), Sloc (E)); -- Use the access type's associated finalization chain else return Make_Selected_Component (Loc, Prefix => New_Reference_To (Associated_Final_Chain (Base_Type (E)), Loc), Selector_Name => Make_Identifier (Loc, Name_F)); end if; else if Is_Dynamic_Scope (E) then S := E; else S := Enclosing_Dynamic_Scope (E); end if; -- When the finalization chain entity is 'Error', it means that there -- should not be any chain at that level and that the enclosing one -- should be used. -- This is a nasty kludge, see ??? note in exp_ch11 while Finalization_Chain_Entity (S) = Error loop S := Enclosing_Dynamic_Scope (S); end loop; if S = Standard_Standard then return New_Reference_To (RTE (RE_Global_Final_List), Sloc (E)); else if No (Finalization_Chain_Entity (S)) then -- In the case where the scope is a subprogram, retrieve the -- Sloc of subprogram's body for association with the chain, -- since using the Sloc of the spec would be confusing during -- source-line stepping within the debugger. declare Flist_Loc : Source_Ptr := Sloc (S); Subp_Body : Node_Id; begin if Ekind (S) in Subprogram_Kind then Subp_Body := Unit_Declaration_Node (S); if Nkind (Subp_Body) /= N_Subprogram_Body then Subp_Body := Corresponding_Body (Subp_Body); end if; if Present (Subp_Body) then Flist_Loc := Sloc (Subp_Body); end if; end if; Id := Make_Defining_Identifier (Flist_Loc, Chars => New_Internal_Name ('F')); end; Set_Finalization_Chain_Entity (S, Id); -- Set momentarily some semantics attributes to allow normal -- analysis of expansions containing references to this chain. -- Will be fully decorated during the expansion of the scope -- itself. Set_Ekind (Id, E_Variable); Set_Etype (Id, RTE (RE_Finalizable_Ptr)); end if; return New_Reference_To (Finalization_Chain_Entity (S), Sloc (E)); end if; end if; end Find_Final_List; ----------------------------- -- Find_Node_To_Be_Wrapped -- ----------------------------- function Find_Node_To_Be_Wrapped (N : Node_Id) return Node_Id is P : Node_Id; The_Parent : Node_Id; begin The_Parent := N; loop P := The_Parent; pragma Assert (P /= Empty); The_Parent := Parent (P); case Nkind (The_Parent) is -- Simple statement can be wrapped when N_Pragma => return The_Parent; -- Usually assignments are good candidate for wrapping -- except when they have been generated as part of a -- controlled aggregate where the wrapping should take -- place more globally. when N_Assignment_Statement => if No_Ctrl_Actions (The_Parent) then null; else return The_Parent; end if; -- An entry call statement is a special case if it occurs in -- the context of a Timed_Entry_Call. In this case we wrap -- the entire timed entry call. when N_Entry_Call_Statement | N_Procedure_Call_Statement => if Nkind (Parent (The_Parent)) = N_Entry_Call_Alternative and then Nkind_In (Parent (Parent (The_Parent)), N_Timed_Entry_Call, N_Conditional_Entry_Call) then return Parent (Parent (The_Parent)); else return The_Parent; end if; -- Object declarations are also a boundary for the transient scope -- even if they are not really wrapped -- (see Wrap_Transient_Declaration) when N_Object_Declaration | N_Object_Renaming_Declaration | N_Subtype_Declaration => return The_Parent; -- The expression itself is to be wrapped if its parent is a -- compound statement or any other statement where the expression -- is known to be scalar when N_Accept_Alternative | N_Attribute_Definition_Clause | N_Case_Statement | N_Code_Statement | N_Delay_Alternative | N_Delay_Until_Statement | N_Delay_Relative_Statement | N_Discriminant_Association | N_Elsif_Part | N_Entry_Body_Formal_Part | N_Exit_Statement | N_If_Statement | N_Iteration_Scheme | N_Terminate_Alternative => return P; when N_Attribute_Reference => if Is_Procedure_Attribute_Name (Attribute_Name (The_Parent)) then return The_Parent; end if; -- A raise statement can be wrapped. This will arise when the -- expression in a raise_with_expression uses the secondary -- stack, for example. when N_Raise_Statement => return The_Parent; -- If the expression is within the iteration scheme of a loop, -- we must create a declaration for it, followed by an assignment -- in order to have a usable statement to wrap. when N_Loop_Parameter_Specification => return Parent (The_Parent); -- The following nodes contains "dummy calls" which don't -- need to be wrapped. when N_Parameter_Specification | N_Discriminant_Specification | N_Component_Declaration => return Empty; -- The return statement is not to be wrapped when the function -- itself needs wrapping at the outer-level when N_Simple_Return_Statement => declare Applies_To : constant Entity_Id := Return_Applies_To (Return_Statement_Entity (The_Parent)); Return_Type : constant Entity_Id := Etype (Applies_To); begin if Requires_Transient_Scope (Return_Type) then return Empty; else return The_Parent; end if; end; -- If we leave a scope without having been able to find a node to -- wrap, something is going wrong but this can happen in error -- situation that are not detected yet (such as a dynamic string -- in a pragma export) when N_Subprogram_Body | N_Package_Declaration | N_Package_Body | N_Block_Statement => return Empty; -- otherwise continue the search when others => null; end case; end loop; end Find_Node_To_Be_Wrapped; ---------------------- -- Global_Flist_Ref -- ---------------------- function Global_Flist_Ref (Flist_Ref : Node_Id) return Boolean is Flist : Entity_Id; begin -- Look for the Global_Final_List if Is_Entity_Name (Flist_Ref) then Flist := Entity (Flist_Ref); -- Look for the final list associated with an access to controlled elsif Nkind (Flist_Ref) = N_Selected_Component and then Is_Entity_Name (Prefix (Flist_Ref)) then Flist := Entity (Prefix (Flist_Ref)); else return False; end if; return Present (Flist) and then Present (Scope (Flist)) and then Enclosing_Dynamic_Scope (Flist) = Standard_Standard; end Global_Flist_Ref; ---------------------------------- -- Has_New_Controlled_Component -- ---------------------------------- function Has_New_Controlled_Component (E : Entity_Id) return Boolean is Comp : Entity_Id; begin if not Is_Tagged_Type (E) then return Has_Controlled_Component (E); elsif not Is_Derived_Type (E) then return Has_Controlled_Component (E); end if; Comp := First_Component (E); while Present (Comp) loop if Chars (Comp) = Name_uParent then null; elsif Scope (Original_Record_Component (Comp)) = E and then Needs_Finalization (Etype (Comp)) then return True; end if; Next_Component (Comp); end loop; return False; end Has_New_Controlled_Component; -------------------------- -- In_Finalization_Root -- -------------------------- -- It would seem simpler to test Scope (RTE (RE_Root_Controlled)) but -- the purpose of this function is to avoid a circular call to Rtsfind -- which would been caused by such a test. function In_Finalization_Root (E : Entity_Id) return Boolean is S : constant Entity_Id := Scope (E); begin return Chars (Scope (S)) = Name_System and then Chars (S) = Name_Finalization_Root and then Scope (Scope (S)) = Standard_Standard; end In_Finalization_Root; ------------------------------------ -- Insert_Actions_In_Scope_Around -- ------------------------------------ procedure Insert_Actions_In_Scope_Around (N : Node_Id) is SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last); Target : Node_Id; begin -- If the node to be wrapped is the triggering statement of an -- asynchronous select, it is not part of a statement list. The -- actions must be inserted before the Select itself, which is -- part of some list of statements. Note that the triggering -- alternative includes the triggering statement and an optional -- statement list. If the node to be wrapped is part of that list, -- the normal insertion applies. if Nkind (Parent (Node_To_Be_Wrapped)) = N_Triggering_Alternative and then not Is_List_Member (Node_To_Be_Wrapped) then Target := Parent (Parent (Node_To_Be_Wrapped)); else Target := N; end if; if Present (SE.Actions_To_Be_Wrapped_Before) then Insert_List_Before (Target, SE.Actions_To_Be_Wrapped_Before); SE.Actions_To_Be_Wrapped_Before := No_List; end if; if Present (SE.Actions_To_Be_Wrapped_After) then Insert_List_After (Target, SE.Actions_To_Be_Wrapped_After); SE.Actions_To_Be_Wrapped_After := No_List; end if; end Insert_Actions_In_Scope_Around; ----------------------- -- Make_Adjust_Call -- ----------------------- function Make_Adjust_Call (Ref : Node_Id; Typ : Entity_Id; Flist_Ref : Node_Id; With_Attach : Node_Id; Allocator : Boolean := False) return List_Id is Loc : constant Source_Ptr := Sloc (Ref); Res : constant List_Id := New_List; Utyp : Entity_Id; Proc : Entity_Id; Cref : Node_Id := Ref; Cref2 : Node_Id; Attach : Node_Id := With_Attach; begin if Is_Class_Wide_Type (Typ) then Utyp := Underlying_Type (Base_Type (Root_Type (Typ))); else Utyp := Underlying_Type (Base_Type (Typ)); end if; Set_Assignment_OK (Cref); -- Deal with non-tagged derivation of private views if Is_Untagged_Derivation (Typ) then Utyp := Underlying_Type (Root_Type (Base_Type (Typ))); Cref := Unchecked_Convert_To (Utyp, Cref); Set_Assignment_OK (Cref); -- To prevent problems with UC see 1.156 RH ??? end if; -- If the underlying_type is a subtype, we are dealing with -- the completion of a private type. We need to access -- the base type and generate a conversion to it. if Utyp /= Base_Type (Utyp) then pragma Assert (Is_Private_Type (Typ)); Utyp := Base_Type (Utyp); Cref := Unchecked_Convert_To (Utyp, Cref); end if; -- If the object is unanalyzed, set its expected type for use -- in Convert_View in case an additional conversion is needed. if No (Etype (Cref)) and then Nkind (Cref) /= N_Unchecked_Type_Conversion then Set_Etype (Cref, Typ); end if; -- We do not need to attach to one of the Global Final Lists -- the objects whose type is Finalize_Storage_Only if Finalize_Storage_Only (Typ) and then (Global_Flist_Ref (Flist_Ref) or else Entity (Constant_Value (RTE (RE_Garbage_Collected))) = Standard_True) then Attach := Make_Integer_Literal (Loc, 0); end if; -- Special case for allocators: need initialization of the chain -- pointers. For the 0 case, reset them to null. if Allocator then pragma Assert (Nkind (Attach) = N_Integer_Literal); if Intval (Attach) = 0 then Set_Intval (Attach, Uint_4); end if; end if; -- Generate: -- Deep_Adjust (Flist_Ref, Ref, Attach); if Has_Controlled_Component (Utyp) or else Is_Class_Wide_Type (Typ) then if Is_Tagged_Type (Utyp) then Proc := Find_Prim_Op (Utyp, TSS_Deep_Adjust); else Proc := TSS (Utyp, TSS_Deep_Adjust); end if; Cref := Convert_View (Proc, Cref, 2); Append_To (Res, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (Proc, Loc), Parameter_Associations => New_List (Flist_Ref, Cref, Attach))); -- Generate: -- if With_Attach then -- Attach_To_Final_List (Ref, Flist_Ref); -- end if; -- Adjust (Ref); else -- Is_Controlled (Utyp) Proc := Find_Prim_Op (Utyp, Name_Of (Adjust_Case)); Cref := Convert_View (Proc, Cref); Cref2 := New_Copy_Tree (Cref); Append_To (Res, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (Proc, Loc), Parameter_Associations => New_List (Cref2))); Append_To (Res, Make_Attach_Call (Cref, Flist_Ref, Attach)); end if; return Res; end Make_Adjust_Call; ---------------------- -- Make_Attach_Call -- ---------------------- -- Generate: -- System.FI.Attach_To_Final_List (Flist, Ref, Nb_Link) function Make_Attach_Call (Obj_Ref : Node_Id; Flist_Ref : Node_Id; With_Attach : Node_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (Obj_Ref); begin -- Optimization: If the number of links is statically '0', don't -- call the attach_proc. if Nkind (With_Attach) = N_Integer_Literal and then Intval (With_Attach) = Uint_0 then return Make_Null_Statement (Loc); end if; return Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_Attach_To_Final_List), Loc), Parameter_Associations => New_List ( Flist_Ref, OK_Convert_To (RTE (RE_Finalizable), Obj_Ref), With_Attach)); end Make_Attach_Call; ---------------- -- Make_Clean -- ---------------- function Make_Clean (N : Node_Id; Clean : Entity_Id; Mark : Entity_Id; Flist : Entity_Id; Is_Task : Boolean; Is_Master : Boolean; Is_Protected_Subprogram : Boolean; Is_Task_Allocation_Block : Boolean; Is_Asynchronous_Call_Block : Boolean; Chained_Cleanup_Action : Node_Id) return Node_Id is Loc : constant Source_Ptr := Sloc (Clean); Stmt : constant List_Id := New_List; Sbody : Node_Id; Spec : Node_Id; Name : Node_Id; Param : Node_Id; Param_Type : Entity_Id; Pid : Entity_Id := Empty; Cancel_Param : Entity_Id; begin if Is_Task then if Restricted_Profile then Append_To (Stmt, Build_Runtime_Call (Loc, RE_Complete_Restricted_Task)); else Append_To (Stmt, Build_Runtime_Call (Loc, RE_Complete_Task)); end if; elsif Is_Master then if Restriction_Active (No_Task_Hierarchy) = False then Append_To (Stmt, Build_Runtime_Call (Loc, RE_Complete_Master)); end if; elsif Is_Protected_Subprogram then -- Add statements to the cleanup handler of the (ordinary) -- subprogram expanded to implement a protected subprogram, -- unlocking the protected object parameter and undeferring abort. -- If this is a protected procedure, and the object contains -- entries, this also calls the entry service routine. -- NOTE: This cleanup handler references _object, a parameter -- to the procedure. -- Find the _object parameter representing the protected object Spec := Parent (Corresponding_Spec (N)); Param := First (Parameter_Specifications (Spec)); loop Param_Type := Etype (Parameter_Type (Param)); if Ekind (Param_Type) = E_Record_Type then Pid := Corresponding_Concurrent_Type (Param_Type); end if; exit when No (Param) or else Present (Pid); Next (Param); end loop; pragma Assert (Present (Param)); -- If the associated protected object declares entries, -- a protected procedure has to service entry queues. -- In this case, add -- Service_Entries (_object._object'Access); -- _object is the record used to implement the protected object. -- It is a parameter to the protected subprogram. if Nkind (Specification (N)) = N_Procedure_Specification and then Has_Entries (Pid) then case Corresponding_Runtime_Package (Pid) is when System_Tasking_Protected_Objects_Entries => Name := New_Reference_To (RTE (RE_Service_Entries), Loc); when System_Tasking_Protected_Objects_Single_Entry => Name := New_Reference_To (RTE (RE_Service_Entry), Loc); when others => raise Program_Error; end case; Append_To (Stmt, Make_Procedure_Call_Statement (Loc, Name => Name, Parameter_Associations => New_List ( Make_Attribute_Reference (Loc, Prefix => Make_Selected_Component (Loc, Prefix => New_Reference_To ( Defining_Identifier (Param), Loc), Selector_Name => Make_Identifier (Loc, Name_uObject)), Attribute_Name => Name_Unchecked_Access)))); else -- Unlock (_object._object'Access); -- object is the record used to implement the protected object. -- It is a parameter to the protected subprogram. case Corresponding_Runtime_Package (Pid) is when System_Tasking_Protected_Objects_Entries => Name := New_Reference_To (RTE (RE_Unlock_Entries), Loc); when System_Tasking_Protected_Objects_Single_Entry => Name := New_Reference_To (RTE (RE_Unlock_Entry), Loc); when System_Tasking_Protected_Objects => Name := New_Reference_To (RTE (RE_Unlock), Loc); when others => raise Program_Error; end case; Append_To (Stmt, Make_Procedure_Call_Statement (Loc, Name => Name, Parameter_Associations => New_List ( Make_Attribute_Reference (Loc, Prefix => Make_Selected_Component (Loc, Prefix => New_Reference_To (Defining_Identifier (Param), Loc), Selector_Name => Make_Identifier (Loc, Name_uObject)), Attribute_Name => Name_Unchecked_Access)))); end if; if Abort_Allowed then -- Abort_Undefer; Append_To (Stmt, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To ( RTE (RE_Abort_Undefer), Loc), Parameter_Associations => Empty_List)); end if; elsif Is_Task_Allocation_Block then -- Add a call to Expunge_Unactivated_Tasks to the cleanup -- handler of a block created for the dynamic allocation of -- tasks: -- Expunge_Unactivated_Tasks (_chain); -- where _chain is the list of tasks created by the allocator -- but not yet activated. This list will be empty unless -- the block completes abnormally. -- This only applies to dynamically allocated tasks; -- other unactivated tasks are completed by Complete_Task or -- Complete_Master. -- NOTE: This cleanup handler references _chain, a local -- object. Append_To (Stmt, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To ( RTE (RE_Expunge_Unactivated_Tasks), Loc), Parameter_Associations => New_List ( New_Reference_To (Activation_Chain_Entity (N), Loc)))); elsif Is_Asynchronous_Call_Block then -- Add a call to attempt to cancel the asynchronous entry call -- whenever the block containing the abortable part is exited. -- NOTE: This cleanup handler references C, a local object -- Get the argument to the Cancel procedure Cancel_Param := Entry_Cancel_Parameter (Entity (Identifier (N))); -- If it is of type Communication_Block, this must be a -- protected entry call. if Is_RTE (Etype (Cancel_Param), RE_Communication_Block) then Append_To (Stmt, -- if Enqueued (Cancel_Parameter) then Make_Implicit_If_Statement (Clean, Condition => Make_Function_Call (Loc, Name => New_Reference_To ( RTE (RE_Enqueued), Loc), Parameter_Associations => New_List ( New_Reference_To (Cancel_Param, Loc))), Then_Statements => New_List ( -- Cancel_Protected_Entry_Call (Cancel_Param); Make_Procedure_Call_Statement (Loc, Name => New_Reference_To ( RTE (RE_Cancel_Protected_Entry_Call), Loc), Parameter_Associations => New_List ( New_Reference_To (Cancel_Param, Loc)))))); -- Asynchronous delay elsif Is_RTE (Etype (Cancel_Param), RE_Delay_Block) then Append_To (Stmt, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_Cancel_Async_Delay), Loc), Parameter_Associations => New_List ( Make_Attribute_Reference (Loc, Prefix => New_Reference_To (Cancel_Param, Loc), Attribute_Name => Name_Unchecked_Access)))); -- Task entry call else -- Append call to Cancel_Task_Entry_Call (C); Append_To (Stmt, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To ( RTE (RE_Cancel_Task_Entry_Call), Loc), Parameter_Associations => New_List ( New_Reference_To (Cancel_Param, Loc)))); end if; end if; if Present (Flist) then Append_To (Stmt, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_Finalize_List), Loc), Parameter_Associations => New_List ( New_Reference_To (Flist, Loc)))); end if; if Present (Mark) then Append_To (Stmt, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_SS_Release), Loc), Parameter_Associations => New_List ( New_Reference_To (Mark, Loc)))); end if; if Present (Chained_Cleanup_Action) then Append_To (Stmt, Make_Procedure_Call_Statement (Loc, Name => Chained_Cleanup_Action)); end if; Sbody := Make_Subprogram_Body (Loc, Specification => Make_Procedure_Specification (Loc, Defining_Unit_Name => Clean), Declarations => New_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmt)); if Present (Flist) or else Is_Task or else Is_Master then Wrap_Cleanup_Procedure (Sbody); end if; -- We do not want debug information for _Clean routines, -- since it just confuses the debugging operation unless -- we are debugging generated code. if not Debug_Generated_Code then Set_Debug_Info_Off (Clean, True); end if; return Sbody; end Make_Clean; -------------------------- -- Make_Deep_Array_Body -- -------------------------- -- Array components are initialized and adjusted in the normal order -- and finalized in the reverse order. Exceptions are handled and -- Program_Error is re-raise in the Adjust and Finalize case -- (RM 7.6.1(12)). Generate the following code : -- -- procedure Deep_<P> -- with <P> being Initialize or Adjust or Finalize -- (L : in out Finalizable_Ptr; -- V : in out Typ) -- is -- begin -- for J1 in Typ'First (1) .. Typ'Last (1) loop -- ^ reverse ^ -- in the finalization case -- ... -- for J2 in Typ'First (n) .. Typ'Last (n) loop -- Make_<P>_Call (Typ, V (J1, .. , Jn), L, V); -- end loop; -- ... -- end loop; -- exception -- not in the -- when others => raise Program_Error; -- Initialize case -- end Deep_<P>; function Make_Deep_Array_Body (Prim : Final_Primitives; Typ : Entity_Id) return List_Id is Loc : constant Source_Ptr := Sloc (Typ); Index_List : constant List_Id := New_List; -- Stores the list of references to the indexes (one per dimension) function One_Component return List_Id; -- Create one statement to initialize/adjust/finalize one array -- component, designated by a full set of indices. function One_Dimension (N : Int) return List_Id; -- Create loop to deal with one dimension of the array. The single -- statement in the body of the loop initializes the inner dimensions if -- any, or else a single component. ------------------- -- One_Component -- ------------------- function One_Component return List_Id is Comp_Typ : constant Entity_Id := Component_Type (Typ); Comp_Ref : constant Node_Id := Make_Indexed_Component (Loc, Prefix => Make_Identifier (Loc, Name_V), Expressions => Index_List); begin -- Set the etype of the component Reference, which is used to -- determine whether a conversion to a parent type is needed. Set_Etype (Comp_Ref, Comp_Typ); case Prim is when Initialize_Case => return Make_Init_Call (Comp_Ref, Comp_Typ, Make_Identifier (Loc, Name_L), Make_Identifier (Loc, Name_B)); when Adjust_Case => return Make_Adjust_Call (Comp_Ref, Comp_Typ, Make_Identifier (Loc, Name_L), Make_Identifier (Loc, Name_B)); when Finalize_Case => return Make_Final_Call (Comp_Ref, Comp_Typ, Make_Identifier (Loc, Name_B)); end case; end One_Component; ------------------- -- One_Dimension -- ------------------- function One_Dimension (N : Int) return List_Id is Index : Entity_Id; begin if N > Number_Dimensions (Typ) then return One_Component; else Index := Make_Defining_Identifier (Loc, New_External_Name ('J', N)); Append_To (Index_List, New_Reference_To (Index, Loc)); return New_List ( Make_Implicit_Loop_Statement (Typ, Identifier => Empty, Iteration_Scheme => Make_Iteration_Scheme (Loc, Loop_Parameter_Specification => Make_Loop_Parameter_Specification (Loc, Defining_Identifier => Index, Discrete_Subtype_Definition => Make_Attribute_Reference (Loc, Prefix => Make_Identifier (Loc, Name_V), Attribute_Name => Name_Range, Expressions => New_List ( Make_Integer_Literal (Loc, N))), Reverse_Present => Prim = Finalize_Case)), Statements => One_Dimension (N + 1))); end if; end One_Dimension; -- Start of processing for Make_Deep_Array_Body begin return One_Dimension (1); end Make_Deep_Array_Body; -------------------- -- Make_Deep_Proc -- -------------------- -- Generate: -- procedure DEEP_<prim> -- (L : IN OUT Finalizable_Ptr; -- not for Finalize -- V : IN OUT <typ>; -- B : IN Short_Short_Integer) is -- begin -- <stmts>; -- exception -- Finalize and Adjust Cases only -- raise Program_Error; -- idem -- end DEEP_<prim>; function Make_Deep_Proc (Prim : Final_Primitives; Typ : Entity_Id; Stmts : List_Id) return Entity_Id is Loc : constant Source_Ptr := Sloc (Typ); Formals : List_Id; Proc_Name : Entity_Id; Handler : List_Id := No_List; Type_B : Entity_Id; begin if Prim = Finalize_Case then Formals := New_List; Type_B := Standard_Boolean; else Formals := New_List ( Make_Parameter_Specification (Loc, Defining_Identifier => Make_Defining_Identifier (Loc, Name_L), In_Present => True, Out_Present => True, Parameter_Type => New_Reference_To (RTE (RE_Finalizable_Ptr), Loc))); Type_B := Standard_Short_Short_Integer; end if; Append_To (Formals, Make_Parameter_Specification (Loc, Defining_Identifier => Make_Defining_Identifier (Loc, Name_V), In_Present => True, Out_Present => True, Parameter_Type => New_Reference_To (Typ, Loc))); Append_To (Formals, Make_Parameter_Specification (Loc, Defining_Identifier => Make_Defining_Identifier (Loc, Name_B), Parameter_Type => New_Reference_To (Type_B, Loc))); if Prim = Finalize_Case or else Prim = Adjust_Case then Handler := New_List (Make_Handler_For_Ctrl_Operation (Loc)); end if; Proc_Name := Make_Defining_Identifier (Loc, Chars => Make_TSS_Name (Typ, Deep_Name_Of (Prim))); Discard_Node ( Make_Subprogram_Body (Loc, Specification => Make_Procedure_Specification (Loc, Defining_Unit_Name => Proc_Name, Parameter_Specifications => Formals), Declarations => Empty_List, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts, Exception_Handlers => Handler))); return Proc_Name; end Make_Deep_Proc; --------------------------- -- Make_Deep_Record_Body -- --------------------------- -- The Deep procedures call the appropriate Controlling proc on the -- the controller component. In the init case, it also attach the -- controller to the current finalization list. function Make_Deep_Record_Body (Prim : Final_Primitives; Typ : Entity_Id) return List_Id is Loc : constant Source_Ptr := Sloc (Typ); Controller_Typ : Entity_Id; Obj_Ref : constant Node_Id := Make_Identifier (Loc, Name_V); Controller_Ref : constant Node_Id := Make_Selected_Component (Loc, Prefix => Obj_Ref, Selector_Name => Make_Identifier (Loc, Name_uController)); Res : constant List_Id := New_List; begin if Is_Inherently_Limited_Type (Typ) then Controller_Typ := RTE (RE_Limited_Record_Controller); else Controller_Typ := RTE (RE_Record_Controller); end if; case Prim is when Initialize_Case => Append_List_To (Res, Make_Init_Call ( Ref => Controller_Ref, Typ => Controller_Typ, Flist_Ref => Make_Identifier (Loc, Name_L), With_Attach => Make_Identifier (Loc, Name_B))); -- When the type is also a controlled type by itself, -- initialize it and attach it to the finalization chain. if Is_Controlled (Typ) then Append_To (Res, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To ( Find_Prim_Op (Typ, Name_Of (Prim)), Loc), Parameter_Associations => New_List (New_Copy_Tree (Obj_Ref)))); Append_To (Res, Make_Attach_Call ( Obj_Ref => New_Copy_Tree (Obj_Ref), Flist_Ref => Make_Identifier (Loc, Name_L), With_Attach => Make_Identifier (Loc, Name_B))); end if; when Adjust_Case => Append_List_To (Res, Make_Adjust_Call (Controller_Ref, Controller_Typ, Make_Identifier (Loc, Name_L), Make_Identifier (Loc, Name_B))); -- When the type is also a controlled type by itself, -- adjust it and attach it to the finalization chain. if Is_Controlled (Typ) then Append_To (Res, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To ( Find_Prim_Op (Typ, Name_Of (Prim)), Loc), Parameter_Associations => New_List (New_Copy_Tree (Obj_Ref)))); Append_To (Res, Make_Attach_Call ( Obj_Ref => New_Copy_Tree (Obj_Ref), Flist_Ref => Make_Identifier (Loc, Name_L), With_Attach => Make_Identifier (Loc, Name_B))); end if; when Finalize_Case => if Is_Controlled (Typ) then Append_To (Res, Make_Implicit_If_Statement (Obj_Ref, Condition => Make_Identifier (Loc, Name_B), Then_Statements => New_List ( Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_Finalize_One), Loc), Parameter_Associations => New_List ( OK_Convert_To (RTE (RE_Finalizable), New_Copy_Tree (Obj_Ref))))), Else_Statements => New_List ( Make_Procedure_Call_Statement (Loc, Name => New_Reference_To ( Find_Prim_Op (Typ, Name_Of (Prim)), Loc), Parameter_Associations => New_List (New_Copy_Tree (Obj_Ref)))))); end if; Append_List_To (Res, Make_Final_Call (Controller_Ref, Controller_Typ, Make_Identifier (Loc, Name_B))); end case; return Res; end Make_Deep_Record_Body; ---------------------- -- Make_Final_Call -- ---------------------- function Make_Final_Call (Ref : Node_Id; Typ : Entity_Id; With_Detach : Node_Id) return List_Id is Loc : constant Source_Ptr := Sloc (Ref); Res : constant List_Id := New_List; Cref : Node_Id; Cref2 : Node_Id; Proc : Entity_Id; Utyp : Entity_Id; begin if Is_Class_Wide_Type (Typ) then Utyp := Root_Type (Typ); Cref := Ref; elsif Is_Concurrent_Type (Typ) then Utyp := Corresponding_Record_Type (Typ); Cref := Convert_Concurrent (Ref, Typ); elsif Is_Private_Type (Typ) and then Present (Full_View (Typ)) and then Is_Concurrent_Type (Full_View (Typ)) then Utyp := Corresponding_Record_Type (Full_View (Typ)); Cref := Convert_Concurrent (Ref, Full_View (Typ)); else Utyp := Typ; Cref := Ref; end if; Utyp := Underlying_Type (Base_Type (Utyp)); Set_Assignment_OK (Cref); -- Deal with non-tagged derivation of private views. If the parent is -- now known to be protected, the finalization routine is the one -- defined on the corresponding record of the ancestor (corresponding -- records do not automatically inherit operations, but maybe they -- should???) if Is_Untagged_Derivation (Typ) then if Is_Protected_Type (Typ) then Utyp := Corresponding_Record_Type (Root_Type (Base_Type (Typ))); else Utyp := Underlying_Type (Root_Type (Base_Type (Typ))); end if; Cref := Unchecked_Convert_To (Utyp, Cref); -- We need to set Assignment_OK to prevent problems with unchecked -- conversions, where we do not want them to be converted back in the -- case of untagged record derivation (see code in Make_*_Call -- procedures for similar situations). Set_Assignment_OK (Cref); end if; -- If the underlying_type is a subtype, we are dealing with -- the completion of a private type. We need to access -- the base type and generate a conversion to it. if Utyp /= Base_Type (Utyp) then pragma Assert (Is_Private_Type (Typ)); Utyp := Base_Type (Utyp); Cref := Unchecked_Convert_To (Utyp, Cref); end if; -- Generate: -- Deep_Finalize (Ref, With_Detach); if Has_Controlled_Component (Utyp) or else Is_Class_Wide_Type (Typ) then if Is_Tagged_Type (Utyp) then Proc := Find_Prim_Op (Utyp, TSS_Deep_Finalize); else Proc := TSS (Utyp, TSS_Deep_Finalize); end if; Cref := Convert_View (Proc, Cref); Append_To (Res, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (Proc, Loc), Parameter_Associations => New_List (Cref, With_Detach))); -- Generate: -- if With_Detach then -- Finalize_One (Ref); -- else -- Finalize (Ref); -- end if; else Proc := Find_Prim_Op (Utyp, Name_Of (Finalize_Case)); if Chars (With_Detach) = Chars (Standard_True) then Append_To (Res, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_Finalize_One), Loc), Parameter_Associations => New_List ( OK_Convert_To (RTE (RE_Finalizable), Cref)))); elsif Chars (With_Detach) = Chars (Standard_False) then Append_To (Res, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (Proc, Loc), Parameter_Associations => New_List (Convert_View (Proc, Cref)))); else Cref2 := New_Copy_Tree (Cref); Append_To (Res, Make_Implicit_If_Statement (Ref, Condition => With_Detach, Then_Statements => New_List ( Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (RTE (RE_Finalize_One), Loc), Parameter_Associations => New_List ( OK_Convert_To (RTE (RE_Finalizable), Cref)))), Else_Statements => New_List ( Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (Proc, Loc), Parameter_Associations => New_List (Convert_View (Proc, Cref2)))))); end if; end if; return Res; end Make_Final_Call; ------------------------------------- -- Make_Handler_For_Ctrl_Operation -- ------------------------------------- -- Generate: -- when E : others => -- Raise_From_Controlled_Operation (X => E); -- or: -- when others => -- raise Program_Error [finalize raised exception]; -- depending on whether Raise_From_Controlled_Operation is available function Make_Handler_For_Ctrl_Operation (Loc : Source_Ptr) return Node_Id is E_Occ : Entity_Id; -- Choice parameter (for the first case above) Raise_Node : Node_Id; -- Procedure call or raise statement begin if RTE_Available (RE_Raise_From_Controlled_Operation) then -- Standard runtime: add choice parameter E, and pass it to -- Raise_From_Controlled_Operation so that the original exception -- name and message can be recorded in the exception message for -- Program_Error. E_Occ := Make_Defining_Identifier (Loc, Name_E); Raise_Node := Make_Procedure_Call_Statement (Loc, Name => New_Occurrence_Of ( RTE (RE_Raise_From_Controlled_Operation), Loc), Parameter_Associations => New_List ( New_Occurrence_Of (E_Occ, Loc))); else -- Restricted runtime: exception messages are not supported E_Occ := Empty; Raise_Node := Make_Raise_Program_Error (Loc, Reason => PE_Finalize_Raised_Exception); end if; return Make_Implicit_Exception_Handler (Loc, Exception_Choices => New_List (Make_Others_Choice (Loc)), Choice_Parameter => E_Occ, Statements => New_List (Raise_Node)); end Make_Handler_For_Ctrl_Operation; -------------------- -- Make_Init_Call -- -------------------- function Make_Init_Call (Ref : Node_Id; Typ : Entity_Id; Flist_Ref : Node_Id; With_Attach : Node_Id) return List_Id is Loc : constant Source_Ptr := Sloc (Ref); Is_Conc : Boolean; Res : constant List_Id := New_List; Proc : Entity_Id; Utyp : Entity_Id; Cref : Node_Id; Cref2 : Node_Id; Attach : Node_Id := With_Attach; begin if Is_Concurrent_Type (Typ) then Is_Conc := True; Utyp := Corresponding_Record_Type (Typ); Cref := Convert_Concurrent (Ref, Typ); elsif Is_Private_Type (Typ) and then Present (Full_View (Typ)) and then Is_Concurrent_Type (Underlying_Type (Typ)) then Is_Conc := True; Utyp := Corresponding_Record_Type (Underlying_Type (Typ)); Cref := Convert_Concurrent (Ref, Underlying_Type (Typ)); else Is_Conc := False; Utyp := Typ; Cref := Ref; end if; Utyp := Underlying_Type (Base_Type (Utyp)); Set_Assignment_OK (Cref); -- Deal with non-tagged derivation of private views if Is_Untagged_Derivation (Typ) and then not Is_Conc then Utyp := Underlying_Type (Root_Type (Base_Type (Typ))); Cref := Unchecked_Convert_To (Utyp, Cref); Set_Assignment_OK (Cref); -- To prevent problems with UC see 1.156 RH ??? end if; -- If the underlying_type is a subtype, we are dealing with -- the completion of a private type. We need to access -- the base type and generate a conversion to it. if Utyp /= Base_Type (Utyp) then pragma Assert (Is_Private_Type (Typ)); Utyp := Base_Type (Utyp); Cref := Unchecked_Convert_To (Utyp, Cref); end if; -- We do not need to attach to one of the Global Final Lists -- the objects whose type is Finalize_Storage_Only if Finalize_Storage_Only (Typ) and then (Global_Flist_Ref (Flist_Ref) or else Entity (Constant_Value (RTE (RE_Garbage_Collected))) = Standard_True) then Attach := Make_Integer_Literal (Loc, 0); end if; -- Generate: -- Deep_Initialize (Ref, Flist_Ref); if Has_Controlled_Component (Utyp) then Proc := TSS (Utyp, Deep_Name_Of (Initialize_Case)); Cref := Convert_View (Proc, Cref, 2); Append_To (Res, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (Proc, Loc), Parameter_Associations => New_List ( Node1 => Flist_Ref, Node2 => Cref, Node3 => Attach))); -- Generate: -- Attach_To_Final_List (Ref, Flist_Ref); -- Initialize (Ref); else -- Is_Controlled (Utyp) Proc := Find_Prim_Op (Utyp, Name_Of (Initialize_Case)); Check_Visibly_Controlled (Initialize_Case, Typ, Proc, Cref); Cref := Convert_View (Proc, Cref); Cref2 := New_Copy_Tree (Cref); Append_To (Res, Make_Procedure_Call_Statement (Loc, Name => New_Reference_To (Proc, Loc), Parameter_Associations => New_List (Cref2))); Append_To (Res, Make_Attach_Call (Cref, Flist_Ref, Attach)); end if; return Res; end Make_Init_Call; -------------------------- -- Make_Transient_Block -- -------------------------- -- If finalization is involved, this function just wraps the instruction -- into a block whose name is the transient block entity, and then -- Expand_Cleanup_Actions (called on the expansion of the handled -- sequence of statements will do the necessary expansions for -- cleanups). function Make_Transient_Block (Loc : Source_Ptr; Action : Node_Id) return Node_Id is Flist : constant Entity_Id := Finalization_Chain_Entity (Current_Scope); Decls : constant List_Id := New_List; Par : constant Node_Id := Parent (Action); Instrs : constant List_Id := New_List (Action); Blk : Node_Id; begin -- Case where only secondary stack use is involved if VM_Target = No_VM and then Uses_Sec_Stack (Current_Scope) and then No (Flist) and then Nkind (Action) /= N_Simple_Return_Statement and then Nkind (Par) /= N_Exception_Handler then declare S : Entity_Id; K : Entity_Kind; begin S := Scope (Current_Scope); loop K := Ekind (S); -- At the outer level, no need to release the sec stack if S = Standard_Standard then Set_Uses_Sec_Stack (Current_Scope, False); exit; -- In a function, only release the sec stack if the -- function does not return on the sec stack otherwise -- the result may be lost. The caller is responsible for -- releasing. elsif K = E_Function then Set_Uses_Sec_Stack (Current_Scope, False); if not Requires_Transient_Scope (Etype (S)) then Set_Uses_Sec_Stack (S, True); Check_Restriction (No_Secondary_Stack, Action); end if; exit; -- In a loop or entry we should install a block encompassing -- all the construct. For now just release right away. elsif K = E_Loop or else K = E_Entry then exit; -- In a procedure or a block, we release on exit of the -- procedure or block. ??? memory leak can be created by -- recursive calls. elsif K = E_Procedure or else K = E_Block then Set_Uses_Sec_Stack (S, True); Check_Restriction (No_Secondary_Stack, Action); Set_Uses_Sec_Stack (Current_Scope, False); exit; else S := Scope (S); end if; end loop; end; end if; -- Insert actions stuck in the transient scopes as well as all -- freezing nodes needed by those actions Insert_Actions_In_Scope_Around (Action); declare Last_Inserted : Node_Id := Prev (Action); begin if Present (Last_Inserted) then Freeze_All (First_Entity (Current_Scope), Last_Inserted); end if; end; Blk := Make_Block_Statement (Loc, Identifier => New_Reference_To (Current_Scope, Loc), Declarations => Decls, Handled_Statement_Sequence => Make_Handled_Sequence_Of_Statements (Loc, Statements => Instrs), Has_Created_Identifier => True); -- When the transient scope was established, we pushed the entry for -- the transient scope onto the scope stack, so that the scope was -- active for the installation of finalizable entities etc. Now we -- must remove this entry, since we have constructed a proper block. Pop_Scope; return Blk; end Make_Transient_Block; ------------------------ -- Needs_Finalization -- ------------------------ function Needs_Finalization (T : Entity_Id) return Boolean is function Has_Some_Controlled_Component (Rec : Entity_Id) return Boolean; -- If type is not frozen yet, check explicitly among its components, -- because the Has_Controlled_Component flag is not necessarily set. ----------------------------------- -- Has_Some_Controlled_Component -- ----------------------------------- function Has_Some_Controlled_Component (Rec : Entity_Id) return Boolean is Comp : Entity_Id; begin if Has_Controlled_Component (Rec) then return True; elsif not Is_Frozen (Rec) then if Is_Record_Type (Rec) then Comp := First_Entity (Rec); while Present (Comp) loop if not Is_Type (Comp) and then Needs_Finalization (Etype (Comp)) then return True; end if; Next_Entity (Comp); end loop; return False; elsif Is_Array_Type (Rec) then return Needs_Finalization (Component_Type (Rec)); else return Has_Controlled_Component (Rec); end if; else return False; end if; end Has_Some_Controlled_Component; -- Start of processing for Needs_Finalization begin return -- Class-wide types must be treated as controlled and therefore -- requiring finalization (because they may be extended with an -- extension that has controlled components. (Is_Class_Wide_Type (T) -- However, avoid treating class-wide types as controlled if -- finalization is not available and in particular CIL value -- types never have finalization). and then not In_Finalization_Root (T) and then not Restriction_Active (No_Finalization) and then not Is_Value_Type (Etype (T))) -- Controlled types always need finalization or else Is_Controlled (T) or else Has_Some_Controlled_Component (T) -- For concurrent types, test the corresponding record type or else (Is_Concurrent_Type (T) and then Present (Corresponding_Record_Type (T)) and then Needs_Finalization (Corresponding_Record_Type (T))); end Needs_Finalization; ------------------------ -- Node_To_Be_Wrapped -- ------------------------ function Node_To_Be_Wrapped return Node_Id is begin return Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped; end Node_To_Be_Wrapped; ---------------------------- -- Set_Node_To_Be_Wrapped -- ---------------------------- procedure Set_Node_To_Be_Wrapped (N : Node_Id) is begin Scope_Stack.Table (Scope_Stack.Last).Node_To_Be_Wrapped := N; end Set_Node_To_Be_Wrapped; ---------------------------------- -- Store_After_Actions_In_Scope -- ---------------------------------- procedure Store_After_Actions_In_Scope (L : List_Id) is SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last); begin if Present (SE.Actions_To_Be_Wrapped_After) then Insert_List_Before_And_Analyze ( First (SE.Actions_To_Be_Wrapped_After), L); else SE.Actions_To_Be_Wrapped_After := L; if Is_List_Member (SE.Node_To_Be_Wrapped) then Set_Parent (L, Parent (SE.Node_To_Be_Wrapped)); else Set_Parent (L, SE.Node_To_Be_Wrapped); end if; Analyze_List (L); end if; end Store_After_Actions_In_Scope; ----------------------------------- -- Store_Before_Actions_In_Scope -- ----------------------------------- procedure Store_Before_Actions_In_Scope (L : List_Id) is SE : Scope_Stack_Entry renames Scope_Stack.Table (Scope_Stack.Last); begin if Present (SE.Actions_To_Be_Wrapped_Before) then Insert_List_After_And_Analyze ( Last (SE.Actions_To_Be_Wrapped_Before), L); else SE.Actions_To_Be_Wrapped_Before := L; if Is_List_Member (SE.Node_To_Be_Wrapped) then Set_Parent (L, Parent (SE.Node_To_Be_Wrapped)); else Set_Parent (L, SE.Node_To_Be_Wrapped); end if; Analyze_List (L); end if; end Store_Before_Actions_In_Scope; -------------------------------- -- Wrap_Transient_Declaration -- -------------------------------- -- If a transient scope has been established during the processing of the -- Expression of an Object_Declaration, it is not possible to wrap the -- declaration into a transient block as usual case, otherwise the object -- would be itself declared in the wrong scope. Therefore, all entities (if -- any) defined in the transient block are moved to the proper enclosing -- scope, furthermore, if they are controlled variables they are finalized -- right after the declaration. The finalization list of the transient -- scope is defined as a renaming of the enclosing one so during their -- initialization they will be attached to the proper finalization -- list. For instance, the following declaration : -- X : Typ := F (G (A), G (B)); -- (where G(A) and G(B) return controlled values, expanded as _v1 and _v2) -- is expanded into : -- _local_final_list_1 : Finalizable_Ptr; -- X : Typ := [ complex Expression-Action ]; -- Finalize_One(_v1); -- Finalize_One (_v2); procedure Wrap_Transient_Declaration (N : Node_Id) is S : Entity_Id; LC : Entity_Id := Empty; Nodes : List_Id; Loc : constant Source_Ptr := Sloc (N); First_Decl_Loc : Source_Ptr; Enclosing_S : Entity_Id; Uses_SS : Boolean; Next_N : constant Node_Id := Next (N); begin S := Current_Scope; Enclosing_S := Scope (S); -- Insert Actions kept in the Scope stack Insert_Actions_In_Scope_Around (N); -- If the declaration is consuming some secondary stack, mark the -- Enclosing scope appropriately. Uses_SS := Uses_Sec_Stack (S); Pop_Scope; -- Create a List controller and rename the final list to be its -- internal final pointer: -- Lxxx : Simple_List_Controller; -- Fxxx : Finalizable_Ptr renames Lxxx.F; if Present (Finalization_Chain_Entity (S)) then LC := Make_Defining_Identifier (Loc, New_Internal_Name ('L')); -- Use the Sloc of the first declaration of N's containing list, to -- maintain monotonicity of source-line stepping during debugging. First_Decl_Loc := Sloc (First (List_Containing (N))); Nodes := New_List ( Make_Object_Declaration (First_Decl_Loc, Defining_Identifier => LC, Object_Definition => New_Reference_To (RTE (RE_Simple_List_Controller), First_Decl_Loc)), Make_Object_Renaming_Declaration (First_Decl_Loc, Defining_Identifier => Finalization_Chain_Entity (S), Subtype_Mark => New_Reference_To (RTE (RE_Finalizable_Ptr), First_Decl_Loc), Name => Make_Selected_Component (Loc, Prefix => New_Reference_To (LC, First_Decl_Loc), Selector_Name => Make_Identifier (First_Decl_Loc, Name_F)))); -- Put the declaration at the beginning of the declaration part -- to make sure it will be before all other actions that have been -- inserted before N. Insert_List_Before_And_Analyze (First (List_Containing (N)), Nodes); -- Generate the Finalization calls by finalizing the list controller -- right away. It will be re-finalized on scope exit but it doesn't -- matter. It cannot be done when the call initializes a renaming -- object though because in this case, the object becomes a pointer -- to the temporary and thus increases its life span. Ditto if this -- is a renaming of a component of an expression (such as a function -- call). -- Note that there is a problem if an actual in the call needs -- finalization, because in that case the call itself is the master, -- and the actual should be finalized on return from the call ??? if Nkind (N) = N_Object_Renaming_Declaration and then Needs_Finalization (Etype (Defining_Identifier (N))) then null; elsif Nkind (N) = N_Object_Renaming_Declaration and then Nkind_In (Renamed_Object (Defining_Identifier (N)), N_Selected_Component, N_Indexed_Component) and then Needs_Finalization (Etype (Prefix (Renamed_Object (Defining_Identifier (N))))) then null; else Nodes := Make_Final_Call (Ref => New_Reference_To (LC, Loc), Typ => Etype (LC), With_Detach => New_Reference_To (Standard_False, Loc)); if Present (Next_N) then Insert_List_Before_And_Analyze (Next_N, Nodes); else Append_List_To (List_Containing (N), Nodes); end if; end if; end if; -- Put the local entities back in the enclosing scope, and set the -- Is_Public flag appropriately. Transfer_Entities (S, Enclosing_S); -- Mark the enclosing dynamic scope so that the sec stack will be -- released upon its exit unless this is a function that returns on -- the sec stack in which case this will be done by the caller. if VM_Target = No_VM and then Uses_SS then S := Enclosing_Dynamic_Scope (S); if Ekind (S) = E_Function and then Requires_Transient_Scope (Etype (S)) then null; else Set_Uses_Sec_Stack (S); Check_Restriction (No_Secondary_Stack, N); end if; end if; end Wrap_Transient_Declaration; ------------------------------- -- Wrap_Transient_Expression -- ------------------------------- -- Insert actions before <Expression>: -- (lines marked with <CTRL> are expanded only in presence of Controlled -- objects needing finalization) -- _E : Etyp; -- declare -- _M : constant Mark_Id := SS_Mark; -- Local_Final_List : System.FI.Finalizable_Ptr; <CTRL> -- procedure _Clean is -- begin -- Abort_Defer; -- System.FI.Finalize_List (Local_Final_List); <CTRL> -- SS_Release (M); -- Abort_Undefer; -- end _Clean; -- begin -- _E := <Expression>; -- at end -- _Clean; -- end; -- then expression is replaced by _E procedure Wrap_Transient_Expression (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); E : constant Entity_Id := Make_Temporary (Loc, 'E', N); Etyp : constant Entity_Id := Etype (N); Expr : constant Node_Id := Relocate_Node (N); begin -- If the relocated node is a function call then check if some SCIL -- node references it and needs readjustment. if Generate_SCIL and then Nkind (N) = N_Function_Call then Adjust_SCIL_Node (N, Expr); end if; Insert_Actions (N, New_List ( Make_Object_Declaration (Loc, Defining_Identifier => E, Object_Definition => New_Reference_To (Etyp, Loc)), Make_Transient_Block (Loc, Action => Make_Assignment_Statement (Loc, Name => New_Reference_To (E, Loc), Expression => Expr)))); Rewrite (N, New_Reference_To (E, Loc)); Analyze_And_Resolve (N, Etyp); end Wrap_Transient_Expression; ------------------------------ -- Wrap_Transient_Statement -- ------------------------------ -- Transform <Instruction> into -- (lines marked with <CTRL> are expanded only in presence of Controlled -- objects needing finalization) -- declare -- _M : Mark_Id := SS_Mark; -- Local_Final_List : System.FI.Finalizable_Ptr ; <CTRL> -- procedure _Clean is -- begin -- Abort_Defer; -- System.FI.Finalize_List (Local_Final_List); <CTRL> -- SS_Release (_M); -- Abort_Undefer; -- end _Clean; -- begin -- <Instruction>; -- at end -- _Clean; -- end; procedure Wrap_Transient_Statement (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); New_Statement : constant Node_Id := Relocate_Node (N); begin -- If the relocated node is a procedure call then check if some SCIL -- node references it and needs readjustment. if Generate_SCIL and then Nkind (New_Statement) = N_Procedure_Call_Statement then Adjust_SCIL_Node (N, New_Statement); end if; Rewrite (N, Make_Transient_Block (Loc, New_Statement)); -- With the scope stack back to normal, we can call analyze on the -- resulting block. At this point, the transient scope is being -- treated like a perfectly normal scope, so there is nothing -- special about it. -- Note: Wrap_Transient_Statement is called with the node already -- analyzed (i.e. Analyzed (N) is True). This is important, since -- otherwise we would get a recursive processing of the node when -- we do this Analyze call. Analyze (N); end Wrap_Transient_Statement; end Exp_Ch7;