1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Namet; use Namet;
28 with Types; use Types;
32 procedure Expand_N_Package_Body (N : Node_Id);
33 procedure Expand_N_Package_Declaration (N : Node_Id);
35 -----------------------------
36 -- Finalization Management --
37 -----------------------------
39 function In_Finalization_Root (E : Entity_Id) return Boolean;
40 -- True if current scope is in package System.Finalization_Root. Used
41 -- to avoid certain expansions that would involve circularity in the
44 procedure Build_Final_List (N : Node_Id; Typ : Entity_Id);
45 -- Build finalization list for anonymous access types, and for access
46 -- types that are frozen before their designated types are known to
49 procedure Build_Controlling_Procs (Typ : Entity_Id);
50 -- Typ is a record, and array type having controlled components.
51 -- Create the procedures Deep_Initialize, Deep_Adjust and Deep_Finalize
52 -- that take care of finalization management at run-time.
54 procedure Build_Late_Proc (Typ : Entity_Id; Nam : Name_Id);
55 -- Build one controlling procedure when a late body overrides one of
56 -- the controlling operations.
58 function Controller_Component (Typ : Entity_Id) return Entity_Id;
59 -- Returns the entity of the component whose name is 'Name_uController'
61 function Controlled_Type (T : Entity_Id) return Boolean;
62 -- True if T potentially needs finalization actions
64 function CW_Or_Controlled_Type (T : Entity_Id) return Boolean;
65 -- True if T is either a potentially controlled type or a class-wide type.
66 -- Note that in normal mode, class-wide types are potentially controlled so
67 -- this function is different from Controlled_Type only under restrictions
70 function Find_Final_List
72 Ref : Node_Id := Empty) return Node_Id;
73 -- E is an entity representing a controlled object, a controlled type or a
74 -- scope. If Ref is not empty, it is a reference to a controlled record,
75 -- the closest Final list is in the controller component of the record
76 -- containing Ref otherwise this function returns a reference to the final
77 -- list attached to the closest dynamic scope (that can be E itself)
78 -- creating this final list if necessary.
80 function Has_New_Controlled_Component (E : Entity_Id) return Boolean;
81 -- E is a type entity. Give the same resul as Has_Controlled_Component
82 -- except for tagged extensions where the result is True only if the
83 -- latest extension contains a controlled component.
85 function Make_Attach_Call
88 With_Attach : Node_Id) return Node_Id;
89 -- Attach the referenced object to the referenced Final Chain 'Flist_Ref'
90 -- With_Attach is an expression of type Short_Short_Integer which can be
91 -- either '0' to signify no attachment, '1' for attachement to a simply
92 -- linked list or '2' for attachement to a doubly linked list.
94 function Make_Init_Call
98 With_Attach : Node_Id) return List_Id;
99 -- Ref is an expression (with no-side effect and is not required to have
100 -- been previously analyzed) that references the object to be initialized.
101 -- Typ is the expected type of Ref, which is either a controlled type
102 -- (Is_Controlled) or a type with controlled components (Has_Controlled).
103 -- With_Attach is an integer expression which is the attchment level,
104 -- see System.Finalization_Implementation.Attach_To_Final_List for the
105 -- documentation of Nb_Link.
107 -- This function will generate the appropriate calls to make sure that the
108 -- objects referenced by Ref are initialized. The generated code is quite
109 -- different for an IS_Controlled type or a HAS_Controlled type, but this
110 -- is not the problem for the caller, the details are in the body.
112 function Make_Adjust_Call
116 With_Attach : Node_Id;
117 Allocator : Boolean := False) return List_Id;
118 -- Ref is an expression (with no-side effect and is not required to have
119 -- been previously analyzed) that references the object to be adjusted. Typ
120 -- is the expected type of Ref, which is a controlled type (Is_Controlled)
121 -- or a type with controlled components (Has_Controlled). With_Attach is an
122 -- integer expression giving the attachment level (see documentation of
123 -- Attach_To_Final_List.Nb_Link param documentation in s-finimp.ads.
124 -- Note: if Typ is Finalize_Storage_Only and the object is at library
125 -- level, then With_Attach will be ignored, and a zero link level will be
126 -- passed to Attach_To_Final_List.
128 -- This function will generate the appropriate calls to make sure that the
129 -- objects referenced by Ref are adjusted. The generated code is quite
130 -- different depending on the fact the type IS_Controlled or HAS_Controlled
131 -- but this is not the problem of the caller, the details are in the body.
132 -- The objects must be attached when the adjust takes place after an
133 -- initialization expression but not when it takes place after a regular
136 -- If Allocator is True, we are adjusting a newly-created object. The
137 -- existing chaining pointers should not be left unchanged, because they
138 -- may come from a bit-for-bit copy of those from an initializing object.
139 -- So, when this flag is True, if the chaining pointers should otherwise
140 -- be left unset, instead they are reset to null.
142 function Make_Final_Call
145 With_Detach : Node_Id) return List_Id;
146 -- Ref is an expression (with no-side effect and is not required to have
147 -- been previously analyzed) that references the object to be Finalized.
148 -- Typ is the expected type of Ref, which is a controlled type
149 -- (Is_Controlled) or a type with controlled components (Has_Controlled).
150 -- With_Detach is a boolean expression indicating whether to detach the
151 -- controlled object from whatever finalization list it is currently
154 -- This function will generate the appropriate calls to make sure that the
155 -- objects referenced by Ref are finalized. The generated code is quite
156 -- different depending on the fact the type IS_Controlled or HAS_Controlled
157 -- but this is not the problem of the caller, the details are in the body.
158 -- The objects must be detached when finalizing an unchecked deallocated
159 -- object but not when finalizing the target of an assignment, it is not
160 -- necessary either on scope exit.
162 procedure Expand_Ctrl_Function_Call (N : Node_Id);
163 -- Expand a call to a function returning a controlled value. That is to
164 -- say attach the result of the call to the current finalization list,
165 -- which is the one of the transient scope created for such constructs.
167 function Make_Handler_For_Ctrl_Operation (Loc : Source_Ptr) return Node_Id;
168 -- Generate an implicit exception handler with an 'others' choice,
169 -- converting any occurrence to a raise of Program_Error.
171 --------------------------------------------
172 -- Task and Protected Object finalization --
173 --------------------------------------------
175 function Cleanup_Array
178 Typ : Entity_Id) return List_Id;
179 -- Generate loops to finalize any tasks or simple protected objects that
180 -- are subcomponents of an array.
182 function Cleanup_Protected_Object
184 Ref : Node_Id) return Node_Id;
185 -- Generate code to finalize a protected object without entries
187 function Cleanup_Record
190 Typ : Entity_Id) return List_Id;
191 -- For each subcomponent of a record that contains tasks or simple
192 -- protected objects, generate the appropriate finalization call.
194 function Cleanup_Task
196 Ref : Node_Id) return Node_Id;
197 -- Generate code to finalize a task
199 function Has_Simple_Protected_Object (T : Entity_Id) return Boolean;
200 -- Check whether composite type contains a simple protected component
202 function Is_Simple_Protected_Type (T : Entity_Id) return Boolean;
203 -- Check whether argument is a protected type without entries. Protected
204 -- types with entries are controlled, and their cleanup is handled by the
205 -- standard finalization machinery. For simple protected types we generate
206 -- inline code to release their locks.
208 --------------------------------
209 -- Transient Scope Management --
210 --------------------------------
212 procedure Expand_Cleanup_Actions (N : Node_Id);
213 -- Expand the necessary stuff into a scope to enable finalization of local
214 -- objects and deallocation of transient data when exiting the scope. N is
215 -- a "scope node" that is to say one of the following: N_Block_Statement,
216 -- N_Subprogram_Body, N_Task_Body, N_Entry_Body.
218 procedure Establish_Transient_Scope (N : Node_Id; Sec_Stack : Boolean);
219 -- Push a new transient scope on the scope stack. N is the node responsible
220 -- for the need of a transient scope. If Sec_Stack is True then the
221 -- secondary stack is brought in, otherwise it isn't.
223 function Node_To_Be_Wrapped return Node_Id;
224 -- return the node to be wrapped if the current scope is transient
226 procedure Store_Before_Actions_In_Scope (L : List_Id);
227 -- Append the list L of actions to the end of the before-actions store in
228 -- the top of the scope stack
230 procedure Store_After_Actions_In_Scope (L : List_Id);
231 -- Append the list L of actions to the beginning of the after-actions store
232 -- in the top of the scope stack
234 procedure Wrap_Transient_Declaration (N : Node_Id);
235 -- N is an object declaration. Expand the finalization calls after the
236 -- declaration and make the outer scope beeing the transient one.
238 procedure Wrap_Transient_Expression (N : Node_Id);
239 -- N is a sub-expression. Expand a transient block around an expression
241 procedure Wrap_Transient_Statement (N : Node_Id);
242 -- N is a statement. Expand a transient block around an instruction