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 -- Expand routines for chapter 9 constructs
29 with Namet
; use Namet
;
30 with Types
; use Types
;
34 type Subprogram_Protection_Mode
is
38 -- This type is used to distinguish the different protection modes of a
39 -- protected subprogram.
41 procedure Add_Discriminal_Declarations
46 -- This routine is used to add discriminal declarations to task and
47 -- protected operation bodies. The discriminants are available by normal
48 -- selection from the concurrent object (whose name is passed as the third
49 -- parameter). Discriminant references inside the body have already
50 -- been replaced by references to the corresponding discriminals. The
51 -- declarations constructed by this procedure hook the references up with
54 -- discriminal_name : discr_type renames name.discriminant_name;
56 -- Obviously we could have expanded the discriminant references in the
57 -- first place to be the appropriate selection, but this turns out to
58 -- be hard to do because it would introduce difference in handling of
59 -- discriminant references depending on their location.
61 procedure Add_Private_Declarations
66 -- This routine is used to add private declarations to protected bodies.
67 -- These are analogous to the discriminal declarations added to tasks
68 -- and protected operations, and consist of a renaming of each private
69 -- object to a selection from the concurrent object passed as an extra
70 -- parameter to each such operation:
71 -- private_name : private_type renames name.private_name;
72 -- As with discriminals, private references inside the protected
73 -- subprogram bodies have already been replaced by references to the
74 -- corresponding privals.
76 procedure Build_Activation_Chain_Entity
(N
: Node_Id
);
77 -- Given a declaration N of an object that is a task, or contains tasks
78 -- (other than allocators to tasks) this routine ensures that an activation
79 -- chain has been declared in the appropriate scope, building the required
80 -- declaration for the chain variable if not. The name of this variable
81 -- is always _Chain and it is accessed by name.
83 function Build_Call_With_Task
(N
: Node_Id
; E
: Entity_Id
) return Node_Id
;
84 -- N is a node representing the name of a task or an access to a task.
85 -- The value returned is a call to the function whose name is the entity
86 -- E (typically a runtime routine entity obtained using RTE) with the
87 -- Task_Id of the associated task as the parameter. The caller is
88 -- responsible for analyzing and resolving the resulting tree.
90 function Build_Corresponding_Record
93 Loc
: Source_Ptr
) return Node_Id
;
94 -- Common to tasks and protected types. Copy discriminant specifications,
95 -- build record declaration. N is the type declaration, Ctyp is the
96 -- concurrent entity (task type or protected type).
98 procedure Build_Master_Entity
(E
: Entity_Id
);
99 -- Given an entity E for the declaration of an object containing tasks
100 -- or of a type declaration for an allocator whose designated type is a
101 -- task or contains tasks, this routine marks the appropriate enclosing
102 -- context as a master, and also declares a variable called _Master in
103 -- the current declarative part which captures the value of Current_Master
104 -- (if not already built by a prior call). We build this object (instead
105 -- of just calling Current_Master) for two reasons. First it is clearly
106 -- more efficient to call Current_Master only once for a bunch of tasks
107 -- in the same declarative part, and second it makes things easier in
108 -- generating the initialization routines, since they can just reference
109 -- the object _Master by name, and they will get the proper Current_Master
110 -- value at the outer level, and copy in the parameter value for the outer
111 -- initialization call if the call is for a nested component). Note that
112 -- in the case of nested packages, we only really need to make one such
113 -- object at the outer level, but it is much easier to generate one per
116 function Build_Protected_Sub_Specification
119 Mode
: Subprogram_Protection_Mode
) return Node_Id
;
120 -- Build specification for protected subprogram. This is called when
121 -- expanding a protected type, and also when expanding the declaration for
122 -- an Access_To_Protected_Subprogram type. In the latter case, Prottyp is
123 -- empty, and the first parameter of the signature of the protected op is
124 -- of type System.Address.
126 procedure Build_Protected_Subprogram_Call
130 External
: Boolean := True);
131 -- The node N is a subprogram or entry call to a protected subprogram.
132 -- This procedure rewrites this call with the appropriate expansion.
133 -- Name is the subprogram, and Rec is the record corresponding to the
134 -- protected object. External is False if the call is to another
135 -- protected subprogram within the same object.
137 procedure Build_Task_Activation_Call
(N
: Node_Id
);
138 -- This procedure is called for constructs that can be task activators
139 -- i.e. task bodies, subprogram bodies, package bodies and blocks. If
140 -- the construct is a task activator (as indicated by the non-empty
141 -- setting of Activation_Chain_Entity, either in the construct, or, in
142 -- the case of a package body, in its associated package spec), then
143 -- a call to Activate_Tasks with this entity as the single parameter
144 -- is inserted at the start of the statements of the activator.
146 procedure Build_Task_Allocate_Block
150 -- This routine is used in the case of allocators where the designated
151 -- type is a task or contains tasks. In this case, the normal initialize
152 -- call is replaced by:
154 -- blockname : label;
155 -- blockname : declare
156 -- _Chain : Activation_Chain;
158 -- procedure _Expunge is
160 -- Expunge_Unactivated_Tasks (_Chain);
165 -- Activate_Tasks (_Chain);
170 -- to get the task or tasks created and initialized. The expunge call
171 -- ensures that any tasks that get created but not activated due to an
172 -- exception are properly expunged (it has no effect in the normal case)
173 -- The argument N is the allocator, and Args is the list of arguments
174 -- for the initialization call, constructed by the caller, which uses
175 -- the Master_Id of the access type as the _Master parameter, and _Chain
176 -- (defined above) as the _Chain parameter.
178 procedure Build_Task_Allocate_Block_With_Init_Stmts
181 Init_Stmts
: List_Id
);
182 -- Ada 2005 (AI-287): Similar to previous routine, but used to expand
183 -- allocated aggregates with default initialized components. Init_Stmts
184 -- contains the list of statements required to initialize the allocated
185 -- aggregate. It replaces the call to Init (Args) done by
186 -- Build_Task_Allocate_Block.
188 function Concurrent_Ref
(N
: Node_Id
) return Node_Id
;
189 -- Given the name of a concurrent object (task or protected object), or
190 -- the name of an access to a concurrent object, this function returns an
191 -- expression referencing the associated Task_Id or Protection object,
192 -- respectively. Note that a special case is when the name is a reference
193 -- to a task type name. This can only happen within a task body, and the
194 -- meaning is to get the Task_Id for the currently executing task.
196 function Convert_Concurrent
200 -- N is an expression of type Typ. If the type is not a concurrent
201 -- type then it is returned unchanged. If it is a task or protected
202 -- reference, Convert_Concurrent creates an unchecked conversion node
203 -- from this expression to the corresponding concurrent record type
204 -- value. We need this in any situation where the concurrent type is
205 -- used, because the actual concurrent object is an object of the
206 -- corresponding concurrent type, and manipulations on the concurrent
207 -- object actually manipulate the corresponding object of the record
210 function Entry_Index_Expression
216 -- Returns an expression to compute a task entry index given the name
217 -- of the entry or entry family. For the case of a task entry family,
218 -- the Index parameter contains the expression for the subscript.
219 -- Ttyp is the task type.
221 procedure Establish_Task_Master
(N
: Node_Id
);
222 -- Given a subprogram body, or a block statement, or a task body, this
223 -- proccedure makes the necessary transformations required of a task
224 -- master (add Enter_Master call at start, and establish a cleanup
225 -- routine to make sure Complete_Master is called on exit).
227 procedure Expand_Access_Protected_Subprogram_Type
(N
: Node_Id
);
228 -- Build Equivalent_Type for an Access_to_protected_Subprogram
230 procedure Expand_Accept_Declarations
(N
: Node_Id
; Ent
: Entity_Id
);
231 -- Expand declarations required for accept statement. See bodies of
232 -- both Expand_Accept_Declarations and Expand_N_Accept_Statement for
233 -- full details of the nature and use of these declarations, which
234 -- are inserted immediately before the accept node N. The second
235 -- argument is the entity for the corresponding entry.
237 procedure Expand_Entry_Barrier
(N
: Node_Id
; Ent
: Entity_Id
);
238 -- Expand the entry barrier into a function. This is called directly
239 -- from Analyze_Entry_Body so that the discriminals and privals of the
240 -- barrier can be attached to the function declaration list, and a new
241 -- set prepared for the entry body procedure, bedore the entry body
242 -- statement sequence can be expanded. The resulting function is analyzed
243 -- now, within the context of the protected object, to resolve calls to
244 -- other protected functions.
246 procedure Expand_Entry_Body_Declarations
(N
: Node_Id
);
247 -- Expand declarations required for the expansion of the
248 -- statements of the body.
250 procedure Expand_N_Abort_Statement
(N
: Node_Id
);
251 procedure Expand_N_Accept_Statement
(N
: Node_Id
);
252 procedure Expand_N_Asynchronous_Select
(N
: Node_Id
);
253 procedure Expand_N_Conditional_Entry_Call
(N
: Node_Id
);
254 procedure Expand_N_Delay_Relative_Statement
(N
: Node_Id
);
255 procedure Expand_N_Delay_Until_Statement
(N
: Node_Id
);
256 procedure Expand_N_Entry_Body
(N
: Node_Id
);
257 procedure Expand_N_Entry_Call_Statement
(N
: Node_Id
);
258 procedure Expand_N_Entry_Declaration
(N
: Node_Id
);
259 procedure Expand_N_Protected_Body
(N
: Node_Id
);
261 procedure Expand_N_Protected_Type_Declaration
(N
: Node_Id
);
262 -- Expands protected type declarations. This results, among other things,
263 -- in the declaration of a record type for the representation of protected
264 -- objects and (if there are entries) in an entry service procedure. The
265 -- Protection value used by the GNARL to control the object will always be
266 -- the first field of the record, and the entry service procedure spec (if
267 -- it exists) will always immediately follow the record declaration. This
268 -- allows these two nodes to be found from the type, without benefit of
269 -- further attributes, using Corresponding_Record.
271 procedure Expand_N_Requeue_Statement
(N
: Node_Id
);
272 procedure Expand_N_Selective_Accept
(N
: Node_Id
);
273 procedure Expand_N_Single_Task_Declaration
(N
: Node_Id
);
274 procedure Expand_N_Task_Body
(N
: Node_Id
);
275 procedure Expand_N_Task_Type_Declaration
(N
: Node_Id
);
276 procedure Expand_N_Timed_Entry_Call
(N
: Node_Id
);
278 procedure Expand_Protected_Body_Declarations
280 Spec_Id
: Entity_Id
);
281 -- Expand declarations required for a protected body. See bodies of
282 -- both Expand_Protected_Body_Declarations and Expand_N_Protected_Body
283 -- for full details of the nature and use of these declarations.
284 -- The second argument is the entity for the corresponding
285 -- protected type declaration.
287 function External_Subprogram
(E
: Entity_Id
) return Entity_Id
;
288 -- return the external version of a protected operation, which locks
289 -- the object before invoking the internal protected subprogram body.
291 function First_Protected_Operation
(D
: List_Id
) return Node_Id
;
292 -- Given the declarations list for a protected body, find the
293 -- first protected operation body.
295 function Make_Task_Create_Call
(Task_Rec
: Entity_Id
) return Node_Id
;
296 -- Given the entity of the record type created for a task type, build
297 -- the call to Create_Task
299 function Make_Initialize_Protection
300 (Protect_Rec
: Entity_Id
)
302 -- Given the entity of the record type created for a protected type, build
303 -- a list of statements needed for proper initialization of the object.
305 function Next_Protected_Operation
(N
: Node_Id
) return Node_Id
;
306 -- Given a protected operation node (a subprogram or entry body),
307 -- find the following node in the declarations list.
309 procedure Set_Discriminals
(Dec
: Node_Id
);
310 -- Replace discriminals in a protected type for use by the
311 -- next protected operation on the type. Each operation needs a
312 -- new set of discirminals, since it needs a unique renaming of
313 -- the discriminant fields in the record used to implement the
316 procedure Set_Privals
320 After_Barrier
: Boolean := False);
321 -- Associates a new set of privals (placeholders for later access to
322 -- private components of protected objects) with the private object
323 -- declarations of a protected object. These will be used to expand
324 -- the references to private objects in the next protected
325 -- subprogram or entry body to be expanded.
327 -- The flag After_Barrier indicates whether this is called after building
328 -- the barrier function for an entry body. This flag determines whether
329 -- the privals should have source names (which simplifies debugging) or
330 -- internally generated names. Entry barriers contain no debuggable code,
331 -- and there may be visibility conflicts between an entry index and a
332 -- a prival, so privals for barrier function have internal names.