1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, 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 3, 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 COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 -- Expand routines for chapter 9 constructs
28 with Types; use Types;
32 type Subprogram_Protection_Mode is
36 -- This type is used to distinguish the different protection modes of a
37 -- protected subprogram.
39 procedure Build_Activation_Chain_Entity (N : Node_Id);
40 -- Given a declaration N of an object that is a task, or contains tasks
41 -- (other than allocators to tasks) this routine ensures that an activation
42 -- chain has been declared in the appropriate scope, building the required
43 -- declaration for the chain variable if not. The name of this variable
44 -- is always _Chain and it is accessed by name.
46 function Build_Call_With_Task (N : Node_Id; E : Entity_Id) return Node_Id;
47 -- N is a node representing the name of a task or an access to a task.
48 -- The value returned is a call to the function whose name is the entity
49 -- E (typically a runtime routine entity obtained using RTE) with the
50 -- Task_Id of the associated task as the parameter. The caller is
51 -- responsible for analyzing and resolving the resulting tree.
53 function Build_Corresponding_Record
56 Loc : Source_Ptr) return Node_Id;
57 -- Common to tasks and protected types. Copy discriminant specifications,
58 -- build record declaration. N is the type declaration, Ctyp is the
59 -- concurrent entity (task type or protected type).
61 procedure Build_Master_Entity (E : Entity_Id);
62 -- Given an entity E for the declaration of an object containing tasks
63 -- or of a type declaration for an allocator whose designated type is a
64 -- task or contains tasks, this routine marks the appropriate enclosing
65 -- context as a master, and also declares a variable called _Master in
66 -- the current declarative part which captures the value of Current_Master
67 -- (if not already built by a prior call). We build this object (instead
68 -- of just calling Current_Master) for two reasons. First it is clearly
69 -- more efficient to call Current_Master only once for a bunch of tasks
70 -- in the same declarative part, and second it makes things easier in
71 -- generating the initialization routines, since they can just reference
72 -- the object _Master by name, and they will get the proper Current_Master
73 -- value at the outer level, and copy in the parameter value for the outer
74 -- initialization call if the call is for a nested component). Note that
75 -- in the case of nested packages, we only really need to make one such
76 -- object at the outer level, but it is much easier to generate one per
79 function Build_Protected_Sub_Specification
82 Mode : Subprogram_Protection_Mode) return Node_Id;
83 -- Build the specification for protected subprogram. This is called when
84 -- expanding a protected type, and also when expanding the declaration for
85 -- an Access_To_Protected_Subprogram type. In the latter case, Prot_Typ is
86 -- empty, and the first parameter of the signature of the protected op is
87 -- of type System.Address.
89 procedure Build_Protected_Subprogram_Call
93 External : Boolean := True);
94 -- The node N is a subprogram or entry call to a protected subprogram.
95 -- This procedure rewrites this call with the appropriate expansion.
96 -- Name is the subprogram, and Rec is the record corresponding to the
97 -- protected object. External is False if the call is to another
98 -- protected subprogram within the same object.
100 procedure Build_Task_Activation_Call (N : Node_Id);
101 -- This procedure is called for constructs that can be task activators
102 -- i.e. task bodies, subprogram bodies, package bodies and blocks. If
103 -- the construct is a task activator (as indicated by the non-empty
104 -- setting of Activation_Chain_Entity, either in the construct, or, in
105 -- the case of a package body, in its associated package spec), then
106 -- a call to Activate_Tasks with this entity as the single parameter
107 -- is inserted at the start of the statements of the activator.
109 procedure Build_Task_Allocate_Block
113 -- This routine is used in the case of allocators where the designated
114 -- type is a task or contains tasks. In this case, the normal initialize
115 -- call is replaced by:
117 -- blockname : label;
118 -- blockname : declare
119 -- _Chain : Activation_Chain;
121 -- procedure _Expunge is
123 -- Expunge_Unactivated_Tasks (_Chain);
128 -- Activate_Tasks (_Chain);
133 -- to get the task or tasks created and initialized. The expunge call
134 -- ensures that any tasks that get created but not activated due to an
135 -- exception are properly expunged (it has no effect in the normal case)
136 -- The argument N is the allocator, and Args is the list of arguments
137 -- for the initialization call, constructed by the caller, which uses
138 -- the Master_Id of the access type as the _Master parameter, and _Chain
139 -- (defined above) as the _Chain parameter.
141 procedure Build_Task_Allocate_Block_With_Init_Stmts
144 Init_Stmts : List_Id);
145 -- Ada 2005 (AI-287): Similar to previous routine, but used to expand
146 -- allocated aggregates with default initialized components. Init_Stmts
147 -- contains the list of statements required to initialize the allocated
148 -- aggregate. It replaces the call to Init (Args) done by
149 -- Build_Task_Allocate_Block.
151 function Concurrent_Ref (N : Node_Id) return Node_Id;
152 -- Given the name of a concurrent object (task or protected object), or
153 -- the name of an access to a concurrent object, this function returns an
154 -- expression referencing the associated Task_Id or Protection object,
155 -- respectively. Note that a special case is when the name is a reference
156 -- to a task type name. This can only happen within a task body, and the
157 -- meaning is to get the Task_Id for the currently executing task.
159 function Convert_Concurrent
163 -- N is an expression of type Typ. If the type is not a concurrent
164 -- type then it is returned unchanged. If it is a task or protected
165 -- reference, Convert_Concurrent creates an unchecked conversion node
166 -- from this expression to the corresponding concurrent record type
167 -- value. We need this in any situation where the concurrent type is
168 -- used, because the actual concurrent object is an object of the
169 -- corresponding concurrent type, and manipulations on the concurrent
170 -- object actually manipulate the corresponding object of the record
173 function Entry_Index_Expression
179 -- Returns an expression to compute a task entry index given the name
180 -- of the entry or entry family. For the case of a task entry family,
181 -- the Index parameter contains the expression for the subscript.
182 -- Ttyp is the task type.
184 procedure Establish_Task_Master (N : Node_Id);
185 -- Given a subprogram body, or a block statement, or a task body, this
186 -- procedure makes the necessary transformations required of a task
187 -- master (add Enter_Master call at start, and establish a cleanup
188 -- routine to make sure Complete_Master is called on exit).
190 procedure Expand_Access_Protected_Subprogram_Type (N : Node_Id);
191 -- Build Equivalent_Type for an Access_to_protected_Subprogram
193 procedure Expand_Accept_Declarations (N : Node_Id; Ent : Entity_Id);
194 -- Expand declarations required for accept statement. See bodies of
195 -- both Expand_Accept_Declarations and Expand_N_Accept_Statement for
196 -- full details of the nature and use of these declarations, which
197 -- are inserted immediately before the accept node N. The second
198 -- argument is the entity for the corresponding entry.
200 procedure Expand_Entry_Barrier (N : Node_Id; Ent : Entity_Id);
201 -- Expand the entry barrier into a function. This is called directly
202 -- from Analyze_Entry_Body so that the discriminals and privals of the
203 -- barrier can be attached to the function declaration list, and a new
204 -- set prepared for the entry body procedure, before the entry body
205 -- statement sequence can be expanded. The resulting function is analyzed
206 -- now, within the context of the protected object, to resolve calls to
207 -- other protected functions.
209 procedure Expand_N_Abort_Statement (N : Node_Id);
210 procedure Expand_N_Accept_Statement (N : Node_Id);
211 procedure Expand_N_Asynchronous_Select (N : Node_Id);
212 procedure Expand_N_Conditional_Entry_Call (N : Node_Id);
213 procedure Expand_N_Delay_Relative_Statement (N : Node_Id);
214 procedure Expand_N_Delay_Until_Statement (N : Node_Id);
215 procedure Expand_N_Entry_Body (N : Node_Id);
216 procedure Expand_N_Entry_Call_Statement (N : Node_Id);
217 procedure Expand_N_Entry_Declaration (N : Node_Id);
218 procedure Expand_N_Protected_Body (N : Node_Id);
220 procedure Expand_N_Protected_Type_Declaration (N : Node_Id);
221 -- Expands protected type declarations. This results, among other things,
222 -- in the declaration of a record type for the representation of protected
223 -- objects and (if there are entries) in an entry service procedure. The
224 -- Protection value used by the GNARL to control the object will always be
225 -- the first field of the record, and the entry service procedure spec (if
226 -- it exists) will always immediately follow the record declaration. This
227 -- allows these two nodes to be found from the type, without benefit of
228 -- further attributes, using Corresponding_Record.
230 procedure Expand_N_Requeue_Statement (N : Node_Id);
231 procedure Expand_N_Selective_Accept (N : Node_Id);
232 procedure Expand_N_Single_Task_Declaration (N : Node_Id);
233 procedure Expand_N_Task_Body (N : Node_Id);
234 procedure Expand_N_Task_Type_Declaration (N : Node_Id);
235 procedure Expand_N_Timed_Entry_Call (N : Node_Id);
237 procedure Expand_Protected_Body_Declarations
239 Spec_Id : Entity_Id);
240 -- Expand declarations required for a protected body. See bodies of both
241 -- Expand_Protected_Body_Declarations and Expand_N_Protected_Body for full
242 -- details of the nature and use of these declarations. The second argument
243 -- is the entity for the corresponding protected type declaration.
245 function External_Subprogram (E : Entity_Id) return Entity_Id;
246 -- return the external version of a protected operation, which locks
247 -- the object before invoking the internal protected subprogram body.
249 function First_Protected_Operation (D : List_Id) return Node_Id;
250 -- Given the declarations list for a protected body, find the
251 -- first protected operation body.
253 procedure Install_Private_Data_Declarations
256 Conc_Typ : Entity_Id;
259 Barrier : Boolean := False;
260 Family : Boolean := False);
261 -- This routines generates several types, objects and object renamings used
262 -- in the handling of discriminants and private components of protected and
263 -- task types. It also generates the entry index for entry families. Formal
264 -- Spec_Id denotes an entry, entry family or a subprogram, Conc_Typ is the
265 -- concurrent type where Spec_Id resides, Body_Nod is the corresponding
266 -- body of Spec_Id, Decls are the declarations of the subprogram or entry.
267 -- Flag Barrier denotes whether the context is an entry barrier function.
268 -- Flag Family is used in conjunction with Barrier to denote a barrier for
271 -- The generated types, entities and renamings are:
273 -- * If flag Barrier is set or Spec_Id denotes a protected entry or an
274 -- entry family, generate:
276 -- type prot_typVP is access prot_typV;
277 -- _object : prot_typVP := prot_typV (_O);
279 -- where prot_typV is the corresponding record of a protected type and
280 -- _O is a formal parameter representing the concurrent object of either
281 -- the barrier function or the entry (family).
283 -- * If Conc_Typ is a protected type, create a renaming for the Protection
286 -- conc_typR : protection_typ renames _object._object;
288 -- * If Conc_Typ has discriminants, create renamings of the form:
290 -- discr_nameD : discr_typ renames _object.discr_name;
292 -- discr_nameD : discr_typ renames _task.discr_name;
294 -- * If Conc_Typ denotes a protected type and has private components,
295 -- generate renamings of the form:
297 -- comp_name : comp_typ renames _object.comp_name;
299 -- * Finally, is flag Barrier and Family are set or Spec_Id denotes an
300 -- entry family, generate the entry index constant:
302 -- subtype Jnn is <Type of Index> range Low .. High;
303 -- J : constant Jnn :=
304 -- Jnn'Val (_E - <Index expression> + Jnn'Pos (Jnn'First));
306 -- All the above declarations are inserted in the order shown to the front
309 function Make_Task_Create_Call (Task_Rec : Entity_Id) return Node_Id;
310 -- Given the entity of the record type created for a task type, build
311 -- the call to Create_Task
313 function Make_Initialize_Protection
314 (Protect_Rec : Entity_Id) return List_Id;
315 -- Given the entity of the record type created for a protected type, build
316 -- a list of statements needed for proper initialization of the object.
318 function Next_Protected_Operation (N : Node_Id) return Node_Id;
319 -- Given a protected operation node (a subprogram or entry body), find the
320 -- following node in the declarations list.
322 procedure Set_Discriminals (Dec : Node_Id);
323 -- Replace discriminals in a protected type for use by the next protected
324 -- operation on the type. Each operation needs a new set of discirminals,
325 -- since it needs a unique renaming of the discriminant fields in the
326 -- record used to implement the protected type.