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gnu / gcc / 9b1856d6c8c54a1b4b7e3a312f46a76f6d89c3df / . / gcc / ada / exp_ch9.adb
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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- E X P _ C H 9 --
-- --
-- B o d y --
-- --
-- $Revision: 1.2 $
-- --
-- Copyright (C) 1992-2001, 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 2, 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 COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Checks; use Checks;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Ch3; use Exp_Ch3;
with Exp_Ch11; use Exp_Ch11;
with Exp_Ch6; use Exp_Ch6;
with Exp_Dbug; use Exp_Dbug;
with Exp_Smem; use Exp_Smem;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Freeze; use Freeze;
with Hostparm;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Restrict; use Restrict;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Ch6;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch11; use Sem_Ch11;
with Sem_Elab; use Sem_Elab;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stand; use Stand;
with Tbuild; use Tbuild;
with Types; use Types;
with Uintp; use Uintp;
with Opt;
package body Exp_Ch9 is
-----------------------
-- Local Subprograms --
-----------------------
function Actual_Index_Expression
(Sloc : Source_Ptr;
Ent : Entity_Id;
Index : Node_Id;
Tsk : Entity_Id)
return Node_Id;
-- Compute the index position for an entry call. Tsk is the target
-- task. If the bounds of some entry family depend on discriminants,
-- the expression computed by this function uses the discriminants
-- of the target task.
function Index_Constant_Declaration
(N : Node_Id;
Index_Id : Entity_Id;
Prot : Entity_Id)
return List_Id;
-- For an entry family and its barrier function, we define a local entity
-- that maps the index in the call into the entry index into the object:
--
-- I : constant Index_Type := Index_Type'Val (
-- E - <<index of first family member>> +
-- Protected_Entry_Index (Index_Type'Pos (Index_Type'First)));
procedure Add_Object_Pointer
(Decls : List_Id;
Pid : Entity_Id;
Loc : Source_Ptr);
-- Prepend an object pointer declaration to the declaration list
-- Decls. This object pointer is initialized to a type conversion
-- of the System.Address pointer passed to entry barrier functions
-- and entry body procedures.
function Array_Type (E : Entity_Id; Trec : Node_Id) return Entity_Id;
-- Find the array type associated with an entry family in the
-- associated record for the task type.
function Build_Accept_Body (Astat : Node_Id) return Node_Id;
-- Transform accept statement into a block with added exception handler.
-- Used both for simple accept statements and for accept alternatives in
-- select statements. Astat is the accept statement.
function Build_Barrier_Function
(N : Node_Id;
Ent : Entity_Id;
Pid : Node_Id)
return Node_Id;
-- Build the function body returning the value of the barrier expression
-- for the specified entry body.
function Build_Barrier_Function_Specification
(Def_Id : Entity_Id;
Loc : Source_Ptr)
return Node_Id;
-- Build a specification for a function implementing
-- the protected entry barrier of the specified entry body.
function Build_Corresponding_Record
(N : Node_Id;
Ctyp : Node_Id;
Loc : Source_Ptr)
return Node_Id;
-- Common to tasks and protected types. Copy discriminant specifications,
-- build record declaration. N is the type declaration, Ctyp is the
-- concurrent entity (task type or protected type).
function Build_Entry_Count_Expression
(Concurrent_Type : Node_Id;
Component_List : List_Id;
Loc : Source_Ptr)
return Node_Id;
-- Compute number of entries for concurrent object. This is a count of
-- simple entries, followed by an expression that computes the length
-- of the range of each entry family. A single array with that size is
-- allocated for each concurrent object of the type.
function Build_Find_Body_Index
(Typ : Entity_Id)
return Node_Id;
-- Build the function that translates the entry index in the call
-- (which depends on the size of entry families) into an index into the
-- Entry_Bodies_Array, to determine the body and barrier function used
-- in a protected entry call. A pointer to this function appears in every
-- protected object.
function Build_Find_Body_Index_Spec
(Typ : Entity_Id)
return Node_Id;
-- Build subprogram declaration for previous one.
function Build_Protected_Entry
(N : Node_Id;
Ent : Entity_Id;
Pid : Node_Id)
return Node_Id;
-- Build the procedure implementing the statement sequence of
-- the specified entry body.
function Build_Protected_Entry_Specification
(Def_Id : Entity_Id;
Ent_Id : Entity_Id;
Loc : Source_Ptr)
return Node_Id;
-- Build a specification for a procedure implementing
-- the statement sequence of the specified entry body.
-- Add attributes associating it with the entry defining identifier
-- Ent_Id.
function Build_Protected_Subprogram_Body
(N : Node_Id;
Pid : Node_Id;
N_Op_Spec : Node_Id)
return Node_Id;
-- This function is used to construct the protected version of a protected
-- subprogram. Its statement sequence first defers abortion, then locks
-- the associated protected object, and then enters a block that contains
-- a call to the unprotected version of the subprogram (for details, see
-- Build_Unprotected_Subprogram_Body). This block statement requires
-- a cleanup handler that unlocks the object in all cases.
-- (see Exp_Ch7.Expand_Cleanup_Actions).
function Build_Protected_Spec
(N : Node_Id;
Obj_Type : Entity_Id;
Unprotected : Boolean := False;
Ident : Entity_Id)
return List_Id;
-- Utility shared by Build_Protected_Sub_Spec and Expand_Access_Protected_
-- Subprogram_Type. Builds signature of protected subprogram, adding the
-- formal that corresponds to the object itself. For an access to protected
-- subprogram, there is no object type to specify, so the additional
-- parameter has type Address and mode In. An indirect call through such
-- a pointer converts the address to a reference to the actual object.
-- The object is a limited record and therefore a by_reference type.
function Build_Selected_Name
(Prefix, Selector : Name_Id;
Append_Char : Character := ' ')
return Name_Id;
-- Build a name in the form of Prefix__Selector, with an optional
-- character appended. This is used for internal subprograms generated
-- for operations of protected types, including barrier functions. In
-- order to simplify the work of the debugger, the prefix includes the
-- characters PT.
procedure Build_Simple_Entry_Call
(N : Node_Id;
Concval : Node_Id;
Ename : Node_Id;
Index : Node_Id);
-- Some comments here would be useful ???
function Build_Task_Proc_Specification (T : Entity_Id) return Node_Id;
-- This routine constructs a specification for the procedure that we will
-- build for the task body for task type T. The spec has the form:
--
-- procedure tnameB (_Task : access tnameV);
--
-- where name is the character name taken from the task type entity that
-- is passed as the argument to the procedure, and tnameV is the task
-- value type that is associated with the task type.
function Build_Unprotected_Subprogram_Body
(N : Node_Id;
Pid : Node_Id)
return Node_Id;
-- This routine constructs the unprotected version of a protected
-- subprogram body, which is contains all of the code in the
-- original, unexpanded body. This is the version of the protected
-- subprogram that is called from all protected operations on the same
-- object, including the protected version of the same subprogram.
procedure Collect_Entry_Families
(Loc : Source_Ptr;
Cdecls : List_Id;
Current_Node : in out Node_Id;
Conctyp : Entity_Id);
-- For each entry family in a concurrent type, create an anonymous array
-- type of the right size, and add a component to the corresponding_record.
function Family_Offset
(Loc : Source_Ptr;
Hi : Node_Id;
Lo : Node_Id;
Ttyp : Entity_Id)
return Node_Id;
-- Compute (Hi - Lo) for two entry family indices. Hi is the index in
-- an accept statement, or the upper bound in the discrete subtype of
-- an entry declaration. Lo is the corresponding lower bound. Ttyp is
-- the concurrent type of the entry.
function Family_Size
(Loc : Source_Ptr;
Hi : Node_Id;
Lo : Node_Id;
Ttyp : Entity_Id)
return Node_Id;
-- Compute (Hi - Lo) + 1 Max 0, to determine the number of entries in
-- a family, and handle properly the superflat case. This is equivalent
-- to the use of 'Length on the index type, but must use Family_Offset
-- to handle properly the case of bounds that depend on discriminants.
procedure Extract_Entry
(N : Node_Id;
Concval : out Node_Id;
Ename : out Node_Id;
Index : out Node_Id);
-- Given an entry call, returns the associated concurrent object,
-- the entry name, and the entry family index.
function Find_Task_Or_Protected_Pragma
(T : Node_Id;
P : Name_Id)
return Node_Id;
-- Searches the task or protected definition T for the first occurrence
-- of the pragma whose name is given by P. The caller has ensured that
-- the pragma is present in the task definition. A special case is that
-- when P is Name_uPriority, the call will also find Interrupt_Priority.
-- ??? Should be implemented with the rep item chain mechanism.
procedure Update_Prival_Subtypes (N : Node_Id);
-- The actual subtypes of the privals will differ from the type of the
-- private declaration in the original protected type, if the protected
-- type has discriminants or if the prival has constrained components.
-- This is because the privals are generated out of sequence w.r.t. the
-- analysis of a protected body. After generating the bodies for protected
-- operations, we set correctly the type of all references to privals, by
-- means of a recursive tree traversal, which is heavy-handed but
-- correct.
-----------------------------
-- Actual_Index_Expression --
-----------------------------
function Actual_Index_Expression
(Sloc : Source_Ptr;
Ent : Entity_Id;
Index : Node_Id;
Tsk : Entity_Id)
return Node_Id
is
Expr : Node_Id;
Num : Node_Id;
Lo : Node_Id;
Hi : Node_Id;
Prev : Entity_Id;
S : Node_Id;
Ttyp : Entity_Id := Etype (Tsk);
--------------------------
-- Actual_Family_Offset --
--------------------------
function Actual_Family_Offset (Hi, Lo : Node_Id) return Node_Id;
-- Compute difference between bounds of entry family.
function Actual_Family_Offset (Hi, Lo : Node_Id) return Node_Id is
function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
-- Replace a reference to a discriminant with a selected component
-- denoting the discriminant of the target task.
function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
Typ : Entity_Id := Etype (Bound);
B : Node_Id;
begin
if not Is_Entity_Name (Bound)
or else Ekind (Entity (Bound)) /= E_Discriminant
then
if Nkind (Bound) = N_Attribute_Reference then
return Bound;
else
B := New_Copy_Tree (Bound);
end if;
else
B :=
Make_Selected_Component (Sloc,
Prefix => New_Copy_Tree (Tsk),
Selector_Name => New_Occurrence_Of (Entity (Bound), Sloc));
Analyze_And_Resolve (B, Typ);
end if;
return
Make_Attribute_Reference (Sloc,
Attribute_Name => Name_Pos,
Prefix => New_Occurrence_Of (Etype (Bound), Sloc),
Expressions => New_List (B));
end Actual_Discriminant_Ref;
begin
return
Make_Op_Subtract (Sloc,
Left_Opnd => Actual_Discriminant_Ref (Hi),
Right_Opnd => Actual_Discriminant_Ref (Lo));
end Actual_Family_Offset;
begin
-- The queues of entries and entry families appear in textual
-- order in the associated record. The entry index is computed as
-- the sum of the number of queues for all entries that precede the
-- designated one, to which is added the index expression, if this
-- expression denotes a member of a family.
-- The following is a place holder for the count of simple entries.
Num := Make_Integer_Literal (Sloc, 1);
-- We construct an expression which is a series of addition
-- operations. See comments in Entry_Index_Expression, which is
-- identical in structure.
if Present (Index) then
S := Etype (Discrete_Subtype_Definition (Declaration_Node (Ent)));
Expr :=
Make_Op_Add (Sloc,
Left_Opnd => Num,
Right_Opnd =>
Actual_Family_Offset (
Make_Attribute_Reference (Sloc,
Attribute_Name => Name_Pos,
Prefix => New_Reference_To (Base_Type (S), Sloc),
Expressions => New_List (Relocate_Node (Index))),
Type_Low_Bound (S)));
else
Expr := Num;
end if;
-- Now add lengths of preceding entries and entry families.
Prev := First_Entity (Ttyp);
while Chars (Prev) /= Chars (Ent)
or else (Ekind (Prev) /= Ekind (Ent))
or else not Sem_Ch6.Type_Conformant (Ent, Prev)
loop
if Ekind (Prev) = E_Entry then
Set_Intval (Num, Intval (Num) + 1);
elsif Ekind (Prev) = E_Entry_Family then
S :=
Etype (Discrete_Subtype_Definition (Declaration_Node (Prev)));
Lo := Type_Low_Bound (S);
Hi := Type_High_Bound (S);
Expr :=
Make_Op_Add (Sloc,
Left_Opnd => Expr,
Right_Opnd =>
Make_Op_Add (Sloc,
Left_Opnd =>
Actual_Family_Offset (Hi, Lo),
Right_Opnd =>
Make_Integer_Literal (Sloc, 1)));
-- Other components are anonymous types to be ignored.
else
null;
end if;
Next_Entity (Prev);
end loop;
return Expr;
end Actual_Index_Expression;
----------------------------------
-- Add_Discriminal_Declarations --
----------------------------------
procedure Add_Discriminal_Declarations
(Decls : List_Id;
Typ : Entity_Id;
Name : Name_Id;
Loc : Source_Ptr)
is
D : Entity_Id;
begin
if Has_Discriminants (Typ) then
D := First_Discriminant (Typ);
while Present (D) loop
Prepend_To (Decls,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Discriminal (D),
Subtype_Mark => New_Reference_To (Etype (D), Loc),
Name =>
Make_Selected_Component (Loc,
Prefix => Make_Identifier (Loc, Name),
Selector_Name => Make_Identifier (Loc, Chars (D)))));
Next_Discriminant (D);
end loop;
end if;
end Add_Discriminal_Declarations;
------------------------
-- Add_Object_Pointer --
------------------------
procedure Add_Object_Pointer
(Decls : List_Id;
Pid : Entity_Id;
Loc : Source_Ptr)
is
Obj_Ptr : Node_Id;
begin
-- Prepend the declaration of _object. This must be first in the
-- declaration list, since it is used by the discriminal and
-- prival declarations.
-- ??? An attempt to make this a renaming was unsuccessful.
--
-- type poVP is access poV;
-- _object : poVP := poVP!O;
Obj_Ptr :=
Make_Defining_Identifier (Loc,
Chars =>
New_External_Name
(Chars (Corresponding_Record_Type (Pid)), 'P'));
Prepend_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uObject),
Object_Definition => New_Reference_To (Obj_Ptr, Loc),
Expression =>
Unchecked_Convert_To (Obj_Ptr,
Make_Identifier (Loc, Name_uO))));
Prepend_To (Decls,
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Obj_Ptr,
Type_Definition => Make_Access_To_Object_Definition (Loc,
Subtype_Indication =>
New_Reference_To (Corresponding_Record_Type (Pid), Loc))));
end Add_Object_Pointer;
------------------------------
-- Add_Private_Declarations --
------------------------------
procedure Add_Private_Declarations
(Decls : List_Id;
Typ : Entity_Id;
Name : Name_Id;
Loc : Source_Ptr)
is
P : Node_Id;
Pdef : Entity_Id;
Def : Node_Id := Protected_Definition (Parent (Typ));
Body_Ent : constant Entity_Id := Corresponding_Body (Parent (Typ));
begin
pragma Assert (Nkind (Def) = N_Protected_Definition);
if Present (Private_Declarations (Def)) then
P := First (Private_Declarations (Def));
while Present (P) loop
if Nkind (P) = N_Component_Declaration then
Pdef := Defining_Identifier (P);
Prepend_To (Decls,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Prival (Pdef),
Subtype_Mark => New_Reference_To (Etype (Pdef), Loc),
Name =>
Make_Selected_Component (Loc,
Prefix => Make_Identifier (Loc, Name),
Selector_Name => Make_Identifier (Loc, Chars (Pdef)))));
end if;
Next (P);
end loop;
end if;
-- One more "prival" for the object itself, with the right protection
-- type.
declare
Protection_Type : RE_Id;
begin
if Has_Attach_Handler (Typ) then
if Restricted_Profile then
Protection_Type := RE_Protection_Entry;
else
Protection_Type := RE_Static_Interrupt_Protection;
end if;
elsif Has_Interrupt_Handler (Typ) then
Protection_Type := RE_Dynamic_Interrupt_Protection;
elsif Has_Entries (Typ) then
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Typ) > 1
then
Protection_Type := RE_Protection_Entries;
else
Protection_Type := RE_Protection_Entry;
end if;
else
Protection_Type := RE_Protection;
end if;
Prepend_To (Decls,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Object_Ref (Body_Ent),
Subtype_Mark => New_Reference_To (RTE (Protection_Type), Loc),
Name =>
Make_Selected_Component (Loc,
Prefix => Make_Identifier (Loc, Name),
Selector_Name => Make_Identifier (Loc, Name_uObject))));
end;
end Add_Private_Declarations;
----------------
-- Array_Type --
----------------
function Array_Type (E : Entity_Id; Trec : Node_Id) return Entity_Id is
Arr : Entity_Id := First_Component (Trec);
begin
while Present (Arr) loop
exit when Ekind (Arr) = E_Component
and then Is_Array_Type (Etype (Arr))
and then Chars (Arr) = Chars (E);
Next_Component (Arr);
end loop;
-- This used to return Arr itself, but this caused problems
-- when used in expanding a protected type, possibly because
-- the record of which it is a component is not frozen yet.
-- I am going to try the type instead. This may pose visibility
-- problems. ???
return Etype (Arr);
end Array_Type;
-----------------------
-- Build_Accept_Body --
-----------------------
function Build_Accept_Body (Astat : Node_Id) return Node_Id is
Loc : constant Source_Ptr := Sloc (Astat);
Stats : constant Node_Id := Handled_Statement_Sequence (Astat);
New_S : Node_Id;
Hand : Node_Id;
Call : Node_Id;
Ohandle : Node_Id;
begin
-- At the end of the statement sequence, Complete_Rendezvous is called.
-- A label skipping the Complete_Rendezvous, and all other
-- accept processing, has already been added for the expansion
-- of requeue statements.
Call := Build_Runtime_Call (Loc, RE_Complete_Rendezvous);
Insert_Before (Last (Statements (Stats)), Call);
Analyze (Call);
-- If exception handlers are present, then append Complete_Rendezvous
-- calls to the handlers, and construct the required outer block.
if Present (Exception_Handlers (Stats)) then
Hand := First (Exception_Handlers (Stats));
while Present (Hand) loop
Call := Build_Runtime_Call (Loc, RE_Complete_Rendezvous);
Append (Call, Statements (Hand));
Analyze (Call);
Next (Hand);
end loop;
New_S :=
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Block_Statement (Loc,
Handled_Statement_Sequence => Stats)));
else
New_S := Stats;
end if;
-- At this stage we know that the new statement sequence does not
-- have an exception handler part, so we supply one to call
-- Exceptional_Complete_Rendezvous. This handler is
-- when all others =>
-- Exceptional_Complete_Rendezvous (Get_GNAT_Exception);
-- We handle Abort_Signal to make sure that we properly catch the abort
-- case and wake up the caller.
Ohandle := Make_Others_Choice (Loc);
Set_All_Others (Ohandle);
Set_Exception_Handlers (New_S,
New_List (
Make_Exception_Handler (Loc,
Exception_Choices => New_List (Ohandle),
Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (
RTE (RE_Exceptional_Complete_Rendezvous), Loc),
Parameter_Associations => New_List (
Make_Function_Call (Loc,
Name => New_Reference_To (
RTE (RE_Get_GNAT_Exception), Loc))))))));
Set_Parent (New_S, Astat); -- temp parent for Analyze call
Analyze_Exception_Handlers (Exception_Handlers (New_S));
Expand_Exception_Handlers (New_S);
-- Exceptional_Complete_Rendezvous must be called with abort
-- still deferred, which is the case for a "when all others" handler.
return New_S;
end Build_Accept_Body;
-----------------------------------
-- Build_Activation_Chain_Entity --
-----------------------------------
procedure Build_Activation_Chain_Entity (N : Node_Id) is
P : Node_Id;
B : Node_Id;
Decls : List_Id;
begin
-- Loop to find enclosing construct containing activation chain variable
P := Parent (N);
while Nkind (P) /= N_Subprogram_Body
and then Nkind (P) /= N_Package_Declaration
and then Nkind (P) /= N_Package_Body
and then Nkind (P) /= N_Block_Statement
and then Nkind (P) /= N_Task_Body
loop
P := Parent (P);
end loop;
-- If we are in a package body, the activation chain variable is
-- allocated in the corresponding spec. First, we save the package
-- body node because we enter the new entity in its Declarations list.
B := P;
if Nkind (P) = N_Package_Body then
P := Unit_Declaration_Node (Corresponding_Spec (P));
Decls := Declarations (B);
elsif Nkind (P) = N_Package_Declaration then
Decls := Visible_Declarations (Specification (B));
else
Decls := Declarations (B);
end if;
-- If activation chain entity not already declared, declare it
if No (Activation_Chain_Entity (P)) then
Set_Activation_Chain_Entity
(P, Make_Defining_Identifier (Sloc (N), Name_uChain));
Prepend_To (Decls,
Make_Object_Declaration (Sloc (P),
Defining_Identifier => Activation_Chain_Entity (P),
Aliased_Present => True,
Object_Definition =>
New_Reference_To (RTE (RE_Activation_Chain), Sloc (P))));
Analyze (First (Decls));
end if;
end Build_Activation_Chain_Entity;
----------------------------
-- Build_Barrier_Function --
----------------------------
function Build_Barrier_Function
(N : Node_Id;
Ent : Entity_Id;
Pid : Node_Id)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (N);
Ent_Formals : constant Node_Id := Entry_Body_Formal_Part (N);
Index_Spec : constant Node_Id := Entry_Index_Specification
(Ent_Formals);
Bdef : Entity_Id;
Bspec : Node_Id;
Op_Decls : List_Id := New_List;
begin
Bdef :=
Make_Defining_Identifier (Loc, Chars (Barrier_Function (Ent)));
Bspec := Build_Barrier_Function_Specification (Bdef, Loc);
-- <object pointer declaration>
-- <discriminant renamings>
-- <private object renamings>
-- Add discriminal and private renamings. These names have
-- already been used to expand references to discriminants
-- and private data.
Add_Discriminal_Declarations (Op_Decls, Pid, Name_uObject, Loc);
Add_Private_Declarations (Op_Decls, Pid, Name_uObject, Loc);
Add_Object_Pointer (Op_Decls, Pid, Loc);
-- If this is the barrier for an entry family, the entry index is
-- visible in the body of the barrier. Create a local variable that
-- converts the entry index (which is the last formal of the barrier
-- function) into the appropriate offset into the entry array. The
-- entry index constant must be set, as for the entry body, so that
-- local references to the entry index are correctly replaced with
-- the local variable. This parallels what is done for entry bodies.
if Present (Index_Spec) then
declare
Index_Id : constant Entity_Id := Defining_Identifier (Index_Spec);
Index_Con : constant Entity_Id :=
Make_Defining_Identifier (Loc, New_Internal_Name ('I'));
begin
Set_Entry_Index_Constant (Index_Id, Index_Con);
Append_List_To (Op_Decls,
Index_Constant_Declaration (N, Index_Id, Pid));
end;
end if;
-- Note: the condition in the barrier function needs to be properly
-- processed for the C/Fortran boolean possibility, but this happens
-- automatically since the return statement does this normalization.
return
Make_Subprogram_Body (Loc,
Specification => Bspec,
Declarations => Op_Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Return_Statement (Loc,
Expression => Condition (Ent_Formals)))));
end Build_Barrier_Function;
------------------------------------------
-- Build_Barrier_Function_Specification --
------------------------------------------
function Build_Barrier_Function_Specification
(Def_Id : Entity_Id;
Loc : Source_Ptr)
return Node_Id
is
begin
return Make_Function_Specification (Loc,
Defining_Unit_Name => Def_Id,
Parameter_Specifications => New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => Make_Defining_Identifier (Loc, Name_uO),
Parameter_Type =>
New_Reference_To (RTE (RE_Address), Loc)),
Make_Parameter_Specification (Loc,
Defining_Identifier => Make_Defining_Identifier (Loc, Name_uE),
Parameter_Type =>
New_Reference_To (RTE (RE_Protected_Entry_Index), Loc))),
Subtype_Mark => New_Reference_To (Standard_Boolean, Loc));
end Build_Barrier_Function_Specification;
--------------------------
-- Build_Call_With_Task --
--------------------------
function Build_Call_With_Task
(N : Node_Id;
E : Entity_Id)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (N);
begin
return
Make_Function_Call (Loc,
Name => New_Reference_To (E, Loc),
Parameter_Associations => New_List (Concurrent_Ref (N)));
end Build_Call_With_Task;
--------------------------------
-- Build_Corresponding_Record --
--------------------------------
function Build_Corresponding_Record
(N : Node_Id;
Ctyp : Entity_Id;
Loc : Source_Ptr)
return Node_Id
is
Rec_Ent : constant Entity_Id :=
Make_Defining_Identifier
(Loc, New_External_Name (Chars (Ctyp), 'V'));
Disc : Entity_Id;
Dlist : List_Id;
New_Disc : Entity_Id;
Cdecls : List_Id;
begin
Set_Corresponding_Record_Type (Ctyp, Rec_Ent);
Set_Ekind (Rec_Ent, E_Record_Type);
Set_Has_Delayed_Freeze (Rec_Ent, Has_Delayed_Freeze (Ctyp));
Set_Is_Concurrent_Record_Type (Rec_Ent, True);
Set_Corresponding_Concurrent_Type (Rec_Ent, Ctyp);
Set_Girder_Constraint (Rec_Ent, No_Elist);
Cdecls := New_List;
-- Use discriminals to create list of discriminants for record, and
-- create new discriminals for use in default expressions, etc. It is
-- worth noting that a task discriminant gives rise to 5 entities;
-- a) The original discriminant.
-- b) The discriminal for use in the task.
-- c) The discriminant of the corresponding record.
-- d) The discriminal for the init_proc of the corresponding record.
-- e) The local variable that renames the discriminant in the procedure
-- for the task body.
-- In fact the discriminals b) are used in the renaming declarations
-- for e). See details in einfo (Handling of Discriminants).
if Present (Discriminant_Specifications (N)) then
Dlist := New_List;
Disc := First_Discriminant (Ctyp);
while Present (Disc) loop
New_Disc := CR_Discriminant (Disc);
Append_To (Dlist,
Make_Discriminant_Specification (Loc,
Defining_Identifier => New_Disc,
Discriminant_Type =>
New_Occurrence_Of (Etype (Disc), Loc),
Expression =>
New_Copy (Discriminant_Default_Value (Disc))));
Next_Discriminant (Disc);
end loop;
else
Dlist := No_List;
end if;
-- Now we can construct the record type declaration. Note that this
-- record is limited, reflecting the underlying limitedness of the
-- task or protected object that it represents, and ensuring for
-- example that it is properly passed by reference.
return
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Rec_Ent,
Discriminant_Specifications => Dlist,
Type_Definition =>
Make_Record_Definition (Loc,
Component_List =>
Make_Component_List (Loc,
Component_Items => Cdecls),
Limited_Present => True));
end Build_Corresponding_Record;
----------------------------------
-- Build_Entry_Count_Expression --
----------------------------------
function Build_Entry_Count_Expression
(Concurrent_Type : Node_Id;
Component_List : List_Id;
Loc : Source_Ptr)
return Node_Id
is
Eindx : Nat;
Ent : Entity_Id;
Ecount : Node_Id;
Comp : Node_Id;
Lo : Node_Id;
Hi : Node_Id;
Typ : Entity_Id;
begin
Ent := First_Entity (Concurrent_Type);
Eindx := 0;
-- Count number of non-family entries
while Present (Ent) loop
if Ekind (Ent) = E_Entry then
Eindx := Eindx + 1;
end if;
Next_Entity (Ent);
end loop;
Ecount := Make_Integer_Literal (Loc, Eindx);
-- Loop through entry families building the addition nodes
Ent := First_Entity (Concurrent_Type);
Comp := First (Component_List);
while Present (Ent) loop
if Ekind (Ent) = E_Entry_Family then
while Chars (Ent) /= Chars (Defining_Identifier (Comp)) loop
Next (Comp);
end loop;
Typ := Etype (Discrete_Subtype_Definition (Parent (Ent)));
Hi := Type_High_Bound (Typ);
Lo := Type_Low_Bound (Typ);
Ecount :=
Make_Op_Add (Loc,
Left_Opnd => Ecount,
Right_Opnd => Family_Size (Loc, Hi, Lo, Concurrent_Type));
end if;
Next_Entity (Ent);
end loop;
return Ecount;
end Build_Entry_Count_Expression;
---------------------------
-- Build_Find_Body_Index --
---------------------------
function Build_Find_Body_Index
(Typ : Entity_Id)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (Typ);
Ent : Entity_Id;
E_Typ : Entity_Id;
Has_F : Boolean := False;
Index : Nat;
If_St : Node_Id := Empty;
Lo : Node_Id;
Hi : Node_Id;
Decls : List_Id := New_List;
Ret : Node_Id;
Spec : Node_Id;
Siz : Node_Id := Empty;
procedure Add_If_Clause (Expr : Node_Id);
-- Add test for range of current entry.
function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id;
-- If a bound of an entry is given by a discriminant, retrieve the
-- actual value of the discriminant from the enclosing object.
-------------------
-- Add_If_Clause --
-------------------
procedure Add_If_Clause (Expr : Node_Id) is
Cond : Node_Id;
Stats : constant List_Id :=
New_List (
Make_Return_Statement (Loc,
Expression => Make_Integer_Literal (Loc, Index + 1)));
begin
-- Index for current entry body.
Index := Index + 1;
-- Compute total length of entry queues so far.
if No (Siz) then
Siz := Expr;
else
Siz :=
Make_Op_Add (Loc,
Left_Opnd => Siz,
Right_Opnd => Expr);
end if;
Cond :=
Make_Op_Le (Loc,
Left_Opnd => Make_Identifier (Loc, Name_uE),
Right_Opnd => Siz);
-- Map entry queue indices in the range of the current family
-- into the current index, that designates the entry body.
if No (If_St) then
If_St :=
Make_Implicit_If_Statement (Typ,
Condition => Cond,
Then_Statements => Stats,
Elsif_Parts => New_List);
Ret := If_St;
else
Append (
Make_Elsif_Part (Loc,
Condition => Cond,
Then_Statements => Stats),
Elsif_Parts (If_St));
end if;
end Add_If_Clause;
------------------------------
-- Convert_Discriminant_Ref --
------------------------------
function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id is
B : Node_Id;
begin
if Is_Entity_Name (Bound)
and then Ekind (Entity (Bound)) = E_Discriminant
then
B :=
Make_Selected_Component (Loc,
Prefix =>
Unchecked_Convert_To (Corresponding_Record_Type (Typ),
Make_Explicit_Dereference (Loc,
Make_Identifier (Loc, Name_uObject))),
Selector_Name => Make_Identifier (Loc, Chars (Bound)));
Set_Etype (B, Etype (Entity (Bound)));
else
B := New_Copy_Tree (Bound);
end if;
return B;
end Convert_Discriminant_Ref;
-- Start of processing for Build_Find_Body_Index
begin
Spec := Build_Find_Body_Index_Spec (Typ);
Ent := First_Entity (Typ);
while Present (Ent) loop
if Ekind (Ent) = E_Entry_Family then
Has_F := True;
exit;
end if;
Next_Entity (Ent);
end loop;
if not Has_F then
-- If the protected type has no entry families, there is a one-one
-- correspondence between entry queue and entry body.
Ret :=
Make_Return_Statement (Loc,
Expression => Make_Identifier (Loc, Name_uE));
else
-- Suppose entries e1, e2, ... have size l1, l2, ... we generate
-- the following:
--
-- if E <= l1 then return 1;
-- elsif E <= l1 + l2 then return 2;
-- ...
Index := 0;
Siz := Empty;
Ent := First_Entity (Typ);
Add_Object_Pointer (Decls, Typ, Loc);
while Present (Ent) loop
if Ekind (Ent) = E_Entry then
Add_If_Clause (Make_Integer_Literal (Loc, 1));
elsif Ekind (Ent) = E_Entry_Family then
E_Typ := Etype (Discrete_Subtype_Definition (Parent (Ent)));
Hi := Convert_Discriminant_Ref (Type_High_Bound (E_Typ));
Lo := Convert_Discriminant_Ref (Type_Low_Bound (E_Typ));
Add_If_Clause (Family_Size (Loc, Hi, Lo, Typ));
end if;
Next_Entity (Ent);
end loop;
if Index = 1 then
Decls := New_List;
Ret :=
Make_Return_Statement (Loc,
Expression => Make_Integer_Literal (Loc, 1));
elsif Nkind (Ret) = N_If_Statement then
-- Ranges are in increasing order, so last one doesn't need a
-- guard.
declare
Nod : constant Node_Id := Last (Elsif_Parts (Ret));
begin
Remove (Nod);
Set_Else_Statements (Ret, Then_Statements (Nod));
end;
end if;
end if;
return
Make_Subprogram_Body (Loc,
Specification => Spec,
Declarations => Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Ret)));
end Build_Find_Body_Index;
--------------------------------
-- Build_Find_Body_Index_Spec --
--------------------------------
function Build_Find_Body_Index_Spec
(Typ : Entity_Id)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (Typ);
Id : constant Entity_Id :=
Make_Defining_Identifier (Loc,
Chars => New_External_Name (Chars (Typ), 'F'));
Parm1 : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uO);
Parm2 : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uE);
begin
return
Make_Function_Specification (Loc,
Defining_Unit_Name => Id,
Parameter_Specifications => New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => Parm1,
Parameter_Type =>
New_Reference_To (RTE (RE_Address), Loc)),
Make_Parameter_Specification (Loc,
Defining_Identifier => Parm2,
Parameter_Type =>
New_Reference_To (RTE (RE_Protected_Entry_Index), Loc))),
Subtype_Mark => New_Occurrence_Of (
RTE (RE_Protected_Entry_Index), Loc));
end Build_Find_Body_Index_Spec;
-------------------------
-- Build_Master_Entity --
-------------------------
procedure Build_Master_Entity (E : Entity_Id) is
Loc : constant Source_Ptr := Sloc (E);
P : Node_Id;
Decl : Node_Id;
begin
-- Nothing to do if we already built a master entity for this scope
-- or if there is no task hierarchy.
if Has_Master_Entity (Scope (E))
or else Restrictions (No_Task_Hierarchy)
then
return;
end if;
-- Otherwise first build the master entity
-- _Master : constant Master_Id := Current_Master.all;
-- and insert it just before the current declaration
Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uMaster),
Constant_Present => True,
Object_Definition => New_Reference_To (RTE (RE_Master_Id), Loc),
Expression =>
Make_Explicit_Dereference (Loc,
New_Reference_To (RTE (RE_Current_Master), Loc)));
P := Parent (E);
Insert_Before (P, Decl);
Analyze (Decl);
Set_Has_Master_Entity (Scope (E));
-- Now mark the containing scope as a task master
while Nkind (P) /= N_Compilation_Unit loop
P := Parent (P);
-- If we fall off the top, we are at the outer level, and the
-- environment task is our effective master, so nothing to mark.
if Nkind (P) = N_Task_Body
or else Nkind (P) = N_Block_Statement
or else Nkind (P) = N_Subprogram_Body
then
Set_Is_Task_Master (P, True);
return;
elsif Nkind (Parent (P)) = N_Subunit then
P := Corresponding_Stub (Parent (P));
end if;
end loop;
end Build_Master_Entity;
---------------------------
-- Build_Protected_Entry --
---------------------------
function Build_Protected_Entry
(N : Node_Id;
Ent : Entity_Id;
Pid : Node_Id)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (N);
Edef : Entity_Id;
Espec : Node_Id;
Op_Decls : List_Id := New_List;
Op_Stats : List_Id;
Ohandle : Node_Id;
Complete : Node_Id;
begin
Edef :=
Make_Defining_Identifier (Loc,
Chars => Chars (Protected_Body_Subprogram (Ent)));
Espec := Build_Protected_Entry_Specification (Edef, Empty, Loc);
-- <object pointer declaration>
-- Add object pointer declaration. This is needed by the
-- discriminal and prival renamings, which should already
-- have been inserted into the declaration list.
Add_Object_Pointer (Op_Decls, Pid, Loc);
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Pid) > 1
then
Complete := New_Reference_To (RTE (RE_Complete_Entry_Body), Loc);
else
Complete :=
New_Reference_To (RTE (RE_Complete_Single_Entry_Body), Loc);
end if;
Op_Stats := New_List (
Make_Block_Statement (Loc,
Declarations => Declarations (N),
Handled_Statement_Sequence =>
Handled_Statement_Sequence (N)),
Make_Procedure_Call_Statement (Loc,
Name => Complete,
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix =>
Make_Identifier (Loc, Name_uObject),
Selector_Name =>
Make_Identifier (Loc, Name_uObject)),
Attribute_Name => Name_Unchecked_Access))));
if Restrictions (No_Exception_Handlers) then
return
Make_Subprogram_Body (Loc,
Specification => Espec,
Declarations => Op_Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc, Op_Stats));
else
Ohandle := Make_Others_Choice (Loc);
Set_All_Others (Ohandle);
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Pid) > 1
then
Complete :=
New_Reference_To (RTE (RE_Exceptional_Complete_Entry_Body), Loc);
else
Complete := New_Reference_To (
RTE (RE_Exceptional_Complete_Single_Entry_Body), Loc);
end if;
return
Make_Subprogram_Body (Loc,
Specification => Espec,
Declarations => Op_Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Op_Stats,
Exception_Handlers => New_List (
Make_Exception_Handler (Loc,
Exception_Choices => New_List (Ohandle),
Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name => Complete,
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix =>
Make_Identifier (Loc, Name_uObject),
Selector_Name =>
Make_Identifier (Loc, Name_uObject)),
Attribute_Name => Name_Unchecked_Access),
Make_Function_Call (Loc,
Name => New_Reference_To (
RTE (RE_Get_GNAT_Exception), Loc)))))))));
end if;
end Build_Protected_Entry;
-----------------------------------------
-- Build_Protected_Entry_Specification --
-----------------------------------------
function Build_Protected_Entry_Specification
(Def_Id : Entity_Id;
Ent_Id : Entity_Id;
Loc : Source_Ptr)
return Node_Id
is
P : Entity_Id;
begin
P := Make_Defining_Identifier (Loc, Name_uP);
if Present (Ent_Id) then
Append_Elmt (P, Accept_Address (Ent_Id));
end if;
return Make_Procedure_Specification (Loc,
Defining_Unit_Name => Def_Id,
Parameter_Specifications => New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier => Make_Defining_Identifier (Loc, Name_uO),
Parameter_Type =>
New_Reference_To (RTE (RE_Address), Loc)),
Make_Parameter_Specification (Loc,
Defining_Identifier => P,
Parameter_Type =>
New_Reference_To (RTE (RE_Address), Loc)),
Make_Parameter_Specification (Loc,
Defining_Identifier => Make_Defining_Identifier (Loc, Name_uE),
Parameter_Type =>
New_Reference_To (RTE (RE_Protected_Entry_Index), Loc))));
end Build_Protected_Entry_Specification;
--------------------------
-- Build_Protected_Spec --
--------------------------
function Build_Protected_Spec
(N : Node_Id;
Obj_Type : Entity_Id;
Unprotected : Boolean := False;
Ident : Entity_Id)
return List_Id
is
Loc : constant Source_Ptr := Sloc (N);
Formal : Entity_Id;
New_Plist : List_Id;
New_Param : Node_Id;
begin
New_Plist := New_List;
Formal := First_Formal (Ident);
while Present (Formal) loop
New_Param :=
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Sloc (Formal), Chars (Formal)),
In_Present => In_Present (Parent (Formal)),
Out_Present => Out_Present (Parent (Formal)),
Parameter_Type =>
New_Reference_To (Etype (Formal), Loc));
if Unprotected then
Set_Protected_Formal (Formal, Defining_Identifier (New_Param));
end if;
Append (New_Param, New_Plist);
Next_Formal (Formal);
end loop;
-- If the subprogram is a procedure and the context is not an access
-- to protected subprogram, the parameter is in-out. Otherwise it is
-- an in parameter.
Prepend_To (New_Plist,
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uObject),
In_Present => True,
Out_Present =>
(Etype (Ident) = Standard_Void_Type
and then not Is_RTE (Obj_Type, RE_Address)),
Parameter_Type => New_Reference_To (Obj_Type, Loc)));
return New_Plist;
end Build_Protected_Spec;
---------------------------------------
-- Build_Protected_Sub_Specification --
---------------------------------------
function Build_Protected_Sub_Specification
(N : Node_Id;
Prottyp : Entity_Id;
Unprotected : Boolean := False)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (N);
Decl : Node_Id;
Protnm : constant Name_Id := Chars (Prottyp);
Ident : Entity_Id;
Nam : Name_Id;
New_Plist : List_Id;
Append_Char : Character;
New_Spec : Node_Id;
begin
if Ekind
(Defining_Unit_Name (Specification (N))) = E_Subprogram_Body
then
Decl := Unit_Declaration_Node (Corresponding_Spec (N));
else
Decl := N;
end if;
Ident := Defining_Unit_Name (Specification (Decl));
Nam := Chars (Ident);
New_Plist := Build_Protected_Spec
(Decl, Corresponding_Record_Type (Prottyp),
Unprotected, Ident);
if Unprotected then
Append_Char := 'N';
else
Append_Char := 'P';
end if;
if Nkind (Specification (Decl)) = N_Procedure_Specification then
return
Make_Procedure_Specification (Loc,
Defining_Unit_Name =>
Make_Defining_Identifier (Loc,
Chars => Build_Selected_Name (Protnm, Nam, Append_Char)),
Parameter_Specifications => New_Plist);
else
New_Spec :=
Make_Function_Specification (Loc,
Defining_Unit_Name =>
Make_Defining_Identifier (Loc,
Chars => Build_Selected_Name (Protnm, Nam, Append_Char)),
Parameter_Specifications => New_Plist,
Subtype_Mark => New_Copy (Subtype_Mark (Specification (Decl))));
Set_Return_Present (Defining_Unit_Name (New_Spec));
return New_Spec;
end if;
end Build_Protected_Sub_Specification;
-------------------------------------
-- Build_Protected_Subprogram_Body --
-------------------------------------
function Build_Protected_Subprogram_Body
(N : Node_Id;
Pid : Node_Id;
N_Op_Spec : Node_Id)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (N);
Op_Spec : Node_Id;
Op_Def : Entity_Id;
Sub_Name : Name_Id;
P_Op_Spec : Node_Id;
Uactuals : List_Id;
Pformal : Node_Id;
Unprot_Call : Node_Id;
Sub_Body : Node_Id;
Lock_Name : Node_Id;
Lock_Stmt : Node_Id;
Unlock_Name : Node_Id;
Unlock_Stmt : Node_Id;
Service_Name : Node_Id;
Service_Stmt : Node_Id;
R : Node_Id;
Return_Stmt : Node_Id := Empty;
Pre_Stmts : List_Id := No_List;
-- Initializations to avoid spurious warnings from GCC3.
Stmts : List_Id;
Object_Parm : Node_Id;
Exc_Safe : Boolean;
function Is_Exception_Safe (Subprogram : Node_Id) return Boolean;
-- Tell whether a given subprogram cannot raise an exception
-----------------------
-- Is_Exception_Safe --
-----------------------
function Is_Exception_Safe (Subprogram : Node_Id) return Boolean is
function Has_Side_Effect (N : Node_Id) return Boolean;
-- Return True whenever encountering a subprogram call or a
-- raise statement of any kind in the sequence of statements N
---------------------
-- Has_Side_Effect --
---------------------
-- What is this doing buried two levels down in exp_ch9. It
-- seems like a generally useful function, and indeed there
-- may be code duplication going on here ???
function Has_Side_Effect (N : Node_Id) return Boolean is
Stmt : Node_Id := N;
Expr : Node_Id;
function Is_Call_Or_Raise (N : Node_Id) return Boolean;
-- Indicate whether N is a subprogram call or a raise statement
function Is_Call_Or_Raise (N : Node_Id) return Boolean is
begin
return Nkind (N) = N_Procedure_Call_Statement
or else Nkind (N) = N_Function_Call
or else Nkind (N) = N_Raise_Statement
or else Nkind (N) = N_Raise_Constraint_Error
or else Nkind (N) = N_Raise_Program_Error
or else Nkind (N) = N_Raise_Storage_Error;
end Is_Call_Or_Raise;
-- Start of processing for Has_Side_Effect
begin
while Present (Stmt) loop
if Is_Call_Or_Raise (Stmt) then
return True;
end if;
-- An object declaration can also contain a function call
-- or a raise statement
if Nkind (Stmt) = N_Object_Declaration then
Expr := Expression (Stmt);
if Present (Expr) and then Is_Call_Or_Raise (Expr) then
return True;
end if;
end if;
Next (Stmt);
end loop;
return False;
end Has_Side_Effect;
-- Start of processing for Is_Exception_Safe
begin
-- If the checks handled by the back end are not disabled, we cannot
-- ensure that no exception will be raised.
if not Access_Checks_Suppressed (Empty)
or else not Discriminant_Checks_Suppressed (Empty)
or else not Range_Checks_Suppressed (Empty)
or else not Index_Checks_Suppressed (Empty)
or else Opt.Stack_Checking_Enabled
then
return False;
end if;
if Has_Side_Effect (First (Declarations (Subprogram)))
or else
Has_Side_Effect (
First (Statements (Handled_Statement_Sequence (Subprogram))))
then
return False;
else
return True;
end if;
end Is_Exception_Safe;
-- Start of processing for Build_Protected_Subprogram_Body
begin
Op_Spec := Specification (N);
Op_Def := Defining_Unit_Name (Op_Spec);
Exc_Safe := Is_Exception_Safe (N);
Sub_Name := Chars (Defining_Unit_Name (Specification (N)));
P_Op_Spec :=
Build_Protected_Sub_Specification (N,
Pid, Unprotected => False);
-- Build a list of the formal parameters of the protected
-- version of the subprogram to use as the actual parameters
-- of the unprotected version.
Uactuals := New_List;
Pformal := First (Parameter_Specifications (P_Op_Spec));
while Present (Pformal) loop
Append (
Make_Identifier (Loc, Chars (Defining_Identifier (Pformal))),
Uactuals);
Next (Pformal);
end loop;
-- Make a call to the unprotected version of the subprogram
-- built above for use by the protected version built below.
if Nkind (Op_Spec) = N_Function_Specification then
if Exc_Safe then
R := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
Unprot_Call :=
Make_Object_Declaration (Loc,
Defining_Identifier => R,
Constant_Present => True,
Object_Definition => New_Copy (Subtype_Mark (N_Op_Spec)),
Expression =>
Make_Function_Call (Loc,
Name => Make_Identifier (Loc,
Chars (Defining_Unit_Name (N_Op_Spec))),
Parameter_Associations => Uactuals));
Return_Stmt := Make_Return_Statement (Loc,
Expression => New_Reference_To (R, Loc));
else
Unprot_Call := Make_Return_Statement (Loc,
Expression => Make_Function_Call (Loc,
Name =>
Make_Identifier (Loc,
Chars (Defining_Unit_Name (N_Op_Spec))),
Parameter_Associations => Uactuals));
end if;
else
Unprot_Call := Make_Procedure_Call_Statement (Loc,
Name =>
Make_Identifier (Loc,
Chars (Defining_Unit_Name (N_Op_Spec))),
Parameter_Associations => Uactuals);
end if;
-- Wrap call in block that will be covered by an at_end handler.
if not Exc_Safe then
Unprot_Call := Make_Block_Statement (Loc,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Unprot_Call)));
end if;
-- Make the protected subprogram body. This locks the protected
-- object and calls the unprotected version of the subprogram.
-- If the protected object is controlled (i.e it has entries or
-- needs finalization for interrupt handling), call Lock_Entries,
-- except if the protected object follows the Ravenscar profile, in
-- which case call Lock_Entry, otherwise call the simplified version,
-- Lock.
if Has_Entries (Pid)
or else Has_Interrupt_Handler (Pid)
or else Has_Attach_Handler (Pid)
then
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Pid) > 1
then
Lock_Name := New_Reference_To (RTE (RE_Lock_Entries), Loc);
Unlock_Name := New_Reference_To (RTE (RE_Unlock_Entries), Loc);
Service_Name := New_Reference_To (RTE (RE_Service_Entries), Loc);
else
Lock_Name := New_Reference_To (RTE (RE_Lock_Entry), Loc);
Unlock_Name := New_Reference_To (RTE (RE_Unlock_Entry), Loc);
Service_Name := New_Reference_To (RTE (RE_Service_Entry), Loc);
end if;
else
Lock_Name := New_Reference_To (RTE (RE_Lock), Loc);
Unlock_Name := New_Reference_To (RTE (RE_Unlock), Loc);
Service_Name := Empty;
end if;
Object_Parm :=
Make_Attribute_Reference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix =>
Make_Identifier (Loc, Name_uObject),
Selector_Name =>
Make_Identifier (Loc, Name_uObject)),
Attribute_Name => Name_Unchecked_Access);
Lock_Stmt := Make_Procedure_Call_Statement (Loc,
Name => Lock_Name,
Parameter_Associations => New_List (Object_Parm));
if Abort_Allowed then
Stmts := New_List (
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Abort_Defer), Loc),
Parameter_Associations => Empty_List),
Lock_Stmt);
else
Stmts := New_List (Lock_Stmt);
end if;
if not Exc_Safe then
Append (Unprot_Call, Stmts);
else
if Nkind (Op_Spec) = N_Function_Specification then
Pre_Stmts := Stmts;
Stmts := Empty_List;
else
Append (Unprot_Call, Stmts);
end if;
if Service_Name /= Empty then
Service_Stmt := Make_Procedure_Call_Statement (Loc,
Name => Service_Name,
Parameter_Associations =>
New_List (New_Copy_Tree (Object_Parm)));
Append (Service_Stmt, Stmts);
end if;
Unlock_Stmt :=
Make_Procedure_Call_Statement (Loc,
Name => Unlock_Name,
Parameter_Associations => New_List (
New_Copy_Tree (Object_Parm)));
Append (Unlock_Stmt, Stmts);
if Abort_Allowed then
Append (
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc),
Parameter_Associations => Empty_List),
Stmts);
end if;
if Nkind (Op_Spec) = N_Function_Specification then
Append (Return_Stmt, Stmts);
Append (Make_Block_Statement (Loc,
Declarations => New_List (Unprot_Call),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stmts)), Pre_Stmts);
Stmts := Pre_Stmts;
end if;
end if;
Sub_Body :=
Make_Subprogram_Body (Loc,
Declarations => Empty_List,
Specification => P_Op_Spec,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts));
if not Exc_Safe then
Set_Is_Protected_Subprogram_Body (Sub_Body);
end if;
return Sub_Body;
end Build_Protected_Subprogram_Body;
-------------------------------------
-- Build_Protected_Subprogram_Call --
-------------------------------------
procedure Build_Protected_Subprogram_Call
(N : Node_Id;
Name : Node_Id;
Rec : Node_Id;
External : Boolean := True)
is
Loc : constant Source_Ptr := Sloc (N);
Sub : Entity_Id := Entity (Name);
New_Sub : Node_Id;
Params : List_Id;
begin
if External then
New_Sub := New_Occurrence_Of (External_Subprogram (Sub), Loc);
else
New_Sub :=
New_Occurrence_Of (Protected_Body_Subprogram (Sub), Loc);
end if;
if Present (Parameter_Associations (N)) then
Params := New_Copy_List_Tree (Parameter_Associations (N));
else
Params := New_List;
end if;
Prepend (Rec, Params);
if Ekind (Sub) = E_Procedure then
Rewrite (N,
Make_Procedure_Call_Statement (Loc,
Name => New_Sub,
Parameter_Associations => Params));
else
pragma Assert (Ekind (Sub) = E_Function);
Rewrite (N,
Make_Function_Call (Loc,
Name => New_Sub,
Parameter_Associations => Params));
end if;
if External
and then Nkind (Rec) = N_Unchecked_Type_Conversion
and then Is_Entity_Name (Expression (Rec))
and then Is_Shared_Passive (Entity (Expression (Rec)))
then
Add_Shared_Var_Lock_Procs (N);
end if;
end Build_Protected_Subprogram_Call;
-------------------------
-- Build_Selected_Name --
-------------------------
function Build_Selected_Name
(Prefix, Selector : Name_Id;
Append_Char : Character := ' ')
return Name_Id
is
Select_Buffer : String (1 .. Hostparm.Max_Name_Length);
Select_Len : Natural;
begin
Get_Name_String (Selector);
Select_Len := Name_Len;
Select_Buffer (1 .. Select_Len) := Name_Buffer (1 .. Name_Len);
Get_Name_String (Prefix);
-- If scope is anonymous type, discard suffix to recover name of
-- single protected object. Otherwise use protected type name.
if Name_Buffer (Name_Len) = 'T' then
Name_Len := Name_Len - 1;
end if;
Name_Buffer (Name_Len + 1) := 'P';
Name_Buffer (Name_Len + 2) := 'T';
Name_Buffer (Name_Len + 3) := '_';
Name_Buffer (Name_Len + 4) := '_';
Name_Len := Name_Len + 4;
for J in 1 .. Select_Len loop
Name_Len := Name_Len + 1;
Name_Buffer (Name_Len) := Select_Buffer (J);
end loop;
if Append_Char /= ' ' then
Name_Len := Name_Len + 1;
Name_Buffer (Name_Len) := Append_Char;
end if;
return Name_Find;
end Build_Selected_Name;
-----------------------------
-- Build_Simple_Entry_Call --
-----------------------------
-- A task entry call is converted to a call to Call_Simple
-- declare
-- P : parms := (parm, parm, parm);
-- begin
-- Call_Simple (acceptor-task, entry-index, P'Address);
-- parm := P.param;
-- parm := P.param;
-- ...
-- end;
-- Here Pnn is an aggregate of the type constructed for the entry to hold
-- the parameters, and the constructed aggregate value contains either the
-- parameters or, in the case of non-elementary types, references to these
-- parameters. Then the address of this aggregate is passed to the runtime
-- routine, along with the task id value and the task entry index value.
-- Pnn is only required if parameters are present.
-- The assignments after the call are present only in the case of in-out
-- or out parameters for elementary types, and are used to assign back the
-- resulting values of such parameters.
-- Note: the reason that we insert a block here is that in the context
-- of selects, conditional entry calls etc. the entry call statement
-- appears on its own, not as an element of a list.
-- A protected entry call is converted to a Protected_Entry_Call:
-- declare
-- P : E1_Params := (param, param, param);
-- Pnn : Boolean;
-- Bnn : Communications_Block;
-- declare
-- P : E1_Params := (param, param, param);
-- Bnn : Communications_Block;
-- begin
-- Protected_Entry_Call (
-- Object => po._object'Access,
-- E => <entry index>;
-- Uninterpreted_Data => P'Address;
-- Mode => Simple_Call;
-- Block => Bnn);
-- parm := P.param;
-- parm := P.param;
-- ...
-- end;
procedure Build_Simple_Entry_Call
(N : Node_Id;
Concval : Node_Id;
Ename : Node_Id;
Index : Node_Id)
is
begin
Expand_Call (N);
-- Convert entry call to Call_Simple call
declare
Loc : constant Source_Ptr := Sloc (N);
Parms : constant List_Id := Parameter_Associations (N);
Pdecl : Node_Id;
Xdecl : Node_Id;
Decls : List_Id;
Conctyp : Node_Id;
Ent : Entity_Id;
Ent_Acc : Entity_Id;
P : Entity_Id;
X : Entity_Id;
Plist : List_Id;
Parm1 : Node_Id;
Parm2 : Node_Id;
Parm3 : Node_Id;
Call : Node_Id;
Actual : Node_Id;
Formal : Node_Id;
N_Node : Node_Id;
N_Var : Node_Id;
Stats : List_Id := New_List;
Comm_Name : Entity_Id;
begin
-- Simple entry and entry family cases merge here
Ent := Entity (Ename);
Ent_Acc := Entry_Parameters_Type (Ent);
Conctyp := Etype (Concval);
-- If prefix is an access type, dereference to obtain the task type
if Is_Access_Type (Conctyp) then
Conctyp := Designated_Type (Conctyp);
end if;
-- Special case for protected subprogram calls.
if Is_Protected_Type (Conctyp)
and then Is_Subprogram (Entity (Ename))
then
Build_Protected_Subprogram_Call
(N, Ename, Convert_Concurrent (Concval, Conctyp));
Analyze (N);
return;
end if;
-- First parameter is the Task_Id value from the task value or the
-- Object from the protected object value, obtained by selecting
-- the _Task_Id or _Object from the result of doing an unchecked
-- conversion to convert the value to the corresponding record type.
Parm1 := Concurrent_Ref (Concval);
-- Second parameter is the entry index, computed by the routine
-- provided for this purpose. The value of this expression is
-- assigned to an intermediate variable to assure that any entry
-- family index expressions are evaluated before the entry
-- parameters.
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else not Is_Protected_Type (Conctyp)
or else Number_Entries (Conctyp) > 1
then
X := Make_Defining_Identifier (Loc, Name_uX);
Xdecl :=
Make_Object_Declaration (Loc,
Defining_Identifier => X,
Object_Definition =>
New_Reference_To (RTE (RE_Task_Entry_Index), Loc),
Expression => Actual_Index_Expression (
Loc, Entity (Ename), Index, Concval));
Decls := New_List (Xdecl);
Parm2 := New_Reference_To (X, Loc);
else
Xdecl := Empty;
Decls := New_List;
Parm2 := Empty;
end if;
-- The third parameter is the packaged parameters. If there are
-- none, then it is just the null address, since nothing is passed
if No (Parms) then
Parm3 := New_Reference_To (RTE (RE_Null_Address), Loc);
P := Empty;
-- Case of parameters present, where third argument is the address
-- of a packaged record containing the required parameter values.
else
-- First build a list of parameter values, which are
-- references to objects of the parameter types.
Plist := New_List;
Actual := First_Actual (N);
Formal := First_Formal (Ent);
while Present (Actual) loop
-- If it is a by_copy_type, copy it to a new variable. The
-- packaged record has a field that points to this variable.
if Is_By_Copy_Type (Etype (Actual)) then
N_Node :=
Make_Object_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc,
Chars => New_Internal_Name ('I')),
Aliased_Present => True,
Object_Definition =>
New_Reference_To (Etype (Formal), Loc));
-- We have to make an assignment statement separate for
-- the case of limited type. We can not assign it unless
-- the Assignment_OK flag is set first.
if Ekind (Formal) /= E_Out_Parameter then
N_Var :=
New_Reference_To (Defining_Identifier (N_Node), Loc);
Set_Assignment_OK (N_Var);
Append_To (Stats,
Make_Assignment_Statement (Loc,
Name => N_Var,
Expression => Relocate_Node (Actual)));
end if;
Append (N_Node, Decls);
Append_To (Plist,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Unchecked_Access,
Prefix =>
New_Reference_To (Defining_Identifier (N_Node), Loc)));
else
Append_To (Plist,
Make_Reference (Loc, Prefix => Relocate_Node (Actual)));
end if;
Next_Actual (Actual);
Next_Formal_With_Extras (Formal);
end loop;
-- Now build the declaration of parameters initialized with the
-- aggregate containing this constructed parameter list.
P := Make_Defining_Identifier (Loc, Name_uP);
Pdecl :=
Make_Object_Declaration (Loc,
Defining_Identifier => P,
Object_Definition =>
New_Reference_To (Designated_Type (Ent_Acc), Loc),
Expression =>
Make_Aggregate (Loc, Expressions => Plist));
Parm3 :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Address,
Prefix => New_Reference_To (P, Loc));
Append (Pdecl, Decls);
end if;
-- Now we can create the call, case of protected type
if Is_Protected_Type (Conctyp) then
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Conctyp) > 1
then
-- Change the type of the index declaration
Set_Object_Definition (Xdecl,
New_Reference_To (RTE (RE_Protected_Entry_Index), Loc));
-- Some additional declarations for protected entry calls
if No (Decls) then
Decls := New_List;
end if;
-- Bnn : Communications_Block;
Comm_Name :=
Make_Defining_Identifier (Loc, New_Internal_Name ('B'));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Comm_Name,
Object_Definition =>
New_Reference_To (RTE (RE_Communication_Block), Loc)));
-- Some additional statements for protected entry calls
-- Protected_Entry_Call (
-- Object => po._object'Access,
-- E => <entry index>;
-- Uninterpreted_Data => P'Address;
-- Mode => Simple_Call;
-- Block => Bnn);
Call :=
Make_Procedure_Call_Statement (Loc,
Name =>
New_Reference_To (RTE (RE_Protected_Entry_Call), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Unchecked_Access,
Prefix => Parm1),
Parm2,
Parm3,
New_Reference_To (RTE (RE_Simple_Call), Loc),
New_Occurrence_Of (Comm_Name, Loc)));
else
-- Protected_Single_Entry_Call (
-- Object => po._object'Access,
-- Uninterpreted_Data => P'Address;
-- Mode => Simple_Call);
Call :=
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (
RTE (RE_Protected_Single_Entry_Call), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Unchecked_Access,
Prefix => Parm1),
Parm3,
New_Reference_To (RTE (RE_Simple_Call), Loc)));
end if;
-- Case of task type
else
Call :=
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Call_Simple), Loc),
Parameter_Associations => New_List (Parm1, Parm2, Parm3));
end if;
Append_To (Stats, Call);
-- If there are out or in/out parameters by copy
-- add assignment statements for the result values.
if Present (Parms) then
Actual := First_Actual (N);
Formal := First_Formal (Ent);
Set_Assignment_OK (Actual);
while Present (Actual) loop
if Is_By_Copy_Type (Etype (Actual))
and then Ekind (Formal) /= E_In_Parameter
then
N_Node :=
Make_Assignment_Statement (Loc,
Name => New_Copy (Actual),
Expression =>
Make_Explicit_Dereference (Loc,
Make_Selected_Component (Loc,
Prefix => New_Reference_To (P, Loc),
Selector_Name =>
Make_Identifier (Loc, Chars (Formal)))));
-- In all cases (including limited private types) we
-- want the assignment to be valid.
Set_Assignment_OK (Name (N_Node));
-- If the call is the triggering alternative in an
-- asynchronous select, or the entry_call alternative
-- of a conditional entry call, the assignments for in-out
-- parameters are incorporated into the statement list
-- that follows, so that there are executed only if the
-- entry call succeeds.
if (Nkind (Parent (N)) = N_Triggering_Alternative
and then N = Triggering_Statement (Parent (N)))
or else
(Nkind (Parent (N)) = N_Entry_Call_Alternative
and then N = Entry_Call_Statement (Parent (N)))
then
if No (Statements (Parent (N))) then
Set_Statements (Parent (N), New_List);
end if;
Prepend (N_Node, Statements (Parent (N)));
else
Insert_After (Call, N_Node);
end if;
end if;
Next_Actual (Actual);
Next_Formal_With_Extras (Formal);
end loop;
end if;
-- Finally, create block and analyze it
Rewrite (N,
Make_Block_Statement (Loc,
Declarations => Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stats)));
Analyze (N);
end;
end Build_Simple_Entry_Call;
--------------------------------
-- Build_Task_Activation_Call --
--------------------------------
procedure Build_Task_Activation_Call (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Chain : Entity_Id;
Call : Node_Id;
Name : Node_Id;
P : Node_Id;
begin
-- Get the activation chain entity. Except in the case of a package
-- body, this is in the node that was passed. For a package body, we
-- have to find the corresponding package declaration node.
if Nkind (N) = N_Package_Body then
P := Corresponding_Spec (N);
loop
P := Parent (P);
exit when Nkind (P) = N_Package_Declaration;
end loop;
Chain := Activation_Chain_Entity (P);
else
Chain := Activation_Chain_Entity (N);
end if;
if Present (Chain) then
if Restricted_Profile then
Name := New_Reference_To (RTE (RE_Activate_Restricted_Tasks), Loc);
else
Name := New_Reference_To (RTE (RE_Activate_Tasks), Loc);
end if;
Call :=
Make_Procedure_Call_Statement (Loc,
Name => Name,
Parameter_Associations =>
New_List (Make_Attribute_Reference (Loc,
Prefix => New_Occurrence_Of (Chain, Loc),
Attribute_Name => Name_Unchecked_Access)));
if Nkind (N) = N_Package_Declaration then
if Present (Corresponding_Body (N)) then
null;
elsif Present (Private_Declarations (Specification (N))) then
Append (Call, Private_Declarations (Specification (N)));
else
Append (Call, Visible_Declarations (Specification (N)));
end if;
else
if Present (Handled_Statement_Sequence (N)) then
-- The call goes at the start of the statement sequence, but
-- after the start of exception range label if one is present.
declare
Stm : Node_Id;
begin
Stm := First (Statements (Handled_Statement_Sequence (N)));
if Nkind (Stm) = N_Label and then Exception_Junk (Stm) then
Next (Stm);
end if;
Insert_Before (Stm, Call);
end;
else
Set_Handled_Statement_Sequence (N,
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Call)));
end if;
end if;
Analyze (Call);
Check_Task_Activation (N);
end if;
end Build_Task_Activation_Call;
-------------------------------
-- Build_Task_Allocate_Block --
-------------------------------
procedure Build_Task_Allocate_Block
(Actions : List_Id;
N : Node_Id;
Args : List_Id)
is
T : constant Entity_Id := Entity (Expression (N));
Init : constant Entity_Id := Base_Init_Proc (T);
Loc : constant Source_Ptr := Sloc (N);
Chain : Entity_Id := Make_Defining_Identifier (Loc, Name_uChain);
Blkent : Entity_Id;
Block : Node_Id;
begin
Blkent := Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
Block :=
Make_Block_Statement (Loc,
Identifier => New_Reference_To (Blkent, Loc),
Declarations => New_List (
-- _Chain : Activation_Chain;
Make_Object_Declaration (Loc,
Defining_Identifier => Chain,
Aliased_Present => True,
Object_Definition =>
New_Reference_To (RTE (RE_Activation_Chain), Loc))),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
-- Init (Args);
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (Init, Loc),
Parameter_Associations => Args),
-- Activate_Tasks (_Chain);
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Activate_Tasks), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Chain, Loc),
Attribute_Name => Name_Unchecked_Access))))),
Has_Created_Identifier => True,
Is_Task_Allocation_Block => True);
Append_To (Actions,
Make_Implicit_Label_Declaration (Loc,
Defining_Identifier => Blkent,
Label_Construct => Block));
Append_To (Actions, Block);
Set_Activation_Chain_Entity (Block, Chain);
end Build_Task_Allocate_Block;
-----------------------------------
-- Build_Task_Proc_Specification --
-----------------------------------
function Build_Task_Proc_Specification (T : Entity_Id) return Node_Id is
Loc : constant Source_Ptr := Sloc (T);
Nam : constant Name_Id := Chars (T);
Tdec : constant Node_Id := Declaration_Node (T);
Ent : Entity_Id;
begin
Ent :=
Make_Defining_Identifier (Loc,
Chars => New_External_Name (Nam, 'B'));
Set_Is_Internal (Ent);
-- Associate the procedure with the task, if this is the declaration
-- (and not the body) of the procedure.
if No (Task_Body_Procedure (Tdec)) then
Set_Task_Body_Procedure (Tdec, Ent);
end if;
return
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Ent,
Parameter_Specifications =>
New_List (
Make_Parameter_Specification (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uTask),
Parameter_Type =>
Make_Access_Definition (Loc,
Subtype_Mark =>
New_Reference_To
(Corresponding_Record_Type (T), Loc)))));
end Build_Task_Proc_Specification;
---------------------------------------
-- Build_Unprotected_Subprogram_Body --
---------------------------------------
function Build_Unprotected_Subprogram_Body
(N : Node_Id;
Pid : Node_Id)
return Node_Id
is
Loc : constant Source_Ptr := Sloc (N);
Sub_Name : Name_Id;
N_Op_Spec : Node_Id;
Op_Decls : List_Id;
begin
-- Make an unprotected version of the subprogram for use
-- within the same object, with a new name and an additional
-- parameter representing the object.
Op_Decls := Declarations (N);
Sub_Name := Chars (Defining_Unit_Name (Specification (N)));
N_Op_Spec :=
Build_Protected_Sub_Specification
(N, Pid, Unprotected => True);
return
Make_Subprogram_Body (Loc,
Specification => N_Op_Spec,
Declarations => Op_Decls,
Handled_Statement_Sequence =>
Handled_Statement_Sequence (N));
end Build_Unprotected_Subprogram_Body;
----------------------------
-- Collect_Entry_Families --
----------------------------
procedure Collect_Entry_Families
(Loc : Source_Ptr;
Cdecls : List_Id;
Current_Node : in out Node_Id;
Conctyp : Entity_Id)
is
Efam : Entity_Id;
Efam_Decl : Node_Id;
Efam_Type : Entity_Id;
begin
Efam := First_Entity (Conctyp);
while Present (Efam) loop
if Ekind (Efam) = E_Entry_Family then
Efam_Type :=
Make_Defining_Identifier (Loc,
Chars => New_Internal_Name ('F'));
Efam_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Efam_Type,
Type_Definition =>
Make_Unconstrained_Array_Definition (Loc,
Subtype_Marks => (New_List (
New_Occurrence_Of (
Base_Type
(Etype (Discrete_Subtype_Definition
(Parent (Efam)))), Loc))),
Subtype_Indication =>
New_Reference_To (Standard_Character, Loc)));
Insert_After (Current_Node, Efam_Decl);
Current_Node := Efam_Decl;
Analyze (Efam_Decl);
Append_To (Cdecls,
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Chars (Efam)),
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark =>
New_Occurrence_Of (Efam_Type, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => New_List (
New_Occurrence_Of
(Etype (Discrete_Subtype_Definition
(Parent (Efam))), Loc))))));
end if;
Next_Entity (Efam);
end loop;
end Collect_Entry_Families;
--------------------
-- Concurrent_Ref --
--------------------
-- The expression returned for a reference to a concurrent
-- object has the form:
-- taskV!(name)._Task_Id
-- for a task, and
-- objectV!(name)._Object
-- for a protected object.
-- For the case of an access to a concurrent object,
-- there is an extra explicit dereference:
-- taskV!(name.all)._Task_Id
-- objectV!(name.all)._Object
-- here taskV and objectV are the types for the associated records, which
-- contain the required _Task_Id and _Object fields for tasks and
-- protected objects, respectively.
-- For the case of a task type name, the expression is
-- Self;
-- i.e. a call to the Self function which returns precisely this Task_Id
-- For the case of a protected type name, the expression is
-- objectR
-- which is a renaming of the _object field of the current object
-- object record, passed into protected operations as a parameter.
function Concurrent_Ref (N : Node_Id) return Node_Id is
Loc : constant Source_Ptr := Sloc (N);
Ntyp : constant Entity_Id := Etype (N);
Dtyp : Entity_Id;
Sel : Name_Id;
function Is_Current_Task (T : Entity_Id) return Boolean;
-- Check whether the reference is to the immediately enclosing task
-- type, or to an outer one (rare but legal).
---------------------
-- Is_Current_Task --
---------------------
function Is_Current_Task (T : Entity_Id) return Boolean is
Scop : Entity_Id;
begin
Scop := Current_Scope;
while Present (Scop)
and then Scop /= Standard_Standard
loop
if Scop = T then
return True;
elsif Is_Task_Type (Scop) then
return False;
-- If this is a procedure nested within the task type, we must
-- assume that it can be called from an inner task, and therefore
-- cannot treat it as a local reference.
elsif Is_Overloadable (Scop)
and then In_Open_Scopes (T)
then
return False;
else
Scop := Scope (Scop);
end if;
end loop;
-- We know that we are within the task body, so should have
-- found it in scope.
raise Program_Error;
end Is_Current_Task;
-- Start of processing for Concurrent_Ref
begin
if Is_Access_Type (Ntyp) then
Dtyp := Designated_Type (Ntyp);
if Is_Protected_Type (Dtyp) then
Sel := Name_uObject;
else
Sel := Name_uTask_Id;
end if;
return
Make_Selected_Component (Loc,
Prefix =>
Unchecked_Convert_To (Corresponding_Record_Type (Dtyp),
Make_Explicit_Dereference (Loc, N)),
Selector_Name => Make_Identifier (Loc, Sel));
elsif Is_Entity_Name (N)
and then Is_Concurrent_Type (Entity (N))
then
if Is_Task_Type (Entity (N)) then
if Is_Current_Task (Entity (N)) then
return
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Self), Loc));
else
declare
Decl : Node_Id;
T_Self : constant Entity_Id
:= Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
T_Body : constant Node_Id
:= Parent (Corresponding_Body (Parent (Entity (N))));
begin
Decl := Make_Object_Declaration (Loc,
Defining_Identifier => T_Self,
Object_Definition =>
New_Occurrence_Of (RTE (RO_ST_Task_ID), Loc),
Expression =>
Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Self), Loc)));
Prepend (Decl, Declarations (T_Body));
Analyze (Decl);
Set_Scope (T_Self, Entity (N));
return New_Occurrence_Of (T_Self, Loc);
end;
end if;
else
pragma Assert (Is_Protected_Type (Entity (N)));
return
New_Reference_To (
Object_Ref (Corresponding_Body (Parent (Base_Type (Ntyp)))),
Loc);
end if;
else
pragma Assert (Is_Concurrent_Type (Ntyp));
if Is_Protected_Type (Ntyp) then
Sel := Name_uObject;
else
Sel := Name_uTask_Id;
end if;
return
Make_Selected_Component (Loc,
Prefix =>
Unchecked_Convert_To (Corresponding_Record_Type (Ntyp),
New_Copy_Tree (N)),
Selector_Name => Make_Identifier (Loc, Sel));
end if;
end Concurrent_Ref;
------------------------
-- Convert_Concurrent --
------------------------
function Convert_Concurrent
(N : Node_Id;
Typ : Entity_Id)
return Node_Id
is
begin
if not Is_Concurrent_Type (Typ) then
return N;
else
return
Unchecked_Convert_To (Corresponding_Record_Type (Typ),
New_Copy_Tree (N));
end if;
end Convert_Concurrent;
----------------------------
-- Entry_Index_Expression --
----------------------------
function Entry_Index_Expression
(Sloc : Source_Ptr;
Ent : Entity_Id;
Index : Node_Id;
Ttyp : Entity_Id)
return Node_Id
is
Expr : Node_Id;
Num : Node_Id;
Lo : Node_Id;
Hi : Node_Id;
Prev : Entity_Id;
S : Node_Id;
begin
-- The queues of entries and entry families appear in textual
-- order in the associated record. The entry index is computed as
-- the sum of the number of queues for all entries that precede the
-- designated one, to which is added the index expression, if this
-- expression denotes a member of a family.
-- The following is a place holder for the count of simple entries.
Num := Make_Integer_Literal (Sloc, 1);
-- We construct an expression which is a series of addition
-- operations. The first operand is the number of single entries that
-- precede this one, the second operand is the index value relative
-- to the start of the referenced family, and the remaining operands
-- are the lengths of the entry families that precede this entry, i.e.
-- the constructed expression is:
-- number_simple_entries +
-- (s'pos (index-value) - s'pos (family'first)) + 1 +
-- family'length + ...
-- where index-value is the given index value, and s is the index
-- subtype (we have to use pos because the subtype might be an
-- enumeration type preventing direct subtraction).
-- Note that the task entry array is one-indexed.
-- The upper bound of the entry family may be a discriminant, so we
-- retrieve the lower bound explicitly to compute offset, rather than
-- using the index subtype which may mention a discriminant.
if Present (Index) then
S := Etype (Discrete_Subtype_Definition (Declaration_Node (Ent)));
Expr :=
Make_Op_Add (Sloc,
Left_Opnd => Num,
Right_Opnd =>
Family_Offset (
Sloc,
Make_Attribute_Reference (Sloc,
Attribute_Name => Name_Pos,
Prefix => New_Reference_To (Base_Type (S), Sloc),
Expressions => New_List (Relocate_Node (Index))),
Type_Low_Bound (S),
Ttyp));
else
Expr := Num;
end if;
-- Now add lengths of preceding entries and entry families.
Prev := First_Entity (Ttyp);
while Chars (Prev) /= Chars (Ent)
or else (Ekind (Prev) /= Ekind (Ent))
or else not Sem_Ch6.Type_Conformant (Ent, Prev)
loop
if Ekind (Prev) = E_Entry then
Set_Intval (Num, Intval (Num) + 1);
elsif Ekind (Prev) = E_Entry_Family then
S :=
Etype (Discrete_Subtype_Definition (Declaration_Node (Prev)));
Lo := Type_Low_Bound (S);
Hi := Type_High_Bound (S);
Expr :=
Make_Op_Add (Sloc,
Left_Opnd => Expr,
Right_Opnd => Family_Size (Sloc, Hi, Lo, Ttyp));
-- Other components are anonymous types to be ignored.
else
null;
end if;
Next_Entity (Prev);
end loop;
return Expr;
end Entry_Index_Expression;
---------------------------
-- Establish_Task_Master --
---------------------------
procedure Establish_Task_Master (N : Node_Id) is
Call : Node_Id;
begin
if Restrictions (No_Task_Hierarchy) = False then
Call := Build_Runtime_Call (Sloc (N), RE_Enter_Master);
Prepend_To (Declarations (N), Call);
Analyze (Call);
end if;
end Establish_Task_Master;
--------------------------------
-- Expand_Accept_Declarations --
--------------------------------
-- Part of the expansion of an accept statement involves the creation of
-- a declaration that can be referenced from the statement sequence of
-- the accept:
-- Ann : Address;
-- This declaration is inserted immediately before the accept statement
-- and it is important that it be inserted before the statements of the
-- statement sequence are analyzed. Thus it would be too late to create
-- this declaration in the Expand_N_Accept_Statement routine, which is
-- why there is a separate procedure to be called directly from Sem_Ch9.
-- Ann is used to hold the address of the record containing the parameters
-- (see Expand_N_Entry_Call for more details on how this record is built).
-- References to the parameters do an unchecked conversion of this address
-- to a pointer to the required record type, and then access the field that
-- holds the value of the required parameter. The entity for the address
-- variable is held as the top stack element (i.e. the last element) of the
-- Accept_Address stack in the corresponding entry entity, and this element
-- must be set in place before the statements are processed.
-- The above description applies to the case of a stand alone accept
-- statement, i.e. one not appearing as part of a select alternative.
-- For the case of an accept that appears as part of a select alternative
-- of a selective accept, we must still create the declaration right away,
-- since Ann is needed immediately, but there is an important difference:
-- The declaration is inserted before the selective accept, not before
-- the accept statement (which is not part of a list anyway, and so would
-- not accommodate inserted declarations)
-- We only need one address variable for the entire selective accept. So
-- the Ann declaration is created only for the first accept alternative,
-- and subsequent accept alternatives reference the same Ann variable.
-- We can distinguish the two cases by seeing whether the accept statement
-- is part of a list. If not, then it must be in an accept alternative.
-- To expand the requeue statement, a label is provided at the end of
-- the accept statement or alternative of which it is a part, so that
-- the statement can be skipped after the requeue is complete.
-- This label is created here rather than during the expansion of the
-- accept statement, because it will be needed by any requeue
-- statements within the accept, which are expanded before the
-- accept.
procedure Expand_Accept_Declarations (N : Node_Id; Ent : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
Ann : Entity_Id := Empty;
Adecl : Node_Id;
Lab_Id : Node_Id;
Lab : Node_Id;
Ldecl : Node_Id;
Ldecl2 : Node_Id;
begin
if Expander_Active then
-- If we have no handled statement sequence, then build a dummy
-- sequence consisting of a null statement. This is only done if
-- pragma FIFO_Within_Priorities is specified. The issue here is
-- that even a null accept body has an effect on the called task
-- in terms of its position in the queue, so we cannot optimize
-- the context switch away. However, if FIFO_Within_Priorities
-- is not active, the optimization is legitimate, since we can
-- say that our dispatching policy (i.e. the default dispatching
-- policy) reorders the queue to be the same as just before the
-- call. In the absence of a specified dispatching policy, we are
-- allowed to modify queue orders for a given priority at will!
if Opt.Task_Dispatching_Policy = 'F' and then
not Present (Handled_Statement_Sequence (N))
then
Set_Handled_Statement_Sequence (N,
Make_Handled_Sequence_Of_Statements (Loc,
New_List (Make_Null_Statement (Loc))));
end if;
-- Create and declare two labels to be placed at the end of the
-- accept statement. The first label is used to allow requeues to
-- skip the remainder of entry processing. The second label is
-- used to skip the remainder of entry processing if the rendezvous
-- completes in the middle of the accept body.
if Present (Handled_Statement_Sequence (N)) then
Lab_Id := Make_Identifier (Loc, New_Internal_Name ('L'));
Set_Entity (Lab_Id,
Make_Defining_Identifier (Loc, Chars (Lab_Id)));
Lab := Make_Label (Loc, Lab_Id);
Ldecl :=
Make_Implicit_Label_Declaration (Loc,
Defining_Identifier => Entity (Lab_Id),
Label_Construct => Lab);
Append (Lab, Statements (Handled_Statement_Sequence (N)));
Lab_Id := Make_Identifier (Loc, New_Internal_Name ('L'));
Set_Entity (Lab_Id,
Make_Defining_Identifier (Loc, Chars (Lab_Id)));
Lab := Make_Label (Loc, Lab_Id);
Ldecl2 :=
Make_Implicit_Label_Declaration (Loc,
Defining_Identifier => Entity (Lab_Id),
Label_Construct => Lab);
Append (Lab, Statements (Handled_Statement_Sequence (N)));
else
Ldecl := Empty;
Ldecl2 := Empty;
end if;
-- Case of stand alone accept statement
if Is_List_Member (N) then
if Present (Handled_Statement_Sequence (N)) then
Ann :=
Make_Defining_Identifier (Loc,
Chars => New_Internal_Name ('A'));
Adecl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Ann,
Object_Definition =>
New_Reference_To (RTE (RE_Address), Loc));
Insert_Before (N, Adecl);
Analyze (Adecl);
Insert_Before (N, Ldecl);
Analyze (Ldecl);
Insert_Before (N, Ldecl2);
Analyze (Ldecl2);
end if;
-- Case of accept statement which is in an accept alternative
else
declare
Acc_Alt : constant Node_Id := Parent (N);
Sel_Acc : constant Node_Id := Parent (Acc_Alt);
Alt : Node_Id;
begin
pragma Assert (Nkind (Acc_Alt) = N_Accept_Alternative);
pragma Assert (Nkind (Sel_Acc) = N_Selective_Accept);
-- ??? Consider a single label for select statements.
if Present (Handled_Statement_Sequence (N)) then
Prepend (Ldecl2,
Statements (Handled_Statement_Sequence (N)));
Analyze (Ldecl2);
Prepend (Ldecl,
Statements (Handled_Statement_Sequence (N)));
Analyze (Ldecl);
end if;
-- Find first accept alternative of the selective accept. A
-- valid selective accept must have at least one accept in it.
Alt := First (Select_Alternatives (Sel_Acc));
while Nkind (Alt) /= N_Accept_Alternative loop
Next (Alt);
end loop;
-- If we are the first accept statement, then we have to
-- create the Ann variable, as for the stand alone case,
-- except that it is inserted before the selective accept.
-- Similarly, a label for requeue expansion must be
-- declared.
if N = Accept_Statement (Alt) then
Ann :=
Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
Adecl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Ann,
Object_Definition =>
New_Reference_To (RTE (RE_Address), Loc));
Insert_Before (Sel_Acc, Adecl);
Analyze (Adecl);
-- If we are not the first accept statement, then find the
-- Ann variable allocated by the first accept and use it.
else
Ann :=
Node (Last_Elmt (Accept_Address
(Entity (Entry_Direct_Name (Accept_Statement (Alt))))));
end if;
end;
end if;
-- Merge here with Ann either created or referenced, and Adecl
-- pointing to the corresponding declaration. Remaining processing
-- is the same for the two cases.
if Present (Ann) then
Append_Elmt (Ann, Accept_Address (Ent));
end if;
end if;
end Expand_Accept_Declarations;
---------------------------------------------
-- Expand_Access_Protected_Subprogram_Type --
---------------------------------------------
procedure Expand_Access_Protected_Subprogram_Type (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Comps : List_Id;
T : constant Entity_Id := Defining_Identifier (N);
D_T : constant Entity_Id := Designated_Type (T);
D_T2 : constant Entity_Id := Make_Defining_Identifier
(Loc, New_Internal_Name ('D'));
E_T : constant Entity_Id := Make_Defining_Identifier
(Loc, New_Internal_Name ('E'));
P_List : constant List_Id := Build_Protected_Spec
(N, RTE (RE_Address), False, D_T);
Decl1 : Node_Id;
Decl2 : Node_Id;
Def1 : Node_Id;
begin
-- Create access to protected subprogram with full signature.
if Nkind (Type_Definition (N)) = N_Access_Function_Definition then
Def1 :=
Make_Access_Function_Definition (Loc,
Parameter_Specifications => P_List,
Subtype_Mark => New_Copy (Subtype_Mark (Type_Definition (N))));
else
Def1 :=
Make_Access_Procedure_Definition (Loc,
Parameter_Specifications => P_List);
end if;
Decl1 :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => D_T2,
Type_Definition => Def1);
Insert_After (N, Decl1);
-- Create Equivalent_Type, a record with two components for an
-- an access to object an an access to subprogram.
Comps := New_List (
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, New_Internal_Name ('P')),
Subtype_Indication =>
New_Occurrence_Of (RTE (RE_Address), Loc)),
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, New_Internal_Name ('S')),
Subtype_Indication =>
New_Occurrence_Of (D_T2, Loc)));
Decl2 :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => E_T,
Type_Definition =>
Make_Record_Definition (Loc,
Component_List =>
Make_Component_List (Loc,
Component_Items => Comps)));
Insert_After (Decl1, Decl2);
Set_Equivalent_Type (T, E_T);
end Expand_Access_Protected_Subprogram_Type;
--------------------------
-- Expand_Entry_Barrier --
--------------------------
procedure Expand_Entry_Barrier (N : Node_Id; Ent : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
Func : Node_Id;
B_F : Node_Id;
Prot : constant Entity_Id := Scope (Ent);
Spec_Decl : Node_Id := Parent (Prot);
Body_Decl : Node_Id;
Cond : Node_Id := Condition (Entry_Body_Formal_Part (N));
begin
-- The body of the entry barrier must be analyzed in the context of
-- the protected object, but its scope is external to it, just as any
-- other unprotected version of a protected operation. The specification
-- has been produced when the protected type declaration was elaborated.
-- We build the body, insert it in the enclosing scope, but analyze it
-- in the current context. A more uniform approach would be to treat a
-- barrier just as a protected function, and discard the protected
-- version of it because it is never called.
if Expander_Active then
B_F := Build_Barrier_Function (N, Ent, Prot);
Func := Barrier_Function (Ent);
Set_Corresponding_Spec (B_F, Func);
Body_Decl := Parent (Corresponding_Body (Spec_Decl));
if Nkind (Parent (Body_Decl)) = N_Subunit then
Body_Decl := Corresponding_Stub (Parent (Body_Decl));
end if;
Insert_Before_And_Analyze (Body_Decl, B_F);
Update_Prival_Subtypes (B_F);
Set_Privals (Spec_Decl, N, Loc);
Set_Discriminals (Spec_Decl, N, Loc);
Set_Scope (Func, Scope (Prot));
else
Analyze (Cond);
end if;
-- The Ravenscar profile restricts barriers to simple variables
-- declared within the protected object. We also allow Boolean
-- constants, since these appear in several published examples
-- and are also allowed by the Aonix compiler.
-- Note that after analysis variables in this context will be
-- replaced by the corresponding prival, that is to say a renaming
-- of a selected component of the form _Object.Var. If expansion is
-- disabled, as within a generic, we check that the entity appears in
-- the current scope.
if Is_Entity_Name (Cond) then
if Entity (Cond) = Standard_False
or else
Entity (Cond) = Standard_True
then
return;
elsif not Expander_Active
and then Scope (Entity (Cond)) = Current_Scope
then
return;
elsif Present (Renamed_Object (Entity (Cond)))
and then
Nkind (Renamed_Object (Entity (Cond))) = N_Selected_Component
and then
Chars (Prefix (Renamed_Object (Entity (Cond)))) = Name_uObject
then
return;
end if;
end if;
-- It is not a boolean variable or literal, so check the restriction
Check_Restriction (Boolean_Entry_Barriers, Cond);
end Expand_Entry_Barrier;
------------------------------------
-- Expand_Entry_Body_Declarations --
------------------------------------
procedure Expand_Entry_Body_Declarations (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Index_Spec : Node_Id;
begin
if Expander_Active then
-- Expand entry bodies corresponding to entry families
-- by assigning a placeholder for the constant that will
-- be used to expand references to the entry index parameter.
Index_Spec :=
Entry_Index_Specification (Entry_Body_Formal_Part (N));
if Present (Index_Spec) then
Set_Entry_Index_Constant (
Defining_Identifier (Index_Spec),
Make_Defining_Identifier (Loc, New_Internal_Name ('I')));
end if;
end if;
end Expand_Entry_Body_Declarations;
------------------------------
-- Expand_N_Abort_Statement --
------------------------------
-- Expand abort T1, T2, .. Tn; into:
-- Abort_Tasks (Task_List'(1 => T1.Task_Id, 2 => T2.Task_Id ...))
procedure Expand_N_Abort_Statement (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Tlist : constant List_Id := Names (N);
Count : Nat;
Aggr : Node_Id;
Tasknm : Node_Id;
begin
Aggr := Make_Aggregate (Loc, Component_Associations => New_List);
Count := 0;
Tasknm := First (Tlist);
while Present (Tasknm) loop
Count := Count + 1;
Append_To (Component_Associations (Aggr),
Make_Component_Association (Loc,
Choices => New_List (
Make_Integer_Literal (Loc, Count)),
Expression => Concurrent_Ref (Tasknm)));
Next (Tasknm);
end loop;
Rewrite (N,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Abort_Tasks), Loc),
Parameter_Associations => New_List (
Make_Qualified_Expression (Loc,
Subtype_Mark => New_Reference_To (RTE (RE_Task_List), Loc),
Expression => Aggr))));
Analyze (N);
end Expand_N_Abort_Statement;
-------------------------------
-- Expand_N_Accept_Statement --
-------------------------------
-- This procedure handles expansion of accept statements that stand
-- alone, i.e. they are not part of an accept alternative. The expansion
-- of accept statement in accept alternatives is handled by the routines
-- Expand_N_Accept_Alternative and Expand_N_Selective_Accept. The
-- following description applies only to stand alone accept statements.
-- If there is no handled statement sequence, or only null statements,
-- then this is called a trivial accept, and the expansion is:
-- Accept_Trivial (entry-index)
-- If there is a handled statement sequence, then the expansion is:
-- Ann : Address;
-- {Lnn : Label}
-- begin
-- begin
-- Accept_Call (entry-index, Ann);
-- <statement sequence from N_Accept_Statement node>
-- Complete_Rendezvous;
-- <<Lnn>>
--
-- exception
-- when ... =>
-- <exception handler from N_Accept_Statement node>
-- Complete_Rendezvous;
-- when ... =>
-- <exception handler from N_Accept_Statement node>
-- Complete_Rendezvous;
-- ...
-- end;
-- exception
-- when all others =>
-- Exceptional_Complete_Rendezvous (Get_GNAT_Exception);
-- end;
-- The first three declarations were already inserted ahead of the
-- accept statement by the Expand_Accept_Declarations procedure, which
-- was called directly from the semantics during analysis of the accept.
-- statement, before analyzing its contained statements.
-- The declarations from the N_Accept_Statement, as noted in Sinfo, come
-- from possible expansion activity (the original source of course does
-- not have any declarations associated with the accept statement, since
-- an accept statement has no declarative part). In particular, if the
-- expander is active, the first such declaration is the declaration of
-- the Accept_Params_Ptr entity (see Sem_Ch9.Analyze_Accept_Statement).
--
-- The two blocks are merged into a single block if the inner block has
-- no exception handlers, but otherwise two blocks are required, since
-- exceptions might be raised in the exception handlers of the inner
-- block, and Exceptional_Complete_Rendezvous must be called.
procedure Expand_N_Accept_Statement (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Stats : constant Node_Id := Handled_Statement_Sequence (N);
Ename : constant Node_Id := Entry_Direct_Name (N);
Eindx : constant Node_Id := Entry_Index (N);
Eent : constant Entity_Id := Entity (Ename);
Acstack : constant Elist_Id := Accept_Address (Eent);
Ann : constant Entity_Id := Node (Last_Elmt (Acstack));
Ttyp : constant Entity_Id := Etype (Scope (Eent));
Call : Node_Id;
Block : Node_Id;
function Null_Statements (Stats : List_Id) return Boolean;
-- Check for null statement sequence (i.e a list of labels and
-- null statements)
function Null_Statements (Stats : List_Id) return Boolean is
Stmt : Node_Id;
begin
Stmt := First (Stats);
while Nkind (Stmt) /= N_Empty
and then (Nkind (Stmt) = N_Null_Statement
or else
Nkind (Stmt) = N_Label)
loop
Next (Stmt);
end loop;
return Nkind (Stmt) = N_Empty;
end Null_Statements;
-- Start of processing for Expand_N_Accept_Statement
begin
-- If accept statement is not part of a list, then its parent must be
-- an accept alternative, and, as described above, we do not do any
-- expansion for such accept statements at this level.
if not Is_List_Member (N) then
pragma Assert (Nkind (Parent (N)) = N_Accept_Alternative);
return;
-- Trivial accept case (no statement sequence, or null statements).
-- If the accept statement has declarations, then just insert them
-- before the procedure call.
-- We avoid this optimization when FIFO_Within_Priorities is active,
-- since it is not correct according to annex D semantics. The problem
-- is that the call is required to reorder the acceptors position on
-- its ready queue, even though there is nothing to be done. However,
-- if no policy is specified, then we decide that our dispatching
-- policy always reorders the queue right after the RV to look the
-- way they were just before the RV. Since we are allowed to freely
-- reorder same-priority queues (this is part of what dispatching
-- policies are all about), the optimization is legitimate.
elsif Opt.Task_Dispatching_Policy /= 'F'
and then (No (Stats) or else Null_Statements (Statements (Stats)))
then
if Present (Declarations (N)) then
Insert_Actions (N, Declarations (N));
end if;
Rewrite (N,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Accept_Trivial), Loc),
Parameter_Associations => New_List (
Entry_Index_Expression (Loc, Entity (Ename), Eindx, Ttyp))));
Analyze (N);
-- Discard Entry_Address that was created for it, so it will not be
-- emitted if this accept statement is in the statement part of a
-- delay alternative.
if Present (Stats) then
Remove_Last_Elmt (Acstack);
end if;
-- Case of statement sequence present
else
-- Construct the block, using the declarations from the accept
-- statement if any to initialize the declarations of the block.
Block :=
Make_Block_Statement (Loc,
Declarations => Declarations (N),
Handled_Statement_Sequence => Build_Accept_Body (N));
-- Prepend call to Accept_Call to main statement sequence
Call :=
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Accept_Call), Loc),
Parameter_Associations => New_List (
Entry_Index_Expression (Loc, Entity (Ename), Eindx, Ttyp),
New_Reference_To (Ann, Loc)));
Prepend (Call, Statements (Stats));
Analyze (Call);
-- Replace the accept statement by the new block
Rewrite (N, Block);
Analyze (N);
-- Last step is to unstack the Accept_Address value
Remove_Last_Elmt (Acstack);
end if;
end Expand_N_Accept_Statement;
----------------------------------
-- Expand_N_Asynchronous_Select --
----------------------------------
-- This procedure assumes that the trigger statement is an entry
-- call. A delay alternative should already have been expanded
-- into an entry call to the appropriate delay object Wait entry.
-- If the trigger is a task entry call, the select is implemented
-- with Task_Entry_Call:
-- declare
-- B : Boolean;
-- C : Boolean;
-- P : parms := (parm, parm, parm);
--
-- -- Clean is added by Exp_Ch7.Expand_Cleanup_Actions.
--
-- procedure _clean is
-- begin
-- ...
-- Cancel_Task_Entry_Call (C);
-- ...
-- end _clean;
-- begin
-- Abort_Defer;
-- Task_Entry_Call
-- (acceptor-task,
-- entry-index,
-- P'Address,
-- Asynchronous_Call,
-- B);
-- begin
-- begin
-- Abort_Undefer;
-- abortable-part
-- at end
-- _clean; -- Added by Exp_Ch7.Expand_Cleanup_Actions.
-- end;
-- exception
-- when Abort_Signal => Abort_Undefer;
-- end;
-- parm := P.param;
-- parm := P.param;
-- ...
-- if not C then
-- triggered-statements
-- end if;
-- end;
-- Note that Build_Simple_Entry_Call is used to expand the entry
-- of the asynchronous entry call (by the
-- Expand_N_Entry_Call_Statement procedure) as follows:
-- declare
-- P : parms := (parm, parm, parm);
-- begin
-- Call_Simple (acceptor-task, entry-index, P'Address);
-- parm := P.param;
-- parm := P.param;
-- ...
-- end;
-- so the task at hand is to convert the latter expansion into the former
-- If the trigger is a protected entry call, the select is
-- implemented with Protected_Entry_Call:
-- declare
-- P : E1_Params := (param, param, param);
-- Bnn : Communications_Block;
-- begin
-- declare
--
-- -- Clean is added by Exp_Ch7.Expand_Cleanup_Actions.
--
-- procedure _clean is
-- begin
-- ...
-- if Enqueued (Bnn) then
-- Cancel_Protected_Entry_Call (Bnn);
-- end if;
-- ...
-- end _clean;
-- begin
-- begin
-- Protected_Entry_Call (
-- Object => po._object'Access,
-- E => <entry index>;
-- Uninterpreted_Data => P'Address;
-- Mode => Asynchronous_Call;
-- Block => Bnn);
-- if Enqueued (Bnn) then
-- <abortable part>
-- end if;
-- at end
-- _clean; -- Added by Exp_Ch7.Expand_Cleanup_Actions.
-- end;
-- exception
-- when Abort_Signal =>
-- Abort_Undefer;
-- null;
-- end;
-- if not Cancelled (Bnn) then
-- triggered statements
-- end if;
-- end;
-- Build_Simple_Entry_Call is used to expand the all to a simple
-- protected entry call:
-- declare
-- P : E1_Params := (param, param, param);
-- Bnn : Communications_Block;
-- begin
-- Protected_Entry_Call (
-- Object => po._object'Access,
-- E => <entry index>;
-- Uninterpreted_Data => P'Address;
-- Mode => Simple_Call;
-- Block => Bnn);
-- parm := P.param;
-- parm := P.param;
-- ...
-- end;
-- The job is to convert this to the asynchronous form.
-- If the trigger is a delay statement, it will have been expanded
-- into a call to one of the GNARL delay procedures. This routine
-- will convert this into a protected entry call on a delay object
-- and then continue processing as for a protected entry call trigger.
-- This requires declaring a Delay_Block object and adding a pointer
-- to this object to the parameter list of the delay procedure to form
-- the parameter list of the entry call. This object is used by
-- the runtime to queue the delay request.
-- For a description of the use of P and the assignments after the
-- call, see Expand_N_Entry_Call_Statement.
procedure Expand_N_Asynchronous_Select (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Trig : constant Node_Id := Triggering_Alternative (N);
Abrt : constant Node_Id := Abortable_Part (N);
Tstats : constant List_Id := Statements (Trig);
Ecall : Node_Id;
Astats : List_Id := Statements (Abrt);
Concval : Node_Id;
Ename : Node_Id;
Index : Node_Id;
Hdle : List_Id;
Decls : List_Id;
Decl : Node_Id;
Parms : List_Id;
Parm : Node_Id;
Call : Node_Id;
Stmts : List_Id;
Enqueue_Call : Node_Id;
Stmt : Node_Id;
B : Entity_Id;
Pdef : Entity_Id;
Dblock_Ent : Entity_Id;
N_Orig : Node_Id;
Abortable_Block : Node_Id;
Cancel_Param : Entity_Id;
Blkent : Entity_Id;
Target_Undefer : RE_Id;
Undefer_Args : List_Id := No_List;
begin
Blkent := Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
Ecall := Triggering_Statement (Trig);
-- The arguments in the call may require dynamic allocation, and the
-- call statement may have been transformed into a block. The block
-- may contain additional declarations for internal entities, and the
-- original call is found by sequential search.
if Nkind (Ecall) = N_Block_Statement then
Ecall := First (Statements (Handled_Statement_Sequence (Ecall)));
while Nkind (Ecall) /= N_Procedure_Call_Statement
and then Nkind (Ecall) /= N_Entry_Call_Statement
loop
Next (Ecall);
end loop;
end if;
-- If a delay was used as a trigger, it will have been expanded
-- into a procedure call. Convert it to the appropriate sequence of
-- statements, similar to what is done for a task entry call.
-- Note that this currently supports only Duration, Real_Time.Time,
-- and Calendar.Time.
if Nkind (Ecall) = N_Procedure_Call_Statement then
-- Add a Delay_Block object to the parameter list of the
-- delay procedure to form the parameter list of the Wait
-- entry call.
Dblock_Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('D'));
Pdef := Entity (Name (Ecall));
if Is_RTE (Pdef, RO_CA_Delay_For) then
Enqueue_Call := New_Reference_To (RTE (RE_Enqueue_Duration), Loc);
elsif Is_RTE (Pdef, RO_CA_Delay_Until) then
Enqueue_Call := New_Reference_To (RTE (RE_Enqueue_Calendar), Loc);
else pragma Assert (Is_RTE (Pdef, RO_RT_Delay_Until));
Enqueue_Call := New_Reference_To (RTE (RE_Enqueue_RT), Loc);
end if;
Append_To (Parameter_Associations (Ecall),
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Dblock_Ent, Loc),
Attribute_Name => Name_Unchecked_Access));
-- Create the inner block to protect the abortable part.
Hdle := New_List (
Make_Exception_Handler (Loc,
Exception_Choices =>
New_List (New_Reference_To (Stand.Abort_Signal, Loc)),
Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc)))));
Prepend_To (Astats,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc)));
Abortable_Block :=
Make_Block_Statement (Loc,
Identifier => New_Reference_To (Blkent, Loc),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Astats),
Has_Created_Identifier => True,
Is_Asynchronous_Call_Block => True);
-- Append call to if Enqueue (When, DB'Unchecked_Access) then
Rewrite (Ecall,
Make_Implicit_If_Statement (N,
Condition => Make_Function_Call (Loc,
Name => Enqueue_Call,
Parameter_Associations => Parameter_Associations (Ecall)),
Then_Statements =>
New_List (Make_Block_Statement (Loc,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Implicit_Label_Declaration (Loc,
Defining_Identifier => Blkent,
Label_Construct => Abortable_Block),
Abortable_Block),
Exception_Handlers => Hdle)))));
Stmts := New_List (Ecall);
-- Construct statement sequence for new block
Append_To (Stmts,
Make_Implicit_If_Statement (N,
Condition => Make_Function_Call (Loc,
Name => New_Reference_To (
RTE (RE_Timed_Out), Loc),
Parameter_Associations => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Dblock_Ent, Loc),
Attribute_Name => Name_Unchecked_Access))),
Then_Statements => Tstats));
-- The result is the new block
Set_Entry_Cancel_Parameter (Blkent, Dblock_Ent);
Rewrite (N,
Make_Block_Statement (Loc,
Declarations => New_List (
Make_Object_Declaration (Loc,
Defining_Identifier => Dblock_Ent,
Aliased_Present => True,
Object_Definition => New_Reference_To (
RTE (RE_Delay_Block), Loc))),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc, Stmts)));
Analyze (N);
return;
else
N_Orig := N;
end if;
Extract_Entry (Ecall, Concval, Ename, Index);
Build_Simple_Entry_Call (Ecall, Concval, Ename, Index);
Stmts := Statements (Handled_Statement_Sequence (Ecall));
Decls := Declarations (Ecall);
if Is_Protected_Type (Etype (Concval)) then
-- Get the declarations of the block expanded from the entry call
Decl := First (Decls);
while Present (Decl)
and then (Nkind (Decl) /= N_Object_Declaration
or else not Is_RTE
(Etype (Object_Definition (Decl)), RE_Communication_Block))
loop
Next (Decl);
end loop;
pragma Assert (Present (Decl));
Cancel_Param := Defining_Identifier (Decl);
-- Change the mode of the Protected_Entry_Call call.
-- Protected_Entry_Call (
-- Object => po._object'Access,
-- E => <entry index>;
-- Uninterpreted_Data => P'Address;
-- Mode => Asynchronous_Call;
-- Block => Bnn);
Stmt := First (Stmts);
-- Skip assignments to temporaries created for in-out parameters.
-- This makes unwarranted assumptions about the shape of the expanded
-- tree for the call, and should be cleaned up ???
while Nkind (Stmt) /= N_Procedure_Call_Statement loop
Next (Stmt);
end loop;
Call := Stmt;
Parm := First (Parameter_Associations (Call));
while Present (Parm)
and then not Is_RTE (Etype (Parm), RE_Call_Modes)
loop
Next (Parm);
end loop;
pragma Assert (Present (Parm));
Rewrite (Parm, New_Reference_To (RTE (RE_Asynchronous_Call), Loc));
Analyze (Parm);
-- Append an if statement to execute the abortable part.
-- if Enqueued (Bnn) then
Append_To (Stmts,
Make_Implicit_If_Statement (N,
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 => Astats));
Abortable_Block :=
Make_Block_Statement (Loc,
Identifier => New_Reference_To (Blkent, Loc),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stmts),
Has_Created_Identifier => True,
Is_Asynchronous_Call_Block => True);
-- For the JVM call Update_Exception instead of Abort_Undefer.
-- See 4jexcept.ads for an explanation.
if Hostparm.Java_VM then
Target_Undefer := RE_Update_Exception;
Undefer_Args :=
New_List (Make_Function_Call (Loc,
Name => New_Occurrence_Of
(RTE (RE_Current_Target_Exception), Loc)));
else
Target_Undefer := RE_Abort_Undefer;
end if;
Stmts := New_List (
Make_Block_Statement (Loc,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Implicit_Label_Declaration (Loc,
Defining_Identifier => Blkent,
Label_Construct => Abortable_Block),
Abortable_Block),
-- exception
Exception_Handlers => New_List (
Make_Exception_Handler (Loc,
-- when Abort_Signal =>
-- Abort_Undefer.all;
Exception_Choices =>
New_List (New_Reference_To (Stand.Abort_Signal, Loc)),
Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (
RTE (Target_Undefer), Loc),
Parameter_Associations => Undefer_Args)))))),
-- if not Cancelled (Bnn) then
-- triggered statements
-- end if;
Make_Implicit_If_Statement (N,
Condition => Make_Op_Not (Loc,
Right_Opnd =>
Make_Function_Call (Loc,
Name => New_Occurrence_Of (RTE (RE_Cancelled), Loc),
Parameter_Associations => New_List (
New_Occurrence_Of (Cancel_Param, Loc)))),
Then_Statements => Tstats));
-- Asynchronous task entry call
else
if No (Decls) then
Decls := New_List;
end if;
B := Make_Defining_Identifier (Loc, Name_uB);
-- Insert declaration of B in declarations of existing block
Prepend_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => B,
Object_Definition => New_Reference_To (Standard_Boolean, Loc)));
Cancel_Param := Make_Defining_Identifier (Loc, Name_uC);
-- Insert declaration of C in declarations of existing block
Prepend_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Cancel_Param,
Object_Definition => New_Reference_To (Standard_Boolean, Loc)));
-- Remove and save the call to Call_Simple.
Stmt := First (Stmts);
-- Skip assignments to temporaries created for in-out parameters.
-- This makes unwarranted assumptions about the shape of the expanded
-- tree for the call, and should be cleaned up ???
while Nkind (Stmt) /= N_Procedure_Call_Statement loop
Next (Stmt);
end loop;
Call := Stmt;
-- Create the inner block to protect the abortable part.
Hdle := New_List (
Make_Exception_Handler (Loc,
Exception_Choices =>
New_List (New_Reference_To (Stand.Abort_Signal, Loc)),
Statements => New_List (
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc)))));
Prepend_To (Astats,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc)));
Abortable_Block :=
Make_Block_Statement (Loc,
Identifier => New_Reference_To (Blkent, Loc),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Astats),
Has_Created_Identifier => True,
Is_Asynchronous_Call_Block => True);
Insert_After (Call,
Make_Block_Statement (Loc,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Implicit_Label_Declaration (Loc,
Defining_Identifier => Blkent,
Label_Construct => Abortable_Block),
Abortable_Block),
Exception_Handlers => Hdle)));
-- Create new call statement
Parms := Parameter_Associations (Call);
Append_To (Parms, New_Reference_To (RTE (RE_Asynchronous_Call), Loc));
Append_To (Parms, New_Reference_To (B, Loc));
Rewrite (Call,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Task_Entry_Call), Loc),
Parameter_Associations => Parms));
-- Construct statement sequence for new block
Append_To (Stmts,
Make_Implicit_If_Statement (N,
Condition => Make_Op_Not (Loc,
New_Reference_To (Cancel_Param, Loc)),
Then_Statements => Tstats));
-- Protected the call against abortion
Prepend_To (Stmts,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Abort_Defer), Loc),
Parameter_Associations => Empty_List));
end if;
Set_Entry_Cancel_Parameter (Blkent, Cancel_Param);
-- The result is the new block
Rewrite (N_Orig,
Make_Block_Statement (Loc,
Declarations => Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc, Stmts)));
Analyze (N_Orig);
end Expand_N_Asynchronous_Select;
-------------------------------------
-- Expand_N_Conditional_Entry_Call --
-------------------------------------
-- The conditional task entry call is converted to a call to
-- Task_Entry_Call:
-- declare
-- B : Boolean;
-- P : parms := (parm, parm, parm);
-- begin
-- Task_Entry_Call
-- (acceptor-task,
-- entry-index,
-- P'Address,
-- Conditional_Call,
-- B);
-- parm := P.param;
-- parm := P.param;
-- ...
-- if B then
-- normal-statements
-- else
-- else-statements
-- end if;
-- end;
-- For a description of the use of P and the assignments after the
-- call, see Expand_N_Entry_Call_Statement. Note that the entry call
-- of the conditional entry call has already been expanded (by the
-- Expand_N_Entry_Call_Statement procedure) as follows:
-- declare
-- P : parms := (parm, parm, parm);
-- begin
-- ... info for in-out parameters
-- Call_Simple (acceptor-task, entry-index, P'Address);
-- parm := P.param;
-- parm := P.param;
-- ...
-- end;
-- so the task at hand is to convert the latter expansion into the former
-- The conditional protected entry call is converted to a call to
-- Protected_Entry_Call:
-- declare
-- P : parms := (parm, parm, parm);
-- Bnn : Communications_Block;
-- begin
-- Protected_Entry_Call (
-- Object => po._object'Access,
-- E => <entry index>;
-- Uninterpreted_Data => P'Address;
-- Mode => Conditional_Call;
-- Block => Bnn);
-- parm := P.param;
-- parm := P.param;
-- ...
-- if Cancelled (Bnn) then
-- else-statements
-- else
-- normal-statements
-- end if;
-- end;
-- As for tasks, the entry call of the conditional entry call has
-- already been expanded (by the Expand_N_Entry_Call_Statement procedure)
-- as follows:
-- declare
-- P : E1_Params := (param, param, param);
-- Bnn : Communications_Block;
-- begin
-- Protected_Entry_Call (
-- Object => po._object'Access,
-- E => <entry index>;
-- Uninterpreted_Data => P'Address;
-- Mode => Simple_Call;
-- Block => Bnn);
-- parm := P.param;
-- parm := P.param;
-- ...
-- end;
procedure Expand_N_Conditional_Entry_Call (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Alt : constant Node_Id := Entry_Call_Alternative (N);
Blk : Node_Id := Entry_Call_Statement (Alt);
Transient_Blk : Node_Id;
Parms : List_Id;
Parm : Node_Id;
Call : Node_Id;
Stmts : List_Id;
B : Entity_Id;
Decl : Node_Id;
Stmt : Node_Id;
begin
-- As described above, The entry alternative is transformed into a
-- block that contains the gnulli call, and possibly assignment
-- statements for in-out parameters. The gnulli call may itself be
-- rewritten into a transient block if some unconstrained parameters
-- require it. We need to retrieve the call to complete its parameter
-- list.
Transient_Blk :=
First_Real_Statement (Handled_Statement_Sequence (Blk));
if Present (Transient_Blk)
and then
Nkind (Transient_Blk) = N_Block_Statement
then
Blk := Transient_Blk;
end if;
Stmts := Statements (Handled_Statement_Sequence (Blk));
Stmt := First (Stmts);
while Nkind (Stmt) /= N_Procedure_Call_Statement loop
Next (Stmt);
end loop;
Call := Stmt;
Parms := Parameter_Associations (Call);
if Is_RTE (Entity (Name (Call)), RE_Protected_Entry_Call) then
-- Substitute Conditional_Entry_Call for Simple_Call
-- parameter.
Parm := First (Parms);
while Present (Parm)
and then not Is_RTE (Etype (Parm), RE_Call_Modes)
loop
Next (Parm);
end loop;
pragma Assert (Present (Parm));
Rewrite (Parm, New_Reference_To (RTE (RE_Conditional_Call), Loc));
Analyze (Parm);
-- Find the Communication_Block parameter for the call
-- to the Cancelled function.
Decl := First (Declarations (Blk));
while Present (Decl)
and then not
Is_RTE (Etype (Object_Definition (Decl)), RE_Communication_Block)
loop
Next (Decl);
end loop;
-- Add an if statement to execute the else part if the call
-- does not succeed (as indicated by the Cancelled predicate).
Append_To (Stmts,
Make_Implicit_If_Statement (N,
Condition => Make_Function_Call (Loc,
Name => New_Reference_To (RTE (RE_Cancelled), Loc),
Parameter_Associations => New_List (
New_Reference_To (Defining_Identifier (Decl), Loc))),
Then_Statements => Else_Statements (N),
Else_Statements => Statements (Alt)));
else
B := Make_Defining_Identifier (Loc, Name_uB);
-- Insert declaration of B in declarations of existing block
if No (Declarations (Blk)) then
Set_Declarations (Blk, New_List);
end if;
Prepend_To (Declarations (Blk),
Make_Object_Declaration (Loc,
Defining_Identifier => B,
Object_Definition => New_Reference_To (Standard_Boolean, Loc)));
-- Create new call statement
Append_To (Parms, New_Reference_To (RTE (RE_Conditional_Call), Loc));
Append_To (Parms, New_Reference_To (B, Loc));
Rewrite (Call,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Task_Entry_Call), Loc),
Parameter_Associations => Parms));
-- Construct statement sequence for new block
Append_To (Stmts,
Make_Implicit_If_Statement (N,
Condition => New_Reference_To (B, Loc),
Then_Statements => Statements (Alt),
Else_Statements => Else_Statements (N)));
end if;
-- The result is the new block
Rewrite (N,
Make_Block_Statement (Loc,
Declarations => Declarations (Blk),
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc, Stmts)));
Analyze (N);
end Expand_N_Conditional_Entry_Call;
---------------------------------------
-- Expand_N_Delay_Relative_Statement --
---------------------------------------
-- Delay statement is implemented as a procedure call to Delay_For
-- defined in Ada.Calendar.Delays in order to reduce the overhead of
-- simple delays imposed by the use of Protected Objects.
procedure Expand_N_Delay_Relative_Statement (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
begin
Rewrite (N,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RO_CA_Delay_For), Loc),
Parameter_Associations => New_List (Expression (N))));
Analyze (N);
end Expand_N_Delay_Relative_Statement;
------------------------------------
-- Expand_N_Delay_Until_Statement --
------------------------------------
-- Delay Until statement is implemented as a procedure call to
-- Delay_Until defined in Ada.Calendar.Delays and Ada.Real_Time.Delays.
procedure Expand_N_Delay_Until_Statement (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Typ : Entity_Id;
begin
if Is_RTE (Base_Type (Etype (Expression (N))), RO_CA_Time) then
Typ := RTE (RO_CA_Delay_Until);
else
Typ := RTE (RO_RT_Delay_Until);
end if;
Rewrite (N,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (Typ, Loc),
Parameter_Associations => New_List (Expression (N))));
Analyze (N);
end Expand_N_Delay_Until_Statement;
-------------------------
-- Expand_N_Entry_Body --
-------------------------
procedure Expand_N_Entry_Body (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Next_Op : Node_Id;
Dec : Node_Id := Parent (Current_Scope);
Ent_Formals : Node_Id := Entry_Body_Formal_Part (N);
Index_Spec : Node_Id := Entry_Index_Specification (Ent_Formals);
begin
-- Add the renamings for private declarations and discriminants.
Add_Discriminal_Declarations
(Declarations (N), Defining_Identifier (Dec), Name_uObject, Loc);
Add_Private_Declarations
(Declarations (N), Defining_Identifier (Dec), Name_uObject, Loc);
if Present (Index_Spec) then
Append_List_To (Declarations (N),
Index_Constant_Declaration
(N, Defining_Identifier (Index_Spec), Defining_Identifier (Dec)));
end if;
-- Associate privals and discriminals with the next protected
-- operation body to be expanded. These are used to expand
-- references to private data objects and discriminants,
-- respectively.
Next_Op := Next_Protected_Operation (N);
if Present (Next_Op) then
Set_Privals (Dec, Next_Op, Loc);
Set_Discriminals (Dec, Next_Op, Loc);
end if;
end Expand_N_Entry_Body;
-----------------------------------
-- Expand_N_Entry_Call_Statement --
-----------------------------------
-- An entry call is expanded into GNARLI calls to implement
-- a simple entry call (see Build_Simple_Entry_Call).
procedure Expand_N_Entry_Call_Statement (N : Node_Id) is
Concval : Node_Id;
Ename : Node_Id;
Index : Node_Id;
begin
-- If this entry call is part of an asynchronous select, don't
-- expand it here; it will be expanded with the select statement.
-- Don't expand timed entry calls either, as they are translated
-- into asynchronous entry calls.
-- ??? This whole approach is questionable; it may be better
-- to go back to allowing the expansion to take place and then
-- attempting to fix it up in Expand_N_Asynchronous_Select.
-- The tricky part is figuring out whether the expanded
-- call is on a task or protected entry.
if (Nkind (Parent (N)) /= N_Triggering_Alternative
or else N /= Triggering_Statement (Parent (N)))
and then (Nkind (Parent (N)) /= N_Entry_Call_Alternative
or else N /= Entry_Call_Statement (Parent (N))
or else Nkind (Parent (Parent (N))) /= N_Timed_Entry_Call)
then
Extract_Entry (N, Concval, Ename, Index);
Build_Simple_Entry_Call (N, Concval, Ename, Index);
end if;
end Expand_N_Entry_Call_Statement;
--------------------------------
-- Expand_N_Entry_Declaration --
--------------------------------
-- If there are parameters, then first, each of the formals is marked
-- by setting Is_Entry_Formal. Next a record type is built which is
-- used to hold the parameter values. The name of this record type is
-- entryP where entry is the name of the entry, with an additional
-- corresponding access type called entryPA. The record type has matching
-- components for each formal (the component names are the same as the
-- formal names). For elementary types, the component type matches the
-- formal type. For composite types, an access type is declared (with
-- the name formalA) which designates the formal type, and the type of
-- the component is this access type. Finally the Entry_Component of
-- each formal is set to reference the corresponding record component.
procedure Expand_N_Entry_Declaration (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Entry_Ent : constant Entity_Id := Defining_Identifier (N);
Components : List_Id;
Formal : Node_Id;
Ftype : Entity_Id;
Last_Decl : Node_Id;
Component : Entity_Id;
Ctype : Entity_Id;
Decl : Node_Id;
Rec_Ent : Entity_Id;
Acc_Ent : Entity_Id;
begin
Formal := First_Formal (Entry_Ent);
Last_Decl := N;
-- Most processing is done only if parameters are present
if Present (Formal) then
Components := New_List;
-- Loop through formals
while Present (Formal) loop
Set_Is_Entry_Formal (Formal);
Component :=
Make_Defining_Identifier (Sloc (Formal), Chars (Formal));
Set_Entry_Component (Formal, Component);
Set_Entry_Formal (Component, Formal);
Ftype := Etype (Formal);
-- Declare new access type and then append
Ctype :=
Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Ctype,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present => True,
Constant_Present => Ekind (Formal) = E_In_Parameter,
Subtype_Indication => New_Reference_To (Ftype, Loc)));
Insert_After (Last_Decl, Decl);
Last_Decl := Decl;
Append_To (Components,
Make_Component_Declaration (Loc,
Defining_Identifier => Component,
Subtype_Indication => New_Reference_To (Ctype, Loc)));
Next_Formal_With_Extras (Formal);
end loop;
-- Create the Entry_Parameter_Record declaration
Rec_Ent :=
Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Rec_Ent,
Type_Definition =>
Make_Record_Definition (Loc,
Component_List =>
Make_Component_List (Loc,
Component_Items => Components)));
Insert_After (Last_Decl, Decl);
Last_Decl := Decl;
-- Construct and link in the corresponding access type
Acc_Ent :=
Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
Set_Entry_Parameters_Type (Entry_Ent, Acc_Ent);
Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Acc_Ent,
Type_Definition =>
Make_Access_To_Object_Definition (Loc,
All_Present => True,
Subtype_Indication => New_Reference_To (Rec_Ent, Loc)));
Insert_After (Last_Decl, Decl);
Last_Decl := Decl;
end if;
end Expand_N_Entry_Declaration;
-----------------------------
-- Expand_N_Protected_Body --
-----------------------------
-- Protected bodies are expanded to the completion of the subprograms
-- created for the corresponding protected type. These are a protected
-- and unprotected version of each protected subprogram in the object,
-- a function to calculate each entry barrier, and a procedure to
-- execute the sequence of statements of each protected entry body.
-- For example, for protected type ptype:
-- function entB
-- (O : System.Address;
-- E : Protected_Entry_Index)
-- return Boolean
-- is
-- <discriminant renamings>
-- <private object renamings>
-- begin
-- return <barrier expression>;
-- end entB;
-- procedure pprocN (_object : in out poV;...) is
-- <discriminant renamings>
-- <private object renamings>
-- begin
-- <sequence of statements>
-- end pprocN;
-- procedure pproc (_object : in out poV;...) is
-- procedure _clean is
-- Pn : Boolean;
-- begin
-- ptypeS (_object, Pn);
-- Unlock (_object._object'Access);
-- Abort_Undefer.all;
-- end _clean;
-- begin
-- Abort_Defer.all;
-- Lock (_object._object'Access);
-- pprocN (_object;...);
-- at end
-- _clean;
-- end pproc;
-- function pfuncN (_object : poV;...) return Return_Type is
-- <discriminant renamings>
-- <private object renamings>
-- begin
-- <sequence of statements>
-- end pfuncN;
-- function pfunc (_object : poV) return Return_Type is
-- procedure _clean is
-- begin
-- Unlock (_object._object'Access);
-- Abort_Undefer.all;
-- end _clean;
-- begin
-- Abort_Defer.all;
-- Lock (_object._object'Access);
-- return pfuncN (_object);
-- at end
-- _clean;
-- end pfunc;
-- procedure entE
-- (O : System.Address;
-- P : System.Address;
-- E : Protected_Entry_Index)
-- is
-- <discriminant renamings>
-- <private object renamings>
-- type poVP is access poV;
-- _Object : ptVP := ptVP!(O);
-- begin
-- begin
-- <statement sequence>
-- Complete_Entry_Body (_Object._Object);
-- exception
-- when all others =>
-- Exceptional_Complete_Entry_Body (
-- _Object._Object, Get_GNAT_Exception);
-- end;
-- end entE;
-- The type poV is the record created for the protected type to hold
-- the state of the protected object.
procedure Expand_N_Protected_Body (N : Node_Id) is
Pid : constant Entity_Id := Corresponding_Spec (N);
Has_Entries : Boolean := False;
Op_Decl : Node_Id;
Op_Body : Node_Id;
Op_Id : Entity_Id;
New_Op_Body : Node_Id;
Current_Node : Node_Id;
Num_Entries : Natural := 0;
begin
if Nkind (Parent (N)) = N_Subunit then
-- This is the proper body corresponding to a stub. The declarations
-- must be inserted at the point of the stub, which is in the decla-
-- rative part of the parent unit.
Current_Node := Corresponding_Stub (Parent (N));
else
Current_Node := N;
end if;
Op_Body := First (Declarations (N));
-- The protected body is replaced with the bodies of its
-- protected operations, and the declarations for internal objects
-- that may have been created for entry family bounds.
Rewrite (N, Make_Null_Statement (Sloc (N)));
Analyze (N);
while Present (Op_Body) loop
case Nkind (Op_Body) is
when N_Subprogram_Declaration =>
null;
when N_Subprogram_Body =>
-- Exclude functions created to analyze defaults.
if not Is_Eliminated (Defining_Entity (Op_Body)) then
New_Op_Body :=
Build_Unprotected_Subprogram_Body (Op_Body, Pid);
Insert_After (Current_Node, New_Op_Body);
Current_Node := New_Op_Body;
Analyze (New_Op_Body);
Update_Prival_Subtypes (New_Op_Body);
-- Build the corresponding protected operation only if
-- this is a visible operation of the type, or if it is
-- an interrupt handler. Otherwise it is only callable
-- from within the object, and the unprotected version
-- is sufficient.
if Present (Corresponding_Spec (Op_Body)) then
Op_Decl :=
Unit_Declaration_Node (Corresponding_Spec (Op_Body));
if Nkind (Parent (Op_Decl)) = N_Protected_Definition
and then
(List_Containing (Op_Decl) =
Visible_Declarations (Parent (Op_Decl))
or else
Is_Interrupt_Handler
(Corresponding_Spec (Op_Body)))
then
New_Op_Body :=
Build_Protected_Subprogram_Body (
Op_Body, Pid, Specification (New_Op_Body));
Insert_After (Current_Node, New_Op_Body);
Analyze (New_Op_Body);
end if;
end if;
end if;
when N_Entry_Body =>
Op_Id := Defining_Identifier (Op_Body);
Has_Entries := True;
Num_Entries := Num_Entries + 1;
New_Op_Body := Build_Protected_Entry (Op_Body, Op_Id, Pid);
Insert_After (Current_Node, New_Op_Body);
Current_Node := New_Op_Body;
Analyze (New_Op_Body);
Update_Prival_Subtypes (New_Op_Body);
when N_Implicit_Label_Declaration =>
null;
when N_Itype_Reference =>
Insert_After (Current_Node, New_Copy (Op_Body));
when N_Freeze_Entity =>
New_Op_Body := New_Copy (Op_Body);
if Present (Entity (Op_Body))
and then Freeze_Node (Entity (Op_Body)) = Op_Body
then
Set_Freeze_Node (Entity (Op_Body), New_Op_Body);
end if;
Insert_After (Current_Node, New_Op_Body);
Current_Node := New_Op_Body;
Analyze (New_Op_Body);
when N_Pragma =>
New_Op_Body := New_Copy (Op_Body);
Insert_After (Current_Node, New_Op_Body);
Current_Node := New_Op_Body;
Analyze (New_Op_Body);
when N_Object_Declaration =>
pragma Assert (not Comes_From_Source (Op_Body));
New_Op_Body := New_Copy (Op_Body);
Insert_After (Current_Node, New_Op_Body);
Current_Node := New_Op_Body;
Analyze (New_Op_Body);
when others =>
raise Program_Error;
end case;
Next (Op_Body);
end loop;
-- Finally, create the body of the function that maps an entry index
-- into the corresponding body index, except when there is no entry,
-- or in a ravenscar-like profile (no abort, no entry queue, 1 entry)
if Has_Entries
and then (Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Num_Entries > 1)
then
New_Op_Body := Build_Find_Body_Index (Pid);
Insert_After (Current_Node, New_Op_Body);
Analyze (New_Op_Body);
end if;
end Expand_N_Protected_Body;
-----------------------------------------
-- Expand_N_Protected_Type_Declaration --
-----------------------------------------
-- First we create a corresponding record type declaration used to
-- represent values of this protected type.
-- The general form of this type declaration is
-- type poV (discriminants) is record
-- _Object : aliased <kind>Protection
-- [(<entry count> [, <handler count>])];
-- [entry_family : array (bounds) of Void;]
-- <private data fields>
-- end record;
-- The discriminants are present only if the corresponding protected
-- type has discriminants, and they exactly mirror the protected type
-- discriminants. The private data fields similarly mirror the
-- private declarations of the protected type.
-- The Object field is always present. It contains RTS specific data
-- used to control the protected object. It is declared as Aliased
-- so that it can be passed as a pointer to the RTS. This allows the
-- protected record to be referenced within RTS data structures.
-- An appropriate Protection type and discriminant are generated.
-- The Service field is present for protected objects with entries. It
-- contains sufficient information to allow the entry service procedure
-- for this object to be called when the object is not known till runtime.
-- One entry_family component is present for each entry family in the
-- task definition (see Expand_N_Task_Type_Declaration).
-- When a protected object is declared, an instance of the protected type
-- value record is created. The elaboration of this declaration creates
-- the correct bounds for the entry families, and also evaluates the
-- priority expression if needed. The initialization routine for
-- the protected type itself then calls Initialize_Protection with
-- appropriate parameters to initialize the value of the Task_Id field.
-- Install_Handlers may be also called if a pragma Attach_Handler applies.
-- Note: this record is passed to the subprograms created by the
-- expansion of protected subprograms and entries. It is an in parameter
-- to protected functions and an in out parameter to procedures and
-- entry bodies. The Entity_Id for this created record type is placed
-- in the Corresponding_Record_Type field of the associated protected
-- type entity.
-- Next we create a procedure specifications for protected subprograms
-- and entry bodies. For each protected subprograms two subprograms are
-- created, an unprotected and a protected version. The unprotected
-- version is called from within other operations of the same protected
-- object.
-- We also build the call to register the procedure if a pragma
-- Interrupt_Handler applies.
-- A single subprogram is created to service all entry bodies; it has an
-- additional boolean out parameter indicating that the previous entry
-- call made by the current task was serviced immediately, i.e. not by
-- proxy. The O parameter contains a pointer to a record object of the
-- type described above. An untyped interface is used here to allow this
-- procedure to be called in places where the type of the object to be
-- serviced is not known. This must be done, for example, when a call
-- that may have been requeued is cancelled; the corresponding object
-- must be serviced, but which object that is not known till runtime.
-- procedure ptypeS
-- (O : System.Address; P : out Boolean);
-- procedure pprocN (_object : in out poV);
-- procedure pproc (_object : in out poV);
-- function pfuncN (_object : poV);
-- function pfunc (_object : poV);
-- ...
-- Note that this must come after the record type declaration, since
-- the specs refer to this type.
procedure Expand_N_Protected_Type_Declaration (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Prottyp : constant Entity_Id := Defining_Identifier (N);
Protnm : constant Name_Id := Chars (Prottyp);
Pdef : constant Node_Id := Protected_Definition (N);
-- This contains two lists; one for visible and one for private decls
Rec_Decl : Node_Id;
Cdecls : List_Id;
Discr_Map : Elist_Id := New_Elmt_List;
Priv : Node_Id;
Pent : Entity_Id;
New_Priv : Node_Id;
Comp : Node_Id;
Comp_Id : Entity_Id;
Sub : Node_Id;
Current_Node : Node_Id := N;
Nam : Name_Id;
Bdef : Entity_Id := Empty; -- avoid uninit warning
Edef : Entity_Id := Empty; -- avoid uninit warning
Entries_Aggr : Node_Id;
Body_Id : Entity_Id;
Body_Arr : Node_Id;
E_Count : Int;
Object_Comp : Node_Id;
procedure Register_Handler;
-- for a protected operation that is an interrupt handler, add the
-- freeze action that will register it as such.
----------------------
-- Register_Handler --
----------------------
procedure Register_Handler is
-- All semantic checks already done in Sem_Prag
Prot_Proc : constant Entity_Id :=
Defining_Unit_Name
(Specification (Current_Node));
Proc_Address : constant Node_Id :=
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Prot_Proc, Loc),
Attribute_Name => Name_Address);
RTS_Call : constant Entity_Id :=
Make_Procedure_Call_Statement (Loc,
Name =>
New_Reference_To (
RTE (RE_Register_Interrupt_Handler), Loc),
Parameter_Associations =>
New_List (Proc_Address));
begin
Append_Freeze_Action (Prot_Proc, RTS_Call);
end Register_Handler;
-- Start of processing for Expand_N_Protected_Type_Declaration
begin
if Present (Corresponding_Record_Type (Prottyp)) then
return;
else
Rec_Decl := Build_Corresponding_Record (N, Prottyp, Loc);
Cdecls := Component_Items
(Component_List (Type_Definition (Rec_Decl)));
end if;
Qualify_Entity_Names (N);
-- If the type has discriminants, their occurrences in the declaration
-- have been replaced by the corresponding discriminals. For components
-- that are constrained by discriminants, their homologues in the
-- corresponding record type must refer to the discriminants of that
-- record, so we must apply a new renaming to subtypes_indications:
-- protected discriminant => discriminal => record discriminant.
-- This replacement is not applied to default expressions, for which
-- the discriminal is correct.
if Has_Discriminants (Prottyp) then
declare
Disc : Entity_Id;
Decl : Node_Id;
begin
Disc := First_Discriminant (Prottyp);
Decl := First (Discriminant_Specifications (Rec_Decl));
while Present (Disc) loop
Append_Elmt (Discriminal (Disc), Discr_Map);
Append_Elmt (Defining_Identifier (Decl), Discr_Map);
Next_Discriminant (Disc);
Next (Decl);
end loop;
end;
end if;
-- Fill in the component declarations.
-- Add components for entry families. For each entry family,
-- create an anonymous type declaration with the same size, and
-- analyze the type.
Collect_Entry_Families (Loc, Cdecls, Current_Node, Prottyp);
-- Prepend the _Object field with the right type to the component
-- list. We need to compute the number of entries, and in some cases
-- the number of Attach_Handler pragmas.
declare
Ritem : Node_Id;
Num_Attach_Handler : Int := 0;
Protection_Subtype : Node_Id;
Entry_Count_Expr : constant Node_Id :=
Build_Entry_Count_Expression
(Prottyp, Cdecls, Loc);
begin
if Has_Attach_Handler (Prottyp) then
Ritem := First_Rep_Item (Prottyp);
while Present (Ritem) loop
if Nkind (Ritem) = N_Pragma
and then Chars (Ritem) = Name_Attach_Handler
then
Num_Attach_Handler := Num_Attach_Handler + 1;
end if;
Next_Rep_Item (Ritem);
end loop;
if Restricted_Profile then
Protection_Subtype :=
New_Reference_To (RTE (RE_Protection_Entry), Loc);
else
Protection_Subtype :=
Make_Subtype_Indication
(Sloc => Loc,
Subtype_Mark =>
New_Reference_To
(RTE (RE_Static_Interrupt_Protection), Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (
Sloc => Loc,
Constraints => New_List (
Entry_Count_Expr,
Make_Integer_Literal (Loc, Num_Attach_Handler))));
end if;
elsif Has_Interrupt_Handler (Prottyp) then
Protection_Subtype :=
Make_Subtype_Indication (
Sloc => Loc,
Subtype_Mark => New_Reference_To
(RTE (RE_Dynamic_Interrupt_Protection), Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (
Sloc => Loc,
Constraints => New_List (Entry_Count_Expr)));
elsif Has_Entries (Prottyp) then
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Prottyp) > 1
then
Protection_Subtype :=
Make_Subtype_Indication (
Sloc => Loc,
Subtype_Mark =>
New_Reference_To (RTE (RE_Protection_Entries), Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (
Sloc => Loc,
Constraints => New_List (Entry_Count_Expr)));
else
Protection_Subtype :=
New_Reference_To (RTE (RE_Protection_Entry), Loc);
end if;
else
Protection_Subtype := New_Reference_To (RTE (RE_Protection), Loc);
end if;
Object_Comp :=
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uObject),
Aliased_Present => True,
Subtype_Indication => Protection_Subtype);
end;
pragma Assert (Present (Pdef));
-- Add private field components.
if Present (Private_Declarations (Pdef)) then
Priv := First (Private_Declarations (Pdef));
while Present (Priv) loop
if Nkind (Priv) = N_Component_Declaration then
Pent := Defining_Identifier (Priv);
New_Priv :=
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Sloc (Pent), Chars (Pent)),
Subtype_Indication =>
New_Copy_Tree (Subtype_Indication (Priv), Discr_Map),
Expression => Expression (Priv));
Append_To (Cdecls, New_Priv);
elsif Nkind (Priv) = N_Subprogram_Declaration then
-- Make the unprotected version of the subprogram available
-- for expansion of intra object calls. There is need for
-- a protected version only if the subprogram is an interrupt
-- handler, otherwise this operation can only be called from
-- within the body.
Sub :=
Make_Subprogram_Declaration (Loc,
Specification =>
Build_Protected_Sub_Specification
(Priv, Prottyp, Unprotected => True));
Insert_After (Current_Node, Sub);
Analyze (Sub);
Set_Protected_Body_Subprogram
(Defining_Unit_Name (Specification (Priv)),
Defining_Unit_Name (Specification (Sub)));
Current_Node := Sub;
if Is_Interrupt_Handler
(Defining_Unit_Name (Specification (Priv)))
then
Sub :=
Make_Subprogram_Declaration (Loc,
Specification =>
Build_Protected_Sub_Specification
(Priv, Prottyp, Unprotected => False));
Insert_After (Current_Node, Sub);
Analyze (Sub);
Current_Node := Sub;
if not Restricted_Profile then
Register_Handler;
end if;
end if;
end if;
Next (Priv);
end loop;
end if;
-- Put the _Object component after the private component so that it
-- be finalized early as required by 9.4 (20)
Append_To (Cdecls, Object_Comp);
Insert_After (Current_Node, Rec_Decl);
Current_Node := Rec_Decl;
-- Analyze the record declaration immediately after construction,
-- because the initialization procedure is needed for single object
-- declarations before the next entity is analyzed (the freeze call
-- that generates this initialization procedure is found below).
Analyze (Rec_Decl, Suppress => All_Checks);
-- Collect pointers to entry bodies and their barriers, to be placed
-- in the Entry_Bodies_Array for the type. For each entry/family we
-- add an expression to the aggregate which is the initial value of
-- this array. The array is declared after all protected subprograms.
if Has_Entries (Prottyp) then
Entries_Aggr :=
Make_Aggregate (Loc, Expressions => New_List);
else
Entries_Aggr := Empty;
end if;
-- Build two new procedure specifications for each protected
-- subprogram; one to call from outside the object and one to
-- call from inside. Build a barrier function and an entry
-- body action procedure specification for each protected entry.
-- Initialize the entry body array.
E_Count := 0;
Comp := First (Visible_Declarations (Pdef));
while Present (Comp) loop
if Nkind (Comp) = N_Subprogram_Declaration then
Sub :=
Make_Subprogram_Declaration (Loc,
Specification =>
Build_Protected_Sub_Specification
(Comp, Prottyp, Unprotected => True));
Insert_After (Current_Node, Sub);
Analyze (Sub);
Set_Protected_Body_Subprogram
(Defining_Unit_Name (Specification (Comp)),
Defining_Unit_Name (Specification (Sub)));
-- Make the protected version of the subprogram available
-- for expansion of external calls.
Current_Node := Sub;
Sub :=
Make_Subprogram_Declaration (Loc,
Specification =>
Build_Protected_Sub_Specification
(Comp, Prottyp, Unprotected => False));
Insert_After (Current_Node, Sub);
Analyze (Sub);
Current_Node := Sub;
-- If a pragma Interrupt_Handler applies, build and add
-- a call to Register_Interrupt_Handler to the freezing actions
-- of the protected version (Current_Node) of the subprogram:
-- system.interrupts.register_interrupt_handler
-- (prot_procP'address);
if not Restricted_Profile
and then Is_Interrupt_Handler
(Defining_Unit_Name (Specification (Comp)))
then
Register_Handler;
end if;
elsif Nkind (Comp) = N_Entry_Declaration then
E_Count := E_Count + 1;
Comp_Id := Defining_Identifier (Comp);
Set_Privals_Chain (Comp_Id, New_Elmt_List);
Nam := Chars (Comp_Id);
Edef :=
Make_Defining_Identifier (Loc,
Build_Selected_Name (Protnm, New_Internal_Name ('E')));
Sub :=
Make_Subprogram_Declaration (Loc,
Specification =>
Build_Protected_Entry_Specification (Edef, Comp_Id, Loc));
Insert_After (Current_Node, Sub);
Analyze (Sub);
Set_Protected_Body_Subprogram (
Defining_Identifier (Comp),
Defining_Unit_Name (Specification (Sub)));
Current_Node := Sub;
Bdef :=
Make_Defining_Identifier (Loc,
Build_Selected_Name (Protnm, New_Internal_Name ('B')));
Sub :=
Make_Subprogram_Declaration (Loc,
Specification =>
Build_Barrier_Function_Specification (Bdef, Loc));
Insert_After (Current_Node, Sub);
Analyze (Sub);
Set_Protected_Body_Subprogram (Bdef, Bdef);
Set_Barrier_Function (Comp_Id, Bdef);
Set_Scope (Bdef, Scope (Comp_Id));
Current_Node := Sub;
-- Collect pointers to the protected subprogram and the barrier
-- of the current entry, for insertion into Entry_Bodies_Array.
Append (
Make_Aggregate (Loc,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Bdef, Loc),
Attribute_Name => Name_Unrestricted_Access),
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Edef, Loc),
Attribute_Name => Name_Unrestricted_Access))),
Expressions (Entries_Aggr));
end if;
Next (Comp);
end loop;
-- If there are some private entry declarations, expand it as if they
-- were visible entries.
if Present (Private_Declarations (Pdef)) then
Comp := First (Private_Declarations (Pdef));
while Present (Comp) loop
if Nkind (Comp) = N_Entry_Declaration then
E_Count := E_Count + 1;
Comp_Id := Defining_Identifier (Comp);
Set_Privals_Chain (Comp_Id, New_Elmt_List);
Nam := Chars (Comp_Id);
Edef :=
Make_Defining_Identifier (Loc,
Build_Selected_Name (Protnm, New_Internal_Name ('E')));
Sub :=
Make_Subprogram_Declaration (Loc,
Specification =>
Build_Protected_Entry_Specification (Edef, Comp_Id, Loc));
Insert_After (Current_Node, Sub);
Analyze (Sub);
Set_Protected_Body_Subprogram (
Defining_Identifier (Comp),
Defining_Unit_Name (Specification (Sub)));
Current_Node := Sub;
Bdef :=
Make_Defining_Identifier (Loc,
Build_Selected_Name (Protnm, New_Internal_Name ('B')));
Sub :=
Make_Subprogram_Declaration (Loc,
Specification =>
Build_Barrier_Function_Specification (Bdef, Loc));
Insert_After (Current_Node, Sub);
Analyze (Sub);
Set_Protected_Body_Subprogram (Bdef, Bdef);
Set_Barrier_Function (Comp_Id, Bdef);
Set_Scope (Bdef, Scope (Comp_Id));
Current_Node := Sub;
-- Collect pointers to the protected subprogram and the
-- barrier of the current entry, for insertion into
-- Entry_Bodies_Array.
Append (
Make_Aggregate (Loc,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Bdef, Loc),
Attribute_Name => Name_Unrestricted_Access),
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Edef, Loc),
Attribute_Name => Name_Unrestricted_Access))),
Expressions (Entries_Aggr));
end if;
Next (Comp);
end loop;
end if;
-- Emit declaration for Entry_Bodies_Array, now that the addresses of
-- all protected subprograms have been collected.
if Has_Entries (Prottyp) then
Body_Id := Make_Defining_Identifier (Sloc (Prottyp),
New_External_Name (Chars (Prottyp), 'A'));
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else E_Count > 1
then
Body_Arr := Make_Object_Declaration (Loc,
Defining_Identifier => Body_Id,
Aliased_Present => True,
Object_Definition =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Reference_To (
RTE (RE_Protected_Entry_Body_Array), Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc,
Constraints => New_List (
Make_Range (Loc,
Make_Integer_Literal (Loc, 1),
Make_Integer_Literal (Loc, E_Count))))),
Expression => Entries_Aggr);
else
Body_Arr := Make_Object_Declaration (Loc,
Defining_Identifier => Body_Id,
Aliased_Present => True,
Object_Definition => New_Reference_To (RTE (RE_Entry_Body), Loc),
Expression =>
Make_Aggregate (Loc,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Bdef, Loc),
Attribute_Name => Name_Unrestricted_Access),
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Edef, Loc),
Attribute_Name => Name_Unrestricted_Access))));
end if;
-- A pointer to this array will be placed in the corresponding
-- record by its initialization procedure, so this needs to be
-- analyzed here.
Insert_After (Current_Node, Body_Arr);
Current_Node := Body_Arr;
Analyze (Body_Arr);
Set_Entry_Bodies_Array (Prottyp, Body_Id);
-- Finally, build the function that maps an entry index into the
-- corresponding body. A pointer to this function is placed in each
-- object of the type. Except for a ravenscar-like profile (no abort,
-- no entry queue, 1 entry)
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else E_Count > 1
then
Sub :=
Make_Subprogram_Declaration (Loc,
Specification => Build_Find_Body_Index_Spec (Prottyp));
Insert_After (Current_Node, Sub);
Analyze (Sub);
end if;
end if;
end Expand_N_Protected_Type_Declaration;
--------------------------------
-- Expand_N_Requeue_Statement --
--------------------------------
-- A requeue statement is expanded into one of four GNARLI operations,
-- depending on the source and destination (task or protected object).
-- In addition, code must be generated to jump around the remainder of
-- processing for the original entry and, if the destination is a
-- (different) protected object, to attempt to service it.
-- The following illustrates the various cases:
-- procedure entE
-- (O : System.Address;
-- P : System.Address;
-- E : Protected_Entry_Index)
-- is
-- <discriminant renamings>
-- <private object renamings>
-- type poVP is access poV;
-- _Object : ptVP := ptVP!(O);
--
-- begin
-- begin
-- <start of statement sequence for entry>
--
-- -- Requeue from one protected entry body to another protected
-- -- entry.
--
-- Requeue_Protected_Entry (
-- _object._object'Access,
-- new._object'Access,
-- E,
-- Abort_Present);
-- return;
--
-- <some more of the statement sequence for entry>
--
-- -- Requeue from an entry body to a task entry.
--
-- Requeue_Protected_To_Task_Entry (
-- New._task_id,
-- E,
-- Abort_Present);
-- return;
--
-- <rest of statement sequence for entry>
-- Complete_Entry_Body (_Object._Object);
--
-- exception
-- when all others =>
-- Exceptional_Complete_Entry_Body (
-- _Object._Object, Get_GNAT_Exception);
-- end;
-- end entE;
-- Requeue of a task entry call to a task entry.
--
-- Accept_Call (E, Ann);
-- <start of statement sequence for accept statement>
-- Requeue_Task_Entry (New._task_id, E, Abort_Present);
-- goto Lnn;
-- <rest of statement sequence for accept statement>
-- <<Lnn>>
-- Complete_Rendezvous;
-- exception
-- when all others =>
-- Exceptional_Complete_Rendezvous (Get_GNAT_Exception);
-- Requeue of a task entry call to a protected entry.
--
-- Accept_Call (E, Ann);
-- <start of statement sequence for accept statement>
-- Requeue_Task_To_Protected_Entry (
-- new._object'Access,
-- E,
-- Abort_Present);
-- newS (new, Pnn);
-- goto Lnn;
-- <rest of statement sequence for accept statement>
-- <<Lnn>>
-- Complete_Rendezvous;
-- exception
-- when all others =>
-- Exceptional_Complete_Rendezvous (Get_GNAT_Exception);
-- Further details on these expansions can be found in
-- Expand_N_Protected_Body and Expand_N_Accept_Statement.
procedure Expand_N_Requeue_Statement (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Acc_Stat : Node_Id;
Concval : Node_Id;
Ename : Node_Id;
Index : Node_Id;
Conctyp : Entity_Id;
Oldtyp : Entity_Id;
Lab_Node : Node_Id;
Rcall : Node_Id;
Abortable : Node_Id;
Skip_Stat : Node_Id;
Self_Param : Node_Id;
New_Param : Node_Id;
Params : List_Id;
RTS_Call : Entity_Id;
begin
if Abort_Present (N) then
Abortable := New_Occurrence_Of (Standard_True, Loc);
else
Abortable := New_Occurrence_Of (Standard_False, Loc);
end if;
-- Set up the target object.
Extract_Entry (N, Concval, Ename, Index);
Conctyp := Etype (Concval);
New_Param := Concurrent_Ref (Concval);
-- The target entry index and abortable flag are the same for all cases.
Params := New_List (
Entry_Index_Expression (Loc, Entity (Ename), Index, Conctyp),
Abortable);
-- Determine proper GNARLI call and required additional parameters
-- Loop to find nearest enclosing task type or protected type
Oldtyp := Current_Scope;
loop
if Is_Task_Type (Oldtyp) then
if Is_Task_Type (Conctyp) then
RTS_Call := RTE (RE_Requeue_Task_Entry);
else
pragma Assert (Is_Protected_Type (Conctyp));
RTS_Call := RTE (RE_Requeue_Task_To_Protected_Entry);
New_Param :=
Make_Attribute_Reference (Loc,
Prefix => New_Param,
Attribute_Name => Name_Unchecked_Access);
end if;
Prepend (New_Param, Params);
exit;
elsif Is_Protected_Type (Oldtyp) then
Self_Param :=
Make_Attribute_Reference (Loc,
Prefix => Concurrent_Ref (New_Occurrence_Of (Oldtyp, Loc)),
Attribute_Name => Name_Unchecked_Access);
if Is_Task_Type (Conctyp) then
RTS_Call := RTE (RE_Requeue_Protected_To_Task_Entry);
else
pragma Assert (Is_Protected_Type (Conctyp));
RTS_Call := RTE (RE_Requeue_Protected_Entry);
New_Param :=
Make_Attribute_Reference (Loc,
Prefix => New_Param,
Attribute_Name => Name_Unchecked_Access);
end if;
Prepend (New_Param, Params);
Prepend (Self_Param, Params);
exit;
-- If neither task type or protected type, must be in some
-- inner enclosing block, so move on out
else
Oldtyp := Scope (Oldtyp);
end if;
end loop;
-- Create the GNARLI call.
Rcall := Make_Procedure_Call_Statement (Loc,
Name =>
New_Occurrence_Of (RTS_Call, Loc),
Parameter_Associations => Params);
Rewrite (N, Rcall);
Analyze (N);
if Is_Protected_Type (Oldtyp) then
-- Build the return statement to skip the rest of the entry body
Skip_Stat := Make_Return_Statement (Loc);
else
-- If the requeue is within a task, find the end label of the
-- enclosing accept statement.
Acc_Stat := Parent (N);
while Nkind (Acc_Stat) /= N_Accept_Statement loop
Acc_Stat := Parent (Acc_Stat);
end loop;
-- The last statement is the second label, used for completing the
-- rendezvous the usual way.
-- The label we are looking for is right before it.
Lab_Node :=
Prev (Last (Statements (Handled_Statement_Sequence (Acc_Stat))));
pragma Assert (Nkind (Lab_Node) = N_Label);
-- Build the goto statement to skip the rest of the accept
-- statement.
Skip_Stat :=
Make_Goto_Statement (Loc,
Name => New_Occurrence_Of (Entity (Identifier (Lab_Node)), Loc));
end if;
Set_Analyzed (Skip_Stat);
Insert_After (N, Skip_Stat);
end Expand_N_Requeue_Statement;
-------------------------------
-- Expand_N_Selective_Accept --
-------------------------------
procedure Expand_N_Selective_Accept (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Alts : constant List_Id := Select_Alternatives (N);
Accept_Case : List_Id;
Accept_List : List_Id := New_List;
Alt : Node_Id;
Alt_List : List_Id := New_List;
Alt_Stats : List_Id;
Ann : Entity_Id := Empty;
Block : Node_Id;
Check_Guard : Boolean := True;
Decls : List_Id := New_List;
Stats : List_Id := New_List;
Body_List : List_Id := New_List;
Trailing_List : List_Id := New_List;
Choices : List_Id;
Else_Present : Boolean := False;
Terminate_Alt : Node_Id := Empty;
Select_Mode : Node_Id;
Delay_Case : List_Id;
Delay_Count : Integer := 0;
Delay_Val : Entity_Id;
Delay_Index : Entity_Id;
Delay_Min : Entity_Id;
Delay_Num : Int := 1;
Delay_Alt_List : List_Id := New_List;
Delay_List : List_Id := New_List;
D : Entity_Id;
M : Entity_Id;
First_Delay : Boolean := True;
Guard_Open : Entity_Id;
End_Lab : Node_Id;
Index : Int := 1;
Lab : Node_Id;
Num_Alts : Int;
Num_Accept : Nat := 0;
Proc : Node_Id;
Q : Node_Id;
Time_Type : Entity_Id;
X : Node_Id;
Select_Call : Node_Id;
Qnam : constant Entity_Id :=
Make_Defining_Identifier (Loc, New_External_Name ('S', 0));
Xnam : constant Entity_Id :=
Make_Defining_Identifier (Loc, New_External_Name ('J', 1));
-----------------------
-- Local subprograms --
-----------------------
function Accept_Or_Raise return List_Id;
-- For the rare case where delay alternatives all have guards, and
-- all of them are closed, it is still possible that there were open
-- accept alternatives with no callers. We must reexamine the
-- Accept_List, and execute a selective wait with no else if some
-- accept is open. If none, we raise program_error.
procedure Add_Accept (Alt : Node_Id);
-- Process a single accept statement in a select alternative. Build
-- procedure for body of accept, and add entry to dispatch table with
-- expression for guard, in preparation for call to run time select.
function Make_And_Declare_Label (Num : Int) return Node_Id;
-- Manufacture a label using Num as a serial number and declare it.
-- The declaration is appended to Decls. The label marks the trailing
-- statements of an accept or delay alternative.
function Make_Select_Call (Select_Mode : Entity_Id) return Node_Id;
-- Build call to Selective_Wait runtime routine.
procedure Process_Delay_Alternative (Alt : Node_Id; Index : Int);
-- Add code to compare value of delay with previous values, and
-- generate case entry for trailing statements.
procedure Process_Accept_Alternative
(Alt : Node_Id;
Index : Int;
Proc : Node_Id);
-- Add code to call corresponding procedure, and branch to
-- trailing statements, if any.
---------------------
-- Accept_Or_Raise --
---------------------
function Accept_Or_Raise return List_Id is
Cond : Node_Id;
Stats : List_Id;
J : constant Entity_Id := Make_Defining_Identifier (Loc,
New_Internal_Name ('J'));
begin
-- We generate the following:
-- for J in q'range loop
-- if q(J).S /=null_task_entry then
-- selective_wait (simple_mode,...);
-- done := True;
-- exit;
-- end if;
-- end loop;
--
-- if no rendez_vous then
-- raise program_error;
-- end if;
-- Note that the code needs to know that the selector name
-- in an Accept_Alternative is named S.
Cond := Make_Op_Ne (Loc,
Left_Opnd =>
Make_Selected_Component (Loc,
Prefix => Make_Indexed_Component (Loc,
Prefix => New_Reference_To (Qnam, Loc),
Expressions => New_List (New_Reference_To (J, Loc))),
Selector_Name => Make_Identifier (Loc, Name_S)),
Right_Opnd =>
New_Reference_To (RTE (RE_Null_Task_Entry), Loc));
Stats := 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 => J,
Discrete_Subtype_Definition =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Qnam, Loc),
Attribute_Name => Name_Range,
Expressions => New_List (
Make_Integer_Literal (Loc, 1))))),
Statements => New_List (
Make_Implicit_If_Statement (N,
Condition => Cond,
Then_Statements => New_List (
Make_Select_Call (
New_Reference_To (RTE (RE_Simple_Mode), Loc)),
Make_Exit_Statement (Loc))))));
Append_To (Stats,
Make_Raise_Program_Error (Loc,
Condition => Make_Op_Eq (Loc,
Left_Opnd => New_Reference_To (Xnam, Loc),
Right_Opnd =>
New_Reference_To (RTE (RE_No_Rendezvous), Loc))));
return Stats;
end Accept_Or_Raise;
----------------
-- Add_Accept --
----------------
procedure Add_Accept (Alt : Node_Id) is
Acc_Stm : constant Node_Id := Accept_Statement (Alt);
Ename : constant Node_Id := Entry_Direct_Name (Acc_Stm);
Eent : constant Entity_Id := Entity (Ename);
Index : constant Node_Id := Entry_Index (Acc_Stm);
Null_Body : Node_Id;
Proc_Body : Node_Id;
PB_Ent : Entity_Id;
Expr : Node_Id;
Call : Node_Id;
begin
if No (Ann) then
Ann := Node (Last_Elmt (Accept_Address (Eent)));
end if;
if Present (Condition (Alt)) then
Expr :=
Make_Conditional_Expression (Loc, New_List (
Condition (Alt),
Entry_Index_Expression (Loc, Eent, Index, Scope (Eent)),
New_Reference_To (RTE (RE_Null_Task_Entry), Loc)));
else
Expr :=
Entry_Index_Expression
(Loc, Eent, Index, Scope (Eent));
end if;
if Present (Handled_Statement_Sequence (Accept_Statement (Alt))) then
Null_Body := New_Reference_To (Standard_False, Loc);
if Abort_Allowed then
Call := Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc));
Insert_Before (First (Statements (Handled_Statement_Sequence (
Accept_Statement (Alt)))), Call);
Analyze (Call);
end if;
PB_Ent :=
Make_Defining_Identifier (Sloc (Ename),
New_External_Name (Chars (Ename), 'A', Num_Accept));
Proc_Body :=
Make_Subprogram_Body (Loc,
Specification =>
Make_Procedure_Specification (Loc,
Defining_Unit_Name => PB_Ent),
Declarations => Declarations (Acc_Stm),
Handled_Statement_Sequence =>
Build_Accept_Body (Accept_Statement (Alt)));
-- During the analysis of the body of the accept statement, any
-- zero cost exception handler records were collected in the
-- Accept_Handler_Records field of the N_Accept_Alternative
-- node. This is where we move them to where they belong,
-- namely the newly created procedure.
Set_Handler_Records (PB_Ent, Accept_Handler_Records (Alt));
Append (Proc_Body, Body_List);
else
Null_Body := New_Reference_To (Standard_True, Loc);
-- if accept statement has declarations, insert above, given
-- that we are not creating a body for the accept.
if Present (Declarations (Acc_Stm)) then
Insert_Actions (N, Declarations (Acc_Stm));
end if;
end if;
Append_To (Accept_List,
Make_Aggregate (Loc, Expressions => New_List (Null_Body, Expr)));
Num_Accept := Num_Accept + 1;
end Add_Accept;
----------------------------
-- Make_And_Declare_Label --
----------------------------
function Make_And_Declare_Label (Num : Int) return Node_Id is
Lab_Id : Node_Id;
begin
Lab_Id := Make_Identifier (Loc, New_External_Name ('L', Num));
Lab :=
Make_Label (Loc, Lab_Id);
Append_To (Decls,
Make_Implicit_Label_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Chars (Lab_Id)),
Label_Construct => Lab));
return Lab;
end Make_And_Declare_Label;
----------------------
-- Make_Select_Call --
----------------------
function Make_Select_Call (Select_Mode : Entity_Id) return Node_Id is
Params : List_Id := New_List;
begin
Append (
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Qnam, Loc),
Attribute_Name => Name_Unchecked_Access),
Params);
Append (Select_Mode, Params);
Append (New_Reference_To (Ann, Loc), Params);
Append (New_Reference_To (Xnam, Loc), Params);
return
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Selective_Wait), Loc),
Parameter_Associations => Params);
end Make_Select_Call;
--------------------------------
-- Process_Accept_Alternative --
--------------------------------
procedure Process_Accept_Alternative
(Alt : Node_Id;
Index : Int;
Proc : Node_Id)
is
Choices : List_Id := No_List;
Alt_Stats : List_Id;
begin
Adjust_Condition (Condition (Alt));
Alt_Stats := No_List;
if Present (Handled_Statement_Sequence (Accept_Statement (Alt))) then
Choices := New_List (
Make_Integer_Literal (Loc, Index));
Alt_Stats := New_List (
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (
Defining_Unit_Name (Specification (Proc)), Loc)));
end if;
if Statements (Alt) /= Empty_List then
if No (Alt_Stats) then
-- Accept with no body, followed by trailing statements.
Choices := New_List (
Make_Integer_Literal (Loc, Index));
Alt_Stats := New_List;
end if;
-- After the call, if any, branch to to trailing statements.
-- We create a label for each, as well as the corresponding
-- label declaration.
Lab := Make_And_Declare_Label (Index);
Append_To (Alt_Stats,
Make_Goto_Statement (Loc,
Name => New_Copy (Identifier (Lab))));
Append (Lab, Trailing_List);
Append_List (Statements (Alt), Trailing_List);
Append_To (Trailing_List,
Make_Goto_Statement (Loc,
Name => New_Copy (Identifier (End_Lab))));
end if;
if Present (Alt_Stats) then
-- Procedure call. and/or trailing statements
Append_To (Alt_List,
Make_Case_Statement_Alternative (Loc,
Discrete_Choices => Choices,
Statements => Alt_Stats));
end if;
end Process_Accept_Alternative;
-------------------------------
-- Process_Delay_Alternative --
-------------------------------
procedure Process_Delay_Alternative (Alt : Node_Id; Index : Int) is
Choices : List_Id;
Cond : Node_Id;
Delay_Alt : List_Id;
begin
-- Deal with C/Fortran boolean as delay condition
Adjust_Condition (Condition (Alt));
-- Determine the smallest specified delay.
-- for each delay alternative generate:
-- if guard-expression then
-- Delay_Val := delay-expression;
-- Guard_Open := True;
-- if Delay_Val < Delay_Min then
-- Delay_Min := Delay_Val;
-- Delay_Index := Index;
-- end if;
-- end if;
-- The enclosing if-statement is omitted if there is no guard.
if Delay_Count = 1
or else First_Delay
then
First_Delay := False;
Delay_Alt := New_List (
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Delay_Min, Loc),
Expression => Expression (Delay_Statement (Alt))));
if Delay_Count > 1 then
Append_To (Delay_Alt,
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Delay_Index, Loc),
Expression => Make_Integer_Literal (Loc, Index)));
end if;
else
Delay_Alt := New_List (
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Delay_Val, Loc),
Expression => Expression (Delay_Statement (Alt))));
if Time_Type = Standard_Duration then
Cond :=
Make_Op_Lt (Loc,
Left_Opnd => New_Reference_To (Delay_Val, Loc),
Right_Opnd => New_Reference_To (Delay_Min, Loc));
else
-- The scope of the time type must define a comparison
-- operator. The scope itself may not be visible, so we
-- construct a node with entity information to insure that
-- semantic analysis can find the proper operator.
Cond :=
Make_Function_Call (Loc,
Name => Make_Selected_Component (Loc,
Prefix => New_Reference_To (Scope (Time_Type), Loc),
Selector_Name =>
Make_Operator_Symbol (Loc,
Chars => Name_Op_Lt,
Strval => No_String)),
Parameter_Associations =>
New_List (
New_Reference_To (Delay_Val, Loc),
New_Reference_To (Delay_Min, Loc)));
Set_Entity (Prefix (Name (Cond)), Scope (Time_Type));
end if;
Append_To (Delay_Alt,
Make_Implicit_If_Statement (N,
Condition => Cond,
Then_Statements => New_List (
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Delay_Min, Loc),
Expression => New_Reference_To (Delay_Val, Loc)),
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Delay_Index, Loc),
Expression => Make_Integer_Literal (Loc, Index)))));
end if;
if Check_Guard then
Append_To (Delay_Alt,
Make_Assignment_Statement (Loc,
Name => New_Reference_To (Guard_Open, Loc),
Expression => New_Reference_To (Standard_True, Loc)));
end if;
if Present (Condition (Alt)) then
Delay_Alt := New_List (
Make_Implicit_If_Statement (N,
Condition => Condition (Alt),
Then_Statements => Delay_Alt));
end if;
Append_List (Delay_Alt, Delay_List);
-- If the delay alternative has a statement part, add a
-- choice to the case statements for delays.
if Present (Statements (Alt)) then
if Delay_Count = 1 then
Append_List (Statements (Alt), Delay_Alt_List);
else
Choices := New_List (
Make_Integer_Literal (Loc, Index));
Append_To (Delay_Alt_List,
Make_Case_Statement_Alternative (Loc,
Discrete_Choices => Choices,
Statements => Statements (Alt)));
end if;
elsif Delay_Count = 1 then
-- If the single delay has no trailing statements, add a branch
-- to the exit label to the selective wait.
Delay_Alt_List := New_List (
Make_Goto_Statement (Loc,
Name => New_Copy (Identifier (End_Lab))));
end if;
end Process_Delay_Alternative;
-- Start of processing for Expand_N_Selective_Accept
begin
-- First insert some declarations before the select. The first is:
-- Ann : Address
-- This variable holds the parameters passed to the accept body. This
-- declaration has already been inserted by the time we get here by
-- a call to Expand_Accept_Declarations made from the semantics when
-- processing the first accept statement contained in the select. We
-- can find this entity as Accept_Address (E), where E is any of the
-- entries references by contained accept statements.
-- The first step is to scan the list of Selective_Accept_Statements
-- to find this entity, and also count the number of accepts, and
-- determine if terminated, delay or else is present:
Num_Alts := 0;
Alt := First (Alts);
while Present (Alt) loop
if Nkind (Alt) = N_Accept_Alternative then
Add_Accept (Alt);
elsif Nkind (Alt) = N_Delay_Alternative then
Delay_Count := Delay_Count + 1;
-- If the delays are relative delays, the delay expressions have
-- type Standard_Duration. Otherwise they must have some time type
-- recognized by GNAT.
if Nkind (Delay_Statement (Alt)) = N_Delay_Relative_Statement then
Time_Type := Standard_Duration;
else
Time_Type := Etype (Expression (Delay_Statement (Alt)));
if Is_RTE (Base_Type (Etype (Time_Type)), RO_CA_Time)
or else Is_RTE (Base_Type (Etype (Time_Type)), RO_RT_Time)
then
null;
else
Error_Msg_NE (
"& is not a time type ('R'M 9.6(6))",
Expression (Delay_Statement (Alt)), Time_Type);
Time_Type := Standard_Duration;
Set_Etype (Expression (Delay_Statement (Alt)), Any_Type);
end if;
end if;
if No (Condition (Alt)) then
-- This guard will always be open.
Check_Guard := False;
end if;
elsif Nkind (Alt) = N_Terminate_Alternative then
Adjust_Condition (Condition (Alt));
Terminate_Alt := Alt;
end if;
Num_Alts := Num_Alts + 1;
Next (Alt);
end loop;
Else_Present := Present (Else_Statements (N));
-- At the same time (see procedure Add_Accept) we build the accept list:
-- Qnn : Accept_List (1 .. num-select) := (
-- (null-body, entry-index),
-- (null-body, entry-index),
-- ..
-- (null_body, entry-index));
-- In the above declaration, null-body is True if the corresponding
-- accept has no body, and false otherwise. The entry is either the
-- entry index expression if there is no guard, or if a guard is
-- present, then a conditional expression of the form:
-- (if guard then entry-index else Null_Task_Entry)
-- If a guard is statically known to be false, the entry can simply
-- be omitted from the accept list.
Q :=
Make_Object_Declaration (Loc,
Defining_Identifier => Qnam,
Object_Definition =>
New_Reference_To (RTE (RE_Accept_List), Loc),
Aliased_Present => True,
Expression =>
Make_Qualified_Expression (Loc,
Subtype_Mark =>
New_Reference_To (RTE (RE_Accept_List), Loc),
Expression =>
Make_Aggregate (Loc, Expressions => Accept_List)));
Append (Q, Decls);
-- Then we declare the variable that holds the index for the accept
-- that will be selected for service:
-- Xnn : Select_Index;
X :=
Make_Object_Declaration (Loc,
Defining_Identifier => Xnam,
Object_Definition =>
New_Reference_To (RTE (RE_Select_Index), Loc),
Expression =>
New_Reference_To (RTE (RE_No_Rendezvous), Loc));
Append (X, Decls);
-- After this follow procedure declarations for each accept body.
-- procedure Pnn is
-- begin
-- ...
-- end;
-- where the ... are statements from the corresponding procedure body.
-- No parameters are involved, since the parameters are passed via Ann
-- and the parameter references have already been expanded to be direct
-- references to Ann (see Exp_Ch2.Expand_Entry_Parameter). Furthermore,
-- any embedded tasking statements (which would normally be illegal in
-- procedures, have been converted to calls to the tasking runtime so
-- there is no problem in putting them into procedures.
-- The original accept statement has been expanded into a block in
-- the same fashion as for simple accepts (see Build_Accept_Body).
-- Note: we don't really need to build these procedures for the case
-- where no delay statement is present, but it is just as easy to
-- build them unconditionally, and not significantly inefficient,
-- since if they are short they will be inlined anyway.
-- The procedure declarations have been assembled in Body_List.
-- If delays are present, we must compute the required delay.
-- We first generate the declarations:
-- Delay_Index : Boolean := 0;
-- Delay_Min : Some_Time_Type.Time;
-- Delay_Val : Some_Time_Type.Time;
-- Delay_Index will be set to the index of the minimum delay, i.e. the
-- active delay that is actually chosen as the basis for the possible
-- delay if an immediate rendez-vous is not possible.
-- In the most common case there is a single delay statement, and this
-- is handled specially.
if Delay_Count > 0 then
-- Generate the required declarations
Delay_Val :=
Make_Defining_Identifier (Loc, New_External_Name ('D', 1));
Delay_Index :=
Make_Defining_Identifier (Loc, New_External_Name ('D', 2));
Delay_Min :=
Make_Defining_Identifier (Loc, New_External_Name ('D', 3));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Delay_Val,
Object_Definition => New_Reference_To (Time_Type, Loc)));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Delay_Index,
Object_Definition => New_Reference_To (Standard_Integer, Loc),
Expression => Make_Integer_Literal (Loc, 0)));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Delay_Min,
Object_Definition => New_Reference_To (Time_Type, Loc),
Expression =>
Unchecked_Convert_To (Time_Type,
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Underlying_Type (Time_Type), Loc),
Attribute_Name => Name_Last))));
-- Create Duration and Delay_Mode objects used for passing a delay
-- value to RTS
D := Make_Defining_Identifier (Loc, New_Internal_Name ('D'));
M := Make_Defining_Identifier (Loc, New_Internal_Name ('M'));
declare
Discr : Entity_Id;
begin
-- Note that these values are defined in s-osprim.ads and must
-- be kept in sync:
--
-- Relative : constant := 0;
-- Absolute_Calendar : constant := 1;
-- Absolute_RT : constant := 2;
if Time_Type = Standard_Duration then
Discr := Make_Integer_Literal (Loc, 0);
elsif Is_RTE (Base_Type (Etype (Time_Type)), RO_CA_Time) then
Discr := Make_Integer_Literal (Loc, 1);
else
pragma Assert
(Is_RTE (Base_Type (Etype (Time_Type)), RO_RT_Time));
Discr := Make_Integer_Literal (Loc, 2);
end if;
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => D,
Object_Definition =>
New_Reference_To (Standard_Duration, Loc)));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => M,
Object_Definition =>
New_Reference_To (Standard_Integer, Loc),
Expression => Discr));
end;
if Check_Guard then
Guard_Open :=
Make_Defining_Identifier (Loc, New_External_Name ('G', 1));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => Guard_Open,
Object_Definition => New_Reference_To (Standard_Boolean, Loc),
Expression => New_Reference_To (Standard_False, Loc)));
end if;
-- Delay_Count is zero, don't need M and D set (suppress warning)
else
M := Empty;
D := Empty;
end if;
if Present (Terminate_Alt) then
-- If the terminate alternative guard is False, use
-- Simple_Mode; otherwise use Terminate_Mode.
if Present (Condition (Terminate_Alt)) then
Select_Mode := Make_Conditional_Expression (Loc,
New_List (Condition (Terminate_Alt),
New_Reference_To (RTE (RE_Terminate_Mode), Loc),
New_Reference_To (RTE (RE_Simple_Mode), Loc)));
else
Select_Mode := New_Reference_To (RTE (RE_Terminate_Mode), Loc);
end if;
elsif Else_Present or Delay_Count > 0 then
Select_Mode := New_Reference_To (RTE (RE_Else_Mode), Loc);
else
Select_Mode := New_Reference_To (RTE (RE_Simple_Mode), Loc);
end if;
Select_Call := Make_Select_Call (Select_Mode);
Append (Select_Call, Stats);
-- Now generate code to act on the result. There is an entry
-- in this case for each accept statement with a non-null body,
-- followed by a branch to the statements that follow the Accept.
-- In the absence of delay alternatives, we generate:
-- case X is
-- when No_Rendezvous => -- omitted if simple mode
-- goto Lab0;
-- when 1 =>
-- P1n;
-- goto Lab1;
-- when 2 =>
-- P2n;
-- goto Lab2;
-- when others =>
-- goto Exit;
-- end case;
--
-- Lab0: Else_Statements;
-- goto exit;
-- Lab1: Trailing_Statements1;
-- goto Exit;
--
-- Lab2: Trailing_Statements2;
-- goto Exit;
-- ...
-- Exit:
-- Generate label for common exit.
End_Lab := Make_And_Declare_Label (Num_Alts + 1);
-- First entry is the default case, when no rendezvous is possible.
Choices := New_List (New_Reference_To (RTE (RE_No_Rendezvous), Loc));
if Else_Present then
-- If no rendezvous is possible, the else part is executed.
Lab := Make_And_Declare_Label (0);
Alt_Stats := New_List (
Make_Goto_Statement (Loc,
Name => New_Copy (Identifier (Lab))));
Append (Lab, Trailing_List);
Append_List (Else_Statements (N), Trailing_List);
Append_To (Trailing_List,
Make_Goto_Statement (Loc,
Name => New_Copy (Identifier (End_Lab))));
else
Alt_Stats := New_List (
Make_Goto_Statement (Loc,
Name => New_Copy (Identifier (End_Lab))));
end if;
Append_To (Alt_List,
Make_Case_Statement_Alternative (Loc,
Discrete_Choices => Choices,
Statements => Alt_Stats));
-- We make use of the fact that Accept_Index is an integer type,
-- and generate successive literals for entries for each accept.
-- Only those for which there is a body or trailing statements are
-- given a case entry.
Alt := First (Select_Alternatives (N));
Proc := First (Body_List);
while Present (Alt) loop
if Nkind (Alt) = N_Accept_Alternative then
Process_Accept_Alternative (Alt, Index, Proc);
Index := Index + 1;
if Present
(Handled_Statement_Sequence (Accept_Statement (Alt)))
then
Next (Proc);
end if;
elsif Nkind (Alt) = N_Delay_Alternative then
Process_Delay_Alternative (Alt, Delay_Num);
Delay_Num := Delay_Num + 1;
end if;
Next (Alt);
end loop;
-- An others choice is always added to the main case, as well
-- as the delay case (to satisfy the compiler).
Append_To (Alt_List,
Make_Case_Statement_Alternative (Loc,
Discrete_Choices =>
New_List (Make_Others_Choice (Loc)),
Statements =>
New_List (Make_Goto_Statement (Loc,
Name => New_Copy (Identifier (End_Lab))))));
Accept_Case := New_List (
Make_Case_Statement (Loc,
Expression => New_Reference_To (Xnam, Loc),
Alternatives => Alt_List));
Append_List (Trailing_List, Accept_Case);
Append (End_Lab, Accept_Case);
Append_List (Body_List, Decls);
-- Construct case statement for trailing statements of delay
-- alternatives, if there are several of them.
if Delay_Count > 1 then
Append_To (Delay_Alt_List,
Make_Case_Statement_Alternative (Loc,
Discrete_Choices =>
New_List (Make_Others_Choice (Loc)),
Statements =>
New_List (Make_Null_Statement (Loc))));
Delay_Case := New_List (
Make_Case_Statement (Loc,
Expression => New_Reference_To (Delay_Index, Loc),
Alternatives => Delay_Alt_List));
else
Delay_Case := Delay_Alt_List;
end if;
-- If there are no delay alternatives, we append the case statement
-- to the statement list.
if Delay_Count = 0 then
Append_List (Accept_Case, Stats);
-- Delay alternatives present
else
-- If delay alternatives are present we generate:
-- find minimum delay.
-- DX := minimum delay;
-- M := <delay mode>;
-- Timed_Selective_Wait (Q'Unchecked_Access, Delay_Mode, P,
-- DX, MX, X);
--
-- if X = No_Rendezvous then
-- case statement for delay statements.
-- else
-- case statement for accept alternatives.
-- end if;
declare
Cases : Node_Id;
Stmt : Node_Id;
Parms : List_Id;
Parm : Node_Id;
Conv : Node_Id;
begin
-- The type of the delay expression is known to be legal
if Time_Type = Standard_Duration then
Conv := New_Reference_To (Delay_Min, Loc);
elsif Is_RTE (Base_Type (Etype (Time_Type)), RO_CA_Time) then
Conv := Make_Function_Call (Loc,
New_Reference_To (RTE (RO_CA_To_Duration), Loc),
New_List (New_Reference_To (Delay_Min, Loc)));
else
pragma Assert
(Is_RTE (Base_Type (Etype (Time_Type)), RO_RT_Time));
Conv := Make_Function_Call (Loc,
New_Reference_To (RTE (RO_RT_To_Duration), Loc),
New_List (New_Reference_To (Delay_Min, Loc)));
end if;
Stmt := Make_Assignment_Statement (Loc,
Name => New_Reference_To (D, Loc),
Expression => Conv);
-- Change the value for Accept_Modes. (Else_Mode -> Delay_Mode)
Parms := Parameter_Associations (Select_Call);
Parm := First (Parms);
while Present (Parm)
and then Parm /= Select_Mode
loop
Next (Parm);
end loop;
pragma Assert (Present (Parm));
Rewrite (Parm, New_Reference_To (RTE (RE_Delay_Mode), Loc));
Analyze (Parm);
-- Prepare two new parameters of Duration and Delay_Mode type
-- which represent the value and the mode of the minimum delay.
Next (Parm);
Insert_After (Parm, New_Reference_To (M, Loc));
Insert_After (Parm, New_Reference_To (D, Loc));
-- Create a call to RTS.
Rewrite (Select_Call,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Timed_Selective_Wait), Loc),
Parameter_Associations => Parms));
-- This new call should follow the calculation of the
-- minimum delay.
Insert_List_Before (Select_Call, Delay_List);
if Check_Guard then
Stmt :=
Make_Implicit_If_Statement (N,
Condition => New_Reference_To (Guard_Open, Loc),
Then_Statements =>
New_List (New_Copy_Tree (Stmt),
New_Copy_Tree (Select_Call)),
Else_Statements => Accept_Or_Raise);
Rewrite (Select_Call, Stmt);
else
Insert_Before (Select_Call, Stmt);
end if;
Cases :=
Make_Implicit_If_Statement (N,
Condition => Make_Op_Eq (Loc,
Left_Opnd => New_Reference_To (Xnam, Loc),
Right_Opnd =>
New_Reference_To (RTE (RE_No_Rendezvous), Loc)),
Then_Statements => Delay_Case,
Else_Statements => Accept_Case);
Append (Cases, Stats);
end;
end if;
-- Replace accept statement with appropriate block
Block :=
Make_Block_Statement (Loc,
Declarations => Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => Stats));
Rewrite (N, Block);
Analyze (N);
-- Note: have to worry more about abort deferral in above code ???
-- Final step is to unstack the Accept_Address entries for all accept
-- statements appearing in accept alternatives in the select statement
Alt := First (Alts);
while Present (Alt) loop
if Nkind (Alt) = N_Accept_Alternative then
Remove_Last_Elmt (Accept_Address
(Entity (Entry_Direct_Name (Accept_Statement (Alt)))));
end if;
Next (Alt);
end loop;
end Expand_N_Selective_Accept;
--------------------------------------
-- Expand_N_Single_Task_Declaration --
--------------------------------------
-- Single task declarations should never be present after semantic
-- analysis, since we expect them to be replaced by a declaration of
-- an anonymous task type, followed by a declaration of the task
-- object. We include this routine to make sure that is happening!
procedure Expand_N_Single_Task_Declaration (N : Node_Id) is
begin
raise Program_Error;
end Expand_N_Single_Task_Declaration;
------------------------
-- Expand_N_Task_Body --
------------------------
-- Given a task body
-- task body tname is
-- <declarations>
-- begin
-- <statements>
-- end x;
-- This expansion routine converts it into a procedure and sets the
-- elaboration flag for the procedure to true, to represent the fact
-- that the task body is now elaborated:
-- procedure tnameB (_Task : access tnameV) is
-- discriminal : dtype renames _Task.discriminant;
--
-- procedure _clean is
-- begin
-- Abort_Defer.all;
-- Complete_Task;
-- Abort_Undefer.all;
-- return;
-- end _clean;
-- begin
-- Abort_Undefer.all;
-- <declarations>
-- System.Task_Stages.Complete_Activation;
-- <statements>
-- at end
-- _clean;
-- end tnameB;
-- tnameE := True;
-- In addition, if the task body is an activator, then a call to
-- activate tasks is added at the start of the statements, before
-- the call to Complete_Activation, and if in addition the task is
-- a master then it must be established as a master. These calls are
-- inserted and analyzed in Expand_Cleanup_Actions, when the
-- Handled_Sequence_Of_Statements is expanded.
-- There is one discriminal declaration line generated for each
-- discriminant that is present to provide an easy reference point
-- for discriminant references inside the body (see Exp_Ch2.Expand_Name).
-- Note on relationship to GNARLI definition. In the GNARLI definition,
-- task body procedures have a profile (Arg : System.Address). That is
-- needed because GNARLI has to use the same access-to-subprogram type
-- for all task types. We depend here on knowing that in GNAT, passing
-- an address argument by value is identical to passing a record value
-- by access (in either case a single pointer is passed), so even though
-- this procedure has the wrong profile. In fact it's all OK, since the
-- callings sequence is identical.
procedure Expand_N_Task_Body (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Ttyp : constant Entity_Id := Corresponding_Spec (N);
Call : Node_Id;
New_N : Node_Id;
begin
Add_Discriminal_Declarations (Declarations (N), Ttyp, Name_uTask, Loc);
-- Add a call to Abort_Undefer at the very beginning of the task
-- body since this body is called with abort still deferred.
if Abort_Allowed then
Call := Build_Runtime_Call (Loc, RE_Abort_Undefer);
Insert_Before
(First (Statements (Handled_Statement_Sequence (N))), Call);
Analyze (Call);
end if;
-- The statement part has already been protected with an at_end and
-- cleanup actions. The call to Complete_Activation must be placed
-- at the head of the sequence of statements of that block. The
-- declarations have been merged in this sequence of statements but
-- the first real statement is accessible from the First_Real_Statement
-- field (which was set for exactly this purpose).
if Restricted_Profile then
Call := Build_Runtime_Call (Loc, RE_Complete_Restricted_Activation);
else
Call := Build_Runtime_Call (Loc, RE_Complete_Activation);
end if;
Insert_Before
(First_Real_Statement (Handled_Statement_Sequence (N)), Call);
Analyze (Call);
New_N :=
Make_Subprogram_Body (Loc,
Specification => Build_Task_Proc_Specification (Ttyp),
Declarations => Declarations (N),
Handled_Statement_Sequence => Handled_Statement_Sequence (N));
-- If the task contains generic instantiations, cleanup actions
-- are delayed until after instantiation. Transfer the activation
-- chain to the subprogram, to insure that the activation call is
-- properly generated. It the task body contains inner tasks, indicate
-- that the subprogram is a task master.
if Delay_Cleanups (Ttyp) then
Set_Activation_Chain_Entity (New_N, Activation_Chain_Entity (N));
Set_Is_Task_Master (New_N, Is_Task_Master (N));
end if;
Rewrite (N, New_N);
Analyze (N);
-- Set elaboration flag immediately after task body. If the body
-- is a subunit, the flag is set in the declarative part that
-- contains the stub.
if Nkind (Parent (N)) /= N_Subunit then
Insert_After (N,
Make_Assignment_Statement (Loc,
Name =>
Make_Identifier (Loc, New_External_Name (Chars (Ttyp), 'E')),
Expression => New_Reference_To (Standard_True, Loc)));
end if;
end Expand_N_Task_Body;
------------------------------------
-- Expand_N_Task_Type_Declaration --
------------------------------------
-- We have several things to do. First we must create a Boolean flag used
-- to mark if the body is elaborated yet. This variable gets set to True
-- when the body of the task is elaborated (we can't rely on the normal
-- ABE mechanism for the task body, since we need to pass an access to
-- this elaboration boolean to the runtime routines).
-- taskE : aliased Boolean := False;
-- Next a variable is declared to hold the task stack size (either
-- the default : Unspecified_Size, or a value that is set by a pragma
-- Storage_Size). If the value of the pragma Storage_Size is static, then
-- the variable is initialized with this value:
-- taskZ : Size_Type := Unspecified_Size;
-- or
-- taskZ : Size_Type := Size_Type (size_expression);
-- Next we create a corresponding record type declaration used to represent
-- values of this task. The general form of this type declaration is
-- type taskV (discriminants) is record
-- _Task_Id : Task_Id;
-- entry_family : array (bounds) of Void;
-- _Priority : Integer := priority_expression;
-- _Size : Size_Type := Size_Type (size_expression);
-- _Task_Info : Task_Info_Type := task_info_expression;
-- _Task_Name : Task_Image_Type := new String'(task_name_expression);
-- end record;
-- The discriminants are present only if the corresponding task type has
-- discriminants, and they exactly mirror the task type discriminants.
-- The Id field is always present. It contains the Task_Id value, as
-- set by the call to Create_Task. Note that although the task is
-- limited, the task value record type is not limited, so there is no
-- problem in passing this field as an out parameter to Create_Task.
-- One entry_family component is present for each entry family in the
-- task definition. The bounds correspond to the bounds of the entry
-- family (which may depend on discriminants). The element type is
-- void, since we only need the bounds information for determining
-- the entry index. Note that the use of an anonymous array would
-- normally be illegal in this context, but this is a parser check,
-- and the semantics is quite prepared to handle such a case.
-- The _Size field is present only if a Storage_Size pragma appears in
-- the task definition. The expression captures the argument that was
-- present in the pragma, and is used to override the task stack size
-- otherwise associated with the task type.
-- The _Priority field is present only if a Priority or Interrupt_Priority
-- pragma appears in the task definition. The expression captures the
-- argument that was present in the pragma, and is used to provide
-- the Size parameter to the call to Create_Task.
-- The _Task_Info field is present only if a Task_Info pragma appears in
-- the task definition. The expression captures the argument that was
-- present in the pragma, and is used to provide the Task_Image parameter
-- to the call to Create_Task.
-- The _Task_Name field is present only if a Task_Name pragma appears in
-- the task definition. The expression captures the argument that was
-- present in the pragma, and is used to provide the Task_Id parameter
-- to the call to Create_Task.
-- When a task is declared, an instance of the task value record is
-- created. The elaboration of this declaration creates the correct
-- bounds for the entry families, and also evaluates the size, priority,
-- and task_Info expressions if needed. The initialization routine for
-- the task type itself then calls Create_Task with appropriate
-- parameters to initialize the value of the Task_Id field.
-- Note: the address of this record is passed as the "Discriminants"
-- parameter for Create_Task. Since Create_Task merely passes this onto
-- the body procedure, it does not matter that it does not quite match
-- the GNARLI model of what is being passed (the record contains more
-- than just the discriminants, but the discriminants can be found from
-- the record value).
-- The Entity_Id for this created record type is placed in the
-- Corresponding_Record_Type field of the associated task type entity.
-- Next we create a procedure specification for the task body procedure:
-- procedure taskB (_Task : access taskV);
-- Note that this must come after the record type declaration, since
-- the spec refers to this type. It turns out that the initialization
-- procedure for the value type references the task body spec, but that's
-- fine, since it won't be generated till the freeze point for the type,
-- which is certainly after the task body spec declaration.
-- Finally, we set the task index value field of the entry attribute in
-- the case of a simple entry.
procedure Expand_N_Task_Type_Declaration (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Tasktyp : constant Entity_Id := Etype (Defining_Identifier (N));
Tasknm : constant Name_Id := Chars (Tasktyp);
Taskdef : constant Node_Id := Task_Definition (N);
Proc_Spec : Node_Id;
Rec_Decl : Node_Id;
Rec_Ent : Entity_Id;
Cdecls : List_Id;
Elab_Decl : Node_Id;
Size_Decl : Node_Id;
Body_Decl : Node_Id;
begin
if Present (Corresponding_Record_Type (Tasktyp)) then
return;
else
Rec_Decl := Build_Corresponding_Record (N, Tasktyp, Loc);
Rec_Ent := Defining_Identifier (Rec_Decl);
Cdecls := Component_Items
(Component_List (Type_Definition (Rec_Decl)));
end if;
Qualify_Entity_Names (N);
-- First create the elaboration variable
Elab_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Sloc (Tasktyp),
Chars => New_External_Name (Tasknm, 'E')),
Aliased_Present => True,
Object_Definition => New_Reference_To (Standard_Boolean, Loc),
Expression => New_Reference_To (Standard_False, Loc));
Insert_After (N, Elab_Decl);
-- Next create the declaration of the size variable (tasknmZ)
Set_Storage_Size_Variable (Tasktyp,
Make_Defining_Identifier (Sloc (Tasktyp),
Chars => New_External_Name (Tasknm, 'Z')));
if Present (Taskdef) and then Has_Storage_Size_Pragma (Taskdef) and then
Is_Static_Expression (Expression (First (
Pragma_Argument_Associations (Find_Task_Or_Protected_Pragma (
Taskdef, Name_Storage_Size)))))
then
Size_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Storage_Size_Variable (Tasktyp),
Object_Definition => New_Reference_To (RTE (RE_Size_Type), Loc),
Expression =>
Convert_To (RTE (RE_Size_Type),
Relocate_Node (
Expression (First (
Pragma_Argument_Associations (
Find_Task_Or_Protected_Pragma
(Taskdef, Name_Storage_Size)))))));
else
Size_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Storage_Size_Variable (Tasktyp),
Object_Definition => New_Reference_To (RTE (RE_Size_Type), Loc),
Expression => New_Reference_To (RTE (RE_Unspecified_Size), Loc));
end if;
Insert_After (Elab_Decl, Size_Decl);
-- Next build the rest of the corresponding record declaration.
-- This is done last, since the corresponding record initialization
-- procedure will reference the previously created entities.
-- Fill in the component declarations. First the _Task_Id field:
Append_To (Cdecls,
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uTask_Id),
Subtype_Indication => New_Reference_To (RTE (RO_ST_Task_ID), Loc)));
-- Add components for entry families
Collect_Entry_Families (Loc, Cdecls, Size_Decl, Tasktyp);
-- Add the _Priority component if a Priority pragma is present
if Present (Taskdef) and then Has_Priority_Pragma (Taskdef) then
Append_To (Cdecls,
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uPriority),
Subtype_Indication => New_Reference_To (Standard_Integer, Loc),
Expression => New_Copy (
Expression (First (
Pragma_Argument_Associations (
Find_Task_Or_Protected_Pragma
(Taskdef, Name_Priority)))))));
end if;
-- Add the _Task_Size component if a Storage_Size pragma is present
if Present (Taskdef)
and then Has_Storage_Size_Pragma (Taskdef)
then
Append_To (Cdecls,
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uSize),
Subtype_Indication => New_Reference_To (RTE (RE_Size_Type), Loc),
Expression =>
Convert_To (RTE (RE_Size_Type),
Relocate_Node (
Expression (First (
Pragma_Argument_Associations (
Find_Task_Or_Protected_Pragma
(Taskdef, Name_Storage_Size))))))));
end if;
-- Add the _Task_Info component if a Task_Info pragma is present
if Present (Taskdef) and then Has_Task_Info_Pragma (Taskdef) then
Append_To (Cdecls,
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uTask_Info),
Subtype_Indication =>
New_Reference_To (RTE (RE_Task_Info_Type), Loc),
Expression => New_Copy (
Expression (First (
Pragma_Argument_Associations (
Find_Task_Or_Protected_Pragma
(Taskdef, Name_Task_Info)))))));
end if;
-- Add the _Task_Name component if a Task_Name pragma is present
if Present (Taskdef) and then Has_Task_Name_Pragma (Taskdef) then
Append_To (Cdecls,
Make_Component_Declaration (Loc,
Defining_Identifier =>
Make_Defining_Identifier (Loc, Name_uTask_Info),
Subtype_Indication =>
New_Reference_To (RTE (RE_Task_Image_Type), Loc),
Expression =>
Make_Allocator (Loc,
Expression =>
Make_Qualified_Expression (Loc,
Subtype_Mark =>
New_Occurrence_Of (Standard_String, Loc),
Expression =>
New_Copy (
Expression (First (
Pragma_Argument_Associations (
Find_Task_Or_Protected_Pragma
(Taskdef, Name_Task_Name)))))))));
end if;
Insert_After (Size_Decl, Rec_Decl);
-- Analyze the record declaration immediately after construction,
-- because the initialization procedure is needed for single task
-- declarations before the next entity is analyzed.
Analyze (Rec_Decl);
-- Create the declaration of the task body procedure
Proc_Spec := Build_Task_Proc_Specification (Tasktyp);
Body_Decl :=
Make_Subprogram_Declaration (Loc,
Specification => Proc_Spec);
Insert_After (Rec_Decl, Body_Decl);
-- Now we can freeze the corresponding record. This needs manually
-- freezing, since it is really part of the task type, and the task
-- type is frozen at this stage. We of course need the initialization
-- procedure for this corresponding record type and we won't get it
-- in time if we don't freeze now.
declare
L : constant List_Id := Freeze_Entity (Rec_Ent, Loc);
begin
if Is_Non_Empty_List (L) then
Insert_List_After (Body_Decl, L);
end if;
end;
-- Complete the expansion of access types to the current task
-- type, if any were declared.
Expand_Previous_Access_Type (N, Tasktyp);
end Expand_N_Task_Type_Declaration;
-------------------------------
-- Expand_N_Timed_Entry_Call --
-------------------------------
-- A timed entry call in normal case is not implemented using ATC
-- mechanism anymore for efficiency reason.
-- select
-- T.E;
-- S1;
-- or
-- Delay D;
-- S2;
-- end select;
-- is expanded as follow:
-- 1) When T.E is a task entry_call;
-- declare
-- B : Boolean;
-- X : Task_Entry_Index := <entry index>;
-- DX : Duration := To_Duration (D);
-- M : Delay_Mode := <discriminant>;
-- P : parms := (parm, parm, parm);
-- begin
-- Timed_Protected_Entry_Call (<acceptor-task>, X, P'Address,
-- DX, M, B);
-- if B then
-- S1;
-- else
-- S2;
-- end if;
-- end;
-- 2) When T.E is a protected entry_call;
-- declare
-- B : Boolean;
-- X : Protected_Entry_Index := <entry index>;
-- DX : Duration := To_Duration (D);
-- M : Delay_Mode := <discriminant>;
-- P : parms := (parm, parm, parm);
-- begin
-- Timed_Protected_Entry_Call (<object>'unchecked_access, X,
-- P'Address, DX, M, B);
-- if B then
-- S1;
-- else
-- S2;
-- end if;
-- end;
procedure Expand_N_Timed_Entry_Call (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
E_Call : Node_Id :=
Entry_Call_Statement (Entry_Call_Alternative (N));
E_Stats : constant List_Id :=
Statements (Entry_Call_Alternative (N));
D_Stat : constant Node_Id :=
Delay_Statement (Delay_Alternative (N));
D_Stats : constant List_Id :=
Statements (Delay_Alternative (N));
Stmts : List_Id;
Stmt : Node_Id;
Parms : List_Id;
Parm : Node_Id;
Concval : Node_Id;
Ename : Node_Id;
Index : Node_Id;
Decls : List_Id;
Disc : Node_Id;
Conv : Node_Id;
B : Entity_Id;
D : Entity_Id;
Dtyp : Entity_Id;
M : Entity_Id;
Call : Node_Id;
Dummy : Node_Id;
begin
-- The arguments in the call may require dynamic allocation, and the
-- call statement may have been transformed into a block. The block
-- may contain additional declarations for internal entities, and the
-- original call is found by sequential search.
if Nkind (E_Call) = N_Block_Statement then
E_Call := First (Statements (Handled_Statement_Sequence (E_Call)));
while Nkind (E_Call) /= N_Procedure_Call_Statement
and then Nkind (E_Call) /= N_Entry_Call_Statement
loop
Next (E_Call);
end loop;
end if;
-- Build an entry call using Simple_Entry_Call. We will use this as the
-- base for creating appropriate calls.
Extract_Entry (E_Call, Concval, Ename, Index);
Build_Simple_Entry_Call (E_Call, Concval, Ename, Index);
Stmts := Statements (Handled_Statement_Sequence (E_Call));
Decls := Declarations (E_Call);
if No (Decls) then
Decls := New_List;
end if;
Dtyp := Base_Type (Etype (Expression (D_Stat)));
-- Use the type of the delay expression (Calendar or Real_Time)
-- to generate the appropriate conversion.
if Nkind (D_Stat) = N_Delay_Relative_Statement then
Disc := Make_Integer_Literal (Loc, 0);
Conv := Relocate_Node (Expression (D_Stat));
elsif Is_RTE (Dtyp, RO_CA_Time) then
Disc := Make_Integer_Literal (Loc, 1);
Conv := Make_Function_Call (Loc,
New_Reference_To (RTE (RO_CA_To_Duration), Loc),
New_List (New_Copy (Expression (D_Stat))));
else pragma Assert (Is_RTE (Dtyp, RO_RT_Time));
Disc := Make_Integer_Literal (Loc, 2);
Conv := Make_Function_Call (Loc,
New_Reference_To (RTE (RO_RT_To_Duration), Loc),
New_List (New_Copy (Expression (D_Stat))));
end if;
-- Create a Duration and a Delay_Mode object used for passing a delay
-- value
D := Make_Defining_Identifier (Loc, New_Internal_Name ('D'));
M := Make_Defining_Identifier (Loc, New_Internal_Name ('M'));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => D,
Object_Definition => New_Reference_To (Standard_Duration, Loc)));
Append_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => M,
Object_Definition => New_Reference_To (Standard_Integer, Loc),
Expression => Disc));
B := Make_Defining_Identifier (Loc, Name_uB);
-- Create a boolean object used for a return parameter.
Prepend_To (Decls,
Make_Object_Declaration (Loc,
Defining_Identifier => B,
Object_Definition => New_Reference_To (Standard_Boolean, Loc)));
Stmt := First (Stmts);
-- Skip assignments to temporaries created for in-out parameters.
-- This makes unwarranted assumptions about the shape of the expanded
-- tree for the call, and should be cleaned up ???
while Nkind (Stmt) /= N_Procedure_Call_Statement loop
Next (Stmt);
end loop;
-- Do the assignement at this stage only because the evaluation of the
-- expression must not occur before (see ACVC C97302A).
Insert_Before (Stmt,
Make_Assignment_Statement (Loc,
Name => New_Reference_To (D, Loc),
Expression => Conv));
Call := Stmt;
Parms := Parameter_Associations (Call);
-- For a protected type, we build a Timed_Protected_Entry_Call
if Is_Protected_Type (Etype (Concval)) then
-- Create a new call statement
Parm := First (Parms);
while Present (Parm)
and then not Is_RTE (Etype (Parm), RE_Call_Modes)
loop
Next (Parm);
end loop;
Dummy := Remove_Next (Next (Parm));
-- In case some garbage is following the Cancel_Param, remove.
Dummy := Next (Parm);
-- Remove the mode of the Protected_Entry_Call call, the
-- Communication_Block of the Protected_Entry_Call call, and add a
-- Duration and a Delay_Mode parameter
pragma Assert (Present (Parm));
Rewrite (Parm, New_Reference_To (D, Loc));
Rewrite (Dummy, New_Reference_To (M, Loc));
-- Add a Boolean flag for successful entry call.
Append_To (Parms, New_Reference_To (B, Loc));
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Etype (Concval)) > 1
then
Rewrite (Call,
Make_Procedure_Call_Statement (Loc,
Name =>
New_Reference_To (RTE (RE_Timed_Protected_Entry_Call), Loc),
Parameter_Associations => Parms));
else
Parm := First (Parms);
while Present (Parm)
and then not Is_RTE (Etype (Parm), RE_Protected_Entry_Index)
loop
Next (Parm);
end loop;
Remove (Parm);
Rewrite (Call,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (
RTE (RE_Timed_Protected_Single_Entry_Call), Loc),
Parameter_Associations => Parms));
end if;
-- For the task case, build a Timed_Task_Entry_Call
else
-- Create a new call statement
Append_To (Parms, New_Reference_To (D, Loc));
Append_To (Parms, New_Reference_To (M, Loc));
Append_To (Parms, New_Reference_To (B, Loc));
Rewrite (Call,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Timed_Task_Entry_Call), Loc),
Parameter_Associations => Parms));
end if;
Append_To (Stmts,
Make_Implicit_If_Statement (N,
Condition => New_Reference_To (B, Loc),
Then_Statements => E_Stats,
Else_Statements => D_Stats));
Rewrite (N,
Make_Block_Statement (Loc,
Declarations => Decls,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc, Stmts)));
Analyze (N);
end Expand_N_Timed_Entry_Call;
----------------------------------------
-- Expand_Protected_Body_Declarations --
----------------------------------------
-- Part of the expansion of a protected body involves the creation of
-- a declaration that can be referenced from the statement sequences of
-- the entry bodies:
-- A : Address;
-- This declaration is inserted in the declarations of the service
-- entries procedure for the protected body, and it is important that
-- it be inserted before the statements of the entry body statement
-- sequences are analyzed. Thus it would be too late to create this
-- declaration in the Expand_N_Protected_Body routine, which is why
-- there is a separate procedure to be called directly from Sem_Ch9.
-- Ann is used to hold the address of the record containing the parameters
-- (see Expand_N_Entry_Call for more details on how this record is built).
-- References to the parameters do an unchecked conversion of this address
-- to a pointer to the required record type, and then access the field that
-- holds the value of the required parameter. The entity for the address
-- variable is held as the top stack element (i.e. the last element) of the
-- Accept_Address stack in the corresponding entry entity, and this element
-- must be set in place before the statements are processed.
-- No stack is needed for entry bodies, since they cannot be nested, but
-- it is kept for consistency between protected and task entries. The
-- stack will never contain more than one element. There is also only one
-- such variable for a given protected body, but this is placed on the
-- Accept_Address stack of all of the entries, again for consistency.
-- To expand the requeue statement, a label is provided at the end of
-- the loop in the entry service routine created by the expander (see
-- Expand_N_Protected_Body for details), so that the statement can be
-- skipped after the requeue is complete. This label is created during the
-- expansion of the entry body, which will take place after the expansion
-- of the requeue statements that it contains, so a placeholder defining
-- identifier is associated with the task type here.
-- Another label is provided following case statement created by the
-- expander. This label is need for implementing return statement from
-- entry body so that a return can be expanded as a goto to this label.
-- This label is created during the expansion of the entry body, which
-- will take place after the expansion of the return statements that it
-- contains. Therefore, just like the label for expanding requeues, we
-- need another placeholder for the label.
procedure Expand_Protected_Body_Declarations
(N : Node_Id;
Spec_Id : Entity_Id)
is
Op : Node_Id;
begin
if Expander_Active then
-- Associate privals with the first subprogram or entry
-- body to be expanded. These are used to expand references
-- to private data objects.
Op := First_Protected_Operation (Declarations (N));
if Present (Op) then
Set_Discriminals (Parent (Spec_Id), Op, Sloc (N));
Set_Privals (Parent (Spec_Id), Op, Sloc (N));
end if;
end if;
end Expand_Protected_Body_Declarations;
-------------------------
-- External_Subprogram --
-------------------------
function External_Subprogram (E : Entity_Id) return Entity_Id is
Subp : constant Entity_Id := Protected_Body_Subprogram (E);
Decl : constant Node_Id := Unit_Declaration_Node (E);
begin
-- If the protected operation is defined in the visible part of the
-- protected type, or if it is an interrupt handler, the internal and
-- external subprograms follow each other on the entity chain. If the
-- operation is defined in the private part of the type, there is no
-- need for a separate locking version of the operation, and internal
-- calls use the protected_body_subprogram directly.
if List_Containing (Decl) = Visible_Declarations (Parent (Decl))
or else Is_Interrupt_Handler (E)
then
return Next_Entity (Subp);
else
return (Subp);
end if;
end External_Subprogram;
-------------------
-- Extract_Entry --
-------------------
procedure Extract_Entry
(N : Node_Id;
Concval : out Node_Id;
Ename : out Node_Id;
Index : out Node_Id)
is
Nam : constant Node_Id := Name (N);
begin
-- For a simple entry, the name is a selected component, with the
-- prefix being the task value, and the selector being the entry.
if Nkind (Nam) = N_Selected_Component then
Concval := Prefix (Nam);
Ename := Selector_Name (Nam);
Index := Empty;
-- For a member of an entry family, the name is an indexed
-- component where the prefix is a selected component,
-- whose prefix in turn is the task value, and whose
-- selector is the entry family. The single expression in
-- the expressions list of the indexed component is the
-- subscript for the family.
else
pragma Assert (Nkind (Nam) = N_Indexed_Component);
Concval := Prefix (Prefix (Nam));
Ename := Selector_Name (Prefix (Nam));
Index := First (Expressions (Nam));
end if;
end Extract_Entry;
-------------------
-- Family_Offset --
-------------------
function Family_Offset
(Loc : Source_Ptr;
Hi : Node_Id;
Lo : Node_Id;
Ttyp : Entity_Id)
return Node_Id
is
function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id;
-- If one of the bounds is a reference to a discriminant, replace
-- with corresponding discriminal of type. Within the body of a task
-- retrieve the renamed discriminant by simple visibility, using its
-- generated name. Within a protected object, find the original dis-
-- criminant and replace it with the discriminal of the current prot-
-- ected operation.
------------------------------
-- Convert_Discriminant_Ref --
------------------------------
function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id is
Loc : constant Source_Ptr := Sloc (Bound);
B : Node_Id;
D : Entity_Id;
begin
if Is_Entity_Name (Bound)
and then Ekind (Entity (Bound)) = E_Discriminant
then
if Is_Task_Type (Ttyp)
and then Has_Completion (Ttyp)
then
B := Make_Identifier (Loc, Chars (Entity (Bound)));
Find_Direct_Name (B);
elsif Is_Protected_Type (Ttyp) then
D := First_Discriminant (Ttyp);
while Chars (D) /= Chars (Entity (Bound)) loop
Next_Discriminant (D);
end loop;
B := New_Reference_To (Discriminal (D), Loc);
else
B := New_Reference_To (Discriminal (Entity (Bound)), Loc);
end if;
elsif Nkind (Bound) = N_Attribute_Reference then
return Bound;
else
B := New_Copy_Tree (Bound);
end if;
return
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Pos,
Prefix => New_Occurrence_Of (Etype (Bound), Loc),
Expressions => New_List (B));
end Convert_Discriminant_Ref;
-- Start of processing for Family_Offset
begin
return
Make_Op_Subtract (Loc,
Left_Opnd => Convert_Discriminant_Ref (Hi),
Right_Opnd => Convert_Discriminant_Ref (Lo));
end Family_Offset;
-----------------
-- Family_Size --
-----------------
function Family_Size
(Loc : Source_Ptr;
Hi : Node_Id;
Lo : Node_Id;
Ttyp : Entity_Id)
return Node_Id
is
Ityp : Entity_Id;
begin
if Is_Task_Type (Ttyp) then
Ityp := RTE (RE_Task_Entry_Index);
else
Ityp := RTE (RE_Protected_Entry_Index);
end if;
return
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Ityp, Loc),
Attribute_Name => Name_Max,
Expressions => New_List (
Make_Op_Add (Loc,
Left_Opnd =>
Family_Offset (Loc, Hi, Lo, Ttyp),
Right_Opnd =>
Make_Integer_Literal (Loc, 1)),
Make_Integer_Literal (Loc, 0)));
end Family_Size;
-----------------------------------
-- Find_Task_Or_Protected_Pragma --
-----------------------------------
function Find_Task_Or_Protected_Pragma
(T : Node_Id;
P : Name_Id)
return Node_Id
is
N : Node_Id;
begin
N := First (Visible_Declarations (T));
while Present (N) loop
if Nkind (N) = N_Pragma then
if Chars (N) = P then
return N;
elsif P = Name_Priority
and then Chars (N) = Name_Interrupt_Priority
then
return N;
else
Next (N);
end if;
else
Next (N);
end if;
end loop;
N := First (Private_Declarations (T));
while Present (N) loop
if Nkind (N) = N_Pragma then
if Chars (N) = P then
return N;
elsif P = Name_Priority
and then Chars (N) = Name_Interrupt_Priority
then
return N;
else
Next (N);
end if;
else
Next (N);
end if;
end loop;
raise Program_Error;
end Find_Task_Or_Protected_Pragma;
-------------------------------
-- First_Protected_Operation --
-------------------------------
function First_Protected_Operation (D : List_Id) return Node_Id is
First_Op : Node_Id;
begin
First_Op := First (D);
while Present (First_Op)
and then Nkind (First_Op) /= N_Subprogram_Body
and then Nkind (First_Op) /= N_Entry_Body
loop
Next (First_Op);
end loop;
return First_Op;
end First_Protected_Operation;
--------------------------------
-- Index_Constant_Declaration --
--------------------------------
function Index_Constant_Declaration
(N : Node_Id;
Index_Id : Entity_Id;
Prot : Entity_Id)
return List_Id
is
Loc : constant Source_Ptr := Sloc (N);
Decls : List_Id := New_List;
Index_Con : constant Entity_Id := Entry_Index_Constant (Index_Id);
Index_Typ : Entity_Id;
Hi : Node_Id := Type_High_Bound (Etype (Index_Id));
Lo : Node_Id := Type_Low_Bound (Etype (Index_Id));
function Replace_Discriminant (Bound : Node_Id) return Node_Id;
-- The bounds of the entry index may depend on discriminants, so
-- each declaration of an entry_index_constant must have its own
-- subtype declaration, using the local renaming of the object discri-
-- minant.
--------------------------
-- Replace_Discriminant --
--------------------------
function Replace_Discriminant (Bound : Node_Id) return Node_Id is
begin
if Nkind (Bound) = N_Identifier
and then Ekind (Entity (Bound)) = E_Constant
and then Present (Discriminal_Link (Entity (Bound)))
then
return Make_Identifier (Loc, Chars (Entity (Bound)));
else
return Duplicate_Subexpr (Bound);
end if;
end Replace_Discriminant;
-- Start of processing for Index_Constant_Declaration
begin
Set_Discriminal_Link (Index_Con, Index_Id);
if Is_Entity_Name (
Original_Node (Discrete_Subtype_Definition (Parent (Index_Id))))
then
-- Simple case: entry family is given by a subtype mark, and index
-- constant has the same type, no replacement needed.
Index_Typ := Etype (Index_Id);
else
Hi := Replace_Discriminant (Hi);
Lo := Replace_Discriminant (Lo);
Index_Typ := Make_Defining_Identifier (Loc, New_Internal_Name ('I'));
Append (
Make_Subtype_Declaration (Loc,
Defining_Identifier => Index_Typ,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark =>
New_Occurrence_Of (Base_Type (Etype (Index_Id)), Loc),
Constraint =>
Make_Range_Constraint (Loc,
Range_Expression => Make_Range (Loc, Lo, Hi)))),
Decls);
end if;
Append (
Make_Object_Declaration (Loc,
Defining_Identifier => Index_Con,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (Index_Typ, Loc),
Expression =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Index_Typ, Loc),
Attribute_Name => Name_Val,
Expressions => New_List (
Make_Op_Add (Loc,
Left_Opnd =>
Make_Op_Subtract (Loc,
Left_Opnd => Make_Identifier (Loc, Name_uE),
Right_Opnd =>
Entry_Index_Expression (Loc,
Defining_Identifier (N), Empty, Prot)),
Right_Opnd =>
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Index_Typ, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (Index_Typ, Loc),
Attribute_Name => Name_First))))))),
Decls);
return Decls;
end Index_Constant_Declaration;
--------------------------------
-- Make_Initialize_Protection --
--------------------------------
function Make_Initialize_Protection
(Protect_Rec : Entity_Id)
return List_Id
is
Loc : constant Source_Ptr := Sloc (Protect_Rec);
P_Arr : Entity_Id;
Pdef : Node_Id;
Pdec : Node_Id;
Ptyp : Node_Id;
Pnam : Name_Id;
Args : List_Id;
L : List_Id := New_List;
begin
-- We may need two calls to properly initialize the object, one
-- to Initialize_Protection, and possibly one to Install_Handlers
-- if we have a pragma Attach_Handler.
Ptyp := Corresponding_Concurrent_Type (Protect_Rec);
Pnam := Chars (Ptyp);
-- Get protected declaration. In the case of a task type declaration,
-- this is simply the parent of the protected type entity.
-- In the single protected object
-- declaration, this parent will be the implicit type, and we can find
-- the corresponding single protected object declaration by
-- searching forward in the declaration list in the tree.
-- ??? I am not sure that the test for N_Single_Protected_Declaration
-- is needed here. Nodes of this type should have been removed
-- during semantic analysis.
Pdec := Parent (Ptyp);
while Nkind (Pdec) /= N_Protected_Type_Declaration
and then Nkind (Pdec) /= N_Single_Protected_Declaration
loop
Next (Pdec);
end loop;
-- Now we can find the object definition from this declaration
Pdef := Protected_Definition (Pdec);
-- Build the parameter list for the call. Note that _Init is the name
-- of the formal for the object to be initialized, which is the task
-- value record itself.
Args := New_List;
-- Object parameter. This is a pointer to the object of type
-- Protection used by the GNARL to control the protected object.
Append_To (Args,
Make_Attribute_Reference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix => Make_Identifier (Loc, Name_uInit),
Selector_Name => Make_Identifier (Loc, Name_uObject)),
Attribute_Name => Name_Unchecked_Access));
-- Priority parameter. Set to Unspecified_Priority unless there is a
-- priority pragma, in which case we take the value from the pragma,
-- or there is an interrupt pragma and no priority pragma, and we
-- set the ceiling to Interrupt_Priority'Last, an implementation-
-- defined value, see D.3(10).
if Present (Pdef)
and then Has_Priority_Pragma (Pdef)
then
Append_To (Args,
Duplicate_Subexpr (Expression (First (Pragma_Argument_Associations
(Find_Task_Or_Protected_Pragma (Pdef, Name_Priority))))));
elsif Has_Interrupt_Handler (Ptyp)
or else Has_Attach_Handler (Ptyp)
then
-- When no priority is specified but an xx_Handler pragma is,
-- we default to System.Interrupts.Default_Interrupt_Priority,
-- see D.3(10).
Append_To (Args,
New_Reference_To (RTE (RE_Default_Interrupt_Priority), Loc));
else
Append_To (Args,
New_Reference_To (RTE (RE_Unspecified_Priority), Loc));
end if;
if Has_Entries (Ptyp)
or else Has_Interrupt_Handler (Ptyp)
or else Has_Attach_Handler (Ptyp)
then
-- Compiler_Info parameter. This parameter allows entry body
-- procedures and barrier functions to be called from the runtime.
-- It is a pointer to the record generated by the compiler to
-- represent the protected object.
Append_To (Args,
Make_Attribute_Reference (Loc,
Prefix => Make_Identifier (Loc, Name_uInit),
Attribute_Name => Name_Address));
if Has_Entries (Ptyp) then
-- Entry_Bodies parameter. This is a pointer to an array of
-- pointers to the entry body procedures and barrier functions
-- of the object. If the protected type has no entries this
-- object will not exist; in this case, pass a null.
P_Arr := Entry_Bodies_Array (Ptyp);
Append_To (Args,
Make_Attribute_Reference (Loc,
Prefix => New_Reference_To (P_Arr, Loc),
Attribute_Name => Name_Unrestricted_Access));
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Ptyp) > 1
then
-- Find index mapping function (clumsy but ok for now).
while Ekind (P_Arr) /= E_Function loop
Next_Entity (P_Arr);
end loop;
Append_To (Args,
Make_Attribute_Reference (Loc,
Prefix =>
New_Reference_To (P_Arr, Loc),
Attribute_Name => Name_Unrestricted_Access));
end if;
else
Append_To (Args, Make_Null (Loc));
Append_To (Args, Make_Null (Loc));
end if;
if Abort_Allowed
or else Restrictions (No_Entry_Queue) = False
or else Number_Entries (Ptyp) > 1
then
Append_To (L,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (
RTE (RE_Initialize_Protection_Entries), Loc),
Parameter_Associations => Args));
else
Append_To (L,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (
RTE (RE_Initialize_Protection_Entry), Loc),
Parameter_Associations => Args));
end if;
else
Append_To (L,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Initialize_Protection), Loc),
Parameter_Associations => Args));
end if;
if Has_Attach_Handler (Ptyp) then
-- We have a list of N Attach_Handler (ProcI, ExprI),
-- and we have to make the following call:
-- Install_Handlers (_object,
-- ((Expr1, Proc1'access), ...., (ExprN, ProcN'access));
declare
Args : List_Id := New_List;
Table : List_Id := New_List;
Ritem : Node_Id := First_Rep_Item (Ptyp);
begin
-- Appends the _object argument
Append_To (Args,
Make_Attribute_Reference (Loc,
Prefix =>
Make_Selected_Component (Loc,
Prefix => Make_Identifier (Loc, Name_uInit),
Selector_Name => Make_Identifier (Loc, Name_uObject)),
Attribute_Name => Name_Unchecked_Access));
-- Build the Attach_Handler table argument
while Present (Ritem) loop
if Nkind (Ritem) = N_Pragma
and then Chars (Ritem) = Name_Attach_Handler
then
declare
Handler : Node_Id :=
First (Pragma_Argument_Associations (Ritem));
Interrupt : Node_Id :=
Next (Handler);
begin
Append_To (Table,
Make_Aggregate (Loc, Expressions => New_List (
Duplicate_Subexpr (Expression (Interrupt)),
Make_Attribute_Reference (Loc,
Prefix => Make_Selected_Component (Loc,
Make_Identifier (Loc, Name_uInit),
Duplicate_Subexpr (Expression (Handler))),
Attribute_Name => Name_Access))));
end;
end if;
Next_Rep_Item (Ritem);
end loop;
-- Appends the table argument we just built.
Append_To (Args, Make_Aggregate (Loc, Table));
-- Appends the Install_Handler call to the statements.
Append_To (L,
Make_Procedure_Call_Statement (Loc,
Name => New_Reference_To (RTE (RE_Install_Handlers), Loc),
Parameter_Associations => Args));
end;
end if;
return L;
end Make_Initialize_Protection;
---------------------------
-- Make_Task_Create_Call --
---------------------------
function Make_Task_Create_Call (Task_Rec : Entity_Id) return Node_Id is
Loc : constant Source_Ptr := Sloc (Task_Rec);
Name : Node_Id;
Tdef : Node_Id;
Tdec : Node_Id;
Ttyp : Node_Id;
Tnam : Name_Id;
Args : List_Id;
Ecount : Node_Id;
begin
Ttyp := Corresponding_Concurrent_Type (Task_Rec);
Tnam := Chars (Ttyp);
-- Get task declaration. In the case of a task type declaration, this
-- is simply the parent of the task type entity. In the single task
-- declaration, this parent will be the implicit type, and we can find
-- the corresponding single task declaration by searching forward in
-- the declaration list in the tree.
-- ??? I am not sure that the test for N_Single_Task_Declaration
-- is needed here. Nodes of this type should have been removed
-- during semantic analysis.
Tdec := Parent (Ttyp);
while Nkind (Tdec) /= N_Task_Type_Declaration
and then Nkind (Tdec) /= N_Single_Task_Declaration
loop
Next (Tdec);
end loop;
-- Now we can find the task definition from this declaration
Tdef := Task_Definition (Tdec);
-- Build the parameter list for the call. Note that _Init is the name
-- of the formal for the object to be initialized, which is the task
-- value record itself.
Args := New_List;
-- Priority parameter. Set to Unspecified_Priority unless there is a
-- priority pragma, in which case we take the value from the pragma.
if Present (Tdef)
and then Has_Priority_Pragma (Tdef)
then
Append_To (Args,
Make_Selected_Component (Loc,
Prefix => Make_Identifier (Loc, Name_uInit),
Selector_Name => Make_Identifier (Loc, Name_uPriority)));
else
Append_To (Args,
New_Reference_To (RTE (RE_Unspecified_Priority), Loc));
end if;
-- Size parameter. If no Storage_Size pragma is present, then
-- the size is taken from the taskZ variable for the type, which
-- is either Unspecified_Size, or has been reset by the use of
-- a Storage_Size attribute definition clause. If a pragma is
-- present, then the size is taken from the _Size field of the
-- task value record, which was set from the pragma value.
if Present (Tdef)
and then Has_Storage_Size_Pragma (Tdef)
then
Append_To (Args,
Make_Selected_Component (Loc,
Prefix => Make_Identifier (Loc, Name_uInit),
Selector_Name => Make_Identifier (Loc, Name_uSize)));
else
Append_To (Args,
New_Reference_To (Storage_Size_Variable (Ttyp), Loc));
end if;
-- Task_Info parameter. Set to Unspecified_Task_Info unless there is a
-- Task_Info pragma, in which case we take the value from the pragma.
if Present (Tdef)
and then Has_Task_Info_Pragma (Tdef)
then
Append_To (Args,
Make_Selected_Component (Loc,
Prefix => Make_Identifier (Loc, Name_uInit),
Selector_Name => Make_Identifier (Loc, Name_uTask_Info)));
else
Append_To (Args,
New_Reference_To (RTE (RE_Unspecified_Task_Info), Loc));
end if;
if not Restricted_Profile then
-- Number of entries. This is an expression of the form:
--
-- n + _Init.a'Length + _Init.a'B'Length + ...
--
-- where a,b... are the entry family names for the task definition
Ecount := Build_Entry_Count_Expression (
Ttyp,
Component_Items (Component_List (
Type_Definition (Parent (
Corresponding_Record_Type (Ttyp))))),
Loc);
Append_To (Args, Ecount);
-- Master parameter. This is a reference to the _Master parameter of
-- the initialization procedure, except in the case of the pragma
-- Restrictions (No_Task_Hierarchy) where the value is fixed to 3.
-- See comments in System.Tasking.Initialization.Init_RTS for the
-- value 3.
if Restrictions (No_Task_Hierarchy) = False then
Append_To (Args, Make_Identifier (Loc, Name_uMaster));
else
Append_To (Args, Make_Integer_Literal (Loc, 3));
end if;
end if;
-- State parameter. This is a pointer to the task body procedure. The
-- required value is obtained by taking the address of the task body
-- procedure and converting it (with an unchecked conversion) to the
-- type required by the task kernel. For further details, see the
-- description of Expand_Task_Body
Append_To (Args,
Unchecked_Convert_To (RTE (RE_Task_Procedure_Access),
Make_Attribute_Reference (Loc,
Prefix =>
New_Occurrence_Of (Get_Task_Body_Procedure (Ttyp), Loc),
Attribute_Name => Name_Address)));
-- Discriminants parameter. This is just the address of the task
-- value record itself (which contains the discriminant values
Append_To (Args,
Make_Attribute_Reference (Loc,
Prefix => Make_Identifier (Loc, Name_uInit),
Attribute_Name => Name_Address));
-- Elaborated parameter. This is an access to the elaboration Boolean
Append_To (Args,
Make_Attribute_Reference (Loc,
Prefix => Make_Identifier (Loc, New_External_Name (Tnam, 'E')),
Attribute_Name => Name_Unchecked_Access));
-- Chain parameter. This is a reference to the _Chain parameter of
-- the initialization procedure.
Append_To (Args, Make_Identifier (Loc, Name_uChain));
-- Task name parameter. Take this from the _Task_Info parameter to the
-- init call unless there is a Task_Name pragma, in which case we take
-- the value from the pragma.
if Present (Tdef)
and then Has_Task_Name_Pragma (Tdef)
then
Append_To (Args,
Make_Selected_Component (Loc,
Prefix => Make_Identifier (Loc, Name_uInit),
Selector_Name => Make_Identifier (Loc, Name_uTask_Info)));
else
Append_To (Args, Make_Identifier (Loc, Name_uTask_Id));
end if;
-- Created_Task parameter. This is the _Task_Id field of the task
-- record value
Append_To (Args,
Make_Selected_Component (Loc,
Prefix => Make_Identifier (Loc, Name_uInit),
Selector_Name => Make_Identifier (Loc, Name_uTask_Id)));
if Restricted_Profile then
Name := New_Reference_To (RTE (RE_Create_Restricted_Task), Loc);
else
Name := New_Reference_To (RTE (RE_Create_Task), Loc);
end if;
return Make_Procedure_Call_Statement (Loc,
Name => Name, Parameter_Associations => Args);
end Make_Task_Create_Call;
------------------------------
-- Next_Protected_Operation --
------------------------------
function Next_Protected_Operation (N : Node_Id) return Node_Id is
Next_Op : Node_Id;
begin
Next_Op := Next (N);
while Present (Next_Op)
and then Nkind (Next_Op) /= N_Subprogram_Body
and then Nkind (Next_Op) /= N_Entry_Body
loop
Next (Next_Op);
end loop;
return Next_Op;
end Next_Protected_Operation;
----------------------
-- Set_Discriminals --
----------------------
procedure Set_Discriminals
(Dec : Node_Id;
Op : Node_Id;
Loc : Source_Ptr)
is
D : Entity_Id;
Pdef : Entity_Id;
D_Minal : Entity_Id;
begin
pragma Assert (Nkind (Dec) = N_Protected_Type_Declaration);
Pdef := Defining_Identifier (Dec);
if Has_Discriminants (Pdef) then
D := First_Discriminant (Pdef);
while Present (D) loop
D_Minal :=
Make_Defining_Identifier (Sloc (D),
Chars => New_External_Name (Chars (D), 'D'));
Set_Ekind (D_Minal, E_Constant);
Set_Etype (D_Minal, Etype (D));
Set_Discriminal (D, D_Minal);
Set_Discriminal_Link (D_Minal, D);
Next_Discriminant (D);
end loop;
end if;
end Set_Discriminals;
-----------------
-- Set_Privals --
-----------------
procedure Set_Privals
(Dec : Node_Id;
Op : Node_Id;
Loc : Source_Ptr)
is
P_Decl : Node_Id;
P_Id : Entity_Id;
Priv : Entity_Id;
Def : Node_Id;
Body_Ent : Entity_Id;
Prec_Decl : constant Node_Id :=
Parent (Corresponding_Record_Type
(Defining_Identifier (Dec)));
Prec_Def : constant Entity_Id := Type_Definition (Prec_Decl);
Obj_Decl : Node_Id;
P_Subtype : Entity_Id;
New_Decl : Entity_Id;
Assoc_L : Elist_Id := New_Elmt_List;
Op_Id : Entity_Id;
begin
pragma Assert (Nkind (Dec) = N_Protected_Type_Declaration);
pragma Assert
(Nkind (Op) = N_Subprogram_Body or else Nkind (Op) = N_Entry_Body);
Def := Protected_Definition (Dec);
if Present (Private_Declarations (Def)) then
P_Decl := First (Private_Declarations (Def));
while Present (P_Decl) loop
if Nkind (P_Decl) = N_Component_Declaration then
P_Id := Defining_Identifier (P_Decl);
Priv :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (P_Id), 'P'));
Set_Ekind (Priv, E_Variable);
Set_Etype (Priv, Etype (P_Id));
Set_Scope (Priv, Scope (P_Id));
Set_Esize (Priv, Esize (Etype (P_Id)));
Set_Alignment (Priv, Alignment (Etype (P_Id)));
-- If the type of the component is an itype, we must
-- create a new itype for the corresponding prival in
-- each protected operation, to avoid scoping problems.
-- We create new itypes by copying the tree for the
-- component definition.
if Is_Itype (Etype (P_Id)) then
Append_Elmt (P_Id, Assoc_L);
Append_Elmt (Priv, Assoc_L);
if Nkind (Op) = N_Entry_Body then
Op_Id := Defining_Identifier (Op);
else
Op_Id := Defining_Unit_Name (Specification (Op));
end if;
New_Decl := New_Copy_Tree (P_Decl, Assoc_L,
New_Scope => Op_Id);
end if;
Set_Protected_Operation (P_Id, Op);
Set_Prival (P_Id, Priv);
end if;
Next (P_Decl);
end loop;
end if;
-- There is one more implicit private declaration: the object
-- itself. A "prival" for this is attached to the protected
-- body defining identifier.
Body_Ent := Corresponding_Body (Dec);
Priv :=
Make_Defining_Identifier (Sloc (Body_Ent),
Chars => New_External_Name (Chars (Body_Ent), 'R'));
-- Set the Etype to the implicit subtype of Protection created when
-- the protected type declaration was expanded. This node will not
-- be analyzed until it is used as the defining identifier for the
-- renaming declaration in the protected operation body, and it will
-- be needed in the references expanded before that body is expanded.
-- Since the Protection field is aliased, set Is_Aliased as well.
Obj_Decl := First (Component_Items (Component_List (Prec_Def)));
while Chars (Defining_Identifier (Obj_Decl)) /= Name_uObject loop
Next (Obj_Decl);
end loop;
P_Subtype := Etype (Defining_Identifier (Obj_Decl));
Set_Etype (Priv, P_Subtype);
Set_Is_Aliased (Priv);
Set_Object_Ref (Body_Ent, Priv);
end Set_Privals;
----------------------------
-- Update_Prival_Subtypes --
----------------------------
procedure Update_Prival_Subtypes (N : Node_Id) is
function Process (N : Node_Id) return Traverse_Result;
-- Update the etype of occurrences of privals whose etype does not
-- match the current Etype of the prival entity itself.
procedure Update_Array_Bounds (E : Entity_Id);
-- Itypes generated for array expressions may depend on the
-- determinants of the protected object, and need to be processed
-- separately because they are not attached to the tree.
-------------
-- Process --
-------------
function Process (N : Node_Id) return Traverse_Result is
begin
if Is_Entity_Name (N) then
declare
E : Entity_Id := Entity (N);
begin
if Present (E)
and then (Ekind (E) = E_Constant
or else Ekind (E) = E_Variable)
and then Nkind (Parent (E)) = N_Object_Renaming_Declaration
and then not Is_Scalar_Type (Etype (E))
and then Etype (N) /= Etype (E)
then
Set_Etype (N, Etype (Entity (Original_Node (N))));
-- If the prefix has an actual subtype that is different
-- from the nominal one, update the types of the indices,
-- so that the proper constraints are applied. Do not
-- apply this transformation to a packed array, where the
-- index type is computed for a byte array and is different
-- from the source index.
if Nkind (Parent (N)) = N_Indexed_Component
and then
not Is_Bit_Packed_Array (Etype (Prefix (Parent (N))))
then
declare
Indx1 : Node_Id;
I_Typ : Node_Id;
begin
Indx1 := First (Expressions (Parent (N)));
I_Typ := First_Index (Etype (N));
while Present (Indx1) and then Present (I_Typ) loop
if not Is_Entity_Name (Indx1) then
Set_Etype (Indx1, Base_Type (Etype (I_Typ)));
end if;
Next (Indx1);
Next_Index (I_Typ);
end loop;
end;
end if;
elsif Present (E)
and then Ekind (E) = E_Constant
and then Present (Discriminal_Link (E))
then
Set_Etype (N, Etype (E));
end if;
end;
return OK;
elsif Nkind (N) = N_Defining_Identifier
or else Nkind (N) = N_Defining_Operator_Symbol
or else Nkind (N) = N_Defining_Character_Literal
then
return Skip;
elsif Nkind (N) = N_String_Literal then
-- array type, but bounds are constant.
return OK;
elsif Nkind (N) = N_Object_Declaration
and then Is_Itype (Etype (Defining_Identifier (N)))
and then Is_Array_Type (Etype (Defining_Identifier (N)))
then
Update_Array_Bounds (Etype (Defining_Identifier (N)));
return OK;
else
if Nkind (N) in N_Has_Etype
and then Present (Etype (N))
and then Is_Itype (Etype (N)) then
if Is_Array_Type (Etype (N)) then
Update_Array_Bounds (Etype (N));
elsif Is_Scalar_Type (Etype (N)) then
Update_Prival_Subtypes (Type_Low_Bound (Etype (N)));
Update_Prival_Subtypes (Type_High_Bound (Etype (N)));
end if;
end if;
return OK;
end if;
end Process;
-------------------------
-- Update_Array_Bounds --
-------------------------
procedure Update_Array_Bounds (E : Entity_Id) is
Ind : Node_Id;
begin
Ind := First_Index (E);
while Present (Ind) loop
Update_Prival_Subtypes (Type_Low_Bound (Etype (Ind)));
Update_Prival_Subtypes (Type_High_Bound (Etype (Ind)));
Next_Index (Ind);
end loop;
end Update_Array_Bounds;
procedure Traverse is new Traverse_Proc;
-- Start of processing for Update_Prival_Subtypes
begin
Traverse (N);
end Update_Prival_Subtypes;
end Exp_Ch9;