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gnu / gcc / a8404c07e7fca388c02c39077865f7d5fa928430 / . / gcc / ada / sem_ch9.adb
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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 9 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2022, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Aspects; use Aspects;
with Atree; use Atree;
with Checks; use Checks;
with Contracts; use Contracts;
with Einfo; use Einfo;
with Einfo.Entities; use Einfo.Entities;
with Einfo.Utils; use Einfo.Utils;
with Errout; use Errout;
with Exp_Ch9; use Exp_Ch9;
with Elists; use Elists;
with Freeze; use Freeze;
with Layout; use Layout;
with Lib; use Lib;
with Lib.Xref; use Lib.Xref;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch5; use Sem_Ch5;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch13; use Sem_Ch13;
with Sem_Elab; use Sem_Elab;
with Sem_Eval; use Sem_Eval;
with Sem_Prag; use Sem_Prag;
with Sem_Res; use Sem_Res;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Sem_Warn; use Sem_Warn;
with Snames; use Snames;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Sinfo.Nodes; use Sinfo.Nodes;
with Sinfo.Utils; use Sinfo.Utils;
with Style;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
package body Sem_Ch9 is
-----------------------
-- Local Subprograms --
-----------------------
function Allows_Lock_Free_Implementation
(N : Node_Id;
Lock_Free_Given : Boolean := False) return Boolean;
-- This routine returns True iff N satisfies the following list of lock-
-- free restrictions for protected type declaration and protected body:
--
-- 1) Protected type declaration
-- May not contain entries
-- Protected subprogram declarations may not have non-elementary
-- parameters.
--
-- 2) Protected Body
-- Each protected subprogram body within N must satisfy:
-- May reference only one protected component
-- May not reference non-constant entities outside the protected
-- subprogram scope.
-- May not contain address representation items, allocators and
-- quantified expressions.
-- May not contain delay, goto, loop and procedure call
-- statements.
-- May not contain exported and imported entities
-- May not dereference access values
-- Function calls and attribute references must be static
--
-- If Lock_Free_Given is True, an error message is issued when False is
-- returned.
procedure Check_Max_Entries (D : Node_Id; R : All_Parameter_Restrictions);
-- Given either a protected definition or a task definition in D, check
-- the corresponding restriction parameter identifier R, and if it is set,
-- count the entries (checking the static requirement), and compare with
-- the given maximum.
procedure Check_Interfaces (N : Node_Id; T : Entity_Id);
-- N is an N_Protected_Type_Declaration or N_Task_Type_Declaration node.
-- Complete decoration of T and check legality of the covered interfaces.
procedure Check_Triggering_Statement
(Trigger : Node_Id;
Error_Node : Node_Id;
Is_Dispatching : out Boolean);
-- Examine the triggering statement of a select statement, conditional or
-- timed entry call. If Trigger is a dispatching call, return its status
-- in Is_Dispatching and check whether the primitive belongs to a limited
-- interface. If it does not, emit an error at Error_Node.
function Find_Concurrent_Spec (Body_Id : Entity_Id) return Entity_Id;
-- Find entity in corresponding task or protected declaration. Use full
-- view if first declaration was for an incomplete type.
-------------------------------------
-- Allows_Lock_Free_Implementation --
-------------------------------------
function Allows_Lock_Free_Implementation
(N : Node_Id;
Lock_Free_Given : Boolean := False) return Boolean
is
Errors_Count : Nat := 0;
-- Errors_Count is a count of errors detected by the compiler so far
-- when Lock_Free_Given is True.
begin
pragma Assert
(Nkind (N) in N_Protected_Type_Declaration | N_Protected_Body);
-- Get the number of errors detected by the compiler so far
if Lock_Free_Given then
Errors_Count := Serious_Errors_Detected;
end if;
-- Protected type declaration case
if Nkind (N) = N_Protected_Type_Declaration then
declare
Pdef : constant Node_Id := Protected_Definition (N);
Priv_Decls : constant List_Id := Private_Declarations (Pdef);
Vis_Decls : constant List_Id := Visible_Declarations (Pdef);
Decl : Node_Id;
begin
-- Examine the visible and the private declarations
Decl := First (Vis_Decls);
while Present (Decl) loop
-- Entries and entry families are not allowed by the lock-free
-- restrictions.
if Nkind (Decl) = N_Entry_Declaration then
if Lock_Free_Given then
Error_Msg_N
("entry not allowed when Lock_Free given", Decl);
else
return False;
end if;
-- Non-elementary parameters in protected procedure are not
-- allowed by the lock-free restrictions.
elsif Nkind (Decl) = N_Subprogram_Declaration
and then
Nkind (Specification (Decl)) = N_Procedure_Specification
then
declare
Par_Specs : constant List_Id :=
Parameter_Specifications
(Specification (Decl));
Par : Node_Id;
begin
Par := First (Par_Specs);
while Present (Par) loop
if not Is_Elementary_Type
(Etype (Defining_Identifier (Par)))
then
if Lock_Free_Given then
Error_Msg_NE
("non-elementary parameter& not allowed "
& "when Lock_Free given",
Par, Defining_Identifier (Par));
else
return False;
end if;
end if;
Next (Par);
end loop;
end;
elsif Nkind (Decl) = N_Subprogram_Declaration
and then
Nkind (Specification (Decl)) = N_Function_Specification
and then
Nkind (Result_Definition (Specification (Decl)))
in N_Has_Entity
and then
Needs_Secondary_Stack
(Entity (Result_Definition (Specification (Decl))))
then
if Lock_Free_Given then
-- Message text is imprecise; "unconstrained" is
-- similar to "needs secondary stack" but not identical.
Error_Msg_N
("unconstrained function result subtype not allowed "
& "when Lock_Free given",
Decl);
else
return False;
end if;
end if;
-- Examine private declarations after visible declarations
if No (Next (Decl))
and then List_Containing (Decl) = Vis_Decls
then
Decl := First (Priv_Decls);
else
Next (Decl);
end if;
end loop;
end;
-- Protected body case
else
Protected_Body_Case : declare
Decls : constant List_Id := Declarations (N);
Pid : constant Entity_Id := Corresponding_Spec (N);
Prot_Typ_Decl : constant Node_Id := Parent (Pid);
Prot_Def : constant Node_Id :=
Protected_Definition (Prot_Typ_Decl);
Priv_Decls : constant List_Id :=
Private_Declarations (Prot_Def);
Decl : Node_Id;
function Satisfies_Lock_Free_Requirements
(Sub_Body : Node_Id) return Boolean;
-- Return True if protected subprogram body Sub_Body satisfies all
-- requirements of a lock-free implementation.
--------------------------------------
-- Satisfies_Lock_Free_Requirements --
--------------------------------------
function Satisfies_Lock_Free_Requirements
(Sub_Body : Node_Id) return Boolean
is
Comp : Entity_Id := Empty;
-- Track the current component which the body references
Errors_Count : Nat := 0;
-- Errors_Count is a count of errors detected by the compiler
-- so far when Lock_Free_Given is True.
function Check_Node (N : Node_Id) return Traverse_Result;
-- Check that node N meets the lock free restrictions
----------------
-- Check_Node --
----------------
function Check_Node (N : Node_Id) return Traverse_Result is
Kind : constant Node_Kind := Nkind (N);
-- The following function belongs in sem_eval ???
function Is_Static_Function (Attr : Node_Id) return Boolean;
-- Given an attribute reference node Attr, return True if
-- Attr denotes a static function according to the rules in
-- (RM 4.9 (22)).
------------------------
-- Is_Static_Function --
------------------------
function Is_Static_Function
(Attr : Node_Id) return Boolean
is
Para : Node_Id;
begin
pragma Assert (Nkind (Attr) = N_Attribute_Reference);
case Attribute_Name (Attr) is
when Name_Max
| Name_Min
| Name_Pred
| Name_Succ
| Name_Value
| Name_Wide_Value
| Name_Wide_Wide_Value
=>
-- A language-defined attribute denotes a static
-- function if the prefix denotes a static scalar
-- subtype, and if the parameter and result types
-- are scalar (RM 4.9 (22)).
if Is_Scalar_Type (Etype (Attr))
and then Is_Scalar_Type (Etype (Prefix (Attr)))
and then
Is_OK_Static_Subtype (Etype (Prefix (Attr)))
then
Para := First (Expressions (Attr));
while Present (Para) loop
if not Is_Scalar_Type (Etype (Para)) then
return False;
end if;
Next (Para);
end loop;
return True;
else
return False;
end if;
when others =>
return False;
end case;
end Is_Static_Function;
-- Start of processing for Check_Node
begin
-- Allocators restricted
if Kind = N_Allocator then
if Lock_Free_Given then
Error_Msg_N ("allocator not allowed", N);
return Skip;
end if;
return Abandon;
-- Aspects Address, Export and Import restricted
elsif Kind = N_Aspect_Specification then
declare
Asp_Name : constant Name_Id :=
Chars (Identifier (N));
Asp_Id : constant Aspect_Id :=
Get_Aspect_Id (Asp_Name);
begin
if Asp_Id = Aspect_Address or else
Asp_Id = Aspect_Export or else
Asp_Id = Aspect_Import
then
Error_Msg_Name_1 := Asp_Name;
if Lock_Free_Given then
Error_Msg_N ("aspect% not allowed", N);
return Skip;
end if;
return Abandon;
end if;
end;
-- Address attribute definition clause restricted
elsif Kind = N_Attribute_Definition_Clause
and then Get_Attribute_Id (Chars (N)) =
Attribute_Address
then
Error_Msg_Name_1 := Chars (N);
if Lock_Free_Given then
if From_Aspect_Specification (N) then
Error_Msg_N ("aspect% not allowed", N);
else
Error_Msg_N ("% clause not allowed", N);
end if;
return Skip;
end if;
return Abandon;
-- Non-static Attribute references that don't denote a
-- static function restricted.
elsif Kind = N_Attribute_Reference
and then not Is_OK_Static_Expression (N)
and then not Is_Static_Function (N)
then
if Lock_Free_Given then
Error_Msg_N
("non-static attribute reference not allowed", N);
return Skip;
end if;
return Abandon;
-- Delay statements restricted
elsif Kind in N_Delay_Statement then
if Lock_Free_Given then
Error_Msg_N ("delay not allowed", N);
return Skip;
end if;
return Abandon;
-- Dereferences of access values restricted
elsif Kind = N_Explicit_Dereference
or else (Kind = N_Selected_Component
and then Is_Access_Type (Etype (Prefix (N))))
then
if Lock_Free_Given then
Error_Msg_N
("dereference of access value not allowed", N);
return Skip;
end if;
return Abandon;
-- Non-static function calls restricted
elsif Kind = N_Function_Call
and then not Is_OK_Static_Expression (N)
then
if Lock_Free_Given then
Error_Msg_N
("non-static function call not allowed", N);
return Skip;
end if;
return Abandon;
-- Goto statements restricted
elsif Kind in N_Goto_Statement | N_Goto_When_Statement then
if Lock_Free_Given then
Error_Msg_N ("goto statement not allowed", N);
return Skip;
end if;
return Abandon;
-- References
elsif Kind in N_Identifier | N_Expanded_Name
and then Present (Entity (N))
then
declare
Id : constant Entity_Id := Entity (N);
Sub_Id : constant Entity_Id :=
Corresponding_Spec (Sub_Body);
begin
-- Prohibit references to non-constant entities
-- outside the protected subprogram scope.
--
-- References to variables in System.Scalar_Values
-- generated because of pragma Initialize_Scalars are
-- allowed, because once those variables are
-- initialized by the binder-generated code, they
-- behave like constants.
if Is_Assignable (Id)
and then not
Scope_Within_Or_Same (Scope (Id), Sub_Id)
and then not
Scope_Within_Or_Same
(Scope (Id),
Protected_Body_Subprogram (Sub_Id))
and then not
(Is_RTU (Scope (Id), System_Scalar_Values)
and then not Comes_From_Source (N))
then
if Lock_Free_Given then
Error_Msg_NE
("reference to global variable& not allowed",
N, Id);
return Skip;
end if;
return Abandon;
end if;
end;
-- Loop statements restricted
elsif Kind = N_Loop_Statement then
if Lock_Free_Given then
Error_Msg_N ("loop not allowed", N);
return Skip;
end if;
return Abandon;
-- Pragmas Export and Import restricted
elsif Kind = N_Pragma then
declare
Prag_Name : constant Name_Id :=
Pragma_Name (N);
Prag_Id : constant Pragma_Id :=
Get_Pragma_Id (Prag_Name);
begin
if Prag_Id = Pragma_Export
or else Prag_Id = Pragma_Import
then
Error_Msg_Name_1 := Prag_Name;
if Lock_Free_Given then
if From_Aspect_Specification (N) then
Error_Msg_N ("aspect% not allowed", N);
else
Error_Msg_N ("pragma% not allowed", N);
end if;
return Skip;
end if;
return Abandon;
end if;
end;
-- Procedure call statements restricted
elsif Kind = N_Procedure_Call_Statement then
if Lock_Free_Given then
Error_Msg_N ("procedure call not allowed", N);
return Skip;
end if;
return Abandon;
-- Quantified expression restricted. Note that we have
-- to check the original node as well, since at this
-- stage, it may have been rewritten.
elsif Kind = N_Quantified_Expression
or else
Nkind (Original_Node (N)) = N_Quantified_Expression
then
if Lock_Free_Given then
Error_Msg_N
("quantified expression not allowed", N);
return Skip;
end if;
return Abandon;
end if;
-- A protected subprogram (function or procedure) may
-- reference only one component of the protected type, plus
-- the type of the component must support atomic operation.
if Kind in N_Identifier | N_Expanded_Name
and then Present (Entity (N))
then
declare
Id : constant Entity_Id := Entity (N);
Comp_Decl : Node_Id;
Comp_Id : Entity_Id := Empty;
Comp_Type : Entity_Id;
begin
if Ekind (Id) = E_Component then
Comp_Id := Id;
elsif Ekind (Id) in E_Constant | E_Variable
and then Present (Prival_Link (Id))
then
Comp_Id := Prival_Link (Id);
end if;
if Present (Comp_Id) then
Comp_Decl := Parent (Comp_Id);
Comp_Type := Etype (Comp_Id);
if Nkind (Comp_Decl) = N_Component_Declaration
and then Is_List_Member (Comp_Decl)
and then List_Containing (Comp_Decl) = Priv_Decls
then
-- Skip generic types since, in that case, we
-- will not build a body anyway (in the generic
-- template), and the size in the template may
-- have a fake value.
if not Is_Generic_Type (Comp_Type) then
-- Make sure the protected component type has
-- size and alignment fields set at this
-- point whenever this is possible.
Layout_Type (Comp_Type);
if not
Support_Atomic_Primitives (Comp_Type)
then
if Lock_Free_Given then
Error_Msg_NE
("type of& must support atomic " &
"operations",
N, Comp_Id);
return Skip;
end if;
return Abandon;
end if;
end if;
-- Check if another protected component has
-- already been accessed by the subprogram body.
if No (Comp) then
Comp := Comp_Id;
elsif Comp /= Comp_Id then
if Lock_Free_Given then
Error_Msg_N
("only one protected component allowed",
N);
return Skip;
end if;
return Abandon;
end if;
end if;
end if;
end;
end if;
return OK;
end Check_Node;
function Check_All_Nodes is new Traverse_Func (Check_Node);
-- Start of processing for Satisfies_Lock_Free_Requirements
begin
if not Support_Atomic_Primitives_On_Target then
if Lock_Free_Given then
Error_Msg_N
("Lock_Free aspect requires target support for "
& "atomic primitives", N);
end if;
return False;
end if;
-- Deal with case where Ceiling_Locking locking policy is
-- in effect.
if Locking_Policy = 'C' then
if Lock_Free_Given then
-- Explicit Lock_Free aspect spec overrides
-- Ceiling_Locking so we generate a warning.
Error_Msg_N
("Lock_Free aspect specification overrides "
& "Ceiling_Locking locking policy??", N);
else
-- If Ceiling_Locking locking policy is in effect, then
-- Lock_Free can be explicitly specified but it is
-- never the default.
return False;
end if;
end if;
-- Get the number of errors detected by the compiler so far
if Lock_Free_Given then
Errors_Count := Serious_Errors_Detected;
end if;
if Check_All_Nodes (Sub_Body) = OK
and then (not Lock_Free_Given
or else Errors_Count = Serious_Errors_Detected)
then
-- Establish a relation between the subprogram body and the
-- unique protected component it references.
if Present (Comp) then
Lock_Free_Subprogram_Table.Append
(Lock_Free_Subprogram'(Sub_Body, Comp));
end if;
return True;
else
return False;
end if;
end Satisfies_Lock_Free_Requirements;
-- Start of processing for Protected_Body_Case
begin
Decl := First (Decls);
while Present (Decl) loop
if Nkind (Decl) = N_Subprogram_Body
and then not Satisfies_Lock_Free_Requirements (Decl)
then
if Lock_Free_Given then
Error_Msg_N
("illegal body when Lock_Free given", Decl);
else
return False;
end if;
end if;
Next (Decl);
end loop;
end Protected_Body_Case;
end if;
-- When Lock_Free is given, check if no error has been detected during
-- the process.
if Lock_Free_Given
and then Errors_Count /= Serious_Errors_Detected
then
return False;
end if;
return True;
end Allows_Lock_Free_Implementation;
-----------------------------
-- Analyze_Abort_Statement --
-----------------------------
procedure Analyze_Abort_Statement (N : Node_Id) is
T_Name : Node_Id;
begin
Tasking_Used := True;
T_Name := First (Names (N));
while Present (T_Name) loop
Analyze (T_Name);
if Is_Task_Type (Etype (T_Name))
or else (Ada_Version >= Ada_2005
and then Ekind (Etype (T_Name)) = E_Class_Wide_Type
and then Is_Interface (Etype (T_Name))
and then Is_Task_Interface (Etype (T_Name)))
then
Resolve (T_Name);
else
if Ada_Version >= Ada_2005 then
Error_Msg_N ("expect task name or task interface class-wide "
& "object for ABORT", T_Name);
else
Error_Msg_N ("expect task name for ABORT", T_Name);
end if;
return;
end if;
Next (T_Name);
end loop;
Check_Restriction (No_Abort_Statements, N);
Check_Potentially_Blocking_Operation (N);
end Analyze_Abort_Statement;
--------------------------------
-- Analyze_Accept_Alternative --
--------------------------------
procedure Analyze_Accept_Alternative (N : Node_Id) is
begin
Tasking_Used := True;
if Present (Pragmas_Before (N)) then
Analyze_List (Pragmas_Before (N));
end if;
if Present (Condition (N)) then
Analyze_And_Resolve (Condition (N), Any_Boolean);
end if;
Analyze (Accept_Statement (N));
if Is_Non_Empty_List (Statements (N)) then
Analyze_Statements (Statements (N));
end if;
end Analyze_Accept_Alternative;
------------------------------
-- Analyze_Accept_Statement --
------------------------------
procedure Analyze_Accept_Statement (N : Node_Id) is
Nam : constant Entity_Id := Entry_Direct_Name (N);
Formals : constant List_Id := Parameter_Specifications (N);
Index : constant Node_Id := Entry_Index (N);
Stats : constant Node_Id := Handled_Statement_Sequence (N);
Accept_Id : Entity_Id;
Entry_Nam : Entity_Id;
E : Entity_Id;
Kind : Entity_Kind;
Task_Nam : Entity_Id := Empty; -- initialize to prevent warning
begin
Tasking_Used := True;
-- Entry name is initialized to Any_Id. It should get reset to the
-- matching entry entity. An error is signalled if it is not reset.
Entry_Nam := Any_Id;
for J in reverse 0 .. Scope_Stack.Last loop
Task_Nam := Scope_Stack.Table (J).Entity;
exit when Ekind (Etype (Task_Nam)) = E_Task_Type;
Kind := Ekind (Task_Nam);
if Kind /= E_Block and then Kind /= E_Loop
and then not Is_Entry (Task_Nam)
then
Error_Msg_N ("enclosing body of ACCEPT must be a task", N);
return;
end if;
end loop;
if Ekind (Etype (Task_Nam)) /= E_Task_Type then
Error_Msg_N ("invalid context for ACCEPT statement", N);
return;
end if;
-- In order to process the parameters, we create a defining identifier
-- that can be used as the name of the scope. The name of the accept
-- statement itself is not a defining identifier, and we cannot use
-- its name directly because the task may have any number of accept
-- statements for the same entry.
if Present (Index) then
Accept_Id := New_Internal_Entity
(E_Entry_Family, Current_Scope, Sloc (N), 'E');
else
Accept_Id := New_Internal_Entity
(E_Entry, Current_Scope, Sloc (N), 'E');
end if;
Set_Etype (Accept_Id, Standard_Void_Type);
Set_Accept_Address (Accept_Id, New_Elmt_List);
if Present (Formals) then
Push_Scope (Accept_Id);
Process_Formals (Formals, N);
Create_Extra_Formals (Accept_Id);
End_Scope;
end if;
-- We set the default expressions processed flag because we don't need
-- default expression functions. This is really more like body entity
-- than a spec entity anyway.
Set_Default_Expressions_Processed (Accept_Id);
E := First_Entity (Etype (Task_Nam));
while Present (E) loop
if Chars (E) = Chars (Nam)
and then (Ekind (E) = Ekind (Accept_Id))
and then Type_Conformant (Accept_Id, E)
then
Entry_Nam := E;
exit;
end if;
Next_Entity (E);
end loop;
if Entry_Nam = Any_Id then
Error_Msg_N ("no entry declaration matches ACCEPT statement", N);
return;
else
Set_Entity (Nam, Entry_Nam);
Generate_Reference (Entry_Nam, Nam, 'b', Set_Ref => False);
Style.Check_Identifier (Nam, Entry_Nam);
end if;
-- Verify that the entry is not hidden by a procedure declared in the
-- current block (pathological but possible).
if Current_Scope /= Task_Nam then
declare
E1 : Entity_Id;
begin
E1 := First_Entity (Current_Scope);
while Present (E1) loop
if Ekind (E1) = E_Procedure
and then Chars (E1) = Chars (Entry_Nam)
and then Type_Conformant (E1, Entry_Nam)
then
Error_Msg_N ("entry name is not visible", N);
end if;
Next_Entity (E1);
end loop;
end;
end if;
Set_Convention (Accept_Id, Convention (Entry_Nam));
Check_Fully_Conformant (Accept_Id, Entry_Nam, N);
for J in reverse 0 .. Scope_Stack.Last loop
exit when Task_Nam = Scope_Stack.Table (J).Entity;
if Entry_Nam = Scope_Stack.Table (J).Entity then
Error_Msg_N
("duplicate ACCEPT statement for same entry (RM 9.5.2 (15))", N);
-- Do not continue analysis of accept statement, to prevent
-- cascaded errors.
return;
end if;
end loop;
declare
P : Node_Id := N;
begin
loop
P := Parent (P);
case Nkind (P) is
when N_Compilation_Unit
| N_Task_Body
=>
exit;
when N_Asynchronous_Select =>
Error_Msg_N
("ACCEPT statement not allowed within an "
& "asynchronous SELECT inner to the enclosing task body",
N);
exit;
when others =>
null;
end case;
end loop;
end;
if Ekind (Entry_Nam) = E_Entry_Family then
if No (Index) then
Error_Msg_N ("missing entry index in accept for entry family", N);
else
Analyze_And_Resolve (Index, Entry_Index_Type (Entry_Nam));
Apply_Scalar_Range_Check (Index, Entry_Index_Type (Entry_Nam));
end if;
elsif Present (Index) then
Error_Msg_N ("invalid entry index in accept for simple entry", N);
end if;
-- If label declarations present, analyze them. They are declared in the
-- enclosing task, but their enclosing scope is the entry itself, so
-- that goto's to the label are recognized as local to the accept.
if Present (Declarations (N)) then
declare
Decl : Node_Id;
Id : Entity_Id;
begin
Decl := First (Declarations (N));
while Present (Decl) loop
Analyze (Decl);
pragma Assert
(Nkind (Decl) = N_Implicit_Label_Declaration);
Id := Defining_Identifier (Decl);
Set_Enclosing_Scope (Id, Entry_Nam);
Next (Decl);
end loop;
end;
end if;
-- If statements are present, they must be analyzed in the context of
-- the entry, so that references to formals are correctly resolved. We
-- also have to add the declarations that are required by the expansion
-- of the accept statement in this case if expansion active.
-- In the case of a select alternative of a selective accept, the
-- expander references the address declaration even if there is no
-- statement list.
-- We also need to create the renaming declarations for the local
-- variables that will replace references to the formals within the
-- accept statement.
Exp_Ch9.Expand_Accept_Declarations (N, Entry_Nam);
-- Set Never_Set_In_Source and clear Is_True_Constant/Current_Value
-- fields on all entry formals (this loop ignores all other entities).
-- Reset Referenced, Referenced_As_xxx and Has_Pragma_Unreferenced as
-- well, so that we can post accurate warnings on each accept statement
-- for the same entry.
E := First_Entity (Entry_Nam);
while Present (E) loop
if Is_Formal (E) then
Set_Never_Set_In_Source (E, True);
Set_Is_True_Constant (E, False);
Set_Current_Value (E, Empty);
Set_Referenced (E, False);
Set_Referenced_As_LHS (E, False);
Set_Referenced_As_Out_Parameter (E, False);
Set_Has_Pragma_Unreferenced (E, False);
end if;
Next_Entity (E);
end loop;
-- Analyze statements if present
if Present (Stats) then
Push_Scope (Entry_Nam);
Install_Declarations (Entry_Nam);
Set_Actual_Subtypes (N, Current_Scope);
Analyze (Stats);
Process_End_Label (Handled_Statement_Sequence (N), 't', Entry_Nam);
End_Scope;
end if;
-- Some warning checks
Check_Potentially_Blocking_Operation (N);
Check_References (Entry_Nam, N);
Set_Entry_Accepted (Entry_Nam);
end Analyze_Accept_Statement;
---------------------------------
-- Analyze_Asynchronous_Select --
---------------------------------
procedure Analyze_Asynchronous_Select (N : Node_Id) is
Is_Disp_Select : Boolean := False;
Trigger : Node_Id;
begin
Tasking_Used := True;
Check_Restriction (Max_Asynchronous_Select_Nesting, N);
Check_Restriction (No_Select_Statements, N);
if Ada_Version >= Ada_2005 then
Trigger := Triggering_Statement (Triggering_Alternative (N));
Analyze (Trigger);
-- Ada 2005 (AI-345): Check for a potential dispatching select
Check_Triggering_Statement (Trigger, N, Is_Disp_Select);
end if;
-- Ada 2005 (AI-345): The expansion of the dispatching asynchronous
-- select will have to duplicate the triggering statements. Postpone
-- the analysis of the statements till expansion. Analyze only if the
-- expander is disabled in order to catch any semantic errors.
if Is_Disp_Select then
if not Expander_Active then
Analyze_Statements (Statements (Abortable_Part (N)));
Analyze (Triggering_Alternative (N));
end if;
-- Analyze the statements. We analyze statements in the abortable part,
-- because this is the section that is executed first, and that way our
-- remembering of saved values and checks is accurate.
else
Analyze_Statements (Statements (Abortable_Part (N)));
Analyze (Triggering_Alternative (N));
end if;
end Analyze_Asynchronous_Select;
------------------------------------
-- Analyze_Conditional_Entry_Call --
------------------------------------
procedure Analyze_Conditional_Entry_Call (N : Node_Id) is
Trigger : constant Node_Id :=
Entry_Call_Statement (Entry_Call_Alternative (N));
Is_Disp_Select : Boolean := False;
begin
Tasking_Used := True;
Check_Restriction (No_Select_Statements, N);
-- Ada 2005 (AI-345): The trigger may be a dispatching call
if Ada_Version >= Ada_2005 then
Analyze (Trigger);
Check_Triggering_Statement (Trigger, N, Is_Disp_Select);
end if;
if List_Length (Else_Statements (N)) = 1
and then Nkind (First (Else_Statements (N))) in N_Delay_Statement
then
Error_Msg_N
("suspicious form of conditional entry call??!", N);
Error_Msg_N
("\`SELECT OR` may be intended rather than `SELECT ELSE`??!", N);
end if;
-- Postpone the analysis of the statements till expansion. Analyze only
-- if the expander is disabled in order to catch any semantic errors.
if Is_Disp_Select then
if not Expander_Active then
Analyze (Entry_Call_Alternative (N));
Analyze_Statements (Else_Statements (N));
end if;
-- Regular select analysis
else
Analyze (Entry_Call_Alternative (N));
Analyze_Statements (Else_Statements (N));
end if;
end Analyze_Conditional_Entry_Call;
--------------------------------
-- Analyze_Delay_Alternative --
--------------------------------
procedure Analyze_Delay_Alternative (N : Node_Id) is
Expr : Node_Id;
Typ : Entity_Id;
begin
Tasking_Used := True;
Check_Restriction (No_Delay, N);
if Present (Pragmas_Before (N)) then
Analyze_List (Pragmas_Before (N));
end if;
if Nkind (Parent (N)) in N_Selective_Accept | N_Timed_Entry_Call then
Expr := Expression (Delay_Statement (N));
-- Defer full analysis until the statement is expanded, to insure
-- that generated code does not move past the guard. The delay
-- expression is only evaluated if the guard is open.
if Nkind (Delay_Statement (N)) = N_Delay_Relative_Statement then
Preanalyze_And_Resolve (Expr, Standard_Duration);
else
Preanalyze_And_Resolve (Expr);
end if;
Typ := First_Subtype (Etype (Expr));
if Nkind (Delay_Statement (N)) = N_Delay_Until_Statement
and then not Is_RTE (Typ, RO_CA_Time)
and then not Is_RTE (Typ, RO_RT_Time)
then
Error_Msg_N ("expect Time types for `DELAY UNTIL`", Expr);
end if;
Check_Restriction (No_Fixed_Point, Expr);
else
Analyze (Delay_Statement (N));
end if;
if Present (Condition (N)) then
Analyze_And_Resolve (Condition (N), Any_Boolean);
end if;
if Is_Non_Empty_List (Statements (N)) then
Analyze_Statements (Statements (N));
end if;
end Analyze_Delay_Alternative;
----------------------------
-- Analyze_Delay_Relative --
----------------------------
procedure Analyze_Delay_Relative (N : Node_Id) is
E : constant Node_Id := Expression (N);
begin
Tasking_Used := True;
Check_Restriction (No_Relative_Delay, N);
Check_Restriction (No_Delay, N);
Check_Potentially_Blocking_Operation (N);
Analyze_And_Resolve (E, Standard_Duration);
Check_Restriction (No_Fixed_Point, E);
-- In SPARK mode the relative delay statement introduces an implicit
-- dependency on the Ada.Real_Time.Clock_Time abstract state, so we must
-- force the loading of the Ada.Real_Time package.
if GNATprove_Mode then
SPARK_Implicit_Load (RO_RT_Time);
end if;
end Analyze_Delay_Relative;
-------------------------
-- Analyze_Delay_Until --
-------------------------
procedure Analyze_Delay_Until (N : Node_Id) is
E : constant Node_Id := Expression (N);
Typ : Entity_Id;
begin
Tasking_Used := True;
Check_Restriction (No_Delay, N);
Check_Potentially_Blocking_Operation (N);
Analyze_And_Resolve (E);
Typ := First_Subtype (Etype (E));
if not Is_RTE (Typ, RO_CA_Time) and then
not Is_RTE (Typ, RO_RT_Time)
then
Error_Msg_N ("expect Time types for `DELAY UNTIL`", E);
end if;
end Analyze_Delay_Until;
------------------------
-- Analyze_Entry_Body --
------------------------
procedure Analyze_Entry_Body (N : Node_Id) is
Id : constant Entity_Id := Defining_Identifier (N);
Decls : constant List_Id := Declarations (N);
Stats : constant Node_Id := Handled_Statement_Sequence (N);
Formals : constant Node_Id := Entry_Body_Formal_Part (N);
P_Type : constant Entity_Id := Current_Scope;
E : Entity_Id;
Entry_Name : Entity_Id;
begin
-- An entry body freezes the contract of the nearest enclosing package
-- body and all other contracts encountered in the same declarative part
-- up to and excluding the entry body. This ensures that any annotations
-- referenced by the contract of an entry or subprogram body declared
-- within the current protected body are available.
Freeze_Previous_Contracts (N);
Tasking_Used := True;
-- Entry_Name is initialized to Any_Id. It should get reset to the
-- matching entry entity. An error is signalled if it is not reset.
Entry_Name := Any_Id;
Analyze (Formals);
if Present (Entry_Index_Specification (Formals)) then
Mutate_Ekind (Id, E_Entry_Family);
else
Mutate_Ekind (Id, E_Entry);
end if;
Set_Etype (Id, Standard_Void_Type);
Set_Scope (Id, Current_Scope);
Set_Accept_Address (Id, New_Elmt_List);
-- Set the SPARK_Mode from the current context (may be overwritten later
-- with an explicit pragma).
Set_SPARK_Pragma (Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Id);
-- Analyze any aspect specifications that appear on the entry body
if Has_Aspects (N) then
Analyze_Aspects_On_Subprogram_Body_Or_Stub (N);
end if;
E := First_Entity (P_Type);
while Present (E) loop
if Chars (E) = Chars (Id)
and then Ekind (E) = Ekind (Id)
and then Type_Conformant (Id, E)
then
Entry_Name := E;
Set_Convention (Id, Convention (E));
Set_Corresponding_Body (Parent (E), Id);
Check_Fully_Conformant (Id, E, N);
if Ekind (Id) = E_Entry_Family then
if not Fully_Conformant_Discrete_Subtypes (
Discrete_Subtype_Definition (Parent (E)),
Discrete_Subtype_Definition
(Entry_Index_Specification (Formals)))
then
Error_Msg_N
("index not fully conformant with previous declaration",
Discrete_Subtype_Definition
(Entry_Index_Specification (Formals)));
else
-- The elaboration of the entry body does not recompute the
-- bounds of the index, which may have side effects. Inherit
-- the bounds from the entry declaration. This is critical
-- if the entry has a per-object constraint. If a bound is
-- given by a discriminant, it must be reanalyzed in order
-- to capture the discriminal of the current entry, rather
-- than that of the protected type.
declare
Index_Spec : constant Node_Id :=
Entry_Index_Specification (Formals);
Def : constant Node_Id :=
New_Copy_Tree
(Discrete_Subtype_Definition (Parent (E)));
begin
if Nkind
(Original_Node
(Discrete_Subtype_Definition (Index_Spec))) = N_Range
then
Set_Etype (Def, Empty);
Set_Analyzed (Def, False);
-- Keep the original subtree to ensure a properly
-- formed tree.
Rewrite
(Discrete_Subtype_Definition (Index_Spec), Def);
Set_Analyzed (Low_Bound (Def), False);
Set_Analyzed (High_Bound (Def), False);
if Denotes_Discriminant (Low_Bound (Def)) then
Set_Entity (Low_Bound (Def), Empty);
end if;
if Denotes_Discriminant (High_Bound (Def)) then
Set_Entity (High_Bound (Def), Empty);
end if;
Analyze (Def);
Make_Index (Def, Index_Spec);
Set_Etype
(Defining_Identifier (Index_Spec), Etype (Def));
end if;
end;
end if;
end if;
exit;
end if;
Next_Entity (E);
end loop;
if Entry_Name = Any_Id then
Error_Msg_N ("no entry declaration matches entry body", N);
return;
elsif Has_Completion (Entry_Name) then
Error_Msg_N ("duplicate entry body", N);
return;
else
Set_Has_Completion (Entry_Name);
Generate_Reference (Entry_Name, Id, 'b', Set_Ref => False);
Style.Check_Identifier (Id, Entry_Name);
end if;
Exp_Ch9.Expand_Entry_Barrier (N, Entry_Name);
Push_Scope (Entry_Name);
Install_Declarations (Entry_Name);
Set_Actual_Subtypes (N, Current_Scope);
-- The entity for the protected subprogram corresponding to the entry
-- has been created. We retain the name of this entity in the entry
-- body, for use when the corresponding subprogram body is created.
-- Note that entry bodies have no Corresponding_Spec, and there is no
-- easy link back in the tree between the entry body and the entity for
-- the entry itself, which is why we must propagate some attributes
-- explicitly from spec to body.
Set_Protected_Body_Subprogram
(Id, Protected_Body_Subprogram (Entry_Name));
Set_Entry_Parameters_Type
(Id, Entry_Parameters_Type (Entry_Name));
-- Add a declaration for the Protection object, renaming declarations
-- for the discriminals and privals and finally a declaration for the
-- entry family index (if applicable).
if Expander_Active
and then Is_Protected_Type (P_Type)
then
Install_Private_Data_Declarations
(Sloc (N), Entry_Name, P_Type, N, Decls);
end if;
if Present (Decls) then
Analyze_Declarations (Decls);
Inspect_Deferred_Constant_Completion (Decls);
end if;
-- Process the contract of the subprogram body after all declarations
-- have been analyzed. This ensures that any contract-related pragmas
-- are available through the N_Contract node of the body.
Analyze_Entry_Or_Subprogram_Body_Contract (Id);
if Present (Stats) then
Analyze (Stats);
end if;
-- Check for unreferenced variables etc. Before the Check_References
-- call, we transfer Never_Set_In_Source and Referenced flags from
-- parameters in the spec to the corresponding entities in the body,
-- since we want the warnings on the body entities. Note that we do not
-- have to transfer Referenced_As_LHS, since that flag can only be set
-- for simple variables, but we include Has_Pragma_Unreferenced,
-- which may have been specified for a formal in the body.
-- At the same time, we set the flags on the spec entities to suppress
-- any warnings on the spec formals, since we also scan the spec.
-- Finally, we propagate the Entry_Component attribute to the body
-- formals, for use in the renaming declarations created later for the
-- formals (see exp_ch9.Add_Formal_Renamings).
declare
E1 : Entity_Id;
E2 : Entity_Id;
begin
E1 := First_Entity (Entry_Name);
while Present (E1) loop
E2 := First_Entity (Id);
while Present (E2) loop
exit when Chars (E1) = Chars (E2);
Next_Entity (E2);
end loop;
-- If no matching body entity, then we already had a detected
-- error of some kind, so just don't worry about these warnings.
if No (E2) then
goto Continue;
end if;
if Ekind (E1) = E_Out_Parameter then
Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1));
Set_Never_Set_In_Source (E1, False);
end if;
Set_Referenced (E2, Referenced (E1));
Set_Referenced (E1);
Set_Has_Pragma_Unreferenced (E2, Has_Pragma_Unreferenced (E1));
Set_Entry_Component (E2, Entry_Component (E1));
<<Continue>>
Next_Entity (E1);
end loop;
Check_References (Id);
end;
-- We still need to check references for the spec, since objects
-- declared in the body are chained (in the First_Entity sense) to
-- the spec rather than the body in the case of entries.
Check_References (Entry_Name);
-- Process the end label, and terminate the scope
Process_End_Label (Handled_Statement_Sequence (N), 't', Entry_Name);
Update_Use_Clause_Chain;
End_Scope;
-- If this is an entry family, remove the loop created to provide
-- a scope for the entry index.
if Ekind (Id) = E_Entry_Family
and then Present (Entry_Index_Specification (Formals))
then
End_Scope;
end if;
end Analyze_Entry_Body;
------------------------------------
-- Analyze_Entry_Body_Formal_Part --
------------------------------------
procedure Analyze_Entry_Body_Formal_Part (N : Node_Id) is
Id : constant Entity_Id := Defining_Identifier (Parent (N));
Index : constant Node_Id := Entry_Index_Specification (N);
Formals : constant List_Id := Parameter_Specifications (N);
begin
Tasking_Used := True;
if Present (Index) then
Analyze (Index);
-- The entry index functions like a loop variable, thus it is known
-- to have a valid value.
Set_Is_Known_Valid (Defining_Identifier (Index));
end if;
if Present (Formals) then
Set_Scope (Id, Current_Scope);
Push_Scope (Id);
Process_Formals (Formals, Parent (N));
End_Scope;
end if;
end Analyze_Entry_Body_Formal_Part;
------------------------------------
-- Analyze_Entry_Call_Alternative --
------------------------------------
procedure Analyze_Entry_Call_Alternative (N : Node_Id) is
Call : constant Node_Id := Entry_Call_Statement (N);
begin
Tasking_Used := True;
if Present (Pragmas_Before (N)) then
Analyze_List (Pragmas_Before (N));
end if;
if Nkind (Call) = N_Attribute_Reference then
-- Possibly a stream attribute, but definitely illegal. Other
-- illegalities, such as procedure calls, are diagnosed after
-- resolution.
Error_Msg_N ("entry call alternative requires an entry call", Call);
return;
end if;
Analyze (Call);
-- An indirect call in this context is illegal. A procedure call that
-- does not involve a renaming of an entry is illegal as well, but this
-- and other semantic errors are caught during resolution.
if Nkind (Call) = N_Explicit_Dereference then
Error_Msg_N
("entry call or dispatching primitive of interface required", N);
end if;
if Is_Non_Empty_List (Statements (N)) then
Analyze_Statements (Statements (N));
end if;
end Analyze_Entry_Call_Alternative;
-------------------------------
-- Analyze_Entry_Declaration --
-------------------------------
procedure Analyze_Entry_Declaration (N : Node_Id) is
D_Sdef : constant Node_Id := Discrete_Subtype_Definition (N);
Def_Id : constant Entity_Id := Defining_Identifier (N);
Formals : constant List_Id := Parameter_Specifications (N);
begin
Generate_Definition (Def_Id);
Tasking_Used := True;
-- Case of no discrete subtype definition
if No (D_Sdef) then
Mutate_Ekind (Def_Id, E_Entry);
-- Processing for discrete subtype definition present
else
Enter_Name (Def_Id);
Mutate_Ekind (Def_Id, E_Entry_Family);
Analyze (D_Sdef);
Make_Index (D_Sdef, N, Def_Id);
-- Check subtype with predicate in entry family
Bad_Predicated_Subtype_Use
("subtype& has predicate, not allowed in entry family",
D_Sdef, Etype (D_Sdef));
-- Check entry family static bounds outside allowed limits
-- Note: originally this check was not performed here, but in that
-- case the check happens deep in the expander, and the message is
-- posted at the wrong location, and omitted in -gnatc mode.
-- If the type of the entry index is a generic formal, no check
-- is possible. In an instance, the check is not static and a run-
-- time exception will be raised if the bounds are unreasonable.
declare
PEI : constant Entity_Id := RTE (RE_Protected_Entry_Index);
LB : constant Uint := Expr_Value (Type_Low_Bound (PEI));
UB : constant Uint := Expr_Value (Type_High_Bound (PEI));
LBR : Node_Id;
UBR : Node_Id;
begin
-- No bounds checking if the type is generic or if previous error.
-- In an instance the check is dynamic.
if Is_Generic_Type (Etype (D_Sdef))
or else In_Instance
or else Error_Posted (D_Sdef)
then
goto Skip_LB;
elsif Nkind (D_Sdef) = N_Range then
LBR := Low_Bound (D_Sdef);
elsif Is_Entity_Name (D_Sdef)
and then Is_Type (Entity (D_Sdef))
then
LBR := Type_Low_Bound (Entity (D_Sdef));
else
goto Skip_LB;
end if;
if Is_OK_Static_Expression (LBR)
and then Expr_Value (LBR) < LB
then
Error_Msg_Uint_1 := LB;
Error_Msg_N ("entry family low bound must be '>'= ^!", D_Sdef);
end if;
<<Skip_LB>>
if Is_Generic_Type (Etype (D_Sdef))
or else In_Instance
or else Error_Posted (D_Sdef)
then
goto Skip_UB;
elsif Nkind (D_Sdef) = N_Range then
UBR := High_Bound (D_Sdef);
elsif Is_Entity_Name (D_Sdef)
and then Is_Type (Entity (D_Sdef))
then
UBR := Type_High_Bound (Entity (D_Sdef));
else
goto Skip_UB;
end if;
if Is_OK_Static_Expression (UBR)
and then Expr_Value (UBR) > UB
then
Error_Msg_Uint_1 := UB;
Error_Msg_N ("entry family high bound must be '<'= ^!", D_Sdef);
end if;
<<Skip_UB>>
null;
end;
end if;
-- Decorate Def_Id
Set_Etype (Def_Id, Standard_Void_Type);
Set_Convention (Def_Id, Convention_Entry);
Set_Accept_Address (Def_Id, New_Elmt_List);
-- Set the SPARK_Mode from the current context (may be overwritten later
-- with an explicit pragma). Task entries are excluded because they are
-- not completed by entry bodies.
if Ekind (Current_Scope) = E_Protected_Type then
Set_SPARK_Pragma (Def_Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Def_Id);
end if;
-- Preserve relevant elaboration-related attributes of the context which
-- are no longer available or very expensive to recompute once analysis,
-- resolution, and expansion are over.
Mark_Elaboration_Attributes
(N_Id => Def_Id,
Checks => True,
Warnings => True);
-- Process formals
if Present (Formals) then
Set_Scope (Def_Id, Current_Scope);
Push_Scope (Def_Id);
Process_Formals (Formals, N);
Create_Extra_Formals (Def_Id);
End_Scope;
end if;
if Ekind (Def_Id) = E_Entry then
New_Overloaded_Entity (Def_Id);
end if;
Generate_Reference_To_Formals (Def_Id);
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Def_Id);
end if;
end Analyze_Entry_Declaration;
---------------------------------------
-- Analyze_Entry_Index_Specification --
---------------------------------------
-- The Defining_Identifier of the entry index specification is local to the
-- entry body, but it must be available in the entry barrier which is
-- evaluated outside of the entry body. The index is eventually renamed as
-- a run-time object, so its visibility is strictly a front-end concern. In
-- order to make it available to the barrier, we create an additional
-- scope, as for a loop, whose only declaration is the index name. This
-- loop is not attached to the tree and does not appear as an entity local
-- to the protected type, so its existence need only be known to routines
-- that process entry families.
procedure Analyze_Entry_Index_Specification (N : Node_Id) is
Iden : constant Node_Id := Defining_Identifier (N);
Def : constant Node_Id := Discrete_Subtype_Definition (N);
Loop_Id : constant Entity_Id := Make_Temporary (Sloc (N), 'L');
begin
Tasking_Used := True;
Analyze (Def);
-- There is no elaboration of the entry index specification. Therefore,
-- if the index is a range, it is not resolved and expanded, but the
-- bounds are inherited from the entry declaration, and reanalyzed.
-- See Analyze_Entry_Body.
if Nkind (Def) /= N_Range then
Make_Index (Def, N);
end if;
Mutate_Ekind (Loop_Id, E_Loop);
Set_Scope (Loop_Id, Current_Scope);
Push_Scope (Loop_Id);
Enter_Name (Iden);
Mutate_Ekind (Iden, E_Entry_Index_Parameter);
Set_Etype (Iden, Etype (Def));
end Analyze_Entry_Index_Specification;
----------------------------
-- Analyze_Protected_Body --
----------------------------
procedure Analyze_Protected_Body (N : Node_Id) is
Body_Id : constant Entity_Id := Defining_Identifier (N);
Last_E : Entity_Id;
Spec_Id : Entity_Id;
-- This is initially the entity of the protected object or protected
-- type involved, but is replaced by the protected type always in the
-- case of a single protected declaration, since this is the proper
-- scope to be used.
Ref_Id : Entity_Id;
-- This is the entity of the protected object or protected type
-- involved, and is the entity used for cross-reference purposes (it
-- differs from Spec_Id in the case of a single protected object, since
-- Spec_Id is set to the protected type in this case).
function Lock_Free_Disabled return Boolean;
-- This routine returns False if the protected object has a Lock_Free
-- aspect specification or a Lock_Free pragma that turns off the
-- lock-free implementation (e.g. whose expression is False).
------------------------
-- Lock_Free_Disabled --
------------------------
function Lock_Free_Disabled return Boolean is
Ritem : constant Node_Id :=
Get_Rep_Item
(Spec_Id, Name_Lock_Free, Check_Parents => False);
begin
if Present (Ritem) then
-- Pragma with one argument
if Nkind (Ritem) = N_Pragma
and then Present (Pragma_Argument_Associations (Ritem))
then
return
Is_False
(Static_Boolean
(Expression
(First (Pragma_Argument_Associations (Ritem)))));
-- Aspect Specification with expression present
elsif Nkind (Ritem) = N_Aspect_Specification
and then Present (Expression (Ritem))
then
return Is_False (Static_Boolean (Expression (Ritem)));
-- Otherwise, return False
else
return False;
end if;
end if;
return False;
end Lock_Free_Disabled;
-- Start of processing for Analyze_Protected_Body
begin
-- A protected body freezes the contract of the nearest enclosing
-- package body and all other contracts encountered in the same
-- declarative part up to and excluding the protected body. This
-- ensures that any annotations referenced by the contract of an
-- entry or subprogram body declared within the current protected
-- body are available.
Freeze_Previous_Contracts (N);
Tasking_Used := True;
Mutate_Ekind (Body_Id, E_Protected_Body);
Set_Etype (Body_Id, Standard_Void_Type);
Spec_Id := Find_Concurrent_Spec (Body_Id);
if Present (Spec_Id) and then Ekind (Spec_Id) = E_Protected_Type then
null;
elsif Present (Spec_Id)
and then Ekind (Etype (Spec_Id)) = E_Protected_Type
and then not Comes_From_Source (Etype (Spec_Id))
then
null;
else
Error_Msg_N ("missing specification for protected body", Body_Id);
return;
end if;
Ref_Id := Spec_Id;
Generate_Reference (Ref_Id, Body_Id, 'b', Set_Ref => False);
Style.Check_Identifier (Body_Id, Spec_Id);
-- The declarations are always attached to the type
if Ekind (Spec_Id) /= E_Protected_Type then
Spec_Id := Etype (Spec_Id);
end if;
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Body_Id);
end if;
Push_Scope (Spec_Id);
Set_Corresponding_Spec (N, Spec_Id);
Set_Corresponding_Body (Parent (Spec_Id), Body_Id);
Set_Has_Completion (Spec_Id);
Install_Declarations (Spec_Id);
Expand_Protected_Body_Declarations (N, Spec_Id);
Last_E := Last_Entity (Spec_Id);
Analyze_Declarations (Declarations (N));
-- For visibility purposes, all entities in the body are private. Set
-- First_Private_Entity accordingly, if there was no private part in the
-- protected declaration.
if No (First_Private_Entity (Spec_Id)) then
if Present (Last_E) then
Set_First_Private_Entity (Spec_Id, Next_Entity (Last_E));
else
Set_First_Private_Entity (Spec_Id, First_Entity (Spec_Id));
end if;
end if;
Check_Completion (Body_Id);
Check_References (Spec_Id);
Process_End_Label (N, 't', Ref_Id);
Update_Use_Clause_Chain;
End_Scope;
-- When a Lock_Free aspect specification/pragma forces the lock-free
-- implementation, verify the protected body meets all the restrictions,
-- otherwise Allows_Lock_Free_Implementation issues an error message.
if Uses_Lock_Free (Spec_Id) then
if not Allows_Lock_Free_Implementation (N, True) then
return;
end if;
-- In other cases, if there is no aspect specification/pragma that
-- disables the lock-free implementation, check both the protected
-- declaration and body satisfy the lock-free restrictions.
elsif not Lock_Free_Disabled
and then Allows_Lock_Free_Implementation (Parent (Spec_Id))
and then Allows_Lock_Free_Implementation (N)
then
Set_Uses_Lock_Free (Spec_Id);
end if;
end Analyze_Protected_Body;
----------------------------------
-- Analyze_Protected_Definition --
----------------------------------
procedure Analyze_Protected_Definition (N : Node_Id) is
procedure Undelay_Itypes (T : Entity_Id);
-- Itypes created for the private components of a protected type
-- do not receive freeze nodes, because there is no scope in which
-- they can be elaborated, and they can depend on discriminants of
-- the enclosed protected type. Given that the components can be
-- composite types with inner components, we traverse recursively
-- the private components of the protected type, and indicate that
-- all itypes within are frozen. This ensures that no freeze nodes
-- will be generated for them. In the case of itypes that are access
-- types we need to complete their representation by calling layout,
-- which would otherwise be invoked when freezing a type.
--
-- On the other hand, components of the corresponding record are
-- frozen (or receive itype references) as for other records.
--------------------
-- Undelay_Itypes --
--------------------
procedure Undelay_Itypes (T : Entity_Id) is
Comp : Entity_Id;
begin
if Is_Protected_Type (T) then
Comp := First_Private_Entity (T);
elsif Is_Record_Type (T) then
Comp := First_Entity (T);
else
return;
end if;
while Present (Comp) loop
if Is_Type (Comp) and then Is_Itype (Comp) then
Set_Has_Delayed_Freeze (Comp, False);
Set_Is_Frozen (Comp);
if Is_Access_Type (Comp) then
Layout_Type (Comp);
end if;
if Is_Record_Type (Comp) or else Is_Protected_Type (Comp) then
Undelay_Itypes (Comp);
end if;
end if;
Next_Entity (Comp);
end loop;
end Undelay_Itypes;
-- Local variables
Prot_Typ : constant Entity_Id := Current_Scope;
Item_Id : Entity_Id;
Last_Id : Entity_Id;
-- Start of processing for Analyze_Protected_Definition
begin
Tasking_Used := True;
Analyze_Declarations (Visible_Declarations (N));
if not Is_Empty_List (Private_Declarations (N)) then
Last_Id := Last_Entity (Prot_Typ);
Analyze_Declarations (Private_Declarations (N));
if Present (Last_Id) then
Set_First_Private_Entity (Prot_Typ, Next_Entity (Last_Id));
else
Set_First_Private_Entity (Prot_Typ, First_Entity (Prot_Typ));
end if;
end if;
Item_Id := First_Entity (Prot_Typ);
while Present (Item_Id) loop
if Ekind (Item_Id) in E_Function | E_Procedure then
Set_Convention (Item_Id, Convention_Protected);
else
Propagate_Concurrent_Flags (Prot_Typ, Etype (Item_Id));
if Chars (Item_Id) /= Name_uParent
and then Needs_Finalization (Etype (Item_Id))
then
Set_Has_Controlled_Component (Prot_Typ);
end if;
end if;
Next_Entity (Item_Id);
end loop;
Undelay_Itypes (Prot_Typ);
Check_Max_Entries (N, Max_Protected_Entries);
Process_End_Label (N, 'e', Prot_Typ);
end Analyze_Protected_Definition;
----------------------------------------
-- Analyze_Protected_Type_Declaration --
----------------------------------------
procedure Analyze_Protected_Type_Declaration (N : Node_Id) is
Def_Id : constant Entity_Id := Defining_Identifier (N);
E : Entity_Id;
T : Entity_Id;
begin
if No_Run_Time_Mode then
Error_Msg_CRT ("protected type", N);
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Def_Id);
end if;
return;
end if;
Tasking_Used := True;
Check_Restriction (No_Protected_Types, N);
T := Find_Type_Name (N);
-- In the case of an incomplete type, use the full view, unless it's not
-- present (as can occur for an incomplete view from a limited with).
if Ekind (T) = E_Incomplete_Type and then Present (Full_View (T)) then
T := Full_View (T);
Set_Completion_Referenced (T);
end if;
Mutate_Ekind (T, E_Protected_Type);
Set_Is_First_Subtype (T);
Reinit_Size_Align (T);
Set_Etype (T, T);
Set_Has_Delayed_Freeze (T);
Set_Stored_Constraint (T, No_Elist);
-- Initialize type's primitive operations list, for possible use when
-- the extension of prefixed call notation for untagged types is enabled
-- (such as by use of -gnatX).
Set_Direct_Primitive_Operations (T, New_Elmt_List);
-- Mark this type as a protected type for the sake of restrictions,
-- unless the protected type is declared in a private part of a package
-- of the runtime. With this exception, the Suspension_Object from
-- Ada.Synchronous_Task_Control can be implemented using a protected
-- object without triggering violations of No_Local_Protected_Objects
-- when the user locally declares such an object. This may look like a
-- trick, but the user doesn't have to know how Suspension_Object is
-- implemented.
if In_Private_Part (Current_Scope)
and then Is_Internal_Unit (Current_Sem_Unit)
then
Set_Has_Protected (T, False);
else
Set_Has_Protected (T);
end if;
-- Set the SPARK_Mode from the current context (may be overwritten later
-- with an explicit pragma).
Set_SPARK_Pragma (T, SPARK_Mode_Pragma);
Set_SPARK_Aux_Pragma (T, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (T);
Set_SPARK_Aux_Pragma_Inherited (T);
Push_Scope (T);
if Ada_Version >= Ada_2005 then
Check_Interfaces (N, T);
end if;
if Present (Discriminant_Specifications (N)) then
if Has_Discriminants (T) then
-- Install discriminants. Also, verify conformance of
-- discriminants of previous and current view. ???
Install_Declarations (T);
else
Process_Discriminants (N);
end if;
end if;
Set_Is_Constrained (T, not Has_Discriminants (T));
-- If aspects are present, analyze them now. They can make references to
-- the discriminants of the type, but not to any components.
if Has_Aspects (N) then
-- The protected type is the full view of a private type. Analyze the
-- aspects with the entity of the private type to ensure that after
-- both views are exchanged, the aspect are actually associated with
-- the full view.
if T /= Def_Id and then Is_Private_Type (Def_Id) then
Analyze_Aspect_Specifications (N, T);
else
Analyze_Aspect_Specifications (N, Def_Id);
end if;
end if;
Analyze (Protected_Definition (N));
-- In the case where the protected type is declared at a nested level
-- and the No_Local_Protected_Objects restriction applies, issue a
-- warning that objects of the type will violate the restriction.
if Restriction_Check_Required (No_Local_Protected_Objects)
and then not Is_Library_Level_Entity (T)
and then Comes_From_Source (T)
then
Error_Msg_Sloc := Restrictions_Loc (No_Local_Protected_Objects);
if Error_Msg_Sloc = No_Location then
Error_Msg_N
("objects of this type will violate " &
"`No_Local_Protected_Objects`??", N);
else
Error_Msg_N
("objects of this type will violate " &
"`No_Local_Protected_Objects`#??", N);
end if;
end if;
-- Protected types with entries are controlled (because of the
-- Protection component if nothing else), same for any protected type
-- with interrupt handlers. Note that we need to analyze the protected
-- definition to set Has_Entries and such.
if (Abort_Allowed or else Restriction_Active (No_Entry_Queue) = False
or else Number_Entries (T) > 1)
and then not Restricted_Profile
and then
(Has_Entries (T)
or else Has_Interrupt_Handler (T)
or else Has_Attach_Handler (T))
then
Set_Has_Controlled_Component (T, True);
end if;
-- The Ekind of components is E_Void during analysis to detect illegal
-- uses. Now it can be set correctly.
E := First_Entity (Current_Scope);
while Present (E) loop
if Ekind (E) = E_Void then
Mutate_Ekind (E, E_Component);
Reinit_Component_Location (E);
end if;
Next_Entity (E);
end loop;
End_Scope;
-- When a Lock_Free aspect forces the lock-free implementation, check N
-- meets all the lock-free restrictions. Otherwise, an error message is
-- issued by Allows_Lock_Free_Implementation.
if Uses_Lock_Free (Defining_Identifier (N)) then
-- Complain when there is an explicit aspect/pragma Priority (or
-- Interrupt_Priority) while the lock-free implementation is forced
-- by an aspect/pragma.
declare
Id : constant Entity_Id := Defining_Identifier (Original_Node (N));
-- The warning must be issued on the original identifier in order
-- to deal properly with the case of a single protected object.
Prio_Item : constant Node_Id :=
Get_Rep_Item (Def_Id, Name_Priority, False);
begin
if Present (Prio_Item) then
-- Aspect case
if Nkind (Prio_Item) = N_Aspect_Specification
or else From_Aspect_Specification (Prio_Item)
then
Error_Msg_Name_1 := Chars (Identifier (Prio_Item));
Error_Msg_NE
("aspect% for & has no effect when Lock_Free given??",
Prio_Item, Id);
-- Pragma case
else
Error_Msg_Name_1 := Pragma_Name (Prio_Item);
Error_Msg_NE
("pragma% for & has no effect when Lock_Free given??",
Prio_Item, Id);
end if;
end if;
end;
if not Allows_Lock_Free_Implementation (N, Lock_Free_Given => True)
then
return;
end if;
end if;
-- If the Attach_Handler aspect is specified or the Interrupt_Handler
-- aspect is True, then the initial ceiling priority must be in the
-- range of System.Interrupt_Priority. It is therefore recommanded
-- to use the Interrupt_Priority aspect instead of the Priority aspect.
if Has_Interrupt_Handler (T) or else Has_Attach_Handler (T) then
declare
Prio_Item : constant Node_Id :=
Get_Rep_Item (Def_Id, Name_Priority, False);
begin
if Present (Prio_Item) then
-- Aspect case
if (Nkind (Prio_Item) = N_Aspect_Specification
or else From_Aspect_Specification (Prio_Item))
and then Chars (Identifier (Prio_Item)) = Name_Priority
then
Error_Msg_N
("aspect Interrupt_Priority is preferred in presence of "
& "handlers??", Prio_Item);
-- Pragma case
elsif Nkind (Prio_Item) = N_Pragma
and then Pragma_Name (Prio_Item) = Name_Priority
then
Error_Msg_N
("pragma Interrupt_Priority is preferred in presence of "
& "handlers??", Prio_Item);
end if;
end if;
end;
end if;
-- Case of a completion of a private declaration
if T /= Def_Id and then Is_Private_Type (Def_Id) then
-- Deal with preelaborable initialization. Note that this processing
-- is done by Process_Full_View, but as can be seen below, in this
-- case the call to Process_Full_View is skipped if any serious
-- errors have occurred, and we don't want to lose this check.
if Known_To_Have_Preelab_Init (Def_Id) then
Set_Must_Have_Preelab_Init (T);
end if;
-- Propagate Default_Initial_Condition-related attributes from the
-- private type to the protected type.
Propagate_DIC_Attributes (T, From_Typ => Def_Id);
-- Propagate invariant-related attributes from the private type to
-- the protected type.
Propagate_Invariant_Attributes (T, From_Typ => Def_Id);
-- Propagate predicate-related attributes from the private type to
-- the protected type.
Propagate_Predicate_Attributes (T, From_Typ => Def_Id);
-- Create corresponding record now, because some private dependents
-- may be subtypes of the partial view.
-- Skip if errors are present, to prevent cascaded messages
if Serious_Errors_Detected = 0
-- Also skip if expander is not active
and then Expander_Active
then
Expand_N_Protected_Type_Declaration (N);
Process_Full_View (N, T, Def_Id);
end if;
end if;
-- In GNATprove mode, force the loading of a Interrupt_Priority, which
-- is required for the ceiling priority protocol checks triggered by
-- calls originating from protected subprograms and entries.
if GNATprove_Mode then
SPARK_Implicit_Load (RE_Interrupt_Priority);
end if;
end Analyze_Protected_Type_Declaration;
---------------------
-- Analyze_Requeue --
---------------------
procedure Analyze_Requeue (N : Node_Id) is
procedure Check_Wrong_Attribute_In_Postconditions
(Entry_Id : Entity_Id;
Error_Node : Node_Id);
-- Check that the requeue target Entry_Id does not have an specific or
-- class-wide postcondition that references an Old or Index attribute.
---------------------------------------------
-- Check_Wrong_Attribute_In_Postconditions --
---------------------------------------------
procedure Check_Wrong_Attribute_In_Postconditions
(Entry_Id : Entity_Id;
Error_Node : Node_Id)
is
function Check_Node (N : Node_Id) return Traverse_Result;
-- Check that N is not a reference to attribute Index or Old; report
-- an error otherwise.
----------------
-- Check_Node --
----------------
function Check_Node (N : Node_Id) return Traverse_Result is
begin
if Nkind (N) = N_Attribute_Reference
and then Attribute_Name (N) in Name_Index
| Name_Old
then
Error_Msg_Name_1 := Attribute_Name (N);
Error_Msg_N
("target of requeue must not have references to attribute % "
& "in postcondition",
Error_Node);
end if;
return OK;
end Check_Node;
procedure Check_Attr_Refs is new Traverse_Proc (Check_Node);
-- Local variables
Prag : Node_Id;
begin
Prag := Pre_Post_Conditions (Contract (Entry_Id));
while Present (Prag) loop
if Pragma_Name (Prag) = Name_Postcondition then
Check_Attr_Refs (First (Pragma_Argument_Associations (Prag)));
end if;
Prag := Next_Pragma (Prag);
end loop;
end Check_Wrong_Attribute_In_Postconditions;
-- Local variables
Count : Natural := 0;
Entry_Name : Node_Id := Name (N);
Entry_Id : Entity_Id;
I : Interp_Index;
Is_Disp_Req : Boolean;
It : Interp;
Enclosing : Entity_Id;
Target_Obj : Node_Id := Empty;
Req_Scope : Entity_Id;
Outer_Ent : Entity_Id;
Synch_Type : Entity_Id := Empty;
-- Start of processing for Analyze_Requeue
begin
-- Preserve relevant elaboration-related attributes of the context which
-- are no longer available or very expensive to recompute once analysis,
-- resolution, and expansion are over.
Mark_Elaboration_Attributes
(N_Id => N,
Checks => True,
Modes => True,
Warnings => True);
Tasking_Used := True;
Check_Restriction (No_Requeue_Statements, N);
Check_Unreachable_Code (N);
Enclosing := Empty;
for J in reverse 0 .. Scope_Stack.Last loop
Enclosing := Scope_Stack.Table (J).Entity;
exit when Is_Entry (Enclosing);
if Ekind (Enclosing) not in E_Block | E_Loop then
Error_Msg_N ("requeue must appear within accept or entry body", N);
return;
end if;
end loop;
Analyze (Entry_Name);
if Etype (Entry_Name) = Any_Type then
return;
end if;
if Nkind (Entry_Name) = N_Selected_Component then
Target_Obj := Prefix (Entry_Name);
Entry_Name := Selector_Name (Entry_Name);
end if;
-- If an explicit target object is given then we have to check the
-- restrictions of 9.5.4(6).
if Present (Target_Obj) then
-- Locate containing concurrent unit and determine enclosing entry
-- body or outermost enclosing accept statement within the unit.
Outer_Ent := Empty;
for S in reverse 0 .. Scope_Stack.Last loop
Req_Scope := Scope_Stack.Table (S).Entity;
exit when Is_Concurrent_Type (Req_Scope);
if Is_Entry (Req_Scope) then
Outer_Ent := Req_Scope;
end if;
end loop;
pragma Assert (Present (Outer_Ent));
-- Check that the accessibility level of the target object is not
-- greater or equal to the outermost enclosing accept statement (or
-- entry body) unless it is a parameter of the innermost enclosing
-- accept statement (or entry body).
if Static_Accessibility_Level (Target_Obj, Zero_On_Dynamic_Level)
>= Scope_Depth (Outer_Ent)
and then
(not Is_Entity_Name (Target_Obj)
or else not Is_Formal (Entity (Target_Obj))
or else Enclosing /= Scope (Entity (Target_Obj)))
then
Error_Msg_N
("target object has invalid level for requeue", Target_Obj);
end if;
end if;
-- Overloaded case, find right interpretation
if Is_Overloaded (Entry_Name) then
Entry_Id := Empty;
-- Loop over candidate interpretations and filter out any that are
-- not parameterless, are not type conformant, are not entries, or
-- do not come from source.
Get_First_Interp (Entry_Name, I, It);
while Present (It.Nam) loop
-- Note: we test type conformance here, not subtype conformance.
-- Subtype conformance will be tested later on, but it is better
-- for error output in some cases not to do that here.
if (No (First_Formal (It.Nam))
or else (Type_Conformant (Enclosing, It.Nam)))
and then Ekind (It.Nam) = E_Entry
then
-- Ada 2005 (AI-345): Since protected and task types have
-- primitive entry wrappers, we only consider source entries.
if Comes_From_Source (It.Nam) then
Count := Count + 1;
Entry_Id := It.Nam;
else
Remove_Interp (I);
end if;
end if;
Get_Next_Interp (I, It);
end loop;
if Count = 0 then
Error_Msg_N ("no entry matches context", N);
return;
elsif Count > 1 then
Error_Msg_N ("ambiguous entry name in requeue", N);
return;
else
Set_Is_Overloaded (Entry_Name, False);
Set_Entity (Entry_Name, Entry_Id);
end if;
-- Non-overloaded cases
-- For the case of a reference to an element of an entry family, the
-- Entry_Name is an indexed component.
elsif Nkind (Entry_Name) = N_Indexed_Component then
-- Requeue to an entry out of the body
if Nkind (Prefix (Entry_Name)) = N_Selected_Component then
Entry_Id := Entity (Selector_Name (Prefix (Entry_Name)));
-- Requeue from within the body itself
elsif Nkind (Prefix (Entry_Name)) = N_Identifier then
Entry_Id := Entity (Prefix (Entry_Name));
else
Error_Msg_N ("invalid entry_name specified", N);
return;
end if;
-- If we had a requeue of the form REQUEUE A (B), then the parser
-- accepted it (because it could have been a requeue on an entry index.
-- If A turns out not to be an entry family, then the analysis of A (B)
-- turned it into a function call.
elsif Nkind (Entry_Name) = N_Function_Call then
Error_Msg_N
("arguments not allowed in requeue statement",
First (Parameter_Associations (Entry_Name)));
return;
-- Normal case of no entry family, no argument
else
Entry_Id := Entity (Entry_Name);
end if;
-- Ada 2012 (AI05-0030): Potential dispatching requeue statement. The
-- target type must be a concurrent interface class-wide type and the
-- target must be a procedure, flagged by pragma Implemented. The
-- target may be an access to class-wide type, in which case it must
-- be dereferenced.
if Present (Target_Obj) then
Synch_Type := Etype (Target_Obj);
if Is_Access_Type (Synch_Type) then
Synch_Type := Designated_Type (Synch_Type);
end if;
end if;
Is_Disp_Req :=
Ada_Version >= Ada_2012
and then Present (Target_Obj)
and then Is_Class_Wide_Type (Synch_Type)
and then Is_Concurrent_Interface (Synch_Type)
and then Ekind (Entry_Id) = E_Procedure
and then Has_Rep_Pragma (Entry_Id, Name_Implemented);
-- Resolve entry, and check that it is subtype conformant with the
-- enclosing construct if this construct has formals (RM 9.5.4(5)).
-- Ada 2005 (AI05-0030): Do not emit an error for this specific case.
if not Is_Entry (Entry_Id)
and then not Is_Disp_Req
then
Error_Msg_N ("expect entry name in requeue statement", Name (N));
elsif Ekind (Entry_Id) = E_Entry_Family
and then Nkind (Entry_Name) /= N_Indexed_Component
then
Error_Msg_N ("missing index for entry family component", Name (N));
else
Resolve_Entry (Name (N));
Generate_Reference (Entry_Id, Entry_Name);
if Present (First_Formal (Entry_Id)) then
-- Ada 2012 (AI05-0030): Perform type conformance after skipping
-- the first parameter of Entry_Id since it is the interface
-- controlling formal.
if Ada_Version >= Ada_2012 and then Is_Disp_Req then
declare
Enclosing_Formal : Entity_Id;
Target_Formal : Entity_Id;
begin
Enclosing_Formal := First_Formal (Enclosing);
Target_Formal := Next_Formal (First_Formal (Entry_Id));
while Present (Enclosing_Formal)
and then Present (Target_Formal)
loop
if not Conforming_Types
(T1 => Etype (Enclosing_Formal),
T2 => Etype (Target_Formal),
Ctype => Subtype_Conformant)
then
Error_Msg_Node_2 := Target_Formal;
Error_Msg_NE
("formal & is not subtype conformant with &" &
"in dispatching requeue", N, Enclosing_Formal);
end if;
Next_Formal (Enclosing_Formal);
Next_Formal (Target_Formal);
end loop;
end;
else
Check_Subtype_Conformant (Enclosing, Entry_Id, Name (N));
end if;
-- Processing for parameters accessed by the requeue
declare
Ent : Entity_Id;
begin
Ent := First_Formal (Enclosing);
while Present (Ent) loop
-- For OUT or IN OUT parameter, the effect of the requeue is
-- to assign the parameter a value on exit from the requeued
-- body, so we can set it as source assigned. We also clear
-- the Is_True_Constant indication. We do not need to clear
-- Current_Value, since the effect of the requeue is to
-- perform an unconditional goto so that any further
-- references will not occur anyway.
if Ekind (Ent) in E_Out_Parameter | E_In_Out_Parameter then
Set_Never_Set_In_Source (Ent, False);
Set_Is_True_Constant (Ent, False);
end if;
-- For all parameters, the requeue acts as a reference,
-- since the value of the parameter is passed to the new
-- entry, so we want to suppress unreferenced warnings.
Set_Referenced (Ent);
Next_Formal (Ent);
end loop;
end;
end if;
end if;
-- AI05-0225: the target protected object of a requeue must be a
-- variable. This is a binding interpretation that applies to all
-- versions of the language. Note that the subprogram does not have
-- to be a protected operation: it can be an primitive implemented
-- by entry with a formal that is a protected interface.
if Present (Target_Obj)
and then not Is_Variable (Target_Obj)
then
Error_Msg_N
("target protected object of requeue must be a variable", N);
end if;
-- Ada 2022 (AI12-0143): The requeue target shall not have an
-- applicable specific or class-wide postcondition which includes
-- an Old or Index attribute reference.
if Ekind (Entry_Id) = E_Entry_Family
and then Present (Contract (Entry_Id))
then
Check_Wrong_Attribute_In_Postconditions
(Entry_Id => Entry_Id,
Error_Node => Entry_Name);
end if;
-- A requeue statement is treated as a call for purposes of ABE checks
-- and diagnostics. Annotate the tree by creating a call marker in case
-- the requeue statement is transformed by expansion.
Build_Call_Marker (N);
end Analyze_Requeue;
------------------------------
-- Analyze_Selective_Accept --
------------------------------
procedure Analyze_Selective_Accept (N : Node_Id) is
Alts : constant List_Id := Select_Alternatives (N);
Alt : Node_Id;
Accept_Present : Boolean := False;
Terminate_Present : Boolean := False;
Delay_Present : Boolean := False;
Relative_Present : Boolean := False;
Alt_Count : Uint := Uint_0;
begin
Tasking_Used := True;
Check_Restriction (No_Select_Statements, N);
-- Loop to analyze alternatives
Alt := First (Alts);
while Present (Alt) loop
Alt_Count := Alt_Count + 1;
Analyze (Alt);
if Nkind (Alt) = N_Delay_Alternative then
if Delay_Present then
if Relative_Present /=
(Nkind (Delay_Statement (Alt)) = N_Delay_Relative_Statement)
then
Error_Msg_N
("delay_until and delay_relative alternatives", Alt);
Error_Msg_N
("\cannot appear in the same selective_wait", Alt);
end if;
else
Delay_Present := True;
Relative_Present :=
Nkind (Delay_Statement (Alt)) = N_Delay_Relative_Statement;
end if;
elsif Nkind (Alt) = N_Terminate_Alternative then
if Terminate_Present then
Error_Msg_N ("only one terminate alternative allowed", N);
else
Terminate_Present := True;
Check_Restriction (No_Terminate_Alternatives, N);
end if;
elsif Nkind (Alt) = N_Accept_Alternative then
Accept_Present := True;
-- Check for duplicate accept
declare
Alt1 : Node_Id;
Stm : constant Node_Id := Accept_Statement (Alt);
EDN : constant Node_Id := Entry_Direct_Name (Stm);
Ent : Entity_Id;
begin
if Nkind (EDN) = N_Identifier
and then No (Condition (Alt))
and then Present (Entity (EDN)) -- defend against junk
and then Ekind (Entity (EDN)) = E_Entry
then
Ent := Entity (EDN);
Alt1 := First (Alts);
while Alt1 /= Alt loop
if Nkind (Alt1) = N_Accept_Alternative
and then No (Condition (Alt1))
then
declare
Stm1 : constant Node_Id := Accept_Statement (Alt1);
EDN1 : constant Node_Id := Entry_Direct_Name (Stm1);
begin
if Nkind (EDN1) = N_Identifier then
if Entity (EDN1) = Ent then
Error_Msg_Sloc := Sloc (Stm1);
Error_Msg_N
("ACCEPT duplicates one on line#??", Stm);
exit;
end if;
end if;
end;
end if;
Next (Alt1);
end loop;
end if;
end;
end if;
Next (Alt);
end loop;
Check_Restriction (Max_Select_Alternatives, N, Alt_Count);
Check_Potentially_Blocking_Operation (N);
if Terminate_Present and Delay_Present then
Error_Msg_N ("at most one of TERMINATE or DELAY alternative", N);
elsif not Accept_Present then
Error_Msg_N
("SELECT must contain at least one ACCEPT alternative", N);
end if;
if Present (Else_Statements (N)) then
if Terminate_Present or Delay_Present then
Error_Msg_N ("ELSE part not allowed with other alternatives", N);
end if;
Analyze_Statements (Else_Statements (N));
end if;
end Analyze_Selective_Accept;
------------------------------------------
-- Analyze_Single_Protected_Declaration --
------------------------------------------
procedure Analyze_Single_Protected_Declaration (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Obj_Id : constant Node_Id := Defining_Identifier (N);
Obj_Decl : Node_Id;
Typ : Entity_Id;
begin
Generate_Definition (Obj_Id);
Tasking_Used := True;
-- A single protected declaration is transformed into a pair of an
-- anonymous protected type and an object of that type. Generate:
-- protected type Typ is ...;
Typ :=
Make_Defining_Identifier (Sloc (Obj_Id),
Chars => New_External_Name (Chars (Obj_Id), 'T'));
Rewrite (N,
Make_Protected_Type_Declaration (Loc,
Defining_Identifier => Typ,
Protected_Definition => Relocate_Node (Protected_Definition (N)),
Interface_List => Interface_List (N)));
-- Use the original defining identifier of the single protected
-- declaration in the generated object declaration to allow for debug
-- information to be attached to it when compiling with -gnatD. The
-- parent of the entity is the new object declaration. The single
-- protected declaration is not used in semantics or code generation,
-- but is scanned when generating debug information, and therefore needs
-- the updated Sloc information from the entity (see Sprint). Generate:
-- Obj : Typ;
Obj_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Obj_Id,
Object_Definition => New_Occurrence_Of (Typ, Loc));
Insert_After (N, Obj_Decl);
Mark_Rewrite_Insertion (Obj_Decl);
-- Relocate aspect Part_Of from the original single protected
-- declaration to the anonymous object declaration. This emulates the
-- placement of an equivalent source pragma.
Move_Or_Merge_Aspects (N, To => Obj_Decl);
-- Relocate pragma Part_Of from the visible declarations of the original
-- single protected declaration to the anonymous object declaration. The
-- new placement better reflects the role of the pragma.
Relocate_Pragmas_To_Anonymous_Object (N, Obj_Decl);
-- Enter the names of the anonymous protected type and the object before
-- analysis takes places, because the name of the object may be used in
-- its own body.
Enter_Name (Typ);
Mutate_Ekind (Typ, E_Protected_Type);
Set_Etype (Typ, Typ);
Set_Anonymous_Object (Typ, Obj_Id);
Enter_Name (Obj_Id);
Mutate_Ekind (Obj_Id, E_Variable);
Set_Etype (Obj_Id, Typ);
Set_SPARK_Pragma (Obj_Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Obj_Id);
-- Instead of calling Analyze on the new node, call the proper analysis
-- procedure directly. Otherwise the node would be expanded twice, with
-- disastrous result.
Analyze_Protected_Type_Declaration (N);
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Obj_Id);
end if;
end Analyze_Single_Protected_Declaration;
-------------------------------------
-- Analyze_Single_Task_Declaration --
-------------------------------------
procedure Analyze_Single_Task_Declaration (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Obj_Id : constant Node_Id := Defining_Identifier (N);
Obj_Decl : Node_Id;
Typ : Entity_Id;
begin
Generate_Definition (Obj_Id);
Tasking_Used := True;
-- A single task declaration is transformed into a pair of an anonymous
-- task type and an object of that type. Generate:
-- task type Typ is ...;
Typ :=
Make_Defining_Identifier (Sloc (Obj_Id),
Chars => New_External_Name (Chars (Obj_Id), Suffix => "TK"));
Rewrite (N,
Make_Task_Type_Declaration (Loc,
Defining_Identifier => Typ,
Task_Definition => Relocate_Node (Task_Definition (N)),
Interface_List => Interface_List (N)));
-- Use the original defining identifier of the single task declaration
-- in the generated object declaration to allow for debug information
-- to be attached to it when compiling with -gnatD. The parent of the
-- entity is the new object declaration. The single task declaration
-- is not used in semantics or code generation, but is scanned when
-- generating debug information, and therefore needs the updated Sloc
-- information from the entity (see Sprint). Generate:
-- Obj : Typ;
Obj_Decl :=
Make_Object_Declaration (Loc,
Defining_Identifier => Obj_Id,
Object_Definition => New_Occurrence_Of (Typ, Loc));
Insert_After (N, Obj_Decl);
Mark_Rewrite_Insertion (Obj_Decl);
-- Relocate aspects Depends, Global and Part_Of from the original single
-- task declaration to the anonymous object declaration. This emulates
-- the placement of an equivalent source pragma.
Move_Or_Merge_Aspects (N, To => Obj_Decl);
-- Relocate pragmas Depends, Global and Part_Of from the visible
-- declarations of the original single protected declaration to the
-- anonymous object declaration. The new placement better reflects the
-- role of the pragmas.
Relocate_Pragmas_To_Anonymous_Object (N, Obj_Decl);
-- Enter the names of the anonymous task type and the object before
-- analysis takes places, because the name of the object may be used
-- in its own body.
Enter_Name (Typ);
Mutate_Ekind (Typ, E_Task_Type);
Set_Etype (Typ, Typ);
Set_Anonymous_Object (Typ, Obj_Id);
Enter_Name (Obj_Id);
Mutate_Ekind (Obj_Id, E_Variable);
Set_Etype (Obj_Id, Typ);
Set_SPARK_Pragma (Obj_Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Obj_Id);
-- Preserve relevant elaboration-related attributes of the context which
-- are no longer available or very expensive to recompute once analysis,
-- resolution, and expansion are over.
Mark_Elaboration_Attributes
(N_Id => Obj_Id,
Checks => True,
Warnings => True);
-- Instead of calling Analyze on the new node, call the proper analysis
-- procedure directly. Otherwise the node would be expanded twice, with
-- disastrous result.
Analyze_Task_Type_Declaration (N);
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Obj_Id);
end if;
end Analyze_Single_Task_Declaration;
-----------------------
-- Analyze_Task_Body --
-----------------------
procedure Analyze_Task_Body (N : Node_Id) is
Body_Id : constant Entity_Id := Defining_Identifier (N);
Decls : constant List_Id := Declarations (N);
HSS : constant Node_Id := Handled_Statement_Sequence (N);
Last_E : Entity_Id;
Spec_Id : Entity_Id;
-- This is initially the entity of the task or task type involved, but
-- is replaced by the task type always in the case of a single task
-- declaration, since this is the proper scope to be used.
Ref_Id : Entity_Id;
-- This is the entity of the task or task type, and is the entity used
-- for cross-reference purposes (it differs from Spec_Id in the case of
-- a single task, since Spec_Id is set to the task type).
begin
-- A task body freezes the contract of the nearest enclosing package
-- body and all other contracts encountered in the same declarative part
-- up to and excluding the task body. This ensures that annotations
-- referenced by the contract of an entry or subprogram body declared
-- within the current protected body are available.
Freeze_Previous_Contracts (N);
Tasking_Used := True;
Set_Scope (Body_Id, Current_Scope);
Mutate_Ekind (Body_Id, E_Task_Body);
Set_Etype (Body_Id, Standard_Void_Type);
Spec_Id := Find_Concurrent_Spec (Body_Id);
-- The spec is either a task type declaration, or a single task
-- declaration for which we have created an anonymous type.
if Present (Spec_Id) and then Ekind (Spec_Id) = E_Task_Type then
null;
elsif Present (Spec_Id)
and then Ekind (Etype (Spec_Id)) = E_Task_Type
and then not Comes_From_Source (Etype (Spec_Id))
then
null;
else
Error_Msg_N ("missing specification for task body", Body_Id);
return;
end if;
if Has_Completion (Spec_Id)
and then Present (Corresponding_Body (Parent (Spec_Id)))
then
if Nkind (Parent (Spec_Id)) = N_Task_Type_Declaration then
Error_Msg_NE ("duplicate body for task type&", N, Spec_Id);
else
Error_Msg_NE ("duplicate body for task&", N, Spec_Id);
end if;
end if;
Ref_Id := Spec_Id;
Generate_Reference (Ref_Id, Body_Id, 'b', Set_Ref => False);
Style.Check_Identifier (Body_Id, Spec_Id);
-- Deal with case of body of single task (anonymous type was created)
if Ekind (Spec_Id) = E_Variable then
Spec_Id := Etype (Spec_Id);
end if;
-- Set the SPARK_Mode from the current context (may be overwritten later
-- with an explicit pragma).
Set_SPARK_Pragma (Body_Id, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (Body_Id);
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Body_Id);
end if;
Push_Scope (Spec_Id);
Set_Corresponding_Spec (N, Spec_Id);
Set_Corresponding_Body (Parent (Spec_Id), Body_Id);
Set_Has_Completion (Spec_Id);
Install_Declarations (Spec_Id);
Last_E := Last_Entity (Spec_Id);
Analyze_Declarations (Decls);
Inspect_Deferred_Constant_Completion (Decls);
-- For visibility purposes, all entities in the body are private. Set
-- First_Private_Entity accordingly, if there was no private part in the
-- protected declaration.
if No (First_Private_Entity (Spec_Id)) then
if Present (Last_E) then
Set_First_Private_Entity (Spec_Id, Next_Entity (Last_E));
else
Set_First_Private_Entity (Spec_Id, First_Entity (Spec_Id));
end if;
-- The entity list of the current scope now includes entities in
-- the spec as well as the body. Their declarations will become
-- part of the statement sequence of the task body procedure that
-- is built during expansion. Indicate that aspect specifications
-- for these entities need not be rechecked. The guards on
-- Check_Aspect_At_End_Of_Declarations are not sufficient to
-- suppress these checks, because the declarations come from source.
declare
Priv : Entity_Id := First_Private_Entity (Spec_Id);
begin
while Present (Priv) loop
Set_Has_Delayed_Aspects (Priv, False);
Next_Entity (Priv);
end loop;
end;
end if;
-- Mark all handlers as not suitable for local raise optimization,
-- since this optimization causes difficulties in a task context.
if Present (Exception_Handlers (HSS)) then
declare
Handlr : Node_Id;
begin
Handlr := First (Exception_Handlers (HSS));
while Present (Handlr) loop
Set_Local_Raise_Not_OK (Handlr);
Next (Handlr);
end loop;
end;
end if;
-- Now go ahead and complete analysis of the task body
Analyze (HSS);
Check_Completion (Body_Id);
Check_References (Body_Id);
Check_References (Spec_Id);
-- Check for entries with no corresponding accept
declare
Ent : Entity_Id;
begin
Ent := First_Entity (Spec_Id);
while Present (Ent) loop
if Is_Entry (Ent)
and then not Entry_Accepted (Ent)
and then Comes_From_Source (Ent)
then
Error_Msg_NE ("no accept for entry &??", N, Ent);
end if;
Next_Entity (Ent);
end loop;
end;
Process_End_Label (HSS, 't', Ref_Id);
Update_Use_Clause_Chain;
End_Scope;
end Analyze_Task_Body;
-----------------------------
-- Analyze_Task_Definition --
-----------------------------
procedure Analyze_Task_Definition (N : Node_Id) is
L : Entity_Id;
begin
Tasking_Used := True;
if Present (Visible_Declarations (N)) then
Analyze_Declarations (Visible_Declarations (N));
end if;
if Present (Private_Declarations (N)) then
L := Last_Entity (Current_Scope);
Analyze_Declarations (Private_Declarations (N));
if Present (L) then
Set_First_Private_Entity
(Current_Scope, Next_Entity (L));
else
Set_First_Private_Entity
(Current_Scope, First_Entity (Current_Scope));
end if;
end if;
Check_Max_Entries (N, Max_Task_Entries);
Process_End_Label (N, 'e', Current_Scope);
end Analyze_Task_Definition;
-----------------------------------
-- Analyze_Task_Type_Declaration --
-----------------------------------
procedure Analyze_Task_Type_Declaration (N : Node_Id) is
Def_Id : constant Entity_Id := Defining_Identifier (N);
T : Entity_Id;
begin
-- Attempt to use tasking in no run time mode is not allowe. Issue hard
-- error message to disable expansion which leads to crashes.
if Opt.No_Run_Time_Mode then
Error_Msg_N ("tasking not allowed in No_Run_Time mode", N);
-- Otherwise soft check for no tasking restriction
else
Check_Restriction (No_Tasking, N);
end if;
-- Proceed ahead with analysis of task type declaration
Tasking_Used := True;
-- The sequential partition elaboration policy is supported only in the
-- restricted profile.
if Partition_Elaboration_Policy = 'S'
and then not Restricted_Profile
then
Error_Msg_N
("sequential elaboration supported only in restricted profile", N);
end if;
T := Find_Type_Name (N);
Generate_Definition (T);
-- In the case of an incomplete type, use the full view, unless it's not
-- present (as can occur for an incomplete view from a limited with).
-- Initialize the Corresponding_Record_Type (which overlays the Private
-- Dependents field of the incomplete view).
if Ekind (T) = E_Incomplete_Type then
if Present (Full_View (T)) then
T := Full_View (T);
Set_Completion_Referenced (T);
else
Mutate_Ekind (T, E_Task_Type);
Set_Corresponding_Record_Type (T, Empty);
end if;
end if;
Mutate_Ekind (T, E_Task_Type);
Set_Is_First_Subtype (T, True);
Set_Has_Task (T, True);
Reinit_Size_Align (T);
Set_Etype (T, T);
Set_Has_Delayed_Freeze (T, True);
Set_Stored_Constraint (T, No_Elist);
-- Initialize type's primitive operations list, for possible use when
-- the extension of prefixed call notation for untagged types is enabled
-- (such as by use of -gnatX).
Set_Direct_Primitive_Operations (T, New_Elmt_List);
-- Set the SPARK_Mode from the current context (may be overwritten later
-- with an explicit pragma).
Set_SPARK_Pragma (T, SPARK_Mode_Pragma);
Set_SPARK_Aux_Pragma (T, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (T);
Set_SPARK_Aux_Pragma_Inherited (T);
-- Preserve relevant elaboration-related attributes of the context which
-- are no longer available or very expensive to recompute once analysis,
-- resolution, and expansion are over.
Mark_Elaboration_Attributes
(N_Id => T,
Checks => True,
Warnings => True);
Push_Scope (T);
if Ada_Version >= Ada_2005 then
Check_Interfaces (N, T);
end if;
if Present (Discriminant_Specifications (N)) then
if Ada_Version = Ada_83 and then Comes_From_Source (N) then
Error_Msg_N ("(Ada 83) task discriminant not allowed!", N);
end if;
if Has_Discriminants (T) then
-- Install discriminants. Also, verify conformance of
-- discriminants of previous and current view. ???
Install_Declarations (T);
else
Process_Discriminants (N);
end if;
end if;
Set_Is_Constrained (T, not Has_Discriminants (T));
if Has_Aspects (N) then
-- The task type is the full view of a private type. Analyze the
-- aspects with the entity of the private type to ensure that after
-- both views are exchanged, the aspect are actually associated with
-- the full view.
if T /= Def_Id and then Is_Private_Type (Def_Id) then
Analyze_Aspect_Specifications (N, T);
else
Analyze_Aspect_Specifications (N, Def_Id);
end if;
end if;
if Present (Task_Definition (N)) then
Analyze_Task_Definition (Task_Definition (N));
end if;
-- In the case where the task type is declared at a nested level and the
-- No_Task_Hierarchy restriction applies, issue a warning that objects
-- of the type will violate the restriction.
if Restriction_Check_Required (No_Task_Hierarchy)
and then not Is_Library_Level_Entity (T)
and then Comes_From_Source (T)
and then not CodePeer_Mode
then
Error_Msg_Sloc := Restrictions_Loc (No_Task_Hierarchy);
if Error_Msg_Sloc = No_Location then
Error_Msg_N
("objects of this type will violate `No_Task_Hierarchy`??", N);
else
Error_Msg_N
("objects of this type will violate `No_Task_Hierarchy`#??", N);
end if;
end if;
End_Scope;
-- Case of a completion of a private declaration
if T /= Def_Id and then Is_Private_Type (Def_Id) then
-- Deal with preelaborable initialization. Note that this processing
-- is done by Process_Full_View, but as can be seen below, in this
-- case the call to Process_Full_View is skipped if any serious
-- errors have occurred, and we don't want to lose this check.
if Known_To_Have_Preelab_Init (Def_Id) then
Set_Must_Have_Preelab_Init (T);
end if;
-- Propagate Default_Initial_Condition-related attributes from the
-- private type to the task type.
Propagate_DIC_Attributes (T, From_Typ => Def_Id);
-- Propagate invariant-related attributes from the private type to
-- task type.
Propagate_Invariant_Attributes (T, From_Typ => Def_Id);
-- Propagate predicate-related attributes from the private type to
-- task type.
Propagate_Predicate_Attributes (T, From_Typ => Def_Id);
-- Create corresponding record now, because some private dependents
-- may be subtypes of the partial view.
-- Skip if errors are present, to prevent cascaded messages
if Serious_Errors_Detected = 0
-- Also skip if expander is not active
and then Expander_Active
then
Expand_N_Task_Type_Declaration (N);
Process_Full_View (N, T, Def_Id);
end if;
end if;
-- In GNATprove mode, force the loading of a Interrupt_Priority, which
-- is required for the ceiling priority protocol checks triggered by
-- calls originating from tasks.
if GNATprove_Mode then
SPARK_Implicit_Load (RE_Interrupt_Priority);
end if;
end Analyze_Task_Type_Declaration;
-----------------------------------
-- Analyze_Terminate_Alternative --
-----------------------------------
procedure Analyze_Terminate_Alternative (N : Node_Id) is
begin
Tasking_Used := True;
if Present (Pragmas_Before (N)) then
Analyze_List (Pragmas_Before (N));
end if;
if Present (Condition (N)) then
Analyze_And_Resolve (Condition (N), Any_Boolean);
end if;
end Analyze_Terminate_Alternative;
------------------------------
-- Analyze_Timed_Entry_Call --
------------------------------
procedure Analyze_Timed_Entry_Call (N : Node_Id) is
Trigger : constant Node_Id :=
Entry_Call_Statement (Entry_Call_Alternative (N));
Is_Disp_Select : Boolean := False;
begin
Tasking_Used := True;
Check_Restriction (No_Select_Statements, N);
-- Ada 2005 (AI-345): The trigger may be a dispatching call
if Ada_Version >= Ada_2005 then
Analyze (Trigger);
Check_Triggering_Statement (Trigger, N, Is_Disp_Select);
end if;
-- Postpone the analysis of the statements till expansion. Analyze only
-- if the expander is disabled in order to catch any semantic errors.
if Is_Disp_Select then
if not Expander_Active then
Analyze (Entry_Call_Alternative (N));
Analyze (Delay_Alternative (N));
end if;
-- Regular select analysis
else
Analyze (Entry_Call_Alternative (N));
Analyze (Delay_Alternative (N));
end if;
end Analyze_Timed_Entry_Call;
------------------------------------
-- Analyze_Triggering_Alternative --
------------------------------------
procedure Analyze_Triggering_Alternative (N : Node_Id) is
Trigger : constant Node_Id := Triggering_Statement (N);
begin
Tasking_Used := True;
if Present (Pragmas_Before (N)) then
Analyze_List (Pragmas_Before (N));
end if;
Analyze (Trigger);
if Comes_From_Source (Trigger)
and then Nkind (Trigger) not in N_Delay_Statement
and then Nkind (Trigger) /= N_Entry_Call_Statement
then
if Ada_Version < Ada_2005 then
Error_Msg_N
("triggering statement must be delay or entry call", Trigger);
-- Ada 2005 (AI-345): If a procedure_call_statement is used for a
-- procedure_or_entry_call, the procedure_name or procedure_prefix
-- of the procedure_call_statement shall denote an entry renamed by a
-- procedure, or (a view of) a primitive subprogram of a limited
-- interface whose first parameter is a controlling parameter.
elsif Nkind (Trigger) = N_Procedure_Call_Statement
and then not Is_Renamed_Entry (Entity (Name (Trigger)))
and then not Is_Controlling_Limited_Procedure
(Entity (Name (Trigger)))
then
Error_Msg_N
("triggering statement must be procedure or entry call " &
"or delay statement", Trigger);
end if;
end if;
if Is_Non_Empty_List (Statements (N)) then
Analyze_Statements (Statements (N));
end if;
end Analyze_Triggering_Alternative;
-----------------------
-- Check_Max_Entries --
-----------------------
procedure Check_Max_Entries (D : Node_Id; R : All_Parameter_Restrictions) is
Ecount : Uint;
procedure Count (L : List_Id);
-- Count entries in given declaration list
-----------
-- Count --
-----------
procedure Count (L : List_Id) is
D : Node_Id;
begin
if No (L) then
return;
end if;
D := First (L);
while Present (D) loop
if Nkind (D) = N_Entry_Declaration then
declare
DSD : constant Node_Id :=
Discrete_Subtype_Definition (D);
begin
-- If not an entry family, then just one entry
if No (DSD) then
Ecount := Ecount + 1;
-- If entry family with static bounds, count entries
elsif Is_OK_Static_Subtype (Etype (DSD)) then
declare
Lo : constant Uint :=
Expr_Value
(Type_Low_Bound (Etype (DSD)));
Hi : constant Uint :=
Expr_Value
(Type_High_Bound (Etype (DSD)));
begin
if Hi >= Lo then
Ecount := Ecount + Hi - Lo + 1;
end if;
end;
-- Entry family with non-static bounds
else
-- Record an unknown count restriction, and if the
-- restriction is active, post a message or warning.
Check_Restriction (R, D);
end if;
end;
end if;
Next (D);
end loop;
end Count;
-- Start of processing for Check_Max_Entries
begin
Ecount := Uint_0;
Count (Visible_Declarations (D));
Count (Private_Declarations (D));
if Ecount > 0 then
Check_Restriction (R, D, Ecount);
end if;
end Check_Max_Entries;
----------------------
-- Check_Interfaces --
----------------------
procedure Check_Interfaces (N : Node_Id; T : Entity_Id) is
Iface : Node_Id;
Iface_Typ : Entity_Id;
begin
pragma Assert
(Nkind (N) in N_Protected_Type_Declaration | N_Task_Type_Declaration);
if Present (Interface_List (N)) then
Set_Is_Tagged_Type (T);
-- The primitive operations of a tagged synchronized type are placed
-- on the Corresponding_Record for proper dispatching, but are
-- attached to the synchronized type itself when expansion is
-- disabled.
Set_Direct_Primitive_Operations (T, New_Elmt_List);
Iface := First (Interface_List (N));
while Present (Iface) loop
Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
if not Is_Interface (Iface_Typ) then
Error_Msg_NE
("(Ada 2005) & must be an interface", Iface, Iface_Typ);
else
-- Ada 2005 (AI-251): "The declaration of a specific descendant
-- of an interface type freezes the interface type" RM 13.14.
Freeze_Before (N, Etype (Iface));
if Nkind (N) = N_Protected_Type_Declaration then
-- Ada 2005 (AI-345): Protected types can only implement
-- limited, synchronized, or protected interfaces (note that
-- the predicate Is_Limited_Interface includes synchronized
-- and protected interfaces).
if Is_Task_Interface (Iface_Typ) then
Error_Msg_N ("(Ada 2005) protected type cannot implement "
& "a task interface", Iface);
elsif not Is_Limited_Interface (Iface_Typ) then
Error_Msg_N ("(Ada 2005) protected type cannot implement "
& "a non-limited interface", Iface);
end if;
else pragma Assert (Nkind (N) = N_Task_Type_Declaration);
-- Ada 2005 (AI-345): Task types can only implement limited,
-- synchronized, or task interfaces (note that the predicate
-- Is_Limited_Interface includes synchronized and task
-- interfaces).
if Is_Protected_Interface (Iface_Typ) then
Error_Msg_N ("(Ada 2005) task type cannot implement a " &
"protected interface", Iface);
elsif not Is_Limited_Interface (Iface_Typ) then
Error_Msg_N ("(Ada 2005) task type cannot implement a " &
"non-limited interface", Iface);
end if;
end if;
end if;
Next (Iface);
end loop;
-- Check consistency of any nonoverridable aspects that are
-- inherited from multiple sources.
Check_Inherited_Nonoverridable_Aspects
(Inheritor => N,
Interface_List => Interface_List (N),
Parent_Type => Empty);
end if;
if not Has_Private_Declaration (T) then
return;
end if;
-- Additional checks on full-types associated with private type
-- declarations. Search for the private type declaration.
declare
Full_T_Ifaces : Elist_Id := No_Elist;
Iface : Node_Id;
Priv_T : Entity_Id;
Priv_T_Ifaces : Elist_Id := No_Elist;
begin
Priv_T := First_Entity (Scope (T));
loop
pragma Assert (Present (Priv_T));
if Is_Type (Priv_T) and then Present (Full_View (Priv_T)) then
exit when Full_View (Priv_T) = T;
end if;
Next_Entity (Priv_T);
end loop;
-- In case of synchronized types covering interfaces the private type
-- declaration must be limited.
if Present (Interface_List (N))
and then not Is_Limited_Type (Priv_T)
then
Error_Msg_Sloc := Sloc (Priv_T);
Error_Msg_N ("(Ada 2005) limited type declaration expected for " &
"private type#", T);
end if;
-- RM 7.3 (7.1/2): If the full view has a partial view that is
-- tagged then check RM 7.3 subsidiary rules.
if Is_Tagged_Type (Priv_T)
and then not Error_Posted (N)
then
-- RM 7.3 (7.2/2): The partial view shall be a synchronized tagged
-- type if and only if the full type is a synchronized tagged type
if Is_Synchronized_Tagged_Type (Priv_T)
and then not Is_Synchronized_Tagged_Type (T)
then
Error_Msg_N
("(Ada 2005) full view must be a synchronized tagged " &
"type (RM 7.3 (7.2/2))", Priv_T);
elsif Is_Synchronized_Tagged_Type (T)
and then not Is_Synchronized_Tagged_Type (Priv_T)
then
Error_Msg_N
("(Ada 2005) partial view must be a synchronized tagged " &
"type (RM 7.3 (7.2/2))", T);
end if;
-- RM 7.3 (7.3/2): The partial view shall be a descendant of an
-- interface type if and only if the full type is descendant of
-- the interface type.
if Present (Interface_List (N))
or else (Is_Tagged_Type (Priv_T)
and then Has_Interfaces
(Priv_T, Use_Full_View => False))
then
if Is_Tagged_Type (Priv_T) then
Collect_Interfaces
(Priv_T, Priv_T_Ifaces, Use_Full_View => False);
end if;
if Is_Tagged_Type (T) then
Collect_Interfaces (T, Full_T_Ifaces);
end if;
Iface := Find_Hidden_Interface (Priv_T_Ifaces, Full_T_Ifaces);
if Present (Iface) then
Error_Msg_NE
("interface in partial view& not implemented by full "
& "type (RM-2005 7.3 (7.3/2))", T, Iface);
end if;
Iface := Find_Hidden_Interface (Full_T_Ifaces, Priv_T_Ifaces);
if Present (Iface) then
Error_Msg_NE
("interface & not implemented by partial " &
"view (RM-2005 7.3 (7.3/2))", T, Iface);
end if;
end if;
end if;
end;
end Check_Interfaces;
--------------------------------
-- Check_Triggering_Statement --
--------------------------------
procedure Check_Triggering_Statement
(Trigger : Node_Id;
Error_Node : Node_Id;
Is_Dispatching : out Boolean)
is
Param : Node_Id;
begin
Is_Dispatching := False;
-- It is not possible to have a dispatching trigger if we are not in
-- Ada 2005 mode.
if Ada_Version >= Ada_2005
and then Nkind (Trigger) = N_Procedure_Call_Statement
and then Present (Parameter_Associations (Trigger))
then
Param := First (Parameter_Associations (Trigger));
if Is_Controlling_Actual (Param)
and then Is_Interface (Etype (Param))
then
if Is_Limited_Record (Etype (Param)) then
Is_Dispatching := True;
else
Error_Msg_N
("dispatching operation of limited or synchronized " &
"interface required (RM 9.7.2(3))!", Error_Node);
end if;
elsif Nkind (Trigger) = N_Explicit_Dereference then
Error_Msg_N
("entry call or dispatching primitive of interface required",
Trigger);
end if;
end if;
end Check_Triggering_Statement;
--------------------------
-- Find_Concurrent_Spec --
--------------------------
function Find_Concurrent_Spec (Body_Id : Entity_Id) return Entity_Id is
Spec_Id : Entity_Id := Current_Entity_In_Scope (Body_Id);
begin
-- The type may have been given by an incomplete type declaration.
-- Find full view now.
if Present (Spec_Id) and then Ekind (Spec_Id) = E_Incomplete_Type then
Spec_Id := Full_View (Spec_Id);
end if;
return Spec_Id;
end Find_Concurrent_Spec;
--------------------------
-- Install_Declarations --
--------------------------
procedure Install_Declarations (Spec : Entity_Id) is
E : Entity_Id;
Prev : Entity_Id;
begin
E := First_Entity (Spec);
while Present (E) loop
Prev := Current_Entity (E);
Set_Current_Entity (E);
Set_Is_Immediately_Visible (E);
Set_Homonym (E, Prev);
Next_Entity (E);
end loop;
end Install_Declarations;
end Sem_Ch9;