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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- P A R . 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. --
-- --
------------------------------------------------------------------------------
pragma Style_Checks (All_Checks);
-- Turn off subprogram body ordering check. Subprograms are in order by RM
-- section rather than alphabetical.
separate (Par)
package body Ch9 is
-- Local subprograms, used only in this chapter
function P_Accept_Alternative return Node_Id;
function P_Delay_Alternative return Node_Id;
function P_Delay_Relative_Statement return Node_Id;
function P_Delay_Until_Statement return Node_Id;
function P_Entry_Barrier return Node_Id;
function P_Entry_Body_Formal_Part return Node_Id;
function P_Entry_Declaration return Node_Id;
function P_Entry_Index_Specification return Node_Id;
function P_Protected_Definition return Node_Id;
function P_Protected_Operation_Declaration_Opt return Node_Id;
function P_Protected_Operation_Items return List_Id;
function P_Task_Items return List_Id;
function P_Task_Definition return Node_Id;
-----------------------------
-- 9.1 Task (also 10.1.3) --
-----------------------------
-- TASK_TYPE_DECLARATION ::=
-- task type DEFINING_IDENTIFIER [KNOWN_DISCRIMINANT_PART]
-- [ASPECT_SPECIFICATIONS]
-- [is [new INTERFACE_LIST with] TASK_DEFINITION];
-- SINGLE_TASK_DECLARATION ::=
-- task DEFINING_IDENTIFIER
-- [ASPECT_SPECIFICATIONS]
-- [is [new INTERFACE_LIST with] TASK_DEFINITION];
-- TASK_BODY ::=
-- task body DEFINING_IDENTIFIER [ASPECT_SPECIFICATIONS] is
-- DECLARATIVE_PART
-- begin
-- HANDLED_SEQUENCE_OF_STATEMENTS
-- end [task_IDENTIFIER]
-- TASK_BODY_STUB ::=
-- task body DEFINING_IDENTIFIER is separate
-- [ASPECT_SPECIFICATIONS];
-- This routine scans out a task declaration, task body, or task stub
-- The caller has checked that the initial token is TASK and scanned
-- past it, so that Token is set to the token after TASK
-- Error recovery: cannot raise Error_Resync
function P_Task return Node_Id is
Aspect_Sloc : Source_Ptr := No_Location;
Name_Node : Node_Id;
Task_Node : Node_Id;
Task_Sloc : Source_Ptr;
Dummy_Node : constant Node_Id := New_Node (N_Task_Body, Token_Ptr);
-- Placeholder node used to hold legal or prematurely declared aspect
-- specifications. Depending on the context, the aspect specifications
-- may be moved to a new node.
begin
Push_Scope_Stack;
Scopes (Scope.Last).Etyp := E_Name;
Scopes (Scope.Last).Ecol := Start_Column;
Scopes (Scope.Last).Sloc := Token_Ptr;
Scopes (Scope.Last).Lreq := False;
Task_Sloc := Prev_Token_Ptr;
if Token = Tok_Body then
Scan; -- past BODY
Name_Node := P_Defining_Identifier (C_Is);
Scopes (Scope.Last).Labl := Name_Node;
Current_Node := Name_Node;
if Token = Tok_Left_Paren then
Error_Msg_SC ("discriminant part not allowed in task body");
Discard_Junk_List (P_Known_Discriminant_Part_Opt);
end if;
if Aspect_Specifications_Present then
Aspect_Sloc := Token_Ptr;
P_Aspect_Specifications (Dummy_Node, Semicolon => False);
end if;
TF_Is;
-- Task stub
if Token = Tok_Separate then
Scan; -- past SEPARATE
Task_Node := New_Node (N_Task_Body_Stub, Task_Sloc);
Set_Defining_Identifier (Task_Node, Name_Node);
if Has_Aspects (Dummy_Node) then
Error_Msg
("aspect specifications must come after SEPARATE",
Aspect_Sloc);
end if;
P_Aspect_Specifications (Task_Node, Semicolon => False);
TF_Semicolon;
Pop_Scope_Stack; -- remove unused entry
-- Task body
else
Task_Node := New_Node (N_Task_Body, Task_Sloc);
Set_Defining_Identifier (Task_Node, Name_Node);
-- Move the aspect specifications to the body node
if Has_Aspects (Dummy_Node) then
Move_Aspects (From => Dummy_Node, To => Task_Node);
end if;
Parse_Decls_Begin_End (Task_Node);
-- The statement list of a task body needs to include at least a
-- null statement, so if a parsing error produces an empty list,
-- patch it now.
if No (First (Statements
(Handled_Statement_Sequence (Task_Node))))
then
Set_Statements (Handled_Statement_Sequence (Task_Node),
New_List (Make_Null_Statement (Token_Ptr)));
end if;
end if;
return Task_Node;
-- Otherwise we must have a task declaration
else
if Token = Tok_Type then
Scan; -- past TYPE
Task_Node := New_Node (N_Task_Type_Declaration, Task_Sloc);
Name_Node := P_Defining_Identifier;
Set_Defining_Identifier (Task_Node, Name_Node);
Scopes (Scope.Last).Labl := Name_Node;
Current_Node := Name_Node;
Set_Discriminant_Specifications
(Task_Node, P_Known_Discriminant_Part_Opt);
else
Task_Node := New_Node (N_Single_Task_Declaration, Task_Sloc);
Name_Node := P_Defining_Identifier (C_Is);
Set_Defining_Identifier (Task_Node, Name_Node);
Scopes (Scope.Last).Labl := Name_Node;
Current_Node := Name_Node;
if Token = Tok_Left_Paren then
Error_Msg_SC ("discriminant part not allowed for single task");
Discard_Junk_List (P_Known_Discriminant_Part_Opt);
end if;
end if;
-- Scan aspect specifications, don't eat the semicolon, since it
-- might not be there if we have an IS.
P_Aspect_Specifications (Task_Node, Semicolon => False);
-- Parse optional task definition. Note that P_Task_Definition scans
-- out the semicolon and possible aspect specifications as well as
-- the task definition itself.
if Token = Tok_Semicolon then
-- A little check, if the next token after semicolon is Entry,
-- then surely the semicolon should really be IS
Scan; -- past semicolon
if Token = Tok_Entry then
Error_Msg_SP -- CODEFIX
("|"";"" should be IS");
Set_Task_Definition (Task_Node, P_Task_Definition);
else
Pop_Scope_Stack; -- Remove unused entry
end if;
-- Here we have a task definition
else
TF_Is; -- must have IS if no semicolon
-- Ada 2005 (AI-345)
if Token = Tok_New then
Scan; -- past NEW
Error_Msg_Ada_2005_Extension ("task interface");
Set_Interface_List (Task_Node, New_List);
loop
Append (P_Qualified_Simple_Name, Interface_List (Task_Node));
exit when Token /= Tok_And;
Scan; -- past AND
end loop;
if Token /= Tok_With then
Error_Msg_SC -- CODEFIX
("WITH expected");
end if;
Scan; -- past WITH
if Token = Tok_Private then
Error_Msg_SP -- CODEFIX
("PRIVATE not allowed in task type declaration");
end if;
end if;
Set_Task_Definition (Task_Node, P_Task_Definition);
end if;
return Task_Node;
end if;
end P_Task;
--------------------------------
-- 9.1 Task Type Declaration --
--------------------------------
-- Parsed by P_Task (9.1)
----------------------------------
-- 9.1 Single Task Declaration --
----------------------------------
-- Parsed by P_Task (9.1)
--------------------------
-- 9.1 Task Definition --
--------------------------
-- TASK_DEFINITION ::=
-- {TASK_ITEM}
-- [private
-- {TASK_ITEM}]
-- end [task_IDENTIFIER];
-- The caller has already made the scope stack entry
-- Note: there is a small deviation from official syntax here in that we
-- regard the semicolon after end as part of the Task_Definition, and in
-- the official syntax, it's part of the enclosing declaration. The reason
-- for this deviation is that otherwise the end processing would have to
-- be special cased, which would be a nuisance.
-- Error recovery: cannot raise Error_Resync
function P_Task_Definition return Node_Id is
Def_Node : Node_Id;
begin
Def_Node := New_Node (N_Task_Definition, Token_Ptr);
Set_Visible_Declarations (Def_Node, P_Task_Items);
if Token = Tok_Private then
Scan; -- past PRIVATE
Set_Private_Declarations (Def_Node, P_Task_Items);
-- Deal gracefully with multiple PRIVATE parts
while Token = Tok_Private loop
Error_Msg_SC ("only one private part allowed per task");
Scan; -- past PRIVATE
Append_List (P_Task_Items, Private_Declarations (Def_Node));
end loop;
end if;
End_Statements (Def_Node);
return Def_Node;
end P_Task_Definition;
--------------------
-- 9.1 Task Item --
--------------------
-- TASK_ITEM ::= ENTRY_DECLARATION | REPRESENTATION_CLAUSE
-- This subprogram scans a (possibly empty) list of task items and pragmas
-- Error recovery: cannot raise Error_Resync
-- Note: a pragma can also be returned in this position
function P_Task_Items return List_Id is
Items : List_Id;
Item_Node : Node_Id;
Decl_Sloc : Source_Ptr;
begin
-- Get rid of active SIS entry from outer scope. This means we will
-- miss some nested cases, but it doesn't seem worth the effort. See
-- discussion in Par for further details
SIS_Entry_Active := False;
-- Loop to scan out task items
Items := New_List;
Decl_Loop : loop
Decl_Sloc := Token_Ptr;
if Token = Tok_Pragma then
P_Pragmas_Opt (Items);
-- Ada 2005 (AI-397): Reserved words NOT and OVERRIDING may begin an
-- entry declaration.
elsif Token in Tok_Entry | Tok_Not | Tok_Overriding then
Append (P_Entry_Declaration, Items);
elsif Token = Tok_For then
-- Representation clause in task declaration. The only rep clause
-- which is legal in a protected declaration is an address clause,
-- so that is what we try to scan out.
Item_Node := P_Representation_Clause;
if Nkind (Item_Node) = N_At_Clause then
Append (Item_Node, Items);
elsif Nkind (Item_Node) = N_Attribute_Definition_Clause
and then Chars (Item_Node) = Name_Address
then
Append (Item_Node, Items);
else
Error_Msg
("the only representation clause " &
"allowed here is an address clause!", Decl_Sloc);
end if;
elsif Token = Tok_Identifier
or else Token in Token_Class_Declk
then
Error_Msg_SC ("illegal declaration in task definition");
Resync_Past_Semicolon;
else
exit Decl_Loop;
end if;
end loop Decl_Loop;
return Items;
end P_Task_Items;
--------------------
-- 9.1 Task Body --
--------------------
-- Parsed by P_Task (9.1)
----------------------------------
-- 9.4 Protected (also 10.1.3) --
----------------------------------
-- PROTECTED_TYPE_DECLARATION ::=
-- protected type DEFINING_IDENTIFIER [KNOWN_DISCRIMINANT_PART]
-- [ASPECT_SPECIFICATIONS]
-- is [new INTERFACE_LIST with] PROTECTED_DEFINITION;
-- SINGLE_PROTECTED_DECLARATION ::=
-- protected DEFINING_IDENTIFIER
-- [ASPECT_SPECIFICATIONS]
-- is [new INTERFACE_LIST with] PROTECTED_DEFINITION;
-- PROTECTED_BODY ::=
-- protected body DEFINING_IDENTIFIER
-- [ASPECT_SPECIFICATIONS]
-- is
-- {PROTECTED_OPERATION_ITEM}
-- end [protected_IDENTIFIER];
-- PROTECTED_BODY_STUB ::=
-- protected body DEFINING_IDENTIFIER is separate
-- [ASPECT_SPECIFICATIONS];
-- This routine scans out a protected declaration, protected body
-- or a protected stub.
-- The caller has checked that the initial token is PROTECTED and
-- scanned past it, so Token is set to the following token.
-- Error recovery: cannot raise Error_Resync
function P_Protected return Node_Id is
Aspect_Sloc : Source_Ptr := No_Location;
Name_Node : Node_Id;
Protected_Node : Node_Id;
Protected_Sloc : Source_Ptr;
Scan_State : Saved_Scan_State;
Dummy_Node : constant Node_Id := New_Node (N_Protected_Body, Token_Ptr);
-- Placeholder node used to hold legal or prematurely declared aspect
-- specifications. Depending on the context, the aspect specifications
-- may be moved to a new node.
begin
Push_Scope_Stack;
Scopes (Scope.Last).Etyp := E_Name;
Scopes (Scope.Last).Ecol := Start_Column;
Scopes (Scope.Last).Lreq := False;
Protected_Sloc := Prev_Token_Ptr;
if Token = Tok_Body then
Scan; -- past BODY
Name_Node := P_Defining_Identifier (C_Is);
Scopes (Scope.Last).Labl := Name_Node;
Current_Node := Name_Node;
if Token = Tok_Left_Paren then
Error_Msg_SC ("discriminant part not allowed in protected body");
Discard_Junk_List (P_Known_Discriminant_Part_Opt);
end if;
if Aspect_Specifications_Present then
Aspect_Sloc := Token_Ptr;
P_Aspect_Specifications (Dummy_Node, Semicolon => False);
end if;
TF_Is;
-- Protected stub
if Token = Tok_Separate then
Scan; -- past SEPARATE
Protected_Node := New_Node (N_Protected_Body_Stub, Protected_Sloc);
Set_Defining_Identifier (Protected_Node, Name_Node);
if Has_Aspects (Dummy_Node) then
Error_Msg
("aspect specifications must come after SEPARATE",
Aspect_Sloc);
end if;
P_Aspect_Specifications (Protected_Node, Semicolon => False);
TF_Semicolon;
Pop_Scope_Stack; -- remove unused entry
-- Protected body
else
Protected_Node := New_Node (N_Protected_Body, Protected_Sloc);
Set_Defining_Identifier (Protected_Node, Name_Node);
Move_Aspects (From => Dummy_Node, To => Protected_Node);
Set_Declarations (Protected_Node, P_Protected_Operation_Items);
End_Statements (Protected_Node);
end if;
return Protected_Node;
-- Otherwise we must have a protected declaration
else
if Token = Tok_Type then
Scan; -- past TYPE
Protected_Node :=
New_Node (N_Protected_Type_Declaration, Protected_Sloc);
Name_Node := P_Defining_Identifier (C_Is);
Set_Defining_Identifier (Protected_Node, Name_Node);
Scopes (Scope.Last).Labl := Name_Node;
Current_Node := Name_Node;
Set_Discriminant_Specifications
(Protected_Node, P_Known_Discriminant_Part_Opt);
else
Protected_Node :=
New_Node (N_Single_Protected_Declaration, Protected_Sloc);
Name_Node := P_Defining_Identifier (C_Is);
Set_Defining_Identifier (Protected_Node, Name_Node);
if Token = Tok_Left_Paren then
Error_Msg_SC
("discriminant part not allowed for single protected");
Discard_Junk_List (P_Known_Discriminant_Part_Opt);
end if;
Scopes (Scope.Last).Labl := Name_Node;
Current_Node := Name_Node;
end if;
P_Aspect_Specifications (Protected_Node, Semicolon => False);
-- Check for semicolon not followed by IS, this is something like
-- protected type r;
-- where we want
-- protected type r IS END;
if Token = Tok_Semicolon then
Save_Scan_State (Scan_State); -- at semicolon
Scan; -- past semicolon
if Token /= Tok_Is then
Restore_Scan_State (Scan_State);
Error_Msg_SC -- CODEFIX
("missing IS");
Set_Protected_Definition (Protected_Node,
Make_Protected_Definition (Token_Ptr,
Visible_Declarations => Empty_List,
End_Label => Empty));
SIS_Entry_Active := False;
End_Statements
(Protected_Definition (Protected_Node), Protected_Node);
return Protected_Node;
end if;
Error_Msg_SP -- CODEFIX
("|extra ""("" ignored");
end if;
T_Is;
-- Ada 2005 (AI-345)
if Token = Tok_New then
Scan; -- past NEW
Error_Msg_Ada_2005_Extension ("protected interface");
Set_Interface_List (Protected_Node, New_List);
loop
Append (P_Qualified_Simple_Name,
Interface_List (Protected_Node));
exit when Token /= Tok_And;
Scan; -- past AND
end loop;
if Token /= Tok_With then
Error_Msg_SC -- CODEFIX
("WITH expected");
end if;
Scan; -- past WITH
end if;
Set_Protected_Definition (Protected_Node, P_Protected_Definition);
return Protected_Node;
end if;
end P_Protected;
-------------------------------------
-- 9.4 Protected Type Declaration --
-------------------------------------
-- Parsed by P_Protected (9.4)
---------------------------------------
-- 9.4 Single Protected Declaration --
---------------------------------------
-- Parsed by P_Protected (9.4)
-------------------------------
-- 9.4 Protected Definition --
-------------------------------
-- PROTECTED_DEFINITION ::=
-- {PROTECTED_OPERATION_DECLARATION}
-- [private
-- {PROTECTED_ELEMENT_DECLARATION}]
-- end [protected_IDENTIFIER]
-- PROTECTED_ELEMENT_DECLARATION ::=
-- PROTECTED_OPERATION_DECLARATION
-- | COMPONENT_DECLARATION
-- The caller has already established the scope stack entry
-- Error recovery: cannot raise Error_Resync
function P_Protected_Definition return Node_Id is
Def_Node : Node_Id;
Item_Node : Node_Id;
Priv_Decls : List_Id;
Vis_Decls : List_Id;
begin
Def_Node := New_Node (N_Protected_Definition, Token_Ptr);
-- Get rid of active SIS entry from outer scope. This means we will
-- miss some nested cases, but it doesn't seem worth the effort. See
-- discussion in Par for further details
SIS_Entry_Active := False;
-- Loop to scan visible declarations (protected operation declarations)
Vis_Decls := New_List;
Set_Visible_Declarations (Def_Node, Vis_Decls);
-- Flag and discard all pragmas which cannot appear in the protected
-- definition. Note that certain pragmas are still allowed as long as
-- they apply to entries, entry families, or protected subprograms.
P_Pragmas_Opt (Vis_Decls);
loop
Item_Node := P_Protected_Operation_Declaration_Opt;
if Present (Item_Node) then
Append (Item_Node, Vis_Decls);
end if;
P_Pragmas_Opt (Vis_Decls);
exit when No (Item_Node);
end loop;
-- Deal with PRIVATE part (including graceful handling of multiple
-- PRIVATE parts).
Private_Loop : while Token = Tok_Private loop
Priv_Decls := Private_Declarations (Def_Node);
if Present (Priv_Decls) then
Error_Msg_SC ("duplicate private part");
else
Priv_Decls := New_List;
Set_Private_Declarations (Def_Node, Priv_Decls);
end if;
Scan; -- past PRIVATE
-- Flag and discard all pragmas which cannot appear in the protected
-- definition. Note that certain pragmas are still allowed as long as
-- they apply to entries, entry families, or protected subprograms.
P_Pragmas_Opt (Priv_Decls);
Declaration_Loop : loop
if Token = Tok_Identifier then
P_Component_Items (Priv_Decls);
P_Pragmas_Opt (Priv_Decls);
else
Item_Node := P_Protected_Operation_Declaration_Opt;
if Present (Item_Node) then
Append (Item_Node, Priv_Decls);
end if;
P_Pragmas_Opt (Priv_Decls);
exit Declaration_Loop when No (Item_Node);
end if;
end loop Declaration_Loop;
end loop Private_Loop;
End_Statements (Def_Node);
return Def_Node;
end P_Protected_Definition;
------------------------------------------
-- 9.4 Protected Operation Declaration --
------------------------------------------
-- PROTECTED_OPERATION_DECLARATION ::=
-- SUBPROGRAM_DECLARATION
-- | ENTRY_DECLARATION
-- | REPRESENTATION_CLAUSE
-- Error recovery: cannot raise Error_Resync
-- Note: a pragma can also be returned in this position
-- We are not currently permitting representation clauses to appear as
-- protected operation declarations, do we have to rethink this???
function P_Protected_Operation_Declaration_Opt return Node_Id is
L : List_Id;
P : Source_Ptr;
function P_Entry_Or_Subprogram_With_Indicator return Node_Id;
-- Ada 2005 (AI-397): Parse an entry or a subprogram with an overriding
-- indicator. The caller has checked that the initial token is NOT or
-- OVERRIDING.
------------------------------------------
-- P_Entry_Or_Subprogram_With_Indicator --
------------------------------------------
function P_Entry_Or_Subprogram_With_Indicator return Node_Id is
Decl : Node_Id := Error;
Is_Overriding : Boolean := False;
Not_Overriding : Boolean := False;
begin
if Token = Tok_Not then
Scan; -- past NOT
if Token = Tok_Overriding then
Scan; -- past OVERRIDING
Not_Overriding := True;
else
Error_Msg_SC -- CODEFIX
("OVERRIDING expected!");
end if;
else
Scan; -- past OVERRIDING
Is_Overriding := True;
end if;
if Is_Overriding or else Not_Overriding then
if Ada_Version < Ada_2005 then
Error_Msg_Ada_2005_Extension ("overriding indicator");
elsif Token = Tok_Entry then
Decl := P_Entry_Declaration;
Set_Must_Override (Decl, Is_Overriding);
Set_Must_Not_Override (Decl, Not_Overriding);
elsif Token in Tok_Function | Tok_Procedure then
Decl := P_Subprogram (Pf_Decl_Pexp);
Set_Must_Override (Specification (Decl), Is_Overriding);
Set_Must_Not_Override (Specification (Decl), Not_Overriding);
else
Error_Msg_SC -- CODEFIX
("ENTRY, FUNCTION or PROCEDURE expected!");
end if;
end if;
return Decl;
end P_Entry_Or_Subprogram_With_Indicator;
Result : Node_Id := Empty;
-- Start of processing for P_Protected_Operation_Declaration_Opt
begin
-- This loop runs more than once only when a junk declaration is skipped
loop
case Token is
when Tok_Pragma =>
Result := P_Pragma;
exit;
when Tok_Not
| Tok_Overriding
=>
Result := P_Entry_Or_Subprogram_With_Indicator;
exit;
when Tok_Entry =>
Result := P_Entry_Declaration;
exit;
when Tok_Function
| Tok_Procedure
=>
Result := P_Subprogram (Pf_Decl_Pexp);
exit;
when Tok_Identifier =>
L := New_List;
P := Token_Ptr;
Skip_Declaration (L);
if Nkind (First (L)) = N_Object_Declaration then
Error_Msg
("component must be declared in private part of " &
"protected type", P);
else
Error_Msg
("illegal declaration in protected definition", P);
end if;
-- Continue looping
when Tok_For =>
Error_Msg_SC
("representation clause not allowed in protected definition");
Resync_Past_Semicolon;
-- Continue looping
when others =>
if Token in Token_Class_Declk then
Error_Msg_SC ("illegal declaration in protected definition");
Resync_Past_Semicolon;
-- Return now to avoid cascaded messages if next declaration
-- is a valid component declaration.
Result := Error;
end if;
exit;
end case;
end loop;
if Nkind (Result) = N_Subprogram_Declaration
and then Nkind (Specification (Result)) =
N_Procedure_Specification
and then Null_Present (Specification (Result))
then
Error_Msg_N
("protected operation cannot be a null procedure",
Null_Statement (Specification (Result)));
end if;
return Result;
end P_Protected_Operation_Declaration_Opt;
-----------------------------------
-- 9.4 Protected Operation Item --
-----------------------------------
-- PROTECTED_OPERATION_ITEM ::=
-- SUBPROGRAM_DECLARATION
-- | SUBPROGRAM_BODY
-- | ENTRY_BODY
-- | REPRESENTATION_CLAUSE
-- This procedure parses and returns a list of protected operation items
-- We are not currently permitting representation clauses to appear
-- as protected operation items, do we have to rethink this???
function P_Protected_Operation_Items return List_Id is
Item_List : List_Id;
begin
Item_List := New_List;
loop
if Token = Tok_Entry or else Bad_Spelling_Of (Tok_Entry) then
Append (P_Entry_Body, Item_List);
-- If the operation starts with procedure, function, or an overriding
-- indicator ("overriding" or "not overriding"), parse a subprogram.
elsif Token = Tok_Function or else Bad_Spelling_Of (Tok_Function)
or else
Token = Tok_Procedure or else Bad_Spelling_Of (Tok_Procedure)
or else
Token = Tok_Overriding or else Bad_Spelling_Of (Tok_Overriding)
or else
Token = Tok_Not or else Bad_Spelling_Of (Tok_Not)
then
Append (P_Subprogram (Pf_Decl_Pbod_Pexp), Item_List);
elsif Token = Tok_Pragma or else Bad_Spelling_Of (Tok_Pragma) then
P_Pragmas_Opt (Item_List);
elsif Token = Tok_Private or else Bad_Spelling_Of (Tok_Private) then
Error_Msg_SC ("PRIVATE not allowed in protected body");
Scan; -- past PRIVATE
elsif Token = Tok_Identifier then
Error_Msg_SC ("all components must be declared in spec!");
Resync_Past_Semicolon;
elsif Token in Token_Class_Declk then
Error_Msg_SC ("declaration not allowed in protected body");
Resync_Past_Semicolon;
else
exit;
end if;
end loop;
return Item_List;
end P_Protected_Operation_Items;
------------------------------
-- 9.5.2 Entry Declaration --
------------------------------
-- ENTRY_DECLARATION ::=
-- [OVERRIDING_INDICATOR]
-- entry DEFINING_IDENTIFIER
-- [(DISCRETE_SUBTYPE_DEFINITION)] PARAMETER_PROFILE
-- [ASPECT_SPECIFICATIONS];
-- The caller has checked that the initial token is ENTRY, NOT or
-- OVERRIDING.
-- Error recovery: cannot raise Error_Resync
function P_Entry_Declaration return Node_Id is
Decl_Node : Node_Id;
Scan_State : Saved_Scan_State;
-- Flags for optional overriding indication. Two flags are needed,
-- to distinguish positive and negative overriding indicators from
-- the absence of any indicator.
Is_Overriding : Boolean := False;
Not_Overriding : Boolean := False;
begin
-- Ada 2005 (AI-397): Scan leading overriding indicator
if Token = Tok_Not then
Scan; -- past NOT
if Token = Tok_Overriding then
Scan; -- part OVERRIDING
Not_Overriding := True;
else
Error_Msg_SC -- CODEFIX
("OVERRIDING expected!");
end if;
elsif Token = Tok_Overriding then
Scan; -- part OVERRIDING
Is_Overriding := True;
end if;
if Is_Overriding or else Not_Overriding then
if Ada_Version < Ada_2005 then
Error_Msg_Ada_2005_Extension ("overriding indicator");
elsif Token /= Tok_Entry then
Error_Msg_SC -- CODEFIX
("ENTRY expected!");
end if;
end if;
Decl_Node := New_Node (N_Entry_Declaration, Token_Ptr);
Scan; -- past ENTRY
Set_Defining_Identifier
(Decl_Node, P_Defining_Identifier (C_Left_Paren_Semicolon));
-- If left paren, could be (Discrete_Subtype_Definition) or Formal_Part
if Token = Tok_Left_Paren then
Scan; -- past (
-- If identifier after left paren, could still be either
if Token = Tok_Identifier then
Save_Scan_State (Scan_State); -- at Id
Scan; -- past Id
-- If comma or colon after Id, must be Formal_Part
if Token in Tok_Comma | Tok_Colon then
Restore_Scan_State (Scan_State); -- to Id
Set_Parameter_Specifications (Decl_Node, P_Formal_Part);
-- Else if Id without comma or colon, must be discrete subtype
-- defn
else
Restore_Scan_State (Scan_State); -- to Id
Set_Discrete_Subtype_Definition
(Decl_Node, P_Discrete_Subtype_Definition);
T_Right_Paren;
Set_Parameter_Specifications (Decl_Node, P_Parameter_Profile);
end if;
-- If no Id, must be discrete subtype definition
else
Set_Discrete_Subtype_Definition
(Decl_Node, P_Discrete_Subtype_Definition);
T_Right_Paren;
Set_Parameter_Specifications (Decl_Node, P_Parameter_Profile);
end if;
end if;
if Is_Overriding then
Set_Must_Override (Decl_Node);
elsif Not_Overriding then
Set_Must_Not_Override (Decl_Node);
end if;
-- Error recovery check for illegal return
if Token = Tok_Return then
Error_Msg_SC ("entry cannot have return value!");
Scan;
Discard_Junk_Node (P_Subtype_Indication);
end if;
-- Error recovery check for improper use of entry barrier in spec
if Token = Tok_When then
Error_Msg_SC ("barrier not allowed here (belongs in body)");
Scan; -- past WHEN;
Discard_Junk_Node (P_Expression_No_Right_Paren);
end if;
P_Aspect_Specifications (Decl_Node);
return Decl_Node;
exception
when Error_Resync =>
Resync_Past_Semicolon;
return Error;
end P_Entry_Declaration;
-----------------------------
-- 9.5.2 Accept Statement --
-----------------------------
-- ACCEPT_STATEMENT ::=
-- accept entry_DIRECT_NAME
-- [(ENTRY_INDEX)] PARAMETER_PROFILE [do
-- HANDLED_SEQUENCE_OF_STATEMENTS
-- end [entry_IDENTIFIER]];
-- The caller has checked that the initial token is ACCEPT
-- Error recovery: cannot raise Error_Resync. If an error occurs, the
-- scan is resynchronized past the next semicolon and control returns.
function P_Accept_Statement return Node_Id is
Scan_State : Saved_Scan_State;
Accept_Node : Node_Id;
Hand_Seq : Node_Id;
begin
Push_Scope_Stack;
Scopes (Scope.Last).Sloc := Token_Ptr;
Scopes (Scope.Last).Ecol := Start_Column;
Accept_Node := New_Node (N_Accept_Statement, Token_Ptr);
Scan; -- past ACCEPT
Scopes (Scope.Last).Labl := Token_Node;
Current_Node := Token_Node;
Set_Entry_Direct_Name (Accept_Node, P_Identifier (C_Do));
-- Left paren could be (Entry_Index) or Formal_Part, determine which
if Token = Tok_Left_Paren then
Save_Scan_State (Scan_State); -- at left paren
Scan; -- past left paren
-- If first token after left paren not identifier, then Entry_Index
if Token /= Tok_Identifier then
Set_Entry_Index (Accept_Node, P_Expression);
T_Right_Paren;
Set_Parameter_Specifications (Accept_Node, P_Parameter_Profile);
-- First token after left paren is identifier, could be either case
else -- Token = Tok_Identifier
Scan; -- past identifier
-- If identifier followed by comma or colon, must be Formal_Part
if Token in Tok_Comma | Tok_Colon then
Restore_Scan_State (Scan_State); -- to left paren
Set_Parameter_Specifications (Accept_Node, P_Parameter_Profile);
-- If identifier not followed by comma/colon, must be entry index
else
Restore_Scan_State (Scan_State); -- to left paren
Scan; -- past left paren (again)
Set_Entry_Index (Accept_Node, P_Expression);
T_Right_Paren;
Set_Parameter_Specifications (Accept_Node, P_Parameter_Profile);
end if;
end if;
end if;
-- Scan out DO if present
if Token = Tok_Do then
Scopes (Scope.Last).Etyp := E_Name;
Scopes (Scope.Last).Lreq := False;
Scan; -- past DO
Hand_Seq := P_Handled_Sequence_Of_Statements;
Set_Handled_Statement_Sequence (Accept_Node, Hand_Seq);
End_Statements (Handled_Statement_Sequence (Accept_Node));
-- Exception handlers not allowed in Ada 95 node
if Present (Exception_Handlers (Hand_Seq)) then
if Ada_Version = Ada_83 then
Error_Msg_N
("(Ada 83) exception handlers in accept not allowed",
First_Non_Pragma (Exception_Handlers (Hand_Seq)));
end if;
end if;
else
Pop_Scope_Stack; -- discard unused entry
TF_Semicolon;
end if;
return Accept_Node;
-- If error, resynchronize past semicolon
exception
when Error_Resync =>
Resync_Past_Semicolon;
Pop_Scope_Stack; -- discard unused entry
return Error;
end P_Accept_Statement;
------------------------
-- 9.5.2 Entry Index --
------------------------
-- Parsed by P_Expression (4.4)
--------------------------
-- 9.5.2 Entry Barrier --
--------------------------
-- ENTRY_BARRIER ::= when CONDITION
-- Error_Recovery: cannot raise Error_Resync
function P_Entry_Barrier return Node_Id is
Bnode : Node_Id;
begin
if Token = Tok_When then
Scan; -- past WHEN;
Bnode := P_Expression_No_Right_Paren;
if Token = Tok_Colon_Equal then
Error_Msg_SC -- CODEFIX
("|"":="" should be ""=""");
Scan;
Bnode := P_Expression_No_Right_Paren;
end if;
else
T_When; -- to give error message
Bnode := Error;
end if;
return Bnode;
end P_Entry_Barrier;
-----------------------
-- 9.5.2 Entry Body --
-----------------------
-- ENTRY_BODY ::=
-- entry DEFINING_IDENTIFIER ENTRY_BODY_FORMAL_PART
-- [ASPECT_SPECIFICATIONS] ENTRY_BARRIER
-- is
-- DECLARATIVE_PART
-- begin
-- HANDLED_SEQUENCE_OF_STATEMENTS
-- end [entry_IDENTIFIER];
-- The caller has checked that the initial token is ENTRY
-- Error_Recovery: cannot raise Error_Resync
function P_Entry_Body return Node_Id is
Dummy_Node : Node_Id;
Entry_Node : Node_Id;
Formal_Part_Node : Node_Id;
Name_Node : Node_Id;
begin
Push_Scope_Stack;
Entry_Node := New_Node (N_Entry_Body, Token_Ptr);
Scan; -- past ENTRY
Scopes (Scope.Last).Ecol := Start_Column;
Scopes (Scope.Last).Lreq := False;
Scopes (Scope.Last).Etyp := E_Name;
Scopes (Scope.Last).Sloc := Token_Ptr;
Name_Node := P_Defining_Identifier;
Set_Defining_Identifier (Entry_Node, Name_Node);
Scopes (Scope.Last).Labl := Name_Node;
Current_Node := Name_Node;
Formal_Part_Node := P_Entry_Body_Formal_Part;
Set_Entry_Body_Formal_Part (Entry_Node, Formal_Part_Node);
-- Ada 2012 (AI12-0169): Aspect specifications may appear on an entry
-- body immediately after the formal part. Do not parse the aspect
-- specifications directly because the "when" of the entry barrier may
-- be interpreted as a misused "with".
if Token = Tok_With then
P_Aspect_Specifications (Entry_Node, Semicolon => False);
end if;
Set_Condition (Formal_Part_Node, P_Entry_Barrier);
-- Detect an illegal placement of aspect specifications following the
-- entry barrier.
-- entry E ... when Barrier with Aspect is
if Token = Tok_With then
Error_Msg_SC ("aspect specifications must come before entry barrier");
-- Consume the illegal aspects to allow for parsing to continue
Dummy_Node := New_Node (N_Entry_Body, Sloc (Entry_Node));
P_Aspect_Specifications (Dummy_Node, Semicolon => False);
end if;
TF_Is;
Parse_Decls_Begin_End (Entry_Node);
return Entry_Node;
end P_Entry_Body;
-----------------------------------
-- 9.5.2 Entry Body Formal Part --
-----------------------------------
-- ENTRY_BODY_FORMAL_PART ::=
-- [(ENTRY_INDEX_SPECIFICATION)] [PARAMETER_PART]
-- Error_Recovery: cannot raise Error_Resync
function P_Entry_Body_Formal_Part return Node_Id is
Fpart_Node : Node_Id;
Scan_State : Saved_Scan_State;
begin
Fpart_Node := New_Node (N_Entry_Body_Formal_Part, Token_Ptr);
-- See if entry index specification present, and if so parse it
if Token = Tok_Left_Paren then
Save_Scan_State (Scan_State); -- at left paren
Scan; -- past left paren
if Token = Tok_For then
Set_Entry_Index_Specification
(Fpart_Node, P_Entry_Index_Specification);
T_Right_Paren;
else
Restore_Scan_State (Scan_State); -- to left paren
end if;
-- Check for (common?) case of left paren omitted before FOR. This
-- is a tricky case, because the corresponding missing left paren
-- can cause real havoc if a formal part is present which gets
-- treated as part of the discrete subtype definition of the
-- entry index specification, so just give error and resynchronize
elsif Token = Tok_For then
T_Left_Paren; -- to give error message
Resync_To_When;
end if;
Set_Parameter_Specifications (Fpart_Node, P_Parameter_Profile);
return Fpart_Node;
end P_Entry_Body_Formal_Part;
--------------------------------------
-- 9.5.2 Entry Index Specification --
--------------------------------------
-- ENTRY_INDEX_SPECIFICATION ::=
-- for DEFINING_IDENTIFIER in DISCRETE_SUBTYPE_DEFINITION
-- [ASPECT_SPECIFICATION]
-- Error recovery: can raise Error_Resync
function P_Entry_Index_Specification return Node_Id is
Iterator_Node : Node_Id;
begin
Iterator_Node := New_Node (N_Entry_Index_Specification, Token_Ptr);
T_For; -- past FOR
Set_Defining_Identifier (Iterator_Node, P_Defining_Identifier (C_In));
T_In;
Set_Discrete_Subtype_Definition
(Iterator_Node, P_Discrete_Subtype_Definition);
if Token = Tok_With then
P_Aspect_Specifications (Iterator_Node, False);
end if;
return Iterator_Node;
end P_Entry_Index_Specification;
---------------------------------
-- 9.5.3 Entry Call Statement --
---------------------------------
-- Parsed by P_Name (4.1). Within a select, an entry call is parsed
-- by P_Select_Statement (9.7)
------------------------------
-- 9.5.4 Requeue Statement --
------------------------------
-- REQUEUE_STATEMENT ::= requeue entry_NAME [with abort];
-- The caller has checked that the initial token is requeue
-- Error recovery: can raise Error_Resync
function P_Requeue_Statement return Node_Id is
Requeue_Node : Node_Id;
begin
Requeue_Node := New_Node (N_Requeue_Statement, Token_Ptr);
Scan; -- past REQUEUE
Set_Name (Requeue_Node, P_Name);
if Token = Tok_With then
Scan; -- past WITH
T_Abort;
Set_Abort_Present (Requeue_Node, True);
end if;
TF_Semicolon;
return Requeue_Node;
end P_Requeue_Statement;
--------------------------
-- 9.6 Delay Statement --
--------------------------
-- DELAY_STATEMENT ::=
-- DELAY_UNTIL_STATEMENT
-- | DELAY_RELATIVE_STATEMENT
-- The caller has checked that the initial token is DELAY
-- Error recovery: cannot raise Error_Resync
function P_Delay_Statement return Node_Id is
begin
Scan; -- past DELAY
-- The following check for delay until misused in Ada 83 doesn't catch
-- all cases, but it's good enough to catch most of them.
if Token_Name = Name_Until then
Check_95_Keyword (Tok_Until, Tok_Left_Paren);
Check_95_Keyword (Tok_Until, Tok_Identifier);
end if;
if Token = Tok_Until then
return P_Delay_Until_Statement;
else
return P_Delay_Relative_Statement;
end if;
end P_Delay_Statement;
--------------------------------
-- 9.6 Delay Until Statement --
--------------------------------
-- DELAY_UNTIL_STATEMENT ::= delay until delay_EXPRESSION;
-- The caller has checked that the initial token is DELAY, scanned it
-- out and checked that the current token is UNTIL
-- Error recovery: cannot raise Error_Resync
function P_Delay_Until_Statement return Node_Id is
Delay_Node : Node_Id;
begin
Delay_Node := New_Node (N_Delay_Until_Statement, Prev_Token_Ptr);
Scan; -- past UNTIL
Set_Expression (Delay_Node, P_Expression_No_Right_Paren);
TF_Semicolon;
return Delay_Node;
end P_Delay_Until_Statement;
-----------------------------------
-- 9.6 Delay Relative Statement --
-----------------------------------
-- DELAY_RELATIVE_STATEMENT ::= delay delay_EXPRESSION;
-- The caller has checked that the initial token is DELAY, scanned it
-- out and determined that the current token is not UNTIL
-- Error recovery: cannot raise Error_Resync
function P_Delay_Relative_Statement return Node_Id is
Delay_Node : Node_Id;
begin
Delay_Node := New_Node (N_Delay_Relative_Statement, Prev_Token_Ptr);
Set_Expression (Delay_Node, P_Expression_No_Right_Paren);
Check_Simple_Expression_In_Ada_83 (Expression (Delay_Node));
TF_Semicolon;
return Delay_Node;
end P_Delay_Relative_Statement;
---------------------------
-- 9.7 Select Statement --
---------------------------
-- SELECT_STATEMENT ::=
-- SELECTIVE_ACCEPT
-- | TIMED_ENTRY_CALL
-- | CONDITIONAL_ENTRY_CALL
-- | ASYNCHRONOUS_SELECT
-- SELECTIVE_ACCEPT ::=
-- select
-- [GUARD]
-- SELECT_ALTERNATIVE
-- {or
-- [GUARD]
-- SELECT_ALTERNATIVE
-- [else
-- SEQUENCE_OF_STATEMENTS]
-- end select;
-- GUARD ::= when CONDITION =>
-- Note: the guard preceding a select alternative is included as part
-- of the node generated for a selective accept alternative.
-- SELECT_ALTERNATIVE ::=
-- ACCEPT_ALTERNATIVE
-- | DELAY_ALTERNATIVE
-- | TERMINATE_ALTERNATIVE
-- TIMED_ENTRY_CALL ::=
-- select
-- ENTRY_CALL_ALTERNATIVE
-- or
-- DELAY_ALTERNATIVE
-- end select;
-- CONDITIONAL_ENTRY_CALL ::=
-- select
-- ENTRY_CALL_ALTERNATIVE
-- else
-- SEQUENCE_OF_STATEMENTS
-- end select;
-- ENTRY_CALL_ALTERNATIVE ::=
-- ENTRY_CALL_STATEMENT [SEQUENCE_OF_STATEMENTS]
-- ASYNCHRONOUS_SELECT ::=
-- select
-- TRIGGERING_ALTERNATIVE
-- then abort
-- ABORTABLE_PART
-- end select;
-- TRIGGERING_ALTERNATIVE ::=
-- TRIGGERING_STATEMENT [SEQUENCE_OF_STATEMENTS]
-- TRIGGERING_STATEMENT ::= ENTRY_CALL_STATEMENT | DELAY_STATEMENT
-- The caller has checked that the initial token is SELECT
-- Error recovery: can raise Error_Resync
function P_Select_Statement return Node_Id is
Select_Node : Node_Id;
Select_Sloc : Source_Ptr;
Stmnt_Sloc : Source_Ptr;
Ecall_Node : Node_Id;
Alternative : Node_Id;
Select_Pragmas : List_Id;
Alt_Pragmas : List_Id;
Statement_List : List_Id;
Alt_List : List_Id;
Cond_Expr : Node_Id;
Delay_Stmnt : Node_Id;
begin
Push_Scope_Stack;
Scopes (Scope.Last).Etyp := E_Select;
Scopes (Scope.Last).Ecol := Start_Column;
Scopes (Scope.Last).Sloc := Token_Ptr;
Scopes (Scope.Last).Labl := Error;
Select_Sloc := Token_Ptr;
Scan; -- past SELECT
Stmnt_Sloc := Token_Ptr;
Select_Pragmas := P_Pragmas_Opt;
-- If first token after select is designator, then we have an entry
-- call, which must be the start of a conditional entry call, timed
-- entry call or asynchronous select
if Token in Token_Class_Desig then
-- Scan entry call statement
begin
Ecall_Node := P_Name;
-- ?? The following two clauses exactly parallel code in ch5
-- and should be combined sometime
if Nkind (Ecall_Node) = N_Indexed_Component then
declare
Prefix_Node : constant Node_Id := Prefix (Ecall_Node);
Exprs_Node : constant List_Id := Expressions (Ecall_Node);
begin
Change_Node (Ecall_Node, N_Procedure_Call_Statement);
Set_Name (Ecall_Node, Prefix_Node);
Set_Parameter_Associations (Ecall_Node, Exprs_Node);
end;
elsif Nkind (Ecall_Node) = N_Function_Call then
declare
Fname_Node : constant Node_Id := Name (Ecall_Node);
Params_List : constant List_Id :=
Parameter_Associations (Ecall_Node);
begin
Change_Node (Ecall_Node, N_Procedure_Call_Statement);
Set_Name (Ecall_Node, Fname_Node);
Set_Parameter_Associations (Ecall_Node, Params_List);
end;
elsif Nkind (Ecall_Node) = N_Identifier
or else Nkind (Ecall_Node) = N_Selected_Component
then
-- Case of a call to a parameterless entry
declare
C_Node : constant Node_Id :=
New_Node (N_Procedure_Call_Statement, Stmnt_Sloc);
begin
Set_Name (C_Node, Ecall_Node);
Set_Parameter_Associations (C_Node, No_List);
Ecall_Node := C_Node;
end;
end if;
TF_Semicolon;
exception
when Error_Resync =>
Resync_Past_Semicolon;
return Error;
end;
Statement_List := P_Sequence_Of_Statements (SS_Eltm_Ortm_Tatm);
-- OR follows, we have a timed entry call
if Token = Tok_Or then
Scan; -- past OR
Alt_Pragmas := P_Pragmas_Opt;
Select_Node := New_Node (N_Timed_Entry_Call, Select_Sloc);
Set_Entry_Call_Alternative (Select_Node,
Make_Entry_Call_Alternative (Stmnt_Sloc,
Entry_Call_Statement => Ecall_Node,
Pragmas_Before => Select_Pragmas,
Statements => Statement_List));
-- Only possibility is delay alternative. If we have anything
-- else, give message, and treat as conditional entry call.
if Token /= Tok_Delay then
Error_Msg_SC
("only allowed alternative in timed entry call is delay!");
Discard_Junk_List (P_Sequence_Of_Statements (SS_Sreq));
Set_Delay_Alternative (Select_Node, Error);
else
Set_Delay_Alternative (Select_Node, P_Delay_Alternative);
Set_Pragmas_Before
(Delay_Alternative (Select_Node), Alt_Pragmas);
end if;
-- ELSE follows, we have a conditional entry call
elsif Token = Tok_Else then
Scan; -- past ELSE
Select_Node := New_Node (N_Conditional_Entry_Call, Select_Sloc);
Set_Entry_Call_Alternative (Select_Node,
Make_Entry_Call_Alternative (Stmnt_Sloc,
Entry_Call_Statement => Ecall_Node,
Pragmas_Before => Select_Pragmas,
Statements => Statement_List));
Set_Else_Statements
(Select_Node, P_Sequence_Of_Statements (SS_Sreq));
-- Only remaining case is THEN ABORT (asynchronous select)
elsif Token = Tok_Abort then
Select_Node :=
Make_Asynchronous_Select (Select_Sloc,
Triggering_Alternative =>
Make_Triggering_Alternative (Stmnt_Sloc,
Triggering_Statement => Ecall_Node,
Pragmas_Before => Select_Pragmas,
Statements => Statement_List),
Abortable_Part => P_Abortable_Part);
-- Else error
else
if Ada_Version = Ada_83 then
Error_Msg_BC ("OR or ELSE expected");
else
Error_Msg_BC ("OR or ELSE or `THEN ABORT` expected");
end if;
Select_Node := Error;
end if;
End_Statements;
-- Here we have a selective accept or an asynchronous select (first
-- token after SELECT is other than a designator token).
else
-- If we have delay with no guard, could be asynchronous select
if Token = Tok_Delay then
Delay_Stmnt := P_Delay_Statement;
Statement_List := P_Sequence_Of_Statements (SS_Eltm_Ortm_Tatm);
-- Asynchronous select
if Token = Tok_Abort then
Select_Node :=
Make_Asynchronous_Select (Select_Sloc,
Triggering_Alternative =>
Make_Triggering_Alternative (Stmnt_Sloc,
Triggering_Statement => Delay_Stmnt,
Pragmas_Before => Select_Pragmas,
Statements => Statement_List),
Abortable_Part => P_Abortable_Part);
End_Statements;
return Select_Node;
-- Delay which was not an asynchronous select. Must be a selective
-- accept, and since at least one accept statement is required,
-- we must have at least one OR phrase present.
else
Alt_List := New_List (
Make_Delay_Alternative (Stmnt_Sloc,
Delay_Statement => Delay_Stmnt,
Pragmas_Before => Select_Pragmas,
Statements => Statement_List));
T_Or;
Alt_Pragmas := P_Pragmas_Opt;
end if;
-- If not a delay statement, then must be another possibility for
-- a selective accept alternative, or perhaps a guard is present
else
Alt_List := New_List;
Alt_Pragmas := Select_Pragmas;
end if;
Select_Node := New_Node (N_Selective_Accept, Select_Sloc);
Set_Select_Alternatives (Select_Node, Alt_List);
-- Scan out selective accept alternatives. On entry to this loop,
-- we are just past a SELECT or OR token, and any pragmas that
-- immediately follow the SELECT or OR are in Alt_Pragmas.
loop
if Token = Tok_When then
if Present (Alt_Pragmas) then
Error_Msg_SC ("pragmas may not precede guard");
end if;
Scan; -- past WHEN
Cond_Expr := P_Expression_No_Right_Paren;
T_Arrow;
Alt_Pragmas := P_Pragmas_Opt;
else
Cond_Expr := Empty;
end if;
if Token = Tok_Accept then
Alternative := P_Accept_Alternative;
-- Check for junk attempt at asynchronous select using
-- an Accept alternative as the triggering statement
if Token = Tok_Abort
and then Is_Empty_List (Alt_List)
and then No (Cond_Expr)
then
Error_Msg
("triggering statement must be entry call or delay",
Sloc (Alternative));
Scan; -- past junk ABORT
Discard_Junk_List (P_Sequence_Of_Statements (SS_Sreq));
End_Statements;
return Error;
end if;
elsif Token = Tok_Delay then
Alternative := P_Delay_Alternative;
elsif Token = Tok_Terminate then
Alternative := P_Terminate_Alternative;
else
Error_Msg_SC
("select alternative (ACCEPT, ABORT, DELAY) expected");
Alternative := Error;
if Token = Tok_Semicolon then
Scan; -- past junk semicolon
end if;
end if;
-- THEN ABORT at this stage is just junk
if Token = Tok_Abort then
Error_Msg_SP ("misplaced `THEN ABORT`");
Scan; -- past junk ABORT
Discard_Junk_List (P_Sequence_Of_Statements (SS_Sreq));
End_Statements;
return Error;
else
if Alternative /= Error then
Set_Condition (Alternative, Cond_Expr);
Set_Pragmas_Before (Alternative, Alt_Pragmas);
Append (Alternative, Alt_List);
end if;
exit when Token /= Tok_Or;
end if;
T_Or;
Alt_Pragmas := P_Pragmas_Opt;
end loop;
if Token = Tok_Else then
Scan; -- past ELSE
Set_Else_Statements
(Select_Node, P_Sequence_Of_Statements (SS_Ortm_Sreq));
if Token = Tok_Or then
Error_Msg_SC ("select alternative cannot follow else part!");
end if;
end if;
End_Statements;
end if;
return Select_Node;
end P_Select_Statement;
-----------------------------
-- 9.7.1 Selective Accept --
-----------------------------
-- Parsed by P_Select_Statement (9.7)
------------------
-- 9.7.1 Guard --
------------------
-- Parsed by P_Select_Statement (9.7)
-------------------------------
-- 9.7.1 Select Alternative --
-------------------------------
-- SELECT_ALTERNATIVE ::=
-- ACCEPT_ALTERNATIVE
-- | DELAY_ALTERNATIVE
-- | TERMINATE_ALTERNATIVE
-- Note: the guard preceding a select alternative is included as part
-- of the node generated for a selective accept alternative.
-- Error recovery: cannot raise Error_Resync
-------------------------------
-- 9.7.1 Accept Alternative --
-------------------------------
-- ACCEPT_ALTERNATIVE ::=
-- ACCEPT_STATEMENT [SEQUENCE_OF_STATEMENTS]
-- Error_Recovery: Cannot raise Error_Resync
-- Note: the caller is responsible for setting the Pragmas_Before
-- field of the returned N_Terminate_Alternative node.
function P_Accept_Alternative return Node_Id is
Accept_Alt_Node : Node_Id;
begin
Accept_Alt_Node := New_Node (N_Accept_Alternative, Token_Ptr);
Set_Accept_Statement (Accept_Alt_Node, P_Accept_Statement);
-- Note: the reason that we accept THEN ABORT as a terminator for
-- the sequence of statements is for error recovery which allows
-- for misuse of an accept statement as a triggering statement.
Set_Statements
(Accept_Alt_Node, P_Sequence_Of_Statements (SS_Eltm_Ortm_Tatm));
return Accept_Alt_Node;
end P_Accept_Alternative;
------------------------------
-- 9.7.1 Delay Alternative --
------------------------------
-- DELAY_ALTERNATIVE ::=
-- DELAY_STATEMENT [SEQUENCE_OF_STATEMENTS]
-- Error_Recovery: Cannot raise Error_Resync
-- Note: the caller is responsible for setting the Pragmas_Before
-- field of the returned N_Terminate_Alternative node.
function P_Delay_Alternative return Node_Id is
Delay_Alt_Node : Node_Id;
begin
Delay_Alt_Node := New_Node (N_Delay_Alternative, Token_Ptr);
Set_Delay_Statement (Delay_Alt_Node, P_Delay_Statement);
-- Note: the reason that we accept THEN ABORT as a terminator for
-- the sequence of statements is for error recovery which allows
-- for misuse of an accept statement as a triggering statement.
Set_Statements
(Delay_Alt_Node, P_Sequence_Of_Statements (SS_Eltm_Ortm_Tatm));
return Delay_Alt_Node;
end P_Delay_Alternative;
----------------------------------
-- 9.7.1 Terminate Alternative --
----------------------------------
-- TERMINATE_ALTERNATIVE ::= terminate;
-- Error_Recovery: Cannot raise Error_Resync
-- Note: the caller is responsible for setting the Pragmas_Before
-- field of the returned N_Terminate_Alternative node.
function P_Terminate_Alternative return Node_Id is
Terminate_Alt_Node : Node_Id;
begin
Terminate_Alt_Node := New_Node (N_Terminate_Alternative, Token_Ptr);
Scan; -- past TERMINATE
TF_Semicolon;
-- For all other select alternatives, the sequence of statements
-- after the alternative statement will swallow up any pragmas
-- coming in this position. But the terminate alternative has no
-- sequence of statements, so the pragmas here must be treated
-- specially.
Set_Pragmas_After (Terminate_Alt_Node, P_Pragmas_Opt);
return Terminate_Alt_Node;
end P_Terminate_Alternative;
-----------------------------
-- 9.7.2 Timed Entry Call --
-----------------------------
-- Parsed by P_Select_Statement (9.7)
-----------------------------------
-- 9.7.2 Entry Call Alternative --
-----------------------------------
-- Parsed by P_Select_Statement (9.7)
-----------------------------------
-- 9.7.3 Conditional Entry Call --
-----------------------------------
-- Parsed by P_Select_Statement (9.7)
--------------------------------
-- 9.7.4 Asynchronous Select --
--------------------------------
-- Parsed by P_Select_Statement (9.7)
-----------------------------------
-- 9.7.4 Triggering Alternative --
-----------------------------------
-- Parsed by P_Select_Statement (9.7)
---------------------------------
-- 9.7.4 Triggering Statement --
---------------------------------
-- Parsed by P_Select_Statement (9.7)
---------------------------
-- 9.7.4 Abortable Part --
---------------------------
-- ABORTABLE_PART ::= SEQUENCE_OF_STATEMENTS
-- The caller has verified that THEN ABORT is present, and Token is
-- pointing to the ABORT on entry (or if not, then we have an error)
-- Error recovery: cannot raise Error_Resync
function P_Abortable_Part return Node_Id is
Abortable_Part_Node : Node_Id;
begin
Abortable_Part_Node := New_Node (N_Abortable_Part, Token_Ptr);
T_Abort; -- scan past ABORT
if Ada_Version = Ada_83 then
Error_Msg_SP ("(Ada 83) asynchronous select not allowed!");
end if;
Set_Statements (Abortable_Part_Node, P_Sequence_Of_Statements (SS_Sreq));
return Abortable_Part_Node;
end P_Abortable_Part;
--------------------------
-- 9.8 Abort Statement --
--------------------------
-- ABORT_STATEMENT ::= abort task_NAME {, task_NAME};
-- The caller has checked that the initial token is ABORT
-- Error recovery: cannot raise Error_Resync
function P_Abort_Statement return Node_Id is
Abort_Node : Node_Id;
begin
Abort_Node := New_Node (N_Abort_Statement, Token_Ptr);
Scan; -- past ABORT
Set_Names (Abort_Node, New_List);
loop
Append (P_Name, Names (Abort_Node));
exit when Token /= Tok_Comma;
Scan; -- past comma
end loop;
TF_Semicolon;
return Abort_Node;
end P_Abort_Statement;
end Ch9;