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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 1 1 --
-- --
-- B o d y --
-- --
-- $Revision: 1.75 $ --
-- --
-- Copyright (C) 1992-1997 Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Einfo; use Einfo;
with Errout; use Errout;
with Features; use Features;
with Lib; use Lib;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Restrict; use Restrict;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Ch5; use Sem_Ch5;
with Sem_Ch8; use Sem_Ch8;
with Sem_Dist; use Sem_Dist;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Stand; use Stand;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
package body Sem_Ch11 is
-----------------------------------
-- Analyze_Exception_Declaration --
-----------------------------------
procedure Analyze_Exception_Declaration (N : Node_Id) is
Id : constant Entity_Id := Defining_Identifier (N);
PF : constant Boolean := Is_Pure (Current_Scope);
begin
Enter_Name (Id);
Set_Ekind (Id, E_Exception);
Set_Exception_Code (Id, Uint_0);
Set_Etype (Id, Standard_Exception_Type);
Set_Is_Statically_Allocated (Id);
Set_Is_Pure (Id, PF);
end Analyze_Exception_Declaration;
--------------------------------
-- Analyze_Exception_Handlers --
--------------------------------
procedure Analyze_Exception_Handlers (L : List_Id) is
Handler : Node_Id;
Choice : Entity_Id;
Id : Node_Id;
H_Scope : Entity_Id := Empty;
procedure Check_Duplication (Id : Node_Id);
-- Iterate through the identifiers in each handler to find duplicates
-----------------------
-- Check_Duplication --
-----------------------
procedure Check_Duplication (Id : Node_Id) is
Handler : Node_Id;
Id1 : Node_Id;
begin
Handler := First_Non_Pragma (L);
while Present (Handler) loop
Id1 := First (Exception_Choices (Handler));
while Present (Id1) loop
-- Only check against the exception choices which precede
-- Id in the handler, since the ones that follow Id have not
-- been analyzed yet and will be checked in a subsequent call.
if Id = Id1 then
return;
elsif Nkind (Id1) /= N_Others_Choice
and then Entity (Id) = Entity (Id1)
then
if Handler /= Parent (Id) then
Error_Msg_N ("duplicate exception choice&", Id);
else
Note_Feature (Exception_Choices, Sloc (Id));
if Ada_83 and then Comes_From_Source (Id) then
Error_Msg_N
("(Ada 83): duplicate exception choice&", Id);
end if;
end if;
end if;
Id1 := Next_Non_Pragma (Id1);
end loop;
Handler := Next (Handler);
end loop;
end Check_Duplication;
-- Start processing for Analyze_Exception_Handlers
begin
Handler := First (L);
Check_Restriction (No_Exceptions, Handler);
-- Loop through handlers (which can include pragmas)
while Present (Handler) loop
-- If pragma just analyze it
if Nkind (Handler) = N_Pragma then
Analyze (Handler);
-- Otherwise we have a real exception handler
else
Id := First (Exception_Choices (Handler));
while Present (Id) loop
if Nkind (Id) = N_Others_Choice then
if Present (Next (Id))
or else Present (Next (Handler))
or else Present (Prev (Id))
then
Error_Msg_N ("OTHERS must appear alone and last", Id);
end if;
else
Analyze (Id);
if Is_Entity_Name (Id)
and then Present (Renamed_Entity (Entity (Id)))
then
Set_Entity (Id, Renamed_Entity (Entity (Id)));
end if;
if not Is_Entity_Name (Id)
or else Ekind (Entity (Id)) /= E_Exception
then
Error_Msg_N ("exception name expected", Id);
else
Check_Duplication (Id);
-- Check for exception declared within generic formal
-- package (which is illegal, see RM 11.2(8))
declare
Ent : Entity_Id := Entity (Id);
Scop : Entity_Id := Scope (Ent);
begin
while Scop /= Standard_Standard
and then Ekind (Scop) = E_Package
loop
if Nkind (Declaration_Node (Scop)) =
N_Package_Specification
and then
Nkind (Original_Node (Parent
(Declaration_Node (Scop)))) =
N_Formal_Package_Declaration
then
Error_Msg_NE
("exception& is declared in " &
"generic formal package", Id, Ent);
Error_Msg_N
("\and therefore cannot appear in , " &
"handler, see 'R'M 11.2(8)", Id);
exit;
end if;
Scop := Scope (Scop);
end loop;
end;
end if;
end if;
Id := Next (Id);
end loop;
-- Deal with choice parameter. The exception handler is
-- a declarative part for it, so it constitutes a scope
-- for visibility purposes. We create an entity to denote
-- the whole exception part, and use it as the scope of all
-- the choices, which may even have the same name without
-- conflict. This scope plays no other role in expansion or
-- or code generation.
Choice := Choice_Parameter (Handler);
if Present (Choice) then
if No (H_Scope) then
H_Scope := New_Internal_Entity
(E_Block, Current_Scope, Sloc (Choice), 'E');
end if;
New_Scope (H_Scope);
Set_Etype (H_Scope, Standard_Void_Type);
Enter_Name (Choice);
Set_Ekind (Choice, E_Variable);
Set_Etype (Choice, RTE (RE_Exception_Occurrence));
end if;
Analyze_Statements (Statements (Handler));
if Present (Choice) then
End_Scope;
end if;
end if;
Handler := Next (Handler);
end loop;
end Analyze_Exception_Handlers;
--------------------------------
-- Analyze_Handled_Statements --
--------------------------------
procedure Analyze_Handled_Statements (N : Node_Id) is
Handlers : constant List_Id := Exception_Handlers (N);
begin
Analyze_Statements (Statements (N));
if Present (Handlers) then
Analyze_Exception_Handlers (Handlers);
elsif Present (Identifier (N)) then
Analyze (Identifier (N));
end if;
end Analyze_Handled_Statements;
-----------------------------
-- Analyze_Raise_Statement --
-----------------------------
procedure Analyze_Raise_Statement (N : Node_Id) is
Exception_Id : constant Node_Id := Name (N);
Exception_Name : Entity_Id := Empty;
P : Node_Id;
Nkind_P : Node_Kind;
begin
Check_Unreachable_Code (N);
Check_Restriction (No_Exceptions, N);
-- Reraise statement
if No (Exception_Id) then
P := Parent (N);
Nkind_P := Nkind (P);
while Nkind_P /= N_Exception_Handler
and then Nkind_P /= N_Subprogram_Body
and then Nkind_P /= N_Package_Body
and then Nkind_P /= N_Task_Body
and then Nkind_P /= N_Entry_Body
loop
P := Parent (P);
Nkind_P := Nkind (P);
end loop;
if Nkind (P) /= N_Exception_Handler then
Error_Msg_N
("reraise statement must appear directly in a handler", N);
end if;
-- Normal case with exception id present
else
Analyze (Exception_Id);
if Is_Entity_Name (Exception_Id) then
Exception_Name := Entity (Exception_Id);
if Present (Renamed_Object (Exception_Name)) then
Set_Entity (Exception_Id, Renamed_Object (Exception_Name));
end if;
end if;
if No (Exception_Name)
or else Ekind (Exception_Name) /= E_Exception
then
Error_Msg_N
("exception name expected in raise statement", Exception_Id);
end if;
end if;
end Analyze_Raise_Statement;
-----------------------------
-- Analyze_Raise_xxx_Error --
-----------------------------
-- Normally, the Etype is already set (when this node is used within
-- an expression, since it is copied from the node which it rewrites).
-- If this node is used in a statement context, then we set the type
-- Standard_Void_Type. This is used both by Gigi and by the front end
-- to distinguish the statement use and the subexpression use.
-- The only other required processing is to take care of the Condition
-- field if one is present.
procedure Analyze_Raise_xxx_Error (N : Node_Id) is
begin
if No (Etype (N)) then
Set_Etype (N, Standard_Void_Type);
end if;
if Present (Condition (N)) then
Analyze_And_Resolve (Condition (N), Standard_Boolean);
end if;
-- Deal with static cases in obvious manner
if Nkind (Condition (N)) = N_Identifier then
if Entity (Condition (N)) = Standard_True then
Set_Condition (N, Empty);
elsif Entity (Condition (N)) = Standard_False then
Rewrite (N, Make_Null_Statement (Sloc (N)));
end if;
end if;
end Analyze_Raise_xxx_Error;
end Sem_Ch11;
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