------------------------------------------------------------------------------ -- -- -- GNAT RUN-TIME COMPONENTS -- -- -- -- A D A . E X C E P T I O N S . L A S T _ C H A N C E _ H A N D L E R -- -- -- -- B o d y -- -- -- -- Copyright (C) 2003 Free Software Foundation, Inc. -- -- -- -- This specification is derived from the Ada Reference Manual for use with -- -- GNAT. The copyright notice above, and the license provisions that follow -- -- apply solely to the contents of the part following the private keyword. -- -- -- -- 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. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- Default version for most targets procedure Ada.Exceptions.Last_Chance_Handler (Except : Exception_Occurrence) is procedure Unhandled_Terminate; pragma No_Return (Unhandled_Terminate); pragma Import (C, Unhandled_Terminate, "__gnat_unhandled_terminate"); -- Perform system dependent shutdown code function Tailored_Exception_Information (X : Exception_Occurrence) return String; -- Exception information to be output in the case of automatic tracing -- requested through GNAT.Exception_Traces. -- -- This is the same as Exception_Information if no backtrace decorator -- is currently in place. Otherwise, this is Exception_Information with -- the call chain raw addresses replaced by the result of a call to the -- current decorator provided with the call chain addresses. pragma Import (Ada, Tailored_Exception_Information, "__gnat_tailored_exception_information"); procedure Tailored_Exception_Information (X : Exception_Occurrence; Buff : in out String; Last : in out Integer); -- Procedural version of the above function. Instead of returning the -- result, this one is put in Buff (Buff'first .. Buff'first + Last) procedure To_Stderr (S : String); pragma Import (Ada, To_Stderr, "__gnat_to_stderr"); -- Little routine to output string to stderr Nline : constant String := String'(1 => ASCII.LF); -- Convenient shortcut Msg : constant String := Except.Msg (1 .. Except.Msg_Length); Max_Static_Exc_Info : constant := 1024; -- This should be enough for most exception information cases -- even though tailoring introduces some uncertainty. The -- name+message should not exceed 320 chars, so that leaves at -- least 35 backtrace slots (each slot needs 19 chars for -- representing a 64 bit address). subtype Exc_Info_Type is String (1 .. Max_Static_Exc_Info); type Str_Ptr is access Exc_Info_Type; Exc_Info : Str_Ptr; Exc_Info_Last : Natural := 0; -- Buffer that is allocated to store the tailored exception -- information while Adafinal is run. This buffer is allocated -- on the heap only when it is needed. It is better to allocate -- on the heap than on the stack since stack overflows are more -- common than heap overflows. procedure Tailored_Exception_Information (X : Exception_Occurrence; Buff : in out String; Last : in out Integer) is Info : constant String := Tailored_Exception_Information (X); begin Last := Info'Last; Buff (1 .. Last) := Info; end Tailored_Exception_Information; begin -- First allocate & store the exception info in a buffer when -- we know it will be needed. This needs to be done before -- Adafinal because it implicitly uses the secondary stack. if Except.Id.Full_Name.all (1) /= '_' and then Except.Num_Tracebacks /= 0 then Exc_Info := new Exc_Info_Type; if Exc_Info /= null then Tailored_Exception_Information (Except, Exc_Info.all, Exc_Info_Last); end if; end if; -- Let's shutdown the runtime now. The rest of the procedure -- needs to be careful not to use anything that would require -- runtime support. In particular, functions returning strings -- are banned since the sec stack is no longer functional. System.Standard_Library.Adafinal; -- Check for special case of raising _ABORT_SIGNAL, which is not -- really an exception at all. We recognize this by the fact that -- it is the only exception whose name starts with underscore. if Except.Id.Full_Name.all (1) = '_' then To_Stderr (Nline); To_Stderr ("Execution terminated by abort of environment task"); To_Stderr (Nline); -- If no tracebacks, we print the unhandled exception in the old style -- (i.e. the style used before ZCX was implemented). We do this to -- retain compatibility. elsif Except.Num_Tracebacks = 0 then To_Stderr (Nline); To_Stderr ("raised "); To_Stderr (Except.Id.Full_Name.all (1 .. Except.Id.Name_Length - 1)); if Msg'Length /= 0 then To_Stderr (" : "); To_Stderr (Msg); end if; To_Stderr (Nline); -- Traceback exists else -- Note we can have this whole information output twice if -- this occurrence gets reraised up to here. To_Stderr (Nline); To_Stderr ("Execution terminated by unhandled exception"); To_Stderr (Nline); To_Stderr (Exc_Info (1 .. Exc_Info_Last)); end if; Unhandled_Terminate; end Ada.Exceptions.Last_Chance_Handler;