| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- ADA.EXCEPTIONS.EXCEPTION_TRACES -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2005, 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, 51 Franklin Street, Fifth Floor, -- |
| -- Boston, MA 02110-1301, 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. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with Unchecked_Conversion; |
| |
| pragma Warnings (Off); |
| with Ada.Exceptions.Last_Chance_Handler; |
| pragma Warnings (On); |
| -- Bring last chance handler into closure |
| |
| separate (Ada.Exceptions) |
| package body Exception_Traces is |
| |
| Nline : constant String := String'(1 => ASCII.LF); |
| -- Convenient shortcut |
| |
| type Exception_Action is access procedure (E : Exception_Occurrence); |
| Global_Action : Exception_Action := null; |
| pragma Export |
| (Ada, Global_Action, "__gnat_exception_actions_global_action"); |
| -- Global action, executed whenever an exception is raised. Changing the |
| -- export name must be coordinated with code in g-excact.adb. |
| |
| Raise_Hook_Initialized : Boolean := False; |
| pragma Export |
| (Ada, Raise_Hook_Initialized, "__gnat_exception_actions_initialized"); |
| |
| procedure Last_Chance_Handler |
| (Except : Exception_Occurrence); |
| pragma Import (C, Last_Chance_Handler, "__gnat_last_chance_handler"); |
| pragma No_Return (Last_Chance_Handler); |
| -- Users can replace the default version of this routine, |
| -- Ada.Exceptions.Last_Chance_Handler. |
| |
| function To_Action is new Unchecked_Conversion |
| (Raise_Action, Exception_Action); |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| procedure Notify_Exception (Excep : EOA; Is_Unhandled : Boolean); |
| -- Factorizes the common processing for Notify_Handled_Exception and |
| -- Notify_Unhandled_Exception. Is_Unhandled is set to True only in the |
| -- latter case because Notify_Handled_Exception may be called for an |
| -- actually unhandled occurrence in the Front-End-SJLJ case. |
| |
| --------------------------------- |
| -- Debugger Interface Routines -- |
| --------------------------------- |
| |
| -- The routines here are null routines that normally have no effect. |
| -- They are provided for the debugger to place breakpoints on their |
| -- entry points to get control on an exception. |
| |
| procedure Unhandled_Exception; |
| pragma Export (C, Unhandled_Exception, "__gnat_unhandled_exception"); |
| -- Hook for GDB to support "break exception unhandled" |
| |
| -- For "break exception", GDB uses __gnat_raise_nodefer_with_msg, which |
| -- is not in this section because it functions as more than simply a |
| -- debugger interface. |
| |
| -------------------------------- |
| -- Import Run-Time C Routines -- |
| -------------------------------- |
| |
| -- The purpose of the following pragma Import is to ensure that we |
| -- generate appropriate subprogram descriptors for all C routines in |
| -- the standard GNAT library that can raise exceptions. This ensures |
| -- that the exception propagation can properly find these routines |
| |
| pragma Propagate_Exceptions; |
| |
| ---------------------- |
| -- Notify_Exception -- |
| ---------------------- |
| |
| procedure Notify_Exception (Excep : EOA; Is_Unhandled : Boolean) is |
| begin |
| -- Output the exception information required by the Exception_Trace |
| -- configuration. Take care not to output information about internal |
| -- exceptions. |
| |
| -- ??? In the Front-End ZCX case, the traceback entries we have at this |
| -- point only include the ones we stored while walking up the stack *up |
| -- to the handler*. All the frames above the subprogram in which the |
| -- handler is found are missing. |
| |
| if not Excep.Id.Not_Handled_By_Others |
| and then |
| (Exception_Trace = Every_Raise |
| or else (Exception_Trace = Unhandled_Raise and then Is_Unhandled)) |
| then |
| To_Stderr (Nline); |
| |
| if Is_Unhandled then |
| To_Stderr ("Unhandled "); |
| end if; |
| |
| To_Stderr ("Exception raised"); |
| To_Stderr (Nline); |
| To_Stderr (Tailored_Exception_Information (Excep.all)); |
| end if; |
| |
| -- Call the user-specific actions |
| -- ??? We should presumably look at the reraise status here. |
| |
| if Raise_Hook_Initialized |
| and then Exception_Data_Ptr (Excep.Id).Raise_Hook /= null |
| then |
| To_Action (Exception_Data_Ptr (Excep.Id).Raise_Hook) (Excep.all); |
| end if; |
| |
| if Global_Action /= null then |
| Global_Action (Excep.all); |
| end if; |
| end Notify_Exception; |
| |
| ------------------------------ |
| -- Notify_Handled_Exception -- |
| ------------------------------ |
| |
| procedure Notify_Handled_Exception is |
| begin |
| Notify_Exception (Get_Current_Excep.all, Is_Unhandled => False); |
| end Notify_Handled_Exception; |
| |
| -------------------------------- |
| -- Notify_Unhandled_Exception -- |
| -------------------------------- |
| |
| procedure Notify_Unhandled_Exception is |
| Excep : constant EOA := Get_Current_Excep.all; |
| |
| begin |
| -- Check whether there is any termination handler to be executed for |
| -- the environment task, and execute it if needed. Here we handle both |
| -- the Abnormal and Unhandled_Exception task termination. Normal |
| -- task termination routine is executed elsewhere (either in the |
| -- Task_Wrapper or in the Adafinal routine for the environment task). |
| |
| Task_Termination_Handler.all (Excep.all); |
| |
| Notify_Exception (Excep, Is_Unhandled => True); |
| Unhandled_Exception; |
| end Notify_Unhandled_Exception; |
| |
| ------------------------- |
| -- Unhandled_Exception -- |
| ------------------------- |
| |
| procedure Unhandled_Exception is |
| begin |
| null; |
| end Unhandled_Exception; |
| |
| ----------------------------------- |
| -- Unhandled_Exception_Terminate -- |
| ----------------------------------- |
| |
| procedure Unhandled_Exception_Terminate is |
| Excep : constant EOA := Save_Occurrence (Get_Current_Excep.all.all); |
| -- This occurrence will be used to display a message after finalization. |
| -- It is necessary to save a copy here, or else the designated value |
| -- could be overwritten if an exception is raised during finalization |
| -- (even if that exception is caught). |
| |
| begin |
| Last_Chance_Handler (Excep.all); |
| end Unhandled_Exception_Terminate; |
| |
| ------------------------------------ |
| -- Handling GNAT.Exception_Traces -- |
| ------------------------------------ |
| |
| -- The bulk of exception traces output is centralized in Notify_Exception, |
| -- for both the Handled and Unhandled cases. Extra task specific output is |
| -- triggered in the task wrapper for unhandled occurrences in tasks. It is |
| -- not performed in this unit to avoid dragging dependencies against the |
| -- tasking units here. |
| |
| -- We used to rely on the output performed by Unhanded_Exception_Terminate |
| -- for the case of an unhandled occurrence in the environment thread, and |
| -- the task wrapper was responsible for the whole output in the tasking |
| -- case. |
| |
| -- This initial scheme had a drawback: the output from Terminate only |
| -- occurs after finalization is done, which means possibly never if some |
| -- tasks keep hanging around. |
| |
| -- The first "presumably obvious" fix consists in moving the Terminate |
| -- output before the finalization. It has not been retained because it |
| -- introduces annoying changes in output orders when the finalization |
| -- itself issues outputs, this also in "regular" cases not resorting to |
| -- Exception_Traces. |
| |
| -- Today's solution has the advantage of simplicity and better isolates |
| -- the Exception_Traces machinery. |
| |
| -- It currently outputs the information about unhandled exceptions twice |
| -- in the environment thread, once in the notification routine and once in |
| -- the termination routine. Avoiding the second output is possible but so |
| -- far has been considered undesirable. It would mean changing the order |
| -- of outputs between the two runs with or without exception traces, while |
| -- it seems preferrable to only have additional outputs in the former |
| -- case. |
| |
| end Exception_Traces; |
