gcc/ada/g-exctra.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                  G N A T . E X C E P T I O N _ T R A C E S               --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --                     Copyright (C) 2000-2008, AdaCore                     --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This package provides an interface allowing to control *automatic* output
  35 --  to standard error upon exception occurrences (as opposed to explicit
  36 --  generation of traceback information using GNAT.Traceback).
  37
  38 --  This output includes the basic information associated with the exception
  39 --  (name, message) as well as a backtrace of the call chain at the point
  40 --  where the exception occurred. This backtrace is only output if the call
  41 --  chain information is available, depending if the binder switch dedicated
  42 --  to that purpose has been used or not.
  43
  44 --  The default backtrace is in the form of absolute code locations which may
  45 --  be converted to corresponding source locations using the addr2line utility
  46 --  or from within GDB. Please refer to GNAT.Traceback for information about
  47 --  what is necessary to be able to exploit this possibility.
  48
  49 --  The backtrace output can also be customized by way of a "decorator" which
  50 --  may return any string output in association with a provided call chain.
  51 --  The decorator replaces the default backtrace mentioned above.
  52
  53 with GNAT.Traceback; use GNAT.Traceback;
  54
  55 package GNAT.Exception_Traces is
  56
  57    --  The following defines the exact situations in which raises will
  58    --  cause automatic output of trace information.
  59
  60    type Trace_Kind is
  61      (Every_Raise,
  62       --  Denotes the initial raise event for any exception occurrence, either
  63       --  explicit or due to a specific language rule, within the context of a
  64       --  task or not.
  65
  66       Unhandled_Raise
  67       --  Denotes the raise events corresponding to exceptions for which there
  68       --  is no user defined handler, in particular, when a task dies due to an
  69       --  unhandled exception.
  70      );
  71
  72    --  The following procedures can be used to activate and deactivate
  73    --  traces identified by the above trace kind values.
  74
  75    procedure Trace_On (Kind : Trace_Kind);
  76    --  Activate the traces denoted by Kind
  77
  78    procedure Trace_Off;
  79    --  Stop the tracing requested by the last call to Trace_On.
  80    --  Has no effect if no such call has ever occurred.
  81
  82    --  The following provide the backtrace decorating facilities
  83
  84    type Traceback_Decorator is access
  85      function (Traceback : Tracebacks_Array) return String;
  86    --  A backtrace decorator is a function which returns the string to be
  87    --  output for a call chain provided by way of a tracebacks array.
  88
  89    procedure Set_Trace_Decorator (Decorator : Traceback_Decorator);
  90    --  Set the decorator to be used for future automatic outputs. Restore
  91    --  the default behavior (output of raw addresses) if the provided
  92    --  access value is null.
  93    --
  94    --  Note: GNAT.Traceback.Symbolic.Symbolic_Traceback may be used as the
  95    --  Decorator, to get a symbolic traceback. This will cause a significant
  96    --  cpu and memory overhead.
  97
  98 end GNAT.Exception_Traces;