gcc/ada/s-exctra.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                S Y S T E M . 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) 2000-2014, 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 3,  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.                                     --
  17 --                                                                          --
  18 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 --  This package provides an interface allowing to control *automatic* output
  33 --  to standard error upon exception occurrences (as opposed to explicit
  34 --  generation of traceback information using System.Traceback).
  35
  36 --  This output includes the basic information associated with the exception
  37 --  (name, message) as well as a backtrace of the call chain at the point
  38 --  where the exception occurred. This backtrace is only output if the call
  39 --  chain information is available, depending if the binder switch dedicated
  40 --  to that purpose has been used or not.
  41
  42 --  The default backtrace is in the form of absolute code locations which may
  43 --  be converted to corresponding source locations using the addr2line utility
  44 --  or from within GDB. Please refer to System.Traceback for information about
  45 --  what is necessary to be able to exploit this possibility.
  46
  47 --  The backtrace output can also be customized by way of a "decorator" which
  48 --  may return any string output in association with a provided call chain.
  49 --  The decorator replaces the default backtrace mentioned above.
  50
  51 with System.Traceback_Entries;
  52
  53 package System.Exception_Traces is
  54
  55    --  The following defines the exact situations in which raises will
  56    --  cause automatic output of trace information.
  57
  58    type Trace_Kind is
  59      (Every_Raise,
  60       --  Denotes the initial raise event for any exception occurrence, either
  61       --  explicit or due to a specific language rule, within the context of a
  62       --  task or not.
  63
  64       Unhandled_Raise
  65       --  Denotes the raise events corresponding to exceptions for which there
  66       --  is no user defined handler, in particular, when a task dies due to an
  67       --  unhandled exception.
  68      );
  69
  70    --  The following procedures can be used to activate and deactivate
  71    --  traces identified by the above trace kind values.
  72
  73    procedure Trace_On (Kind : Trace_Kind);
  74    --  Activate the traces denoted by Kind
  75
  76    procedure Trace_Off;
  77    --  Stop the tracing requested by the last call to Trace_On.
  78    --  Has no effect if no such call has ever occurred.
  79
  80    --  The following provide the backtrace decorating facilities
  81
  82    type Traceback_Decorator is access
  83      function (Traceback : Traceback_Entries.Tracebacks_Array) return String;
  84    --  A backtrace decorator is a function which returns the string to be
  85    --  output for a call chain provided by way of a tracebacks array.
  86
  87    procedure Set_Trace_Decorator (Decorator : Traceback_Decorator);
  88    --  Set the decorator to be used for future automatic outputs. Restore
  89    --  the default behavior (output of raw addresses) if the provided
  90    --  access value is null.
  91    --
  92    --  Note: System.Traceback.Symbolic.Symbolic_Traceback may be used as the
  93    --  Decorator, to get a symbolic traceback. This will cause a significant
  94    --  cpu and memory overhead.
  95
  96 end System.Exception_Traces;