gcc/ada/libgnat/s-traceb.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                     S Y S T E M . T R A C E B A C K                      --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1999-2018, Free Software Foundation, Inc.         --
  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 a method for generating a traceback of the current
  33 --  execution location. The traceback shows the locations of calls in the call
  34 --  chain, up to either the top or a designated number of levels.
  35
  36 pragma Compiler_Unit_Warning;
  37
  38 pragma Polling (Off);
  39 --  We must turn polling off for this unit, because otherwise we get
  40 --  elaboration circularities with System.Exception_Tables.
  41
  42 with System.Traceback_Entries;
  43
  44 package System.Traceback is
  45
  46    ----------------
  47    -- Call_Chain --
  48    ----------------
  49
  50    procedure Call_Chain
  51      (Traceback   : in out System.Traceback_Entries.Tracebacks_Array;
  52       Max_Len     : Natural;
  53       Len         : out Natural;
  54       Exclude_Min : System.Address := System.Null_Address;
  55       Exclude_Max : System.Address := System.Null_Address;
  56       Skip_Frames : Natural := 1);
  57    --  Store up to Max_Len code locations in Traceback, corresponding to the
  58    --  current call chain.
  59    --
  60    --    Traceback is an array of addresses where the result will be stored.
  61    --
  62    --    Max_Len is the length of the Traceback array. If the call chain is
  63    --    longer than this, then additional entries are discarded, and the
  64    --    traceback is missing some of the highest level entries.
  65    --
  66    --    Len is the number of addresses returned in the Traceback array
  67    --
  68    --    Exclude_Min/Exclude_Max, if non null, provide a range of addresses
  69    --    to ignore from the computation of the traceback.
  70    --
  71    --    Skip_Frames says how many of the most recent calls should at least
  72    --    be excluded from the result, regardless of the exclusion bounds and
  73    --    starting with this procedure itself: 1 means exclude the frame for
  74    --    this procedure, 2 means 1 + exclude the frame for this procedure's
  75    --    caller, ...
  76    --
  77    --  On return, the Traceback array is filled in, and Len indicates the
  78    --  number of stored entries. The first entry is the most recent call,
  79    --  and the last entry is the highest level call.
  80
  81    function C_Call_Chain
  82      (Traceback : System.Address;
  83       Max_Len   : Natural) return Natural;
  84    pragma Export (C, C_Call_Chain, "system__traceback__c_call_chain");
  85    --  Version that can be used directly from C
  86
  87 end System.Traceback;