gcc/ada/libgnat/s-traceb.adb

   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 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1999-2017, 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 is the default version of this package
  33
  34 --  Note: this unit must be compiled using -fno-optimize-sibling-calls.
  35 --  See comment below in body of Call_Chain for details on the reason.
  36
  37 pragma Compiler_Unit_Warning;
  38
  39 package body System.Traceback is
  40
  41    procedure Call_Chain
  42      (Traceback   : System.Address;
  43       Max_Len     : Natural;
  44       Len         : out Natural;
  45       Exclude_Min : System.Address := System.Null_Address;
  46       Exclude_Max : System.Address := System.Null_Address;
  47       Skip_Frames : Natural := 1);
  48    --  Same as the exported version, but takes Traceback as an Address
  49
  50    ------------------
  51    -- C_Call_Chain --
  52    ------------------
  53
  54    function C_Call_Chain
  55      (Traceback : System.Address;
  56       Max_Len   : Natural) return Natural
  57    is
  58       Val : Natural;
  59    begin
  60       Call_Chain (Traceback, Max_Len, Val);
  61       return Val;
  62    end C_Call_Chain;
  63
  64    ----------------
  65    -- Call_Chain --
  66    ----------------
  67
  68    function Backtrace
  69      (Traceback   : System.Address;
  70       Len         : Integer;
  71       Exclude_Min : System.Address;
  72       Exclude_Max : System.Address;
  73       Skip_Frames : Integer)
  74       return        Integer;
  75    pragma Import (C, Backtrace, "__gnat_backtrace");
  76
  77    procedure Call_Chain
  78      (Traceback   : System.Address;
  79       Max_Len     : Natural;
  80       Len         : out Natural;
  81       Exclude_Min : System.Address := System.Null_Address;
  82       Exclude_Max : System.Address := System.Null_Address;
  83       Skip_Frames : Natural := 1)
  84    is
  85    begin
  86       --  Note: Backtrace relies on the following call actually creating a
  87       --  stack frame. To ensure that this is the case, it is essential to
  88       --  compile this unit without sibling call optimization.
  89
  90       --  We want the underlying engine to skip its own frame plus the
  91       --  ones we have been requested to skip ourselves.
  92
  93       Len := Backtrace (Traceback   => Traceback,
  94                         Len         => Max_Len,
  95                         Exclude_Min => Exclude_Min,
  96                         Exclude_Max => Exclude_Max,
  97                         Skip_Frames => Skip_Frames + 1);
  98    end Call_Chain;
  99
 100    procedure Call_Chain
 101      (Traceback   : in out System.Traceback_Entries.Tracebacks_Array;
 102       Max_Len     : Natural;
 103       Len         : out Natural;
 104       Exclude_Min : System.Address := System.Null_Address;
 105       Exclude_Max : System.Address := System.Null_Address;
 106       Skip_Frames : Natural := 1)
 107    is
 108    begin
 109       Call_Chain
 110         (Traceback'Address, Max_Len, Len,
 111          Exclude_Min, Exclude_Max,
 112
 113          --  Skip one extra frame to skip the other Call_Chain entry as well
 114
 115          Skip_Frames => Skip_Frames + 1);
 116    end Call_Chain;
 117
 118 end System.Traceback;