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) 1999-2015, 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
37pragma Compiler_Unit_Warning;
38
39package 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
118end System.Traceback;
119