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) 1999-2019, 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 version uses System.Machine_State_Operations routines
33
34with System.Machine_State_Operations;
35
36package body System.Traceback is
37
38   use System.Machine_State_Operations;
39
40   procedure Call_Chain
41     (Traceback   : System.Address;
42      Max_Len     : Natural;
43      Len         : out Natural;
44      Exclude_Min : System.Address := System.Null_Address;
45      Exclude_Max : System.Address := System.Null_Address;
46      Skip_Frames : Natural := 1);
47   --  Same as the exported version, but takes Traceback as an Address
48
49   ----------------
50   -- Call_Chain --
51   ----------------
52
53   procedure Call_Chain
54     (Traceback : System.Address;
55      Max_Len   : Natural;
56      Len       : out Natural;
57      Exclude_Min : System.Address := System.Null_Address;
58      Exclude_Max : System.Address := System.Null_Address;
59      Skip_Frames : Natural := 1)
60   is
61      type Tracebacks_Array is array (1 .. Max_Len) of Code_Loc;
62      pragma Suppress_Initialization (Tracebacks_Array);
63
64      M     : Machine_State;
65      Code  : Code_Loc;
66
67      Trace : Tracebacks_Array;
68      for Trace'Address use Traceback;
69
70      N_Skips  : Natural := 0;
71
72   begin
73      M := Allocate_Machine_State;
74      Set_Machine_State (M);
75
76      --  Skip the requested number of frames
77
78      loop
79         Code := Get_Code_Loc (M);
80         exit when Code = Null_Address or else N_Skips = Skip_Frames;
81
82         Pop_Frame (M);
83         N_Skips := N_Skips + 1;
84      end loop;
85
86      --  Now, record the frames outside the exclusion bounds, updating
87      --  the Len output value along the way.
88
89      Len := 0;
90      loop
91         Code := Get_Code_Loc (M);
92         exit when Code = Null_Address or else Len = Max_Len;
93
94         if Code < Exclude_Min or else Code > Exclude_Max then
95            Len := Len + 1;
96            Trace (Len) := Code;
97         end if;
98
99         Pop_Frame (M);
100      end loop;
101
102      Free_Machine_State (M);
103   end Call_Chain;
104
105   procedure Call_Chain
106     (Traceback   : in out System.Traceback_Entries.Tracebacks_Array;
107      Max_Len     : Natural;
108      Len         : out Natural;
109      Exclude_Min : System.Address := System.Null_Address;
110      Exclude_Max : System.Address := System.Null_Address;
111      Skip_Frames : Natural := 1)
112   is
113   begin
114      Call_Chain
115        (Traceback'Address, Max_Len, Len,
116         Exclude_Min, Exclude_Max,
117
118         --  Skip one extra frame to skip the other Call_Chain entry as well
119
120         Skip_Frames => Skip_Frames + 1);
121   end Call_Chain;
122
123   ------------------
124   -- C_Call_Chain --
125   ------------------
126
127   function C_Call_Chain
128     (Traceback : System.Address;
129      Max_Len   : Natural) return Natural
130   is
131      Val : Natural;
132   begin
133      Call_Chain (Traceback, Max_Len, Val);
134      return Val;
135   end C_Call_Chain;
136
137end System.Traceback;
138