process-cpp  3.0.0
A simple convenience library for handling processes in C++11.
backtrace.cpp
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1 /*
2  * Copyright © 2014 Canonical Ltd.
3  *
4  * This program is free software: you can redistribute it and/or modify it
5  * under the terms of the GNU Lesser General Public License version 3,
6  * as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11  * GNU Lesser General Public License for more details.
12  *
13  * You should have received a copy of the GNU Lesser General Public License
14  * along with this program. If not, see <http://www.gnu.org/licenses/>.
15  *
16  * Authored by: Thomas Voß <thomas.voss@canonical.com>
17  */
18 
19 #include "backtrace.h"
20 
21 #include <cxxabi.h>
22 
23 #include <execinfo.h>
24 
25 namespace bt = core::posix::backtrace;
26 
27 namespace impl
28 {
29 std::tuple<std::string, bool> demangle(const std::string& symbol)
30 {
31  int status = 1;
32  auto result = abi::__cxa_demangle(symbol.c_str(),
33  nullptr,
34  nullptr,
35  &status);
36 
37  if (!result || status != 0)
38  {
39  return std::make_tuple(std::string(), false);
40  }
41 
42  std::string s{result};
43  ::free(result);
44 
45  return std::make_tuple(s, true);
46 }
47 
48 struct Frame : public bt::Frame
49 {
50  struct Symbol : public bt::Frame::Symbol
51  {
52  Symbol(const char* symbol) : raw_(symbol)
53  {
54  auto first = raw_.find_first_of("(");
55  auto last = raw_.find_last_of(")");
56 
57  if (first != std::string::npos && last != std::string::npos)
58  {
59  auto mangled_symbol = raw_.substr(first+1,
60  (last-1) - (first+1));
61 
62  auto plus = mangled_symbol.find_first_of("+");
63  if (plus != std::string::npos)
64  mangled_symbol.erase(plus);
65 
66  std::tie(demangled_, is_cxx_) = demangle(mangled_symbol);
67  if (!is_cxx_)
68  demangled_ = raw_;
69  }
70  }
71 
72  bool is_cxx() const
73  {
74  return is_cxx_;
75  }
76 
77  std::string demangled() const
78  {
79  return demangled_;
80  }
81 
82  std::string raw() const
83  {
84  return raw_;
85  }
86 
87  std::string raw_;
88  std::string demangled_;
89  bool is_cxx_ = false;
90  };
91 
92  std::size_t depth_;
95 
96  Frame(std::size_t depth, void* frame_pointer, const char* symbol)
97  : depth_(depth),
98  frame_pointer_(frame_pointer),
99  symbol_(symbol)
100  {
101  }
102 
103  std::size_t depth() const
104  {
105  return depth_;
106  }
107 
108  virtual void* frame_pointer() const
109  {
110  return frame_pointer_;
111  }
112 
113  const Symbol& symbol() const
114  {
115  return symbol_;
116  }
117 };
118 }
119 
120 std::shared_ptr<bt::Frame::Symbol> bt::Frame::Symbol::for_testing_from_raw_symbol(const char* symbol)
121 {
122  return std::shared_ptr<bt::Frame::Symbol>(new impl::Frame::Symbol(symbol));
123 }
124 
126 {
127  static const unsigned int max_frames=64;
128  void *frames[max_frames];
129 
130  auto frame_count = ::backtrace(frames, max_frames);
131  auto symbols = ::backtrace_symbols(frames, frame_count);
132 
133  struct Scope
134  {
135  Scope(char** symbols) : symbols(symbols)
136  {
137  }
138 
139  ~Scope()
140  {
141  ::free(symbols);
142  }
143 
144  char** symbols = nullptr;
145  } scope{symbols};
146 
147  for (int i = 0; i < frame_count; i++)
148  {
149  impl::Frame frame(i, frames[i], symbols[i]);
150  if (!handler(frame))
151  return;
152  }
153 }
Frame(std::size_t depth, void *frame_pointer, const char *symbol)
Definition: backtrace.cpp:96
const Symbol & symbol() const
symbol returns the symbolic representation of this frame.
Definition: backtrace.cpp:113
The Frame class models an individual frame of a backtrace.
Definition: backtrace.h:37
std::function< bool(const Frame &frame)> FrameHandler
FrameHandler is the functor invoked for every frame of a backtrace.
Definition: backtrace.h:106
std::tuple< std::string, bool > demangle(const std::string &symbol)
Definition: backtrace.cpp:29
void visit_with_handler(const FrameHandler &handler)
visit_with_handler iterates the backtrace of the calling program, invoking the handler for every fram...
Definition: backtrace.cpp:125
std::size_t depth_
Definition: backtrace.cpp:92
std::string demangled_
Definition: backtrace.cpp:88
Symbol symbol_
Definition: backtrace.cpp:94
bool is_cxx() const
Definition: backtrace.cpp:72
std::size_t depth() const
depth returns the depth of this frame in the overall backtrace.
Definition: backtrace.cpp:103
void * frame_pointer_
Definition: backtrace.cpp:93
std::string demangled() const
Definition: backtrace.cpp:77
Symbol(const char *symbol)
Definition: backtrace.cpp:52
std::string raw() const
Definition: backtrace.cpp:82
virtual void * frame_pointer() const
frame_pointer returns the the raw frame pointer of this frame.
Definition: backtrace.cpp:108
std::string raw_
Definition: backtrace.cpp:87