git.m6w6.name Git - m6w6/libmemcached/blob - src/libmemcached/backtrace.cc

   1 /*
   2     +--------------------------------------------------------------------+
   3     | libmemcached - C/C++ Client Library for memcached                  |
   4     +--------------------------------------------------------------------+
   5     | Redistribution and use in source and binary forms, with or without |
   6     | modification, are permitted under the terms of the BSD license.    |
   7     | You should have received a copy of the license in a bundled file   |
   8     | named LICENSE; in case you did not receive a copy you can review   |
   9     | the terms online at: https://opensource.org/licenses/BSD-3-Clause  |
  10     +--------------------------------------------------------------------+
  11     | Copyright (c) 2006-2014 Brian Aker   https://datadifferential.com/ |
  12     | Copyright (c) 2020 Michael Wallner   <mike@php.net>                |
  13     +--------------------------------------------------------------------+
  14 */
  15
  16 #include "mem_config.h"
  17
  18 #include "libmemcached/backtrace.hpp"
  19
  20 #include <cstdio>
  21 #include <cstdlib>
  22 #include <cstring>
  23
  24 #if HAVE_BACKTRACE
  25
  26 #  include BACKTRACE_HEADER
  27
  28 #  if HAVE_ABI____CXA_DEMANGLE
  29 #    include <cxxabi.h>
  30 #    define USE_DEMANGLE 1
  31 #  else
  32 #    define USE_DEMANGLE 0
  33 #  endif
  34
  35 #  ifdef HAVE_DLFCN_H
  36 #    include <dlfcn.h>
  37 #  endif
  38
  39 const int MAX_DEPTH = 50;
  40
  41 void custom_backtrace(void) {
  42   void *backtrace_buffer[MAX_DEPTH + 1];
  43
  44   int stack_frames = backtrace(backtrace_buffer, MAX_DEPTH);
  45   if (stack_frames) {
  46     char **symbollist = backtrace_symbols(backtrace_buffer, stack_frames);
  47     if (symbollist) {
  48       for (int x = 0; x < stack_frames; x++) {
  49         bool was_demangled = false;
  50
  51         if (USE_DEMANGLE) {
  52 #  ifdef HAVE_DLFCN_H
  53           Dl_info dlinfo;
  54           if (dladdr(backtrace_buffer[x], &dlinfo)) {
  55             char demangled_buffer[1024];
  56             const char *called_in = "<unresolved>";
  57             if (dlinfo.dli_sname) {
  58               size_t demangled_size = sizeof(demangled_buffer);
  59               int status;
  60               char *demangled;
  61               if ((demangled = abi::__cxa_demangle(dlinfo.dli_sname, demangled_buffer,
  62                                                    &demangled_size, &status))) {
  63                 called_in = demangled;
  64                 fprintf(stderr, "---> demangled: %s -> %s\n", demangled_buffer, demangled);
  65               } else {
  66                 called_in = dlinfo.dli_sname;
  67               }
  68
  69               was_demangled = true;
  70               fprintf(stderr, "#%d  %p in %s at %s\n", x, backtrace_buffer[x], called_in,
  71                       dlinfo.dli_fname);
  72             }
  73           }
  74 #  endif
  75         }
  76
  77         if (was_demangled == false) {
  78           fprintf(stderr, "?%d  %p in %s\n", x, backtrace_buffer[x], symbollist[x]);
  79         }
  80       }
  81
  82       ::free(symbollist);
  83     }
  84   }
  85 }
  86
  87 #else  // HAVE_BACKTRACE
  88
  89 void custom_backtrace(void) {
  90   fprintf(stderr, "Backtrace null function called\n");
  91 }
  92 #endif // HAVE_BACKTRACE