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 #  ifdef HAVE_ABI____CXA_DEMANGLE
  29 #    include <cxxabi.h>
  30 #  endif
  31
  32 #  ifdef HAVE_DLFCN_H
  33 #    include <dlfcn.h>
  34 #  endif
  35
  36 const int MAX_DEPTH = 50;
  37
  38 void custom_backtrace(void) {
  39   void *backtrace_buffer[MAX_DEPTH + 1];
  40
  41   int stack_frames = backtrace(backtrace_buffer, MAX_DEPTH);
  42   if (stack_frames) {
  43     char **symbollist = backtrace_symbols(backtrace_buffer, stack_frames);
  44     if (symbollist) {
  45       for (int x = 0; x < stack_frames; x++) {
  46         bool was_demangled = false;
  47
  48 #  ifdef HAVE_ABI____CXA_DEMANGLE
  49 #    ifdef HAVE_DLFCN_H
  50           Dl_info dlinfo;
  51           if (dladdr(backtrace_buffer[x], &dlinfo)) {
  52             char demangled_buffer[1024];
  53             const char *called_in = "<unresolved>";
  54             if (dlinfo.dli_sname) {
  55               size_t demangled_size = sizeof(demangled_buffer);
  56               int status;
  57               char *demangled;
  58               if ((demangled = abi::__cxa_demangle(dlinfo.dli_sname, demangled_buffer,
  59                                                    &demangled_size, &status))) {
  60                 called_in = demangled;
  61                 fprintf(stderr, "---> demangled: %s -> %s\n", demangled_buffer, demangled);
  62               } else {
  63                 called_in = dlinfo.dli_sname;
  64               }
  65
  66               was_demangled = true;
  67               fprintf(stderr, "#%d  %p in %s at %s\n", x, backtrace_buffer[x], called_in,
  68                       dlinfo.dli_fname);
  69             }
  70           }
  71 #    endif
  72 #  endif
  73
  74         if (was_demangled == false) {
  75           fprintf(stderr, "?%d  %p in %s\n", x, backtrace_buffer[x], symbollist[x]);
  76         }
  77       }
  78
  79       ::free(symbollist);
  80     }
  81   }
  82 }
  83
  84 #else  // HAVE_BACKTRACE
  85
  86 void custom_backtrace(void) {
  87   fprintf(stderr, "Backtrace null function called\n");
  88 }
  89 #endif // HAVE_BACKTRACE