stacktrace.h

   1 // stacktrace.h (c) 2008, Timo Bingmann from http://idlebox.net/
   2 // published under the WTFPL v2.0
   3
   4 #ifndef __STACKTRACE_H__
   5 #define __STACKTRACE_H__
   6
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <execinfo.h>
  10 #include <cxxabi.h>
  11
  12 /** Print a demangled stack backtrace of the caller function to FILE* out. */
  13 static inline void print_stacktrace(FILE *out = stderr, unsigned int max_frames = 63)
  14 {
  15         fprintf(out, "stack trace:\n");
  16
  17         // storage array for stack trace address data
  18         void* addrlist[max_frames+1];
  19
  20         // retrieve current stack addresses
  21         int addrlen = backtrace(addrlist, sizeof(addrlist) / sizeof(void*));
  22
  23         if (addrlen == 0) {
  24                 fprintf(out, "  <empty, possibly corrupt>\n");
  25                 return;
  26         }
  27
  28         // resolve addresses into strings containing "filename(function+address)",
  29         // this array must be free()-ed
  30         char** symbollist = backtrace_symbols(addrlist, addrlen);
  31
  32         // allocate string which will be filled with the demangled function name
  33         size_t funcnamesize = 256;
  34         char* funcname = (char*)malloc(funcnamesize);
  35
  36         // iterate over the returned symbol lines. skip the first, it is the
  37         // address of this function.
  38         for (int i = 1; i < addrlen; i++) {
  39                 char *begin_name = 0, *begin_offset = 0, *end_offset = 0;
  40
  41                 // find parentheses and +address offset surrounding the mangled name:
  42                 // ./module(function+0x15c) [0x8048a6d]
  43                 for (char *p = symbollist[i]; *p; ++p) {
  44                         if (*p == '(')
  45                                 begin_name = p;
  46                         else if (*p == '+')
  47                                 begin_offset = p;
  48                         else if (*p == ')' && begin_offset) {
  49                                 end_offset = p;
  50                                 break;
  51                         }
  52                 }
  53
  54                 if (begin_name && begin_offset && end_offset && begin_name < begin_offset) {
  55                         *begin_name++ = '\0';
  56                         *begin_offset++ = '\0';
  57                         *end_offset = '\0';
  58
  59                         // mangled name is now in [begin_name, begin_offset) and caller
  60                         // offset in [begin_offset, end_offset). now apply
  61                         // __cxa_demangle():
  62
  63                         int status;
  64                         char* ret = abi::__cxa_demangle(begin_name,
  65                                         funcname, &funcnamesize, &status);
  66                         if (status == 0) {
  67                                 funcname = ret; // use possibly realloc()-ed string
  68                                 fprintf(out, "  %s : %s+%s\n",
  69                                                 symbollist[i], funcname, begin_offset);
  70                         } else {
  71                                 // demangling failed. Output function name as a C function with
  72                                 // no arguments.
  73                                 fprintf(out, "  %s : %s()+%s\n",
  74                                                 symbollist[i], begin_name, begin_offset);
  75                         }
  76                 } else {
  77                         // couldn't parse the line? print the whole line.
  78                         fprintf(out, "  %s\n", symbollist[i]);
  79                 }
  80         }
  81
  82         free(funcname);
  83         free(symbollist);
  84 }
  85
  86 #endif // __STACKTRACE_H__