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 /**
  13  * @brief Print a demangled stack backtrace of the caller function to file
  14  * descriptor fd.
  15  */
  16 static inline void print_stacktrace(int fd = STDERR_FILENO, unsigned int max_frames = 63)
  17 {
  18         dprintf(fd, "stack trace:\n");
  19
  20         // storage array for stack trace address data
  21         void* addrlist[max_frames+1];
  22
  23         // retrieve current stack addresses
  24         int addrlen = backtrace(addrlist, sizeof(addrlist) / sizeof(void*));
  25
  26         if (addrlen == 0) {
  27                 dprintf(fd, "  <empty, possibly corrupt>\n");
  28                 return;
  29         }
  30
  31         // resolve addresses into strings containing "filename(function+address)",
  32         // this array must be free()-ed
  33         char** symbollist = backtrace_symbols(addrlist, addrlen);
  34
  35         // allocate string which will be filled with the demangled function name
  36         size_t funcnamesize = 256;
  37         char* funcname = (char*)malloc(funcnamesize);
  38
  39         // iterate over the returned symbol lines. skip the first, it is the
  40         // address of this function.
  41         for (int i = 1; i < addrlen; i++) {
  42                 char *begin_name = 0, *begin_offset = 0, *end_offset = 0;
  43
  44                 // find parentheses and +address offset surrounding the mangled name:
  45                 // ./module(function+0x15c) [0x8048a6d]
  46                 for (char *p = symbollist[i]; *p; ++p) {
  47                         if (*p == '(')
  48                                 begin_name = p;
  49                         else if (*p == '+')
  50                                 begin_offset = p;
  51                         else if (*p == ')' && begin_offset) {
  52                                 end_offset = p;
  53                                 break;
  54                         }
  55                 }
  56
  57                 if (begin_name && begin_offset && end_offset && begin_name < begin_offset) {
  58                         *begin_name++ = '\0';
  59                         *begin_offset++ = '\0';
  60                         *end_offset = '\0';
  61
  62                         // mangled name is now in [begin_name, begin_offset) and caller
  63                         // offset in [begin_offset, end_offset). now apply
  64                         // __cxa_demangle():
  65
  66                         int status;
  67                         char* ret = abi::__cxa_demangle(begin_name,
  68                                         funcname, &funcnamesize, &status);
  69                         if (status == 0) {
  70                                 funcname = ret; // use possibly realloc()-ed string
  71                                 dprintf(fd, "  %s : %s+%s\n",
  72                                                 symbollist[i], funcname, begin_offset);
  73                         } else {
  74                                 // demangling failed. Output function name as a C function with
  75                                 // no arguments.
  76                                 dprintf(fd, "  %s : %s()+%s\n",
  77                                                 symbollist[i], begin_name, begin_offset);
  78                         }
  79                 } else {
  80                         // couldn't parse the line? print the whole line.
  81                         dprintf(fd, "  %s\n", symbollist[i]);
  82                 }
  83         }
  84
  85         free(funcname);
  86         free(symbollist);
  87 }
  88
  89 static inline void print_stacktrace(FILE *out, unsigned int max_frames = 63)
  90 {
  91         print_stacktrace(fileno(out), max_frames);
  92 }
  93
  94 #endif // __STACKTRACE_H__