1#include <corkscrew/backtrace.h>
2#include <corkscrew/symbol_table.h>
3#include <stdio.h>
4#include <stdlib.h>
5
6int do_backtrace(float /* just to test demangling */) {
7  const size_t MAX_DEPTH = 32;
8  backtrace_frame_t* frames = (backtrace_frame_t*) malloc(sizeof(backtrace_frame_t) * MAX_DEPTH);
9  ssize_t frame_count = unwind_backtrace(frames, 0, MAX_DEPTH);
10  fprintf(stderr, "frame_count=%d\n", (int) frame_count);
11  if (frame_count <= 0) {
12    return frame_count;
13  }
14
15  backtrace_symbol_t* backtrace_symbols = (backtrace_symbol_t*) malloc(sizeof(backtrace_symbol_t) * frame_count);
16  get_backtrace_symbols(frames, frame_count, backtrace_symbols);
17
18  for (size_t i = 0; i < (size_t) frame_count; ++i) {
19    char line[MAX_BACKTRACE_LINE_LENGTH];
20    format_backtrace_line(i, &frames[i], &backtrace_symbols[i],
21                          line, MAX_BACKTRACE_LINE_LENGTH);
22    if (backtrace_symbols[i].symbol_name != NULL) {
23      // get_backtrace_symbols found the symbol's name with dladdr(3).
24      fprintf(stderr, "  %s\n", line);
25    } else {
26      // We don't have a symbol. Maybe this is a static symbol, and
27      // we can look it up?
28      symbol_table_t* symbols = NULL;
29      if (backtrace_symbols[i].map_name != NULL) {
30        symbols = load_symbol_table(backtrace_symbols[i].map_name);
31      }
32      const symbol_t* symbol = NULL;
33      if (symbols != NULL) {
34        symbol = find_symbol(symbols, frames[i].absolute_pc);
35      }
36      if (symbol != NULL) {
37        int offset = frames[i].absolute_pc - symbol->start;
38        fprintf(stderr, "  %s (%s%+d)\n", line, symbol->name, offset);
39      } else {
40        fprintf(stderr, "  %s (\?\?\?)\n", line);
41      }
42      free_symbol_table(symbols);
43    }
44  }
45
46  free_backtrace_symbols(backtrace_symbols, frame_count);
47  free(backtrace_symbols);
48  free(frames);
49  return frame_count;
50}
51
52struct C {
53  int g(int i);
54};
55
56__attribute__ ((noinline)) int C::g(int i) {
57  if (i == 0) {
58    return do_backtrace(0.1);
59  }
60  return g(i - 1);
61}
62
63extern "C" __attribute__ ((noinline)) int f() {
64  C c;
65  return c.g(5);
66}
67
68int main() {
69  flush_my_map_info_list();
70  f();
71
72  flush_my_map_info_list();
73  f();
74
75  return 0;
76}
77