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