1 #include <corkscrew/backtrace.h> 2 #include <corkscrew/symbol_table.h> 3 #include <stdio.h> 4 #include <stdlib.h> 5 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 48 __attribute__ ((noinline)) void g() { 49 fprintf(stderr, "g()\n"); 50 do_backtrace(); 51 } 52 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 62 int main() { 63 return f(5); 64 } 65
