diff options
Diffstat (limited to 'debug/backtracesyms.c')
| -rw-r--r-- | debug/backtracesyms.c | 81 |
1 files changed, 73 insertions, 8 deletions
diff --git a/debug/backtracesyms.c b/debug/backtracesyms.c index a010664..3fabf26 100644 --- a/debug/backtracesyms.c +++ b/debug/backtracesyms.c @@ -1,5 +1,5 @@ /* Return list with names for address in backtrace. - Copyright (C) 1998, 2000 Free Software Foundation, Inc. + Copyright (C) 1998-2012 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. @@ -17,13 +17,20 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ +#include <assert.h> #include <execinfo.h> +#include <stdio.h> #include <stdlib.h> #include <string.h> +#include <ldsodefs.h> -/* Assume the worst for the width of an address. */ -#define WORD_WIDTH 16 +#if __ELF_NATIVE_CLASS == 32 +# define WORD_WIDTH 8 +#else +/* We assyme 64bits. */ +# define WORD_WIDTH 16 +#endif char ** @@ -31,16 +38,37 @@ __backtrace_symbols (array, size) void *const *array; int size; { + Dl_info info[size]; + int status[size]; int cnt; size_t total = 0; char **result; - /* We can compute the text size needed for the symbols since we print - them all as "[+0x<addr>]". */ - total = size * (WORD_WIDTH + 6); + /* Fill in the information we can get from `dladdr'. */ + for (cnt = 0; cnt < size; ++cnt) + { + struct link_map *map; + status[cnt] = _dl_addr (array[cnt], &info[cnt], &map, NULL); + if (status[cnt] && info[cnt].dli_fname && info[cnt].dli_fname[0] != '\0') + { + /* We have some info, compute the length of the string which will be + "<file-name>(<sym-name>+offset) [address]. */ + total += (strlen (info[cnt].dli_fname ?: "") + + strlen (info[cnt].dli_sname ?: "") + + 3 + WORD_WIDTH + 3 + WORD_WIDTH + 5); + + /* The load bias is more useful to the user than the load + address. The use of these addresses is to calculate an + address in the ELF file, so its prelinked bias is not + something we want to subtract out. */ + info[cnt].dli_fbase = (void *) map->l_addr; + } + else + total += 5 + WORD_WIDTH; + } /* Allocate memory for the result. */ - result = malloc (size * sizeof (char *) + total); + result = (char **) malloc (size * sizeof (char *) + total); if (result != NULL) { char *last = (char *) (result + size); @@ -48,8 +76,45 @@ __backtrace_symbols (array, size) for (cnt = 0; cnt < size; ++cnt) { result[cnt] = last; - last += 1 + sprintf (last, "[+%p]", array[cnt]); + + if (status[cnt] + && info[cnt].dli_fname != NULL && info[cnt].dli_fname[0] != '\0') + { + if (info[cnt].dli_sname == NULL) + /* We found no symbol name to use, so describe it as + relative to the file. */ + info[cnt].dli_saddr = info[cnt].dli_fbase; + + if (info[cnt].dli_sname == NULL && info[cnt].dli_saddr == 0) + last += 1 + sprintf (last, "%s(%s) [%p]", + info[cnt].dli_fname ?: "", + info[cnt].dli_sname ?: "", + array[cnt]); + else + { + char sign; + ptrdiff_t offset; + if (array[cnt] >= (void *) info[cnt].dli_saddr) + { + sign = '+'; + offset = array[cnt] - info[cnt].dli_saddr; + } + else + { + sign = '-'; + offset = info[cnt].dli_saddr - array[cnt]; + } + + last += 1 + sprintf (last, "%s(%s%c%#tx) [%p]", + info[cnt].dli_fname ?: "", + info[cnt].dli_sname ?: "", + sign, offset, array[cnt]); + } + } + else + last += 1 + sprintf (last, "[%p]", array[cnt]); } + assert (last <= (char *) result + size * sizeof (char *) + total); } return result; |