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Eliminate one heap allocation in dwarf_find_debug_frame()

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Allocate `tab' from stack in dwarf_find_debug_frame(), as it's only a
few members and we only need it locally in the function.
This commit is contained in:
Tommi Rantala 2012-08-27 13:24:22 +03:00
parent 90d7baea35
commit fce25d74c9
1 changed files with 12 additions and 23 deletions
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35
src/dwarf/Gfind_proc_info-lsb.c
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@ -332,18 +332,6 @@ struct debug_frame_tab
uint32_t size; uint32_t size;
}; };
static struct debug_frame_tab *
debug_frame_tab_new (unsigned int base_size)
{
struct debug_frame_tab *tab = malloc (sizeof (struct debug_frame_tab));
tab->tab = calloc (base_size, sizeof (struct table_entry));
tab->length = 0;
tab->size = base_size;
return tab;
}
static void static void
debug_frame_tab_append (struct debug_frame_tab *tab, debug_frame_tab_append (struct debug_frame_tab *tab,
unw_word_t fde_offset, unw_word_t start_ip) unw_word_t fde_offset, unw_word_t start_ip)
@ -412,7 +400,7 @@ dwarf_find_debug_frame (int found, unw_dyn_info_t *di_debug, unw_word_t ip,
unw_word_t item_start, item_end = 0; unw_word_t item_start, item_end = 0;
uint32_t u32val = 0; uint32_t u32val = 0;
uint64_t cie_id = 0; uint64_t cie_id = 0;
struct debug_frame_tab *tab; struct debug_frame_tab tab;
Debug (15, "loaded .debug_frame\n"); Debug (15, "loaded .debug_frame\n");
@ -435,7 +423,9 @@ dwarf_find_debug_frame (int found, unw_dyn_info_t *di_debug, unw_word_t ip,
/* Find all FDE entries in debug_frame, and make into a sorted /* Find all FDE entries in debug_frame, and make into a sorted
index. */ index. */
tab = debug_frame_tab_new (16); tab.length = 0;
tab.size = 16;
tab.tab = calloc (tab.size, sizeof (struct table_entry));
while (addr < (unw_word_t) (uintptr_t) (buf + bufsize)) while (addr < (unw_word_t) (uintptr_t) (buf + bufsize))
{ {
@ -488,7 +478,7 @@ dwarf_find_debug_frame (int found, unw_dyn_info_t *di_debug, unw_word_t ip,
{ {
Debug (15, "start_ip = %lx, end_ip = %lx\n", Debug (15, "start_ip = %lx, end_ip = %lx\n",
(long) this_pi.start_ip, (long) this_pi.end_ip); (long) this_pi.start_ip, (long) this_pi.end_ip);
debug_frame_tab_append (tab, debug_frame_tab_append (&tab,
item_start - (unw_word_t) (uintptr_t) buf, item_start - (unw_word_t) (uintptr_t) buf,
this_pi.start_ip); this_pi.start_ip);
} }
@ -499,18 +489,17 @@ dwarf_find_debug_frame (int found, unw_dyn_info_t *di_debug, unw_word_t ip,
addr = item_end; addr = item_end;
} }
debug_frame_tab_shrink (tab); debug_frame_tab_shrink (&tab);
qsort (tab->tab, tab->length, sizeof (struct table_entry), qsort (tab.tab, tab.length, sizeof (struct table_entry),
debug_frame_tab_compare); debug_frame_tab_compare);
/* for (i = 0; i < tab->length; i++) /* for (i = 0; i < tab.length; i++)
{ {
fprintf (stderr, "ip %x, fde offset %x\n", fprintf (stderr, "ip %x, fde offset %x\n",
(int) tab->tab[i].start_ip_offset, (int) tab.tab[i].start_ip_offset,
(int) tab->tab[i].fde_offset); (int) tab.tab[i].fde_offset);
}*/ }*/
fdesc->index = tab->tab; fdesc->index = tab.tab;
fdesc->index_size = tab->length; fdesc->index_size = tab.length;
free (tab);
} }
di->format = UNW_INFO_FORMAT_TABLE; di->format = UNW_INFO_FORMAT_TABLE;