* dwarf2-frame.c (dwarf2_build_frame_info): Discard --gc-section

leftover FDEs.
This commit is contained in:
Pedro Alves 2009-10-28 19:28:57 +00:00
parent 1a587334a9
commit 875cdfbb54
2 changed files with 53 additions and 14 deletions

View File

@ -1,3 +1,8 @@
2009-10-28 Pedro Alves <pedro@codesourcery.com>
* dwarf2-frame.c (dwarf2_build_frame_info): Discard --gc-section
leftover FDEs.
2009-10-28 Pedro Alves <pedro@codesourcery.com>
* infrun.c (keep_going): Wrap with resume_cleanups.

View File

@ -2101,7 +2101,9 @@ dwarf2_build_frame_info (struct objfile *objfile)
if (fde_table.num_entries != 0)
{
struct dwarf2_fde_table *fde_table2;
int i, j;
struct dwarf2_fde *fde_prev = NULL;
struct dwarf2_fde *first_non_zero_fde = NULL;
int i;
/* Prepare FDE table for lookups. */
qsort (fde_table.entries, fde_table.num_entries,
@ -2110,22 +2112,54 @@ dwarf2_build_frame_info (struct objfile *objfile)
/* Copy fde_table to obstack: it is needed at runtime. */
fde_table2 = (struct dwarf2_fde_table *)
obstack_alloc (&objfile->objfile_obstack, sizeof (*fde_table2));
fde_table2->num_entries = 0;
/* Since we'll be doing bsearch, squeeze out identical (except for
eh_frame_p) fde entries so bsearch result is predictable. */
for (i = 0, j = 0; j < fde_table.num_entries; ++i)
{
const int k = j;
/* Check for leftovers from --gc-sections. The GNU linker sets
the relevant symbols to zero, but doesn't zero the FDE *end*
ranges because there's no relocation there. It's (offset,
length), not (start, end). On targets where address zero is
just another valid address this can be a problem, since the
FDEs appear to be non-empty in the output --- we could pick
out the wrong FDE. To work around this, when overlaps are
detected, we prefer FDEs that do not start at zero.
obstack_grow (&objfile->objfile_obstack, &fde_table.entries[j],
sizeof (fde_table.entries[0]));
while (++j < fde_table.num_entries
&& (fde_table.entries[k]->initial_location
== fde_table.entries[j]->initial_location))
/* Skip. */;
}
Start by finding the first FDE with non-zero start. Below
we'll discard all FDEs that start at zero and overlap this
one. */
for (i = 0; i < fde_table.num_entries; i++)
{
struct dwarf2_fde *fde = fde_table.entries[i];
if (fde->initial_location != 0)
{
first_non_zero_fde = fde;
break;
}
}
/* Since we'll be doing bsearch, squeeze out identical (except
for eh_frame_p) fde entries so bsearch result is predictable.
Also discard leftovers from --gc-sections. */
for (i = 0; i < fde_table.num_entries; i++)
{
struct dwarf2_fde *fde = fde_table.entries[i];
if (fde->initial_location == 0
&& first_non_zero_fde != NULL
&& (first_non_zero_fde->initial_location
< fde->initial_location + fde->address_range))
continue;
if (fde_prev != NULL
&& fde_prev->initial_location == fde->initial_location)
continue;
obstack_grow (&objfile->objfile_obstack, &fde_table.entries[i],
sizeof (fde_table.entries[0]));
++fde_table2->num_entries;
fde_prev = fde;
}
fde_table2->entries = obstack_finish (&objfile->objfile_obstack);
fde_table2->num_entries = i;
set_objfile_data (objfile, dwarf2_frame_objfile_data, fde_table2);
/* Discard the original fde_table. */