[PATCH] Fix an undefined behavior in record_line
Bernd Edlinger
bernd.edlinger@hotmail.de
Fri Mar 13 11:15:35 GMT 2020
Additionally do not completely remove symbols
at the same PC than the end marker, instead
make them non-is-stmt breakpoints.
Also fix the condition when the line table need to be resized,
that was wasting one element.
2020-03-10 Bernd Edlinger <bernd.edlinger@hotmail.de>
* buildsym.c (record_line): Fix ub and preserve lines at eof.
---
gdb/buildsym.c | 28 +++++++++++-----------------
1 file changed, 11 insertions(+), 17 deletions(-)
diff --git a/gdb/buildsym.c b/gdb/buildsym.c
index 7155db3..e090fdb 100644
--- a/gdb/buildsym.c
+++ b/gdb/buildsym.c
@@ -695,7 +695,7 @@ struct blockvector *
}
}
- if (subfile->line_vector->nitems + 1 >= subfile->line_vector_length)
+ if (subfile->line_vector->nitems >= subfile->line_vector_length)
{
subfile->line_vector_length *= 2;
subfile->line_vector = (struct linetable *)
@@ -705,27 +705,21 @@ struct blockvector *
* sizeof (struct linetable_entry))));
}
- /* Normally, we treat lines as unsorted. But the end of sequence
- marker is special. We sort line markers at the same PC by line
- number, so end of sequence markers (which have line == 0) appear
- first. This is right if the marker ends the previous function,
- and there is no padding before the next function. But it is
- wrong if the previous line was empty and we are now marking a
- switch to a different subfile. We must leave the end of sequence
- marker at the end of this group of lines, not sort the empty line
- to after the marker. The easiest way to accomplish this is to
- delete any empty lines from our table, if they are followed by
- end of sequence markers. All we lose is the ability to set
- breakpoints at some lines which contain no instructions
- anyway. */
+ /* The end of sequence marker is special. We need to reset the
+ is_stmt flag on previous lines at the same PC, otherwise these
+ lines may cause problems. All we lose is the ability to set
+ breakpoints at some lines which contain no instructions anyway. */
if (line == 0 && subfile->line_vector->nitems > 0)
{
- e = subfile->line_vector->item + subfile->line_vector->nitems - 1;
- while (subfile->line_vector->nitems > 0 && e->pc == pc)
+ e = subfile->line_vector->item + subfile->line_vector->nitems;
+ do
{
e--;
- subfile->line_vector->nitems--;
+ if (e->pc != pc)
+ break;
+ e->is_stmt = 0;
}
+ while (e > subfile->line_vector->item);
}
e = subfile->line_vector->item + subfile->line_vector->nitems++;
--
1.9.1
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