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[RFA] (display_uses_solib_p): Redo loop, scan element list backwards.
- From: dje at google dot com (Doug Evans)
- To: ppluzhnikov at google dot com, gdb-patches at sourceware dot org
- Date: Tue, 17 Mar 2009 21:36:26 -0700 (PDT)
- Subject: [RFA] (display_uses_solib_p): Redo loop, scan element list backwards.
Hi.
I noticed sigbpt.exp is failing.
I was getting a "Value out of range" error inside display_uses_solib_p.
I traced it to the expression elements array being referenced out of bounds.
I think this patch is the right fix.
The expression elements array needs to be scanned backwards
when using operator_length: it examines the element at the _end_
of the array.
Ok to check in?
2009-03-17 Doug Evans <dje@google.com>
* printcmd.c (display_uses_solib_p): Redo loop, scan element list
backwards.
Index: printcmd.c
===================================================================
RCS file: /cvs/src/src/gdb/printcmd.c,v
retrieving revision 1.147
diff -u -p -r1.147 printcmd.c
--- printcmd.c 9 Mar 2009 22:38:37 -0000 1.147
+++ printcmd.c 18 Mar 2009 04:28:26 -0000
@@ -1763,18 +1763,23 @@ static int
display_uses_solib_p (const struct display *d,
const struct so_list *solib)
{
- int i;
+ int endpos;
struct expression *const exp = d->exp;
+ union exp_element *const elts = exp->elts;
if (d->block != NULL
&& solib_contains_address_p (solib, d->block->startaddr))
return 1;
- for (i = 0; i < exp->nelts; )
+ for (endpos = exp->nelts; endpos > 0; )
{
- int args, oplen = 0;
- const union exp_element *const elts = exp->elts;
+ int i, args, oplen = 0;
+ exp->language_defn->la_exp_desc->operator_length (exp, endpos,
+ &oplen, &args);
+ gdb_assert (oplen > 0);
+
+ i = endpos - oplen;
if (elts[i].opcode == OP_VAR_VALUE)
{
const struct block *const block = elts[i + 1].block;
@@ -1789,11 +1794,9 @@ display_uses_solib_p (const struct displ
if (section && section->objfile == solib->objfile)
return 1;
}
- exp->language_defn->la_exp_desc->operator_length (exp, i + 1,
- &oplen, &args);
- gdb_assert (oplen > 0);
- i += oplen;
+ endpos -= oplen;
}
+
return 0;
}