This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
Re: [PATCH] Catch exception in value_rtti_indirect_type
- From: Pedro Alves <palves at redhat dot com>
- To: Simon Marchi <simon dot marchi at ericsson dot com>, gdb-patches at sourceware dot org
- Cc: simon dot marchi at polymtl dot ca
- Date: Thu, 04 Dec 2014 17:47:36 +0000
- Subject: Re: [PATCH] Catch exception in value_rtti_indirect_type
- Authentication-results: sourceware.org; auth=none
- References: <1411174953-8930-1-git-send-email-simon dot marchi at ericsson dot com>
On 09/20/2014 02:02 AM, Simon Marchi wrote:
> In the situation described in bug 17416 [1],
Could you paste that in the commit log please?
> an exception thrown in
> value_ind can propagate too far and leave an half-built variable object,
> leading to a wrong state. This patch adds a TRY_CATCH to catch it and
> makes value_rtti_indirect_type return NULL in that case, meaning
> that the type of the pointed object could not be found.
>
> If you want, I can also integrate the test case provided in the bug
Yes please.
> description. I just don't know how to name it without giving it a
> ridiculously long name such as
> mi-var-list-children-with-print-object-on-and-a-null-pointer-to-a-structure-that-contains-a-pointer-to-a-structure.exp.
Perhaps mi-var-list-children-invalid-grandchild.exp.
>
> I tested the change on my machine, Ubuntu 14.10 x86-64.
>
> gdb/Changelog:
>
> * valops.c (value_rtti_indirect_type): Catch exception thrown by
> value_ind.
>
> [1] https://sourceware.org/bugzilla/show_bug.cgi?id=17416
> ---
> gdb/valops.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/gdb/valops.c b/gdb/valops.c
> index e1decf0..c1a0c86 100644
> --- a/gdb/valops.c
> +++ b/gdb/valops.c
> @@ -3609,7 +3609,18 @@ value_rtti_indirect_type (struct value *v, int *full,
> if (TYPE_CODE (type) == TYPE_CODE_REF)
> target = coerce_ref (v);
> else if (TYPE_CODE (type) == TYPE_CODE_PTR)
> - target = value_ind (v);
> + {
> + volatile struct gdb_exception except;
> +
> + TRY_CATCH (except, RETURN_MASK_ERROR)
> + {
> + target = value_ind (v);
> + }
> + if (except.error == MEMORY_ERROR)
> + return NULL;
> + else if (except.error != GDB_NO_ERROR)
> + throw_exception (except);
Indentation looks odd. But, could you write it like this instead ?
volatile struct gdb_exception except;
TRY_CATCH (except, RETURN_MASK_ERROR)
{
target = value_ind (v);
}
if (except.reason < 0)
{
if (except.error == MEMORY_ERROR)
{
/* Add comment here. */
return NULL;
}
throw_exception (except);
}
Thanks,
Pedro Alves